Volume 5 Issue 2

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Original Articles
THE BEHAVIOR OF H AT THE AMORPHOUS SEMICONDUCTOR MULTILAYER INTERFACES
WANG Shulin, CHENG Ruguang
Chin. Phys. Lett. 1988, 5 (2): 49-52 .  
Abstract   PDF(pc) (45KB) ( 670 )
The H evolution spectra of a-Si:H/a-SiNx:H and a-Si:H/a-Si:H multilayers are reported. It is found that interface H evolution occurs at a higher temperature, which suggests that the interface-bonded H state is different from the bulk one.
STUDY OF SUPERCONDUCTING MATERIAL YBa2Cu3O9-δ BY POSITRON ANNIHILATION TECHNIQUE
ZHU Shengyun, LI Anli, BAI Xixiang, DU Hongshan, LI Donghong, ZHENG Xianmiao, ZHANG Wanjing, CHEN KaiYuan
Chin. Phys. Lett. 1988, 5 (2): 53-56 .  
Abstract   PDF(pc) (40KB) ( 517 )
Characteristics of superconducting and semiconductor materials with the same composition have been studied at room temperature, 94K, and 77K by the positron annihilation technique. The results indicate that the phase transition of electronic structure in the superconducting material takes place in the superconducting state.
A STUDY OF SUPERCONDUCTIVITY IN Y-Ba-Cu-F-O SYSTEM
J.H. Jia, J.y. Jiang, G.R. Liu, Y.M.Gao, Q.Q. Zheng, J.J. Du, W.G. Yao
Chin. Phys. Lett. 1988, 5 (2): 57-60 .  
Abstract   PDF(pc) (48KB) ( 404 )
High temperature superconductivity, up to 258K, was observed in the Y1Ba2Cu3F2xO7-x-δ(0.2≤x≤1) bulk materials prepared by means of conventional ceramic-technique. X-ray diffraction analysis shows that these materials are multiphase. It is believed that to obtain a high Tc superconducting material with Tc near room temperature is possible. though the high Tc state of samples is now very unstable.



SINGLE AND DOUBLE ELECTRON CAPTURE INTO EXCITED STATES IN COLLISIONS BETWEEN IONS AND NEUTRALS
PAN Guangyan, LEI Ziming, YANG Feng, LIU Jiarui, YU Dehong, SUN Xiang
Chin. Phys. Lett. 1988, 5 (2): 61-64 .  
Abstract   PDF(pc) (46KB) ( 476 )
Recent experimental results on charge transfer into excited States in collisions between single and double charged ions with He, Ne, Ar , H2 and O2 are presented , respectively . Laboratory energy range of the ion beams of Heq+, Arq+, Ne+ ( q = 1 , 2 ) ions is (70-170)xq KeV. The optical measurement was performed by an optical multichannel analysis system (OMA).

EFFECT OF INTERACTIONS BETWEEN ELECTRONS AND LO ON THE Tc OF SUPERCONDUCTORS
SUN Yinlong, SHENG Yi, LIU Fusui
Chin. Phys. Lett. 1988, 5 (2): 65-68 .  
Abstract   PDF(pc) (41KB) ( 497 )
By studying the high-frequency peak with method of numerical solution of Elia shberg equation, the importance of electron-LO interactions in the high-Tc superconductors is shown.
THE VECTOR GLUEBALL AND ITS QUANTUM CHROMODYNAMICS SUM RULE
RAO Jianguo, LIU Jueping
Chin. Phys. Lett. 1988, 5 (2): 69-72 .  
Abstract   PDF(pc) (39KB) ( 370 )
A gauge invariant and Lorentz-irreducible three-gluon conserved vector current is constructed, and the mass of the vector glueball is calculated in the framework of the Quantum Chromodynamics sum rules.
CHARGE FLUCTUATION AND HIGH-Tc SUPERCONDUCTIVITY
ZHU Zizhong, YE Ling, ZHANG Kaiming
Chin. Phys. Lett. 1988, 5 (2): 73-76 .  
Abstract   PDF(pc) (51KB) ( 447 )
Cluster model is used to simulate several optical vibration modes of oxygen in the layered perovskite La-Ba-Cu-O. It is found that only the breathing mode of oxygen induces a charge fluctuation between Cusites. The charge fluctuation is reasonably large and may have important implications in the high-Tc superconductivity.
THE THEORETICAL STUDY OF SUPERCONDUCTIVITY IN OXIDE BaPb1-xBixO3
WANG Wenguo, MA Benkun
Chin. Phys. Lett. 1988, 5 (2): 77-80 .  
Abstract   PDF(pc) (39KB) ( 505 )
A local Hamiltonian is introduced to study BaPb1-xBixO3. The usual CPA method is used to deal with the substitutional disorder effect. The superconducting Tc ~ x relation is calculated and the result is in agreement with experiments. Some remarks on the characteristics of oxide superconductivity are presented.



ON THE BAMBOO BOUNDARY INTERNAL FRICTION PEAK IN 99.9999 ALUMINIUM
CHENG Bolin, GE Tingsui ( T.S.Ke)
Chin. Phys. Lett. 1988, 5 (2): 81-84 .  
Abstract   PDF(pc) (43KB) ( 451 )
An internal friction peak has been observed in bamboo crystals of 99.9999wt%(6N) Al. The height of the peak was found to be proportional to the number of bamboo boundaries contained in the specimen. Analysis of the relaxation parameters of this peak shows that this is a new peak associated with the presence of bamboo boundaries.
THE BEHAVIOURS OF ELASTIC MODULUS AND ULTRASONIC ATTENUATION IN NdFeB MAGNET
WANG Ruju, LI Fengying, WANG Jifang, LUO Yang*
Chin. Phys. Lett. 1988, 5 (2): 85-88 .  
Abstract   PDF(pc) (49KB) ( 488 )
The elastic modulus and attenuation coefficient of polycrystalline NdFeB magnet have been measured at different temperatures by ultrasonic method. At room temperature, the elastic modulus shows small but apparent anisotropy, while at low temperatures the ultrasonic velocity and attenuation coefficient are both changed anomalously. We suppose that this phenomenon is caused by the abrupt change of the direction of magnetization.

NUCLEAR EFFECT IN DRELL-YAN PROCESS
BI Pinzhen, LU Hefu(Hoff Lu)
Chin. Phys. Lett. 1988, 5 (2): 89-91 .  
Abstract   PDF(pc) (30KB) ( 357 )
The quark-gluon model of nuclei is used to study nuclear effect in Drell-Yan process. It turns out that it agrees with the experiment nicely. The results suggest that the internal quark structure of nucleons depends on the surrounding environment.
THE ACCRETION OF MOVING COSMIC STRING
ZHOU Zhihong
Chin. Phys. Lett. 1988, 5 (2): 93-95 .  
Abstract   PDF(pc) (26KB) ( 456 )
The accretion of matter onto moving cosmic string is discussed carefully. It is found that the accreting matter in the wake has not only transverse velocity but also vertical velocity. The vertical velocity of the accreting matter depends on that of moving string.
12 articles