This is the condition for really the lion's share of chemistry, biology, and other kinds of changes we'll be concerned with.

这就是绝大部分,生物变化，化学变化，和其他变化所关心的条件。

麻省理工公开课 - 热力学与动力学课程节选

Whereas under these conditions, these quantities, if you look at free energy change, for example at constant temperature and pressure, H you can still calculate H.

但是，在这些条件下，这些物理量，如果我们考察自由能的变化,例如在恒定的温度和压强下，我们仍然可以计算。

麻省理工公开课 - 热力学与动力学课程节选

This normal weight animal like this has its whole equilibrium thrown off, its homeostasis thrown off when its dietary conditions change.

在饮食条件发生变化时,这些正常体重动物的生理平衡被打破,于是摈弃了原来的平衡饮食

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

This Is our condition for spontaneous change.

这就是自发变化的条件。

麻省理工公开课 - 热力学与动力学课程节选

And the motivation for choosing a pair like that is easy to see, if we look at our condition for spontaneous change or general condition.

我们这样选择的动机,很明显，如果考察我们所考虑的自发变化的条件,或者更一般的条件。

麻省理工公开课 - 热力学与动力学课程节选

You just change volume to pressure and basically you're looking at enthalpy under a constant -- anything that's done at a constant volume path with energy, there's the same thing happening under constant pressure path for enthalpy.

可以看到这就是把体积换成了压强,一般我们都是在一种恒定状态下,考虑焓的，任何在恒容条件下,能伴随能量变化的东西，也在恒压条件下伴随焓同样地变化,所以你可以经常。

麻省理工公开课 - 热力学与动力学课程节选

How many moles of gas are there in each case, in reactants and products? If that changes, of course you know that the pressure in there is going to change at constant volume if the amount of gas in there is changing.

在反应物和生成物中，各有多少摩尔的气体？,如果它发生了变化,当然在等体条件下，如果气体的总量,发生了变化，压强也会发生变化。

麻省理工公开课 - 热力学与动力学课程节选

That's our condition for spontaneous change.

这就是自发变化的条件。

麻省理工公开课 - 热力学与动力学课程节选

And I can calculate what happens to G under those conditions.

因为在化学反应中组分就是这样变化的,我能够计算在这些条件下G的变化。

麻省理工公开课 - 热力学与动力学课程节选