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

Corn has become the first major crop in place of rice and wheat in recent years, thereby significantly influencing the lives of people given the increase in production of corn. Corn snapping roller is the main component of a corn harvesting machine and exerts a crucial effect on the quality of corn harvest. Aiming at the problems of serious grains gnawing and large loss of falling grains in the operation of vertical and horizontal roll corn harvester, a theoretical model of maize excitation heading suitable for mechanized harvesting was established under the condition of separation of ear and stalk of maize under the guidance of excitation theory. Under the guidance of the model, the shape structure and configuration of the picking roll suitable for the corn excitation movement were constructed and optimized, and the corresponding excitation heading testbed was developed. Box-Behnken experimental design method was used to study the effects of key parameters such as edge number, amplitude and rotation speed of excitation picking roll on grain loss rate and gnawing rate during ear picking. The regression equation between experimental factors and inspection indexes was established, and the corresponding response surface was generated. The results showed that the number of edges, the amplitude and the rotation speed of the picking roll had significant effects on the grain loss rate and the gnawing rate during harvesting. Finally, under the guidance of the theory of nonlinear programming, the best combination of the above three experimental factors was obtained, namely, the rotation speed of the picking roll of 950r/min, the number of edges of 8, and the amplitude of 0.75cm. Under these conditions, the average loss rate of corn grains during heading process was 0.228%, and the average breakage rate of corn grains was 0.124%, which was lower than the national technical standard of corn harvesting machinery. The research result provided theoretical support for the popularization and application of this technology.