数值方程

Stability is one of the most important conditions in which we numerically solve the wave equations.

稳定性是数值计算波动方程的最重要条件之一。

The earth is modeled as an oblate and rotating spheroid, and higher order terms in the multiple expansion of gravitational fields are considered. To avoid singularities in computations, the quaternion representation of the spacecraft attitude is used in the angular kinetic model equations.

其中地球被描述为绕短轴自转的椭球体，重力场梯度由四阶Jeffery常数描述，航天飞机的姿态运动用四元素法描述，以避免模型方程中的数值奇异点。

Based on the one-dimension two-phase drift flow model, the simulation of system characteristic under HTRL-5 condition was performed.

基于一维两相四方程漂移流模型，采用数值模拟的方法对5MW低温核供热堆热工模拟回路（HTRL-5）的自然循环进行模拟，分析在自然循环系统中存在的分岔特性及其参数效应。

This paper presents an I-V equation that is available in the whole on-state region by numerical simulation, and creates the I-V Characteristic Macromodel.

因此在数值模拟的基础上提出了全导通区域的伏安特性方程，建立了LDMOS I-V特性的宏模型。

The impact of capillary pressure on twophase flow in waterwettish reservoir is studied. The one dimensional control differential equation is derived,and solved by numerical limited difference method.

首先建立一维渗流模型和相应的渗流微分控制方程，用数值差分的方法进行求解，并绘制产量图和采出程度图，分析启动压力梯度和毛管力对水驱油效果的影响。

Through onflow κ-ε equation and structuralization are not even reseau, the simulation of model of numeric wind tunnel that uses test and verify of wind tunnel experiment 4 punch position is different, but the light steel architecture with same size, be based on load of above model wind to distributing the configuration that puts forward to defy wind actively.

通过湍流κ-ε方程和结构化非均匀网格，采用风洞实验验证的数值风洞模型模拟了4个开洞位置不同，但尺寸相同的轻钢建筑，并基于以上模型风荷载分布提出主动抗风的结构形式。

Based on the axial symmetric N-S equation of compressible liquid, we establish the onflow model to simulate convergent nozzles' free jet with different internal parameters by using structural grid and finite volume of quadratic precision.

建立了会聚型喷嘴的湍流模型，根据可压缩流体轴对称N－S方程，采用结构网格和二阶精度的有限体积法，对不同内部形状参数的会聚型喷嘴自由射流进行了数值模拟。

Here mainly introduces five natures of the initial value problems, In several aspects summed up as the following : whether there are solutions to the problems, whether the only solution, the existence of solutions interval extent; Initial issues under what conditions have a solution--Cauchy - Piano existence theorem; how the district between the definition of a solution to open up a larger interval up; initial value problems for the sole condition --- Lipschitz conditions; 3、the numerical solution of the initial value problems of Ordinary Differential equations .

在这里主要介绍了初值问题的5个方面的性质，分别在这几个方面中总结了以下内容：初值问题是否有解，解是否惟1，解的存在区间有多大；初值问题在什么条件下有解----柯西-皮亚诺存在定理；怎样把在小区间上有定义的解开拓到较大的区间上去；初值问题解的惟1性条件---李普希茨条件；3：常微分方程初值问题的数值解法。

Based on which then digesting and absorbing, we should develop the effective dynamic simulation software based on Spatial Operator Algebra,for the sake of providing effective simulation software for the elecmechanical project sphere of

0算法的程序实现，本文在Mathemati.a环境下编制了链式多体系统空间算子代数符号分析程序，并用其推导了若干算例动力学方程的显示表达；此外，本文还在Delphi环境下编制了链式多体系统正反向动力学数值分析软件。

Numerical simulation example shows that, under satisfying constraint conditions of equation of state, it is feasible to obtain the optimal trajectory by optimal control and genetic algorithm.

数值仿真算例表明，在满足状态方程约束条件下，通过最优控制解法和遗传算法求取最优弹道方法可行。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新