-
Mr.Obama spoke in advance of meeting at the U.N. late Wednesday of foreign ministers of the five permanent U.N.Security Council member countries and Germany - the P5+1, who have been trying to re-engage Iran in negotiations on its nuclear program.
VOA: standard.2009.09.23
-
The other thing is that we can re-write our h c n in terms of bonds.
还有一件事是我们可以用键的形式来表示氰化氢。
-
So we know that we can relate to z effective to the actual energy level of each of those orbitals, and we can do that using this equation here where it's negative z effective squared r h over n squared, we're going to see that again and again.
我们知道我们可以将有效电荷量与,每个轨道的实际能级联系起来，我们可以使用方程去解它,乘以RH除以n的平方,它等于负的有效电荷量的平方,我们将会一次又一次的看到它。
-
Let's suppose n is 1000, and we're running at nanosecond speed.
假入我们一秒钟运算十亿次，我们已经看过了对数级，线性增长的。
-
Like what the heck have we been spending our time for-- our time on with Bubble Sort and with Selection Sort and in fact there's plenty of other N squared sorts that we're not even gonna bother looking at.
真见鬼，我们竟然在-,冒泡排序和选择排序上花时间,而事实上，还有很多我们根本都不想考虑的,复杂度为N平方的排序方法。
-
So, we're going to have n independent assets; they could be stocks.
假设我们有n个相互独立的资产;,假设是股票。
-
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
-
So, what we're saying is that we have n equals to 4, and m sub I being equal to negative 2.
我们说的是ｎ等于４,ｍｌ等于－２
-
Negative 1 plus 0 should add up to negative 1, if in fact, we're correct for the c n anion.
负一加上零应该等于负一，如果是这样，我们对于氰离子的结果就是正确的。
-
So, if we think about the second case here where we have c n minus, now we're talking about a molecule with a net charge of negative 1.
那么，如果我们考虑的是第二个例子,也就是氰离子，那么现在我们讨论的是一个净电荷量为负一的分子。
-
In contrast, if we're taking the wave function and describing it in terms of n, l, m sub l, and now also, the spin, what are we describing here?
相反，如果我们考虑一个波函数,然后用ｎ，ｌ，ｍ小标ｌ,还有自旋，我们描述的是什么？
-
So we have 4 plus 5, but we're actually not done yet, because it's c n minus, so if we have minus, we actually have an extra electron in our molecule.
我们有四个加上五个，但是我们实际上还没做完，因为这是个负离子，所以如果我们有这个负号，那么我们的分子实际上还有一个额外的电子。
-
So, for example, down here I wrote that it was n 2 and that it was h 2, but when I re-wrote the molecules up here, you saw that it's an h h single bond where it's a nitrogen-nitrogen triple bond.
比如，在这下面我写的是氮分子2,而这个是氢分子，但我在上面把这些分子的形式改写了，大家可以看到,这是一个氢与氢之间的单键，含一个氮与氮之间的三键。
-
So let's just think exactly what this means, and that means that if we take away function and we define it in terms of n, l and m sub l, what we're defining here is the complete description of an orbital.
让我们来考虑一下这是什么意思，这是说如果我们不考虑波函数,而是用ｎ，ｌ，ｍ下标ｌ来定义它，我们定义的,是一个轨道的完整描述。
-
So another way to say that is, in a sense, if we're thinking about the excited state of a hydrogen atom, the first excited state, or the n equals 2 state, what we're saying is that it's actually bigger than the ground state, or the 1 s state of a hydrogen atom.
换句话说，如果我们激发一个氢原子，第一激发态或者说ｎ等于２的态，我们说它比氢原子基态,或者说１ｓ态要大。
-
And I want to really highlight here we're talking about for a hydrogen atom orbitals - with the same n value have the same energy.
我想强调的是,我们所说的,都是对单个的氢原子,和言的,对于同样的n值能量相同。
-
So, for example, if we're talking about the n equals 2 state, all of these four orbital descriptions are going to have the same energy.
例如，当我们说n等于2的态，所有这四个轨道的能量,都是相同的。
-
We can plug this in further when we're talking about the visible part of the light spectrum, because we know that for n final equals 2, then that would mean we plug in 2 squared here, so what we get is 1 over 4.
当我们讨论可见光谱的时候,我们可以把这个代进去,因为我们知道n末是等于2的,这意味着我们可以。
-
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。
-
We're getting further away from the nucleus because we're jumping, for example, from the n equals 2 to the n equals 3 shell, or from the n equals 3 to the n equals 4 shell.
我们将会离原子核越来越远,因为我们在跃迁，比如从，n，等于，2，的壳层到n等于，3，的壳层，或者从，n，等于，3，的壳层到n等于，4，的壳层。
-
So if we have a 3 d orbital, we're talking about n minus l minus 1, what is n equal to? What is l equal to?
如果我们有一个3d轨道，我们用ｎ减去ｌ减去１,ｎ等于多少？ｌ等于多少？
-
psi So we're going to for psi, and before that, we're going to figure out that instead of n just that one quantum number n, we're going to have a few other quantum numbers that fall out of solving the Schrodinger equation for what psi is.
我们要讲到，但在这之前，我们已经知道了,主量子数，现在我们需要知道，其他一些,解psi的薛定谔方程,所需要的量子数。
-
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。
-
That's why in the earlier models of the atom, they're not horrible to sometimes think about just each n value as a little ring around.
这就是为什么在早期原子模型中，人们没有感觉到把每一个，n，都想象成,一个绕核的小圆圈有什么不妥。
-
And when we make these comparisons, one thing I want to point out is that we need to keep the constant principle quantum number constant, so we're talking about a certain state, so we could talk about the n equals 2 state, or the n equals 3 state.
当我们做这些比较时，我想指出的一件事是,我们需要保持常量原则,保持量子数是常数，所以我们在讨论一个确定的态时，我们可以谈论n等于2的态，或者n等于3的态。
-
So if we're keeping n the same, we look and what we saw was that size actually decreases as we increase the value of l.
如果我们保持ｎ不变，我们看到随着ｌ值的,增大尺寸变小。
-
So we know that we're in the n equals 5 state, so we can find what the binding energy is here.
我们知道,我们在n等于5的态，我们可以找到结合能是多少。
-
So instead of being equal to negative z squared, now we're equal to negative z effective squared times r h all over n squared.
这里不再等于-z的平方，现在我们等于-有效的z的平方,乘以RH除以n的平方。
-
And when we talk about size, I'm again just going to say the stipulation we're not talking about an absolute classical concept here, but in general we're going to picture it being much further away from the nucleus as we move up in terms of n.
当我们说到尺寸时，我们只是说――,经典的绝对的概念，而是它大约,离原子核有多远。
-
So, there are 2 different things that we can compare when we're comparing graphs of radial probability distribution, and the first thing we can do is think about well, how does the radius change, or the most probable radius change when we're increasing n, when we're increasing the principle quantum number here?
当比较这些径向概率分布图,的时候，我们可以比较两个东西，第一个就是考虑当我们增加ｎ,当我们增加主量子数的时候，半径怎么变，最可能半径怎么变化？
应用推荐