One of the electrodes could be heated, which would cause it to emit electrons – a process called thermionic emission.

其中一个电极可以加热，然后发射电子——这个过程称为" 热电子发射" 。

In 1904, English physicist John Ambrose Fleming developed a new electrical component called a thermionic valve, which housed two electrodes inside an airtight glass bulb - this was the first vacuum tube.

1904 年英国物理学家约翰·安布罗斯·弗莱明开发了一种全新的电子部件叫" 热电子管" ，就是在一个密封玻璃灯泡里放了 2 个电极——这是世上第一个真空管。