Volume 7 Issue 10

Previous Issue    Next Issue

Current Issue

Original Articles
DIRAC-BERGMANN FORMALISM OF THE FERMI-BOSE TRANSMUTATION IN (2+1)-DIMENSIONS
CHEN Yixin, NI Guangjiong*
Chin. Phys. Lett. 1990, 7 (10): 433-436 .  
Abstract   PDF(pc) (46KB) ( 649 )
The model of charged particles coupled to the pure Chern-Simons gauge field in (2+1)-dimensions is canonically quantized by Dirac-Bergmann algorithm. It is demonstrated that the Chern-Simons term in Abelian gauge theory turns bosons to fermions.
PERFORMING A 2-DIMENSIONAL LINEAR TRANSFORM WITH A HOLOGRAPHIC MASK
CHEN Yansong, ZHENG Shihai, LI Dehua, YANG Guozhen
Chin. Phys. Lett. 1990, 7 (10): 437-440 .  
Abstract   PDF(pc) (46KB) ( 548 )
Based on the configuration of coherent optical system composed of a holographic mask and two Fourier transform lenses, an approach of performing a 2-dimensional (2-D) linear transform is suggested. The 2-D Walsh-Hadamard transform of order 32 is tested, and the experimental results are given.
PROPAGATING CRACK IN A STRIP AND ITS EXACT SOLUTION
FAN Tianyou
Chin. Phys. Lett. 1990, 7 (10): 441-444 .  
Abstract   PDF(pc) (52KB) ( 507 )
This letter reports some results on propagating crack in a strip, which are exact solutions with closed form and reduced to the exact solutions in static case given by the author before, as crack speed V tends to zero. These results are significant in the research of seismology, materials science, and engineering.
GROWTH OF DIAMOND-LIKE FILMS BY DC PLASMA CHEMICAL VAPOR DEPOSITION
ZHAN Rujuan, GAO Kelin, ZOU Zuping, WANG Yanxia, LIU Jiezhou, XIANG Zhilin, LIU Hongtu, WU Zhiqiang, YE Jian, ZHOU Guien, WANG Changsui
Chin. Phys. Lett. 1990, 7 (10): 445-448 .  
Abstract   PDF(pc) (60KB) ( 472 )
Diamond-like films have been deposited by dc plasma chemical vapor deposition (CVD). During deposition, the characteristics of the plasma have been measured by means of the Langmuir single probe. The structure of the deposits has been studied by X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy.
A FULL CURRENT AC-MODULATION EXPERIMENT IN CT-6B TOKAMAK
HAN Gonghe, QI Xiazhi, WANG Wenshu, ZHENG Shaobai, LIU Mahe*
Chin. Phys. Lett. 1990, 7 (10): 449-452 .  
Abstract   PDF(pc) (60KB) ( 536 )
A full current ac-modulating tokamak discharges have been achieved in the CT-6B device. Obvious modulating changes are observed in plasma current, loop voltage, soft X-ray radiations, electron density, Hα line emission, and hard X-ray radiations when the modulating pulse is added. The continuous tokamak operation with many cycles of low frequency modulating plasma current indicates the possibility of steady state tokamak operation.
THE PROPERTY OF FH(NCO-) CENTER IN KCl
YANG Zhengju, QIAN Guoliang, WANG Qikun, QI Ming
Chin. Phys. Lett. 1990, 7 (10): 453-456 .  
Abstract   PDF(pc) (49KB) ( 432 )
The property of the newly discovered F-aggregate center, FH(NCO-) center, was investigated. Several new peaks located in ultraviolet region and infrared region are found, which are considered to be the new electronic state of F-center and the new vibration states of NCO- of the coupling F- NCO- pairs. The quite novel behavior of these peaks under thermal treatment is given.
ELASTICITY MODULUS OF RANDOM COMPOSITE AND ELASTIC PERCOLATION FAILURE OF SOLIDS
ZHENG Maosheng, ZHENG xiulin
Chin. Phys. Lett. 1990, 7 (10): 457-460 .  
Abstract   PDF(pc) (46KB) ( 449 )
The elasticity modulus of random composite is obtained in 2 and 3 dimensional spaces, based on the solutions of over-matching problems in elastic mechanics. A system with 2 components is also considered, and the calculated results are in good agreement with available references. Further, taking the voids and defects in materials as the second phase with zero modulus, one can easily obtain the expressions for predicting modulus and threshold of the elastic percolation failure of materials containing voids, and the results agree excellently with those in available literatures.
THIN FILMS Bi(Pb)-Sr-Ca-Cu-O (Tc (zero)=105K) PREPARED BY ION BEAM SPUTTERING
ZHOU Ping, DONG Ziwen, LIU Guirong, YANG Qiansheng, ZHAO Zhongxian
Chin. Phys. Lett. 1990, 7 (10): 461-464 .  
Abstract   PDF(pc) (59KB) ( 514 )
High temperature superconducting Bi(Pb)-Sr-Ca-Cu-O thin films have been deposited onto single crystals (100) MgO substrates heated at 400°C by ion beam sputtering and were post annealed in air. The film properties are sensitive to the annealing conditions. The best films show an onset transition temperature of approximately 120K and zero resistance at 105K. X-ray diffraction shows the films to have high c-axis orientation with a high Tc phase. The composition of film was determined by inductively coupled plasma-atomic emission spectrometry analysis, and their morphology was observed by scanning electron microscopy.
FOURIER TRANSFORM INFRARED SURFACE ENHANCED RAMAN SCATTERING FROM PYRIDINE IN Ag COLLOIDS
ZHANG Pengxiang*, WANG Xuan, GOU Zengguang
Chin. Phys. Lett. 1990, 7 (10): 465-468 .  
Abstract   PDF(pc) (57KB) ( 514 )
We report the surface enhanced Raman scattering (SERS) from pyridine in Ag colloids by Fourier transform (FT) infrared Raman spectrometer. The enhancement factors were estimated as 3.4x105 for pyridine in Ag colloids and 5.4 x105 for the same sample but with the addition of a small amount of KCl. The considerable enhancement in infrared indicates the necessity of further refinement of the currently proposed SERS models.
RAMAN SCATTERING OF POLARITONS IN A KTiOPO4 CRYSTAL
XU Liwen
Chin. Phys. Lett. 1990, 7 (10): 469-472 .  
Abstract   PDF(pc) (68KB) ( 579 )
The spontaneous Raman scattering of polaritons in the biazial orthorhombic KTiOPO4(KTP) crystal was investigated with a cw Ar+ laser. The dispersion branches of polaritons associated with A1-phonons have been calculated from spectral data for different wave vector directions from near-forward scattering experiments. The angular dependence of Raman scattering efficiency (RSE) in 60-300cm-1 and 500-800cm-1 regions are shown schematically. The collective interaction of multi-mode lattice vibrations and an “overall” effect are discussed phenomenally.
SUPERCONDUCTING FILMS PREPARED BY ELECTRON CYCLOTRON RESONANCE PLASMA IONS DEPOSITION
WEN Haihu, SHENG Yanya, ZHANG Fengying, SHI Yicai, REN Zhaoxing, CAO Xiaowen
Chin. Phys. Lett. 1990, 7 (10): 473-476 .  
Abstract   PDF(pc) (52KB) ( 534 )
An Y-Ba-Cu-O superconducting film with onset temperature Tc (onset)= 91K and zero resistance temperature Tc (end)=81.4K has been obtained for the first time by wing electron cyclotron resonance (ECR) plasma ions deposition technique. The relationship between the composition of the film and the atmosphere as well as the distance between the target and substrate has also been given.
A SOLVABLE MODEL IN QUANTUM COSMOLOGY IN THE BRANS-DICKES THEORY
ZHU zonghong, HUANG Chaoguang*, LIU Liao
Chin. Phys. Lett. 1990, 7 (10): 477-480 .  
Abstract   PDF(pc) (48KB) ( 492 )
The Wheeler-DeWitt equation for the Brans-Dicke's theory of gravitation is constructed in the minisuperspace approximation and solved for a simple model in which the matter field is absent and the cosmological “constant”,Λ (), in the Brans-Dicke's theory is equal to zero.



12 articles