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Characteristics of energy dissipation in hyperconcentrated flows

International Journal of Sediment Research 2008年第4期23卷 387-397页

作者： An-ping SHU 1,Qing-quan LIU2.Yu-jun YI 3.and Zhi-dong ZHANG 41 Assoc.Prof.,School of Environment,Key Laboratory of Water and Sediment sciences of Ministry of Education,beijing {2. {3.,beijing 100875,China2.Prof.,institute of Mechanics,Chinese Academy of sciences,beijing 100080,China3.Lecturer,Dr.,School of Environment,beijing {2. {3.,beijing 100875,China4 Graduate student,School of Environment,beijing {2. {3.,beijing 100875,China [a]Assoc. Prof. School of Environment Key Laboratory of Water and Sediment sciences of Ministry of Education beijing normal {2. beijing 100875 China [b]Prof. institute of Mechanics Chinese Academy of sciences beijing 100080 China [c]Lecturer Dr. School of Environment beijing normal {2. beijing 100875 China. The project is supported by the National Natural science Foundation of China (Grant No. 10672.2.) [d]Graduate student School of Environment beijing normal {2. beijing 100875 China

An equilibrium equation for the turbulence energy in sediment-laden flows was derived on the basis of solid–liquid two-phase flow theory. The equation was simplified for two-dimensional, uniform, steady and fully developed turbulent hyperconcentrated flows. An energy efficiency coefficient of suspended-load motion was obtained from the turbulence energy equation, which is defined as the ratio of the sediment suspension energy to the turbulence energy of the sediment-laden flows. Laboratory experiments were conducted to investigate the characteristics of energy dissipation in hyperconcentrated flows. A total of 115 experimental runs were carried out, comprising 70 runs with natural sediments and 45 runs with cinder powder. Effects of sediment concentration on sediment suspension energy and flow resistance were analyzed and the relation between the energy efficiency coefficient of suspended-load motion and sediment concentration was established on the basis of experimental data. Furthermore, the characteristics of energy dissipation in hyperconcentrated flows were identified and described. It was found that the high sediment concentration does not increase the energy dissipation; on the contrary, it decreases flow resistance.

关键词： Hyperconcentrated flows Turbulence energy Efficiency coefficient Energy dissipation

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Proton induced X-ray emission (PIXE) analysis of sources of porcelain body of Ru Guan and Jun Guan porcelains

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science China(Physics,Mechanics & Astronomy) 2006年第4期49卷 411-420页

作者： LI Guoxia1, ZHAO Weijuan1, LI Rongwu2. SUN Hongwei1, GUO Min1, WANG Yanfang1, LIU Hui1, ZHAO Qingyun3. SUN Xinmin3. ZHAO Wenjun3.& CHENG Huansheng4 1. Faculty of Physical Engineering, Zhengzhou university, Zhengzhou 450052. China 2. Department of Physics, beijing normal university,{2., China 3. {3. of Cultural Relic and Archaeology of Henan Province, Zhengzhou 450000, China 4. {3. of Modern Physics, Fudan university, Shanghai 2.043., China Faculty of Physical Engineering Zhengzhou University Zhengzhou 450052 China Department of Physics Beijing Normal University Beijing 100875 China institute of Cultural Relic Archaeology of Henan Province Zhengzhou 450000 China institute of Modern Physics Fudan University Shanghai 200433 China

3. samples of Ru Guan porcelain body and 50 samples of Jun Guan porcelain body (both kinds being in different body colors) were selected with the purpose of finding out the source of raw materials and their classification relationship so as to search for ways of non-destructive discrimination. Proton induced X-ray emission (PIXE) has been applied to these samples to determine their chemical elements. The data of seven major chemical elements collected from these samples were further studied through fuzzy cluster analysis. Results indicate that the origin of raw materials of Jun Guan porcelain body samples is comparatively more concentrated in certain places, while that of Ru Guan porcelain body samples is scattered about. The places of origin of raw materials of the majority of Ru Guan and Jun Guan porcelain body samples have something in common, but some differences still exist. It might be an important way for non-destructive discrimination among Ru Guan and Jun Guan porcelains by combining PIXE with fuzzy cluster analysis.

关键词： Ru Guan and Jun Guan porcelain, source of porcelain body, PIXE, fuzzy cluster analysis, non-destructive discrimination.

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The correlation of multi-angle thermal infrared data and the choice of optimal view angles

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science China Earth sciences 2004年第6期47卷 570-576页

作者： FAN Wenjie1 & XU Xiru1,2.1.institute of Remote Sensing and GIS of Peking university,{2. 100871,China 2.Center of Remote Sensing and GIS of{3.,{2. 100875,China 1. institute of Remote Sensing and GIS of Peking university 100871 Beijing China 2. Center of Remote Sensing and GIS of beijing normal university 100875 Beijing China

Based on the matrix formula of thermal infrared radiant system, the components temperature can be retrieved by the inversive matrix. Around the stability problem of retrieved result, the research work we did was focused on (i) the correlation of (wk,j) which is the key to affect the retrieval accuracy, (ii) a general method which can help us find the number of retrievable parameters and evaluate the retrieval error before its performance, (iii) the choice of “optimal viewing angle group” based on the formula of absolute error propagation. The row winter wheat field was chosen as an example. The results can provide a theoretical basis for multi-angle thermal infrared remote sensing and components temperature retrieval.

关键词： components temperature retrieval, correlation, number of retrievable parameters, optimal viewing angle group.

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Anomalous magnetotransport in LaMn_(1-x)Te_xO_3

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science China(Physics,Mechanics & Astronomy) 2009年第7期52卷 987-992页

作者： TAN GuoTai1,2. CHEN ZhengHao3.& ZHANG XiaoZhong4,5 1 Key Laboratory of Beam Technology & Materials Modification of the Ministry of Education, institute of Low Energy Nuclear Physics, beijing normal university,{2., China 2.{3. Radiation Center,{2., China 3.Laboratory of Optical Physics, institute of Physics, Chinese Academy of sciences, {3. 100080, China 4 Key Laboratory of Advanced Materials of the Ministry of Education, Department of Materials science and Engineering, Tsinghua university, {3. 100084, China 5 {3. National Center for Electron Microscopy, Tsinghua university, {3. 100084, China 1. Key Laboratory of Beam Technology & Materials Modification of the Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing 100875 China 2. beijing Radiation Center Beijing 100875 China 3. Laboratory of Optical Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China 4. Key Laboratory of Advanced Materials of the Ministry of Education Department of Materials Science and Engineering Tsinghua University Beijing 100084 China 5. beijing National Center for Electron Microscopy Tsinghua University Beijing 100084 China

The LaMn1-xTexO3.δ (x=0.1, 0.2. 0.3. were synthesized using solid-state reaction method for the first time. X-ray photoemission spectrum (XPS) shows that in the samples the Te ions have a valence of Te4+, and Mn3. ions are partly converted into Mn2. and Mn4+ due to the excess oxygen and Te doping. The magnetotransport associated with Mn2., Mn3. and Mn4+ was investigated. The experimental results show that the samples are insulator at 0 T when the amount of Mn3. is much larger or less than the sum of Mn2. and Mn4+; by contrast, the samples display metal to insulator transition with increasing temperature when the amount of Mn3. is close to the sum of Mn2. and Mn4+. These anomalous magnetotransport behaviors were analyzed in the frame of the double-exchange (DE) mechanism.

关键词： colossal magnetoresistance La-Te-Mn-O magnetotransport

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Principle of small target detection for hyperspectral imagery

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science China Earth sciences 2007年第8期50卷 1225-1231页

作者： GENG XiuRui1,2.3.& ZHAO YongChao2.3.4 1 Research Center for Remote Sensing and GIS, Department of Geography, beijing normal university,{3., China 2.State Key Laboratory of Remote Sensing {2., Chinese Academy of {2.s, beijing 100101, China 3.institute of Erectronics, Chinese Academy of {2.s, beijing 100080, China 4 Center for for Assessment and Monitoring of Forest and environmental Resources and Division of Ecosystem {2.s {13. of California Berkeley, CA 9472.-3.14, USA 1. Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University Beijing 100875 China 2. State Key Laboratory of Remote Sensing science Chinese Academy of Sciences Beijing 100101 China 3. institute of Erectronics Chinese Academy of Sciences Beijing 100080 China 4. Center for for Assessment and Monitoring of Forest and environmental Resources and Division of Ecosystem sciences University of California Berkeley CA 94720-3114 USA

This paper generalizes the progress of algorithms in small target detection for hyperspectral imaging, and finds that whitening the image is the key point of many methods in small target detection. An al-gorithm is presented to detect desired targets by converting large targets into small ones based on the weighted sample autocorrelation matrix.

关键词： hyperspectral whiten target detection

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Speciation of the elements and compositions on the surfaces of dust storm particles:The evidence for the coupling of iron with sulfur in aerosol during the long-range transport

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Chinese science Bulletin 2005年第8期50卷 738-744页

作者： ZHANG Xingying1,2. ZHUANG Guoshun1,2.3. CHEN Jianmin2.& XUE Huaxin2.1. Center for Atmospheric Environment Study, Department of Chemistry, beijing normal university, beijing 100875, China 2. Center for Atmospheric Chemistry Study, Department of Environ- mental {2. and Engineering, Fudan {3., Shanghai 2.043., China 3. LAPC/NZC, institute of Atmospheric Physics, NZC/LAPC, Chinese Academy of {2.s, beijing 10002., China Center for Atmospheric Environment Study Department of Chemistry Beijing Normal University Beijing 100875 China Center for Atmospheric Chemistry Study Department of Environmental Science and Engineering Fudan University Shanghai 200433 China LAPC/NZC Institute of Atmospheric Physics NZC/LAPC Chinese Academy of Sciences Beijing 100029 China

The speciation of the elements on the surface of the particles collected during dust storm and non-dust storm in beijing and Inner Mongolia was studied by XPS. The ma- jor species of iron on the surface were oxides, sulfate, silicate, FeOOH and minor part sorbed on SiO2.Al2.3. Sulfate is the dominant species of sulfur on the surface. SiO2.and Al2.3.are the main components of Si and Al on the surface respectively. One of the most important findings was that the Fe(II) (FeS and FeSO4) produced could account for up to 44.3. and 45.6% of the total Fe on the surface in the aerosol sample collected at that night and next day of the “peak” time of the dust storm occurring on March 2., 2.02. while Fe2.SO4)3. one of the Fe(III) species on the surface decreased from 67.1% to 49.5% and 48.0% respectively. Both S and Fe en- riched on the surface of aerosol particles. Fe(II) accounted for 1.3.?5.3. of total Fe in bulk aerosol samples during dust storm. These results provided strong evidence to sup- port the hypothesis of the coupling between iron and sulfur in aerosols during the long-range transport, which would have important impact on the global biogeochemical cycle.

关键词：物种形成原理 XPS 大气悬浮物 Fe-S结合粒子集合

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An asymptotic result of super-Brownian motion on hyperbolic space

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Chinese science Bulletin 1997年第15期42卷 1240-1244页

作者： TANG JiashanDepartment of Mathematics, beijing normal university, beijing 100875, China {2. of Mathematics, Shantou {3., Shantou 515063. China Department of Mathematics Beijing Normal University Beijing China institute of Mathematics Shantou University Shantou China

SUPERPROCESS is one kind of measure-valued branching Markov processes. In the recentdecades many results of superprocesses on Euclidean spaces and on general abstract spaces havebeen obtained, but there is only little work on Riemannian manifold. In this note, wewill consider the super-Brownian motions on the hyperbolic space of dimension d and give anasymptotic result of this process (see Corollary 1 below). Iscoe investigated a similar prob-

关键词： hyperbolic space radial super-Brownian motion hitting probability asymptotic.

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

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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 {3.,Jointly Sponsored by institute of Remote Sensing Applications,Chinese Academy of {3.s and{3.,beijing 100101,China 2.State Key Laboratory of Remote Sensing {3.,Jointly Sponsored by{3. and institute of Remote Sensing Applications of Chinese Academy of {3.s,beijing 100875,China 3.Graduate university of Chinese Academy of {3.s,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

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A HIGH-ORDER FINITE DIFFERENCE METHOD FOR UNSTEADY CONVECTION-DIFFUSION PROBLEMS WITH SOURCE TERM

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Journal of Hydrodynamics 1999年第2期11卷 97-102页

作者： Yang Zhi-feng Wang Xuan(State Key Laboratory of Environment Simulation and Pollution Control, institute of environmental {2.s,{3., beijing 100875, P. R. China.) beijing normal Univ Beijing China

The convection and diffusion are the basic processes in fluid flow and heat& mass transfer. The upwind and evolution functions for the convection term are introduced to give a comprehensive transformation to one-dimensional unsteady convection-diffusion equation involving source term. The corresponding compact fourth-order finite difference methed is developed. With the trans formation, the authors overcome the difficultyin dealing with the convection term, and the high-order expression for the convection-diffusion term can be conveniently obtained. The proposed difference scheme with thefourth-order accuracy and unconditional stability can fully reflect the upwind and evolutioneffects of the convection. The calculated results show that the errors of the referencescheme are 600 or 6000 times those of the proposed scheme for the same computationalgrid. With the one time decrease of the space grid, the errors of the proposed scheme andthe reference scheme reduce about 2. times and 2.times respectively. It is evident that theaccuracy of the proposed scheme is remarkably higher than that of the reference scheme.

关键词： convection-diffusion compact difference method comprehensive transformation unsteady computational fluid dynamics

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Effective solutions to a global 3. visual system in networking environments

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science China Earth sciences 2005年第11期48卷 2032-2039页

作者： ZHANG Liqiang1,2. ZHANG Yan3. YANG Chongjun2. LIU Suhong1, REN Yingchao2. RUI Xiaoping2.& LIU Donglin2.1. State Key Laboratory of Remote Sensing sciences, School of Geography and Remote Sensing, beijing normal university,{2., China 2. State Key Laboratory of Remote Sensing sciences, institute of Remote Sensing Applications, Chinese Academy of sciences, beijing 101001, China 3. institute of Geographical sciences and Natural Resources Research, Chinese Academy of sciences, beijing 101001, China 1. State Key Laboratory of Remote Sensing sciences School of Geography and Remote Sensing Beijing Normal University 100875 Beijing China 2. Chinese Academy of sciences State Key Laboratory of Remote Sensing SciencesInstitute of Remote Sensing Applications 101001 Beijing China 3. institute of Geographical sciences and Natural Resources Research Chinese Academy of Sciences 101001 Beijing China

The development of Web-based global 3. visual system has made progresses. However, there exist few mature and effective ways for managing, transmitting and visualizing massive spatial data. Based on the related work, the paper illustrates the ellipsoidal quadtree technique for rapid access multi-scale and multiple level geographical data, integrates the streaming with level-of-detail rendering method for transmitting the data on the network, and im-plements large-scale terrain surface simplification using M-band wavelet transforms and mul-tiresolution triangulations. We fulfil a web-based global terrain visual system using COM com-ponents on the basis of the above techniques. The system has a good prospect in the military simulation and city plans.

关键词： massive spatial data, streaming transmission, system architecture, M-band wavelet

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