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Volume 5 Issue 11
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Original Articles
SPIN-POLARIZED BAND FOR Zn0.5Mn0.5Se
HE Xiaoguang, HUANG Meichun
Chin. Phys. Lett. 1988, 5 (11): 481-484 .  
Abstract   PDF(pc) (59KB) ( 566 )
The electronic band structures, density of states and magnetic parameters for layer structural Zn0.5Mn0.5Se in ferromagnetic ( F) phase have been calculated, using self-consistent linearized muffin-tin orbital method in atomic sphere approximation (LMTOASA). The p-d repulsion model is used to explain the band structure and distribution of density of states (DOS). The antiferromagnetic band structure is qualitatively analysed for this material in terms of p-d repulsion mechanism.
BIFURCATIONS AND CHAOS IN A CIRCULAR COUETTE SYSTEM
LIU Shusheng, SUN Yongda, CHAI Lu
Chin. Phys. Lett. 1988, 5 (11): 485-488 .  
Abstract   PDF(pc) (62KB) ( 432 )
The techniques of the laser light scattering and the flow visualization are used to study the bifurcations and chaos in a circular Couette system. Two different routes to turbulence are observed. A physical understanding of the results is given based on the nonlinear interaction.
CHAOTIC BEHAVIOR AND SELF-OSCILLATION IN DC DISCHARGE PLASMA
JIANG Yong, WANG Haida, YU Changxuan
Chin. Phys. Lett. 1988, 5 (11): 489-492 .  
Abstract   PDF(pc) (62KB) ( 527 )
Three routes to chaos in a DC discharge plasma under different initial conditions are reported. It is shown that these chaotic phenomena come from the self-oscillation of plasma and the plasma sheaths have contribution to this instability especially in negative space potential.
THE INTERACTION OF ELECTRON PLASMA WAVES WITH ION ACOUSTIC SOLITONS
DING Weixing, JIANG Yong, YU Changxuan, XIANG Zhilin
Chin. Phys. Lett. 1988, 5 (11): 493-496 .  
Abstract   PDF(pc) (51KB) ( 352 )
The first experiments on the head-on collision of Electron Plasma Waves (EPW) and ion acoustic solitons have been performed in a multipole plasma device. It has been observed that frequency of EPW increases during the interaction.
ELECTROSTATIC POTENTIAL DISTRIBUTION IN MICROSCOPIC REGIONS BY ELECTRON HOLOGRAPY
MA Jian, FU Shufen, CHEN Jianwen, WANG Zhijiang, CAO Hanqing*
Chin. Phys. Lett. 1988, 5 (11): 497-500 .  
Abstract   PDF(pc) (48KB) ( 416 )
The electron hologram of a static microfield is obtained in JEM-200CX type electron microscope, using as Möllenstedt electron static biprism as beam splitter. Recontruction of this hologram by a M-Z interferometer gives the equal potential lines of the microfield.
31p ( p,α) 28Si REACTION FROM Ep=l.00-4.01 MeV
FANG Dufei*, YANG Fujia**, E.G. Bilpuch, G.E.Mitchel
Chin. Phys. Lett. 1988, 5 (11): 501-504 .  
Abstract   PDF(pc) (43KB) ( 476 )
By using the principle of detailed balance, the thermonuclear reaction rates for the 28Si (α , p ) 31p reaction were evaluated from the 31p ( p ,α ) 28Si resonance parameters. The reaction rates vary from 1.75x10-1 to 1.08 x104 in the region T9=2-5, which agree with the theoretical predictions.
MODIFIED TAKAGIS EQUATION OF X-RAY DIFFRACTION
SUN Changde
Chin. Phys. Lett. 1988, 5 (11): 505-508 .  
Abstract   PDF(pc) (39KB) ( 417 )
Takagi's equation is modified using a new of approximation. It is generally the case that the perturbation of polarizability is not zero: h(r)≠0. When the crystal is perfect or distorted uniformly, h(r)=0.
EXPERIMENTAL INVESTIGATIONS ON THE WALL IN NEMATICS
SUN Zhengmin
Chin. Phys. Lett. 1988, 5 (11): 509-512 .  
Abstract   PDF(pc) (54KB) ( 383 )
The static and dynamical characters of the wall in nematics at the magnetic field above the Fredericks transition have been investigated experimentally. The dependence of the width, the speed and the relaxation time of the wall on the reduced magnetic field were measured. The linear dependence of the speed of the wall on the tilt angle of the magnetic field was also revealed.
OBSERVATIONS OF COMPLEX NONLINEAR BEHAVIOR IN THE NEURONLIKE OUTPUT OF CRYOGENICALLY COOLED SILICON DEVICES
MA Shining*, D.D. Coon, A.G.U. Perera
Chin. Phys. Lett. 1988, 5 (11): 513-516 .  
Abstract   PDF(pc) (55KB) ( 392 )
The experimental observations about the complex nonlinear behavior of spontaneous pulsing of dc biased, p-i-n diodes RC circuits are reported. Time intervals series between successive pulses in spike trains were analyzed. Transitions from quasiperiodicity into chaos via mode-locking were observed. The phase portrait is analyzed to reveal that the system is really characterized by a strange attractor. Finally, the embedding algorithm has applied to determine the fractal dimension of the attractor.
THE RELATION BETWEEN ICOSAHEDRAL AND β-W SYMMETRY
ZHANG Baoshan*, MAI Zhenhong, HUI Mengjun, TAO Shichong**
Chin. Phys. Lett. 1988, 5 (11): 517-520 .  
Abstract   PDF(pc) (63KB) ( 427 )
Using X-ray precession method, it is found that the distribution of reciprocal lattice of β-W structure is lust the distortion of the reciprocal space of A16Li3Cu quasicrystal structure. Except the distortion, the X-ray diffraction patterns along 5-fold, 3-fold and 2-fold axes can be observed. Their angular relations satisfy well with those of the perfect icosahedral symmetry; and all the diffraction spots can be indexed approxmately to be six-dimension and strictly in three-dimension.
COMPUTERIZED SIMULATION OF LiCl GLASS USING MOLECULAR DYNAMICS METHOD
SHAO Jun*, CHEN Nianyi, XU Hua
Chin. Phys. Lett. 1988, 5 (11): 521-523 .  
Abstract   PDF(pc) (32KB) ( 500 )
In molecular simulation of LiCl glass, it is observed that the peak of the radial distribution splits into two subpeaks in the temperature range from 498K to 298K. The diffusion coefficients of Li+ and C1- ions at 498K are 7 and 4 times greater than those at 298K respectively. It is shown that cavities present in the simulated fluids. The dependence of the properties of the cavity on the temperature is studied. It is clear that when the fluid is quenched into a glass, the cavity structure of the parent fluid is frozen in also.
NEW METHOD IN CALORIMETRY FOR SUPERHIGH ENERGY HADRONS
TANG Xiaowei
Chin. Phys. Lett. 1988, 5 (11): 524-526 .  
Abstract   PDF(pc) (33KB) ( 592 )
A new method in calorimetry for superhigh energy hadrons is proposed. The main feature of the method is the effective detection of soft neutrons, abundantly present in the superhigh energy hadron showers, by using neutron detectors insensitive to minimum ionizing particles. Such a calorimeter allows us to selectively detect the hadrons in the environment of high backgrounds of electrons, photons and muons.
12 articles