So that's a big help. And equilibrium happens when there isn't any possible change of state that would satisfy this.

这个非常方便，当所有的变化,都无法满足这个公式的时候,系统就达到了平衡。

麻省理工公开课 - 热力学与动力学课程节选

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