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The experts at N.I.H.say you may have to repeat this process a few times.
VOA: special.2010.03.31
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Boy, there's a dumb question, because I've been telling you n log n for the last two lectures the complexity is n log n, but let's see if it really is.
孩子们，这是一个愚蠢的问题，因为前两节课的时候我就已经告诉你们了,复杂度是,但是让我们来看一下是不是真的是这样。
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But it grows pretty rapidly, as n goes up, and I'm going to show you an example in a second.
解决问题需要的时间会急剧增长，一会儿我会让大家看个例子的,我想大家注意的还是。
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So, why don't you go ahead and tell me, keeping that in mind, which atom in terms of h c or n would you expect to be in the center of hydrogen cyanide?
那么，请大家来告诉我，并且记住它，你认为氢，碳和氮中哪个原子,应该在氰化氢的中间呢？
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It turns out there's a new function strlen S-T-R-L-E-N that you probably have not used yet called strlen, S-T-R-L-E-N, programmers early on and still like to be succinct but communicates sufficiently what they mean.
结果这里有个新的函数,你可能没有使用过，叫做，早期的和现在的程序员喜欢简洁地,但是能充分的传达他们的意思。
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He constantly warns his son, who was kind of an n'er do well, that, "You better work hard, " Or, "You better work a little harder and pay more attention to what you're doing.
他不断提醒那一事无成的儿子,"你要加倍用功,哪怕只是稍微用点心,对你做的事要更上心
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So, the optimal thing to do if you live in a world like this n is to get n as large possible and you can reduce the standard deviation of the portfolio very much and there's no cost in terms of expected return.
如果现实中也这样简单的话,那么你就尽量增大,这样就能让投资组合的标准差,就会大大降低,从预期收益率的角度来看,这样做的成本是零。
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But, once you get beyond n equals one, 2s2 2p6 3s2 3s6 it's always 2s2, 2p6, 3s2, 3s6.
但是，一旦你让n大于，它就总是。
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N And we can keep doing"T","A","N", ? and I think you see where it is going.
然后接着移动字母，T，A，和，我想大家应该知道后面是哪些字母了吧。
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N You can even abbreviate and put Y or N.
甚至可以缩写Y或。
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If you start with only one, you have two pieces of DNA, then you'll get 2 to the Nth fragments after N cycles because each cycle you're doubling the number.
如果你从仅仅一个DNA开始,你有两条DNA链,经过N次循环后,就得到二的N次方个DNA片段,因为每次循环都使其数量翻倍
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And if you put this in the well-ventilated area, if you prepare this outside, the h c n gas will actually be released into the air, so you're safe, you can eat it later.
而如果你把它们放在通风良好的地方，在室外处理，那么氰化氢气体,将会被释放到空气中，这样你就安全了，过后就可以吃了。
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And we talked about the equation you can use for radial nodes last time, and that's just n minus 1 minus l.
我们讲过这个用于,计算径向节点的方程，也就是ｎ减去ｌ减去１
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Ah, n times, because for each value of i, I'm going to do that m thing, n*m so that is, close to what you said, right?
因此这就和你说的差不多了对不对？,这个问题的复杂度为，让我写下来，是-对不对，是？
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But mathematically, we've mentioned this before, log N or really to be precise, log base 2 of N, is the way you express this mathematically.
但从数学上说，之前我们已经提到过了，准确地说是log，N，以2为底N的对数，这就是它在数学上的表示。
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If you have a sample with n observations, it's the summation I = 1 to n of xi/n--that's the average.
如果你有n个观测值,对Xi从i=1到n求和再除以n
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Down here, I've just got two things to merge, and then I've got things of size two to merge and then things of size four to merge. But notice a trade off. I have n operations if you like down there of size one.
但是n的大小是不同的，是吗？在这里我们只要合并两个元素,然后是合并长度为2的列表,接下来是合并长度为4的列表,但是观察一下之间的权衡关系。
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n If you want a literal percent, it's %% and then backslash n.
如果你想要一个百分比常量，就用%%，然后，反斜杠。
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Now, it's kind of a cyclical argument here because how do you sort the left half of N elements?
在这儿有点循环的意思,那么如何对N个元素中的左半部分进行排序呢？
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So, it turns out that n is not the only quantum number needed to describe a wave function, however. There's two more you can see come out of it.
事实上，n不是描述一个波函数需要的,唯一的量子数，你们可以看到，还需要，两个量子数。
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So the key word here is that we asked you to identify the third excited state. So, what white is n equal 4 Ok to for the third excited state? 4 OK.
这里的关键的地方是我,要你们找到第三激发态,第三激发态的n等于多少？
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So the running time of the problem where the input is T of size N as expressed here formulaically, T of N, the running time of an algorithm, given an input of size N. You know what?
因此一个输入为N的问题的运行时间,在这儿的公式表示为，如果输入为N，那么此算法的运行时间,是多少呢？
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N Well, here is a list of size N. How many times can you divide a list of size N by 2, right?
这是一个大小为N的列表，将一个大小为,的列表除以2需要几次呢？
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You have n branches on the tree and you count the number of leaves and sum them up.
一共有n根树枝,你数了叶子的数量然后把他们加起来
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Thank you. Sorry, I've got the wrong glasses on but you're absolutely right, and in case the rest of you didn't hear it, n squared.
我看不清，但你绝对是对的,你们其他人可能没听清,是n的平方。
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How many times you can divide N by 2 before you get down to 1?
在得到1之前需要将N除以2做几次呢？
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If n is greater than zero, I decided I would say, "You picked a positive number, backslash n," so put the cursor on the next line, else if n was not less than zero, I say, "You picked a negative number, backslash n."
如果n比0大，我就决定来说：,“你选择了一个整数，反斜杠n“，所以你把光标,放在下一行，另外如果n不小于0，我说：,“你选择一个负数，反斜杠n“
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And when you talk about n for an orbital, it's talking about the shell that shell is kind of what you picture when you think of a classical picture of an atom where you have 1 energy level, the next one is further out, the next one's further away.
当你们谈到，某个轨道的n时，你们说的是壳层，壳层就是,你想象，一个原子,的经典图像时的场景,你有一个能级，下一个再更远的地方，再下一个又更远。
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And what you can see is that 0 for any n that has an l equals 0, you can see here how there's only one possibility for and orbital description, and that's why we don't need to include the m m when we're talking about and s orbital.
你们可以看到,对于任何n，如果l等于，你们从这里可以看到，只有，一种,可能的轨道描述，所以,当讨论s轨道的时候,不需要考虑。
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And you have to get N from experimental evidence.
同时你们也会通过实验得到N的值。
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