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Analysis on cohesive crack opening displacement considering the strain softening effect

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science china(Physics,{2. & Astronomy) 2006年第1期49卷 88-101页

作者： WANG Limin1, XU Shilang2.& ZHAO Xiqiang3.1. mechanics department, Shandong {2. of technology, Zibo 2.5049, china 2. Civil Engineering department, Dalian {2. of technology, Dalian 11602., china 3. Mathematics department, Ocean {2. of china, Qingdao 2.6071, china mechanics department Shandong University of Technology Zibo China Civil Engineering department Dalian University of Technology Dalian China Mathematics department Ocean University of China Qingdao China

In order to investigate the crack propagation in quasi-brittle materials like rock, ceramic and concrete, Hillerborg and his co-researchers abstracted the fracture process zone in front of a stress free crack in terms of a “fictitious crack zone”. On the fictitious crack zone, cohesive stresses distribute following a given softening relationship of stress vs. crack opening. Based on the polynomial or power series expression of cohesive crack opening displacement, the relationship of the cohesive stress vs. the crack opening displacement is established using elastic theory and integral equation, and some unknown physics variables are obtained using variation approach. The calculation results gained in this paper are close to the experimentally test ones.

关键词： cohesive crack, softening, dissipation work, variation approach.

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.,Wuhan {3.,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.,Wuhan {3.,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.,Wuhan {3.,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.,Wuhan {3.,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 {2. of science and technology, Wuhan 43.074, china 2. College of Transportation, Wuhan {2. of technology, Wuhan 43.063. china 3. department of Mathematics and Physics, Anhui {2. of science and technology, Huainan 2.2.01, china) 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

Passive sensitization increases histamine-stimulated calcium signaling and NF-κB transcription activity in bronchial epithelial cells

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Acta Pharmacologica Sinica 2006年第6期27卷 708-714页

作者： Si JIN~(2.5)Dan TIAN~3.Jian-guo CHEN~4 Li-ping ZHU~2.Sheng-yuan LIU~2.Di-xun WANG~2.2.department of Pathophysiology,Tongji Medical College,huazhong university of science and technology Key Laboratory of Pulmonary Disease of Ministry of Health of {2.,Wuhan 43.03.,{2. 3.department of Pathology,Tongji Medical College.huazhong university of science and technology.Wuhan 43.03.,{2. 4 department of Pharmacology,Tongji Medical College,huazhong university of science and technology,Wuhan 43.03.,{2. department of Pathophysiology Tongji Medical College Huazhong University of Science and Technology Key Laboratory of Pulmonary Disease of Ministry of Health of china Wuhan China department of Pathology Tongji Medical College Huazhong University of Science and Technology Wuhan China department of Pharmacology Tongji Medical College Huazhong University of Science and Technology Wuhan China

Aim:To find out if the two aspects of asthma（chronic airway inflammation andbronchial hyperresponsiveness）are related to hypersensitivity of calcium signal-ing in bronchial epithelial ***:Porcine bronchial epithelial cells（PBEC）were divided into sensitized（S）and nonsesitized（N）*** group S,the cellswere preincubated with serum from ovalbumin sensitized guinea *** group N,the cells were preincubated with serum from nonsensitized guinea *** calcium imaging and ELISA-based NF-κ3.activity were used to evaluate thehistamine-stimulated intracellular free calcium level and NF-κB activity,***:First,0.1μmol/L histamine could induce [Ca2.]ioscillationsin PBEC of group S,but not in group ***,1/Jmol/L histamine could induce[Ca2.]ioscillations of PBEC in both group S and group *** [Ca2.]ioscillationfrequency of PBEC was significantly higher in group S than in group N,thoughthe[Ca2.]ioscillation amplitude showed no difference between the two ***,when 10 μmol/L histamine was used to stimulate PBEC a transient initialincrease followed by a sustained elevation（FSE）of [Ca2.]iwas observed in PBECin both *** amplitude of the FSE of [Ca2.]iin PBEC was significantlyhigher in group S than in group *** subsequent NF-κB activity was in accor-dance to the calcium oscillation frequency evoked by histamine,but not to ***:It was suggested that the increased sensitivity of calciumsignaling in bronchial epithelial cells might contribute to the exorbitant inflamma-tion or increased susceptibility in asthmatic airway epithelial cells.

关键词： asthma histamine calcium signaling bronchi epithelial cell nuclear factor of kappaB

Inhibition of ethanol-induced toxicity by tanshinone ⅡA in PC12.cells

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Acta Pharmacologica Sinica 2006年第6期27卷 659-664页

作者： Xian-fang MENG~2.Xiao-jing ZOU~3.Bin PENG~2.Jing SHI~2.Xin-min GUAN~2.Chun ZHANG~(4,5)2.department of Neurobiology,Tongji Medical College,huazhong university of science and technology,Wuhan 43.03.,{2. 3.department of Anesthesiology,4 department of Nephrology,Union Hospital,Tongji Medical College,huazhong university of science and technology,Wuhan 43.02..{2. department of Neurobiology Tongji Medical College Huazhong University of Science and Technology Wuhan China department of Anesthesiology Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China department of Nephrology Union Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China

Aim:To observe the effects of tanshinone IIA(Tan IIA)on the neurotoxicityinduced by ethanol in PC 12.cells and to explore its protective ***:PC 12.ell survival was measured by MTT *** formation of reactive oxygenspecies(ROS)and lactate dehydrogenase(LDH)release were detected by 2.,7′-dichlorofluorescin(DCF)fluorescence and calorimetric method,*** of cell apoptosis was monitored by flow *** expression ofp53.was detected by immuno-fluorescence and flow ***:Ethanolsignificantly impaired the survival of PC12.cells as demonstrated by MTT *** also induced significant ROS formation and increased LDH ***-incubation with Tan IIA in the culture medium significantly reversed these *** caused cell apoptosis and the upregulation of p53.*** anti-apoptosis effects of Tan IIA on ethanol-induced toxicity were accompanied by thedownregulation of pro-apoptotic p53.protein ***:Tan IIAcan protect neurons from apoptosis and might serve as a potential therapeuticdrug for neurological disorders induced by ethanol.

关键词： apoptosis ethanol PC12.cells p53 tanshinone ⅡA