This paper puts forward some methods of solving mechanical efficiency of tackle-block hoping to help students break through difficulties .

本文 就 有关 滑轮 组机械效率的解题提出一些解决方法，有助于帮助学生突破难点。

The problem about mechanical efficiency of tackle-block is the key point in junior high school mechanics and also the difficult point .

滑轮 组机械效率问题是初中力学中的重点，也是初中力学 解题的难点。

For work feature of tackle-block mechanism compensating amplitude of variation on machinery lifting using traditional mono-objective optimization and numerical solution on design of the mechanism the optimum result can not satisfy the requirement of economy and stability in the meantime and is not accurate enough .

由于补偿 滑轮 组 变幅机构在起重机械中工作特点的需要，传统的单目标优化方法和优化数值解法，在同时满足设计的经济性与稳定性以及优化解的精度 方面 存在不足。