查询词典 finite difference approximation

A total reflection border and the implementation of a new field source excitation for the finite-difference time-domain method are built to satisfy D'Alembert's method.

提出了利用达朗伯公式行波法分析光导开关传输线的新方法，建立了电磁波时域有限差分中边界条件及源的设置方法。

The good agreement of experimental results with the simulated values shows that D'Alembert's method coupled with the finite-difference time-domain method could be used to study and accurately analyze the pulse circuit from the electromagnetic viewpoint.

仿真和实验结果良好的一致性证明了达朗伯公式行波法结合时域有限差分法可以从电磁场角度研究并精确分析脉冲产生电路。

In this paper,the in- fluence of the coupling aperture on the sound energy decay and coupling constant in the primary room is investigated by means of the finite-difference time-domain method,and the investigation is limited within the low-frequency range.

文中运用时域有限差分法，在低频范围内模拟了耦合窗面积的改变对主厅中不同位置的耦合常数和声能衰减的影响。

Using finite difference time domain method, the electromagnetic field distribution of THz wave is simulated in a THz 2D PC splitter and by plane wave expansion method the dispersion relation and defect modes are achieved in a THz rotated PC waveguide.5. A woodpile three-dimensional (3D) PC with face-centered-tetragonal symmetry is one of the most popular 3D PCs because of its favorable band gap characteristics. Based on the woodpile fct lattice structure, we propose a novel woodpile THz lattice structure with comparatively decreased symmetry, better band gap properties and easy fabrication by varying some structure parameters.

计算结果为利用非线性光学差频方法产生THz辐射源的实验研究提供了深入和全面的理论基础；四、利用平面波展开法，通过改变二维THz光子晶体的结构参数，对二维THz光子晶体完全带隙进行了优化，分析出两种适合工作在THz波段的二维光子晶体结构；采用时域有限差分法和平面波展开法，计算出THz波在二维光子晶体"T"型分束波导，45度旋转波导中传输的电磁场分布以及缺陷模；五、Woodpile面心立方四角结构是三维光子晶体中被研究最广泛的结构之一。

After determining the control equation and defined problems for infiltration, redistribution and evaporation, implicit finite difference method was used for ponded infiltration, semi-infinite soil redistribution and semi-infinite evaporation. The calculated results agreed well with measured data.

9在确定了入渗、再分布及蒸发的控制方程及定解问题基础上，采用隐式差分格式对垂直一维积水入渗、半无限土体再分布及半无限土体蒸发进行了数值模拟，与计算结果对比表明，计算值与实测值比较符合。

Because the time series generated from finite difference equation with chaos may also possess exponential distribution of probability density. Additionally, irregular dynamics has ever been attributed to the presence of stochastic noise in many systems, but actually it may result from chaotic process in deterministic system.

近年来对非线性动力系统的深入研究发现：观察到某一过程具有指数型概率密度事件分布并不足以确定它就是泊松过程，由具有混沌行为的有限差分方程所产生的时间序列也可具有指数型概率密度分布；在许多系统中，过去归因于随机噪声的不规则动力学特性，实际上很有可能是由确定性系统中的混沌过程所致。

Numerical model tests show that the method proposed by this paper is as accurate as nine-point finite-difference when permeability tensor is in diagonal form, and it can simulate more complicated cases when permeability is in full-tensor form.

CVFE网格是非正交网格，本文混合运用有限差分和有限元方法计算折算压力梯度，得到与有限差分和PEBI网格不同的离散形式，提出了根据流量符号判定上游的方法，使模型更为合理。

Numerical model tests show that the method proposed by this paper is as accurate as nine-point finite-difference when permeability tensor is in diagonal form, and it can simulate more complicated cases when permeability is in full-tensor form. Its application prospect is more extensive in fine detailed reservoir simulation.

模型计算表明，对于形式简单的对角渗透率张量，本文方法可以与九点差分格式相比，精度是可靠的，并且该方法还能模拟完全各向异性渗透率张量，对于精细油藏数值模拟，其应用范围将更为广泛。

This model is a group of partial differential equations. Th solution is obtained with finite difference method to give a differential equation of gas pressure, temperature and rate and its calculation step.

该模型是一组偏微分方程，采用有限差分法对其进行求解，给出了计算气体压力、温度、速度的差分方程和详细的计算步骤。

The disadvantage of Thermal-Network Method which is based on Finite Difference Method is pointed out.

介绍了节点网络法在航天器热分析中的应用，说明了它的优点，也指出了它的不足之处。

We have something to do in the new stage.

在这段崭新的时期中，我们有一些要做的。

The difference between tourism decision-making under uncertainty and risky tourism decision-making is indistinctive.

其中不确定性旅游决策和风险旅游决策的界线比较模糊，两者的区分是相对的。