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Determination of the Thermal Expansion Coefficient of Concrete at Early Ages by Using Temperature-stress Testing Machine

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Journal of wuhan university of Technology(Materials Science) 2006年第4期21卷 146-149页

作者：霍凯成 Hubei Key Laboratory of Roadway Bridge & Structure engineering Wuhan University of TechnologyWuhan 430070China

By using the uptodate temperatuer-stress testing machine, the thermal expansion coefficient of concrete at early ages was studied and indicative conclusions were achieved ： temperature rising due to hydration heat is not directly correlated with cracking, but the temperature and stress evolation process should be taken into consideration in the same time. Proper chemical admixtures and mineral cornpasitions can improve the mechanical properties of concrete such as thermal expansion coefficient, which is very indicative in practice.

关键词： concrete coefficient of thermal expansion temperature-stress test

Prediction of Tumor Outcome Based on Gene Expression Data

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wuhan university Journal of Natural Sciences 2004年第2期9卷 177-182页

作者： Liu Juan 1,2, Hitoshi Iba 3.1. School of Computer, wuhan university, wuhan 43.072, Hubei, china 2. State Key Laboratory of Software {3., wuhan 43.072, Hubei, china 3. Department of Frontier Informatics, university of Tokyo, Tokyo 113.8656, Japan School of Computer Wuhan University Wuhan Hubei China State Key Laboratory of Software engineering Wuhan Hubei China Department of Frontier Informatics University of Tokyo Tokyo Japan

Gene expression microarray data can be used to classify tumor types. We proposed a new procedure to classify human tumor samples based on microarray gene expressions by using a hybrid supervised learning method called MOEA+WV (Multi-Objective Evolutionary Algorithm+Weighted Voting). MOEA is used to search for a relatively few subsets of informative genes from the high-dimensional gene space, and WV is used as a classification tool. This new method has been applied to predicate the subtypes of lymphoma and outcomes of medulloblastoma. The results are relatively accurate and meaningful compared to those from other methods. Key words bioinformatics - tumor classification - Pareto optimization - MOEA CLC number Q 786 - TP 181 Foundation item: Supported by the National Natural Science Foundation of china (603.1009), the Foundation of Young Scholars of Ministry of Education of china (150118) and Chenguang Project of wuhan City (211121009).Biography: Liu Juan (1970-), female, Associate Professor, Postdoctoral, research direction: bioinformatics, data mining, machine learning.

关键词： bioinformatics tumor classification Pareto optimization MOEA

Algorithm of graph isomorphism with threedimensional DNA graph structures

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Progress in Natural Science:Materials International 2005年第2期15卷 86-89页

作者： LIU Guangwu 1,2*, YIN Zhixiang 1,3. XU Jin1 and DONG Yafei1(1. Department of Control Science and engineering, Hua Zhong university of Science and Technology, wuhan 43.074,{3. 2. college of Transportation, wuhan university of Technology, wuhan 43.063.{3. 3. Department of Mathematics and Physics, Anhui university of Science and Technology, Huainan 23.001,{3.) Dept. of Control Science and Eng. Huazhong Univ. of Sci. and Technol. Wuhan 430074 China Coll. of Transportation Wuhan Univ. of Technology Wuhan 430063 China Dept. of Mathematics and Physics Anhui Univ. of Sci. and Technol. Huainan 232001 China

An algorithm for solving the graph isomorphism problem with 3.D DNA structures is proposed in this paper. The k-armed branched junction molecules are used to code k-degree vertices. Double stranded molecules are used to code edges. Then the molecules are mixed in a tube to be ligated. The result can be detected by gel electrophoresis. The time complexity of the algorithm is O(n2), where n is the number of vertices of the graph.

关键词： DNA computing DNA graph structure graph isomorphism

Second-order consensus in networks of dynamic agents with communication time-delays

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Journal of Systems engineering and Electronics 2010年第1期21卷 88-94页

作者： Bo Yang1,2, Huajing Fang3. and Hua Wang4 1. School of Navigation, wuhan university of Technology, wuhan 43.063. P. R. china 2. wuhan Second Ship Design and Research Institute, wuhan 43.064, P. R. china 3. Department of Control Science and engineering, Huazhong university of Science and Technology, wuhan 43.074, P. R. china 4. Department of Aerospace and Mechanical engineering, Boston university, Boston MA02215, USA School of Navigation Wuhan University of Technology Wuhan 430063 P. R. China wuhan Second Ship Design and Research Institute Wuhan 430064 P. R. China Department of Control Science and engineering Huazhong University of Science and Technology Wuhan 430074 P. R. China Department of Aerospace and Mechanical engineering Boston University Boston MA02215 USA

This paper proposes second-order consensus protocols with time-delays and gives the measure of the robustness of the protocols to the time-delay existing in the network of agents with second-order dynamics. By employing a frequency domain method, it is proven that the information states and their time derivatives of all the agents in the network achieve consensus asymptotically, respectively, for appropriate communication timedelay if the topology of weighted network is connected. Particularly, a tight upper bound on the communication time-delay that can be tolerated in the dynamic network is found. The consensus protocols are distributed in the sense that each agent only needs information from its neighboring agents, which reduces the complexity of connections between neighboring agents significantly. Numerical simulation results are provided to demonstrate the effectiveness and the sharpness of the theoretical results for second-order consensus in networks in the presence of communication time-delays.

关键词： second-order consensus protocols dynamic networks algebraic graph theory frequency domain analysis com-munication constraints.

HCWCI/Carbon Steel Bimetal Liner by Liquid-Liquid Compound Lost Foam Casting

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Journal of Iron and Steel Research International 2012年第10期19卷 13-19页

作者： XIAO Xiao-feng1,2, YE Sheng-ping2, YIN Wei-xin3. XUE Qiong4 (1. School of Mechanical engineering and Automation, wuhan Textile university, wuhan 43.073. Hubei, china 2. State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong university of Science and Technology, wuhan 43.074, Hubei, china 3. wuhan Zhike Abrasive-Resistant Material Science and Technology Development Co Ltd, wuhan 43.073. Hubei, china 4. college of Science, wuhan university of Technology, wuhan 43.079, Hubei, china) School of Mechanical engineering and Automation Wuhan Textile University Wuhan Hubei China State Key Laboratory of Material Processing and Die and Mould Technology Huazhong University of Science and Technology Wuhan Hubei China wuhan Zhike Abrasive-Resistant Material Science and Technology Development Co Ltd Wuhan Hubei China college of Science Wuhan University of Technology Wuhan Hubei China

Impact, friction and corrosion from the grinding balls and the grinding medium during the mineral processing result in liner breakage. Liner, made from Hadfield steel or alloyed steel, could not have served in wet grinding environment for more than ten months. Composite liner, made from HCWCI (high Cr white cast iron) and carbon steel, has been developed successfully with liquid-liquid composing process based on LFC (lost foam casting). The microstructure of composite was analyzed with optical microscope, SEM (scanning electron microscope)/EDX energy-dispersive X-ray and XRD (X-ray diffraction). According to micrograph, the combination region of two metals was staggered like dogtooth, no mixtures occurred between two liquid metals, and its interface presented excellent metallurgical bonding state. The results of mechanical property test show that, the hardness of HRC, the fracture toughness, and the bending strength are more than 61, 16.5 J/cm2 and 1 600 MPa, respectively. Comparison between liners made from bimetal composite and alloyed steel has also been investigated in industrial hematite ball mill. The results of eight months test in wet grinding environment prove that the service life of bimetal composite liner is three times as long as that of one made from alloyed steel.

关键词： composite liner bimetal liquid-liquid compound composite interface lost foam casting high Cr white cast iron

A Hybrid Genetic Algorithm for Reduct of Attributes in Decision System Based on Rough Set Theory

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wuhan university Journal of Natural Sciences 2002年第3期7卷 285-289页

作者： Dai Jian\|hua 1,2 , Li Yuan\|xiang 1,2 ,Liu Qun 3.1. State Key Laboratory of Software engineering, wuhan university, wuhan 43.072, Hubei,{3. 2. School of Computer, wuhan university, wuhan 43.072, Hubei, china 3. School of Computer Science, Lab. of Software Eng. Wuhan Univ. Wuhan 430072 China Sch. of Comp. Wuhan Univ. Wuhan 430072 China Sch. of Comp. Sci. Chongqing Univ. of Post and Telecom. Chongqing 400065 China

Knowledge reduction is an important issue when dealing with huge amounts of data. And it has been proved that computing the minimal reduct of decision system is NP-complete. By introducing heuristic information into genetic algorithm, we proposed a heuristic genetic algorithm. In the genetic algorithm, we constructed a new operator to maintaining the classification ability. The experiment shows that our algorithm is efficient and effective for minimal reduct, even for the special example that the simple heuristic algorithm can’t get the right result.

关键词： rough set reduction genetic algorithm heuristic algorithm

Fractal Analysis of Gas Diffusion Layer in PEM Fuel Cells

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Journal of wuhan university of Technology(Materials Science) 2006年第1期21卷 22-25页

作者：石英肖金生 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070ChinaSchool of Automation Wuhan University of Technology Wuhan 430070 China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070ChinaSchool of Automotive EngineeringWuhan University of Technology Wuhan 430070China

The aim of this study is to show how fractal analysis can be effectively used to characterize the texture of porous solids. The materials under study were carbon papers, the backing material of the gas diffusion layer （GDL） in Proton Exchange Membrane Fuel Cell （PEMFC）. The fractal dimensions were calculated by analyzing data from mercury porosimetry. The polytotrafluoroethylene （PTFE） treated carbon paper shows a significantly high fractal dimension value than pare sample, and the high fractal dimension signifies that the physical complexity of the pore surface is enhanced. The fractal dimension can be used as a valid parameter to monitor the textural evolution of the samples as the treatment progresses, as this behaves in a similar way to other textural parameters. The use of fractal analysis in conjunction with the results of classical characterization methods leads to a better understanding of textural modificatious in the processing of materials.

关键词： PEMFC gas diffusion layer fractal dimension mewury porosimetry

Internal Curing Using Water-releasing Material for High Strength Micro-expansive Concrete

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Journal of wuhan university of Technology(Materials Science) 2009年第3期24卷 510-513页

作者：吕林女 School of Science Wuhan University of Technology

Due to its low water content, it is difficult for expansive agent to have an effective expansive effect on high strength concrete to compensate its extensive shrinkage and form a certain expansion. To solve this problem, water-releasing material with water storage and releasing characteristics was incorporated into high strength micro-expansive concrete to provide internal curing, and expansive effect of expansive agent was improved. Migration of water from initially saturated water-releasing material to the surrounding hydrating cement paste was investigated. Based on a given efficient diffusion distance of water stored in water-releasing material, the mass and real water-cement ratio of cured cement paste were estimated. At the same time, the effect of internal curing of water-releasing material on the volume deformation of high strength micro-expansive concrete was investigated.

关键词： water-releasing material high strength concrete expansive internal curing

Interfacial Microstructure and Properties of Ti(C, N)/Ni Bonded by Transient Liquid-phase Diffusion

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Journal of wuhan university of Technology(Materials Science) 2009年第3期24卷 432-439页

作者：周世权熊惟皓 School of Mechanical Science and engineering Huazhong University of Science and Technology Department of Mechanical engineering University of Waterloo School of Materials Science and engineering Huazhong University of Science and Technology

Effects of the main process parameters（temperature and time） on microstructure and properties of Ti（C, N）/Ni interface bonded by （Cu＋Nb） interlayer in a vacuum diffusion bonding device were investigated. The interfacial microstructures consisted initially of Ni3.b metallic compound and eutectic of Ni3.b ＋ CuNiss, and finally transformed to （Ti, Nb）（C, N）＋Ni3.b near Ti （C, N） and NiCuss ＋ Ni3.b near Ni when diffusion bonding temperature was 1 523.1 573.K. It was clear that Cu was a constituent in the transient liquid phase （TLP） into which Ni was dissolved by forming Cu-Ni transition liquid. Nb was dissolved in Cu-Ni transition liquid rapidly. Ti （C, N） conld be wetted by resultant Ni-Nb-Cu transient liquid phase which was followed by a little （Ti, Nb）（C, N） solid solution formed at interface. This increased the interface combining capability. Ultimately the interface shear strength was able to reach 140 MPa. The theoretle analysis and experimental results show that the growth of interfacial reaction layer Ni3.b accords with parabola law, and the activation energy of diffusion reaction is 115.0±0.5 kJ/mol, while the diffusion reaction speed constant is 12.53.mm/s^1/2.

关键词： vacuum diffusion bonding transient liquid phase (TLP) diffusion bonding interlayer activation energy