And I wanted to do it a different way which is a little bit convoluted, but it introduces the idea of a thermodynamic cycle, and it's something that we're going to use a lot in the class.

现在我将用另一种,有些复杂的办法来推导这一关系，在这一过程中引入,我们今后会常接触到的,热力学循环的概念。

麻省理工公开课 - 热力学与动力学课程节选