So this isn't the most useful form that we can have, but what we'll see shortly is that from this, we can then derive further criteria for essentially any set of variables or any set of external constraints, like constant temperature or pressure or volume and so forth that we might set.

所以这不是我们所能得到的最有用的形式，但是我们会很快看到，我们能够进一步推导出包含任意变量,或者任意约束的自发过程判断标准，比如说恒定的温度，压强,体积或者其他我们能够给出的约束。

麻省理工公开课 - 热力学与动力学课程节选

So that's going to results in an expansion where the new volume new temperature new pressure and an external pressure, p2 which is p2 which is a smaller pressure.

这样经过膨胀,到达了,状态为V2，T2，p2的末态，外界压强也降低到。

麻省理工公开课 - 热力学与动力学课程节选