Volume 7 Issue 8

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Original Articles
YANG-BAXTER EQUATION, ALGEBRAS AND BRAID GROUP FOR THE Zn-SYMMETRIC STATISTICAL MODEL
WEI Hua, HOU Boyu
Chin. Phys. Lett. 1990, 7 (8): 337-340 .  
Abstract   PDF(pc) (48KB) ( 865 )
For the Zn-symmetric statistical model the Yang-Baxter equation and the equations for the operator representations is reduced to explicit spectroparameter-independent forms, and the quantum algebra for the representations is obtained. Moreover, we present some elliptic representations of braid group, which include a new trigonometric representation as degenerated case.

NON-TOPOLOGICAL SOLITON IN NUCLEAR MEDIUM
ZHANG Jianwei, JIN Hongli*, QIU Xijun
Chin. Phys. Lett. 1990, 7 (8): 341-344 .  
Abstract   PDF(pc) (57KB) ( 449 )
The bag constant and the size increment of a nucleon (soliton) embedded in nuclear medium, are calculated in a non-topological soliton model. These results may be understood as arising from the change of the vacuum properties in the presence of the dense nuclear medium. The calculated quantities are in reasonable agreement with the empirical values.
REPORT ON DETERMINATION OF THE REST MASS OF ELECTRON NEUTRINO WITH 3H β RAY SPECTROSCOPY
MEI Zhenyue, KE Zunjian, WU Weimin, ZHAO Zhengguo*
Chin. Phys. Lett. 1990, 7 (8): 345-348 .  
Abstract   PDF(pc) (51KB) ( 510 )
With an iron free double focusing β ray spectrometer and Bergkvist electrostatic compensated Ti3H and implantated tritium source, we studied β ray spectrum of 3H near the end point. We found that if the rest mass of electron neutrino is positive, the value must be less than the experimental uncertainty now attainable.
EFFECTS OF THE LATENT HEAT AND PARTICLE DISTRIBUTION ON THE DILEPTON SPECTRUM
HE Zejun, ZHANG Jiaju, LI Panlin, QIU Xijun
Chin. Phys. Lett. 1990, 7 (8): 349-352 .  
Abstract   PDF(pc) (54KB) ( 462 )
The previously derived relativistic hydrodynamic equation from energy-momentum conservation is generalized to include the particle number conservation. From calculation on the basis of the new formalism we find that the particle distribution and latent heat significantly change the characteristic dilepton spectrum for the formation of a quark matter, which had been predicted by the other author.
MARKOV PROCESS ANALYSIS OF ATOM PROBE DATA
WANG Qi, T. J. Kinkus*, REN Dagang
Chin. Phys. Lett. 1990, 7 (8): 353-356 .  
Abstract   PDF(pc) (56KB) ( 441 )
A geometry model of field evaporation process is set up; with this model the field evaporation process can be described as Markov process. Its application to the earliest stage of phase transition is studied. For comparison, Camus’system Fe-Cr 45 at.% is calculated again, and the same result is extracted from our method and intimated in our experimental data.
EFFECT OF GRAIN BOUNDARY NETWORK ON PATTERN FORMATION IN a-Ge/Au BILAYER FILMS
HOU Jianguo, WU Ziqin, A. L. Vasilev, N. A. Kiselev
Chin. Phys. Lett. 1990, 7 (8): 357-360 .  
Abstract   PDF(pc) (114KB) ( 789 )
The a-Ge/p-Au bilayer thin films with different Au grain sizes were prepared. After annealing, different patterns of Ge appeared in the film morphology. It is found that the fractal dimensions of the patterns are highly dependent on the grain size of Au, and the experimental results indicate that the fractal formation in such system is truly dominated by the local latent temperature field.
THE EFFECTS OF Sc-Cu SUBSTITUTION ON Y-Ba-Cu-O SYSTEMS
WANG Huaiyu, ZHANG Liyuan, LIU Fusui, WANG Enge
Chin. Phys. Lett. 1990, 7 (8): 361-364 .  
Abstract   PDF(pc) (59KB) ( 463 )
The electronic densities of states of YBa2Cu2ScO7 high Tc materials, including two cases of Sc substituting Cul and Cu2 sites, have been calculated, and the results are compared with that3of YBa2Cu3O7 and Y0.5Sc0.5Ba2Cu3O7 systems. Sc-Cu2 replacement will largely influence the electronic structure of Cu-O layers. However, Sc-Cul replacement is more possible.
A NEW PERMANENT MAGNETIC MATERIALS CRYSTALLIZED FROM AMORPHOUS Co84-xBxZr16 ALLOYS
SHEN Baogen, GUO Huiqun, YANG Linyuan, ZHAO Jian gao
Chin. Phys. Lett. 1990, 7 (8): 365-368 .  
Abstract   PDF(pc) (47KB) ( 433 )
The crystallization of amorphous Co84-xBxZr16 alloys and the influence of heat treatment on its hard magnetic properties are studied. The dependence of B-content on crystallization temperature of the samples is determined from differential scanning calorimetric (DSC) traces. The intrinsic coercivities iHc are found to increase with increasing annealing temperature and go through a mazimum then to lower values. A coercivity of 2.7kOe and an energy product of 4.0MGOe are obtained at room temperature in Co82B2Zr16 alloy annealed at 660°C for a short time. These alloys would be expected as an applicable mate rid for permanent magnet.


ON THE MAGNETIC ANISOTROPY OF THE Co AND γ-Fe2O3 ULTRAFINE PARTICLES
LUO Helie, SUN Ke, NIE xiangfu*
Chin. Phys. Lett. 1990, 7 (8): 369-372 .  
Abstract   PDF(pc) (51KB) ( 354 )
The anisotropy constants K of γ-Fe2O3, Co-γ-Fe2O3 and Co ultrafine particles precipitated in Cu-Co alloy have been measured by wing the equations for describing the relaxation of superparamagnetic particles. It is found that the anisotropy constant K of Co-γ-Fe2O3 fine particles is greater than that of γ-Fe2O3 by about 50%; the K value of Co ultrafine particles of a radius equal to 36Å is greater than that of to 48Å by about 100%. This phenomenon has been interpreted as the existence of surface anisotropy of the Co ultrafine particles.
MAGNETIC AND 57Fe MÖSSBAUER STUDY OF YFe12-xVx COMPOUNDS
YANG Chunli, ZHOU Rongjie, LI Fashen, ZHONG Wending*, LAN Jian*
Chin. Phys. Lett. 1990, 7 (8): 373-376 .  
Abstract   PDF(pc) (48KB) ( 541 )
Using Mössbauer spectroscopy and magnetic measurement, the hyperfine coupling coefficient of YFe12-xVx(x=2,3,4) was determined approximately A=14.85T/μB. The reasons of changes of the hyperfine parameters depending on the concentration of vanadium atom were also discussed.
ENHANCEMENT OF KERR ROTATION OF THIN Fe FILMS
XU Yongbing, LU Mu, ZHAI Hongru, MIAO Yongzhi, WANG Hao, ZHOU Shiming, CAI Jianwang
Chin. Phys. Lett. 1990, 7 (8): 377-380 .  
Abstract   PDF(pc) (51KB) ( 712 )
The magneto-optical Kerr rotation spectra in the region 400-700nm is studied for single layer Fe films. Experimental and theoretical calculation show that in the whole measurement wavelength range an enhancement of Kerr rotation occurs when the thickness of Fe is smaller than about 150Å. The thickness dependence of Kerr rotation of single layer Fe and Fe/Cu bilayer is compared. It is concluded that the Kerr rotation is dependent sensitively on the optical constants of underlying materials and the thickness of magnetic layer.
THE WORLD SHEET INSTANTON ON COSMIC ORBIFOLD
YAN Jun*, LI Jiangnan, HU Shike
Chin. Phys. Lett. 1990, 7 (8): 381-384 .  
Abstract   PDF(pc) (47KB) ( 462 )
The number of the topological degrees of freedom is calculated by using the world sheet instanton action. The result has shown that the topology quantum field may be the unbroken phase of string theory.
12 articles