The Joule experiment was a constant energy experiment, right. Here we're going to have to find a constant enthalpy experiment, and that is going to be the Joule-Thomson experiment. That's going to extract out a physical meaning to this derivative here.

非常像焦耳实验,焦耳实验是一个能量恒定的实验,我们这里要做的是，找到一个焓不变的实验,也就是焦耳-汤姆逊实验,这个实验可以把这里的微分式形象化。

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

So we're talking about an experiment when you generate-- Each experiment generates both an x and a y observation and we know when x is high, y also tends to be high, or whether it's the other way around.

这里说的是由试验产生的,每一次试验可以获得一组x与y的观察值,当x值大的时候,y值可能也大,或者相反

耶鲁公开课 - 金融市场课程节选