So the force that you're pushing down on here is the external pressure times the area.

或者压缩功的概念,在活塞上施加压力。

麻省理工公开课 - 热力学与动力学课程节选

Your compressing it really fast, all right, so you're changing the pressure.

你把它压缩的非常快，好的，那么你改变了压力。

麻省理工公开课 - 热力学与动力学课程节选

Or in many kinds of gas refrigerators where you push a gas through a nozzle close to room temperature, what you find is that the gas coming out on the other side under lower pressure is cooler than the gas that went through on the other side.

或者在很多种压缩气体式冰箱中,你让气体通过接近室温的管口,你会发现从压力低的一边,出来的气体比通过,另一边的气体更冷,真正的冰箱实际上通过。

麻省理工公开课 - 热力学与动力学课程节选