数值技术

Students who are interested on plasma physics on steady-state operations, computer simulation and numerical calculation of radial electric field are welcomed.

可招收超导托卡马克稳态运行的实验以及控制技术、等离子体高约模和等离子体中径向电场的数值模拟计算专业学生。

This dissertation involves the study of the growth dynamics of colloidal particles under unequilibrium and irreversibility condition. Firstly, it is of interest to investigate whether the ideal diffusion or reaction-limited aggregation universal behavior can be observed for the initially polydisperse practical system of basic yttrium carbonate as well. The fractal structure of basic yttrium carbonate aggregate cluster was observed using transmission eletron microscopy. The aggregation kinetics of basic yttrium carbonate colloids was studed using dynamic 1ight-scattering techniques. At 1.00mol/l NaCl solution the fast diffusion-limited aggregation behavior was observed with an increase in the aggregate size over time described by a power law. The aggregates are characterized by a fractal dimension D=1.82. The disordered and ramified cluster is consisted of primary colloidal particles and tenuous and more open. These are in good agreement with those observed for other colloidal system such as colloidal gold (1.86), silica (1.85) and polystyrene latex (1.82) in diffusion-limited aggregation from the static and dynamic light scattering by Lin. Therefore ideal diffusion-limited aggregation behavior can be observed in practical polydisperse system as well. Smoluchwski and fractal theories were used to obtain the aggregation rate constant for initially polydisperse system for the first time.

本论文研究胶粒的非平衡不可逆聚集动态学，分为两个部分，第一部分是通过实验研究一个新的初始多分散的碱式碳酸钇胶粒实际体系中，聚集标度性质的普适性，即使用透射电子显微技术观测聚集粒子簇的分形结构，使用动态激光光散射研究碱式碳酸钇胶粒的聚集动力学，胶粒带电而产生静电排斥作用使得碱式碳酸钇胶粒处于稳定状态，当加入电解质NaCl溶液时，碱式碳酸钇胶粒间的Debye-Hückel屏蔽距离缩短，从而降低静电排斥能垒，引起胶粒发生不可逆聚集，加入电解质NaCl的浓度为1.00mol/l时，碱式碳酸钇胶粒进行快速聚集，经历扩散控制聚集机理，形成结构疏松、更为开放的分形聚集粒子簇，其分形维数为1.82，碱式碳酸钇胶粒聚集增长动力学遵循幂函数增长规律，与Lin等使用静态激光光散射和动态激光光散射测量硅胶(1.85)、金胶(1.86)和聚苯乙烯胶乳(1.82)在扩散控制聚集状态形成聚集粒子簇的分形维数值以及粒子簇聚集增长的动力学规律相一致，表明胶粒聚集标度性质的普适性质在初始多分散的实际体系中也是存在的，首次由动态激光光散射的实验数据得到初始多分散胶粒分形粒子簇的聚集速率常数，并且其值与Smoluchowski聚集速率理论预期相符。

After finishing holistic analyses, and considering the specific and relative research on database technique"s application in the remote structural collaborative experiment, this thesis explores and discusses that the proposed database organization scheme can promote the efficiency of the data"s reposting in the Remote Structural Collaborative Experiment, the efficiency of the remote data exchange, and puts out the improving design compared with the NCREE system, that is to use middleware to realize the separation of the experimental process and DBMS and to set up buffer pool to solve the problems, such as to solve network replacement by getting back the experiment.

在完成了整体分析设计之后，针对数据库技术在远程结构协同实验中的应用作了具体的相关研究，探讨了本文提出的数据库组织方案在远程协同实验中可以提高数据入库效率以及远程数据交换效率以及对比NCREE系统设计提出了改进的设计思想，即采用中间件以实现试验进程与DBMS分离以及设立缓冲池以解决网络复位而要恢复试验等问题，并且还研究了在协同实验中分析中的常用数值积分算法，并着重探讨分析了算子分裂算法。

The wall function is adopted such that a resultant stream-wise velocity, U, is expressed by a local friction velocity at a first grid point to the wall of the computation domain.

和实测资料的对比验证了数值计算和边界处理技术的合理可靠性，并进一步分析复式断面明渠二次流运动的流动结构和特性。

Nonsingular H-matrix; generalized H-matrix; eigenvalue; numerical radius; matrix splitting; saddle point problem; Krylov subspace method; preconditioning technique

基础科学，数学，代数、数论、组合理论非奇H-矩阵；广义H-矩阵；特征值；数值半径；矩阵分裂；鞍点问题； Krylov子空间法；预处理技术

Compared with ENOR and SMOR, the only two existing MOR analysis methods for RCS interconnect circuits, Block SAPOR overcomes their deficiencies of numerical instability or limited reduction accuracy.

Block SAPOR克服了现有的RCS互连电路降阶算法ENOR和SMOR存在的数值不稳定和降阶精度有限的不足，是目前为止最有效的二阶系统降阶技术。

This paper focuses on four important aspects as follows. The first one is the establishment of variational quations which provides the mathematics theories for the finite element method of HMT; the second one is for the study of scalar/node and vector/edge finite element method; the third one is about how to solve faster for the large-sacled matrix system of scalar/node and vector/edge finite element; and the last one is achieving the forward modeling with high precision of HMT method.

主要包括四部分：建立与高频大地电磁法边值问题相等价的变分问题，为有限元数值计算奠定数理基础；标量/矢量有限元方法的研究；加速标量/矢量有限元矩阵系统方程迭代求解技术的研究；实现高频大地电磁参数精确快速正演模拟的研究。

A display technique of surface rendering was developed in order to display the numerical simulation results of 3-D scalar field physical quantity of the whole casting during solidification process visually and precisely.

为了更直观和准确地显示整个铸件各部位在凝固过程中各时刻的三维标量场物理量的数值模拟结果，设计了一种称之为表面绘制的显示技术。

By means of schlieren method, experiments and analogdata technique, the phenomena and data in the process of PSFP are comprehensively observed, recorded, and analyzed. The dynamics and thermophysics characteristics of plasma jet and the powder in it are revealed. Also the impact of characteristics mentioned above on the precision, property and microscopic structure are studied.

结合纹影成像等测试方法，本文通过实验与数值模拟技术，全面考察、记录和分析等离子熔射成形过程的现象与数据，揭示等离子射流及射流中粉粒的动力学和热物理特性，并研究了上述特性对熔射成形零件精度、性能及微观结构的影响规律。

A number of experimental, theoretical and computational studies have been conducted to explore the Scramjet techniques in the past decades.

在过去的几十年中，人们对超燃冲压发动机技术进行了大量的试验、理论及数值计算研究。

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。