And in something like a consumer internet company like Facebook, that constant real time interaction and experimentation is something that the very best entrepreneurs do.

像脸谱网这样的,用户导向型的互联网公司，即时交流，不断试验,是企业家最佳的生财之道。

斯坦福公开课 - 扎克伯格谈Facebook创业过程课程节选

If you have a real gas and you write du is Cv dT and your path is not a constant volume path, then you are making a mistake. But for an ideal gas, you can always write this. And this turns out to be very useful to remember.

对于真实气体，如果其变化过程,不是恒容的，du=Cv*dT就不成立，但对于理想气体,这条规则永远成立,这一点非常有用，请记住。

麻省理工公开课 - 热力学与动力学课程节选