数值方法

Based on Douglas operators, the modified wide beam propagation is presented and the number dissipate is minimized without nearly increasing the memory and computing time. The method is also more stable and accurate than ordinary WBPM. Finally, A novel wide-angle low-loss dielectric slab waveguide Y branch is presented and analyzed by modified WBPM.

接着，本论文还分析广角BPM差分格式所具有的数值色散来源，并在不增加计算时间和内存的前提下，应用Doglas算子大大地减小数值色散带来的误差，提高了计算精度，提出了改进的WBPM，而且还发现这种方法有具计算稳定的优点。

In order to survey the numerical diffusion induced by mesh rezoning and variables remap in ALE method,some calculations had been done,and comparisons show that the smoothing does exist,but the numerical dissipation is not serious,it do no harm to physical picture.

为考察ALE方法网格重分、物理量重映导致的数值扩散对计算精度的影响，进行了一些计算比较，结果显示，虽然存在一定程度的抹平现象，但是网格重分带来的数值耗散并不大，对物理图象并没有显著的影响。

On the other hand, a service provider may receive many requests at the same time, and because of the limited resources, it can't serve all of them. Consequently, for both service requesters and providers, there is a challenge of selecting interaction partners. This can be achieved by our proposed one-to-many service negotiation model.

在这个模型中，利用模糊命题表示协商参与者对服务的约束，这些约束是非数值化的；使用效用函数表示对数值化的服务非功能属性的偏好，采用二者相结合的方法建模对服务非功能属性的偏好选择。

In the paper, based on reading and studying a great number of references about fluid dynamic technique and numerical computing methods of flow field, 3-D Numerical simulations and visual analysis of the flow field in hydraulic poppet valve with inside flow work condition were obtained by CFD software Fluent.

本文在参阅大量国内外有关计算流体力学和流场数值计算方法相关资料的基础上，用CFD软件Fluent对内流工况液压锥阀内部流场进行了三维数值模拟及可视化分析。

Cavitations is the major problems of designing water hydraulic valve, understanding the relationship between shape of valve and cavitations , avoiding cavitations is extremely important, this paper, the numerical simulation and visualization research of flow field is carried out to research relation between the flow field of poppet valve and the length of valve seat by finite volume numerical method.

气穴是研制水压阀存在的主要难题，认识阀口形状与气穴的关系，避免产生气穴现象是极其重要，本文应用有限体积数值计算方法针对阀座倒角长度变化对水压阀阀道内流场的影响进行数值模拟和可视化研究，得到了一些有益的结论：倒角长度的改变对阀口间隙以及阀芯锥面与柱面相接的地方的负压会产生比较大的影响

With method given by the paper, the impeller and volute of centrifugal pump can been designed according to the flow rate and head, and take optimization choosing with numerical test to aubstitute for real pump or model teat.

用本文提出的方法，可以根据设计工况点或高效点的流量与压头的要求，通过数值计算，确定离心泵通流部分的形状和尺寸，并且用数值试验进行优化选择，以代替多种方案的模型或实物试验进行优化方案的选择。

The inner force of the line element for underground structure have been calculated using the traditional finite element mesh and high-order manifold method to guarantee the numerical precision of the line element and overcome the disadvantages due to the geometry error between the actual position and computational position of the beam and truss element in common use.

用传统的有限元网格和流形方法的高阶覆盖位移函数来进行地下结构的杆、梁单元计算，保证了线单元模拟的数值精度，同时又克服了常用的杆、梁线单元计算位置与实际位置不相符合从而带来计算误差和结构设计不便等缺点，提供了一种解决结构数值计算的较好的途径。

The following are main contents studied: A finite element method for Navier-Stokes equation with ALE formulation is considered and by combined with theNewmark method of numerical intergration a pressure correction scheme is obtained for the solution of the FE formulation of N-S equation. Because the incompressibility condition can be satisfied approximately in this scheme, the interpolation functions of elements can be equalorder for the velocity field and pressure field. In the ALE formulation the fluid-solid interaction analysis became a three-field coupling problem of the fluid field, the solid field and the fluid dynamic mesh. The properties and charactiristices of this three-field coupling problem are deeply discussed.

研究的主要内容有：主容器中流体大晃动是一种强非线性问题，文中研究了求解ALE描述的粘性流体N-S方程的有限元方法，以有利于大晃动自由液面的跟踪和流体大晃动中非线性现象的描述；并结合Newmark数值积分法推出了求解ALE型N-S方程的压力修正解法，由于这种解法可以近似满足不可压条件，因此可以采用速度场和压力场等阶插值的有限元离散格式，从而较好地解决了普遍采用的不等阶插值解法中，速度场和压力场数值精度不一致、程序编制不便等的不足。

The method comprises the following steps of: starting the watchdog; counting from 0, the watchdog detects that the system reads the counting value; calculating the remainder after the counting value is divided by a pre-arranged value; re-counting from the remainder by the watchdog.

方法包括：看门狗启动，从0开始计数，看门狗检测到系统读取计数值，计算计数值除以预设值后所得的余数，看门狗从该余数起重新开始计数。

Finally, some examples of two-dimensional and three-dimensional bodies are given, at the same time the Richardson's extrapolations of these numerical results are calculated.

最后，给出了一些二维，三维的任意导体的数值结果，并且给出了这些数值结果的Richardson外推值，计算结果与文献以及精确解都吻合的比较好，从而说明了该方法的有效性和准确性。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。