And the temperature scale that turns out to be well-defined and ends up giving us the concept of an absolute zero is the ideal gas thermometer.

比如理想气体温标,它有精确的定义,并能引出绝对零度的概念,今天我们就先来谈谈它。

麻省理工公开课 - 热力学与动力学课程节选

B=0 There's going to be some temperature where B is equal to zero. In that case, your gas is going to look awfully like an ideal gas.

在某个温度,这时，实际气体的表现，十分接近理想气体,高于这一温度它是正的。

麻省理工公开课 - 热力学与动力学课程节选

This quantity is exactly zero for an ideal gas and we'll discover why eventually it has to do with what we mean by an ideal gas it turns out.

对理想气体它是零,这点我们接下来会知道是,为什么，这与为什么我们叫它理想气体有关。

麻省理工公开课 - 热力学与动力学课程节选

So this is a very small number and for ideal gases, eta J is equal to zero.

这是一个，很小的数。

麻省理工公开课 - 热力学与动力学课程节选

And if that's equal to zero, that means that the Joule-Thomson coefficient for an ideal gas is also equal to zero. We're going to actually prove this later in the course.

说明理想气体的,焦耳-汤姆逊系数也等于0。,详细的证明过程,会在以后的课上给出。

麻省理工公开课 - 热力学与动力学课程节选

So for an ideal gas then, dH/dp under 0 constant temperature, that has to be equal to zero.

所以对于理想气体,偏H偏p在恒温下，等于。

麻省理工公开课 - 热力学与动力学课程节选

And we saw that, you saw that the Joule coefficient for an ideal gas was zero.

我们会发现，你们也会发现,理想气体的焦耳系数是零。

麻省理工公开课 - 热力学与动力学课程节选

dq It's an ideal gas in adiabatic expansion 0 dq is equal to zero.

说明,等于。

麻省理工公开课 - 热力学与动力学课程节选

The atoms or molecules in the gas don't know that there are other atoms and molecules in the gas, and then you end up with this universal property. All right, so gases that have this universal property, even when the pressure is not zero, those are the ideal gases.

可以忽略,这样就得到了理想气体的性质,在有限压强下,依然能保持这些性质的气体，被称为理想气体，本课中我们把大部分气体，都作为理想气体来处理。

麻省理工公开课 - 热力学与动力学课程节选

but right now you're going to have to take it for granted. So, if the Joule-Thomson coefficient is equal to zero, just like we wrote, du = Cv dT du = Cv dT for an ideal gas, we're going to dH = Cp dT have dH = Cp dT for an ideal gas as well.

但是现在请你们应该把它看成理所当然的,所以，如果焦耳-汤姆逊系数等于零,就像我们写的，对于理想气体,我们也可以得到对于理想气体。

麻省理工公开课 - 热力学与动力学课程节选

Right now we told you Joule did all these experiments and he found out that for an ideal gas, that the limit in and ideal gas 0 case was that the eta J was equal to zero.

现在我告诉你们焦耳,做了所有这些实验,他发现对于理想气体,在极限情况下理想气体的ηJ等于。

麻省理工公开课 - 热力学与动力学课程节选

Now, for an ideal gas, du/dV under =0 constant temperature is equal to zero.

对于理想气体，温度一定,时偏U偏V等于零。

麻省理工公开课 - 热力学与动力学课程节选

du/dV under constant temperature was equal to zero for an ideal gas. And by analogy, we expect the same thing to be true here, because enthalpy and energy have all this analogy going on here. So let's look at an ideal gas.

偏U偏V在恒温下等于零,可以类比，我们希望在这里也一样，因为焓和能量有很强的类比性，让我们看看理想气体,【理想气体】

麻省理工公开课 - 热力学与动力学课程节选