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LAMINATED PIEZOELECTRIC PLATE FOR ACTIVE UNDERWATER ACOUSTIC CONTROL

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Acta Mechanica Solida Sinica 2001年第4期14卷 306-311页

作者： Zhao Hanzhong (department of mechanics,{2. University of {3. and technology,wuhan 43.074,china) department of mechanics Huazhong Univ. of Sci. and Technol. Wuhan 430074 China

The pressure reflected from a bi-laminated piezoelectric plate hasbeen determined using the Thomson-Haskell matrix method. The plate iscomposed of a piezoelectric layer with grounded vacuum and An elasticlayer in contact with the fluid. An incident plane wave in the fluidmedium strikes the plate at dif- Ferent angles. The required electricpotential across the piezoelectric layer to cancel the reflectionfrom the Fluid/elastic boundary has been determined for thepiezoelectric material PZT-5 at various thickness parame- Ters andincident frequencies.

关键词： underwater acoustic control laminated piezoelectric plate acousticscattering acoustic radiation

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,{2. University of {3. and technology,wuhan 43.074,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

LAMINATED VISCOELASTIC PLATE WITH INCLUSIONS FOR PASSIVE UNDER-WATER ACOUSTIC CONTROL

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Acta Mechanica Solida Sinica 2002年第1期15卷 23-29页

作者： Zhao Hanzhong (department of mechanics,{2. University of {3. and technology,wuhan 43.074,china) department of mechanics Huazhong Univ. of Sci. and Technol. Wuhan 430074 China

The effectiveness of a fluid-loaded sandwiched viscoelastic layerin suppressing acoustic scat- tering and radiation has been estimatedusing the Thomson-Haskell matrix method. The GU (Gaunaurd andUberall) resonance theory has been adopted to handle three types ofviscoelastic substrates with air -filled in- Clusions. The effects ofthe varying thickness of the substrates, the volume fractions of theinclusions and fre- Quencies of incident waves have been studied todetermine the optimal strategies of signal reduction. In theInvestigation, the monopole resonance phenomena of the inclusionshave been taken into account.

关键词： underwater acoustic control laminated viscoelastic plate air-filledinclusion

ACOUSTIC REFLECTION FROM A PERIODIC ELASTIC/PIEZOELECTRIC PLATE

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Acta Mechanica Solida Sinica 2003年第4期16卷 321-326页

作者： Zhao Hanzhong (department of mechanics,{2. University of {3. and technology,wuhan 43.074,china) department of mechanics Huazhong Univ. of Sci./Technology Wuhan 430074 China

The acoustic reflected pressure from a periodic elastic/piezoelectric laminated plate is studied for the purpose of acoustic reflection control.A finite difference/boundary integral procedure to determine the reflected pressure from the fluid-loaded plate is *** the numerical model,a Green's function in the form of infinite sum is employed and a boundary integral is performed to replace the fluid pressure at fluid/solid interface by a continuum of point sources weighted by the normal acceleration of the elastic *** equation system is then solved only in the solid *** is demonstrated that an appropriate applied voltage potential across the piezoelectric layer has the effect of cancelling the fundamental propagating mode,and there,is no reflection for frequencies up to the cut-off frequency of the next propagating mode if the fundamental mode has been eliminated.

关键词： acoustic reflection periodic plate finite difference boundary integral

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 {2.) 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 52.-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

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, china 2. College of Transportation, wuhan University of technology, wuhan 43.063. china 3. department of Mathematics and Physics, Anhui University of science and technology, Huainan 2.2.01, china) department of Control science and Engineering Hua Zhong University of Science and Technology Wuhan 430074 China. College of Transportation Wuhan University of Technology Wuhan 430063 China. department of Mathematics and Physics Anhui University of Science and Technology 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

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 {2. and {3., wuhan 43.074, 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.

GREEN'S FUNCTIONS FOR A 2. ANISOTROPIC MEDIUM WITH A HYPERBOLIC BOUNDARY

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Acta Mechanica Solida Sinica 2000年第1期13卷 17-24页

作者： Hu Yiantai Huang Yuying Chen Chuanyao (department of mechanics,{2. University of {3. and technology,wuhan 43.074,china) huazhong Univ Sci & Technol Dept Mech Wuhan 430074 Peoples R China

By using Stroh's formalism and the conformal mapping technique,this paper derives simple exphcit Green's functions of a piezoelectric anisotropic body with a free or fixed hyperbolic *** corresponding elastic fields in the medium are obtained,*** particular,degenerated solutions of an ex- ternal crack from those of a hyperbolic problem are analysed in *** the singular stress fields and the fracture mechanics parameters are *** solutions obtained are valid not only for plane and antiplane problems but also for the coupled ones between inplane and outplane deformations.

关键词： Stroh's formalism conformal mapping Green's functions external crack stress intensity factors

HOPF BIFURCATION OF A NONLINEAR RESTRAINED CURVED PIPE CONVEYING FLUID BY DIFFERENTIAL QUADRATURE METHOD

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Acta Mechanica Solida Sinica 2003年第4期16卷 345-352页

作者： Wang Lin Ni Qiao Huang Yuying (department of mechanics,{2. University of {3. and technology,wuhan 43.074,china) department of mechanics Huazhong University of Science and Technology Wuhan 430074 China

This paper proposes a new method for investigating the Hopf bifurcation of a curved pipe conveying fluid with nonlinear spring *** nonlinear equation of motion is derived by forces equilibrium on microelement of the system under *** spatial coordinate of the system is discretized by the differential quadrature method and then the dynamic equation is solved by the Newton-Raphson *** numerical solutions show that the inner fluid velocity of the Hopf bifurcation point of the curved pipe varies with different values of the parameter, nonlinear spring *** on this,the cycle and divergent motions are both found to exist at specific fluid flow velocities with a given value of the nonlinear spring *** results are useful for further study of the nonlinear dynamic mechanism of the curved fluid conveying pipe.

关键词： curved fluid conveying pipe Hopf bifurcation nonlinear vibration DQM