get back to the initial point is going to require some input from outside, like heat or extra work or extra heat or something because you've done an irreversible process.

如果要逆转它,回到初始点，就需要外界的投入，比如额外的功，额外的热量等等,因为你进行了一个不可逆过程。

麻省理工公开课 - 热力学与动力学课程节选

So w, the work is less for the irreversible process than the reversible process.

不可逆过程中系统对外界,做的功要比可逆过程时小。

麻省理工公开课 - 热力学与动力学课程节选

Wirr Minus w irreversible, this is the work which is done to the environment by the system, -Wrev minus w irreversible is always smaller than minus w reversible.

一点提示，不可逆过程中系统,对外界做的功，总是小于,之前我们。

麻省理工公开课 - 热力学与动力学课程节选