So what they do is, they're describing how these thermodynamic properties change, in terms of only state functions and state variables.

他们的作用是描述,随着状态函数和状态变量的变化，系统的热力性质如何变化。

麻省理工公开课 - 热力学与动力学课程节选

All right, so this is the heat flowing in or out of the system, and these are all functions of state.

好的，这就是系统的热量变化,这些都是态函数。

麻省理工公开课 - 热力学与动力学课程节选

are all functions of state and parameters that we can control like temperature and pressure.

公式里面的全部都是态函数,我们控制态函数的参数比如温度或者压强。

麻省理工公开课 - 热力学与动力学课程节选

Delta u, delta H, familiar state functions, q w changes in their values, q, w, heat and work.

U，△H，很熟悉的态函数，它们的值在变化；

麻省理工公开课 - 热力学与动力学课程节选

But since these are all simply state functions and quantities, this is generally true.

但是因为这些量都是态函数或者量,所以这个结果是普遍成立的。

麻省理工公开课 - 热力学与动力学课程节选

This is very different from the functions of state like pressure and temperature.

联系初末两态的整个过程,这与压强。

麻省理工公开课 - 热力学与动力学课程节选

There's no change in them, and then we also looked at some at non-state functions, work and heat, and saw that those aren't zero going around a cycle. Of course you can do work in a cyclic process, and heat can be exchanged with the environment at the same time.

它们不会有变化，然后我们研究了,一些非态函数，功和热量，并看到,沿着循环行进一周的话,它们并不是零，当然你可以在,一个循环过程中做功，而同时热量可以在系统,与外界环境之间进行交换。

麻省理工公开课 - 热力学与动力学课程节选

So now, this equation here relates three state functions together: the pressure the volume, and the temperature. Now, if you remember, we said that if you had a substance, if you knew the number of moles and two properties, you knew everything about the gas.

压强，体积和温度,大家应该还记得,我们提过，只要知道气体的摩尔数,和任意两个状态函数,就可以推导出其他的状态函数，这样，我们可以把它改写成。

麻省理工公开课 - 热力学与动力学课程节选

G Here, A and G, we've already got as functions of these easily controlled, conveniently controlled state variables.

这里，A和，我们已经把它们写成了，容易控制的状态变量的函数。

麻省理工公开课 - 热力学与动力学课程节选

And it's more dramatic if the system is a gas p T2 V2 p, T2, V2, And let's look at what happens to U these functions of state, to H to u under this transformation.

如果是气体这个系统,就更具有趣了,让我们看看H和，在这个变化中态函数会发生什么变化。

麻省理工公开课 - 热力学与动力学课程节选

Cv The only difference is it'll be Cp instead of Cv, B but there it is for pathway B. There it is for C a pathway C. So the state functions that we're familiar with are doing what we expect they ought to be doing, right? If you go around in a cycle, starting and ending at the same place the state functions have to stay the same.

是Cp而不是，这是路径,这是路径,所以我们熟悉的态函数的行为,正与我们预期的相同，对吧？,如果你沿着循环走一圈,开始和结束于同一个位置。

麻省理工公开课 - 热力学与动力学课程节选