固定信号 meaning in English

fixed signal
permanent signal

Fixed , vertical road traffic signs - part 1 : fixed signs
固定立式道路交通信号.第1部分:固定信号
Railway transport equipment . signalling equipment for rail vehicles . fixed signalling . electric signals . arrangement and characteristics
铁路运输设备.铁路车辆信号设备.固定信号装置.电信号.配置和特性
The relation between the photo - voltage , photocurrent of photocell and light intensity measured by photocell is discussed . it can be explained by light - induced scattering that the sppc wave is diffracted in the course of being produced . we utilize cu : knsbn crystal to correct a distorted picture because of its super sppc characteristic
针对掺杂量为1000ppm的cr ： sbn晶体，研究了不同的信号光、泵浦光强度比对四波混频相位共轭反射率的影响，并在固定信号光、泵浦光强度的情况下，研究了不同光束夹角对相位共轭反射率的影响。