A numerical Hartree-Fock program for diatomic molecules

This paper describes an algorithm and a computer program which solves numerically (virtually exactly) equations of the restricted open-shell Hartree-Fock and Hartree-Fock-Slater model for diatomic molecules     

Comparative studies on electronic transport due to the reduced dimensionality at the heterojunctions of GaAs/A1xGa(1−x)As and GaxIn(1−x)As/InP systems at low temperatures

Comparative studies on ac/dc mobility due to the reduced dimensionality of spatially confined low dimensional systems, at the heterojunctions of GaAs/A1_xGa_(1−x)As and Ga_xIn_(1−x)As/InP forming quasi-two dimensional (Q2D) and quasi-one dimensional (Q1D) systems have been made. The effect of various low temperature nonphonon scattering mechanisms such as ionized impurity, alloy disorder scattering and surface roughness scattering mechanisms; and phonon scattering mechanisms such as acoustic phonon via deformation potential and piezoelectric scattering mechanisms on the systems has been studied. It is found that the surface roughness scattering mechanism dominates in Q2D system whereas acoustic phonon scattering mechanism dominates in Q1D system due to which the nature and magnitude of the temperature dependent dc/ac mobility curves shows significant variation. Whereas, it is observed that the confinement does not change the nature of the frequency dependent real and imaginary parts of ac mobility curves. However, the mobility is found to be enhanced with effective mass and also due to the confinement, i.e. the mobility for Q1D system is higher than that for Q2D system.     

浅谈砖混结构构造柱施工质量缺陷及处理方法

从钢筋、砌体、模板、混凝土施工等方面，对砖混结构中构造柱施工的质量缺陷原因作了分析，并从这几个方面，提出了具体的处理方法和相应的质量控制措施。     

Close Approach of a Spherical Particle and a Quantised Vortex in Helium II

To interpret the results of recent experiments which used the Particle Image Velocimetry (PIV) method it is necessary to understand the interaction of the particles with the quantised vortices. We present numerical calculations of the close approach of a small spherical particle to a vortex line. The collision time scale compares well with approximate analytical results.     

A program for the simulation and analysis of open atmospheric balloon soundings

The equation of motion for a balloon in an atmosphere is generalized but placed in proper context by taking into account some fluid theory results and a few factors not considered in previous works. The design of a computer program becomes necessary to find solutions. A code that allows to perform 2D simulations of open balloons flights is developed. The coupled integrodifferential nature of the problem represented a significant challenge for a satisfactory implementation.     

q 类似 Jaynes-Cummings 模型的精确解

给出了单模ｑ形变光场与两能级原子强相互作用模型的精确解，进而讨论了原子的崩塌——回复效应及ｑ形变光场光子的分布函数的时间演化。     

Thermal and optical properties of Cd1-x Zn x S thin films by photoacoustics

Ternary compounds Cd_1-x Zn _x S for various Zn concentration in thin films are synthesized by spray pyrolysis and studied by photoacoustics technique for thermal and optical properties. The thermal diffusivity as a function of the alloy composition measured by photoacoustics shows a maximum at x = 0.6. The optical band gap increases with zinc concentration and the continuous change indicates the formation of solid solution.     

Package for calculations and simplifications of expressions with Dirac matrices (MatrixExp)

This paper describes a package for calculations of expressions with Dirac matrices. Advantages over existing similar packages are described. MatrixExp package is intended for simplification of complex expressions involving γ-matrices, providing such tools as automatic Feynman parameterization, integration in d-dimensional space, sorting and grouping of results in a given order. Also, in comparison with the existing similar package Tracer, the presented package MatrixExp has more enhanced input possibility. User-available functions of MatrixExp package are described in detail. Also an example of calculation of Feynman diagram for process b→sγg with application of functions of MatrixExp package is presented.

Program summary

Title of program:MatrixExpCatalogue identifier:ADWBProgram summary URL:http://cpc.cs.qub.ac.uk/summaries/ADWBProgram obtainable from:CPC Program Library, Queen's University of Belfast, N. IrelandLicensing provisions:noneProgramming language:MATHEMATICAComputer:PC PentiumOperating system:WindowsNo. of lines in distributed program, including test data, etc.: 1551No. of bytes in distributed program, including test data, etc.: 16 040Distribution format:tar.gzRAM:loading the package uses approx. 3 500 000 bytes of RAM. However memory required for calculations depends heavily on the expressions in the view, as the package uses recursive functions, and MATHEMATICA dynamically allocates memory. Package has been tested to work on PC Pentium II 233 MHz with 128 Mb of memory calculating typical diagrams of contemporary calculations.Nature of problem:Feynman diagram calculation, simplification of expressions with γ-matricesSolution method:Analytic transformations, dimensional regularization, Feynman parameterizationRestrictions:MatrixExp package works only with single line of expressions (G[l1,]), in contrast to the Tracer package that works with multiple lines, i.e., the following is possible in Tracer, but not in MatrixExp: G[l1,]**G[l2,]**G[l3,], which will return the result of G[l1,]**G[l1,]**G[l1,]….Unusual features:noneRunning time:Seconds for expressions with several different γ-matrices on Pentium IV 1.8 GHz and of the order of a minute on Pentium II 233 MHz. Calculation times rise with the number of matrices.     

Fuelling and Diagnostics with Pellet Injection in the HL-1M Tokamak

The pellet injection experiments for fuelling and diagnostics have been carried out on the HL-1M tokamak. The eight-pellet injector was installed on HL-1M. A reliable monitordetector and camera system was set up to take initial pellet photographs and measure the initial pellet speed and size. High fuelling efficiency of 60 % - 100 % and a density profile with a peaking factor of 1.8 - 2.0 were obtained. The maximum density close to 10^14/cm^3 in HL-1M was achieved with newly optimized combined fuelling techniques. Two typical models of pellet ablation have been utilized for simulative calculation of the ablation rates in HL-1M. In comparison with the distribution of the measured Hα emission intensity from the digital data of the CCD camera, the experimental result seems more optimistic for core fuelling than theoretical predictions by the two models. The safety factor profile q（r） has been extracted from the information provided by the CCD camera during the pellet injection. The reliability of the measured results depends mainly on the calibration of the imaging space position. Based on the calibration, the measured q-profile becomes more reasonable than those published previously for the same shot number and same photograph.