查询词典 numerical calculation

Through numerical calculation and comparison with the complete formula,the accuracy of the approximate formula for calculation of reflection coefficient often used in AVA method for gas hydrate is discussed.

通过与完整公式的对比，对AVA常用的反射系数近似计算式的精度进行了讨论，同时分析了地震波速度、泊松比、密度等参数对于BSR反射系数的不同贡献。

The application of calculating machine is not confined to the scientific calculation again, And even more used in control, Non- numerical calculation such as administration along with data handling and so on.

自1946年第一台计算机问世以来，计算机产业的飞速发展已远远超出了人们对它的预料，而随着Internet应用在全球范围内的日益普及，计算机的应用已不再局限于科学计算，而更多地用于控制、管理以及数据处理等非数值计算的处理工作。

Then the boundary element integral equation of interior and exterior form is deduced in detail, also the form with corner coefficient. The significance for numerical calculation and principle of the singular integral is analyzed, and a non-isoparametric transformation method is presented to calculate weak singular integral and Cauchy integral, the method presented provides us a very simple way to computer the two kinds of singular integral of Helmholtz boundary integral equation, and it is easy to program in computer. After the difficulty of the calculation for multi-frequency of Helmholtz boundary element is explained, a method named SECHIEF (Series Expansion Combined Helmholtz Integral Equation Formulation), which is focused on the computational efficiency, is presented.

对结构声辐射的边界积分方程的内部形式与外部形式进行了详细的推导，给出了角点系数的计算方法与边界积分方程的形式，在此基础上，分析了奇异积分产生的原理及其对数值计算的重要性，提出了一种计算奇异积分的非等参(来源：Ae8a8BC论文网www.abclunwen.com)单元的变换方法，该方法给Helmholtz 声学边界积分方程中的弱奇异积分与Cauchy 奇异积分的计算以及编程提供了极大便利。

In order to analyze the influence of the center air pipe diameter change on the combustion effect, numerical modeling was applied to numerical calculation on the temperature field of such type of boiler,through which temperature field in five different schemes were obtained. In addition, the influence law of change of the diameter of the center air pipe on the temperature field was analyzed. The temperature of the nearly-back wall region takes on a firstly decreasing and then increasing change with the diametrical decrease of the central wind pipe.

为研究改变中心风管直径后的4层燃烧器对炉膛燃烧的影响，采用数值模拟的方法对该型锅炉炉内的温度场进行数值计算，得到5种不同方案下该型锅炉炉内的温度场分布，并分析了中心风管直径的改变对炉内温度场的影响规律，即后墙近壁区温度随着中心风管直径的减小呈现先降低后升高的趋势。

In this thesis, we focus on the theory for the interaction of molecular dipole moment with external electric field and use the numerical simulation to investigate the rotational state-selection of polar molecules in a hexapole electric field and the laser-field role of alignment or orientation for molecules based on semi-classical treatment, the detail is the numerical calculation for a quantum mechanical treatment of molecules and their interaction with the external field and a classical electrodynamical treatment for static electric field.

本文研究是在描述分子偶极矩（永久偶极矩或诱导偶极矩）和外电场相互作用的基础上，我们建立了对分子态选择和角动量取向、准直研究的半经典理论框架（即分子体系状态、能量及与外场相互作用使用量子理论描述，分子的运动轨迹使用经典电动力学描述），并利用数值计算方法对静电场和随时间变化电场作用下分子的转动态选择、取向和准直过程进行了研究。

Based on Collins integral formula and the expansion of the hard aperture function into a finite sum of complex Gaussian functions,the approximate analytical expression of the diffraction field of Gaussian beam by a circular disc is derived,and its characteristics are analyzed by the numerical calculation and numerical simulation.

基于圆孔光阑函数展开为复高斯函数和的方法，用Colins积分公式，导出了高斯光束照射下圆盘衍射的光场近似解析表达式，经计算机数值计算，对高斯光束照射下圆盘衍射的衍射特性进行了详细的分析

The authors make basic research for the numerical calculation of cooling waters flow in the engines, on the bases of research results obtained with numerical method of incompressible fluid.

本文在作者已完成的不可压缩流体三维流动数值模拟研究的基础上，对发动机冷却水三维流动的数值模拟方法进行了基础性研究。

Establish the steady-state and transient model using the three hydrodynamics equations (Continuity equation, Momentum equation and Energy equation). By comparing different state equation, it selects the BWRS state equation which is considered the most accurate state equation in current natural gas measurement. It calculates compression factor, density and other Thermal parameters based on BWRS state equation. In Numerical solution of the steady-state and transient model, compression factor, friction coefficient and all the other Thermal parameters are recalculated in each small time step to reduce the numerical calculation error.

在稳态模型的建立上，利用流体力学三大方程(连续性方程、运动方程和能量方程)，通过比较不同的状态方程选用了目前被认为最精确的用于天然气计量的BWRS状态方程，并以此方程为基础进行压缩因子、密度等热物性参数的计算；在稳态模型的求解上，选用容易计算，精度较高的标准型龙格—库塔(Runge-Kutta)法进行数值求解，并且在迭代过程的每一小步都重新计算燃气的压缩因子，摩阻系数等所有的计算参数，以减少数值计算的误差。

The numerical calculation of integration is an important branch of numerical analysis.

积分的数值计算是数值分析的一个重要分支。

A general Godunov finite difference schemes-WENO schemes which had fifth-order accuracy was used to make a numerical calculation for 2-dimensional axis symmetrical laser-supported plasma flow field under laser ablated solid target and laser ablated propulsion efficiency parameters(mechanical coupling coefficient etc.) was obtained by the simulation.The models of the calculation of ionization degree of plasma and the interaction between laser beam and plasma and the simplified eos of plasma were considered in the simulation.

采用针对高温气体电离度的一种近似计算方法，以及具有五阶精度的广义Godunov差分格式-加权本质无振荡格式WENO(weighted essentially non-oscillatory schemes)，给出了高温气体状态方程的简便描述，并考虑激光与等离子体的相互作用，模拟了强激光与固体靶相互作用时激光支持靶面等离子体流场的动态物理过程，并给出了不同参数条件下激光烧蚀固体靶的推进效应参数。

I am sure after a few weeks of adaptation and familiarization I will have no difficulty in functioning on a daily basis in an English speaking society or in participating fully in graduate studies.

在大学的三年的学习生活不仅给予我自身的充实，更重要的是磨练和培养了我较强的自觉能力和严谨，踏实的作风以及不怕困难的精神，对未来充满了信心！

As the first volcanoes erupted, one of the gases that bellowed out was steam.

在第一批火山喷发时，喷出的气体之一就是水蒸汽。