If you want to have an infinitestimally small change, you end up writing dh is dq sub p.

这是对于有限的变化而言的,如果是一个无限小的变化。

麻省理工公开课 - 热力学与动力学课程节选

It's tabulated in books, and this we can measure p in the experiment. Delta p here is the change in pressure from the left side to the right side, and we can put a thermometer, measure the temperature before the experiment and measure the temperature after the experiment.

这列在书上，这个量我们在,实验中也可以测量，在这里Δ,是从左边到右边的压强变化，我们可以放一个温度计，去测量实验前的温度,再去测量试验后的温度。

麻省理工公开课 - 热力学与动力学课程节选

v We don't know what it is yet. In order to change this from a p to a V, you have to use the chain rule. So let's use the chain rule.

为了把这里的p变成,我们需要利用链式法则,好，让我们使用链式法则。

麻省理工公开课 - 热力学与动力学课程节选

We're going to change the pressure above, Pext right now there's a p external, which is equal to p on the inside.

来改变外界条件，可以改变外界的压强，它将与气体压强p相等。

麻省理工公开课 - 热力学与动力学课程节选

So if you're going to turn the crank v on the math correctly, you're going Cv to have to change this p into a V somehow.

所以如果哟啊正确地推导,我们需要把这个p变成,因为从数学上说这不是。

麻省理工公开课 - 热力学与动力学课程节选