-
On the other hand, temperature, volume and pressure are variables that are much easier in the lab to keep constant.
另一方面，温度，体积和压强,在实验室中比较容易保持恒定。
-
To ask questions like how much heat is released in a chemical reaction that takes place at constant temperature.
当我们想要知道,当一个化学反应在恒定的温度下发生时,会放出多少热量时。
-
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。
-
We know how the volume and temperature vary with respect to each other at constant pressure.
知道在恒定压强下,体积如何随着温度变化。
-
State one goes to state two. Let's have constant T.
在恒定的温度下。
-
So then, just like we saw, analogous to what saw just before, dS/dp it's T dS/dp at constant T.
就像我们看到的,就像我们刚才看到的一样，结果是T乘以恒定温度下的。
-
dS/dV There's some variation, dS/dV, at constant temperature.
这里有一点变化，即恒定温度下的。
-
If I'm working under conditions of constant temperature and volume, that's very useful.
如果在恒定的温度和体积下,进行一个过程，这是非常方便的。
-
You're running, you're shaking a beaker up here at room temperature.
你跑步，震动烧杯，这都是在恒定温度和压强的情况下的过程。
-
So this isn't the most useful form that we can have, but what we'll see shortly is that from this, we can then derive further criteria for essentially any set of variables or any set of external constraints, like constant temperature or pressure or volume and so forth that we might set.
所以这不是我们所能得到的最有用的形式，但是我们会很快看到，我们能够进一步推导出包含任意变量,或者任意约束的自发过程判断标准，比如说恒定的温度，压强,体积或者其他我们能够给出的约束。
-
du/dV So now our du/dV, dp/dT at constant T is just T times dp/dT which is just p over T minus p, it's zero.
现在我们的恒定温度下的，等于T乘以dp/dT，在这里,等于p除以T，最后再减去p，结果是0。
-
pV Also A plus pV and G is minimized at equilibrium with constant temperature and pressure.
同时等于亥姆赫兹自由能A加上,同时在恒定的温度和压强下。
-
dA/dT dS/dV So this is negative dS/dV.
是负S，It’s，negative，S。,这个二阶偏导数是负的恒定温度下的。
-
du/dV at constant T. And so, what is it?
求恒定温度下的du/dV，但是，这个量是什么？
-
p dA/dV, at constant T, must be negative p.
在恒定温度下，dA/dV等于。
-
So if you had a high temperature, this a small compared to b. If you're negative which means that dT/dp at constant H is less than zero.
高于反转温度，这一项相比于b很小,意味着H恒定时,偏T偏p小于零。
-
du/dT constant pressure is the direct derivative with respect to temperature here, which is sitting by itself under constant volume keeping this constant but there is temperature sitting right here too.
偏U偏T，p恒定是对,温度的直接微分，而它本身对体积不变,保持它不变，但是这里也有一个温度,这就是偏U偏V，T恒定。
应用推荐