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Volume 8 Issue 9
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Original Articles
On Charged Black Hole in Multidimensional Theory with Ricci-Flat Internal Spaces
S. B. Fadeev, V. D. Ivashchuk, V. N. Melnikov
Chin. Phys. Lett. 1991, 8 (9): 439-441 .  
Abstract   PDF(pc) (78KB) ( 415 )
A generalization of the Reissner-Nordstrom solution for the case of n internal Ricci-flat spaces is obtained.
Lyapunov Exponents and General Dimensions of Strange Attractor of Electrodynamic Cone Loudspeaker
TONG peiqing, MIAO Gaoqing, NI Wansun, WEI Rongjue
Chin. Phys. Lett. 1991, 8 (9): 442-445 .  
Abstract   PDF(pc) (142KB) ( 492 )
Lyapunov exponents, Lyapunov dimension and general dimensions have been determined from a time series of electrodynamic cone loudspeaker. It is found that a low-dimensional chaotic at tractor has one positive largest exponent, and the Lyapunov dimension is in concordance with the Hausdorff dimension which calculated by general correlation integrated method.
Probe-Hole Field Emission Microscope System Controlled by Computer
GONG Yunming, ZENG Haishan
Chin. Phys. Lett. 1991, 8 (9): 446-449 .  
Abstract   PDF(pc) (210KB) ( 445 )
A probe-hole field emission microscope system, controlled by an Apple II computer, has been developed and operated successfully for measuring the work function of a single crystal plane. The work functions on the clean W(100) and W(111) planes are measured to be 4.67eV and 4.45eV, respectively.
A Classical Chiral Invariant Theory Method of N-N Interaction
QI Lijie, HE Guozhu
Chin. Phys. Lett. 1991, 8 (9): 450-453 .  
Abstract   PDF(pc) (135KB) ( 344 )
Within the framework of meson exchange theory, the N-N interaction is derived by a classical field method from a chiral σ-ω model. The nuclear potential derived is similar to the ordinary one boson exchange potential.
Sudden Jump of Hartree-Fock Solution and Phase Transition
WU Shishu, YAO Yujie, JING Xiaogong, ZHAO Guoquan
Chin. Phys. Lett. 1991, 8 (9): 454-457 .  
Abstract   PDF(pc) (223KB) ( 418 )
The physical implication of a sudden jump of the Hartree-Fock solution is studied by means of a solvable model, where not only such jump occurs but also the phase transition (PT) of a many-particle system can be demonstrated explicitly. It is found that there is no close relation between the jump and PT. The reason for this irrelevancy is explored and explained.
Observation of Optical Bistability Hysteresis Loop with Surface Waves in Doped Polymer Film
YE Peixian, YU Zuhe, ZHANG Zhanxiang, SHEN Yuquan*, FU Xingfa*
Chin. Phys. Lett. 1991, 8 (9): 458-460 .  
Abstract   PDF(pc) (171KB) ( 507 )
Optical bistability hysteresis loop has been observed experiment ally with a setup using prism excitation of surface wave in a doped polymer thin film. A simple model has been developed to analyze its operation. The observed bistability hysteresis loop can be explained in terms of surface plasmon excitation and laser induced refractive index variations.
A Mixed Nonlinear Optical Process in Sodium Vapour
ZHANG Peng, ZHANG Yuying, SUN Taoheng
Chin. Phys. Lett. 1991, 8 (9): 461-464 .  
Abstract   PDF(pc) (179KB) ( 379 )
A mixed nonlinear optical process has been studied. This process consists of a stimulated hyper-Raman scattering which has a reasonable tuning range in both forward and backward, a four-wave parametric mixing emission in forward where the tuning range extends over 300cm-1 and an optical pumped stimulated emission.
Simulation of Particle Diffusion in Magnetic Field and Stochastic Electrostatic Field
HU Xiwei
Chin. Phys. Lett. 1991, 8 (9): 465-468 .  
Abstract   PDF(pc) (135KB) ( 449 )
The evolution of the transverse turbulent diffusion of charged particles is given by particle simulation. The simulated relative diffusion, first, rises rapidly as tα (α > 3). Then it oscillates obviously and increases slowly in an average value. Finally, it tends asymptotically to the relative diffusion in a spatially uncorrelated stochastic field(white noise). The simulated results are quite different from previous analytic theorly.
In Situ Observation of KB5 Crystal Growth Under Purely Diffusion Gel Systems by Holographic Interferometry
CHEN Wanchun, SHEN Yunxue, MA Wenyi, LI Ming, CHEN Yansong
Chin. Phys. Lett. 1991, 8 (9): 469-471 .  
Abstract   PDF(pc) (148KB) ( 529 )
KB5O8.4H2O (KB5) crystals have been grown in an agar-agar gel by temperature decrease method for simulating crystal growth in space. Nucleation and growth have been followed by interferometric holography. A concentration field surrounding the growing crystals was obtained and a Liesegang ring was observed. The pattern are visualized directly to reveal physical phenomena of purely diffusion crystal growth kinetics.
Beam Induced Degradation Effect in Ion Beam Analysis of Polymer
YANG Guohua, ZHU Dezhang, PAN Haochang, XU Hongjie, CHEN Shoumian
Chin. Phys. Lett. 1991, 8 (9): 472-475 .  
Abstract   PDF(pc) (227KB) ( 516 )
The question of whether ion beam analysis technique can be applied to the study of polymers has been investigated. Degradation of mylar foil under MeV ion beam irradiation was observed. In order to describe the degradation process of mylar foil under ion beam irradiation quantitatively, only one dose-independent degradation cross section for each of hydrogen and oxygen was needed. Our results suggest that proton or He+ ion combined with rotation of the target (scanning area of 20mm2) can be used to study the mylar foil without substantially changing the compositions of the target up to ion fluence 5 x 1015/cm2.
Phase Transitions of Ultradiffusion Model on Vicsek Snowflakes Fractal
WANG Xiaomin, TAO Ruibao*
Chin. Phys. Lett. 1991, 8 (9): 476-479 .  
Abstract   PDF(pc) (212KB) ( 391 )
Through an exact real space renormaligation group approach, we analysed the ultradiffusion with a hierarchical pattern of hopping rates defined on Vicsek snowflackes fractal. The transition from anomalous to normal diffusion is shown to occur in the arbitrary n-dimension (n-D) case. In the presence of external field, we find another unusual transition which is essentially different from the one for biased ultradiffusion of 1-D multifurcating hierarchical system.
Magnetic Depopulation of Subbands in Very Narrow Quantum Channels
DU Qinghong, MAO Jianmin, WANG Taihong, CHENG Wenqin, ZHOU Junming, HUANG Qi
Chin. Phys. Lett. 1991, 8 (9): 480-483 .  
Abstract   PDF(pc) (212KB) ( 478 )
A model for electrons confined in narrow conducting channels in the presense of a magnetic field is presented which takes into account a cut-off in the filling of the subbands. Such a cut-off gives rise to energy separated subbands resulting in a relation between sublevel index n and inverse magnetic field B-1 such that in the high field regime it envolves into an original form as in a 2D case and in the moderate field regime it shows pronounced deviation horn linearity.
Flux Creep and Pinning Potential in Melt-grown YBCO
GUO Shuquan, WU Peijun, ZHANG Jinlong, FAN Zhanguo*
Chin. Phys. Lett. 1991, 8 (9): 484-486 .  
Abstract   PDF(pc) (105KB) ( 553 )
At temperature 77K and magnetic field 1-5 T, measurement of voltage-current curve in the melt-grown YBCO has been performed. The characteristics of the curves were found to be of an exponential form for E < lμV/cm. The behaviour is consistent with the flux creep model. The flux pinning potential energy has been calculated.
Ge Film Contacts to Radio Frequency Sputtered Y-Ba-Cu-O Superconductor Film
ZHANG Bei, QIAN Yi, TONG Litai, CHEN Haiying, WANG Guizhi QIAO Yongping, XING Miaoxiang, FENG Qingrong, LIU Zunxiao LAN Jian, DAI Yuandong
Chin. Phys. Lett. 1991, 8 (9): 487-490 .  
Abstract   PDF(pc) (148KB) ( 570 )
The semiconductor-superconductor con tact system of Ge/Y-Ba-Cu-O(YBCO)/ SrTiO3 has been successfully fabricated by two steps of deposition. The YBCO film in the contact of Ge/YBCO did not lose its superconductivity and its Tc (on set) did not degrade as well. The top layer of Ge was polycrystalline with preferred orientation corresponding to the epitaxial structure of the underlayer of YBCO.
Time-Resolved Infrared Study of 355 nm Laser Photolysis of (η6-C6H6)Cr(CO)3 in Gas Phase
WANG Wenhua, JIN Pei, LIU Yanwei, SHE Yongbo, FU Kejian
Chin. Phys. Lett. 1991, 8 (9): 491-494 .  
Abstract   PDF(pc) (245KB) ( 429 )
The time-resolved infrared absorption spectra obtained upon 355 nm laser photolysis of the gas phase (η6-C6H6)Cr(CO)3 are presented. (η6-C6H6)Cr(CO)2 is produced upon absorption of a single ultroviolet photon. The bands observed at 1917 and 1981 cm-1 are assigned to B1 and A1 terminal carbonyl-stretching modes of (η6-C6H6)Cr(CO)2 with local C2v symmetry. The bond angle of OC-Cr-CO in (η6-C6H6)Cr(CO)2 is estimated to be 101°. The rate constant for reaction of (η6-C6H6)Cr(CO)2 with CO is determined as (3.4 ± 0.2) x l05 Torr-1s-1at 80°C.
15 articles