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

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

And, if this quantity is less than zero, the bonding is favorable.

如果这个数小于，能够形成键。

麻省理工公开课 - 固态化学导论课程节选

And, so you propose that there is no, that this derivative is zero, and that the internal energy is given simply by this quantity.

你认为这是零，这个微分是零，内能仅仅由,这个简单的量决定。

麻省理工公开课 - 热力学与动力学课程节选

And that implies that since the quantity we want is given by this quantity, which is zero times a constant, the quantity we want is also zero.

因为我们需要的量,是由这个量乘以一个常数，因为这个量是零，因此我们需要的量也是零。

麻省理工公开课 - 热力学与动力学课程节选

That great deal of specificity implies that heat is also path-dependent and again we have the convention that if heat is added to the system, the quantity is greater than zero.

热也是与路径有关的,根据通常的习惯,如果我们对系统加热，其符号取为正。

麻省理工公开课 - 热力学与动力学课程节选

And so now we have this quantity, p times v bar, and the limit of p goes to zero is equal to a constant times the temperature.

不仅仅对氢气或氮气适用，在p趋于0的极限下,它适用于任何气体。

麻省理工公开课 - 热力学与动力学课程节选

We have an interpolation scheme between zero and 273.16 with two values for this quantity, and we have a linear interpolation that defines our temperature scale, our Kelvin temperature scale.

的两个值做线性插值,就得到了开尔文温标,直线的斜率等于水的三相点,也就是这一点处的f的值,再除以273。16，这是这条直线的斜率，这个量，f在三相点处的值。

麻省理工公开课 - 热力学与动力学课程节选