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Science China Chemistry 2010年第3期53卷 519-527页

作者： ZHANG Yu1,2,SUN PeiJian1,2 & GAN ZhiHua1 1CAS Key Laboratory of Engineering Plastics,Institute of Chemistry,chinese academy of sciences,beijing 100190,China 2{4. University of chinese academy of sciences,beijing 100039,China 1. CAS Key Laboratory of Engineering Plastics Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China2. Graduate University of Chinese Academy of Sciences Beijing 100039 China

A series of controllable amphiphilic block copolymers composed of poly(ethylene oxide)(PEO) as the hydrophilic block and poly(ε-caprolactone)(PCL) as the hydrophobic block with the amino terminal group at the end of the PEO chain(PCL-b-PEO-NH2) were *** on the further reaction of reactive amino groups,diblock copolymers with functional carboxyl groups(PCL-b-PEO-COOH) and functional compounds RGD(PCL-b-PEO-RGD) as well as the triblock copolymers with thermosensitive PNIPAAm blocks(PCL-b-PEO-b-PNIPAAM) were *** well-controlled structures of these copolymers with functional groups and blocks were characterized by gel permeation chromatography(GPC) and 1H NMR *** copolymers with functionalized hydrophilic blocks were fabricated into microspheres for the examination of biofunctions via cell culture experiments and in vitro drug *** results indicated the significance of introducing functional groups(e.g.,NH2,COOH and RGD) into the end of the hydrophilic block of amphiphilic block copolymers for biomedical potentials in tissue engineering and controlled drug release.

关键词： amphiphilic block copolymers biodegradable polymers functional terminal group cell growth drug release

Genesis of ^(230)Th excess in basalts from mid-ocean ridges and ocean islands:Constraints from the global U-series isotope database and major and rare earth element geochemistry

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Science China Earth sciences 2010年第10期53卷 1486-1494页

作者： ZHANG GuoLiang1,2 & ZENG ZhiGang1 1 Key Laboratory of Marine Geology and Environment,Institute of Oceanology,chinese academy of sciences,Qingdao 266071,China 2 graduate University of chinese academy of sciences,beijing 10004.,China 1. Key Laboratory of Marine Geology and Environment Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Based on 230Th-238U disequilibrium and major element data from mid-ocean ridge basalts(MORBs) and ocean island basalts(OIBs),this study calculates mantle melting parameters,and thereby investigates the origin of 230Th excess.(230Th/238U) in global MORBs shows a positive correlation with Fe8,Po,Na8,and Fmelt(Fe8 and Na8 are FeO and Na2O contents respectively after correction for crustal fractionation relative to MgO = 8 wt%,Po=pressure of initial melting and Fmelt=degree of melt),while 230Th excess in OIBs has no obvious correlation with either initial mantle melting depth or the average degree of mantle ***,compared with the MORBs,higher(230Th/238U) in OIBs actually corresponds to a lower melting *** suggests that the 230Th excess in MORBs is controlled by mantle melting conditions,while the 230Th excess in OIBs is more likely related to the deep garnet *** vast majority of calculated initial melting pressures of MORBs with excess 230Th are between 1.0 and 2.5 GPa,which is consistent with the conclusion from experiments in recent years that DU>DTh for Al-clinopyroxene at pressures of >1.0 *** initial melting pressure of OIBs is 2.2-3.5 GPa(around the spinel-garnet transition zone),with their low excess 226Ra compared to MORBs also suggesting a deeper mantle ***,excess 230Th in MORBs and OIBs may be formed respectively in the spinel and garnet stability *** addition,there is no obvious correlation of K2O/TiO2 with(230Th/238U) and initial melting pressure(Po) of MORBs,so it is proposed that the melting depth producing excess 230Th does not tap the spinel-garnet transition *** and MORBs in both(230Th/238U) vs.K2O/TiO2 and(230Th/238U) *** plots fall in two distinct areas,indicating that the mineral phases which dominate their excess 230Th are ***/Yb-Ce curves of fast and slow ridge MORBs are similar,while,in comparison,the Ce/Yb-Ce curve for OIBs shows more influence from *** mechanism

关键词： excess 230Th clinopyroxene garnet spinel-lherzolite mid-ocean ridge ocean island

Pollen limitation and variation in floral longevity in gynodioecious Potentilla tanacetifolia

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Journal of Systematics and Evolution 2011年第6期49卷 539-545页

作者： 1,2Hong YAO 1Yi-Bo LUO 1(State Key Laboratory of Systematic and Evolutionary Botany,Institute of Botany,chinese academy of sciences,beijing 100093,China) 2({4. University of the chinese academy of sciences,beijing 10004.,China) (State Key Laboratory of Systematic and Evolutionary Botany Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (graduate University of the chinese academy of sciences Beijing 100049 China) *Correspondence: Yi-Bo LUO *Correspondence: E-mail: luoyb@*** Tel.: 86-10-62836514 Fax: 86-10-6259084..

Pollination limitation is common in flowering plants and is thought to be a factor driving the evolution of floral *** plasticity of floral longevity to pollination may be an adaptation of plants to pollen ***,this adaptation is less critical in short-lived *** evaluate pollen limitation and the plasticity of floral longevity to pollination in Potentilla tanacetifolia,a gynodioecious herb with short-lived flowers,we analyzed its breeding system,tested sex-differential pollen limitation,and compared variations in floral display size in natural populations in Duolun County,Inner Mongolia,*** pollination experiments and pollinator exclusion treatments revealed that *** is self-compatible and non-autonomously apomictic and shows sex-differential pollen *** plasticity of floral longevity to pollination was observed;the floral duration of female plants was prolonged by approximately 3-4.hours with pollination exclusion ***,the percentage of flowers displayed on female plants during pollination exclusion treatment was significantly higher than that during natural *** natural pollination conditions,the percentage of flowers displayed on female plants was significantly higher than on hermaphrodite ***,approximately 50%of the pollen grains spread out of the anthers of hermaphrodite flowers within 2 h of anthesis;the number of pollen grains adhering to the stigmas of hermaphrodite flowers was significantly higher than that adhering to female flowers when flowers shed their *** results indicate that variation in floral longevity may be an adaptive strategy to pollination conditions for gynodioecious ***.

关键词： floral longevity gynodioecy plasticity pollen limitation Potentilla tanacetifolia.

An improved imaging algorithm for fixed-receiver bistatic SAR

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Science China(Information sciences) 2010年第7期53卷 1461-1469页

作者： GENG XuPu1,2,3, HU YingHui1,2, YAN HongHui2 & WANG YanFei2 1graduate school of the chinese academy of {4., beijing 100039, China 2Institute of Electronics, chinese academy of {4., beijing 100190, China 3beijing Institute of Environment Features, beijing 100854. China 1. graduate school of the chinese academy of {4. Beijing 100039 China2. Institute of Electronics Chinese Academy of Sciences Beijing 100190 China3. Beijing Institute of Environment Features Beijing 100854 China

Based on the signal model of fixed-receiver bistatic SAR, this paper analyzes the characteristics of azimuth-variant, which includes variation of range migration curve and variation of Doppler rate caused by different azimuth position of targets. Then, an extended nonlinear chirp scaling (NLCS) algorithm is proposed, with its flowchart and phase compensation functions being provided. Simulation results show that the algorithm is available for the characteristics of azimuth-variant of fixed-receiver bistatic SAR, and good focused radar images could be acquired.

关键词： synthetic aperture radar (SAR) bistatic SAR fixed-receiver characteristics of azimuth-variant range cell migration correction (RCMC)

Rational redesign of inhibitors of furin/kexin processing proteases by electrostatic mutations

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Acta Pharmacologica Sinica 2004年第12期25卷 146-152页

作者： Xiao-hui CAI, Qing ZHANG, Da-fu DING2 Key Laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological sciences, chinese academy of sciences, {4. school of the chinese academy of sciences, Shanghai 200031, China Key Laboratory of Proteomics Institute of Biochemistry and Cell Biology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Graduate School of the Chinese Academy of Sciences Shanghai 200031 China

AIM: To model the three-dimensional structure and investigatethe interaction mechanism ofthe proprotein convertase furin/kexin and their inhibitors (eglin c mutants). METHODS: The three-dimensional complex structures of furin/ kexin with its inhibitors, eglin c mutants, were generated by modeller program using the newly published X-ray crystallographical structures of mouse furin and yeast kexin as templates. The electrostatic interaction energy of each complex was calculated and the results were compared with the experimentally determined inhibition con- stants to find the correlation between them. RESULTS: High quality models of furin/kexin-eglin c mutants were obtained and used for calculation of the electrostatic interaction energies between the proteases and their inhibitors. The calculated electrostaticenergies of interaction showeda linear correlation to the experimental inhibition constants. CONCLUSION: The modeled structures give good explanations of the specificity of eglin c mutants to furin/ kexin. The electrostatic interactions play important roles in inhibitory activity of eglin c mutants to furin/kexin. The results presented here provided quantitative structural and functional information concerning the role of the charge- charge interactions in the binding of furin/kexin and their inhibitors.

关键词： furin kexin eglin c drug design electrostatic mutation

A 12-bit multichannel ADC for pixel detectors in particle physics and nuclear imaging

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Science China(Technological sciences) 2010年第5期53卷 1208-1214页

作者： WEI Wei1,2,3,WANG Zheng1,3 & ZHAO JingWei1,3 1 Institute of High Energy Physics,chinese academy of sciences,beijing 10004.,China 2 {4. University of chinese academy of sciences,beijing 10004.,China 3 Key Lab of Nuclear Detection Technology and Nuclear Electronics of chinese academy of sciences,beijing 10004.,China 1. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Key Lab of Nuclear Detection Technology and Nuclear Electronics of Chinese Academy of Sciences Beijing 100049 China

Modern pixel detectors in nuclear and particle physics experiments and also in nuclear imaging,starve for highly integrated application specified integrated circuit(ASIC),whereas in China the study of ASIC still stays far away from practical *** lack of ASIC strictly limits the research and development of domestic high energy physics field.A 12-bit multichannel ADC designed for high density readout is introduced as a major candidate for solution.A precise model is discussed and the simulation fully agrees with the model,which indicates a key principle of *** is performed according to the given rule,and novel layout techniques are carried *** results in all aspects are also obtained,showing an excellent real performance,which satisfies the practical requirement.

关键词： application specified integrated circuit high density readout Wilkinson ADC multi-channel ADC

Polynomial regression calculation of the Earth's position based on millisecond pulsar timing

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Research in Astronomy and Astrophysics 2012年第2期12卷 219-234页

作者： Feng Tian 1,2,Zheng-Hong Tang 1,Qing-Zeng Yan 1,2 and Yong Yu 11 Shanghai Astronomical Observatory,chinese academy of sciences,Shanghai 200030,China 2 graduate University of chinese academy of sciences,beijing 10004.,China Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 China graduate University of chinese academy of sciences Beijing 100049 China

Prior to achieving high precision navigation of a spacecraft using X-ray observations, a pulsar rotation model must be built and analysis of the precise posi- tion of the Earth should be performed using ground pulsar timing observations. We can simulate time-of-arrival ground observation data close to actual observed values before using pulsar timing observation data. Considering the correlation between the Earth＇s position and its short arc section of an orbit, we use polynomial regression to build the correlation. Regression coefficients can be calculated using the least square method, and a coordinate component series can also be obtained; that is, we can calcu- late Earth＇s position in the Barycentric Celestial Reference System according to pulse arrival time data and a precise pulsar rotation model. In order to set appropriate param- eters before the actual timing observations for Earth positioning, we can calculate the influence of the spatial distribution of pulsars on errors in the positioning result and the influence of error source variation on positioning by simulation. It is significant that the threshold values of the observation and systematic errors can be established before an actual observation occurs; namely, we can determine the observation mode with small errors and reject the observed data with big errors, thus improving the positioning result.

关键词： autonomous positioning - millisecond pulsar - pulsar timing - re-gression analysis

Debris Flow Hazard Assessment Based on Support Vector Machine

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Wuhan University Journal of Natural sciences 2006年第4期11卷 897-900页

作者： YUAN Lifeng 1, 2 , ZHANG Youshui 3 1. Institute of Mountain Hazards and Environment, chinese academy of sciences, Chengdu 61004., Sichuan, China 2. graduate University of chinese academy of sciences, beijing 10004., China 3. Institute of Geographical sciences and Natural Resources Research, chinese academy of sciences, beijing 100101, China Institute of Mountain Hazards Environment Chinese Academy of Sciences 610041 Chengdu Sichuan China graduate University of chinese academy of sciences 100049 Beijing China Institute of Geographical sciences Natural Resources Research Chinese Academy of Sciences 100101 Beijing China

Seven factors, including the maximum volume of once flow , occurrence frequency of debris flow , watershed area , main channel length , watershed relative height difference , valley incision density and the length ratio of sediment supplement are chosen as evaluation factors of debris flow hazard degree. Using support vector machine （SVM） theory, we selected 259 basic data of 37 debris flow channels in Yunnan Province as learning samples in this study. We create a debris flow hazard assessment model based on SVM. The model was validated though instance applications and showed encouraging results.

关键词： debris flow hazard assessment support vector machine (SVM)

Estimating surface evapotranspiration using combined MODIS and CBERS-02 data

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Science China(Technological sciences) 2005年第S2期48卷 145-160页

作者： XIN Xiaozhou1,2, LIU Qinhuo1, TANG Yong1,3, TIAN Guoliang1, GU Xingfa1, LI Xiaowen1,2, ZHENG Hongsheng4.& CHEN Jiayi4.1. State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing Applications, chinese academy of sciences, beijing 100101, China 2. Research Center for Remote Sensing and GIS, Department of Geography, beijing Normal University, beijing 100875, China 3. graduate University of chinese academy of sciences, beijing 100039, China 4. Department of Atmospheric Physics, Peking University, beijing 100871, China 1. State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences 100101 Beijing China2. Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University 100875 Beijing China3. Graduate University of Chinese Academy of Sciences 100039 Beijing China4. Department of Atmospheric Physics Peking University 100871 Beijing China

Spatial scale error is one of the most serious problems in the estimates of land surface heat fluxes of sensible and latent from satellite-borne data such as MODIS 1km resolution reflectance and emissive data. One of the feasible and economic ways to decrease the spatial scale error is to use high resolution land use class data together with the MODIS data. CBERS-02 data were used to produce land use class of Baiyangdian area, Hebei Province, China in the autumn of 2004. The area ratio of each class in MODIS pixel was calculated, and used to derive the heat fluxes of the mixed pixel. The results showed that the estimated heat fluxes of soil, sensible and latent have been changed remarkably after using the high resolution land class data. It could be concluded from the comparison between simulated and ground-measured fluxes as well as the theoretical analysis that high resolution land class data are useful to diminishing the scale error of heat fluxes estimated from low resolution satellite data.

关键词： surface evapotranspiration spatial scale error MODIS CBERS land class.

SAR IMAGING SIMULATION OF HORIZONTAL FULLY TWO-DIMENSIONAL INTERNAL WAVES

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Journal of Hydrodynamics 2006年第3期18卷 294-302页

作者： SHEN Hui HE Yi-Jun Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China graduate school of the chinese academy of {4. Beijing 100039 China

Based on the research of Lynett and Liu, a new horizontal fully two-dimensional internal wave propagation model with rotation effect was deduced, which can be used to simulate the characteristics of internal waves in a horizontal fully two-dimensional plane. By combining the imaging mechanism of Synthetic Aperture Radar（SAR）, a simulation procedure was fatherly acquired, which can simulate the propagation characteristics of oceanic internal waves into SAR images. In order to evaluate the validity of the proposed simulation procedure, case studies are performed in South China Sea and results from simulation procedure are analyzed in detail. A very good consistency was found between the simulation results and satellite images. The proposed simulation procedure will be a possible foundation for the quantitative interpretation of internal waves from fully two-dimensional satellite images.

关键词： oceanic internal waves imaging simulation,Synthetic Aperture Radar (SAR)