查询词典 finite difference approximation

Using the orthonormalization technique, we obtain a finite difference representation of wavelets.

利用正交规范化，获得了小波的有限差分表示。

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。

Temperature field is obtained by Direct Finite Difference Method with parallelepiped mesh elements and the latent heat release is handled with a combination of equivalent specific heat method and temperature recovery method.

计算方法采用直交剖分的直接差分法；潜热处理采用等价比热法与温度修正法相结合的方法；在节约内存量和提高计算速度的基础上尽可能提高计算精度，并在三者之间取得合理平衡；对直交剖分带来的误差采用了热容量修正技术；针对不同铸造合金的凝固特点，对收缩缺陷判据进行了研究和扩展。

The main research work and its results are: 1Empirical results are analysed for the relations of fault displacement and earthquake magnitude, and difference between permanent ground deformation and maxium dynamic relative displacement on the two sides of fault; 2An analytic method is proposed for resopnse of a buried pipeline due to earthquake fault movement; 3A new shell model with an equivalent boundary and relted finite element analysis method are proposed for estimating response of a buried pipeline under large fault movement; 4By the proposed method, damage performance of water supply steel pipelines with large diameter is simulated to the real cases in Kocaeli Earthquake and Ji-Ji Earthquake, and simulating results show the real failure mode of pipes is revealed; 5Effects of overlying soil and soft/hard interlayers are analyzed on ground rupture mode and degree due to earthquake fault, and some earthquake rupture phenomena in soil layers are theoretically described for the first time; 6Pipeline response characters are discussed for the case of considering effects of soil layers on ground rupture mode; 7Research results and proposed method are applied in seismic analysis of pipline acrossing fault in the Gas Tansportation Project from West to East in China.

主要工作和成果包括：1）分析了不同断层位错形式下地表破裂位错量与震级之间的经验关系，并基于集集地震近断层记录分析了断层两侧永久地面变形和地震动相对位移幅值之间的差别，为合理地考虑地震断层位错地面变形动态影响提供了依据；2）发展了断层位错地面大变形下管线反应分析模型并给出物理概念明确、简单实用的解析分析方法；3）建立了断层位错下埋地管线反应分析的等效边界壳模型有限元方法，方法中引入了以非线性弹簧形式模拟离断层较远处管段影响的等效边界，简化了计算模型并突出了近断层处管体反应；4）利用等效边界壳模型方法，对土耳其地震和集集地震中大口径埋地管线震害进行了模拟，结果表明所提方法可以更清地解释震害所表现的管体破坏特征；5）研究了覆盖土层和软硬夹层的存在对断层位错地面破裂形式和程度的影响，首次从理论上解释了某些地震地表破裂现象；6）探讨了考虑土层对断层位错地面变形影响的管体反应特征；7）本项目成果已在西气东输工程的管道跨断层抗震问题分析中得到了应用。

The three-dimensional calculation model by means of finite difference analysis software based on the weathered rock slope of Liu-Wu highway at K45+950 was used to analysis the stability of the high slope during the course of excavation, and the result of the support plane and the optimized protection plan were evaluated.

根据六武高速公路K45＋950段风化岩质边坡的实际情况，通过有限差分软件建立三维计算模型，分析研究段高边坡开挖过程中的稳定性，并对支护方案进行评价，优化加固方案。

Simple finite difference method is proposed for calculating polarizability of conductors and dielectrics in various shapes in radial and cylindrical coordinates.

bstract：使用简单的有限差分法来计算在圆与圆柱座标系中导体和介电质在不同的形状的可极化性。

Research on deep anti-sliding stability and reinforcement of entirety polygonal line gravity dam;2. The 2D Elastoplastic Finite Difference Method is adopted to analyze the deep anti-sliding stability for the dam foundation of Longkou hydropower station factory dam.

采用二维有限差分程序对龙口水利枢纽混凝土重力坝厂房坝段进行深层抗滑稳定分析，采用强度折减方法，根据特征点位移突变临界破坏判据和止水帷幕部位夹层错动量达到1mm临界破坏判据分别得出了厂房坝段的两个深层抗滑稳定安全系数。

In the process of simulation, the thesis also considers the module both sides potsherd part (there are no related reports in domestic and foreign), uses methods of finite difference and iteration to obtain the temperature field distribution and electricity generation performance quantitative relations under certain working condition.

在数值模拟过程中，本文把模块两端的陶瓷片部分亦考虑进去(这在国内外文献上尚无此方面的相关报道)，采用有限差分及迭代等方法，得到了一定工作条件下，模块的温度场分布和发电性能等诸多内在的数量关系。

Taking water as an example, the pressure gradient was numerically calculated by finite difference method.

采用有限差分法对水在内管做行星运动的环空中流动的压力梯度进行了数值计算。

Firstly, based on the method of pressure-velocity coupling introduced by SIMPLE algorithm and a revised method of solving the unsteady equation of stream function and vorticity on uniform grid, a special algorithm called primitive-variable-time-dependent approach is formed in the present study. In this algorithm the Navier-Stokes equation in primitive variable form is solved by using the time-dependent approach on non-uniform staggered grid system. The second-order accuracy finite difference is used for the first and second partial derivatives of all variables of the convective terms and diffusion terms.

首先，本文在SIMPLE算法系列处理速度与压力耦合问题的思路和均匀网格下改进的关于流函数涡量方程的数值求解方法的基础上，将非定常原始变量Navier-Stokes方程的求解推广至非等距交错网格剖分，形成了具有本文特色的原始变量时间推进方法，其中对流项和扩散项中各变量的各阶导数均采用二阶精度公式，包括温度在内的离散方程组采用ADI迭代方法求解。

A strange and mysterious deep sea creature.

一种奇异、神秘的深海生物。

It's a yellow rectangle .

这是黄色的长方形。