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An architecture for mobile database management system

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Journal of university of science and {2. Beijing 2002年第2期9卷 156-160页

作者： Dong Li and Yucai Feng Computer school, Huazhong university of {2. and technology, wuhan 430074, china Computer school Huazhong University of Science and Technology Wuhan 430074 China

In order to design a new kind of mobile database management system (DBMS)more suitable for mobile computing than the existent DBMS, the essence of database systems in mobilecomputing is analyzed. An opinion is introduced that the mobile database is a kind of dynamicdistributed database, and the concept of virtual servers to translate the clients' mobility to theservers' mobility is proposed. Based on these opinions, a kind of architecture of mobile DBMS, whichis of versatility, is presented. The architecture is composed of a virtual server and a local DBMS,the virtual server is the kernel of the architecture and its functions are described. Eventually,the server kernel of a mobile DBMS prototype is illustrated.

关键词： mobile database dynamic distributed database DBMS architecture virtual server data region

Magnesia Modification of Alkali-Activated Slag Fly Ash Cement

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Journal of wuhan university of {2.(Materials science) 2011年第1期26卷 121-125页

作者：沈卫国 Key Laboratory of Silicate Materials science and Engineering of Ministry of Education Wuhan University of Technology school of Materials science and Engineering Wuhan University of Technology

A new type of magnesia modification alkali-activated cement was prepared, the strength, setting time, shrinkage ratio and cracking behavior, as well as the composition and structure of the hydration product were investigated. The results indicate that the setting time of this cement is similar to that of the ordinary commercial cements; its strength reaches the standard of 42.5 degree cement, its cracking resistance has been remarkably improved because of the micro-aggregate effect of fly ash and shrinkage compensating of magnesia.

关键词： alkali-activated cement crack magnesia volume stability hydration

Research of Environment-friendly Low Emissivity Glass

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Journal of wuhan university of {2.(Materials science) 2007年第2期22卷 385-387页

作者：余峰 school of Civil Engineering and Architecture Wuhan University of Technology

The environment-friendly glasses which integrate function and structure were introduced, among these glasses can save energy very efficiently due to its low infrared emissivity. The fundamental principle of the low emissivity glass and the research progress of this kind glass were analyzed. Meanwhile, high performance and low applied development trend of emissivity glass were reviewed.

关键词： low emissivity glass(Low-E) environment-friendly research progress development trend

Surface Nanocrystallization of Magnesium Alloy AZ91D by High-Energy Shot Peening

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Journal of wuhan university of {2.(Materials science) 2009年第4期24卷 515-519页

作者：张津 school of Materials science & Engineering University of Science and Technology Beijing College of Materials science & Engineering Chongqing University of Technology

High-energy shot peening （HESP）, a method to produce severe plastic deformation by high velocity flying balls, was applied on die cast magnesium alloy AZ91D. Effects of surface nanocrystallization by HESP and heat treatment at different temperatures were investigated. The mi- crostructure evolution was conducted using X-ray diffraction （XRD） and field emission scanning electronic microscopy （FESEM）. The hardness was measured by microhardness tester. The experimental results show that surface nanocrystrallization of AZ91D obtained by HESP would lead to the increase of microhardness. Low temperature heated at 100℃ for 1 h do not change the property obviously. However, both the microstructure and microhardness vary greatly after heat treatment at 400℃ for 1 h.

关键词： AZ91 D surface nanocrystallization HESP microhardnss corrosion resistance

Damping Properties of Flexible Epoxy Resin

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Journal of wuhan university of {2.(Materials science) 2008年第3期23卷 411-414页

作者：王翔刘韩星 school of Materials science and Engineering Wuhan University of Technology State Key Laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of Technology

Amino-terminated polyethers and amino-terminated polyurethane were used as curing agent to cure the epoxy resin together and get a series of cured products. The damping properties of the composites were studied by DMA test at different measurement frequencies. Damping mechanical tests show that the flexible epoxy resin has higher loss factor than common epoxy. The highest loss factor reaches 1.57. Also the height and position of loss factor peak of the flexible epoxy resin varies by changing the content of amino-terminated polyethers. Results shows that the flexible epoxy resin can be used as damping polymer materials at room temperature or in common frequency range.

关键词： flexible epoxy damping properties amino-terminated polyethers amino-terminated polyurethane

THEORETICAL DESIGN AND MOTION PLANNING OF NONHOLONOMIC MANIPULATOR

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Chinese Journal of Mechanical Engineering 2004年第2期17卷 222-225页

作者： Tan Yuegang Deng Yuhui WU Zhengping school of Mechanical and Electronic Engineering,wuhan {2. of technology,wuhan 430070, china Department of science and technology Studies University College London WC1E 6BT UK school of Mechanical and Electronic Engineering Wuhan University of Technology Wuhan 430070 China

A new nonholonomic transmission mechanism is proposed based on thenonholonomic theory and nonlinear control principle, and combined with conditions of thenonholonomic motion planning and control, that is researched to compose method of the motiontransfer chain from this transmission mechanism, on which a new nonholonomic manipulator isdesigned. This nonholonomic manipulator is a controllable multi-joint manipulator that actuated onlyby two-servo electromotor. Its motion expresses the characteristic of nonholonomy constraint andnonlinear, and that also satisfies the chained form convertibility. And then, using the nonlinearcontrol principle of chained system, motion characteristic of the nonholonomic manipulator isapplied. From simulation verification and analysis, the usefulness of the theoretical design andcontrol strategies is shown, and that is important in design and research of handiness robot andmulti-finger robot hand.

关键词： Nonholonomic system Nonholonomic motion planning Nonlinear controlMulti-joint Manipulator

Dynamic Mechanical and Thermal Properties of Cross-linked Polystyrene/Glass Fiber Composites

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Journal of wuhan university of {2.(Materials science) 2010年第5期25卷 780-784页

作者：朱泉峣陈文 school of Materials science and Engineering Wuhan University of Technology State Key Laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of Technology

Cross-linked polystyrene/glass fiber composites were fabricated using cross-linked polystyrene （CLPS） as matrix and E-glass fiber as the reinforcement. Surfaces of E-glass fibers were modified by vinyl triethoxysilane （VTES）, vinyl trimethoxysilane （VTMS） and γ-methacryloylpropyl trimethoxysilane （MPS）. The treated glass fibers were analyzed by fourier transform infrared spectroscopy （FTIR）. Dynamic mechanical thermal analysis （DMTA） and thermo-gravimetric analysis （TGA） were employed to investigate the effect of glass fibers surface modification on viscoelastic behavior and thermal properties. The morphology of fracture surfaces of various composites was observed by scanning electron microscopy （SEM）. The results revealed that these coupling agents were connected to the surfaces of the fibers by chemical bonding. Dynamic mechanical properties as well as thermal stability of the composites were improved considerablely, but to varying degrees depending on the fiber modification. The diversities of improvement of properties were attributed to the different interfacial adhesion between CLPS matrix and the glass fibers.

关键词： polymer-matrix composite cross-linked polystyrene (CLPS) fiber/matrix bond dynamic mechanical thermal analysis.

Electrically Conductive Concrete for Heating Using Steel Bars as Electrodes

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Journal of wuhan university of {2.(Materials science) 2010年第3期25卷 523-526页

作者：侯作富 school of Mechanical Engineering Yangtze University

The steel bars with good electrical conductivity were used as two kinds of electrodes in the making of carbon fiber（CF） electrically conductive concrete for *** results of the pertinent experiments illustrate the design is *** change in electrical resistivity over three years＇ hydration time was studied when steel bars were used as lateral face electrodes and top bottom surface electrodes *** temperature rise test was conducted to verify the heating properties of two kinds of *** only the study can reduce the CF volume content of electrically conductive concrete for heating to 0.58% or 0.36% according to different design,but also it will enhance the carrying capacity of the concrete roadway for heating.

关键词： steel bar carbon fiber electrical resistivity temperature rise

Relationship between Retrographical and Physical Properties of Aggregates

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Journal of wuhan university of {2.(Materials science) 2010年第4期25卷 678-681页

作者：庞凌 school of sciences Wuhan University of Technology

The relationship between petrographical and physical properties of limestone, basalt, granite and gneiss was investigated. Petrographical data were quantified from polished thin sections with a polarising microscope to determine the modal composition. The properties of resistance to fragmentation and abrasion were determined by Los Angeles abrasion test and crushing test. The shape characteristic was measured by Flakiness index test. The experimental results indicate that abundance of fineto medium-grained minerals （especially of plagioclase, quartz and feldspar） are prime, and strong micrographic intergrowth texture with interlocking grain boundaries have the great positive influence on the physical properties. It is also indicated that petrographical properties and surface texture of rocks can decide the potentiality of rocks as raw materials with high quality on resisting fragmentation and abrasion. Analysis of Integration of petrographical data and mechanical properties is ideal for the selection of aggregates used in asphalt concrete.

关键词： aggregate petrography physical properties flakiness index