So let's figure out the bond order for our two molecules here that we figured out the electron configuration for.
让我们看看这里,两个分子的键序是多少。
So the integers are totally ordered the reals are totally ordered lots of things are, the rationals are totally ordered.
对正数来说,这样的序列是排好序的,对实数也是如此,对很多事情都是如此。
/2 So the bond order is going to be equal to 1/2, and then it will be 2 minus 2.
它的键序等于,然后乘以2减去2。
So if you now reverse the story that we're telling here, what was the next line supposed to be after sorting left half?
回退到这个过程中来,在对左半部分排完序后,下一步该做什么呢?
What bothers Socrates most about our democracy is a certain kind of instability, its tendency to be pulled between extremes of anarchy, between lawlessness and tyranny.
苏格拉底对我们民主最感困扰的是,不稳定性,倾向于失序两端,拉扯的特性,即介于目无法纪与专制之间。
I haven't said how I'm going to get those sorted lists, but imagine I had two sorted lists like that.
我还没有说明我怎么才能得到已排序的列表,但是想像一下我现在已经有,两个已排序好序的列表了。
And you can go ahead and tell me what you think the bond order is going to be for this molecule.
你们告诉我你觉得,这个分子的键序应该是怎样的。
And if I'm walking down the list, this is probably order of the length of the list s because I'm looking at each element once.
这可能大概就是数组的长度,因为我会遍历数组中的每个元素一次,现在你可能会想,等等,数组已经排好序了。
All right, so the bonding order, you're correct, should be 2, if we subtract the number of bonding minus anti-bonding electrons and take that in 1/2.
好,你们是对的,键序为,如果我们用成键数,减去反键数除以2。
So what we see is a bond order of 0, and again, the bond is very, very weak.
我们看到键序是0,同样的,键非常非常的弱。
So let me give you an example. Suppose I want to merge two lists, and they're sorted.
我想合并两个列表,并且这两个列表已经排好序了。
- So again, if you're unwinding what's going on here, this-- we sorted the left half which meant sort the left half, then the right half then the merge.
同样,如果你展开正在进行的一切-,我们已对左半部分排好了序,接着右半部分,接着合并。
We don't seem to be doing that just yet, certainly not as badly, alright, so at this point in the story I have a sorted list of size 4.
当然现在我们不需要那样做,此时此刻,我已对整个问题中大小为4的列表排好序了。
PROFESSOR: And I didn't write up there but it is one, 1 and we can see that it's 1, 2 because it's 1/2 of 2, 4 minus 2, so 1/2 of 2, the bonding order is going to be equal to one.
教授:我没有写出来,但是是1,我们可以看到为什么是,因为它等于1/2的2,4减去,所以1/2的2,键序等于1。
So we know that it's 1, because we have 1, 2, 3, 4 bonding, minus 2 anti-bonding, and 1/2 of that is a bond order of 1.
我们知道它是,因为我们有1,2,3,4个成键,减去2个反键,它的一半就是键序为1。
Again. Basic premise of binary search, or at least we set it up was, imagine I have a sorted list of elements. We get, in a second, to how we're going to get them sorted, and I want to know, is a particular element in that list..
好,二分查找的基本前提,或者是我们建立二分查找的基础,我们已经有了一个排好序的元素列表,我们就需要知道如何来快速的排序,如何从列表中找到特定的元素。
So let's just prove that to ourselves and figure out the bond order just using valence electrons.
让我们证明一下这一点,来看看只用价电子算出键序。
Let's assume that I could somehow get to the stage where I've got two sorted lists.
让我们来假设目前的情况是:,我已经有两个已排好序的列表。
I remind you, I know you're not really listening to me, but that's OK. I reminded you at the beginning of the lecture, I said, let's assume we have a sorted list, and then let's go search it.
没关系,我告诉过你在课程的开始,我们假设这是一个排好序的列表,然后才进行的搜索,那实际上有序列表从哪里来的呢?
If I look for, say, minus 1, you might go, gee, wait a minute, if I was just doing linear search, I would've known right away that minus one wasn't in this list, because it's sorted and it's smaller than the first elements.
如果我要查找-1,你可能要怒了,呵呵,等一等,如果我用的是线性查找,我不会知道-1不在这个列表中,但是列表是排好序的,1又比第一个元素小。
And this is now consistent with my claim that I have sorted a list of size N equals 1.
这与我之前所说的是一致的,我已经将N为1的一个序列排好了序。
He also shows, however, that normal politics is, itself, dependent upon extraordinary politics, periods of crisis, anarchy, instability, revolution, where the normal rules of the game are suspended.
然而他也同时了解到常态政治,本身有赖于破例政治,诸如危机,失序,不稳定,革命等时期,当游戏的常态规范,遭搁置。
And the basic idea was that we had some sort of a line and we knew the answer was somewhere between this point and this point.
去学习的二分搜索是有联系的,这种方法的基础思想,是我们有一个线性的序集,我们也明白答案在其中的某一段区间。
All right? Because if I don't do any swaps on a pass through the algorithm, then it says everything's in the right order.
好么?因为如果我,这一遍没有做任何交换,那么就意味着已经排好序了。
For hydrogen our bond order is going to equal 1/2, 2 minus 0.
对于氢原子键序等于1/2,2减去。
I have sorted with the smaller problem 1 because that smaller problem right now is of size 1 and so it's sort of obviously the case that this cup is now sorted.
对这个较小的问题我已经排好序了,因为在这个小问题中只有1个元素1,那么很明显,这个杯子已经是有序的了。
/2 So this would mean the bond order is equal to 1/2, and in terms of valence electrons, how many bonding valence electrons do we have?
这意味着键序等于,对于价电子,有多少个成键价电子?
So for the bond order we want to take 1/2 of the total number of bonding electrons, so that's going to be 4 minus anti-bonding is 4, so we end up getting a bond order that's equal to 0.
键序等于1/2乘以,总的成键电子数,也就是4,减去反键电子数,也就是4。,所以最后得到键序为0。
What kind of a bond is a bond order of 1?
什么样的键键序是1?
So now, I need to merge the sorted halves.
现在,我需要合并已排好序的部分。
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