查询词典 first approximation

The harmonic field of electric dipole source on the uniform earth surface is converted into transient field by inverse Laplace transform,and the Bz/ t transient curve is calculated.The Hz transient curves on the stratified earth surface are obtained from cosine transform calculated by broken line approximation.

由逆拉普拉斯变换将均匀大地面上的电偶极子源谐变电磁场转换为瞬变电磁场，并计算出Bzt瞬态曲线；对分层大地面上的瞬变电磁场，采用折线逼近法计算余弦变换得出Hz瞬态曲线。

Methods Ionization chamber and film dosimetry methods were used to compare the angular dose distribution, point source approximation in the area close to the source,the coincidence of inverse square law of source strength and the scatter and attenuation in water medium,of a cylindrical, miniature 192 Ir source and "the ideal point source".

用电离室法与胶片法实测国产192Ir放射源空间剂量角分布、点源的近似性与源强反平方定律的符合性以及水介质散射与衰减特性，并与点源剂量分布特性比较。

The main contents include studying purpose, researching object, the introduction about this course; governing equations, boundary conditions for an inviscid irrotational flow, linearized approximation for small-amplitude waves; illuminations of wave factors and relevant physical variables; the propagating waves in deep and shallow water; discussion of physical meanings of group velocity.

包括学习目的、研究对象、主要内容简介；控制方程，描述无粘、无旋运动的边界条件，对边界条件的线性化近似；波要素和有关物理量的介绍；深水和浅水条件下的行波问题；讨论群速度的物理意义。

Using RBF neural network substitutes BP network as the approximation of implicit performance function, and the response surface is formed in the sphere of hyper-pyramid at iteration step.

采用径向基函数神经网络，代替目前常用的BP网络，迭代过程中在超锥体的范围内构造响应面，逼近隐式的非线性功能函数。

Established a series of results on the Jacobi approximation, and proposed the Jacobi spectral method for singular problems, which produces the possibility of using spectral mcthod for problems in a ball.

最近，郭本瑜教授等建立了一套相当完整的Jacobi正交逼近理论，并提出了适合于一类奇异问题的Jacobi谱方注。

Results show that radial basis function and point interpolation methods possess Kronecker Delta function property, but the robustness is poor in some cases; the MLS approximation function does not possess Kronecker Delta function property, but it has good robustness. Differences among the three discretization schemes of meshless method are as follows:the collocation method requires no numerical integration and very little computational time while its robustness is poor; Galerkin method is not a truly meshless method due to the background meshes required for integration; the Petrov-Galerkin method is a truly meshless method and need numerical integration in each sub-domain, so it needs more computational time.

分析结果显示：径向基函数和点插值法均具有d 函数属性，但计算稳定性差；移动最小二乘近似函数不具有d 函数属性，但计算比较稳定；无网格方法中的3种离散方法不同之处在于：配点法不需要积分，计算量小，计算稳定性差；Galerkin方法需要借助背景网格进行积分，它不是真正的无网格方法；Petrov-Galerkin方法，是一种真正的无网格方法，它需要对每个子域进行积分，计算工作量较大。

In particular, with Kronecker product approximation technique, the lowerbound of concurrence can be obtained up to various orders.

尤其引入了Kronecker积近似技术，可以方便地得到concurrence的下界不同程度的近似。

In order to eliminate the ringing effect,Antireflective boundary conditions and Kronecker product approximation is used for the new image formation.

为了消除恢复图像边界的振铃效应，推导了新的光学成像过程数学模型，该模型采用反镜像边界条件并利用直积近似对卷积核进行处理。

According to the special structure of the coefficient matrix arising from the SUPG discretization of convection-diffusion problem, or the MAC discretization of the Oseen problem, we use Kronecker product approximation to design the preconditioner.

第一章讨论预条件技术，针对对流扩散问题和 Oseen 问题离散后系数矩阵所具有的特殊结构，用近似 Kronecker 积构造预条件子。

The main goal of this article is the application of Lagrange multiplier to domain decomposition for generalized Stokes problem; This method is very suitable to the finite element space approximation.

本文的主要目的在于将Lagrange乘子技术应用于广义Stokes问题的非匹配网格上的区域分裂解法中；这种方法非常适用于有限元空间近似。

"Second Life is remarkably easy to work with, and is very popular,"

"第二次生命是显着容易的工作，并且很受欢迎，"

For example, we usually assume that materials are homogeneous and isotropic and free of internal defects or flaws.

为了得到适合有限元分析的模型，我们必须经过如图2所示的简化步骤。