数值方程

The obtained results a re compared with analytic solution and those from integral equation and other me ans. It is shown that the staggered grid finite difference method combined with the Biconjugate gradient iterative solver processed with divergence correction and incomplete Cholesky decomposition procedures can efficiently improve the three dimensional electromagnetic calculation with high accuracy and stability.

经与解析方法、积分方程等其他方法的计算结果对比表明，交错网格有限差分法结合散度校正和不完全乔累斯基分解预处理的双共轭梯度迭代方法进行正演计算，速度快、精度高、结果稳定，能适应三维复杂介质的数值模拟，为三维电磁反演奠定了基础。

Some improvement on the original Poisson equation numerical generation grid method in which the control over grid concentrativeness partly lost due to the grid improvement on orthogonality was made.

在最初Poisson方程数值生成网格方法中对汇聚性的控制并不十分有力，因为随着迭代次数的增加，正交性得到改善，但离壁距离以及网格线分布难以保证。

Mathematical model was set up,on the basis of dynamics formulation,normal expanse of the target interface ,and supposed concrete medium was constringent material.

根据弹体动力学基本方程和假定混凝土为可压缩材料，基于弹靶接触表面处靶体材料的法向膨胀性，对跳弹现象进行理论分析，在合理假设的前提下，建立了跳弹现象的数学模型； 2）针对该模型编制计算机程序，在给定初始入射速度、入射角后可以判断出能否产生跳弹现象，输出产生跳弹现象时所对应的初始侵彻条件，并通过穷举法得出跳弹临界相图，对于斜侵入情况，能计算出弹体在不同侵彻阶段下的运行时间并能绘制出侵彻轨迹，结合现有的试验数据，进行对比分析，二者符合良好，证实了理论分析模型的合理性； 3）开展了跳弹现象的数值模拟研究。

In this paper , we consider the Expanded Mixed Finite Element Method and mixed covolume method for the quasilinear parabolic integro-differential equation and quasilinear parabolic problem.

本文中我们采用扩展混合有限元方法和混合体积元方法数值模拟了二阶拟线性抛物型积分微分方程和二阶拟线性抛物问题。

The fre-quency equations are derived according to stress match, consid-ering gear as a thin bar and adopting exponential horn. Then the influences of vibration of transformer which consists of horn and gear are explored, which come from the length of horn and the machining frequency. It has been discovered that the reso-nance frequency of the horn is the detune one of transformer and the resonance frequency is not same as one of horn, which provide theoretical rules for transformer design.

鉴于此，根据应力耦合，将齿轮作为圆盘，采用指数型变幅杆，推导频率方程，对变幅杆的设计长度和变幅器振动频率进行数值分析，发现变幅杆的共振频率恰好是变幅器的失谐频率，变幅器的共振频率与变幅杆的固有频率也不相同，这能够为超声珩齿变幅器的设计提供理论依据。

Based on coupled nonlinear Schr?dingar equation, the numerical solutions of pulse propagation in fibers were obtained with Split-step Fourier Method.

本文以耦合非线性薛定谔方程为理论模型，采用分步傅立叶方法进行数值计算，仿真研究了满足特定要求的多程放大系统前端脉冲经光纤传输后引起失真的原因。

Physical and numerical models were establishedased on NˉS c ontrol equations and RNG kˉεturbulence model, the interior flow fields of the nozzles were analyzed through num erical method, both the flow parameters change trend and thrust speciality of the asymmetry quadrate nozzle were resea rched.

文中建立了非对称方形尾喷管及传统轴对称尾喷管的物理数学模型，基于N S方程和RNG kε湍流模型，对两种尾喷管三维内流场进行了数值分析，研究了非对称方形尾喷管内部流动参数的变化趋势及其推力特性。

The impo rtance of so lu t ion s of A lgeb raic R iccat i Equat ion s are simp ly show n. Som e good num erical m ethods fo r AREs are described, st ressing som ew hat at the wo rk of the au tho r. Fu rther study t rends are also m en t ioned.

简单说明解两类代数R iccat i 方程的重要意义，简要综述自80 年代以来在发展它们的数值解法方面的一些研究进展，偏重作者在这方面所做的一点工作，指出今后在这方面研究的方向。

A method of computing rifle explorator solid contour curve;2. Real-Time Ensuring Technology in Artillery Rifle Manufacturing;3. It takes a long period to design an electrochemical machining cathode for machining the mixed rifle with large spiral angle and the experiments are difficult.

针对火炮炮管大缠角混合膛线电解加工中阴极研制周期长、设计难度大的问题，采用Visual C++对阴极工作齿按弹道方程运动生成膛线的过程进行了数值模拟，建立了阴极工作齿的三维模型和膛线加工模型，给出了该模型的求解算法。

Based on the Hertzian contact theory, the pressure distribution on balls of a pair of angular contact ball bearing under three dimensional loading conditions was analyzed.

本文首先介绍了Hertz接触理论的基本特点与求解过程，对于实际存在的有限长线接触问题进行了详细讨论并完成了对该问题基本积分方程的一维数值求解。。。

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。