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Scheme for Entanglement Concentration of Unknown Multiparticle Greenberger-Horne-Zeilinger or W Class States

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Communications in Theoretical physics 2007年第12期48卷 1025-1028页

作者： SONG Wei hefei National Laboratory for Physical sciences at Microscale and department of {3. physics,university of science and technology of china,hefei 2.0026,china hefei National Laboratory for Physical sciences at Microscale and department of {3. physics University of Science and Technology of China Hefei 230026 China

We present,two schemes for concentrating unknown nonmaximally entangled Greenberger Horme-Zeilinger(GHZ) or W class *** first scheme for concentrating the nonmaximally entangled GHZ state is based on linearoptical *** second scheme for concentrating the W class states can be applied to a wide variety of atomic *** of our schemes are not postselection ones and are within the current technologies.

关键词： entanglement concentration GHZ class states W class states

A Note on Wigner Functions and *-Genvalue Equation

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Communications in Theoretical physics 2009年第4期51卷 605-608页

作者： JING Si-Cong LIN Bing-Sheng department of modern physics,{3. of science and technology of china,hefei 2.0026,china department of modern physics University of Science and Technology of China Hefei 230026 China

In deformation quantization,static Wigner functions obey functional *-genvalue equation,which is equiv-alent to time-independent Schr■dinger equation in Hilbert space operator formalism of quantum *** equiv-alence is proved mostly for Hamiltonian with form H=（1/2）■;+V（■）[***,***.60（1964）581].In this note we generalize this proof to a very general Hamiltonian H（■,■）and give examples to support it.

关键词： Wigner function *-genvalue equation deformation quantization

Free Volume Changes in γ-Irradiated Polyethylene and Polytetraflourethylene

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Journal of Materials science & technology 2000年第3期16卷 302-304页

作者： Xianyi ZHOU (Dept. of modern physics, university of science and technology of china,{3.027, china) Linhua ZHAI (department of physics, Anhui Normal university, Wuhu 241000, china) Jiangfeng DU and Rongdian HAN (department of modern physics, Univers department of modern physics University of Science and Technology of China Hefei 230027 China department of physics Anhui Normal University Wuhu 241000 China

Positron lifetime spectrum was measured and the change of the free volume was studied for commercial polyethylene (PE) and polytetrafluoroethylene (PTFE) during 7-irradiation processing up to 265 kGy. The free volume size increases but the crystallinity decreases as irradiation dose increases in PE. Both qualities (free volume size and crystallinity) in PTFE display an opposite behavior. The fractional free volume reduces monotonically with increasing irradiation dose in both PE and PTFE. The competition between the crosslinkmg and the splitting decomposition in polymers can be used to understand the free volume changes with irradiation dose.

关键词： PTFE Irradiated Polyethylene and Polytetraflourethylene

Z^+(443.) and Analogous Heavy Flavor States

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原子核物理评论 2009年第S1期26卷 39-43页

作者： DING Gui-jun(department of modern physics,{3. of science and technology of china,hefei 2.0026,china) department of modern physics University of Science and Technology of ChinaHefei 230026China

We have studied Z+(443.)as a D*D1 molecule from the quark model,state mixing effect is considered by solving the coupled channel Schrdinger equation numerically. More precise measurements of Z+(443.)mass and width,partial wave analysis are helpful to understand its structure. If it lies below the D*D1 threshold,molecule interpretation with JP=1-is favored,and JP=0-can not be ruled out. Otherwise Z+(443.)may be a virtual state with JP=2-. The analogous heavy flavor mesons Z+bb and Z++bc are considered as well,and the masses predicted in our model are in agreement with the predictions from the potential model and QCD sum rule.

关键词： nonrelativistic quark model hadronic molecule coupled-channel analysis

A study of two-dimensional magnetic polaron

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science china(physics,Mechanics & Astronomy) 2006年第4期49卷 421-429页

作者： LIU Tao1, ZHANG Huaihong1, FENG Mang1,2 & WANG Kelin1,3.1. School of science, Southwest university of science and {3., Mianyang 62.010, china 2. Wuhan Institute of physics and Mathematics, Chinese Academy of sciences, Wuhan 43.070, china 3. department of modern physics, university of science and technology of china, hefei 2.0026, china School of science Southwest University of Science and Technology Mianyang China Wuhan Institute of physics and Mathematics Chinese Academy of Sciences Wuhan China department of modern physics University of Science and Technology of China Hefei China

By using the variational method and anneal simulation, we study in this paper the self-trapped magnetic polaron (STMP) in two-dimensional anti-ferromagnetic material and the bound magnetic polaron (BMP) in ferromagnetic material. Schwinger angular momentum theory is applied to changing the problem into a coupling problem of carriers and two types of Bosons. Our calculation shows that there are single-peak and multi-peak structures in the two-dimensional STMP. For the ferromagnetic material, the properties of the two-dimensional BMP are almost the same as that in one-dimensional case; but for the anti-ferromagnetic material, the two-dimensional STMP structure is much richer than the one-dimensional case.

关键词： self-trapped magnetic polaron, bound magnetic polaron, impurity potential, anti-ferromagnet.

A STUDY OF OSCILLATING FLOWS OVER PROPAGATING RIPPLES:PART Ⅱ. VORTICITY DYNAMICS

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Journal of Hydrodynamics 2000年第1期12卷 8-15页

作者： Lu Xi yun department of modern Mechanics, university of science and technology of china,{3.026, P.R.china Univ of science and technology of China Hefei China

Vortex shedding for an oscillating flow over ripples is numerically investigated by solving 2 D time dependent incompressible Navier Stokes equations in curvilinear coordinates. The dynamics of vortex structures generated by flow separation is studied in order to understand some phenomena which take place near the bottom and in particular to get insight into the mechanism through which sediment grains are lifted up and maintained in suspension. Based on our calculated results, some important phenomena, such as vortex shedding, vortices pairing, vortices coalescence, vortex interaction with the free shear layer and so on, can be found. The behaviors of energy dissipation in the flow field and of shear stress along the ripple surface are also discussed for studying the dynamics of sediment grains in suspension and to obtain new information on the suspended load over the ripples.

关键词： oscillating flow ripple vorticity dynamics separation flow

DIRECT NUMERICAL SIMULATIONS OF TURBULENT CHANNEL FLOWS WITH CONSIDERATION OF THE BUOYANCY EFFECT OF THE BUBBLE PHASE

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Journal of Hydrodynamics 2011年第3期23卷 282-288页

作者： LIU Nan-sheng CHENG Bao-guo QUE Xia LU Xi-yun department of Modem Mechanics University of Science and Technology of China Hefei 230026 China department of Computer science and technology Hefei University of Technology Hefei 230009 China

Turbulent channel flows with consideration of the buoyancy effect of the bubble phase is investigated by means of the Direct Numerical Simulation （DNS）. This two-phase system is solved by a two-way coupling Lagrangian-Eulerian approach. The Reynolds number based on the friction velocity and the half-width of the channel is 194, and the gravitational acceleration varies from -0.5 to 0.5, ranging from the upflow to the downflow cases. This study aims to reveal the influence of buoyancy on the turbulence behavior and the bubble motion. Some typical statistical quantities, including the averaged velocities and velocity fluctuations for the fluid and bubble phases, as well as the flow structures of the turbulence fluctuations, are analyzed.

关键词： Direct Numerical Simulations (DNS) turbulent bubbly flow upflow/downflow turbulence fluctuations bubble statistics turbulence structures

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

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science china(physics,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 technology,Maanshan 243.02,china 2 {3. of modern physics,university of science and technology of china,hefei 2.0026,china School of Electric Engineering and Information Anhui University of Technology Maanshan China department of modern physics University of Science and Technology of China Hefei China

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

Computation on pipe dynamic response induced by deflagration of H_2 and air mixture

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science china(physics,Mechanics & Astronomy) 2010年第2期53卷 199-208页

作者： ZHANG YaJun,LIU YaDong,ZHANG ZhuHe & XU ShengLi department of modern Mechanics,university of {3. and technology of china,hefei 2.0026,china department of modern Mechanics University of Science and Technology of China Hefei China

Computation is devoted to evaluating structural safety of a heat exchanger inside a reactor whose geometry can be simplified as outer and inner pipes as well as a chamber. This paper has numerically studied deflagration of hydrogen air mixture and pipe dynamic responses. The Navier-Stokes equations coupled with multi-species mass equation are solved by TVD scheme to get flow-field solution based on MPI and multi-block methods. Combustion is described by a 11-species and 23.step reaction model. The source term is treated implicitly to involve species production and depletion. Ignition is approximated by input energy CpT per unit mass in a specified period and zone. Finally,contours of pressure and OH mass fraction at different time pe-riods and pressure histories at fixed points are obtained. When loading is specified as wall pressure,virtual work theorem in Lagrangian frame which describes pipe response is solved by FEM to obtain stress and strain distributions. Results show that shock waves can be generated and reflected on the walls of the chamber and pipes. The shock waves and flame can not be dis-sipated in a narrow gap spanning 2 mm. Meanwhile,stress waves are generated. They propagate outwards on the inner and outer pipe walls. At the gap exit,shock wave diffracts and impacts on the inner pipe walls. Coupled with hot jet from the gap,reignition occurs on the inner pipe wall surfaces. Then,flame catches up the leading shock and shock front deforms into a planar one although the shock front passes through a short divergent section downstream. Also,stress concentrates along the intersected lines among the top,bottom and side walls. This means that the chamber is an easily damaged component. The methods provided in this paper can be used to evaluate structural safety.

关键词： shock wave chemical reaction finite difference method finite element method (FEM)) dynamic response