数值稳定性

But this case is a common problem that often meets in samples of reprocessing.In this dissertation, an indirect fluorescence analysis method to analyze trace neptunium is discussed.

本文利用DTPA-Tb与DTPA-Np稳定性的显著差异，DTPA-Tb的络合常数的对数值是22.71，而DTPA-Np的络合常数的对数值为29.8，由Np~(4+)置换出DTPA-Tb中的Tb~(3+)。

The joint effect of active and reactive power on the voltage stability of a typical power system was considered by analysing the two parameter bifurcation problem related to nonlinear oscillation phenomena. Numerically, as the active power P1 increases, the Hopf points get closer and eventually coincide at P1=1.455 43 the cyclic fold curve gets closer and closer to the Hopf curve and finally intersects the Hopf curve at a singular point the period-doubling points also get closer and finally coincide at P1≈0.65. The stability behaviour is pre-determined using the normal form approach near the limit point of the Hopf curve. Hence, in the power system attention should be paid to both the consumption of active power and the decrease in the reactive power to prevent nonlinear oscillations. A controller can be designed to absorb some active power and to avoid the nonlinear oscillations that damage the system components.

针对一个典型的单机无穷大电力系统，通过分析系统的双参数分岔的非线性振荡现象，综合考虑有功和无功功率对电压稳定性的影响数值分析表明，随着有功功率的增加，电力系统的Hopf点越来越靠近，最终合为一点在P1=1.455 43处同时圈折cyclic fold 曲线也越来越靠近Hopf曲线，并在Hopf曲线的稳定与不稳定临界点处与Hopf曲线相交倍周期分岔点也随着越来越靠近，最终在P1≈0.65 合为一点应用正规形理论方法，初步确定了Hopf曲线极限点附近的稳定性态因而，电力系统应注意让负荷利用有功功率，减少无功功率的产生以防止非线性振荡另外，可以设计一个稍微吸收网络的有功功率的控制器，以避免因周期振荡而造成电力系统仪器的损坏或电压崩溃

By adapting the existed numerical methods for ordinary and delay differential equations, and matching certain suitable numerical quadrature formulas, Rosenbrock methods are constructed for delay integro-differential equations, the stability criteria of the methods are derived.

通过改造现有常及离散型延迟微分方程的数值方法，并匹配以适当数值求积公式，构造了求解时滞积分微分方程的Rosenbrock方法，导出了其稳定性准则。

Both the results for the numerical stability and the methods used in the stability analysis of the paper are new and valuable.

在随机延迟微分方程数值方法的稳定性研究中，无论是本文中得到的稳定性结论还是分析问题时使用的方法都是全新的，因此具有一定的价值。

Introduction to the fundamental idea, error analysis, stability analysis of numerical

说明数值方法的理论基础，并进行数值解的稳定性与误差分析。

Introduction to the fundamental idea, error analysis, stability analysis of numerical methods

课程目的：说明数值方法的理论基础，并进行数值解的稳定性与误差分析。

Stability, numerical dispersion and boundary condition are the several key problems in the seismic modeling.

稳定性，数值频散和边界是数值模拟中的关键性问题。

Three different numerical iterative algorithms are developed and the accuracy and stabilities of them are compared. Tension and compression instabilities are studied and effects of Conservative Smoothing Approach and artificial viscosity on stabilities are discussed. Based on Taylor series expansion, Modified SPH method is proposed. The discrete forms of the function and its first derivative estimations of the kernel function are deduced in both one and two dimensional space.

讨论了三种不同的数值迭代算法对计算精度和稳定性的影响；分析了不稳定性产生的根源，包括拉伸不稳定和压缩不稳定，探讨了保守光滑算法和人为粘性对稳定性的影响；在Taylor展开的基础上提出了一种修正的SPH方法，并推导一维和二维情形下函数的核估计和函数的一阶导数核估计的离散形式，结果表明，二维情形下MSPH方法可以很好的改善边界粒子的计算精度。

The numerical techniques developed here, including the high accuracy method of using expansions in orthogonal functions in normal direction and the effective algebraic mapping to deal with the problem of infinite region, can raise the calculation precision and the convergence velocity greatly.

文中所发展的方法，如，在法向上采用高精度的高阶谱方法和对无限区域数值问题的更为有效的代数变换处理等，提高了计算精度和收敛速度；同时，通过预估校正迭代法，使抛物化稳定性方程中重要的正规化条件得到满足，保证了数值计算的稳定。

Therefore,it is necessary to research diffusion equation for suspended sediment because it describes the sediment move process in the water body.The equation is a various coefficients second-order linear partial differential equa-tion,such equation under complex boundary condition is very difficult to get its analytical solution,while its numerical solution relative analytical solution is more easier and has the obvious superiority:simple,the computation convenience.but to get a kind of difference format which is good accuracy and stability is not easy.

泥沙扩散方程实际上是一个变系数的二阶线性偏微分方程，这样的方程在各种复杂边界条件下求解是十分困难的，求它的解析解在数学上存在着难以克服的障碍，无法求出其精确解，因此常用数值方法求它的近似解，相比较而言，数值方法有着明显的优势：即简单灵活、计算方便快捷，但要寻找一种精度高、稳定性好、计算方便的差分格式也并非易事。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。