dS/dV And that, now, we know must equal dS/dV, with a positive sign. At constant temperature.

我们知道这个等于恒定温度下的，符号为正。

麻省理工公开课 - 热力学与动力学课程节选

In other words, T surrounding dS has to be greater than zero, and of course temperature is always positive.

换句话说这就意味着，环境温度T乘以dS必须大于零，当然环境温度T是正的。

麻省理工公开课 - 热力学与动力学课程节选

Above some temperature is going to be positive, below some temperature is going to be negative.

低于这一温度它是负数，我们一般忽略这些高阶项。

麻省理工公开课 - 热力学与动力学课程节选