最小密度

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。

An extremely high temperature of anode humidification is also unreasonable; as a result, when the current density is high, the liquid water should be injected directly into anode gas channel to guarantee both high inlet H〓 concentration and well-humidified membrane. 4. The utilization of Pt in the cathode catalyst layer will decrease with the increasing current density; as a result, based on the principle of maximal Pt utilization, the catalyst layer can be designed much thinner or not uniformly in the catalyst distribution.

而在此截面上，交指型流场燃料电池阳极侧的液态水饱和度的极值位置并不确定；在电池阴极处，液态水饱和度的极值总是出现在z=0.002m处的气体扩散层和膜的界面上，并且该处的液态水饱和度沿x方向存在一个最大值，与此相应的氧气的质量浓度分数在该处达到极小值，因此极限电流密度将首相出现该处，但总体来说液态水饱和度沿x方向的分布较为均匀。4。

At present the main problem that the power electronic integration technology is faced with is how to make volume of module smaller, cheaper and more density of power, better capability of cooling, less parasitical parameter and applied in more situations. One of the main problems is the cooling of integrated module.

目前混合封装电力电子集成技术面临的主要问题是如何将模块的体积做的更小，成本更低，功率密度更大，传热性能更好，寄生参数更小及满足更多的应用场合，而其中最主要的一个问题就是集成模块的散热问题。

At present the main problem that the power electronic integration technology is faced with is how to make volume of module smaller, cheaper and more density of power, better capability of cooling, less parasitical parameter and applied in more situations.

目前混合封装电力电子集成技术面临的主要问题是如何将模块的体积做的更小，成本更低，功率密度更大，传热性能更好，寄生参数更小及满足更多的应用场合，而其中最主要的一个问题就是集成模块的散热问题。

The summary of the adopted models contains a two-scale k-ε turbulence model,the scalar joint probability density functiontransport equation approach,the augmented reduced mechanismfor methane oxidation (consisting of 16 species and 12 lumped reaction steps),the Euclidean minimum spanning treesmall scale mixing model etc.

所采用的数学物理模型包括双尺度的k-ε湍流模型，标量联合的概率密度函数输运方程方法，甲烷氧化的ARM简化化学反应机理(包含16种组分，12步总包反应)和欧几里德最小生成树小尺度混合模型。

HRCT(high resolution computed tomography) at present has been the perfect technique of CT in the spatial and contrast resodution and the best imaging method of assessments of small sati solitary nodular lesions and bronchiolar diseases in the lungs.

高分辨率 CT目前是一种使空间和密度分辨率尽可能完善的 CT技术，是当今评价肺内小结节性病灶和细支气管疾病最理想的影像方法。

The cooling capability of water-cooling and oil-cooling was small and the currentdensity of the stator winding was low.

水外冷和油冷的最大冷却能力比较小，定子绕组的最大电流密度也比较低。

Such a mesh point expansion curve to the actual business card printing and membership card making great advantage because mesh point expansion in General with the ink density by, the largest amplitude modulated net changes in the middle and the naked eye, so people can easily see that different (people on the most sensitive of South).

这样的网不面蔓延弧线给本质制卡和会员卡制息带来了很不小的劣势，因为网不面蔓延凡是随着油墨密度的增增而变不小，调幅网最不小改变爆发在洋间调上，所以人肉目可以很便当不离看不入不同。

Such a mesh point expansion curve to the actual business card printing comes with a great advantages because mesh point expansion in General with the ink density by, the largest amplitude modulated net changes in the middle and the naked eye, so people can easily see that different (people on the most sensitive of South).

这样的网不面蔓延弧线给本质制卡带来了很不小的劣势，因为网不面蔓延凡是随着油墨密度的增增而变不小，调幅网最不小改变爆发在洋间调上，所以人肉目可以很便当不离看不入不同。

As the density of breast tissue itself very poor, many small lesions showed calcification, the breast X-ray photography is the traditional diagnostic radiology in the most difficult examination of the machinery and technology of the most stringent requirements.

由于乳腺组织本身的密度差很小，很多病变表现为微小钙化，因此乳腺X线摄影是传统放射诊断中最困难的检查方法，对机器及技术的要求也最严格。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。