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Constraints of authigenic carbonates on trace elements (Sr,Mg) of lacustrine ostracod shells in paleoenviron-ment reconstruction and its mechanism

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Science china Earth sciences 2008年第5期51卷 654-664页

作者： HU Guang1,2. JIN ZhangDong1 & ZHANG Fei3 1 State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, chinese academy of {2., Xi’an 710075, china 2.graduate University of the chinese academy of {2., beijing 100049, china 3 College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 2.0095, china State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an 710075 China graduate University of the chinese {2. of sciences Beijing 100049 China College of Resources and Env

Molar ratios of Mg/Ca and Sr/Ca were measured in two species of ostracod shells preserved in the upper core (15–55 m) of the Hequing Basin in Yunnan Province, southwest china. By correlating the molar ratios between Mg/Ca and Sr/Ca and comparing them with Sr concentrations of the sediments, we suggested that: (1) the molar Mg/Ca and Sr/Ca ratio variations in respective ostracod primo reflected the changes in its ambient water composition and ecology; (2. the molar Sr/Ca ratios responded better to the salinity change linearly than Mg/Ca without aragonite precipitation in the system, and otherwise there was no linear relation between them; and (3) the molar Sr/Ca ratios were mainly controlled by salinity and authigenic carbonate precipitation, whereas the molar Mg/Ca ratios were related to both salinity and temperature. In fact, the rate of ostracod growth owing to temperature controls the fluctuation of Mg/Ca in shells. Here, more attentions should be paid to the constraint of authigenic mineral precipitation processes on the trace elements in ostracod shells and to the correlation between these trace elements in biogenic carbonates and compositions of the sediments in systems and in future in vitro experiments.

关键词： ostracod shell molar Sr/Ca ratio molar Mg/Ca ratio environmental response Heqing Basin

Birthrates and delay times of Type Ia supernovae

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Science china(Physics,Mechanics & Astronomy) 2010年第3期53卷 586-590页

作者： WANG Bo1,2.3, LIU ZhengWei1,2.3, HAN YunKun1,2.3, LEI ZhenXin1,2.3, LUO YangPing1,2.3 & HAN ZhanWen1,2.1National Astronomical Observatories/Yunnan Observatory, chinese academy of {2., Kunming 650011, china 2.ey Laboratory for the Structure and Evolution of Celestial Objects, chinese academy of {2., Kunming 650011, china 3graduate University of chinese academy of {2.,{12., china 1. National Astronomical Observatories/Yunnan Observatory Chinese Academy of Sciences Kunming 650011 China2. Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650011 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Type Ia supernovae (SNe Ia) play an important role in diverse areas of astrophysics, from the chemical evolution of galaxies to observational cosmology. However, the nature of the progenitors of SNe Ia is still unclear. In this paper, according to a detailed binary population synthesis study, we obtained SN Ia birthrates and delay times from different progenitor models, and compared them with observations. We find that the Galactic SN Ia birthrate from the double-degenerate (DD) model is close to those inferred from observations, while the birthrate from the single-degenerate (SD) model accounts for only about 1/2.2.3 of the observations. If a single starburst is assumed, the distribution of the delay times of SNe Ia from the SD model is a weak bimodality, where the WD + He channel contributes to the SNe Ia with delay times shorter than 100 Myr, and the WD + MS and WD + RG channels to those with age longer than 1 Gyr.

关键词： binaries: close stars: evolution supernovae: general white dwarfs

Kumada chain-growth polycondensation as a universal method for synthesis of well-defined conjugated polymers

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Science china Chemistry 2010年第8期53卷 1620-1633页

作者： GENG YanHou1,HUANG Li1,2.WU ShuPeng1,2.& WANG FoSong1 1State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry,chinese academy of {2.,Changchun 13002.,china 2.4} University of chinese academy of {2.,beijing 100049,china 1. State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun 130022 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Kumada chain-growth polycondensation (KCGP) is a novel method for the synthesis of well-defined conjugated *** the Ni-catalyst can transfer in an intramolecular process to the propagating chain end,the polymerization follows chain-growth *** this newly developed method,various conjugated polymers,such as polythiophenes,poly(p-phenylene) (PPP),polypyrrole (PPy),and polyfluorene with controlled molecular weights and relatively narrow polydispersities (PDIs),have been ***,the polymerizations for poly(3-alkylthiophene)s (P3ATs),PPP,and PPy exhibited quasi-living characteristics,which allows preparing polymer brushes,fully-conjugated block copolymers,and macroinitiators and macro-reactants for the synthesis of rod-coil block *** the current review,the progress in this new area is summarized.

关键词： chain growth polycondensation conjugated polymers Kumada reaction block copolymers polymer brush

A computational model for feature binding

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Science china(Life sciences) 2008年第5期51卷 470-478页

作者： SHI ZhiWei1,2. SHI ZhongZhi1, LIU Xi1,2.& SHI ZhiPing1 1 Key Laboratory of Intelligent Information Processing, Institute of Computing Technology, chinese academy of {2., beijing 100190, china 2.graduate University of chinese academy of {2., beijing 100049, china Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China graduate University of chinese {2. of sciences Beijing 100049 China

The "Binding Problem" is an important problem across many disciplines, including psychology, neuroscience, computational modeling, and even philosophy. In this work, we proposed a novel computational model, Bayesian Linking Field Model, for feature binding in visual perception, by combining the idea of noisy neuron model, Bayesian method, Linking Field Network and competitive mechanism. Simulation Experiments demonstrated that our model perfectly fulfilled the task of feature binding in visual perception and provided us some enlightening idea for future research.

关键词： Binding Problem computational model Bayesian Linking Field Model

Characterization of GLUT4-containing vesicles in 3T3-L1 adipocytes by total internal reflection fluorescence microscopy

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Science china(Life sciences) 2009年第7期52卷 665-671页

作者： WANG Yan1,2.ZHANG JinZhong1,2.CHEN Yu1,2.JIANG Li1,2.JI Wei1,2.& XU Tao1 1 National Laboratory of Biomacromolecules,Institute of Biophysics,chinese academy of {2.,beijing 100101,china 2.graduate University of chinese academy of {2.,beijing 100049,china 1. National Laboratory of Biomacromolecules Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China 2. graduate University of chinese {2. of sciences Beijing 100049 China

Insulin-responsive GLUT4(glucose transporter 4) translocation plays a major role in regulating glucose uptake in adipose tissue and *** or not there is a specialized secretory GSV(GLUT4 storage vesicle) pool,and more importantly how GSVs are translocated to the PM(plasma membrane) under insulin stimulation is still under *** the present study,we systematically analyzed the dynamics of a large number of single GLUT4-containing vesicles in 3T3-L1 adipocytes by TIRFM(total internal reflection fluorescence microscopy).We found that GLUT4-containing vesicles can be classified into three groups according to their mobility,namely vertical,stable,and lateral GLUT4-containing *** these groups,vertical GLUT4-containing vesicles exclude transferrin receptors and move towards the PM specifically in response to insulin stimulation,while stable and lateral GLUT4-containing vesicles contain transferrin receptors and show no insulin *** data demonstrate that vertical GLUT4-containing vesicles correspond to specialized secretory GSVs,which approach the PM directly and bypass the constitutive recycling pathway.

关键词： GLUT4 IRAP-pHluorin GSV transferring TIRFM

Mechanism and Defense on Malicious Code

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Wuhan University Journal of Natural sciences 2005年第1期10卷 83-88页

作者： WEN Wei-ping 1,2.3, QING Si-han 1,2.31. Institute of Software, the chinese academy of {2., beijing 100080, china 2.Engineering Research Center for Information Security Technology, the chinese academy of {2., beijing 100080, china 3.graduate School of the chinese academy of {2., beijing 100080, china Institute of Software the Chinese Academy of Sciences Beijing 100080 China

With the explosive growth of network applications, the threat of the malicious code against network security becomes increasingly serious. In this paper we explore the mechanism of the malicious code by giving an attack model of the malicious code, and discuss the critical techniques of implementation and prevention against the malicious code. The remaining problems and emerging trends in this area are also addressed in the paper.

关键词： malicious code attacking model mechanism defense system security network security

Variation properties of ionospheric eclipse factor and ionospheric influence factor

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Progress in Natural Science:Materials International 2005年第6期15卷 573-576页

作者： ZHAO Chunmei 1,2.*, YUAN Yunbin1, OU Jikun1 and CHEN Jinping3(1. Institute of Geodesy and Geophysics, chinese academy of {2., Wuhan 430077, china 2. graduate School of chinese academy of {2., beijing 100039, china 3. Department of Precision Instrument and Mechanology, Tsinghua University, beijing 100084, china) Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China graduate School of chinese {2. of sciences Beijing 100039 China Department of Precision Instrument and Mechanology Tsinghua University Beijing 100084 China

The concepts and calculation methods of ionospheric eclipse factor (IEF) and ionospheric influence factor (IFF) are further illustrated. The temporal and spacial variation properties of IEF and IFF are studied, which shows that the properties are influenced by the geographic position and season. The possibility of improving the precision of using GPS data to determine ionospheric delay based on the above variation properties is also analysed.

关键词： GPS ionospheric eclipse factor ionospheric influence factor

Triaxial ellipsoid models of the Moon based on the laser altimetry data of Chang'E-1

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Science china Earth sciences 2010年第11期53卷 1594-1601页

作者： WANG WenRui1,2.3, LI Fei1, LIU JianJun1, REN Xin2. ZOU XiaoDuan2.3, MU LingLi2. YAN JianGuo1, ZOU YongLiao2. ZHANG HongBo2. Lü Chang2. LIU JianZhong2. ZUO Wei2. SU Yan2. WEN WeiBin2. BIAN Wei2. WANG Min2. LI ChunLai2.& OUYANG ZiYuan2.1 School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, china 2.National Astronomical Observatory of chinese {2. of sciences, beijing 100012. china 3 graduate School of chinese {2. of sciences, beijing 100049, china 1. School of Geodesy and Geomatics Wuhan University Wuhan 430079 China2. National Astronomical Observatory of Chinese Academy of Sciences Beijing 100012 China3. Graduate School of Chinese Academy of Sciences Beijing 100049 China

Lunar geodetic parameters, which play an important role in lunar exploration, can be calculated from the gravity and topography data. With the CE-1 altimetry data and LP gravity model, we calculate such geodetic parameters as the principle moment of inertia, the principle inertia axes, equatorial radius, polar radius, mean radius, flattening and offset between center of mass and center of figure (DCOM-COF). According to the CE-1 altimetry data and the above geodetic parameters, a tri-axial ellipsoid (CE-1-LAM-GEO) and a tri-axial level ellipsoid (CE-1-LAM-LEVEL) are calculated individually, providing mass center and figure center offset (DCOM-COF) and parameters more reliable in direction and magnitude.

关键词： Chang’E-1 laser altimetry data lunar ellipsoid lunar gravity

Studies on BEPC upgrade from pretzel to double-ring

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Science china(Physics,Mechanics & Astronomy) 2010年第11期53卷 2084-2089页

作者： ZHANG Chuang Institute of High Energy Physics,chinese academy of {2.,beijing 100049,china 1. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China

Physics opportunity in the charm and τ energy region calls for higher luminosity of the beijing Electron-Positron Collider (BEPC).The BEPC has experienced continuous improvement since its completion in ***,as a major upgrading project of the BEPC,aims at enhancing its luminosity of factor 30–100,following the principle of "one machine,two purposes" as adopted in BEPC,so that both high energy physics and synchrotron radiation experiments can be carried out with *** the BEPC to BEPCII,the double-ring scheme with multi-bunch e +-e-collision in the large crossing angle was studied in comparison with the single-ring pretzel *** the dedicated synchrotron radiation operation,artful "bridges" are designed to connect two halves of the outer ring in both the southern and the northern crossing *** paper reviews the studies on the BEPC upgrade from pretzel to double-ring structure of BEPCII.

关键词： collider storage ring high energy physics synchrotron radiation