It turns out that this quantity here, which is called eta of J the Joule free expansion parameter, is not quite zero.

这个量后来被，称作焦耳膨胀系数,其实并不等于零。

麻省理工公开课 - 热力学与动力学课程节选

This one turns out to be the heat capacity, and this one turns out to be something that we measure in the Joule-free expansion.

其实，这就是热容，这是焦耳自由膨胀实验中,我们要测量的物理量。

麻省理工公开课 - 热力学与动力学课程节选

So the Joule free expansion involves opening this valve and asking what happens when this gas moves into the other bulb or distributes between the two.

焦耳自由膨胀就是,打开阀门后的过程,气体从一个腔跑到另一个腔,并在它们之间平均分配。

麻省理工公开课 - 热力学与动力学课程节选