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Late this year, scientists and politicians are to gather in Copenhagen for a key global climate-change summit in an effort to thrash out a consensus on cutting heat-trapping greenhouse gasses.
VOA: standard.2009.03.12
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Now, the coefficient that relates the amount of heat in to the temperature change is obviously going to be different for these two cases.
在这两个例子中,很显然联系热量和温度变化的系数,是不一样的。
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So we don't really need to put in a certain amount of heat and change the temperature of the products and the calorimeter and so on.
所以我们实际上并不需要输入,一定的热量，改变生成物,和量热计的温度之类。
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Now, I know how to relate the heat flow to temperature change, through the heat capacity.
现在我知道怎样把能量的流动,和温度的变化联系起来，通过热容。
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The boundary is impervious to transfer of heat like a thermos Anything that happens inside of the thermos is an adiabatic change because the thermos has no connection in terms of energy to the outside world.
边界不能传递热量,像热水瓶一样,热水瓶里发生的任何事,都是绝热变化,因为热水瓶与外部世界,没有能量方面的联系。
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Heat capacity relates the amount of heat that you add to the system to the change in temperature, and this is the relationship.
热容联系起给系统提供的,热量和温度的变化，关系式是这样的：
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And there's a certain property associated with heat flow with b and it didn't change.
具有某种与热量流动有关,的特定的性质,它是不变的。
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You're always wasting energy into heat somewhere when you dochange that involves mechanical change.
当进行与机械运动有关的变化时,总会有能量变成热量而被浪费掉。
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Now, you can have a change of temperature without any heat being involved.
不进行热量传递也可以改变温度,想象有一个热绝缘的盒子。
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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 if I do that then I can find out the change in enthalpy of this reaction. It's just going to be the heat of formation of these three moles of water, minus the heat of formation of the iron oxide. OK.
我就能得到这个,反应的焓的变化,它就是三摩尔水,的生成热，减去氧化铁的,生成热，好。
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It's just how much heat is involved when we change the temperature. Now, the products have some heat capacity associated with them right, it takes a certain amount of heat if we make their temperature change, to either put it in or take it away, depending on which direction the temperature is changing.
问题就是当我们改变温度时,有多少热量发生了转移,生成物具有一定的热容,如果我们改变,它们的温度，就要输入或,提取一定的热量,这取决于温度改变的方向。
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It expands. You change your constraints on your system, you heat it up some more, then you take the heat source away, and you put it back in contact with the atmosphere. And you cool it a little bit, change the constraints, cool it a little bit more, and heat, and you've got a closed cycle engine.
让它与大气接触冷却,改变约束，使它继续冷却，然后又再次加热,这就是循环热机，我们以前也研究过，更复杂的机器。
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And because there is an explicit relationship between u, delta u, q and w, you can always find the easy way to derive the change in internal energy or the heat or the work.
因为Δu，q和w之间,有明确的关系，一般来说,内能或热或功的变化,易于计算。
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Or I could have a non-adiabatic, I could take the same temperature change, by taking a flame, or a heat source and heating up my substance. So, clearly q is going to depend on the path.
也能改变温度，绝热指的是没有热传递，在非绝热条件下，也同样可以升温,比如用火或者热源加热，这样，q也应当与路径有关。
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