I think this was a vacuum tube system where there is no drag. 我认为这是一个真空集热管系统,其中有没有阻力。
Battery used to heat the filaments of a vacuum tube. 能够把真空管(VT)的细丝加热的电池。
An electron tube is generally used for amplification, and vacuum tube is another term for this device. 电子管通常用来放大,而真空管(VT)则是电子管的另一名称。
A vacuum tube that amplifies a flow of electrons. 能够增强电子流量的真空管(VT)。
Currently the most frequently used solar energy collection devices are mainly flat-plate collector and vacuum tube collector. 目前使用最多的太阳能收集装置主要有平板型集热器,真空管(VT)集热器两种。