数值方法

And it's also pointed out that the factions such as configuration of complex networks, charactristics of flood, impounding of lakes or reservoirs, structuralized method in compiling programme etc.

第一章较为系统地介绍了河网数值模拟的发展状况，分析了河网模拟的两种方法，即水文学方法和水动力学方法的特点、演进以及优缺点。

The method based on blind number is a kind of discrete numerical calculation method, and the example unfurls its flexible fully and proves that this optimization method is reasonable and practicable.

基于盲数的方法是一种离散化的数值计算方法，算例充分展示了其灵活性，证明了该优化方法是合理的和实用的。

In the second part of of this thesis, we firstly derivate the operation condition of intracavity SHG of dualwavelength laser from the rate equation, and then numerically calculate the relationship between the laser operation parpmeters and the pumping powers. And then we discuss two possible ways to get balancing outputs of the harmonic waves of the two wavelengths. By comparing the two ways, we find that the method by increasing the geometrical factor of 1079. 5nm SHG has the higher efficiency than the method by adding the additional loss of 1079. 5nm basic wave. Besides, the first method is easier to realize in experiment than the second method.

本论文第二部分从速率方程出发，通过求解速率方程的稳态解得到了Nd：YAP腔内倍频双波长激光的连续运转条件，数值计算得到了随泵浦功率变化的激光运转情况；计算、分析了通过增加主波长的倍频耦合几何因子和增加主波长的腔内损耗两种方法获得均衡的双波长倍频输出的运转情况，通过二者的比较，发现增加倍频耦合几何因子的方法比增加损耗的方法效率更高，而且在实验上更易于实现。

In order to study the dynamic and instability rule and gain a damping evaluation method according to the test result, damping research ways of several foreign and domestic foil bearing types were compared. The interaction among cells was considered based on the approach of separating damping from stiffness. An effective damping evaluation method was developed based on the energy dissipation method. The structural damping of two-layer free plate foil bearing was analyzed on the basis of energy dissipation method.

为了更好地研究箔片轴承的动特性和稳定性，得出与实验结果相符合的评价方法，首先对国内外几种有关箔片轴承库仑阻尼的研究方法进行了比较，根据阻尼和刚度分离评估的思想，考虑箔片之间和箔片单元之间的相互作用，基于能量耗散的思想提出了一种有效的箔片轴承阻尼评估方法，最后对双层同向自由平箔结构箔片轴承的结构阻尼进行了详细分析和数值比较。

Then, in terms of the proposed tuning scheme and frequency-domain control theory, some decupling control methods are studied for the multivariable processes with time delays. The main contribution lies in: 1 For single-parameter diagonal controllers and full matrix controllers of the multivariable control system, a robust tuning scheme is proposed.

首先，给出了系统面临乘性输入、乘性输出，以及加性不确定性时，保证系统鲁棒稳定性的充分条件，并依据此条件，提出了计算控制参数整定范围的解析方法；然后，给出了参数估计方法，用来在参数整定范围内预测初始控制参数；最后，通过主导极点或幅值率调节方法，进一步优化出满足时域设计指标的控制参数值。

In this dissertation the"Penalty"finite element method was employed to compute the velocity of the three-dimensional flow of power-law fluid in a profile die. In order to decrease the needed computer memory and raise the stability of numerical simulation, a set of decoupled methods such as PFEM, pseudo-body force method and transformation of momentum equation to the elliptic equation was developed to establish the general finite element equations to compute the distributions of velocity and viscoelastic stress of the three-dimensional viscoelastic flow of the Phan ThienTanner fluid in a profile die. During numerical simulation of the extrudate swell of the PTT fluid, the flow in the die and out of the die was analyzed separately, which demands less computer memory.

本文建立了求解挤出口模内幂律流体流动速度场的通用三维罚有限元模型；对于非线性粘弹性的Phan Thien-Tanner流体，为了降低模拟计算对计算机硬件的要求，并使模拟计算更加稳定，采用了一种去耦算法，包括罚有限元方法、拟体力方法和动量方程的椭圆类方程转化方法，并建立了求解速度场和粘弹性应力场的总体有限元方程；对于PTT流体的挤出胀大问题，提出了挤出胀大熔体口模内外分离模拟法，这样可以显著降低数值模拟对计算机硬件的要求。

In this dissertation the"Penalty"finite element method was employed to compute the velocity of the three-dimensional flow of power-law fluid in a profile die. In order to decrease the needed computer memory and raise the stability of numerical simulation, a set of decoupled methods such as PFEM, pseudo-body force method and transformation of momentum equation to the elliptic equation was developed to establish the general finite element equations to compute the distributions of velocity and viscoelastic stress of the three-dimensional viscoelastic flow of the Phan ThienTanner fluid in a profile die. During numerical simulation of the extrudate swell of the PTT fluid, the flow in the die and out of the die was analyzed separately, which demands less computer memory. The key techniques used in numerical simulation of the three-dimensional extrusion from dies such as decision of boundary conditions, creation of initial velocity field, selection of penalty factor, high Weissenberg number problem , regeneration of the free surface were studied in detail.

中文题名聚合物异型材口模挤出三维流动研究副题名外文题名 Study on three-dimensional flow of polymer melts during the process of profile extrusion from dies 论文作者涂志刚导师柳和生包忠诩教授学科专业材料加工工程研究领域\研究方向学位级别博士学位授予单位南昌大学学位授予日期2001 论文页码总数148页关键词挤出成型聚合物材料挤出口模聚合物异型材馆藏号BSLW /2003 /TQ320 /9 本文建立了求解挤出口模内幂律流体流动速度场的通用三维罚有限元模型；对于非线性粘弹性的Phan Thien-Tanner流体，为了降低模拟计算对计算机硬件的要求，并使模拟计算更加稳定，采用了一种去耦算法，包括罚有限元方法、拟体力方法和动量方程的椭圆类方程转化方法，并建立了求解速度场和粘弹性应力场的总体有限元方程；对于PTT流体的挤出胀大问题，提出了挤出胀大熔体口模内外分离模拟法，这样可以显著降低数值模拟对计算机硬件的要求。

Stability of 14 high-cut slopes in Guangdong province is analyzed with typical rock mass structure analysis method and stereographic projection method, and with the numerical simulation method UDEC this paper simulated the excavation and reinforcement courses of the important slopes. Some conclutions and suggestions are based the analysis above.

本文结合广东某省道沿线14个高陡岩石边坡的开挖和支护方案的选择设计，运用常用的岩体结构分析方法和赤平投影方法对边坡的稳定性进行了分析，采用UDEC数值模拟方法对一些重点边坡的开挖支护进行了模拟，得出了以下一些结论： 1、边坡支护形式的选择应遵循&安全绿色、水土保持、恢复自然、环保之路&的设计原则。

The history of meteorological satellites, the principle of meteorological remote sensing and retrieval methods for atmospheric parameters are introduced comprehensively in this thesis. The principle of Advanced TIROS Operational Vertical Sounder on board the new generation of National Oceanic and Atmospheric Adminisstration polar-orbiting satellites and the retrieval methods for temperature, humidity and wind profiles are given indetails.

本论文系统介绍了气象卫星的发展、遥感原理以及大气参数反演方法；详细介绍了NOAA/ATOVS传感器工作原理及其大气温度、湿度、风矢量廓线反演方法；对MM5中尺度气象数值预报模式、数据同化方法也作了简要介绍。

Based on these, an improving μ-synthesis is presented, with which the high-purity distillation is designed well. 2. The robust performance problem of MIMO plant is explained with the plant direction angle, which shows that the robust performance varies with different input uncertainties and the μ-synthesis should be applied correctly according to the uncertainty structure. 3. Condition number and bandwidth are the important items for robust performance design in MIMO system. The H〓 two-block problems can not deal with the robust performance design of MIMO system because of the condition number cancellation. A general μ-synthesis procedure for MIMO system with uncertainties is presented. 4. For the SISO system, the object function in robust performance is amplified by at most 〓 than that of H〓 two-block problems in value: So the robust performance of SISO system can be done with the H〓 two-block problems to avoid the complicated μ-synthesis procedure. 5. All the conclusions and methods presented in this paper are demonstrated by some typical design examples.

从而形成一种改进的μ综合方去，并对精馏塔病态对象进行了鲁棒性能设计，得到令人满意的结果；（2）利用对象的方向角解释了MIMO对象鲁棒性能设计出现问题的原因，并提出不同输入摄动形式下系统的鲁棒性能问题也并不相同，因此利用μ综合处理鲁棒性能设计时，应根据不同的摄动情况采用不同的结构进行设计：（3）条件数问题和带宽问题是MIMO系统鲁棒性能设计的两个主要问题，指出由于条件数对消的存在使得一般H〓两块问题无法处理MIMO系统的鲁棒性能设计，而μ综合方法则是处理MIMO系统鲁棒性能设计的有效方法，并给出了其处理MIMO系统鲁棒性能设计的一般性方法；（4）提出对于SISO系统H〓两块问题（S/T问题、S/KS问题）的设计指标函数与鲁棒性能设计的μ指标函数在数值上最大差〓倍，因此对于一般SISO系统的鲁棒性能设计可以简单地用一般的H〓的两块问题处理，而避免μ综合设计的复杂过程；（5）本文中提出的结论和算法都利用H〓/μ发展中的典型例子：Doyle-Stein问题，Safonov的战斗机模型，精馏塔对象等进行了设计验证。

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。