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X-ray diffraction is one of the most common and efficient ways to measure a superlattice structure. This dissertation displays the detail results for characterization of Ge〓Si〓/Si superlattices by x-ray diffraction (including x-ray small angle diffraction and double crystal diffraction). It was found, when the growth temperature is lower, the intensities of xray small angle diffraction peaks are modulated by a periodical function, which indicates that both sets of interfaces of the superlattice is highly flat; when the growth temperature is higher, the diffraction peak intensities are simply decay with the increase of diffraction vector, which indicates that one set of interfaces is highly flat but another is not; when the growth temperature is very high, the diffraction peaks are reduced more rapidly, which indicates that both sets of interfaces are not ideal.

本文详细介绍了用X-射线衍射（包括X-射线小角衍射和双晶衍射）方法对Ge〓Si〓/Si超晶格结构特性测试的结果，尤其是发现，当Ge〓Si〓/Si超晶格的生长温度较低时，X-射线小角衍射谱峰的强度随着衍射波矢的增加而周期性调制，表明超晶格的两套界面都十分平整；当生长温度较高时，Ge〓Si〓Si超晶格的X-射线小角衍射谱峰的强度随着衍射波矢呈简单的衰减变化，对应于超晶格内有一套界面不平整的情况；当生长温度进一步提高时，X-射线小角衍射峰明显减少，表明超晶格内两套界面都不理想。

Ti-Si composite materials are mixed at atomic scale, and Ti-O-Si bond appears in all of the samples with different TiO2 content; the mixed oxides are mainly existed in the form of amorphous pattern, anatase appears when the TiO2 content is more than 80%, but compared with the intension of pure TiO2, it has not integrate structure. The acetic content has great influence in the specific area and crystal structure of the mixed oxides. 20TiSi has good heat stability, still possesses 11m2/g after calcined at 1100℃; calcinations on the large scale of temperature does not cause the break of Ti-O-Si bond, TiO2 is well dispersed in 20TiSi calcined at 1100℃, and it still existed in the form of amorphous.

结果表明：制得的Ti-Si复合氧化物具有很高的比表面积，在TiO_2含量为10％时达到681.5m~2／g，Ti原子进入Si-O四面体结构中，形成Si-O-Ti键，复合氧化物的稳定性好，当TiO_2含量低于60 wt％时，以无定型形式存在；当含量为80％时，出现锐钛矿型TiO_2，但与纯TiO_2相比晶型不完整：醋酸对Ti-Si复合氧化物的比表面积、晶型都有很大的影响；TiO_2含量为20％的20TiSi经1100℃高温焙烧后，仍有较高的比表面积(11m~2／g)，稳定性好，在较宽的温度范围内焙烧，没有引起Ti-O-Si键的断裂，分散度高，没有出现晶型TiO_2。

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。

With rising of Si concentration in the alloy melt, small Si-Si peaks were found in Gaussian separation of RDF of the melts, implying Si-Si clusters with covalence bond in the melt, whose area firstly reduce in low temperature range (below 875℃) and secondly increase in high temperature (over 875℃).

分解结果表明，在共晶与过共晶熔体结构中，存在着Si-Si共价键的小峰，该峰对应着熔体的Si原子集团，其数量随着温度的升高，在测量温度范围内先降低后升高。

Modifying agent Sr can weaken the covalence bond of Si-Si clusters in the Al-Si melts, reducing the size and amount of Si-Si clusters, and restrain the segregation of Si atoms in melt and strengthen the nucleation of Al phase.

变质元素Sr具有削弱液态Al-Si合金中Si-Si共价键的倾向，使得合金液中的Si原子集团的尺寸与数目减小，从而抑制了Si相的优先析出。

It can be obtained that the structure of liquid Fe〓Si〓 alloys changes to be more open with increasing Si concentration. The Gauss decomposition of radial distribution function exhibits a Gaussian peak at about r=0.370nm on RDF of pure liquid Si as well as Fe-Si alloys, which means there are Si-Si covalence both in pure liquid Si and Fe-Si alloys.

对纯Fe、纯Si和Fe-Si合金的径向分布函数的Gauss分解显示，在纯Si径向分布函数的r=0.370nm附近存在一Gauss峰，表明纯Si熔体中存在Si-Si共价键；而在Fe-Si合金径向分布函数的同一距离范围内也存在一Gauss峰，表明Fe-Si合金熔体中也存在Si-Si共价键。

On the other hand, in the ground state of NiSin(n=1-6) and Ni2Sin(n=1-6) clusters, electronic charges is transferred from Si-Si bond to Ni-Si bond, forming Ni-Si covalent bond, and the Mulliken overlap population of Ni-Si is positive, which I'orming bonding orbital and contribute to the stability of clusters.

另外，基态NiSi_n(n=1-6)团簇中，电荷从Si-Si键向Ni-Si键转移，形成Ni-Si共价键，Ni-Si重叠布局为正，为成键轨道，增强团簇的稳定性。

After linearisation by restriction enzyme PacI, the recombinant plasmids were transfected into HEK 293-cells and amplified to give large quantities of infectious recombinant adenovirus carrying the sequences of si-FOXO1s, designated Ad-si-FOXO1-1, Ad-si-FOXO1-2, Ad-si-FOXO1-3, Ad-si-FOXO-pan and Ad-NC, respectively.

人工合成si-FOXO1s的cDNA序列，退火形成的双链cDNA克隆到腺病毒表达载体pAdTrack-CMV上，经PmeI线性化后与pAdEasy-1细胞内同源重组，最后在HEK293细胞中包装为重组腺病毒，分别命名为Ad-si-FOXO1-1、Ad-si-FOXO1-2、Ad-si-FOXO1-3、Ad-si-FOXO-pan和Ad-NC。

Finally, the relationship between the performance of doped a-Si: H and process conditions is discussed, which includes the deposition of n〓-a-Si: H and p〓-a-Si: H, the relationship between dark conductivity, photoconductivity of boron light-doped a-Si: H and process conditions, and the relationship between the stability of LCLV and S-W effect of a-Si: H.

最后讨论了掺杂a-Si：H的性能与工艺条件的关系，包括重掺杂n〓、p〓非晶硅的制备，硼轻掺杂a-Si：H的暗态电导率与工艺条件的关系，硼轻掺杂a-Si：H的光电导与工艺条件的关系，以及液晶光阀的稳定性与a-Si：H的S-W效应。

In the interfacial layer near to SiC, elements Pd and Ni preferentially diffused to SiC and resulted in the reaction products of Pd-Si phase, Ni-Si phase and graphite. In the reaction zone further away from the SiC, mainly elements Cr and V in the brazing filler participated in the interface reaction, and formed Cr-C, Cr-Si, Cr5Si3C. In the central part of the joint, the matrix was composed of Pd-Si, Ni-Si and V-Si phases, on which some blocky carbides V2C, Cr23C6 distributed scatteringly.

MPa。微观分析表明，在靠近SiC的界面反应层中，主要是Pd和Ni优先与SiC反应生成相应的Pd-Si相，Ni-Si相和石墨；接头中在离SiC稍远的区域，主要是Cr和V与母材扩散进入钎缝且未与Pd和Ni反应的C和Si发生反应，生成Cr-C， Cr-Si， Cr5Si3C 等相；钎缝中心区的基体由Pd-Si，Ni-Si和V-Si相组成，其上弥散分布着块状碳化物V2C和Cr23C6。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。