查询词典 approximation methods in physics

The history and the present conditions of the atomic physics are synoptically reviewed; highly ionized atomic systems are frequently met in the study of the experiment physics, astrophysics and nuclear physics, the study of them is of great benefit of the development of the related experiment and theoretic physics.

简要地回顾了原子分子物理学发展的历史及现状，特别阐述了高离化原子，因为高离化原子在实验物理、天体物理以及核物理中经常遇到，所以研究它们的性质可以促进相关的实验物理以及理论物理的发展。

Imparting the process develops through learning the history to physics in the process of physics knowledge make an on-the-spot investigation, announce the historical rule that physics happening, development and evolution and its corresponding epistemological and methodology change, the basic trend that develops to physics and its position in science and technology and action put forward scientific specification, conduce to a student understanding the mankind to know the basic rule that produces progress to nature, understanding physicist is known and discover theorematic, mensurable basic method, thereby " with Shi Weijian ", be experienced better and use these theorem, law.

在传授物理学知识的过程中通过对物理学历史发展过程的考察，揭示物理学发生、发展和演化及其相应的熟悉论和方法论变革的历史规律，并对物理学发展的基本趋向和它在科学技术中的地位和功能提出科学的说明，有助于学生了解人类对自然界熟悉发生发展的基本规律，了解物理学家熟悉和发现定理、定律的基本方法，从而&以史为鉴&，更好地心得和运用这些定理、定律。

Using the experiences fo the Middle School physics study assessment of other regions for references, directed by the new physics curriculum, based on the pluralistic intelligence theory, the constructive theory and the cooperative study theory, this paper focuses of the problems existing in the Middle School physics study assessment of the local region, tyring to establish a new Middle School physics study assessment system.

本研究以本地区初中物理学习评价的现存问题为着手点，借鉴其他地区初中物理学习评价的经验，以物理新课程理念为目标指向，以多元智能理论、建构主义理论以及合作学习理论为理论背景，建构了初中物理发展性学习评价体系。

And the direction query efficiency based on multi-approximate index is compared with that based on taditional external approximation index. 2 The algorithms of nearest neighbor and reverse nearest neighbor about point, line and ploygen based on multi-approximate index are proposed after the virous methods of distance measure are discussed in detail. And the query efficiency of NN and RNN based on multi-approximate index is compared with that based on taditional external approximation index. 3 The basic concept of semi-join and the strategy of distance-direction semi-join are introduced. And the model of distance relationship, direction relationship and the bounding for spatial object are discussed. Then the method is presented about how to implement the query of distance-direction semi-join, and the efficiency of the algorithm based on multi-approximate index is compared with that based on taditional external approximation index.

即：1在方向关系矩阵模型、开域方向模型基础上，讨论了基于多重近似索引下的定性与定量方向检索方法，并通过实验对基于多重近似索引与外部近似索引下的方向检索效率进行了对比分析；2详细讨论了各种距离度量方法，提出了基于多重近似索引下的点、线、面的最邻近查询和反最邻近查询算法，并通过实验对基于多重近似索引与外部近似索引下的最邻近查询和反最邻近查询效率进行比较分析；3介绍了半连接的基本概念，探讨了距离关系、方向关系以及空间对象数量的约束模型，给出了基于多重近似索引下的距离方向半连接实现方法，并通过实验对基于多重近似索引与外部近似索引下的距离方向半连接的效率进行了比较分析。

For the given endpoint interpolation conditions, a new approximation method of multidegree reduction is presented. Using Chebyshev polynomial approximation theory, the nearly best uniform approximation under the interpolation conditions of endpoints can be obtained.

对于给定的首末端点的各阶插值条件，给出了一种新的一次降多阶逼近算法，应用Chebyshev多项式逼近理论达到了满足端点插值条件下的近似最佳一致逼近。

Applying the Euler method to the equation and particularly using the interpolation technique on variable delay, the Euler approximation is obtained. The discrete Euler approximation is extended to the continuous Euler approximation. It is proved that the Euler numerical solutions will converge strongly to the true solution under the local Lipschitz condition.

对方程应用欧拉方法，特别地对变延迟部分运用插值技巧进行数值离散后，将离散的欧拉格式延拓为连续的欧拉格式，从而得到欧拉格式在局部Lipschitz条件下强收敛到解析解。

The main results are as follows: the relations between local fractional integrated semigroups and the corresponding Cauchy problem, global fractional integrated semigroups and regularized semigroups are given; introduction of the notion of regularized resolvent families, and the generation theorem and analyticity criterions for regularized resolvent families are obtained; the spectral inclusions between fractional resolvent family and its generator, and the approximation for fractional resolvent families in the cases of generators approximation and fractional orders approximation; elliptic operators with variable coefficients generating fractional resolvent family on L^2 by using numerical range techniques; and the L^p theory for elliptic operators with real coefficients highest order are obtained by Sobolev''s inequalities and the a priori estimates for elliptic operators; and a kind of coercive differential operators generates fractional regularized resolvent family by applying the Fourier multiplier method, functional calculus and some basic properties of Mittag-Leffler functions.

主要结论是：给出了局部分数次积分半群和相应的Cauchy问题的关系以及分数次积分半群和正则半群的关系；引入了正则预解族的概念，并给出了其生成定理和解析生成法则；给出了分数次预解族与其生成元的谱包含关系，并研究了在生成元逼近和分数阶逼近两种情况下相应的预解族的逼近问题；利用数值域方法证明了具变系数的椭圆算子在L^2上生成分数次预解族；利用Sobolev不等式和椭圆算子的先验估计证明了具变系数的椭圆算子在其最高项系数为实数时在L^p上生成分数次预解族；运用Fourier乘子理论、泛函演算和Mittag-Leffler函数证明了一类强制微分算子可以生成分数次正则预解族，并给出了该预解族的范数估计。

The moving least squares approximation makes only require least squares approximation with regard to functional value on all nodes. It makes no require for the residual of derivative approximation.

移动最小二乘近似只要求近似函数在各节点处的误差的平方和最小，对近似函数导数的误差没有任何约束。

After introducing the primary approximation approaches for curve and surface offset, we give an optimal approximation approach for offsetting curve based on shifting control points, which relies on approximating the normal by Legendre polynomial approximation.

在全面介绍了等距曲线曲面逼近的主要方法以后，作者首先利用Legendre多项式得到基曲线法矢曲线的最佳平方逼近，由此给出了基于控制顶点偏移的等距曲线最优逼近的算法，它在算法效果和效率上都远优于其他同类算法。

This paper firstly established a general mathematical model for the approximation to gradient and suggested two optimization principles of the approximation model,and then developed two optimal algorithms to reach minimum anisotropy or minimum approximation error while...

提出了通用梯度近似算法的数学模型和两种优化准则，进而推导出两种梯度近似的优化算法。

When this condition occurs, inbound replication with the source partner is stopped on the destination domain controller and event ID 2042 is logged in the Directory Services event log.

计算机密码学是研究计算机信息加密、解密及其变换的科学，是数学和计算机的交义学科，也是一门新兴的学科。

Instructions: click on the thumbnails to see a larger image, then use the left-right arrow keys to scroll through the slideshow.

使用说明：滑鼠点在小图上即可放大观赏。开启后键盘左右键可用来换照片。