电子对

It is suggested that pair production may play an important role in the X-ray emission region which is formed by the accretion of a compact object.

本文提出：在致密星的吸积所形成的 X 射线发射区中，电子对的产生起着重要的作用。

Alternatively, the spectral softening above 2 GeV could be due to gamma-ray absorption via photon-photon pair production on the soft X-ray photon field of the host active galactic nucleus, but such an interpretation would require the dissipation region to be located very close (l~100 gravitational radii) to the black hole, which would be inconsistent with the X-ray spectrum of the source.

另外的关于2 GeV以上能谱变软的可能解释是高能光子和寄主活动星系核的软X射线辐射场通过电子对产生反应而被吸收，但是这个解释要求反应区域要很靠近中心黑洞(1~100倍引力半径)，这和3C 454.3的X射线测量谱相矛盾。

Therefore there exist the so called vacuum fluctuations. In the QED, for example, there exist the effects of zero-point oscillations of photons, the effects of vacuum polarization of electron-positron paris, and so on. They all could result in observable consequences , such as the anomalous magnetic moment of the electron, the spontaneous emission of atoms in excited states, the Lamb shift and the Casimir effect, which have been verfied in experiments.

例如，在量子电动力学中真空中存在着光子的真空零点振动效应，正负电子对的真空极化效应等等，它们都导致可观测的物理效果，如磁矩反常、激发态原子自发辐射、兰姆移动、卡西米尔效应等。

A new way of calculating bond energy is proposed proceeding from LCAO-MO.

从LCAO-MO出发，给出了一个计算键能的近似方法，即EAB-∑∑CaiSabCbiεi为第i个占据分子轨道中的一对电子对A-B键键能的贡献。

In superconductors, the bosons are the pairs of bound electrons thAT form AT the Fermi surface

在超导体中，玻色子是在费密表面形成的束缚态电子对。

The sulphur atom in the intermediate has sp2 hybridization, and the remaining p orbital is symmetrical to the d orbital of the metal center. Thus, the lone pair on the p orbital can have interaction with the d orbital to form a π bond, which leads to the coplanarity of the center of Cp ring, Ru, P, S and Si atoms, rather than the deviation of P, S and Si atoms from the plane.

该中间体中，硫原子采取sp2杂化，硫原子剩余的一个p轨道与金属中心上的d轨道具有相同的对称性，因而该p轨道上的孤电子对可与金属中心上的d轨道形成π键，导致Cp环中心， Ru， S1， P和Si原子在同一平面内，而不是S1， P和Si原子偏离该平面。

It is almost always the electron-pair donor in a covalent Bond.

在共价键中它总是电子对的施主。

Covalent bond A chemical bond in which one or more pairs of electrons are shared between two atoms.

共价键：一般指两个原子接合时，通过形成共有电子对而产生的化学键。

Lewis acids are electron pair acceptors, and Lewis bases are electron pair donors.

P74 Lewis酸是电子对接收者，而Lewis碱是电子对给予者。

When determining/working out/predicting the shape of a molecule, we need to consider the fact that the repulsions between lone pairs and other pairs are stronger than those between bonding pairs and other pairs.

P18 在推测分子形状时，我们需要考虑孤对电子对其它电子对的斥力比成键电子对对其它电子对的斥力大。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。