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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 Energy physics, Chinese Academy of Sciences, Beijing 100049, china 2. Graduate School of Chinese Academy of Sciences, Beijing 100049, china {3., zhoukou normal university, zhoukou 466100, china 4. Research Imaging Center, university of Texas Health Science Center, San Antonio, Texas 78229, 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 3.0027, china) Key Laboratory of Nuclear Analysis Techniques Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China Graduate School of Chinese Academy of Sciences Beijing 100049 China department of physics Zhoukou Normal University Zhoukou 466100 China Research Imaging Center University of Texas Health Science Center San Antonio TX 78229 United States National ASIC Design and Engineering Center Institute of Automation Chinese Academy of Sciences Beijing 100049 China department of physics Zhejiang University Hangzhou 310027 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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Superconductivity of small metal grains

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Science china(physics,Mechanics & Astronomy) 2005年第4期48卷 431-441页

作者： ZHENG Renrong1 CHEN Zhiqian2 & ZHU Shunquan1,3.1. department of physics, Shanghai normal {3., Shanghai 20023., china 2. department of physics, Southwest normal {3., Chongqing 400715, china 3. department of Computer and Electric Technology, Shanghai Business School, Shanghai 201400, china department of physics Shanghai Normal University Shanghai China department of physics Southwest Normal University Chongqing China department of Computer and Electric Technology Shanghai Business School Shanghai China

The formulas of the energy gap and superconducting critical temperature appropriate for systems with both odd and even number of electrons are derived; the bases of the derivations are BCS theory and energy level statistics. Numerical results qualitatively agree with the experimental phenomena. i.e., the superconductivity of small metallic grains will first enhance then decrease to zero when the grain are getting smaller and smaller. The calculations indicate that the above phenomena happen in the metallic grains belonging to Gaussian Orthogonal Ensemble (GOE) and Gaussian Unitary ensemble (GUE) with zero spin; The superconductivity of small metallic grains in Gaussian Symplectic Ensemble (GSE) will monotonically decrease to zero with the decreasing of the grain size. The analyses suggest that the superconductivity enhancements come from pairing and the balance of the strengths between spin-orbital coupling and external magnetic field. In order to take the latter into account, it is necessary to include the level statistics given by Random Matrix Theory (RMT) in describing small metallic grains.

关键词： size effect, superconductivity enhancements, small metallic grains.

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Steel Slag as an Iron Fertilizer for Corn Growth and Soil Improvement in a Pot Experiment

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Pedosphere 2006年第4期16卷 519-524页

作者： WANG Xian CAI Qing-Sheng College of Life Sciences Nanjing Agricultural University Nanjing 210095 （China） department of Biology Zhoukou Normal College Zhoukou 366000 （China）

The feasibility of steel slag used as an iron fertilizer was studied in a pot experiment with corn. Slag alone or acidified slag was added to two Fe-deficient calcareous soils at different rates. Results showed that moderate rates (10 and 20 g kg-1) of slag or acidified slag substantially increased corn dry matter yield and Fe uptake. Application of steel slag increased the residual concentration of ammonium bicarbonate-diethylenetriamine pentaacetic acid (AB-DTPA) extractable Fe in the soils. The increase of extractable Fe was usually proportional to the application rate, and enhanced by the acidification of slag. Steel slag appeared to be a promising and inexpensive source of Fe to alleviate crop Fe chlorosis in Fe-deficient calcareous soils.

关键词： corn growth iron fertilizer pot experiment soil improvement steel slag

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Bell States and Two-Qubit Logic Gate with Superconducting Charge Qubits Coupling to a Nanomechanical Resonator

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Communications in Theoretical physics 2007年第12期48卷 999-1002页

作者： LIAO Jie-Qiao~1 and WANG Xin-Wen~(2,3.~1 department of physics,Hunan normal {3.,Changsha 410081,china~2 department of physics,Beijing normal {3.,Beijing 100875,china~3.department of Electronic Engineering and physics,Hunan {3. of Science and Engineering,Yongzhou 425100,china department of physics Hunan Normal University Changsha 410081 China department of physics Beijing Normal University Beijing 100875 China department of Electronic Engineering and physics Hunan University of Science and Engineering Yongzhou 425100 China

We propose a scheme for generating Bell states involving two SQUID-based charge qubits by coupling themto a nanomechanical *** also show that it is possible to implement a two-qubit logic gate between the twocharge qu... 详细信息

关键词： Bell states superconducting charge qubit two-qubit logic gate nanomechanical resonator

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From the Green's Function in Tight-Binding Representation to Interatomic Many-body Potentials

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Journal of Materials Science & Technology 1999年第4期15卷 315-319页

作者： Shaojun LIU(department of physics, Beijing normal {3., Beijing 100875, china)Xiaobo WEI(department of physics, Liuzhou College of Education, Liuzhou 545005, china)Zhaodou CHEN Jun CAI and Benkun MA(department of physics, Beijing normal {3., department of physics Beijing Normal University Beijing 100875 China department of physics Liuzhou College of Education Liuzhou 545005 China

In this paper, we deduce the analytical form of many-body interatomic potentials based on the Green's function in tight-binding representation. The many-body potentials are expressed as the functions of the hopping integrals which are the physical origin of cohesion of atoms. For thesimple case of s-valent system, the inversion of the many-body potentials are discussed in detail by using the lattice inversion method.

关键词： Rev Li Chen From the Green’s Function in Tight-Binding Representation to Interatomic Many-body Potentials body

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D-Dimensional Dirac Fermions BEC-BCS Crossover Thermodynamics

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Communications in Theoretical physics 2007年第7期48卷 99-106页

作者： CHEN Ji-Sheng Institute of Particle physics & physics department,Central{3. normal university,Wuhan 43.079,china Institute of Particle physics & physics department Central China Normal University Wuhan 430079 China

An effective relativistic continuum massive Proca Lagrangian action is used to account for the Lorentzvector condensation effects on the equation of state of the strongly interacting fermions *** interior quantumfluctuation effects are incorporated as an external field approximation indirectly through a fictive generalized ThomsonProblem counterterm *** general analytical formulas for the d-dimensional thermodynamics are given nearthe unitary limit region,In the non-relativistic limit for d=3.the universal dimensionless coefficientε=4/9 andenergy gap △/ε_f=5/18 are reasonably consistent with the existing theoretical and experimental *** the unitarylimit for d=2 and T=0,the universal coefficient can even approach the extreme occasion ξ=0 corresponding to theinfinite effective fermion mass m~*=∞,which can be mapped to the strongly coupled two-dimensional electrons and isquite similar to the three-dimensional Bose-Einstein condensation of ideal boson ***,for d=1,the universalcoefficient ξ is negative,implying the non-existence of phase transition from superfluidity to normal *** solutionsmanifest the quantum Ising universal class characteristic of the strongly coupled unitary fermions gas.

关键词： unitary fermions thermodynamics BEC-BCS crossover statistical methods

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X-ray spectra induced in highly charged 40Ar^q+ interacting with Au surface

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Science china(physics,Mechanics & Astronomy) 2006年第2期49卷 203-212页

作者： ZHANG Xiao’an1,2, XIAO Guoqing1, YANG Zhihu1, CHEN Ximeng3. ZHAO Yongtao1, LI Fuli4, ZHANG Yinping1, CUI Ying3. ZHANG Hongqiang3. XU Xu3. SHAO Jianxiong3.& ZHAN Wenlong11. Institute of Modern physics, Chinese Academy of Sciences, Lanzhou 73.000, china 2. department of physics, Xianyang normal university, Xianyang 712000, china 3. department of Modern physics, Lanzhou university, Lanzhou 73.000, china 4. department of Applied physics, Xi’an Jiaotong university, Xi’an 710049, china Institute of Modern physics Chinese Academy of Sciences Lanzhou China department of physics Xianyang Normal University Xianyang China department of Modern physics Lanzhou University Lanzhou China department of Applied physics Xi’an Jiaotong University Xi’an China

By use of optical spectrum technology, the spectra of X-ray induced by highly charged 40Arq+ ions interacting with Au surface have been studied. The results show that the argon Kα X-ray were emitted from the hollow atoms formed below the surface. There is a process of multi-electron exciting in neutralization of the Ar16+ion, with electronic con-figuration 1s2 in its ground state below the solid surface. The yield of the projectile Kα X-ray is related to its initial electronic configuration, and the yield of the target X-ray is related to the projectile kinetic energy.

关键词： highly charged ion hollow multi-electron excitation X- ray.

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The information entropy of a static dilaton black hole

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Science china(physics,Mechanics & Astronomy) 2008年第2期51卷 113-125页

作者： LIU ChengZhou Institute of Theoretical physics, Binzhou university, Binzhou 256600, china {3. of physics, Beijing normal university, Beijing 100875, china Institute of Theoretical physics Binzhou University Binzhou China department of physics Beijing Normal University Beijing China

In accordance with holographic principle, by calculating the statistical entropy of the quantum field just at the event horizon of the Garfinkle-Horowitz-Strominger dilaton black hole, the information entropy of the black hole was investigated and the Bekenstein-Hawking formula was obtained. The results show that black hole entropy is identical with the statistical entropy of the quantum field at the horizon. Using the generalized uncertainty relation, the divergence of the state density near the event horizon in usual quantum field theory was removed, and the cutoffs and the little mass approximation in the heat gas method of black hole entropy were avoided. Thus, the microstates of the massive scalar field just at the event horizon of the static dilaton black hole were studied directly and a description on holograph principle was presented. By using residue theorem, the integral difficulty in the calculation was overcome, and the information entropy and the Bekenstein-Hawking formula were obtained quantitatively. Compared with the black hole entropy from the loop quantum gravity, the consistency of methods and results of calculating black hole entropy in non-commutative quantum field theory and loop quantum gravity was investigated. By this, the gravity correction constant in the generalized uncertainty relation was suggested and the sense of holographic principle was discussed.

关键词： black hole entropy holographic principle non-commutative quantum field theory event horizon loop quantum gravity

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Accurate studies on the full vibrational energy spectra and molecular dissociation energies for some electronic states of N_(2)molecule

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Science china(physics,Mechanics & Astronomy) 2005年第4期48卷 385-398页

作者： REN Weiyi1,2, SUN Weiguo1, HOU Shilin3.& FENG Hao4 1. Institute of physics, College of Chemical Engineering, Sichuan university, Chengdu 610065, china 2. Institute of Theoretical physics, Xihua normal university, Nanchong 63.002, china 3. department of physics, china Oceanography university, Qingdao 266003. china 4. College of physics, Sichuan university, Chengdu 610065, china Institute of physics College of Chemical Engineering Sichuan University Chengdu China Institute of Theoretical physics Xihua Normal University Nanchong China department of physics China Oceanography University Qingdao China College of physics Sichuan University Chengdu China

It is usually very difficult to directly obtain molecular dissociation energy De and all accurate high-lying vibrational energies for most diatomic electronic states using modern experimental techniques or quantum theories, and it is also very difficult to give accurate analytical expression for diatomic molecular dissociation energy. This study proposes a new analytical formula for obtaining accurate molecular dissociation energy based on the LeRoy and Bernstein’s energy expression in dissociation limit. A set of full vibrational energy spectra for some electronic states of N2 molecule are studied using the algebraic method (AM) suggested recently, and the corresponding accurate molecular dissociation energies are evaluated using the proposed new formula and high-lying AM vibrational energies. The results show that the AM spectra and the new theoretical dissociation energies agree excellently with experimental data, and thereby providing a new physical approach to generating accurate dissociation energies for electronic states of diatomic molecules.

关键词： vibrational energy, dissociation energy, nitrogen molecule, algebraic method.

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Optimal reactions for the synthesis of superheavy nucleus ^(270)Hs

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Science china(physics,Mechanics & Astronomy) 2006年第6期49卷 641-648页

作者： LIU Zuhua1,3.& BAO Jingdong1,2 1. Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing normal university, Beijing 100875, china 2. {3. department, Beijing normal university, Beijing 100875, china 3. china Institute of Atomic Energy, Beijing 102413. china Key Laboratory of Beam Technology and Material Modification of Ministry of Education Beijing Normal University Beijing China china Institute of Atomic Energy Beijing China physics department Beijing Normal University Beijing China

The superheavy nucleus 270Hs is expected to be a “double-magic” deformed nucleus. We have calculated its cross sections of evaporation residue for the reactions 248Cm(26Mg,4n)270Hs, 244Pu(3.Si,4n)270Hs, 23.U(3.S,4n)270Hs and 226Ra(48Ca,4n)270Hs using a two-parameter Smoluchowski equation. It is found from our results that 226Ra(48Ca,4n)270Hs and 23.U(3.S,4n)270Hs are two optimal reactions for the synthesis of the superheavy nucleus 270Hs due to their large negative Q-values.

关键词： diffused fusion barrier,Smoluchowski equation,superheavy nuclei.

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