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fMRI time series analysis based on stationary wavelet and spectrum analysis

Progress in Natural Science:Materials International 2006年第11期16卷 1171-1176页

作者： ZHI Lianhe~ 1,2.3 , ZHAO Xia~4, SHAN Baoci~1**, PENG Silong~5, YAN Qiang~1, YUAN Xiuli~1 and TANG Xiaowei~ 1,6 (1. Key Laboratory of nuclear Analysis Techniques, institute of High {2. physics, Chinese Academy of Sciences, beijing 100049, china 2. Graduate School of Chinese Academy of Sciences, beijing 100049, china 3. Department of physics, Zhoukou normal university, Zhoukou 466100, china 4. Research Imaging Center, university of Texas Health Science Center, San Antonio, Texas 782.9, USA 5. National ASIC Design and Engineering Center, institute of Automation, Chinese Academy of Sciences, beijing 100049, china 6. Department of physics, Zhejiang university, Hangzhou 31002., china) [a]Key Laboratory of nuclear Analysis Techniques Institute of High Energy Physics Chinese Academy of Sciences Beijing China [b]Graduate School of Chinese Academy of Sciences Beijing China [c]Department of physics Zhoukou Normal University Zhoukou China [d]Research Imaging Center University of Texas Health Science Center San Antonio Texas USA [e]National ASIC Design and Engineering Center Institute of Automation Chinese Academy of Sciences Beijing China [f]Department of physics Zhejiang University Hangzhou China

The low signal to noise ratio (SNR) of functional MRI (fMRI) prefers more sensitive data analysis methods. Based on stationary wavelet transform and spectrum analysis, a new method with high detective sensitivity was developed for analyzing fMRI time series, which does not require any prior assumption of the characteristics of noises. In the proposed method, every component of fMRI time series in the different time-frequency scales of stationary wavelet transform was discerned by the spectrum analysis, then the components from noises were removed using the stationary wavelet transform, finally the components of real brain activation were detected by cross-correlation analysis. The results obtained from both simulated and in vivo visual experiments illustrated that the proposed method has much higher sensitivity than the traditional cross-correlation method.

关键词： fMRI stationary wavelet transform spectrum analysis data analysis.

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Isomerization of B_6,B_6^- and B_6^+ clusters

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Science china Chemistry 2010年第1期53卷 202-209页

作者： WEI GongMin1,PU ZhiFeng2.ZOU Rong3,LI GuoLiang2.3 & LUO Qiong2.3 1Department of physics,Capital normal {2.,beijing 100048,china 2.tate Key Laboratory of Explosion Science and Technology beijing institute of Technology,beijing 100081,china 3Center for Computational Quantum Chemistry,South china normal {2.,Guangzhou 510631,china 1. Department of physics Capital Normal University Beijing 100048 China2. State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China3. Center for Computational Quantum Chemistry South China Normal University Guangzhou 510631 China

The interconversions between isomers with the same spin multiplicity of neutral B6 and charged B6-and B6+ clusters have been investigated at the B3LYP/6-311+G level of theory,including determination of the minimum energy pathways with transition states connecting the corresponding reactants and *** dynamic calculations,2. isomers were optimized,including 11 novel *** order to further refine the energies,single-point B3LYP/6-311+G(3df) calculations were carried out on the corresponding B3LYP/6-311+G geometries of all isomers of B6,B6-and B6+ and the corresponding isomerization transition *** stability of each isomer of B6(singlet and triplet states),B6-(doublet state) and B6+(doublet state) was analyzed from both thermodynamic and dynamic viewpoints.

关键词： B6 transition state intrinsic reaction coordinate barrier height

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Calculation of triaxial superdeformation in ^(174)Hf

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Science china(physics,Mechanics & Astronomy) 2007年第5期50卷 553-557页

作者： YU ShaoYing1,2.4, LI XiaoWei2. SHEN CaiWan1,5 & CHEN YongShou3,4 1 School of Science, Huzhou Teachers College, Huzhou 313.00, china 2.College of Mathematics, {2. and Information Engineering, Zhejiang {2. university, Jinhua 32.000, china 3 china institute of Atomic energy, beijing 102.13. china 4 institute of Theoretical {2., Chinese Academy of Sciences, beijing 100080, china 5 Center of Theoretical nuclear {2., National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou 730000, china 1. School of Science Huzhou Teachers College Huzhou 313000 China 2. College of Mathematics Physics and Information Engineering Zhejiang Normal University Jinhua 321000 China 4. institute of Theoretical physics Chinese Academy of Sciences Beijing 100080 China 5. Center of Theoretical nuclear physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000 China 3. china institute of Atomic {2. Beijing 102413 China

A two-dimensional Total Routhian Surface (TRS) calculation with the fixed hexa- decapole deformation ε4 = 0.03 was carried out for several configurations of 174Hf. Results indicate that the shell corrections have an important contribution to the formation of triaxial superdeformation in 174Hf and some possible configuration assignments are made to the 4 TSD bands experimentally found in 174Hf.

关键词： Total Routhian Surface (TRS), triaxial superdeformation, configuration

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Constraints on smoothness parameter and dark energy using observational H(z) data

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Research in Astronomy and Astrophysics 2011年第2期11卷 125-136页

作者： Hao-Ran Yu1,Tian Lan1,Hao-Yi Wan2.Tong-Jie Zhang1,3 and Bao-Quan Wang4 1 Department of Astronomy,beijing normal {2.,beijing 100875,china 2.Business Office,beijing Planetarium,beijing 100044,china 3 Center for High energy physics,Peking {2.,beijing 100871,china 4 Department of physics,Dezhou {2.,Dezhou 2.302.,china Department of Astronomy Beijing Normal University Beijing 100875 China Business Office Beijing Planetarium Beijing 100044 China Center for High energy physics Peking University Beijing 100871 China Department of physics Dezhou University Dezhou 253023 China

With large-scale homogeneity,the universe is locally inhomogeneous,clustering into stars,galaxies and larger *** property is described by the smoothness parameter α which is defined as the proportion of matter in the form of intergalactic *** we consider the inhomogeneities over a small scale,there should be modifications of the cosmological distances compared to a homogenous *** and Roeder developed a second-order ordinary differential equation（D-R equation） that describes the angular diameter distance-redshift relation for inhomogeneous cosmological ***,we may obtain the D-R equation for observational H（z） data（OHD）.The density-parameter ΩM,the state of dark energy ω,and the smoothness-parameter α are constrained by a set of OHD in a spatially flat XCDM universe as well as a spatially flat XCDM *** using a χ2.minimization method,we get α = 0.81＋0.19-0.2. and ΩM = 0.32.0.12.0.06 at the 1σ confidence *** we assume a Gaussian prior of ΩM = 0.2. ± 0.1,we get α = 0.93＋0.07-0.19 and ΩM = 0.31＋*** the XCDM model,α is constrained to α≥ 0.80 but ω is weakly constrained around-1,where ω describes the equation of state of the dark energy（pX = ωρX）.We conclude that OHD constrains the smoothness parameter more effectively than the data of SNe Ia and compact radio sources.

关键词： cosmology -- dark energy -- cosmological parameters

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Optimization of the imaginary time step evolution for the Dirac equation

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Science china(physics,Mechanics & Astronomy) 2011年第2期54卷 231-235页

作者： LI FangQiong1,ZHANG Ying2.LIANG HaoZhao2.3 & MENG Jie4,2.5 1Guizhou university for Nationalities,Guiyang 55002.,china 2.tate Key Lab {2. physics & Technology,School of physics,Peking university,beijing 100871,china 3Institut de Physique Nucle’aire,IN2.3-CNRS and Universite’ Paris-Sud,F-91406 Orsay Cedex,France 4School of physics and {2. energy Engineering,Beihang university,beijing 100191,china 5Department of physics,university of Stellenbosch,Stellenbosch,South Africa 1. Guizhou university for Nationalities Guiyang 550025 China2. State Key Lab Nuclear Physics & Technology School of Physics Peking University Beijing 100871 China3. Institut de Physique Nucléaire IN2P3-CNRS and Université Paris-Sud F-91406 Orsay Cedex France4. School of Physics and Nuclear Energy Engineering Beihang University Beijing 100191 China5. Department of Physics University of Stellenbosch Stellenbosch South Africa

Taking the single neutron levels of 12. in the Fermi sea as examples,the optimization of the imaginary time step(ITS) evolution with the box size and mesh size for the Dirac equation is *** the weakly bound states,in order to reproduce the exact single-particle energies and wave functions,a relatively large box size is *** long as the exact results can be reproduced,the ITS evolution with a smaller box size converges faster,while for both the weakly and deeply bound states,the ITS evolutions are less sensitive to the mesh ***,one can find a parabola relationship between the mesh size and the corresponding critical time step,i.e.,the largest time step to guarantee the convergence,which suggests that the ITS evolution with a larger mesh size allows larger critical time step,and thus can converge faster to the exact *** conclusions are very helpful for optimizing the evolution procedure in the future self-consistent calculations.

关键词： Dirac equation Schrdinger-like equation imaginary time step method convergence

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Multisymplectic five-point scheme for the nonlinear wave equation

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Chinese Science Bulletin 2003年第S2期48卷 24-29页

作者： WANG Yushun~(1,2., WANG Bin~1, YANG Hongwei~1 & WANG Yunfeng~1 1. LASG, institute of Atmospheric physics, Chinese Academy of Sciences, {2. 10002.. china 2. Permanent address: School of Mathematics and Computer Science, Nanjing normal university, Nanjing 2.0097. china Chinese Acad Sci Inst Atmospher Phys LASG Beijing 100029 Peoples R China Nanjing normal Univ Sch Math & Comp Sci Nanjing 210097 Peoples R China

In this paper, we introduce the multisymplecticstructure of the nonlinear wave equation, and prove that theclassical five-point scheme for the equation is multisymplec-tic. Numerical simulations of this multisymplectic scheme onhighly oscillatory waves of the nonlinear Klein-Gordonequation and the collisions between kink and anti-kink soli-tons of the sine-Gordon equation are also provided. The mul-tisymplectic schemes do not need to discrete PDEs in thespace first as the symplectic schemes do and preserve notonly the geometric structure of the PDEs accurately, but alsotheir first integrals approximately such as the energy, themomentum and so on. Thus the multisymplectic schemeshave better numerical stability and long-time numerical be-havior than the energy-conserving scheme and the symplec-tic scheme.

关键词： symplectic schelne energy-conserving scheme multisymplectic scheme nonlinear wave equation.

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Convergence for Imaginary Time Step evolution in the Fermi and Dirac seas

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Science china(physics,Mechanics & Astronomy) 2010年第2期53卷 327-330页

作者： LI FangQiong1,ZHANG Ying2.& MENG Jie2.3,4 1Guizhou university for Nationalities,Guiyang 55002.,china 2.tate Key Lab Nucl. Phys. & Tech.,School of {2.,Peking university,beijing 100871,china 3School of {2. and nuclear energy Engineering,Beihang university,beijing 100191,china 4Department of {2.,university of Stellenbosch,Stellenbosch,South Africa 1. Guizhou university for Nationalities Guiyang 550025 China2. State Key Lab Nucl. Phys. & Tech. School of Physics Peking University Beijing 100871 China3. School of Physics and Nuclear Energy Engineering Beihang University Beijing 100191 China4. Department of Physics University of Stellenbosch Stellenbosch South Africa

The convergence for the Imaginary Time Step (ITS) evolution with time step is investigated by performing the ITS evolution for the Schrdinger-like equation and the charge-conjugate Schrdinger-like equation deduced from Dirac equation for the single proton levels of 12. in both the Fermi and Dirac seas. For the guaranteed convergence of the ITS evolution to the "exact" results,the time step should be smaller than a "critical" time step Δtc for a given single-particle level. The "critical" time step Δtc is more sensitive to the quantum numbers |κ| than to the energy of the single-particle level. For the single-particle levels with the same κ,their "critical" time steps are in the same order. For the single-particle levels with similar energy,a relatively small (large) "critical" time step for larger (smaller) |κ| is needed. These conclusions can be used in the future self-consistent calculation to optimize the evolution procedure.

关键词： Dirac equation Schrdinger-like equation Imaginary Time Step method convergence

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Sediment transport capacity of hyperconcentrated flow

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Science china(physics,Mechanics & Astronomy) 2008年第8期51卷 961-975页

作者： SHU AnPing1,2.& FEI XiangJun2.1 School of Environment & Key Laboratory of Water and Sediment Sciences,Ministry of Education,beijing normal {2.,beijing 100875,china 2.State Key Laboratory of Hydroscience and Engineering,Tsinghua {2.,beijing 100084,china School of Environment & Key Laboratory of Water and Sediment Sciences Ministry of Education Beijing Normal University Beijing 100875 China State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China

As one of the most important components of river mechanics,sediment transport capacity of sediment-laden flows has attracted much attention from many researchers working on river mechanics and hydraulic engineering. Based on the time-averaged equation for a turbulent energy equilibrium in solid and liquid two-phase flow,an expression for the efficiency coefficient of suspended load movement was derived for the two-dimensional,steady,uniform,fully-developed turbulent flow. A new structural expression of sediment transport capacity was achieved. Using 115 runs of flume experimental data,which were obtained through two kinds of sediment transport experiments in the state of equilibrium,in combination with the basic rheological and sediment transporting characteristics of hyperconcentrated flow,the main parameters in the structural expression of sediment transport capacity were calibrated,and a new formula of sediment transport capacity for hyperconcentrated flow was developed. A large amount of field data from the Yellow River,Wuding River,and Yangtze River,etc. were adopted to verify the new formula and good agreement was obtained. These results above contribute to an improved theoretical system of river mechanics and a reliable tool for management of rivers carrying high concentration of sediments.

关键词： hyperconcentrated flow turbulent energy equilibrium efficiency coefficient sediment transport capacity

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Dense coding scheme using superpositions of Bell-states and its NMR implementation

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Science china(physics,Mechanics & Astronomy) 2005年第1期48卷 57-67页

作者： ZHANG Jingfu, XIE Jingyi, DENG Zhiwei & LU Zhiheng Key Laboratory for Quantum Information and Measurements, Department of physics, Tsinghua university, {2. 100084, china Center for Quantum Information, Tsinghua university, {2. 100084, china Department of Materials Science and Engineering, beijing normal university, {2. 100875, china Testing and Analytical Center, beijing normal university, {2. 100875, china Department of physics, beijing normal university, {2. 100875, china 1. Key Laboratory for Quantum Information and Measurements Department of Physics Tsinghua University 100084 Beijing China 2. Center for Quantum Information Tsinghua University 100084 Beijing China 3. Department of Materials Science and Engineering Beijing Normal University 100875 Beijing China 4. Testing and Analytical Center Beijing Normal University 100875 Beijing China 5. Department of physics Beijing Normal University 100875 Beijing China

Dense coding using superpositions of Bell-states is proposed. The generalized Grover's algorithm is used to prepare the initial entangled states, and the reverse process of the quantum algorithm is used to determine the entangled state in the decoding measurement. Compared with the previous schemes, the superpositions of two Bell-states are exploited. Our scheme is demonstrated using a nuclear magnetic resonance (NMR)quantum computer. The corresponding manipulations are obtained. Experimental results show a good agreement between theory and experiment. We also generalize the scheme to transmit eight messages by introducing an additional two-state system.

关键词： dense coding, superpositions of Bell-states, generalized Grover's algorithm, nuclear magnetic res-onance, quantum computer.

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A phenomenological equation of state for isospin asymmetric nuclear matter

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Science china(physics,Mechanics & Astronomy) 2009年第10期52卷 1494-1505页

作者： CHEN LieWen1,2.1 Department of physics,Shanghai Jiao Tong university,Shanghai 2.02.0,{2. 2.Center of Theoretical nuclear physics,National Laboratory of Heavy Ion Accelerator,Lanzhou 730000,{2. Department of physics Shanghai Jiao Tong University Shanghai 200240 China Center of Theoretical nuclear physics National Laboratory of Heavy Ion Accelerator Lanzhou 730000 China

A phenomenological momentum-independent(MID) model is constructed to describe the equation of state(EOS) for isospin asymmetric nuclear matter,especially the density dependence of the nuclear symmetry {2. Esym(ρ).This model can reasonably describe the general properties of the EOS for symmetric nuclear matter and the symmetry {2. predicted by both the sophisticated isospin and momentum dependent MDI model and the Skyrme-Hartree-Fock *** find that there exists a nicely linear correlation between Ksym and L as well as between J0/K0 and K0,where L and Ksym represent,respectively,the slope and curvature parameters of the symmetry {2. at the normal nuclear density ρ0,while K0 and J0 are,respectively,the incompressibility and the third-order derivative parameter of symmetric nuclear matter at ρ*** correlations together with the empirical constraints on K0,L and Esym(ρ0) lead to an estimation of -477 MeV Ksat,2.-2.1 MeV for the second-order isospin asymmetry expansion coefficient for the incompressibility of asymmetric nuclear matter at the saturation point.

关键词： equation of state of nuclear matter isospin the symmetry energy

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