the total amount of the work that we can get out is just given by the area inside this curve.

能够输出的功就是,我们可以得出来,曲线所包围的面积。

麻省理工公开课 - 热力学与动力学课程节选

You couldn't just run something successfully in a cycle and get work out of it, using the heat from the hot reservoir, without also converting some of the heat that came in to heat that would flow into a cold reservoir.

如果一样东西在循环工作过程中,只有热从高温热源中流出，而没有热流入低温热源，那么此过程,不可能对外做功,不可能把所有热。

麻省理工公开课 - 热力学与动力学课程节选