-
Of course in the reversible case, you're always pushing against an external pressure, which is essentially equal to the internal pressure.
当然在可逆的情况下，外压力，总是，等于内部压力。
-
pV=RT dT here because the pressure is constant, dV=RdT/p so dV is equal to R over p dT.
因为对1摩尔气体有，于是。
-
Because it's so important. And I should add and also under reversible work, where the external pressure is equal to the internal pressure.
而且我还要说应该在外部压强,和内部压强相等的,可逆过程中引入它。
-
This is just an equality. I have a constant pressure dH process. This term here is equal to zero.
这是一个等式，这是个恒压过程,这项等于零，这意味着。
-
We know the pressure is equal to force per area.
我们知道压强等于力除以面积。
-
So, these two are equal to each other as well which tells me that this derivative, Cp dH/dT constant pressure is Cp.
所以这两者也相等,这告诉我们在恒压下微分，等于。
-
Because what we've done is we forced p, pressure here, to be equal to the external pressure.
因为这里我们让内部的压强，等于外部的压强。
-
dV dT Is equal to minus dV/dT at constant pressure.
它等于，负的恒定压强下的。
-
First let's set the external pressure equal to zero.
首先，让外部压强为零。
-
Now, if this is an ideal gas, we know that pressure is equal to nRT over volume.
如果这是一个理想气体系统，我们知道压强等于nRT除以体积。
-
We're going to change the pressure above, Pext right now there's a p external, which is equal to p on the inside.
来改变外界条件，可以改变外界的压强，它将与气体压强p相等。
-
dT That means that dH is also equal to dH/dT, constant pressure dT. All right, so now I've T ot more dH/dT under constant pressure.
也等于偏H偏T恒压乘以，现在我已经得到了在恒压,状态下的偏H偏。
-
du But here you've got pressure constant. du, T this is du, not H here. du/dT is only equal Cv to Cv when the volume is constant, not when the pressure is constant.
这里是压强横笛，du，这是，不是H，偏U偏,只在体积恒定时等于，而不是压强恒定时。
应用推荐