一带电粒子，尤指一电子，由导电材料在高温时发射出。

An electrically charged particle, especially an electron, emitted by a conducting material at high temperatures.

youdao

一带电粒子，尤指一电子，由导电材料在高温时发射出。

An electrically charged particle, especially an electron, emitted by a conducting material at high temperatures.

youdao