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Volume 9 Issue 7
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Original Articles
A Note on Infinite Conservation Laws in Liouville Equation
WU Pingfeng, GUAN Xiwen, XIONG Zhuang, ZHOU Huanqiang
Chin. Phys. Lett. 1992, 9 (7): 337-340 .  
Abstract   PDF(pc) (127KB) ( 483 )
In this note, two Lax representations are presented for the Liouville equation. From each representation one may deduce an infinite family of conserved quantities in involution. However, members coming from different families are not in involution to each other.
SU(2) x U(l)5 Model of Electroweak Interaction
Chin. Phys. Lett. 1992, 9 (7): 341-344 .  
Abstract   PDF(pc) (163KB) ( 512 )
Regarding the weak hypercharge y in the standard model as a non-foundamental quantum number and decomposing it as the sum of three kinds of lepton numbers l1,l2,l3, the baryon number b and the weak strange numbers, we obtain an electroweak model with symmetry group SU(2)L x U (l) l1 x U(1)l2 x U (1)13, x U(1)b x U(1)s, where five neutral weak vector particles arise, with one of them being the same as, Z0 in the standard model and the other four being the new Z’s.

A Rigorous Spectral Representation of Relativistic Random Phase Approximation
WU Sliishu, YAO Yujie, SU Junchen, FU Manzheng, CUI Tian
Chin. Phys. Lett. 1992, 9 (7): 345-348 .  
Abstract   PDF(pc) (227KB) ( 479 )
A rigorous spectral representation of relativistic random-phase approximation is presented. Explicit expression is derived for the effective particle-hole interaction which contains the direct term Kan, the exchange term Ksc and the kernel for the fermion line renormalization Kfr. It is shown that according to our method, not only Kanan but also Ksc and Kfr can be given rigorously in a form which depends only on one ω(energy)-variable and they all take account of the retardation effect properly.
Note on the Nuclear α-Particle Model Wavefunction with a Simple Gaussian Form
LI Qingrun
Chin. Phys. Lett. 1992, 9 (7): 349-351 .  
Abstract   PDF(pc) (140KB) ( 603 )
The wavefunctions with a simple Gaussian form for the α-particle in the light nuclei have been used in some literatures. This note shows that this type of the α-particle wavefunction can not fit the experimental data for electron scattering.
Temperature Effect in (K0.5Na0.5)0.2 (Sr0.75Ba0.25)0.9Nb2O6: Cu Crystal Self-Pumped Phase-Conjugator
XU Jingjun, LIU Simin, WU Yuanqing, ZHANG Guangyin, SUN Daliang*, SONG Yongyuan*, CHEN Huanchu*
Chin. Phys. Lett. 1992, 9 (7): 352-354 .  
Abstract   PDF(pc) (148KB) ( 469 )
A reflectivity of 45% of the self-pumped phase-conjugate wave in (K0.5Na0.5)0.2 (Sr0.75Ba0.25)0.9Nb2O6: Cu crystal at the environmental temperature T~70°C has been obtained. The temperature effect in this kind of self-pumped phase-conjugator is studied.

Local Ordering of Sc and Nb Cations in Pb2ScNbO6
ZHENG Jianguo, LI Qi, FENG Duan, C.Boulesteix*
Chin. Phys. Lett. 1992, 9 (7): 355-358 .  
Abstract   PDF(pc) (242KB) ( 432 )
Two types of the ordered structures associated with the ordering of Sc and Nb cations in the perovskite-type compound Pb2ScNbO6 were revealed by electron diffraction, and the 111-type ordering was further confirmed by a special high resolution electron microscopy. The 111-type ordered domains, from a few unit cells to 3nm in size, distribute in the matrix with a disordered structure, and exhibit a characteristic of local ordering.

Field-Biased Diffusion-Limited Aggregation in Electrochemical Deposition System
PENG Gongwen*, TIAN Decheng
Chin. Phys. Lett. 1992, 9 (7): 359-362 .  
Abstract   PDF(pc) (196KB) ( 613 )
We extend the diffusion-limited aggregation model of Witten and Sander to the electrochemical deposition system by considering the effects of the external electric field. A jump probability for field-biased-diffusion is reasonably deduced, which enables us to obtain a series of loopless random fractals with varying fractal dimensions.
Surface-Enhanced Resonance Raman Spectra of Langmuir-Blodgett Films of Tetra-Lauryl Chloroaluminum Phthalocyanine
LUO Tao, ZHANG Weiqing, GAN Fuxi
Chin. Phys. Lett. 1992, 9 (7): 363-366 .  
Abstract   PDF(pc) (222KB) ( 812 )
The Langmuir-Blodgett (LB) films of tetra-lauryl chlor oaluminum phthalocya-nine (TLAlClPc) and a 1:1 mixture of TLAlClPc and stearyl alcohol (SA) were prepared. The Raman spectrum of solid TLAlClPc in KBr pellet was investigated. All the Raman lines were assigned. The surface-enhanced resonance Raman spectra of the LB films deposited on the silver island film that were vacuum-deposited on glass slides have been observed.

Transmission Electron Microscopy Investigations of Misfit Dislocation Interactions in GaAs/lnGaAs Superlattices on GaAs (001) Substrates
ZOU Jin, JIANG Shusheng, D. J. H. Cockayne, ZHANG Yunwu, GUO Xiang, PENG Zhengfu
Chin. Phys. Lett. 1992, 9 (7): 367-370 .  
Abstract   PDF(pc) (225KB) ( 473 )
The complex configurations and interactions of misfit dislocations in strained GaAs/InGaAs superlattices on GaAs (001) substrates have been studied by transmission electron microscopy under the two-beam or weak beam conditions. The observed interactions between a pair of 60°misfit dislocations and an orthogonal 60°misfit dislocation are theoretically explained.

Concentration Profiling of Fluorine in F-doped SnO2 Film
XU Bingzhang, XIA Yueyuan, TAN Chunyu, CHEN Youpeng, LI Shuying, ZHENG Zongshuang*, JIANG Weilin*
Chin. Phys. Lett. 1992, 9 (7): 371-374 .  
Abstract   PDF(pc) (209KB) ( 525 )
Depth profiles of fluorine in F-doped tin oxide (FTO) films prepared by atmospherical pressure chemical vapour deposition method have been studied by use of 19F(p,αγ ) 16O resonance nuclear reactions near 872.1 keV. A proper convolution method was used to get the real depth profiles of fluorine from the measured γ-ray excitation curves. Secondary ion mass spectrometry in conjunction with Rutherford backscattering spectrometry analysis was used to determine the density of the FTO films. It was found that the density of the films is markedly different from an earlier reported value.
Thermal Conversion of Semi-insulating GaAs due to Gallium Vacancies and Anti-structure Disorders
WENG Yumin, ZHENG Qingping, FAN Zhineng, ZONG Xiangfu
Chin. Phys. Lett. 1992, 9 (7): 375-378 .  
Abstract   PDF(pc) (239KB) ( 561 )
Rapid thermal annealing induced acceptor levels and their annealing behavior in semi-insulating GaAs were investigated using the photoluminescence technique. Results suggest that the introduction of excess of VGa and GaAs, related acceptors might lead to thermal conversion of GaAs wafers.
Magneto-Optical Kerr Effect of Compositionally Modulated Co/Pt Films
ZHOU Shiming, ZHAI Hongru, SONG Jingtao*, ZHANG Hongyan, LU Mu, JIANG Shulian
Chin. Phys. Lett. 1992, 9 (7): 379-382 .  
Abstract   PDF(pc) (181KB) ( 470 )
In this paper the magneto-optical polar Kerr rotation spectra of compositionally modulated films (CMF) Co/Pt are calculated by using Fresnel's equations. For CMF Co/Pt with dCo/dpt=1/2, 1 and 2 the magneto-optical Kerr rotation at any wavelength increases with the increasing modulation wavelength in the wavelength region from 200 to 800nm. For CMF Co/Pt of constant dpt the Kerr rotation increases with dco increasing while of constant dco the Kerr rotation increases with dpt decreasing. From numerical calculations it is suggested that for CMF Co/Pt with small dpt the Pt sublayer is polarized and has a positive contribution to the Kerr rotation of CMF Co/Pt.

Two-Dimensional Transport Properties of Germanium Bicrystal at Low Temperature
XIA Yiben*, ZHENG Guozhen, GUO Shading, SUN Jinxi
Chin. Phys. Lett. 1992, 9 (7): 383-385 .  
Abstract   PDF(pc) (168KB) ( 416 )
Two-dimensional properties of grain boundaries in germanium bicrystals are studied at liquid helium temperature ranging from 1.6 to 4.2K. The experimental results indicate that the magnetoresistivity for 8°tilt angle increases exponentially with the magnetic field intensity square in weak magnetic field and with the linear magnetic field intensity in strong magnetic field. The phenomena are explainable with the percolation theory.
Retroreflection Characteristics of the Surface Under Diode Laser Radiation
LIU Wenqing, WANG Yaping, JIANG Rongxi, XIA Yuxing
Chin. Phys. Lett. 1992, 9 (7): 386-389 .  
Abstract   PDF(pc) (191KB) ( 555 )
The retroreflection characteristics of metal surfaces sprayed with different mixture of Si3N4 powder and plastic powder were evaluated by an automatic system developed at our laboratory, which normally used to measure the absolute retroreflectance of various surfaces without any reference standard. The preliminary results obtained seem to indicate that the characterization of the retroreflection distribution can be controlled as needed by selecting the sample surface material and/or its mixture. This property may be used in analysis of target signatures.

Quantum Temperature Near the Ring Singularity in the Kerr Space-Time
ZHAO Zheng
Chin. Phys. Lett. 1992, 9 (7): 390-392 .  
Abstract   PDF(pc) (100KB) ( 513 )
There exists a local event horizon at the ring singularity in the equatorial plane of the Kerr black hole, whose surface gravity diverges. The Hawking temperature near the ring is infinite if the relation between the temperature and the surface gravity is still valid.

15 articles