That's why we always talk about irreversible expansion, because it's easy to write down an irreversible expansion.

这就是我们总是,讨论不可逆膨胀的原因，因为它,比较容易描述。

麻省理工公开课 - 热力学与动力学课程节选

So anyway, when we talk about periodic trends, it doesn't always match up.

无论如何，当我们讨论元素周期律时，要知道它并不是总能与实际情况相符。

麻省理工公开课 - 化学原理课程节选

So I said before when we were talking about single atoms, we always define the zero energy as when an electron was actually ejected, but now, when we talk about chemical reactions taking place, it's very, very rare that we're actually going to be talking about anything that gets to this point here.

我之前说过，当我们讨论单个原子的时候，我们总是把零点能,定在电子被发射出去以后，但是现在，当我们讨论化学反应发生的时候，非常非常罕见出现，确实达到,这种程度的情况。

麻省理工公开课 - 化学原理课程节选