检索结果-南通市图书馆

Journal of Computational Mathematics 1997年第4期15卷 319-326页

作者： Lie-heng Wang (state key laboratory of Scientific and Engineering Computing, ICMSEC, Chinese Academy of Sciences, Beijing, China) 中科院计算数学与科学工程计算所科学与工程计算国家重点实验室北京

This paper is devoted to study of an iterative procedure for domain decomposition method of second order elliptic problem with mixed boundary conditions (i.e., Dirichlet condition on a part of boundary and Neumann condition on the another part of boundary). For the pure Dirichlet problem, Marini and Quarteroni [3], [4] considered a similar approach, which is extended to more complex problem in this paper.

关键词： EH Math AN ITERATIVE PROCEDURE FOR DOMAIN DECOMPOSITION METHOD OF SECOND ORDER ELLIPTIC PROBLEM WITH MIXED BOUNDARY CONDITIONS

Genomics,metagenomics,and microbial oceanography—A sea of opportunities

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2011年第4期54卷 473-480页

作者： FANG JiaSong 1,2 &ZHANG Li 3 1 state key laboratory of Marine Geology,Tongji University,Shanghai 200092,China 2 College of Natural and Computational Sciences,Hawaii Pacific University,Kaneohe,HI 96744,USA 3state key laboratory of Geological Processes and Mineral resources,Faculty of Earth Sciences,China University of Geosciences,Wuhan 430074,China state key laboratory of Marine Geology Tongji University Shanghai China College of Natural and Computational Sciences Hawaii Pacific University Kaneohe USA state key laboratory of Geological Processes and Mineral resources Faculty of Earth Sciences China University of Geosciences Wuhan China

Microbial oceanography is an emerging discipline resulted from the interaction,cross-fertilization and integration of life science and ocean *** oceanography integrates the principles of marine microbiology,microbial ecology and oceanography to study the role of microorganisms in the biogeochemical dynamics of natural marine *** application of genomics tools to study marine microbes is resulting in rapid advancements in microbial oceanography that has important implications in global carbon cycle,climate change,and ecosystem *** we review the application of genomics and metagenomics in microbial oceanography and suggest future directions in microbial oceanography research.

关键词： microbial oceanography genomics metagenomics genes biomass bacteria archaea eukarya phylogeny physiology metabolism ecology biogeochemistry microbiology ecosystem function

Exploring the deep biosphere

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2011年第2期54卷 157-165页

作者： FANG JiaSong1,2 & ZHANG Li3 1 state key laboratory of Marine Geology, Tongji University, Shanghai 200092, China 2 College of Natural and Computational Sciences, Hawaii Pacific University, Kaneohe, HI 96744, USA 3 state key laboratory of Geological Processes and Mineral resources, Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China state key laboratory of Marine Geology Tongji University Shanghai China College of Natural and Computational Sciences Hawaii Pacific University Kaneohe USA state key laboratory of Geological Processes and Mineral resources Faculty of Earth Sciences China University of Geosciences Wuhan China

Over the past two decades, scientific drilling into sediments and rocks in the ocean and the continent has revealed the presence of physiologically and phylogenetically complex microbial life in the deep subsurface. Microorganisms, most of which have no cultured or known relatives in the surface biosphere, have been discovered in sediments and rock at depth as deep as 1 km below the seafloor and more than 3 km deep in the continent. The deep biosphere probably represents the most voluminous part of the global biosphere and may constitute as much as 50% of the Earth’s biomass. In this article, we review the current knowledge of and most recent advances in studying the deep biosphere and suggest directions in future research.

关键词： deep biosphere Thomas Gold microorganism biomass DNA ribosome ODP CARD-FISH dark energy lipids serpentinization

Simulation of influence of multi-defects on long-term working performance of high arch dam

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2011年第S1期54卷 1-8页

作者： ZHANG GuoXin ,LIU Yi,ZHENG CuiYing & FENG Fan state key laboratory of Simulation and Regulation of Water Cycle in River Basin,Beijing 100038,China China Institute of Water resources and Hydropower Research,Beijing 100038,China state key laboratory of Simulation and Regulation of Water Cycle in River Basin Beijing China

As an integrated structure,an arch dam is assumed to bear loads in its design ***,multi-defects,such as cracks and the opening of transverse joints,are unavoidable during construction and ***-defects will reduce the structural integrity and stiffness of the dam and affect its working performance and degree of *** the current paper,a numerical model of defects and a simulation method of a high arch dam are *** Chencun arch dam is analyzed as a case *** entire course simulation analysis of the Chencun arch dam from construction to operation is carried out,through which the opening of the transverse and longitudinal joints,formation of cracks,and their influence on deformation and stress of the dam are *** to the results of the analysis,appropriate measures should be adopted to prevent the development of cracks,and observation should be strengthened for a more timely discovery of risks.

关键词： high arch dam crack multi-defects working performance

Integrated modeling of nitrogen oxides formation in diesel engines

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第12期17卷 1476-1481页

作者： Song Jinou, Yao Chunde and Wang Hongfu(state key laboratory of Engine, Tianjin University, Tianjin 300072, China) state key laboratory of Engine Tianjin University Tianjin 300072 China

To account for the effects of both chemistry and flow turbulence, the present study proposes an integrated NO sub-model that combines the extended Zel’dovich mechanism and engine CFD computations to simulate the NO histories in a diesel engine. NOx sub-model parameters and pollutant formation mechanisms can be more easily investigated by solving the NOx sub-model. The new NO formation model incorporating the effects of both chemical kinetics and turbulent mixing was applied to simulate a diesel engine with a quiescent combustion chamber, and one with a re-entrant combustion chamber; the premise of the model being the reaction rate is mainly determined by a kinetic timescale and a turbulent timescale. The results indicate that the predicted NO formulation from the new model agrees well with the measured data. As the utilization of fossil fuels continues to increase, the control of NOx emissions is a worldwide concern; and it is imperative to understand fully the NOx reaction processes in combustion systems. This technology has the potential to enhance the application of various combustion techniques used to reduce NOx emissions from practical combustion systems.

关键词： nitrogen oxides (NOx) combustion turbulence diesel.

METHODS OF MODERN DESIGN FOR CYLINDRICAL GEAR DRIVE BASED ON THE INTERNET

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2002年第1期15卷 62-65页

作者： Lin Chao Li Runfang state key laboratory of Mechanical Transmission，Chongqing University， Chongqing 400044，China Chongqing University State Key Laboratory of Mechanical Transmission 重庆 400044

The basic principle of modern design of cylindrical gear drive based on theInternet is described. The methods of optimized design, finite element analysis, CAD design and webdesign as well as research and development entity of three parties such as institute research unit(or university), enterprise and customer are also studied. Its purpose is to provide a necessaryfoundation for realizing the design of cylindrical gear drive from different location on the modemInternet and to explore a practice application route.

关键词： Internet Cylindrical gear Mechanical model

GIS and ANN model for landslide susceptibility mapping

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical Sciences 2001年第3期11卷 374-381页

作者： XU Zeng-wang (state key laboratory of resources and Environment Information System, Institute of Geographic Sciences and Natural resources Research, CAS, Beijing 100101, China) state key laboratory of resources and Environment Information System Institute of Geographic Sciences and Natural Resources Research CAS

Landslide hazard is as the probability of occurrence of a potentially damaging landslide phenomenon within specified period of time and within a given area. The susceptibility map provides the relative spatial probability of landslides occurrence. A study is presented of the application of GIS and artificial neural network model to landslide susceptibility mapping, with particular reference to landslides on natural terrain in this paper. The method has been applied to Lantau Island, the largest outlying island within the territory of Hong Kong. A three-level neural network model was constructed and trained by the back-propagate algorithm in the geographical database of the study area. The data in the database includes digital elevation modal and its derivatives, landslides distribution and their attributes, superficial geological maps, vegetation cover, the raingauges distribution and their 14 years 5-minute observation. Based on field inspection and analysis of correlation between terrain variables and landslides frequency, lithology, vegetation cover, slope gradient, slope aspect, slope curvature, elevation, the characteristic value, the rainstorms corresponding to the landslide, and distance to drainage Une are considered to be related to landslide susceptibility in this study. The artificial neural network is then coupled with the ArcView3.2 GIS software to produce the landslide susceptibility map, which classifies the susceptibility into three levels: low, moderate, and high. The results from this study indicate that GIS coupled with artificial neural network model is a flexible and powerful approach to identify the spatial probability of hazards.

关键词： GIS artificial neural network model landslide susceptibility mapping

Advances of multiplex and high throughput biomolecular detection technologies based on encoding microparticles

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2011年第8期54卷 1185-1201页

作者： ZHAO XiangWei, ZHAO YuanJin & GU ZhongZe state key laboratory of Bioelectronics Southeast University, Nanjing 210096, China state key laboratory of Bioelectronics Southeast University Nanjing 210096 China.

The rapid developments of genomics and proteomics have driven the demand for multiplex and high throughput analysis of large numbers of biomolecules in the fields of medical diagnostics, drug discovery, and environmental monitoring. Encoding the biomolecular binding events is the key technique to fulfill this demand, in which microparticles play the most important roles. This review outlines the development of multiplex and high throughput biodetections, and highlights the most recent advances in the field of encoding microparticles, together with problems that need to be resolved.

关键词： multiplex bioassays multiplex labels encoded microcarrier binding assays high throughput screening

A computational trust model for access control in P2P

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2010年第5期53卷 896-910页

作者： LANG Bo state key laboratory of Software Development Environment, Beihang University, Beijing 100191, China state key laboratory of Software Development Environment Beihang University Beijing China

Trust brings a new method for building scalable and fine-grained access control mechanism in P2P systems. The quantificational expression of trust and the calculation of trust in a trust network are the basis of trust degree based access control. In this paper, the properties of trust is analyzed by referring to the fruits from social science; the semantics of trust in the context of access control is described, and a trust degree based access control model named TDBAC is introduced. Basing on the properties and semantics of trust, a computational trust model which includes a multilevel comprehensive evaluation method for expressing direct trust and calculators for computing recommended trust is put forward. To compute trust in a trust network, an algorithm that transforms a trust network to a computable expression is given. The algorithm simplifies the computation process and is also flexible.

关键词： trust management access control trust degree based access control computational trust model trust graph expression

Calculation of maximum ground movement and deformation caused by mining

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2011年第S3期21卷 562-569页

作者： LI Pei-xian1, 2, TAN Zhi-xiang1, 2, DENG Ka-zhong1, 2 1. key laboratory for Land Environment and Disaster Monitoring of state Bureau of Surveying and Mapping, China University of Mining and Technology, Xuzhou 221116, China 2. Jiangsu key laboratory of resources and Environmental Information Engineering, China University of Mining and Technology, Xuzhou 221116, China key laboratory for Land Environment and Disaster Monitoring of state Bureau of Surveying and Mapping China University of Mining and Technology Xuzhou 221116 China Jiangsu key laboratory of resources and Environmental Information Engineering China University of Mining and Technology Xuzhou 221116 China

In order to know the maximum mining ground deformation of arbitrary surface point, directions of the maximum surface tilt, curvature,horizontal displacement and horizontal deformation caused by multi-working faces were deduced based on probability integral method. The distribution forms of surface deformations in all direction φ∈[0, 2π] were obtained and also equations of maximum deformations were given based on calculation of mining ground deformation in direction φ. A mining subsidence analysis system was developed with VB6.0. The system implements the probability integral mining subsidence prediction with direct integration method, and it can avoid errors of arbitrary shaped working face subdivision of traditional method, and accuracy of mining subsidence prediction can be improved with the direct integral method. The system implements the contour chart and profile chart and also data analysis automation by manipulation of the SURFER kernel function and it complements the defect of existing subsidence prediction software. Calculation of maximum deformations caused by multi-working faces mining in a coal mine of Xuzhou, China was shown as application example. Engineering application indicates that maximum deformation of mining ground surface can be calculated and analyzed by the system. The research provides a theoretical basis and calculation tool for mining subsidence prediction and analysis.

关键词： mining subsidence probability integral method movement and deformation system development