Absorption spectroscopy using a coherent transition radiation millimeter wave light source

The characteristics and applicability of the absorption spectroscopy system using the coherent transition radiation light source have been investigated. The configurations of the system are relatively simple. The operational conditions of an electron linear accelerator have been evaluated. The stability of the light intensity has been within ±2–3% in a wavenumber range of 4–13 cm⁻¹. The light intensity has been found to be more than six orders of magnitude higher than that for the lowest limit for detection.     

晶体中三阶有效非线性系数的计算方法

经过对ｘ（３）ｉｊｋｌ的脚标进行简化压缩处理，首次得出了全部晶体点群共１１种不同的Ｘ（３）ｉｍ矩阵表达形式及Ｋｌｅｉｎｍａｎ对称条件成立下的简化形式，给出了各类晶体中四波相互作用过程中Ｘ（３）＾ｅｆｆ的计算方法。     

Gravitational-wave research with resonant antennas

Summary A brief historical survey of the GW experiments is presented. In particular, the experiments with resonant detectors are illustrated and the problems arising when comparing data of different detectors for the search of coincidences are discussed. The experimental results so far obtained are shown, among them the correlation during the SN1987A with various GW and neutrino detectors. Finally a warning for the long times needed to improve the sensitivity of the GW detectors is given and the improvements expected with spherical resonant detectors are mentioned.     

Momentum space distribution of electrons in an atom using hydrogenic wave functions

A formulation is developed to derive exact analytic expressions for electron-electron correlation and density of electrons in momentum space using hydrogenic wave functions. It is shown that for large atoms the expression for density of electrons has a simple form.     

大平面二极管虚阴极振荡器的宽脉冲微波辐射

给出了产生宽脉冲微波辐射的大平面天鹅绒二极管虚阴极振荡器的结构和测试装置，测得了二极管中阴－阳极等离子体的闭合速率为３０～４３ｋｍ／ｓ，获得了微波辐射的最大脉宽为１．５μｓ，产生的微波峰值功率约为１５ＭＷ，频率为０．５ＧＨＺ，指出这种平面二极管型虚阴极振荡器在辐射脉宽，辐射频率和辐射功率三者之间存在着物理上的制约关系，认为同轴型虚阴极振荡器是突破这种制约关系的一个新途径．     

山背波:对飞机的潜在威胁

山背波对飞机的潜在威胁现已毋庸置疑。为了提高在这方面作出更确切判断的能力并能进一步找出实践中可行的相应措施，首要的问题就是必须对山背波本身有足够的认识，而这正是当前国内文献中极为薄弱的环节。有鉴于此，本文系统地、较全面地介绍了山背波这种独特的次声波，对其发生机理和基本特征、以及作为其直接衍生物的相关云相和晴空湍流－－后者正是对飞机的主要潜在威胁所在－－作出简明扼要的评述。     

顶端受集中力偶的双材料平面界面接合楔体的对数奇异应力场

应用复变函数方法,通过构造复函数形式的特解序列,从理论上研究了顶端受集中力偶的双材料平面界面接合楔体的应力场,给出了相应的经典解,发现其存在一次和二次佯谬,相应的应力具有(Inr)／r2和(In2r)／r2的奇异性。     

Axisymmetric shock wave interaction with a cone: a benchmark test

Results of the benchmark test are presented of comparing numerical schemes solving shock wave of M_s = 2.38 in nitrogen and argon interacting with a 43∘ semi-apex angle cone and corresponding experiments. The benchmark test was announced in Shock Waves Vol. 12, No. 4, in which we tried to clarify the effects of viscosity and heat conductivity on shock reflection in conical flows. This paper summarizes results of ten numerical and two experimental applications. State of the art in studies regarding the shock/cone interaction is clarified. PACS 01.50.Kw, 47.15.Pn Communicated by K. Takayama     

对声波和弹性波传播模拟的Hamilton系统方法

建立了离散化网格上的准粒子体系，引入此体系的Hamilton系统描述，用来模拟声波和弹性波的传播.介绍了准粒子间相互作用的九点模型并给出互作用系数.证明了Hamilton系统方法 和声波、弹性波方程的关系，并给出两个方法中所使用物理量的关系.使用辛算法对给定的 介质模型进行数值模拟. 关键词： Hamilton系统方法 九点互作用模型 声波方程 弹性波方程 辛算法     

广义对称正则长波方程的勒让德和切贝雪夫拟谱方法

本文考虑了具齐次边界条件的广义对称正则长波方程的Legendre和Chebyshev拟谱方法，构造了半离散和全离散的Legendre和Chebyshev拟谱格式，从理论上得到了这些格式对应的最优误差估计。