But, if you look more carefully, you will find that this is a blend of three different forms of carbon.

但是，如果你们再认真一点，会发现,它是三种形式的碳的混合物。

麻省理工公开课 - 固态化学导论课程节选

So, using those, now, what happens if we take the second derivative of A, the mixed derivative, partial with respect to T and the partial with respect to V.

如果我取A的二阶导数,混合导数，对T偏微分,再对V偏微分。

麻省理工公开课 - 热力学与动力学课程节选