查询词典 symmetry

In this paper, we sort out the traditional theory of the symmetry of the system, from the perspective of scientific thinking to explore the origin of the universe and the evolution of mechanisms of material logic, focusing on symmetry and Non-symmetry, and analyze the theoretical thinking and dialectical thinking of the broken symmetry, and we explore the value of epistemology and significance of methodology from symmetry to the broken symmetry.

本文对传统的对称性理论进行了系统梳理，从科学思维方法的角度探讨宇宙起源和物质演化机制的认识逻辑，围绕对称性和非对称性、以及对称性破缺的理论思维和辩证思维的特点进行了分析，并探讨了从对称性到对称性破缺认识过程中的认识论价值和方法论意义。

Secondly, three kinds of mathematics model of optical vortex beams were introduced here. Then the propagation dynamics of optical vortex beams through the non-axis symmetry system is studied, this chapter includes the introduction of the symmetry vortex beam and the non- symmetry vortex beam, the deduction of the Collins diffract integral formula for the non-axis symmetry system, and the transformation of the vortex beam passing through the non-axis symmetry system has been described by using the numerical simulation. Then the general calculation for the orbit momentum of vortex beams, the matrix form for the orbit momentum of vortex beams, and the photon method to describe the orbit momentum of vortex beams are also introduced here. Finally, the interference about optical vortex beams was studied.

本文对涡旋光束进行了较为全面的介绍和研究，主要内容包括：（1）光学涡旋光束的基本理论，主要是介绍了单个光学涡旋光束在柱坐标中的一些表征，涡旋光束的奇异相位和光学涡旋的相位结构；（2）光学涡旋光束的三种数学模型；（3）光学涡旋光束在非轴对称光学系统中的传播动力学，其中介绍了对称涡旋光束与非对称涡旋光束，推导了非轴对称光学系统的 Collins 衍射积分公式，并利用计算机模拟图描述了对称涡旋光束经过非轴对称光学系统后涡旋形态的改变；（4）涡旋光束轨道角动量的一般计算，涡旋光束轨道角动量的矩阵形式，光子法描述涡旋的轨道角动量；（5）涡旋光束的干涉。

This article according to the function image axial symmetry and the point symmetry basic principle,the use function taylor series expansion,determines and seeks the polynomial function image the axis of symmetry or the center of symmetry.

根据函数图象轴对称及点对称的基本原理，利用函数的泰勒级数展开式，来判定和寻找函数图象的对称轴或对称中心。

We present the fundamental theories of Noether symmetries and conserved quantities of mechanco-electrical dynamical systems, including variation principle of the system, Noether symmetry transformation, Noether quasi-symmetry transformation, generalized Noether quasi-symmetry transformation, Killing equations, Noether theorem, the form of conserved quantity. And then the basic theory of Lie symmetry is advanced, including the determining equation, structure equation and the form of conserved quantity.

给出机电动力系统的Noether对称性和守恒量基本理论，包括系统的变分原理、Noether对称性变换、Noether准对称性变换、广义Noether准对称性变换、Killing方程、Noether定理和守恒量的形式；给出机电动力系统Lie对称性的基本理论，包括确定方程、结构方程以及守恒量的形式。

For example, Keyfitz made the classification of the bifurcations in one state variable, without symmetry up to codimension 7; Golubitsky and Schaeffer obtained the classification of the bifurcation problems in one state variable with Z_2 symmetry, in one parameter up to codimension 3; Golubitsky and Roberts studied the classification of degenerate Hopf bifurcation in two state variables with dihedron D_4 symmetry, in one parameter up to topological codimension 2; Melbourne obtained the classification of bifurcations in three state variables with octahedral symmetry, in one parameter, up to

需要指出的是以上研究均没有考虑分歧参数的对称性，Futer，Sitta和Stewart的工作虽然考虑了分歧参数的对称性，但仅限于分歧参数与状态变量具有相同的对称性，他们得到了状态变量与分歧参数均关于二面体群D_4对称，拓扑余维数不大于1的分歧问题的分类。高守平和李养成则讨论状态变量和分歧参数均具有对称性且对称性可以不同的分歧问题，并给出了状态(来源：A770707BC论文网www.abclunwen.com)变量关于二面体群D_4对称，分歧参数关于S~1对称，拓扑余维不超过1的分歧问题的分类。本文第一章讨论两个状态变量关于二面体群D_3对称，两个分歧参数关于O(2)对称的分歧问题，给出了该类分歧问题在非退化条件q(0)≠0下所有情形的分类与相应的识别条来源：AdadaBC论文网www.abclunwen.com

As we well know, the symmetry reduction methods related to group theory, such as the Lie point symmetry method, conditional symmetry, generalized conditional symmetry and etc, are effective tools to study the exact solutions of the nonlinear partial differential equations.

众所周知，与群论有关的对称约化方法，如李点对称方法，条件对称方法，一般条件对称方法等，是研究非线性偏微分方程精确解的有效方法。

According to the some properties of the differentiation ,I found that the symmetry of the graph is closely related to the first-order differentiation and the second-order differentiation .from this ,I search for a way to identify the symmetry of the functional graph for the direct line or the central symmetry of the functional graph for the some dot .

摘 要：利用导数的一些性质，发现了函数图象的对称性与函数的一阶、二阶导数的密切关系。根据这些关系，找到了一种判定函数图象是否关于某一直线对称或关于某点成中心对称的方法。

This paper reveals the relationship between the parity of derivative function and the symmetry of the graph function, finding a effective way to judge whether the functional graph can have the axial symmetry or central symmetry.

揭示了函数导数的奇偶性与函数图像对称性的关系，发现了一种可以用来判定函数图像是否具有轴对称性或中心对称性的有效方法。

3D seismic migration algorithms of holding circular symmetry ;2. Assuming that the point spread function is circular symmetry and considering that the image is actually complex conjugate symmetry in frequency domain, authors establish a new cost function in frequency domain.

算法假设退化系统的点扩散函数具有圆对称性，并考虑图像的频域具有复共轭对称性，在频域里建立了新的优化判据；采用共轭梯度算法搜索判据，从而在有实际物理意义的区域中收敛于最优解；对光学成像系统常见的离焦、衍射模糊问题进行了仿真；用该算法实现了其退化图像的恢复，给出并分析了结果。

Two types of viral symmetry have been recognized, the cubical symmetry and helical symmetry

已经证实病毒有两种对称型，即立体对称和螺旋对称。

In contrast to the ubiquitous rising-sun-with-rays military flag of the Japanese, Chinese banners and ensigns feature a range of designs.

与遍地都是的太阳军旗不同，中国人的旗帜和徽章设计得各式各样。

From their small corner of Feng's Guangzhou headquarters -- a jumble of pink leashes, squeezable rubber steaks, and plastic doggy Santas for Fido's stocking -- Soleil's designers come up with at least five new products a month.

从Feng 设在广州总部的产品展示柜台上可以看到，Soleil的设计师每月至少设计出5件新产品。