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Upper-bound limit analysis based on the natural element method

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Acta Mechanica Sinica 2012年第5期28卷 1398-1415页

作者： shu-tao Zhou Ying-Hua Liu Department of Engineering Mechanics AMLTsinghua University

The natural element method （NEM） is a newly- developed numerical method based on Voronoi diagram and Delaunay triangulation of scattered points, which adopts natural neighbour interpolation to construct trial functions in the framework of Galerkin method. Owing to its distinctive advantages, the NEM is used widely in many problems of computational mechanics. Utilizing the NEM, this paper deals with numerical limit analysis of structures made up of perfectly rigid-plastic material. According to kinematic the- orem of plastic limit analysis, a mathematical programming natural element formulation is established for determining the upper bound multiplier of plane problems, and a direct iteration algorithm is proposed accordingly to solve it. In this algorithm, the plastic incompressibility condition is handled by two different treatments, and the nonlinearity and nons- moothness of the goal function are overcome by distinguishing the rigid zones from the plastic zones at each iteration. The procedure implementation of iterative process is quite simple and effective because each iteration is equivalent to solving an associated elastic problem. The obtained limit load multiplier is proved to monotonically converge to the upper bound of true solution. Several benchmark examples are investigated to validate the significant performance of the NEM in the application field of limit analysis.

关键词： Upper bound limit analysis Meshless methodNatural neighbour interpolation Natural element methodMathematical programming Iteration algorithm

AN OPTIMIZATION METHOD OF AQUATIC ENVIRONMENTAL CAPACITY FOR TIDAL RIVER NETWORK

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Journal of Hydrodynamics 2006年第2期18卷 237-242页

作者： ZHANG shu-tao WANG Dao-zeng Department of Mathematics College of Science China Jiliang University Hangzhou 310018 China Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

By using the high-efficiency of four-stage calculation method named ＂channel-junction-channel＂ and considering the influence of temporal and spatial variation of aquatic environmental capacity, an optimization method of aquatic environmental capacity for tidal river network was worked out. The method not only reflects characteristics of unsteady flow with variable directions, but also indicates that aquatic environmental capacity is influenced by boundary condition and water quality standard, etc. It has been applied to the regional program of Pudong area in Shanghai, and the computed results agree well with the practical data.

关键词： tidal river network optimization environmental capacity point source pollution

Conceptual understandings of the ecological engineering issues in China and abroad

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Journal of Environmental Sciences 2000年第2期12卷 78-83页

作者： Xu, Fu-Liu tao, shu Departemnt of Urban and Environemmal Sciences Peking University Beijing 100871 China

The research on ecological engineering has been lasting for more than four decades. As a new, cheaper, environmentally acceptable and alternative techniques, ecological engineering has been applied to many aspects, including ecoagricultural engineering, ecosystem restoration, environmental conservation, and pollution control. This paper presents a conceptual understanding on the issues of ecological engineering, including its origin, concepts, goals, principles and applications.

关键词： ecological engineering ecologist engineer CLC number: X171 4 Document code: A

An Efficient Synthesis of Ethyl 7-Chloro-6-fluoro-l-methyl-4-oxo-1, 4-dihydro-[1, 3]thiazeto[3, 2-a]quinoline-3-carboxylate as Intermediate of the Prulifloxacin Containing Tricyclic Fluoroquinolone

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Chinese Chemical Letters 2006年第6期17卷 714-716页

作者： shu tao MA Hong Xiang LOU School of Pharmacy Shandong University Jinan 250012

Novel ethyl 7-chloro-6-fluoro-l-methyl-4-oxo-1, 4-dihydro-[1, 3]thiazeto[3, 2-a]quino- line-3-carboxylate 2 was prepared from 3-chloro-4-fluoroaniline in eight steps. It can be used as a new intermediate for the synth... 详细信息

关键词： Synthesis tricyclic fluoroquinolone.

Quantum Dynamics of a Single Trapped Ion Interacting with Standing Laser Pulses

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Communications in Theoretical Physics 2004年第4X期42卷 599-604页

作者： LIFei HAIWen-Hua CHONGGui-shu XIEQiong-tao DepartmentofPhysics HunanNormalUniversityChangsha410081China

A classically chaotic system consisting of a Paul trapped ion and a sequences of standing laser pulses is treated quantum-mechanically. Under the circumstance of time-dependence, we derive the transition probability from the ion's motional state n to n', and find, in the first-order approximation, the classically chaotic character *** analysis and numerical calculations show that by regulating the phase parameter φ we can control the transition probability. When φ reaches some specific values, the transition from the state n to n' is forbidden and, for some laser periods, resonance occurs, which leads to the corresponding transitions between different motional states.

关键词：离子俘获量子动力学高斯激光束量子器件标准激光脉冲相位参数

Deformation mechanism and hydrocarbon significance of Eocene organic-rich fine-grained soft sediments in the Leijia Region,Liaohe Depression

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Frontiers of Earth Science 2024年第1期18卷 83-97页

作者： Yijie WEN Jianguo ZHANG shu tao Chenyu CAI School of Energy Resources China University of Geosciences(Beijing)Beijing 100083China Key Laboratory of Strategy Evaluation for Shale Gas(Ministry of Land Resources) China University of Geosciences(Beijing)Beijing 100083China School of Foreign Languages China University of Geosciences(Beijing)Beijing 100083China

The deformation structure of soft sediments has always been a research hotspot,which is of great significance for analyzing the tectonic and sedimentary evolution background of a basin,as well as the physical properties of *** studies have reported that a large number of soft sediment deformation structures are developed in the western part of Liaohe *** this study,through core observation and thin section identification,various types of deformation structures are identified in the core samples which are collected from the upper Es4 in the Leijia region,western sag of Liaohe depression,such as liquefied dikes,liquefied breccia,convoluted laminae,annular bedding,synsedimentary faults,vein structures,*** on the characteristics of core structure,single well profile and continuous well profile,combined with the regional background,this study clarifies that the deformation structure of soft sediments in the study area is mainly caused by seismic *** is found that the permeability and porosity of deformation layers in the study area are higher than those of the undeformation layers,which proves that the deformation structure of soft sediments has a good effect on improving the physical properties of reservoirs.

关键词： soft sediment deformation structure Liaohe depression organic-rich fine-grained soft sediments hydrocarbon significance

Monotonicity and Best Approximation in Banach Lattices

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Acta Mathematica Sinica,English Series 2009年第5期25卷 785-794页

作者： shu tao CHEN Xin HE H. HUDZIK Department of Mathematics Harbin Normal University Harbin 150080 P. R. China Faculty of Mathematics and Computer Science Adam Mickiewicz University Umultowska 87 61-614 Poznan Poland

Hudzik and Kurc discussed some best approximation problems in Banach lattices by means of monotonicities. This paper deals with more general best approximation problems in Banach lattices. Existence, uniqueness, stabi... 详细信息

关键词： Banach lattice uniform monotonicity strict monotonicity upper (lower) locally uniform monotonicity best approximation

Productivity matching and quantitative prediction of coalbed methane wells based on BP neural network

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Science China(Technological Sciences) 2011年第5期54卷 1281-1286页

作者： LU YuMin TANG DaZhen XU Hao tao shu Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism School of Energy Resources China University of Geosciences Beijing 100083 China

It is a great challenge to match and predict the production performance of coalbed methane (CBM) wells in the initial production stage due to heterogeneity of coalbed, uniqueness of CBM production process, complexity of porosity-permeability variation and difficulty in obtaining some key parameters which are critical for the conventional prediction methods (type curve, material balance and numerical simulation). BP neural network, a new intelligent technique, is an effective method to deal with nonlinear, instable and complex system problems and predict the short-term change quantitatively. In this paper a BP neural model for the CBM productivity of high-rank CBM wells in Qinshui Basin was established and used to match the past gas production and predict the futural production performance. The results from two case studies showed that this model has high accuracy and good reliability in matching and predicting gas production with different types and different temporal resolutions, and the accuracy increases as the number of outliers in gas production data decreases. Therefore, the BP network can provide a reliable tool to predict the production performance of CBM wells without clear knowledge of coalbed reservoir and sufficient production data in the early development stage.

关键词： BP neural network coalbed methane well productivity matching quantitative prediction

Polycyclic aromatic hydrocarbons in ambient air,surface soil and wheat grain near a large steel-smelting manufacturer in northern China

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Journal of Environmental Sciences 2017年第7期29卷 93-103页

作者： Weijian Liu Yilong Wang Yuanchen Chen shu tao Wenxin Liu Laboratory for Earth Surface Processes College of Urban and Environmental SciencesPeking UniversityBeijing 100871China

The total concentrations and component profiles of polycyclic aromatic hydrocarbons（PAHs） in ambient air,surface soil and wheat grain collected from wheat fields near a large steel-smelting manufacturer in Northern China were *** on the specific isomeric ratios of paired species in ambient air,principle component analysis and multivariate linear regression,the main emission source of local PAHs was identified as a mixture of industrial and domestic coal combustion,biomass burning and traffic *** total organic carbon（TOC） fraction was considerably correlated with the total and individual PAH concentrations in surface *** total concentrations of PAHs in wheat grain were relatively low,with dominant low molecular weight constituents,and the compositional profile was more similar to that in ambient air than in *** with more significant results from partial correlation and linear regression models,the contribution from air PAHs to grain PAHs may be greater than that from soil PAHs.

关键词： PAHs Ambient air Surface soil Wheat grain Steel-smelting activity