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Volume 12 Issue 7
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Original Articles
Regularities of the Band Structures for the Even-Even Rare-Earth Nuclei
ZHAO Yumin (Y. M. Zhao), CHEN Yan, ZONG Hongshi
Chin. Phys. Lett. 1995, 12 (7): 385-389 .  
Abstract   PDF(pc) (5554KB) ( 735 )
The parametrizations, VNP and VNP /Vpair , are extracted empirically from nuclear binding energies. The systematics in the VNP and VNP /Vpairchemes, together with elegant regularities of the excitation energies for the ground, β and γ bands for the even-even nuclei in the rare-earth region are reported letter.
Impact-Parameter Dependence of the Electronic Energy Loss of Protons in Solids
WANG Nengping, HUO Yukun, PAN Zhengying, SHAO Qiyun
Chin. Phys. Lett. 1995, 12 (7): 389-392 .  
Abstract   PDF(pc) (205KB) ( 452 )
We calculate the electronic energy loss of the low- and intermidiate-energy proton in collision with a solid atom as a function of the impact-parameter by using the linear-response dielectric theory, the semiclassical approximation and local electron density approximation. The correlation and exchange interaction of the electron gas in solids is taken into consideration by using a local-field-correction dielectric function. With the formalism we also calculate the electronic stopping cross section of protons in solids.
Scattering Window Material: Transparent A12O3 Ceramics and Its Fabrication
LI Yi, SU Xiyu, SONG Lianke, ZHANG Binglin, MENG Xiangsheng
Chin. Phys. Lett. 1995, 12 (7): 393-395 .  
Abstract   PDF(pc) (170KB) ( 383 )
A kind of highly transparent A12O3 ceramics is fabricated in a way of reducing the scattering origins such as the boundary scattering and the facies-difference scattering. The ceramics is a hopeful substitute of the optoelectronic detector windows made of crystalline A12O3 with several advantages such as lower cost, improvement of detecting accuracy and increase of the damage threshold etc.
Dark Solitary-Wave Solutions in Bulk Linear Media with Group Velocity Dispersion
LI Zhonghao, ZHOU Guosheng
Chin. Phys. Lett. 1995, 12 (7): 396-399 .  
Abstract   PDF(pc) (222KB) ( 431 )
A dark envelope solitary-wave solution in bulk dispersive linear media is obtained from the (3+1)-dimensional time-space coupled linear wave equation by taking account of the interplay between physical effects of transverse confinement and group velocity dispersion (GVD) effect under certain appropriate conditions. The characteristics of the solution are discussed in both normal and anomalous GVD regions.
Macro-Experimental Observation of the Staggered Mode in Lattice System
LOU Senyue, YU Jun, LIN Ji, HUANG Guoxiang,
Chin. Phys. Lett. 1995, 12 (7): 400-403 .  
Abstract   PDF(pc) (193KB) ( 410 )
The staggered mode of solitons in polyacetylene which is first discovered by Sun et al. is one of the typical gap soliton studied in lattice system. Using a one dimensional damped and parametrically driven pendulum lattice, we have observed a stable staggered mode which can be explained successfully by a nonlinear Schrödinger equation under the multiple scale approximation.
Triple Plasmon Decay of Electromagnetic Pump Wave
HU Xiwei
Chin. Phys. Lett. 1995, 12 (7): 404-407 .  
Abstract   PDF(pc) (133KB) ( 400 )
A fluid description of the triple plasmon decay process has been provided. The linear and nonlinear analyses suggest that this parameter process will occur very likely at the local area where the plasma density is about nc/9. The analyses with saddle point method of integration indicate also that the triple plasmon decay process is absolutely unstable.
Conformation-Change-Independent Anchoring of Liquid Crystals on Polymer Liquid Crystal Langmuir-Blodgett Films
ZHU Yangming, WEI Yu
Chin. Phys. Lett. 1995, 12 (7): 408-411 .  
Abstract   PDF(pc) (233KB) ( 442 )
The monolayers of a polymer liquid crystal at an air-water interface undergo successive phase transitions caused by conformation changes. In different phases, the polymer liquid crystal Langmuir-Blodgett (LB) films are prepared to align liquid crystals homeotropically. The alignment property of the LB films is independent of the conformational changes of aligning agents.
Quasi-One-Dimensional Organic Polymer Ferromagnet Based on Polaron
FANG Zhong, LIU Zuli, HU Huifang, YAO Kailun*
Chin. Phys. Lett. 1995, 12 (7): 412-415 .  
Abstract   PDF(pc) (204KB) ( 443 )
A new kind of organic polymer ferromagnet based on polaron is proposed. In this kind of polymer, there are no organic free-radicals, which are rather reactive and unstable, instead spins are provided by polarons. Allowing for full lattice relaxation, the system is studied self-consistently by Peierls-Hubbard model. The formation energies of polarons are calculated. The possible ferromagnetism in polymers of this type is demonstrated.
Possible Evidence for Superlocalization on Fractal Network from the Thermopower Data
WANG Xiaobin, JIANG Qing, ZHANG Zhehua, TIAN Decheng
Chin. Phys. Lett. 1995, 12 (7): 416-419 .  
Abstract   PDF(pc) (0KB) ( 360 )
The theory for the thermoelectric power in the variable-range hopping is extended to the fractal regime where the wavefunctions of the electronic states are superlocalized. The thermopower is shown to scale as TD/(D+ ), where D is the fractal dimension and  the superlocalization exponent. Recent thermopower data on doped polyacetylene samples are examined and it is found that their temperature dependence agrees with the present theory. The superlocalization exponent obtained is consistent with existing theory and numerical results. We demonstrate that the data can be regarded as evidence for the superlocalization on fractal network.
Generation of Electron Traps at High Field in Silicon Oxide Films
B. L. Yang, H. Wong, Y. C. Cheng
Chin. Phys. Lett. 1995, 12 (7): 420-423 .  
Abstract   PDF(pc) (216KB) ( 719 )
Temperature dependences of the high-field electron trapping in a SiO2 thin film for temperature ranging from 100 to 423K are investigated. It is found that in the investigated temperature range, when the temperature decreases the effective surface density of the electron traps in the film decreases; the energy levels of the effective electron traps at high field concentrate at very narrow energy range. The thermal generation rate is found to be 1.283x1010/cm2.K and its activation energy is 0.192eV. Based on these results, a model for the electron traps generated at high field in thin oxide is proposed.
Optical Absorption Spectra of Cr3+ and Cr4+ in Sr3Ga2Ge4O14 Garnet Crystals
XU Jun, DENG Peizhen, ZHANG Qiang, GAN Fuxi
Chin. Phys. Lett. 1995, 12 (7): 424-427 .  
Abstract   PDF(pc) (191KB) ( 519 )
Single crystals of Sr3Ga2Ge4O14:Cr are grown by the Czochralski method. The polarized optical absorption spectra of Cr in visible and near-infrared wavelength are presented and analyzed. It is suggested that Cr enters the octahedral and tetrahedral positions as Cr3+ and Cr4+respectively.
Carriers Confinement for Polymer Electroluminescent Devices with Multilayer Structure
MA Yuguang, TIAN Wenjing, XUE Shanhua*, HUANG Jinsong*, LIU Shiyong*, SHEN Jiacong
Chin. Phys. Lett. 1995, 12 (7): 428-430 .  
Abstract   PDF(pc) (151KB) ( 496 )
The polymer electroluminescence (EL) device with PBD as carriers confinement layer yields bright blue emission having intensity of 300cd/m2, in same case the device without PBD layer have luminance only 44 cd/m2. The effect of PBD layer on EL characteristic was studied. The results show that only in EL devices with PBD thick-ness over 30nm, the holes are completely confined in emitting layer. The luminance over 2000cd/m2 can be obtained by inserting an electron injecting layer between the negative electrode and PED to increase the electron injection.
Isotope Fractionation in the Sputtering of 63Cu-65Cu
ZHENG Liping, CUI Fuzhai*
Chin. Phys. Lett. 1995, 12 (7): 431-434 .  
Abstract   PDF(pc) (224KB) ( 424 )
Under 2keV Xe ion bombardment of a 63Cu69.165Cu30.9 isotope mixture, isotope fractionation difference between small and large polar emission angles, δ(15°)-δ(75°), was calculated by use of a dynamic Monte Carlo program. Calculation results show that δ(15°)-δ(75°) is large at both the zero fluence and the high fluence, then it minimizes at a low fluence of 1.6x 1015 ions/cm2 between two fluence limits. An important cause of this minimum is that the surface composition gradient of 63Cu maximiles at the fluence of 1.6x1015 ions /cm2.
Study of Diamond Nucleation on Porous Silicon
BAI Yizhen, WANG Chunlei, JIN Zengsun, LÜ, Xianyi, ZOU Guangtian
Chin. Phys. Lett. 1995, 12 (7): 435-437 .  
Abstract   PDF(pc) (173KB) ( 502 )
Diamond films have been deposited on porous silicon with microwave plasma chemical vapour deposition method. Nucleation density and site have been observed and analyzed by using scanning electron micrography. Experimental results showed that the nucleation density changes with the porosity and the nucleation occurs mostly on the edge of the pores. Reasons of these phenomena are discussed.
Effective ac Conductivity of a Suspension of Charged Particles in Electrolyte Solution by Collocation Method
NI Fusheng, GU Guoqing, CHEN Kangmin
Chin. Phys. Lett. 1995, 12 (7): 438-441 .  
Abstract   PDF(pc) (175KB) ( 444 )
A collocation method is employed to study the effective ac conductivity of a suspension of charged particles in electrolyte solution. The method is very effective over a wide range of particle concentration and no longer restricted to the assumption made by the Rayleigh method that the two phases of a suspension have the same dielectric constants.
An Analyses of Internal Magnetic Field in Moment Actuator
QIU Shuye*, B. M. Gibbs
Chin. Phys. Lett. 1995, 12 (7): 442-444 .  
Abstract   PDF(pc) (184KB) ( 440 )
A medium size moment actuator is decribed. It consists of two parallel identical magnetostrictive rods. Magnetic biases with parallel and series magnetic paths, respectively, are discussed. Analysis for a branch of the parallel magnetic paths is conducted. Conversion coefficients from electrical to mechanical energy for three prototype moment actuators with different magnetic paths are measured to support the analyses for the internal magnetic field of the actuator in theory.
Hawking Evaporation for the 2 + 1 Dimensional Radiating Black Hole
CAI Ronggen, ZHANG Yijun, SU Rukeng,
Chin. Phys. Lett. 1995, 12 (7): 446-448 .  
Abstract   PDF(pc) (96KB) ( 457 )
By using a metric which is a counterpart of four dimensional Vaidya metric, we have investigated the Hawking evaporation of the 2 + 1 dimensional radiating black hole. The Hawking temperature of this radiating black hole is given. In a specific case, our result reduces to that of Banados. Teitelboim and Zanelli’s.
17 articles