原子结构

The results show: the strongest bond is the Al-Al bond in the segregated cell without containing vacancy, where the Al atomic covalence radius is greater than that of Li atom in the cell; while the strongest bond is the Al-Li bond in the segregated cell containing vacancy, and the Al atomic covalence radius in the cell is less than that of Li atom. Since the difference of electronagativity between the Al and Li atoms is obvious, it is inclined to formed the Al-Li segregated cell of short range order structure in the condition of vacancy present. The short range order structure containing vacancy is probably the embryo or precursor structure of the metastable phase δ′(Al3Li). Because the strongest covalent bond in the Al-Li-vacancy segregated cell in alloy formed in quenching is the main strength reason for supersaturated solid solution of alloy. The bond net of succeeding precipitation of δ′(Al3Li) has the picture of anisotropic Al-Al bonding and the bond intensity enhanced. Since the δ′(Al3Li) is coherence with matrix, the bond net strength is enhanced by the precipitation of δ′(Al3Li) and so strengthen the alloy.

计算结果表明：不包含空位的偏聚晶胞的键络最强键为Al—Al键，其中Al原子的共价半径较Li原子的共价半径要大；而含空位的偏聚晶胞的最强键为Al—Li键， Al原子的共价半径要比Li原子的共价半径要小；在空位存在的情况下，由于Al原子与Li原子的电负性相差明显，促使Al和Li原子结合，倾向形成Al-Li短程序结构偏聚区，这种含空位的短程序结构很可能就是δ′(Al3Li)亚稳相的前兆结构和生长胚胎；由于Al-Li-空位有序偏聚晶胞的Al—Li键络比基体键络要强许多，因此，淬火过程中合金生成的Al-Li-空位偏聚晶胞对合金过饱和固溶体起主要强化作用；后续析出的δ′(Al3Li)亚稳相键络各项异性显著，键络强度明显提高；由于Al3Li与基体共格，其大量均匀弥散析出起到提升基体整体键络强度，同样对合金产生强化作用。

The results show: the strongest bond is the Al-Al bond in the segregated cell without containing vacancy, where the Al atomic covalence radius is greater than that of Li atom in the cell; while the strongest bond is the Al-Li bond in the segregated cell containing vacancy, and the Al atomic covalence radius in the cell is less than that of Li atom. Since the difference of electronagativity between the Al and Li atoms is obvious, it is inclined to formed the Al-Li segregated cell of short range order structure in the condition of vacancy present. The short range order structure containing vacancy is probably the embryo or precursor structure of the metastable phase δ'(Al3Li). Because the strongest covalent bond in the Al-Li-vacancy segregated cell in alloy formed in quenching is the main strength reason for supersaturated solid solution of alloy. The bond net of succeeding precipitation of δ'(Al3Li) has the picture of anisotropic Al-Al bonding and the bond intensity enhanced. Since the δ'(Al3Li) is coherence with matrix, the bond net strength is enhanced by the precipitation of δ'(Al3Li) and so strengthen the alloy.

计算结果表明：不包含空位的偏聚晶胞的键络最强键为Al-Al键，其中Al原子的共价半径较Li原子的共价半径要大；而含空位的偏聚晶胞的最强键为Al-Li键，Al原子的共价半径要比Li原子的共价半径要小；在空位存在的情况下，由於Al原子与Li原子的电负性相差明显，促使Al和Li原子结合，倾向形成Al-Li短程序结构偏聚区，这种含空位的短程序结构很可能就是δ'(Al3Li)亚稳相的前兆结构和生长胚胎；由於Al-Li-空位有序偏聚晶胞的Al-Li键络比基体键络要强许多，因此，淬火过程中合金生成的Al-Li-空位偏聚晶胞对合金过饱和固溶体起主要强化作用；后续析出的δ'(Al3Li)亚稳相键络各项异性显著，键络强度明显提高；由於Al3Li与基体共格，其大量均匀弥散析出起到提升基体整体键络强度，同样对合金产生强化作用。

In addition, some modifications on several computational methods are also presented. Using LMTO method the electronic structure of several systems are studied, and some results are obtained. They are: The ideal Nb (100) surface has three surface states, the multi-layer relaxed surface has two surface states. The surface energy of the ideal surface is higher than that of the relaxed surface, that means that the multi-layer relaxed surface is more stable than the former one, which supports the LEED results. The mono-layer relaxed Ag (111) surface is the most stable one among several" stable surface models"presented by several researchers. The surface energy of Ag (111) surface is higher than that of surface Ag (001), which supports some experimental results such as different reaction rate at different surface orientations for the same material. The surafce states of Si (111) surface not only locate near the Fermi level, but also in the valence band, which agrees well with Cohen's conclusion. Si (111)-H is an effective model for analysing the surface states and H adsorbed on the back surface is a good method for improving the convincingness of the results obtained on thinner slab models. The surface stability depends on three different kinds of MoSi〓(001) surfaces, the surface with mono-layer Si is the most stable one, and the surface with Mo at the first layer is the most unstable one among them. These are consistant with the Kemoda's experimental results. The valence bands of clean or K adsorbed CdTe (111) surface agrees well with the synchrotron radiation studies. The surface of CdTe (111) consists of four kinds of surface models which show different surface electronic structures and different surface structure stabilities. The conclusion agrees well with Wu's experimental work. The different absorbed alkali metals on the CdTe (111) surface give different adsorption characteristics which have relations not only with the valence electrons, but also with the core ones of the alkali metals. The electonic structures of Si-C alloys are different from that of Si-Ge alloys, and the energy band gaps of Si-C alloys do not increase linearly with Carbon concentration, our conclusion supports Alexander's results, but conflicts with Soref's one.

现分述如下： LMTO方法及其应用方面：1）通过对Nb（100）表面电子态分析发现清洁理想表面有三个表面态，多层弛豫表面有两个表面态；表面能大小说明多层弛豫表面更稳定，支持了LEED结果。2）通过对采用不同方法获得的几种不同Ag（111）表面稳定结构的表面能计算分析，给出了单层弛豫表面为Ag（111）表面的最稳定结构；从Ag（111）单层弛豫表面和Ag（001）表面的表面能比较，发现了Ag（001）表面表面能要比Ag（111）小的，表明了同种物质不同表面取向将表现出不同物理、化学性质，这是与实验中得出的结论是吻合的，3）通过对Si（111）表面态分析，不仅发现了Si（111）表面不仅具有居于费米能级附近的悬挂键所对应的表面态，而且还有很多表面态位于价带能量范围内，与Cohen等结果一致，H饱和slab模型背表面相当于增加了slab层的厚度，是一有效的变相增加slab层厚的方法，弛豫表面较清洁理想表面价带谱们低能端的少许移动，预示着总能降低，说明弛豫表面较清洁理想表面稳定。4）MoSi〓具有三种表面，从费米能级上态密度值大小得到单层Si表面最稳定，Mo原子为表层原子的表面最不稳定，双层Si原子表面居中的结论，这与Kemoda等人实验结果是一致的。5）通过对CdTe（111）表面表面电子态、表面结构稳定性及表面H、碱金属吸附的电子结构系列研究，不仅得出了CdTe（111）清洁及碱金属K吸附价带谱与同步辐射光电子谱相吻合的结果，而且发现了CdTe（111）表面具有四类不同原子近邻特征，表现出四类不同的表面结构及电子结构特征：不同表面态分布、不同的表面结构稳定性（表层原子与次层原子成三键有一悬挂键的表面要比表层原子与次层原子成一键有三悬挂键稳定（与Wu等人实验结果一致））、不同的H吸附特性。

Crystal lattice constants are close to other experiment results. Three kinds of chemical bonds exist among Mg and B atoms, between magnesium and boride is ionic bond and metallic bond is the predominant interaction in the layer formed by magnesium atoms. A strong covalent bond in the form of sp2 hybrid between boride atoms is the most important factors which can affect the transition temperature of MgB2. Population analysis clearly shows that electrons are transferred from Mg to B, as a result, the electron-phonon coupling in the layer of B is very strong.

规范保守赝势的计算结果表明，晶格常数与实验值误差在很小的范围内，分析了引起MgB2(001)面结构超导转变时电子浓度和偏态密度的变化情况，发现构成该超导体结构的成键有3种，着重从结构的电子浓度变化分析了其超导特性，六角蜂窝状结构中硼原子间相互作用为sp2杂化的共价键，镁原子和硼原子之间是离子键结合，镁原子层是金属键结合，镁原子的价电子部分转移到硼原子的pz轨道，部分电子为镁原子层共用。

All the atomic shells for the examined atoms are shown and the """"""""reasonable"""""""" electron numbers are given. Especially for atomic subshell and shell structure of transition elements are correctly predicated. This theory provides uniform and objective criterion for shell structure of isolated atom, and the intrinsic and theoretical basis for the shell structure given by other methods. This theory provides a kind of new method for describing the atomic shell structure.

该理论可以揭示原子的全部壳层结构，产生基本合理的电子数，尤其是正确的预示了原子的亚壳层结构和过渡元素的壳层结构；依据该理论所确定的原子内禀壳层结构为孤立原子的壳层结构提供了统一的客观标准，为其它方法所确定的壳层结构提供了内在的理论依据；原子内禀壳层结构理论为度量孤立原子中处于束缚态下电子排布的壳层结构，提供了清晰的物理图像，为描述原子的壳层结构提供了一种新方法和新理论。

In the 2A1 distorted trigonal bipyramid structure ,the single non equivalent Ga atom has the population of 4s 4p ,while the two equivalent Ga atoms have the population of 4s 4p .this compares with a Ga population of 4s 4p in the undistorted D3h structure ,hence the jahn-teller distortion causes depletion of the charge density on the 4s orbital of the non-equivalent Ga atom, and enhancement of charge density on the 4s orbital for the two equivalent atoms .an opposite trend is observed for the 4p orbitals of these Ga atoms .the P population for the two equivalent atoms is 3s 3p .the populations of the other 2B1 state with the edge-capped tetrahedral structure are similar with the exception that all three Ga atoms have similar but not identical populations .

在2A1被变形的三角bipyramid结构，唯一非等效Ga原子有4s 4p的人口，而二个等效Ga原子在未变形的D3h结构有4s 4p 。this的人口和4s相比4p的Ga人口，因此jahn出纳畸变在non-equivalent Ga原子的4s轨道导致电荷密度的取尽，并且电荷密度的改进在4s轨道为二个等效原子。an在趋向对面对这些Ga原子4p轨道被观察。the人口为二个等效原子是另一个2B1状态3s 3p 。the人口与边缘加盖的四面体结构是相似的P 除之外全部三个Ga原子有相似，但不相同人口。

The calculated results show that azido in azides has linear structure , the most optimized CaN6 has linear structure , and the most optimized (CaN6)n (n=2～5) clusters have chain structure of perpendicularity of approximate diamond composed by two azido with two Ca atoms . The middle N atoms of azido show positive, the N atoms at both ends of azido show negative, and the N atoms effected with Ca atoms directly show more negative . There is strong ionic bond between the Ca and N atoms. The IR spectra of the most optimized (CaN6)n (n=1～5) clusters have four vibrational sections , the whole strongest vibrational peak lies in 2195～2280cm-1,and the vibrational mode is anti-symmetric stretching vibration of N-N bonds in azido . Stability analysis show that (CaN6)3 and (CaN6)5 clusters are more stable than other clusters .

结果表明，叠氮化合物中叠氮基以直线型存在，CaN6团簇的最稳定结构为线型结构，(CaN6)n(n=2～5)团簇首先由两个叠氮基与两个Ca原子构成一个近似菱形，再由菱形相互垂直形成链状最稳定结构；叠氮基中间的N原子显示正电性，两端的N原子显示负电性，且与Ca直接作用的N原子负电性更强，金属Ca原子和N原子之间形成很强的离子键；(CaN6)n(n=1～5)团簇最稳定结构的IR光谱分为4个部分，其最强振动峰均位于2195～2280cm-1，振动模式为叠氮基中N-N键的反对称伸缩振动；稳定性分析显示，(CaN6)3和(CaN6)5团簇相对于其他团簇较为稳定。

Van de Graaff generators are the current workhorses of nuclear structure research.

范德格喇夫加速器是研究原子结构的通用工具。

How unlikely, that a short-lived biped on a two-bit planet should be able to gauge the speed of light, lay bare the structure of an atom, or calculate the gravitational tug of a black hole.

一个微不足道的行星上的短命两足动物居然能测出光速、揭示原子结构、计算黑洞的重力作用，多难以置信！

Perutz successfully worked out the different arrangements of the structures of all the atoms of haemoglobin.

Perutz成功地发现了所有血红蛋白原子结构的不同组成。

If you are unfortunate enough to the lovelorn, please tell me, I will help you out, really, please contact me!

如果你不幸失恋了，请告诉我，我会帮助你摆脱困境，真的，请联系我啦！

China's plan to cut energy intensity by 20 percent and pollutant discharges by 10 percent between 2006 and 2010 is a case in point.

中国计划在2006年到2010间降低20%的能源强度和减少10%的主要污染物排放，就是一个这样的例子。