This should be particularly bothersome to you because, as you've already experienced in 5.60, There are a lot of partial derivatives.
对你们来说这可能很让人头疼,就像你们在5。60里体验过的那样,这有很多偏微分和变量。
I can get better grades and you know, better average rather than going different uni, so.
我可以得到更好的成绩,中等偏上,比去其他大学要好。
So, all I want to do now is look at the derivatives of the free energies with respect to temperature and volume and pressure.
我现在所要做的一切就是,考察自由能对,温度,体积和压强的偏导数。
The baby is being approached, goes like this , smiles like this , and then the aversion .
有人走近这个婴儿,像这样,眉毛上挑凝视,开始微笑,像这样笑,大笑头偏向左,然后是讨厌的人,大笑头避开。
If you can kick the ball very hard, but not very accurately, then if you try and shoot to the left or right, you're slightly more likely to miss.
如果你只会大力抽射但是缺乏精准,当你射向左路或者右路时,你有可能会射偏
Little coffins, people were smaller then.
窄小的棺材,那时的人们身材偏小
It gets in the way of arriving too quickly at meaning, if indeed one arrives at meaning at all.
当你想理解含义时却偏不让你迅速理解,前提是你真的理解了。
Now when it reaches up to the right more towards the heart of that red zone, " 100 spikes per second.
现在,当它移动到,右上侧偏红色区域的时候,我们会听到嗑哩的声音,每秒钟100次,we,may,hear,“keri…
But, of course, it's going to come from the fact that these second derivatives are also equal.
但是,结果同样是依赖于,二阶混合偏导数相等。
So for an ideal gas then, dH/dp under 0 constant temperature, that has to be equal to zero.
所以对于理想气体,偏H偏p在恒温下,等于。
That is, it's easy to write down straight away that dG with respect to temperature at constant pressure S is minus S.
这就是说,可以很简单的写出dG在,恒定压强下对温度的偏导数,是负。
When you say that, it implies that the differential is given by this pair of partial derivatives.
这就意味着,内能的微分,等于偏u偏T,保持体积不变。
We have discovered that this partial derivative that appears in the definition, the abstract definition of the differential for internal energy, is just equal to the constant volume heat capacity.
我们还发现,这个偏微分出现在了,内能的偏微分,定义式中,它也就是热容。
Now let's take it in the other order.
我们用另一种顺序求二阶偏导数。
And then we can take the derivative with respect to temperature, it's just R over molar volume minus b.
这样我们求,压强对温度的偏导数,结果等于R除以摩尔体积V杠减去b的差。
p This is going to get us dH/dp constant temperature. What is this experiment?
这帮助我们理解恒温条件下的偏H偏,那么这个实验具体是什么呢?
G We can take the derivative of G with respect to how much material there is.
我们可以取,对物质总量的偏导数。
Can determine how entropy is going to behave as the volume changes.
这些偏导数,你就可以知道当体积变化时熵如何变化。
These things have to be equal to each other.
这两个偏导数是相等的。
Because these mixed second derivatives are the same thing.
因为这两个混合二阶偏导数,是相等的。
v du/dV under constant temperature. du/dT v under constant volume. You use the Joule expansion to find these quantities.
像偏u偏v,恒温下的偏u偏,恒容下的偏u偏,你们知道怎么运用焦耳定律。
So d/dT of dA/dV, just like this.
即对dA/dV求对温度T的偏导数。
What is dH/dT as a function, keeping pressure constant, what is dH/dp, keeping temperature constant?
恒定时偏H偏T是什么,温度恒定时的偏H偏p又是什么呢?,好的,让我们解决第一个问题?
So we already know that. So now we can write CpdT or differential dH as Cp dT plus dH/dp, pdp constant temperature, dp.
我们已经知道了这个,所以我们现在,可以写出H的微分式:dH等于,加上恒温时的偏H偏。
So we have dH/dT keeping pressure constant, is du/dT keeping pressure constant.
等于偏U偏T,p恒定加上,偏pv偏T,p恒定。
Now, for an ideal gas, du/dV under =0 constant temperature is equal to zero.
对于理想气体,温度一定,时偏U偏V等于零。
We already did that. OK, dH/dT constant pressure is Cp. That was easy one.
我们已经做过这个计算了,好的,在恒压,状态下的偏H偏T就是Cp,这个很简单。
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。
If T is less than T inversion, you have the opposite case, and dT/dp is greater than zero.
如果T比转变温度低,情况就相反,偏T偏p大于零。
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