Rare tau decays from B ABAR

The BABAR experiment has now completed data taking and with an integrated luminosity of 531 fb-1 of e+e-collision data has recorded some 480 million tau-pair events.Various studies of suppressed,rare and forbidden decays of the tau have been conducted,including searches for high-multiplicity decays,for second-class hadronic weak currents,and for lepton-flavour violation.     

Steps and facets at the surface of soft crystals

We consider the shape of crystals which are soft in the sense that their elastic modulus μ is small compared to their surface tension γ, more precisely μa < γ where a is the lattice spacing. We show that their surface steps penetrate inside the crystal as edge dislocations. As a consequence, these steps are broad with a small energy which we calculate. We also calculate the elastic interaction between steps a distance d apart, which is a 1/d ² repulsion. We finally calculate the roughening temperatures of successive facets in order to compare with the remarkable shapes of lyotropic crystals recently observed by Pieranski et al. [#!Pieranski!#,#!EPJ!#]. Good agreement is found. Received 25 June 2001     

Binding Energy of an Exciton Bound to Ionized Acceptor in Quantum Dots

Binding energiesfor an exciton (X) trapped in the two-dimensional quantum dot by a negative ion located on the z axis at a distance from the dot plane are calculated by using the method of few-body physics.This configuration is called a barrier (A^-,X) center.The dependence of the binding energy of the ground state of the barrier (A^-,X)center on the electron-to-hole mass ratio for a few values of the distance d between the fixed negative ion on the z axis and the dot plane is obtained.We find that when d → 0,the barrier (A^-,X) center has not any bound state.We also studied the stability and binding energy of the ground state of the barrier (A^-,X) center in a parabolic quantum dot as a function of the distance d between the fixed negative ion on the z axis and the dot plane.     

半导体异质结及其在光电子学中的应用—2000年诺贝尔物理奖评述

瑞典皇家科学院2000年10月10日宣布,将2000年度诺贝尔物理奖授予三位科学家,他们是俄罗斯科学院圣彼得的堡约飞技术物理研究所的Zh.Alferpv、美国加利福尼亚大学的Herbert Kroemer和美国德克萨斯仪器公司的Jack S.Kilby,以表彰他们为现代信息技术,特别是他们发明的高速晶体管、激光二极管和集成电路（芯片）所作出的奠基性贡献,Kilby由于发明并发展了集成电路技术而获奖,通过这项发明,微电子学成为所有现代技术的基础,Kilby的获奖成果已有另文（见2001年第3期《物理》）述评,Alferov和Kroemer则是由于他们在半导体异质结及其在电子和光电子学中的应用方面的突出贡献而获奖,该不仅就两位诺贝尔物理奖得主在异质结及其在光电子中的应用方面的贡献进行评述。     

Comment on “A Comparison Between Broad Histogram and Multicanonical Methods”

A recent paper by A. R. Lima, P. M. C. de Oliveira, and T. J. P. Penna [J. Stat. Phys. 99:691 (2000)], seems to contain at least two mistakes which deserve comment, one concerning the numerical data, the other being of a conceptual kind.     

气体激光器射频至微波放电激发的某些规律

本文研究了射频至微波激发的Xe和He-Ne原子激光器及CO₂分子激光器,结合各具体激光器的实验结果对其放电物理进行了讨论,提出获得高效率的关键是有效控制放电空间的电子能量,得出了一些有指导意义的结论.     

大学物理虚拟实验的网络教学系统

介绍了基于当前Internet网络环境实现仿真实验远程教学的方案和技术,为各种实验的远程教学开发与应用提供了一种可行的新模式。     

探讨制定物理教学仪器标准应遵循的原则

教学仪器的标准是保障教学仪器为教学服务的准绳,是教学仪器技术性能的基础。本文从物理教学仪器的教育功能出发,研究、探讨制订物理教学仪器标准应遵循的原则。     

静电演示教具的发展与创新

静电演示实验在教学中的作用是电脑动画不能取代的;静电演示教具由于采用现代高压静电电源有了质的飞跃;指出静电演示教具的创新要遵循的几条原则。     

诺贝尔物理奖的思考与展望

2 0 0 0年的诺贝尔物理奖奖给了集成电路的发明人 ,从“纯理论”转向“技术科学”体现了科学交叉与融合 ,并结合我国国情进行了思考和展望。