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Influence of Additives on the Formation of Electrodeposits in the Concrete Cracks

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Journal of Wuhan university of Technology(materials science) 2011年第2期26卷 367-371页

作者：储洪强 Key Laboratory of Advanced Civil engineering materials Ministry of EducationTongji University college of Mechanics and materials Hohai University

The electrodeposition method for rehabilitation of the cracked reinforced concrete,based on the electrochemical technique,was presented *** aim of this study was to evaluate the influence of additive on the formation of electrodeposits in the concrete *** mortar specimens of size 40 mm×40 mm×160 mm were immersed in electrolyte solutions（ZnSO4,MgSO4）,and a constant current was applied between the reinforced steel and the external electrode for 15 *** of surface coating,rate of crack closure and rate of crack filling depth were measured and the appearance of electrodeposits in the cracks was *** experimental results demonstrate that,under the experimental conditions,rate of surface coating and crack filling depth increase,while rate of crack closure decreases as the percengtage of additive *** addition,the electrodeposits become more denser and the microstructure varies with additive content,while the compositions of electrodeposits do not change.

关键词： repair of cracks additive formation microstructure

Manufacture of the Ultrafine Grain WC/Co Cemented Carbides by Combined Sintering Processing

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International Journal of Minerals,Metallurgy and materials 1999年第3期13卷 208-213页

作者： Binghai Liu Yue Zhang Shixi Ouyang Qikai Li(Institute of Technical Physics and Chemistry, East china university of science and Technology , shanghai 200237, china)(material science and engineering School. university of science and Technology Beijing, Beijing 100083, china)(State Key Laboratory for Synthesis and Processing of Advanced materials. Wuhan university of science and Technology, Wuhan 430070, china,) E china Univ Sci & Technol Inst Tech Phys & Chem Shanghai 200237 Peoples R China Univ Sci & Technol Beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China Wuhan Univ Sci & Technol State Key Lab Synth & Proc Adv Mat Wuhan 430070 Peoples R China

A new kind of sintering process, combined sintering process. i.e. vacuum sintering plus hot isolate pressure sintering (HIP), was introduced for producing ultrafine WC-10% Co (mass fraction. so as the follows) cemented carbides. The effects of some processing parameters on the microstructure and mechanical properties of the obtained cemented carbides were studied. The results show that the rapid shrinkage and the pronounced densification of tile cemented carbides took place during the vacuum sintering stage, which is intinaately correlated with the local liquid sintering occurred during this earl} sintering stage for the high surface activity of ultrafine WC-Co powder. The way of high pressure imposing. isothermal treatment cycle during *** sintering and HIP sintering stage directly influence the densitication of compacts and the mechanical properties of the produced WC-10%Co cemented carbides.

关键词： ultrafine WC-Co cemented carbides vacuum sintering HIP sintering

A NEWε-GENERALIZED PROJECTION METHOD OF STRONGLY SUB-FEASIBLE DIRECTIONS FOR INEQUALITY CONSTRAINED OPTIMIZATION

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Journal of Systems science & Complexity 2011年第3期24卷 604-618页

作者： Jinbao JIAN Guodong MA Chuanhao GUO college of Mathematics and Information science Guangxi University Nanning 530004 China Department of Mathematics and Computer science Yulin Normal University Yulin 537000 China college of science Shanghai University Shanghai 200444 China.

In this paper, the nonlinear optimization problems with inequality constraints are discussed. Combining the ideas of the strongly sub-feasible directions method and the s-generalized projection technique, a new algorithm starting with an arbitrary initial iteration point for the discussed problems is presented. At each iteration, the search direction is generated by a new s-generalized projection explicit formula, and the step length is yielded by a new Armijo line search. Under some necessary assumptions, not only the algorithm possesses global and strong convergence, but also the iterative points always get into the feasible set after finite iterations. Finally, some preliminary numerical results are reported.

关键词： E-generalized projection global and strong convergence inequality constraints method of strongly sub-feasible directions optimization.

Preparation and Kinetics of the Thermal Decomposition of Nanosized CuC_2O_4-ZnC_2O_452H_2O

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Wuhan university Journal of Natural sciences 2006年第3期11卷 667-671页

作者： CHEN donghua HUANG Lianrong TANG Wanjun Hubei Key Laboratory for Catalysis and material science/college of Chemical and Materal science South-Central University for Nationalities Wuhan 430074 Hubei China

The physical mixture of nanosized CuC2O4-ZnC2O4·2H2O, as precursors of CuO-ZnO, have been prepared by the one-step solid state reaction method at room temperature. The thermal decomposition processes taking place in the solid state oxalate mixture of nanometer CuC2O4-ZnC2O4·2H2O have been studied in static air using TG, DSC, XRD and TEM techniques. TEM showed that the grain size of the decomposition product is 5-15 nm. The values of the activation energy Eα were determined using the isoconversional procedure of KAS method and the Ozawa method. The most possible mechanism function f（α） of the thermal decompositions of nanosized CuC2O4-ZnC2O4·2H2O are defined using the comparative method, function models of tbe decomposition of CuC2O4 and ZnC2O4, follow tbe same mechanism function ＂Avrami-Erofeev equalion＂. The pre-exponential factor A is obtained on the basis of Eα and f（α）, thus the thermal analysis kinetic triplet of the decompositions of nanosized CuC2O4-ZnC2O4·2H2O are determined.

关键词： nanoparticle copper oxalate zinc oxalate kinetics characterization

Review on abort trajectory for manned lunar landing mission

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science china(Technological sciences) 2010年第10期53卷 2691-2698页

作者： XI XiaoNing1, HUANG WenDe2 & WANG Wei2,3 1 college of Mechatronics engineering and Automation, National university of Defense Technology, Changsha 410073, china 2.college of Aerospace and material engineering, National university of Defense Technology, Changsha 410073, china 3 School of Surveying and Spatial Information System, university of New South Wales, Sydney, NSW 2052, Australia 1. college of Mechatronics engineering and Automation National University of Defense Technology Changsha 410073 China2. College of Aerospace and Material Engineering National University of Defense Technology Changsha 410073 China3. School of Surveying and Spatial Information System University of New South Wales Sydney NSW 2052 Australia

Abort trajectory is a passage that ensures the astronauts to return safely to the earth when an emergency occurs. Firstly,the essential elements of mission abort are analyzed entirely based on summarizing the existing studies. Then,abort trajectory requirement and rational selection for different flight phases of typical manned lunar mission are discussed specifically. Considering a trade-off between the two primary constrains of an abort,the return time of flight and energy requirement,a general optimizing method for mission abort is proposed. Finally,some suggestions are given for china’s future manned lunar landing mission.

关键词： manned lunar landing mission abort trajectory design free return trajectory

Nanostructured ZnO Films Electrodeposited on Hydrophilic Substrate Utilizing Cooperative Surface Assembly

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Journal of Wuhan university of Technology(materials science) 2006年第3期21卷 72-75页

作者：杨立荣 Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education Materials School Tianjin UniversityTianjin 300072 China.College of Material Science and Engineering Hebei Polytechnic UniversityTangshan 063009China

Nanoporous amorphous ZnO films with lamellar structure were electrodetposited on the hydrophilir substrate by utilizing cooperative surface aussembly of anionic sodium dodecyl sulfonate （ SDS ） at a very low concentration and inorganic species Zn （ NO3 ）2 under the influence of an electrostatic potential. The deposited films were characterized by X-ray diffraction （XRD） in the range of lou, angle and wide-angle, X-ray photoelectron spectroscopy （ XPS）, scanning electron microscopy （SEM）, and UV-Vis light absorption *** formation mechanism of the films was elementarily discussed.

关键词： electrochemical deposition nanoporous ZnO film assembly

A Discrete Spectral Problem and Related Hierarchy of Discrete Hamiltonian Lattice Equations

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Communications in Theoretical Physics 2007年第8期48卷 193-198页

作者： XU Xi-Xiang college of science,Shandong Uniersity of science and Technology,Qingdao 266510,chinaCAO Wei-Li college of science,Uniersity of shanghai for science and Technology,shanghai 200093,china college of science Shandong University of Science and Technology college of science University of Shanghai for Science and Technology

Staring from a discrete matrix spectral problem,a hierarchy of lattice soliton equations is presentedthough discrete zero curvature *** resulting lattice soliton equations possess non-local Lax *** structures are esta... 详细信息

关键词： lattice soliton equation zero curvature representation Hamiltonian structure Liouville integrability

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 university of science and Technology,Wuhan 430074,china 2 Research Center for Advanced Manufacturing,Southern Methodist university,3101 Dyer Street,Dallas,Texas 75205,USA 3 college of material science and engineering,Huazhong university of science and Technology,Wuhan 430074,china 1. State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and Technology Wuhan 430074 China 2. Research Center for Advanced Manufacturing Southern Methodist University 3101 Dyer Street Dallas Texas 75205 USA 3. college of material science and engineering Huazhong University of Science and Technology Wuhan 430074 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

Short cycle structures for graphs on surfaces and an open problem of Mohar and Thomassen

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science china Mathematics 2006年第2期49卷 212-224页

作者： REN Han & DENG Mo Department of Mathematics, East china Normal university, shanghai 200062, china college of Mathematics & Information science, Northwest Normal university, Lanzhou 730070, china 1. Department of Mathematics East China Normal University Shanghai 200062 China 2. college of Mathematics & Information science Northwest Normal University Lanzhou 730070 China

In this paper we investigate cycle base structures of a (weighted) graph and show that much information of short cycles is contained in an MCB (i.e., minimum cycle base). After setting up a Hall type theorem for base-transformation, we give a sufficient and necessary condition for a cycle base to be an MCB. Furthermore, we show that the structure of MCB in a (weighted)graph is unique. The property is also true for those having a longest length (although much work has been down in evaluating MCB, little is known for those having a longest length). We use those methods to find out some unknown properties for short cycles sharing particular properties in (unweighted) graphs. As applications, we determine the structures of short cycles in an embedded graph and show that there exist polynomially bounded algorithms in finding a shortest contractible cycle and a shortest two-sided cycle provided such cycles exist. Those answer an open problem of B. Mohar and C. Thomassen.

关键词： cycle base facial cycle graph embedding.