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1、电磁场理论 （第一讲） Electromagnetic Field Theory ( Lecture 1 ),盛新庆 （Sheng Xin-Qing）,电磁仿真中心 （Center for Electromagnetic Simulation）北京理工大学信息科学技术学院 （School of Information Science and Technology，Beijing Institute of Technology）电子信箱： 电话: 68949049 http:/ http:/,Outline,A Brief Introduction of This CourseExplain
2、the title; Importance; Contents; Reference books;The Physical Background of Establishing Electromagnetic Wave Theory,Title of This Course,Electromagnetic Field Theory Electromagnetic Wave Theory Electric Electrics Electronics Magnetic Magnetism Theory:,A statement or group of statements established
3、by reasoned argument based on known facts, intended to explain a particular fact or event ( Longman Dic.) Set of reasoned ideas intended to explain facts or events(Oxford Dic.) 人们由实践概括出来的关于自然界和社会的知识的有系统的结论 （现代汉语词典）,Importance of This Course,One of Fundamental Courses in Our Information AgeWireless C
4、ommunications (Satellite communication Mobile Phone), Radar, et al.stealthy aircraft, low-observable targets One of Masterworks in the whole mankind civilization history,Content of This Course,How is Electromagnetic Field Theory established? (Ch.1) Physical Background, Mathematical Background, Acade
5、mic Tradition BackgroundHow to employ Electromagnetic Field Theory to solve the typical problems in the current information Age? Propagation and Transmission, Radiation, Scattering (Ch.2, Ch.3, Ch.4),Reference Books of This Course,电磁波述论，盛新庆，科学出版社Field and Wave Electromagnetics，David K. Cheng, 清华大学出版
6、社Exercise Problems：http:/,Requirement of This Course,You are required to do exercises and examinations in English.,Physical Background of Establishing Electromagnetic Wave Theory,Knowledge in Electrics and Magntism Before Coulombs LawAfter Coulombs Law,Before Coulombs Law,Eastern 100BC-100A.D. tribo
7、electricity, triboluminescence 500BC magnetic stone 1000A.D. Compass, magnetic declination angle 1600A.D. Electric in Ligntning Western 600BC amber 1492A.D. magnetic declination angle,Observation,Coulombs Law,Coulomb, French, 1736-1806 1784-1785,Torsion balance,1772 Cavendish,1785 Coulomb,1872 Maxwe
8、ll,1971 Williams et al.,permittivity,Amperes Law,Oersted, 1777-1851, Denmark,1820,Magnetized needle,Biot-Savart-Laplace,Amperes Law,permeability,Faradays Law,1, Varing Electric Current 2, Varing Magnetic Field ,Faraday, 1791-1867, Britain 1831,Neumann, 1798-1895, Germany,Electromotive force,Mathemat
9、ical Background of Establishing Electromagnetic Wave Theory,Calculus Newton, 1642-1727, Britian Leibnitz, 1646-1716, Germany Vector Analysis Hamilton, 1805-1865, Britain Gibbs, 1839-1903, U.S.A Heaviside, 1850-1925, Britain,Vector Analysis,Definition of VectorVector Representation Transformations of
10、 Vector Representation in Different Coordinate Systems,Vector Representation,z,x,y,z,Transformations of Vector Representation in Different Coordinate Systems,z,Vector Addition and Substration,？,Dot Multiplication of Vectors,A,B,Commutative,Distributive,Cross Multiplication of Vectors,A,B,anticommuta
11、tive,Vector Identities,Vector Analysis,OperatorsGradient Divergence Curl,Gradient of a Scalar Field,Cartesian Coordinates,Cylindrical Coordinates,Spherical Coordinates,The gradient operator usually operates on a scalar physical quantity, and the result of the operation is a vector whose magnitude eq
12、uals to the maximum rate of change of the physical quantity per unit distance and whose direction is along the direction of maximum increase.,Vector Identities,Divergence of a Vector Field,Cartesian Coordinates,Cylindrical Coordinates,Spherical Coordinates,Definition,Gauss Theorem,Net outward flux o
13、f F per unit volume as the volume about the point tends to zero.,Example,If , find (or div A) at the point (1,-1,1).,At point (1,-1,1),Curl of a Vector Field,Cartesian Coordinates,Cylindrical Coordinates,Spherical Coordinates,Definition,Stokess Theorem,Net circulation flux of F per unit area as the
14、area about the point tends to zero Direction is the normal direction of the area,Example,If , find (or curl A) at the point (1,-1,1).,At point (1,-1,1),Often-Used Symbols,Vector Identities,If , we can define,Vector can expressed as the gradient of a scalar field,Vector Identities,Vector Theorems,Fir
15、st-Kind Scalar Green Theorem,Second-Kind Scalar Green Theorem,First-Kind Vector Green Theorem,Second-Kind Vector Green Theorem,Helmholtzs Theorem,A vector field is determined to within an additive constant if both its divergence and its curl are specified everywhere.,Western Academic Tradition,西方科学的发展是以两个伟大的成就为基础，那就是：希腊哲学家发明的形式逻辑体系（在欧几里得几何学中），以及通过系统的实验发现有可能找出因果关系（在文艺复兴时期）。-爱因斯坦文集第一卷第574页,Development of Western Academic Tradition,Euclid （欧几里得）Euclids Elements 几何原本 I. Newton （牛顿） Mathematical Principle of Natural Philosophy 自然哲学的数学原理 I. Kant （康德）Critique of Pure Reason 纯粹理性的批判,
