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Volume 7 Issue 11
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Original Articles
COMMENTS ON THE HIGH SPIN SPECTROSCOPY OF 163Lu
CHEN Yongshou, YANG Chunxiang
Chin. Phys. Lett. 1990, 7 (11): 481-484 .  
Abstract   PDF(pc) (64KB) ( 431 )
The new striking feature of anomalously low second band crossing frequency observed in 163Lu is interpreted as the shape variation with the quasiparticle (q.p.) configurations as a result of the deformation driving of the rotating q.p. high-j orbits. On the assumption that the crossing frequency is basically determined by an average over deformations before and after the crossing, the experimental data is reproduced very well by the present model calculation.
CHIRAL SYMMETRY AND NUCLEAR INTERACTION
SU Rukeng, YANG Shijie, CAI Shengshan, ZHENG Guotong*
Chin. Phys. Lett. 1990, 7 (11): 485-488 .  
Abstract   PDF(pc) (46KB) ( 444 )
After summing the bubble diagrams of pion meson, σ meson and ω meson, the nucleon-nucleon interaction of Chiral σ -ω model is investigated. The technique of dimensional regularization and the counterterms for renormalization are introduced. The nuclear force of Chiral σ -ω model is given.

ORIGIN OF THE REPULSIVE CORE OF NUCLEAR FORCE
XU Xiaoming, QIU Xijun
Chin. Phys. Lett. 1990, 7 (11): 489-492 .  
Abstract   PDF(pc) (51KB) ( 394 )
A soliton model for a baryon is extended to study nucleon-nucleon interaction by virtue of the relativistic two-quark-cluster theory. A repulsive core is obtained mainly due to the one gluon exchange interaction and quark exchange between two nucleons. In this connexion the relativistic effect of quark motion must be considered for producing the repulsive core.
STUDY OF THE COLLECTIVE MOTION OF NUCLEI BY MONTE-CARLO SIMULATION
WANG Zhongqi
Chin. Phys. Lett. 1990, 7 (11): 493-496 .  
Abstract   PDF(pc) (50KB) ( 335 )
In this paper, Monte Carlo method has been used to trace the motion of particles in a vibrating container, the energy exchange between the collective motion and the internal motion of single particle is studied. The amount of energy exchange is effected by the frequency of nuclear vibration especially by the relevant amplitude.
PICOSECOND NARRO W-BAND SUPERLUMINESCENT OPTICAL PARAMETRIC SELF-AMPLIFICATION IN β-BaB2O4 CRYSTAL PUMPED AT 354.7nm
DENG Daoqun, XU Zuyan, WANG Yunping, ZHENG Wanhua, LIU Xiang, WU Baichang*, CHEN Chuangtian*
Chin. Phys. Lett. 1990, 7 (11): 497-499 .  
Abstract   PDF(pc) (47KB) ( 426 )
A tunable picosecond narrow band β-BaB2O4 (BBO) superluminescent optical parametric self-amplification (OPSA) pumped by the third harmonic of an actively-passively mode-locked Nd:YAG laser has been demonstrated. The output wavelength of the OPSA was tunable from 406.6nm to 2777nm. The maximum energy conversion efficiency was 11%. The maximum peak power of the visible output was as high as 13MW.

FREQUENCY SPECTRUM ANALYSIS OF ULTRASONIC PULSE EXCITED BY LASER AT METAL SURFACES
BAI Yuhai, PEI Liwei, FANG Qiping, YAN Yuping
Chin. Phys. Lett. 1990, 7 (11): 500-502 .  
Abstract   PDF(pc) (48KB) ( 434 )
The frequency spectrum of laser-excited ultrasonic wave has been measured in various metals including aluminum, steel and copper, at both free and modified surfaces. The result shows that the material and surface modification affect the spectrum.
INCOMMENSURATE -COMMENSURATE PHASE TRANSITION IN NiTi(Fe) ALLOY
WANG Weizhong, QIAN Hua, WANG Zixiao
Chin. Phys. Lett. 1990, 7 (11): 503-505 .  
Abstract   PDF(pc) (36KB) ( 371 )
Incommensurate phase(IC)-commensurate phase(R) transition in NiTi(Fe) alloy is dealt with Landau theory. The order parameters are the complex amplitudes of the charge density waves (CDWs). This transition is a first-order one. The condition that incommensurate phase can exist is obtained.
SELF- AND IMPURITY-DIFFUSION MECHANISMS IN UNDOPED AND MODULATION-DOPED (GaA1)As SUPERLATTICES
WANG Enge
Chin. Phys. Lett. 1990, 7 (11): 506-509 .  
Abstract   PDF(pc) (47KB) ( 411 )
The charged states of antisites and interstitials in undoped and n- or p-type Si modulation-doped ( GaAl ) As superlattices have been determined by the calculated electronic structures wing recursion method within tight-binding formalism. Based on the behavior of these point defects, some new mechanisms that describe the self-diffusion and impurity diffusion processes are suggested and discussed.
PREPARATION OF THERMALLY EVAPORATED CdTe THIN FILMS
Shahzad Naseem, Naseer-ud-Din, Khadim Hussain
Chin. Phys. Lett. 1990, 7 (11): 510-513 .  
Abstract   PDF(pc) (56KB) ( 322 )
Thin films of cadmium telluride were prepared by evaporating cadmium telluride powder in a vacuum of less than 10-4 Torr. The substrate temperature was varied systematically from room temperature to 300°C. The results of optical and structural characterizations have revealed that the films posses a high value of absorption coefficient with a bandgap value in the range 1.475-1.769eV, and that the films are of cubic structure with a preferred orientation along (111) plane. Four probe measurements have shown that resistivity of these films is affected by the change in substrate temperature, with the lowest value (12.6Ω-cm) being at 200°C.

RELATION BETWEEN THE EFFECTS OF FINITE THICKNESS AND TILTED MAGNETIC FIELDS IN THE FRACTIONAL QUANTUM HALL EFFECT
CHEN Yingjian
Chin. Phys. Lett. 1990, 7 (11): 514-517 .  
Abstract   PDF(pc) (54KB) ( 502 )
We present an approximate mathematical relation between the finite thickness and the tilted magnetic fields'effects in the fractional quantum Hall effect. We show that the experimental results for the 2/3 filling can be explained qualitatively by the existing theoretical results, and the Monte Carlo results for ground state energy vs finite thickness of two-dimensional layer at 1/3 filling can be rewritten in the form of ground state energy vs tilt angle.
EFFECT OF NITROGEN CONTENT IN a-Si:H/a-SiNx:H MULTILAYERS ON CONDUCTIVE MECHANISM
HE Yuliang, YU Bin, LIU Xiangna
Chin. Phys. Lett. 1990, 7 (11): 518-521 .  
Abstract   PDF(pc) (63KB) ( 410 )
We studied the effect of nitrogen content in a-SaNx:H barrier layers to a-Si:H/a-SiNx:H mutilayers with different thickness of a-Si:H well layers. It was shown that, except quantum well effect, the ratio of N/Si and interfacial defects of multilayers have influence on the conduction mechanism. The activation energy of mobility ΔE is equal to 0.17±0.03eV which is attributed to the interfacial scattering.
PHOTOLUMINESCENCE SPECTRA OF STRAINED HETEROSTRUCTURE OF InP ON GaAs SUBSTRATE GROWN BY METAL ORGANIC CHEMICAL VAPOR DEPOSITION
TENG Da, ZHUANG Weihua
Chin. Phys. Lett. 1990, 7 (11): 522-525 .  
Abstract   PDF(pc) (57KB) ( 408 )
A high-energy shift of the band-band recombination has been observed in photoluminescence spectra of the strained InP layer grown on GaAs substrate. The InP layer is under biaxial compressive strain at temperatures below the growth temperature, because the thermal expansion coefficient of InP is smaller than that of GaAs. The strain value determined by the energy shift of the band-edge peak is in good agreement with the calculated thermal strain. A band to carbon acceptor recombination is also identified.

INSULATOR TO SUPERCONDUCTOR TRANSITION OF Pb DOPED 2201 SINGLE CRYSTAL IN Bi-SYSTEM BY OXYGEN DEFICIENCY
LIU Yongqian, HUANG Yuzhen, CHEN Liquan, CHEN Hong, LI Jianqi, NI Yongming, JIA Shunlian, ZHAO Zhongxian
Chin. Phys. Lett. 1990, 7 (11): 526-528 .  
Abstract   PDF(pc) (59KB) ( 396 )
Flux method was used to grow large 2201 single crystal in Bi-Sr-Cu oxide. The as-grown crystal was nonsuperconductor and showed semiconductivity in resistivity curve. After it was reduced in flowing N2 at 570°C and appropriate oxygen vacancies were induced, superconductivity with Tonc=6K was obtained. The great influence of oxygen deficience on superconductivity is evident. Also, the incorporation of Pb adjusted the modulation pattern.
13 articles