Another reason is that a small change in temperature can mean the difference between snow and rain.

VOA: special.2010.01.05

Heat capacity relates the amount of heat that you add to the system to the change in temperature, and this is the relationship.

热容联系起给系统提供的,热量和温度的变化，关系式是这样的：

麻省理工公开课 - 热力学与动力学课程节选

That's the property that's going to give us the change in temperature.

这就是能给我们,温标定义的物质特性。

麻省理工公开课 - 热力学与动力学课程节选

There is a change in temperature, right?

温度会改变，对吧？

麻省理工公开课 - 热力学与动力学课程节选

If you double everything in the system, the temperature is not going to change, it's not going to double.

如果你把系统中所有的东西增加一倍，温度是不会变的，它不会跟着增加一倍。

麻省理工公开课 - 热力学与动力学课程节选

Now, the coefficient that relates the amount of heat in to the temperature change is obviously going to be different for these two cases.

在这两个例子中,很显然联系热量和温度变化的系数,是不一样的。

麻省理工公开课 - 热力学与动力学课程节选

We looked at pressure change before, actually, in discussing the third law, the fact that the entropy goes to zero as the absolute temperature goes to zero for a pure,perfect crystal.

在讨论热力学第三定律的时候，我们讨论过压强变化,即对于纯净的完美晶体,随着温度下降到绝对零度熵也变成零。

麻省理工公开课 - 热力学与动力学课程节选

In other words, how much does the temperature of the whole thing change when you put an ordinary amount of material in there and run a reaction, right. Well, what do you do?

当你放入通常数量的材料,并进行反应时,整个装置的温度,改变有多少，你要做什么？

麻省理工公开课 - 热力学与动力学课程节选

So we don't really need to put in a certain amount of heat and change the temperature of the products and the calorimeter and so on.

所以我们实际上并不需要输入,一定的热量，改变生成物,和量热计的温度之类。

麻省理工公开课 - 热力学与动力学课程节选

It only cares what temperature is. If temperature is constant, there's no change in energy.

如果温度是常数,能量就没有变化，对理想气体。

麻省理工公开课 - 热力学与动力学课程节选

Now let's change the pressure and temperature and sweep through a whole range of pressures and temperatures and measure the volume in every one of them.

然后改变气压和温度,并且让气压和温度,取便所有可能的数值,测量相应的体积。

麻省理工公开课 - 热力学与动力学课程节选

It's tabulated in books, and this we can measure p in the experiment. Delta p here is the change in pressure from the left side to the right side, and we can put a thermometer, measure the temperature before the experiment and measure the temperature after the experiment.

这列在书上，这个量我们在,实验中也可以测量，在这里Δ,是从左边到右边的压强变化，我们可以放一个温度计，去测量实验前的温度,再去测量试验后的温度。

麻省理工公开课 - 热力学与动力学课程节选

It's just how much heat is involved when we change the temperature. Now, the products have some heat capacity associated with them right, it takes a certain amount of heat if we make their temperature change, to either put it in or take it away, depending on which direction the temperature is changing.

问题就是当我们改变温度时,有多少热量发生了转移,生成物具有一定的热容,如果我们改变,它们的温度，就要输入或,提取一定的热量,这取决于温度改变的方向。

麻省理工公开课 - 热力学与动力学课程节选