查询词典 differential

In the PFD, both the differentials and non-differential terms in the differential equation are discretized, and the coefficients of the power series are determined by means of eliminating the truncation error of the corresponding modified scheme, then the high accurate difference scheme is obtained.

摄动有限差分方法在微分方程的差分近似中，离散微商项的同时，也离散非微商项，把非微商项摄动展开成网格步长△x的幂级数，并通过提高差分格式相应修正微分方程误差阶的方法求出摄动幂级数系数，从而获得高精度差分格式。

In this paper, we construct the differential equation to solve the unconstrained optimization problem. Such methods solving the ill-conditioned problems are very effective. It indicates that the asymptotically stable region of explicit the Euler method to solve the differential equation equals to the descent region of the gradient method to solve the original unconstrained optimization problem.

我们发现，在用Euler方法求解二次优化问题的等价动力系统的方程时，由方法的步长确定的稳定区域对应于这些方法所得到的迭代公式的步长满足单调下降算法的条件确定的单调下降区域，因此我们可以利用这个性质构造解无约束优化问题的数值方法而不采用标准的常微分方程的数值求解公式。

We establish a differential equation system via Newton method, and prove that the solution of nonlinear complementarity problems is exact the equilibrium point of differential equation system.

应用了牛顿的方法建立了微分方程系统，证明了非线性互补问题的解是所构造微分方程系统的渐近稳定平衡点，并给出了算法，证明了算法具有二阶收敛速度。

In this paper,by using the idea of F-expansion method (where F is a known solution of an ordinary differential equation with fourth positive power nonlinearity),the problem of seeking the exact solutions of the generalized BBM equation with any positive power nonlinearity is changed into seeking the exact solutions of an ordinary differential equation with fourth positive power nonlinearity.

利用F-展开法的思想(F是一阶四次常微分方程的一个解)，将求含有任意次正幂项非线性广义BBM方程的精确解转化为求一阶四次常微分方程的精确解。

The matrix differential equation is solved using method of steps and applying Laplace transform. Using this method and exact solution of the matrix differential equation with delayed arguments was....

待流场达稳态后，於注水井筛段注入追踪剂并在抽水井筛段量测浓度穿透曲线，使用适当数学模式分析其浓度穿透曲线及上、下井筛段泄降差，即可同时。。。。

For the long composite cylindrical panels, including the influences of the transverse shear deformation, rotatory inertia and initial geometric imperfections, the nonlinear dynamic equations of the long composite cylindrical panels were derived from Hamilton's philosophy. The nonlinear partial differential equations were transformed to ordinary differential equations by expansion in series and solved numerically by fourthorder Runge-Kutta method.

针对含初始几何缺陷的复合材料圆柱曲板，考虑横向剪切变形、转动惯量、初始几何缺陷以及非扁壳等诸多因素，利用Hamilton原理导出复合材料长圆柱曲板的非线性动力方程；用级数展开把非线性偏微分方程组转化为二阶常微分方程组，并由四阶Runge-Kutta方法数值求解。

By changing differential equations into nonlinear integral equation,we study the existence of positive solution of a class of second order differential equations problems by the fixed point theorem of cone expansion and compression,and the fixed point index theorem,then we obtain two multiple positive .

通过将常微分方程转化为非线性积分方程，利用锥拉伸和锥压缩不动点定理和不动点指数讨论了一类二阶常微分方程的正解存在性问题，在一定条件下，得到了几个多重正解定理，同时证明了与此相关的主要引理

It is impossible to logically infer the classically expressed geodesic differential equation from the ontology differential geometry. Besides, the initial proposition how to construct a functional extreme value problem for the shortest curve on a surface, which was supposed first by Gauss, would be an improper formal expression with a wrong premise.

不仅仅无法由"实体论"微分几何逻辑地推导出经典的测地线方程，而且Gauss曾经为"曲面上最短线"问题所构造的泛函极值命题，实质上属于一个"前提认定"完全错误的不当表述。

Moreover,using Ito differential formul a to the constructed Lyapunov function along solutions of lto stochastic differential systems,Lyapunov method is adopted to set up the fundamental theory of dissipativity in the module corresponding to the theory on the dissipativity of deterministic ordinary dif- fere.

提出了有关Ito型随机微分系统耗散性理论的新概念：按模耗散、按模等度耗散和按模一致耗散，并利用Lyapunov方法，借助于Ito 微分公式沿着Ito型随机微分系统的解对所构造的Lyapunov函数求导数，给出了Ito型随机微分系统有关按模耗散理论的一些代数判据，获得了与确定性常微分系统耗散性理论相对应的结论，最后的算例证明了该方法的有效性和可行性。

Moreover, students should know some basic theories of initial value problem of differential equation, stability theory and first order linear or quasi-linear differential equations.

稳定性理论或一阶线性偏微分方程有所认识。

Pradeep Indulkar, a senior official at the Maharashtra state Home Ministry say 101 human were killed and 287 injured.

马哈拉施特拉邦内政部高级官员Pradeep Indulkar称，有101人在冲突中丧生，287人受伤。

Mark Frei, a senior vice president of West, says 80% of West's homeagents have some college education, compared with 30% of those whowork in office-based call centers.

Frei说，该公司80%在家办公的人员都拥有本科学位，而在公司电话中心工作的人中只有30%拥有本科学位。