So for an ideal gas then, dH/dp under 0 constant temperature, that has to be equal to zero.

所以对于理想气体,偏H偏p在恒温下，等于。

麻省理工公开课 - 热力学与动力学课程节选

First, free velocity, constant velocity can be obtained for free without doing anything.

首先,速度是无偿的,恒定速度不需外力作用就能无偿获得

耶鲁公开课 - 基础物理课程节选

We can also do a similar thing, and I'll keep my distance from the board, but we can instead be holding x constant, for example, putting x to be equal to zero, and then all we're doing is considering the electric field as a function of t.

我们也可以做类似的事情,把x固定为一个常数,例如令x等于零，然后,考虑电场作为时间的函数,这种情况下，我们划掉。

麻省理工公开课 - 化学原理课程节选