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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 10004., china 2. Graduate School of Chinese Academy of sciences, Beijing 10004., 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, Beijing 10004., 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.

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Heterogeneous reaction of formaldehyde on the surface of TiO_2 particles

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Science china Chemistry 2010年第12期53卷 2644-2651页

作者： XU BingYe 1,2,ZHU Tong 1,TANG XiaoYan 1 & SHANG Jing 1 1 State Key joint laboratory of environmental Simulation and Pollution Control College of environmental {4. and Engineering,Peking university,Beijing 100871,china 2 Zhejiang Province environmental Monitoring Center,Hangzhou 310012,china State Key joint laboratory of environmental Simulation and Pollution Control College of environmental sciences and Engineering Peking University Beijing China Zhejiang Province environmental Monitoring Center Hangzhou China

The heterogeneous reaction of formaldehyde (HCHO) on the surface of titanium dioxide (TiO2) was investigated in situ using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) combined with ion chromatography (IC),X-ray diffraction (XRD),and transmission electron microscopy (TEM).Formate,dioxymethylene,methoxy,and polyoxymethylene were observed in the infrared spectra of TiO2 particles during the *** the surface of TiO2,the adsorbed HCHO was first oxidized to dioxymethylene and further oxidized to *** effects of temperature and ultraviolet radiation (UV) on the reaction products and reactive uptake coefficients were studied,and the results indicate that the reaction rate can be accelerated at increasing temperatures as well as under *** heterogeneous reaction mechanisms of HCHO on the surface of TiO2 in the dark and under UV irradiation are *** measurements show that formate formation on TiO2 is second order in HCHO concentration and the initial reactive uptake coefficients at room temperature calculated with the Brunauer-EmmettTeller specific surface area are (0.5-5) × 10-8 ([HCHO]:1 × 1013-2 × 10 14.molecules/cm3).A linear function relationship exists between the uptake coefficient and the *** apparent activation energy of the reaction was also determined.

关键词： DRIFTS formaldehyde heterogeneous reaction reactive uptake coefficient TiO2

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Boron isotopic fractionation in laboratory inorganic carbonate precipitation:Evidence for the incorpora-tion of B(OH)_3 into carbonate

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Science china Earth sciences 2008年第12期51卷 1776-1785页

作者： XIAO YingKai1,2, LI HuaLing1,3, LIU WeiGuo4. WANG XiuFang1 & JIANG ShaoYong5 1 Qinghai Institute of Salt Lakes, Chinese Academy of sciences, Xining 810008, china 2 State Key laboratory of environmental Geochemistry, Institute of Geochemistry, Chinese Academy of sciences, Guiyang 550002, china 3 Nanjing Institute of Geology and Mineral Resources, Nanjing 210016, china 4.State Key laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of sciences, Xi’an 710075, china 5 State Key laboratory for Mineral Deposits Research, Department of Earth sciences, Nanjing university, Nanjing 210093, china Qinghai Institute of Salt Lakes Chinese Academy of Sciences Xining China State Key laboratory of environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang China Nanjing Institute of Geology and Mineral Resources Nanjing China State Key laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China State Key laboratory for Mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing China

A laboratory inorganic carbonate precipitation experiment at high pH of 8.96 to 9.34.was conducted, and the boron isotopic fractionations of the precipitated carbonate were measured. The data show that boron isotopic fractionation factors (αcarb-3) between carbonate and B(OH)3 in seawater range 0.937 and 0.965, with an average value of 0.953. Our results together with those reported by Sanyal and collabo-rators show that the αcarb-3 values between carbonate and B(OH)3 in solution are not constant but are negatively correlated with the pH of seawater. The measured boron isotopic compositions of carbonate precipitation (δ11Bcarb) do not exactly lie on the best-fit theoretical δ 11B4.pH curves and neither do they exactly parallel any theoretical δ 11B4.pH curves. Therefore, it is reasonable to argue that a changeable proportion of B(OH)3 with pH of seawater should also be incorporated into carbonate except for the dominant incorporation of B(OH)4. in carbonate . Hence, in the reconstruction of the paleo-pH of sea-water from boron isotopes in marine biogenic carbonates, the use of theoretical boron isotopic frac-tionation factor (α4.3) between B(OH)4. and B(OH)3 is not suitable. Instead, an empirical equation should be established.

关键词： boron isotopic fractionation biogenic carbonate B(OH)3 incorporation

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Preliminary results of the study on wind erosion in the Qinghai-Tibetan Plateau using 137Cs technique

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Chinese Science Bulletin 2000年第11期45卷 1019-1025页

作者： YAN Ping, DONG Guangrong, ZHANG Xinbao & ZHANG Yiyun1. Key laboratory of environmental Change and Natural Disaster, the Ministry of Education of china, Beijing Normal university, Beijing 100875, china 2. Institute of Desert Research, Chinese Academy of sciences, Lanzhou 730000, china 3. Institute of Mountain Hazards and Environment, Chinese Academy of sciences, Chengdu 61004., china 4. Department of Physics, Sichuan Union university, Chengdu 61004., china Key laboratory of environmental Change and Natural Disaster the Ministry of Education of China Beijing Normal University Beijing China Institute of Desert Research Chinese Academy of Sciences Lanzhou China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu China Department of Physics Sichuan Union University Chengdu China

The worldwide fallout of caesium-137 (137Cs) associated with the nuclear weapon tests during the 1950s and 1960s has provided a valuable man-made tracer for studies of soil erosion and sediment delivery. But relatively few researchers have used it to estimate wind erosion. In this note, the 137Cs technique is introduced into the studies of wind erosion and its modern processes inthe Qinghai-Tibetan Plateau. Two 137Cs reference inventories of 982.11 and 2 376.04.Bq · m-2 wereestablished preminarily, distributed in the south and middle-north parts of the studied arearespectively. By analyzing the patterns of 137Cs depth profiles from sampling sites, the aeolianprocesses of erosion and deposition in nearly 4. years have been revealed, i.e. the shrub coppicedunes (S1) and semi-fixed dunefields (S3) experienced the alternation of erosion and deposition,while the grasslands (S4. S6 and S7) and dry farmlands (S5) suffered erosion only. By using 137Csmodel, the average wind erosion rates for shrub coppice

关键词： 137Cs technique Qinghai-Tibetan Plateau wind erosion.

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Effect of carbon source on the denitrification in constructed wetlands

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Journal of environmental sciences 2009年第8期21卷 1036-1043页

作者： LU Songliu, HU Hongying, SUN Yingxue, YANG Jia ESPC State Key joint laboratory, Department of environmental Science and Engineering, Tsinghua university, Beijing 100084. {4.. ESPC State Key joint laboratory Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China

The ability of constructed wetlands with different plants in nitrate removal were investigated. The factors promoting the rates of denitrification including organic carbon, nitrate load, plants in wetlands, pH and water temperature in field were systematically investigated. The results showed that the additional carbon source （glucose） can remarkably improve the nitrate removal ability of the constructed wetland. It demonstrated that the nitrate removal rate can increase from 20% to more than 50% in summer and from 10% to 30% in winter, when the nitrate concentration was 30-4. rag/L, the retention time was 24.h and 25 mg/L dissolved organic carbon （DOC） was ploughed into the constructed wetland. However, the nitrite in the constructed wetland accumulated a little with the supply of the additional carbon source in summer and winter, and it increased from 0.15 to 2 mg/L in the effluent. It was also found that the abilities of plant in adjusting pH and temperature can result in an increase of denitrification in wetlands. The seasonal change may also impact the denitrification.

关键词： constructed wetland carbon source denitrification nitrate nitrite

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The gravitational gradient tensor’s invariants and the related boundary conditions

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Science china Earth sciences 2010年第5期53卷 781-790页

作者： YU JinHai1,2,3 & ZHAO DongMing4.1 College of Earth Science, Graduate university of Chinese Academy of sciences, Beijing 10004., china 2 Institute of Geodesy and Geophysics, Chinese Academy of sciences, {4. 4.0077, china 3 State Key laboratory of Astronautic Dynamics, Xi’an 71004., china 4.Zhengzhou Institute of Surveying and Mapping, Zhengzhou 4.0052, china College of Earth Science Graduate University of Chinese Academy of Sciences Beijing China Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan China State Key laboratory of Astronautic Dynamics Xi’an China Zhengzhou Institute of Surveying and Mapping Zhengzhou China

Here we report new approaches of recovering the Earth gravitational field from GOCE (Gravity field and steady-state Ocean Circulation Explorer) gradiometric data with the help of the gradient tensor’s invariants. Our results only depend on GOCE satellite’s position and gradiometry, in other words, they are completely independent of the satellite attitude. First, starting from the invariants, linearization models are established, which can be referred as the general boundary conditions on the satellite’s orbit. Then, the spherical approximation expressions for the models are derived, and the corresponding solving methods for them are discussed. Furthermore, considering effects of J2-term, the spherical approximation models are improved so that the accuracies of the boundary conditions can be theoretically raised to O ( J 2/2 T), which is approximately equivalent to O(T2). Finally, some arithmetic examples are constructed from EGM96 model based on the derived theories, and the computational results illustrate that the spherical models have accuracies of 10-7 and the order recovering the gravitational field can reach up to 200, and the models with regard to effect of J2-term have accuracies of 10-8 and the order can reach up to 280.

关键词： the Earth’s gravitational field gravitational gravidiometry tensor’s invariant

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china's energy, environment and policy perspective

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Journal of environmental sciences 2000年第3期12卷 270-274页

作者： ZHANG Shi\|qiu (Center for environmental sciences, Peking university, Beijing 100871, china) Center for environmental sciences Peking University Beijing 100871 China

This paper discusses the specific features of the energy in china, and addresses those key challenges in china is that the co\|exist of (1) higher total energy production and lower per capita level; (2) lower per capita energy resources level with unrational energy consumption structure; (3) lower energy utilization efficiency and higher energy conservation potential; and (4. unequal distribution of energy resources. It reviews the key environmental problems related to the feature of energy production and consumption. Based on the analysis, the author furthers addresses the policy and actions needed.

关键词： energy energy production energy consumption environment policy

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Effects of Citral on Aspergillus flavus Spores by Quasi-elastic Light Scattering and Multiplex Microanalysis Techniques

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Acta Biochimica et Biophysica Sinica 2004年第4期36卷 277-283页

作者： Man LUO1,2, Li-Ke JIANG2, Yao-Xiong HUANG3, Ming XIAO4. Bo LI4. and Guo-Lin ZOU1* 1College of Life sciences, wuhan university, wuhan 4.0072, {4. 2College of Life sciences, Anhui Agricultural university, Hefei 230036, {4. 3 Institute of Biomedical Engineering, Ji’nan university, Guangzhou 510632, {4. 4.inistry of Education Key laboratory for Biodiversity Science and Ecological Engineering, the Institute of Biodiversity Science, Fudan university, Shanghai 2004.3, {4. College of Life sciences Wuhan UniversityWuhan 430072 China College of Life sciences Anhui Agricultural UniversityHefei 230036 China Institute of Biomedical Engineering Ji'nan UniversityGuangzhou 510632 China Ministry of Education Key laboratory for Biodiversity Science and Ecological Engineering the Institute of Biodiversity Science Fudan UniversityShanghai 200433 China

Citral refined from Litsea cubeba oil has been found to have a strong influence on fungi, especially Aspergillus flavus. Multiplex microanalysis and quasi-elastic light scattering techniques were applied to study the effects of citral on Aspergillus flavus spores from the levels of membrane, organelle and intracellular macromolecule. It was found that citral injured the wall and the membrane of A. flavus spore, resulting in decrease of its elasticity. After entering the cell, citral not only influenced the genetic expression of mitochondrion reduplication and its morphology, but also changed the aggregation of protein-like macromolecules. As a result, cells, organelles and macromolecules lost their normal structures and functions, eventually leading to the loss of germination ability of A. flavus spores. Since Litsea cubeba oil as food additive and antifungal agent is safe and less poisonous, it is important to elucidate the inhibitory mechanisms of Litsea cubeba oil on the germination ability of A. flavus spore.

关键词： citral Aspergillus flavus spore multiplex microanalysis techniques quasi-elastic light scattering technique

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A HIGH-ORDER-ACCURATE DIFFERENCE SCHEME WITH UNCONDITIONAL STABILITY FOR THE DIFFUSION EQUATION ON NONUNIFORM GRIDS

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Journal of Hydrodynamics 2001年第1期13卷 92-98页

作者： Wang Xuan, Yang Zhi-feng State Key laboratory of Environment Simulation and Pollution Control, Institute of environmental sciences, Beijing Normal university, Beijing 100875, {4.[WT5”HZ] Beijing Normal Univ. Beijing 100875 China

WT5”BZ]A high-order-accurate difference scheme with unconditional stability is developed for the diffusion equation on nonuniform grids. The theoretical analysis shows that the accuracy of this scheme is between third order and fourth order, and fourth-order accuracy is achieved in the case of the same grid steps being used within the computational domain. Two numerical examples are given to demonst ate the advantages of the proposed scheme. Compared with the conventional difference scheme, more accurate numerical solution can be obtained by using the proposed scheme even with relatively larger grid sizes. It is also pointed out that the appropriate structure of the nonuniform grid can not only make the proposed scheme more practical, but lead to a solution superior to that for a uniform grid structure. [WT5”HZ]

关键词： ]finite difference scheme diffusion equation nonuniform grid high accuracy computational fluid dynamics

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Characteristics of Ca2+-exocytosis coupling in isolated mouse pancreatic β cells

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Acta Pharmacologica Sinica 2006年第7期27卷 933-938页

作者： Qian GE~(2,4. Yong-ming DONG~(2,4. Zhi-tao HU~2 Zheng-xing WU~(2,5) Tao XU~(2,3,5)2 College of Life Science and Technology,Huazhong university of Science and Technology,wuhan 43.074,china 3 National laboratory of Biomacromolecules,Institute of Biophysics,Chinese Academy of {4.,Beijing 100101,china College of Life Science and Technology Huazhong University of Science and Technology Wuhan China National laboratory of Biomacromolecules Institute of Biophysics Chinese Academy of Sciences Beijing China

Aim:To characterize Ca2+-stimulated exocytosis in isolated mouse pancreatic β***:An improved method was described for isolation of mouse pan-creatic β cells by collagenase *** Ca2+channel current and the membranecapacitance were examined by using the whole-cell patch clamp ***:Using depolarization and flash photolysis of caged Ca2+toinduce Ca2+-dependent exocytosis in β cell from KM mouse,we have explored thecharacteristics of the Ca2+channel current and the relationship between Ca2+signals and *** averaged peak Ca2+current measured at +20 mV was-60±6 pA（n=13）.Conclusion:We characterized three kinetically different pools ofvesicles in mouse pancreatic β cells,namely an immediately releasable pool,areadily releasable pool,and a reserve pool.

关键词： mouse pancreatic βcells Ca2+-exocytosis coupling

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