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Volume 14 Issue 1
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Original Articles
New Symmetry Constraints of the Modified Kadomtsev-Petviashvili Equation
LOU Sen-yue, CHEN Li-li, WU Qi-xian
Chin. Phys. Lett. 1997, 14 (1): 1-4 .  
Abstract   PDF(pc) (182KB) ( 426 )
Using the inner parameter dependent symmetry constraints of the modified Kadomtsev-Petviashvili equation, we get an integrable (2 + 1)-dimensional multi-component Burgers and a (2 + 1)-dimensional integrable extensions of the derivative nonlinear Schrödinger equation.
General Deformed Oscillators
PAN Feng, DAI Lian-rong
Chin. Phys. Lett. 1997, 14 (1): 5-8 .  
Abstract   PDF(pc) (157KB) ( 383 )
General deformed oscillators are studied. Unitary representations of the corresponding boson algebra are discussed. Many interesting properties of the spectra and matrix elements of the boson algebra are also presented.
Quantum Radiative Correction on the Mass of Electron in a Cavity
NI Guang-jiong, CHEN Su-qing
Chin. Phys. Lett. 1997, 14 (1): 9-12 .  
Abstract   PDF(pc) (158KB) ( 361 )
When an electron is moving through a cavity, its mass is modified due to the boundary effect on the virtual photon. The shift of self energy is calculated at the one loop level by means of Plana formula to yield analytical result.
Accessing the Final-State Interactions in the Semi-inclusive Two-Pion Annihilation at the Future Tau-Charm Factory
YANG Jian-jun, LU Wei, LI Guang-lie,
Chin. Phys. Lett. 1997, 14 (1): 13-16 .  
Abstract   PDF(pc) (165KB) ( 336 )
Measuring the single spin asymmetry for the inclusive almost back-to-back two-pion production by electron-positron annihilation to access the corresponding final-state interactions is suggested. Such an experiment will be a spin-off of the future high luminosity Tau-Charm Factory. On the basis of the positivity of the photon fragmentation tensor, an upper bound is derived to the single spin asymmetry suggested.
Superdeformed Bands in 167Lu and 171Ta
WU Xiao-guang, YANG Chun-xiang, ZHENG Hua, LIU Xiang-an, SHEN Cai-wan, CHEN Yong-shou, MA Ying-jun, LU Jing-bin, WEN Shu-xian, LI Guang-sheng, LI Sheng-gang, YUAN Guan-jun, WENG Pei-kun, LIU Yun-zuo
Chin. Phys. Lett. 1997, 14 (1): 17-19 .  
Abstract   PDF(pc) (165KB) ( 473 )
High spin states of the odd-proton nucleus 167Lu have been studied via 152Sm(19F, 4n)167Lu reaction at 87MeV beam energy. A weakly populated new rotationa1 band has been observed and assigned as i13/2 proton 1/2+[660] band. This new band and the 1/2++[660] band in 171Ta from the early work are classified as superdeformed bands with triaxiality.
Inherent Nodal Structures of the Wavefunctions of a 4-Boson System
BAO Cheng-guang
Chin. Phys. Lett. 1997, 14 (1): 20-23 .  
Abstract   PDF(pc) (204KB) ( 431 )
The effect of a kind of nodal surfaces originated from the inherent symmetry on a 4-boson system has been investigated. It was found that these surfaces determine the accessibility of specific geometric structures.
Dependence of Dilepton Production in the Baryon-Rich Quark-Gluon Fireball on the Initial Temperature
HE Ze-jun, ZHANG Jia-ju, QIU Xi-jun
Chin. Phys. Lett. 1997, 14 (1): 24-27 .  
Abstract   PDF(pc) (231KB) ( 410 )
In the study of dilepton production of a baryon-rich quark-gluon fireball based on the full stopping scenario via a relativistic hydrodynamic model, it is found that for the fixed initial baryon chemical potential with increasing initial temperature a peak indicating the formation of the baryon-rich quark-gluon matter appears in the total dilepton yield.
Shear Stress Distribution in the Vicinity of Tilting Disk Heart Valve Model
SUN Yong-da
Chin. Phys. Lett. 1997, 14 (1): 28-31 .  
Abstract   PDF(pc) (368KB) ( 563 )
The visualizations of pulsatile flows through tilting disk heart valve models were completed by means of the technique of the dynamic flow birefringence. The distribution of the fluid shear stresses in the near vicinity of heart valve model.
A Phase-Perturbation Technique for Light Scattering from Randomly Dielectric Rough Surfaces
ZHANG Xiang-dong, WU Zhen-sen, WU Cheng-ke
Chin. Phys. Lett. 1997, 14 (1): 32-35 .  
Abstract   PDF(pc) (169KB) ( 362 )
With the theory of rough surfaces scattering, a numerical formula for calculating the bistatic and backscattering radar cross section from randomly dielectric rough surfaces is derived by using phase-perturbation technique. The backscattering laser radar cross sections per unit of some rough samples are computed at λ = 1.06μm. The numerical results are in good agreement with experimental data.
Mutually Pumped Phase-Conjugate Mirror : Two Arches Configuration
ZHANG Liang-min, SHAO Zong-shu, ZHANG Jing-wen, CHEN Jun, MU Xiao-dong, CHEN Huan-chu, JIANG Min-hua
Chin. Phys. Lett. 1997, 14 (1): 36-39 .  
Abstract   PDF(pc) (259KB) ( 393 )
A mutually pumped phase conjugator with a novel photorefractive crystal of copper-doped potassium sodium strontium barium niobate is reported, in which both incoherent beams are incident upon the negative c face and they travel in geometric paths similar to the outline of two arches. The maximum reflectivity attains 21%. The tolerance of the output to both incident angles and positions is assessed. No apparent cross talk is observed. A cross-readout mechanism is also used to explain phase-conjugate reflectivity production. It is verified that the configuration can be realized easily for a crystal with two longer a sides.
Extension of Harmonic Order by Applying the Interference of Pulses
HU Su-xing, XU Zhi-zhan, HAN Shen-sheng
Chin. Phys. Lett. 1997, 14 (1): 40-43 .  
Abstract   PDF(pc) (268KB) ( 373 )
A method is suggested to extend the order of harmonic generation from gas target by applying the interference effect of two pulses of which one is delayed with odd multiples of half-period relative to the other. It means the laser-atom interaction time can be shortened and the saturation intensity of laser-atom interaction is improved so that the atom can emit more higher-order harmonic. With the suggestion, one can extend the harmonic to the plateau cut-off predicted by harmonic generation theory. The numerical simulation gives some insights on this method.
A Bipartition Model with Single-Scattering Approximation for the Calculations of Reflection of Energetic Ions from Surfaces
HOU Qing, TENG Li-jian, LUO Zheng-ming
Chin. Phys. Lett. 1997, 14 (1): 44-46 .  
Abstract   PDF(pc) (174KB) ( 364 )
A bipartition model for ion transport in solids has been presented. Unlike the earlier bipartition model, a single-scattering approximation has been adopted and angular correlation of energy transfer has been partly taken into account. By the present bipartition model, the reflection coefficients and energy spectrum of reflected ions have been calculated. The results show that the present bipartition model gives better descriptions of reflection although it is simpler in calculation than the earlier bipartition model.
Energy Confinement for Reversed Field Pinch Plasma in Experiment of SWIP-RFP Device
LI Qiang, LUO Cui-wen, ZHANG Peng, LI Jie-ping, YI Ping, ZHAO Chang-lin, XUE Jun
Chin. Phys. Lett. 1997, 14 (1): 47-50 .  
Abstract   PDF(pc) (215KB) ( 531 )
The energy confinement of reversed field pinch (RFP) plasmas on SWIP-RFP device is studied, the energy confinement time is quantitatively calculated. The results show that the resistive toroidal voltage is about 50V and the energy confinement time is about 45μs for a better discharge. It is consistent with the scaling results of the RFP devices.
Diffusion of Ion Implanted As in Si1-xGex Epilayers
ZOU Lü-fan, WANG Zhan-guo, SUN Dian-zhao, FAN Ti-wen, LIU Xue-feng, ZHANG Jing-wei
Chin. Phys. Lett. 1997, 14 (1): 51-54 .  
Abstract   PDF(pc) (244KB) ( 355 )
Diffusion of implanted As ion in relaxed Si1-xGex was studied as a function of Ge content over a wide range of Ge fractions (0-43%) and annealing temperature, and was compared to diffusion in Si. Experimental results showed that the As diffusion is enhanced with increasing annealing temperature for certain Ge content and strongly dependent on the higher Ge content and the faster As diffusion.
Unibond Synthesis of Silicon on Insulator Material
ZHANG Miao, ZHU Shi-yang, LI Jin-hua, NI Ru-shan, LIN Cheng-lu
Chin. Phys. Lett. 1997, 14 (1): 55-58 .  
Abstract   PDF(pc) (274KB) ( 610 )
High quality silicon on insulator (SOI) materials have been successfully produced using the unibond method, a new member of SOI technology. The quality of SOI samples has been investigated by using cross-section transmission electron microscopy, Rutherford backscattering and channeling spectrometry and spreading resistance probe technology. Experimental results indicate that both the thickness uniformity and the crystalline quality of the top Si layer are good. The interface between the top Si layer and SiO2 buried layer is very sharp and straight.

Effect of 2s Orbitals on the Electronic Hopping in Polyacetylene
TONG Guo-ping
Chin. Phys. Lett. 1997, 14 (1): 59-62 .  
Abstract   PDF(pc) (174KB) ( 564 )
The extended Wannier function constructed by hydrogen-like atom wave function is used to calculate the electronic hopping and the density of the states of trans-polyacetylene with a single-chain planar structure. In this technique 2s and 2pz orbitals are taken into account. The computed result shows that the electronic hopping interactions, especially non-neighbor hopping, are considerably affected by 2s orbitals, which are able not only to narrow the energy bandwidth and the gap but also to weaken the nearest neighbor hopping slightly and to enhance the non-neighbor hopping greatly.
Influence of Strong Electron-Electron Interaction on the Peierls Transition
HU Lian, K.Y. Szeto, SUN Xin
Chin. Phys. Lett. 1997, 14 (1): 63-66 .  
Abstract   PDF(pc) (235KB) ( 362 )
The influence of short-ranged Coulomb repulsion of strongly correlated electrons on the Peierls transition for a quasi-one-dimensional system is investigated. It shows that the influence varies with the band filling and proves that the condition of single-occupation leads to a singularity on the density of states at half-filling which enhances dimerization. It also shows that dimerization is suppressed by the increase of U in the region of large-U and proves that increasing nearest-neighbor interaction V will suppress the Peierls transition temperature at half-filling, and strongly enhance it for band-filling at n ≈ 1/4, which means the enhancement of tetramer-ization for a quarter-filled band.
Multiple Non-exponential Decay of Photo-induced Excess Electrons in Heterostructures
HE Li-xiong
Chin. Phys. Lett. 1997, 14 (1): 67-70 .  
Abstract   PDF(pc) (234KB) ( 391 )
The derivative -dN(t)/dlgt of photo-induced excess electrons N(t) in GaAs-Al0.3 Ga0.7As and In0.15Ga0.85As-Al0.2Ga0.8As heterostructures with respect to 1gt shows a spectrum with pronounced peak-structure. The apparent capture energies, the lifetime prefactors, the apparent lifetime distribution, and the derivative decay quantities of individual lifetimes were analyzed to distinguish capture mechanisms.
Light Emitting Diode Based on Tb(AcAc)3Phen
CHEN Li-chun, WANG Xiang-jun, ZHANG Ruo-hua, DENG Zhen-bo, YAO Jian-quan, Jennifer Carter
Chin. Phys. Lett. 1997, 14 (1): 71-73 .  
Abstract   PDF(pc) (168KB) ( 473 )
A diode with Tb(AcAc)3Phen as the emitting layer and PPV, Alq3 as the hole and electron transporting layers was demonstrated. The emission of the diode had the unique line spectrum of pure Tb3+. The injected electron and hole recombination region was discussed.
Flexible Blue Light Emitting Diodes Made from Dye Doped Poly (N-Vinylcarbazole) with Multilayer Structure
CHEN Bai-jun, HOU Jing-ying, HUANG Jing-song, LIU Shi-yong
Chin. Phys. Lett. 1997, 14 (1): 74-76 .  
Abstract   PDF(pc) (157KB) ( 586 )
Flexible blue light emitting diodes (LEDs) were fabricated by using poly(N-vinylcarbazole) (PVK) doped with high fluorescence dye, 1, 1, 4, 4-tetraphen1-1,3-butadiene (TPB), as a emitter layer, a layer of tris(8-quinolino1ato)aluminum (Ⅲ) (Alq3) as an electron-transporting layer,and a layer of 2-(4-biphenylyl)-5-(4-tertbutypheny)-1-3,4-oxadiazole (PBD) as hole-blocking layer; a cell structure of flexible substrate/indium-tin-oxide /PVK:TPB/PBD/Alq3/Al was employed. In this cell structure, carrier injection from the electrodes to the doped PVK layer and concomitant electroluminescence from doped PVK were observed at room temperature with dcbias voltage of 4V. Blue emission peaks at about 465nm. This kind of LED is about 200μm thick and can be curled or bent repeatedly at sharp angles without failure.

On the Discrepancy of Coronal Magnetic Fields in Solar Optics and Radio
MA Yue-hua, LI Xiao-qing
Chin. Phys. Lett. 1997, 14 (1): 77-80 .  
Abstract   PDF(pc) (185KB) ( 322 )
The discrepancy on the coronal magnetic field between solar optics and radio is analysed by using magnetic fibril concept with filling factor and fractal structure model. The magnetic field of about 100 G considered in solar optics is the mean value in a large scale, and that of about 1000 G in solar radio should be the value of fine structures inside “macro” loop.

21 articles