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Volume 12 Issue 8
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Original Articles
Wave Functional of Spherically-Symmetric Space-Time with Λ in Self-Dual Representation
HUANG Chaoguang
Chin. Phys. Lett. 1995, 12 (8): 449-452 .  
Abstract   PDF(pc) (0KB) ( 189 )
The constraint equations of the spherically symmetric gravity coupled to non-zero cosmological constant are solved classically and then quantized canonically. The wave functional of the system in the self-dual representation is obtained, which is different from the Chern-Simons state.

Site-Pairing of Electron in Doped C60
ZHANG Guoping, FU Rongtang, SUN Xin, Y. Takahashi
Chin. Phys. Lett. 1995, 12 (8): 453-456 .  
Abstract   PDF(pc) (203KB) ( 372 )
Going beyond both a simple perturbative theory and Hartree-Fock treatment, the Gutzwiller variational scheme is employed to clarify the possibility of electron site-pairing in doped C60. It is shown that this pairing can be induced by electron-phonon interaction rather than electron-electron interaction. Our results are supported by EPR experiments.
Design of Diffractive Optical Elements for Implementing Optical Interconnects and Beam Splitting
CHEN Yansong, LI Dehua
Chin. Phys. Lett. 1995, 12 (8): 457-460 .  
Abstract   PDF(pc) (214KB) ( 330 )
A design approach for optical interconnect system and beam splitting composed of a phase-only diffractive optical element is described. The diffractive optical element is of 16 phase levels, so its efficiency may reach very high. Three examples of interconnect and beam splitting patterns are carried out with this design approach and the satisfactory results are given.
Frequency Tuning Feature of a Reditron Oscillator
LING Genshen, LI Xiangsheng, WANG Yong, LI Chuanlu, TAN Qimei, LI Pingping
Chin. Phys. Lett. 1995, 12 (8): 461-464 .  
Abstract   PDF(pc) (165KB) ( 434 )
We report some experimental results which confirm the theoretical analysis of the tuning feature of a reditron oscillator. Here, we produce high power microwave at 10 GHz, and the tuning range of the reditron is 8-13.32 GHz which is controlled by changing both the voltage and the anode-to-cathode separation. We also report a measurement method of the anode-to-cathode distance.
Stable Mg- Zn-Y Quasicrystals
LUO Zhiping, ZHANG Shaoqing, ZHAO Dongshan, TANG Yali, SUI Haixin
Chin. Phys. Lett. 1995, 12 (8): 465-468 .  
Abstract   PDF(pc) (152KB) ( 468 )
By conventional air-cooled casting method, cast ingots with large contents of stable Mg-Zn-Y quasicrystals were obtained. It was shown that most of the quasicrystals are of face-centered icosahedral type, while a few of them belong to simple icosahedral type. The quasicrystals were stable during the continuous heating with the temperature below 868K. The oxidizing reactions were observed at high temperature. This is the characteristic of Mg-Zn-Y alloys, which differs from that of A1 base alloys.
Microdefects in Te-Rich PbTe Bulk Crystal
WANG Geya, SHI Tiansheng, ZHANG Suying*
Chin. Phys. Lett. 1995, 12 (8): 469-472 .  
Abstract   PDF(pc) (206KB) ( 446 )
The microdefects in Te-rich PbTe coating material grown by Bridgman technique have been studied via transmission electron microscopy. The results indicate that the major microdefects in Te-rich PbTe crystal are plate-like defects lying on {100} plane and homogeneously distributed in the matrix with density about 1.7x1016/cm3. They are originated from the precipitation of native point defects in Te-rich PbTe which occured in the cooling and annealing process and presented in the form of plates consisting of Te anti-site atoms or interstitial Te atoms.
Calculation of the Orientational Phase Transition Temperature in Solid C60
XIN Houwen, YANG Lingfa, OUYANG Lizhi
Chin. Phys. Lett. 1995, 12 (8): 473-476 .  
Abstract   PDF(pc) (170KB) ( 557 )
A method is developed to describe the orientationel phase transition in solid C60, considering both Lennard-Jones atomic pair potentials and Coulombic forces. We obtained the active mode while the transition occurs, and the calculated transition temperature agrees with experiments.
Thermal Diffusivity of Diamond Films With Substrates
CUI Jingbiao, FANG Rongchuan
Chin. Phys. Lett. 1995, 12 (8): 477-480 .  
Abstract   PDF(pc) (194KB) ( 348 )
Diamond films were prepared by hot-filament chemical vapour deposition system. Photothermal deflection technique has been used to measure thermal diffusivity of diamond films with substrates. The influence of silicon or quartz substrate on the measurement of thermal diffusivity of film is presented. A simple two-layer model has been given to explain the effect of substrates on the measurement of thermal diffusivity and used to draw thermal diffusivity of diamond film from effective thermal diffusivity of film/substrate system.
Electron Band Structure of C60 Single Crystal Using Synchrotron Radiation
BAO Shining, HE Peimo, XU Yabo, DONG Yuhui, QIAN Haijie, JIA Jinfeng, YANG Yi, K. Yibulaxin, LIU Fengqin, LU Sihua, WU Sicheng,
Chin. Phys. Lett. 1995, 12 (8): 481-484 .  
Abstract   PDF(pc) (222KB) ( 577 )
Electron band structure of C60 single crystal has been investigated using synchrotron radiation. On the cleaved (111) surface of the C60 single crystal the angle-resolved ultraviolet photoelectron spectra were measured at normal emission with varying photon energy from 12.7 to 28.2eV. The valence band dispersions in L-r-L direction were successfully observed. The dispersions are 0.14 and 0.17eV for the highest occupied molecular orbitals (HOMO) and HOMO-1 derived band respectively.

Interpretation of the Giant Magnetoresistance Oscillation with the Thickness of Ferromagnetic Layer in Magnetic Multilayers
ZHAO Pingbo, LI Bozang, PU Fuke(PU Fucho)
Chin. Phys. Lett. 1995, 12 (8): 485-488 .  
Abstract   PDF(pc) (188KB) ( 376 )
In virtue of Mott mechanism, we calculate the giant magnetoresistance(GMR) in Fe/Cr superlattices. Our results show that the GMR oscillations with the thickness of the ferromagnetic layer is due to the finite size effect of magnetic itinerant holes. The calculation is consistent with the experimental observation.
Break Down of Vertical-Bloch-Line Chains in the First Kind of Dumbbell Domain Walls Subjected to an in-Plane Field
GUO Gexin, LU Wei, SUN Huiyuan, NIE Xiangfu, MENG Guangqing, HAN Baoshan
Chin. Phys. Lett. 1995, 12 (8): 489-492 .  
Abstract   PDF(pc) (223KB) ( 438 )
Experiments were statistically carried out on the behavior of the vertical-Bloch-line (VBL) chains of the first kind of dumbbell domains (IDs) in garnet bubble films subjected to an in-plane field, Hip. It was found that for IDs the critical in-plane field, (Hip)ID, above which their VBL chains disappear, is the same as that of ordinary hard bubbles (OHBs), H'ip. However, for IDS, the critical range of Hip for VBL chain softening is larger than that of OHBs. Besides, we also found some details of the softening process, e.g., the collapse field range of the remaining IDs shrinks rapidly towards H0,mas, and this very narrow range can maintain until all IDs are softened.

Soliton Compression Due to Cross-Phase-Modulation in the Normal Dispersive Optical Fibers
XU Wencheng, LIU Junmin, LIAO Changjun, LIU Songhao
Chin. Phys. Lett. 1995, 12 (8): 493-496 .  
Abstract   PDF(pc) (190KB) ( 391 )
A new method is proposed to compress soliton pulses in the normal dispersive optical fibers through cross-phase-modulation of two pulses. The optimum fiber length for optimum compression is obtained for given values of the pulses and fiber parameters.
Computer Simulation of Surface Damages at Atomic Scale Inducedby Cluster Impacting
PAN Zhengying, LI Rongwu, HO Yukun
Chin. Phys. Lett. 1995, 12 (8): 497-500 .  
Abstract   PDF(pc) (196KB) ( 426 )
A many-body hybrid potential, which is the combination of the tight-binding and the Moliere potential, has been developed. The surface damages at atomic scale caused by gold clusters, with energy of 3250eV, impacting on gold crystals have been investigated by molecular dynamics simulation. The results are compared with that from the two-body Moliere potential.
Relationship Between the Formation of Clusters in Electrorheological Fluids and Their Fractal Dimension
WU Feng, TANG Xinlu, YANG Yuegui, WANG Xiaohong
Chin. Phys. Lett. 1995, 12 (8): 501-504 .  
Abstract   PDF(pc) (167KB) ( 431 )
In this paper, the scaling properties of aggregation of particles in electrorheological fluids (ERF) are analyzed. It is found that the cluster size is related to both the space dimension and its fractal dimension, i. e. the structure of cluster. By analyzing the experimental data and the results of computer simulations we have shown that the fractal dimension of the particle clusters in ERF is one for 2-dimensional space and 5/4 for 3-dimensional space.
Structure and Evolution of an Isothermal Thin Accretion Disk Around a Black Hole
ZHOU Hongnan, HUANG Keliang
Chin. Phys. Lett. 1995, 12 (8): 505-508 .  
Abstract   PDF(pc) (193KB) ( 388 )
In this paper, we construct an isothermal thin accretion disk model around a black hole for which the vertical mass density is expressed as ρ = ρ0e-z2/2z02. The hydrostatic equilibrium equations of the model disk and their difference forms are derived. We solve the basic balance equations by numerical method. According to the calculation results, the structure and evolution of model disk are discussed.
Quantum Field Theory of the Universe in the Induced Gravity
SHEN Yougen
Chin. Phys. Lett. 1995, 12 (8): 509-512 .  
Abstract   PDF(pc) (139KB) ( 385 )
The quantum field theory on the universe in the induced theory of gravity is discussed in detail. After the wave function of the universes was regarded as a universe field operator in the minisuperspace, not only the difficulty in a probabilistic interpretation in the quantum cosmology can be circumvented, but also the conclusion of the multiple production of universes is obtained. We find the distribution of these universes created from ‘nothing’ is the planck distribution.
16 articles