It's related to the heat capacity, the constant volume of heat capacity and something you could measure.
它联系了热能,恒容热容和一些,我们能够测量的物理量。
So, the system that gets designed in order to implement the cruise control
而那个为了实现恒速控制的系统,
Because we did work at constant pressure, and so it's just volume difference times pressure.
因为是在恒压下做功,所以功就等于体积变化乘以压力。
But just how does that kind of knowledge help us deal with the constant ebb and flow of political life?
但那种知识,如何协助,我们面对政治生活中的,恒存起伏?
What we needed was some mechanism of exerting some fixed force.
我们需要的是一些能够产生恒力的装置
Remember, it's one and a half times inflation rate plus a half time the GDP utilization 1 plus 1.
注意,公式是,1。5倍通货膨胀率,加上0。5倍实际GDP与名义GDP的百分比,再加上恒常数。
So, these two are equal to each other as well which tells me that this derivative, Cp dH/dT constant pressure is Cp.
所以这两者也相等,这告诉我们在恒压下微分,等于。
It's constant pressure. OK, so now, last time you looked at the Joule expansion to teach you how to relate derivatives like du/dV.
这是恒压的,好,上节课你们,学习了焦耳定律,以及怎样进行导数间的变换。
You just change volume to pressure and basically you're looking at enthalpy under a constant -- anything that's done at a constant volume path with energy, there's the same thing happening under constant pressure path for enthalpy.
可以看到这就是把体积换成了压强,一般我们都是在一种恒定状态下,考虑焓的,任何在恒容条件下,能伴随能量变化的东西,也在恒压条件下伴随焓同样地变化,所以你可以经常。
This is in many ways for Socrates the fundamental political question of all times.
这在很多层面上对苏格拉底,都是基本的恒时政治问题。
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。
It is taking place inside this thing, and it's a constant pressure, and we'll do it reversibly, right. So that's what we've got.
它是绝热的,在这个内反应,是在恒压下,它是可逆的,对吧?
OK, so this, what I've sketched here would be a constant pressure calorimeter. There's a reaction.
好,我画的就是一个恒压量热计,其中进行一个反应。
so that's what we think we know in constant pressure calorimetry.
好,我想这就是我们,在恒压量热法中所知道的。
This depends on the path. It tells you right here the path is constant pressure. These don't depend on the path, right. V doesn't care how you v get there. u doesn't care how you get there.
这由变化的具体路径决定,这个小脚标表明过程是恒压的,这些量都与具体路径无关,即不管是通过什么路径使得体积变化为Δ
it's zero. Delta H1 is zero, right.
处于恒压下,它是零。
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。
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。
Adiabatic q equal to zero. It's also delta H 0 which is zero. The two didn't necessarily follow because remember, delta H is dq so p is only true for a reversible constant pressure process.
在这个过程中ΔH等于,绝热的所以q等于0,而ΔH也等于,这两个也不一定有因果关系,因为,记住,ΔH等于dq只有在恒压。
Over here, we have dq=Cp dT, the heat, the proportionality between heat - and temperature rise is given by this, the constant pressure heat capacity.
这里我有dq=CpdT,这是热量,这是联系热量,和温度变化的系数,恒压热容。
er is a vector at each point of length one pointing radially away from the center.
r 是一个模长恒为 1 的矢量,方向沿半径向外
If you have a real gas and you write du is Cv dT and your path is not a constant volume path, then you are making a mistake. But for an ideal gas, you can always write this. And this turns out to be very useful to remember.
对于真实气体,如果其变化过程,不是恒容的,du=Cv*dT就不成立,但对于理想气体,这条规则永远成立,这一点非常有用,请记住。
This is just an equality. I have a constant pressure dH process. This term here is equal to zero.
这是一个等式,这是个恒压过程,这项等于零,这意味着。
Only those in other words engaged in the continual struggle to clarify their thinking to remove sources of contradiction and incoherence only those people can be said to live worthwhile lives.
换言之,也仅有那些身处,持恒挣扎于厘清其思维的人,于移除矛盾及无条理源头的人,仅有那些人,才称得上是值得活的生命。
So, the question we are going to ask is the following, "If I tell you that a particle has a constant acceleration a, can you tell me what the position x is?"
接下来要问的问题就是,如果我说某质点加速度恒为a,你能告诉我它的位移x是多少吗
This piston is being brought out, so we expect 0 the work to be negative, negative. And we start o V2 ut with zero volume. We end up with a volume p2 of V2, and the external pressure is constant to p2.
所以我们可以想象功是负的,开始的时候体积是,最终的容积是,外界的压力恒为。
So what we've discovered from this relationship dq that du at constant volume is equal to dq v.
从这个关系式里我们发现,恒体积时的du等于恒体积时的。
Normally this is used for a reaction in the condensed phases and liquid usually.
通常它是用于凝聚态,液体相的反应,这是一个恒压量热计。
Let's label that two. It's still at constant pressure.
我们把这个标为II,它仍然是在恒压下。
The constraint isn't constant temperature because the temperature is going to be changing.
是在不停变化的,不是恒压,因为我们已经有Δp了。
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