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

A multi-helical rod pelleted Cistanchis precision seed metering device was designed to address the problems of current imperfect induction mechanism of Cistanche which requires multiple rounds of replanting, as well as the problems of narrow dispersal surface and poor uniformity within the dispersal surface of Cistanchia seed metering device. A helical rod mechanism was used to move the seed along the helical and the dispersal surface which was expanded by installing ten helical rods.The kinetic model of pelleted Cistanche seeds and helical rod was established, and the key structural parameters of the helical rods were theoretically analyzed and determined. Based on the agronomy of Cistanchis cultivation and the parameters of pelletised Cistanchis seeds of specific specifications, the theoretical seeding rate was calculated. The effects of key parameters such as pitch, depth and rotational speed on seeding performance were analyzed by using the discrete element method. The model of pelleted Cistanchis seed metering device was constructed by EDEM. The variation coefficients of seeding uniformity and seeding capacity were used as the test indexes, and the ranges of pitch, depth and rotational speed were determined through a single factor test. The test results showed that the optimal parameter range of pitch was 15~20 mm, the optimal parameter range of thread depth was 7~9 mm, and the optimal range of rotational speed was 60~100 r/min. The BoxBehnken central combination test of three-factor and three-level was carried out, and a multiple regression model was established. The variance and response surface analyses were performed by Design-Expert software, the helical rod structure and working parameters were obtained through objective optimization. The optimal pitch of the helical rod was 17.77 mm, the depth was 7.81 mm,，and the rotational speed was 83.32 r/min. The bench test showed that the variation coefficient of seeding uniformity and seeding capacity were 3.75% and 5.33%, respectively. The design met the agronomic requirements of seed dispersal under the imperfect induction mechanism of pelleted Cistanche, and provided a reference for research programme of seed metering device to improve the uniformity of seed dispersal in the dispersal surface of pelleted Cistanche.