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Three-year changes of surface albedo of degraded grassland and cropland surfaces in a semiarid area

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Chinese Science Bulletin 2008年第8期53卷 1246-1254页

作者： LIU HuiZhi1↑, TU Gang2,3 & DONG WenJie4 1 State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, institute of Atmospheric Physics, Chi- nese Academy of Sciences, beijing 100029, china 2 Laboratory of Research for Middle-High Latitude Circulation System and East Asia Monsoon, china Meteorological administration, Changchun 130062, china 3 institute of Meteorological Science of Jilin Province, Changchun 130062, china 4 National Climate Center, beijing 100081, china State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Laboratory of Research for Middle-High Latitude Circulation System and East Asia Monsoon China Meteorological Administration Changchun China institute of Meteorological Science of Jilin Province Changchun China National Climate Center Beijing China

Diurnal, seasonal and interannual variations of surface albedo of degraded grassland and cropland surfaces at a semiarid area of Tognyu have been investigated based on the continuous three years observational data from 2003 to 2005. The changes of surface albedo with solar elevation angle and soil moisture have been discussed also. It has been found that surface albedo has almost the same diurnal and seasonal variations on degraded grassland and cropland surfaces in the semiarid area, while sur- face albedo is large in winter and small in summer. The diurnal variation of the surface albedo has re- lationship with the weather condition. The diurnal cycle of the surface albedo likes the "U" shape curve in sunny day, while it is low-high after the rain, and high-low after the snow. The surface albedo has large variation in cloudy day, while it has no any variation in overcast day. The large difference of the surface albedo can be 0.04 in winter between two land surfaces, because the snow has large effects on the surface albedo in winter. The rainfall is an important factor in summer on the surface albedo, while the difference of the surface albedo is 0.01 only between two land surfaces. The differences of the surface albedo can also be 0.04 in autumn due to vegetation growing. The seasonal-average surface albeo from 2003―2005 is 0.25, 0.22, 0.24, 0.32 respectively in spring, summer, autumn and winter on the degraded grassland surface,while it is 0.25, 0.21, 0.22, 0.33 respectively in spring, summer, autumn and winter on the cropland surface. The surface albedo becomes smaller with the increase of solar elevation angle. When the solar elevation angle is greater than 40°, the surface albedo changes very little and tends to be a constant. The surface albedo has negative exponent functions with soil moisture in the growing season.

关键词：半干旱地区表面反照率土壤湿度草地退化

Different roles of Ekman pumping in the west and east segments of the South china Sea Warm Current

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Acta Oceanologica Sinica 2011年第3期30卷 1-13页

作者： WANG Qiang WANG Yinxia BO Hong ZHOU Weidong WANG Dongxiao Key Laboratory of Tropical Marine Environmental Dynamics South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China Graduate School of the Chinese Academy of Sciences Beijing 100049 China South china Sea Marine Engineering and Environment institute of State Oceanic administration Guangzhou 510300 China Virginia institute of Marine Science College of William and Mary VA 23062 USA

A three-dimensional model is used to investigate the mechanism of the South china Sea （SCS） winter counter-current （also known as the SCS Warm Current, or the SCSWC）, which flows against the wind. The model can reproduce the structure of the band-like currents over the northern shelf of the SCS, including the westward coastal current and slop current, and the SCSWC sandwiched in between. Sensitivity experiments are designed to understand the different roles of Ekman pumping of the SCSWC at different longitude. The results show that the Ekman pumping drives the SCSWC in the west segment. In the east, it is not the Ekman pumping but the intrusion of the Kuroshio that drives the SCSWC.

关键词： SCSWC Ekman pumping northern South china Sea numerical model

Crustal P-wave velocity structure in Lower Yangtze region:Reinterpretation of Fuliji-Fengxian deep seismic sounding profile

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Crustal P-wave velocity structure in Lower Yangtze region:Re...

IR STUDY ON MONOMOLECULAR PARTICLE AGGLOMERATES OF POLYSTYRENE OBTAINED BY FREEZE-DRYING OF ITS DILUTE SOLUTION

中国科学院地质与地球物理研究所2006学术年会

作者： BAI Zhiming~1 & WANG Chunyong~2 1.institute of geology and Geophysics,Chinese Academy of Sciences,beijing 100029,china 2.institute of Geophysics,china earthquake administration,beijing 100081,china

The finite-difference inversion method and Rayinvr technique had been employed to interpret the wide-angle seismic reflection/refraction data of the Fuliji-Fengxian deep seismic sounding(DSS) profile in Lower Yangtze region,hence the velocity structure was acquired and conclusions were summarized as follows:(1) The velocity model along this profile can be divided into three large layers vertically(upper,middle and lower crusts) and six blocks laterally,and this velocity distribution agrees with the feature of stable platform.(2) The depth of Moho discontinuity is 30-36 *** thickness of the upper crust is 10.5-13.0km,where the lateral velocity varies strongly,and the velocity increases to 6.2 kms at ***,the velocity distributions in the bottom layer of middle crust and lower crust have an apparent *** velocity in upper layer of middle crust,lower layer of middle crust,lower crust and uppermost mantle is 5.9-6.2,6.3-6.4,6.6-7.0 and 8.06-8.29 kms,respectively.(3) On two sides of the Tanlu fault belt(TFB),the mid-crustal velocity structure is quite different, nevertheless no apparent discrimination in velocity distribution and boundary topography exhibits in lower crust,hence it is inferred that the Jiashan segment of TFB had probably cut through whole crust in the Mesozoic,and the fault behaviour in lower crust had disappeared due to the low viscosity produced by the orogenic extension or crustal balance,while the fault features in the rigid middle-upper crust have been preserved up to the present.(4) The moderate earthquakes with Ms>5.0 nearby Zhenjiang are related to the deep faults extending into the lower crust,and the earthquakes were probably induced by the energy been transferred from mantle lithosphere to upper-mid crust along the deep faults,and aggregated at some preferable tectonic positions.

关键词： eastern china Fuliji -Fengxian DSS profile wide-angle seismic data velocity structure Tanlu fault belt earthquake

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Chinese Journal of Polymer Science 2002年第4期20卷 381-383页

作者： Song Wang Qing-hua Wang Rong-shi cheng Research Center of Materials beijing institute of Technology beijing 100081, china Department of Chemistry Nanjing University Nanjing 210093, china Nanjing Univ Dept Chem Nanjing 210093 Peoples R China beijing Inst Technol Ctr Mat Res Beijing 100081 Peoples R China

The monomolecular particle agglomerates of polystyrenes were obtained by freeze-drying of its very dilute solutions of 1.3 x 10(-5)-2.0 x 10(-5) g/mL in benzene:cylcohexane (100:1) solvents, and they were annealed at room temperature for hundred days before use. According to C-13-NMR measurement the polystyrenes should be practically atactic. The number average molecular weights of the samples are 2.80 x 10(3), 2.00 x 10(4), and 1.55 x 10(6), respectively. The freeze-dried aPS with a molecular weight higher than 10(4) show two new IR absorption bands at 1098 and 1261 cm(-1), which are absent in the normal aPS and freeze-dried styrene oligomer. It was also found that the low molecular weight samples can only form powders, whereas the freeze-dried aPS with higher molecular weight form a mixture of powders and fibrils, of which the longer fibrils show a much stronger 1261 cm(-1) band than the shorter fibrils and the powder. It seems that the 1261 cm(-1) band corresponds to the stacking behavior of monomolecular particles.

关键词： monomolecular particles atactic polystyrene FTIR spectroscopy

Climate change tendency and grassland vegetation response during the growth season in Three-River Source Region

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Science china Earth Sciences 2010年第10期53卷 1506-1512页

作者： QIAN Shuan1,FU Yang2 & PAN FeiFei3 1 National Meteorological Center,beijing 100081,china 2 Qinghai Meteorological Research institute,Xining 810001,china 3 Department of Geography,University of North Texas,Denton,TX 76203,USA 1. National Meteorological Center Beijing 100081 China2. Qinghai Meteorological Research Institute Xining 810001 China3. Department of Geography University of North Texas Denton TX 76203 USA

Climate change,climate suitablity change for grassland vegetation,and grassland response to climate change during the growth season are studied systematically by using meteorological data of temperature,precipitation,and length of sunlight from 1961 to 2007,NOAA/AVHRR NDVI from 1982 to 2006,and observations of grass height,biomass,and coverage in enclosed grassland from 1994 to *** models are developed to evaluate climate change and the climatic suitability of grassland vegetation *** temperature,accumulative precipitation,and length of sunlight during the growth season increased from 1961 to 2007 at rates of 0.24°C/10 yr,2.32 mm/10 yr,and 2.81 h/10 yr,*** increase rates of ave-rage temperature between April and May,and between June and August are 0.17 and 0.30°C/10 yr;accumulative rainfall between April and May increased at a rate of 2.80 mm/10 yr,and accumulative rainfall between June and August decreased at a rate of 0.38 mm/10 yr;the increase rates of accumulative length of sunlight between April and May,and between June and August are 2.15 and 1.2 h/10 *** climatic suitability of grassland vegetation growth showed an increasing trend,and the increase rate between April and May is greater than that between June and *** NDVI observations from 1982 to 2006 and measurements of grass height,dry biomass,and coverage from 1994 to 2006 show that the climate change has resulted in an increase in plant productivity of the grassland in Three-River Source *** some protection measures are taken as soon as possible,the deteriorated grassland in Three-River Source Region can recover.

关键词： climate change climate suitability change grassland vegetation Three-River Source Region

Approximation of dense-n/2-subgraph and table compression problems

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Science china Mathematics 2005年第9期48卷 1223-1233页

作者： XU Dachuan~1 HAN Jiye~2 & DU Dongle~3 1. College of Applied Sciences,beijing University of Technology,beijing 100022,china 2. institute of Applied Mathematics,Academy of Mathematics and Systems Science,Chinese Academy of Sciences,beijing 100080,china 3. Faculty of administration,University of New Brunswick,P.O.Box 4400,Fredericton,NB E3B 5A3,Canada College of Applied Sciences Beijing University of Technology Beijing 100022 China institute of Applied Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China Faculty of administration University of New Brunswick P.O. Box 4400 Fredericton NB E3B 5A3 Canada

We develop improved approximation algorithms for two NP-hard problems: the dense-n/2-subgraph and table *** on SDP relaxation and advanced rounding techniques,we first propose 0. 5982 and 0. 5970-approximation algorithms respec- tively for the dense-n/2-subgraph problem (DSP) and the table compression problem (TCP). Then we improve these bounds to 0. 6243 and 0. 6708 respectively for DSP and TCP by adding triangle inequalities to strengthen the SDP *** results for TCP beat the 0. 5 bound of a simple greedy algorithm on this problem,and hence answer an open question of Anderson in an affirmative way.

关键词： dense-n/2-subgraph problem(DSP) table compression problem(TCP) SDP approximation ratio

Therapeutic angiogenesis induced by human hepatocyte growth factor (HGF) gene in rat myocardial ischemia models

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Science Bulletin 2003年第3期48卷 273-276页

作者： WU Danli1*, ZHANG Yourong2*, LAO Miaofen1, QIU Zhaohua1, HA Xiaoqin1 & WU Zuze (WU Cutse)1 1. Department of Experimental Hematology, institute of Radiation Medi-cine, beijing100850, china 2. General Hospital of the People抯 Liberation Army of china, beijing 100853, china Department of Experimental Hematology Institute of Radiation Medicine Beijing 100850 China

In order to investigate the feasibility of myo-cardial ischemia gene therapy, we cloned human hepatocyte growth factor gene from human placenta cDNA library by the RT-PCR method. Recombination adenovirus Ad-HGF was constructed by the method of co-transfection and ho-mologous recombination of plasmids in 293 cells. Ad-HGF was amplified in 293 cells and purified through CsCl density gradient centrifugation. Ad-HGF could be expressed in rat primary myocardial cells and HGF secreted into the culture media, which was tested by ELISA. The distribution and persistence of adenovirus in rat were investigated by green fluorescence protein as a report gene. In vivo we found that intramyocardial administration of Ad-HGF could induce angiogenesis in rat myocardium after ligation of coronary artery. The results suggested that Ad-HGF was effective in vitro and in vivo, and the data for designing human trial of gene therapy—— mediated cardiac angiogenesis were pro-vided.

关键词： myocardial ischemia gene therapy recombination ade-novirus hepatocyte growth factor.

Construction and application of formal ontology for mine

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中国有色金属学会会刊：英文版 2011年第S3期21卷 577-582页

作者： cheng Gang 1, 2, ZHANG Yin-ling1, 2, WANG Fei 1 ,2, ZHANG Zhen-hui 3, GUO Yu-xiang1, 2 1. Key Laboratory of Mine Spatial Information Technologies of State Bureau of Surveying and Mapping, Henan Polytechnic University, Jiaozuo 454003, china 2. School of Surveying and land Information Engineering, Henan Polytechnic University, Jiaozuo 454003, china 3. Qingdao Branch of Naval Aeronautical Engineering institute, Qingdao 266041, china Henan Polytech Univ Key Lab Mine Spatial Informat Technol State Bur Surveying & Mapping Jiaozuo 454003 Peoples R China Henan Polytech Univ Sch Surveying & Land Informat Engn Jiaozuo 454003 Peoples R China Naval Aeronaut Engn Inst Qingdao Branch Qingdao 266041 Peoples R China

Digital mine is the only way for the development of mining industry in china. Due to lack of appropriate standards and norms, and different awareness in the field of digital mine among academia and industry insiders, the meaning for digital mine is still unclear. Starting from the nature of mining and removing of views of specialized fields, this paper constructs formal ontology for digital mine and proposes the four levels for it. The ontology clarifies the concept world for digital mine, defines the meaning of concepts and relations clearly, provides a reference for the standard construction for digital mine and provides a unified semantic framework for the integration of heterogeneous mine data. Meanwhile, it can provide formal reasoning knowledge for expert system of digital mine and improve the intelligence and automation while the machine automatically interpreting and processing mine spatial data.

关键词： Digital mine formalization ontology concept world semantic share

Crystal structure of human eIF2B alpha subunit

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生物物理学报 2009年第S1期25卷 327-328页

作者： cheng Zhang1,2, Zhiyi Wei1,2, Hang Xu1, Weimin Gong1,2 1 institute of Biophysics, CAS, 15 Datun-Road, Chaoyang District, beijing, 100101 2 School of Life Sciences, University of Science and Technology of china, Hefei, Anhui, 230026

In translation initiation, eIF2 is responsible for delivering initiator tRNA to ribosome, and such delivery only occurs when GTP is bound to eIF2. eIF2B, a guanine nucleotide

关键词： eIF2Bα crystal structure Rossmann fold