数值的

Base on the analysis of the grating linear displacement measurement theory,t he measure errors especially the subdivision error of the grating scale,this paper focuses on the theory of switch and merge of dual grating scales'signals,builds the design criteria of high speed high precision displacement measurement by using dual grating sales,designs the switch picking reference with high precision and fast switch and merge method,analyses the errors brought in by switch and merge of the duals grating scales.

针对光栅尺的电子细分信号具有细分误差的特性，本文提出了对莫尔条纹信号不细分的方法以提高双光栅尺信号切换合成值的精度。经过对双光栅计数切换基准、切换与合成特征和规律的探讨，本文设计了实现双光栅尺双重测量、计数值切换合成法的硬件电路，主要通过可编程芯片FPGA，设计了双光栅尺信号处理的各电路模块，如双光栅尺信号四倍频辨向模块、速度判断模块、切换模块、计数值合成处理模块。

civil engineering and architecture construction ; shield tunnel ; ground settlement ; peck formula ; reliability

盾构施工过程中地表沉降的构成及其机理见表1[2]，表1中影响地表沉降的诸多因素都是随机的，若将确定的参数代入经验公式进行计算或进行数值模拟，所得的结果也是确定的数值，这样可信程度是很低的。

Applications of face-fired boilers are not so many on our country's industry, So the researches on it, especially on high-duty boilers (for example 330MW), are very limited. And further study is needed to make up for domestic vacancy about this. Author of this paper has done some researches on 330MW boiler both in theory and experiments by applying Computer Aided Test principles. Numerical simulation is dominating part of CAT, also the core of this paper.

对冲燃烧锅炉在我国的应用并不是很多，所以对它所进行的研究极为有限，特别是对于较大容量(如330MW)的机组，相应的试验和数值计算都很少，很多的问题仍等待进一步的研究，本文正是为了填补国内的空白，从理论和试验的角度，运用计算机辅助优化数值试验原理和方法，对330MW对冲锅炉进行研究。

Based on numerical simulation flow after treatment methods and implementation. This paper drawing river ice jam thickness contour map, vertical water flow under the ice jam contour map as an example, the use of Surfer software described in detail various graphics rendering; Focused on the Surfer with VB programming software secondary development to achieve flow numerical simulation after treatment, showed that automatic change the data files to the Surfers;Introduced Active automation technology and Visual Basic Application Program Interface, and the interface technology will combinate VB powerful software development capabilities and Surfer software powerful mapping functions , achieve the key code and the mapping results map examples: under the ice sheet flow velocity field vertical contour map, three-dimensional wire-frame plans, such as flow field vector graphics, and dynamic display and output the graphics.

基于水流数值模拟后处理的方法与实现，本文以绘制河流冰塞厚度等值线图、冰塞下水流纵向流速等值线图为例，详细介绍了运用Surfer软件绘制各种图形的方法；重点阐述了用VB编程对Surfer软件进行二次开发实现水流数值模拟后处理，显示向Surfer数据文件自动转换的过程；介绍了Active自动化技术及其与VB应用程序的接口技术，并利用该接口技术将VB的强大软件开发能力和Surfer软件强大的绘图功能相结合，给出了实现该接口技术的关键代码以及绘制成果图件的实例：冰盖下流速场纵向流速等值线图、三维线框图、流场矢量图等图形，并输出图形与动态显示。

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

The analysis shows that with given grid size higher accurate difference scheme can give higher resolutions with wider range of scales, or with given accuracy large grid size can be used for the higher accurate difference scheme. The second part is the numerical simulation of two-dimensional axisymmetric jet. The simulation results show the structure in the near field and the initial transition. In the near field, Kelvin-Helmholtz instability leads to the formation of vortex ring, and nonlinear growth leads to the merging of vortex ring. This is the main instability form. Under the assumption of axisymmetry and two-dimensional computing conditions, the results are applicable only in the near field.

第二部分采用高精度的差分格式对二维轴对称射流进行了数值模拟，模拟结果显示了射流流场结构和涡结构的发展过程，在射流流场近区，K-H失稳导致涡环的产生以及非线性效应的增长导致涡环的对并是射流失稳的主要形式；分析指出在轴对称假设下的射流数值模拟只适用于射流近区的分析。

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。

Because the rate of ET and HT reactions is determined by the coupling term J, and in long range ET and HT systems the degeneracy of the π orbitals of donor and acceptor is lifted through mixing with the bridge orbitals of appropriate symmetry by an amount △E. Because the △E splittings are proportional to electronic coupling, so we can use the static quantity △E to exploring the dynamic quantity J, and to make a detailed study on the microscopic influence of coupling mechanism in ET and HT process.

由于电子转移和空穴转移反应速率的大小决定于反应的耦合因子，在长程电子转移和空穴转移体系中，给体和受体的简并π轨道由于与饱和桥之间的TB作用而产生一定的分裂能，此分裂能又与耦合因子的数值成正比，因此，我们可以用静态的分裂能数值间接地表征动态的耦合因子，从而详细研究电子转移和空穴转移过程中耦合机理的微观影响因素。

In the second part of this thesis, the physical model, which used to describe the evolution of highly charged ions in the EBIT and provided by Penetrate, are discussed in detail. Based on this model, we have some modifications. The modified physical model takes the effect of the geometry of drift tube, the cumulation of space charge, and ionization heating into account.

在论文第二部分，我们详细讨论了Penetrate所提出的用来描述高价态离子在电子束离子阱中演化的物理模型，并在Penetrate所提出的物理模型基础上做了部分修正，修正后的物理模型考虑了漂移管的几何位形、电离加热以及电子束的空间电荷累积的影直流电弧等离子体发生器的数值模拟及电子束离子阱物理研究响，利用修正后的物理模型，对高价态离子在EBI下中演化过程进行详细地数值模拟。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。