du=dq+dw So our first law, du is dq plus dw.
热力学第一定律。
Well, dq is equal to zero and dw is equal to zero dq=0 dw=0 because it's isolated.
隔离的孤立系统,这时。
dq=0 But if it's adiabatic, then dq is equal zero, du=dw and for an adiabatic process, then du is equal to dw.
但如果它是绝热的,那么,因此对于绝热过程。
dU=dq+dw Well from the first law, du is equal to dq plus dw, and I wrote down everything I knew at the beginning here.
第一定律“,前面我们已经,看到了。
dw=0 Well for constant volume, dw is equal to zero.
约束是恒定体积,此时。
So the delta v here is an exact differential, but this dw is not.
你是如何,到达这个状态的。
One is, du, u is called the internal energy dw or just the energy, is equal to dq plus dw.
其中一个是:du,u是内能,或能量,等于dq加上。
dU=dq+dw Still know that du is dq plus dw.
所以。
dq=0 dw=-pdV I wrote dq equals zero I wrote what dw was.
这样的式子。
TdS It comes from the fact that dq reversible is T dS, pdV and dw reversible is minus p dV.
这个结论来自于:可逆过程下dq等于,做功dw等负的。
Reversible. Reversible means that if I looked at dw it's minus p reversible.
接下来是“可逆“,他说明当计算dw=-PextdV时。
I also want to assume for our present purposes that there's only pressure volume work going on, which is to say I want to put pdV p dV in here minus p dV for dw.
同时假定,对于我们目前的目的而言,只有压强做功这就是说,我要把这里的dw替换为负。
du=0 So du is equal to zero because dq and dw are both zero.
因此,因为dq和dw都等于零。
pdv It's an isothermal expansion, so dw is just negative p dV.
因此dw等于负,这就是。
So there's p v work and it's given by the integral minus p external dv or just the integral from one to two of dw.
我们知道对于pv系统来说,功w可以写成黑板上的两种不同形式。
应用推荐