电平衡

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。

There is a small action range in archery.Simple methods and analysis is inadequate,so the author,on the basis of testing the archery athletes in national team with the Qualisisy infrared photoelectric testing system,Footscan sole pressure testing system,Noraxon myoelectricity remote testing system, etc,analyzes comprehensively the action technique of the athletes in national team from the posture,body motion characteristics,body posture equilibrium and stability,distribution of centre sole pressure, myoelectricity characteristics,etc,with the methods of relative software and data statistics.The conclusions and the suggestions are as follows:Conclusion:Firstly,the communality of posture angle,muscle strength,the activation order of main muscle during raising the bow, raising the bow and the timing of the raising could be used as the evaluation index of technique action in archery;Secondly,the length of the time needed in the different periods couldn\'t be used as technique evaluation index since it has no relation with the result.But the time of raising and pulling back the row is relatively fixed,and the time has a positive relation with the archery achievement of the national team in China.Thirdly,the central index of the sole pressure could be used as the reference criterion of selecting athletes and forecasting achievement.During playing archery,the interrelation between the central index of the sole pressure and the achievement is different individually and in different periods.Fourthly,there is low stability of the archery athletes in the front and back direction during the action, caused by the athletes\' posture disequilibrium of dorsal abdominal muscle and non-professional sport shoes..Fifthly,kinematics and electromyography shows that the people on archery in China haven\'t taken the raising and pulling back the row seriously.

射箭的肢体动作幅度小，简单的手段和分析不能满足其需要，笔者结合各种运动生物力学仪器优点及射箭项目的特性，选用Qualisisy红外光点测试系统、Footscan足底压力测试系统、Noraxon肌电遥测系统等对国家队射箭队运动员进行多方位的测试，运用相关软件及数理统计方法，对运动员的射箭动作技术，从射箭动作的姿态构架、肢体运动特点，身体姿态平衡稳定性、足底压力中心分布、肌电特性等进行全面分析，结论及建议如下：结论：第一，姿态角、肌肉用力激活程度、举弓阶段主要用力肌肉激活顺序、举弓、开弓时间等的一致性可作为射箭技术动作评价指标；第二，各动作阶段所用时间的长短不能作为技术评价指标，但举、开弓的时间相对较固定，开举弓时间比与中国国家队射箭成绩正弱相关达到显著性；第三，闭眼状态下足底压力中心单位面积轨迹长与144支箭最好成绩正相关达到显著性，可作为身体素质、选材及成绩预测的参考依据；实射时身体平衡的足底压力中心指标与成绩的相关程度具有个体性差异、阶段性差异；第四，射箭运动员实射时身体在前后方向上的稳定性较差，这与运动员的站立姿态、腹背肌力量的不匹配以及射箭没有专业运动鞋有关；第五，运动学及肌电学都表明中国射箭训练对举弓、开弓阶段的重视不够，背部肌肉用力特征不明显，撒放技术合理性不高。

Telephone circuit in which the two conductors are electrically balanced to each other and to the ground.

电话电路中，两个导体彼此之间能够达到电平衡以及和地之间的平衡。

The mechanism of wetting and electroosmosis of carbon cathode is discussed by the application of surface and capillary chemistry theories, on the basis of determination of relative phenomena in this melts; The hysteresis effect of wetting angle is studied and the velocity equation of carbon cathode electroosmosis is deduced.

归纳了熔液中碳溶胶、CO〓溶胶以及Al〓C〓胶体稳定性的影响因素。（6）根据对熔液中炭阴极湿润和电渗现象的研究，通过界面化学理论和毛细管界面理论的应用，讨论了熔液中炭阴极湿润和电渗机理。研究了熔液中炭阴极湿润角滞后效应产生的原因在于测量时体系的不平衡。推导了炭阴极电渗速率的理论方程。

Based on the equation of piezoelectricity and Hamilton principle, a generalized piezoelectric laminated thin shell is analysed and the dynamic equation is derived.

本文从压电本构方程和Hamilton原理出发，对一般的压电层合薄壳进行了力—电耦合分析，推导出了该结构力—电耦合的动力平衡方程，在理论上进行了深入的研究。

The control principle of electrostatic shaping was introduced according to the balance between electrostatic force and resulting force formed by membrane deformation and the complex shaping process of SMEC. Then, taking the trisection circularity electrode for an example, the distribution characteristic of electric potential in the electrostatic field was analyzed, namely, the expression of potential function in the electrostatic field was deduced by Laplacian equation. And then, by combining the difference equation with electric potential expression, the numerical solutions of electrostatic force in single electrode mode and trisection circularity electrode mode were disposed. Finally, the calculated figure was compared with the ideal paraboloid and comparison shows that more accuracy would be achieved by multi-electrode control.

根据静电力与薄膜变形载荷作用力之间的平衡关系和静电拉伸薄膜反射镜成形的复杂过程，介绍了薄膜反射镜静电成形的控制原理；以三等分环状电极为例，分析了静电场中空间电势分布特性，即从拉普拉斯方程推导出静态场势函数的表达式；然后，利用差分与电势方程结合的方法，对单电极电场力和三等分环状电极电场力进行了数值求解；最后，将计算面形与理想抛物面进行了比较，结果显示，单电极情况下得到的薄膜反射镜面形不是理想抛物面，若采用多电极控制可获得更高的控制精度。

The control principle of electrostatic shaping was introduced according to the balance between electrostatic force and resulting force formed by membrane deformation and the complex shaping process of SMEC. Then, taking the trisection circularity electrode for an example, the distribution characteristic of electric potential in the electrostatic field was analyzed, namely, the expression of potential function in the electrostatic field was deduced by Laplacian equation. And then, by combining the difference equation with electric potential expression, the numerical solutions of electrostatic force in single electrode mode and trisection circularity electrode mode were disposed.

根据静电力与薄膜变形载荷作用力之间的平衡关系和静电拉伸薄膜反射镜成形的复杂过程，介绍了薄膜反射镜静电成形的控制原理；以三等分环状电极为例，分析了静电场中空间电势分布特性，即从拉普拉斯方程推导出静态场势函数的表达式；然后，利用差分与电势方程结合的方法，对单电极电场力和三等分环状电极电场力进行了数值求解；最后，将计算面形与理想抛物面进行了比较，结果显示，单电极情况下得到的薄膜反射镜面形不是理想抛物面，若采用多电极控制可获得更高的控制精度。

The results show that the equiaxed zone ratio of the casting billet is greatly increased,with its soidification structure is obviously improved,and the momentum values of the electromagnetic forces both parallel to and perpendicular to the direction of the traveling magnetic field pulsate periodically with time.

采用三相通入不同电流的非平衡线性电磁搅拌技术进行了铸坯的静态浇铸实验，并对电磁搅拌过程中钢液内的电磁力各分量的瞬时值进行了理论分析·结果表明，当采用将电磁搅拌器的三相通入不同电流的非平衡线性电磁搅拌时，在钢液内所产生的电磁力是脉动的，其大小呈周期性变化，尤其是垂直于磁场运动方向上的电磁力，其脉动的幅度很大·由此认为，当采用将搅拌器的三相通入不同电流的非平衡线性电磁搅拌时，所产生的垂直于磁场运动方向上的脉动电磁力是提高等轴晶比率，改善铸坯凝固组织的一个重要原

The invention ensures that the SVC can not only complete the unbalanced load equalization compensation but also control the stabilization, thereby raising the precision of the susceptance computation of the SVC, guaranteeing the balance compensation of the charge, improving the performance in the stabilization control of the SVC voltage and maintaining the voltage stabilization of a common connection joint.

本发明能让其中SVC既能进行不平衡负荷平衡化补偿，又能对稳定控制，提高了静止无功补偿器电纳计算的精度，确保负荷的平衡补偿，改善了SVC电压稳定控制时的性能，维持公共连接点的电压稳定，具有较高的鲁棒性和响应速度。

The method is based on a variable structure to control the SVC, wherein, the variable structure control method comprises two aspects of the unbalanced load equalization compensation and the parameter control of a PI controller, wherein, the unbalanced load equalization compensation adopts the SVC compensation susceptance computational method which is based on the synchronous rotation reference coordinate transformation of a virtual symmetrical three-phase system; meanwhile, in the stabilization control of the system voltage, the ant colony algorithm optimization method is adopted to real time adjust and to optimize the parameter kp and ki of the PI controller.

本发明公开了一种静止无功补偿器的不平衡补偿和蚁群优化方法，基于变结构对静止无功补偿器SVC进行控制，其中变结构控制方法包括不平衡负荷平衡化补偿和PI控制器的参数控制两个方面，其中不平衡负荷平衡化补偿采用基于虚拟对称三相系统的同步旋转参考坐标变换的SVC补偿电纳计算方法；同时在系统电压稳定控制时，采用蚁群算法优化方法，对PI控制器的参数kp、ki进行实时调整、寻优。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。