safe interval的意思|示意

Compared with the old signal system, the (signal system of) quasi-moving block shortens the safe distance of inter-train tracking interval and improves railway passing capability.

准移动闭塞信号系统研究的追踪列车间的安全间隔距离与旧的信号系统下相比较短，缩短了列车的追踪间隔时间，有利于提高铁路通过能力。

Conclusion: Chaihu injection was safe and feasible when used suitable interval and frequency to dropping nose.

结论：柴胡注射液采用适宜的给药间隔和给药次数滴鼻是安全、可行的。

The questionnaires were distributed to 668 families randomly in rural areas. The questions involve in the categories of the pesticides and frequencies of use and safe interval period and so on.

随机抽取668名农户进行问卷调查，内容涉及施用农药的种类、频次、施药安全间隔期等。