OH分子基态（X2Π）的结构与势能函数

采用密度泛函理论的B3LYP方法和二次组态相互作用(QCISD(T))方法优化计算了OH分子基态(X²Π)的平衡结构、振动频率和离解能.根据原子分子反应静力学原理，导出了OH分子基态(X²Π)的合理离解极限，采用最小二乘法拟合Murrell-Sorbie函数得到了相应的势能函数和与该基态相对应的光谱常数(B_e，α_e，ω_e和ω_eχ_e)，计算结果与实验数据符合得相当好. 关键词： OH分子 2Π)')" href="#">基态(X²Π) 势能函数     

试论在物理实验教学中施行创新教育

物理实验作为物理教学的基本手段，有其特殊的教学功能，不仅能够为学生提供学习的感性材料，验证物理定律，而且能够提供科学的思维方法，加深学生对基本知识的认识程度，激发他们的求知欲，培养探索能力．而众多的物理概念、规律正是通过观察和实验再认真地加以思索和总结得到的．     

Effect of bias condition on heavy ion radiation in bipolar junction transistors

The characteristic degradations in a silicon NPN bipolar junction transistor(BJT) of 3DG142 type are examined under irradiation with 40-MeV chlorine(Cl) ions under forward,grounded,and reverse bias conditions,respectively.Different electrical parameters are in-situ measured during the exposure under each bias condition.From the experimental data,a larger variation of base current(I B) is observed after irradiation at a given value of base-emitter voltage(V BE),while the collector current is slightly affected by irradiation at a given V BE.The gain degradation is affected mostly by the behaviour of the base current.From the experimental data,the variation of current gain in the case of forward bias is much smaller than that in the other conditions.Moreover,for 3DG142 BJT,the current gain degradation in the case of reverse bias is more severe than that in the grounded case at low fluence,while at high fluence,the gain degradation in the reverse bias case becomes smaller than that in the grounded case.     

激光驱动高亮度电子束源

采用激光驱动光阴级和１００ｋＶ直流加速间隙可产生宽度为５０～１００ｐｓ的高亮度脉冲电子束．该装置主要由光阴极制备室和直流加速间隙组成．可以用化学气相沉积、离子注入和离子束增强沉积等方法制备光阴极．通过用ＥＧＵＮ和ＰＯＩＳＳＯＮ程序模拟,给出了直流加速间隙的物理设计．光源采用一台主被动双锁的Ｎｄ:ＹＡＧ激光器,可工作在１０６４、５３２和２６６ｎｍ三个波长,重复频率为１０Ｈｚ．此外,也论述了光阴极制备室与超与腔结合的超导高亮度注入器的有关问题. A DC high brigytness laser driven by photoemissive electron gun is being developed at Peking University,in order to produce 50～100ps electron bunches of high quality.The gun consists of a photocathode preparation chamber and a DC acceleration cavity.Different ways of fabricating photocathode,such as chemical vapor deposition,ion beam implantation and ion beam enhanced deposition,can be adopted.The acceleration gap is designed with the aid of simulation codes EGUN and POISSON,100kV DC high voltage is...     

火焰原子吸收法测定人体胆结石中的铜、锌、钙、镁

本文介绍了火焰原子吸收法测定人体胆结石中铜、锌、钙、镁元素含量的测试条件及介质的影响，测试结果表明该方法具有较好的准确度和精密度，适合于医学临床应用。     

1.3μm分布反馈二极管激光器组件

开发了一种用于光纤公用天线电视（ＣＡＴＶ）的分布反馈激光二极管组成，组件包括１．３μｍＩｎＧａＡｓ／ＩｎＰ双沟－平面掩埋双异质结（ＤＣ－ＰＢＨ）分布反馈激光二极管和光隔离器，封装在蝴蝶型管壳内，组件的出纤线性功率为２．５ｍＷ，并具有极低的失真。     

具有双陷波特性的超宽带天线设计

设计了一款基于共面波导馈电的小型化具有双陷波特性的超宽带天线,该天线的带宽在3～14 GHz内,电压驻波比(VSWR)小于2。在辐射贴片上通过开L型和半圆环缝隙实现了在3.3～3.7 GHz和5.150～5.825 GHz的双频段的陷波特性,抑制了802.16无线城域网和无线局域网对超宽带系统的干扰,在整个工作频段具有稳定的增益和良好的全向性。通过对天线模型进行加工制作并测量,测试结果表明:天线的带宽是3～14 GHz,在3.3～3.7 GHz和5.15～5.825 GHz频段内VSWR大于4,实现了天线的双陷波特性。该天线尺寸小、结构紧凑的特点,适合现代的无线通信系统。     

Experimental investigation of supersonic radiation propagation in low-density plastic and copper-doped foams

1 Introduction The investigation of supersonic radiation wave transporting in low density foam pro-duced by thermal radiation is of crucial importance in inertial confinement fusion (ICF) research[1]. When the intense radiation flux is incident in the media, first, a supersonic heat wave is formed which propagates into the undisturbed material. In time, due to the increasing mass of heated material, it slows down and is overtaken by a shock wave,thus becoming of the ablative type. Normally, …