Heat capacity relates the amount of heat that you add to the system to the change in temperature, and this is the relationship.

热容联系起给系统提供的,热量和温度的变化，关系式是这样的：

麻省理工公开课 - 热力学与动力学课程节选

So we immediately get du at constant S and V is less than zero.

这样我们马上就得到以下结论：,在等熵，等容条件下dU必须小于零。

麻省理工公开课 - 热力学与动力学课程节选