For example, F x y z if I have an equation that looks like this, f of x, y, z.
打个比方,我有个这样的方程。
x y z And I have another equation f of x, y, z.
若我有另一个方程。
That's it. Again, these other p dxy dyz - or the d x y, d y z, those are going to be those more complicated linear combinations, you don't need to worry about them.
同样,这些p轨道,或者,它们是一些,很复杂的线性组合,你们,不用管它。
It was awkward teaching an introduction Y and probably for that reason while I was teaching Lit 300, which was then called Lit Y, Z Paul de Man was teaching Lit Z.
教入门课非常尴尬,也许正因为这样,我教文学300时,当时它还叫文学,保罗,德,曼教教文学。
X Y Z It's more interestingly named an X or Y or Z.
你也可以把它命名为。
All right, it's so if I looked at it, sorry, IF x is less than y, THEN check to see IF x is less than z, and if that's true, print out x is the smallest.
好,代码是这样的,对不起,是不是x比y小,然后去看看是不是x比z小,如果都为真的话,显示x为最小值。
So you can see if you take phi, and you move it over 90 degrees, we're right here in the y z plane.
你们可以看到,把phi转到90度,它就是yz面。
Suppose f of x, y, z equals k1, that is my equation, s1 and it gives me a solution s1.
假设我的方程是这样,然后给出了一个解。
The power of linearity is F=k1+k2 if I come across f of x, y, z equals k1 plus k2, if it is a linear equation, I don't have to go and solve it all over again.
线性的威力是,一个方程,如果它是个线性方程,那么我就不用再去解他了。
XYZ I might as well do it as x, y, z because we are talking about something that is going in three space.
我最好设成,因为我们在讨论,三维的事物。
And just as with variables, you should use some common sense, some style here, and the function's name should X Y communicate what it does, calling it X or Y or Z is generally not all that helpful.
就像变量,你使用一些常识,一些类型,和函数名需要,传达它所做的事情,把它叫做,或者Z通常是没有什么用处的。
px And I arbitrarily chose to put it in the 2 p x, 2pz we also could have put it in the 2 p y or the 2 p z, it doesn't matter where you double up, they're all the same energy.
我任意地选择放入至,我们也可以把它放入2py或,它与你在哪双倍填充没有关系,它们都在相同的能级。
This now has, gee, a funny thing, x it says IF x is less than y AND x is less than z, then do something.
代码现在有,啊,一个有趣的东西,代码先是判断x是不是小于y并且,是不是小于z,然后做一些事情。
Um-hmm. So, it's going to be the y z nodal plane, or in other words, we can say it's any place where phi is equal to 90 degrees.
嗯,是yz平面,换句话说,是在phi等于90度的面。
So, you can see, it's much easier to describe that as one term, r here, instead of using both y and z.
所以,你们可以看到,用r而不是y和z来做描述,使得它变得更为简单。
And now we get the p orbitals, remember we want to fill up 1 orbital at a time before we double up, so we'll put one in the 2 p x, then one in the 2 p z, and then one in the 2 p y.
我们到了p轨道,记住在双倍填充之前,我们想要每次填充至一个轨道,所以我们在2px填充一个然后2pz填充一个,然后2py填充一个。
So, we can have the 2 p x, 2 p y, and 2 p z orbitals.
所以我们有2个px2个py2个pz轨道。
Z So it would be incorrect to try to assign this to a variable X or Y or Z, because it doesn't actually give me anything back.
这个是错误的,来赋值这个给变量X或Y或,因为它的确没有返回什么给我。
It adds x to y and stores it into z. But if someone wants to be a even a little more snarky, what does this program do?
它把x加上y,再把结果存到z中,但是如果有人,想要做的有点不合常理点呢,那这个程序会做什么?
Now, unlike high school math or in algebra Z where you call things X and Y and Z, in programming, in computer science, you're actually dealing with humans where it's useful to have a variable name that's more descriptive than X and Y and Z.
不像高中数学或者代数中,称为X和Y和,在程序设计和计算机科学里,你实际上是在和人打交道,在这里有个描述性比xyz更强的,变量名称是很重要的。
So it's OK to not specify. I want to point out, pz whether you're in the p x, the p y, or the p z, unless a question specifically m asks you to specify the m sub l, which occasionally will happen, but if it doesn't happen you just write it like this.
我想指出的是,无论你在px,py或,除非一个问题特别地,让你指出l下面的,这种情况有时会发生,这样就可以了,但是如果它不做要求你们写成。
All right, so one thing that I want to point out, which I said many, many times on Friday, and this is perhaps the last time I'll say it, but one last time is we can think about why we only see a line for the 2 p orbital, versus we don't see separate lines for a 2 p x, a 2 p y, and a 2 p z.
好的,我还要指出一个问题,这个问题我在上周五已经说了很多很多次了,这可能是我最后一次提到它,但是这最后一次让我们来考虑一下,为什么我们只看到了一条,对应于,2,p,轨道的线,而不是分别对应于,2,p,x,2,p,y,2,p,z,的线?
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