查询词典 global differential geometry

On the base of these, and the ideas of mathematical curriculum reform and the course of the reform of solid geometry, combining with educational reality and students" psychology, put forward some thoughts about solid geometry of middle school in future:(1) The arrangement of curriculum content should. give consideration to both the logical sequence of knowledge and the development of students" psychology, and make them united;(2) Paying great attention to the analogy of plane geometry and solid geometry;(3) Some respects remained to be strengthened about solid geometry in senior middle school;(4) Emphasizing the importance of conversion in solid geometry;(5) Stressing on the combination of solid geometry and algebra and other subjects;(6) The design of the content of solid geometry should have certain elasticity, and make solid geometry and modern education technology well combined.

在此基础上，又植根于近年来我国数学课程改革的理念和立体几何课程改革的进展，并结合我国的教育实际与学生心理，对未来中学立体几何课程的设胃提出若干思考：(1)课程内容的编排，要兼顾知识的逻辑顺序和学尘的心理发展相统一；(2)重视平面几何和立体几何的类比；(3)高中阶段立体几何有待加强的几个方面；(4)强调变换在立体几何中的重要性；(5)注意将立体几何和代数及其他学科相结合；(6)立体几何内容的设计要有一定的弹性，并注意与现代教育技术相结合。

As we all known, with the founding of Euclidean geometry in ancient Greece, with the development of analytic geometry and other kinds of geometries, with F.Kline" s Erlanger program in 1872 and the new developments of geometry in 20th century such as topology and so on, man has developed their understand of geometry. On the other hand, Euclid formed geometry as a deductive system by using axiomatic theory for the first time. The content and method of geometry have dramatically changed, but the geometry curriculum has not changed correspondingly until the first strike from Kline and Perry" s appealing.

纵观几何学发展的历史，可以称得上波澜壮阔：一方面，从古希腊时代的欧氏综合几何，到近代解析几何等多种几何的发展，以及用变换的方法处理几何的埃尔朗根纲领，到20世纪拓扑学、高维空间理论等几何学的新发展，这一切都在不断丰富人们对几何学的认识；另一方面，从欧几里得第一次使用公理化方法把几何学组织成一个逻辑演绎体系，到罗巴切夫斯基非欧几何的发现，以及希尔伯特形式公理体系的建立，极大地发展了公理化思想方法，不管是几何学的内容还是方法都发生了质的飞跃。

During the course of the well-known "new mathematics" campaign, the status of Euclidean geometry was completely overthrown in I960" s. After deeply thought of "new mathematics", the standpoint that geometry curriculum should reflect the content and method of modern geometry and be in touch with the student" s real life was agreed on. Other countries have tried some significant attempts. We can find from some geometry textbooks that the methods of transform and vector have appeared as a normal part. Simultaneous, not only the new developments of geometry such as Topology have been referred , but also the connection between geometry and practice has been strengthened.In China, geometry curriculum is also in the during of innovation.

而学校几何课程在二千年的时间里一直没有多大的变化，直到二十世纪初"克莱因—培利运动"的第一次冲击，到60年代"新数学"运动的全盘改革，以及之后的深入反思，中学几何课程要反映现代几何学的内容和方法以及紧密联系于实践的观点已经受到普遍的重视，国外的几何课程已经在这方面做了不少有意义的尝试，从国外的一些几何教材中可以发现：变换、向量等工具已经作为正式的内容进入几何教学，拓扑学等几何的新发展也开始在教材中有所体现；几何课程与实践之间的联系更是在很大程度上得以加强。

The book is structured so that the reader may choose parts of the text to read and still take away a completed picture of some area of differential geometry Beginning at the introductory level with curves in Euclidean space, the sections become more challenging, arriving finally at the advanced topics which form the greatest part of the book:transformation groups, the geometry of differential equations,geometric structures, the equivalence problem the geometry of elliptic operators, G-structures and contact geometry.

这本书是结构，以便读者可以选择部分文本阅读，还带了一个完整的画面，有些地区的微分几何开始入门级和曲线的部分，在欧氏空间变得更有挑战性，终于到达了高级的主题，形成了最大的一部分书：变换团体、几何的微分方程、几何结构、等价问题的几何形状，G-structures椭圆算子和接触几何。

The paper consists of four chapters:In chaper 1, we introduce the background and signficance, research and actuality on oscillation of functional partial differential equations; we present research subject in this paper;In chaper 2, we discuss oscillatory property of systems of parabolic differential equations with delays and obtain necessary and sufficient conditions for the oscillation of their solutions; we show the difference between oscillatory property of systems of parabolic differential equations with delays and that of systems of partial differential equtions without delays; we explain the main results with examples;In chapter 3, we discuss oscillatory property of systems of functional parabolic differential equations of neutral type; we obtain some sufficient conditions for the oscillation or full oscillation of their solutions under some conditions; we explain the main results with examples;In chapter 4, we discuss oscillatory property of systems of functional hyperbolic differential equations of neutral type; we obtain sufficient conditions for the oscillation or full oscillation of their solutions under some conditions; we explain the main results with examples.

全文共分四章：第一章简要介绍了泛函偏微分方程的振动的背景和意义、对其研究的简单历史和现状，给出了本文的主要研究对象；第二章讨论了一类时滞抛物方程组解的振动性质，获得了判断其所有解振动的一个易于验证的充要条件；指出了这类具有时滞偏差变元的抛物方程组解的振动性质和不具有时滞偏差变元的抛物方程组解的振动性质的差异；并举例对主要结果进行阐明；第三章讨论了一类中立型抛物方程组解的振动性质，获得了在给定的条件下其所有解振动或全振动的若干充分条件；并举例对主要结果进行阐明；第四章讨论了一类中立型双曲方程组解的振动性质，获得了在给定的条件下其所有解振动或全振动的若干充分条件；并举例对主要结果进行阐明。

Results A view of better understanding origins of Gaussian intrinsic differential geometry is presented,and the intrinsic relation between Gauss′s thought of intrinsic differential geometry and of his non-Euclidean geometry is brought to light and discussed.

结果 总结分析了高斯建立的内蕴微分几何的思想和渊源，揭示了其与非欧几何学的内在联系。

First of all,we have given some of the basic concepts of differential equations, described the constant coefficient linear ordinary differential equation solution, for a class of second-order variable coefficient linear ordinary differential equation initial value problem, an approximate solution, the method is first unknown function of a definition for N sub-interval, and then in between each district within a constant coefficient ordinary differential equations similar to the replacement, the solution has been the problem as similar to the original analytical solution, and then gives a detailed second-order change order coefficient of linear homogeneous ordinary differential equation solution examples, the examples of the approximate method proposed in this paper is valid.

首先给出了微分方程的一些基本概念，讲述了常系数线性常微分方程的解法，针对一类二阶变系数线性常微分方程初值问题，提出了一个近似解法，本方法是先对未知函数的一个定义区间作N等分，然后在每一个小区间内用一个常系数常微分方程近似替换，所得到的解作为原问题的近似解析解，随后详细给出了一个求二阶变系数齐次线性常微分方程的解的实例，该实例说明本文提出的近似方法是有效的。

In order to obtain more general solution of second order linear differential equation with constant coefficients, which is important in theory and practice, on the basis of knowing a special of the second order linear differential equation with constant coefficients and by using the method of variation of constant, the second order linear differential equation with constant coefficients is transferred to the reduced differential equation and a general formula of the second order linear differential equation with constant coefficients is derived.

为了更多地得到理论上和应用上占有重要地位的二阶常系数线性非齐次微分方程的通解，这里使用常数变易法，在先求得二阶常系数线性齐次微分方程一个特解的情况下，将二阶常系数线性非齐次微分方程转化为可降阶的微分方程，从而给出了一种运算量较小的二阶常系数线性非齐次微分方程通解的一般公式，并且将通解公式进行了推广，实例证明该方法是可行的。

Content: By learning this course, students should grasp the elementary solution of first order differential equation, the structure theory of linear differential equation or system of linear differential equations and the solution of constant coefficient differential equation or system of constant coefficient differential equations.

主要内容：通过对本课程学习，使学生掌握一阶微分方程的初等解法、线性微分方程的结构理论和常系数方程的解法，对微分方程初值问题的一些基础理论有一定的了解，对

Limited slip differential is improved according to common differential. Not having the common differentials disadvantage of dividing the torque into two equal parts, limited slip differential can give most torque or even all torque to another driving wheel which is not revolving in order to make use of the friction of this driving wheel to produce enough traction. This will greatly increase the dynamical capability, the passing capability, the stability and the safety of automobiles on different friction roads. So limited slip differential is substitute for common differential.

防滑差速器是对普通差速器的革新与改进，它克服了普通差速器只能平均分配扭矩的缺点，可以使大部分甚至全部扭矩传给另外一个不滑转的驱动轮，以充分利用这一驱动轮的附着力而产生足够的牵引力，大大提高了汽车在双附着系数路面上的动力性和通过性，显著改善了汽车操纵稳定性，有效地提高了汽车行驶安全性，是普通差速器的理想替代产品。

Hanna: That's over now, isn't it?

都结束了，对吗

You must be ill. You look so pale.

你一定是病了，你的脸色苍白。