The prior various crossing adopt electric bells or ordinary transistor audible devices, and have the problems of difficult volume adjustment, large noise disturbance, etc.
目前各类道口采用的电铃及一般晶体管音响装置，存在着音量不易调整，噪音干扰大等问题。
2
Experimenting repeatedly, by our limited equipments we provided the qualified photomask for the study of 3dg460 microwave low-noisetransistor.
经过反复实验，在现有设备条件下，为3dg460微波低噪声晶体管的研制提供了合格光刻版。
3
In chapter six, the application of higher order statistics in detection low-frequency noise of transistor is discussed.