查询词典 simultaneous differential equations

Any high Re number flow over bodies consists of three basic flows: the flow with convection-dominant in all spatial directions, the flow with convection-diffusion competition in all directions and the flow with convection-dominant in part directions and convection-diffusion competition in part directions, which is called the interacting shear flow; the features of the three basic flows are different; their simplest conservation equations, i.e. the Euler equations, Navier-Stokes equations and diffusion parabolized NS equations, have different mathematical characteristics; there is a great disparity in domains of the three basic flows and the domains of NS equations are very small. Therefore, adopting Euler-DPNS-NS equation system to analyze and compute high Re number flows over bodies is a logical approach. There exists a mutual examined-complemented relationship of this approach with the usual one of adopting only NS equations.

主要内容如下：（1）高Re数绕流包含3种基本流动：所有方向对流占优流动、所有方向对流扩散竞争流动和部分方向对流占优部分方向对流扩散竞争流动，3个基本流动的特征彼此不同且在流场中所占领域大小彼此相差悬殊，NS方程区域很小，它们的最简单控制方程组Euler、Navier-Stokes和扩散抛物化NS方程组的数学性质彼此不同，因此利用Euler-DPNS-NS方程组体系分析计算高Re数绕流流动就是一个合乎逻辑的选择，该法与利用单一NS方程组的常用方法可以彼此检验和补充。

Method］reversed sural neurofasciocutaneous flap with muscle was applied for repairing the soft tissue defect simultaneous open fracture of tibia lower section 6 cases,the soft tissue defect simultaneous chronic osteomyelitis of tibia lower section 5 case,the soft tissue defect of sole of foot simultaneous calcaneus epicarp 3 case, the soft tissue defect of sole of foot simultaneous calcaneus osteomyelitis or dead space 2 case. the scope of the flap was 18 c m×13 cm～11 c m×7 c m and that of the gastrocnemius flap was 4 cm×3 cm～9 c m×6 cm,the thickness was 1～3 cm,the skin flap was bigger than the muscle flap.

方法］自2004年6月以来，应用带肌肉的腓动脉穿支蒂腓肠神经营养血管皮瓣修复小腿下段及足踝部软组织缺损16例，其中胫骨下段开放性骨折伴软组织缺损6例，胫骨下段软组织缺损伴慢性骨髓炎5例，足后跟足底软组织缺损伴跟骨表层组织缺损3例，跟骨骨髓炎伴窦道2例，皮瓣面积30 cm×10 cm～6 cm× 4.5cm，切取的腓肠肌瓣面积4 cm×3 cm～9 cm×6 cm，肌肉厚度1～3 cm，皮瓣面积比肌瓣的面积要大。

Main contributions and achievements are as follows:A general non-equilibrium rigorous model for RDP is developed in this thesis. Based on the pseudo-homogenous assumption, two main factors reaction and separation are de-coupled, and an RDP model with the same format as that for a traditional distillation process is established. To solve the model with a large number of algebraic equations, modified M-K equations with tri-diagonal matrix form are developed based on the improved Separation Efficiency Functions, which greatly increases the iteration efficiency. This thesis also develops a general reactive distillation dynamic model. Through splitting of the differential variables based on SEFS, large-scaled differential algebraic equations can be solved with the improved Gear's algorithm which makes the dynamic model suitable for the on-line application. A simulation platform for the control loop design and evaluation of RDP by introducing control system equations into the dynamic model is also developed.A lactic acid purification pilot-scale RDP is investigated.

论文对热点问题——反应精馏过程的建模与优化控制相关技术进行了深入的研究，取得了一系列成果：1、建立了反应精馏过程机理模型，基于拟均相假设，将反应和分离过程进行解耦，推导出反应精馏过程的非平衡级稳态模型和动态模型，通过引入推广的分离效率函数，对模型变量进行了合理划分，显著提高了模型求解效率；将动态模型和控制系统方程结合，建立了反应精馏过程控制系统研究的辅助工具。2、全面分析了乳酸提纯反应精馏新工艺试验装置，利用本文建立的过程机理模型，对该试验装置进行了稳态和动态性能分析及水力学核算；设计和分析了单边质量控制方案，比较了间接和直接物料平衡控制两种方案的控制性能。

The numerical calculation commonly used for the Delphi process more than 100, including solutions of linear algebraic equations, interpolation, numerical integration, special, function approximation, eigenvalue problems, data fitting equation Root and solve nonlinear equations, functions and the extreme optimization, statistical data description, Fourier transform spectra, solution of ordinary differential equations reconciliation partial differential equations.

本书共有数值计算中常用的Delphi子过程100多个，内容包括解线性代数方程组、插值、数值积分、特殊函数、函数逼近、特征值问题、数据拟合、方程求根和非线性方程组求解、函数的极值和最优化、数据的统计描述、傅里叶变换谱方法、解常微分方程组和解偏微分方程组。

Neutral differential equations with variable sign coefficients are separated into neutral differential equations with positive and negative coefficients by transformation. According to the characteristic of these equations, a real number set with supremum is constructed, and sufficient conditions for oscillation of all solutions to neutral equations with variable sign coefficients are obtained.

通过变换将具有变号系数的中立型微分方程分解为具有正负系数的中立型微分方程；分析具有正负系数中立型微分方程的特征，构造存在上确界的实数集；并对中立型微分方程的解作细致分析，得到了具有变号系数中立型微分方程所有解振动的充分条件。

Neutral differential equations with variable sign coefficients are separatedinto neutral differential equations with positive and negative coefficients bytransformation.According to the characteristic of these equations,a real number setwith supremum is constructed,and sufficient conditions for oscillation of all solutionsto neutral equations with variable sign coefficients are obtained.

通过变换将具有变号系数的中立型微分方程分解为具有正负系数的中立型微分方程；分析具有正负系数中立型微分方程的特征，构造存在上确界的实数集；并对中立型微分方程的解作细致分析，得到了具有变号系数中立型微分方程所有解振动的充分条件。

This course offers advanced topics for students who have learned ordinary differential equations. The course includes linear algebra which has topics as matrices, linear systems of equations, eigenvalue problems, vector differential and integral calculus. Fourier series, orthogonal functions, Fourier transforms and partial differential equations will also be introduced.

本课程为提供已有常微分方程式基础的同学修习，内容包括线性代数，矩阵运算，特徵值问题，向量的微分与积分，一阶线性微分方程组，傅力叶级数和正交函数，傅力叶转换，并将对椭圆，抛物线，双曲线型式的偏微分方程式作概略介绍。

The main contents include: Some preliminary theory (introduction to Sobolev spaces and variational formulations for differential equations); finite element methods for one-dimensional elliptic problems; the construction methods for general finite elements; error estimates for interpolation operators and inverse inequalities for finite element spaces; a priori and a posteriori error estimates for the finite element method for high-dimensional elliptic problems; some typical spectral methods for partial differential equations; error analysis for the spectral approximation for some linear and nonlinear partial differential equations.

主要内容有：准备知识（Sobolev空间的基本概念和主要结果，微分方程的变分描述）；一维椭圆型方程有限元方法；一般有限元的构造；插值算子误差估计和逆不等式；高维椭圆型方程的先验、后验误差估计；求解偏微分方程的几类谱方法；线性与非线性问题谱逼近的误差分析等。

Firstly, the existence and uniqueness of the solution for neutral stochastic functional differential equations with infinite delay under the uniformly Lipschitz condition, linear grown condition and contractive condition can be directly derived; And the moment estimate of the solution and the estimate for error between the approximate solution and the accurate solution can be both given; If the uniformly Lipschitz condition is replaced by the local Lipschitz condition, the existence and uniqueness theorem can be gained; Meanwhile, the existence and uniqueness of the global solution in the interval 0,+∞ can also be obtained; Secondly, L~p-exponential estimate of the solution for neutral stochastic functional differential equations with infinite delay can be studied; At length, the theorem of the local solution about neutral stochastic functional differential equations with infinite delay only under the local Lipschitz condition and the contractive condition can be established.

首先，在一致Lipschitz条件，线性增长条件和压缩性条件下，直接得到了具无限时滞中立型随机泛函微分方程解的存在惟一性，并给出了解的矩估计，近似解与精确解之间的误差估计；将一致Lipschitz条件替换为局部Lipschitz条件，也得到了具无限时滞中立型随机泛函微分方程解的存在惟—性，同时，也给出了在整个区间0，+∞上具无限时滞中立型随机泛函微分方程解的存在惟一性定理；其次，也讨论了具无限时滞中立型随机泛函微分方程解的L~p指数估计；最后，在局部Lipschitz条件和压缩性条件下，建立了具无限时滞中立型随机泛函微分方程局部解的存在惟一性定理。

In studing methods,partial func-tional differential equations sum up the theories and methods of ordinary differentialequations,partial differential equations,the semigroup theory and the fixed-pointtheory in functional analysis and the basic concepts,theories and methods suit-able for the partial differential equations with delay are formed.

偏泛函微分方程在研究方法上综合了常微分方程的理论方法和泛函分析中算子半群、不动点理论以及偏微分方程的理论方法，并形成了以时滞为基本特征的泛函微分方程的基本概念、理论和方法。

Sodium citrate; calcium carbonate; calcium hydroxide; potassium bicorbonate; magnesium carbonate; ferrous sulphate; Zinc sulphate; copper sulphate; manganese sulphate; potassium iodide; sodium selenite.

柠檬酸钠；碳酸钙；氢氧化钙；碳酸氢钾；碳酸镁；硫酸亚铁；硫酸锌；硫酸铜；硫酸锰；碘化钾；亚硒酸钠。

All this to say that I'm glad filmmaking hasn't become completely ironic. I can enjoy an ironic film as much as the next person, but they usually involve a message of some sort. One that's delivered in a smirkingly clever way that requires little in the way of talent.

所有这些都是说，我很高兴电影制作没有变成完全讽刺艺术，我可以和下一个人一样享受讽刺电影的乐趣，虽然他们经常会被划归到一定级别，技术方面不需要很高的才能。