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Effect of Powder Particle Size on the Properties and Microstructure of Ti(C,N)-Based Cermet

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Rare Metals 2001年第1期20卷 47-51页

作者： Yong Zheng, Weihao Xiong (Key State Laboratory of Die technology, Huazhong university of science and technology, wuhan 430074, china) Huazhong Univ Sci & Technol Key State Lab Die Technol Wuhan 430074 Peoples R China

The influence of raw powder particle size on the properties and microstructures of Ti (C, N)-based cermets has been studied. The conclusions are as follows: The microstructures of cermets were composed of two kinds of grains, the one with black cores surrounded by obvious rim structures, and the other whose cores were white with unconspicuous rim structures and adhesive phase. In the cermet made from fine powders, the amount of grains with white cores was much more than that in cermet made from coarse powders. In addition, their properties were also much better.

关键词： Ti(C, N)-based cermet powder particle size property microstructure

Weak martingale Hardy spaces and weak atomic decompositions

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science china Mathematics 2006年第7期49卷 912-921页

作者： HOU Youliang & REN Yanbo School of Mathematics and Statistics, wuhan university, wuhan 430072, china Department of Mathematics & Physics, Henan university of science and technology, Luoyang 471003, china 1. School of Mathematics and Statistics Wuhan University Wuhan 430072 China 2. Department of Mathematics & Physics Henan University of Science and Technology Luoyang 471003 China

In this paper we define some weak martingale Hardy spaces and three kinds of weak atoms. They are the counterparts of martingale Hardy spaces and atoms in the classical martingale Hp-theory. And then three atomic decomposition theorems for martingales in weak martingale Hardy spaces are proved. With the help of the weak atomic decompositions of martingale, a sufficient condition for a sublinear operator defined on the weak martingale Hardy spaces to be bounded is given. Using the sufficient condition, we obtain a series of martingale inequalities with respect to the weak Lp-norm, the inequalities of weak (p ,p)-type and some continuous imbedding relationships between various weak martingale Hardy spaces. These inequalities are the weak versions of the basic inequalities in the classical martingale Hp-theory.

关键词： martingale, weak Hardy space, weak atom, atomic decomposition.

ON THE ALMOST SURELY ASYMPTOTIC BOUNDS OF A CLASS OF ORNSTEIN-UHLENBECK PROCESSES IN INFINITE DIMENSIONS

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Journal of Systems science & Complexity 2008年第3期21卷 416-426页

作者： Yuhong LI college of Hydropower and Information Engineering Huazhong University of Science and Technology Wuhan 430074 China

Given a real-valued separable M-type 2 Banach space X with the p-th power of the norm of C2-class, the almost sure asymptotic upper bounds of the solutions of the Ornstein-Uhlenbeck Processes described by the following equations {dz（t）=A（t,z（t））dt＋σ（t,z（t））dW（t）,z（0）=z0∈X,are investigated. This study generalizes the corresponding well-known finite dimensional results of Lapeyre （1989） and Mao （1992）.

关键词： Almost surely asymptotic bounds infinite dimension M-type 2 Banach space Ornstein-Uhlenbeck Processes

ACOUSTIC REFLECTION FROM A BAFFLED ELASTIC/PIEZOELECTRIC PLATE

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Acta Mechanica Solida Sinica 2002年第2期15卷 156-162页

作者： Zhao Hanzhong (Department of Mechanics,Huazhong university of science and technology,wuhan 430074,china) Department of Mechanics Huazhong Univ. of Sci. and Technol. Wuhan 430074 China

A finite difference/boundary integral procedure to determine theacoustic reflected pressure from a fluid-loaded bi-laminated plate isdescribed. The bi-laminate is composed of a piezoelectric layer andan elastic layer in contact with the fluid, and is held by anacoustically hard baffle. In the numerical model, the fluid pressureat fluid/solid interface is replaced by a continuum of point sourcesweighted by the normal acceleration of the elastic plate, and thegoverning equation system is solved in the solid domain.

关键词： acoustic reflection baffled palte finite difference boundary integral

DEFICIENT INFORMATION MODELING OF MECHANICAL PRODUCTS FOR CONCEPTUAL SHAPE DESIGN

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Chinese Journal of Mechanical Engineering 2002年第1期15卷 1-5,26页

作者： Liu Jihong Shu Huilin CAD Center，Huazhong university of science and technology，wuhan 430074，china CAD Center Huazhong University of Science and Technology Wuhan 430074

In allusion to the deficient feature of product information in conceptualdesign, a framework of deficient information modeling for conceptual shape design is put forward,which includes qualitative shape modeling (a qualitative solid model), uncertain shape modeling (anuncertain relation model) and imprecise shape modeling (an imprecise region model). In theframework, the qualitative solid model is the core, which represents qualitatively (using symbols)the conceptual shapes of mechanical products. The uncertain relation model regarding domainrelations as objects and the imprecise region model regarding domains as objects are used to dealwith the uncertain and imprecise issues respectively, which arise from qualitative shape modeling orexist in product information itself.

关键词： Conceptual shape design Qualitative solid model Spatial cognition

Structure and Properties of Mg-doped SrBi_4Ti_4O_(15) Bi-layered Compounds

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Journal of wuhan university of technology(Materials science) 2008年第5期23卷 675-677页

作者：郝华 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

The structure and properties of Mg-doped SrBi4Ti4O15（SBT） were dicussed. Mg substitution into SBT had two possibilities states with the dopant amount variety. Mg cation substituted mostly into Sr^2＋ and the amount proportion was 68.11%.Mg ion will substitute into Ti ion site in perovskite layer when the doping amount increases. Polarization increases sharply when x=0.1 and then decreases becauses of the domain pinning. The Curie temperature of Mg-doped SBT is about 300 ℃ and there is a broad diffuse phase transition near Tc with a flat peak near the Ta of SBT.

关键词： Mg-doped bismuth layer structure ferroelectrics ferroelectric properties

Optimality strategy of a sealed-offer simultaneous bargaining protocol

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science china(Information sciences) 2011年第1期54卷 79-90页

作者： ZHANG LinLan1,2,CHEN XueGuang2 & HONG Liu2 1School of Business,Hubei university,wuhan 430062,china 2Institute of Systems Engineering,Huazhong university of science and technology,wuhan 430074,china 1. School of Business Hubei University Wuhan 430062 China2. Institute of Systems Engineering Huazhong University of Science and Technology Wuhan 430074 China

Alternating-offer bargaining protocol is the most predominant way for solving bilateral bargaining ***,alternating-offer may consume much time and cause a low effciency in some ***, a deadlock in which both negotiators are unwilling to concede or refuse to disclose more information may arise. Then mediation is *** paper presents an agent-based sealed-offer simultaneous bargaining protocol by introducing a nonbiased *** information of both agents is considered completely *** our agent-based model,both agents simultaneously submit their respective offers to the mediate *** offers of each agent are not revealed to the *** design can discourage counter-speculation and effectively control fraud and misrepresentation in a certain ***,we analyze how an agent can exploit the available information in selecting a strategy that maximizes its expected utility and give the optimal offers of each agent at each stage of the *** groups of automated experiments are conducted to evaluate the performance of the proposed automated negotiation procedure.

关键词： automated negotiation bargaining sealed-bid optimal strategy

A self-calibration algorithm for cross array in the presence of mutual coupling

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science china(Information sciences) 2011年第4期54卷 836-848页

作者： HU XiaoQin 1,2,CHEN Hui 2,WANG YongLiang 2 & CHEN JianWen 2 1 college of Electronic science and Engineering,National university of Defense technology,Changsha 410073,china 2 Key Lab of wuhan Radar Academy,wuhan 430019,china 1. college of Electronic science and Engineering National University of Defense Technology Changsha 410073 China2. Key Lab of Wuhan Radar Academy Wuhan 430019 China

In this paper,a novel blind mutual coupling self-calibration algorithm especially tailored to cross array is *** method compensates for the mutual coupling not only between sensors in each subarray but also between two *** the property of coupling matrix,the proposed method requires neither the calibration sources in known locations nor the multidimensional nonlinear *** method can jointly estimate the DOAs of the incoming signals and the unknown mutual coupling coefficients,and has high estimation precision and low computational *** analysis and computer simulations show the effectiveness of the proposed algorithm.

关键词： cross array mutual coupling self-calibration DOA estimation

Sandwich Magnetoelectric Composites of Polyvinylidene Fluoride,Tb-Dy-Fe Alloy,and Lead Zireonate Titanate

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Journal of wuhan university of technology(Materials science) 2007年第4期22卷 596-599页

作者：赵广辉熊传溪 State Key Laboratory of Advanced technology for Materials Synthesis and Processing School of Computer science and technology Wuhan University of TechnologyWuhan 430070China School of Materials science and Engineering Wuhan University of TechnologyWuhan 430070China

The novel sandwich composites were prepared by sandwiching a polyvinylidene fluoride/Tb- Dy-Fe alloy composite （PVDF/Terfenol-D） between polyvinylidene fluoride/lead zirconate titanate composites （PVDF/PZT）. The maximum magnetoelectric effect voltage coefficient, （dE/dn）33max, of the sandwich composites is higher than that of three-phase composites at their own optimal loading level of Terfenol-D. This is attributed to less interface relaxations of strain and better polarization of the sandwich composites. When the volume fraction of Terfenol-D is higher than 0.10, no coupling interaction for three-phase composites could be observed, but （dE/dn）33max of sandwiched composites still reached 20 mV/（***）. At high magnetic field intensity, the magnetoelectric effect voltage coefficient, （dE/dn）33, of sandwich composites is higher than that of three-phase composites; at low magnetic field intensity, （dE/dn）33 of sandwich composites is lower than that of three-phase composites. At their resonance frequency, the （dE/dn）33max of the sandwich composites and the three phase composites are 150 mV/（***） and 42 mV/（cmoOe）, respectively. This significant increase of （dE/ dn）33max at resonance frequency confirms the improvement of maximum magnetoelectric effect coefficient via sandwich-structured composites.

关键词： magnetoelectric piezoelectric sandwiched composites