The letters H-E-P-A represent the words High Efficiency Particulate Air.

VOA: special.2009.07.14

So if you're working with cyanide in the lab as potassium cyanide or sodium cyanide, those are what are called p h s's, it's a rating for different kinds of chemicals.

因此如果你在实验室中,需要用到氰化物，比如氰化钾或者氰化钠，这就是所谓的，“P，H，S“,这是化学药品有害程度的一个级别。

麻省理工公开课 - 化学原理课程节选

Adiabatic q equal to zero. It's also delta H 0 which is zero. The two didn't necessarily follow because remember, delta H is dq so p is only true for a reversible constant pressure process.

在这个过程中ΔH等于,绝热的所以q等于0，而ΔH也等于,这两个也不一定有因果关系,因为，记住，ΔH等于dq只有在恒压。

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