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A template of rat brain based on fMRI T2. imaging

Progress in Natural Science:Materials International 2005年第6期15卷 502-506页

作者： HU Zhenghui1, WU Yigen2. WANG Xiaochuan3. WANG Jianzhi3. CHEN Feiyan1 and TANG Xiaowei1*(1. {2. of physics and Bio-X Laboratory, Zhejiang {2., Hangzhou 3.002.,{3. 2. Institute of High Energy physics and Key Laboratory of Nuclear Analysis Techniques, Chinese Academy of Sciences,Beijing 10003.,{3. 3. {2. of Pathophysiology, Tongji Medical College, Huazhong {2. of Science and Technology, Wuhan 43.03.,{3.) department of physics and Bio-X Laboratory Zhejiang University Hangzhou 310027 China Institute of High Energy physics and Key Laboratory of Nuclear Analysis Techniques Chinese Academy of Sciences Beijing 100039 China department of Pathophysiology Tongji Medical College Huazhong University of Science and Technology Wuhan 430030 China

The development of functional magnetic resonance imaging (fMRI) technology has made it possible to carry out functional brain imaging experiments in small animals. Usually, group data is required to form the assessment of population, which can not only increase the sensitivity of the overall experiment, but also allow the generalization of the conclusion to the whole population. In order to average the signals of functional brain images from different subjects, it is necessary to put all the mapping images into the same standard space (template image). However, up to now, most animal brain templates remain unavailable and it must be done by ourselves. In this study, a template image based on the brains of eight male Wistar rats is obtained, and it is successfully used in our present Alzheimer disease (AD)-like rat model studies as template for spatially normalizing images to the same stereotaxical space. The fMRI results processed with statistical parametric mapping (SPM99) software are in agreement with the results from immunohistochemical experiment, which proves that this method is universally applicable to the pathologic models of other small animals and to human brain lesion studies.

关键词： fMRI animal model atlas template normalization T*2.

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Properties and applications of cold supersonic gas jet

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Science china(physics,Mechanics & Astronomy) 2006年第6期49卷 709-715页

作者： ZHANG Shaofeng1,2.MA Xinwen1,2.LIU Huiping2.LI Bin1,2.& ZHU Xiaolong1,2.1. Institute of modern physics,Chinese Academy of Sciences,{2. 73.000,{3. 2. Graduate university of Chinese Academy of Sciences,Beijing 100049,{3. 1. Institute of modern physics Chinese Academy of Sciences Lanzhou 730000 China 2. Graduate university of Chinese Academy of Sciences Beijing 100049 China

By analyzing the formation mechanism of a supersonic gas jet,a set of equations which describe the atomic beam properties were established. The influence of initial temperature,initial pressure,background gas pressure and pumping speed was discussed in detail. A simulation program was developed based on the equations,and the results under different initial conditions were obtained. The results are in good agreement with the experimental data,and suggest that,in order to get much smaller transverse momentum in collision experiments,it is necessary to lower the initial temperature and the initial pressure of the supersonic gas jet,together with increasing the pumping speed. These results are very instructive for construction of a new generation of cold supersonic gas jets.

关键词： cold supersonic gas jet,zone of silence,nozzle,skimmer.

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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,{3. 2. Laboratory of Optical physics, Institute of physics and Center for Condensed Matter physics, Chinese Academy of Sciences, Beijing 100080,{3. 3. General Research Institute for Nonferrous Metals, Beijing 100088,{3. 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.u3.7–5 (Y12.0} 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.

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Effect of Substrate-Water Interaction on the Wetting Behavior in Water-Oil and Substrate-Water-Oil Systems

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Wuhan university Journal of Natural Sciences 2003年第4A期8卷 1097-1102页

作者： Yuan Yin-quan 1,2., Zou Xian-wu 1 , Jin Zhun-zhi 1 1. School of physics and Technology, Wuhan university, Wuhan 4{2.072. Hubei,{2. 2. {{2. of physics, Xiaogan university, Xiaogan 4{2.100, Hubei,{2. Wuhan university School of Physics and Technology Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***) Xiaogan university Department of Physics Xiaogan Hubei China (GRID:grid.49470.3e) Wuhan university School of Physics and Technology Wuhan Hubei China (GRID:grid.49470.3e) (ISNI:***)

The effects of the substrate-water interaction on the wetting behavior in water-oil and surfactant-water-oil systems confined by one substrate which has the preferential interaction to one species of particles have been investigated by using the free energy analysis and discontinuous molecular dynamic simulations. As the preferential interaction between the substrate and water particles varies from small repulsion to large attraction, the partial drying, partial wetting and complete wetting state are observed in sequence. In addition, the wetting behavior of surfactant aqueous solution on the substrate is not only dependent on the interaction, but also limited by the maximum equilibrium concentration of surfactants at the interface.

关键词： wetting behavior wetting transition preferential interaction substrate

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Advancement and prospect of short-term numerical climate prediction

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Chinese Science Bulletin 2001年第18期46卷 1497-1502页

作者： CHOU Jifan & XU Ming1. department of Atmospheric Sciences, lanzhou university, {2. 73.000,{3. 2. Training Center of Chinese Meteorological Administration, Beijing 100081,{3. department of Atmospheric Sciences Lanzhou University Lanzhou China Training Center of Chinese Meteorological Administration Beijing China

The defects of present methods of short-term numerical climate prediction are discussed in this paper, and four challenging problems are put forward. Considering our under developed computer conditions, we should innovate in the approcuch of numerical climate prediction on the basis of our own achievements and experiences in the field of short-term numerical climate prediction. It is possibly an effective way to settle the present defects of short-term numerical climate prediction.

关键词： short-term climate numerical prediction defects innovation.

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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 {2., Tsinghua {2., Beijing 100084,{3. 2. Center of Quantum Information Science and Technology, Tsinghua National Laboratory for information Science and Technology, Beijing 100084,{3. 3. Institute of {2., School of Sciences, Beijing {2. of Posts and Telecommunications, Beijing 100876,{3.) Key Laboratory for Atomic and Molecular NanoSciences and Department of Physics Tsinghua University Beijing 100084 China Center of Quantum Information Science and Technology Tsinghua National Laboratory for information Science and Technology Beijing 100084 China Institute of physics School of Sciences Beijing University of Posts and Telecommunications Beijing 100876 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.

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Comprehensive evaluation of mechanism of "chimney effect" using principles of magnetism, geochemistry and mineralogy

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Chinese Science Bulletin 1998年第9期43卷 743-748页

作者： LIU Qingsheng 1, CHENG Tongjin 2.and LIU Shugen 3.1. department of Applied Geo{2.,{2. {3. of Geosciences, Wuhan 43.074,{2. 2. Center of Petroleum Geochemistry,{2. National Star Petroleum Corporation, Hefei 2.0}02.,{2. 3. The St department of Applied Geophysics China University of Geosciences Wuhan China Center of Petroleum Geochemistry China National Star Petroleum Corporation Hefei China The State Key Laboratory of Oil/Gas Reservoir Geology and Exploitation of china Chengdu Institute of Technology Chengdu China

Study of forming mechanism of "chimney-effect" (CE) has important significance for basic theory and applications of non-seismic geophysical and geochemical methods locating oil/gas reservoirs. The theoretical basis of comprehensive evaluation of mechanism of CE using principles of magnetism, geochemistry and mineralogy has been reviewed, with the problems to be solved: (ⅰ) study for the relationship between process of oil/gas migration and geochemical field; (ⅱ) analysis of genesis of magnetic, geochemical and mineralogical anomaly; (ⅲ) interpretation of surface soil magnetism and geochemical anomaly combined with seismic data.

关键词： chimney effect (CE) hydrocarbon microseepage oil/gas accumulation.

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Implementation of a multiple round quantum dense coding using nuclear magnetic resonance

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Science china(physics,Mechanics & Astronomy) 2005年第6期48卷 706-715页

作者： ZHANG Jingfu1, XIE Jingyi2. WANG Chuan1, DENG Zhiwei3. LU Zhiheng4, & LONG Guilu1,5 1. Key Laboratory For Quantum Information and Measurements of MOE, department of {2., Tsinghua {2., Beijing 100084,{3. 2. department of Materials Science and Engineering, Beijing Normal {2., Beijing 100875, china 3. Testing and Analytical Center, Beijing Normal {2., Beijing 100875,{3. 4. department of {2., Beijing Normal {2., Beijing 100875, china 5. Key Laboratory For atomic and Molecular Nanosciences, Tsinghua {2., Beijing 100084,{3. 1. Key Laboratory For Quantum Information and Measurements of MOE Department of Physics Tsinghua University 100084 Beijing China 2. department of Materials science and Engineering Beijing Normal University 100875 Beijing China 3. Testing and Analytical Center Beijing Normal University 100875 Beijing China 4. department of physics Beijing Normal University 100875 Beijing China 5. Key Laboratory For Atomic and Molecular Nanosciences Tsinghua University 100084 Beijing China

A multiple round quantum dense coding scheme based on the quantum phase estimation algorithm is proposed and implemented in a three qubit nuclear magnetic resonance (NMR) quantum computer. Using an m + 1 qubit system, Bob can transmit one of 2.+1 messages to Alice, through manipulating only one qubit and exchanging it between Alice and Bob for m rounds. The information capacity is enhanced to m + 1 bits as compared to m bits in a classical scheme. The scheme has been demonstrated in NMR system, and the experimental results show a good agreement between theory and experiment.

关键词： quantum dense coding, multiple round, nuclear magnetic resorance

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Quantum statistical entropy corresponding to cosmic horizon in five-dimensional spacetime

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Science china(physics,Mechanics & Astronomy) 2008年第2期51卷 140-146页

作者： ZHAO Ren1,2.& ZHANG ShengLi1 1 department of Applied physics, Xi’an Jiaotong {2., Xi’an 710049,{3. 2.department of physics, Shanxi Datong {2., Datong 03.009,{3. department of Applied physics Xi’an Jiaotong University Xi’an 710049 China department of physics Shanxi Datong University Datong 037009 China

The generalized uncertainty relation is introduced to calculate the quantum statis-tical entropy corresponding to cosmic horizon. By using the new equation of state density motivated by the generalized uncertainty relation, we discuss entropies of Bose field and Fermi field on the background of five-dimensional spacetime. In our calculation, we need not introduce cutoff. There is no divergent logarithmic term in the original brick-wall method. And it is obtained that the quantum statistical en-tropy corresponding to cosmic horizon is proportional to the area of the horizon. Further it is shown that the entropy corresponding to cosmic horizon is the entropy of quantum state on the surface of horizon. The black hole's entropy is the intrinsic property of the black hole. The entropy is a quantum effect. In our calculation, by using the quantum statistical method, we obtain the partition function of Bose field and Fermi field on the background of five-dimensional spacetime. We provide a way to study the quantum statistical entropy corresponding to cosmic horizon in the higher-dimensional spacetime.

关键词： quantum statistical entropy generalized uncertainty relation high-dimensional spacetime

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Some properties on multivariate filter banks with a matrix factorization

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Progress in Natural Science:Materials International 2005年第2期15卷 20-30页

作者： LIAN Qiaofang1, XIAO Hongying2. and CHEN Qiuhui3.1. department of Mathematics, Beijing Jiaotong {2., Beijing 100044,{2. 2. Institute of Mathematics, Academy of Mathematics and System Sciences, Chinese Academy of Sciences, Beijing 100080,{2. 3. department of Scientific Computing and Computer Applications, Zhongshan {2., Guangzhou 5102.5,{2.) department of Mathematics Beijing Jiaotong University Beijing 100044 China. Institute of Mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China. department of Scientific Computing and Computer Applications Zhongshan University Guangzhou 510275 China

A class of multivariate filter banks with a matrix factorization has been developed by Chen et al. The main purpose of this paper is to discuss some further properties of this kind of filter bank, such as the completeness, accuracy of the corresponding scaling functions and the relationships with Daubechies' wavelets and the multi-wavelets provided by Chui and Lian. Moreover, some examples are given to show that this kind of filter bank has a higher accuracy for the scaling functions.

关键词： filter banks completeness accuracy matrix factorization

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