检索结果-南通市图书馆

Estimating surface evapotranspiration using combined MODIS and CBERS-02 data

在线全文

学校读者我要写书评

暂无评论

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 {3., beijing 100875, china 3. Graduate {3. of Chinese Academy of Sciences, beijing 10003., china 4. Department of Atmospheric Physics, Peking {3., 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.

Carbon isotope composition of the Lower Triassic marine carbonates, Lower Yangtze Region, South china

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第3期49卷 225-241页

作者： ZUO Jingxun1,2, TONG Jinnan3. QIU Haiou4.& ZHAO Laishi3.1. Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, china 2. Henan Institute of Geological Survey, Zhengzhou 4.0007, china 3. State Key Laboratory of Geological Processes and Mineral Resources at china {3. of geosciences, Wuhan 4.0}074. china 4. Faculty of Material Sciences and Chemical Engineering, china {3. of geosciences, Wuhan 4.0}074. china 1. Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China 2. Henan Institute of Geological Survey Zhengzhou 450007 China 3. State Key Laboratory of Geological Processes and Mineral Resources at china university of geosciences Wuhan 430074 China 4. Faculty of Material Sciences and Chemical Engineering China University of Geosciences Wuhan 430074 China

Studies on three Lower Triassic sections located on the shallow water platform, the deep water slope and in the deep water basin in the Lower Yangtze Region, South china, show the similar trend of carbon isotope evolution. Biostratigraphic correlations among the Lower Triassic sections on the basis of standard conodont zones indicate that three negative shifts occurred in the Griesbachian, the Smithian and the late Spathian stages respectively, and one distinctly positive shift occurred in the early Spathian stage. Trend of carbon isotope evolution of the Lower Triassic reflects some significant changes in the global carbon cycle. Moreover, δ 13. background values are intensively controlled by palaeogeographic environment. In general, δ 13. values from deep-water slope carbonates are lighter than those from carbonate platform and heavier than those from deep-water basin carbonates. The positive carbon isotope excursion may be induced by a significant amount of organic carbon burial in marine sediments and increase in primary productivity. The large negative carbon isotope excursions during the Early Triassic in Lower Yangtze Region are interpreted to relate to volcano eruptions based on tuffaceous claystone interlayers observed near the Permian-Triassic boundary, the Induan- Olenekian boundary and the Lower Triassic-Middle Triassic boundary.

关键词： Lower Triassic, carbon isotope compositions, palaeogeography, volcanic eruptions, Lower Yangtze Region.

Three-point bending fracture characteristics of bulk metallic glasses

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 654-657页

作者： FAN ZhenJun, ZHENG ZhiYuan & JIAO ZengBao School of Materials Sciences and Technology, china university of geosciences,{3. 1. School of Materials Sciences and Technology China University of Geosciences Beijing 100083 China

This paper presents the SEM micrographs for the three-point bending fracture surfaces of Zr-based, Ce-based and Mg-based bulk metallic glasses (BMGs), which show the dimple structures in the three kinds of BMGs. The shapes of the giant plastic deformation domain on the fracture surface are similar but the sizes are different. The fracture toughness KC and the dimple structure size of the Zr-based BMG are both the largest, and those of the Mg-based BMG are the smallest. The fracture toughness KC and the dimple structure size of the Ce-based BMG are between those of the Zr-based and the Mg-based BMG. Through analyzing the data of different fracture toughnesses of the BMGs, we find that the plastic zone width follows w = (KC/σY)2/(6π).

关键词： metallic glass fracture surface tree-point bending

Compressive fracture characteristics of Zr-based bulk metallic glass

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2010年第5期53卷 823-827页

作者： FAN ZhenJun,ZHENG ZhiYuan & JIAO ZengBao School of Materials Sciences and Technology,china university of geosciences,{3. {4.china 1. School of Materials Sciences and Technology China University of Geosciences Beijing 100083 China

The compressive fracture characteristics of Zr-based bulk metallic glass under uniaxial compression tests are *** zigzag rheological behavior is observed in the compression stress-strain curves of amorphous *** room temperature the uniaxial compression fracture takes place along the plane which is at a 4.-degree angle to the direction of the compressive *** microstructure of a typical fracture pattern is the vein network.A unique,finger-like vein pattern is found to exist at the fracture surface of Zr-based bulk metallic glass.

关键词： bulk metallic glass fracture surface compressive fracture

Unfolding of a Quadratic Integrable System with a Homoclinic Loop

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2002年第4期18卷 737-754页

作者： Lin Ping PENG Department of Applied Mathematics. beijing university of Aeronautics and Astronautics. beijing {3. P. R. {4. Department of Applied Mathematics Beijing University of Aeronautics and Astronautics Beijing 100083 P. R. China

In this paper, we make a complete study of the unfolding of a quadratic integrable system with a homoclinic loop. Making a Poincare transformation and using some new techniques to estimate the number of zeros of Abelian integrals, we obtain the complete bifurcation diagram and all phase portraits of systems corresponding to different regions in the parameter space. In particular, we prove that two is the maximal number of limit cycles bifurcating from the system under quadratic non- conservative perturbations.

关键词： A quadratic integrable system A homoclinic loop Unfolding

Carbon Solubility and Mass Action Concentrations of Fe-Cr-C Melts

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2000年第2期14卷 86-91页

作者： Jtan Zhang(Metallurgy School, university of Science and Technology beijing, beijing 100083. china) Metallurgy School University of Science and Technology Beijing Beijing 100083 China

An empirical equation of carbon solubility in Fe-Cr-C melts is regressed based on the experimental data from references. Acalculating model of mass action concentrations for these melts is formulated on the basis of the coexistence theory of metaIlic melts in-volving compound formation, the phase diagram of Cr-C system as well as thermodynamic data of Fe-Cr-C melts. According to the mod-el, the standard Gibbs free energies of formation of CrC and Cr3.2 are obtained. Satisfactory agreement between the calculated and me-asured values shows that the model can reflect the structural characteristics of Fe-Cr-C melts.

关键词： activity, coexistence theory mass action concentration saturated state

Application of annexation principle to the study of thermodynamic properties of Ag-Bi-In metallic melts

在线全文

学校读者我要写书评

暂无评论

Journal of university of Science and Technology beijing 2003年第1期10卷 18-20页

作者： Jian ZhangMetallurgy school, university of Science and Technology beijing, beijing 100083. china Metallurgy school University of Science and Technology Beijing Beijing 100083 China

Based on the measured activities, the phase diagrams and the annexation principle, the calculating models of mass action concentrations for Ag-Bi and Ag-Bi-In melts have been formulated. The calculated results agree with practice and obey the mass action law, showing that the models formulated can reflect the structural characteristics of both melts. Meanwhile, it confirms that annexation principle is applicable to the Ag-Bi-In metallic melts. The melts involving eulectic which give rise to phase separation, and in which activities exhibit positive deviation from Raoult's law is the basic cause of melts transforming from homogeneous to heterogeneous ones.

关键词： the mass action law annexation principle two phase melts activity, mass action concentration

Electrical Properties of Expanded Graphite Intercalation Compounds

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2001年第3期17卷 371-374页

作者： Xiuyun CHUAN Department of Geology, Peking university, beijing 100871, china Daizhang CHEN and Xunruo ZHOU Department of Materials Science, china university of geosciences, beijing 100083. china E-mail: cxyljhcj@*** Peking Univ Dept Geol Beijing 100871 Peoples R China china Univ Geosci Dept Mat Sci Beijing 100083 Peoples R China

The intercalation compounds of CuCl2 were synthesized with expanded graphite, whose magnitude of the electrical conductivity is about 10(3.S(.)cm(-1). Their electrical conductivity is 3.similar to6 times as high as that of the expanded graphite, and about 10 times as high as that of GIC made of the non-expanded graphite. The microanalysis results of chemical compounds by X-ray energy spectrum scanning of TEM testified that the atomic ratio of chloride and cupric is nonstoichoimetric. The multivalence and exchange of electrovalence of the cupric ion was confirmed by the XPS-ESCA. Vacancy of chlorine anion increases the concentration of charge carrier. The special stage structure, made of graphite and chloride, produces a weak chemical bond belt and provides a carrier space in the direction of GIC layer. These factors develop the electrical properties.

关键词： In Ph Electrical Properties of Expanded Graphite Intercalation Compounds Graphite ESCA

Application of Fuzzy Weight of Evidence to Mineral Potential Mapping in Eastern Tianshan,Xinjiang Province,Northwestern china

在线全文

学校读者我要写书评

暂无评论

地学前缘 2009年第S1期16卷 168-169页

作者： Jingning Huang,Pengda Zhao china university of geosciences({3.),{3. 100083.china.

The eastern Tianshan metallogenic belt(E92°-96°, N4.°-4.0}),one of the most important Cu-Ni-Au mineral districts in china,is located at the conjunction of the Siberian plate and Tarim *** fuzzy weight of evidence method(FWofE) is applied to predict and delineate the most prospective areas for copper resource based on the available

关键词： fuzzy weight of evidence eastern Tianshan metallogenic belt copper