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Multipartite Entanglement in Heisenberg Model

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Communications in Theoretical Physics 2008年第6期49卷 1449-1452页

作者： ren Jie zhu Shi-Qun School of Physical Science and Technology Suzhou University Suzhou 215006 China

The effects of anisotropy and magnetic field on multipartite entanglement of ground state in Heisenberg XY model are investigated. The multipartite entanglement increases as a function of the inverse strength of the external field when the degree of anisotropy is finite. There are two peaks when the degree of anisotropy is γ=±1. When the degree of anisotropy increases further, the multipartite entanglement will decrease and tend to a constant. The threshold of the inverse strength of the external field for generating multipartite entanglement generally decreases with the increasing of qubits.

关键词： multipartite entanglement ground state Heisenberg model

Attack-Induced Entanglement of Noninteracting Fermi Gas

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Communications in Theoretical Physics 2008年第6期49卷 1439-1442页

作者： ren Jie zhu Shi-Qun School of Physical Science and Technology Suzhou University Suzhou 215006 China

The bipartite entanglement in Fermi gas without interaction is investigated when there ace three fermions in the system. The negativity and the yon Neumann entropy are employed to measure the entanglement of the system. The position of the third fermion can affect the entanglement between the first and the second fermions. The entanglement can be enhanced or suppressed when the third fermion changes its position. When the two fermions are at the same position or when their distance is more than 2.0/kF, the third fermion cannot affect them.

关键词： Fermi gas entanglement entropy

Structural topology optimization under stationary random base acceleration excitations

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Chinese Journal of Aeronautics 2019年第6期32卷 1416-1427页

作者： fei HE Hongqiang LIAO Jihong zhu Zhongze GUO Institute of Systems Engineering China Academy of Engineering PhysicsMianyang 621900China State IJR Center of Aerospace Design and Additive Manufacturing Northwestern Polytechnical UniversityXi’an 710072China

Structural topology optimization subjected to stationary random base acceleration excitations is investigated in this paper. In the random response analysis, the Large Mass Method(LMM) which attributes artificial large mass values at each driven nodal Degree Of Freedom(DOF) to transforming the base acceleration excitations into force excitations is proposed. The Complete Quadratic Combination(CQC) which is commonly used to calculate the random responses in previous optimization has been proven to be computationally expensive especially for large-scale problems. In order to conquer this difficulty, the Pseudo Excitation Method(PEM) and the combined method of PEM and Mode Acceleration Method(MAM) are adopted into the dynamic topology optimization, and random responses are calculated using these two methods to ascertain a high efficiency over the CQC. A density-based topology optimization method minimizing dynamic responses is then formulated based on the integration of LMM and PEM or the combined method of PEM and MAM. Numerical examples are presented to verify the accuracy of the proposed schemes in dynamic response analysis and the quality of the optimized design in improving dynamic performance.

关键词： Dynamic response Large mass method Mode acceleration method Pseudo excitation method Random base acceleration excitations Topology optimization

Modeling of Strip Heating Process in Vertical Continuous Annealing Furnace

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Journal of Iron and Steel Research International 2012年第5期19卷 29-36页

作者： WAN fei WANG Yong-qin QIN Shu-ren The State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqing 400044China

The mechanism for heat transfer of radiation is usually adopted to heat strip in vertical continuous annealing furnace. The rate of heat transfer among strip and other objects can be hugely affected by the parameters of strip speed, geometry factors and radiating characteristic of surfaces of strip, radiating tubes and walls of furnace. A model including all parameters is proposed for calculating the heat transfer coefficient, predicting the strip tempera- ture and boundary temperature of strip through analyzing these parameters. The boundary temperature is a important datum and different from average arithmetic value of temperature of strip and temperature in furnace. Also, the model can be used to analyze the relation for temperature of strip and heat transfer coefficient, total heat transfer quantity and heating time. The model is built by using the radiating heat transfer rate, the Newtonrs law of cooling, and lumped system analysis. The results of calculation are compared to the data from production line. The comparisons indicate that the model can well predict the heating process. The model is already applied for process control in pro- duction line. Also, this research will provide a new method for analyzing the radiation heat transfer.

关键词： vertical continuous annealing furnace (VCAF) radiation tube section (RTS) radiation heat transfer heat transfer coefficient heat transfer rate

Modeling of Strip Temperature in Rapid Cooling Section of Vertical Continuous Annealing Furnace

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Journal of Iron and Steel Research International 2012年第11期19卷 27-32页

作者： WAN fei WANG Yong-qin QIN Shu-ren State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqing 400044China Baosteel Engineering and Technologies Group Co Ltd Shanghai 201900China

The strip temperature is affected by many factors in rapid cooling section （RCS） of the vertical continuous annealing furnace （VCAF）. They can he divided into four types： the physical properties of cooling gas, the geometry characteristics of configuration of cooling equipment, the heat transfer between the strip and the cooling gas, and the conductivity of the strip. It aims to model the strip temperature in the cooling section based on the fundamental heat transfer theory and the four aspects factors. The model for transient Nusselt number is obtained by considering Reynolds number, Prandtl number and geometry characteristics of RCS. Then cooling model of the strip transient temperature is built by Nusselt number, heat transfer coefficient and heat conductivity of the strip. The results are compared with the data from production line. The comparisons indicate that the model can well predict cooling temperature of the strip. It is hoped that the proposed model can be used for design and control of the vertical continuous annealing furnace.

关键词： rapid cooling jet impinging convection heat transfer coefficient

Accessibility and Homology Bounded Strong Unstable Foliation for Anosov Diffeomorphisms on 3-torus

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Acta Mathematica Sinica,English Series 2017年第1期33卷 71-76页

作者： Yan ren Shao Bo GAN Peng fei ZHANG School of Mathematical Sciences Peking University Department of Mathematics and Statistics Universityof Massachusetts

We give three equivalent conditions for non-accessibility of an Anosov diffeomorphism on the 3-torus with a partially hyperbolic splitting. Since accessibility is an open property, this gives a negative answer to Hammerlindl＇s question about homology boundedness of strong unstable foliation. Keywords Partially hyperbolic, accessible, homology bounded

关键词： Partially hyperbolic accessible homology bounded

Limiting Case of 1D Delta Anyon Model

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Communications in Theoretical Physics 2008年第12期50卷 1265-1268页

作者： zhu ren-Gui WANG An-Min College of Physics and Electronic Information Anhui Normal University Wuhu 241000 China Department of Modern Physics University of Science and Technology of China Hefei 230026 China

In order to analyze a limiting case of the 1D delta anyon model,the coupling strength of the δ interactionc is modified to become a function of the anyonic parameter κ.A pedagogic derivation of the solution for this modifiedmodel using the method of anyon-boson mapping plus Bethe ansatz is *** limiting case as κ→π andsimultaneously c→0,which was previously neglected,is *** unexpected properties of this limiting case *** BAEs are compared with previous results.

关键词： anyon Bethe ansatz

A new test on the conditional capital asset pricing model

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Applied Mathematics(A Journal of Chinese Universities) 2015年第2期30卷 163-186页

作者： LI Xia-fei CAI Zong-wu ren Yu Wang Yanan Institute for Studies in Economics The MOE Key Lab of Econometrics and Fujian Key Lab of Statistical Sciences Xiamen University Department of Economics University of Kansas

Testing the validity of the conditional capital asset pricing model （CAPM） is a puzzle in the finance literature. Lewellen and Nagel[14] find that the variation in betas and in the equity premium would have to be implausibly large to explain important asset-pricing anomalies. Unfortunately, they do not provide a rigorous test statistic. Based on a simulation study, the method proposed in Lewellen and Nagel[14] tends to reject the null too frequently. We develop a new test procedure and derive its limiting distribution under the null hypothesis. Also, we provide a Bootstrap approach to the testing procedure to gain a good finite sample performance. Both simulations and empirical studies show that our test is necessary for making correct inferences with the conditional CAPM.

关键词： Asset pricing model bootstrap test conditional CAPM large sample theory

Anomalously Large Deformation in Some Medium and Heavy Nuclei

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Communications in Theoretical Physics 2005年第4X期44卷 687-696页

作者： CHEN Ding-Han ren Zhong-Zhou TAI fei Department of Physics Nanjing University Nanjing 210008 China Center of Theoretical Nuclear Physics National Laboratory of Heavy-Ion Accelerator at Lanzhou Lanzhou 730000China

We investigate the properties of the Ce isotopes with neutron number N =60 - 90 and the properties of the heavy nuclei near 242Am within the framework of deformed relativistic mean-field （RMF） theory. A systematic comparison between theoretical results and experimental data is made. The calculated binding energies, two-neutron separation energies, and two-proton separation energies are in good agreement with experimental ones. The variation trend of experimental quadrupole deformation parameters on the Ce isotopes can be approximately reproduced by the RMF model. It is found that there exists an abnormally large deformation in the ground state of proton-rich Ce isotopes. This phenomenon can be the general behavior of proton-rich nuclei on the neighboring isotopic chains such as Nd and Sin isotopes. For the heavy nuclei near ^242 Am the properties of the ground state and superdeformed isomeric state can be approximately reproduced by the RMF model. The mechanism of the appearance of anomalously large deformation or superdeformation is analyzed and its influence on nuclear properties is discussed. Parther experiments to study the anomalously large deformation in some proton-rich nuclei are suggested.

关键词： superdeformation proton-rich Ce nuclei isomeric state of ^242Am constraint relativistic meanfield calculation