Free radical is a group of one or more than one unpaired electrons stayed high energy excited state which molecule induced by physical or chemical factors produce .

自由基是由于分子在物理或化学因素作用下产生 含有一个或一个以上的 不 配对电子，处于一种 不 稳定的高能激发态。

There are B-H bond H-H bond and atom-molecular bond in BH + 4 and BH4 . There are four equivalent B-H bonds in BH-4 . In the case of BH4 there is an unpaired electron that occurs near the boron atom .

BH4+和BH4中都存在BH键、HH键和原子-分子键；而 BH4-中存在着四个相同的BH键；

All unpaired atom molecule and atomic group are called free radicals which exist in body widely .

凡是 具有 未 成对 电子的原子、分子或原子团都称为自由基，在体内分布广泛。

Literally a radical is a molecule that reacts easily with other chemicals because of an unpaired electron .

精确地说，因为有 孤电子，所以分子中的基团与其他化学物质反应更加容易。

Their unpaired electrons make the atoms behave like tiny permanent magnets that align with and strengthen an applied magnetic field .

它们的 未 成对电子使原子成为小型的永磁体，它们 沿 外磁场排列，并因此增强外磁场。

On the other hand the double helix DNA molecule with low symmetry has a lot of hanging bonds and the unpaired electrons of these hanging bonds may come into the π - electrons system .

另一方面DNA分子具有双螺旋结构，其对称性较低，分子中存在大量的悬挂键，这些悬挂键上的 未 成对电子也会进入π&电子系统。

Isolation of dorsal unpaired median ( DUM ) neurons from the central nervous system of the cockroach Periplaneta americana and patch-clamp recording of their voltage-gated sodium current

美洲大蠊中枢 DUM神经元的分离和电压门控Na~+电流的记录

So the only way I can get an unpaired is to put it alone in another orbital .

所以获得不 成对 电子的唯一方法是，把它放在另一个轨道上。

There is a EPR signal with the characteristics of delocalization unpaired electrons ;

有非定域化 不 成对电子特征的顺磁共振信号；

And what I want to point out that we just figured out for molecular orbital theory is that o2 is a biradical because remember the definition of a radical is when we have an unpaired electron .

我要指出的是，我们刚利用分子轨道理论，指导了O2是二价自由基，因为记住，自由基的定义是，有个未 配对的电子。

Because these things are unpaired we have already seen how unpaired electrons play a role in the Stern-Gerlach experiment .

因为它们都是 未 成对的，我们已经发现，在Stern-Gerlach实验中，未成对电子扮演怎样一个角色了。

According to the classification of free radicals the Character of the molecular orbital occupied by the unpaired electron was presented .

提出按 未 完成对电子 占据的分子轨道特性对自由基系统进行分类。

A free radical is a molecular fragment having an unpaired electron .

自由基是一种具有未 配对电子的分子碎体。

And I cannot have an unpaired electron in the same orbital .

我不可能在同一个轨道，得到 不 成对电子。

You can see that we have two unpaired electrons in this molecule here one in the pi2 p x star and one in the pi2 p y star orbital .

你们可以看到我们这个，分子力有两个 未 配对电子，一个在π2px星，一个在π2py星轨道。

So we can bring in four hydrogen atoms which will each contribute another unpaired electron .

我们可以引入4个氢原子，每个贡献一个 未 配对的电子。

Three unpaired electrons in nitrogen .

有三个 未 成 键电子在氮 原子中。

So now what we have is four unpaired electrons .

现在我们有4个 未 配对电子。

The results were analyzed with unpaired t test and correlativity test .

所有结果采用 非 配对t检验和相关性分析。

An atom or group of atoms with at least one unpaired electron .

至少含有一个 不 成对电子的原子或原子团。

But what we see we have is that we only have two unpaired electrons here .

但我们看到，我们只有两个 未 配对的电子。

The free radical theory of aging posits that substances with unpaired electrons attack the body 's molecules and cause the functional decline of organs over time .

衰老的自由基学说指出，自由基中的 不 配对电子攻击人体内其他物质的分子，从而进行 配对，引起器官功能衰退。

Free radicals develop when atoms in the body 's cells have unpaired electrons which can lead to damage to different parts of the cell including DNA .

自由基发生是当身体细胞中的原子有 单电子，能导致包括DNA在内的细胞不同部分的破坏。

And again we have the pairing of the unpaired electrons and we have two orbitals coming together .

同样，我们有 未 配对电子的配对，我们有两个轨道结合。

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。

S & we don 't have to hybridize it it already has only one unpaired electron in a1 s orbital .

s-我们不用杂化它，它已经有而且仅有一个 未 配对电子在s轨道里。

H2 So the simplest case we can think of is with h2 where we have two unpaired electrons each in a1 s orbital of a separate h atom .

最容易想到的例子是2，我们有两个 未 配对电子，每个都在一个分开的1s轨道上。

These unpaired electrons are the cause for the high chemical reactivity of free radicals .

由于这些 不 配对电子，这些分子或原子常 具有高度的化学活性。

Electron spin resonance technique ( ESR ) is a type of magnetic resonance . It can be used to study on asymmetric electron system . An unpaired electron system also can be studied with self-rotate marking method for ESR technique .

电子自旋共振（ElectronSpinResonance，简称ESR）技术是磁共振技术的一种，它可以对不成对的电子体系进行研究，而且对于 不 成对电子体系，可以采用自旋标记技术进行ESR的研究。