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Science China(Technological Sciences) 2011年第4期54卷 793-798页

作者： bao tengfei1,2.3.xu baosong1,{2.,{3. key laboratory of hydrology-water Resources and hydraulic engineering,hohai university,nanjing 2.0098,China 2.ational engineering Research Center of water Resources Efficient Utilization and engineering Safety,nanjing 2.0098,China 3.ollege of water Conservancy and Hydropower engineering,hohai university,nanjing 2.0098,China state key {2. of {3.-water Resources and hydraulic engineering Hohai University Nanjing China National engineering Research Center of water Resources Efficient Utilization and engineering Safety Nanjing China College of water Conservancy and Hydropower engineering Hohai University Nanjing China

A hybrid method of limit equilibrium and finite element internal force for analysis of arch dam stability against sliding is *** finite element internal force method(FEIFM) is used to provide more accurate thrust forces acting on the faces of a slip body,and the limit equilibrium method(LEM) is employed to evaluate the factor of safety of the slip *** method presented can deal with a slip body with large amount of geometrically complex slip *** addition,compared with the traditional LEM,it can meet the balance condition of the forces in the slip *** example shows that the factor of safety obtained by the method presented agrees well with the theoretical solution.A practical example is also presented to demonstrate the application of the method in the stability analysis of an arch dam *** results from the examples show that the method is promising in analysis of arch dam stability against sliding.

关键词： arch dam stability against sliding limit equilibrium method finite element internal force method

Multivariate analysis in dam monitoring data with PCA

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Science China(Technological Sciences) 2010年第4期53卷 1088-1097页

作者： YU Hong1,2.WU ZhongRu1,2.bao tengfei1,2.& ZHANG Lan1,2.1 state {2. {3. of hydrology-water Resources and hydraulic engineering,hohai university,nanjing 2.0098,China 2.National engineering Research Center of water Resources Efficient Utilization and engineering Safety,hohai university,nanjing 2.0098,China state key {2. of {3.-water Resources and hydraulic engineering Hohai University Nanjing China National engineering Research Center of water Resources Efficient Utilization and engineering Safety Hohai University Nanjing China

Given the limitation of traditional univariate analysis method in processing the multicollinearity of dam monitoring data,this paper reconstructs the multivariate response variables by introducing principal component analysis(PCA) method,explores the ways of determining principal components(PCs),and extracts a few PCs that have major influence on data *** steady observation series,a control field for the whole observation values has been established based upon PCA;for unsteady observation series that have significant tendency,a control field for the future observation values has been constructed according to PC statistical predication *** methods have already been applied to an actual project and the results showed that data interpretation method with PCA can not only realize data reduction,lower data redundancy,and reduce noise and false alarm rate,but also be effective to data analysis,having a broad application prospect.

关键词： dam safety monitoring multivariate response variables principal component analysis data reduction

Back analysis of mechanical parameters of roller compacted concrete dam

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Science China(Technological Sciences) 2010年第3期53卷 848-853页

作者： GU ChongShi 1,2.3,LI Bo 1,xu GuangLei 4 &YU Hong 1,2.3.1 {3. key {2. of hydrology-water Resources and hydraulic engineering,hohai university,nanjing 2.0098,China 2College of water Conservancy Hydropower,hohai university,nanjing 2.0098,China 3.ational engineering Research Center of water Resources engineering Safety,Efficient Utilization and nanjing 2.0098,China 4 nanjing hydraulic Research Institute,nanjing 210029,China state key {2. of {3.-water Resources and hydraulic engineering Hohai University Nanjing China College of water Conservancy Hydropower Hohai University Nanjing China National engineering Research Center of water Resources engineering Safety Efficient Utilization and Nanjing Nanjing China nanjing hydraulic Research Institute Nanjing China

In view of the diversity and complexity of mechanical parameters of roller compacted concrete dam(RCCD),the uniform design method,partial least-squares regression(PLS)and least squares support vector machine(LSSVM)were applied to the back analysis of RCCD with the use of the complex nonlinear relationship between dam mechanical parameters and dam *** the process of back analysis,the initial samples of parameters were designed with uniform design ***,a transversely isotropic model of RCCD was established by *** *** this model,training samples of LSSVM model could be *** then,the complex nonlinear relationship between relative values of hydraulic components of dam displacements and mechanical parameters was ***,actual relative values of dam hydraulic components are isolated from the measured data of dam displacements by using *** inputting the isolated relative values into LSSVM model,the back analysis values of RCCD mechanical parameters can be *** example analysis showed that mechanical parameters obtained by the above-mentioned back analysis method are reasonable,and the back analysis method is feasible.

关键词： roller compacted concrete dam mechanical parameters back analysis

Analysis of crack propagation in concrete structures with structural information entropy

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Science China(Technological Sciences) 2010年第7期53卷 1943-1948页

作者： bao tengfei1’2. PENG Yan1’2. CONG PeiJiang1’2.& WANG JiaLin1’2.1 state {2. {3. of hydrology-water Resources and hydraulic engineering, hohai university, nanjing 2.002., China 2.National engineering Research Center ofwater Resources Efficient Utilization and engineering Safety, hohai university, nanjing 2.002., China state key {2. of {3.-water Resources and hydraulic engineering Hohai University Nanjing China National engineering Research Center of water Resources Efficient Utilization and engineering Safety Hohai University Nanjing China

The propagation of cracks in concrete structures causes energy dissipation and release, and also causes energy redistribution in the structures. Entropy can characterize the energy redistribution. To investigate the relation between the propagation of cracks and the entropy in concrete structures, cracked concrete structures are treated as dissipative structures. Structural information entropy is defined for concrete structures. A compact tension test is conducted. Meanwhile, numerical simulations are also carried out. Both the test and numerical simulation results show that the structural information entropy in the structures can characterize the propagation of cracks in concrete structures.

关键词： crack entropy concrete sun

Field experiments on greenhouse gas emissions and nitrogen and phosphorus losses from rice paddy with efficient irrigation and drainage management

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Science China(Technological Sciences) 2011年第6期54卷 1581-1587页

作者： PENG ShiZhang1,2.YANG ShiHong1,2.xu JunZeng1,2.& GAO HuanZhi1,2.1state {2. {3. of {2.-water Resources and hydraulic engineering,hohai university,nanjing 2.0098,China 2.ollege of water Conservancy and Hydropower engineering,hohai university,nanjing 2.0098,China state key {2. of {3.-water Resources and hydraulic engineering Hohai University Nanjing China College of water Conservancy and Hydropower engineering Hohai University Nanjing China

Greenhouse gas emissions,nitrogen and phosphorous losses through ammonia volatilization,leaching and surface drainage from rice paddy under efficient irrigation and drainage were analyzed based on field experimental data in order to reveal the eco-environmental impacts of efficient irrigation and drainage on rice *** results showed that total methane emission from rice paddy under the controlled irrigation was reduced by more than 80% and total nitrous oxide emission increased by 15.9% compared with flooding *** comprehensive global warming potentials(GWP) of methane and nitrous oxide were 62.2.0}gCO2.m-2.for rice paddy under the controlled irrigation,reduced by 68.0% compared with flooding *** to large reduction in seepage and surface drainages,nitrogen and phosphorous losses through leaching were reduced by 40.1% and 54.8%,nitrogen and phosphorous losses through surface drainage were reduced by 53.9% and 51.6% from rice paddy under efficient irrigation and drainage compared with traditional irrigation and *** loss through ammonia volatilization was reduced by 14.0%.Efficient irrigation and drainage management is helpful to mitigate greenhouse gases emission,nitrogen and phosphorus losses and their pollution on ground{2. and surface {2..

关键词： efficient irrigation and drainage nitrogen and phosphorus greenhouse gas ammonia volatilization paddy field

Application analysis of empirical mode decomposition and phase space reconstruction in dam time-varying characteristic

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Science China(Technological Sciences) 2010年第6期53卷 1711-1716页

作者： ZHANG ZhiJun1,2.3,GU ChongShi1,2.bao tengfei1,2.ZHANG Lan1,2.& YU Hong1,2.1 {2. {3. {2. of hydrology-water Resources and hydraulic engineering,hohai university,nanjing 2.0098,China 2.National engineering Research Center of water Resources Efficient Utilization and engineering Safety,hohai university,nanjing 2.0098,China 3.Department of Civil,Environmental and Geomatic engineering,Swiss Federal Institute of Technology,Zurich 8093.Switzerland state key {2. of {3.-water Resources and hydraulic engineering Hohai University Nanjing China National engineering Research Center of water Resources Efficient Utilization and engineering Safety Hohai University Nanjing China Department of Civil Environmental and Geomatic Engineering Swiss Federal Institute of Technology Zurich Switzerland

In view of some courses of the time-varying characteristics processing in the analysis of dam deformation,the paper proposes a new method to analyze the dam time-varying characteristic based on the empirical mode decomposition and phase space reconstruction *** of all,to reduce the influences on the traditional statistical model from human factors and assure the analysis accuracy,response variables of the time-varying characteristic are obtained by the way of the empirical mode decomposition;and then,a phase plane of those variables is reconstructed to investigate their processing *** methods have already been applied to an actual project and the results showed that data interpretation with the assists of empirical mode decomposition and phase space reconstruction is effective in analyzing the perturbations of response variables,explicit in reflecting the entire development process,and valid for obtaining the evolution rules of the time-varying *** methodology is a powerful technical support for people to further master the rules of dam operation.

关键词： dam safety monitoring dam time-varying characteristic empirical mode decomposition phase space reconstruction

A Feedback-Based Web Search Engine

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Wuhan university Journal of Natural Sciences 2004年第5期9卷 561-568页

作者： ZHANG Wei-feng 1,2.3 , xu {2.-wen 2.3,4 , ZHOU Xiao-yu 2.3,4 1. Department of Computer Science and engineering, nanjing {2. of Posts and Telecommunications, nanjing 2.0003. Jiangsu, China 2. Department of Computer Science and engineering, Southeast {2., nanjing 2.0096, Jiangsu, China 3. Jiangsu Institute of Software Quality, nanjing 2.0096 Jiangsu, China 4. The {13. key laboratory of Software engineering, Wuhan {2., Wuhan 43.072. Hubei, China Department of Computer Science and engineering Nanjing University of Posts and Telecommunications Nanjing Jiangsu China Department of Computer Science and engineering Southeast University Najing Jiangsu China Jiangsu Institute of Software Quality Nanjing Jiangsu China The state key {2. of Software {3. Wuhan University Wuhan Hubei China

Web search engines are very useful information service tools in the Internet. The current web search engines produce search results relating to the search terms and the actual information collected by them. Since the selections of the search results cannot affect the future ones, they may not cover most people’s interests. In this paper, feedback information produced by the user’s accessing lists will be represented by the rough set and can reconstruct the query string and influence the search results. And thus the search engines can provide self-adaptability. key words WWW - search engine - query reconstruction - feedback CLC number TP 3.1. 13..4 Foundation item: Supported by the National Natural Science Fundation of China (603.3.66). National Grand Fundamental Research 973.Program of China (2.02.B3.2.0). Opening Foundation of state key {3. of Software {2. in Wuhan university, Opening Foundation of Jiangsu key {3. of Computer Information Processing Technology in Soochow universityBiography: ZHANG Wei-feng (1975-), male, Ph.D. research direction: artificial intelligence, search engine, data mining, network language.

关键词： WWW search engine query reconstruction feedback

A NEW MEASURE FOR DIRECT MEASUREMENT OF THE BED SHEAR STRESS OF WAVE BOUNDARY LAYER IN WAVE FLUME

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Journal of Hydrodynamics 2007年第4期19卷 517-524页

作者： HUO Guang WANG Yi-gang YIN bao-shu YOU Zai-jin key laboratory of Coastal Disaster and Defense Ministry of Education Hohai University Nanjin 210098China Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China state key {2. of {3.-water Resources and hydraulic engineering Hohai University Nanjing 210098 China Coastal Unit. Department of Natural Resources Dangar NSW Australia

In this article, a shear plate was mounted on the bottom in a wave flume and direct measurements of the smooth and rough bed shear stress under regular and irregular waves were conducted with the horizontal force exerted on the shear plates by the bottom shear stress in the wave boundary layer. Under immobile bed condition, grains of sand were glued uniformly and tightly onto the shear plate, being prevented from motion with the fluid flow and generation of sand ripples. The distribution of the bottom mean shear stress varying with time was measured by examining the interaction between the shear plate and shear transducers. The relation between the force measured by the shear transducers and its voltage is a linear one. Simultaneous measurements of the bottom velocity were carried out by an Acoustic Doppler Velocimeter （ADV）, while the whole process was completely controlled by computers, bottom shear stress and velocity were synchronously measured. Based on the experimental results, it can be concluded that （1） the friction coefficient groews considerably with the increase of the Reynolds number, （2. the shear stress is a function varying with time and linearly proportional to the velocity. Compared with theoretical results and previous experimental data, it is shown that the experimental method is feasible and effective, A further study on the bed shear stress under regular or irregular waves can be carried out. And applicability to the laboratory studies on the initiation of sediments and the measurement of the shear stress after sediment imigration.

关键词： wave boundary layer friction coefficient,shear plate shear stress Acoustic Doppler Velocimeter (ADV)

Building Feedback-Regulation System Through Atomic Design for Highly Active SO_(2.Sensing

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Nano-Micro Letters 2024年第7期16卷 343-357页

作者： Xin Jia Panzhe Qiao Xiaowu Wang Muyu Yan Yang Chen bao-Li An Pengfei Hu Bo Lu Jing xu {2.gang xue Jiaqiang xu NEST Lab Department of ChemistryCollege of SciencesShanghai UniversityShanghai 200444People’s Republic of China Shanghai Synchrotron Radiation Facility Zhangjiang LabShanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204People’s Republic of China School of Chemistry and Materials Science University of Science and Technology of ChinaHefei 230026People’s Republic of China key laboratory of Organic Compound Pollution Control {2.(MOE) School of Environmental and Chemical EngineeringShanghai UniversityShanghai 200444People’s Republic of China Shanghai university Instrumental Analysis&Research Center of Shanghai UniversityShanghai 200444People’s Republic of China

Reasonably constructing an atomic interface is pronouncedly essential for surface-related gas-sensing ***,we present an ingen-ious feedback-regulation system by changing the interactional mode between single Pt atoms and adjacent S species for high-efficiency SO_(2.*** found that the single Pt sites on the MoS_(2.surface can induce easier volatiliza-tion of adjacent S species to activate the whole inert S ***,the activated S species can provide a feedback role in tailoring the antibonding-orbital electronic occupancy state of Pt atoms,thus creating a combined system involving S vacancy-assisted single Pt sites(Pt-Vs)to synergistically improve the adsorption ability of SO_(2.gas ***-more,in situ Raman,ex situ X-ray photoelectron spectroscopy testing and density functional theory analysis demonstrate the intact feedback-regulation system can expand the electron transfer path from single Pt sites to whole Pt-MoS_(2.supports in SO_(2.gas *** with wireless-sensing modules,the final Pt1-MoS_(2.-def sensors array can further realize real-time monitoring of SO_(2.levels and cloud-data storage for plant *** a fundamental understanding of the intrinsic link between atomic interface and sensing mechanism is thus expected to broaden the rational design of highly effective gas sensors.

关键词： Feedback-regulation system Atomic interface SO_(2.sensor Single-atom sensing mechanism Intelligent-sensing array

Effect of streambed sediment on benthic ecology

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International Journal of Sediment Research 2009年第3期24卷 325-338页

作者： xuehua DUAN1, Zhao-Yin WANG2. Mengzhen xu{2. and Kang ZHANG41 Ph.D., Jiangyin Environmental Monitoring Station, Jiangyin 2.44{2., China, Dept. of hydraulic {{2., Tsinghua {2.,2.Prof., state key laboratory of Hydroscience and {{2., Tsinghua {2., Beijing 100084, China, {2.Doctoral candidate, state key laboratory of Hydroscience and {{2., Tsinghua {2., Beijing 100084, China,4 Doctoral candidate, state key laboratory of Hydroscience and {{2., Tsinghua {2., Beijing 100084, China Ph.D. Jiangyin Environmental Monitoring Station Jiangyin 214431 China Dept. of Hydraulic Engineering Tsinghua University Prof. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China Tel: 86-10-62773448(O) Doctoral candidate State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China

Benthic macroinvertebrates have been commonly used as indicator species for assessment of aquatic ecology. Streambed sediment, or substrate, plays an important role in habitat conditions for macroinvertebrate communities. Field investigations were done to study the benthic diversity and macroinvertebrate compositions in various stream substrata. Sampling sites with different bed sediment, latitude, and climate were selected along the Yangtze River, the Yellow River, the East River, and the Juma River, in China. The results show that benthic community structures found in different substrata clearly differ, while those found in substrata of similar composition and flow conditions but in different macroclimates are similar. The study, thus, demonstrates that the benthic macroinvertebrate community is mainly affected by substrate composition and flow conditions, but is generally unaffected by latitudinal position and macroclimate. Taxa richness of the macroinvertebrate community was found to be the highest on hydrophyte-covered cobbles, high on moss-covered bedrock, and low on clay beds and cobble beds devoid of plant biomass. Sandy beds are compact and unstable, thus, no benthic macroinvertebrates were found colonizing such substrata. Aquatic insects account for most of the macroinvertebrates collected in these rivers. Different insects dominate in different types of substrata: mainly EPT species (Ephemeroptera, Plecoptera, Trichoptera) in cobble, gravel, and moss-covered bedrock; and Chironomidae larvae in clay beds. The relation between the number of species in the samples and the size of the sampling area fits a power function of the species area. One square meter (1m2. is suggested as the minimum sampling area. A substrate suitability index is proposed by integrating the suitability of sediment, periphyton, and benthic organic materials for macroinvertebrates. The biodiversity of macroinvertebrates increases linearly with the substrate suitability index. Benthic ta

关键词： Streambed sediment Macroinvertebrates Benthic ecology Substrate suitability Biodiversity