CORRELATION EFFECTS ON THE GROUNDSTATES OF THREE-ELECTRON QUANTUM DOTS IN A STRONG MAGNETIC FIELD

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SEMICLASSICAL THEORY IN PHASE SPACE FOR MOLECULAR PROCESSES:FORMALISM BASED ON DYNAMICAL CHARACTERISTIC FUNCTION

A new semiclassical theory is formulated by introducing a newdistribution function to be propagated in phase space.primarily this theoryis intended to describe molecular collisions such as chemical reactions,but     

A PATTERN RECOGNITION APPROACH FOR TONE CLASSIFICATION OF ISOLATED SYLLABLE IN PUTONGHUA

In this paper,a new approach of pattern recognition for tone classification of Putonghua Which is im-portant for speech recognition of Putonghua is discribed.In this method,four parameters of the fundamen-tal frequency trajectory are selected based on a large number of statistical experiments.It is assumed thatthe four parameters satisfy multidimensional Gaussion distribution and a non-Euclidean distancefunction for each tone class is derived according to the rule of minimum probability of calssification error.the optimal decision results are obtained in a sense of statistics.It is proved that this method provides verysatisfactory results by the experiments for speaker-independent tone classification of Putonghua.     

GENERALIZED GREEN''''S FUNCTIONS OF SURFACE EXCITATION OF ELASTIC WAVE FIELDS IN A PIEZOELECTRIC HALF-SPACE

Since the generalized Green's functions,which correspond to surface excitation of elastic wavefields in a half-space of piezoelectric crystal,are independent of excitation conditions and only depen-dent on material parameters and orientation,they can be investigated in advance and independently. It is shown that the generalized Green's functions can be written as a sum of three parts repre-senting separately a surface wave,a bulk wave and an electrostatic effect. We also confirm that the surface wave part and the bulk wave part at the far field of the generalizedGreen's functions can be expressed by analytical expressions,and thus,the surface wave field and thefar field of bulk wave among the excited elastic wave fields can be evaluated exactly. Finally,as an example,the generalized Green's functions for the 6 mm crystal are given.     

CONDITIONAL SIMILARITY REDUCTION APPROACH: JIMBO－MIWA EQUATION

The direct method developed by Clarkson and Kruskal (1989 J. Math. Phys. 30 2201) for finding the symmetry reductions of a nonlinear system is extended to find the conditional similarity solutions. Using the method of the Jimbo－Miwa (JM) equation, we find that three well-known (2+1)-dimensional models－the asymmetric Nizhnik--Novikov－Veselov equation, the breaking soliton equation and the Kadomtsev-Petviashvili equation－can all be obtained as the conditional similarity reductions of the JM equation.     

TODA–HEISENBERG CHAIN: INTERACTING σ-FIELDS IN TWO DIMENSIONS

We study a (2 + 1)-dimensional system that can be viewed as an infinite number of O(3) σ-fields coupled by a nearest-neighbour Heisenberg-like interaction. We reduce the field equations of this model to an integrable system that is closely related to the two-dimensional relativistic Toda chain and the Ablowitz–Ladik equations. Using this reduction we obtain the dark-soliton solutions of our model.     

MOVING GRATING AND ITS PHASE SHIFT IN LiNbO_3:Fe CRYSTAL

Spatial phase shift of moving grating in LiNbO_3:Fe crystal iscalculated on the basis of photorefractive dynamic equations.It is shown that themoving grating is a self-established phase grating that generates backward dynamiclight scattering.     

SCIENCE IN CHINA Series G: Physics, Mechanics & Astronomy SUBJECT INDEX TO VOLUME 48 (2005)

A Legendre orthogonal moment based 3D edge operator ................ ZHANG Hui, SHU Huazhong, LUO Limin et al. (1) Scaling of ac susceptibility and the nonlinear response function of high-temperature superconductors ..................... ................................................................................................. CHEN Kaixuan, NING Zhenhua, XU Hengyi et al. (14) The space environment monitor aboard FY-2 satellite....................ZHU Guangwu, LI Baoquan, W…     

RELAMINAR1ZATI0N OF DEVELOPING TURBULENT FLOW IN A 180° CURVED SQUARE CHANNEL: A STUDY BASED ON TEMPERATURE FLUCTUATION MEASUREMENTS

The stabilizing effects of centrifugal forces, for slightly heated airflow in a 180° curved square channel with nearly fully developed entry flow, are studied by temperature fluctuation measurements for Reynolds numbers in the transition range. Re = 2,000–4,500. The relaminarization process is caused by secondary flow due to centrifugal forces. This study confirms the feasibility of using a fine thermocouple (12·7μm) to study flow transition phenomena. The results are presented in both time and frequency domains.