海森伯与纳粹的铀计划

文章分析了海森伯在第二次世界大战期间的科学活动及1941年在哥本哈根与玻尔会见的背景,指出在第二次世界大战期间,尽管海森伯是纳粹铀计划的负责人,但他实际上并未积极参与纳粹原子弹的研制.     

有关二战期间海森伯历史问题的再探讨——答秦克诚先生

感谢《物理》编辑部转来秦克诚先生的读者来信[1] (以下简称《秦》信 ) ,使我们有机会对秦先生关于笔者《海森伯与纳粹的铀计划》[2 ] (以下简称《海》文 )一文的几点质疑给予答复 ,这样既能修正笔者行文时的疏忽 ,使《海》文中的一些提法更准确 ,也对读者负了责 .为明确起见 ,仍按《秦》信质疑的顺序说明 .(1)《海》文讲到了海森伯 194 3年的新西兰讲演 ,经再次查阅资料发现这一点有误 ,应该是 194 3年的荷兰讲演 ,确系笔者的疏忽 .对此笔者向《物理》编辑部和读者表示歉意 .《海》文中的这一段 ,全部都说的是二战期间海森伯访问被德国占领…     

为了遥远的祭奠——漫话海森伯

最初,我深为惊恐.我感到,通过原子现象的表面,我正在窥测着一个奇妙的内部,而对自然界如此慷慨地展现在我面前的丰富的数字结构,使我感到眼花缭乱.     

科学讨论与海森伯的测不准原理

通过对物理学有关史实的分析,论证了科学讨论在海森伯成才过程和测不准原理创建过程中所起的重要、关键作用,科学讨论是培养创造性人才和进行科技创新活动的有效途径。     

海森伯1941年向玻尔讲了什么

 沃尔讷·海森伯于1939年10月至1945年4月参加了法西斯德国的“铀计划”。他和博特、迪布讷、魏茨泽克等一道,于1939年被德国军械局确定为核裂变研究的负责人。海森伯又于1941年参加重水型反应堆的研制,1942年6月正式参加了对德国原子弹研制的领导。尽管战前和战时他对国社党的倒行逆施胸有抵触、心存烦恼,但纳粹政府对他一直是比较信任的。希特勒德国于1938～1941年占领欧洲许多国家后,先后在各国设立“德意志科学研究所”,进行法西斯文化渗透。     

对《海森伯与纳粹的铀计划》一文质疑

物理》编辑部 :贵刊今年 3月号发表了《海森伯与纳粹的铀计划》(以下简称《海》文 )一文 .海森伯是一个复杂的人物 .开始时曾被纳粹分子攻击为“白色犹太人” ,受到调查 ,后来却担任了纳粹铀计划的科学负责人 .对于海森伯的人品 ,存在着尖锐的争论 .海森伯的这一发展过程 ,也值得进行深入的研究和分析 .但是这封信不谈这些问题 .我们只想指出 ,《海》文中存在许多不符合史实之处 ,有的甚至违背常理 .现举几项荦荦大者如下 :1 文中说到海森伯 194 3年在新西兰讲演 ,并且还有“荷兰同行的描述” ,使我大为惊异 .按 194 3正是二战方酣之时 ,那…     

人本主义物理教育与研究性学习——从现代著名物理学家的成长中得到的启示

本文在对近代物理学革命和爱因斯坦、玻尔等人成长过程的研究中,提出了人本主义物理教育的理念,而研究性学习则是这个教育理念下的一种具体形式,并认为在当前条件下,它是走向人本主义物理教育的最佳选择.     

磁场对一维Heisenberg链低能行为的影响

用Jordan-Wigner变换和玻色化方法研究了一维1/2自旋Heisenberg链.在外加磁场作用下,模型的Fermi速度与Fermi动量均被改变,从而玻色化过程也受到影响.对一维Heisenberg链的反铁磁相(AFM)与顺磁相(PM)分别做了讨论,得出了模型基态能及磁化与外加磁场的关系并给出了公度-非公度阈值磁场h′_cl及上阈值磁场h_c2. 关键词： Heisenberg链 磁场 强关联     

混合Heisenberg自旋体系动态相变的滞后标度

采用Monte Carlo方法对离散混合经典Heisenberg自旋体系在周期性外场驱动下动态相变行为进行了模拟计算.在典型Heisenberg自旋体系的哈密顿量基础上,引入表征非晶相的随机各向异性能项(比例为X)和表征晶体相的单轴各向异性能项(比例为1-X),考察了该混合自旋体系磁滞后回线面积A_area随X和单轴各向异性常数A及随机各向异性常数D的变化规律,并确定了该类自旋体系动态相变新的滞后标度关系A_area-A^δD^{η关键词： 海森堡模型 Monte Carlo模拟 磁滞标度 非晶纳米晶}     

原子分子工程的设计基础—计算机及其程序设计

阐述了计算机科学对原子分子学科研究的重要作用，针对原子与分子领域中一些典型的问题，介绍了计算方法及程序设计，并对有关课题编出了计算程序。从而表明：借助于计算机可使原子与分子研究工作规范化、工程化，计算机及其程序设计是原子分子工程的设计基础     

A Toss without a Coin: Information,Discontinuity, and Mathematics in Quantum Theory

The article argues that—at least in certain interpretations, such as the one assumed in this article under the heading of “reality without realism”—the quantum-theoretical situation appears as follows: While—in terms of probabilistic predictions—connected to and connecting the information obtained in quantum phenomena, the mathematics of quantum theory (QM or QFT), which is continuous, does not represent and is discontinuous with both the emergence of quantum phenomena and the physics of these phenomena, phenomena that are physically discontinuous with each other as well. These phenomena, and thus this information, are described by classical physics. All actually available information (in the mathematical sense of information theory) is classical: it is composed of units, such as bits, that are—or are contained in—entities described by classical physics. On the other hand, classical physics cannot predict this information when it is created, as manifested in measuring instruments, in quantum experiments, while quantum theory can. In this epistemological sense, this information is quantum. The article designates the discontinuity between quantum theory and the emergence of quantum phenomena the “Heisenberg discontinuity”, because it was introduced by W. Heisenberg along with QM, and the discontinuity between QM or QFT and the classical physics of quantum phenomena, the “Bohr discontinuity”, because it was introduced as part of Bohr’s interpretation of quantum phenomena and QM, under the assumption of Heisenberg discontinuity. Combining both discontinuities precludes QM or QFT from being connected to either physical reality, that ultimately responsible for quantum phenomena or that of these phenomena themselves, other than by means of probabilistic predictions concerning the information, classical in character, contained in quantum phenomena. The nature of quantum information is, in this view, defined by this situation. A major implication, discussed in the Conclusion, is the existence and arguably the necessity of two—classical and quantum—or with relativity, three and possibly more essentially different theories in fundamental physics.     

A New Book of Numbers: On the Precise Definition of Quantum Variables and the Relationships between Mathematics and Physics in Quantum Theory

Following Asher Peres’s observation that, as in classical physics, in quantum theory, too, a given physical object considered “has a precise position and a precise momentum,” this article examines the question of the definition of quantum variables, and then the new type (as against classical physics) of relationships between mathematics and physics in quantum theory. The article argues that the possibility of the precise definition and determination of quantum variables depends on the particular nature of these relationships.     

THE CANONICAL TRANSFORMATION AND THE SPIN WAVE IN TWO DIMENSIONAL HEISENBERG ANTIFER-ROMAGNETIC SYSTEM

The canonical transformation in two dimensional Heisenberg antiferromagnetic system is given in this paper.It is found that under this transformation the 2D Heisenberg antiferromagnetic model is the nonlinear O(3) σ model with a topological term in the continnum limit.Since there exists a large uncertainty when one chooses the canonical variables,it is not completely concluded that whether the topological term really occurs in this system.Finally,the physical meaning of the canonical transformation is also investigated,and it is found that it corresponds to the collective excitations of system spins,i.e.,a kind of spin waves exists in this case.     

一种有效的量子Monte Carlo模拟方法及其关于二维反铁磁Heisenberg模型的研究

提出一种关于二维反铁磁Heisenberg模型(AFMH)的Monte Carlo模拟新方法。该方法避免了对于相应三维经典自旋系统作模拟计算时的禁态问题和阻错困难。研究还表明,该方法在整个温度区域内的取样迭代效率高,克服了在连续极限下的临界慢化现象,使之能够在更低的温度下进行AFMH的数值研究。     

北京自由电子激光装置的设计研究

北京自由电子激光装置(BFEL)是一台工作在中红外区的康普顿型FEL振荡器。由一台30MeV的射频电子直线加速器提供电子束。特点之一是用微波电子枪作为高亮度注入器。本文首先概述了BFEL的一般情形和物理参数.接着用解析公式和模拟的方法论证了电子束的设计目标和激光器的运转特征。最后阐述了BFEL各部分采取的技术路线的特点,内容包括微波枪、加速器和微波系统、调制器、输运系统、摇摆磁铁、光学腔、电子束诊断、准直、自发辐射和激光实验。     

“Yet Once More”: The Double-Slit Experiment and Quantum Discontinuity

This article reconsiders the double-slit experiment from the nonrealist or, in terms of this article, “reality-without-realism” (RWR) perspective, grounded in the combination of three forms of quantum discontinuity: (1) “Heisenberg discontinuity”, defined by the impossibility of a representation or even conception of how quantum phenomena come about, even though quantum theory (such as quantum mechanics or quantum field theory) predicts the data in question strictly in accord with what is observed in quantum experiments); (2) “Bohr discontinuity”, defined, under the assumption of Heisenberg discontinuity, by the view that quantum phenomena and the data observed therein are described by classical and not quantum theory, even though classical physics cannot predict them; and (3) “Dirac discontinuity” (not considered by Dirac himself, but suggested by his equation), according to which the concept of a quantum object, such as a photon or electron, is an idealization only applicable at the time of observation and not to something that exists independently in nature. Dirac discontinuity is of particular importance for the article’s foundational argument and its analysis of the double-slit experiment.