The communication abbacy that assured an earth station thereby but by other 3 grounds stage repeat coverage, assure the dependability of communication.

从而保证了一个地面站的通可由其他三个地面台重复覆盖，保证通的可性。

When this method is applied to the spiral bevel gears of an airplane engine, the results show that it is more reasonable than TCA and the precontrol method.

提出了一种在初始设计阶段就可保证弧具有预期加载接触性能的主动设计方法，并将其用于某航空发动机中央传动弧的面综合。