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"We use some kind of light oil that we heat up and we actually work it into the oily feathers.
VOA: standard.2010.06.08
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But it's a good story, Joule decided that there must be a direct relationship between work and heat.
所以说，这只是一个不错的故事而已，焦耳认为功和热之间,一定具有某种直接的联系。
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When I flail my arms around I generate work and heat. This is not a constant volume process.
这不是一个恒容过程,但如果我是一个系统，当我做这些的时候。
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The same temperature increase, work and heat, and we have a relationship between heat and work.
同样的温度升高，功和热，因此我们可以得到功和热的关系了。
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That is, it gives us the relationship between energy and work and heat.
热力学第一定律阐述了,能量，功和热之间的关系。
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Last time you heard about work and heat.
上节课我们学习了功和热。
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Now let's compare what happens to work and heat.
现在让我们比较一下功和热量的变化。
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Or there was a relationship between work and heat.
或者功和热之间有某种联系。
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So here are expressions for work and heat.
这是功和热量的表达式。
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There's no change in them, and then we also looked at some at non-state functions, work and heat, and saw that those aren't zero going around a cycle. Of course you can do work in a cyclic process, and heat can be exchanged with the environment at the same time.
它们不会有变化，然后我们研究了,一些非态函数，功和热量，并看到,沿着循环行进一周的话,它们并不是零，当然你可以在,一个循环过程中做功，而同时热量可以在系统,与外界环境之间进行交换。
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And the idea was that gravity did work on the water and falling, and that work led to the generation of heat.
焦耳的想法是,重力对水，做了功。
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And in practical terms, we can define the efficiency as the ratio of the heat in to the work out.
在实际中，我们定义,效率为热与功的比值。
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One is that he observed when people were machining cannon barrels, a lot of heat was generated, and there was a lot of work done.
第一种说法说焦耳发现,制作加农炮筒时，会产生大量的热，同时这中间有大量的做功。
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The relationship between heat and work was initially proposed in the 1940's by Joule.
热量和功的关系首先是,由焦耳在1940年提出的。
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You can take heat energy and convert it to work energy and vice versa, and it doesn't say anything about that you have to waste heat if you're going to transform heat into work.
你可以把热能便成功,也可以反过来,但它对于如果你要把热变成功,就必须浪费热量这件事只字未提,它只是说这是能量。
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Is this possible? That's what the first law says it's possible; work is heat, and heat is work, and they're the same thing. You can break even 100% maybe. So let's go back and see what work is.
00%的效率,我们可以从大气中吸收热量，用来驱动我们的汽车,效率也应该能达到。
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Delta u, delta H, familiar state functions, q w changes in their values, q, w, heat and work.
U，△H，很熟悉的态函数，它们的值在变化；
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So again, for both heat and work we don't get the same result. Now let's look at our special function, right. So here's path A.
所以，再一次说明，对于热量和功,我们得到的结果是不同的,现在让我们看看我们的特殊函数。
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OK, so let's go through this and see what we would do which is to calculate the heat and the work. This is well insulated.
好的，让我们开始然后看看,我们该怎样计算热量和功的大小,这是完全绝热的，所以。
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So that's our work in this path and heat.
这就是这个过程中的功和热。
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You couldn't just run something successfully in a cycle and get work out of it, using the heat from the hot reservoir, without also converting some of the heat that came in to heat that would flow into a cold reservoir.
如果一样东西在循环工作过程中,只有热从高温热源中流出，而没有热流入低温热源，那么此过程,不可能对外做功,不可能把所有热。
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And so maybe the work generated the heat.
因此或许功产生了热。
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There's an interplay between the energy inside the gas which is the heat energy which is allowing me to do all that work to be outside, and so I'm using up some of the energy that's inside the gas to do the work on the outside.
即使没有热传递,能量也能以,做功的形式传递出去，气体的一部分内能,转化成了功。
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And the first law says, well heat and work are different forms of energy, and we can add them, and the path dependence of these two things is somehow cancelled in the fact that we have this internal energy.
热力学第一定律说，热和功是能量的不同表现形式，我们可以把它们加起来,它们与路径相关的部分相互抵消,我们就有了内能。
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This is providing work that's being used in here, but if you take the whole outside of the surroundings and this whole thing is the system, no net work, these things cancel each other, and yet heat's going up.
如果把外面的全部当成环境，把这里的全部当成系统,那么就没有净的功，它们相互抵消了，热量向上传输，会发生什么？
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It makes sense, right, because you know we got less work out and delta u is the same right, so it must be that less heat got transferred.
这是显而易见的，因为输出的功更少,且Δu相等，所以需要的热量更少。
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U It's u, because u is to q plus w right, heat and work, but it's adiabatic. So there's no heat, exchange with the environment, and it's constant volume, so there's no p dV work, right.
什么是零？是U，因为,等于q加w，热量和功，但这是绝热的，所以系统与环境间没有热量交换；,同时它是灯体的，所以也没有pdV形式的功。
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All right, now what we're going to learn next time and Bob Field is going to teach the lecture next time, is how heat and work are related, and how they're really the same thing, and how they're related through the first law, through energy conservation.
这节课就到这里,下节课将由Bob，Field讲授,我们将学习功与热量的关系，认识到它们在本质上的相同之处，并通过热力学第一定律，亦即能量守恒定律，把它们联系起来。
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