检索结果-南通市图书馆

Temporal and spatial variations of δ^(15)N and δ^(18)O for atmospheric N_2. above the oceanic surface from Shanghai to Antarctica

引用

Science China earth sciences 2008年第6期51卷 899-910页

作者： ZHU RenBin1, LIU YaShu1, XU Hua2. MA Jing2.& SUN LiGuang1 1 institute of Polar {3., University of Science and Technology of China, Hefei 2.002., China 2.State Key Laboratory of Soil and Sustainable Agriculture, institute of Soil Science, Chinese {3. of sciences, Nanjing 2.0091, China 1. institute of Polar environment University of Science and Technology of China Hefei 230026 China 2. State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210091 China

During the 2.nd Chinese Antarctic Research Expedition (CHINARE-2.), the atmospheric gas samples above the oceanic surface and near the surface were collected on the track for the scientific ship "Xuelong" and on Millor Peninsula of eastern Antarctica, respectively, using the Tedlar gas bags. Every day the sampling times were 10:00 and 2.:00 (local time), respectively. In the laboratory, high-precision measurement of the isotopic compositions for N2. in these gas samples was conducted using Thermo Finnigan MAT-2.3.Isotopic Mass Spectrometer with a fully automated interface for the pre-GC concen-tration (PreCon) of trace gases. The temporal and spatial variations of δ 15N and δ 18O in atmospheric N2. were analyzed. The mean δ 15N and δ 18O-N2. values above the oceanic surface were (7.2.±0.50)‰ and (44.52.0.52.‰, respectively. From 3.°N to Antarctica, the δ 15N (6.05‰―7.88‰) linearly increased with the rate of about 0.01‰ with the latitude while the δ 18O (43.05‰―48.78‰) showed a large fluctua-tion. The δ 15N negatively correlated with air temperature and N2. concentration, and slightly positively correlated with δ 18O. The summertime variations of δ 15N and δ 18O-N2. appeared the same trend on Millor Peninsula of eastern Antarctica. They significantly positively correlated with each other and negatively with N2. concentration. The δ 15N and δ 18O-N2. at different sites averaged (7.42.0.3.)‰ and (44.69±0.49)‰, respectively, slightly higher than those above the oceanic surface, significantly higher than those of atmospheric N2. in the low-latitude regions of Northern Hemisphere. The predominant factors affecting the spatial variations of δ 15N and δ 18O values were also discussed. The isotopic data given in this study can help to investigate the global and regional N2. budgets.

关键词： nitrous oxide Antarctica atmosphere δ^(15)N δ^(18)O isotope ocean

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Petrogenesis and significance of early Yanshanian syenite-granite complex in eastern Nanling Range

引用

Science China earth sciences 2005年第7期48卷 912-924页

作者： CHEN Peirong1, ZHOU xinmin1, ZHANG Wenlan1, LI Huimin2. FAN Chunfang1, SUN Tao1, CHEN Weifeng1 & ZHANG Min1 1. State Key Laboratory of Mineral Deposits Research, Department of earth {3., Nanjing University, Nanjing 2.0093. China 2. Tianjin {2. of Geology and Mineral Resources, China Geological Survey, Tianjin 3.0170, China State Key Laboratory of Mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing 210093 China Tianjin institute of Geology and Mineral Resources China Geological Survey Tianjin 300170 China

In the eastern Nanling Range there exists the early Yanshanian syenite-granite assemblage. A representative example is the Pitou-Tabei complex composed of the Tabei syenite pluton and the Pitou syenogranite pluton in southern Jiangxi Province. U-Pb zircon dating yields ages of 188.6±2.2.Ma for the Tabei pluton and 186.3.1.1 Ma for the Pitou pluton. The Tabei syenite is characterized by relatively low SiO2.content (62.40% - 68.75%), high alkalis (K2.+Na2. = 10.56%-11.96%), low percent K2./Na2. ratios (0.56-0.93., metaluminous fea- ture (A/CNK = 0.80-1.00), enrichment in LILE (Rb, Ba, K) and HFSE (Th, U, Nb, Ta, Zr, and so on), weakly negative to positive Eu anomalies (δ Eu = 0.63.1.82., relatively low (87Sr/86Sr)i (0.70412.0.70543., and relatively high ε Nd(t) (3.14-3.52.. The Pitou syenogranite is charac- terized by high silicon content (SiO2.= 71.06%-76.2.%), relatively low alkalis (K2.+Na2. = 8.10%-9.80%), high percent K2./Na2. ratios (1.2.-1.94), metaluminous feature (A/CNK = 0.94-1.07), enrichment in Rb, Th (U), K, depletion in Ba, Nb, Ta, Sr, P , Zr, Ti, high ΣREE (av- eraging 451.03.μg/g), strong negative Eu anomalies (δ Eu = 0.2.-0.3.), relatively high (87Sr/86Sr)i (0.70805-0.70912., and relatively low ε Nd( t ) (?5.3.-?6.2.). The Tabei syenite and Pitou syenogranite both have the characteristics of A-type granites. The former is considered to be from the asthenosphere mantle, and the latter was the product of the crust-mantle mixture. They both were probably formed in a rifting setting.

关键词： syenite-granite assemblage single zircon U-Pb age rifting environment Nanling Range.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Natural vegetation of geological and historical periods in Loess Plateau

Natural vegetation of geological and historical periods in L...

引用

中国科学院地质与地球物理研究所2.03.术年会

作者： L Houyuan~1,LIU Dongsheng(LIU Tungsheng~1) & GUO Zhengtang~(1,2. 1.institute of Geology and Geophysics,Chinese academy of {2., Beijing 10002.,China 2.institute of earth environment,Chinese academy of {2.,xi’an 710075,China

The study of natural vegetation of geological and historical periods in the Loess Plateau is an important scientific and practical issue for the development of northwestern ***,interpretation of the natural vegetation before human reclamation is still *** paper aims to analyze the potential factors that cause the difference in knowledge of Holocene natural vegetation developing in different topographies of the Loess *** distribution of paleovegetation in this region shows significant difference among rocky mountains,valleys,and Yuan lands(the plain area),*** does not follow the natural vegetation zonation,as that in eastern China *** Yuan lands with thick loess accumulation were never covered by a vast of dense forests during the ***(or open forests) developed preferably in valleys in the southern part of the Plateau and rocky mountains on the Plateau during the warm period of the *** of local vegetation outside of the Loess Plateau are more subjected to the control of geomorphology and ground water.

关键词： Loess Plateau paleovegetation

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Scale effects of leaf area index inversion based on environmental and disaster monitoring satellite data

引用

Science China earth sciences 2010年第S1期53卷 92-98页

作者： ZHANG Hao1,LI xiaoWen1,2.CAO Chunxiang1,YANG Hua2.GAO MengXu1,3.ZHENG Sheng1,3.XU Min1,3.xiE DongHui2.JIA HuiCong1,JI Wei1,ZHAO Jian1,3.CHEN Wei1,3.& NI xiLiang1,3.1 State Key Laboratory of Remote Sensing Science,Jointly Sponsored by institute of Remote Sensing Applications,Chinese academy of {2. and Beijing Normal University,Beijing 100101,China 2.State Key Laboratory of Remote Sensing Science,Jointly Sponsored by Beijing Normal University and institute of Remote Sensing Applications of Chinese academy of {2.,Beijing 100875,China 3.Graduate University of Chinese academy of {2.,Beijing 100049,China 1. State Key Laboratory of Remote Sensing Science Jointly Sponsored by Institute of Remote Sensing Applications Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China2. State Key Laboratory of Remote Sensing Science Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing Applications of Chinese Academy of Sciences Beijing 100875 China3. Graduate University of Chinese Academy of Sciences Beijing 100049 China

The spatial distribution of sub-pixel components has an impact on retrieval accuracy,and should be accounted for when inverting a three-dimensional adiative transfer model to retrieve leaf area index(LAI).To investigate this effect,we constructed three realistic scenarios with the same LAI values and other properties,except that the simulated plants had different *** implemented the radiosity method to subsequently produce synthetic bidirectional reflectance factor(BRF) datasets based upon these simulated *** inversion was conducted using these data,which showed that spatial distribution affects retrieval *** inversion was also conducted for LAI based on charge-coupled device(CCD) data from the environment and Disaster Monitor Satellite(HJ-1),which depicted both forest and drought-resistant crop land *** showed that heterogeneity in coarse-resolution remote sensing data is the main error source in LAI *** spatial distribution of global fractal dimension index,which can be used to describe the area of sub-pixel components and their spatial distribution modes,shows good consistency with the coarse resolution LAI inversion error.

关键词： HJ-1 leaf area index scale effect spatial distribution

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Anatomical variations of living and fossil Liquidambar leaves:A proxy for paleoenvironmental reconstruction

引用

Science China earth sciences 2011年第4期54卷 493-508页

作者： xiAO Liang 1,2.3.4,SUN BaiNian 1,2.,LI xiangChuan 1,REN Wenxiu 1 &JIA Hui 1 1 Key Laboratory of Western China's environmental Systems of the Ministry of Education and College of earth and environment Science,Lanzhou University,Lanzhou 73.000,China 2.State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing {3. of Geology and Palaeontology,Chinese academy of sciences,Nanjing 2.0008,China 3.College of Arts and sciences,Bryant University,Smithfield RI 02.17,U.S.A. 4 Key Laboratory of Western China's Mineral Resources and Geological Engineering of Ministry of Education,Chang’an University,xi’an 710054,China 1. Key Laboratory of Western China’s environmental Systems of the Ministry of Education and College of earth and environment Science Lanzhou University Lanzhou 730000 China2. State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China3. College of Arts and Sciences Bryant University Smithfield RI 02917 USA4. Key Laboratory of Western China’s Mineral Resources and Geological Engineering of Ministry of Education Chang’an University Xi’an 710054 China

Based on living ***,we have established that such epidermal cell properties as epidermal cell circumference(Circum.) ,undulation index(UI) ,epidermal cell area(EA) on both upper and lower epidermis and the corresponding epidermal cell density(ED) ,are suitable to differentiate between sun and shade ***,stomatal properties on the lower epidermis,including stomatal length(SL) ,stomatal pore length(PL) and the corresponding stomatal density(SD) ,are reliable parameters to identify sun/shade *** this anatomical approach was applied to 18 leaf remains of *** from the Miocene xiannanshan Formation,Zhejiang Province(eastern China) ,and the fossil leaves were sorted into two groups,namely,sun and shade *** indicates that anatomical differences between sun and shade leaves found in living species could be used for fossil ***,the variation of UI between sun and shade morphotypes is larger on the upper epidermis as compared with the lower epidermis,showing that the UI on the upper epidermis is more sensitive to environmental *** addition,anatomical features are more variable in sun leaves than in shade leaves for both modern and fossil Liquidambar,suggesting sun leaves may be more sensitive to environmental *** leaves can then be a better indicator of paleoenvironmental ***,stomatal parameters of sun morphotype should be adopted on reconstructing paleoenvironments using Liquidambar leaf *** the other hand,the three-lobed fossil *** leaf assemblage in the xiananshan Formation is represented by an almost similar percentage of sun and shade morphotypes(56%and 44%,respectively) ,which is attributed to the short transport before *** a result,identifying sun/shade morphotypes are very useful in reconstructing paleoenvironments based on fossil leaves of Liquidambar.

关键词： Liquidambar formosana Liquidambar miosinica leaf anatomy the Miocene xiananshan Formation sun and shade leaves

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Estimating forest aboveground biomass using HJ-1 Satellite CCD and ICESat GLAS waveform data

引用

Science China earth sciences 2010年第S1期53卷 16-25页

作者： 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 {2. and Beijing Normal University,institute of Remote Sensing Applications,Chinese academy of {2.,Beijing 100101,China 2.raduate University of Chinese academy of {2.,Beijing 100049,China 3.epartment of Geography University of Maryland,College Park,MD 2.742.USA 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 Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Department of Geography University of Maryland College Park MD 20742 USA

The ecosystem in northeastern China and the Russian Far East is a hotspot of scientific research into the global carbon *** aboveground biomass(AGB) is an important component in the land surface carbon *** 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 *** resulted statistical regression models have a R2.0.68 for conifer and R2.0.71 for broadleaf *** models were used to estimate biomass for all GLAS footprints of forest located in the study *** 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 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 2. t ha-1,and the mean error of all validation samples is 5.74 t *** pixel-level biomass map was then stratified into different biomass levels to illustrate the AGB spatial distribution pattern in this *** was found that HJ-1 wide-swath data and GLAS waveform data can be combined to estim

关键词： Disaster and environment Monitoring and Forecast Satellite ICESat GLAS waveform boreal forest forest aboveground biomass multiple linear regression

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Structural stability of C60 films under the bombardment of 1.95 GeV Kr ions

引用

Science Bulletin 2010年第31期 3532-3536页

作者： YAO CunFeng1,2.FU YunChong3.JIN YunFan1*,WANG ZhiGuang1,ZANG Hang1,2.WEI KongFang1,GOU Jie1,MA YiZhun1,2.& SHEN TieLong1,2.1 institute of Modern Physics,Chinese academy of {2.,Lanzhou 73.000,China 2.Graduate University of Chinese academy of {2.,Beijing 100049,China 3.institute of earth environment,Chinese academy of {2.,xi'an 710075,China

The structural stability of C60 films under the bombardment of 1.95 GeV Kr ions is *** irradiated C60 films were analyzed by Fourier Transform Infrared(FTIR) spectroscopy and Raman scattering *** analytical results indicate that the irradiation induced a decrease of icosahedral symmetry of C60 molecule and damage of C60 films;different vibration modes of C60 molecule have different irradiation sensitivities;the mean efficient damage radius obtained from experimental data is about 1.47 nm,which is in good agreement with thermal spike model prediction.

关键词： 1.95 GeV Kr ions C60 films structural stability efficient damage radius thermal spike model

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Electrochemical reduction of carbon dioxide to produce formic acid coupled with oxidative conversion of biomass

引用

Journal of Energy Chemistry 2024年第5期92卷 705-729页

作者： xi Liu Yifan Wang Zhiwei Dai Daihong Gao Xuebing Zhao Key Laboratory of Industrial Biocatalysis Ministry of EducationTsinghua UniversityBeijing 100084China institute of Applied Chemistry Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

Electrochemical reduction of CO_(2.(CO_(2.RR)has become a research hot spot in recent years in the context of carbon *** is one of the most promising products obtained by electrochemical reduction of CO_(2. due to its high energy value as estimated by market price per energy unit and wide application in chemical *** is the most abundant renewable resource in the natural *** biomass o{3.dative conversion with CO_(2.RR driven by renewable electricity would well achieve carbon *** this work,we comprehensively reviewed the current research progress on CO_(2.RR to produce HCOOH and coupled system for conversion of biomass and its derivatives to produce value-added ***-and Bi-based electrocatalysts are discussed for CO_(2.RR with regards to the structure of the catalyst and reaction ***-o{3.dation reactions of biomass derived sugars,alcohols,furan aldehydes and even polymeric components of lignocellulose were reviewed as alternatives to replace oxygen evolution reaction(OER)in the conventional electrolysis *** was recommended that to further improve the efficiency of the coupled system,future work should be focused on the development of more efficient and stable catalysts,careful design of the electrolytic cells for improving the mass transfer and development of environment-friendly processes for recovering the formed formate and biomass o{3.dation products.

关键词： Electrochemical reduction of CO_(2. Formic acid Oxidative conversion of biomass Lignocellulose Coupled system

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mid-Pleistocene vermiculated red soils in southern China as an indication of unusually strengthened East Asian monsoon

Mid-Pleistocene vermiculated red soils in southern China as ...

引用

中国科学院地质与地球物理研究所2.06学术年会

作者： YIN Qiuzhen~1 & GUO Zhengtang~(2.1) 1.institute of Geology and Geophysics,Chinese academy of {2.,Beijing 10002.,China 2.institute of earth environment,Chinese academy of {2.,xi’an 710075,China

The mid-Pleistocene vermiculated red soils(VRS) from Xuancheng(Anhui Province) and Bose(Guangxi) are studied through soil micromorphological,mineralogical and chemical *** results indicate a polygenetic nature of the VRS,having experienced multiple soil-forming *** main stages have been recognized,attributable to distinct climate *** include the formation of the homogeneous matrix of a red soil(stage 1), development of the white veins within the soil profile(stage 2.,and formation of juxtaposed textural features(stage 3..The white veins,resulting from iron-depletion in the groundmass of the homogeneous matrix of a red soil,required abundant rainfall without significant seasonal *** geographically widely spread VRS south of the Yangtze River in China implies a Mid-Pleistocene extreme East Asian summer *** climate extreme might be closely linked with the changes in the strength of NADW.

关键词： vermiculated red soil paleosols micromorphology paleoclimate mid-Pleistocene East Asian monsoon

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Selective adsorption of tetracycline by β-CD-immobilized sodium alginate aerogel coupled with ultrafiltration for reclaimed water

引用

Chinese Journal of Chemical Engineering 2024年第4期68卷 27-34页

作者： xi Quan Jun Zhang Linlin Yin Wei Zuo Yu Tian State Key Laboratory of Urban Water Resource and environment(SKLUWRE) School of EnvironmentHarbin Institute of TechnologyHarbin 150090China

In this work,a novel composite material based on β-cyclodextrin-immobilized sodium alginate aerogel(β-CD/NaAlg) was developed utilizing cross-linker of epichlorohydrin and applied as an adsorbent to remove tetracycline antibiotics from reclaimed wastewater.A series of characterizations were utilized to confirm the successful synthesis of the adsorbent and this β-CD/NaAlg presented a three-dimensional network at the nanoscale or *** optimal conditions(pH=4,t=8 h,β-CD:NaAlg=9,adsorbent dosage = 1.5 g·L-1),the maximum removal rate of β-CD/NaAlg to tetracycline was 70%.The adsorption behavior of tetracycline on β-CD/NaAlg conformed to the Freundlich isotherm model(R2.0.9977) and the pseudo-second-order kinetic model(R^(2.=0.9993..Moreover,the adsorbent still removed 55.3. of tetracycline after five ***,the adsorbent was integrated with ultrafiltration to adsorb tetracycline antibiotics from simulated reclaimed wastewater,and the removal rate of tetracycline reached 78.9% within 2.*** existence of Cr(Ⅵ) had a negligible impact on tetracycline removal,while the presence of humic acid exhibited a promoting *** possible adsorption mechanisms were also elucidated through X-ray photoelectron spectroscopy and density functional theory *** summary,β-CD/NaAlg represents an environmentally friendly,efficient,and sustainable adsorbent for removing tetracycline antibiotics from reclaimed water.

关键词： b-CD/NaAlg aerogel Covalent grafting Tetracycline antibiotics Ultrafiltration Selective adsorption Reclaimed water

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：