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CHAOTIC　ANALYsIs　OF　sUBHArMONIC　rEsONANT　WAVEs　IN　UNDAMPED　AND　DAMPED　sTrINGs

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Journal of Hydrodynamics 1995年第1期7卷 92-104页

作者： Albert C. J. Luo, ray P. s. Han (department of mechanical & Industrial engineering,university of Manitoba,Winnipeg,Manitoba r3T 2N2, Canada)Xiang Yu-min(department of Physics ,sichuan Instutue of Industry and Chemical Technology,Zigong,sichuan 643033, P. Univ of Manitoba Winnipeg Canada

The chaotic phenomena of subharmonic resonant waves in undamped and damped strings are investigated in this paper. The model consists of a constant-tension, stretched string whose partial differential equation is derived by taking into account its exact configuration. simplification via a Taylor series expansion of the curvature term and then employing the Galerkin method, an ordinary differential equation for the nonlinear dyamics is obtained. For the undamped case, we can formulate the Hamiltonian energy form of the conservative string, under the influence of an external periodic excitation. This permits the subharmonic resonant condition for this system to be derived. We truncate the resulting infinite number of subharmonic resonant waves to just two waves by renormalizing the Hamiltonian energy function near the subharmonic resonant orbit of the system. Adopting the renormalization group technique for the nit6raction of the two subharmonic resonant waves, an approximate chaotic condition associated with the subharmonic resonance of this system is determined. For the case fo the damped string, the minimum condition for the bifurcation of the subharmonic resonant wave is computed using the incremental energy balance method. For model verification, we carried out numerical simulations and they show good agreement with our analytical results.

关键词： chaos subharmonic resonant waves undamped and damped strings,incremental energy balance method renormalization group technique.

Phytoestrogen genistein decreases contractile response of aortic artery in vitro and arterial blood pressure in vivo

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Acta Pharmacologica sinica 2004年第3期25卷 59-64页

作者： Hong-fang LI1,Long-de WANG2,song-yi QU department of Physiology,Lanzhou Medical college,Lanzhou 730000 2Affiliated Hospital,Gansu Chinese Medical college,Lanzhou 730020,China department of Physiology Lanzhou Medical College Affiliated Hospital Gansu Chinese Medical College

AIM: To determine the mechanisms of effects of phytoestrogen genistein on the contracted rabbit aortic arteries in vitro, and observe the effect of genistein and 17-β estradiol on mean arterial pressure (MAP) in ovariectomized (OVX) rats. METHODs: (1) strips of rabbit aortic smooth muscle were suspended in organ baths containing Kreb’s solution, and then isometric tension was measured. (2) Female mature Wistar rats underwent a bilateral ovariectomy (OVX). sham-operated rats (sHAM) were used as controls. After administration of genistein (0.4 mg·kg-1·d-1, sc), 17-β estradiol (1 mg·kg-1·d-1, sc) or theirvehicle sesame oil for 21 d,MAP was measured. rEsULTs: (1) similar to 17-β estradiol, genistein could dose-dependently relax 40 mmol/L KCl-precontracted arterial strips. Incubation with Nω-L-nitro-arginine (L-NNA), methylene blue (MB), indomethacin, propranolol or endothelium removal did not affect relaxation induced by genistein. In calcium-free solution containing 0.01mmol/L egtazic acid (EGTA), genistein inhibited not only the first phase contraction induced by noradrenaline (NA), but also the second contraction induced by CaCl2. In addition, genistein could reduce the contractile responses of NA, KCl and CaCl2, and shift their cumulative concentration-response curves rightward. (2) MAP in OVX rats was significantlyhigher compared with that of sHAM rats. However,after chronically treatment with genistein or 17-β estradiol for 21 d the baseline MAP in OVX rats was reduced significantly. CONCLUsIONs: (1) The vasodilator effect of genistein in vitro is endothelium independent and not related to the nitric oxide, its mechanisms being probably due to inhibition of Ca2+ influx through calcium channels in a noncompetitive manner and Ca2+ release from intracellular store induced by NA. (2) Administration of genistein or 17-β estradiol can chronically decrease MAP in OVX rats.

关键词： genistein aorta smooth muscle muscle relaxation calciumchannel vascular endothelium blood pressure

Effect of Interface on mechanical Property of steel-mushy Al-20sn Bonding Plate

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Journal of Wuhan university of Technology(Materials science) 2006年第1期21卷 60-62页

作者：张鹏 department of mechanical engineering Beijing Jiaotong University Beijing 100044 China

The ratio of Fe-Al compound at interace, which could determine the quarttity of Fe-Al compound at the interace of steel-mushy Al- 20 sn bonding plate, was used to characterize the interfacial structure of steel-mushy Al-20 sn bonding plate quantitatively. The effect of ratio of Fe-Al compound at interface on interacial shear strength was investigated perfectly. The results show that the relationship between ratio of Fe-Al compound at interace and interfacial shear strength is s = 3.3 ＋ 1.91 t - 0.0135t^2 （ where t is ratio of Fe-Al compound at in- terface and s is interfacial shear strength ）. When the ratio of Fe-Al compound at interface is 71%, the largest interfacial shear strength 70.9 MPa is got. This reasonable ratio of Fe-Al compound at interface is a quarttitative criterion of interfacial embrittlement. When the ratio of Fe-Al compound at interface is higher than 71% , interfacial embrittlement will occur.

关键词： interfacial structure ratio of Fe-Al compound at interface interfacial shear strength

Preparation and Gas Permeation of supported γ-Al_2O_3 Membranes Used as substrate Layer for Microporous Membranes

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Journal of Wuhan university of Technology(Materials science) 2005年第3期20卷 27-30页

作者：韦奇 department of Materials science & engineering University of Science & Technology of China college of Materials science & engineering Beijing University of Technology Beijing 100022China

γ-Al2O3 membranes were successfidly deposited on the top of porous α-Al2O3 support by sol-gel process and characterized by means of XrD , sEM, N2 adsorption and gas permeation. The γ-Al2O3 membranes, free of pin-holes and cracks, adhere tightly to the supports and have a thlekness of about 7μm. When sintered at 400 ℃ , γ-Al2O3 membranes have a rutrrow pore size distribution, with a pore diameter of 3.6nm, and the transport of both H2 and CO2 in supported γ-Al2O3 membrane is governed by Knudsen mechanism, with H2 permeance of 3.3× 10^-6 molm^-2Pa^-1s^-1 and H2/ CO2 permselectivity close to the ideal Knudsen value at 50 ℃ . The γ-Al2O3 membranes are suitable for being used as the substrates of microparoas membranes .

关键词： supported γ-Al2O3 membranes hydrogen separation gas transport

structure and Pozzolanic Activity of Calcined Coal Gangue during the Process of mechanical Activation

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Journal of Wuhan university of Technology(Materials science) 2009年第2期24卷 326-329页

作者：郭伟 department of Material engineering Yancheng Institute of Technology Institute of Material science and engineering Nanjing University of Technology

On the basis of analyzing coal gangue＇s chemical and mineral compositions, the structure change of coal gangue during the mechanical activation was investigated by XrD, FTIr, NMr, and the mechanical strength of the cement doped coal gangue with various specific surface area was tested. The experimental results indicate that, the lattice structure of metakaolin in coal gangue samples calcined at 700 ℃ disorganizes gradually and becomes disordered, and the lattice structure of α-quartz is distorted slightly. The pozzolanic activity of the coal gangue increases obviously with its structural disorganization.

关键词： coal gangue mechanical activation structure NMr tetrahedron

CErAMIC MATrIX COMPOsITE sYNTHEsIZED BY THE PUrE Al+NaOH sELF-OXIDATION

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Acta Metallurgica sinica(English Letters) 2001年第4期14卷 296-302页

作者： s.X. He1), s. Yuan2), J. Wang1) and B.D. sun1) 1) department of Marterials science and engineering, shanghai Jiao Tong university, shanghai 200030, China 2) department of Marterials science and Engineerin Dept. of Mat. sci. Shanghai Jiaotong Univ. Shanghai 200030 China

An Al2O3 ceramic matrix composite was fabricated by self-oxidation of pure Al+NaOH, and its microstructure, mechanical properties and growth mechanism were analyzed. Experimental results show that the composite possesses better mechanical properties, higher density and faster growth velocity than that made of Al-Mg-si alloy. The composite grows primarily along the crucible wall and its microstructure is characterized by a periodic wavy like structure.

关键词： Aluminum Caustic soda Oxidation synthesis (chemical)

Adsorptive desulfurization on a heteroatoms Y zeolite prepared by secondary synthesis

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science China Chemistry 2010年第1期53卷 281-286页

作者： TANG Ke1,HONG Xin1,ZHAO YongHua1,sONG LiJuan2 & sUN ZhaoLin2 1school of Material and Chemical engineering,Liaoning Institute of Technology,Jinzhou 121001,China 2college of Petrochemical engineering,Liaoning university of Petroleum & Chemical Technology,Fushun 113001,China 1. school of Material and Chemical engineering Liaoning Institute of Technology Jinzhou 121001 China2. College of Petrochemical Engineering Liaoning University of Petroleum & Chemical Technology Fushun 113001 China

Gallium atoms have been introduced into the framework of Y zeolite by treating the zeolite with an aqueous solution of ammonium hexafluoro *** of various model fuels containing about 500 μg/g sulfur has been studied over the synthesized Y zeolite(GaAlY).The sulfur adsorption capacity is 7.0,17.4,14.5,16.9,6.9 and 5.8 mg(s)/g adsorbent for thiophene,tetrahydrothiophene(THT),4,6-dimethyldibenzothiophene(4,6-DMDBT),dibenzophiophene(DBT),benzothiophene(BT) and 4-methyldibenzothiophene(4-MDBT),*** charges on the s atom in thiophene,THT,4,6DMDBT,DBT,BT and 4-MDBT,calculated using the density functional theory(DFT),are-0.159,-0.298,-0.214,-0.211,-0.193 and-0.188,respectively,implying that the s-M bond between the adsorption sites and thiophene is much weaker than that between the adsorption sites and THT,4,6-DMDBT or *** sulfur removal of FCC gasoline on GaAlY is 68%.

关键词： isomorphous substitution DFT model fuels adsorptive desulfurization

Taurine Inhibits Myocardial Fibrosis via PKC-ErK1/2 signaling Pathways

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Chemical research in Chinese Universities 2012年第1期28卷 84-90页

作者： WANG Li-ying1,2, LI Hong1 and YANG shi-jie1 1. department of Pharmacology, Norman Bethune college of Medicine, Jilin university, Changchun 130021, P. r. China 2. department of Physiology, Basic Medicine college, Beihua university, Jilin 132013, P. r. China Jilin Univ Norman Bethune Coll Med Dept Pharmacol Changchun 130021 Peoples R China Beihua Univ Basic Med Coll Dept Physiol Jilin 132013 Jilin Peoples R China

Previous studies have demonstrated the important role of taurine in inhibiting proliferation of myofibrob lasts（myoFb） and myocardial fibrosis. However, the underlying mechanisms are unclear. The present study was de signed to shed light on this issue through exploring the signal pathways via in vitro experiments. Angiotension II （AngII） treatment significantly increased myoFb proliferation and the levels of collagens I and III（P〈0.05）, whereas taurine, PKCα（PKC： protein kinase C） specific inhibitor L-threo-dihydro-sphingosine（D4681）, ErK1/2 inhibitor （PD98095） abrogated myoFb proliferation and collagen levels（P〈0.05, P〈0.01, respectively）, and increased the G0/G1 phase rate and decreased s phase rate. Immunocytochemistry, confocal fluorescence staining and image analy sis showed that taurine could inhibit the translocation and expression of p-PKCαin membrane, and then inhibit nuc lear translocation and expression of p-ErK1/2. These results have statistically significant differences compared with those of AngII group（P〈0.01）. Western blot results also show that taurine could inhibit the protein expression of p-PKCα and p-ErK1/2. We used p-PKCα specific inhibitor D4681 in order to elucidate the relationship between p-PKCα and p-ErK1/2 in signal transduction pathways. Finally, the results show that the protein expression of p-ErK1/2 and nuclear translocation were suppressed in D4681 group.

关键词： Taurine Myocardial fibrosis Proliferation signal transduction Cardiac remodeling

Torque model of hydro turbine with inner energy loss characteristics

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science China(Technological sciences) 2010年第10期53卷 2826-2832页

作者： ZENG Yun1,2, GUO YaKun2, ZHANG LiXiang1, XU TianMao3 & DONG HongKui4 1 Construction engineering college, Kunming university of science and Technology, Kunming 650051, China 2 school of engineering, university of Aberdeen, Aberdeen AB24 3UE, uk 3 Computing Center, Kunming university of science and Technology, Kunming 650051, China 4 Hydraulic Energy department, Yunnan Electric Power Test and research Institute, Kunming 650217, China 1. Construction engineering college Kunming University of Science and Technology Kunming 650051 China2. School of Engineering University of Aberdeen Aberdeen AB24 3UE UK3. Computing Center Kunming University of Science and Technology Kunming 650051 China4. Hydraulic Energy Department Yunnan Electric Power Test and Research Institute Kunming 650217 China

This paper presents the result and analysis of the composition of energy loss occurring in the hydro turbine. Two new types of energy losses,namely the hydraulic loss in the flow channel and the impact loss,are defined. All losses within the hydro turbine are divided into four types and the loss coefficients are defined accordingly. Expressions or characteristic descriptions of these losses as well as the calibration method of the loss coefficients are presented. Furthermore,the torque model of the hydro turbine where the inner energy loss takes place is established. The developed model has been used to calculate the power loss due to the mechanical friction generated by the units’ rotation to solve the difficulty of measurements of the mechanical friction loss in the hydro turbine. The definition of the impact loss explains the phenomenon that the loss of no-load is greater than that of the rated operation. A set of conversion coefficients are defined using the characteristic parameters at the rated operation,which are used to transform the parameters in the torque model into those that are easily measured. Therefore,the expression of the hydro turbine power is converted into a function that has the main servomotor displacement as its single variable. This makes the proposed model be convenient to use. Finally,the proposed model and methods are calibrated and verified using the measured data of a hydropower plant. Good agreement between the modeled results and the measurements indicates that the proposed model can represent the inner energy loss characteristics of the hydro turbine.

关键词： hydraulic loss in flow channel impact loss loss coefficients conversion coefficients