探讨无固定悬挂点单摆的周期

简谐振动在高中物理竞赛中既是重点又是难点.单摆的自由微振动是简谐振动,无固定悬挂点单摆其纵振动也是谐振动(下面讨论过程即作出证明),但求解其周期对中学生而言难度很大.本文运用多种方法对其进行探讨,并比较了各种解法,对中学物理竞赛辅导有一定的启示.     

物理竞赛理论命题的发展趋势

我国中学生物理竞赛始于1984年,以后每年举行一次.国际中学生物理奥林匹克竞赛始于1967年,也是每年一次.国内有《全国中学生物理竞赛内容提要》作为命题的依据,基本上符合教育部1983年颁发的全日制高中物理教学纲要.国际物理竞赛大纲相当于我国工科高等院校普通物理的教学水平.国际、国内物理竞赛的命题越来越难了.国际上许多国家要求降低命题难度,以便有较多的人获奖,同时也避免分数太低的尴尬.国际竞赛奖牌的分数线以及数量都不是赛前设定的.以金牌为例,总分前三名的平均分乘以0.9,再去除小数便是金牌线.如果题目偏难,高分很少,获奖人数便少.如1994年在北京举办的第25届竞赛,就只有6人获金牌.1998年在冰岛举办的第29届竞赛也只有11人获金牌,当年还有得零分的参赛者.     

从中学生物理实验竞赛看中学物理实验教学

从中学生物理实验竞赛看中学物理实验教学刘雪林（北京大学物理系１００８７１）笔者曾多次参加过北京市中学生物理实验竞赛的组织工作．这里就竞赛中遇到的和平时了解到的一些情况谈谈对中学里物理实验教学的看法和建议，供中学物理老师们参考．近年来，我国中学物理实验...     

物理竞赛辅导中培养学生创新能力教学初探

中学物理竞赛问题所包含的知识容量较大,问题情景新颖,题中渗透了较多的物理学研究方法和思维方法,集科研性、综合性、方法性、实践性于一体,它是培养优秀学生的创新意识、创新能力、创新精神的肥沃土壤.在中学物理竞赛辅导教学中培养学生的创新能力是进行物理创新教学的一种重要途径,它的重要性在于培养将来进行科学研究和创新的潜在的"金牌选手".下面就在物理竞赛辅导教学中如何培养学生的创新能力谈几点做法.     

对一道物理竞赛题解答的质疑

第十七届全国中学生物理竞赛预赛试题获得中学物理教师的普遍好评.题目灵活,难度适中,既能与中学物理教学相衔接,又能考出考生的能力与水平,而且结合了一些近代物理知识,起到了很好的导向作用.     

中学生物理实验学习心理探究

掌握中学生物理实验学习心理是教师上好实验课的基础. 从物理实验心理学角度出发, 探讨中学生物 理实验学习心理. 系统阐述中学物理实验过程中学生思维障碍, 提出解决学生实验学习心理的问题对策, 有助于提 升中学生物理实验课堂的有效性, 充分激发学生对物理实验的兴趣, 调动他们的课堂积极性     

浅谈高中物理资优生能力培养——以物理竞赛与大学先修能力要求为例

构建高质量的拔尖人才贯通培养体系是新时代教育强国的需要,为高校培养拔尖创新人才成了示范性高中的一项重要任务.对于高中资优生来说,物理竞赛与大学先修课程是两门重要的课程,而这两门课程在能力的要求有着很大的差别,本文以两个经典的物理问题为例,对比处理相同问题采用不同的方法,将探讨高中物理竞赛与大学先修(CAP)物理力学在高中学生物理学科能力培养的要求.也为广大物理教师对高中物理资优生的能力培养提供参考.     

三杆堆放的静力学问题

静力学问题虽然在高考中逐渐淡化,但却是物理竞赛中的热点和难点问题,尤其是从2009年第26届全国高中物理竞赛后进行了一系列的改革,使得经典的静力学问题在竞赛中焕发了新的青春.本文从典型的三杆堆放问题出发,对解决静力学问题     

“第六届全国中学生物理竞赛”中电学实验考试成绩分析

第六届全国中学生物理竞赛中电学实验考试得分情况如下表所示: 从表中得分情况可以看出,近几年由于在中学物理教学中加强了实验教学工作,考生的实验动手能力有所加强,具体表现在: 1.考生连接线路速度快、差错少,在125名考生中,只有12人连续出现小错误。 2.考生基本会使用常见的电学实验仪     

物理教学应加强科学思维能力的培养

 物理教学要适应现代教育的改革要求,进一步强化素质教育,最主要的是对学生进行科学素质的教育。强调科学素质教育的目的,就是使学生在物理学习中受到科学方法、科学思维和科学态度等方面的训练,使他们以后从事任何职业都受益无穷,因此,在物理教学中加强对学生科学思维能力的培养势在必行。一、培养科学思维能力是物理教学的基本任务物理知识本身的特点就决定了物理教学对学生的思维能力有较高的要求。在全日制中学物理教学大纲中就明确提出：“在整个高中物理教学中都要注意对学生进行抽象思维的训练。”     

Physics Without Physics

David Finkelstein was very fond of the new information-theoretic paradigm of physics advocated by John Archibald Wheeler and Richard Feynman. Only recently, however, the paradigm has concretely shown its full power, with the derivation of quantum theory (Chiribella et al., Phys. Rev. A 84:012311, 2011; D’Ariano et al., 2017) and of free quantum field theory (D’Ariano and Perinotti, Phys. Rev. A 90:062106, 2014; Bisio et al., Phys. Rev. A 88:032301, 2013; Bisio et al., Ann. Phys. 354:244, 2015; Bisio et al., Ann. Phys. 368:177, 2016) from informational principles. The paradigm has opened for the first time the possibility of avoiding physical primitives in the axioms of the physical theory, allowing a re-foundation of the whole physics over logically solid grounds. In addition to such methodological value, the new information-theoretic derivation of quantum field theory is particularly interesting for establishing a theoretical framework for quantum gravity, with the idea of obtaining gravity itself as emergent from the quantum information processing, as also suggested by the role played by information in the holographic principle (Susskind, J. Math. Phys. 36:6377, 1995; Bousso, Rev. Mod. Phys. 74:825, 2002). In this paper I review how free quantum field theory is derived without using mechanical primitives, including space-time, special relativity, Hamiltonians, and quantization rules. The theory is simply provided by the simplest quantum algorithm encompassing a countable set of quantum systems whose network of interactions satisfies the three following simple principles: homogeneity, locality, and isotropy. The inherent discrete nature of the informational derivation leads to an extension of quantum field theory in terms of a quantum cellular automata and quantum walks. A simple heuristic argument sets the scale to the Planck one, and the currently observed regime where discreteness is not visible is the so-called “relativistic regime” of small wavevectors, which holds for all energies ever tested (and even much larger), where the usual free quantum field theory is perfectly recovered. In the present quantum discrete theory Einstein relativity principle can be restated without using space-time in terms of invariance of the eigenvalue equation of the automaton/walk under change of representations. Distortions of the Poincaré group emerge at the Planck scale, whereas special relativity is perfectly recovered in the relativistic regime. Discreteness, on the other hand, has some plus compared to the continuum theory: 1) it contains it as a special regime; 2) it leads to some additional features with GR flavor: the existence of an upper bound for the particle mass (with physical interpretation as the Planck mass), and a global De Sitter invariance; 3) it provides its own physical standards for space, time, and mass within a purely mathematical adimensional context. The paper ends with the future perspectives of this project, and with an Appendix containing biographic notes about my friendship with David Finkelstein, to whom this paper is dedicated.     

物理竞赛中的物理图象

图象处理法是物理竞赛中常用的处理方法,主要表现在图象的"面积"与图象的交点两个方面.     

Chinese Physics C(Formerly High Energy Physics and Nuclear Physics)

<正>Monthly,founded in 1977Published monthly in hard copy by Science Press and online by the Institute of High Energy Physics of the Chinese Academy of Sciences(domestic)and by IOP Publishing,Temple Circus,Temple Way,Bristol BS1 6HG,UK(international).     

Physics Needs Philosophy. Philosophy Needs Physics

Contrary to claims about the irrelevance of philosophy for science, I argue that philosophy has had, and still has, far more influence on physics than is commonly assumed. I maintain that the current anti-philosophical ideology has had damaging effects on the fertility of science. I also suggest that recent important empirical results, such as the detection of the Higgs particle and gravitational waves, and the failure to detect supersymmetry where many expected to find it, question the validity of certain philosophical assumptions common among theoretical physicists, inviting us to engage in a clearer philosophical reflection on scientific method.     

物理美学对物理教学的意义

在实施新课程改革的大背景下,运用理论与实践相结合的方法就物理美学对物理教学的意义做了论述,以引起同行们对物理美学研究及其应用的关注．     

物理教育的使命:传承物理精神

目前很多中学的物理教育中存在着不尽如人意之处，如初中阶段不求甚解的记忆，高中阶段大量的习题操练，更为严重的是，物理教师的物理精神越来越淡漠，教学成了解题训练，缺乏“假设-实验-观察-探索”的精神，没有真正将学生领进物理学大门．那么，教师怎样才能很好地传承物理精神。将学生带进奇妙的物理世界呢？     

Physics of fracture

This article first presents introductory material which should make it possible for the person unfamiliar with fracture to read the papers of this series. Then material of a basic physical nature regarding cracks in materials is presented. Emphasis is placed on the effects of chemical attack of bonds at a crack tip, and on the basic physical cause for a material to exhibit a tough (desirable) or a brittle (undesirable) overall aspect.