I managed to find price indexes for Norway and Netherlands going back to 1890 and compared that with the U.S.

我找到了挪威和荷兰1890年的,价格指数数据,和当时的美国作比较

耶鲁公开课 - 金融市场课程节选

v du/dV under constant temperature. du/dT v under constant volume. You use the Joule expansion to find these quantities.

像偏u偏v，恒温下的偏u偏,恒容下的偏u偏,你们知道怎么运用焦耳定律。

麻省理工公开课 - 热力学与动力学课程节选

And because there is an explicit relationship between u, delta u, q and w, you can always find the easy way to derive the change in internal energy or the heat or the work.

因为Δu，q和w之间,有明确的关系，一般来说,内能或热或功的变化,易于计算。

麻省理工公开课 - 热力学与动力学课程节选