查询词典 central difference

In the process of discretization of the auxiliary function, the traditional central difference formula is replaced by the backward difference formula, and numerical results show the method is of good stability.

在辅助函数的离散过程中用后向差分公式代替传统的中心差分公式，数值结果显示出良好的稳定性。

Central difference method and backward difference method were used for transient thermal analyzing,and the result suggested that two methods have same accurate for this problem.

太阳辐射热流、地球红外辐射热流及地球反照热流是航天器产生不均匀时变温度场主要热量来源。

Tridiagonal block matrix elemination and sweep algorithm is successfully applied to solve the large matrix involved; central difference method is supplemented to Houbolt method to form a time integration method with estimation and correction, to solve the time integration of second order implicit non-linear equation; simplification of system equation by decoupling between the physical coordinates x and y further improves the calculation accuracy and speed.

其中：成功地引入块三对角矩阵追赶法求解上述问题构成的大型矩阵；提出中心差分法+Houbolt法的预估计—校正时间积分法，以解决二阶隐式非线性方程的时间积分问题；系统方程在物理坐标x和y上的"解耦"简化，使计算速度和计算精度得以进一步的提高。

Numerical simulations of the three dimension viscous flow over the SUBOFF-1 model provided by DARPA and other two models are processed by solving RANS equations withκ-εtwo-equation turbulence model and finite volume method, and with SIMPLEC method for pressure-linked terms, central difference shemes for temporal derivative terms, and second-order upwind schemes for convective and diffusive terms.

本文基于RANS方程，采用κ-ε两方程湍流模型来封闭控制方程，采用有限体积法离散控制方程，对于速度压力关联方程，应用协调一致的SIMPLEC算法求解，变化率项用中心差分，对流扩散项采用二阶迎风格式，分别对DARPA提出的裸艇体SUBOFF-1模型以及另外两种回转体模型进行了数值模拟计算。

This is the central difference between the embryonic European market and that of the US.

这就是刚刚起步的欧洲市场与美国市场之间的主要差别。

The simulation results show that estimation performance of the proposed algorithm is much better than the standard particle filterand central difference particle filter.

仿真结果表明，所提出算法的估计性能要明显优于标准的粒子滤波和中心差分卡尔曼粒子滤波。

A one-sided difference approximation is used for convection terms and a second-order central difference approximation for diffusion term.

二阶一边差分逼近用于对流项的离散，二阶中心差分逼近用于扩散项的离散。

This model used the finite—difference approximation to the advection— dispersion equation. The spatial derivatives in the flow equation are approximated by central difference written about grid—block boundaries and time derivatives are approximated by a fully implicit backward scheme.

水流方程的空间导数采用中心差分格式离散，时间导数采用隐式差分格式离散，建立了土壤水分和污染物在各种饱和度的条件下迁移转化方程耦合求解的二维数值计算模型。

Equations are differenced by control volume algorithm , convection term is differenced by up wind difference algorithm , diffusion term and continuity equation are differenced by central difference algorithm .

采用控制容积法对控制方程组进行离散，对流项采用迎风差分格式，扩散项、连续方程采用中心差分格式。

The finite difference time-domain method is stable and easy to be used, but due to the fact that it approximates the space derivatives in Maxwells curlequations by central difference, FDTD usually requires more than 20 grids perwavelength to achieve acceptable accuracy. As a contrast, pseudospectraltime-domain method approximates the space derivatives by pseudospectralmethod, which guarantees the accuracy, theoretically requiting only 2 grids perwavelength.

传统的电磁场数值算法——时域有限差分法稳定而易于实现，但由于FDTD采用中心差分近似Maxwell旋度方程的微分，每个波长上需要取的网格数通常较多，而时域伪谱法采用伪谱法求微分，理论上每个波长只需要取两个网格便可以达到较高的精度。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。