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

The corn planting model of full straw returning and no-tillage sowing techniques was used in the northeastern part of China. Due to the thick and abundant maize straws, limited the quality and efficiency of sowing operations and reduced crop yield, the concave disk row cleaners with star-tooth capable of efficient straw cleaning in whole straw mulching fields were designed. The kinematic pattern of straw particles at surface of disc row cleaner during the operation was clarified through the use of theoretical analysis, the main structural parameters affecting the operational quality of the row cleaners were clarified, and the range of values of each parameter were determined. Combined with rotational orthogonal test design and EDEM discrete element simulation technology, the optimal structural parameter combination of the row cleaner was achieved. The performance of the row cleaners was verified by field comparison test. The results showed that the main structural parameters affecting the performance of the device were radius of gyration of the disk, projection length of disk camber and radius of curvature. When the radius of gyration of the disk was 152.5mm, the projection length of disk camber was 50.9mm,and the radius of curvature was 160mm, the working performance of the row cleaners was the best, and the straw cleaning rate and working resistance were 92.2% and 142.6N, respectively. The working performance of the row cleaners was better than that of the plane row cleaners, and the operation quality was stable, which satisfied the agronomic and technical requirements of no-till planting.