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Pairwise entanglement and local polarization of Heisenberg model

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Science china(Physics,Mechanics & Astronomy) 2008年第10期51卷 1515-1522页

作者： xi xiaoQiang1,2. ZHANG Tao3, YUE RuiHong3,4 & LIU WuMing2.1 Department of Applied Mathematics and Physics, xi’an Institute of Post and Telecommunications, xi’an 710061, china 2.Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, chinese academy of sciences, Beijing 100080, china 3 Institute of Modern Physics, Northwest University, xi’an 710069, china 4 Department of Physics, Ningbo University, Ningbo 3152.1, china Department of Applied Mathematics and Physics Xi’an Institute of Post and Telecommunications Xi’an China Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing China Institute of Modern Physics Northwest University Xi’an China Department of Physics Ningbo University Ningbo China

The characteristics of pairwise entanglement and local polarization (LP) are dis-cussed by studying the ground state (states) of the Heisenberg XX model. The re-sults show that: the ground state (states) is (are) composed of the micro states with the minimal polarization (0 for even qubit and 1/2.for odd qubit); LP and the prob-ability of the micro state have an intimate relation, i.e. the stronger the LP, the smaller the probability, and the same LP corresponds to the same probability; the pairwise entanglement of the ground state is the biggest in all eigenvectors. It is found that the pairwise entanglement is decreased by the state degeneracy and the system size. The concurrence approaches a fixed value of about 0.3412.(for odd-qubit chain) or 0.3491 (for even-qubit chain) if the qubit number is large enough.

关键词： Heisenberg XX model local polarization pairwise entanglement

EPR studies of Mn^(2.) in the Loess Plateau of central china: Implication for variation of the East Asia summer monsoon

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chinese Science Bulletin 1998年第1期43卷 72-75页

作者： CHEN Jun\+1, JI Junfeng\+1, SU Yuanxia\+2.and LU Huayu\+31. Department of Earth sciences, Nanjing University, Nanjing 2.0093, china 2. Center of Material Analysis, Nanjing University, Nanjing 2.0093, china 3. xi’an Laboratory of Loess and Qu Department of Earth sciences Nanjing University Nanjing China Center of Material Analysis Nanjing University Nanjing China xi’an Laboratory of Loess and Quaternary Geology Chinese Academy of Sciences Xi’an China

Mn 2. EPR intensity recorded in the chinese loess_paleosol sequence shows close correlation with magnetic susceptibility and Sr content as well as the oscillation of paleoclimate. Thus Mn 2. EPR signal can serve as an... 详细信息

关键词： paleomonsoon loess paleosol EPR signal of Mn 2.

Anticoagulation property and security of artificial heart valve material

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Science china(Technological sciences) 2005年第2期48卷 145-162页

作者： WANG xianghui1, , LIU xianghuai1,2., 3, ZHANG Feng2. LI Changrong2. YU Liujiang2. ZHENG Zhihong2. WANG xi2. JIANG Zhenbin4, CHEN Anqing4 & XU Jingfang3 1. Department of Physics, East china Normal University, Shanghai 2.0062. china 2. Ion Beam Lab, Shanghai Institute of Mini-system and information,{2.,Shanghai 2.0050, china 3. Department of Electronics, School of Information Science and Technology, East china Normal Univer- sity, Shanghai 2.0062. china 4. Shanghai Cardiovascular Institute, Zhongshan Hospital, Shanghai 2.0032. china Department of Physics East China Normal University Shanghai China Ion Beam Lab Shanghai Institute of Mini-system and information Chinese Academy of Sciences Shanghai China Department of Electronics School of Information Science and Technology East China Normal University Shanghai China Shanghai Cardiovascular Institute Zhongshan Hospital Shanghai China

Heart valve diseases threaten human health. One reliable way to save lives of such patients is to replace the pathologically changed heart valves by artificial ones. Over 2.million patients have received LTI-carbon heart valve’s implantation. However, the thrombosis after the implantation is one of the difficulties that need to be solved. In order to improve the blood compatibility and security of mechanical heart valves, ion beam technology was used to modify the surface properties of the materials. The investigation results have been summarized in this paper.

关键词： artificial heart valve, ion implantation, plasma immersed ion implantation, ion beam enhanced deposition.

Distributions of fatty acids in a stalagmite related to paleoclimate change at Qingjiang in Hubei,southern china

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Science china Earth sciences 2005年第9期48卷 1463-1469页

作者： xiE Shucheng1,HUANG Junhua1,WANG Hongmei2.YI Yi1,HU Chaoyong1, CAI Yanjun3 & CHENG Hai4 1. Faculty of Earth Science,china University of Geosciences,Wuhan 430074,china 2. School of Environmental Studies,china University of Geosciences,Wuhan 430074,china 3. SKLLQG,Institute of Earth Environment,chinese academy of sciences,xi’an 710075,china 4. Department of Geology and Geophysics,University of Minnesota,MN55455,USA Faculty of Earth Science China University of Geosciences Wuhan China School of Environmental Studies China University of Geosciences Wuhan China SKLLQG Institute of Earth Environment Chinese Academy of Sciences Xi’an China Department of Geology and Geophysics University of Minnesota USA

Fatty acids extracted from a subtropical stalagmite at Qingjiang in Southern china’s Hubei Province were analysed using gas chromatography-mass spectrometry. These n-alkanoic acids range from C14 to C2. in carbon number, maximizing at C16, with a second dominance at C2.. In contrast to the stalagmite analysed, the overlying soils are characterized by the dominance of heavy-molecular-weight homologues (>C2.). The n-fatty acids in the stalagmite were proposed to be contributed by both the soil ecosystems and the microbes harboring in the percolating water and the cave. The ratios of unsaturated to saturated n-fatty acids (C16:1i/C16:0, C18:1/C18:0) appear to show trends comparable with the oxygen isotope records of the stalagmite carbonate, with enhanced values associated with the cold episode such as Heinrich event 1. This paleoclimate-dependent record of the n-fatty acids might reflect microbial changes in physiology and activity in response to the temperature. This record shows somewhat difference from the previous paleoclimate signal extracted from n-alkanols and n-alkan-2.ones of the same stalagmite. The acid record fails to document the well-known Younger Dryas event which was effectively shown by the latter two biomarkers derived from soil ecosystems. This discrepancy might result from the changing biogeochemical impact on different lipid fractions as well as the varied organism populations in different ecosystems.

关键词： biomarker, ecosystem, microbe, speleothem, paleoclimate, Quaternary.

Generation of surface electrons in femtosecond laser-solid interactions

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Science china(Physics,Mechanics & Astronomy) 2006年第3期49卷 335-340页

作者： XU Miaohua1, LI Yutong1, YUAN xiaohui1,2. ZHENG Zhiyuan1, LIANG Wenxi1, YU Quanzhi1, ZHANG Yi1, WANG Zhaohua1, WEI Zhiyi1 & ZHANG Jie1 1. Key Laboratory of Optical Physics, Institute of Physics, chinese academy of sciences, Beijing 100080, china 2. State Key Laboratory of Transient Optics Technology, chinese academy of sciences, xi’an 710068, china Key Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing China State Key Laboratory of Transient Optics Technology Chinese Academy of Sciences Xi’an China

The characteristics of hot electrons produced by p-polarized femtosecond laser-solid interactions are studied. The experimental results show that the outgoing electrons are mainly emitted in three directions: along the target surface, the normal direction and the laser backward direction. The electrons flowing along the target surface are due to the confinement of the electrostatic field and the surface magnetic field, while the electrons in the normal direction due to the resonant absorption.

关键词： hot electrons,surface magnetic field,femtosecond laser pulses

Focal plane wave-front sensing algorithm for high-contrast imaging

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Science china(Physics,Mechanics & Astronomy) 2009年第8期52卷 1284-1288页

作者： DOU JiangPei1,2.3,REN DeQing1,2.4,ZHU YongTian1,2.& ZHANG xi1,2.3 1 National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology,chinese academy of {2.,Nanjing 2.0042.china 2.Key Laboratory of Astronomical Optics & Technology,Nanjing Institute of Astronomical Optics & Technology,chinese academy of {2.,Nanjing 2.0042.china 3 Graduate University of chinese academy of sciences,Beijing 100049,china 4 Physics & Astronomy Department,California State University Northridge,18111 Nordhoff Street,Northridge,California 91330-82.8,USA National Astronomical Observatories/Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences Nanjing China Key Laboratory of Astronomical Optics & Technology Nanjing Institute of Astronomical Optics & Technology Chinese Academy of Sciences Nanjing China Graduate University of chinese academy of sciences Beijing China Physics & Astronomy Department California State University Northridge Northridge USA

High-contrast imaging provided by a coronagraph is critical for the direction imaging of the Earth-like planet orbiting its bright parent star.A major limitation for such direct imaging is the speckle noise that is induced from the wave-front error of an optical *** derive an algorithm for the wave-front measurement directly from 3 focal plane *** 3 images are achieved through a deformable mirror to provide specific phases for the optics *** introduce an extra amplitude modulation on one deformable mirror configuration to create an uncorrelated wave-front,which is a critical procedure for wave-front *** simulation shows that the reconstructed wave-front is consistent with the original wave-front theoretically,which indicates that such an algorithm is a promising technique for the wave-front measurement for the high-contrast imaging.

关键词： high-contrast imaging multi-image algorithm speckle nulling technique wave-front sensing

Effects of huperzine A on secretion of nerve growth factor in cultured rat cortical astrocytes and neurite outgrowth in rat PC12.cells

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Acta Pharmacologica Sinica 2005年第6期26卷 673-678页

作者： Li-li TANG, Rui WANG, xi-can TANG~2.State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological sciences, chinese academy of sciences, Shanghai 2.12.3,{2. State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China

Aim: To study the effects of huperzine A (HupA) on neuritogenic activity and the expression of nerve growth factor (NGF). Methods: After being treated with 10 μmol/L HupA, neurite outgrowth of PC 12.cells was observed and counted under phase-contrast microscopy. Mitogenic activity was assayed by [~3H]thymidine incorporation. Cell cytotoxicity was evaluated by lactate dehydrogenase (LDH) release. AChE activity, mRNA and protein expression were measured by the Ellman’s method, RT-PCR, and Western blot, respectively. NGF mRNA and protein levels were determined by RT-PCR and ELISA assays. Results: Treatment of PC 12.cells with 10 渭mol/L HupA for 48 h markedly increased the number of neurite-bearing cells, but caused no significant alteration in cell viability or other signs of cytotoxicity. In addition to inhibiting AChE activity, 10 渭mol/L HupA also increased the mRNA and protein levels of this enzyme. In addition, following 2.h exposure of the astrocytes to 10 渭mol/L HupA, there was a significant up-regula-tion of mRNA for NGF and P75 low-affinity NGF receptor. The protein level of NGF was also increased after 2. h treatment with HupA. Conclusion: Our findings demonstrate for the first time that HupA has a direct or indirect neurotrophic activity, which might be beneficial in treatment of neurodegenerative disorders such as Alzheimer disease.

关键词： huperzine A nerve growth factor neurite outgrowth: acetylcholinesterase inhibitors

Simultaneous Strain and Temperature Measurement with Optical Fiber Gratings: Error Analysis

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chinese Journal of Lasers 2000年第3期9卷 52-57页

作者： JIA Hongzhi LI Yulin (xi’an Institute of Optics & Precision Mechanics, The chinese academy of sciences, xi’an 710068, china) 中科院西安光学精密机械所陕西西安

Many schemes designed to simultaneously measure strain and t emperature with optical fiber grating sensors have been reported in recent years. In this paper, the influence of systematic errors associated with the measurement process is analyzed and the error formulas are derived. The results are applied to a range of techniques that are of current interest in the literature. The performance of these schemes is contrasted with respect to the influence of wavelength measurement error and sensitivity matrix error.

关键词： fiber grating sensors strain measurement temperature measurement error analysis

Nash-equilibrium strategies of orbital TargetAttacker-Defender game with a non-maneuvering target

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chinese Journal of Aeronautics 2024年第10期37卷 365-379页

作者： Yifeng LI xi LIANG Zhaohui DANG School of Astronautics Northwestern Polytechnical UniversityXi’an 710072China Beijing Institute of Astronautical Systems Engineering Beijing 100076China

This study investigates the orbital Target-Attacker-Defender(TAD)game problem in the context of space *** this game,the Attacker and the Defender compete for a Target that is unable to maneuver due to its original mission *** paper establishes three TAD game models based on the thrust output capabilities:unconstrained thrust output,thrust constrained by an upper bound,and fixed thrust *** models are then solved using differential game theory to obtain Nash equilibrium solutions for the game problems,and the correctness and effectiveness of the solution methods are verified through ***,an analysis of the winning mechanisms of the game is conducted,identifying key factors that influence the game’s outcomes,including weight coefficients in payoffs,the maximum thrust acceleration limit,and the initial game *** the unique characteristics of space missions,a specific focus is given to the analysis of the Defender’s initial states in the hovering formation and in-plane circling formation,revealing overall success patterns for defense strategies from these two *** summary,this study provides valuable insights into the control strategies and winning mechanisms of orbital TAD games,deepening our understanding of these games and offering practical guidance to improve success rates in real-world scenarios.

关键词： Target-Attacker-Defender problem Differential game TPBVP Continuous thrust Orbital game