把二次型化为标准形的方法

任何一个二次型f=n↑∑↑i,j=1αijxixj都可以通过非退化的线性变换变成标准形f=λ1y1^2 λ2y2^2 … λnyn^2，这个问题不仅在数学上，而且在物理学、工程学、经济学等领域中都是一个重要的问题，变换的方法很多，但工程数学教材中一般只用了正交变换法和拉格朗日配方法，现以一题为例，     

Counter-Rotating Transition Mediated Coherent Effects in Spontaneous Emission in a Three-Level Atom

The coherent effects including counter-rotating coupling on spontaneous emission are presented for a microwave driven V-type three-level atom. Novel coherent effects are realized： （i） There is an infinite series of spectral lines, which are separated by the microwave frequency, independent of the separation of the excited states, no matter whether the microwave transition is resonant or not. This is in sharp contrast to the case of the weak coupling, where the spectral interval is mainly determined by the separation of the excited states. （ii） Selective appearance and inhibition of the spectral lines are obtained simply by varying the microwave Rabi frequency. （iii） Spectral lines have a twofold structure. The physical mechanisms are analysed by employing the dressed states representation.     

Oscillator strengths for 2 ^2P-n ^2D transitions of lithium-like systems with Z=11 to 20

The dipole-length, velocity and acceleration absorption oscillator strengths for the 1s^22p－1s^2nd(3≤n≤9) transitions of the lithium-like systems with Z=11 to 20 are calculated using the energies and the multiconfiguration interaction wavefunctions obtained from a full core plus correlation method. The agreement between the f-values calculated from the length, velocity and acceleration formulae is excellent. Our results agree closely with the experimental data available in the literature. Combining these discrete oscillator strengths with the single-channel quantum defect theory, the discrete oscillator strengths for the transitions from 1s^22p state to highly excited states (n≥10) and the oscillator strength densities corresponding to the bound-free transitions are obtained.     

对原子体系最低能量原理表述问题的再讨论--答胡昆明同志

《大学物理》１９９６年第２期“读者来信”栏目里刊出了胡昆明同志的信（以下简称来信）．来信指出，发表在该刊１９９４年第１０期上王文赜等同志的文章“对原子体系的最低能量原理表述的分析”（以下简称王文），“存在失误之处，文中给出的多电子原子中体系能同轨道能...     

普通物理学课程改革的新尝试——记联合国教科文组织大学基础物理课合作项目

近年来，国内外都在对大学的物理课进行改革探讨，以求建立起新的课程标准。我国工科、理科、农林科的各个院校也都在物理教学改革上做了不少工作，并正在不断深入进行，为了能加强国际合作，联合国教科组织于1990年起建立了名为“联合国教科组织大学基     

广义逆矩阵行处理法程序实现

本文给出广义逆矩阵适应行处理法的理论结果，并设计算法，用ＦＯＲＴＲＡＮ７７语言和Ｃ语言表现算法的主要部分。     

Up-Conversion Luminescence of a High Soluble Zinc Phthalocyanine-Epoxy Derivative

Synthesis and photoelectric properties of a high soluble zinc phthalocyanine-epoxy derivative are investigated. The derivative can be solubilized in convenient solvents, such as Ctt30tt, Ctt3Ctt20tt and H2O. The fluorescence and UV-visible analyses indicate that the ZnPc-epoxy derivative still maintains the plane structure which comesfrom Zn(4,4′,4″,4-ta)Pc and the derivative has obvious up-conversion luminescence in room temperature. The up-conversion luminescence can be explained by the selection rule depending on the two-photon absorption.     

医学院校物理教学中的几点体会

本文就医学院校的物理教学谈了个人的几点体会     

一本颇具时代特色的大学物理教材

由同济大学王少杰、顾牡教授等主编的《大学物理学》(第二版 ) 2 0 0 2年于同济大学出版社正式出版 .这是继 1 996年以来 ,编者历经 5年的教学实践 ,积累经验、不断探索 ,再次精心修订出版的 .因此在出版后立即得到了广大读者的欢迎 ,该教材于 2 0 0 4年获得上海市高等学校优秀