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Influence of magnetic current on the ground state entanglement in an isotropic transverse XY chain

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Progress in Natural science:Materials International 2007年第10期17卷 1147-1151页

作者： Liu Dan1,2., Zhang Yong3 and Long Guilu1,2.1. Key Laboratory for Atomic and Molecular Nanosciences, and Department of physics, Tsinghua University, Beijing 100084, {2. 2. Center of Quantum information science and technology, Tsinghua National Laboratory for information science and technology, Beijing 100084, {2. 3. Institute of physics, school of sciences, Beijing University of Posts and Telecommunications, Beijing 100876, {2.) Key Laboratory for Atomic and Molecular Nanosciences and Department of Physics Tsinghua University Beijing 100084 China

We study the ground state entanglement in a three-qubit XY chain under the influence of a magnetization current. It is found that the ground state changes from a W state to a disentangled state as the magnetic field varies. When the Lagrange multiplier λ>3, namely under a strong magnetic current, the ground state holds onto a W state for a large range of the magnetic field strength. A phase transition to the magnetization-current phase occurs under a certain condition.

关键词： Heisenberg-XY chain magnetic-current phase transition.

Large-eddy simulations and vortex structures of turbulent jets in crossflow

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science china({2.,Mechanics & Astronomy) 2007年第1期50卷 118-132页

作者： GUAN Hui1,2.& WU ChuiJie2.1 school of Mechanical and Power Engineering,East china University of {2. and technology,Shanghai 2.02.7,china 2.Research Center for Fluid Dynamics,PLA University of {2. and technology,nanjing 2.1101,china school of Mechanical and Power Engineering East China University of Science and Technology Shanghai China Research Center for Fluid Dynamics PLA University of Science and Technology Nanjing China

Using the method of large-eddy simulation, the 3-dimensional turbulent jets in crossflow with stream-wise and transverse arrangements of nozzle are simulated, emphasizing on the dynamical process of generation and evolution of vortex structures in these flows. The results show that the basic vortex structures in literatures, such as the counter-rotating vortex pair, leading-edge vortices, lee-side vortices, hanging vortices, kidney vortices and anti-kidney vortices, are not independent physical substances, but local structures of the basic vortex structure of turbulent jets in crossflow-the 3-D stretching vortex rings originating from the orifice of the nozzle, which is discovered in this study. Therefore, the most important large-scale structures of turbulent jets in crossflow are unified to the 3-D vortex rings which stretch and twist in stream-wise and swing in transverse directions. We also found that the shedding frequencies of vortex rings are much lower than the one corresponding to the appearance of leading-edge and lee-side vortices in the turbulent jets.

关键词： turbulent jet in crossflow coherent structure large-eddy simulation

Bell violation for the thermal states of an XXZ spin chain with Dzialoshiski-Moriya interaction

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science china({2.,Mechanics & Astronomy) 2010年第11期53卷 2074-2079页

作者： MA XiaoSan 1 & WANG AnMin 2.1 school of Electric Engineering and information,Anhui University of {2.,Maanshan 2.3002.china 2.Department of Modern physics,University of science and {2. of china,Hefei 2.002.,china Anhui University of technology School of Electric Engineering and Information Maanshan China (GRID:grid.440650.3) (ISNI:***) University of science and technology of {2. Department of Modern Physics Hefei China (GRID:grid.59053.3a) (ISNI:***)

The effect of Dzialoshiski-Moriya (DM) interaction on the violation of Bell inequality for thermal states of interacting qubits via a two-qubit XXZ spin chain is *** results imply that the DM interaction and anisotropy taking a large positive value can enhance the Bell violation and improve the threshold temperatures of *** the comparison between the Bell violation and thermal entanglement,we find that the threshold temperatures of thermal entanglement are higher than those of the Bell *** implies that some states are entangled but the Bell inequality is not violated.

关键词： Bell violation threshold temperatures DM interaction

Interactive group decision making procedure based on uncertain multiplicative linguistic preference relations

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Journal of Systems Engineering and Electronics 2010年第3期21卷 408-415页

作者： Zeshui Xu1,2.1.College of Economics and Management,Southeast University,nanjing 2.0096,P.R.china 2.Institute of {2.s,University of {2. and technology of the PLA,nanjing 2.0007,P.R.china College of Economics and Management Southeast University Nanjing 210096 P. R. China Institute of sciences University of Science and Technology of the PLA Nanjing 210007 P. R. China

Group decision making problems are investigated with uncertain multiplicative linguistic preference *** unbalanced multiplicative linguistic label set is introduced,which can be used by the experts to express their linguistic preference information over *** uncertain linguistic weighted geometric mean operator is utilized to aggregate all the individual uncertain multiplicative linguistic preference relations into a collective one,and then a simple approach is developed to determine the experts＇ weights by utilizing the consensus degrees among the individual uncertain multiplicative linguistic preference relations and the collective uncertain multiplicative linguistic preference ***,a practical interactive procedure for group decision making is proposed based on uncertain multiplicative linguistic preference relations,in which a possibility degree formula and a complementary matrix are used to rank the given ***,the proposed procedure is applied to solve the group decision making problem of a manufacturing company searching the best global supplier for one of its most critical parts used in assembling process.

关键词： group decision making uncertain multiplicative linguistic preference relations unbalanced multiplicative linguistic label set consensus degree interaction.

COMBINATION OF PITCH SYNCHRONOUS ANALYSIS AND FISHER CRITERION FOR SPEAKER IDENTIFICATION

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Journal of Electronics(china) 2007年第6期24卷 828-834页

作者： Zeng Yumin Wu Zhenyang school of information {2. and Engineering Southeast University Nanjing 210096 China school of physics and {2. Nanjing Normal University Nanjing 210097 China

A novel text independent speaker identification system is proposed. In the proposed system, the 12.order perceptual linear predictive cepstrum and their delta coefficients in the span of five frames are extracted from the segmented speech based on the method of pitch synchronous analysis. The Fisher ratios of the original coefficients then be calculated, and the coefficients whose Fisher ratios are bigger are selected to form the 13-dimensional feature vectors of speaker. The Gaussian mixture model is used to model the speakers. The experimental results show that the identification accuracy of the proposed system is obviously better than that of the systems based on other conventional coefficients like the linear predictive cepstral coefficients and the Mel-frequency cepstral coefficients.

关键词： Speaker identification Perceptual linear predictive Pitch synchronous analysis Fisher criterion

A computational investigation of boron-doped chromium and chromium clusters by density functional theory

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science china({2.,Mechanics & Astronomy) 2010年第5期53卷 812-817页

作者： GE GuiXian1,JING Qun1 & LUO YouHua2.3 1 Key Laboratory of Ecophysics and Department of physics,Normal College,Shihezi University,Xinjiang 832.03,{2. 2.school of science,East {2. University of science and technology,Shanghai 2.02.7,{2. 3 Institute of Theoretical physics,school of physics and {12. Optoelectronics,Henan University,Kaifeng 475004,{2. Key Laboratory of Ecophysics and Department of physics Normal College Shihezi University Xinjiang 832003 China

The geometries,stabilities and electronic properties of Crn and CrnB(n=2.9) clusters have been systematically investigated by density functional *** results suggest that the lowest energy structures for CrnB clusters can be obtained by substituting one Cr atom in Crn+1 clusters with B *** geometries of CrnB clusters are similar to that of Crn+1 clusters except for local structural *** second-order difference and fragmentation energy show Cr4,Cr6,Cr8,Cr3B,Cr5B and Cr8B cluster are the most stable among these studied *** impurity B increases the stabilities of chromium *** B is doped on the Crn clusters,cluster geometry does dominate positive role in enhancing their *** doped B atom does not change the coupling way of the Cr site in Crn clusters,but breaks the symmetry and the Cr atoms are no longer *** doped B atom increases the total magnetic moments of Crn in most cases.

关键词： Crn and CrnB clusters geometries electronic properties

A generalized mean shift tracking algorithm

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science china({2. sciences) 2011年第11期54卷 2373-2385页

作者： CHEN JianJun 1,4,ZHANG SuoFei 1,AN GuoCheng 2.& WU ZhenYang 1,31 school of information {2. and Engineering,Southeast University,nanjing 2.0096,china 2.Intelligence Engineering Lab,Institute of Software Chinese Academy of {2.s,Beijing 100190,china 3 Key Laboratory of Underwater Acoustic Signal Processing of Ministry of Education,Southeast University,nanjing 2.0096,china 4 nanjing Research Institute of Electronic technology,nanjing 2.0013,china school of information {2. and Engineering Southeast University Intelligence Engineering Lab Institute of Software Chinese Academy of Sciences nanjing Research Institute of Electronic technology

CAMSHIFT algorithm and Comaniciu/Meer algorithm are two fundamental frameworks of mean shift procedure for video target *** paper generalizes the two well-known mean shift tracking algorithms,originally due to Bradski and Comaniciu/Meer.A new general similarity function which defines the distance between the target model and target candidate is employed to calculate the pixel weights and the target *** target size is iteratively estimated and updated based on the zeroth order moment of the pixel *** we prove that both the CAMSHIFT algorithm and the Comaniciu/Meer algorithm can be included in the generalized mean shift tracking *** tracking performances of three mean shift algorithms in the unified framework are shown and compared in the experimental results.

关键词： mean shift CAMSHIFT video target tracking similarity measure

On the interannual variation in spring atmospheric inter-hemispheric oscillation linked to synchronous climate in china

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Progress in Natural science:Materials International 2009年第9期19卷 1125-1131页

作者： Chuhan Lu, Zhaoyong Guan * Key Laboratory of Meteorological Disaster of Ministry of Education and College of Atmospheric sciences, nanjing University of {2. science and technology, nanjing 2.0044, china Key Laboratory of Meteorological Disaster of Ministry of Education and College of Atmospheric sciences Nanjing University of Information Science and Technology Nanjing 210044 China

Based on NCEP/NCAR monthly mean reanalysis data and surface observations of Chinese stations, inter-hemispheric oscillations (IHO) of spring atmospheric mass on an interannual basis in conjunction with the linkage to the synchronous climate over china are studied. Results suggest that the spring IHO exhibits a significant seesaw pattern for air mass at bi-hemispheric mid-high latitudes, with a consistent vertical circulation structure. The EOF decomposition of zonally mean surface pressures without signals of Arctic Oscillation (AO) and Antarctic Oscillation (AAO) indicates that the EOF1 IHO feature is remarkable, with the corresponding time coeficients correlated with the spring IHO index (IIHO) at 0.93; the spring IHO bears a close relation to the synchronous climate in china, showing the surface pressure, temperature and relative humidity over the country to be in good correlation with IIHO; the spring duststorms in Qinghai, Gansu, Shaanxi and Inner Mongolia have bearing on IHO. Positive-phase IIHO promotes the strengthening of the Siberian high, during which zonal winds between 60°E and 150°W show a longitudinal teleconnection structure extending from the Arctic to Antarctica, leading to positive westerly wind anomalies over Asia, affecting the spring climate of china.

关键词： Air mass Inter-hemispheric oscillation (IHO) Spring climate china

Distributed modeling of the beginning and ending dates and durations of limited temperatures over the rugged terrain of Chongqing

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Progress in Natural science:Materials International 2009年第12期19卷 1739-1746页

作者： Xinfa Qiu~a,Guoping Shi~a,Yan Zeng~(b,*),Zongya Bian~a,Jingmei Wei~c a Department of GIS,school of Remote Sensing,nanjing University of {2. science & technology,nanjing 2.0044,china b Jiangsu Institute of Meteorological sciences,nanjing 2.0008,china c Jinling College,nanjing University,nanjing 2.0089,china Department of GIS School of Remote Sensing Nanjing University of Information Science & Technology Nanjing 210044 China Jiangsu Institute of Meteorological sciences Nanjing 210008 China Jinling College Nanjing University Nanjing 210089 China

A physically based empirical model was established for the beginning and ending dates(BED) of limited *** used were daily mean temperatures from 34 conventional stations in the Chongqing region,measured from 1961 to *** this model in combination with the distributed modeling results of monthly mean temperatures,we developed a method for creating a distributed simulation of the BED and durations of limited temperatures in the rugged terrain of *** distribution maps were generated at a resolution of 100×100 m for the BED and durations of the limited temperatures of 0,10,15 and *** suggest that the distributed model is able to successfully reveal the macroscopic trends and local *** the modeled BED,the mean absolute bias error is 0.6-2.4 d. Cross-validation and case-year tests show mean absolute bias errors of 1.3-2.8 d and 0.7-2.5 d,*** shows that the simulation results are consistent with the field *** implies that the simulations are as good as observations,thus providing a viable technique for simulating mountainous heat resources using conventional meteorological data.

关键词： Distributed modeling Chongqing Limited temperature Beginning and ending date