dT/dp is mu JT. So for a real gas like air, this is a positive number. It's not zero.

所以对于像空气这样的真实气体，这是一个正数，不等于零。

麻省理工公开课 - 热力学与动力学课程节选

I remember walking around the square during mu lunch hour, walking faster and faster trying to get around, four or five different classes of kids, all of whom were verbally abusive to me, and feeling there was no place that I belong there was no place that I felt connected to other kids.

我记得我在广场周围走着,那会儿正是午餐时间，我越走越快,想翘过接下来的四五个不同的班级,班上的孩子都对我恶言相向过，我觉得自己无处可去,我找不到自己和其他孩子相联系的地方。

麻省理工公开课 - 媒体、教育、市场课程节选

JT dT/dp is positive, well that's mu JT.

偏T偏p就是μ

麻省理工公开课 - 热力学与动力学课程节选