对称部分的

The most parts of thesis as follows:1. Five symmetrical intra-molecular charge transfer oligomeric phenylene vinylene light emitting materials were designed and synthesized using oligomeric phenylene vinylene as a framework.2. The structures of target molecule were characterized by ~1HNMR,~(13)CNMR, IR, MS and element analysis.3. In order to study the influence of the location and numbers of electron-donor and electron-acceptor on their photoelectric performance by changing length of OPV chain, the UV spectra and fluorescence spectra of target compounds has been compared. We have researched into main factors effecting on material emitting red-shift; organic electroluminescence device was prepared using the compound P4. The capability of eletroluminescence was researched.4. The photoelectric properties of P4 was explained by quantum chemical calculation (the Gaussian 98 quantum chemistry program). It is greatly contributed know the whole process of charge transfer to guide the design of red emitters.

本文研究的内容主要包括以下部分：(1)设计并合成5个对称的以齐聚苯乙烯类为骨架的分子内电荷转移型齐聚苯乙烯类发光材料；(2)通过IR，MS，~1H-NMR，~(13)C-NMR和元素分析对所合成的目标化合物进行表征；(3)通过对目标化合物的紫外光谱和荧光光谱比较分析，研究改变OPV的长度，电子给体和电子受体的位置及数量对其光电性能的影响，探讨材料发射红移的主要因素；选取性能良好的目标化合物P4制备成OELD器件，对其电致发光性能进行研究；(4)运用Gaussian98量子化学程序包，采用量子化学方法对目标化合物P4的光电性能从理论加以解释，进一步认识荷移跃迁的整个过程，为红光材料的设计加以指导。

A wind- and motor-powered land vehicle with a fore-and-aft longitudinal axis comprising a body supported by wheels, at least one of said wheels fixed to rotate in a plane parallel to the fore-and-aft axis of said vehicle, an airfoil system comprised of two vertically extending airfoils rigidly mounted on said body in an arrangement having bilateral symmetry about a vertical plane through said fore-and-aft axis, said airfoil system providing a forward propelling force of said vehicle when the airfoil system is subjected to certain cross wind conditions, and self-contained motor propulsion means on said vehicle for providing acceleration from a stationary position and for propelling the vehicle either independently or in combination with propelling forces generated by wind action on said airfoil system, each airfoil having a plurality of airfoil sections telescopically fitted together, the lower airfoil section being rigidly mounted in fixed relationship to said body, said airfoil system including a retracting mechanism for lowering upper airfoil sections of said airfoil system when desired and for subsequently extending said airfoil system, said retracting mechanism including a plurality of linkages interconnecting said sections and an actuator means operatively connected between said body and to said linkages for lowering and extending each airfoil, and an intermediate airfoil extending between the upper sections of each of said airfoils so as to provide an inverted U-shaped airfoil.

风力和电动机驱动的陆地车辆与前列和尾部长轴组成的一个机构的支持，车轮，至少有一说，车轮固定在一个旋转平面平行的前列和前后轴的说，车辆，翼型系统组成的两个垂直扩展翼型硬性安装在说，机构在安排后，双边对称约一垂直面说，通过国内外和前后轴，表示翼型系统提供了一个向前推进的力量说，车辆时，翼型系统是受到某些横风条件下，和自我载电机推进的手段就表示，车辆提供加速从一个固定的立场和为推进车辆单独或结合，与推进力量所产生的风的行动表示翼型系统，每个机翼有一个多元化翼型第telescopically装在一起，较低的翼型节被硬性安装在固定的关系，说身体，说翼型系统包括一个撤消的机制，降低上翼型章节说，翼型系统时，理想的和其后再将说，翼型制度，说收回机制包括多元化的联系互连说，部分和一个致动器的手段手术之间的连接说，身体和说，联系降低，并延长每翼型，及一个中间翼型延长之间的路段上的每说翼型，以便提供一个倒U -形翼型。

This thesis consists of three chapters .In chapter one , the distributions of the last exit time and the corresponding results of Brownian motion in Markov process are introduced ,and previous remarkable achievements on the excursion of Brownian motion are numerated too ,also ,we introduce the main results and the history of elliptic diffusion process; In chapter two ,we summarily describe the excursion in Markov process and the result of the first hitting time of the elliptic diffusion process ; In last chapter ,we study estimates for the distributions of above three maximum excursions and minimum excursion in the elliptic diffusion process on R (d≥3), which leads the excursion of Brownian motion on ball on R (d≥3) to become a particular case .

全文共分三章，第一章介绍对称Markov过程中布朗运动的未离时分布及相关研究结果，列举了前人对布朗运动的游程问题的研究成果，并用较多篇幅介绍了一类特殊且非常重要的扩散过程——一致椭圆扩散过程的研究历史和本文的主要研究结果；第二章介绍Markov过程有关停时及游程的概念，叙述了一致椭圆扩散过程的定义，并给出了一致椭圆扩散过程有关首中时的结果；第三章是本文的核心部分，详细讨论了暂留一致椭圆扩散过程关于R~d(d≥3)上球的三类极大游程和极小游程的分布估计，使得布朗运动关于球的游程问题成为特例。

I'm strongly against the death penalty — it's an eye for an eye.

我不赞成死刑——这是以牙还牙的报复行为。

And to get you the support you need, we're enlisting all elements of our national power: our diplomacy and development, our economic might and our moral suasion, so that you and the rest of our military do not bear the burden of our security alone.

并给你们所须的支援，我们正徵召国家所有各种的力量：我们的外交及发展，我们的经济力量与道德劝说，所以你们与其他军人不须要孤独地负起国家安全的责任。