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1.
在量子力学中,与算符本征值相对应的本征函数具有完全正交归一性,但在量子力学教材中大多没有给出算符本征函数正交归一性的详细证明。参照相关资料证明了一维无限深势阱和线性谐振子哈密顿算符本征函数、角动量平方算符本征函数的正交归一性。  相似文献   

2.
算符理论是量子力学课程的重要教学内容,其中两个力学量算符的对易及其本征函数问题是算符理论中的一个难点。简并情况下两个对易算符的本征函数系问题更为复杂,很多传统教材中都没有进行详细分析和讨论。该文利用一种简单的方法证明了简并情况下两个对易算符具有共同本征函数系的结论,并提出了寻找两个对易算符的共同本征函数系的两种简单方法—交集法与线性组合法。该文有助于教师和学生深刻地领会和求解两个对易算符的共同本征函数问题。  相似文献   

3.
本文通过对力学量算符及其本征函数的讨论,给出测量偏差定义以物理意义,并指出算符对易不是两力学量同时有确定值的充分或必要条件,两算符是否有共同的本征函数才是对应力学量在测量中是否有确定值的条件:在共同的本征函数态中两力学量同时有确定值,偏差满足测不准关系。本文还给出两力学量是否有共同本征函数所必须满足的条件,同时指出一类不对易算符没有共同的本征函数。  相似文献   

4.
简并态评论     
前言在量子力学中,表示系统状态的波函数(或状态函数,态函数)与某算符所对应的本征函数是两个基本的概念,也是两个不同的概念。但是,它们又有密切的联系:系统的波函数可以写成系统的某力学量算符所对应的本征函数的迭加,当对这个力学量进行测量时,波函数编缩为被测得的力学量的值所对应的本征函数。这时,系统的态就由这个本征函数表示。  相似文献   

5.
在原子物理教学中,要讲清量子力学初步这一章,需要介绍本征值方程、本征值、本征函数的概念,在这基础上介绍力学量如何用算符来表示,讲清算符和它所表示的力学量之间的关系。  相似文献   

6.
在量子力学教学中,注意合理安排教学过程,把握量子力学教学的基本框架,重视基本概念的教学,提出把态叠加原理和本征函数系的正交归一性作为教学主线,指出在量子力学教学中要重视力学量用线性厄米算符表示的思想.  相似文献   

7.
本文将■、■的共同本征函数用■、■的共同本征函数系{yim}来展开,应用一般角动量理论,求出其展开系数的递推公式,因而也就求出了■、■的共同本征函数。  相似文献   

8.
从量子力学中力学量算符与经典力学量的对应原则,合时薛定谔方程的求解方法、力学量算符的对易关系及测不准关系的推导与解释来证明 ih■不是能量算符  相似文献   

9.
算符不是测量符号。算符对态矢量的作用并不和力学量的测量直接对应,本文讨论了算符与力学量测量的关系、对两个力学量同时进行测量的物理含意,以及算符的对易性与测量的相容性之间的联系。从而澄清了某些习以为常的模糊概念。  相似文献   

10.
从教学研究的角度出发,对于量子力学中的量子化概念、应用某一力学量表象中的母算符的对易关系来简化一般力学量算符对易关系的计算、叠加原理展开系数在复数域的取值及物理意义和粒子占有数表象等问题进行了分析和讨论,澄清了一些误解,加深了对一些概念和方法的理解和认识。  相似文献   

11.
定义了在随机变量Y =y的条件下 ,随机变量X的条件特征函数 ,并讨论了X的特征函数与条件特征函数的关系以及条件特征函数的若干性质  相似文献   

12.
Kolmogorov微分方程组系数矩阵算子的正则值和点谱   总被引:1,自引:0,他引:1  
研究了在一定条件下Kolmogorov微分方程组系数矩阵算子的正则值,并证明了算子有一本征值具有非负本征函数.  相似文献   

13.
本文根据特征值与特征函数展开理论,用极其简单的矩阵形式,对纤维增强复合材料层合板中各种断裂模型的界面裂纹奇异性问题进行了一系列的理论推导。计算了各种情况下的应力奇异性值,提出了具有一般奇异性的扇形奇异裂纹单元。最后,分析了复合材料中的边界层效应、层面离层、层板横裂等情况的奇异应力场。计算结果表明,本文的方法是行之有效的。  相似文献   

14.
表象理论是量子力学的基础内容之一。文章通过讨论量子力学力学量算符和态矢量在动量表象和坐标表象下的形式。用实例说明了在动量表象下处理一些问题的优越性。  相似文献   

15.
利用一般多项式与多项式矩阵的升幂综合除法,解决算子多项式矩阵的逆的形式幂级数展开问题,进而得到常系数非齐次线性微分方程组求特解的新方法.  相似文献   

16.
There are some curved interfaces in ocean acoustic waveguides. To compute wave propagation along the range with some marching methods, a flattening of the internal interfaces and a transforming equation are needed. In this paper a local or-thogonal coordinate transform and an equation transformation are constructed to flatten interfaces and change the Helmholtz equation as a solvable form. For a waveguide with a flat top, a flat bottom and n curved interfaces, the coefficients of the trans-formed Helmholtz equation are given in a closed formulation which can be thought of as an extension of the formal work related to the equation transformation with two curved internal interfaces. In the transformed horizontally stratified waveguide, the one-way reformulation based on the Dirichlet-to-Neumann (DtN) map is then used to reduce the boundary value problem to an initial value problem. Numerical implementation of the resulting operator Riccati equation uses a large range step method to discretize the range variable and a truncated local eigenfunction expansion to approximate the operators. This method is particularly useful for solving long range wave propagation problems in slowly varying waveguides. Furthermore, the method can also be applied to wave propagation problems in acoustic waveguides associated with varied density.  相似文献   

17.
Against a backdrop of some two decades of sustained economic growth in Ghana, this paper argues that there are a series of sustainability challenges related to technical and vocational skills development (TVSD) that need to be addressed. This paper analyses several sustainability dimensions of TVSD related to: promoting the sustainability of education-for-all achievements through expanding post-basic education and TVSD; identifying sustainable financing mechanisms for an expansion of TVSD; promoting and sustaining equitable access; ensuring that expansion in quantity does not lead to a compromise on the achievement and sustainability of quality and relevance issues; promoting the sustainability of TVSD expansion by widening opportunities for lifelong learning; creating an enabling environment for skills utilization through sustainable employment growth.  相似文献   

18.
本文用逆算符方法研究原子的Thomas—Fermi模型,给出了该模型的解析式,显示了该方法的优越性,逆算符方法有很大的普适性,特别适用于对复杂问题的定量计算,在原子结构的计算中有应用和发展的前途。  相似文献   

19.
This paper deals with a parabolic system in a multi-dimentional bounded domain Ω Rn with the smooth boundary Ω. We discuss an inverse parabolic problem of determining the indirectly measurable internal heat distribution at any intermediate moment from the heat distribution measurements in arbitrary accessible subdomain ωΩ at some time-interval. Our main result is the Holder stability estimate in the inverse problem and the proof is completed with a Carleman estimate and a eigenfunction expansion for parabolic equations.  相似文献   

20.
Developing countries have been quite successful at expanding enrollments in education, especially at the lower levels. But for any given level of efficiency, increased enrollments require increased resources, in order to maintain quality. If these resources are not forthcoming, the increase in educational quantity may come at the expense of quality. Is there a quantity–quality trade-off and what public policies can diminish it, in the face of strong constraints on public budgets? This paper explores the negative impact of such an enrollment expansion—unaccompanied by increased numbers of teachers—on school conditions and learning, using a cross-district time series analysis of Tamil Nadu, India as a case in point. It examines alternative policies which can be used to avoid such negative effects—by more efficient use of existing public resources and by expansion of over-all educational resources through greater reliance on private management and finance.  相似文献   

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