ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

Aiming at the need of precision rice hill-direct-seeding, the precision hill-direct-seeding seed-metering device for rice was designed with the rebound dipper, the work principle of seed-metering device was stated and the movement track of rice seed was analyzed in the process of seeder’s dropping by means of the Matlab software, the evaluation test of the seed-metering device was conducted by using three kinds of rice, which were Longdao 6, Longqingdao 2 and Longqingdao 3, and rotational quadratic orthogonal experiments was carried out to further analyze the effects of qualified rate, reseeding rate and missing rate on seeding performance, including rotation speed of spinning disk and height of hopper. The JPS-12 detecting and experimental set of seed-metering device was selected to test sowing performances. Experimental data was analyzed by Design-Expert software so as to establish the mathematical model between the experimental factors and indexes. The result showed that the best operational parameter combination was that as the rotation speed of spinning disk was 29.34r/min and height of seed hopper was 60mm, the qualified rate and reseeding rate of Longdao 6 were 87.23% and 9.56%, the qualified rate and reseeding rate of Longqingdao 2 were 90.86% and 6.97%, the qualified rate and reseeding rate of the Longqingdao 3 were 89.12% and 7.46%, The sowing performance can meet the requirement of precision rice hill-direct-seeding. The research provided a theoretical reference for the improvement design of precision hill-direct-seeding seed-metering device for rice.