查询词典 evolution equation

Nonlinear evolution equation is an important mathematical model for describing physical phenomenon and an important field in the contempary study of nonlinear physics, especially in the study of soliton theory.

非线性演化方程是描述物理现象的一类重要数学模型，也是非线性物理特别是孤立子理论最前沿的研究课题之一。

Then, integrating the damage evolution equation by means of variable separation method, an integral expression of stresslife relation can be established.

利用分离变量方法对损伤演化方程积分，得到构件的应力与寿命关系的积分表达式。

Using the pulse in the shape of sech 2, the approximate solution has been obtained and compared with the numerical simulation of evolution equation.

在此基础上给出了双曲正割型输入脉冲在介质中的传输特性，得到了近似解析解，并与直接演化高阶非线性薛定谔方程作了比较。

The following are the major work in this thesis which has been studied and still needs to be studied further in the future: 1 An improved adjoint variational method is developed, thus it can be applied to the LAGFD-WAM Wave Numerical Model for data assimilation; 2 A linear evolution equation of spectral perturbation is derived in order to analyze its increasing or decreasing mechanism.

本论文主要完成了以下几个方面的研究： 1）建立了推广形式的共轭变分同化方法，使之能够应用于LAGFD-WAM海浪数值模式； 2）导出了扰动谱线性演化方程，分析了扰动谱增长、衰减机制，考察了涌浪情况下扰动谱的持续时效问题及风浪情况下扰动的演变过程； 3）利用波谱共轭方程初步分析了同化模型中距离泛函的敏感性及敏感区域空间分布； 4）将推广的共轭变分方法应用于海浪谱能量平衡方程，建立了连续形式的海浪同化模型，特别是严格导出了风输入、破碎、底摩擦、波波非线性相互作用和波流相互作用各源函数的共轭源函数表示式； 5）分别进行了波谱层次上和有效波高层次上的同化试验，并对数值结果进行了分析。

By the numerical simulations of the free surface velocity histories and based on the best consistence between the computational results and the experimental ones, the material parameters in the damage evolution equation and the spoliation criterion are obtained.

通过自由面速度历史的数值模拟，并基于计算结果与试验结果间的最佳一致性，得到了损伤演化方程和层裂准则中的材料参数。

According to the concept of strain energy of cracked materials, the orientation tensor of crack was defined. Considering the crack-closing and friction between crack surface under compression, The damage tensor, damage strain and effective elastic modulus were formulated. A method for discrete description of damage mechanism was given, and the evolution equation of discrete orientation density of crack was obtained. The relationship of micromechanism and the macro-representation of concrete failure were studied.

从含裂纹材料的变形能出发，引出了裂纹的方位张量；在考虑裂纹受压闭合与滑动摩擦的基础上，给出了损伤张量、损伤应变和有效弹性系数的表达式，在损伤机构离散化方法的基础上，给出了方位密度的演化方程；将上述损伤理论应用于混凝土的损伤分析，研究了混凝土破坏的微观机制与宏观表现的关系及Griffith准则和Mohr-Coulomb准则的相似性问题，对修正的Griffith准则进行了改进。

A physical model describing the heat and mass transfer processes of the evaporating thin film is set up and an evolution equation which shows the development regularity of dimensionless film thickness with time is obtained from the liquid vapor interfacial conditions.

论文对平面蒸发薄液膜的传热传质过程建立了物理模型，从汽液界面上的边界条件得到无量纲液膜厚度随时间变化的发展方程。

A nonlinear evolution equation for the radiation field in magnetically insulated transmission line oscillator is derived and the threshold conditions of the nonlinear unstable solution are studied.

导出了磁绝缘传输线振荡器中辐射场的非线性演化方程，并讨论了在临界值点附近可能出现非线性不稳定解的条件。

In this paper, We obtain the solutions for nonisospectral evolution equation heirar-chies and r-sysmetry hierarchies by the inverse scattering transform, Hirota method and Wronskian technique, we also investigate the properties of these solutions.

本文利用反散射变换、Hirota方法、Wronskian技巧研究了非等谱发展方程族和等谱方程的τ方程族的精确解以及解的性质。

Based on linear elastic fracture theory, a damage evolution equation for composite soild propellant under uniaxial tension is derived. Main mecrosopic of material are determined through fittin the experiment data of constant rate tension. Then, the integrate constitutive equations found is close to microlevel.

基于线弹性断裂理论，提出了一个适合复合固体推进剂的脱湿微裂纹损伤发展方程，通过部分单向定速拉伸试验数据拟合确定其主要的细观参数，从而得到了复合固体推进剂在细观水平上完整且封闭的本构方程组。

Lugalbanda was a god and shepherd king of Uruk where he was worshipped for over a thousand years.

Lugalbanda 是神和被崇拜了一千年多 Uruk古埃及喜克索王朝国王。

I am coming just now,' and went on perfuming himself with Hunut, then he came and sat.

我来只是现在，'歼灭战perfuming自己与胡努特，那麼，他来到和SAT 。