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Particle tunnels across the horizon of Garfinkle-Horowitz-Strominger dilaton black hole

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Science China(physics,Mechanics & Astronomy) 2007年第5期50卷 601-610页

作者： FANG HengZhong1 & ZHAO Zheng2.1 department of physics, China{2. of Petroleum, Dongying 2.7061, China 2.department of physics, Beijing Normal{2., Beijing 100875, China department of physics China University of Petroleum Dongying 257061 China department of physics Beijing Normal University Beijing 100875 China

We promote the work of Parikh and Wilczek on the black hole radiation to the emission of massive and charged particles from Garfinkle-Horowitz-Strominger black hole. The energy and charge of the space-time are conservational during the course of the evaporation. The calculation shows that the emission spectrum is not precisely thermal, while has a correction, and the conclusion supports the view- point of information conservation.

关键词： Hawking radiation, black body spectrum, barrier, information loss, entropy of black hole, Komar energy

Boundary element-free method for elastodynamics

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Science China(physics,Mechanics & Astronomy) 2005年第6期48卷 641-657页

作者： CHENG Yumin1 & PENG Miaojuan2.1. Shanghai Institute of Applied Mathematics and Mechanics, Shanghai university, Shanghai 2.0072. China 2. department of Civil Engineering, Shanghai university, Shanghai 2.0072. China 1. Shanghai Institute of Applied Mathematics and Mechanics Shanghai University 200072 Shanghai China 2. department of Civil Engineering Shanghai University 200072 Shanghai China

The moving least-square approximation is discussed first. Sometimes the method can form an ill-conditioned equation system, and thus the solution cannot be obtained correctly. A Hilbert space is presented on which an orthogonal function system mixed a weight function is defined. Next the improved moving least-square approximation is discussed in detail. The improved method has higher computational efficiency and precision than the old method, and cannot form an ill-conditioned equation system. A boundary element-free method (BEFM) for elastodynamics problems is presented by combining the boundary integral equation method for elastodynamics and the improved moving least-square approximation. The boundary element-free method is a meshless method of boundary integral equation and is a direct numerical method compared with others, in which the basic unknowns are the real solutions of the nodal variables and the boundary conditions can be applied easily. The boundary element-free method has a higher computational efficiency and precision. In addition, the numerical procedure of the boundary element-free method for elastodynamics problems is presented in this paper. Finally, some numerical examples are given.

关键词： moving least-square approximation, improved moving least-square approximation, elastodynamics, boundary integral equation, meshless method, boundary element-free method, Fourier eigen transform.

Quantum explanation for time phase relations in radiation of the plasma induced by laser ablating aluminum

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原子与分子物理学报 2001年第3期18卷 265-268,272页

作者： LI Zun ying 1 , SONG Yi zhong 2.(1.department of physics, Linyi Teachers{2. ZIP:2.6005 2. Biomaterials Lab, department of materiel science, the southern zone, Shandong{2.) 临沂师范专科学校山东 276005 山东大学山东

According to time distribution of Al Ⅰ396.15 nm emission in the plasma induced by laser ablating Aluminum, based on quantum mechanics, we have suggested a hypothesis of transient steady state of atom, which could give our experimental results overall and reasonable explanation in quantum. We suggested that there should be a certain atomic state between ground and excited state of Aluminum atom, so called transient steady state. The transient steady state was that aluminum atom had already absorbed a certain photon, but the valence electron had not transited to external orbit. That is to say, aluminum atom had not transited into excited state, but changed into a certain state called transient steady state between ground and excited state. Seen from the point of atomic energy level, the transient steady state is identical to the level of excited state. The transient steady state was one of the most important models storing energy. The hypothesis could roundly and reasonably explain our experimental results.

关键词：铝激光烧蚀激光诱导时间分辨光谱等离子体

Electro-mechanical response of functionally graded beams with imperfectly integrated surface piezoelectric layers

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Science China(physics,Mechanics & Astronomy) 2006年第5期49卷 513-525页

作者： YAN Wei1 & CHEN Weiqiu1,2.1. department of Civil Engineering, Zhejiang university, Hangzhou 31002., China 2. State Key Lab of CAD & CG, Zhejiang university, Hangzhou 31002., China 1. department of Civil Engineering Zhejiang University Hangzhou 310027 China 2. State Key Lab of CAD & CG Zhejiang University Hangzhou 310027 China

The time-dependent behavior of a simply-supported functionally graded beam bonded with piezoelectric sensors and actuators is studied using the state-space method. The creep behavior of bonding adhesives between piezoelectric layers and beam is characterized by a Kelvin-Voigt viscoelastic model, which is practical in a high temperature circumstance. Both the host elastic functionally graded beam and the piezoelectric layers are orthotropic and in a state of plane stress, with the former being inhomogeneous along the thickness direction. A laminate model is employed to approximate the host beam. Moreover, the coupling effect between the elastic deformation and electric field in piezoelectric layers is considered. Results indicate that the viscoelastic property of interfacial adhesives has a significant effect on the function of bonded actuators and sensors with time elapsing.

关键词： functionally graded beam piezoelectric layers Kelvin-Voigt model state-space method

Interannual variability of Antarctic Oscillation and its influence on East Asian climate during boreal winter and spring

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Science China Earth Sciences 2006年第5期49卷 554-560页

作者： FAN Ke1,2.3 & WANG Huijun2.1. Nansen-Zhu International Research Center, Institute of Atmospheric physics, Chinese Academy of Sciences, Beijing 10002., China 2. department of Atmospheric Science, Yunnan{2., Kunming 650091, China 3. Graduate{2. of the Chinese Academy of Sciences, Beijing 100049, China 1. Nansen-Zhu International Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. department of Atmospheric Science Yunnan University Kunming 650091 China 3. Graduate university of the Chinese Academy of Sciences Beijing 100049 China

The interannual variability of Antarctic Oscillation (AAO) and its influence on East Asian climate during both boreal winter and spring are addressed. The results show that the positive AAO anomaly decreases the cold activity over East Asia during both boreal winter and spring. AAO-related barotropic meridional teleconnection from Antarctic to Arctic is found through analysis of mean me- ridional circulations. This meridional teleconnection is remarkable over Eurasia during boreal winter and over the Pacific Ocean during boreal spring. The results also show that zonal mean zonal wind at high latitudes in Southern Hemisphere has well positive correlation with that of Eurasia during boreal winter and has negative correlation with Pacific North American teleconnection (PNA) during boreal spring, which again display the meridional teleconnection. Thus, local meridional teleconnection is a possible linkage for interaction of circulations at mid-high latitudes between both hemispheres.

关键词： Antarctic Oscillation, Eurasian west wind, meridional teleconnection, mean meridional circulation.

Liver X receptor agonist T0901317 reduces atherosclerotic lesions in apoE^(-/-) mice by up-regulating NPC1 expression

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Science China(Life Sciences) 2008年第5期51卷 418-429页

作者： OU Xiang1,2. DAI XiaoYan1, LONG ZhiFeng3, TANG YaLing1, CAO DongLi1, HAO XinRui1, HU YanWei1, LI XiaoXu1 & TANG ChaoKe1 1 Institute of Cardiovascular Research, Key Laboratory for Atherosclerology of Hunan Province, university of South China, Heng- yang 42.001, China 2.department of Physiology, Medical College of{2., shaoguan 512.2., China 3 department of Histology and Embryology, university of South China, Hengyang 42.001, China Institute of Cardiovascular Research Key Laboratory for Atherosclerology of Hunan Province University of South China Hengyang 421001 China department of Physiology Medical College of Shaoguan University Shaoguan 512026 China department of Histology Embryology University of South China Hengyang 421001 China

In this study, we studied the effect of liver X receptor (LXR) agonist T0901317 on Niemann-Pick C1 protein (NPC1) expression in apoE-/- mice. Male apoE-/- mice were randomized into 4 groups, baseline group (n=10), control group (n=14), treatment group (n=14) and prevention group (n=14). All of the mice were fed with a high-fat/high-cholesterol (HFHC) diet containing 15% fat and 0.2.% cholesterol. The baseline group treated with vehicle was sacrificed after 8 weeks of the diet. The control group and the prevention group were treated with either vehicle or T0901317 daily by oral gavage for 14 weeks. The treatment group was treated with vehicle for 8 weeks, and then was treated with the agonist T0901317 for additional 6 weeks. Gene and protein expression was analyzed by real-time quantitative PCR, immunohistochemistry and Western blotting, respectively. Plasma lipid concentrations were measured by commercially enzymatic methods. We used RNA interference technology to silence NPC1 gene expression in THP-1 macrophage-derived foam cells and then detected the effect of LXR agonist T0901317 on cholesterol efflux. Plasma triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C) and apoA-I concentrations were markedly increased in T0901317-treated groups. T0901317 treatment reduced the aortic atherosclerotic lesion area by 64.2. in the prevention group and 58.3% in the treatment group. LXR agonist treatment increased NPC1 mRNA expression and protein levels in the small intestine, liver and aorta of apoE-/- mice. Compared with the normal cells, cholesterol efflux of siRNA THP-1 macrophage-derived foam cells was significantly decreased, whereas cholesterol efflux of LXR agonist T0901317-treated THP-1 macrophage-derived foam cells was significantly increased. Our results suggest that LXR agonist T0901317 inhibits atherosclerosis development in apoE-/- mice, which is related to up-regulating NPC1 expression.

关键词： Niemann-Pick C1 protein liver X receptor agonist atherosclerosis plaque

Approaches to improving critical current density of YBCO superconducting thick films deposited by electrophoresis

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Science China(physics,Mechanics & Astronomy) 2004年第2期47卷 165-172页

作者： ZHU Yabin1,2. ZHOU Yueliang2. LIU Zhen2. WANG Shufang2. CHEN Zhenghao2. L?Huibin2. YANG Guozhen2. XIAO Ling3, REN Hongtao3, JIAO Yulei3 & ZHENG Minghui3 1. department of physics, College of Science, Beijing Jiaotong{2., Beijing 100044, China 2. Laboratory of Optical physics, Institute of physics and Center for Condensed Matter physics, Chinese Academy of Sciences, Beijing 100080, China 3. General Research Institute for Nonferrous Metals, Beijing 100088, China Correspondence should be addressed to Zhu Yabin (email: ybzhu@***) 1. department of physics College of Science Beijing Jiaotong University 100044 Beijing China 2. Laboratory of Optical physics Institute of physics and Center for Condensed Matter physics Chinese Academy of Sciences 100080 Beijing China 3. General Research Institute for Nonferrous Metals 100088 Beijing China

Fabrication of YBCO superconducting thick films by electrophoresis has been widely reported. However, the value of critical current density (J c) is far from what the practical application requires. The superconducting thick films are obtained using top-seeded melt growth method with different proportional Y2.aCuO5 (Y2.1) addition. High-pressure oxygen has been used in the annealing process to improve the uniformity of the oxygen content in the superconducting thick films. When 40mol% Y2.1 powder is added to the YBa2.u3O7–5 (Y12.) powder,J c for the superconducting thick film by approaches described above reaches 7.008×103 A/cm2.(77 K, 0 T), which is greater than the value ever reported.

关键词： YBCO thick films, electrophoretic deposition, melt-textured.

Modulation on the collective response behavior by the system size in two-dimensional coupled cell systems

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Science China(physics,Mechanics & Astronomy) 2006年第3期49卷 304-312页

作者： ZHANG Jiqian1, SHEN Chuansheng1,2.& CUI Zhifeng1 1. College of physics and Electronic Information, Anhui Normal university, Wuhu 2.1000, China 2.{2. of Educational Technology, Anqing Teachers College, Anqing 2.6011, China College of physics Electronic Information Anhui Normal University Wuhu 241000 China department of Educational Technology Anqing Teachers College Anqing 246011 China

By the intracellular calcium ionic minimal model proposed by Berridge, we investigated the collective response of two-dimensional (N×N) coupled cell systems to the external stimulation using numerical simulation methods. With a coupled intensity fixed and an appropriate coupled cell number chosen, the kinetic system size resonance was discovered. At the same time, it was found that the system size responding to the external stimulation for different coupled intensities transferred too, especially when the coupled intensity increased, the range of the corresponding system size extended. These phe- nomena illustrate that the coupled cell number and the coupled intensity can play con- structive roles in noisy coupled systems, by which the biology system would probably improve its capability to respond to the external stimulation.

关键词： cell coupling,collective response,system size resonance

Entropy product measure for multipartite pure states

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Science China(physics,Mechanics & Astronomy) 2006年第5期49卷 606-615页

作者： CAO Wancang1,2. LIU Dan2. PAN Feng3 & LONG Guilu2.4 1. department of physics, Chifeng College, Chifeng 02.001, China 2. Key Laboratory for Quantum Information and Measurements, department of physics, Tsinghua university, Beijing 100084, China 3. department of physics, Liaoning Normal university, Dalian 11602., China 4. Key Laboratory for Atomic and Molecular Nano-Sciences, Tsinghua university, Beijing 100084, China Correspondence should be addressed to Long Guilu department of physics Chifeng College Chifeng 024001 China Key Laboratory for Quantum Information Measurements Department of Physics Tsinghua University Beijing 100084 China department of physics Liaoning Normal University Dalian 116029 China Key Laboratory for Atomic Molecular Nano-Sciences Tsinghua University Beijing 100084 China

An entanglement measure for multipartite pure states is formulated using the product of the von Neumann entropy of the reduced density matrices of the constituents. Based on this new measure, all possible ways of the maximal entanglement of the triqubit pure states are studied in detail and all types of the maximal entanglement have been compared with the result of ‘the average entropy’. The new measure can be used to calculate the degree of entanglement, and an improvement is given in the area near the zero entropy.

关键词： multipartite pure state von Neumann entropy entanglement measure