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Senator Kit Bond of Missouri told Fox News Sunday many of those returned to Yemen are now active in al-Qaida.
VOA: standard.2010.01.03
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So there's not a lot of room in the government bond market or other high-quality bond markets to generate excess returns.
所以对于政府债券或者优质债券,超额收益的空间不大
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It's much more relevant to set our zero point energy as the separation of a bond in terms of talking about the reactions that we'll usually be dealing with here.
更好的是把零点能定在,键断裂的时刻,在讨论化学反应的时候,而我们以后将经常遇到化学反应。
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Likewise, the element that is a good electron acceptor in an electron transfer reaction is going to be the element that is going to hog the electrons in a covalent bond.
同样的，这个元素在一个电子转移反应中,是个很好的受赠者它将成为在共价电子,中吸引电子的元素。
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The yield-to-maturity on an indexed bond is already in real terms because the coupons are indexed to inflation.
这种债券的到期收益率,就是实际收益率,因为票息已经被通胀指数化了
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And the activation in another area of the brain, the interna insula that would help us to put the oppisite choice of the bond running away from risk.
而大脑中另一区域的活动，即岛叶内部活动，可以帮助我们作出相反决策,即选择“债券“来远离风险。
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Well, if it is a good electron donor in an electron transfer reaction, if the same element finds itself in a covalent bond, it is going to be a good electron donor, although it is not full transfer.
如果它是一个在电子反应中,的好捐赠者，如果相同电子发现他在共价电子里，它将成为一个好的捐赠者，虽然没有完全转换。
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All right, so that's really all there is to thinking about valence bond theory in terms of the most simple explanation here.
好了，这就是,价电子轨道理论的,最简单的解释。
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We can also think about the distance, the bond distance. So, which would you say is going to be shorter in this case?
我们还可以考虑一下距离，键的距离那么，大家认为其中哪一个键会更短一些？
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Because step five is that we need to fill in our bonding electrons, and we start it with filling in two electrons per bond.
因为第五步要做的是将我们的成键电子填在这，所以我们开始在每个键处填上两个电子。
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As we see a little bit later, I could talk about the carbon-hydrogen bond in methane where there is a plurality of bonds. In this case, there is only the one bond but I just want to get the formulas.
因为我们后来看到一点点，我能讨论甲烷中的碳氢共价键,那有许多共价键，这种情况下，这只有一条共价键,但我想得到氟。
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We're already using it up in this pi bond here, so that means we're limited to only two other spots on the molecule, so we have three.
我们已经把它用到这个π键里去了，所以这意味着,我们在分子里只剩下两个位置，所以一共是三个。
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So it's very important to be keeping in mind that any time you see a double bond, you have a pi bond there, so you're not going to see any rotation around the bond axis.
所以你们要记住,任何时候你们看到一个双键，这里面有π键，你们不会看到关于键轴的任何转动。
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The first one will be above and below the bond axis is where we'll see the electron density, and the second will be perpendicular to that, so it will be a density in front of and behind the bond axis.
第一个是在键轴之上和之下,我们可以看到电子密度，另外一个垂直于它，所以在键轴之前和之后有电子密度。
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/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？
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So, in talking about covalent bonds, we should be able to still apply a more general definition of a chemical bond, which should tell us that the h 2 molecule is going to be lower in energy than if we looked at 2 separate hydrogen atom molecules.
那么，既然提到了共价键，我们应该还可以,给化学键下一个更普遍的定义,那就是告诉我们氢分子能量应该更低,与两个分开的氢的单原子分子相比。
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Any time two orbitals come straight on together in that internuclear axis, you're going to have a sigma bond.
任何时候两个轨道,在核间轴上直接到一起，你就能得到sigma键。
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The bond markets,in general, and the high-quality bonds in particular are probably easiest to value.
一般来说,债券市场,尤其是优质债券,可能是最容易定价的
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Well, in '26, the-- i've shorted the one-period bond and so I have to pay out one dollar, but that's exactly what I wanted to do.
6年 我卖空的一年期债券到期了,我需要偿还一美元,不过这恰是我要做的
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So we know we always want to have our systems in as low an energy as possible, so it makes sense that a bond would happen any time we got a lower energy when we combine two atoms, versus when we keep them separate.
我们知道我们总是希望使我们的系统,处于能量尽可能低的状态，因此就应该有化学键产生,一旦我们合并两个原子之后体系的能量变得更低，相较于分开时。
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So we're going to finish talking about molecular orbital theory, we'll switch over to discussing bonding in larger molecules, even larger than diatomic, so we'll move on to talking about valence bond theory and hybridization.
我们要结束关于分子轨道理论的讨论，转向讨论大分子的成键，比二原子分子更大的分子，我们会继续讨论价电子成键理论,和杂化。
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Yeah, we'd expect to see a single bond in hydrogen.
嗯，我们预计在氢分子里会看到一个单键。
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The Born-Haber cycle was designed to allow us to calculate the energetics of, in particular,the ionic bond.
伯恩哈勃循环,可以让我们计算能量，特别是离子键的。
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So in order to rotate a double bond, you have to actually break the pi bond, so essentially what you're doing is breaking the double bond.
为了能够旋转双键，你必须打破一个π键，本质上我们要做的就是打破双键。
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In valence bond theory, the focus is on discussing the bonds, but it should look very familiar to you, because there's two types of bonds that we want to discuss here.
在价电子成键理论中，所关注的是讨论成键，但这对于你们来说应该很熟悉，因为这是我们要讨论的两种键。
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The ability of an atom to attract electrons, and in particular, in a covalent bond.
原子对电子的吸引能力，特别是在共价键中。
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So, using our simple valence bond theory, what we would expect is that we want to pair up any unpaired electrons in methane with unpaired electrons from hydrogen and form bonds.
利用简单的价电子成键理论，我们预计,要把所有甲烷中没有配对的电子,和氢原子中没有配对的电子配对来形成键。
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So in terms of thinking about ethane, we actually have two bond types that we're going to be describing just in terms of the carbon-carbon bond and then the carbon h bonds.
对于乙烷，我们有两种键,我们继续讨论一下,碳碳键,和碳氢键。
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So, what this lets us do now is directly compare, for example, the strength of a bond in terms of a hydrogen atom and hydrogen molecule, compared to any kind of molecule that we want to graph on top of it.
因此，这让我们现在可以做到直接进行比较，比如，将一个氢原子，和一个氢分子的键的强度，与任何其它类型的分子进行比较,我们只需要把它的曲线也画在这幅图上。
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If I'm going to be active in terms of managing my portfolio, should I spend my time and energy trying to beat the bond market?
如果我想主动地管理我的投资组合,是否应投入时间和精力,专注于战胜债券市场呢
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