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What's happening there? Well, the selection of reactants has been done judiciously to provide either heat or to provide something that's cool.
就会感到这东西，比如说变冷了，对吧？,这里发生了什么？这些反应物都是,被仔细的选出来的，能够提供热量或制冷。
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However, the thing to remember is, when you look at heats of reaction under those conditions it's all well and good.
相反，需要记住，当你需要知道反应中放出的热量时,这些量是很有用的。
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One is that 2,000 calories is the average for the typical person, but, of course, people have greatly differing calorie needs.
一是2000卡路里是常人所需的平均值,当然,人们需要的热量是大大不同的
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The heater is on, it's producing heat until a negative signal is registered, 'oh we've gone too high', and then it turns off.
加热器会开着,一直产生热量直到它得到一个关闭的信号,噢我们弄得太热了,然后就关闭了
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All right, so this is the heat flowing in or out of the system, and these are all functions of state.
好的，这就是系统的热量变化,这些都是态函数。
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Adiabatic meaning there's no heat involved, and we're going to see how that differs from the isothermal expansion and compression.
绝热意味着没有热量的传递，我们将看到它,与等温过程的区别。
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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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You calculate how much heat is released in the reaction. And then what's going to matter is what's the heat capacity of the whole, of the calorimeter?
就是计算在反应中,放出了多少热量,接下来关键的是,整个量热计的热容是多少？
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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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So, in a sense, it says, you know, if you wanted to build a boat that took energy out of the warmth of the air to sail around the world, you can do that.
因此，某种意义上说，它宣称如果你想要造一艘船,通过从空气中获取热量,这是可以做到的。
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We know it has to big anyway, since we can extract heat from it without changing the temperature.
我们知道它必须很大，因为我们得从中提取热量,但不改变它的温度。
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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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Fat has twice the calories per unit weight that protein or carbohydrate sugar has, as a consequence, has the greatest survival value.
单位重量中脂肪的热量含量,是蛋白质和碳水化合物的两倍,因此,脂肪才是最能维持生存的物质
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Men will need more calories than women, people who are very active will need more then people who are less active, etc.
男人所需的热量多于女人,活跃的人比安静的人需要更多的热量等等
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Did--were people surprised by the number of calories that you total up at the end of the day?
有没有人对自己一天的热量摄取量,感到吃惊的
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So the expansion against lower pressure draws less heat from the hot reservoir right.
所以压强较低时的膨胀,从高温热源吸收的热量更少。
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It's now, all we have to do is say we're going to have heat at constant volume.
我们需要做的就是,计算恒定体积下的热量。
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a You know that what will happen is that heat will flow from a to b from b to c and from a to c. That's common-sense.
你知道会发生的是热量从流向,从流向,以及从流向。
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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。
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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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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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I don't want to have to deal with heat escaping to the outside environment in a way that might be difficult or complicated to measure or calculate.
我可不想处理跑到,环境中去的热量，那测量或,计算起来会非常麻烦和复杂。
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It amounts to 2 to 3% of calories for the average consumer, and as I mentioned, Trans fats are not so good.
平均每位消费者,有2-3%的热量来自反式脂肪,正如我所说,反式脂肪不那么好
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Now you go to a Mexican restaurant and if you want to be virtuous you have the salad.
人们走进一家墨西哥餐馆,想吃的健康低热量些,于是选择了沙拉
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OK, but in order to relate turning these physical knob to this quantity here, which we don't have a very good feel for, we've got to have a feel for the slopes.
热量是怎么进一步改变的,但是为了把这些物量同我们，不是很理解的焓联系起来，我们对微分已经有了一定的了解。
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We're going to find other properties that do care about the history of the system like work, that you put in the system, or heat that you put in the system, or some other variables But you can't use those to define the equilibrium state.
我们还会发现其他一些,与系统的历史有关的性质,比如你对系统做的功，或者你向系统传递的热量，或其他的变量,但你不能用它们,来定义平衡态。
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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 you can see what the heat involved in a process like that is as well.
你就能看到在类似这样的,过程中热量是如何变化的。
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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 know the heat isn't going to flow from a cold body to a hot body without putting some work in to make that happen.
大家知道热量不会自发地,从冷的物理流动到热的物理,除非对它做功。
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