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fMRI time series analysis based on stationary wavelet and spectrum analysis

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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,{3., china 2. {4. School of chinese academy of Sciences,{3., china 3. Department of Physics, Zhoukou Normal University, Zhoukou 4.6100, 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,{3., china 6. Department of Physics, Zhejiang University, Hangzhou 3.0027, 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.

A Test on Different Types of the Time Curve of Hardness Ratio of Gamma-Ray Bursts based on the Curvature Effect

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chinese Journal of Astronomy and Astrophysics 2008年第4期8卷 451-464页

作者： Lan-Wei Jia National Astronomical Observatories/Yunnan Observatory,chinese academy of Sciences,Kunming 650011,china {3. School of chinese academy of Sciences,beijing 10004.,china National Astronomical Observatories/ Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China and graduate School of chinese academy of Sciences Beijing 100049 China

We analyzed a sample of 66 gamma-ray bursts （GRBs） and statistically confirmed the prediction on the time curve of the hardness ratio of GRBs made by Qin et al. based on the curvature effect. In their analysis, GRB pulses are divided into three types according to the shape of their raw hardness ratio （RHR） time curves, defined as to include the background counts to the signal counts, so as to make use of counts within small time intervals. Of the three types, very hard sources exhibit a perfect pulse-like profile （type 1）, hard bursts possess a pulse-like profile with a dip in the decay phase （type 2）, and soft bursts show no pulse-like profile but have only a dipped profile （type 3.. In terms of the conventional hardness ratio, type 3.sources are indeed generally softer than those of type 1 and type 2, in agreement with the prediction. We found that the minimum value of RHR is sensitive in distinguishing the different types. We propose that GRB pulses can be classified according to the minimum value of RHR and that the different type sources may be connected with different strengths of the shock or/and the magnetic field.

关键词： gamma-rays burst -- gamma-rays observations - methods statistical

Construction of AFLP-based genetic linkage maps for the chinese shrimp Fenneropaeneus chinensis

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chinese Science Bulletin 2008年第8期53卷 1205-1216页

作者： TIAN Yi1,2,3.4. KONG Jie1↑ & WANG WeiJi1 1 Yellow Sea Fisheries Research Institute, chinese academy of Fishery Science, Qingdao 266071,{3. 2 College of Life Science and Technology, Dalian Fisheries University, Dalian 116023.{3. 3.Institute of Oceanology, chinese academy of Sciences, Qingdao 266071,{3. 4.graduate University of chinese academy of Sciences, beijing 10004.,{3. chinese Acad Fisheries Sci Yellow Sea Fisheries Res Inst Qingdao 266071 Peoples R China.

Fenneropaeneus chinensis is an important species in marine fishery resources and aquaculture in china. A genetic linkage map is essential for improving the efficiency of its breeding by marker-as- sisted selection and identifying commercially important genes. Linkage maps of F. chinensis were constructed with an F2 mapping population (110 progenies) using amplified fragment length polymor- phic (AFLP) marker in this study. Fifty-five AFLP primer combinations produced 53. AFLP markers fitting for map strategy in mapping family. The markers with 3.1 segregating ratios were analyzed using F2 intercross model for the common linkage map, while the markers with 1:1 ratio were analyzed using the pseudo-testcross strategy. The maps of male, female and common were constructed. The female map included 103.markers that formed 28 linkage groups, covering a total length of 1090 cM. All mark- ers were linked with the linkage groups. Segregation distortion was observed for 6 of 103.markers in the female map. The average distance between markers was 14.53.cM and ranged from 4.4.to 24.8 cM. The male map included 14. markers that formed 3. linkage groups. Ten markers remained unlinked in male map. Segregation distortion was observed for 7 of 14. markers in the male map. The total dis- tance of male map covered 1617 cM. The average distance between markers was 16.3. cM. The male map was 3..6% longer than the female map, which may reflect sex-specific recombination rates in chinese shrimp. The common map was composed of 216 markers, including in 4. linkage groups covering a total distance of 1772.1 cM. Two markers remained unlinked. No distorted markers of 216 markers were shown in the common map. The distance between markers was 10.4. cM. An average estimated genome size for the chinese shrimp was 24.0 cM, which was consistent with the relative size of the Penaeid genome. The distribution of AFLP markers was relatively even in chromosomes of Chi- nese shrimp maps. The linkage analysis

关键词： AFLP 海洋渔业虾中国

Observation results of relativistic electrons detected by Fengyun-1 satellite and analysis of relativistic electron enhancement (REE) events

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Science china(Physics,Mechanics & Astronomy) 2008年第12期51卷 1947-1956页

作者： YANG XiaoChao1,2↑ & WANG ShiJin1 1 Center for Space Science and Applied Research, chinese academy of Sciences, beijing 100190,{3. 2 {4. University of chinese academy of Sciences, beijing 10004.,{3. 1. Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China 2. graduate University of chinese academy of Sciences Beijing 100049 China

The space particle component detector on Fengyun-1 satellite which works at the sun-synchronous orbit of about 870 km altitude has detected relativistic electrons for a long time. In comparison with the SAMPEX satellite observations during 1999–2004. the relativistic electron data from Fengyun-1 satellite from June 1999 to 2005 are used to analyze the relativistic electron enhancement (REE) events at the low earth orbit, and the possible correlation among REE events at the low earth orbit, high-speed solar wind and geomagnetic storms is discussed. The statistical result presents that 4. REE events are found in total during this time period, and the strong REE events with the maximum daily average flux > 4.0 cm?2·srt-1·s?1 occur mostly during the transition period from solar maximum to solar minimum. Among these 4. REE events, four strong REE events last a longer time period from 26-to 51-day and correlate closely with high speed solar wind and strong geomagnetic storms. Meanwhile, several strong geomagnetic storms occur continuously before these REE events, and these continuous geomagnetic storms would be an important factor causing these long-lasting strong REE events. The correlation analysis for overall 4. events indicates that the strength of the REE events correlates with the solar wind speed and the strength of the geomagnetic storm, and the correlation for strong REE events is much stronger than that for weak REE events.

关键词： relativistic electron enhancement low earth orbit high-speed solar wind geomagnetic storm

Geographical Agglomeration of chinese Manufacturing Industries

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中国人口·资源与环境：英文版 2007年第2期5卷 3-11页

作者： Zhang Hua 1, 2, Zheng Wei3.1. Institute of Geographical Sciences and Natural Resources Research, chinese academy of Sciences, beijing 100101,{3. 2. {4. School of the chinese academy of Sciences, beijing 10003.,{3. 3. School of Geography, beijing Normal University, beijing 100875,{3. Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China graduate School of the chinese academy of Sciences Beijing 100039 China School of Geography Beijing Normal University Beijing 100875 China

Based on the plant level data from the First National Census of Basic Units, the Second National Census of Basic Units, and the First National Economic Census of china, this paper ex- amines the geographical agglomeration of chinese manufacturing industries at a more disaggregated level both by industrial classi-fication and spatial unit analysis. Applying the agglomeration index proposed by Maurel and Sedillot, studies show that the most agglomerated industries are resource-intensive, and capital and technology intensive while industries demanding localized inputs or serving localized markets or favored by local governments are fairly dispersed. The more disaggregated industries are more spa- tially agglomerated. At the finer spatial scale, industries are more dispersed. Results indicate that within-county spillovers are stronger than nearby-county spillovers, and within-prefecture spillovers are stronger than nearby prefecture spillovers. Local- ized spillovers are still quite substantial at a range beyond that of counties. Comparing the agglomeration index of chinese manu- facturing industries in 1996, 2001 and 200{3. agglomeration seems to be a general tendency. Results also indicate that some industries have experienced remarkable changes in their levels of agglom- eration in the period 1996–200{3.

关键词： industrial agglomeration manufacturing industries the MS index

Ionization state of cosmic hydrogen by early stars and quasars

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Research in Astronomy and Astrophysics 2009年第6期9卷 665-681页

作者： Xiao-Chun Mao1,2 1 National Astronomical Observatories, chinese academy of Sciences, beijing 100012,{3. 2 {4. University of chinese academy of Sciences, beijing 10004.,{3. National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China graduate University of chinese academy of Sciences Beijing 100049 China

Cosmic hydrogen is reionized and maintained in its highly ionized state by the ultraviolet emission attributed to an early generation of stars and quasars. The Lyα opacity observed in absorption spectra of high-redshift quasars permits more stringent constraints on the ionization state of cosmic hydrogen. Based on density perturbation and structure formation theory, we develop an analytic model to trace the evolution of the ionization state in the post-overlap epoch of reionization, in which the bias factor is taken into account. For quasars, we represent an improved luminosity function by utilizing a hybrid approach for the halo formation rate that is in reasonable agreement with the published measurements at 2 ≤ z ≤ 6. Comparison with the classic Press-Schechter mass function of dark matter halos, we demonstrate that the biased mass distribution indeed enhances star formation efficiency in the overdense environment by more than 25 per cent following the overlap of ionized bubbles. In addition, an alternative way is introduced to derive robust estimates of the mean free path for ionizing photons. In our model, star-forming galaxies are likely to dominate the ionizing background radiation beyond z = 3. and quasars contribute equally above a redshift of z ～ 2.5. From 5 ≤ z ≤ 6, the lack of evolution in photoionization rate can thus be explained by the relatively flat evolution in star formation efficiency, although the mean free path of ionizing photons increases rapidly. Moreover, in the redshift interval z ～ 2 - 6, the expected mean free path and Gunn-Peterson optical depth obviously evolve by a factor of ～ 500 and ～50 respectively. We find that the relative values of critical overdensities for hydrogen ionization and collapse could be 4.0% at z ≈2 and 2% at z ≈6, suggesting a rapid overlap process in the overdense regions around instant quasars following reionization. We further illustrate that the absolute estimates of the fraction of neutral hydrogen computed fr

关键词： cosmology theory -- formation galaxies -- quasars general -- diffuse radiation -- intergalactic medium

Valuations on arithmetic surfaces

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Science china Mathematics 2009年第1期52卷 66-76页

作者： XU Ning Department of Mathematics, graduate School of chinese academy of Sciences,{3.,{4. Department of Mathematics Graduate School of Chinese Academy of Sciences Beijing 100049 China

In this paper, we give the definition of the height of a valuation and the definition of the big field ? p,G , where p is a prime and G ? ? is an additive subgroup containing 1. We conclude that ? p,G is a field and ? p,G is algebraically closed. Based on this the author obtains the complete classification of valuations on arithmetic surfaces. Furthermore, for any m ? p,G n ∈ ?, let V m,n be an ∝-vector space of dimension n - m + 1, whose coordinates are indexed from m to n. We generalize the definition of ? p,G , where p is a prime and G ? V m,n is an additive subgroup containing 1. We also conclude that ? p,G is a field if m ? 0 ? n.

关键词： valuation height rank totally ordered group big field transcendental number 14.10

Geomorphologic evidence of phased uplift of the northeastern Qinghai-Tibet Plateau since 14.million years ago

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Science china Earth Sciences 2004年第9期47卷 822-833页

作者： LU Huayu1, WANG Xiaoyong1, AN Zhisheng1, MIAO Xiaodong1, ZHU Rixiang3. MA Haizhou2, LI Zhen4. TAN Hongbing2 & WANG Xianyan1 1. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, chinese academy of Sciences, Xi’an 710075{3. 2. Qinghai Institute of Salt Lakes, chinese academy of Sciences. Xining 810008,{3. 3. Institute of Geology and Geophysics, chinese academy of Sciences, beijing 100029,{3. 4. Department of Geography, Qinghai Normal University, Xining 810008,{3. chinese Acad Sci Inst Earth Environm State Key Lab Loess & Quaternary Geol Xian 710075 Peoples R China chinese Acad Sci Qinghai Inst Salt Lakes Xining 810008 Peoples R China chinese Acad Sci Inst Geol & Geophys Beijing 100029 Peoples R China Qinghai Normal Univ Dept Geog Xining 810008 Peoples R China

A typical sequence of fluvial terraces and aeolian deposits overlying these ter- races were multidisciplinary investigated. New evidences for uplift process of the northeastern Qinghai-Tibetan Plateau in the past 14.million years were obtained. At least 11 river terraces along Huangshui, the first-class tributary of Yellow River, at the Xining-Huzhu region are identi- fied. While the first one (T1) is classified as an accumulation terrace, the others are all basement river terraces, which consist of the Tertiary sandstone and siltstone bedrock, fluvial gravel and pebbles and the overlying aeolian loess-Red Clay deposit. Samples from the aeolian deposits were examined for paleomagnetic stratigraphic reconstruction (103. samples), luminescence dating (16 samples), magnetic susceptibility and grain-size distribution (more than 4.00 sam- ples). The luminescence dating and stratigraphic correlation suggest that terraces of Tll, T10, T8, T7, T3. T2, T1 were formed at 14. 11.3. 1.55, 1.2, 0.15, 0.07 and 0.01 million years ago, re- spectively. Sedimentological analysis and geomorphological observation indicate that formation and evolution of these terraces were mainly driven by tectonic uplift. Therefore, the terrace se- quence provides an ideal geological record, of the uplift process of the northeastern during the past 14.million years, and the timings of the terraces formation are regarded as the timings of tectonic uplift. The significant uplifting events took place at 14. 11.3. 1.2 and 0.15 mil- lion years ago, respectively. The fluvial incision at the Xining-Huzhu region is less than 100 m during a period of ~12 million years in the Miocene era (between the Tll and T9), while the Huangshui River had incised 4.2 m during the past 1.2 million years (from T7 to the present floodplain). The river incision process clearly demonstrates that accelerated rising of the north- eastern Qinghai-Tibet Plateau during the late Cenozoic, and provides new evidence of previous thoughts

关键词： river terrace, tectonic uplift, loess-Red Clay, the past 14 million years, northeastern Qinghai-Tibet Plateau.

Time of impact of fragment P2 of comet SL 9 on Jupiter

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chinese Science Bulletin 1997年第5期42卷 396-398页

作者： ZHOU Hongnan,QIAN Bochen, HUANG Keliang and LI Qibin1. Department of Astronomy, Nanjing University, Nanjing 210093. china 2. Shanghai Observatory, chinese academy of Sciences, Shanghai 20003., china 3. Physics Department, Nanjing Normal University, Nanjing 210097, china 4. beijing Astronomical Observatory, chinese academy of Sciences, beijing 100080, china Department of Astronomy Nanjing University Nanjing China Shanghai Observatory Chinese Academy of Sciences Shanghai China Physics Department Nanjing Normal University Nanjing China beijing Astronomical Observatory Chinese Academy of Sciences Behijing China

FROM 1994.07-16 to 1994.07-22, 21 fragments of comet SL 9 impacted against Jupiter in succession. During the impact period the impact of fragments D, E, K, N, P2 and S was observed in china. We used a 1.56-m telescope with the CCD camera of Shanghai Observatory to monitor Jupiter and its Galilean Satellites, obtaining 1000 high-quality images at B, V, I wave bands. Our data on optical wave bands are rather complete and valuable in the world. Specially, we got some images of Jupiter, Io and Europa in the impact time of fragment P2 impacting against Jupiter. This will help us understand the precise time, position, depth and energy of the P2’s collision. In this note, we report the impact time of fragment P2 of comet SL 9 and Jupiter. Since the impact of comet SL 9 was expected to take place on the side of Jupiter

关键词： comet comet Shoemaker-Levy 9 impacting against Jupiter impact time.