2016年第47卷第2期共收錄55篇
1.
Accession number: 20161202133056
Title: Effect of vacuum concentration on CO2absorption performance and phytotoxicity of biogas slurry
Authors: He, Qingyao1 ; Wang, Wenchao1; Cai, Kai1; Yan, Shuiping1 ; Zhang, Yanlin1
Author affiliation: 1 College of Engineering, Huazhong Agricultural University, Wuhan, China
Corresponding author: Yan, Shuiping ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 200-207
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Raw biogas slurry (RBS) was concentrated to obtain the concentrated biogas slurry (CBS) and the diluted phase (DP) condensed by the gas phase under the conditions of 50 and 2 kPa in vacuum concentration device. CO2absorption performances of RBS, CBS and DP were investigated, and the germination index (GI) values of Chinese cabbage seeds germinated by these solutions after CO2absorption were evaluated as well. Results showed that when the concentration degree of RBS was about 4, the pH value of CBS was increased from 7.87 to 8.73, and its saturated CO2loading was increased by about 26.70%. Additionally, the removal efficiency of ammonium nitrogen was up to 86.41% due to the conversion of ammonium nitrogen into free ammonia and then extracted from biogas slurry by vacuum operation. Most of the free ammonia was condensed and collected into the DP. Therefore, DP's pH value and CO2loading were up to 10.05 and 0.075 mol/L, respectively. However, the net CO2absorption capacity contributed by CBS and DP was 21.3% lower than that of RBS due to the volatile loss of ammonia during concentration. Results from the germination of Chinese cabbage seeds by the CO2-rich solutions of RBS, CBS and DP showed that all the GI values were higher than 0.8, implying their low phytotoxicities. The result implied that concentrating RBS may result in the decrease of the cropland area required to dispose the biogas slurry. Moreover, CO2absorption enhancement by adding different additives was investigated and compared as well. Aiming at the same saturated CO2loading value, adding sodium salts into biogas slurry was superior to adding ammonia additives in terms of low phytotoxicity, which may be attributed to the great increase of ammonium nitrogen concentration in the latter solutions.
Number of references: 22
Main heading: Loading
Controlled terms: Ammonia - Atmospheric composition - Biogas - Carbon dioxide - Cultivation - Detoxification - Electric circuit breakers - Nitrogen - Nitrogen removal - pH - Salts - Seed
Uncontrolled terms: Absorption capacity - Absorption enhancement - Absorption performance - Biogas slurry - Chinese cabbage seeds - Concentration degree - Phytotoxicity - Removal efficiencies
Classification code: 522 Gas Fuels - 691.2 Materials Handling Methods - 801 Chemistry - 801.1 Chemistry, General - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821.3 Agricultural Methods - 821.4 Agricultural Products
DOI: 10.6041/j.issn.1000-1298.2016.02.026
Database: Compendex
2.
Accession number: 20161202133078
Title: Capture and analysis of soot formed inside combustion diesel spray flame
Authors: Deng, Peng1 ; Ding, Hongyuan1; Deng, Lei1; Meng, Xianchao2; Huang, Ronghua2
Author affiliation: 1 Wuhan Second Ship Design and Research Institute, Wuhan, China
2 School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 364-368 and 389
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: In order to investigate the evolution principle of soot formed inside the diesel spray flame, a soot trapping device was developed based on the thermophoretic phenomenon. The device was applied to a constant-volume combustion chamber to capture the soot formed during the combustion process of diesel spray. The soot captured was then observed and imaged by the high-resolution transmission electron microscopy. Soot images were taken at 200 nm and 10 nm scales to investigate their overall and local detailed features. The evolution of soot was analyzed according to its macro and micro structure characters. Furthermore, the soot particle size along the spray flame axial was investigated by image processing program based on Matlab. The result showed that the production of primary particles formed inside the flame promoted the aggregation of soot, the number of primary particles was increased at 60 mm and 80 mm downstream of the spray, and then it was decreased at 80 mm and 100 mm downstream of the spray. Meanwhile, the number of aggregated soot particles was increased along the spray axis. The diameter of the primary particles was about 30 nm, and the diameter of soot aggregation particles was no larger than 100 nm. In addition, the internal arrangement of the primary particles trended to be less chaos. The carbon coated copper gird survived the extreme environments inside the chamber without being burnt, warped, melted or oxidized. The device works well and it provides a new experimental method for the soot formation mechanism research at typical high pressure and high temperature environment inside the modern diesel engine.
Number of references: 20
Main heading: Agglomeration
Controlled terms: Carbon - Combustion - Combustion chambers - Diesel engines - Diesel fuels - Dust - Electron microscopy - High resolution transmission electron microscopy - Image processing - MATLAB - Particle size - Soot
Uncontrolled terms: Combustion pro-cess - Constant volume combustion bomb - Constant volume combustion chambers - Extreme environment - High pressure and high temperature - New experimental method - Spray combustion - Thermophoretic
Classification code: 451.1 Air Pollution Sources - 523 Liquid Fuels - 612.2 Diesel Engines - 654.2 Rocket Engines - 741.3 Optical Devices and Systems - 802.3 Chemical Operations - 804 Chemical Products Generally - 921 Mathematics
DOI: 10.6041/j.issn.1000-1298.2016.02.048
Database: Compendex
3.
Accession number: 20161202133076
Title: Design and test of urea-SCR control system for diesel engine
Authors: Hu, Jie1, 2 ; Wang, Lihui1, 2; Wang, Tiantian1, 2
Author affiliation: 1 Hubei Key Laboratory of Advanced Technology of Automotive Parts, Wuhan University of Technology, Wuhan, China
2 Hubei Collaborate Innovation Center for Automotive Components Technology, Wuhan University of Technology, Wuhan, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 349-356
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: SCR after-treatment is the mainstream technology to reduce the NOxemission amount. The self-developed SCR system's composition, operating and reactor mechanism were presented, and the coordinate control strategy was used to assure that the system's inner module was operated regularly, the original emission model and chemical reaction kinetics model were adopted to obtain the raw value of urea supply amount, the exhaust temperature correction model was introduced to fix the instantaneous emission temperature, the relation between exhaust temperature and amount of NH3storage was used to effectively control the NH3leak amount, and failure warning was made according to the OBD regulation when NOxemission exceeded the standard. Each operation point had a NH3coverage ratio threshold which can ensure NH3leakage volume ratio was less than 1.0×10-5during the rapid heating process and try to improve the NOxconversion efficiency. According to the research results of the NH3coverage ratio and storage, the estimation model was established, and the leakage control strategy was put forward. The sensors and actuators of the system, original machine emission MAP and target conversion rate MAP were calibrated. The dosing control unit using above control strategy was adopted in the target engine. Test results showed that the brake specific emissions of NOxin ESC and ETC were 1.52 g/(kW?h) and 2.09 g/(kW?h), respectively, which indicated that the self-developed SCR control system can effectively reduce the NOxemission amount and reach the national IV emission regulation.
Number of references: 19
Main heading: Selective catalytic reduction
Controlled terms: Calibration - Control systems - Diesel engines - Engines - Metabolism - Reaction kinetics - Urea
Uncontrolled terms: Control strategies - Coordinate control - Emission regulation - Estimation models - Exhaust temperature - Rapid heating process - Selective catalytic reduction systems - Sensors and actuators
Classification code: 451.2 Air Pollution Control - 612.2 Diesel Engines - 731.1 Control Systems - 802.2 Chemical Reactions - 804.1 Organic Compounds
DOI: 10.6041/j.issn.1000-1298.2016.02.046
Database: Compendex
4.
Accession number: 20161202133054
Title: Dynamic change analysis of rainfall erosivity and river sediment discharge of He-Long reach of the Yellow River from 1957 to 2011
Authors: Fu, Jinxia1 ; Zhang, Peng1; Zheng, Fenli1, 2 ; Guan, Yinghui1; Gao, Yan1
Author affiliation: 1 College of Resources and Environment, Northwest A&F University, Yangling; Shaanxi, China
2 Institute of Soil and Water Conservation, Ministry of Water Resources, Chinese Academy of Sciences, Yangling; Shaanxi, China
Corresponding author: Zheng, Fenli ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 185-192 and 207
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The dynamic change of rainfall erosivity and river sediment discharge as well as the correlation between river sediment discharge and rainfall erosivity were analyzed based on daily rainfall data and yearly sediment discharge of 12 rainfall stations located in He-Long reach of the Yellow River from 1957 to 2011. Meanwhile, the impact and contribution of rainfall erosivity changes and human activities on the river sediment discharge changes were quantitatively evaluated. The main methods used were the moving average, linear trend estimation, Mann-Kendall nonparametric test, cumulative departure curve and double mass curve. The results showed that rainfall erosivity in He-Long reach from 1957 to 2011 shifted from 378.1 MJ?mm/(hm2?h?a) to 2324.6 MJ?mm/(hm2?h?a) with a mean of 1319.7 MJ?mm/(hm2?h?a), and rainfall erosivity did not exhibit significant downtrend. The decrement of rainfall erosivity per year in 1957-2011 was 9.7 MJ?mm/(hm2?h?a). The changing trend of rainfall erosivity was divided into three stages during past 55 years in He-Long reach, which consisted of a rapid declining trend from 1957 to 1974, a slow decreasing trend from 1975 to 1999, and a slow increasing trend from 2000 to 2011.The declining rates of the first and second stages were 83.7% and 66.6%, respectively, and the increasing rate of the third stage was 42.7%. With rainfall erosivity in 1957-1969 as a reference, rainfall erosivities in the 1970s, 1980s, 1990s and the first 12 years of the 21st century were decreased by 15.9%, 19.5%, 27.5% and 22.7%, respectively. The river sediment discharge in He-Long reach from 1957 to 2011 shifted from 9×106t to 2.14×109t with a mean of 5.60×108t, and river sediment discharge showed highly significant downtrend. The decrement of river sediment discharge in 1957-2011 was 1.9×107t/a. With river sediment discharge in 1957-1969 as a reference, river sediment discharges in the 1970s, 1980s, 1990s and the first 12 years of the 21st century were decreased by 27.3%, 64.1%, 54.8% and 88.7%, respectively. The Mann-Kendall nonparametric test and the cumulative departure curve showed that the abrupt change of river sediment discharge appeared in 1979.There was a better linear correlation between river sediment discharge and rainfall erosivity. According to the double mass curve equation, the contributions of rainfall erosivity to the river sediment discharge changes in the 1980s, 1990s and the first 12 years of the 21st century were 22.6%, 44.3% and 19.0%, respectively; while the contributions of human activities to the river sediment discharge changes were 77.4%, 55.7% and 81.0%, respectively. Therefore, the impact of human activities on the river sediment discharge changes was dominated. Although rainfall erosivity in two periods of 1980-1989 and 2000-2011 was similar, river sediment discharge in 2000-2011 was decreased by 67.6%, compared with that in 1980-1989.Thus, the river sediment discharge changes were mainly caused by human activities and the decrement of river sediment discharge per year caused by human activities was 2.5×108t in 2000-2011.
Number of references: 32
Main heading: Rivers
Controlled terms: Rain - Sediments
Uncontrolled terms: Contribution - Human activities - Long reach - Rainfall erosivity - Sediment discharge
Classification code: 443.3 Precipitation - 483 Soil Mechanics and Foundations
DOI: 10.6041/j.issn.1000-1298.2016.02.024
Database: Compendex
5.
Accession number: 20161202133050
Title: Effects of straw mulching on tillage soil temperature and growth of spring highland barley in high altitude cold region
Authors: Shi, Xueshuang1, 2 ; Li, Fahu1 ; Pubu, Duoji3; Gao, Jianxin3; Li, Yongfeng4; Qu, Zhen3
Author affiliation: 1 College of Water Resources and Civil Engineering, China Agricultural University, Beijing, China
2 Lazi Water Authority, Lazi, China
3 Institute of Agricultural Sciences of Rikaze District, Tibet Autonomous Region, Rikaze, China
4 Hydrology and Water Resources Survey Bureau, Tibet Autonomous Region, Lhasa, China
Corresponding author: Li, Fahu ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 151-160
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Soil temperature influences crop growth and its grain formation in high altitude cold region. Field plot experiments were conducted in order to investigate the effects of straw mulching on tillage soil temperature and the grain yield of spring highland barley in high altitude cold region of Tibet, China. Four experimental treatments, including straw mulching application rates of 0 (control), 5000 (M1), 10000 (M2), and 15000 kg/hm2(M3), were designed. The results showed that straw mulching on soil surface could adjust soil temperature significantly. Compared with the control treatment, average daily soil temperature was lowered by 2.8~3.9 at seedling stage but it was raised by 0.4~1.8 at other growth stages of spring highland barley after straw mulching application. Straw mulching significantly reduced plant height (2.29%~16.53%) and dry matter weight (3.98%~25.93%) at seedling and jointing stages, but it increased plant height and dry matter weight by 3.12%~10.31% and 2.17%~18.26% at the filling and mature stages of spring highland barley, respectively, and it significantly decreased root mass density in 0~20 cm soil layer, but it was increased in other soil depths. Straw mulching significantly increased the thousand seed weight (4.65%~13.95%) and grain yield (4.30%~13.50%) of spring highland barley. To a certain extent, straw mulching also lowered the spike length and the grain number in each spike of spring highland barley. Generally, there was no significantly statistical difference among different straw mulching application rates (M1~M3) in soil temperature, but significant differences existed among M1~M3 in the growth parameters (except ear length and seeds per ear) of spring highland barley. Straw mulching is advantageous to the thriving growth of seedlings and the increase of grain yield of spring highland barley.
Number of references: 32
Main heading: Grain (agricultural product)
Controlled terms: Agricultural machinery - Agriculture - Grain growth - Soils - Temperature
Uncontrolled terms: Application rates - Cold regions - Control treatments - Grain yield - Growth parameters - Soil temperature - Statistical differences - Straw mulching
Classification code: 483.1 Soils and Soil Mechanics - 641.1 Thermodynamics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 933.1.2 Crystal Growth
DOI: 10.6041/j.issn.1000-1298.2016.02.020
Database: Compendex
6.
Accession number: 20161202133057
Title: Characteristics of continuous hydrogen production within groove-type flat panel photo-biological reactor
Authors: Zhang, Chuan1 ; Wang, Baowen1; Wang, Weishu1; Song, Xiaoyong1; Cheng, Min2; Zhang, Quanguo3
Author affiliation: 1 Institue of Electric Power, North China University of Water Resources and Electric Power, Zhengzhou, China
2 Key Laboratory of Low-grade Energy Utilization Technologies and Systems, Ministry of Education, Chongqing University, Chongqing, China
3 Collaborative Innovation Center of Biomass Energy in Henan Province, Zhengzhou, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 208-214
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Aiming for promoting cell-immobilization in the bioreactor and enhancing continuous hydrogen production, a novel groove-type flat panel photo-biological reactor (GFPR) was developed. Photosynthetic bacteria (PSB) strain of Rhodopseudomonaspalustris was successfully attached on the groove-type surface of transparent material and generated PSB type biofilm. Strategies on improving continuous photo-biological hydrogen production within GFPR were comprehensively investigated. Experimental results revealed that hydrogen production rate, substrate degradation efficiency and light conversion efficiency of GFPR were obviously increased to 1.17 mmol/(L?h), 77.5% and 20.15%, respectively, under specific operating conditions of 590 nm of light wavelength, 9 W/m2of light intensity, 55 mmol/L of inlet substrate concentration and 960 mL/h of flow rate with glucose-based medium. Methods such as choosing proper light wavelength, light intensity to accelerate photophosphorylation for photosynthetic bacteria to accomplish hydrogen production metabolism and enhancing substrate transportation using convective mass transfer process were proved to be the effective way for promoting performance of photo-biological hydrogen production within the cell immobilized reactor operated under continuous flow mode. The experiment results were introduced to further research photo-biological reactor for practical hydrogen production.
Number of references: 23
Main heading: Photobiological hydrogen production
Controlled terms: Bacteria - Biofilms - Cell immobilization - Conversion efficiency - Degradation - Efficiency - Hydrogen production - Mass transfer - Mass transportation - Substrates
Uncontrolled terms: Biological hydrogen production - Continuous hydrogen production - Convective mass transfer - Groove-type - Light conversion - Photo-biological reactors - Photosynthetic bacteria (PSB) - Substrate degradation efficiency
Classification code: 462.5 Biomaterials (including synthetics) - 522 Gas Fuels - 525.5 Energy Conversion Issues - 641.3 Mass Transfer - 802.2 Chemical Reactions - 913.1 Production Engineering
DOI: 10.6041/j.issn.1000-1298.2016.02.027
Database: Compendex
7.
Accession number: 20161202133067
Title: Effect on determining polymeric pigments and tannins in wine with high content of sugars by A-H method
Authors: Yuan, Chunlong1 ; Zhou, Yali1; Han, Fuliang1; Su, Pengfei1; Wang, Shasha1
Author affiliation: 1 College of Enology, Northwest A&F University, Yangling; Shaanxi, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 280-287
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Polymeric pigments and tannins are essential components in grape and wine. A common method for measuring polymeric pigments and tannins in grape and wine is using protein precipitation assay (A-H). In order to investigate the impact of sugars on tannins and polymeric pigments determined by the A-H method, the concentrations of polymeric pigments and tannins in wine samples were tested after adding different amounts of sugars (glucose, fructose and sucrose). The experiment result showed that after all the treatments the contents of non-protein-precipitable small polymeric pigments (SPP)and total polymeric pigments (TPP) were affected significantly by sugars (glucose, fructose and sucrose) in wine, and the effect of sucrose was greater than those of glucose and fructose. However, difference was found in the amount of protein-precipitable large polymeric pigments (LPP). Some of treatments by sucrose and glucose had significant impact on the concentration of LPP, but the content of LPP was affected insignificantly by fructose in wine. One possible explanation for the different impacts of sugars on polymeric pigments and tannins was that sugars could have significant influence on the combination of protein with polymeric pigments. Meanwhile, the experiment result also indicated that sugars (glucose, fructose and sucrose) can significantly decrease the content of tannins in wine. Therefore, caution needs to be exerted when using the A-H method to determine polymeric pigments and tannins in wine with high content of sugars.
Number of references: 17
Main heading: Polymers
Controlled terms: Flavonoids - Fructose - Glucose - Proteins - Sugar (sucrose) - Sugars - Tannins - Wine
Uncontrolled terms: High-content - Protein precipitation - Wine sample
Classification code: 804.1 Organic Compounds - 815.1 Polymeric Materials - 822.3 Food Products
DOI: 10.6041/j.issn.1000-1298.2016.02.037
Database: Compendex
8.
Accession number: 20161202133042
Title: Design and test of high clearance agricultural machine with four-wheel diamond arrangement
Authors: Fan, Guoqiang1, 2 ; Zhang, Xiaohui1, 2 ; Wang, Jinxing1, 2; Feng, Haiming1, 2; Yang, Qinglu1, 2; Sun, Fengtao3
Author affiliation: 1 College of Mechanical and Electrical Engineering, Shandong Agricultural University, Taian, China
2 Shandong Provincial Key Laboratory of Horticultural Machineries and Equipments, Taian, China
3 Taian Hysoon Machinery Company Limited, Taian, China
Corresponding author: Zhang, Xiaohui ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 84-89
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: In order to provide farm operation machine for corn and sugarcane at the late growing stage, a high clearance machine with four-wheel diamond arrangement was designed. Gantry structure was adopted with high ground clearance, low gravity center, short turning radius and good stability. To ensure the steering angle of the front wheel which was the same as that of the rear wheel, and the rotation direction was opposite, a set of drag link was designed, so that the turning radius was reduced. An adjusting mechanism consisting of extension tubes and hydraulic cylinder was adopted between side wheel and the central body, the wheel-base could be accurately regulated in a wide range, thus different planting spaces could be adapted, and the compaction on crop roots could also be reduced. The same adjustment mechanism was also used in the height direction of left and right wheels, and the machine could be leveled on the slope, and rollover could be avoided when the machine worked on a large slope. The corresponding hydraulic system and mechanical system were designed for walking drive, adjusting mechanism and auxiliary devices. The test results indicated that the maximum crossing altitude was 2.8 m, the anti-tipping capacity was increased by 2.4 times than that of traditional scheme, the track adjustment range was 0~1000 mm, and the machine could be leveled on the slope with inclination angle less than or equal to 25 °.
Number of references: 11
Main heading: Agricultural machinery
Controlled terms: Diamonds - Hydraulic equipment - Hydraulic machinery - Liquid sloshing - Machining - Wheels
Uncontrolled terms: Accurately regulated - Adjusting mechanism - Adjustment mechanisms - Agricultural machine - Diamond arrangement - Hydraulic cylinders - Mechanical systems - Rotation directions
Classification code: 482.2.1 Gems - 601.2 Machine Components - 604.2 Machining Operations - 631.1 Fluid Flow, General - 632.2 Hydraulic Equipment and Machinery - 821.1 Agricultural Machinery and Equipment
DOI: 10.6041/j.issn.1000-1298.2016.02.012
Database: Compendex
9.
Accession number: 20161202133069
Title: Winter wheat yield forecasting based on time series of MODIS NDVI
Authors: Huang, Jianxi1 ; Luo, Qian1; Liu, Xiaoxuan1; Zhang, Jie2
Author affiliation: 1 College of Information and Electrical Engineering, China Agricultural University, Beijing, China
2 Department of Geography, University of Maryland, College Park, United States
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 295-301
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The large regional-scale crop yield forecasting is of great significance to ensure national food security and agricultural sustainable development. To predict regional-scale winter wheat yield, the winter wheat forecasting method proposed by Becker-Reshef was implemented in major winter wheat planting areas in China. Firstly, the winter wheat planting areas were extracted through time series of MODIS NDVI with 250 m spatial resolution in Hebei, Henan and Shandong Provinces. Winter wheat adjusted NDVI peak at the heading stage was used to analyze the correlation with winter wheat yield on the purest wheat pixels from 2000 to 2010.Winter wheat yield prediction models were established through the regression statistical relationship between NDVI peak at heading stage and winter wheat yield at the prefecture-city unit from 2000 to 2009. The results showed that the dense wheat planted cities had good model accuracy. Finally, the accuracy of prediction models was evaluated by using the statistical winter wheat yield in 2010. The results showed that winter wheat yields could be forecasted two months in advance with average forecasting error of 7.49%, and the yield forecasting method using adjusted NDVI peak at heading stage had considerable potential applications at the prefecture-city scale in China. The study provides basis and a method for other crops yield forecasting in agricultural regions.
Number of references: 15
Main heading: Crops
Controlled terms: Agriculture - Food supply - Forecasting - Radiometers - Time series
Uncontrolled terms: Average forecasting error - Crop yield forecasting - Forecasting methods - Modis ndvi - Statistical relationship - Winter wheat - Winter wheat yields - Yield forecasting
Classification code: 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.4 Agricultural Products - 822.3 Food Products - 922.2 Mathematical Statistics - 944.7 Radiation Measuring Instruments
DOI: 10.6041/j.issn.1000-1298.2016.02.039
Database: Compendex
10.
Accession number: 20161202132557
Title: Design and experiment of compliant parallel humanoid wrist joint polishing robot
Authors: Zhu, Wei1, 2 ; Wang, Yuan1; Shen, Huiping1; Deng, Jiaming1; Xu, Zhaotang2
Author affiliation: 1 School of Mechanical Engineering, Changzhou University, Changzhou, China
2 Jiangsu Digital Manufacture Technology Main Lab., Huaiyin, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 402-407 and 348
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: In the polishing process of free surface, the traditional intelligent control robot has some problems such as complex programming complexity and difficulty in controlling. A humanoid wrist joint compliant parallel mechanism 3SPS+S used in polishing robot was designed according to the principle of inverse adaptive motion of flexible, and its moving platform can output three rotations. Firstly, the inverse motion equation of the mechanism was established to obtain the relation between deformation quantity of the three flexible branched chains and attitude of the moving platform. Secondly, the mechanics model was deduced through analyzing deformation forces of flexible chains, grinding force and output moment of the tool. Furthermore, simulation was executed based on the 3D model for the target of the tool posture change and the constant grinding force, and the ranges of some work parameters were obtained through the prototype test. Lastly, taking a car shell as a grinding object, an experiment was designed to validate whether the grinding tool mounted on the moving platform could fit rapidly to the shell surface when humanoid wrist joint compliant parallel mechanism wholly moved along a given simple track under driving of a 6-DOF manipulator. Both simulation and test results showed that the position and attitude of the tool can be changed rapidly as changing the geometry of the workpiece through using the grinding mechanism, and it can keep the contact force unchanged between the grinding head and the workpiece. Because of several advantages, such as simple design, flexible movement and convenient control, this kind of mechanism previously has good application value.
Number of references: 17
Main heading: Compliant mechanisms
Controlled terms: Chains - Deformation - Equations of motion - Grinding (machining) - Industrial robots - Intelligent robots - Machine design - Mechanisms - Polishing - Robot programming - Robots
Uncontrolled terms: Deformation forces - Grinding mechanism - Grinding robots - Mechanics modeling - Parallel mechanisms - Polishing processs - Programming complexity - Wrist joints
Classification code: 601 Mechanical Design - 601.3 Mechanisms - 602.1 Mechanical Drives - 604.2 Machining Operations - 731.5 Robotics - 731.6 Robot Applications - 921.2 Calculus - 931.1 Mechanics
DOI: 10.6041/j.issn.1000-1298.2016.02.054
Database: Compendex
11.
Accession number: 20161202133032
Title: Influence of axial-flow pumping system operating conditions on hydraulic performance of elbow inlet conduit
Authors: Yang, Fan1 ; Xie, Chuanliu1; Liu, Chao1; Yuan, Yao2; Shi, Lijian1
Author affiliation: 1 School of Hydraulic, Energy and Power Engineering, Yangzhou University, Yangzhou, China
2 Water Resources Research Institute of Jiangsu Province, Yangzhou, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 15-21
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: In order to investigate the hydraulic performance of elbow inlet conduit, the three-dimensional fluid flow inside an axial-flow pumping system was simulated based on the Reynolds time-averaged Navier-Stokes equations, the RNG k-Ε turbulent flow model and the law of the wall. To verify the accuracy and reliability of the calculation results, a model test was conducted on the high-precision hydraulic machinery test bed. It was found that the calculated results agreed well with the measured results. The hydraulic performance parameters of elbow inlet conduit were analyzed quantitatively considering the hydraulic interaction of inlet conduit and impeller. The stability and uniformity of flow were analyzed by using static distortion index of outlet section in elbow inlet conduit. The mathematical model of static distortion index and flow rate coefficient was established with the method of regress analysis. The stability and uniformity of flow were good under the high efficiency conditions, while it was the worst under the large operating condition. The different operating conditions of pumping system had little effect on the velocity-weighted drift angle of outlet section. The maximum difference of velocity-weighted drift angle was 0.91°. The average static pressure ratio of linear contraction segment was 0.943, while the average static pressure ratio of elbow segment was 0.826. The average hydraulic efficiency was 99.215% for elbow inlet conduit. The uniformity of cross section was affected under the condition of boundary constraint. The conversion rate of pressure energy and kinetic energy was high in the elbow segment. The important technology of optimization design is elbow segment for elbow inlet conduit.
Number of references: 21
Main heading: Navier Stokes equations
Controlled terms: Axial flow - Computer simulation - Flow of fluids - Hydraulic machinery - Kinetic energy - Kinetics - Pumping plants - Pumps - Turbulent flow
Uncontrolled terms: Axial flow pump - Boundary constraints - Different operating conditions - Flow rate coefficients - Hydraulic efficiency - Hydraulic performance - Inlet conduits - Static-pressure ratio
Classification code: 446 Waterworks - 618.2 Pumps - 631.1 Fluid Flow, General - 632.2 Hydraulic Equipment and Machinery - 723.5 Computer Applications - 921.2 Calculus
DOI: 10.6041/j.issn.1000-1298.2016.02.002
Database: Compendex
12.
Accession number: 20161202133041
Title: Development and application of test bench for flexible chassis
Authors: Song, Shujie1 ; Li, Yining2; Qu, Jiwei2; Zhou, Wei2; Zhang, Zongling1; Guo, Kangquan2, 3
Author affiliation: 1 College of Food Science and Engineering, Northwest A&F University, Yangling; Shaanxi, China
2 College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling; Shaanxi, China
3 Engineering Research Centre for Agricultural Equipment, Yangling; Shaanxi, China
Corresponding author: Guo, Kangquan ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 77-83
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Flexible chassis is a four-wheel-independent-drive and four-wheel-independent-steer electric vehicle with four in-wheel motors. In order to resolve some key issues about dynamics of the flexible chassis and find its control strategy, a new type of test bench with four turntables was designed for testing the flexible chassis. The flexible chassis was connected to the bench through two groups of sensors with measurement directions being perpendicular to each other. A measurement and control system based on LabView was developed for the test bench, and it can control and record the rotating speeds and electric current of the eight in-wheel motors and the forces of the four force sensors. Firstly, the whole structure design was completed, the working principle of the device was analyzed and a testing system was developed. Secondly, the bench and assemble observation system were made. Finally, the experiment was carried out. The experiment contained two parts. For the fixed rotation speeds of four wheels of flexible chassis, the changing processes of the rotating speed, electric current and the forces at a rotation speed of 55 r/min were monitored and analyzed with two different movement postures of chassis. For the different rotation speeds, the same indexes were analyzed to find the final results. In different motion states of flexible chassis, it took 2~3 s for in-wheel motors' rotation speed to increase from 0 to stable state. Tractions of flexible chassis can reach 1132 N and 1165 N, respectively, when running up-down and left-right; driving force of each in-wheel motor, running at a constant speed, was different, so real-time automatic adjustment of each in-wheel motors' current was required to ensure the coordinated movement of each wheel when driving independently. The test results could provide basic data for study of flexible chassis and it also proved that the bench was feasible and efficient. The research results provided theoretical and technical references for design of the new type of test bench.
Number of references: 15
Main heading: Electric machine control
Controlled terms: Chassis - Control systems - Digital storage - Phonographs - Rotating machinery - Rotation - Shafts (machine components) - Speed - Traction motors - Wheels
Uncontrolled terms: Automatic adjustment - Control strategies - Coordinated movement - Development and applications - Measurement and control systems - Observation systems - Structure design - Test benches
Classification code: 601.1 Mechanical Devices - 601.2 Machine Components - 662.4 Automobile and Smaller Vehicle Components - 722.1 Data Storage, Equipment and Techniques - 731.1 Control Systems - 731.2 Control System Applications - 752.3.1 Sound Reproduction Equipment - 931.1 Mechanics
DOI: 10.6041/j.issn.1000-1298.2016.02.011
Database: Compendex
13.
Accession number: 20161202133039
Title: Design and experiment of tube-outputting device for vegetable grafting machine using tube-grafting method
Authors: Chu, Jia1 ; Zhang, Tiezhong1, 2 ; Zhang, Libo1; Zhang, Wenbo1; Wen, Tao1; Yin, Quan1
Author affiliation: 1 College of Engineering, China Agricultural University, Beijing, China
2 Key Laboratory of Soil-Machine-Plant Systematic Technology, Ministry of Agriculture, Beijing, China
Corresponding author: Zhang, Tiezhong ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 64-70
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Tube-grafting is a kind of vegetable seedling grafting with closed or open tube. Compared with using grafting clips, tube has the features of cheepness, well grafting wound moisturizing and so on. Grafting with tubes can not only reduce the grafting production cost, but also can improve the survival rate of grafting seedlings. In today's tube-grafting situation, it basically relies on manual grafting operation at home and abroad. There is much significance to develop a tube-grafting machine. The most important and key part of a tube-grafting machine is the tube-providing part, which provides the tube one-by-one and matches the pace of grafting processing. To provide tubes for a grafting machine based on tube-grafting method, a special tube-outputting mechanism was designed. The mechanism consisted of a vibration sorting-tube device, a tube duct and a tube one-by-one delivery unit. Experiments were conducted in laboratory, the results showed that at the voltage of 185 V, the variation coefficient of tube-outputting by the vibration sorting-tube device reached the lowest value of 61.75%. In this situation, the tubes were put out steadily. And the success rate of tube delivery by tube one-by-one delivery unit was 100%. The tube one-by-one delivery unit worked perfectly in the experiment. And the mechanism was available in situations of variable tube numbers. It can provide tube one-by-one with pace of grafting and it is useful for future development of grafting machines based on tube-grafting method.
Number of references: 13
Main heading: Tubes (components)
Controlled terms: Design - Experiments - Grafting (chemical) - Tubing - Vegetables
Uncontrolled terms: Grafting method - Grafting seedlings - Key parts - Production cost - Survival rate - Variation coefficient - Vegetable seedlings
Classification code: 619.1 Pipe, Piping and Pipelines - 802.2 Chemical Reactions - 821.4 Agricultural Products - 901.3 Engineering Research
DOI: 10.6041/j.issn.1000-1298.2016.02.009
Database: Compendex
14.
Accession number: 20161202133046
Title: Effect of mulching on transfer and distribution of salinizated soil nutrient in hetao irrigation district
Authors: Liang, Jiancai1 ; Li, Ruiping1 ; Shi, Haibin1; Li, Zhen1; Lu, Xinghang1; Bu, Huailiang1
Author affiliation: 1 Hydraulic and Civil Engineering College, Inner Mongolia Agricultural University, Huhhot, China
Corresponding author: Li, Ruiping ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 113-121
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Field scale autumn irrigation experiments were conducted on the salinity soil in Hetao Irrigation District to study the variation of soil nutrient in autumn irrigation, freeze thawing and growth periods of maize with different mulching approaches. Seven treatments were contained as follows: mixed chopped maize straw mulching amount of 1.2 (F1.2), 0.9 (F0.9), 0.6 (F0.6) and 0.3 kg/m2(F0.3), as well as the whole maize straw (YZ) mulching, plastic film (DM) mulching, and no mulching (CK). Results showed that water table was high after autumn irrigation, soil water had a recharge and discharge relationship with groundwater during the autumn irrigation and freeze-thawing periods. The transfer and migration of soil nutrient occurred simultaneously. The changing law of soil nutrient was complex during the autumn irrigation and freeze-thawing periods. The soil surface mulching altered the water-soil environment of soil. The nutrient content had differences between treatments. The rangeability of whole effect nutrient was small during the experiment period. But the rangeability of available nutrient was large. Analyzing the feeder capability of surface soil before seeding stage of maize, it was showed that the treatment of straw mulching had small soil total N content but got huge supply intensity. It required nitrogen when the spring sowing happened. The treatment of straw mulching had small soil total P content but owned huge supply intensity. It needed phosphorus fertilizer for the spring sowing, which could ensure the growth of crops. Generally, the soil total K content and the potassium supply intensity of straw mulching treatments were higher than those of CK. Compared with CK, straw mulching made the surface soil be capable of satisfying the potassium fertilizer demand during the growth period. After the experiment period, the whole soil N content of DM in surface soil was decreased by 0.10 g/kg under the same fertilizer condition. The rangeability of other treatments was small. The soil total P content of each treatment was increased after experiment, and the soil total K contents of CK and DM were also increased, but the soil total K contents of F1.2 and F0.9 were decreased. The available N contents of YZ, F1.2 and DM were increased. The available K and P contents for each treatment were increased after experiment. The soil organic matter contents of F1.2, F0.9 and CK were increased after experiment, however, it was decreased for other treatments.
Number of references: 19
Main heading: Soils
Controlled terms: Fertilizers - Forestry - Groundwater - Irrigation - Nutrients - Potassium - Potassium fertilizers - Recharging (underground waters) - Soil moisture - Thawing
Uncontrolled terms: Freezing-thawing - Hetao irrigation districts - Maize - Mulching - Soil nutrients
Classification code: 444.2 Groundwater - 483.1 Soils and Soil Mechanics - 549.1 Alkali Metals - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821.2 Agricultural Chemicals - 821.3 Agricultural Methods
DOI: 10.6041/j.issn.1000-1298.2016.02.016
Database: Compendex
15.
Accession number: 20161202133048
Title: Effects of biodegradable film mulching planting patterns on soil nutrient and nitrogen use efficiency of summer maize
Authors: Zhou, Changming1 ; Li, Yuannong1 ; Gu, Xiaobo1; Yin, Minhua1; Zhao, Xi1
Author affiliation: 1 Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling; Shaanxi, China
Corresponding author: Li, Yuannong ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 133-142 and 112
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: In order to reveal the effects of biodegradable film mulching cultivation on soil nutrient and nitrogen use efficiency, a two-year field experiment was carried out in 2013 and 2014 to determine and calculate nitrate nitrogen and other nutrient contents in soil, nitrogen contents and yields of summer maize, partial factor productivity (PFP) and nitrogen agronomic efficiency (AE). Four treatments, including flat planting without mulching (CK), flat planting with biodegradable film mulching (M1), ridge-furrow planting with biodegradable film mulching over ridge only (M2) and ridge-furrow planting with biodegradable film mulching over ridges (M3), with three replicates were conducted. The results showed that nutrient content in 0~50 cm soil layer was increased under all mulching treatments compared with that under CK, especially available N, P and K contents were significantly increased. The reduction range of average nitrate nitrogen content in 0~200 cm soil layer reached the maximum at 20~60 d after sowing, and nitrate nitrogen peak value in different soil depths presented gradually downward migration trend with increment of the days after sowing. Summer maize nitrogen accumulation under M1, M2 and M3 were higher than that under CK, and achieved the greatest amount during 20~40 d after sowing. The PFP and AE under the three mulching treatments were significantly higher than that under CK (P<0.05). The nitrogen use efficiency under M3 was greater than that under M1 and M2 and it was increased by 49.30% and 33.10%, respectively. Overall, it could be concluded that the treatment of ridge-furrow planting with biodegradable film mulching (M3) reached the best effect on promoting nutrient uptake and improving yield of summer maize in drought area.
Number of references: 29
Main heading: Nitrogen
Controlled terms: Cultivation - Efficiency - Forestry - Nitrates - Nutrients - Soils
Uncontrolled terms: Biodegradable film - Nitrate nitrogen - Nitrogen accumulation - Nitrogen content - Nitrogen-use efficiency - Nutrient contents - Partial factor productivity - Summer maize
Classification code: 483.1 Soils and Soil Mechanics - 804 Chemical Products Generally - 804.2 Inorganic Compounds - 821.3 Agricultural Methods - 913.1 Production Engineering
DOI: 10.6041/j.issn.1000-1298.2016.02.018
Database: Compendex
16.
Accession number: 20161202133066
Title: Instrumental and sensory aroma analysis of noble-rot wine from artificial botrytized grapes
Authors: Tao, Yongsheng1, 2 ; Liu, Jibin1; Lan, Yuanyuan1; Chen, Chaoqi1; Li, Aihua3
Author affiliation: 1 College of Enology, Northwest A&F University, Yangling; Shaanxi, China
2 Shaanxi Engineering Research Center for Viti-Viniculture, Northwest A&F University, Yangling; Shaanxi, China
3 College of Food Science and Engineering, Northwest A&F University, Yangling; Shaanxi, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 270-279 and 315
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: It is known to all that noble-rot wine, a sweet wine made from botrytized grapes, has high cost for its special flavor. Aromas of sweet wines made from artificially botrytized grapes and botrytized juice were studied to evaluate the winemaking process of botrytized wines. Normally harvested Vitis vinifera Var. Ecolly grape was obtained in Yangling, Shaanxi Province, China. The grapes and juice were botrytized artificially by Botrytis spp. with high level of glycosidase activity. The winemaking process normally used for making sweet wine was used to make the artificial noble-rot wines. Normal sweet white wine and wine made from air-dried grapes were used as controls. The aromas of wine samples taken in April of the following year were subjected to chemical and sensory analyses. Botrytis-infected wines contained few higher alcohols but contained high esters and fatty acids, especially acetate esters, which were more likely due to high volatile acids induced by fungal infection. More varietal aroma-active compounds, especially terpenols and norisoprenoids, were detected in wines made from botrytized grapes and air-dried grapes than those in normal sweet white wine and botrytized juice made wine. The treatment of over-ripe grapes promoted hydrolysis of aroma precursors, meanwhile, the metabolic activity of B. cinerea also promoted the hydrolysis. Moreover, hydroxy benzoate esters were typical compounds in botrytis-infected wines and γ-decalactone, phenyl acetic acid and 2-nonanone were unique in wine made from botrytized grapes. The wine made from botrytized grapes had the most complex aroma profile, with sweet fruity, caramel, mango and toast flavors; wine made from botrytized juice had fewer aromas. Therefore, grapes botrytized artificially with B. cinerea could be used to make noble-rot wines with high aroma quality.
Number of references: 30
Main heading: Wine
Controlled terms: Chemical analysis - Esters - Fatty acids - Hydrolysis - Odors - Sensory analysis - Volatile fatty acids
Uncontrolled terms: Artificially botrytized grape - Fungal infection - GC-MS - Higher alcohols - Metabolic activity - Phenylacetic acid - Varietal aromas - Wine aromas
Classification code: 802.2 Chemical Reactions - 804.1 Organic Compounds - 822.3 Food Products
DOI: 10.6041/j.issn.1000-1298.2016.02.036
Database: Compendex
17.
Accession number: 20161202133052
Title: Free infiltration characteristics of muddy water film hole irrigation with different film hole diameters
Authors: Fei, Liangjun1 ; Wang, Jinhui1; Jin, Shijie1
Author affiliation: 1 Institute of Water Resources and Hydro-Electric Engineering, Xi'an University of Technology, Xi'an, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 172-178
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: According to indoor free infiltration of muddy water film hole irrigation test data and free infiltration of clean water film hole irrigation as contrast, the free infiltration characteristics of muddy water film hole irrigation with different film hole diameters were investigated, the relationships between muddy water film hole irrigation infiltration and vertical one-dimensional muddy water infiltration was studied, the relationships between free infiltration of muddy water film hole infiltration parameters, wetting front movement parameters and different film hole diameters were established, and the cumulative infiltration volume model per unit film hole area of free infiltration of muddy water film hole irrigation with different film hole diameters, side infiltration volume model per unit film hole area, steady infiltration rate and wetting front movement model were put forward. The results showed that with the increase of film hole diameter of free infiltration for muddy water, the cumulative infiltration volume of single point of film hole was increased gradually, cumulative infiltration volume per unit film hole area and side infiltration volume per unit film hole area were decreased, the fitting parameters of K and α for cumulative infiltration volume per unit film hole area were decreased, and Kcof side infiltration volume per unit film hole area was decreased, while αcwas increased. Within the same infiltration time, vertical and horizontal wetting front movement distances were gradually increased with the increase of film hole diameter.
Number of references: 19
Main heading: Infiltration
Controlled terms: Irrigation - Wetting
Uncontrolled terms: Cumulative infiltrations - Film holes - Fitting parameters - Infiltration characteristic - Infiltration parameters - Muddy waters - Side infiltration volume - Steady infiltration rate
Classification code: 821.3 Agricultural Methods
DOI: 10.6041/j.issn.1000-1298.2016.02.022
Database: Compendex
18.
Accession number: 20161202132554
Title: Mechanical characteristics of bionic walking foot on soft sand
Authors: Wang, Ying1 ; Li, Jianqiao1 ; Zhang, Guangquan1; Huang, Han1
Author affiliation: 1 Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun, China
Corresponding author: Li, Jianqiao ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 384-389
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Slipping and sinking easily happens on soft terrain, and it will affect the tractive performance of the vehicle. The passing ability on the soft terrain is very important for agricultural terrain-machine and mobile mechanism. Chinese mitten crab is a kind of common arthropod in China, which inhabits the shore of river and lake with mud everywhere. Viewed this way, the capability of going through soft terrain of crab is valuable for designing bionic walking mechanism and agricultural machine, which works on the sand, swamp, beach or wetland. Four bionic walking feet compared with cylinder foot were designed by learning from the Chinese mitten crab dactylopodite. Experiments were separately carried out on dry sand, wet sand, coarse sand and fine sand. Through experimentation the impact of the shape and grooves for foot on in-soil force, bearing force, pullout force and propulsive force were examined. Moreover, the order and contribution rate of every experiment factor on propulsive force were analyzed by orthogonal tests, range analysis and ANOVA. The results showed that the bionic walking foot had superior mechanical characteristics than cylinder foot on sand. In-soil forces of cone shape bionic foot were 64.71%~95.43% smaller than those of cylinder foot. The bearing force of cylinder bionic foot with grooves was 9.48%~24.31% larger than that of cylinder foot. Moisture content was the most critical influence factor on propulsive force. And the propulsive force was increased by about 3.84% with bionic walking foot. For all the bionic walking feet, the pullout forces were smaller, and the maximum reduction reached 89.83%, which indicated that the energy consumption of bionic feet was smaller. The bionic feet could be applied in various walking mechanism for different working conditions. This research provides basis for the design and optimization of soil contact parts for walking mechanism on soft terrain.
Number of references: 19
Main heading: Bionics
Controlled terms: Agricultural machinery - Agriculture - Crashworthiness - Cylinders (shapes) - Energy utilization - Landforms - Mechanical properties - Sand - Shellfish - Soils - Wetlands
Uncontrolled terms: Agricultural machine - Chinese mitten crabs - Contribution rate - Design and optimization - Mechanical characteristics - Propulsive forces - Tractive performance - Walking foot
Classification code: 461.1 Biomedical Engineering - 461.9 Biology - 481.1 Geology - 483.1 Soils and Soil Mechanics - 525.3 Energy Utilization - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 914.1 Accidents and Accident Prevention - 951 Materials Science
DOI: 10.6041/j.issn.1000-1298.2016.02.051
Database: Compendex
19.
Accession number: 20161202133040
Title: Design and experiment of optimization control system for variable fertilization in winter wheat field based on fuzzy PID
Authors: Chen, Man1 ; Lu, Wei1; Wang, Xiaochan1, 2 ; Sun, Guoxiang1, 2; Zhang, Yu1, 2
Author affiliation: 1 College of Engineering, Nanjing Agricultural University, Nanjing, China
2 Jiangsu Province Engineering Laboratory for Modern Facilities Agricultural Technology and Equipment, Nanjing, China
Corresponding author: Wang, Xiaochan ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 71-76
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: In order to achieve real-time variable dressing at winter wheat jointing stage, the fertilizer quantity real-time adjustment algorithm based on fuzzy PID control was studied. To achieve the optimal control of fertilizer, the rotation speed and opening of fertilizer apparatus were real-timely adjusted online. With ITAE criterion as the fitness function, the initial values of PID controller parameters were determined based on particle swarm optimization algorithm (PSO). The algorithm combined the traditional PID control with fuzzy algorithm by acquiring the real-time parameters, such as the crop canopy real-time spectral information (Normalized differential vegetation index, NDVI), rotation speed and opening. The parameters of PID were set online and the rotation speed and opening of fertilizer apparatus were real-timely adjusted to achieve optimal control of variable dressing. Results showed that the fuzzy PID had good dynamic stability and tracking performance. A fluctuation existed on fertilizing amount during the process of fertilization. But the variation coefficient of fertilizing amount was small with the maximum value of 3.22% and average value of 2.09%, which met the requirements of field variable fertilization. In the laboratory tests, the maximum overshoot of rotation speed was about 11.96%, the maximum overshoot of opening did not exceed 14.94%, and the system precision could reach above 87%. In the field experiments, the maximum overshoot of rotation speed was about 12.80%, the maximum overshoot of opening did not exceed 14.79%, and the system precision could reach above 86%. The system had good stability, accuracy and rapidity and it was able to satisfy the agriculture technical requirements.
Number of references: 16
Main heading: Three term control systems
Controlled terms: Algorithms - Crops - Fertilizers - Fuzzy sets - Optimal control systems - Optimization - Parameter estimation - Particle swarm optimization (PSO) - Rotation - Speed
Uncontrolled terms: Control parameters - Fuzzy - pid controls - Particle swarm optimization algorithm - Variable fertilizations - Winter wheat
Classification code: 731.1 Control Systems - 804 Chemical Products Generally - 821.4 Agricultural Products - 921.5 Optimization Techniques - 931.1 Mechanics
DOI: 10.6041/j.issn.1000-1298.2016.02.010
Database: Compendex
20.
Accession number: 20161202133037
Title: Optimization and experiment on feeder for small-scale pellet mill
Authors: Peng, Fei1, 2 ; Li, Tengfei1, 2; Kang, Hongbin1; Zhang, Guodong1; Kong, Dandan1; Wang, Hongying1, 2
Author affiliation: 1 College of Engineering, China Agricultural University, Beijing, China
2 National Agricultural Products Processing Technology & Equipment Research and Development Center, Ministry of Agriculture, Beijing, China
Corresponding author: Wang, Hongying ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 51-58
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The discrete element analysis software EDEM was used to numerically simulate the working process. The change regulation of feeding mass and the instability and uneven “pulse” phenomenon of materials caused by the end section of helical blade were quantitatively studied. The spindle diameter X1, pitch of screw X2, and feeding rate X3were selected as the influencing factors, and the feeding mass flow rate Y1, stability Y2, drop speed of the materials Y3were selected as evaluating indicators, and experiments were conducted by the simulation model under quadratic orthogonal rotation design. Based on the software regression analysis of Design-Expert 8.0.6 and response surface analysis method, the relationships between the three influencing factors and feeding evaluating indicators were established. The reliability of the simulation model was verified by comparing the performance of virtual scraper with the feeder for small-scale pellet mill. The results showed that X1, X2and X3were significantly correlated with Y1and Y2(P<0.01 and P<0.05, respectively), but no correlation was found with Y3. By using response surface method, the optimal aggregative index could be obtained under the condition that the spindle diameter X1was 35 mm, the pitch of screw X2was 57 mm and the rotation rate X3was 139(°)/s. Under this condition, the volatility of feeding mass was reduced and the stability was improved. The virtual test designed by the optimized parameters showed that the feeding mass flow rate was 13.89 g/s, and the stability of mass flow rate was 8.46 g/s. The verifying test of the physical prototype indicated that the mass flow rate was increased by 4.28% and the coefficient of variation was reduced by 16.11%.
Number of references: 17
Main heading: Feeding
Controlled terms: Experiments - Flow rate - Mass transfer - Pelletizing - Regression analysis - Screws - Stability - Surface analysis - Surface properties - Virtual reality
Uncontrolled terms: EDEM - Feeder - Pellet mills - Response surface method - Simulation and optimization
Classification code: 605 Small Tools and Hardware - 631 Fluid Flow - 641.3 Mass Transfer - 691.2 Materials Handling Methods - 723 Computer Software, Data Handling and Applications - 901.3 Engineering Research - 922.2 Mathematical Statistics - 951 Materials Science
DOI: 10.6041/j.issn.1000-1298.2016.02.007
Database: Compendex
21.
Accession number: 20161202133043
Title: Effects of rainfall patterns on hillslope erosion with longitudinal ridge in typical black soil region of Northeast China
Authors: Zheng, Fenli1, 2 ; Bian, Feng2; Lu, Jia1; Qin, Chao1; Xu, Ximeng1
Author affiliation: 1 State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling; Shaanxi, China
2 College of Natural Resource and Environment, Northwest A&F University, Yangling; Shaanxi, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 90-97
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Longitudinal ridge, as one of the main tillage management, causes severe soil erosion on hillslope scale and makes great contribution to the soil loss in typical black soil region of Northeast China. Rainfall pattern is one of the main factors influencing hillslope erosion. The simulated experimental study was conducted to investigate the effects of rainfall patterns on hillslope erosion with longitudinal ridge in the typical black soil region. According to the erosive rainfall standard and rainfall pattern characteristics of natural rainfalls in the typical black soil region, the experimental design included five patterns of simulated rainfalls with the same total rainfall amount of 87.5 mm, covering intensive-type (rainfall intensity distribution was 50-75-100-125 mm/h), reduced-type (rainfall intensity distribution was 125-100-75-50 mm/h), peak-type (rainfall intensity distribution was 50-75-100-125-100-75-50 mm/h), valley-type (rainfall intensity distribution was 100-75-50-75-100 mm/h) and uniform-type (rainfall intensity was 75 mm/h), and the slope gradient was 5° which was the critical slope gradient of changing longitudinal ridge to contour cultivation. The results showed that total runoff volume had little difference among five rainfall patterns, while obvious differences in soil loss were observed. Soil loss of the peak-type treatment was 1.20, 1.63, 1.78 and 1.80 times higher than those of the valley-type, reduced-type, uniform-type and intensive-type treatments, respectively. Occurring frequency of three rainfall patterns (peak-type, valley-type and reduced-type) occupied more than 70% of total natural rainfall events, which could be one of the key reasons caused severe hillslope soil erosion with longitudinal ridge in this region. The time sequences of rainfall intensity in each rainfall pattern had great effects on runoff, soil erosion and their contribution rates to total runoff and soil loss. Except for 125 mm/h rainfall intensity, rainfall intensities occurred at the initial stage of the rainfall pattern had more contributions to total soil loss, compared with the rainfall intensities appeared at the middle stage and the end stage.
Number of references: 26
Main heading: Rain
Controlled terms: Erosion - Landforms - Runoff - Soils
Uncontrolled terms: Black soil region of northeast chinas - Hillslope erosion - Longitudinal ridge - Rainfall patterns - Simulated rainfall
Classification code: 442.1 Flood Control - 443.3 Precipitation - 481.1 Geology - 483.1 Soils and Soil Mechanics
DOI: 10.6041/j.issn.1000-1298.2016.02.013
Database: Compendex
22.
Accession number: 20161202133033
Title: Effect of uneven spacing blade on hydrodynamic noise of centrifugal pump
Authors: Tan, Minggao1 ; Zhang, Jing1; Liu, Houlin1; Wang, Yong1; Huang, Haoqin1
Author affiliation: 1 Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 22-27 and 34
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: In order to analyze the effect of uneven spacing blade on the flow induced noise of centrifugal pump, a single-stage single-suction vertical centrifugal pump with six blades was chosen as the research object. Firstly, based on the theory of automatic rotor balance, three impeller models with uneven spacing blade were established, then with the purpose of extracting the dipole source of the wall of volute and leakage flow, the whole flow passage numerical simulation of model pumps was executed by applying CFD. The results of vibration simulation based on model response were compared with vibration experiment to verify the certain feasibility of NVH simulation, the simulation of hydrodynamic noise was further completed by applying BEM. The final work was to analyze the simulation results of the uneven spacing blade models and the original impeller model, the results showed that there were little differences in total SPL between uneven spacing blade models, which had lower total SPL and spectrum of SPL than original impeller model in general. New peaks of SPL were produced at 145 Hz and its harmonic frequency in uneven spacing blade models, except for the peaks of SPL at original blade frequency and its harmonic frequency, and the energy of noise was more disperse, the spectrum of noise was more stable. Compared with the other two models, the model with θminof 50°could do better when considering the blade frequency and the characteristics of exterior noise at 145 Hz, and it had better noise performance. The results of the research can provide reference for further optimization of the noise of centrifugal pump.
Number of references: 19
Main heading: Pumps
Controlled terms: Centrifugal pumps - Computational fluid dynamics - Fluid dynamics - Hydrodynamics - Impellers - Leakage (fluid) - Thermal noise
Uncontrolled terms: Harmonic frequency - Hydrodynamic noise - Noise and vibration - Simulation of models - Uneven spacing blade - Vibration experiment - Vibration simulation - Whole flow passage
Classification code: 601.2 Machine Components - 618.2 Pumps - 931.1 Mechanics
DOI: 10.6041/j.issn.1000-1298.2016.02.003
Database: Compendex
23.
Accession number: 20161202133060
Title: Drying characteristics of apple slices during contact ultrasound reinforced heat pump drying
Authors: Liu, Yunhong1 ; Miao, Shuai1; Sun, Yue1; Li, Xiaofang1; Wang, Leyan1; Zhu, Wenxue1
Author affiliation: 1 College of Food and Bioengineering, Henan University of Science and Technology, Luoyang, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 228-236
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: In order to investigate the enhancing effect of contact ultrasound treatment on conventional heat pump drying, an ultrasound device was installed in the heat pump dryer, and contact ultrasound reinforced heat pump drying of apple slices was carried out to study the effects of ultrasound power, drying temperature and sample thickness on drying characteristics. The results showed that the internal mass transfer process of samples could be enhanced by putting samples on the ultrasound radiation board directly during heat pump drying. Drying time was shortened and drying rate was improved with the increases of ultrasound power and drying temperature and the decrease of sample thickness. The influence of ultrasound treatment on drying rate was decreased with the reduction of moisture content. Obviously strengthened effect of contact ultrasound on drying rate could be observed at low temperature and thin thickness, while it was reduced with the increases of drying temperature and thickness. The values of effective moisture diffusivity (Deff) ranged from 1.333×10-10m2/s to 1.651×10-9m2/s, and it was increased at high ultrasound power and drying temperature. After the contact ultrasound treatment, the numbers and sizes of the tiny holes inside apple slice were improved. With ultrasound power of 60 W, many micro-tunnels were even produced in the organizational structure of apple slices, which was also beneficial to enhance internal moisture diffusion. Therefore, contact ultrasound technology is an effective method to increase the drying rate of heat pump drying and shorten drying time obviously as well.
Number of references: 32
Main heading: Thermoacoustics
Controlled terms: Drying - Fruits - Heat pump systems - Mass transfer - Moisture - Plants (botany) - Pumps - Reinforcement - Temperature - Ultrasonics
Uncontrolled terms: Apple slices - Drying characteristics - Effective moisture diffusivity - Heat pump drying - Internal mass transfer - Organizational structures - Ultrasound technology - Ultrasound treatments
Classification code: 616.1 Heat Exchange Equipment and Components - 618.2 Pumps - 641.1 Thermodynamics - 641.3 Mass Transfer - 753.1 Ultrasonic Waves - 821.4 Agricultural Products - 951 Materials Science
DOI: 10.6041/j.issn.1000-1298.2016.02.030
Database: Compendex
24.
Accession number: 20161202132555
Title: Control system based on single chip microcomputer for small-scale electrostatic charged combustion
Authors: Shi, Yanling1
Author affiliation: 1 Engineering Basis for Teaching and Training Center, South China Agricultural University, Guangzhou, China
Corresponding author: Shi, Yanling ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 390-395
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: A control system based on single chip microcomputer was designed for small-scale electrostatic charged combustion equipment, and some experiments were carried out using the control system. The liquid ethanol was used as fuel and a glass capillary tube with inner diameter of 0.9 mm was used as nozzle in the combustion experimental system. The external electric field system was composed of a high voltage DC power source, two copper plate electrodes with diameter of 50 mm, 1 MΩ resistance and 5 nF capacity. The control system was based on a single chip microcomputer and a voltage feedback stepping motor, and a STC89C52 chip, a driver chip for the stepping motor, a digital to analog conversion chip, a MAX232 level switch chip, a LCD1602 display and a matrix keyboard were applied. The voltage sampling signals combined with the relevant parameters inputted from the keyboard were used to real-timely control the stepping motor. The high voltage direct current power source was adjusted by the stepping motor and then the combustion and flame could be controlled. Serial data and experimental results using real-time acquisition between personal computer and microcontroller indicated that the circuit current increased with the decrease of electrode spacing; and it decreased with the increase of flow rate of ethanol. Too big flow rate of ethanol, too high voltage, or air turbulence all caused discharge between the plates, flame oscillation or even extinction. The detected voltage was used as a feedback variable and compared with the set value inputted from the keyboard. The stepping motor was used as an actuator to quickly adjust the high voltage DC power. Thus, the real-time closed-loop control of the small-scale combustion and flame system was achieved.
Number of references: 21
Main heading: Electric machine control
Controlled terms: Closed loop control systems - Combustion - Combustion equipment - Computers - Control systems - DC power transmission - Digital to analog conversion - Electric discharges - Electric fields - Electrodes - Electrostatics - Ethanol - HVDC power transmission - Microcomputers - Oscillating flow - Personal computers - Stepping motors
Uncontrolled terms: Closed-loop control - Experimental system - External electric field - Glass capillary tubes - High voltage direct current - Real time acquisition - Real-time closed loops - Single chip microcomputers
Classification code: 521.2 Combustors - 631.1 Fluid Flow, General - 701.1 Electricity: Basic Concepts and Phenomena - 705.3 Electric Motors - 706.1.1 Electric Power Transmission - 722.4 Digital Computers and Systems - 723.2 Data Processing and Image Processing - 731.1 Control Systems - 731.2 Control System Applications - 804.1 Organic Compounds
DOI: 10.6041/j.issn.1000-1298.2016.02.052
Database: Compendex
25.
Accession number: 20161202133045
Title: Transpiration modeling of apple trees based on sap flow measurements
Authors: Liu, Chunwei1, 2 ; Qiu, Rangjian2, 3; Wang, Zhenchang4; Guo, Weihua4
Author affiliation: 1 Jiangsu Provincial Key Laboratory of Agricultural Meteorology, Nanjing University of Information Science and Technology, Nanjing, China
2 College of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, China
3 Center for Agricultural Water Research in China, China Agricultural University, Beijing, China
4 College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 105-112
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Sap flow is a key character in the understanding of plant hydraulic functioning and it is crucial in determining water consumption research of agriculture in Northwest China. The field experiment was conducted during 2008-2010 at the Shiyanghe Experimental Station for Water-Saving in Agriculture and Ecology. The site has a continental temperate climate with mean annual sunshine duration of more than 3000 h, mean annual temperature of 8 and mean annual precipitation of 164 mm. Apple trees (Malusdomestica Borkh. cv. Golden Delicious) were planted in 1981, with row spacing of 6 m and plant spacing of 4 m. The experimental plots were irrigated four times per year by flood irrigation to avoid tree water stress. After measuring trunk sap flow using heat pulse method and wind speed, net radiation, relative humidity, air temperature with an automatic meteorological station, the seasonal variation of sap flow was analyzed and the daily transpiration was modeled using seasonal evapotranspiration model by canopy gap distribution (Cj), dual crop coefficient method (Kcb) and Priestley-Taylor method (PT). The Cj model combined hourly changes in canopy gap fraction to calculate the cover ratio of soil under the canopy and bare soil outside the canopy for soil evaporation, which was constant in the clumping model. Results showed that the seasonal sap flow increased at the beginning of the growing stages and reached peak value of 6.5 mm/d in mid-June. The Cj model performed well in modeling daily transpiration. Compared with the trunk sap flow, the average transpiration, determination coefficient (R2), mean absolute error (MAE) and Nash and Sutcliffe modeling efficiency (NSE) of Cj model were 2.51 mm/d, 0.49, 0.93 mm/d and 0.01, respectively. The Cj model and PT model were better in the leaf expanding period than in fruit expanding period for transpiration modeling, while the Kcbmodel kept stable during the whole season. The Cj model could decrease the effect of time lag of sap flow and be used for long time daily transpiration modeling. The long time scale transpiration modeling provided an efficient method for establishing the irrigation schedule in Northwest China.
Number of references: 28
Main heading: Evapotranspiration
Controlled terms: Agriculture - Atmospheric humidity - Atmospheric movements - Atmospheric temperature - Crops - Forestry - Fruits - Irrigation - Plants (botany) - Soils - Transpiration - Water conservation - Water supply - Wind
Uncontrolled terms: Apple trees - Crop coefficient - Priestley-Taylor - Seasonal evapotranspirations - Trunk sap flows
Classification code: 443.1 Atmospheric Properties - 444 Water Resources - 446.1 Water Supply Systems - 461.9 Biology - 483.1 Soils and Soil Mechanics - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI: 10.6041/j.issn.1000-1298.2016.02.015
Database: Compendex
26.
Accession number: 20161202132558
Title: Design and performance analysis of lamina emergent mechanisms S-LET-shaped flexure hinge
Authors: Qiu, Lifang1 ; Pang, Daqian1; Chen, Jiaxing1; Yang, Jianhong1
Author affiliation: 1 School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China
Corresponding author: Yang, Jianhong ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 408-412
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Flexure hinges are significant components for achieving the action of lamina emergent mechanisms (LEMs). It has always been a challenge to design the suitable flexure hinges. The key problem is how to design and accomplish the flexible hinges with fine performance and high accuracy. Analysis on bending deformation of S-shaped flexible hinge and LET-shaped flexure hinge was compared to find a higher precision flexure hinge which was more stable in working status. A new type of flexure hinge was designed which combined the features of LET-shaped hinge with S-shaped hinge. It was named as S-LET-shaped flexure hinge. The structure of the S-LET-shaped flexure hinge was designed and the bending stiffness equivalent was presented. According to the characteristics of the bending stiffness, the bending stiffness equivalent correction coefficient of S-LET-shaped flexure hinge was proposed. By analyzing of bending equivalent stiffness for different dimensions of S-LET-shaped flexure hinges, the correction coefficient of bending equivalent stiffness was obtained and the effectiveness of bending equivalent stiffness was verified. Finally, the results of the finite element simulation of hinge bending deformation and torsion deformation were compared among S-shaped, LET-shaped and S-LET-shaped hinges. The bending deformation capacity of S-LET-shaped hinge was between S-shaped and LET-shaped hinges and the torsional deformation capacity of S-LET-shaped hinge was the smallest among the three kinds of hinges.
Number of references: 21
Main heading: Hinges
Controlled terms: Bending (deformation) - Compliant mechanisms - Deformation - Finite element method - Stiffness
Uncontrolled terms: Correction coefficients - Deformation capacity - Equivalent stiffness - Finite element simulations - Flexure hinge - Lamina emergent mechanisms - Performance analysis - Torsional deformations
Classification code: 921.6 Numerical Methods - 931.1 Mechanics - 951 Materials Science
DOI: 10.6041/j.issn.1000-1298.2016.02.055
Database: Compendex
27.
Accession number: 20161202133059
Title: Joint optimization of purchasing cost-recall scale model of fresh-cut vegetables based on batch association
Authors: Yang, Xinting1 ; Wang, Jian1, 2; Qian, Jianping1; Xing, Bin1; Cao, Wenqin2; Wang, Guiyong2
Author affiliation: 1 Beijing Research Center for Information Technology in Agriculture, Beijing, China
2 School of Mechatronic Engineering, East China Jiaotong University, Nanchang, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 222-227
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The batch mixing exists for fresh-cut vegetables from purchasing, processing to packaging, and there is mutual restrictive relationship between batch mixing degree and purchasing cost. The single-objective model cannot meet the requirement of flexible production. Therefore, a kind of purchasing cost-recall model was proposed to build batch relations between raw material and order products. According to production plan and process flow of fresh-cut processing enterprise, taking the batch mixing degree and the purchasing cost as objective functions, a mixed-integer linear programming model was established to meet the order requirements and the suppliers' raw material conditions. Since the weight of recall number was more important than that of procurement costs, and high correspondence relationship existed between recall number and batch mixing degree, the hierarchical sequence method was used to solve the multi-object model. The established model was analyzed by the LINGO software in the step-by-step solution process. The model performance was evaluated with parameters, such as purchase cost, average number of recall and the maximum number of recall. The results showed that with the increase of batch mixing degree, the procurement costs of raw materials were reduced gradually. When batch mixing degree was 10, the lowest cost of purchase was 2840.33 yuan, the average recall quantity was 177.50 kg, and the maximum recall quantity was 420 kg. In order to evaluate the practical applicability of the model, the average recall ratio and maximum recall ratio were introduced. The results showed that when batch mixing degree was 10, the average recall ratio and maximum recall ratio were 15.5% and 36.8%, respectively, which were suitable for medium and small fresh-cut processing enterprises.
Number of references: 22
Main heading: Costs
Controlled terms: Integer programming - Mixing - Multiobjective optimization - Production control - Sales - Vegetables
Uncontrolled terms: Batch mixing - Correspondence relationships - Fresh-cut - Hierarchical sequences - Mixed integer linear programming model - Purchase cost - Recall - Single objective models
Classification code: 802.3 Chemical Operations - 821.4 Agricultural Products - 911 Cost and Value Engineering; Industrial Economics - 913.2 Production Control - 921.5 Optimization Techniques
DOI: 10.6041/j.issn.1000-1298.2016.02.029
Database: Compendex
28.
Accession number: 20161202133079
Title: Regulated method based on fuel economy for regulated two-stage turbocharging system of diesel at different altitudes
Authors: Zhao, Changlu1 ; Li, Changjiang1; Han, Kai1; Xia, Meng1
Author affiliation: 1 School of Mechanical Engineering, Beijing Institute of Technology, Beijing, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 369-376
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: A regulated two-stage turbocharging system was matched for a 6 V diesel engine for the purposes of improving its performance at plateau, as well as solving the problems of turbo surge, overspeed and overheat of exhaust when diesel engine running at high altitude (4.5 km). The simulation model of the regulated two-stage turbocharging diesel engine at different altitudes (0 m and 4.5 km) was set up based on the calibrated original diesel engine model. The influence rule of bypass flow rate of high-pressure stage turbine on the performance parameters of diesel at different altitudes (0 m and 4.5 km) was studied. And the influence mechanism of bypass flow rate of high-pressure stage turbine on fuel economy was analyzed, IMEPg and PMEP were key factors which seriously affected the BSFC when adjusted the bypass flow rate of high-pressure stage turbine. Meanwhile, the influence rule of altitude on IMEPg and PMEP was illuminated, which could be used to explain the influence mechanism of altitude on BSFC of diesel engine. The economic regulated law and reliability regulated law of the turbo system at different altitudes (0 m and 4.5 km) were obtained through the optimization of bypass flow rate. The range of economic regulated law was wider than that of reliability regulated law, and it could observably reduce the BSFC within its regulated area compared with reliability regulated law. At altitude of 4.5 km, the range of economic regulated law was narrower than that at altitude of 0 m. In addition, at medium and high loads, the BSFC was higher than that at altitude of 0 m; however, at low load, the BSFC was lower than that at altitude of 0 m.
Number of references: 16
Main heading: High pressure effects
Controlled terms: Compressors - Diesel engines - Engines - Flow rate - Fuel economy - Reliability - Turbines
Uncontrolled terms: Diesel - High pressure - Influence mechanism - Influence rule - Performance parameters - Plateau - Simulation model - Two-stage turbocharging
Classification code: 525.2 Energy Conservation - 612.2 Diesel Engines - 618.1 Compressors - 631 Fluid Flow
DOI: 10.6041/j.issn.1000-1298.2016.02.049
Database: Compendex
29.
Accession number: 20161202133031
Title: Research progress of computational model for rotating turbulent flow in fluid machinery
Authors: Wang, Fujun1
Author affiliation: 1 Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System, China Agricultural University, Beijing, China
Corresponding author: Wang, Fujun ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 1-14
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Rotating turbulent flows are widely existed in pumps, turbines, compressors and other fluid machinery. The three-dimensional stochastic fluctuations are very strong in this kind of flow. The high adverse pressure gradient, large streamline curvature and complex wall surface in rotating turbulent flow have significant effects on the performance of fluid machinery. Although a lot of turbulence models have been developed, there is no universal turbulence model that could be used to simulate rotating turbulent flow in fluid machinery. Each turbulence model has its own applicable scope. The prediction performance of the existing turbulence models either in physical or numerical aspects has not yet met the actual need of fluid machinery. Aiming at strong rotating and large curvature turbulent flow, the turbulence models were reviewed. From three aspects of the high Reynolds number flow in turbulent core area, the low Reynolds number flow near wall and the transition flow from laminar to turbulent areas, the applicability of existing turbulence models for fluid machinery was analyzed. The problems of two series turbulence models, including Reynolds-averaged Navier-Stokes models and scale-resolving simulation models used in solving rotating turbulent flow were compared. The typical Reynolds-averaged Navier-Stokes models introduced included Spalart-Allmaras, k-Ε, k-ω, V2F and RSM models. The typical scale-resolving simulation models included LES, SAS, DES and ELES models. The effective methods to use the suitable turbulence model for different problems and different targets were investigated. The development trend of turbulence model and the application of turbulence model in fluid machinery were discussed.
Number of references: 80
Main heading: Flow of fluids
Controlled terms: Machinery - Navier Stokes equations - Reynolds number - Stochastic systems - Turbulence models - Turbulent flow
Uncontrolled terms: Adverse pressure gradient - Fluid machineries - High Reynolds number flows - Low Reynolds number flow - Prediction performance - Reynolds averaged navier-stokes models - Stochastic fluctuation - Streamline curvature
Classification code: 631.1 Fluid Flow, General - 921.2 Calculus - 961 Systems Science
DOI: 10.6041/j.issn.1000-1298.2016.02.001
Database: Compendex
30.
Accession number: 20161202133075
Title: Simulation and experiment of pressure characteristics for pneumatic shifting actuator
Authors: Shen, Wenchen1, 2 ; Hu, Yuhui1, 2 ; Yu, Tianxiao1, 2; Xi, Junqiang1, 2; Chen, Huiyan1, 2
Author affiliation: 1 School of Mechanical Engineering, Beijing Institute of Technology, Beijing, China
2 Research Center of Intelligent Vehicle, Beijing Institute of Technology, Beijing, China
Corresponding author: Hu, Yuhui ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 338-348
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: It brings great difficulties to select structure and design for automated mechanical transmission shifting actuator, because pneumatic shifting actuator has characteristics of highly-lag response and strong nonlinearity, which leads to big errors when only adopting regular steady-state analysis. Focusing on the features of pressure formed in the chamber of a pneumatic shifting actuator controlled by high-speed on/off valves, a nonlinear mathematical model integrated electricity, magnetism, machinery and fluid power theory was built, which was used to describe the dynamic coupling speciality of the pneumatic shifting actuator. In order to evaluate the accuracy of the model, two indexes including average relative error and maximum relative error were adopted. Compared simulated results with practical ones, the small errors showed that the actuator model was reasonable enough to simulate the dynamic characteristics of pneumatic actuator. Through simulation, several factors, such as volume of pressure chamber controlled by electric valves, the effective areas of electric valve inlet and outlet, were analyzed and they had great influence on the buildup of pressure in the chamber. Finally, the model can be directly used to optimize the structural parameters of pneumatic actuator or to validate some complex control algorithms, which is a good platform to solve shifting force control problem during pneumatic shifting process. However, the nonlinear equations of the system are so complex that they will not be able to calculate on a real-time platform unless they are simplified. The further work is to simplify the complex model into a simple one, which will not reduce the dynamic characteristics sharply and can be run on a real-time platform such as DSpace.
Number of references: 20
Main heading: Pneumatic actuators
Controlled terms: Actuators - Algorithms - Errors - Machinery - Mechanical actuators - Nonlinear equations - Pneumatic equipment - Pneumatics
Uncontrolled terms: Automated mechanical transmissions - Complex control algorithms - Dynamic characteristics - High-speed on/off valve - Maximum relative errors - Nonlinear mathematical model - On/off valves - Pressure characteristics
Classification code: 632.3 Pneumatics - 632.4 Pneumatic Equipment and Machinery - 732.1 Control Equipment
DOI: 10.6041/j.issn.1000-1298.2016.02.045
Database: Compendex
31.
Accession number: 20161202133080
Title: Identification of gas-liquid two-phase flow patterns in hydraulic braking pipeline based on cluster analysis
Authors: Li, Xiaolu1 ; Wang, Wenyue1; Zhang, Yuanhui1; Wu, Shanqiang1; Li, Yuntang1
Author affiliation: 1 College of Electrical and Mechanical Engineering, China Jiliang University, Hangzhou, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 377-383
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The automobile braking liquid is in a gas-liquid two-phase state. The gas-liquid two-phase flow in hydraulic braking pipeline is complicated and difficult to be detected. To detect the flow patterns in hydraulic braking pipeline effectively, an experimental bench was built up by mounting a transparent quartz pipe in a hydraulic braking system of automobile, and a flow pattern identification method was proposed based on the gray level co-occurrence matrix and hierarchical cluster analysis. Totally 160 images of gas-liquid two-phase flow patterns in the hydraulic braking pipeline were captured by a digital high speed camera, the feature parameters of gray level co-occurrence matrix of images were extracted by using image processing techniques, and then these feature parameters were used as source data, which were analyzed by the hierarchical cluster analysis method. In order to improve the accuracy of cluster analysis, different sample spaces and class spaces were compared to find the best combination of sample space and class space. Finally, the flow pattern intelligent identification was realized. The test results indicated that the brake fluid was a gas-liquid two-phase flow in hydraulic braking pipeline of automobile, whose flow patterns were recognized as bubbly flow, plug flow, slug flow and annular flow. The cluster analysis results also proved that the method was successful to identify the four typical flow patterns in hydraulic braking pipeline of automobile, and the whole identification accuracy was up to 95.625%. Especially for bubble flow and slug flow, their identification accuracies were 100%. Due to its high speed and high accuracy, the method provided an effective way for researching the flow patterns of gas-liquid two-phase flow in the hydraulic braking system.
Number of references: 18
Main heading: Two phase flow
Controlled terms: Automobiles - Cluster analysis - Flow patterns - Gases - Hierarchical systems - High speed cameras - Image processing - Liquids - Pipelines
Uncontrolled terms: Flow pattern identification - Gas - liquid two-phase flows - Gray level co-occurrence matrix - Hierarchical cluster analysis - Hydraulic braking
Classification code: 619.1 Pipe, Piping and Pipelines - 631.1 Fluid Flow, General - 662.1 Automobiles - 723 Computer Software, Data Handling and Applications - 742.2 Photographic Equipment - 961 Systems Science
DOI: 10.6041/j.issn.1000-1298.2016.02.050
Database: Compendex
32.
Accession number: 20161202133058
Title: Performance of reheating solar organic Rankine cycle system for power generation
Authors: Zhao, Guochang1 ; Wang, Yong1; Thompson, Scott2; Song, Liping3; Wang, Zhenhua4; Sun, Qi4
Author affiliation: 1 Faculty of Aerospace Engineering, Shenyang Aerospace University, Shenyang, China
2 Mechanical Engineering, Mississippi State University, MS, United States
3 Science and Technology Association, Shenyang Aerospace University, Shenyang, China
4 AVIC Shenyang Engine Design and Research Institute, Shenyang, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 215-221
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Solar low-temperature waste heat sources below 200 were analyzed from the perspective of thermodynamics and an organic Rankine cycle (ORC) power generation system of solar reheat using trough collectors based on the basic solar power ORC generation system was designed. The thermal efficiency of working fluids and the influence of various parameters on the system were studied by establishing a thermodynamic calculation model with four chosen organic substances. The thermal efficiency and net output power of the reheat ORC system and the basic Rankine cycle at different evaporation temperatures, as well as the influence of operating environment on the system were studied by modeling analysis of parabolic trough collector and ORC system. When the reheating pressure ratio was 0.25, results showed that the reheating ORC system can efficiently improve the total efficiency of the system, and the output power increased linearly as evaporation temperature increased. The effect of different working fluids on the ORC system was compared, and the efficiency increase was the largest when using R245fa, which was increased by 4.3%. As the evaporation temperature increased, the overall system efficiency with R245fa as working fluid firstly increased quickly but then increased slowly, and reached the largest value at evaporation temperature between 110 and 130. Wind speed had minimal influence on the system efficiency, causing changes of only around 1%, while light intensity had great influence on the system efficiency. As light intensity increased, the total efficiency of the system was increased by 5%.
Number of references: 15
Main heading: Collector efficiency
Controlled terms: Cost effectiveness - Evaporation - Fluids - Industrial heating - Rankine cycle - Refrigerating machinery - Reheat cycle - Solar energy - Temperature - Thermodynamics - Waste heat - Wind
Uncontrolled terms: Low-temperature waste heats - Organic Rankine Cycle(ORC) - Organic Rankine cycles - Organic working fluid - Parabolic trough collectors - Reheating - Solar organic Rankine cycle - Thermal efficiency
Classification code: 443.1 Atmospheric Properties - 525.4 Energy Losses (industrial and residential) - 614.2 Steam Power Plant Equipment and Operation - 641.1 Thermodynamics - 642.1 Process Heating - 644.3 Refrigeration Equipment and Components - 657.1 Solar Energy and Phenomena - 702.3 Solar Cells - 802.3 Chemical Operations - 911.2 Industrial Economics
DOI: 10.6041/j.issn.1000-1298.2016.02.028
Database: Compendex
33.
Accession number: 20161202133063
Title: Effects of different sterilization conditions on physicochemical properties of SPI during frozen storage
Authors: Chen, Zhenjia1, 2 ; Shi, Xiaodi1; Du, Yumeng1; Yao, Meiyi1; Guo, Shuntang1
Author affiliation: 1 College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
2 College of Food Science and Engineering, Shanxi Agricultural University, Taigu, China
Corresponding author: Guo, Shuntang ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 251-257
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The effects of different sterilization conditions on the physicochemical properties of soybean protein isolate (SPI) during frozen storage were studied to gain scientific knowledge and provide basis for supplying soy foods with good quality. SPI was prepared after sterilized at 65, 90 and UHT (denoted as 65SPI, 90SPI and USPI), respectively. The changes of physicochemical properties of protein dispersions (2%, pH value 7.0) subjected to frozen storage at -18 were investigated. The results showed that three types of sterilization all resulted in heat denaturation of proteins. Compared with control SPI, the soluble proteins content and free SH groups of 90SPI and 65SPI were dropped sharply while the viscosity and particle size were increased greatly. However, there were no marked changes of USPI. In addition, hydrophobic domains of 90SPI and USPI were exposed to a higher extent and their AB subunits were in dissociation state according to non-reducing SDS-PAGE. SPI with different sterilization treatments underwent different chemical and physical changes during frozen storage. The solubility, viscosity, free and total SH groups of protein trended down gradually with the increase of frozen time, while particle size and exposed extent of hydrophobic domains were increased during frozen storage. Some soluble aggregations associated with disulfide bonds were observed in the SDS-PAGE electrophoresis of 65SPI and 90SPI solutions after frozen storage.
Number of references: 24
Main heading: Sterilization (cleaning)
Controlled terms: Covalent bonds - Electrophoresis - Hydrophobicity - Particle size - Proteins - Viscosity
Uncontrolled terms: Frozen storage - Heat denaturation - Hydrophobic domains - Physicochemical property - Scientific knowledge - Sds-page electrophoresis - Soybean protein isolates - Soybean protein isolates (SPI)
Classification code: 801 Chemistry - 804.1 Organic Compounds - 931.2 Physical Properties of Gases, Liquids and Solids
DOI: 10.6041/j.issn.1000-1298.2016.02.033
Database: Compendex
34.
Accession number: 20161202132556
Title: Visualization and numerical simulation of hydrodynamic cavitation in multi-hole orifice plate
Authors: He, Zhixia1, 2 ; Chen, Yuhang1; Ji, Changhao1
Author affiliation: 1 School of Energy and Power Engineering, Jiangsu University, Zhenjiang, China
2 Institute for Energy Research, Jiangsu University, Zhenjiang, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 396-401
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The multi-hole orifice plate is a simple hydrodynamic device which can be used for intensification of liquid-liquid heterogeneous micromixing for preparing biodiesel or emulsified diesel. A flow visualization experiment system with transparent hydrodynamic cavitation reactor was set up to investigate the cavitation in the orifice plate and the outlet of the orifice plate. The effects of upstream pressure and cavitation number on the change of hydrodynamic cavitation were investigated. As the cavitation in orifice plates is transient, the numerical simulation was combined to give a more detailed flow insight and predict the cavitation inception and development. SST and LES models were used to simulate the cavitating flow in orifice plates. The experimental results showed that with the increase of upstream pressure the cavitation incepted in the orifice plate, and the discharge coefficient increased at first. In the next stage, cavitation extended to the outlet of the testing orifice plate with the decrease of discharge coefficient which was caused by cavitation choking flow. Also from the experimental images, it was concluded that some cavity bubbles merged into large-scale bubbles and existed in the downstream region of the orifice plate which seemed to cause the choking flow. Compared the numerical simulation results with the experimental results measured by high speed camera, it was found that SST model can predict the average length of cavitation but it can hardly simulate the transient cavitating flow. LES model can well predict the cloud cavitation and the re-entrant jet which is central to the process of cloud cavitation shedding. The results also showed that with the development and collapse of cloud cavitation, the length of cavity changed periodically. In addition, the detatils of the re-entrant jet were shown in LES simulation.
Number of references: 19
Main heading: Cavitation
Controlled terms: Computer simulation - Emulsification - Flow visualization - Fluid dynamics - Forecasting - High speed cameras - Hydrodynamics - Numerical models - Orifices - Visualization
Uncontrolled terms: Cavitation inception - Cavitation number - Discharge coefficients - Downstream region - Hydrodynamic cavitations - Hydrodynamic devices - Multi-hole orifice - Visualization experiment
Classification code: 631.1 Fluid Flow, General - 631.1.1 Liquid Dynamics - 723.5 Computer Applications - 742.2 Photographic Equipment - 802.3 Chemical Operations - 921 Mathematics - 931.1 Mechanics
DOI: 10.6041/j.issn.1000-1298.2016.02.053
Database: Compendex
35.
Accession number: 20161202133044
Title: Influence of temperature on emitter clogging with fertigation through drip irrigation system
Authors: Liu, Lu1 ; Li, Kangyong2; Niu, Wenquan1, 2 ; Li, Yuan1; Xu, Jian1; Zhang, Mingzhi2
Author affiliation: 1 Institute of Soil and Water Conservation, Northwest A&F University, Yangling; Shannxi, China
2 College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling; Shannxi, China
Corresponding author: Niu, Wenquan ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 98-104
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Fertilizers injected into the drip irrigation system may contribute to serious clogging, which occurs due to multiple factors, including water quality, water condition, hydraulic parameters and system design. To better understand the causes and process of emitter clogging of fertigation at different irrigation water temperature levels, laboratory experiments were conducted to investigate the effects of irrigation water temperature on the sensitivity of emitter clogging. Three different particle gradations and three different fertilizer concentrations were investigated through the intermittent drip irrigation method in summer and winter, respectively. Experiment results showed that the temperature of irrigation water was an important factor causing clogging with remarkable coupling effect with water quality. The anti-clogging performance of emitter in summer was always better than that in winter for both scenarios of fertilization and no fertilization. The acceleration of drip clogging with fertilization was affected by the sediment gradation and the season. When the content of sediment particles (with diameter of 0.034~0.1 mm) became high, the fertilizer concentration could be more sensitive to clogging in winter than that in summer. The fertilizer concentration became more sensitive to clogging when the content of sediment particles (with diameter of 0~0.034 mm) were high in summer than that in winter. The number of effective irrigation frequency in summer was 1.26~1.43 times as much as it was in winter. However, the irrigation water temperature could not change its effect on clogging caused by sediment gradation and fertilization concentration. Therefore, it is recommended that the irrigation frequency can be reduced when the temperature stays low, and the fertilizer concentration can be controlled at a low level when irrigation is applied with fertilizer.
Number of references: 26
Main heading: Irrigation
Controlled terms: Fertilizers - Sediments - Temperature - Water - Water quality
Uncontrolled terms: Clogging - Drip irrigation systems - Emitter - Hydraulic parameters - Irrigation frequency - Laboratory experiments - Mass concentration - Sediment particles
Classification code: 445.2 Water Analysis - 483 Soil Mechanics and Foundations - 641.1 Thermodynamics - 804 Chemical Products Generally - 821.3 Agricultural Methods
DOI: 10.6041/j.issn.1000-1298.2016.02.014
Database: Compendex
36.
Accession number: 20161202133064
Title: Enrichment of probiotics in fresh-cut fruits using magnetic-electric process method
Authors: Yang, Na1 ; Jin, Yamei1; Xu, Yue1; Xu, Xueming1, 2 ; Jin, Zhengyu1, 2
Author affiliation: 1 School of Food Science and Technology, Jiangnan University, Wuxi, China
2 State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
Corresponding author: Xu, Xueming ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 258-263 and 322
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Probiotic enrichment in fresh-cut fruits was achieved in the impregnation system when induced alternating electric field was used in conjunction with rotating perpendicular magnetic field. The method was intended to promote the efficiency of Lactobacillus rhamnosus diffusion into the tissues of apples and strawberries based on the experimental transformer structure. The amount of probiotic in the sample tissues was investigated under the influence of voltage levels (1 V/cm, 2 V/cm, 3 V/cm), voltage frequencies (50 Hz, 200 Hz, 400 Hz), magnetic field intensities (260 Gs, 900 Gs, 1300 Gs), rotating magnetic frequencies (0.1 Hz, 1 Hz, 10 Hz), temperature (20, 40, 60, 80) and the pH values (3.2, 3.5, 4.6, 5.5, 6.9, 8.1, 10.7) of the impregnation solutions. It was demonstrated that high voltage levels and magnetic field intensities were conducive to the diffusion of probiotics into the sample tissues. The highest amount of probiotic in the sample tissues was achieved at system voltage of 3 V/cm and magnetic field intensity of 1300 Gs. The maximum amounts of probiotic in fresh-cut apples and strawberries were increased to 9.23×108CFU/g and 1.22×108CFU/g, respectively. Impregnation solutions with low pH values were conducive for the accumulation of probiotics in the samples. The highest amounts of Lactobacillus rhamnosus were 4.32×108CFU/g and 5.4×107CFU/g in the fresh-cut apples and strawberries, respectively, during processing at pH values of 6.9 and 8.1 which showed lower living bacterium content in fresh-cut fruits compared with the samples in the acidic impregnation solution. The optimal electric field frequency and magnetic field frequency for impregnation treatment of fresh-cut apples through this magnetic-electric method were at 200 Hz and 1 Hz, respectively. The proposed impregnation method can provide a reference for probiotic enrichment of fresh-cut fruits.
Number of references: 16
Main heading: Impregnation
Controlled terms: Bacilli - Electric fields - Fruits - Histology - Magnetic fields - Magnetism - pH - Tissue
Uncontrolled terms: Alternating electric field - Electric field frequency - Electrical methods - Fresh-cut fruits - Magnetic field frequency - Magnetic-field intensity - Perpendicular magnetic fields - Probiotics
Classification code: 461.2 Biological Materials and Tissue Engineering - 461.9 Biology - 701.1 Electricity: Basic Concepts and Phenomena - 701.2 Magnetism: Basic Concepts and Phenomena - 801.1 Chemistry, General - 821.4 Agricultural Products
DOI: 10.6041/j.issn.1000-1298.2016.02.034
Database: Compendex
37.
Accession number: 20161202133061
Title: Structure-parameter optimization of gas distributor for rapeseed fluidized bed dryer
Authors: Zhang, Jianping1, 2 ; Lu, Yubin2; Wang, Xiaohong1; Li, Xingping2
Author affiliation: 1 School of Engineering Science, University of Science and Technology of China, Hefei, China
2 Key Laboratory of Testing Technology for Manufacturing Process, Ministry of Education, Southwest University of Science and Technology, Mianyang, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 237-244
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: In order to optimize the structure-parameter of gas distributor for the rapeseed fluidized bed dryer, the open porosity ratio and the arrangement holes mode of gas distributor were optimized through numerical simulation software of Fluent based on Euler two-fluid model and standard k-Ε turbulence model. The results showed that open porosity ratio of 15.84% and uneven circular holes arrangement were the optimized structure-parameters of gas distribution for the rapeseed fluidized bed drying, which enhanced liquidity of hot air, reduced hot air to gather in the local area, made gas-particle two phase flow normally fluidize, and achieved the homogenized distribution of rapeseed particle in fluidized bed without channeling phenomenon and dead zone. The simulation results were verified through the experiment. The drying kinetics curves of gas distributor of different open porosity ratios and arrangement holes modes were comparative analysis based on experiment data, which showed that the drying rate of gas distribution with open porosity ratio of 15.84% and uneven circular holes arrangement was the biggest compared with the other types. Therefore, the gas distribution with open porosity ratio of 15.84% and uneven circular holes arrangement was the optimum. The results of numerical simulation and experiment were consistent. The results testified that the optimized best gas distribution was reasonable and feasible. Therefore, the gas distribution is an ideal gas distribution to shorten the rapeseed drying time for the engineering application.
Number of references: 27
Main heading: Fluidized beds
Controlled terms: Computer software - Dryers (equipment) - Drying - Fluidized bed process - Gases - Numerical models - Oilseeds - Porosity - Structural optimization - Turbulence models - Two phase flow
Uncontrolled terms: Arrangement holes mode - Engineering applications - Fluidized bed dryers - Gas distributor - Gas-particle two-phase flows - Numerical simulation software - Open porosity - Rapeseed
Classification code: 631.1 Fluid Flow, General - 723 Computer Software, Data Handling and Applications - 821.4 Agricultural Products - 921 Mathematics - 921.5 Optimization Techniques - 931.2 Physical Properties of Gases, Liquids and Solids
DOI: 10.6041/j.issn.1000-1298.2016.02.031
Database: Compendex
38.
Accession number: 20161202133049
Title: Effect of water and nitrogen coupling on yield and quality of arabica coffee in dry-hot area
Authors: Liu, Xiaogang1 ; Hao, Kun1; Han, Zhihui1; Yu, Ning1; Yang, Qiliang1; Liu, Yanwei1
Author affiliation: 1 Faculty of Modern Agricultural Engineering, Kunming University of Science and Technology, Kunming, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 143-150 and 160
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The yield and quality of arabica coffee cannot be guaranteed because of serious contradictory of water and heat, soil impoverishment and serious seasonal drought in Yunnan dry-hot valley. The objective of the research was to explore water and fertilizer management mode for good quality and proper yield of arabica coffee. Four levels of irrigation in dry season, i.e., sufficient irrigation level (W1) and three deficit irrigation levels (W2, W3and W4), were designed with irrigation amounts for W2, W3and W4as 80%, 60% and 40% of W1, respectively, and three levels of nitrogen, i.e., N1(140 g/plant), N2(100 g/plant), N3(60 g/plant), were applied. The effect of drip irrigation and nitrogen levels on yield, quality and water use efficiency (WUE) of arabica coffee was studied by field experiments for two consecutive years, and the comprehensive nutritional quality was evaluated by principal component analysis. The results showed that compared with W4treatment, improving irrigation amount increased dry bean yield and chlorogenic acid of dry bean by 42.8%~151.0% and 16.9%~31.5%, respectively. WUE was firstly increased and then decreased with irrigation amount, WUE of W2treatment was the largest. Improving nitrogen application rate increased dry bean yield, WUE, protein and chlorogenic acid of dry bean by 32.9%~42.6%, 32.0%~45.8%, 5.9%~9.7% and 7.0%~12.6%, respectively, and the yield of dry bean and WUE of N2were the largest compared with N3treatment. Compared with W4N3treatment, improving irrigation amount and nitrogen application rate could increase dry bean yield and WUE by 22.0%~307.5% and 18.2%~205.3%, respectively. W1N2treatment obtained the largest average dry bean yield of 5 587.42 kg/hm2in two years. Principal component analysis showed that the comprehensive nutritional quality of W2N2treatment was the best, and in coordination between water and nitrogen resulted in decrease of yield and quality. Compared with W4N3, W2N2treatment increased dry bean yield and WUE greatly, meanwhile it increased protein and chlorogenic acid but reduced fiber of dry bean significantly. On the basis of water-saving and high efficiency along with good quality and proper yield, the suitable mode of water and nitrogen management of arabica coffee was the combination of W2and N2treatments (W2N2) in arid-hot area.
Number of references: 30
Main heading: Quality control
Controlled terms: Drought - Efficiency - Fertilizers - Image quality - Irrigation - Nitrogen - Nitrogen fertilizers - Principal component analysis - Proteins - Water conservation
Uncontrolled terms: Comprehensive evaluation - Deficit irrigation - Fertilizer management - Nitrogen application rates - Nitrogen management - Nutritional qualities - Water-use efficiency - Yield
Classification code: 444 Water Resources - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.3 Agricultural Methods - 913.1 Production Engineering - 913.3 Quality Assurance and Control - 922.2 Mathematical Statistics
DOI: 10.6041/j.issn.1000-1298.2016.02.019
Database: Compendex
39.
Accession number: 20161202133068
Title: Factors affecting dynamic laser speckle activity of beef
Authors: Dong, Qingli1 ; Jin, Man1; Hu, Menghan1; Liu, Baolin1
Author affiliation: 1 School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 288-294 and 301
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Dynamic laser speckle technique, also termed as dynamic biospeckle, is a portable and non-invasive as well as low-cost screening tool for online or point-of-sale applications on agricultural products. A custom made dynamic laser speckle system mainly consisted of a He-Ne laser generator operating at the four wavelengths of 405 nm, 520 nm, 635 nm and 780 nm, respectively, an industrial CMOS camera for the sequential images acquisition, a computer and a height adjustable sample stage. The lighting and imaging units were placed into an illumination chamber to avoid the interference of natural light. In order to optimize the measurement conditions of dynamic laser speckle technique for the beef quality evaluation, a temporal history of speckle patterns viz. inertia moment was used as speckle activity to assess the effects of the laser incident angle, laser wavelength, and lighting intensity on beef dynamic biospeckle quality. The single factor experimental design was first applied for determining preliminary suitable lighting conditions for the later Box-Behnken experimental design. Subsequently, a response surface regression function of three lighting factors was obtained to optimize the measurement conditions for beef dynamic biospeckle. Above results demonstrated that the speckle activity could reach 476.04, the R2value was 0.992, root mean square error value was 8.14, bias factor (Bf) and accuracy factor (Af) values were within the acceptable range of 1.0<Bf<Af<1.05 via the optimal processing. Therefore, for the further beef biospeckle measurement, the lighting conditions are as follows: lighting intensity is 30 mW, laser wavelength is 635 nm and laser incident angle is 15°. In a conclusion, the analysis of different lighting factors for the biospeckle acquisition might improve the qualitative or quantificational identification accuracy of beef dynamic biospeckle, and also provide the theoretical reference for the biospeckle measurement of the other foods.
Number of references: 31
Main heading: Speckle
Controlled terms: Agricultural products - Beef - CMOS integrated circuits - Computer operating systems - Lighting - Mean square error - Meats - Quality control - Statistics
Uncontrolled terms: Box-Behnken experimental design - Condition optimizations - Identification accuracy - Laser speckle - Lighting conditions - Measurement conditions - Rapid detection - Root mean square errors
Classification code: 714.2 Semiconductor Devices and Integrated Circuits - 741.1 Light/Optics - 821.4 Agricultural Products - 822.3 Food Products - 913.3 Quality Assurance and Control - 922.2 Mathematical Statistics
DOI: 10.6041/j.issn.1000-1298.2016.02.038
Database: Compendex
40.
Accession number: 20161202133053
Title: Vertical distribution characteristics of heavy metals in lake under different hydrodynamic conditions
Authors: Lu, Jian'gang1 ; Zhong, Xie2; Wu, Haizhen1, 2 ; Wang, Hua3
Author affiliation: 1 Jiangxi Water Resources Institute, Nanchang, China
2 Jiangxi Provincial Institute of Water Sciences, Nanchang, China
3 Key Laboratory of Integrated Regulation and Resource Development on Shallow Lake, Ministry of Education, Hohai University, Nanjing, China
Corresponding author: Wu, Haizhen ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 179-184 and 97
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The movement of lake sediments under different hydrodynamic conditions was simulated, and vertical distribution characteristics of heavy metals in lake under different hydrodynamic conditions were explored with self-designed circulating flume and sediments sampled from Xingzi section of Poyang Lake. The flume device was composed of inlet tank (0.5 m3), test area (2 m in length, 1 m in width, and 0.5 m in height), outlet tank (0.5 m3), storage tank (1 m3) and pump (maximum flow rate of 100 m3/h). Prior to testing, sediment was spread at the flume bottom, and lightly pressed and flattened to a thickness of 8 cm. After remaining it untouched for 0.5 h, water was added into the device. Water depth in the flume was controlled at 140 cm. Water was pumped from the storage tank into the inlet tank, and flowed through the test area, the outlet tank and eventually returned to the tank. During the test, the flow rate in the flume was gradually increased from 0 cm/s, and its flow rate was set through the control of the gate as 0 cm/s, 5 cm/s, 15 cm/s, 25 cm/s, 35 cm/s, 45 cm/s and 65 cm/s. To ensure that the water flowed through the flume at least once, the testing period was maintained 1 h under each flow rate, and then immediately proceeded to the next flow rate until it reached the maximum flow rate. During the test, the incipient motion characteristics of sediment, including critical motion state, slight motion state and plenty motion state, were initially simulated. The water depth in the flume was divided into four layers. The total heavy metal concentration and dissolved heavy metal concentration were measured at different flow rates and different water depths. In order to minimize deviation, heavy metal concentration was measured three times and the average value was taken under each group of water flow and water depth condition. When the sediment was in critical motion state at flow rate of less than 25 cm/s, a diluted suspension at the sediment surface was appeared with the increase of flow rate. The total heavy metal concentrations were similar at different water depths in this period. When the sediment was in slight motion state at flow rate of 25 cm/s to 50 cm/s, water became turbid, with part of the sediment washed up. Shear stress at sediment surface was obviously larger than that in critical motion state, and the total heavy metal concentrations were increased from water surface to bottom, although it was not obvious. When the sediment was in plenty motion state at flow rate of 60 cm/s to 70 cm/s, a large amount of sediment was washed up, and water became turbid in a short period. Large quantities of heavy metals in the sediment were released into water, and the total heavy metal concentration was increased obviously along the water depth direction. In addition, by analyzing the concentrations of dissolved Cu, Zn, Cd and Pb in each layer with curve fitting method, vertical distribution characteristics of heavy metals under different hydrodynamic conditions were revealed. The basic formula was established between heavy metal concentration and height above sediment surface. The results showed that when the hydrodynamic condition was strong, the concentrations of dissolved Cu, Zn, Pb were increased logarithmically from water bottom to water surface. Furthermore, to detect the applicability of the established formula, the testing results were applied to measurement of Poyang Lake, water samples collected from Poyang Lake Bridge section and Xingzi section at 0.3 m, 0.8 m, 1.3 m and 1.8 m above sediment were used to measure the dissolved heavy metal concentration. Flow rate at the two sections were 39 cm/s, 75 cm/s and 44 cm/s, 68 cm/s, respectively, when the samples were collected. By substituting the measured data into the established formula, the obtained result showed that the relative error between calculation results and measured results was within ±15%. The formula was applicable at flow rate of 65 cm/s to 75 cm/s in lakes with sediment grain size of 50 μm to 200 μm. The established formula was basically reasonable. The device was feasible for the experiment with strong operability. The research results could provide references for revealing heavy metal release characteristics under different water conditions.
Number of references: 17
Main heading: Copper
Controlled terms: Cadmium - Curve fitting - Digital storage - Dissolution - Flow of water - Flow rate - Fluid dynamics - Heavy metals - Hydrodynamics - Lakes - Lead - Metal testing - Pollution - Sediments - Shear stress - Suspended sediments - Suspensions (fluids) - Tanks (containers) - Zinc
Uncontrolled terms: Calculation results - Curve fitting methods - Flume - Heavy metal concentration - Heavy metal release - Hydrodynamic conditions - Po-yang lakes - Vertical distributions
Classification code: 483 Soil Mechanics and Foundations - 531 Metallurgy and Metallography - 544.1 Copper - 546.1 Lead and Alloys - 546.3 Zinc and Alloys - 549.3 Nonferrous Metals and Alloys excluding Alkali and Alkaline Earth Metals - 619.2 Tanks - 631 Fluid Flow - 631.1.1 Liquid Dynamics - 722.1 Data Storage, Equipment and Techniques - 802.3 Chemical Operations - 804 Chemical Products Generally - 921.6 Numerical Methods - 931.1 Mechanics
DOI: 10.6041/j.issn.1000-1298.2016.02.023
Database: Compendex
41.
Accession number: 20161202133077
Title: Combustion characteristic of premixed hydrogen/oxygen mixture in catalytic micro-combustor
Authors: Pan, Jianfeng1 ; Liu, Qisheng1; Lu, Qingbo1; Pan, Zhenhua1
Author affiliation: 1 School of Energy and Power Engineering, Jiangsu University, Zhenjiang, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 357-363
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The premixed hydrogen/oxygen combustion process in a catalytic micro-combustor was numerically simulated with CFD software. The interaction between gas-phase and catalytic reaction was analyzed by changing inlet parameters on the basis of experimental verification. Meanwhile, the blow-off limits for combustor with and without catalyst were also investigated. The results showed that gas-phase reaction was subdued with the intermediate products consumed in catalytic reaction. At the same velocity, the flame temperature of catalytic combustor was lower than that of non-catalytic combustor. The OH mass fraction near up-wall of Pt cell in catalytic combustion chamber was also lower than that near up-wall of SiC cell in non-catalytic combustor. While owing to the exothermic surface reaction with Pt cell, the temperature of Pt cell in catalytic combustor was higher than that of SiC cell in non-catalytic combustor. Catalytic reaction was dominant near the surface of catalyst, while gas-phase reaction was dominant away from the surface. The OH mass fraction distribution trend near the inner up-wall in catalytic combustor was consistent with that near the inner up-wall in non-catalytic combustor. The blow-off limit can be widened by adding catalyst. The blow-off limits for combustor with and without catalyst were 46 m/s and 22 m/s, respectively. At equivalence ratio of 1.0, the strongest activity of catalytic was shown, and the gas-phase reaction was obviously restrained. With the increase of equivalence ratio, the mean temperature of out-wall was risen at the beginning and then it was dropped later. The highest mean temperature of out-wall was achieved with equivalence ratio of 1.0.
Number of references: 25
Main heading: Combustors
Controlled terms: Catalysis - Catalyst activity - Catalysts - Cells - Chemical reactions - Combustion chambers - Computational fluid dynamics - Computer simulation - Cytology - Gases - Phase interfaces - Platinum - Reaction intermediates - Silicon carbide - Surface reactions
Uncontrolled terms: Blowoff limit - Catalytic combustion chambers - Catalytic combustors - Combustion characteristics - Experimental verification - Gas-phase reactions - Intermediate product - Mass fraction distribution
Classification code: 461.2 Biological Materials and Tissue Engineering - 521.2 Combustors - 547.1 Precious Metals - 654.2 Rocket Engines - 723.5 Computer Applications - 801.4 Physical Chemistry - 802.2 Chemical Reactions - 804 Chemical Products Generally - 804.2 Inorganic Compounds
DOI: 10.6041/j.issn.1000-1298.2016.02.047
Database: Compendex
42.
Accession number: 20161202133071
Title: Identification of fusarium head blight wheat based on hyperspectral imaging technology
Authors: Liang, Kun1, 2 ; Du, Yingying1; Lu, Wei1, 2; Wang, Ce1; Xu, Jianhong3; Shen, Mingxia1, 2
Author affiliation: 1 College of Engineering, Nanjing Agricultural University, Nanjing, China
2 Jiangsu Province Engineering Lab. for Modern Facility Agriculture Technology and Equipment, Nanjing Agricultural University, Nanjing, China
3 Institute of Food Quality and Safety, Jiangsu Academy of Agricultural Sciences, Nanjing, China
Corresponding author: Shen, Mingxia ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 309-315
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Fusarium head blight is one of the main infection diseases in wheat, and the infection of wheat has serious impact on food safety. In order to explore the rapid and nondestructive detection of wheat scab, the identification of wheat scab was carried out using spectral analysis and image processing in hyperspectral imaging technology. Standard normal variable transform (SNV) and multiple scatter correction (MSC) methods were used for spectral data pretreatment, and continuous projection algorithm (CARS) and the positive adaptive weighted (SPA) algorithm were used to select wavelength. The results showed that the determination coefficients (R2) of MSC-SPA and SNV-SPA were 0.9019 and 0.9006, respectively, the root mean square errors were 0.2238 and 0.2232, respectively, and the numbers of selected wavelength were 7 and 5, respectively. Support vector machine (SVM) and BP neural network algorithms were used for modeling. The results showed that the accuracy of the four models were above 90%. The accuracy rates of MSC-SPA-SVM and SNV-SPA-SVM were 97.08% and 94.17% for model calibration set, respectively, and those for the model validation set were 98.33% and 97.50%, respectively, which were better than those for model calibration set. According to image information analysis of disease wheat in hyperspectral image, the principal component analysis method was applied, and the best wavelength image was chosen at 627.698 nm according to the weight coefficient. Image processing method was used for preprocessing, feature extraction, etc. The morphological parameters and texture feature parameters of the best wavelength image were extracted respectively, and the optimal parameters of the model were selected according to the correlation analysis of the feature parameters. Ten-fold cross-validation method was adopted to establish linear discriminant analysis, support vector machine and BP neural network identification models. The results showed that the recognition accuracy of the three identification algorithms were all above 90%, which indicated that the proposed method were feasible and effective.
Number of references: 21
Main heading: Image processing
Controlled terms: Algorithms - Calibration - Discriminant analysis - Face recognition - Feature extraction - Fungi - Image analysis - Image retrieval - Imaging techniques - Mean square error - Neural networks - Principal component analysis - Processing - Spectroscopy - Spectrum analysis - Support vector machines
Uncontrolled terms: Determination coefficients - Fusarium head blights - Hyperspectral imaging technologies - Identification model - Image processing - methods - Linear discriminant analysis - Principal component analysis method - Wheat
Classification code: 723 Computer Software, Data Handling and Applications - 746 Imaging Techniques - 913.4 Manufacturing - 922 Statistical Methods - 922.2 Mathematical Statistics
DOI: 10.6041/j.issn.1000-1298.2016.02.041
Database: Compendex
43.
Accession number: 20161202133038
Title: Real-time localization research of transplanting based on machine vision
Authors: Tan, Minghao1 ; Cao, Qixin1 ; Qiu, Qiang1; Leng, Chuntao1
Author affiliation: 1 Research Institute of Robot, Shanghai Jiao Tong University, Shanghai, China
Corresponding author: Cao, Qixin ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 59-63
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: A machine vision based real-time localization system for transplanting machine was proposed. The system can realize real-time detection of the plug tray's position and get the right coordinate for each planting accurately. By off-line calibration using point cloud, equation of the conveyor belt's plane was determined. With the equation, the plug tray was separated from the background in the point cloud. The 2D mask was got by using the point cloud of the plug tray. Then the contour of the plug tray was detected in the 2D mask, the plug tray's position was determined and each hole's coordinate was calculated in its corresponding simple connected area before planting the first graft seedling. After that, considering the movement during each time's planting caused by vibration, re-localization needed to be done. To do the re-localization, SURF feature points detection was done in the color image before and after last planting. Then the SURF feature points were matched, and the homography matrix was computed based on random sample consensus algorithm, which was used to calculate the coordinate of the hole. The experiment results showed that the system could achieve high precision for localization of the hole in the transplanting plug tray and it was little influenced by the lighting conditions and background color.
Number of references: 19
Main heading: Computer vision
Controlled terms: Belt conveyors - Image matching
Uncontrolled terms: Feature points detections - Lighting conditions - Localization - Plug tray - Random sample consensus - Real-time localization - Transplanting - Transplanting machine
Classification code: 692.1 Conveyors - 723.5 Computer Applications
DOI: 10.6041/j.issn.1000-1298.2016.02.008
Database: Compendex
44.
Accession number: 20161202133035
Title: Instability and interfacial coherent structure of free round turbulent jet
Authors: Yang, Minguan1 ; Yan, Longlong1; Wang, Yuli2; Gong, Chen1; Lu, Jin'gang1
Author affiliation: 1 School of Energy and Power Engineering, Jiangsu University, Zhenjiang, China
2 Department of Mechanics, Royal Institute of Technology, Stockholm, Sweden
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 35-44
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: As a basic flow form, free round turbulent jet has been used in various industry fields such as water jet cutting, water cleaning, fuel spray, etc. To understand the development of jet and some of its underlying characteristics, it is crucial that the mechanism of jet instability should be recognized. A robust two-phase flow large eddy simulation (LES) algorithm was applied to predict the liquid instability and the coherent structure of free round turbulent jet. The main objective was to characterize the liquid instability mechanism without resorting stability analysis. Special attention was focused on how the instability and the eddy structure in the near field of round jet were affected by the imposed inlet velocity and disturbance. In this respect, the cases within the range of Re=10000~80000 at various disturbance intensities were tested. Results revealed that the velocity and disturbances played an important role in the stability of liquid jet. The unperturbed liquid core length and scale of surface wave were decreased, and a wide variety of vortexes were produced in the near field of jet with velocity and disturbance intensity increased. The decay rates of average velocity along the central axis of jet were similar under different disturbance intensities at the same Reynolds number (or different Reynolds numbers at the same disturbance intensity). The positive entrainment was enhanced and the radial spread of the jet along the streamwise became more significant with the Reynolds number increased.
Number of references: 20
Main heading: Fighter aircraft
Controlled terms: Decay (organic) - Jets - Large eddy simulation - Liquids - Plasma stability - Reynolds number - Stability - Surface waves - Two phase flow - Velocity
Uncontrolled terms: Average velocity - Coherent structure - Eddy structures - Inlet velocity - Instability mechanisms - Jet instability - Stability analysis - Waterjet cutting
Classification code: 631 Fluid Flow - 631.1 Fluid Flow, General - 652.1.2 Military Aircraft - 801.2 Biochemistry - 921 Mathematics - 932.3 Plasma Physics
DOI: 10.6041/j.issn.1000-1298.2016.02.005
Database: Compendex
45.
Accession number: 20161202133062
Title: Rapid identification of common bacilli in vinegar culture based on near-infrared spectroscopy
Authors: Shi, Jiyong1 ; Hu, Xuetao1; Zhu, Yaodi1; Shen, Tingting1; Zou, Xiaobo1; Xu, Yiwei1
Author affiliation: 1 School of Food and Biological Engineering, Jiangsu University, Zhenjiang, China
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 245-250
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Microbial flora and microorganism metabolites in vinegar culture are the key factors influencing Zhenjiang vinegar unique taste and flavor. Studying the rapid identification of microorganism is uniquely conducive to monitor community composition and dynamic changes and guarantee the quality of vinegar. Rapid identification of five similar bacilli was acquired using near-infrared spectra. Firstly, 120 spectra from five common bacilli (each common bacillus had 24 spectra) were obtained by near-infrared, and PCR was applied to identify the microorganism of five bacilli (namely Baclicus lincheniformis, Bacillus pumilus, Lactobacillus acidophilus, Acetobacterium balch and Bacillus subtilis). Simultaneously, KNN and LS-SVM were employed to establish identification model of five kinds of common bacilli. Results indicated that the best predictive precision of KNN model can be reached when principal component signals were four and parameter K was three, and precision rates of calibration set and prediction set were 86.25% and 85.00%, respectively. The precision rates of calibration set and prediction set were 100% and 97.50%, respectively, in LS-SVM model provided the principal component signals were four. There was non-linear correlation between near-infrared spectrum and characteristic of bacillus, and the prediction and precision of LS-SVM identification would be better. The research results laid the basis for rapid monitoring of microbial community and dynamic changes.
Number of references: 27
Main heading: Principal component analysis
Controlled terms: Acetic acid - Bacilli - Bacteriology - Calibration - Forecasting - Infrared devices - Near infrared spectroscopy - Spectroscopy - Support vector machines
Uncontrolled terms: Community composition - Lactobacillus acidophilus - Microbial communities - Near infrared spectra - Non-linear correlations - Principal Components - Rapid identification - Solid fermentations
Classification code: 461.9 Biology - 723 Computer Software, Data Handling and Applications - 804.1 Organic Compounds - 922.2 Mathematical Statistics
DOI: 10.6041/j.issn.1000-1298.2016.02.032
Database: Compendex
46.
Accession number: 20161202133036
Title: Effect of draft tube depth on performance of axial flow fixed-blade turbine
Authors: Yang, Jing1 ; Song, Huating2; Huang, Zhida3; Liu, Jian2; Wang, Zhengwei1
Author affiliation: 1 Department of Thermal Engineering, Tsinghua University, Beijing, China
2 Xinhua Hydropower Company Limited, Beijing, China
3 College of Electrical and Information Engineering, Changsha University of Science and Technology, Changsha, China
Corresponding author: Wang, Zhengwei ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 45-50
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The performance of draft tube plays an important role in the efficiency and stability of hydraulic turbine. To improve the hydraulic performance of an axial flow fixed-blade hydro-turbine, the depth of draft tube was studied by changing the draft tube cone height using numerical simulation. Three different modified cases of draft tube depth were conducted and analyzed. The results showed that the recovery coefficients and the diffusion losses of draft tube were increased with its depth increasing within limits. However, the fraction losses were decreased with it. Thus, the draft tube depth of 3.0D1was chosen as the initial scheme by comprehensive consideration of the efficiency and economic factors. Besides, the turbulence kinetic energy, pressure fluctuations and force components acting on the runner were compared to judge the effect of draft tube depth on stability. The results showed that the increase of depth was favorable for the flow field stability at rated conditions. The turbulence kinetic energy at both the inlet and outlet of the cone was reduced with the heightening of draft tube cone, which also proved the flow field interaction between the draft tube and runner. The flow improvement in draft tube would in turn reduce the disturbance to runner outlet, which also explained the decreases of the peak to peak value and force components in runner. The areas lower than the critical cavitation pressure on the suction side of blades was almost unchanged compared with the original draft tube.
Number of references: 18
Main heading: Hydraulic turbines
Controlled terms: Axial flow - Computer simulation - Flow fields - Hydraulic motors - Kinetic energy - Kinetics - Numerical models - Tubes (components) - Turbine components - Turbomachine blades - Turbulence
Uncontrolled terms: Blade turbine - Cavitation pressure - Draft tubes - Hydraulic performance - Loss analysis - Pressure fluctuation - Recovery coefficients - Turbulence kinetic energy
Classification code: 617 Turbines and Steam Turbines - 617.1 Hydraulic Turbines - 619.1 Pipe, Piping and Pipelines - 631.1 Fluid Flow, General - 632.2 Hydraulic Equipment and Machinery - 723.5 Computer Applications - 921 Mathematics
DOI: 10.6041/j.issn.1000-1298.2016.02.006
Database: Compendex
47.
Accession number: 20161202133073
Title: ABS control of electric vehicle based on electromagnetic-mechanical coupled regenerative braking system
Authors: Zhang, Zhongfu1 ; Wang, Guoye1 ; Mao, Enrong1; Zhang, Yanli2; Zhang, Lu1, 3; He, Changran1
Author affiliation: 1 College of Engineering, China Agricultural University, Beijing, China
2 Chinese Academy of Agricultural Mechanization Sciences, Beijing, China
3 College of Transportation, Inner Mongolia University, Huhhot, China
Corresponding author: Wang, Guoye ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 323-329
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: For the deficiency of current electric vehicle compound regenerative braking, a new design of electromagnetic-mechanical coupled regenerative braking system was proposed (referred to as EMCB), and the coupled mechanism and dynamic model were analyzed. For the deficiency of conventional ABS discrete on-off control, a continuous-state control of anti-lock braking control strategy was proposed based on EMCB system and fuzzy-adaptive sliding mode control for electric vehicle. With Matlab/Simulink the dynamic model of EMCB and controller model were established, and the vehicle model was built by CarSim. With the co-simulation platform of Matlab/Simulink and CarSim, the braking energy recovery, braking stability and braking efficiency were studied and simulated in case of straight braking condition on step adhesive coefficient road and cornering braking condition on low adhesive coefficient road. The results showed that the ABS control strategy had good responsiveness, robustness and slip control performance. Fuzzy-adaptive variable structure control was insensitive to the road conditions and system model and control variable was flat and smooth, it reduced the demand of executive system. The control strategy ensured braking stability and braking efficiency at the limit of adhesion and large angle steering, which can maintain high recovery efficiency and increase the driving range of electric vehicles effectively.
Number of references: 20
Main heading: Anti-lock braking systems
Controlled terms: Adaptive control systems - Braking - Dynamic models - Dynamics - Electric automobiles - Electric machine control - Electric vehicles - MATLAB - Recovery - Regenerative braking - Roads and streets - Sliding mode control - Transportation - Variable structure control - Vehicles
Uncontrolled terms: Braking energy recoveries - Braking stabilities - Continuous state - Electromagnetic braking - Recovery efficiency - Regenerative braking systems - Slip ratio - System modeling and control
Classification code: 406.2 Roads and Streets - 602 Mechanical Drives and Transmissions - 662.1 Automobiles - 731 Automatic Control Principles and Applications - 921 Mathematics
DOI: 10.6041/j.issn.1000-1298.2016.02.043
Database: Compendex
48.
Accession number: 20161202133065
Title: Effects of saccharomyces cerevisiae on lactobacillus growth and biofilm formation
Authors: Ren, Xiaopu1, 2 ; Xu, Qian1, 2; Li, Mingyang1, 2; Niu, Xiyue1, 2
Author affiliation: 1 College of Life Science, Tarim University, Alar, China
2 Production & Construction Group Key Laboratory of Special Agricultural Products Further Processing in Southern Xinjiang, Tarim University, Alar, China
Corresponding author: Niu, Xiyue ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 264-269 and 287
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The co-existence of Saccharomyces cerevisiae and Lactobacillus widely exists in fermented food and their co-existence endows fermented foods with quite different flavors and tastes. Meanwhile, a large number of active substances and prebiotic substances were added to the fermented foods and they were very beneficial to human health. Five Saccharomyces cerevisiae strains and six Lactobacillus strains from different fermented foods were used in the research. Semi-quantitative assay was performed to examine effects of Lactobacillus co-cultured with Saccharomyces cerevisiae and the metabolites on Lactobacillus growth and biofilm formation. The results showed that all of the five Saccharomyces cerevisiae strains could promote Lactobacillus growth but had different effects on biofilm formation. All of the Saccharomyces cerevisiae metabolites did not have obvious effects on Lactobacillus growth but also had effects on biofilm formation in different degrees. Especially, extremely significant promotion was found in the co-existence groups of E+1, B+3 and E+3, and extremely significant inhibition was also found in the co-existence groups of B+1, D+9 and E+9. It may be due to the strict selection roles of each other between the two strains. Meanwhile, comparing co-existence groups with metabolites groups, there was no very obvious connection. It appeared that different active substances acted different roles in the co-existence groups and metabolites groups.
Number of references: 23
Main heading: Yeast
Controlled terms: Biofilms - Biomolecules - Metabolites
Uncontrolled terms: Active substance - Biofilm formation - Co-cultures - Different effects - Lactobacillus - Lactobacillus strains - Quantitative assay - Saccharomyces cerevisiae strains
Classification code: 461.9 Biology - 462.5 Biomaterials (including synthetics) - 822.3 Food Products
DOI: 10.6041/j.issn.1000-1298.2016.02.035
Database: Compendex
49.
Accession number: 20161202133070
Title: Estimation of wheat leaf nitrogen content based on simulated multi-spectral broadband reflectance
Authors: Li, Fenling1 ; Chang, Qingrui1 ; Shen, Jian1; Wang, Li1
Author affiliation: 1 College of Natural Resources and Environment, Northwest A&F University, Yangling; Shaanxi, China
Corresponding author: Chang, Qingrui ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 302-308
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: Crop nitrogen content estimation by remote sensing technique is a topic research in remote sensing monitoring of agricultural parameters. Monitoring of crop nitrogen content based on multi-spectral satellite data is still at the exploratory stage. Ground-based canopy spectral reflectance and leaf nitrogen content of winter wheat were measured in field, and plot experiments consisted of varied nitrogen fertilization levels and winter wheat varieties across the whole growth stage. Multi-spectral broadband reflectance data of six satellites were simulated using the measured hyper-spectral reflectances and spectral response functions of Landsat 8, SPOT 6, HJ-1A, HJ-1B, GF-1 and ZY-3.Spectral indices derived from simulated broadband spectral reflectance data across the visible and near infrared bands were used to construct the LNC estimation models. The results showed that there were no significant differences between simulated broadband reflectances and spectral indices among six satellite platforms; all the selected spectral indices were significantly related with the LNC in the whole wheat growth period and all the estimation models based on the ten spectral indices passed the significance test respectively; transformed chlorophyll absorption in reflectance index/optimized soil-adjusted vegetation index (TCARI/OSAVI), chlorophyll absorption in reflectance index (TCARI) and ratio vegetation index (RVI) were more sensitivity than the other spectral indices in LNC estimation with the noise equivalent less than 1.6; TCARI/OSAVI was proved to be the best spectral index for LNC estimation with determination coefficient R2of 0.62 and noise equivalent of 1.26.
Number of references: 33
Main heading: Reflection
Controlled terms: Chlorophyll - Crops - Infrared devices - Nitrogen - Optical waveguides - Remote sensing - Satellites - Sensitivity analysis - Vegetation
Uncontrolled terms: Canopy spectral reflectance - Determination coefficients - Leaf nitrogen content - Multi-spectrum - Nitrogen fertilization level - Spectral response functions - Unified Modeling - Winter wheat
Classification code: 655.2 Satellites - 714.3 Waveguides - 804 Chemical Products Generally - 804.1 Organic Compounds - 821.4 Agricultural Products - 921 Mathematics
DOI: 10.6041/j.issn.1000-1298.2016.02.040
Database: Compendex
50.
Accession number: 20161202133074
Title: Double objectives optimization of asymmetric steering mechanism based on pareto-optimal solution
Authors: Yao, Xinhua1 ; Lü, Maoyin1; Xu, Yuetong1 ; Xu, Guanhua1, 2; Feng, Zhenli3
Author affiliation: 1 Zhejiang Province Key Laboratory of Advanced Manufacturing Technology, Zhejiang University, Hangzhou, China
2 Zhejiang University Kunshan Innovation Institute, Kunshan, China
3 Ningbo Ruyi Group Co. Ltd., Ningbo, China
Corresponding author: Xu, Yuetong ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 330-337
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: According to the steering demand of four-way forklift truck, a kind of asymmetric steering mechanism (ASM) which is applicable to the four-way forklift truck was developed. In order to solve the steering performance deterioration in horizontal and longitudinal modes leaded by optimizing longitudinal and horizontal steering performances unilaterally and the disunion of optimization results data leaded by optimizing longitudinal and horizontal steering performances, the movement mathematics model of longitudinal four-wheel steering and horizontal two-wheel steering of ASM were established, respectively. The optimal mathematics model of longitudinal four-wheel steering and horizontal two-wheel steering were established. The asymmetry constraint of left and right steerings in the longitudinal four-wheel steering mode was put forward. Double objectives optimization functions aiming at approaching the Ackermann ideal steering performance were established. The Pareto-optimal solution set of ASM's double objectives optimization functions was obtained by using the improved particle swarm optimization (PSO) algorithm. Finally, taking the non-dominated solution in the case that optimization results of steering performance were improved by 32.1% and 38.9% in the longitudinal and horizontal steering modes respectively as example, the proximity of steering performance in the longitudinal and horizontal steering modes to the Ackermann ideal steering performance and the rotation error of steering wheels were analyzed. The study provides theoretical reference for the optimization design of ASM.
Number of references: 12
Main heading: Four wheel steering
Controlled terms: Algorithms - Materials handling equipment - Optimal systems - Optimization - Pareto principle - Particle swarm optimization (PSO) - Steering - Trucks - Wheels
Uncontrolled terms: Fork lift trucks - Nondominated solutions - Optimization design - Optimization function - Pareto optimal solutions - Particle swarm optimization algorithm - Steering mechanisms - Steering performance
Classification code: 601.2 Machine Components - 663.1 Heavy Duty Motor Vehicles - 663.2 Heavy Duty Motor Vehicle Components - 691.1 Materials Handling Equipment - 921.5 Optimization Techniques - 961 Systems Science
DOI: 10.6041/j.issn.1000-1298.2016.02.044
Database: Compendex
51.
Accession number: 20161202133055
Title: Adsorption mechanism of ammonium nitrogen onto rice husk biochar
Authors: Du, Yanhong1 ; Jiang, Enchen1 ; Li, Zhiyu1; Zhang, Shijun1; Li, Shibo1; Wang, Mingfeng1
Author affiliation: 1 College of Materials and Energy, South China Agricultural University, Guangzhou, China
Corresponding author: Jiang, Enchen ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 193-199 and 214
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The adsorption mechanism of rice husk biochar to ammonium nitrogen was investigated. The influence of biochar amount, particle size, original concentration and pH value of ammonium nitrogen solution and shaking time on the adsorption characteristics were explored. The results showed that the unit adsorption quantities of ammonium nitrogen were increased with the increase of original concentration and pH value of ammonium nitrogen solution. The adsorption rate reached the highest point within 60 min and then kept unchanged within 90 min. The adsorption equilibrium of ammonium nitrogen was gained within 1.5 h. The maximum adsorption for ammonium nitrogen solutions was 81.14 mg/kg. Additionally, the effect of particle size on the adsorption process was significant. High adsorption quantities of ammonium nitrogen were got with small particle size and the adsorption capacity of rice husk biochar reached the maximum with particle size of 0.25 mm. The adsorption mechanism was investigated using thermodynamic and kinetics analyses. The results indicated that the adsorption behavior of biochar for ammonium nitrogen was inhomogeneous and it belonged to one of polymolecular layer fitted by Freundlich model properly. Quasi-dynamic equations were matched well with adsorption process of biochar to ammonium nitrogen, which included the diffusion in the fluid film, shift inside the grains and surface adsorption process by physical adsorption.
Number of references: 23
Main heading: Adsorption
Controlled terms: Nitrogen - Particle size - pH
Uncontrolled terms: Adsorption capacities - Adsorption characteristic - Adsorption equilibria - Adsorption kinetics - Adsorption mechanism - Ammonium nitrogen - Bio chars - Isothermal adsorption
Classification code: 801.1 Chemistry, General - 802.3 Chemical Operations - 804 Chemical Products Generally
DOI: 10.6041/j.issn.1000-1298.2016.02.025
Database: Compendex
52.
Accession number: 20161202133034
Title: Influence of relative installation positions of guide vane and volute tongue on radial force in centrifugal pump
Authors: Jiang, Wei1 ; Zhu, Xiangyuan1; Li, Guojun1 ; Liu, Pengfei1
Author affiliation: 1 Key Laboratory of Thermal Fluid Science and Engineering, Ministry of Education, Xi'an Jiaotong University, Xi'an, China
Corresponding author: Li, Guojun ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 28-34
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The unsteady numerical simulation of centrifugal pump using SST model was conducted under different relative installation positions of guide vane and tongue. The errors of efficiency and head between test and simulation were within 5%. Investigation results showed that when the guide vane and volute tongue installation angle α was 25°, the head and efficiency were higher than those at other installation positions under various operating conditions. The minimal efficiency and head were occurred at α of 5°. When the flow rate Q was 24 m3/h and 32 m3/h, the maximum and minimum efficiencies differences were 1% and 1.4%, respectively; when Q was 40 m3/h, 48 m3/h and 56 m3/h, the differences of the maximum and minimum efficiencies were 2.2%, 2.4% and 4.5%, respectively. The velocity at impeller outlet changed with different time steps, which caused the radial force vectors acting on the impeller appeared much irregular distribution. The influence of different relative installation positions of guide vane and tongue on the radial force was mainly attributed to its influence on the static pressure at impeller outlet which led to asymmetric output of static pressure, and affected the impeller radial force. When α was 41° and 25°, the symmetry of the impeller outlet static pressure was significantly better than those of other relative positions, and the radial force was smaller than those at α of 5° and 59°. When volute tongue apart gradually closed to guide vane, the efficient and head of pump were lower. The highest efficient and head occurred when volute tongue was in middle of two vane, which can be a guidance to engineering practice.
Number of references: 18
Main heading: Impellers
Controlled terms: Centrifugal pumps - Computer simulation - Efficiency - Flow measurement - Numerical models - Pumps
Uncontrolled terms: Different time steps - Engineering practices - Installation angle - Installation position - Operating condition - Radial forces - Relative positions - Unsteady numerical simulations
Classification code: 601.2 Machine Components - 618.2 Pumps - 631.1 Fluid Flow, General - 723.5 Computer Applications - 913.1 Production Engineering - 921 Mathematics
DOI: 10.6041/j.issn.1000-1298.2016.02.004
Database: Compendex
53.
Accession number: 20161202133047
Title: Effects of water and nitrogen coupling on nitrogen nutrition index and radiation use efficiency of winter oilseed rape (brassica napus l.)
Authors: Gu, Xiaobo1 ; Li, Yuannong1 ; Du, Yadan1; Zhou, Changming1; Yin, Minhua1; Yang, Dan1
Author affiliation: 1 Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling; Shaanxi, China
Corresponding author: Li, Yuannong ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 122-132
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: In order to determine the reasonable amount of irrigation and nitrogen fertilizer for winter oilseed rape (Brassica napus L.) at stem elongation stage, which is significantly important for improving water and nitrogen use efficiency, increasing yield and quality and decreasing environmental pollution, a two-year (2012-2013 and 2013-2014) field experiment was conducted to evaluate the effects of different irrigation and nitrogen applications on aboveground dry biomass accumulation, nitrogen nutrition index (NNI), radiation use efficiency (RUE), yield, water use efficiency (WUE) and nitrogen partial factor productivity (NPFP) of winter oilseed rape in Yangling District of Shaanxi Province. There were three irrigation levels (I0:0 mm; I1:60 mm; I2:120 mm, I2was approximately equal to local traditional irrigation amount) and three nitrogen levels (N0:0 kg/hm2; N1:80 kg/hm2; N2:160 kg/hm2, N2was approximately equal to local traditional nitrogen application amount). The results showed that irrigation and nitrogen could obviously improve aboveground dry biomass, RUEand yield. Compared with I1N2, I2N1and I2N2, the aboveground dry biomass of I1N1was reduced by 0.80%, 9.18% and 11.12%, respectively. Under treatments of I0N1, I0N2, I2N1and I2N2, nitrogen deficiency of winter oilseed rape occurred at different days after irrigation and nitrogen treatments, which was unbeneficial for the growth of winter oilseed rape. While the NNIof I1N1and I1N2were always higher than 1 at different stages, and the NNIof I1N1was fluctuated around 1, which indicated nitrogen status was optimum, but the NNIof I1N2was much greater than 1, which indicated nitrogen was excess. Irrigation and nitrogen had significant interaction effects on RUEin two years (P<0.05), and I1N1could significantly improve RUEof winter oilseed rape in both drought year (2012-2013) and rainy year (2013-2014). The promotion of RUEwas not obvious or even presented a downward trend when excessive irrigation or nitrogen application was conducted. In 2012-2013, seed yield of I1N1was significantly lower than those of I2N1and I2N2(P<0.05), and it was reduced by 6.02% and 4.76%, respectively. While in 2013-2014, no significant difference was found among I1N1, I2N1and I2N2(P>0.05). In both years, irrigation and nitrogen had significant interaction effects on crop evapotranspiration (ET), WUEand NPFP(P<0.05). In 2012-2013 and 2013-2014, yield of winter oilseed rape ranged from 1 534 kg/hm2to 3 024 kg/hm2and from 2 318 kg/hm2to 3 746 kg/hm2, ET ranged from 195 mm to 339 mm and from 318 mm to 426 mm, WUEranged from 7.9 kg/(hm2?mm) to 10.4 kg/(hm2?mm) and from 7.2 kg/(hm2?mm) to 9.4 kg/(hm2?mm). Among all of the irrigation and nitrogen treatments, I2N1achieved the highest seed yield within two years, the average yield, ET and WUEof which were 3 385 kg/hm2, 374 mm and 9.1 kg/(hm2?mm), respectively. While I1N1achieved the highest WUEin both years, the average WUEof which was 9.9 kg/(hm2?mm), with average yield of 3 264 kg/hm2, average ET of 333 mm. Therefore, compared with I2N1, I1N1could save water amount of 42.5 mm, and improve WUEby 8.79% with yield just reducing by 3.57%. From the perspective of saving water and fertilizer, and simultaneously achieving the goal of increasing yield, the I1N1(irrigation amount was 60 mm and nitrogen application amount was 80 kg/hm2) treatment was recommended as an appropriate irrigation and nitrogen fertilization schedule for winter oilseed rape at stem elongation stage.
Number of references: 26
Main heading: Nitrogen fertilizers
Controlled terms: Biomass - Efficiency - Elongation - Fertilizers - Irrigation - Nitrogen - Nutrition - Oilseeds - Plants (botany) - Radiation effects - Water pollution - Water supply
Uncontrolled terms: Crop evapotranspiration - Environmental pollutions - Nitrogen nutrition - Oil seed rape - Partial factor productivity - Radiation use efficiency - Saving water and fertilizers - Stem elongations
Classification code: 446.1 Water Supply Systems - 453 Water Pollution - 461.7 Health Care - 804 Chemical Products Generally - 821.3 Agricultural Methods - 821.4 Agricultural Products - 913.1 Production Engineering
DOI: 10.6041/j.issn.1000-1298.2016.02.017
Database: Compendex
54.
Accession number: 20161202133072
Title: Control strategy of BSG vehicle idling start-stop system
Authors: Lu, Jiapeng1 ; Li, Youde1 ; Lü, Jinghua2; Zhao, Jian1
Author affiliation: 1 College of Automobile Engineering, Jilin University, Changchun, China
2 Product Development Department, FAW Car Company Limited, Changchun, China
Corresponding author: Li, Youde ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 316-322
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The belt driven starter generator (BSG) system structure, working principle and working mode were introduced, the oil-saving principle of start-stop system, the relationship between idle speed and oil-saving rate, and the relationship between idle time ratio and oil-saving rate were analyzed. According to the driver's safety, driving habits and comfort, fuel economy and emission, the BSG start-stop system control strategy was formulated, which included engine automatic stopping strategy, engine automatic starting strategy, start-stop system shutdown strategy, and start-stop coordination strategy. The start-stop control parameters threshold values of battery SOC, catalyst temperature, engine water temperature, environmental temperature, and braking system vacuum pressure were set. The strategies were applied to the real vehicle. On the revolving drum, the fuel consumption and emissions were tested in NEDC cycle with the carbon balance method and instantaneous fuel consumption equipment. On the road, the fuel consumption was tested in NEDC cycle and actual road conditions. The test results showed that the proposed control strategy was correct, the threshold value of control parameters was reasonable, and the control strategy satisfied the requirement of idle start-stop function. The revolving drum test results showed that the BSG system could save oil by 4%~5% in NEDC cycle, and it could save oil by more than 12% in city conditions. The BSG vehicle emission met the national V emission standard. The CO and THC pollutants were decreased significantly, and the NOxpollutants were increased slightly. The road fuel consumption test results showed that during the morning rush of the city, the BSG system could save oil by more than 8.1%.
Number of references: 20
Main heading: Fuel economy
Controlled terms: AC generator motors - Carbon - Engines - Fuel consumption - Fuels - Ignition - Neutron emission - Pollution - Roads and streets - Starters - Transportation - Vehicles
Uncontrolled terms: Carbon balance method - Catalyst temperature - Control parameters - Control strategies - Coordination strategy - Environmental temperature - Starter generators - Water temperatures
Classification code: 406.2 Roads and Streets - 521.1 Fuel Combustion - 525.2 Energy Conservation - 525.3 Energy Utilization - 705.2.1 AC Generators - 804 Chemical Products Generally
DOI: 10.6041/j.issn.1000-1298.2016.02.042
Database: Compendex
55.
Accession number: 20161202133051
Title: Fine root distribution characteristics of plant community in different vegetation zones in hill-gully region of loess plateau
Authors: Kou, Meng1 ; Jiao, Juying1, 2 ; Wang, Qiaoli3; Yin, Qiulong4
Author affiliation: 1 Institute of Soil and Water Conservation, Ministry of Water Resources, Chinese Academy of Sciences, Yangling; Shaanxi, China
2 Institute of Soil and Water Conservation, Northwest A&F University, Yangling; Shaanxi, China
3 College of Resources and Environment, Northwest A&F University, Yangling; Shaanxi, China
4 College of Forestry, Northwest A&F University, Yangling; Shaanxi, China
Corresponding author: Jiao, Juying ([email protected])
Source title: Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title: Nongye Jixie Xuebao
Volume: 47
Issue: 2
Issue date: February 25, 2016
Publication year: 2016
Pages: 161-171
Language: Chinese
ISSN: 10001298
CODEN: NUYCA3
Document type: Journal article (JA)
Publisher: Chinese Society of Agricultural Machinery
Abstract: The objective of this study was to clarify the characteristics of fine roots (diameter d≤2 mm) parameters (root biomass, root length density and specific root length) in 0~20 cm soil layer under different plant communities in forest zone, forest steppe zone and steppe zone of the Yan river basin in hill-gully region of Loess Plateau. Soil drill method was used to collect root samples. Vernier caliper was used to measure root diameter in two grades of 0~1 mm and 1~2 mm. Root length of two diameter grades was measured, then root samples were dried to constant weight at 85 and weighed. The main results were as follows: (1) In the three vegetation zones, the proportion of root length density (d≤1 mm) and root biomass of different communities accounted for 90% and 53% of the total fine root, respectively. The root (d≤1 mm), which accounted for a large proportion of the total fine root, not only contributed greatly for the plant growth, but also played an important role in improving soil structure. (2) Root biomass (d≤2 mm) of different plant communities showed a decreasing trend from southern forest zone to northern steppe zone, while specific root length showed a increasing trend from southern forest zone to northern steppe zone, root length density in steppe zone was significantly lower than those in other two vegetation zones (P<0.05). The variation tendency of root length density and root biomass was the same, and root length density and root biomass of tree community and shrub community were higher than those of herb community. But specific root length of herb community was significantly higher than those of tree community and shrub community (P<0.05). (3) Root length density and root biomass of tree community, shrub community and Lespedeza davurica dominated community were higher than those of other communities, the root growth of these communities was vigorous, and root system of these communities developed well. The specific root lengths of Sophora viciifolia, Periploca sepium and Bothriochloa ischaemun respectively dominated communities were higher than those of other communities, thus these communities had stronger potential ability to absorb soil moisture and nutrients, and higher growth rate. (4) The root parameters of Sophora viciifolia, Periploca sepium, Artemisia gmelinii and Bothriochloa ischaemun respectively dominated communities, which distributed in forest steppe zone, were significantly bigger than those of other communities distributed in the other two vegetation zones (P<0.05). It indicated that these communities could absorb soil moisture and nutrients more efficiently and play an important role in increasing soil anti-erodibility in forest steppe zone.
Number of references: 40
Main heading: Plants (botany)
Controlled terms: Biomass - Ecology - Forestry - Landforms - Moisture - Nutrients - Sediments - Soil moisture - Soils - Vegetation
Uncontrolled terms: Anti-erodibility - Forest-steppe zone - Plant communities - Potential ability - Root biomass - Root length density - Specific root length - Variation tendencies
Classification code: 454.3 Ecology and Ecosystems - 481.1 Geology - 483 Soil Mechanics and Foundations - 483.1 Soils and Soil Mechanics
DOI: 10.6041/j.issn.1000-1298.2016.02.021
Database: Compendex
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