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EXPERIMENTAL STUDY ON TRIBOLOGICAL PROPERTIES OF FULLERENE COPOLYMER NANOBALL

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Chinese Journal of Mechanical Engineering 2000年第3期13卷 201-205页

作者： Lei Hong (School of Mechanical science and Engineering, huazhong university of science and technology) Guan Wenchao, Liao Daoxun (huazhong university of science and technology) 华中科技大学湖北武汉

A novel fullerene-styrene-maleic anhydride copolymer is reported. TEM analyses shows it is water- soluble nanoball of average diameter of about 83 nm. The tribological behavior is evaluated by foul-ball machine. It was found that addition of fullerene copolymer to base stock (2%triethanolamine aqueous solution)resulted in a raise in load-carrying ability(F value)from 130 N to maximum 480 N, and a reduction in coefficient of friction from 0.235 to minimum 0. 063. SEM analyses indicates that the wear scare obtained with fullerene copolymer exhibited mild scratches, while sharp grooving and serious pull-out phenomnon were observed in the presence of base stock without additive .The improvements in friction, wear and load-carrying capacity are probably due to the presence of fullerene copolymer nanoballs, which may act as molecule ball bearings, which in turn lead to elastic rolling lubrication.

关键词： Water-soluble Fullerene copolymer Nanoball Fricition and wear Microcosmic elastic rolling8

A New Clustering Algorithm for Categorical Attributes

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International Journal of Minerals,Metallurgy and Materials 2000年第4期14卷 318-322页

作者： Songfeng Lu, Zhengding Lu (College of Computer science and technology, huazhong university of science and technology, Wuhan 430074, China) College of Computer science and technology Huazhong University of Science and Technology Wuhan 430074 China

In traditional data clustering, similarity of a cluster of objects is measured by distance between objects. Such measures are not appropriate for categorical data. A new clustering criterion to determine the similarity between points with categorical attributes is pre- sented. Furthermore, a new clustering algorithm for categorical attributes is addressed. A single scan of the dataset yields a good clus- tering, and more additional passes can be used to improve the quality further.

关键词： data mining clustering similarity Information

FRACTAL GEOMETRY STUDY OF CORRELATION BETWEEN IMPACT TOUGHNESS OF STEEL AND PARAMETERS OF FREE-CUTTING PHASE

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Acta Metallurgica Sinica(English Letters) 1992年第4期5卷 250-255页

作者： JIANG Laizhu CUI Kun huazhong university of science and technology,Wuhan,China huazhong Univ of science and Technology Wuhan China

Studies were made of the calculation of fractal dimension of transverse impact fracture sur- face,and of the correlation between impact toughness of steel and parameters of free-cutting phase by means of the developed fractal geometry model of crack *** is believed that the area fraction,f,of free-cutting phase is negligibly influential to the longitudinal im- pact toughness,as f1 .While the aspect ratio,saying ratio of length to width,of free-cut. ting phase is inversely influential to the transverse impact *** may .be the reason why the transverse impact toughness of free-cutting steel containing more rare earth contrast to sulphur is even higher than the low sulphur containing steel.

关键词： fractal geometry impact toughness free-cutting phase

A quasi-physical algorithm for solving the linear separation problem in n-dimensional space

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Journal of Central South university of technology 2001年第4期8卷 272-277页

作者： HUANG Jia yuan (College of Computer science, huazhong university of science and technology, Wuhan 430074, China) College of Computer science Huazhong University of Science and Technology Wuhan China

A quasi physical algorithm was proposed for solving the linear separation problem of point set in n dimensional *** original idea of the quasi physical algorithm is to find an equivalent physical world for the primitive mathematical problem and to observe the vivid images of the motion of matter in it so as to be inspired to obtain an algorithm for solving the mathematical problem. In this work, the electrostatics with two kinds of matter is found to be the equivalent physical world. As a result,the proposed algorithm is evidently more efficient and robust than the famous LMS algorithm and ETL algorithm. The efficiency of the quasi physical algorithm is about 10-50 times of the LMS algorithm’s for representative instances. A typical Boolean valued instance shows that it is hard for ETL algorithm but very easy for the quasi physical *** this instance, point set A and B is {000, 010, 011, 111} and {001,100}, respectively.

关键词： linear separation problem neural network algorithm quasi-physical method electrostatics

METHOD TO SOLVE ELASTIC CONJUGATE SURFACES IN MULTI-TEETH MESHING

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Chinese Journal of Mechanical Engineering 2002年第4期15卷 348-352页

作者： Yi ChuanyunSchool of Mechanical science and Engineering, huazhong university of science and technology,Wuhan 430074, China School of Mechanical science and Engineering Huazhong University of Science and Technology Wuhan 430074

A method to solve the elastic conjugate surfaces in multi-teeth meshing ispresented. In mechanical manufacturing and design, there exist a lot of problems relating toconjugate surfaces, such as three-dimensional engagement, steel rolling and workpiece machining,which cause great effects on the quality of machining and performances of transmission. This methoddescribes relation between conjugate motion and elastic deformation in the process of mesh-in andmesh-out, and can be used to determine the profile of gear tooth by a certain given load sharing.

关键词： multi-teeth meshing elastic conjugate surfaces

Convergence analysis for general linear methods applied to stiff delay differential equations

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Progress in Natural science:Materials International 2002年第6期12卷 16-22页

作者： ZHANG Chengjian(Department of Mathematics, huazhong university of science and technology, Wuhan 430074, China) huazhong Univ Sci & Technol Dept Math Wuhan 430074 Peoples R China

For Runge-Kutta methods applied to stiff delay differential equations (DDEs), the concept of D-convergence was proposed, which is an extension to that of B-convergence in ordinary differential equations (ODEs) . In this paper, D-convergence of general linear methods is discussed and the previous related results are improved. Some order results to determine D-convergence of the methods are obtained.

关键词： D-convergence general linear methods stiff delay differential equations.

Evolution of Bright Screening-photovoltaic Spatial Optical Solitons

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Chinese Journal of Lasers 2001年第5期10卷 28-33页

作者： LIU Jinsong (State Key Laboratory of Laser technology, huazhong university of science and technology, Wuhan 430074, China) 华中科技大学激光技术国家重点实验室湖北武汉

A numerical analysis of the dynamical evolution of bright screening photovoltaic (SP) spatial solitons in biased photovoltaic photorefractive materials in the case of neglecting the material loss and the diffusion is presented. When an incident optical beam is a bright SP soliton, the beam propagates along a linear path with its shape kept unchanged. When the incident optical beam is slightly different from a bright SP soliton, the beam reshapes itself and tries to evolve into a bright SP soliton after a short distance. However, when the incident optical beam is significantly different from a SP bright soliton, the beam cannot evolve into a stable bright SP soliton, and tends to experience periodic compression and expansion. For a low intensity input beam, the wave experiences a periodic process of compression first and then expansion during the initial part of the cycle. For a high intensity input beam, however, the wave will initially diffract and then experiences compression during the cycle.

关键词： nonlinear optics spatial optical solitons photorefractive effects

A VARIATIONAL SOLUTION OF COUPLED VIBRATION FOR MODERATELY THICK FLOATING PLATE SEATED ON THE SEA FLOOR WITH VARIABLE WATER DEPTH

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Acta Mechanica Sinica 1988年第3期4卷 275-283页

作者： Huang Yuying huazhong university of science and technology huazhong university of science and technology Huazhong China

Based on Reissner’s plate theory, a localized variational principle for the coupled vibrations ofmoderately thick floating plates seated on the sea floor with variable water depth is presented in this paper. Itwill be a powerful tool to formulate various approximate methods of moderately thick floating plates. Bymeans of this variational principle a formula for calculating the natural frequencies of moderately thickfloating plates is also obtained. A numerical example shows that high accuracy and computational time savingmay be achieved in calculation.

关键词： vibration moderately thick plate interaction of structure and fluid variational principle

An architecture for mobile database management system

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

作者： Dong Li and Yucai Feng Computer School, huazhong university of science and technology, Wuhan 430074, China Comp. Sch. Huazhong Univ. of Sci. and Technol. 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