OK, for most gases, T inversion is much 300K greater than 300 degrees Kelvin. Much greater than room temperature.

好，对大多数气体,转变温度都高于,比室温高很多。

麻省理工公开课 - 热力学与动力学课程节选

But now, so this is where the refrigeration comes in. So if you take a gas, and you're below the inversion temperature and you make it go through this irreversible process, the gas comes out colder from that side than that side.

这就是冰箱的原理,如果在低于转变温度,的情况下我们将气体经过,这个不可逆过程,气体出来的温度将比这边低。

麻省理工公开课 - 热力学与动力学课程节选

We use a liquid helium. And so in order to make a liquid helium, you can't take helium at room temperature and do this, because if you did, you would just heat it up, because the room temperature is above the inversion temperature, so Joule-Thomson would heat up the helium.

为了得到液氦,不能再常温,做这个实验,否则就是加热氦气，因为室温高于它的转变温度,所以焦耳-汤姆孙，实验会加热氦气。

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Now if you're at the temperature which is b higher than the inversion temperature, in that case here, a over RT is small compared to b, and this is going to turn out to be negative.

T>Tinv】,这时a/bR小于,结果是负数，因此如果温度。

麻省理工公开课 - 热力学与动力学课程节选

So in this experiment here, delta p is less than zero. You need to have this whole thing greater than zero. So delta T is less than zero as well. So if you're below the inversion temperature and you do the Joule-Thomson experiment, you're going to end up with something that's colder on this side than that side.

所以在这个实验中，Δp小于零,这全部都大于零,因此ΔT也小于零,所以如果在低于转变,温度的情况下做焦耳-汤姆孙实验,最后的结果是,这边的温度比这边低。

麻省理工公开课 - 热力学与动力学课程节选