非最后的

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。

In the first approach the metadata extraction is viewed as a classification problem. Three statistic classification models, including Support Vector Machines, Perceptron with Uneven Margins, and Maximum Entropy are studied. The approach suffers from the problems of ignoring the variance in lengths of documents and ignoring the dependency of text units within documents. To solve the problems, our second approach takes the metadata extraction as a sequence data labeling problem and makes full use of the sequential information.

论文首先研究了基于分类的元数据抽取方法，考察了支持向量机、非对称间隔感知机和最大熵模型在ADME中的应用；然后针对分类方法中存在的忽略文档之间的差异、不考虑文档上下文等问题，提出了基于序列数据标注模型的抽取方法，并结合最大熵马尔可夫模型、投票感知机模型和条件随机场模型进行了研究；最后本文根据前两种方法的设计思想和优缺点，研究提出一种新的结构预测模型—— CDASP（Coordinate Descent Algorithm for Structure Prediction），并将其应用于元数据的自动抽取中。

Finally, discriminate analysis obtains that the degree of departmentalization has the obvious difference between the domestic and foreign retail properties.

最后利用鉴别分析得到国内外的商场在业种「部门化程度」上的确有明显的差异；国内的商场大多以单层面积较小、楼层数较高且以部门化的方式作为业种的配置型态；而国外的商场大多以单层面积较为广大、楼层数少且以非部门化的方式配置其业种。

Chapter two proposes the unified form of Hojman"s conservation law and Lutzky"s conservation law. Firstly, the author introduces the general Lie group of transformations that the variations of both the time and the generalized coordinates are considered, derives the determining equation of Lie symmetry for the system, presents a new conservation law, which contains the Hojman"s and the Lutzky"s conservation law as two special cases, and obtains a condition to exclude trivial Hojmans conserved quantities.

第二章，Hojman定理和Lutzky定理的统一形式：首先，引入一般意义下的Lie变换群(即位型变量q_s和时间变量t同时变换)，给出系统的Lie对称性确定方程，提出一个新的守恒律，Hojman定理与Lutzky定理则分别是这个新守恒律在两个特殊情况下的推论，导出一个可排除平凡Hojman守恒量的定理，并分别讨论了Birkhoff系统和非完整系统的Lie对称性和Hojman守恒量，最后，讨论了Hamilton系统的梅对称性与Lie对称性的关系，给出了由梅对称性求Hojman守恒量的方法。

Firstly, according to the difficulties in the optimization of chemical engineering and the intrinsic disadvantage of deterministic optimization algorithms, this work analyzed the importance and advantage of stochastic algorithms, and proposed some important aspects in research on them. Secondly, genetic algorithm was applied to two problems of data driven modeling, one of which was combination problem, the other was mixed integer nonlinear programming. Thirdly, systemic investigations were made on the basic structure, dynamic behavior and modifications of particle swarm optimization. Lastly, two kinds of proposed PSO algorithms were applied on calculation of phase equilibrium, which is nonconvex optimization.

本文首先根据化工优化中存在的困难和确定性优化算法内在的缺点，分析了随机优化算法的重要性，并提出研究随机优化算法应注意的问题；其次，将遗传算法应用于两个数据驱动建模问题，一为组合优化问题，一为混合整数优化问题；再次，从粒子群优化算法的基本结构、运动行为、改进方法做了系统的研究：最后，将提出的两种改进粒子群优化算法应用于相平衡计算问题，为非凸全局优化问题。

Combining NA samples the EB estimation with convergence rates is also obtained; Thirdly, for one-parameter exponential distribution family, we give the parameters' EB estimator that is admissible and asymptotically optimal with convergence rates. Finally, Bayesian and hierarchical Bayesian approaches are applied to analyze the reliability performances for series system with cold standby units and the numerical simulation results show that multiple Bayes estimator is superior to Bayes estimator.

其次，针对一类双边截断分布族，在非对称linex损失下构造了经验Bayes决策函数，建立了它的收敛速度，给出了渐近最优的证明；并结合NA样本研究了参数的经验Bayes估计及其收敛速度；接着给出了指数族参数的经验Bayes估计，证明了它是渐近最优的，也是可容许的，同时也获得了该EB估计的收敛速度；最后，运用Bayes与多层Bayes方法研究了具有冷贮备部件串联系统的可靠性指标的估计，并给出了数值模拟结果，结果表明多层Bayes估计优于Bayes估计。

Firstly, the equation for stress intensity factors under static uniform pressure is used as the reference case, and then the weight function for a thick-walled cylinder containing a radial edge crack can be worked out. Secondly, the dynamic stresses in uncracked thick-walled cylinders are solved under internal impulsive pressure by using mode shape function method. The solution consists of a quasi-static solution satisfying inhomogeneous boundary conditions and a dynamic solution satisfying homogeneous boundary conditions, and the history and distribution of dynamic stresses in thick-walled cylinders are derived in terms of Fourier–Bessel series. Finally, the dynamic stress intensity factor equations for thick-walled cylinder containing a radial edge crack subjected to internal impulsive pressure are given by dynamic weight function method.

首先采用静态内压下的应力强度因子作为参考解，得到了带径向边裂纹厚壁圆筒的权函数；然后用振型函数方法推导无裂纹厚壁圆筒在冲击内压下的动应力响应，分析中将相应的弹性动力学方程解分为满足非齐次边界条件的准静态解和满足齐次边界条件的动态解的叠加，利用傅立叶-贝塞尔级数展开，推导出了厚壁圆筒内动应力的响应历程和分布规律；最后由动应力权函数方法导出带径向边裂纹厚壁筒在冲击内压下的动态应力强度因子计算公式。

Then we in-vest gate Seiberg-Witten map, which defines the equivalence relation of the gauge symmetries in different spaces. We also analyse the U gauge electromagnetic field in noncommutative space. Finally we discuss the ambiguities of Seiberg-Witten map, and find although that some part of the ambiguities can be absorbed by gauge transformation and hence negligible, the existence of the matter field makes some other parts difficult to be absorbed by gauge transformation or field redefinition.

然后利用Seiberg-Witten映射，我们研究了不同空间的规范对称性的等价问题，并对非对易空间的电磁场进行了微扰分析，最后我们对Seiberg-Witten映射的松动进行了讨论，研究发现这些松动中的一部分可以由规范变换吸收因而是可以忽略的，由于物质场的存在，另外一部分很难用规范变换和场的重定义吸收。

Based on moving least squares surface, the differential properties of each sample point on PSO are first evaluated. In terms of covariance analysis, the elliptical splat of sample point is then determined on its tangent plane. Finally, the splats are rendered from far to near by using elliptical weighted average filtering. According to the differential properties, moreover, the suggestive contours of PSG are attained so that non-photorealistic rendering of PSG is realized.

首先根据构造的移动最小二乘曲面计算采样点的表面几何属性，然后根据协方差分析确定点元在其切平面上的椭圆表示，最后采用椭圆加权平均滤波从远到近单遍绘制各点元，此外，根据表面几何属性确定点模型的轮廓线，实现了点模型的非真实感绘制。

Louise Arbour, head of the International Crisis Group, says the Sri Lanka model consists of three parts: what she dubs "scorched-earth tactics"(full operational freedom for the army, no negotiations with terrorists, no ceasefires to let them regroup); next, ignoring differences between combatants and non-combatants (the new Icg report documents many such examples); lastly, the dismissal of international and media concerns.

国际危机组织领导人露易丝阿尔布尔，说斯里兰卡模式由三部分组成：她戏称为&焦土战术&的战术（军队完全的自主行动权、绝不与恐怖分子谈判、绝不停火给恐怖分子重整旗鼓的机会）；其次，忽略战斗人员和非战斗人员的差异（国际危机组织一份新报告记录了很多这样的例子）；最后，不予理会国际方面和媒体方面的关注。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。