针对油茶果机械化采摘漏采率高、损伤率大的问题,设计了一款摇枝式油茶果采摘机.根据摇枝式采摘工作原理,完成了关键部件的结构设计,计算分析了采摘头夹持油茶枝的夹持力,对油茶枝和油茶果振动过程进行力学分析,建立力学方程并求解.结果 表明,夹持油茶枝时最大压力为2 826 N,振动对树枝产生的径向力约为57.5 N、法向力约为78.2 N,夹持和振动都不会对枝条造成损伤.为保证采摘机安全性,对横梁架进行了静力学分析,经计算其弯曲变形为0.000 5 mm,远小于最大许用弯曲挠度.设计了四因素三水平正交试验,结果表明,最佳作业参数组合为:采摘装置的采摘时间10s、电机输出频率35 Hz、采摘头的振幅5 cm及采摘爪的夹持位置(夹持油茶枝的夹持中心到油茶树冠层距离)10 ～ 20 cm,此时油茶果采净率为95.2％,花苞损伤率为17.2％.对摇枝式油茶果采摘机进行了田间试验,对枝条的损伤基本符合采摘要求.

Four-year-old transplanted Pinus tabulaeformis seedlings were grown in pots under the treatment of three different levels of natural light intensity,soil moisture content and seedling water content.The root activity of transplanted P.tabulaeformis seedlings under the interaction of three factors was studied.The results showed that the root activity of transplanted P.tabulaeformis seedlings was reduced gradually with the decrease of natural light intensity and seedling water content and the increase of soil moisture content.The root activity of transplanted P.tabulaeformis seedlings under natural light was significantly higher than that under shadow when seedling water content was 63% or soil moisture content was 30%;when the transplanted seedlings were under one of the conditions of natural light,63% seedling water content or 30% soil moisture content,the root activity of transplanted seedlings was significantly changed with the change of other two factors;when the transplanted seedlings were under the natural light intensity and 53% natural light intensity,or 30% and 50% soil moisture content,the root activity was reduced with the seedling water loss.