检索结果-南通市图书馆

fMRI time series analysis based on stationary wavelet and spectrum analysis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

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. Department of physics, 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 310027, 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.

Hard X-ray lags of Cygnus X-1 on short timescales

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 150-152页

作者： JIN Jing1,LU Yu2.3,QU JinLu2 & LI TiPei1,2 1 Department of Engineering physics & Center for Astrophysics,Tsinghua University,beijing 100084,china 2 Key Laboratory of Particle Astrophysics,institute of high energy physics,chinese academy of sciences,beijing 100049,china 3 Graduate University of chinese academy of sciences,beijing 100049,china Department of Engineering physics & Center for Astrophysics Tsinghua University Beijing China Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China

Calculating the time lags over different timescales using the cross-correlation technique may lead to a biased estimate of small *** a timescale for lightcurve binning,we propose to subtract the local average instead of the global average during the cross-correlation,in order to filter variations on timescales larger than the bin *** new method allows us to make an unbiased estimate of the time lags using RXTE/PCA data on timescales as small as-5 ms,where the Fourier technique becomes *** calculate the time lag spectra of Cygnus X-1 at different spectral states with the new method,and find that the source appears to have similar X-ray lags on small timescales independent of its spectral states.

关键词： spectral lags Cygnus X-1 data analysis

Light collection of the POLAR detector

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 43-46页

作者： DONG YongWei,LI YanGuo,WU BoBing,ZHANG YongJie & ZHANG ShuangNan Key Laboratory of Particle Astrophysics,institute of high energy physics,chinese academy of sciences,beijing 100049,china Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China

POLAR is a compact polarimeter dedicated to measuring the polarization of GRBs between 50-350 *** light collection of 200 mm×6 mm×6 mm plastic bars has been simulated and optimized in order to get uniform response to X-rays at different points along one single *** to the Monte Carlo results,the amplitude uniformity strongly depends on the level of polishing of the scintillator surface and the covering.A uniformity of 89% is achieved with a prototype constructed by a non position-sensitive PMT and an array of 4×4 bars.

关键词： plastic scintillator light collection gamma-ray burst polarimeter

SVOM gamma ray monitor

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 40-42页

作者： DONG YongWei,WU BoBing,LI YanGuo,ZHANG YongJie & ZHANG ShuangNan Key Laboratory of Particle Astrophysics,institute of high energy physics,chinese academy of sciences,beijing 100049,china Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China

The space-based multi-band astronomical Variable Object Monitor(SVOM) mission is dedicated to the detection,localization and broad-band study of gamma-ray bursts(GRBs) and other high-energy transient *** gamma ray monitor(GRM) onboard is designed to observe GRBs up to 5 *** this instrument,one of the key GRB parameters,Epeak,can be easily measured in the hard X-ray *** can achieve a detection rate of 100 GRBs per year which ensures the scientific output of SVOM.

关键词： gamma-ray burst Epeak triple phoswich

Observation of signature inversion in the πh_(9/2)(×)νi_(13/2) oblate band

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2005年第4期48卷 442-449页

作者： XIE Chengying1,2, ZHOU Xiaohong1,2, ZHANG Yuhu1, GUO Yingxiang1, LEI Xiangguo1, ZHENG Yong1, LIU Minliang1, SONG Litao1, WANG Hualei1, YU Haiping1, GUO Wentao 1, LUO Peng1, WU Zhijun1, ZHU Lihua3 & WU Xiaoguang3 ⒈ institute of Modern physics, chinese academy of sciences, Lanzhou 730000, china ⒉ Graduate School of the chinese academy of sciences, beijing 100049, china ⒊ institute of Atomic energy Research, beijing 102413, china institute of Modern physics Chinese Academy of Sciences Lanzhou China Graduate School of the chinese academy of sciences Beijing China institute of Atomic energy Research Beijing China

high-spin states in 190Tl have been studied via the 160Gd(35Cl, 5nγ) reaction. The level scheme, consisting of the π h9 /2 νi13/2 oblate band and a cascade with character of single particle excitations, has been established. Spin values have been firmly assigned to the oblate band in 190Tl, resulting in low-spin signature inversion in the π h9 /2 νi13/2 oblate band for the first time. Based on the similarity of the level structure in doubly odd Tl nuclei, spin values for the oblate bands in 192―200Tl should be re-assigned, and a consistent low-spin signature inversion has occurred in these oblate deformed nuclei. The low-spin signature inversion phenomena can be interpreted qualitatively by using the 2-quasiparticle plus rotor model including p-n residual interactions.

关键词： deformed odd-odd 190Tl, oblate rotational bands, signature inversion, 2-qp+rotor model.

Unsteady Numerical Simulation of Hot Streak/Blades Interaction and Film Cooling

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2010年第5期19卷 402-409页

作者： Weilin Yi,Lucheng Ji and Yunhan Xiao Research Center for energy and Power,chinese academy of sciences,beijing,china Key Laboratory of Advanced energy and Power,chinese academy of sciences,(institute of Engineering Thermophysics),beijing,china P.O.Box 2706,beijing 100190,china Research Center for energy and Power Chinese Academy of Sciences Beijing China Key Laboratory of Advanced energy and Power Chinese Academy of Sciences (Institute of Engineering Thermophysics) Beijing China beijing China

Deeply research on management and application of hot streak is an important way to breakthrough technique obstacle of aero engine hot *** method is a useful instrument to investigate the correlative *** the paper developed independently three dimensional unsteady parallel computational code-MpiTurbo based on Fortran 90 and MPI at Linux operating *** unsteady numerical simulation was carried out to investigate impacts of the factors,which included circumferential locations of hot streak and clocking positions of blade rows,on the thermal environment of a 1+1 counter-rotating *** results clearly indicated that clocking positions of hot streak/blade row and blade row/blade row had great influence on the time-averaged temperature distribution of the third blade ***,it can be effective for improving thermal environment of turbine to optimize blade parameters and clocking *** film cooling layout was designed by the repetitious steady simulation based on source term *** the flow structure detail was given by the unsteady simulation.

关键词： hot streak turbine parallel computation film cooling

Study of D^0-D^0 mixing at a giga-Z linear collider

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2010年第11期53卷 1953-1956页

作者： LI HaiBo 1 & YANG MaoZhi 2 1 institute of high energy physics,P.O.Box 918,beijing 100049,china 2 School of physics,Nankai University,Tianjin 300071,china institute of high energy physics Beijing China School of physics Nankai University Tianjin China

The possibility of studying D 0-D 0 mixing at a giga-Z linear collider "Z factory" where 10 9 hadronic Z 0 decays can be accumulated is *** discuss the sensitivity for the measurements of neutral D mixing *** results are compared to those attainable at B *** find that the typical decay length of the neutral D mesons at Z factory is about 10 times larger than that at B *** addition,the resolution of the vertex detector of a giga-Z factory is 2.3 times better than that of B *** proper time resolution at Z factory is about 20-30 times better than that at B *** the determination of the mixing parameters at a giga-Z factory is more precise.

关键词： Z factory D0 mesons mixing B factory

Primary scientific results of Chang'E-1 lunar mission

在线全文

学校读者我要写书评

暂无评论

Science china Earth sciences 2010年第11期53卷 1565-1581页

作者： OUYANG ZiYuan1,2, LI ChunLai1, zou YongLiao1, ZHANG HongBo1, Lü Chang1, LIU JianZhong1, LIU JianJun1, ZUO Wei1, SU Yan1, WEN WeiBin1, BIAN Wei1, ZHAO BaoChang3, WANG JianYu4, YANG JianFeng3, CHANG Jin5, WANG HuanYu6, ZHANG XiaoHui7, WANG ShiJin7, WANG Min1, REN Xin1, MU LingLi1, KONG DeQing1, WANG XiaoQian1, WANG Fang1, GENG Liang1, ZHANG ZhouBin1, ZHENG Lei1, ZHU XinYing1, ZHENG YongChun1, LI JunDuo1, zou XiaoDuan1, XU Chun1, SHI ShuoBiao1, GAO YiFei1 & GAO GuanNan1 1 National Astronomical Observatories, chinese academy of sciences, beijing 100012, china 2 institute of Geochemistry, chinese academy of sciences, Guiyang 550002, china 3 Xi’an institute of Optics and Precision Mechanics, chinese academy of sciences, Xi’an 710119, china 4 Shanghai institute of Technical physics, chinese academy of sciences, Shanghai 200083, china 5 Purple Mountain Observatory, chinese academy of sciences, Nanjing 210008, china 6 institute of high energy physics, chinese academy of sciences, beijing 100049, china 7 Center for Space Science and Applied Research, chinese academy of sciences, beijing 100190, china National Astronomical Observatories Chinese Academy of Sciences Beijing China institute of Geochemistry Chinese Academy of Sciences Guiyang China Xi’an institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an China Shanghai institute of Technical physics Chinese Academy of Sciences Shanghai China Purple Mountain Observatory Chinese Academy of Sciences Nanjing China institute of high energy physics Chinese Academy of Sciences Beijing China Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China

The strategic plan for the development of the unmanned chinese Lunar Exploration Program is characterized by three distinct stages: "orbiting around", "landing on" and "returning from" the Moon. The first chinese lunar probe, Chang'E-1, which was successfully launched on October 24th, 2007 at Xichang Satellite Launch Center, and guided to crash on the Moon on March 1st, 2009, at 52.36°E, 1.50°S, in the north of Mare Fecunditatis, is the first step towards the "orbiting around" stage. The Chang'E-1 mission lasted 495 days, exceeding the expected life-span by about four months. A total of 1.37 TB raw data was received from Chang'E-1. It was then processed into 4 TB scientific data products at various levels. Many scientific results have been obtained by analyzing these data, including especially the "global lunar image from the first chinese lunar explora- tion mission". All scientific goals of Chang'E-1 have been achieved. It provides much useful materials for further advances of lunar sciences and planetary chemistry. Meanwhile, these results will serve as a firm basis for future chinese lunar missions.

关键词： lunar orbiter Chang’E-1 scientific data results

Challenges in the theoretical investigations of lipid membrane configurations

在线全文

学校读者我要写书评

暂无评论

chinese physics B 2013年第2期22卷 36-44页

作者：涂展春 Department of physics Beijing Normal University Kavli institute for Theoretical physics china Chinese Academy of Sciences

We report some key results in the theoretical investigations of configurations of lipid membranes and present several challenges in this field,which involve（i）the exact solutions to the shape equation of lipid vesicles,（ii）the exact solutions to the governing equations of open lipid membranes,（iii）the neck condition of two-phase vesicles in the budding state,（iv） the nonlocal theory of membrane elasticity,and（v）the relationship between the symmetry and the magnitude of the free energy.

关键词： configuration lipid membrane