产生平衡的

In this thesis,based on the DFT+NEGF first-principles method,we construct a lead-molecule-lead sandwich system with single benzene-based molecule to investigate the relationship between the structure and properties of the molecular devices and the factors that influence properties of the molecular devices.Our computational investigations on these molecular devices are primarily concentrated on the effect of contact geometry between molecules and electrodes,the effect of side groups,the effect of different torsion angle between two phenyl rings and the effect of external electric field.This thesis consists of five chapters:In Chapter one,we mainly introduce the research background and development of the molecular electronics,including the experimental fabrication of molecular electronic components and theoretical simulation methods.Afterwards we discuss the questions that need to be solved in this area.Finally,the main contents of this thesis are listed.In Chapter two,we introduce the theoretical methods used in this thesis, including the main first-principles calculation methods,i.e.,the Density-Functionmethod and nonequilibrium Green\'s function.

本论文拟采用密度泛函理论和非平衡格林函数相结合的第一性原理计算方法，选取苯基小分子作为研究对象，构建了金属电极/有机小分子/金属电极三明治结构体系，系统地研究了苯基分子器件结构的改变与分子电输运性质之间的关系以及影响分子器件电输运性质的相关因素，其中重点研究了分子与电极间可能的接触结构改变、官能团、分子间的扭转角以及外电场对苯基分子电输运性质的影响，本论文主要包括以下五个章节的内容：第一章为综述部分，主要介绍了分子电子学产生的背景、分子器件的研究意义、当前研究分子器件的实验和主要理论方法，以及目前在研究分子器件中存在的一些问题，最后给出了本论文的主要研究内容和技术路线。

Thus, it is reasonable to speculate that impairment of lung tissues resulting from the imbalance between protease and antiprotease system due to α〓AD may be predisposed to the development of lung cancer, and may also be related to the susceptibility to lung cancer.

AT活性降低使个体发展为肺癌的危险性增加。我们有理由推测由于α〓AT缺乏导致的弹性蛋白酶/抗弹性蛋白酶平衡系统的失衡，进而产生的肺组织损伤可能是肺癌发生的前期病变和重要基础。

Nearly all the wine Americans drank was imported, largely from Madeira, and to continue to purchase dutied, foreign beverages both worsened the American balance of payments and cast doubts upon the patriotism of the purchasers.

因为几乎所有美国人喝的葡萄酒都是进口的，主要是来自马德拉岛。而继续购买课税的外国饮料恶化了美国的收支平衡，并使人对这些购买者的爱国主义产生怀疑。

Meanwhile, the surface layer gets fine crystal grain with dispersive and homogeneous distribution of WC grains and Co binder from rapid melting and resolidification during HIPIB irradiation. Minimizing the mean free path in Co binder by decreasing the WC grain size leads to an increase in resistance to plastic deformation in the binder.

HIPIB强烈非平衡作用下的重熔和再结晶使WC晶粒细化且分布更均匀，同时，表层析出弥散分布的Co_3w_9C_4相，使Co粘结相产生强化，导致Co粘结相的平均自由程降低，从而增强了Co粘结相抵抗塑性变形的能力，提高了辐照硬质合金的耐磨性能。

Process and mechanism of electrodeposited Zn-Fe-Si02 composite coatings were studied, including some contents as follow: Potential-pH plots of Zn-H2O and Fe-H2O systems were drawn, and the thermomechanical analysis was made. Results showed that the region of zinc and iron's codeposition was wide, which provided theoretic basis for electrodepositing Zn-Fe alloy. But the balance potential of zinc was greatly different from iron's, so in order to make zinc and iron codepositing, some complexant must be added into electroplating solution.

本文研究了电沉积Zn-Fe-SiO_2复合镀层的工艺和机理，主要包括以下几个方面：绘制了Zn-H-2O系和Pe-H_2O系的电位-pH图，并对其进行了热力学分析，结果表明，锌和铁发生共沉积的区域很大，这就对电沉积Zn-Fe合金的可能性提供了理论依据，但是锌和铁的平衡电位差别较大，所以，必须在镀液中添入一定量的配合剂才能使锌铁产生共沉积。

In order to break through the traditional aquarium tank requires frequent water exchange limitations, our factory also offers tailor-made ecological fluid, can guarantee the water quality of the long-term stability, but also effective bactericidal, at the same time have a suitable water, grass, fish breeding grounds for bacteria have to maintain the Aquarium of the ecological balance of the murals inside.

为了突破传统柜式水族箱需要经常换水的局限，我厂还提供特制的生态液，能保证水质的长期稳定，还能有效杀菌，同时产生适合水、草、鱼儿繁殖的有益菌，保持了水族壁画箱内的生态平衡。

Since ventilation and evaporative cooling are the primary means for temperature adjustment in the duck house, a relationship for the traveling distance of water particles under various thermal environment was first established. This allows for the evaluation of efficiency of foggers for evaporative cooling. The relationship was then incorporated into a mathematical model based on the energy and mass conservation principle to simulate the transient change of outdoor temperature and humidity.

由於通风与喷雾降温为调节半开放式鸭舍内温度的主要方法，首先我们推导出雾粒在完全蒸发前移动距离与热环境条件的方程式，以计算於不同热环境条件下，不同大小雾粒的蒸发比率，从而评估喷雾降温的效率；次而利用质能平衡原理建立鸭舍内喷雾降温热环境模式，以计算及预测鸭舍内受外界热环境影响而产生的温湿度变化。

Water can make the redox inside body is able to run, in order to produce the quantity of heat that body place needs, nutriment, it is the haemal circulation with be maintained the temperature, balance that maintains the electrolyte inside body, normal, OK still that water can adjust make digestive gland secretes digestive juice to promote food to digest absorb, the phenomenon that reachs precaution to improve constipation, water still can make your skin water bright water bright, advantage is great.

水可以使体内的氧化还原作用得以运作，以产生身体所需的热量、营养素，水可以调节体温、维持体内电解质的平衡、维持正常的血液循环、还可以使消化腺分泌消化液促进食物消化吸收、及预防改善便秘的现象，水还可以使你的皮肤水亮水亮，好处多多。

Acetone and methyl ethyl ketone does have a strong solubility, due to solvent inks are pigment dispersant through a combination of bond and bond formation of throwing power, and too strong solvents will destroy this balance, resulting in pigment dispersion instability precipitation, the ultimate plug nozzle.

丙酮和丁酮确实有很强的溶解性，由于溶剂墨水中的颜料是被分散剂通过键与键的结合形成分散能力的，过强的溶剂会破坏这种平衡，造成颜料分散的不稳定，产生沉淀，最终堵塞喷头。

In view of the performance of the spreading sequences for spread～spectrum communication system, the performances on auto～correlation, cross～correlation, even and odd cross～correlation, mean square root of auto～correlation's side～lobe, mean square root of cross～correlation and balance of the new sequences were analyzed.

对一种新型的渐进理想的混沌映射模式，从扩频通信对扩频序列的要求出发，详细分析了该映射产生的混沌序列的自相关、互相关特性，偶互相关、奇互相关特性，以及自相关旁瓣均方根\，互相关均方根和平衡性。

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。