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Numerical simulation of the transient multiphase field during plasma deposition manufacturing composite materials

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science china(Physics,Mechanics & Astronomy) 2009年第4期52卷 508-517页

作者： KONG FanRong1,2.ZHANG HaiOu1 & WANG GuiLan3 1 State Key Laboratory of Digital Manufacturing Equipment and technology,huazhong {2. of science and technology,wuhan 430074,china 2.Research Center for Advanced Manufacturing,Southern Methodist {2.,3101 Dyer Street,Dallas,Texas 752.5,USA 3 College of Material science and engineering,huazhong {2. of science and technology,wuhan 430074,china State Key Laboratory of Digital Manufacturing Equipment and technology Huazhong University of Science and Technology Wuhan China Research Center for Advanced Manufacturing Southern Methodist University Dallas USA College of Material science and engineering Huazhong University of Science and Technology Wuhan China

A solid/liquid/gas unified model has been developed to investigate the gradient composition formation during the plasma deposition manufacturing(PDM) composite materials process. In this model,an enthalpy porosity model was applied to deal with the melting and solidification of the deposited layer,and a level-set approach was introduced to track the evolution of the free surface of the molten pool and the deposited layer. Moreover,complicated physical phenomena occurring at the liquid/gas interface,including forced convection heat loss,heat emission and plasma heat source,have been incorporated into the governing equations by source terms. In this study,the numerical experiment of nickel base alloy powder deposited on the medium steel substrate by PDM technique was implemented based on the staggered grid and SIMPLEC algorithm. Concentration gradient distribution of the solute material at the composite material interface,fluid flow and temperature distribution in the molten pool and the deposited layer have been investigated in detail.

关键词： plasma deposition manufacturing composite material solid/liquid/gas unified model level-set approach

A MODEL FOR CONCRETE DURABILITY DEGRADATION IN FREEZE-THAWING CYCLES

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Acta Mechanica Solida Sinica 2003年第4期16卷 353-358页

作者： Wei Jtm Wu Xinghao Zhao Xiaolong (School of Civil engineering and Mechanics,huazhong {2. of science and technology,wuhan 430074,china) Sch. of Civ. Eng. and Mechanics Huazhong Univ. of Sci./Technology Wuhan 430074 China

Up to now,how to control the durability of concrete structures is still a pending research topic in civil *** to the fact that concrete durability can be affected by many non-mechanical factors,it is very difficult to research durability only based on mechanics. However,the phenomenon of failure caused by non-mechanical factors is similar to that caused by *** frost durability reflects the comprehensive durability of concrete in a certain sense, the specific failure process is analyzed and a damage model is introduced,which can describe the durability degradation process of concrete in the whole freeze-thawing cycle.

关键词： concrete durability damage frost durability

Cu+Al_2._3 composite coating on AISI 1045 steel surface by laser cladding

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中国有色金属学会会刊：英文版 1999年第3期9卷 462-467页

作者： Wang Maoqiu(王毛球), Xie Changsheng(谢长生), Zeng Dawen(曾大文) School of Materials science and engineering,{2., wuhan 430074, P. R. china huazhong Univ of science and Technology Wuhan China

Perfect composite coatings have been successfully produced with preplaced mixture of Cu+Al 2. 3(2.～2.%) on AISI 1045 steel substrate by using a 2.kW CO 2.laser. A suitable amount of Al 2. 3 in Cu as additive can improve the processing conditions of laser cladding. Fe rich particles were observed in the clad layer during microstructural observation with SEM and chemical composition analysis by EDAX. The experimental results showed that microhardnesses of the coatings were over 150HV 0.05 and the electric resistivities were about 4.0×10 -8 ～4.5×10 -8 Ω·m. Perfect composite coatings have been successfully produced with preplaced mixture of Cu+Al 2. 3(2.～2.%) on AISI 1045 steel substrate by using a 2.kW CO 2.laser. A suitable amount of Al 2. 3 in Cu as additive can improve the processing conditions of laser cladding. Fe rich particles were observed in the clad layer during microstructural observation with SEM and chemical composition analysis by EDAX. The experimental results showed that microhardnesses of the coatings were over 150HV 0.05 and the electric resistivities were about 4.0×10 -8 ～4.5×10 -8 Ω·m.

关键词： laser cladding conductive coating microhardness tests resistance

Early Age Compressive Strength of Pastes by Electrical Resistivity Method and Maturity Method

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Journal of wuhan university of {2.(Materials science) 2011年第5期26卷 983-989页

作者：肖莲珍 School of Materials science and engineering Wuhan Institute of Technology

The compressive strength development of Portland cement pastes was investigated by the electrical resistivity method and the maturity *** experiments were carried out on the cement pastes with different water-cement ratios at different curing *** results show that the application of the maturity method has limitation to obtain the *** is found that both of the compressive strength and the electrical resistivity follow hyperbolic trend for all the *** hyperbolic equation of each mix is obtained to estimate the ultimate resistivity value which can probably be *** relationship between electrical resistivity and compressive strength of the cement pastes is established based on the test results and interpreted by the empirical Archie equation and a strength-porosity *** relationship between the electrical resistivity after temperature correction and the compressive strength was linear and independent of curing temperature and water-cement ratio.

关键词： electrical resistivity cement hydration compressive strength maturity method

A Study on the Design for Object-Oriented Adaptive Decision-Making Teams

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Journal of Systems engineering and Electronics 2002年第1期13卷 68-73页

作者： Xiao Bing, Qu Tan & Wang Mingzhe huazhong university of science and technology, wuhan 430074,P.R.{2. huazhong university of {2. and technology Wuhan 430074 P. R. China

The modern war features a highly distributed coordination. In the face of great time constrains, it is important to change command organizations to adapt to the real environment. Therefore it's a key step to set up adaptive C2.teams. In this paper, the relational problems about distributed C2.organizational structure adaptation are discussed, and the methodology for team decision making design based on the object oriented technique is studied.

关键词： Adaptation Decision making team Colored Petri net Object oriented.

INTEGRATED APPROACH TO ASSEMBLY SEQUENCE PLANNING OF C0MPLEX PRODUCTS

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Chinese Journal of Mechanical engineering 2004年第2期17卷 181-184页

作者： Wang Junfeng Liu Jihong Zhong Yifang CAD Center,huazhong university of {2. and technology,wuhan 430074, china CAD Center Huazhong University of Science and Technology Wuhan 430074

Assembly sequence planning will be more difficult due to the increasingcomplexity of products. An integrated approach to assembly sequence planning of complex productsapplying de-composition-planning-combination strategy is presented. First, an assembly is decomposedinto a hierarchical structure using an assembly structure representation based on connectors. Then,an assembly planning system is used to generate the sequences that are locally optimal for eachleaf partition hi the structure hierarchy. By combining the local sequences systematically in abottom-up manner and choosing suitable ones from the merged sequences, the assembly sequence of eachparent structure including the whole assembly is generated. An integrated system has beencompleted. A complex product is given to illustrate the feasibility and the practicality of theapproach.

关键词： Assembly sequence planning Assembly decomposition Structure hierarchy Sequence combination

Terahertz radiation sources based on free electron lasers and their applications

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science china(Information sciences) 2012年第1期55卷 1-15页

作者： TAN Ping1,HUANG Jiang2.LIU KaiFeng2.XIONG YongQian2.FAN MingWu1,2.1Department of Electronic and Information engineering,huazhong {2. of science and technology,wuhan 430074,china 2.ollege of Electrical and Electronic engineering,State Key Laboratory of Advanced Electromagnetic engineering and technology,huazhong {2. of science and technology,wuhan 430074,china Department of Electronic and Information engineering Huazhong University of Science and Technology College of Electrical and Electronic engineering State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Scie

The tunability,high power and flexible picoseconds-pulse time structure of terahertz(THz)radiation make the THz free-electron laser(FEL)a very attractive THz source of coherent *** paper focuses on the development and perspectives of THz radiation sources based on the *** principles of the low gain THz FEL oscillator,the SASE THz FEL amplifier and the supperradiant THz FEL are reviewed briefly,and the key technologies of THz FEL,such as injector,accelerator,undulator and optical cavity,are discussed,*** current status of and future prospects for THz radiation sources based on the FEL are emphasized in this *** research and development have shown bright future in free-electron laser(FEL)THz radiation *** potential applications can be carried out in the field of imaging,material research,biology medicine,communication,diagnostics and many others.

关键词： terahertz source terahertz applications free electron laser

Detection of bursts in neuronal spike trains by the mean inter-spike interval method

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Progress in Natural science:Materials International 2009年第2期19卷 229-235页

作者： Lin Chena,b,Yong Deng c,Weihua Luo a,Zhen Wang a,Shaoqun Zenga,a Hubei Bioinformatics and Molecular Imaging Key Laboratory,huazhong university of {2. and technology,wuhan 430074,china b College of Mechanical engineering,Guangxi university,Nanning,530004,china c College of Optoelectronic {2. of engineering,huazhong university of {2. and technology,wuhan 430074,china Hubei Bioinformatics and Molecular Imaging Key Laboratory Huazhong University of Science and Technology Wuhan 430074 China College of Mechanical engineering Guangxi University Nanning 530004 China College of Optoelectronic science of engineering Huazhong University of Science and Technology Wuhan 430074 China

Bursts are electrical spikes firing with a high frequency,which are the most important property in synaptic plasticity and information processing in the central nervous system. However,bursts are difficult to identify because bursting activities or patterns vary with phys-iological conditions or external stimuli. In this paper,a simple method automatically to detect bursts in spike trains is described. This method auto-adaptively sets a parameter (mean inter-spike interval) according to intrinsic properties of the detected burst spike trains,without any arbitrary choices or any operator judgment. When the mean value of several successive inter-spike intervals is not larger than the parameter,a burst is identified. By this method,bursts can be automatically extracted from different bursting patterns of cultured neurons on multi-electrode arrays,as accurately as by visual inspection. Furthermore,significant changes of burst variables caused by electrical stimulus have been found in spontaneous activity of neuronal network. These suggest that the mean inter-spike interval method is robust for detecting changes in burst patterns and characteristics induced by environmental alterations.

关键词： Inter-spike interval Bursts Spike trains Multi-electrode arrays

APPROACH ON INTELLIGENT OPTIMIZATION DESIGN BASED ON COMPOUND KNOWLEDGE

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Chinese Journal of Mechanical engineering 2003年第3期16卷 300-304页

作者： Yao Jianchu Zhou JiYu JunSchool of Mechanical scienceand engineering,{2. university of scienceand technology,wuhan 430074, china School of Mechanical science and engineering Huazhong University of Science and Technology Wuhan 430074

A concept of an intelligent optimal design approach is proposed, which isorganized by a kind of compound knowledge model. The compound knowledge consists of modularizedquantitative knowledge, inclusive experience knowledge and case-based sample knowledge. By usingthis compound knowledge model, the abundant quantity information of mathematical programming and thesymbolic knowledge of artificial intelligence can be united together in this model. The intelligentoptimal design model based on such a compound knowledge and the automatically generateddecomposition principles based on it are also presented. Practically, it is applied to theproduction planning, process schedule and optimization of production process of a refining &chemical work and a great profit is achieved. Specially, the methods and principles are adaptablenot only to continuous process industry, but also to discrete manufacturing one.

关键词： Intelligent optimization Automatic modeling Compound knowledge Expertsystem