数值方程

Based on initial condition, during certain time span, numerical analysis method of differential equation, algebra iteration and optimization method are used to solve response of generalized system and to analyze stability of generalized system.

从初始条件出发，在一定时间长度上，采用微分方程数值积分法、代数迭代和优化方法来求解系统响应，获得非线性广义系统稳定性的数值分析方法。

By applying the explicit and implicit Euler methods to the neutral delay differential equation, two difference equations of the numerical solution are obtained.

把显式Euler方法和隐式Euler方法分别应用到这个中立型微分方程，得到了两个关于数值解的差分方程。

Through the numerical computation and comparison with the exact solutions of one dimensional linear convection equation and nonlinear equation, accuracy of the first order upwind scheme is analyzed in detail.

摘 要：通过对一维线性对流方程和一维非线性对流方程的数值求解，对一阶迎风差分格式的精度作了较详细的分析。

The particle motion differential equation is analysed detailedly and the three-dimensional direct numerical method of particle motion differential equation is established.

论文对颗粒运动微分方程进行详细的分析讨论，建立了三维颗粒运动微分方程的直接模拟数值方法。

In this paper,a numerical well test method is presented to study the inter-well interference effect on the well test curve,which used PEBI grid and gave the discrete control equations of oil-water-phase flow .

本文用数值试井方法研究了井间干扰对试井曲线的影响，采用PEB I网格技术，给出了在PEB I网格下油水两相流动控制方程的离散形式，并耦合了井筒存储和表皮系数公式，得到了压力降落数值试井问题的产量模型。

This paper introduces the food refrigerated theory and the basis of the current industry refrigerated developments in the situation; And then in the long cylindrical-shaped food heat conduction process and the mathematical model using the method of differential thermal conduction equations for discrete, Programming come through long cylindrical-shaped food cooling process numerical solution; After further analysis of numerical solution of the test results; Finally, the impact of the cooling process food all relevant factors, such as moisture content, wind speed and temperature of the cooling medium for in-depth research, while comparing the different shapes of food to food cooling process.

本文首先介绍了有关食品冷冻冷藏的基础理论和目前冷冻冷藏行业的发展的发展概况；然后研究了长圆柱状食品热传导过程的数学模型并利用差分的方法对热传导方程进行离散，通过编程得出长圆柱状食品冷却过程的数值解；之后再分析解对数值解的结果进行验证；最后对影响食品冷却过程的各相关因素，如含水率、风速和冷却介质温度等进行了深入的研究，同时又对比了不同形状的食品对食品冷却过程的影响。

Fourth precision solution can be derived from two grid sets solution with a second precision central difference scheme by Richardson extrapolation. It reduces the amount of calculation. Uncertainty is determined from the discretization error analysis. A finer grid calculation is made to validate the extrapolation scheme.

对于2阶精度中心差分格式的2套网格数值解，用Richardson外推法可以得到4阶精度的解，其工作量比直接求解4阶离散方程的工作量减少许多；对于计算中的数值不确定度，用该方法分析了离散误差，并用逐次加密网格的方法探讨了外推法的合理性。

A parallel solution method is proposed for the simulation of the elliptic mild slope equation and implemented on a personal computer cluster.

提出了椭圆型缓坡方程的一种并行数值模拟方法，并在微机群集并行系统上进行了数值实现。

The influences of the shock thickness and Alfven waves on the particle acceleration by diffusive shock waves are numerically studied through solving one-dimensional diffusive equation including the second-order Fermi effect. It is shown that the spectral index of the energetic particles strongly depends on the shock thickness. For example, the spectral index increases from 2.1 to 3.7 in the low energy range of 3-10 MeV and from 2.5 to 5.0 in the high energy range of 20-60 MeV as the thickness increases. The spectral index decreases from 4.3 to 3.1 as the particle injection energy increases. The spectral index decreases from 4.0 to 1.8 at the quasi-steady stage with the enhancement of the compression ratio from 2 to 4. The results indicate that under the influence of Alfven waves, the energetic particle spectrum at lower energy becomes flat and the spectral index decreases from 2.5 to 0.6 in the low energy range of 3-10 MeV and from 11.6 to 5.0 in the high energy range of 20-60 MeV. At the same time, the rollover energy reaches 19.6 MeV. The spectral index decreases from 5.8 to 2.9 as the energy density of Alfven waves increase. All these results are basically consistent with the theoretical models, as well as the observations of typical energetic particle events.

通过数值求解包含二阶费米加速的一维扩散方程，探讨在准平行激波条件下激波厚度和级联阿尔芬波对粒子加速的影响，研究粒子分布函数的演化与激波厚度和阿尔芬波强度的内禀关系，计算结果表明：(1)考虑激波厚度时，谱指数明显依赖于激波厚度，随着厚度从0.32增大到2.56，低能端(3-10MeV)谱指数逐渐从2.1增加到3.7，高能端(20-60MeV)谱指数从2.4增大到5.0，能谱逐渐变软；当初始注入粒子动量增大1.3倍，质子能谱指数从4.3减小到3.1，且与零厚度激波加速的谱指数差值缩小；厚度不变时，随着压缩比从2增加到4，准稳态分布时低能端(3-10MeV)粒子能谱指数逐渐从4.0减小到1.8谱变硬；(2)在级联阿尔芬波的影响下，随着时间的增大，粒子在低能处(3-10MeV)的谱指数从2.5减小到0.6高能端(20-60MeV)谱指数从11.6减小到5.0，能谱变硬，拐点能量值从7.5MeV增大到为19.6MeV；随着波的能量密度增大，谱指数从5.8减小到2.9，这表明阿尔芬波强度越大，加速效率越高，通过与激波厚度解析结果和高能粒子事件的观测能谱比较发现两者是一致的，说明数值模拟结果是可靠的。

Then the basic fundamental and method of the computation of thermal load of the heated parts of internal-combustion engine are elaborated, the deflective differential equation of heat conduction, basic equation and boundary condition of the theory of thermo elasticity and numerical computation by FEA are introduced.

接着阐述了求解内燃机受热零部件热负荷的基本原理和方法，介绍了热传导的偏微分方程、热弹性理论的基本方程和边界条件确定的原则以及用有限元法进行的数值求解。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。