Because P and S waves travel at different but fairly constant speeds, the interval between their arrivals increases in proportion to the distance from the earthquake focus, or initial rupture point.

由于 P 波和 S 波以不同但相当恒定的速度传播，它们到达的间隔与到震源或初始破裂点的距离成比例地增加。

youdao

Normally I couldn't do that Vdp because this term would have p dV plus V dp, but we've specified the pressure is constant, so the dp part is zero.

一般情况下我不能这么写,因为这一项会包含pdV和，但是我们已经假定压强为常数，所以包含dp的部分等于零。

youdao

H We also saw that dS for constant H and p was greater than zero.

我们同样可以看到如果保持自由焓,和压强不变熵的变化dS也是大于零的。

youdao

So, the first obvious one is to take V1 to V2 first with p constant. So take this path here.

从初态到末态可以有无数种路径2,甚至像这样，我们只研究两种。

麻省理工公开课 - 热力学与动力学课程节选

p This is going to get us dH/dp constant temperature. What is this experiment?

这帮助我们理解恒温条件下的偏H偏,那么这个实验具体是什么呢？

麻省理工公开课 - 热力学与动力学课程节选

OK, so now we have the other one, p dH/dp constant temperature.

好的，现在我们来研究另一个量，在恒温条件下的偏H偏。

麻省理工公开课 - 热力学与动力学课程节选

At 8:20 p.m. on the day of the explosion the pressure data suggest there was a constant flow of sea water being pumped into the drill pipe that was displacing the heavier mud system which was the primary pressure control for the well.

WSJ: The Oil Disaster Is About Human, Not System, Failure