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2001年, 第10卷, 第2期　刊出日期：2001-02-15 上一期    下一期

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HIGHER DIMENSIONAL PAINLEVé INTEGRABLE MODELS FROM THE REAL NONLINEAR EVOLUTION EQUATIONS 阮航宇, 陈一新 2001 (2):  87-96.  doi: 10.1088/1009-1963/10/2/301 摘要 ( 897 )   PDF(269KB) ( 424 )   A conformal invariant asymptotic expansion approach to solve any nonlinear integrable and nonintegrable models with any dimension is proposed. Many new Painlevé integrable models with the same dimension can be obtained at the same time. Taking the (2+1)-dimensional KdV-Burgers (KdVB) equation, (3+1)-dimensional Zabolotskaya-Khokhlov and Kudomtsev-Petviashvili (ZKKP) equation as concrete examples, we obtain some new higher dimensional conformal invariant models with Painlevé property and the approximate solutions of these models. In certain special cases, some of the approximate solutions become exact. 相关文章 | 计量指标

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ADAPTIVE NONLINEAR FEEDBACK CONTROL OF CHAOTIC SYSTEMS BASED ON REDUCED PARAMETER QUADRATIC PREDICTORS 张家树, 万继宏, 肖先赐 2001 (2):  97-102.  doi: 10.1088/1009-1963/10/2/302 摘要 ( 1049 )   PDF(239KB) ( 803 )   An adaptive nonlinear feedback-control method is proposed to control continuous-time chaotic dynamical systems, where the adaptive nonlinear controller acts on only one-dimensional error signal between the desired state and the observed chaotic state of a system. The reduced parameter adaptive quadratic predictor used in adaptive feedback cancellation of the nonlinear terms can control the system to any desired state. Computer simulation results on the Lorenz system are shown to demonstrate the effectiveness of this feedback-control method. 相关文章 | 计量指标

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SUPERSYMMETRIC SU(1|2) GAUDIN MODEL 曹俊鹏, 侯伯宇, 岳瑞宏 2001 (2):  103-108.  doi: 10.1088/1009-1963/10/2/303 摘要 ( 951 )   PDF(259KB) ( 436 )   In this paper, we propose a supersymmetric SU(1|2) Gaudin model and have derived its eigenvalues. We also present the well-defined eigenstates through the quasi-classical limit of the eigenstates in the supersymmetric t-J model. 相关文章 | 计量指标

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BETHE ANSATZ FOR SUPERSYMMETRIC MODEL WITH Uq[osp(1|2)] SYMMETRY 杨文力 2001 (2):  109-112.  doi: 10.1088/1009-1963/10/2/304 摘要 ( 977 )   PDF(200KB) ( 486 )   Using the algebraic Bethe ansatz method, we obtain the eigenvalues of the transfer matrix of the supersymmetric model with Uq[osp(1|2)] symmetry under periodic boundary and twisted boundary condition. 相关文章 | 计量指标

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EXACT SOLUTION FOR EXTENDED ESSLER-KOREPIN-SCHOUTENS MODEL WITH OPEN BOUNDARY CONDITIONS 李广良, 岳瑞宏, 石康杰, 侯伯宇 2001 (2):  113-116.  doi: 10.1088/1009-1963/10/2/305 摘要 ( 900 )   PDF(212KB) ( 375 )   The eigenvalue of the transfer matrix is obtained for the extended Essler-Korepin-Schoutens model with open boundary conditions. The energy of the system and the Bethe equations of the model are given also. 相关文章 | 计量指标

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LEVEL DENSITY AND FINITE-TEMPERATURE SPECIFIC HEAT OF NUCLEUS 104Pd UNDER MICROSCOPIC IBM 石筑一, 刘庸, 桑建平 2001 (2):  117-120.  doi: 10.1088/1009-1963/10/2/306 摘要 ( 1317 )   PDF(208KB) ( 579 )   By using the microscopic sdgIBM-Fmax approach, procedure of canonical ensemble average and saddle point approximation, thermodynamics of nucleus is established under microscopic IBM. Calculations of spectrum, level density and finite-temperature specific heat for the nucleus 104Pd are carried out. The calculated values are coincident with the experimental data reported recently. The results predict that the shape phase transition in ground state band appears at about T≈0.230MeV and the phase transition of thermal excitation mode takes place at T≈0.630MeV for nucleus 104Pd. 相关文章 | 计量指标

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STUDY OF THE FOUR-WAVE MIXING DIFFRACTION EFFICIENCY OF LONGITUDINAL-FIELD MULTIPLE-QUANTUM-WELL PHOTOREFRACTIVE DEVICE GROWN AT LOW TEMPERATURE 陆沅, 李春勇, 张燕峰, 黄绮, 傅盘铭, 张治国, 吕兰斌, 陈宏智, 曲昌智, 汤俊雄 2001 (2):  121-123.  doi: 10.1088/1009-1963/10/2/307 摘要 ( 912 )   PDF(199KB) ( 315 )   We investigate the relationship between the beam intensity and the four-wave mixing diffraction efficiency of longitudinal-field multiple-quantum-well(LMQW) photorefractive device grown at low temperature. The optimum beam intensity is found. We also explain the different mechanisms of the effect of beam intensity on the diffraction efficiency of the LMQW device and the transverse-field MQW device. Some advice on how to improve the diffraction efficiency is given. 相关文章 | 计量指标

CLASSICAL AREAS OF PHENOMENOLOGY

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A NOVEL SCHEME FOR XGM WAVELENGTH CONVERSION BASED ON SINGLE-PORT-COUPLED SOA 张新亮, 黄德修, 孙军强, 刘德明 2001 (2):  124-127.  doi: 10.1088/1009-1963/10/2/308 摘要 ( 1320 )   PDF(251KB) ( 614 )   A novel scheme for wavelength conversion based on cross-gain modulation (XGM) in single-port-coupled semiconductor optical amplifier (SOA), in which the input and output share one port, is brought forward. Experimental results and theoretical analysis show that this scheme can be achieved with simple implementation, high output extinction ratio and large input dynamic range. Based on this novel scheme, 2.5 Gbit/s wavelength up conversion with 12.8 nm span has been demonstrated with the output extinction ratio as high as 15 dB. 相关文章 | 计量指标

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FRACTAL VISCOUS FINGERING AND ITS SCALING STRUCTURE IN RANDOM SIERPINSKI CARPET 田巨平, 姚凯伦 2001 (2):  128-133.  doi: 10.1088/1009-1963/10/2/309 摘要 ( 951 )   PDF(309KB) ( 898 )   Viscous fingering (VF) in random Sierpinski carpet is investigated by means of successive over-relaxation technique and under the assumption that bond radii are of Rayleigh distribution. In the random Sierpinski network, the VF pattern of porous media in the limit M→∞ (M is the viscosity ratio and equals to η2/η1 where η1 and η2 are the viscosities of the injected and displaced fluids, respectively) is found to be similar to the diffusion-limited aggregation (DLA) pattern. The interior of the cluster of the displacing fluid is compact on long length scales when M=1, and the pores in the interior of the cluster have been completely swept by the displacing fluid. For finite values of M such as M≥10, the pores in the interior of the cluster have been only partly swept by the displacing fluid on short length scales. But for values of M in 1f(α) sites have velocites scaling as L-α; and the scaling function f(α) is measured and its variation with M is found. 相关文章 | 计量指标

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STUDY OF THE CORRELATION BETWEEN POWER DEPOSITION OF THE LOWER HYBRID WAVES AND THE HARD X-RAY RADIATION ON HT-7 TOKAMAK 石跃江, 万宝年, 凌必利, 丁伯江 2001 (2):  134-138.  doi: 10.1088/1009-1963/10/2/310 摘要 ( 955 )   PDF(317KB) ( 515 )   A seven-channel NaI(Tl) detector array installed on an HT-7 superconducting tokamak has been used to detect the hard X-ray (Ehν>20keV) emitted from the plasma. The physical mechanism of the lower hybrid waves propagating and absorbed in the plasma is investigated by the measurement of hard X-ray radial profile at different discharge parameters. 相关文章 | 计量指标

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EXPERIMENTAL EVIDENCE OF THE SELF-SIMILARITY AND LONG-RANGE CORRELATIONS OF THE EDGE FLUCTUATIONS IN HT-6M TOKAMAK 王文浩, 俞昌旋, 闻一之, 许宇鸿, 凌必利, 龚先祖, 刘保华, 万宝年 2001 (2):  139-144.  doi: 10.1088/1009-1963/10/2/311 摘要 ( 1073 )   PDF(280KB) ( 500 )   To better understand long-time-scale transport dynamics, the rescaled range analysis techniques, the autocorrelation function (ACF) and the probability distribution function (PDF) are used to investigate long-range dependences in edge plasma fluctuations in HT-6M tokamak. The results reveal the self-similar characters of the electrostatic fluctuations with self-similarity parameters (Hurst exponent) ranging from 0.64 to 0.79, taking into consideration the {\vec E}r×{\vec B} rotation-sheared effect. Fluctuation ACFs of both the ion saturation current and the floating potential, as well as PDF of the turbulence-induced particle flux, have two distinct time scales. One corresponds to the decorrelation time scale of local fluctuations (μs) and the other lasts to the order of the confinement time (ms). All these experimental results suggest that some of the mechanisms of the underlying turbulence are consistent with plasma transport as characterized by self-organized criticality(SOC). 相关文章 | 计量指标

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POSITRON ANNIHILATION STUDY ON SURFACE STRUCTURE OF BIOLOGICAL SAMPLES IMPLANTED BY IONS WITH LOW ENERGY 陆挺, 郁伟中, 周宏余, 朱光华, 汪新福, 王超 2001 (2):  145-147.  doi: 10.1088/1009-1963/10/2/312 摘要 ( 1092 )   PDF(181KB) ( 703 )   The organic materials of biological samples, such as lima bean and peanut, were implanted respectively by nitrogen ions with an energy of 100 keV and vanadium ions with an energy of 200 keV. The positron annihilation lifetime spectra of implanted and non-implanted samples were compared with each other especially in τ3 and I3. The experimental results showed that before implantation there were many small holes with diameters of 0.48 and 0.7 nm respectively in lima bean and peanut. After ion implantation, the size of holes would be changed because of organism cross linking and scission. The effective penetration range of implantation of ions with low energy into biological samples is about 200μm. 相关文章 | 计量指标

CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES

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EFFECT OF ZnFe22O4 DOPING ON THE OPTICAL PROPERTIES OF TiO2 THIN FILMS 李广海, 吴玉程, 张立德 2001 (2):  148-151.  doi: 10.1088/1009-1963/10/2/313 摘要 ( 1098 )   PDF(183KB) ( 1131 )   Amorphous TiO2 thin films and ZnFe2O4 doped TiO2 composite films were deposited by radio frequency magnetron sputtering. The effect of ZnFe2O4 doping on the optical properties of TiO2 thin films was reported. Our results show that the absorption edge of TiO2 thin films and composite films exhibits a blue shift with decreasing annealing temperature. The absorption edge of composite films has moved to visible spectrum range, and a very large red shift occurs in comparison with TiO2 thin film. An enhanced photoluminescence in ZnFe2O4 doped anatase TiO2 thin film at room temperature was observed. 相关文章 | 计量指标