If I look at different points in my container during that path, I'm going to have to use a different value of pressure or different value of temperature That's not an equilibrium state, and that process turns out then to be an irreversible process.

如果我要研究在路径中容器里的,不同的点，我就得在容器里不同的点上使用,不同的压强值,或不同的温度值,实际上这不是个平衡态，这个过程是,不可逆过程。

麻省理工公开课 - 热力学与动力学课程节选

And of course, in either case, w delta u is q plus w, so it's q irreversible plus w irreversible, u being a state function it's the same in either case.

当然了，在这两个过程中，Δu都等于q加，因此现在是q不可逆加w不可逆，同时u在这两个过程中都是态函数。

麻省理工公开课 - 热力学与动力学课程节选