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Response of remotely sensed Normalized Difference Water Deviation Index to the 2006 Drought of eastern Sichuan Basin

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Science china earth sciences 2008年第5期51卷 748-758页

作者： ZHANG WenJiang1, LU QiFeng2, GAO ZhiQiang3.& PENG Jian4 1 school of Water Resource and Hydropower, Sichuan university, Chengdu 610065, china 2 National Satellite Meteorological Center, china Meteorological Administration, beijing 100081, china 3.Institute of Geographic sciences and Natural resources Research, Chinese Academy of sciences, beijing 100101, china 4 school of Environmental sciences, Peking university, beijing 100871, china school of Water Resource and Hydropower Sichuan University Chengdu China National Statellite Meteorological Center China Meteorological Administration Beijing China Institute of Geographic sciences and Natural resources Research Chinese Academy of Sciences Beijing China school of Environmental sciences Peking University Beijing China

One of the most serious droughts in last century occurred in eastern Sichuan Basin in the summer of 2006 (hereinafter called the Drought). The response of Moderate Resolution Imaging Spectroradiometer (MODIS, boarding on NASA satellites of Terra and Aqua) to the Drought was analyzed in order to reach one practicable monitoring solution for regional soil moisture. Temporal process and spatial extension of the Drought were firstly estimated with ground meteorological and hydrological observations. Then, for the whole region of Sichuan and Chongqing, the remotely sensed Normalized Difference Water In- dex (NDWI) for the summers of 2001―2006 were calculated based on 8-day composite MODIS products, which were further used to construct a new water index (Normalized Difference Water Deviation Index, NDWDI) to examine the sensitivity of remote sensing in the Drought. The study showed that the NDWDI is more sensitive to regional drought than other absolute-soil-moisture-based indices. With the new index, the study extracted the spatial-temporal characteristics of the 2006 Drought, and explored its developing and withdrawing processes, which agreed with related statistics. Compared with ground method of drought observation, the NDWDI-based remote sensing solution of this paper is more pref- erable and practicable in that the local soil properties of water consumption and supply are implicitly taken into account, and the spatial representativity limit of ground observation is circumvented to a degree as satellite remotely senses the earth surface in a way of two-dimensional pixel matrix. So, the NDWDI-based method can be used to monitor regional soil water stress situation more practically and efficiently.

关键词： Sichuan Basin drought Normalized Difference Water Deviation Index response of remote sensing regional scale

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The new interpretation of support vector machines on statistical learning theory

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Science china Mathematics 2010年第1期53卷 151-164页

作者： ZHANG ChunHua 1 , TIAN YingJie 2 & DENG NaiYang 3.1 school of Information, Renmin university of china, {3. 100872, china 2 Research Center on Fictitious Economy and Data Science, Chinese Academy of sciences, {3. 100080, china 3.College of Science, china Agricultural university, {3. 100083, china school of Information Renmin University of China Research Center on Fictitious Economy and Data Science Chinese Academy of Sciences College of Science China Agricultural University

This paper is concerned with the theoretical foundation of support vector machines (SVMs). The purpose is to develop further an exact relationship between SVMs and the statistical learning theory (SLT). As a representative, the standard C-support vector classification (C-SVC) is considered here. More precisely, we show that the decision function obtained by C-SVC is just one of the decision functions obtained by solving the optimization problem derived directly from the structural risk minimization principle. In addition, an interesting meaning of the parameter C in C-SVC is given by showing that C corresponds to the size of the decision function candidate set in the structural risk minimization principle.

关键词： C-support vector classification the minimization principle of the structural risk KKT conditions

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Three-point bending fracture characteristics of bulk metallic glasses

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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 {3. of Geosciences, beijing 100083, china 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

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Preliminary notes on soft-bodied fossil concentrations from the Early Cambrian Chengjiang deposits

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Science Bulletin 2006年第20期51卷 2482-2492页

作者： HAN Jian1, SHU Degan1,2, ZHANG Zhifei1, LIU Jianni1, ZHANG Xingliang1 & YAO Yang1 1. Department of Geology and Key Laboratory for Continental Dynam- ics, Northwest university, Xi’an 710069, china 2. school of {3. sciences and resources, china university of Geo- sciences, beijing 100083, china Department of Geology and Key Laboratory for Continental Dynamics Northwest University Xi''an 710069 China school of earth sciences and {3. China University of Geo-sciences Beijing 100083 China

The efforts of labor-intensive collecting in the Early Cambrian Chengjiang deposits in eastern Yunnan Province, china led to the discovery of many horizons containing exceptionally well preserved soft-bodied fossil concentrations, many of which can be assigned to either monospecific concentrations or paucispecific concentrations. The features of these fossil concentrations support the hypothesis that frequent storm events producing tempestites mainly contributed to the preservation of abundant soft- bodied fossils in the Chengjiang deposits, and indi- cate that the balance of the ecological web in this region was probably frequently destroyed or upset by such storm events during that geological time. Ani- mals in a fossil assemblage in such fossil concentra- tions probably occupied similar ecological biotopes.

关键词： Early Cambrian Chengjiang fauna preservation soft- bodied fossil concentration (SFC).

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Compressive fracture characteristics of Zr-based bulk metallic glass

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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 {3. of Geosciences,beijing 100083.china china university of Geosciences School of Materials Sciences and Technology Beijing China (GRID:grid.162107.3) (ISNI:***)

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 45-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

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Re-Os(ICP-MS)dating of the massive sulfide ores from the Jinchuan Ni-Cu-PGE deposit

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Science china earth sciences 2005年第10期48卷 1672-1677页

作者： YANG Gang1,2, DU Andao1, LU Jiren3. QU Wenjun1 & CHEN Jiangfeng2 1. National Research Center of Geoanalysis, beijing 10003., china 2. Laboratory for earth Material Cycling, {3. of earth and Space sciences, university of Science and Technology of china, Hefei 23.026, china 3. Institute of Mineral Resource, Chinese Academy of Geological sciences, beijing 10003., china National Research Center of Geoanalysis university of Science and Technology of china Chinese Academy of Geological sciences

Massive sulfide ore from the Jinchuan Ni-Cu-PGE deposit was dated by Re-Os technique using Carius Tube digestion, Os distillation, Re extraction by acetone and ICP-MS measurement. An isochron giving an age of 83. ± 3. Ma, initial 187Os/188Os ratio of 0.279 ± 0.018 (MSWD = 1.7) and γOs = 13. ± 15 is obtained. The Re-Os age obtained agrees, within analytical uncertainties, with previous SHRIMP zircon U-Pb age of 827 ± 8 Ma (n=5, MSWD = 4.3.. The result suggests that the deposit was formed at Neoproterozoic and that the formation of the Jinchuan Ni-Cu-PGE sulfide deposit may be closely related to the plume activity, which were attributed to the breakup of the Rodinia supercontinent. The high γOs of the massive ores sug-gests that crustal material was involved in the formation of the Jinchuan deposit, however, the quantity of the added crustal material is less than 10%.

关键词： Jinchuan Ni-Cu-PGE deposit, Re-Os dating, ICP-MS.

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3. Integrated Geological Modeling in Tongshan Copper Deposit,Heilongjiang Province,china

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地学前缘 2009年第S1期16卷 282-283页

作者： Gongwen Wang,Limei Wang,Ge Cui,Chengyin Tan,Shanyan Jin school of earth sciences and {3.,china university of Geosciences(beijing),beijing 100083.china.

In this paper,3.-GIS reconstruction and interpolation approach,additional virtual borehole technology and BP network technology are used to explore the concealed ore *** virtual borehole has same function as reality b... 详细信息

关键词： 3. geological modeling virtual borehole BP network mineral exploration Tongshan copper deposit

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INFINITE ELEMENT METHOD FOR THE EXTERIOR PROBLEMS OF THE HELMHOLTZ EQUATIONS

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Journal of Computational Mathematics 2000年第6期18卷 657-672页

作者： Lung-an Ying (school of Mathematical sciences, Peking university, {3. 100871, china) 北京大学北京 100871

There are two cases of the exterior problems of the Helmholtz equation. If λ ≥ 0 the bilinear form is coercive, and if λ < 0 it is the scattering problem. We give a new approach of the infinite element method, which enables us to solve these exterior problems as well as corner problems. A numerical example of the scattering problem is given. [ABSTRACT FROM AUTHOR]

关键词： Helmholtz equation exterior problem infinite element method

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Node ordinal encoded genetic algorithm for the optimal allocation of water resources

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Progress in Natural Science:Materials International 2005年第5期15卷 448-452页

作者： YANG Xiaohua1*, YANG Zhifeng 1,2, SHEN Zhenyao1 and LI Jianqiang3.1. State Key Laboratory of Water Environment Simulation, school of Environment, beijing Normal university, beijing 100875, china 2. Key Laboratory for Water and Sediment sciences Ministry of Education, school of Environment, beijing Normal university, beijing 100875, china 3. Water resources and Hydropower Planning and Design General Institute, MWR, beijing 100011, china) State Key Laboratory of Water Environment Simulation School of Environment Beijing Normal University Beijing 100875 China Key Laboratory for Water and Sediment sciences Ministry of Education School of Environment Beijing Normal University Beijing 100875 China Water resources and Hydropower Planning and Design General Institute MWR Beijing 100011 China

A new method, node ordinal encoded genetic algorithm (NOEGA), is proposed for solving water resources optimal allocation problems, in which the capacity of water resources is split into a number of smaller parts so that successive operations can be overlapped. Our objective is to maximize the whole benefit function. To overcome the “dimensionality and algorithm complexity curse” while searching for solutions and looking for an optimal solution, the operations of one-point crossover operator, gene exchange operator, gene random operator, gene shift operator and node ordinal strings are established. It is proved to be an effective optimal method in searching for global solutions. The NOEGA does not need a diversity of initial population, and it does not have the problem of immature convergence. The results of two cases show that using NOEGA to solve the optimal allocation model is very efficient and robust. In addition, the algorithm complexity of NOEGA is discussed.

关键词： water resources optimal allocation node ordinal code genetic algorithm.

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Geochemical simulation of the formation of brine and salt minerals based on Pitzer model in Caka Salt Lake

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Science china earth sciences 2004年第8期47卷 720-726页

作者： LIU Xingqi1, CAI Keqin2 & YU Shengsong3.1. Nanjing Institute of Geography and Limnology, Chinese Academy of sciences, Nanjing 210008, china 2. china {3. of Geosciences, beijing 100083, china 3. Institute of Salt Lakes, Chinese Academy of sciences, Xining 810008, china Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing China china university of Geosciences Beijing China Institute of Salt Lakes Chinese Academy of Sciences Xining China

The geochemical simulation of the formation of brine and salt minerals based on Pitzer model was made in Caka Salt Lake. The evolution of the mixed surface-water and the mineral sequences were calculated and compared with the hydrochemical compositions of the brine and the salt minerals of the deposit in Caka Salt Lake. The results show that the formation temperature of the lake is between 0°C and 5°C, which is well identical with other studies. The mixing of salt-karst water with the surface waters, neglected by the former researchers, is very important to the formation of the lake, indicating that the initial waters resulting in the formation of the lake are multi-source. It is the first time to use Pitzer model in china for making geochemical simulation of the formation and evolution of inland salt lake and satisfactory results have been achieved.

关键词： Pitzer model,Caka Salt Lake,geochemical simulation,salt-karst water.

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