it becomes a gray area but it should be pretty clear if you can treat something is reversible are irreversible.
这是个灰色区域,但什么可以当作可逆过程处理,而什么要当作不可逆过程,这是相当清楚的。
I mean we can, we can sort of understand why OK, the total energy, if we measure it, we measure a process which is not reversible.
例如我们易于理解为什么,当试图测量一个不可逆系统的总能量,给出的或许。
Now,that thing that wakes up after this complete irreversible amnesia will no doubt eventually develop a personality,a set of beliefs,memories.
这人在经历了完全不可逆的失忆后醒来,最终发展出了自己的人格,信念和记忆。
You've irreversibly changed that substance because you've changed the structure of all the proteins inside.
蛋白质的结构发生不可逆的变化,因为蛋白质内部的全部结构都改变了
get back to the initial point is going to require some input from outside, like heat or extra work or extra heat or something because you've done an irreversible process.
如果要逆转它,回到初始点,就需要外界的投入,比如额外的功,额外的热量等等,因为你进行了一个不可逆过程。
Because if it's irreversible, it's very likely that I don't know what the pressure inside the system is doing while this is happening.
因为对不可逆过程,系统内部的压强,没有明确的定义,气体不处于平衡态。
Now, if we go back to our Carnot cycle which is a set of reversible paths, it's useful to compare this to what happens in an irreversible case.
如果回到卡诺循环,它是由一系列可逆过程组成,我们将它,和不可逆过程的情况相比较。
That's why we always talk about irreversible expansion, because it's easy to write down an irreversible expansion.
这就是我们总是,讨论不可逆膨胀的原因,因为它,比较容易描述。
OK, so now we're going to do the same kind of experiment, but irreversibly. An irreversible adiabatic.
现在来在,不可逆的条件下,完成相同的实验。
And I want to make sure everybody figured out that it really was an irreversible expansion.
或者多孔塞的,不可逆的等焓过程。
We can do it reversibly, or we can do it irreversibly.
它可以是可逆的,也可以是不可逆的。
that instead of all the steps being reversible, let's just put in one irreversible step.
不是所有的过程都是可逆的,其中有一个过程不可逆。
So w, the work is less for the irreversible process than the reversible process.
不可逆过程中系统对外界,做的功要比可逆过程时小。
If it was non-reversible, I would be allowed to put an initial point and a final point, but I wouldn't be allowed to put a path between them like this, connecting them together.
如果是不可逆过程,我可以画出过程的初态点,和末态点,但是我不能再像这样,画出连接这两个点的,路径曲线来。
STUDENT: .
学生:不可逆压缩也可以:,通过快速的压缩实现吗?
No, pretty much things are either reversible or irreversible.
不,几乎所有的都是要么可逆,要么不可逆。
Wirr Minus w irreversible, this is the work which is done to the environment by the system, -Wrev minus w irreversible is always smaller than minus w reversible.
一点提示,不可逆过程中系统,对外界做的功,总是小于,之前我们。
Like something is almost reversible and almost irreversible.
就像什么东西是几乎可逆的,或几乎不可逆的。
So suppose we do it irreversibly.
假设它是不可逆的。
Now, you all know that we can make irreversible changes in proteins, you can denature them completely, that's what happens when you cook an egg for example.
现在你们都懂蛋白能够发生不可逆的改变,能够完全变性,比如在你煮鸡蛋的时候就是这样
So now let's look at the efficiency of our irreversible engine.
再来看看,不可逆热机的效率。
I think it's, but it's more complicated, but you're basically right, basically right.
它比不可逆膨胀更复杂,但是你的观点从原则上来说是对的。
So for an irreversible process, I wouldn't really be allowed to put a path there.
不可逆过程,是无法画出路径曲线来的。
So it's that the irreversible efficiency is lower than the reversible one.
所以不可逆过程的效率,小于可逆过程的效率。
T2 STUDENT: From T2 reversible is greater than T2 irreversible, saying that T2 reversible is .
学生:可逆过程的,比不可逆过程的T2更高,也就是可逆过程的T2更热。
But now, so this is where the refrigeration comes in. So if you take a gas, and you're below the inversion temperature and you make it go through this irreversible process, the gas comes out colder from that side than that side.
这就是冰箱的原理,如果在低于转变温度,的情况下我们将气体经过,这个不可逆过程,气体出来的温度将比这边低。
PROFESSOR: A boundary between reversible and irreversible?
教授:可逆与,不可逆间的边界?
It's an irreversible expansion.
这里的膨胀过程是不可逆的。
And for the spontaneous change which happens irreversibly That means that'll be dq irreversible.
对于不可逆的自发过程,这说明dq是不可逆的,当过程是可逆时。
That - irreversible changes happen all the time too but here I'm talking about very subtle small changes where you're changing the structure of the protein but only a little bit such that it can go back.
这种不可逆的改变时时刻刻都在发生,但我在这里想讲的是,对蛋白质结构进行微小的改变,小到这种改变是可逆的
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