差分法

For more and more people buy houses and cars on mortgage loan in modern society,we build the mathematical models of average monthly installment and average degressive corpus installment by using dynamic system model and the first order linear difference equation ,and with the real example to show its usage in our life,meanwhile it giving us the reasons of differences between this two arithmetic.

针对当前社会上流行的按揭贷款买房、购车等现象，利用动力系统模型与一阶线性差分方程，分别建立了月均等额还款与等额本金递减还款法的数学模型，并结合实例说明其在经济生活中的具体运用，同时还给出了两种算法所产生差额的原因所在。

When we analyse rigid body with the theory of limit equilibrium, we do not obtain always reasonable maximal principle in physics, and the maximal value is the result of soil plasticity deformation.(2) Thoroughly commenting the typical method of slices from their satisfid equilibrium conditions, calculational parameter and their convergence, the thesis sortes the methods into four kinds. The first satisfies all kinds of equilibrium conditions, can obtain interslice force and the factor of safety.

2从满足的平衡条件、求解的参数及其解收敛性等，分析了各种常用极限平衡条分法，将其分为四类，第一类方法既满足力的平衡，也满足力矩平衡，能获得条间力和稳定系数的收敛解；第二类方法只满足一个方向力的平衡和力矩平衡，只能求得稳定系数；第三类方法既满足力的平衡，也满足力矩平衡，但不是严格的静定问题，解的收敛性差；第四类方法满足两个方向力的平衡，不满足力矩平衡，可求得稳定系数和条间力的大小，不能求得条间力方向。

Computer simulation and design were performed on the basis of the method of moments by using a software package (IE3D), and a Finite-Difference Time-Domain code.

本文的计算机仿真和设计使用基于矩量法的软件工具包（IE3D），以及时域有限差分方法代码实现。

A fourth-order compact finite difference alternating-direction-implicit algorithm is proposed for solving the unsteady-state Navier-Stokes equations of fluid flow and heat transfer using the streamfunction-vorticity formulation. Point-successive overtaxation iteration is used to achieve the steady solutions.

本文构造了求解二维非定常涡量流函数形式Navier-Stokes方程组的一种四阶紧致交错方向隐式差分算法，对包括能量方程在内的离散化方程组采用逐次超松驰迭代法求得稳定解，求解了二维非定常粘性不可压缩流体的流动与传热问题。

Mei.Application of the measured equation of invariance to solve scattering problems involving a penetrable medium.

Dai。一种提取多层介质多导体互连线电磁参数的快速算法：有限差分-不变性测试方程法。

Also the response amplitude will be changed with the initial conditions due to the nonlinear properties of the cables.Taking the bending stiffness, cable sag and cable inclination into consideration, the space vibration control of the cables using the visco-elastic dampers in cable-stayed bridges is investigated by joining the center difference method and the state space strategy. Both the maximum modal damping ration and the optimal damper size are obtained, then the practical suggestions are proposed for the design of the dampers. The space nonlinear vibration equations of the cable-damper system are derived, and anew hybrid method for solving the cable-damper system is presented by combing the Newmark method and Pseudo-force technology. According to the known properties of the cable-damper system, the nonlinear transient responses are analyzed under all kinds of excitations. Based on the transient response, the control effectiveness of the visco-elastic dampers is further demonstrated.

综合考虑了拉索抗弯刚度、垂度的影响，研究了粘弹性阻尼器对斜拉桥拉索的空间振动控制，联合中心差分方法及状态空间法，得出了拉索面内、外振动各阶模态可能达到的最大阻尼比及相应的最优阻尼器系数，并对斜拉桥拉索的阻尼器设计提出了参考建议：考虑拉索抗弯刚度、垂度及几何非线性，导出了索-阻尼器系统的空间振动非线性方程组，结合Newmark方法及伪力(Pseudo-Force)方法，创新地提出了求解非线性方程组的杂交方法，根据拉索-阻尼器系统的阻尼特性，在各种荷载作用下，对索-阻尼器系统的非线性瞬态振动响应进行了研究，从系统响应的角度更加直接地验证了阻尼器的控制效果。

This research process the ionosphere-free triple-differenced carrier phase observation which consist of double frequency GPS observations from the GPS receiver carried on the CHAMP and 40 IGS tracking stations. Besides, the tropospheric correction model, solid earth tide correction, mass center correction of the satellite, earth rotation correction and antenna phase center correction are incorporated. Finally, determine the satellite short-arc orbit with the pure geometry, kinematic, method.

本研究利用CHAMP卫星上装载之GPS接收器所接收之双频观测量与地面上40个IGS追踪站组成三次差分无电离层观测量，并改正观测量中之对流层误差、固体潮误差、质量中心改正、地球自转、天线相位中心偏差等误差量，以纯几何之动态法求定低轨卫星之短弧轨道位置。

The nonlinear equations are dealt by the quasi linear iteration equation,at last,by the orthogonal discrete method,the solutions of the initial problem are obtained.

本文建立的载流板壳二维磁弹性问题的数值计算方法——差分正交离散法不仅对二维问题有效，同样也为三维磁弹性的边值问题的解决奠定了理论基础。

First, the FD results are compared with those obtained by a Real Axis Integration method for a monopole source in an open borehole vertically imbedded in homogeneous formation.

首先，针对均匀地层中单极子声源在裸眼井中激发的声场，将有限差分的结果和实轴积分法的结果进行对比验证。

If the step of the linear system question is not very high, direct solving method is better; if coefficient matrix of the linear system question is not regular and large-sparse matrix , direct solving method does not settle the storage question.

而在求解线性方程组的许多实际问题中，尤其在偏微分方程的差分方法与有限元方法求解问题之中，方程具有重要的特征，一是多为大型稀疏矩阵；二是满足一些条件如对称正定、对角占优等，这使迭代法得到广泛的应用。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。