If you have a quantity which is constant over any closed path, that quantity is a thermodynamics state function.

如果有一个物理量,对任何闭合回路积分是常数，这个物理量就是一个热力学态函数。

麻省理工公开课 - 热力学与动力学课程节选

All right, so I need to tell you the path, when I go from one state to the other.

好，当我从一个状态过渡到另一个状态时，我需要告诉你们路径。

麻省理工公开课 - 热力学与动力学课程节选

The amount of work you've put in to get here depends on the path. It's not a function of state.

这些量就能,决定系统的状态了。

麻省理工公开课 - 热力学与动力学课程节选

So the system will not be described by a single state variable during the path.

因此系统将不能被,路径上的单一状态变量描述。

麻省理工公开课 - 热力学与动力学课程节选

Now remember, we went through before how it's a state function but to calculate it, you'd need to find a reversible path, along which you can figure this out.

请记住，我们不需要知道它是怎样的一个态函数,只计算就可以了，你需要找到一条可逆路径，沿着这条路径就能算得这个结果。

麻省理工公开课 - 热力学与动力学课程节选