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12018 Chinese Guidelines for Prevention and Treatment of Hypertension——A report of the Revision Committee of Chinese Guidelines for Prevention and Treatment of Hypertension显示文摘Table of Contents Preamble 1 Prevalence of hypertension in Chinese population 1.1 Prevalence,incidence and epidemic trend of hypertension in Chinese population 1.2 Awareness,treatment and control of Hypertension in China 1.3 Important risk factors for hypertension in Chinese population 2 Hypertension and cardiovascular risk 2.1 Relationship between blood pressure and cardiovascular risk 2.2 Cardiovascular risk characteristics of hypertension population in China 3 Diagnostic evaluation 3.1 Medical history 3.2 Physical examination 3.3 Laboratory examinations 3.4 Genetic analysis 3.5 BP measurement 3.6 Evaluation of target organ damage.Joint Committee for Guideline Revision Chinese Hypertension League Chinese Society of Cardiology Hypertension Committee of the Chinese Medical Doctor Association Hypertension Branch of the China Association for the Promotion of International Exchanges of Health Care Hypertension Branch of the Chinese Geriatrics Society Li–Sheng LIU 2019Journal of Geriatric Cardiology2019,16,3:95
2CO_2浓度变化和气候变化对中国陆地生态系统净初级生产及其平衡的影响(英文)显示文摘本文应用陆地生态系统模型(TEM,4.0)对中国陆地生态系统在目前气候下的净初级生产力,以及在CO2浓度增加和气候变化后的净初级生产力的变化进行了预测。气候变化模型采用三种大气环流模型生成,即:GISS、GFDL和OSU模型。在当前气候条件和CO2浓度(312.5×10-6)下,TEM模型预测中国陆地生态净初级生产力为3,653TgC·a-1(1012gC·a-1)。温带常绿阔叶林是生产力最高的生物区,占有中国净初级生产力的最大比例。NPP的空间格局主要与降水量和温度的空间分布相关联。中国陆地生态系统的年净初级生产力对CO2浓度和气候的变化敏感。在陆地区域尺度上,其年净初级生产力仅在CO2浓度上升至519×10-6的情况下可增加6.0%(219TgC·a-1)。在气候变化而无CO2浓度变化的条件下,净初级生产力的响应在GISS气候方案下表现为1.5%(54.8TgC·a-1)的降低,在GFDL-q气候方案下表现为8.4%(306.9TgC·a-1)的增加。在气候和CO2浓度均发生变化的情况下,净初级生产力有较大程度的增加,在GISS气候方案下的增加比例为18.7%(683TgC·a-1),在GFDL-q气候?Xiao 1,2 , X., J.M.Melillo 1, D.W.Kicklighter 1, Y.Pan 1, A.D.McGuire 3 and J.Helfrich 1 ( 1The Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA 02543, USA) ( 2 The Joint Program on the Science and Policy of Globa 1998植物生态学报1998,22,2:35
3Effect of carbon source on the denitrification in constructed wetlands显示文摘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 30–40 mg/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 effuent. 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.LU Songliu, HU Hongying, SUN Yingxue, YANG Jia ESPC State Key Joint Laboratory, Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. 2009Journal of Environmental Sciences2009,21,8:40
4An Outbreak of NCIP (2019-nCoV) Infection in China --Wuhan, Hubei Province, 2019−2020显示文摘Emerging and re-emerging pathogens are great challenges to the public health(1).A cluster of cases of viral pneumonia of unknown etiology(VPUE),now known as novel coronavirus-infected pneumonia(NCIP),occurred in Wuhan,Hubei Province and was reported to health authorities on December 29,2019(2).A national,provincial,and municipal joint investigation team has been assembled to conduct field investigations and implement disease control and prevention measures.This report shows interim results of the investigation and makes recommendations for response measures.The 2019-nCoV Outbreak Joint Field Epidemiology Investigation Team Qun Li 2020China CDC weekly2020,2,5:31
5The roles of heterogeneous chemical processes in the formation of an air pollution complex and gray haze显示文摘Urban and regional air pollutions are characterized by high concentrations of secondary pollutants such as photo-oxidants (mainly ozone) and fine particulate matter,which are formed through chemical reactions of the primary pollutants emitted from various sources.The accumulation of these pollutants under stagnant meteorological conditions results in the formation of gray haze,reducing visibility and causing major impacts on human health and climate.In an air pollution complex,the coexistence of high concentrations of primary and secondary gaseous and particulate pollutants provides a large amount of reactants for heterogeneous reactions on the surface of fine particles;these reactions change the oxidizing capacity of the atmosphere,as well as chemical compositions along with the physicochemical and optical properties of particulate matter,thereby accelerating formation of the air pollution complex and gray haze.Using in situ technologies,such as diffuse reflectance infrared Fourier-transform spectroscopy and single-particle Raman spectroscopy,we systematically investigated the reaction kinetics and mechanisms of gaseous pollutants (i.e.,NO2,SO2,O3,and formaldehyde) on the surfaces of the major components of atmospheric particles such as CaCO3,kaolinite,montmorillonite,NaCl,sea salt,Al2O3,and TiO2.We found that the main reaction products were sulfate,nitrate,or formate,which can change the hygroscopicity and light extinction parameters of those particles significantly.By analyzing the reaction kinetics of these heterogeneous reactions,we identified synergetic mechanisms of the three ternary reaction systems,i.e.,NO2-particlesH2O,SO2-particles-O3,and organics/SO2-particles–UV illumination.These synergetic mechanisms can provide experimental and theoretical bases for understanding the feedback mechanisms and nonlinear processes in the formation of an air pollution complex and gray haze.ZHU Tong,SHANG Jing & ZHAO DeFeng State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China 2011Science China Chemistry2011,54,1:24
6Heterogeneous reactions on the surface of fine particles in the atmosphere显示文摘Fine particles play an important role in the atmosphere. Research on heterogeneous reactions on the surface of fine particles is one of the frontier areas of atmospheric science. In this paper, physical and chemical characteristics of fine particles in the atmosphere and the interactions between trace gases and fine particles are described, methods used in heterogeneous reactions research are discussed in detail, progress in the study of heterogeneous reactions on the surface of fine particles in the atmosphere is summarized, existing important questions are pointed out and future research directions are suggested.DING Jie & ZHU Tong State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences, Peking University, Beijing 100871, China Correspondence should be addressed to Zhu Tong (e-mail:tzhu@ pku.edu.cn) 2003Chinese Science Bulletin2003,48,21:24
7Change of surface cover greenness in China between 2000 and 2010显示文摘Surface greenness reflects the situation of vegetation cover.Vegetation index calculated from the Red and Near Infrared bands of remote sensing images,whose values indicate the level of photosynthetic activity,is monotonically related to surface greenness when vegetation canopy does not fully cover the background soil.Especially for desert regions,vegetation index is positively correlated with vegetation coverage.Therefore,vegetation index can be used to study the change in greenness of desert areas.This study collected MODIS Normalized Difference Vegetation Index (NDVI) data from 2000 to 2010 and analyzed their change over China in this period.The results showed that an increasing trend of NDVI occurred over 66.84% (OLS fitting) or 64.27% (LAD fitting) of China,indicating that China's greenness is increasing overall.Meanwhile,desertification of China decreased.Areas showing large increase in greenness are found in Shaanxi,Shanxi,Ningxia,Henan,Shandong,Qinghai,and Gansu while regions with large decrease in greenness are found in Northeast Inner Mongolia,South Tibet,Jiangsu,and Shanghai.Changes of Qinghai,Gansu,Xinjiang and South Tibet could probably be driven by climate factors.Decrease of greenness in Northeast Inner Mongolia was related to agricultural reclamation.Decrease of greenness in Jiangsu and Shanghai was related to rapid urbanization.Climate factors did not exhibit obvious correspondence to the large increase in greenness in Shaanxi,Shanxi,Ningxia and Gansu,indicating that the changes might have been caused by human factors.The reduction of desert areas in China could probably have been caused by human management and protection at the national scale.LIU Shuang1,4& GONG Peng1,2,31State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Institute of Remote Sensing Applications of Chinese Academy of Sciences,and Beijing Normal University, Beijing 100101, China 2Institute for Global Change Studies & Center for Earth System Science, Tsinghua University, Beijing 100084, China 3Department of Environmental Science, Policy and Management, University of California, Berkeley, CA94720, USA 4Graduate University of Chinese Academy of Sciences, Beijing 100049, China 2012Chinese Science Bulletin2012,57,22:23
8Estimating forest aboveground biomass using HJ-1 Satellite CCD and ICESat GLAS waveform data显示文摘The ecosystem in northeastern China and the Russian Far East is a hotspot of scientific research into the global carbon balance.Forest aboveground biomass(AGB) is an important component in the land surface carbon cycle.In this study,using forest inventory data and forest distribution data,the AGB was estimated for forest in Daxinganlin in northeastern China by combining charge-coupled device(CCD) data from the Small Satellite for Disaster and Environment Monitoring and Forecast(HJ-1) and Geoscience Laser Altimeter System(GLAS) waveform data from the Ice,Cloud and land Elevation Satellite(ICESat).The forest AGB prediction models were separately developed for different forest types in the research area at GLAS footprint level from GLAS waveform parameters and field survey plot biomass in the Changqing(CQ) Forest Center,which was calculated from forest inventory data.The resulted statistical regression models have a R2=0.68 for conifer and R2=0.71 for broadleaf forests.These models were used to estimate biomass for all GLAS footprints of forest located in the study area.All GLAS footprint biomass coupled with various spectral reflectivity parameters and vegetation indices derived from HJ-1 satellite CCD data were used in multiple regression analyses to establish biomass prediction models(R2=0.55 and R2=0.52 for needle and broadleaf respectively).Then the models were used to produce a forest AGB map for the whole study area using the HJ-1 data.Biomass data obtained from forest inventory data of the Zhuanglin(ZL) Forest Center were used as independent field measurements to validate the AGB estimated from HJ-1 CCD data(R2=0.71).About 80% of biomass samples had an error less than 20 t ha-1,and the mean error of all validation samples is 5.74 t ha-1.The pixel-level biomass map was then stratified into different biomass levels to illustrate the AGB spatial distribution pattern in this area.It was found that HJ-1 wide-swath data and GLAS waveform data can be combined to estimate forest biomass with good precision,and the biomass data can be used as input data for future carbon budget analysis.GUO ZhiFeng1,CHI Hong1,2 & SUN GuoQing1,3 1State Key Laboratory of Remote Sensing Science,Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University,Institute of Remote Sensing Applications,Chinese Academy of Sciences,Beijing 100101,China 2Graduate University of Chinese Academy of Sciences,Beijing 100049,China 3Department of Geography University of Maryland,College Park,MD 20742,USA 2010Science China Earth Sciences2010,53,S1:21
9A Genome-wide Functional Characterization of Arabidopsis Regulatory Calcium Sensors in Pollen Tubes显示文摘Calcium, an ubiquitous second messenger, plays an essential and versatile role in cellular signaling. The diverse function of calcium signals is achieved by an excess of calcium sensors. Plants possess large numbers of calcium sensors, most of which have not been functionally characterized. To identify physiologically relevant calcium sensors in a specific cell type, we conducted a genome-wide functional survey in pollen tubes, for which spatiotemporal calcium signals are well-characterized and required for polarized tip growth. Pollen-specific members of calmodulin (CaM), CaM-like (CML), calcium-dependent protein kinase (CDPK) and calcineurin B-like protein (CBL) families were tagged with green fluorescence protein (GFP) and their localization patterns and overexpression phenotypes were characterized in tobacco pollen tubes. We found that several fusion proteins showed distinct overexpression phenotypes and subcellular localization patterns. CDPK24-GFP was localized to the vegetative nucleus and the generative cell/sperms. CDPK32-GFP caused severe growth depolarization. CBL2-GFP and CBL3-GFP exhibited dynamic patterns of subcellular localization, including several endomembrane compartments, the apical plasma membrane (PM), and cytoskeleton-like structures in pollen tubes. Their overexpression also inhibited pollen tube elongation and induced growth depolarization. These putative calcium sensors are excellent candidates for the calcium sensors responsible for the regulation of calcium homeostasis and calciumdependent tip growth and growth oscillation in pollen tubes.Liming Zhou1,2, Ying Fu1,2 and Zhenbiao Yang2,3 (1State Key Laboratory of Plant Physiology and Biochemistry, Department of Plant Sciences, College of Biological Sciences, China Agricultural University, Beijing 100193, China 2China Agricultural University (CAU)-University of California, Riverside (UCR) Joint Center for Biological Sciences and Biotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China 3Center for Plant Cell Biology and Department of Botany and Plant Sciences, University of California, Riverside, CA 92521, USA) 2009Journal of Integrative Plant Biology2009,51,8:21
10Relationships between δ ^(18)O in summer precipitation and temperature and moisture trajectories at Muztagata, western China显示文摘Based on summer observations of stable isotope of precipitation at Muztagata, western China, during 2002―2003, this paper presents the relationship between δ 18O in precipitation and air temperature, and discusses the effect of moisture transport on δ 18O in precipitation. Results show that air temperature correlates positively with δ 18O in precipitation, and the temperature effect controls the δ 18O of precipitation in this area. The Muztagata region exhibits high δ 18O values in summer precipi-tation, similar to those shown at stations in adjacent regions. According to the results of our model set up to trace the moisture trajectories, the westerlies and local moisture circulation contribute to varia-tions of oxygen isotopes in precipitation. In addition, the impacts of the moisture transport distance, the moisture transport level, and the incursion of the polar air mass also influence the variations of δ 18O in precipitation. The moisture origins and transport mechanisms also contribute to the variation of δ 18O in precipitation at Muztagata.YU Wusheng1,2, YAO Tandong1,2, TIAN Lide1,2, LI Zhen2, SUN Weizhen2 & WANG Yu2 1. Laboratory of Environment and Process on Tibetan Plateau, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2. Key Laboratory of Cryosphere and Environment, Jointly Established by Cold and Arid Regions Environmental and Engi-neering Research Institute and Institute of Tibetan Plateau Research, Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences, China Meteorological Administration, CAS, Lanzhou 730000, China 2006Science China Earth Sciences2006,49,1:18
11Degradation of 4-chlorophenol in aqueous solution by γ-radiation and ozone oxidation显示文摘The degradation of 4-chlorophenol (4-CP) by using gamma rays generated by a 60Co source in the presence of O3 was investigated. The radiolysis of 4-CP and the kinetics of 4-CP min-eralization were analyzed based on the determination of total organic carbon (TOC). The influence of initial 4-CP concentration and the free radicals scavengers (such as NaHCO3 and t-butanol) on the 4-CP degradation was also studied. The results showed that when the radiation rate was 336 Gy·min?1, 4-chlorophenol at concentration of 10 mg·L?1 could be completely degraded at the radiation dose of 2 kGy. The degradation of 4-chlorophenol could be described by a first-order reaction model, the rate constant of 4-CP degradation by combined ozonation and radiation was 0.1016 min?1, which was 2.4 times higher than the sum of radiation (0.0294 min?1) and ozonation (0.0137 min?1). It re-vealed that the combination of radiation and ozonation resulted in synergistic effect, which can re-markably increase the degradation efficiency of 4-CP.HU Jun1, WANG Jianlong1,2 & CHEN Rong1 1. Laboratory of Environmental Technology, Institute of Nuclear Energy Technology, Tsinghua University, Beijing 100084, China 2. State Key Joint Laboratory of Environmental Simulation and Pollution Control, Tsinghua University, Beijing 100084, China Correspondence should be addressed to Wang Jianlong 2006Science China Chemistry2006,49,2:16
12Radiometric cross-calibration of the CBERS-02 CCD camera with the TERRA MODIS显示文摘For the application of the CCD camera, the most important payload on CBERS-02, the key is to provide long-term stable radiometric calibration coefficients. Although the vicarious calibration had been proved successful, it had its limitations such as test site requirement and unsuitable for historical data. Cross-calibration is one of the alternative methods, but it needs synchro surface spectrum to achieve spectral band matching factors. Our effort is to probe the influences on these factors. Simulations with a lot of surface spectrum showed that the factors changed with the viewing geometry, atmospheric condition and surface targets. However, simulating with the same viewing geometry and atmospheric condition, the spectral band matching factors of the same or similar surface targets’ spectrum acquired from different dates and different places would like to be consistent to each other within 1%―5%. Thus, the synchro measurement data can be substituted by the same or similar target from other source. Based on this method, using the MODIS as the reference, the cross-calibration was performed for CCD camera. The research demonstrated that the traditional method with single calibration site was inappropriate for CCD camera, since the offsets for its four spectral bands were not zeros. With four calibration sites, these offsets were obtained. And the camera was detected to degrade with dates based on four times of cross-calibrations.LI Xiaoying1,2,3, GU Xingfa1,3,4, MIN Xiangjun5, YU Tao1,3, FU Qiaoyan5, ZHANG Yong1,2,3 & LI Xiaowen1,3 1. State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University, Beijing 100101, China 2. Graduate University of Chinese Academy of Sciences, Beijing 100039, China 3. The Center for National Spaceborne Demonstration, Beijing 100101, China 4. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84914 Avignon, France 5. China Center for Resource Satellite Data and Application, Beijing 100830, China 2005Science China(Technological Sciences)2005,48,S2:15
13Variations of δ^(18)O in precipitation from the Muztagata Glacier, East Pamirs显示文摘Expeditions to Muztagata (in the eastern Pamirs) during the summer seasons of 2002 and 2003 collected precipitation samples and measured their oxygen isotopes. The δ 18O in precipita-tion displays a wide range, varying from ?17.40‰ to +1.33‰ in June-September 2002 and from ?22.31‰ to +4.59‰ in May-August 2003. The δ 18O in precipitation correlates with the initial tem-perature of precipitation during the observing periods. The positive correlation between δ 18O and tem- perature suggests that δ 18O can be used as an indicator of temperature in this region. The δ 18O values in fresh-snow samples collected from two snow events at different elevations on the Muztagata Gla-cier show a strong “altitude effect”, with a ratio of nearly ?0.40‰ per 100 m from 5500 m to 7450 m.LI Zhen1, YAO Tandong1,2, TIAN Lide1,2, XU Baiqing1,2 & Wu Guangjian2 1. Key Laboratory of Cryosphere and Environment, Jointly Established by Cold and Arid Regions Environmental and Engi-neering Research Institute and Institute of Tibetan Plateau Research, Chinese Academy of Sciences and Chinese Academy of Meteorological Sciences, China Meteorological Administration, CAS, Lanzhou 730000, China 2. Laboratory of Environment and Process on Tibetan Plateau, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China 2006Science China Earth Sciences2006,49,1:14
14Pollution characteristics of atmospheric fine particles and their secondary components in the atmosphere of Shenzhen in summer and in winter显示文摘Two field measurements for atmospheric fine particles were conducted in Baoan district of Shenzhen during the summer and winter in 2004. Totally 30 sets of 24 h samples were collected, and then the mass concentrations and chemical compositions were determined. The seasonal varia- tions and secondary pollution characteristics of fine particles during the sampling periods were dis-cussed with meteorological factors. The results show that seasonal variations of atmospheric particles are significant in Shenzhen. The average mass concentrations of PM2.5 and PM10 in summer were 35 μg·m-3 and 57 μg·m-3, respectively, and those in winter were 99 μg·m-3 and 135 μg·m-3, respec-tively. The concentrations of both PM2.5 and PM10 in winter increased 184% and 137%, respectively, compared to those in summer. PM2.5 accounted for 61% and 75% of PM10 in summer and in winter, respectively, indicating severe fine particle pollution in Shenzhen. During the summer and winter sampling periods, the mean OC/EC ratios were 3.4 and 1.6, respectively. The estimated secondary organic carbon (SOC) averagely accounted for 56% and 6% of the total OC in summer and in winter, respectively, which implies a major contribution of SOC to OC in summer. During the continuous high temperature period in summer, both the concentrations and fractions of secondary aerosol compo-nents in PM2.5 were highly elevated, suggesting severe secondary pollution again. The prevailing wind was from South China Sea in summer, and the air quality was good. The prevailing wind in winter was from China's Mainland to the north, and the polluted air mass led to poor air quality.NIU Yuwen1,2,HE Lingyan1,2,HU Min2,ZHANG Jing2 & ZHAO Yunliang2 1. Shenzhen Graduate School of Peking University,Shenzhen 518055,China 2. State Joint Key Laboratory of Environmental Simulation and Pollution Control,College of Environmental Sciences,Peking University,Beijing 100871,China 2006Science China Chemistry2006,49,5:12
15The diurnal and seasonal characteristics of urban heat island variation in Beijing city and surrounding areas and impact factors based on remote sensing satellite data显示文摘Based on the land surface temperature (LST), the land cover classification map,vegetation coverage, and surface evapotranspiration derived from EOS-MODIS satellite data, and by the use of GIS spatial analytic technique and multivariate statistical analysis method, the urban heat island (UHI) spatial distribution of the diurnal and seasonal variabilities and its driving forces are studied in Beijing city and surrounding areas in 2001. The relationships among UHI distribution and landcover categories, topographic factor, vegetation greenness, and surface evapotranspiration are analyzed. The results indicate that: (i) The significant UHI occur in Beijing city areas in the four seasons due to high heat capacity and multi-reflection of compression building, as well as with special topographic features of its three sides surrounded by mountains,especially in the summer. The UHI spatial distribution is corresponding with the urban geometry structure profile. The LST difference is approximately 4-6℃ between Beijing city and suburb areas, comparatively is 8- 10℃ between Beijing city area and outer suburb area in northwestern regions. (ii) The UHI distribution and intensity in daytime are different from nighttime in Beijing city area, the nighttime UHI is obvious. However, in the daytime, the significant UHI mainly appears in the summer, the autumn takes second place, and the UHI in the winter and the spring seem not obvious. The surface evapotranspiration in suburb areas is larger than that in urban areas in the summer, and high latent heat exchange is evident, which leads to LST difference between city area and suburb area. (iii) The reflection of surface landcover categories is sensitive to the UHI, the correlation between vegetation greenness and UHI shows obviously negative.The scatterplot shows that there is the negative correlation between NDVI and LST (R2 = 0.6481).The results demonstrate that the vegetation greenness is an important factor for reducing the UHI,and large-scale construction of greenbelts can considerably reduce the UHI effect.ZHANG Jiahua, HOU Yingyu, LI Guicai, YAN Hao YANG Limin & YAO Fengmei The Chinese Academy of Meteorological Sciences, Beijing 100081, China The National Meteorological Center, Beijing 100081, China The National Satellite Meteorological Center, Beijing 100081, China Joint Laboratory for Geoinformation Science, The Chinese University of Hong Kong, Hong Kong, China Department of Geosciences, Graduate School of Chinese Academy of Sciences, Beijing 100039, China 2005Science China Earth Sciences2005,48,z2:11
16High time resolution observation and statistical analysis of atmospheric light extinction properties and the chemical speciation of fine particulates显示文摘In recent years,the visibility deterioration caused by regional fine particulate pollution becomes one of the crucial air pollution problems in the urban areas of our country.The rapid variation of visibility and fine particulates make it difficult to estimate the relationship between them precisely and accurately unless high time resolution observation data can be accessed.This study aims to fill this gap in the field of atmospheric science by establishing a formula using multiple linear regressions.Excellent fitting goodness (R2=0.913,n=3167) was obtained using 10 min average of high-resolution real-time light scattering coefficients,light absorption coefficients,main chemical speciation concentration in PM1 and some meteorological parameters from 17 Jan to 16 Feb,2009.It shows that the average light extinction coefficient during the observation in the winter of Shenzhen was measured to be 290 ± 183 Mm?1,consisting of 72% of light scattering and 21% of absorption.In terms of the percentage contribution of PM1 chemical species to the total light extinction,the organic matter was estimated to be most with an average of 45%,followed by ammonium sulfate with an average of 24%.The contributions of black carbon and ammonium nitrate were 17% and 12%,respectively.Besides,the diurnal variation of light extinction was investigated as well in this study.YAO TingTing1,HUANG XiaoFeng1,HE LingYan1,HU Min2,SUN TianLe1,XUE Lian1,LIN Yun1,ZENG LiWu1 & ZHANG YuanHang2 1Key Laboratory for Urban Habitat Environmental Science and Technology,School of Environment and Energy,Peking University Shenzhen Graduate School,Shenzhen 518055,China 2State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China 2010Science China Chemistry2010,53,8:10
17HJ-1A HSI on-orbit radiometric calibration and validation research显示文摘The calibration experiment data at Dunhuang radiometric calibration site in October, 2008 were used to achieve the on-orbit radiometric calibration for HJ-1A hyper spectral imager (HSI). Two other field experiments data were used to validate the Dunhuang calibration results. One field experiment took place in Inner-Mongolia, China in September, 2008, and the other field experiment took place in Lake Frome, Australia in February, 2009. Finally, the ‘confidence interval of calibration error’ concept was put forward for quantitatively computing the calibration coefficient error confidence interval. The results showed that the Dunhuang calibration results in 2008 had high reliability. The confidence intervals of calibration error for all HSI channels were between 2% to 12%, which could satisfy the requirement of the HSI quantitative applications.GAO HaiLiang1,2,3*, GU XingFa1,3*, YU Tao1,3, GONG Hui1,2,3, LI JiaGuo1,2,3 & LI XiaoYing1,3 1 State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University, Beijing 100101, China 2 Graduate University of Chinese Academy of Sciences, Beijing 100039, China 3 Center for National Spaceborne Demonstration, Beijing 100101, China 2010Science China(Technological Sciences)2010,53,11:10
18Synchronous estimation of DTM and fractional vegetation cover in forested area from airborne LIDAR height and intensity data显示文摘We proposed a method to separate ground points and vegetation points from discrete return,small footprint airborne laser scanner data,called skewness change algorithm.The method,which makes use of intensity of laser scanner data,is especially applicable in steep,and forested areas.It does not take slope of forested area into account,while other algorithms consider the change of slope in steep forested area.The ground points and vegetation points can be used to estimate digital terrain model(DTM) and fractional vegetation cover,respectively.A few vegetation points which were classified into the ground points were removed as noise before the generation of DTM.This method was tested in a test area of 10000 square meters.A LiteMapper -5600 laser system was used and a flight was carried out over a ground of 700―800 m.In this tested area,a total number of 1546 field measurement ground points were measured with a total station TOPCON GTS-602 and TOPCON GTS -7002 for validation of DTM and the mean error value is -18.5 cm and the RMSE(root mean square error) is ±20.9 cm.A data trap sizes of 4m in diameter from airborne laser scanner data was selected to compute vegetation fraction cover.Validation of fractional vegetation cover was carried out using 15 hemispherical photographs,which are georeferenced to centimeter accuracy by differential GPS.The gap fraction was computed over a range of zenith angles 10° using the gap light analyzer(GLA) from each hemispherical photograph.The R2 for the regression of fractional vegetation cover from these ALS data and the respective field measurements is 0.7554.So this study presents a method for synchronous estimation of DTM and fractional vegetation cover in forested area from airborne LIDAR height and intensity data.BAO YunFei1,2,CAO ChunXiang1,ZHANG Hao1,CHEN ErXue3,HE QiSheng1,2,HUANG HuaBing1,LI ZengYuan3,LI XiaoWen1,4 & GONG Peng1 1 State Key Laboratory of Remote Sensing Science,jointly sponsored by the Institute for Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University,Beijing 100101,China 2 Graduate University of the Chinese Academy of Sciences,Beijing 100049,China 3 Institute of Forest Resource Information Technique,the Chinese Academy of Forestry,Beijing 100091,China 4 Research Center for Remote Sensing and GIS,Department of Geography and Beijing Key Laboratory for Remote Sensing of Environment and Digital Sites,Beijing Normal University,Beijing 100875,China 2008Science China(Technological Sciences)2008,51,S2:10
19Detection of the urban heat island in Beijing using HJ-1B satellite imagery显示文摘Satellite images are used extensively in studying the urban heat island(UHI) phenomenon.We evaluated the suitability of thermal infrared(TIR) data from the HJ-1B satellite for detecting UHI using a case study in Beijing.Two modified algorithms for retrieving the land surface temperature(LST) from HJ-1B data were tested.The results were compared with LST images derived from a Landsat TM thermal band and the MODIS LST output.The spatial pattern of UHI generated using HJ-1B data matched well with that produced using TM and MODIS data.Of the two algorithms,the mono-window algorithm performed better but further tests are necessary.With more frequent coverage than TM and higher spatial resolution than MODIS,the HJ-1B TIR data present a unique opportunity to study thermal environments in cities in China and neighboring countries.YANG Jun1,GONG Peng2,ZHOU JinXing3,HUANG HuaBing2 & WANG Lei2 1 Key Laboratory of Silviculture and Conservation,Ministry of Education,Beijing Forestry University,Beijing 100083,China 2 State Key Laboratory of Remote Sensing Science,jointly sponsored by the Institute of Remote Sensing Applications,Chinese Academy of Sciences and Beijing Normal University,Beijing 100101,China 3 Institute of Desertification Studies,Chinese Academy of Forestry,Beijing 100091 China 2010Science China Earth Sciences2010,53,S1:9
20Distributions of dimethylsulfide in the Bohai Sea and Yellow Sea of China显示文摘Dimethylsulfide(DMS) measurements in the surface seawater of China eastern coastline were conducted during March 9—10, 1993 in Bohai Sea along the cruise from Dalian to Tianjin and during September 24—25, 1994 in Yellow Sea along the cruise from Shanghai to Qingdao. On the cruise in Bohai Sea DMS concentrations varied from 0.11 to 2.63 nmol/L with an average of 1.31 nmol/L, while DMS flux was estimated to be 0.85 μmol/(m 2·d) with the range of 0.04—3.12 μmol/(m 2·d). On the cruise in Yellow Sea DMS concentrations varied from 0.95 to 7.48 nmol/L with an average of 2.89 nmol/L, and DMS flux was estimated to be 7.94 μmol/(m 2·d) with the range of 0.11—18.88 μmol/(m 2·d). Variations in DMS concentrations along the latitude in Yellow Sea were observed larger than those along the longitude in Bohai Sea. DMS concentrations and fluxes had a similar spatial trend both in Bohai Sea and Yellow Sea with the correlation coefficients of 0.75 and 0.64, respectively.HU Min *, TANG Xiao-yan, LI Jin-long, MA Qi-ju (State Joint Key Laboratory of Environmental Simulation and Pollution Control Center for Environmental Sciences, Peking University, Beijing 100871, China. 2003Journal of Environmental Sciences2003,15,6:8
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