Snippets of physics

How does one study quantum mechanics in an accelerated frame? The answer to this question leads to some surprising insights into the solutions of the Schräodinger equation for harmonic oscillator!     

Schroedinger方程向经典力学的过渡

薛定谔方程是量子力学的基本方程，其地位与经典物理中的牛顿运动方程相当。文章从薛定谔方程出发，用普朗克常数的方式以及在坐标表象中求动量平均值的方法对量子力学与经典力学之间的关系进行了详细讨论。结果表明，在普朗克常数h→0的极限情况下，量子力学就过渡到经典物理学；微观粒子的运动在平均值的意义上是遵从牛顿第二定律的，量子效应只是围绕经典平均值的一种涨落，即量子涨落。     

光——现代"物理学之后"的黑暗

本文通过对量子力学和相对论中相关光的问题的分析,认为正是量子力学和相对论中对光理解的错误导致了今天的物理学和哲学的相关错误。     

Hans bethe, quantum mechanics, and the lamb shift

An elementary derivation of the Lamb Shift, as originally given by Hans Bethe, is attempted, with a short historical background on the evolution of QED since the beginning of the last century. The treatment is for a non-relativistic electron, in keeping with Bethe’s proverbial insight into the problem, which renders irrelevant the effect of the electron spin on the problem. The Kramer idea of renormalization is implemented through a simple subtraction of the self-energy of a free electron from that of the electron bound in a hydrogen atom. A N Mitra has had a long teaching service from 1955 to 1994 when he retired from Delhi University as INSA Einstein Professor of physics. He spent a year (1995) as visiting professor at NIAS (Bangalore). Since then he has been working as a free-lance writer-cum-researcher in physics, with periodic publications on scientific matters of current interests. Concern for man and his fate must always form the chief interest of all technical endeavors. Never forget this in the midst of your diagrams and equations.     

爱因斯坦和玻尔之争与理想实验

综述了爱因斯坦与玻尔关于量子力学基础理论的争论及内容,分析了论战形成的原因及在其论战过程中提出的三个理想实验。讨论了爱因斯坦应用理想实验是为了强调量子理论内在逻辑的一致性和因果律,符合其一贯的哲学思想。     

量子力学双波理论的非局域性

在以“非局域性”为标题的学术论著中,非局域性是有名的EPR论文~([1])中所体现的那种“局域性”的对立面,是A．Einstein同 N．Bobr~([2])所争论的焦点,而不是一些数学家~([3])所谈论的那种东西。数学家所谈沦的局域性是指类拟于“孤立波”那样的“鼓包”,而非局域性则是这种     

The renaissance of continuum mechanics

Continuum mechanics, just as the name implies, deals with the mechanics problems of all continua, whose physical （or mechanical） properties are assumed to vary continuously in the spaces they occupy. Continuum mechanics may be seen as the symbol of modem mechanics, which differs greatly from current physics, the two often being mixed up by people and even sci- entists. In this short paper, I will first try to give an illustration on the differences between （modem） mechanics and physics, in my personal view, and then focus on some important current research activities in continuum mechanics, attempting to identify its path to the near future. We can see that continuum mechanics, while having a dominating impact on engineering design in the 20th century, also plays a pivotal role in modem science, and is much closer to physics, chemistry, biology, etc. than ever before.     

Pauli矩阵的若干性质及应用

以Pauli矩阵为工具，讨论Clifford代数、Dirac代数及量子逻辑门的有关性质     

关于量子力学中算符的几点注记

给出了构成量子力学中厄密算符的一般规则以及广义坐标及其共轭动量下的对易关系,同时,对非厄密算符也作了说明．     

对量子力学哥本哈根学派之解释的思考

量子力学的形式体系建立超前于物理诠释,这为量子力学解释群的形成提供了现实的可能性前提。但量子力学和经典物理学语言体系分别蕴涵着不同的本体预设,描述宏观世界的经典力学与描述微观世界的量子力学在作用机制、质点抽象、概率的应用均有本质的区别。因而,借助经典物理学的概念描述微观物理实在图景会在本质上存在不适应性。在此语境下,我们认为,尽管哥本哈根学派之解释有不足之处,但目前在整体上还没有哪种解释比它更优越。     

Key topics for quantum mechanics at secondary schools: a Delphi study into expert opinions

This article describes a Delphi study aiming to investigate which quantum mechanics topics experts consider to be important to teach at the secondary level, and what arguments these experts give. A series of three questionnaires was administered to experts in the fields of quantum physics, mathematics, chemistry and biophysics (n?=?17, 12, 11 for the first, second, and third questionnaires, respectively; the number of participants changed due to attrition). Several experts from this group (n?=?9) were also interviewed. Results show that there is consensus on the topics considered to be important, i.e. duality, wave functions and atoms. Experts mainly based their topic ranking on relations between concepts, and on what quantum mechanics topics they consider to be fundamental. The topics that were considered less important were often described as too difficult or too complex.     

一个力学模型的矩阵及其特性

通过对一个力学问题的分析,构建了它的数学模型f=ATCAx,其系数矩阵T=ATCA是一个包含数字-1,2,-1的三对角矩阵。仅对矩阵T施行初等变换所得到的LU,LDLT分解等,具有非常简单的表示形式,它们在数值上呈现出很好的规律性;进一步的分析表明,这个力学系统是稳定的正定系统。     

一维谐振子能量本征值两种解法探讨

介绍了波动力学中解微分方程法和代数法在求解量子力学中一维谐振子能量本征值问题中的应用，并分析讨论了这两种方法的特点。     

The History of Teaching Quantum Mechanics in Greece

In this work, our goal is to examine the attitude of the Greek scientific community towards Quantum Mechanics and establish the history of teaching of this theory in Greece. We have examined Physics textbooks written by professors of the University of Athens, as well as records of public speeches, university yearbooks from 1923 to 1970, articles in popular scientific magazines, political and philosophical publications and lemmas of encyclopedias that were influencing the public at the time. Our research shows that Quantum Mechanics in Greece was involved in the debate between the political left and right and the church organizations of the period, leading to an extremely idealistic misinterpretation of the theory. As a result, Quantum Mechanics was late to establish itself in Greece, with the first structured and autonomous course on Quantum Mechanics appearing as late as 1962.     

Plagiarism software: no magic bullet!

The ready availability of Internet resources has made it easier than ever for students to plagiarize and many higher education institutions have resorted to checking essays with plagiarism detection software. Student behaviour is likely to change in response to this increased scrutiny but not necessarily in the desired direction. Internet technology facilitates a ‘cut and paste’ assembly‐line approach to essay writing that will persist despite the use of plagiarism software. It is predicted that students will resort to increased use of paraphrase in order to drop below the radar of the detection software. To illustrate this trend, samples of student essays are analysed and limitations of plagiarism software discussed. The paper concludes with suggestions for developing a coordinated institutional policy on plagiarism, and recommends that policy encompass training and educational initiatives to complement any enforcement strategy using plagiarism software.     

双电子体系自旋算符及其本征矢的矩阵表示

运用表象理论讨论了双电子体系自旋角动量算符及其本征矢分别在^Sz,^Sx和^Sy表象的相互转化,得到了简洁实用的表达形式.     

（He2Pb）^＋团簇的量子力学方法研究

本论文介绍了排列通道量子力学方法（MACQM）的计算步骤,讨论了（He2Pb）^＋团簇的形成机理,并且采用排列通道量子力学方法对（He2Pb）^＋团簇基态能量进行计算,为研究氡子体团簇基态能量提供了全新的计算方法。