Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume:44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:207-212
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:To access the growth information of crops fast, non-destructively in real-time, a four band multi-spectral sensor of crop was developed based on spectral monitoring mechanism of crop growth indicators. Optical filtering technique was used to improve the input signal to noise ratio of optical radiation. Based on crop canopy characteristics and operating environment in the field, the suitable structure parameters of detection lens was designed, ensuring that sensitivity and resolution effect of multi-spectral sensor. The weak spectral information amplifying circuit was built by T-type resistance network. Through calibration, the relational model of multi-spectral sensor and FieldSpec Pro FR2500 spectrometer was obtained, the coefficient of determination of which was 0.802 8, 0.806 8, 0.818 5 and 0.890 0 respectively. The wheat test results showed that the average measurement error of the sensor were 5.6%, 4.6%, 1.4% and 4.5% respectively. The sensor could realize real-time online tests of crop canopy reflectance spectra to provide strong support for the development of the crop growth monitoring equipment.
Number of references:22
Main heading:Sensors
Controlled terms:Crops
Uncontrolled terms:Coefficient of determination - Crop canopy reflectance - Growth information - Monitoring mechanisms - Multispectral sensors - Operating environment - Spectral information - Structure parameter
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:175-181
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Headspace solid-phase microextraction (HS-SPME) was applied to the analysis of volatile components in apple juice. There are differences among parameters for the extraction of esters, alcohols and aldehydes. Therefore a model of fuzzy comprehensive evaluation was established and used to optimize the parameters of microextraction. The result of fuzzy comprehensive evaluation was set as the response. The extraction conditions were optimized by using a response surface experimental design to analyze the effect of three factors: extraction temperature, extraction time and NaCl concentration. Optimal extraction conditions for esters, alcohols and aldehydes were obtained when the extraction temperature was 51.3°C, extraction time was 45.2 min and NaCl concentration was 0.252 g/mL. For the proposed method, the linearity was good in the considered concentration ranges (R2≥0.983). Recoveries ranged from 87.6% to 106.3% and showed good accuracy. The relative standard deviation was less than 10.09%.
Number of references:19
Main heading:Extraction
Controlled terms:Aldehydes - Esterification - Esters - Fruit juices - Fuzzy set theory - Optimization - Surface properties - Volatile organic compounds
Author affiliation:1 Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
2 University of Chinese Academy of Sciences, Beijing 100039, China
3 College of Resources and Environment, Northwest A and F University, Yangling, Shaanxi 712100, China
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:89-95
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:In order to explore the changes in speciation and plant availability of heavy metals in flooded rice paddies after air drying, flooded soil samples were collected in the typical area in Yangtze River Delta, and the flooded and air dried soil samples were treated with BCR sequential extraction method. Amended with atomic absorption spectrophotometer, the fractions of Cd, Cr, Cu, Ni and Pb were measured. The result showed that acid soluble was 11.5%, oxidisable was 21.5%, residual was 29.2%, reducible was 33.7% for flooded soil. After air drying, acid soluble and reducible fraction decreased while the residual fraction increased. The sensitive order was Ni>Pb>Cd>Cu, and Cr remained steady. In flooded condition, the plant availability of Cd, Ni and Cu were higher than Pb, and Cr was the lowest. After being air-dried, the plant availability of Ni, Cd and Cu decreased while Pb increased. It was concluded that the air dried samples could not exactly show the real speciation of heavy metals, and the plant availability of heavy metals was underestimated.
Number of references:34
Main heading:Floods
Controlled terms:Drying - Lead - Nickel - Soil surveys
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:164-168
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:The effects of density, resin content and hot-pressing temperature on mechanical properties of reconsolidated square material of cotton stalk were investigated by single factor test. The result showed that modulus of elasticity, bending strength and compression strength of cotton stalk reconsolidated square material gradually increased with the increase of density (0.5 g/cm3, 0.6 g/cm3 and 0.7 g/cm3) and resin content (8%, 10% and 12%) during the range of experiment. With the hot-pressing temperature rising, these mechanical properties increased initially(from 160°C to 180°C)and then decreased (from 180°C to 200°C). At other technology condition being equal, the mechanical properties of cotton stalk reconsolidated square material used phenol-formaldehyde (PF) were obviously superior to those used the melamine modified urea-formaldehyde (MUF). The mechanical properties of cotton stalk reconsolidated square material with density of 0.7 g/cm3 could be equivalent to mature wood of plantation grown poplar.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:232-236 225
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Aiming at the problem of the missing shadow information of remote-sensing images existing in the karst peak and depression area, 14 relations of SGS(Sequential Gaussian simulation) for NDVI(Normal different vegetation index) of Guohua ecological experimental area were obtained in Guangxi Zhuang Autonomous Region. The simulation results were compared with ordinary Kriging. Validation results indicated that the NDVI of the study area was impacted intrinsic factors and performed strong spatial autocorrelation. With the increase of the number of simulations, the correlation coefficient between the simulation and verify values increased, and the mean absolute error (MAE) and root mean square error (RMSE) reduced. Along with the increase of simulation times, SGS simulation precision was gradually improved, and the precision of SGS was higher than that of OK (Ordinary Kriging) interpolation when simulation times were more than 50 times. Using SGS methods to predict the missing shadow information can provide a new idea and method for evaluation and ecological reconstruction of the karst rock desertification.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:19-24
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:A double eigen angle steady-state flow rig was used to measure three modified options of intake port on a single cylinder four stroke gasoline engine. The results showed that improving combustion by enhancing swirl might reduce the flow capacity while improving tumble ratio appropriately could also increase the intake flow coefficient. Based on the dimensionless swirl ratio and tumble ratio, a group of simple formulas which were used to calculate the inclined swirl characteristic parameters were proposed, and related experiments were accomplished to prove their effectiveness. Additionally, linear regression analysis was conducted between the dimensionless swirl ratio at the condition characteristic angle α of 60° and the dimensionless inclined swirl ratio synthesized by swirl ratio and tumble ratio, and the correlation coefficient of three options were 0.96, 0.97 and 0.97 respectively. It was concluded that the performance of intake port could be evaluated by the dimensionless swirl ratio at a certain angle α instead of swirl ratio and tumble ratio.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:108-112
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:A soil fertility fuzzy evaluation model based on the contribution of microorganism was proposed. The microorganism kinetics were used to analyze the direct and indirect ecological effect on the soil fertility. The contribution of the microorganism was converted to the available nutrient element on the basis of the original non-biological evaluation index weight structure to calculate the weights which the traditional method was difficult to determine. The evaluating grade of the whole factors was divided and the appropriate membership function parameters were determined. The soil fertility fuzzy evaluation model was established. According to the correlation analysis between the evaluation results and the crop productions, it was showed that the correlation coefficient of the evaluation was higher than the traditional methods, which was more reasonable than the other evaluations.
Author affiliation:1 Lab. of Special Purpose Equipment and Advanced Processing Technol., Min. of Edu. and Zhejiang Prov., Zhejiang University of Technology, Hangzhou 310032, China
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:242-246
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:With the aim to realize the safe and stable picking of spherical fruit, a type of picking end-grasper was designed based on the flexible penumatic actuator (FPA). The end-grasper was mainly composed of a base and three fingers driven by FPAs. The kinematics of finger tips in the base coordinate was established. The force model of spherical fruit grasping under discretional orientation was analyzed and the grasping mathematic model was built. The experimental results showed that the designed spherical fruit end-grasper could pick and hold mature fruit under discretional orientation and the mathematic model could be adopted in fruit-picking practice control.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:264-269
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:An assessment system for sustainability in the greenhouse viticulture was developed based on the database technology, network technology and emergy analysis theory. Firstly, a complex analysis on production process of greenhouse viticulture was conducted and a model to assess sustainability based on emergy was proposed. Then, the data from Changli county was acquired to test the system. Results showed that the system could assess the sustainability of the greenhouse viticulture system effectively, and identified the key factor in sustainable development, as well as promoted the standardized management of plantation production and improved the capacity for sustainable development of greenhouse viticulture industry.
Number of references:17
Main heading:Sustainable development
Controlled terms:Greenhouses - Planning
Uncontrolled terms:Assessment system - Complex analysis - Database technology - Design and implementations - Emergy analysis - Network technologies - Production process - Sustainability assessment
Classification code:402.1 Industrial and Agricultural Buildings - 403 Urban and Regional Planning and Development - 911.2 Industrial Economics
DOI:10.6041/j.issn.1000-1298.2013.05.046
Database:Compendex
10. Accession number:20132416422594
Title:WSN layout experiment based on radio frequency propagation tests in citrus orchard
Author affiliation:1 Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
2 Faculty of Engineering and Surveying, University of Southern Queensland, Toowoomba QLD4350, Australia
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:213-218
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:The layout of wireless sensor network (WSN) in citrus orchards was analyzed concerning radio frequency (RF) signal strength attenuation and packet loss rate of WSN based on radio wave propagation characteristics. Accordingly, a simply equipped WSN network was deployed and tested. The attenuation of radio wave was studied in the tests with the carrier frequencies of 433 MHz and 2.4 GHz in the circumstance of different combinations of impact factors including data rate, packet length, transmission distances, etc. The two RF signal strength linear models (433 MHz and 2.4 GHz) were built in citrus orchards with the related determination coefficients for fitting-curves ranging from 0.957 031 to 0.971 218 and 0.954 6 to 0.986 3. Signal attenuation tests showed that the CC1110 (433 MHz) had a better performance in long distance communication with data rate lower than 1.2 kb/s and the average received signal strength was higher than the 2.4 GHz's with the same output power. While the CC2530 (2.4 GHz) provided lower packet loss rate compared with the CC1110 (433 MHz) in transmitting in the same data rate. For WSN configuration, short data packet and low data rate were recommended according to the test results. A ZigBee star network was constructed and experimented with the guidance provided by signal attenuation tests. Statistics showed that the average success rate for communication was higher than 84%.
Number of references:16
Main heading:Wireless sensor networks
Controlled terms:Curve fitting - Orchards - Radio waves - Signal processing - Wave propagation - Zigbee
Uncontrolled terms:Citrus orchards - Determination coefficients - Long distance communication - Network layout - Propagation channels - Radio frequency propagation - Received signal strength - WSN
Classification code:711 Electromagnetic Waves - 716.1 Information Theory and Signal Processing - 722.3 Data Communication, Equipment and Techniques - 821.3 Agricultural Methods - 921.6 Numerical Methods
DOI:10.6041/j.issn.1000-1298.2013.05.037
Database:Compendex
11. Accession number:20132416422566
Title:Experiment of mitigation of low frequency pressure fluctuation in draft tube by axial water jet
Authors:Li, Zhangchao1 ; Chang, Jinshi1
Author affiliation:1 College of Water Conservancy and Civil Engineering, China Agricultural University, Beijing 100083, China
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:45-49
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:A structure was designed to reduce the pressure fluctuation in the draft tube by axial water jet. And the water was obtained from the spiral case through the runner cone into the draft tube. Pressure fluctuation model test of the Francis turbine with and without axial water jet was carried on. And the pressure pulsation amplitude and frequency characteristics with and without axial water jet at four part loads were analyzed. The mitigation effect of pressure fluctuation with axial water jet was studied. It was shown that at part load operation there was a vortex rope in the draft tube and the frequency of the rope was about 1/5 rotating frequency. This vortex rope caused strong low frequency pressure fluctuation. It was the main reason for the unsteady operation of the turbine. With axial water jet the amplitude of the low frequency pressure fluctuation was significantly reduced, but the frequency was not changed obviously. Axial water jet made the vortex move downstream and played an inhibitory effect of the double-vortex.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:141-147 153
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:In order to improve the hydrolysis efficiency of cellulose materials, an artificial composite system CN6 was constructed by using different substrates and complementary enzymes. By detecting the filter paper enzyme activity and cellulose degradation rate, the optimum fermentation conditions of CN6 were determined as follows: culture temperature of 30-37°C and initial pH value of 7.0. The metabolic process of CN6 was proved to be stable. The complex strains CN6 was applied to biogas fermentation of cow dung as raw material in a laboratory scale reactors. The results showed that the volatile fatty acid (VFA) was increased by 26.5%-30.6% in 0-15 d of fermentation. At the end of fermentation, the cellulose degradation rate and cumulative biogas production were increased by 6.8% and 18.4% compared with that of the control.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:74-78
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:To analyze the rotor dynamics of the multistage pump, it is necessary to calculate the dynamic coefficients of journal bearing. The derivatives of the Reynolds equation were transformed into difference forms. The Reynolds equation was solved by programming in the Matlab, then the distribution of the static pressure was obtained. The dimensionless pressure was determined by width-diameter ratio and eccentricity ratio. To get the eccentricity ratio, the bearing capacity was calculated by using Simpson's integral formula. The eccentricity ratio was changed by using interpolation method until bearing capacity equal the reverse supporting force. The pressure of small disturbance was obtained by programming and calculating the dynamic coefficients. The width-diameter ratio and eccentricity ratio was set as 0.2 and 0.4 respectively. Compared the results of this algorithm with that of the short bearing approximation, it showed that this algorithm was reliable. The results showed that the cross-damping coefficients of one journal bearing were almost equal. The diagrams of the journal bearing's pressure with small disturbance were drawn by Matlab.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:127-134
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Based on the indoor model test, the head loss in the clear water filtration and optimal drainage time in the pollution state of the 80 mesh and 120 mesh self-cleaning screen filter was studied. The results showed that in the filtering state, general expression of clean water head loss was deduced through establishing Bernoulli equation from inlet to outlet of the filter. Two mesh head loss experience expression was obtained under different water flows (0-220 m3/h). In the drainage conditions of two filters with five different discharge pressure differentials and three corresponding different sediment concentration, the rule of the curve showed that water sediment concentration of the drain changes with drainage time increasing at first and then decreasing. An inflection point appeared at 15 s, and the outfall's sediment tended to stabilization when the discharge time reached to 20 s. To ensure the effect of discharge of the filter and saving water, the optimal discharge time of the filter was set to 20-30 s in theory. Based on the experiments and error analysis, the optimal discharge time expression of 120 mesh filter's was deduced. The results showed that the values of theory and test agreed well.
Number of references:18
Main heading:Discharge (fluid mechanics)
Controlled terms:Error analysis - Experiments - Optimization - Water filtration - Water pollution
Uncontrolled terms:Bernoulli equations - Discharge pressures - Discharge time - Drainage condition - Head loss - Microirrigation - Screen filters - Sediment concentration
Classification code:407 Maritime and Port Structures; Rivers and Other Waterways - 445.1 Water Treatment Techniques - 453 Water Pollution - 901.3 Engineering Research - 921.5 Optimization Techniques - 921.6 Numerical Methods
DOI:10.6041/j.issn.1000-1298.2013.05.023
Database:Compendex
15. Accession number:20132416422573
Title:Grassland water balance simulations using CoupModel in loess hilly and gully region
Author affiliation:1 State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A and F University, Yangling, Shaanxi 712100, China
2 Bureau of Water Conservancy in Lvliang City, Lvliang 033001, China
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:79-88
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:In the loess hilly and gully region of northern Shaanxi Province, the CoupModel was used to simulate the water balance of the soil-vegetation-atmosphere in the south- and north-facing slopes of grasslands. The simulation results showed that simulated values of soil water content and soil temperature was generally in good agreement with measured values in the investigated stands, implying that the CoupModel could be successfully applied to demonstrate the complex interactions between hydrological processes in the soil-vegetation-atmosphere system. Soil evaporation in the south-facing slope of grassland was higher than that in the north-facing slope, while vegetation transpiration in the south-facing slope was lower than that in the north-facing slope, indicating that there was a significant difference of water exchanges between the interfaces of atmosphere and soil, and soil and vegetation. In the dry year, vegetation transpiration and soil evaporation were the main components of water consumption in the investigated stands, which was more than the precipitation and water input was lower than water output in the soil reservoir. While in the wet year, 20% of precipitation was recharged and stored in the soil reservoir. This study indicated that water transfer and balance in the south-facing and north-facing slopes was quite different. Since there was high soil evaporation and low water storage in the south-facing slope, it is important to carefully choose planting species during the processes of the sloping land conversion program.
Uncontrolled terms:CoupModel - Hydrological process - Loess hilly and gully region - Significant differences - Soil evaporations - Soil vegetation atmospheres - Water balance - Water balance simulation
Classification code:821 Agricultural Equipment and Methods; Vegetation and Pest Control - 802.3 Chemical Operations - 801.4 Physical Chemistry - 744.1 Lasers, General - 643 Space Heating, Ventilation and Air Conditioning - 483.1 Soils and Soil Mechanics - 483 Soil Mechanics and Foundations - 481.1 Geology - 446.1 Water Supply Systems - 446 Waterworks - 444 Water Resources - 441.2 Reservoirs - 402 Buildings and Towers
DOI:10.6041/j.issn.1000-1298.2013.05.016
Database:Compendex
16. Accession number:20132416422569
Title:Optimization for vortex pump based on response surface method
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:59-65
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:The optimization method of vortex pump design was established based on experimental design theory and the response surface approximation. Taking the maximum efficient, high effective area and stability of head-flow curves in the small flow region as the objective functions, the structural parameters of model pump were screened by Plackett-Burman experimental design method. The selected parameters were divided into three levels: significant factor, the second significant factor and non-significant factors, according to their influences on objective functions. Finally, the optimal design points for each level of structural parameters were determined by central composite design, Box-Behnken design and the response surface analysis method. Based on the computational fluid dynamics (CFD) results, the response surface approximation model for the pump structural parameters and multi-objective function were built to analyze the interaction between the effects of structural parameters. Furthermore, experimental research was done for the pump at the optimum working point. It was found that experimental results correspond well with the response surface approximation, with a relative efficiency deviation of 4.89%. The optimized pump improved significantly in performance than before. Thus, it is concluded that the response surface optimization design method based on experimental design theory can be used to optimize the design of vortex pump.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:188-193
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:In order to offer a portable, quick and precise method and instrument for measuring moisture content of coarse cereals, a moisture meter was designed based on dielectric properties and C51 language. DC charge/discharge circuit, digital temperature sensor DS18B20 and equal-arm bridge circuit were used to detect the values of capacitance, temperature and bulk density of coarse cereals. Millet was used as sample to study the influence of moisture content, temperature and bulk density on capacitance with the self-made moisture meter. Mathematical model, describing their relationship, was regressed and verified. The accuracy in predicting moisture content from obtained capacitance and temperature was tested. The results showed that the measurement precision for moisture content was ±0.5% and the response time was less than 3s when the moisture content in wet basis was within 11%-19% and in temperature of 5-40°C.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:270-275
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:In order to improve robot manipulator's tracking accuracy, a hybrid controller consisting of a functional link neural network sub-controller (FLNNC) and a computed torque sub-controller (CTC) was introduced into the manipulator, which made use of CTC to drive the manipulator reaching its desired position roughly while employed the FLNNC to compensate the tracking error caused by the dynamic uncertainty and disturbance of the robot. To accomplish this, firstly, a nominal dynamic model of the manipulator was established, and the dynamic uncertainty of the robot manipulator was modeled and formulized. And then, a control system with two close loops was built for the manipulator, and the computed-torque control law based on the nominal manipulator model was planned for the system. Moreover, a functional link neural network (FLNN) being capable of approximating the dynamic uncertainty term of the robot was designed in the system, and the weight learning algorithm for the FLNN was derived. Finally, simulations were made on that system so as to validate the hybrid controller. The results showed that both the position error and speed tracking error of the robot joints could be controlled within ±0.001 rad and±0.001 rad/s, which meant that the proposed hybrid controller was able to make the robots tracking desired trajectory with high precision.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:113-118 142
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Eight kinds of substrates were used in the experiment of the soilless culture. The water retention parameters, such as porosity, coefficient of permeability, water retention curve and diffusivity were measured. It was obtained that water diffusivity and water content of substrates conformed to empirical formula D(θ)=aebθ and showed the variability of exponential function and high correlation coefficient. The perlite and vermiculite had high speed of water supply, but low water retaining capacity and irrigation efficiency. The total porosity of other six substrates except for perlite and vermiculite varied from 70% to 90%, and their water-air ratios were between 2.0-4.0. Therefore, they could be used as seedling and culture substrates. Based on the comprehensive matrix analysis, the result showed that the optimal ratio of peat and perlite was 2:1, and that of peat, vermiculite and perlite was 3:1:1.
Number of references:31
Main heading:Substrates
Controlled terms:Diffusion in liquids - Hydraulic conductivity - Peat - Porosity - Water supply
Uncontrolled terms:Coefficient of permeability - Correlation coefficient - Culture substrate - Empirical formulas - Irrigation efficiency - Soilless-culture - Water retention curve - Water retention parameter
Classification code:931.2 Physical Properties of Gases, Liquids and Solids - 801 Chemistry - 632.1 Hydraulics - 524 Solid Fuels - 503 Mines and Mining, Coal - 461 Bioengineering and Biology - 446.1 Water Supply Systems
DOI:10.6041/j.issn.1000-1298.2013.05.021
Database:Compendex
20. Accession number:20132416422584
Title:Purification of CH4 from CH4/CO2 mixture using carbon-based adsorbents
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:154-157
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:The removal of CO2 from a CO2/CH4 mixture using commercial carbon-based adsorbents was researched at ambient temperature (25°C) under low pressure (0.2 MPa). The performance in separating CO2 from its mixture with CH4 using carbon-based adsorbents was compared with 13X molecular sieve. The results indicated carbon molecular sieve could separate the mixture well but its selectivity was lower than 13X molecular sieve. However, carbon molecular sieve could be well regenerated, which was much better than 13X molecular sieve. These results suggested that carbon-based molecular sieve might be more suitable than zeolites for CO2 removal from biogas in a pressure swing adsorption cycle.
Classification code:522 Gas Fuels - 802.3 Chemical Operations - 803 Chemical Agents and Basic Industrial Chemicals - 804 Chemical Products Generally - 804.2 Inorganic Compounds
DOI:10.6041/j.issn.1000-1298.2013.05.027
Database:Compendex
21. Accession number:20132416422605
Title:Coefficient recursive algorithm for manipulator trajectory planning based on cubic splines
Authors:An, Kai1
Author affiliation:1 Shandong Aerospace Electro-Technology Institute, Yantai 264003, China
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:276-280
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:The algorithm for manipulator trajectory planning based on cubic splines relates to the inversion of the matrix with higher order, and hence, the operation becomes very complex. As a result, the response rate of the manipulator was reduced certainly. In view of this situation, a recursive algorithm to obtain the coefficients of cubic splines was put forward. The recursive algorithm did not require any matrix inversion, and the initial values of recursion came from the boundary conditions expressed by recursive formula. The methods to determine initial values and the recursive formula were presented according to three different boundary conditions. Simulation result showed that the improved algorithm not only can simplify the computes, but also can obtain desired coefficients of cubic splines.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:50-54 112
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Both the impeller and inlet guided vanes were studied. Considering the inlet prewhirl by using radial inlet guided vanes, the calculation formula of the pump's maximum shaft power and its corresponding flow rate were deduced. The effects of inlet guided vanes' geometric parameters on theoretical head curves, power curves, theoretical maximum flow rate, maximum shaft power and its corresponding flow rate were also analyzed. Then eight schemes with different geometric parameters were numerically simulated by using CFD software, the validity of the formula was verified by comparing numerical result and formula calculation, indicating that it can provide guidance for the design of non-overload centrifugal pump.
Number of references:17
Main heading:Centrifugal pumps
Controlled terms:Flow rate
Uncontrolled terms:Calculation formula - Geometric parameter - Inlet guide vane - Maximum flow rate - Non-overload - Numerical results - Prewhirl flow - Provide guidances
Classification code:618.2 Pumps - 631 Fluid Flow
DOI:10.6041/j.issn.1000-1298.2013.05.010
Database:Compendex
23. Accession number:20132416422595
Title:Correlation between nitrogen vertical distribution and spectral characteristics of flue-cured tobacco
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:219-225
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:The quantitative relationship between vertical distribution of above-ground nitrogen accumulation and canopy reflectance spectra in flue-cured tobacco (Nicotiana tabacum L.) was studied. It aimed at determining the contribution of leaf layers especially middle layer and lower layer to canopy reflectance, and constructing vertical distribution inversion model of nitrogen accumulation in different leaf layers and its combination in flue-cured tobacco. The field experiments with different nitrogen levels were conducted. The time-course measurements were taken on canopy spectral reflectance and weights and nitrogen contents in different plant parts and leaf layers during the experimental period. By means of analysis of correlation with experimental results, it was found that RVI(810, 680) could efficiently inverse the ANA in middle layer, upper-middle layer and the whole plant layers of flue-cured tobacco. DλRed could efficiently inverse the ANA of lower layer, middle-lower layer of flue-cured tobacco. It was concluded that ANA in middle, lower layer and the whole plantlets of flue-cured tobacco could be monitored directly by key vegetation indices.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:148-153
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:According to the current problem of materials' singleness and biogas slurry and residue handling difficultly in large and medium-sized biogas engineering, wet and dry coupling anaerobic fermentation combined with dry and wet fermentation was put forward, namely wet fermentation used livestock and poultry manure as raw materials, and dry fermentation used mixture of straw and biogas slurry and residue from wet fermentation as fermentation substrate. The effect of wet and dry coupling ratio-biogas residue straw ratio and leachate recirculation on fermentation properties were studied, and the results show that with the increase of BRSR, start time is shorten and the biogas production increases. TS of leachate from dry fermentation is below 1%, achieves the effect of the solid-liquid separation, is conducive to leachate recycling and spraying, solves the difficult problem of biogas slurry and residue treatment from wet anaerobic fermentation, and realizes the cyclic utilization of biogas slurry.
Uncontrolled terms:Anaerobic fermentation - Anaerobic fermentation process - Characteristic test - Cyclic utilizations - Fermentation substrates - Leachate recirculation - Solid-liquid separation - Wet and dry
Classification code:453.2 Water Pollution Control - 522 Gas Fuels - 802.2 Chemical Reactions - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.5 Agricultural Wastes
DOI:10.6041/j.issn.1000-1298.2013.05.026
Database:Compendex
25. Accession number:20132416422564
Title:Thermodynamic analysis of regenerative organic Rankine cycle
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:35-40 30
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:A regenerative organic Rankine cycle (ORC) system was designed to recover and utilize the waste heat energy from engine exhaust gas efficiently. The mathematical model of regenerative ORC was built up in Matlab and the influences of the factors such as suction pressure, evaporating pressure and expander inlet temperature on system performance were analyzed. Then the regenerative ORC was compared with the basic ORC by using a combined first and second law analysis. According to the results, when the evaporating pressure remained constant, the regenerative ORC system thermal efficiency and exergy efficiency would increase at first, then decrease with the increasing of suction pressure. The mass flow rate increased while the heat transfer rate in the evaporator decreased first and then increased with the increasing of suction pressure. By comparing the two configurations, it was seen that regenerative ORC produced higher efficiency with a lower irreversibility and could recover waste heat energy more effectively.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:96-100
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:A series of flume experiments with a silt loam taken from Beijing were conducted to measure water flow velocity with two methods, the electrolyte tracer method and dye tracer method. A solute injector, a data logger for control and data acquisition was used for flow velocity measurement. The experiment involved three slope gradients (5°, 10° and 20°), and three flow rates (64 L/min, 128 L/min and 256 L/min). The results showed that the velocity of ephemeral gully water flow tended to decrease with slope length. The velocity increased with flow rate and slope gradient. The velocity measured by the electrolyte tracer method under the given experimental condition ranged from 0.55 m/s to 1.60 m/s, as compared with 0.71 m/s to 1.45 m/s by the dye tracer method. The velocities measured by the two methods were compared under different slope gradients and flow rates. The velocities measured by the dye tracer tended to be lower than those measured by the electrolyte tracer method. Considering the strong dilution and disturb effects of high rate water flow and strong turbulence on dye tracer, visual detection of dye movement should have caused later detection of the dye movement in water flow. All these indicate that the measured velocity of ephemeral flow seems rational.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:247-252
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:A method for fruit recognition and feature extraction based on the color and shape features of kiwifruit in nature was studied. It could reduce the influences of complicated background, different kiwi growth state and natural lighting condition. First, R-G color component was chosen by comparing different color spaces. Then the optimum partition coefficient of nR-G color characteristics was determined according to the image evaluation method of error segmentation pixel, and 0.9R-G was selected finally. The Otsu method was used for threshold segmentation and morphological operation was employed to remove residual noise, and then the regions of target fruits and backgrounds were successfully separated. The image boundary was extracted by Canny operator and consequent elliptic Hough transform, which made the target fruit be recognized separately. Also, fruit features as centroid coordinates, long axis end coordinates, long axis length and short axis length were extracted. By using this method, 49 images including 110 fruits were tested. Test results demonstrated that the recognition ratio of separate fruit, adjacency fruit, partial sheltering fruit and overlapped fruit were 96.9%, 92.0%, 86.6% and 81.6%, respectively.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:258-263 287
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:An improved multi-classification algorithm of weighted support vector data description (WSVDD) was applied for the recognition of infected pine by utilizing the visible and near-infrared images acquired by the double spectrum camera fixed on the unmanned aerial vehicle (UAV) platform. Each color component for visible and near-infrared images acquired by the double spectrum camera was extracted as the color feature of the corresponding pixel on the basis of the difference of content information. Then the texture feature of the central pixel was acquired by extracting the gray level co-occurrence matrix of the adding window image block. The weight coefficient was used for the WSVDD of each kind of sample in order to realize the multi-classification and recognition of pine state. Here the weight coefficient was determined by building the weight function on the center distance of the training sample. Compared with the other methods such as manual work, aerial and satellite remote sensing, this method for acquiring the remote sensing image by using the UAV platform and the double spectrum camera was more operable, more low-cost etc. The experiment results showed that the WSVDD multi-classification algorithm could recognize the infected pine more accurately than the traditional methods of support vector machine(SVM) and support vector data description(SVDD).
Classification code:511.2 Oil Field Equipment - 652.1 Aircraft, General - 723 Computer Software, Data Handling and Applications - 741 Light, Optics and Optical Devices - 741.3 Optical Devices and Systems - 742.2 Photographic Equipment
DOI:10.6041/j.issn.1000-1298.2013.05.045
Database:Compendex
29. Accession number:20132416422568
Title:Influence of axial stress on critical rotational speed of multistage centrifugal pump rotor
Authors:Tian, Yabin1 ; Qi, Xueyi1
Author affiliation:1 School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050, China
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:55-58 88
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:The dry state critical speed of the rotor of the high speed multistage centrifugal pump of 3×8 3/4-10stg HSB was first calculated by means of the method of finite element and ANSYS software. After that, the effects on the critical speed of the rotor impressed by the support stiffness, gyroscopic couple, fluid softening effect, and mouth ring support, were computed respectively. Finally, the effect of the axial stress on the critical speed of the rotor was computed. The results showed that critical speed of the immersion rotor still existed deviation when only considering the fluid-solid coupling effect, and that considering the effect of the axial stress on the rotor dynamic characteristics the first critical speed was improved by 21% based on the fluid-solid coupling, and the ones of other order were also improved. It illustrated that the axial stress had an important effect on the critical speed of the rotor system and could improve the rotor stability.
Number of references:12
Main heading:Speed
Controlled terms:Centrifugal pumps - Finite element method
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:194-201
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:The United States has the most advanced equipment and applications in agricultural aviation. It also has a complete service system in agricultural aviation. This article introduced the current status of aerial applications including service, equipment, and aerial application techniques. It had a complete system including various components for aerial applications which could fit into the different applications. It had practical application of different advanced technologies such as GPS autonomous guidance, variable rate technology, and application models. This article also summarized the techniques in remote sensing, spatial statistic, and variable rate controls, and how these technologies had been used in yield estimation and monitoring for crop water and nutrient stresses, and also pest damages. This article also showed the current status of USA precision aerial application and also provided some thought of the future direction in precision aerial applications including real-time imaging processing, variable rate technologies, and multisensory data fusion.
Number of references:40
Main heading:Agriculture
Controlled terms:Aviation - Data fusion - Global positioning system - Remote sensing - Technology
Classification code:431.1 Air Transportation, General - 716.3 Radio Systems and Equipment - 723.2 Data Processing and Image Processing - 731.1 Control Systems - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 901 Engineering Profession
DOI:10.6041/j.issn.1000-1298.2013.05.034
Database:Compendex
31. Accession number:20132416422558
Title:Electronic throttle control system based on bilateral servo with force feedback
Authors:Gong, Mingde1 ; Tian, Bo1 ; Wang, Hui1
Author affiliation:1 Institute of Mechanical Science and Engineering, Jilin University, Changchun 130025, China
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:1-6 24
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:To eliminate the lack of driving tele-presence, the errors from nonlinearity and dynamic modeling uncertainty, the control algorism based on the bilateral servo with force feedback and the theory of master-slave tele-manipulation was presented for electronic throttle system. The position deviation between ideal angle and real angle was used as input signal. The dynamic robust compensator controlled the accelerator pedal by-wire to make driver's perception of feedback force. The fuzzy sliding mode controller based on equivalent controlled the real angle of electronic throttle to track the ideal angle. The simulation presents effectiveness of the designed control algorism. The experimental results on the electronic 6-DOF driving simulator show that the control algorism can eliminate the position errors rapidly and accurately, provides driving tele-presence and enhances the robustness and adaptive ability.
Number of references:13
Main heading:Algorithms
Controlled terms:Control systems - Errors - Robust control - Sliding mode control - Uncertainty analysis
Uncontrolled terms:Accelerator pedals - Driving simulator - Electronic throttle - Electronic throttle control system - Force feedback - Fuzzy sliding mode controller - Modeling uncertainties - Robust compensators
Classification code:723 Computer Software, Data Handling and Applications - 731 Automatic Control Principles and Applications - 731.1 Control Systems - 921 Mathematics - 922.1 Probability Theory
DOI:10.6041/j.issn.1000-1298.2013.05.001
Database:Compendex
32. Accession number:20132416422589
Title:Determination of arsenic in red wine by flow injection-hydride atomic absorption
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:182-187
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Red wine was processed by microwave digestion. Gas concentration, flow, acidity, dosage, potassium borohydride and oxidized time were optimized in the flow injection-hydride atomic absorption (FI-HAAS) of detecting arsenic. Appropriate measurement parameters were established. FI-HAAS of detecting arsenic in red wine was established. The optimal parameters of arsenic detection of red wine in the FI-HAAS were as follows: taking argon as carrier gas, hydrochloric acid as the hydride reaction acid medium, the carrier gas velocity of 120 mL/min, current-carrying acidity of 1%, the hydrochloric acid of 8%, borohydride potassium concentration of 10 mg/mL, sodium hydroxide concentration of 0.6%, KI-ascorbic acid as the prereductant, concentration of 1%, dosage of 0.5 mL, and oxidation time of 10 min.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:13-18
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:In order to accurately simulate the actual turbocharged engine exhaust pressure wave conditions for turbocharger dynamic characteristics measurement, the characteristic of engine exhaust pressure wave and the goal of pulse generator design were analyzed. A pulse generator rotating disc profile optimization was put forward on the basis of former research. The pulse generator used to simulate ICE to produce pressure wave was designed by using 1-D simulation and 3-D CFD. Experiment was carried out on the proposed generator. The experiment result showed that the pressure wave produced by pulse generator was similar to that of ICE, which proved the feasibility and validation of the optimization and the calculation method. A comparatively perfect design system of pulse generator was put forward.
Number of references:12
Main heading:Pulse generators
Controlled terms:Design - Exhaust systems (engine) - Experiments - Optimization - Superchargers - Three dimensional computer graphics - Turbomachinery
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:135-140
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Compared with the rapid development of livestock and poultry farming industry in China in recent years, the recycling technology of animal faeces wastes seems to be relatively stagnant. The untreated animal faeces wastes are piled up optionally, which causes the pollution of air, water and soil even the great harm to human health. Therefore, it is urgent to prevent and control the pollution of animal faeces wastes. The resource utilization of animal faeces wastes is an effective measure to prevent and control the pollution at the source. For this reason, the pollution, the resource nature and the technical condition of animal faeces wastes were carefully combing in this writing. What's more, various recycling technologies of animal faeces wastes were analyzed, such as energy regeneration, fertilizer conversion and feed conversion. Finally, the direction for the development of resource utilization of animal faeces wastes in China was shown clearly.
Number of references:46
Main heading:Animals
Controlled terms:Agriculture - Pollution control - Recycling - Wastes - Water pollution
Uncontrolled terms:Anaerobic fermentation - Effective measures - Energy regeneration - Farming industry - Human health - Recycling technology - Resource utilizations - Technical conditions
Classification code:452.3 Industrial Wastes - 453 Water Pollution - 454.2 Environmental Impact and Protection - 821 Agricultural Equipment and Methods; Vegetation and Pest Control
DOI:10.6041/j.issn.1000-1298.2013.05.024
Database:Compendex
35. Accession number:20132416422571
Title:Structural strength analysis of multistage submersible pump impeller based on fluid-structure interaction
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:70-73 100
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:To accurately figure out the stress and the deformation of the impeller, the one-way fluid-structure interaction was performed, utilizing the ANSYS Workbench. The pressure of the fluid flow and the centrifugal force imposed on the impeller respectively were used to evaluate the maximum equivalent stress and deformation of the impeller. Then the effect of two loads jointly imposed on the impeller was obtained. Based on these procedures, the stress and deformation behavior under different flow rates were numerically investigated. And the structural strength of the impeller was also checked. The results showed that the maximum equivalent stress and the deformation were primarily determined by the fluid flow pressure, and were less affected by the centrifugal force. With increasing flow rate, the maximum equivalent stress increased gradually and then decreased, while the deformation gradually decreased. The strength check result showed that the impeller could meet the strength requirement.
Author affiliation:1 Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, South China Agricultural University, Guangzhou 510642, China
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:202-206 212
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:As a supplement to the traditional field information collection, a collection method based on small aircraft was presented. The working principle of the four-rotor aircraft was introduced. Collection platform structure contained five parts of the field information was designed. The prototype load was 3.5 kg. The endurance time was longer than 20 min. An inertial measurement system was also designed. The fusion algorithm weight coefficient K of the system was 12 in the test when roll angle error was less than 0.5°. PID closed loop control was used to achieve hover flight in the height of 3 m and the offset error did not exceed 5 m. The platform equipped with a GPS receiver Trimble 5700 for the real-time data sampling experiments. The error between manual sampling and flight sampling data was 1.4 m. It indicated that the platform had the basic capability of the acquisition of farmland location information.
Number of references:12
Main heading:Aircraft
Controlled terms:Farms - Global positioning system - Measurements
Uncontrolled terms:Collection methods - Field informations - Fusion algorithms - Inertial measurement system - Location information - Pid closed-loop controls - Weight coefficients - Working principles
Classification code:944 Moisture, Pressure and Temperature, and Radiation Measuring Instruments - 943.3 Special Purpose Instruments - 943 Mechanical and Miscellaneous Measuring Instruments - 942 Electric and Electronic Measuring Instruments - 941 Acoustical and Optical Measuring Instruments - 821 Agricultural Equipment and Methods; Vegetation and Pest Control - 652.1 Aircraft, General
DOI:10.6041/j.issn.1000-1298.2013.05.035
Database:Compendex
37. Accession number:20132416422601
Title:Identification for weedy rice at seeding stage based on hyper-spectral imaging technique
Author affiliation:1 Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, Jiangsu University, Zhenjiang 212013, China
2 College of Engineering, Jiangxi Agricultural University, Nanchang 330045, China
3 Department of Mechanical and Electrical Engineering, Jiangsu Polytechnic College of Agriculture and Forestry, Jurong 212400, China
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:253-257 163
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:The weedy rice and rice in growth period of 10 d were investigated. The hyper-spectral image data were captured from weedy rice and rice leaves. After image data were filtered, the feature images at wavelength of 1 448.89 nm and 1 469.89 nm were optimized by principal component analysis method. For each feature image, shape feature, texture feature and color feature were extracted, and 18 feature variables in all were attained. Neural network method was used to build the discriminate model. The discriminating rates for weedy rice and rice were both 100% in training set. The discriminating rate for weedy rice was 92.86% and the discriminating rate for rice was 96.88% in prediction set. Experimental results showed that the hyper-spectral imaging technology could be used to identify weedy rice and rice at seeding stage.
Number of references:17
Main heading:Spectroscopy
Controlled terms:Imaging techniques - Neural networks - Principal component analysis
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:119-126
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:The leaves anatomical structures of three broomcorn millet varieties were observed and analyzed by optical microscopy and scanning electron microscopy, and their drought resistances were evaluated by ANOVA analysis, clustering analysis, correlation analysis and subordinate function. The results showed that broomcorn millet leaves had the xerophytic structure characteristics. The mesophyll cells were rectangular, and their long axis was perpendicular to blade surface; stomas distributed in up and down epidermis, stomas in down epidermis were sunken, and their density was larger than that in up epidermis. Moreover, the up and down epidermis had wax and epidermal hair. There were significant or extreme significant differences in 10 indices out of 18 selected indices and clustered into four groups. Through correlation analysis, mesophyll cell size, long cell length of up epidermis, stomata length of down epidermis and alveolar cells length were selected as the typical index of each group, respectively. According to the results of subordinate function, the sorting order of drought resistance from strong to weak was Longmi No.8, Neimi No.5 and Yumi No.3.
Number of references:44
Main heading:Drought
Controlled terms:Correlation methods - Optical microscopy - Scanning electron microscopy
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:41-44
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:By means of adopting large eddy simulation, the whole flow passage of the pump with 3-D unsteady numerical study methods was analyzed and features of fluctuation pressure of flow field inside the pump in operating states was got. The result showed that flow pattern inside the pump was complex. The frequency of fluctuation pressure was determined by rotation frequency of the pump, impeller vane number and the number of fixed guide vanes, etc. Fluctuating pressure amplitude first gradually reduced and then gradually increased along the volute weeks from the snail tongue to the volute outlet. It decreased rapidly along pumps radial from the impeller to the volute, but not changed significantly in the diffusion segment. The research method and conclusions have practical value for insuring safety operation of the super size centrifugal pump.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:237-241 231
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:To meet the scheduling demands of dispatching the agricultural machinery to the reasonable farmlands, time-windows based temporal and spatial scheduling model for agricultural machinery resources was built, which serialized decision-making processes and got optimal solutions for each process. The prototype system was developed, which realized functions like data input, model computing, dispatching command generation, center navigation and so on. Cooperating with an agricultural association in Beijing, the system was tested in practice. The experiment results showed that the model could perform well in practice, which improved the management and working efficiency of the agricultural association.
Uncontrolled terms:Command generation - Decision making process - Optimal solutions - Prototype system - Scheduling models - Temporal and spatial - Time windows - Working efficiency
Classification code:821 Agricultural Equipment and Methods; Vegetation and Pest Control - 821.1 Agricultural Machinery and Equipment - 912.2 Management
DOI:10.6041/j.issn.1000-1298.2013.05.041
Database:Compendex
41. Accession number:20132416422585
Title:Effects of plastic and straw bulking agents on swine manure composting
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:158-163
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:In order to study the effects of plastic bulking agents on processing of swine manure composting, three parallel composting experiments were conducted with laboratory scale composting reactors. Same amount of swine manure was mixed with equal volume of wheat straw or plastic bulking agents. Temperature, oxygen concentration, moisture content, volatile solid content, soluble carbohydrate content, cellulose content, crude fat content and crude protein content were monitored and recorded respectively. Mathematical models were employed to detect changing of free space and its effect on composting substrate decomposition. According to the results of composting experiments, temperature of composting pile using wheat straw as bulking agents raised faster than the one with plastic bulking agents at the beginning of the composting. Meanwhile wheat straw bulking agents showed better performance on water holding capacity. However, plastic bulking agents was better at keeping free air space of the whole composting pile.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:66-69 95
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Based on the assumption of tiny bubbly flow, the gas-liquid two-phase flow in a multiphase rotodynamic pump was numerically simulated with two-fluid model in both steady and unsteady modes. In the simulation, the inlet gas volume fraction was 15%. The k-ω based SST model was used for turbulence. The drag force and the added mass force were accounted for in the interfacial momentum transfer terms. Through the analyses of the distribution of gas volume fraction and velocity vectors, the unsteady flow characteristic in the multiphase pump was explored. The results demonstrated that a phenomenon named "discontinuous air mass movement" would occur in the two-phase transport process. The formation of this phenomenon was related to the bubble size and the interfacial forces acting on the gas, and only in unsteady simulation could this phenomenon be observed. Also, it was found that the locations of gas vortexes in meridional plane were almost fully corresponding to the regions of high gas volume fraction, which illustrated that gas vortex was one of the main factors that led to gas accumulation. In addition, through comparison of the external characteristics between the simulation and the experiment, the reliability of the numerical method was validated.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:294-298
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Based on the traditional stiffness mapping matrix, a stiffness mapping model of modified Delta mechanism was established. The model considered both the influence of stiffness of active joints and external load and the influence of gravities factor and all parts' elastic deformation under the constraint force on the mechanism stiffness so that it was more general and exact than any other stiffness models. Evaluating the stiffness characteristic of parallel mechanism by stiffness matrix form was not intuitive. An idea was proposed to evaluate the stiffness performance by the elastic deformation of the mechanism. The static constrained forces of all joints were calculated by using the principle of virtual work. The elastic deformation under the constrained force and gravity was calculated by superposition principle. At last, the comprehensive elastic deformation of the mechanism was obtained by coordinate transformation method. The stiffness characteristic of the mechanism was further analyzed.
Classification code:421 Strength of Building Materials; Mechanical Properties - 422 Strength of Building Materials; Test Equipment and Methods - 601.3 Mechanisms - 818 Rubber and Elastomers - 951 Materials Science
DOI:10.6041/j.issn.1000-1298.2013.05.051
Database:Compendex
44. Accession number:20132416422562
Title:Influence factor analysis of fuel evaporation in intake stroke
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:25-30
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Visualization technique was adopted to study influence of intake air velocity on fuel injection. Results showed that evaporation of fuel could be promoted by increasing velocity of intake air. Influence of intake air on evaporation of spray was different if spray angle was changed. For the engine used in study, more fuel can enter cylinder directly if fuel was injected on the back of intake valve and inlet. With increasing distance of fuel injection, front end area of spray increased and more fuel would enter cylinder directly. Evaporation of spray can be promoted by high temperature back flow. Fuel injected before intake stroke would reflect against the inlet and intake valve, evaporation of reflected fuel could be promoted by intake air.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:226-231
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:By using retrieved LAI from SPOT remote sensing data, the relationship between leaf area index and the normalized difference vegetation index was studied. The regular pattern of LAI in deference growth stages was combined to estimate models between LAI from remote sensing data and yield of sugarcane. After optimizing the models, the best model for sugarcane yield estimation was determined. The results showed that a strong positive correlation between LAI and NDVI was obtained. A quadratic function model was the best regression model for the whole growth stage (R2=0.842 9). Statistical yield were compared with yield simulated with LAI. The relative error was 2.6%. The estimation of sugarcane yield estimates could be improved by combining remotely sensed data. This study provided the reference for estimating the regional yield of sugarcane in China.
Uncontrolled terms:Leaf Area Index - Normalized difference vegetation index - Positive correlations - Quadratic function - Regression model - Remote sensing data - Remotely sensed data - Yield
Classification code:731.1 Control Systems - 821.4 Agricultural Products - 921 Mathematics - 922.2 Mathematical Statistics
DOI:10.6041/j.issn.1000-1298.2013.05.039
Database:Compendex
46. Accession number:20132416422587
Title:Effects analysis of solidity on aerodynamic performance of straight-bladed vertical axis wind turbine
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:169-174 168
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Solidity is a significant design parameter for straight-bladed vertical axis wind turbine (S-VAWT) which has great impacts on aerodynamic performance. Mechanical models at local flow field were built to obtain the relationship between solidity and aerodynamic performance. Numerical investigations were implemented for the dynamic mechanical properties of blade, and efforts were devoted into the influences of radius, chord length and blade number on power coefficient. Experimental investigations were conducted to verify the accuracy and reliability of calculation results. From the results, it was concluded that, self-starting performance at low tip speed ratio was improved by increasing solidity, while the effective region of tip speed ratio to generate high power become smaller. Power coefficient of two and four supporting arms was almost the same when solidity was 0.628, but power output of four was more stable. Parameters of solidity played different role in contribution to power coefficient. Chord length had great effects on increasing the peak of power coefficient, while the blade number will reduce the power coefficient.
Number of references:13
Main heading:Wind turbines
Controlled terms:Aerodynamics - Mechanical properties - Well pumps
Uncontrolled terms:Aero-dynamic performance - Mechanical model - Power coefficients - Solidity - Vertical axis wind turbines
Classification code:446.1 Water Supply Systems - 615.8 Wind Power (Before 1993, use code 611 ) - 651.1 Aerodynamics, General - 951 Materials Science
DOI:10.6041/j.issn.1000-1298.2013.05.030
Database:Compendex
47. Accession number:20132416422606
Title:Hobbing process strategy for non-circular helical gears and performance analyses for functional models
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:281-287
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:The application of non-circular helical gears has been restricted to its manufacturing techniques. To realize their hobbing process, based on the strategy of a five-axle linkage, two basic mathematical models of the schemes of work piece extra rotation or hob extra rotation were deduced according to the kinematic principle. The models were simplified based on the algorithms of the equal arc length or equal rotate angle or equal polar angle, which composed the six implementing schemes and functional models. The models obtained were analyzed about the dynamic property of the five synchronal axes, including both their velocities or angular velocities and their accelerations or angular accelerations, by using Matlab. Finally, the two optimization models that equal arc length & work piece extra rotation and equal arc length & hob extra rotation with high accuracy and efficiency were obtained, which have highly dynamic comprehensive performance. The models were demonstrated to be valid by hobbing testing, and the results between the testing of tooth flanks and computer simulations were in good agreement.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:7-12
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Opening and closing process of high pressure common rail injector are affected directly by dynamic response characteristics of solenoid valve. In order to research the dynamic response characteristics of solenoid valve, experimental investigation was first conducted on the drive current and the power source voltage. Relationships between flux linkage and drive current of solenoid valve under different air gaps were acquired from the experimental results according to the principle of drive circuit. Electromagnetic model of the solenoid valve was built based on the relationships acquired. Then dynamic model of armature was built according to the working principle of solenoid valve. Finally, electromechanical model of the solenoid valve consisting of electromagnetic model and dynamic model was built and simulated in Matlab/Simulink. Special experiment was designed to verify the electromechanical model. Simulation and experiment results showed a good agreement with each other.
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:101-107
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Effect of the sodium adsorption ratio (SAR) and salt concentration of irrigated water on soil water infiltration and salt-water distribution in wetted soil volume under negative hydraulic head were analyzed by laboratory experiments. Results indicated that the relationships between each next parameter and time, maximal horizontal wetted distance (X), maximal vertical wetted distance (Z), and accumulated infiltration (I) were a power function. X, Z and I increased with the increasing of salt concentration and decreasing of SAR. The distribution of water content and electric conductivity in wetted soil volume could be described as a series of concentric ellipsoid, and had the linear relationship with the square of semi-axis of ellipse (A2). With the increasing of A, water content decreased and electric conductivity increased in wetted soil volume. With the increasing of SAR, average soil water content decreased and average electric conductivity increased under certain salt concentration. Salt concentration had no significant impact on average soil water content and average electric conductivity under certain SAR.
Number of references:16
Main heading:Infiltration
Controlled terms:Electric conductivity - Electric conductivity measurement - Soil moisture - Water quality - Water supply systems - Wetting
Uncontrolled terms:Distribution of water - Laboratory experiments - Linear relationships - Salt concentration - Salt-water distribution - Sodium adsorption ratio - Soil volume - Soil water content
Classification code:446.1 Water Supply Systems - 453.2 Water Pollution Control - 483.1 Soils and Soil Mechanics - 701.1 Electricity: Basic Concepts and Phenomena - 931.2 Physical Properties of Gases, Liquids and Solids - 942.2 Electric Variables Measurements
DOI:10.6041/j.issn.1000-1298.2013.05.019
Database:Compendex
50. Accession number:20132416422607
Title:Dynamic characteristic optimization of feed system based on kriging metamodel
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:288-293
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:A dynamic characteristic optimization method of feed system based on improved Kriging metamodel was proposed. On the foundation of dynamic model derivation of screw-nut assembly and accurate multi-flexible body dynamic model of feed drive system, the dynamic characteristic of feed system was optimized by taking the Kriging metamodel based on the trust parameters update with the assessment of tool motion (maximum ratio of vibration acceleration), which adopted the column as the design object under the condition of assembly. The optimization result showed that both the structure of column and dynamic performance of feed system from motor to tool were improved.
Number of references:24
Main heading:Optimization
Controlled terms:Dynamic models - Machine tools
Uncontrolled terms:Dynamic characteristics - Dynamic performance - Feed drive systems - Feed systems - Kriging meta models - Meta model - Optimization method - Vibration acceleration
Source title:Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery
Abbreviated source title:Nongye Jixie Xuebao
Volume::44
Issue:5
Issue date:May 2013
Publication year:2013
Pages:31-34
Language:Chinese
ISSN:10001298
CODEN:NUYCA3
Document type:Journal article (JA)
Publisher:Chinese Society of Agricultural Machinery, No. 1 Beishatan Deshengmen Wai, Beijing, 100083, China
Abstract:Combustion experiments of CH4, H2 and CO were carried out in a spark-ignition engine under 1 500 r/min engine speed, and the combustion and emission characteristics were analyzed. The results showed that H2 had the fastest burning velocity, the highest thermal efficiency and the lowest NOx emission. Comparing with CO, CH4 had higher thermal efficiency, lower NOx emission and poorer lean burn ability. In practical application, it had potential to improve lean burn limit and thermal efficiency of biogas by mixing with H2.