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 uniformity of current corn wide and delta-row narrow planting mode under high speed (10~16 km/h) operation of precision seed-metering device and the delta-row sowing effect of lack of targeted evaluation indexes of the problem, a double-cavity double-disc staggered synchronous rotary pneumatic high-speed precision planter was designed and the zigzag qualification index of the “delta-row” evaluation of the effect was put forward. The effect of “delta-row” was evaluated. The basic structure and working principle of the seed discharger were described, the key structural parameters of the seed discharging disc were determined by theoretical analysis and numerical simulation, the mechanical model of the seed charging process was established, and it was determined that the charging height, operating speed, and the positive pressure value of the air cavity were the main factors affecting the performance of the seed discharger. The three-factor, five-level Central Composite test was conducted with seed filling height, operating speed, air cavity pressure value as the influencing factors, and the “delta-row” qualification index and the maize seeds, namely “WAYO 187”, “DECA C2235”,，“AOYO RED A9” and “FARLEY 1439”, were used to conduct the sowing test of the optimal parameter combinations of seeders. The results showed that the optimal parameter combination of the seed dispenser was 40.598 mm of seed filling height, 3.763 kPa of positive air cavity pressure and 11.358 km/h of operation speed, and the delta-row qualification index W of the parameter combination was 94% and the coefficient of variation of the two-row spacing W1 was 6.11%, which was in line with the optimization results, and it can satisfy the requirements of high-speed precision sowing of maize in the delta-row dense-planting mode.