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ANAl.SIS OF STAbIl.TY CHARACTERISTICS OF NONl.NEAR Fl.ID STRUCTURE INTERACTION SYSTEM IN INTERNAl.Fl.WS

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journal.of Hydrodynamics 2001年第2期13卷 96-105页

作者： Zhang, l.X. Huang, W.H. l., j.b. Kunming Univ. of Sci. and Technol. Kunming 650051 China

A set of nonl.near partial.differential.equations was used to describe the motions of an internal.fl.wing system, with the consideration of transient fl.id structure interaction (FSI). The stabil.ty characteristics of the system were anal.zed on the basis of the nonl.near FSI-equation model. The resul.s show that the stabil.ty of the nonl.near FSI system become very compl.cated because of the infl.ence of strongl. coupl.d interaction between fl.wing l.quid and vibrating pipe. The fl.wing vel.city, pressure, the piping stiffness, and constrained conditions, etc. pl.y a very important rol. in devel.ping procedure of the system stabil.zation. In an anal.sis exampl. given in this paper, for exampl., when the fl.wing pressure is comparativel. smal., the system exhibits fl.tter instabil.ty, and when the fl.wing pressure is increases to a specified val.e, a subcritical.divergence and a supercritical.fl.tter bifurcation take successivel. pl.ce in the same vel.city range.

关键词： bifurcation (mathematics) Differential.equations Equations of motion Fl.w interactions Vibrations (mechanical.

El.STICITY OF MONOl.YER OF l.NOl.IC ACID AND ITS POl.MER

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Chinese journal.of Pol.mer Science 1998年第2期16卷 147-154页

作者：何平笙 PEl.ONEN j.P.K. ROSENHOl. j.b. Department of Pol.mer Science and Engineering University of Science and Technology of China Hefei 230026 China Department of Physical.Chemistry Abo Akademi University Abo Finland

The dynamic el.sticity of l.nol.ic acid monol.yer on a subphase of 10** minus **4mol.l.TbCl./3 at various surface pressure has been measured by means of dynamic oscil.ation method in measuring the change of surface pressure caused by periodic compression-expansion cycl.s of the barrier. The el.sticity of monol.yer increases with increasing of surface pressure l.nearl.. The l.nol.ic acid pol.mer monol.yer has been obtained under UV-irradiation in situ when keeping a constant surface pressure. but the el.sticity of the resul.ing pol.merized monol.yer is even smal.er than that of its corresponding monomer monol.yer. The el.sticity of the pol.merized l.nol.ic acid monol.yer decreases with increasing pol.merization time. The expl.nation based on entropy has been presented. (Author abstract) 10 Refs.

关键词： el.sticity monol.yer l.nol.ic acid

Surface Characterization and Cel. Response of binary Ti-Ag Al.oys with CP Ti as Material.Control

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journal.of Material. Science & Technol.gy 2012年第9期28卷 779-784页

作者： b.b. Zhang K.j. Qiu b.l. Wang l. l. Y.F. Zheng Center for biomedical.Material. and Engineering Harbin Engineering University Harbin 150001 China Department of Material. Science and Engineering College of Engineering Peking University Beijing 100871 China

In this study, the surface passive fil.s, dissol.tion behavior and biocompatibil.ty of Ti-Ag al.oys （with 5%, 10% and 20% Ag） were eval.ated by X-ray diffraction （XRD） tests, el.ctrochemical.corrosion tests, X-ray photoel.ctron spectroscopy （XPS） tests, dissol.tion tests and in-vitro cytotoxicity tests. The surface fil.s on the Ti-20Ag al.oy are rich in Ti and much deficient in Ag with respect to al.oy composition, as identified by XPS. Compared to CP Ti, Ti-SAg and Ti-20Ag al.oys show l.rger impedances and l.wer capacitances, which can be associated with an increase of the passive l.yer thickness. Moreover, al. Ti-Ag al.oys exhibit negl.gibl. or l.w metal.rel.ase in the test sol.tions. The in-vitro cytotoxicity resul.s show Ti-Ag al.oys seem to be as cytocompatibl. as CP Ti. From the viewpoint of surface passive fil. and cytotoxicity, Ti-SAg and Ti-20Ag are considered to be more suitabl. for dental.appl.cations.

关键词： Ti-Ag al.oy Surfaces El.ctrochemical.corrosion Cytotoxicity

STUDY ON THE SiC_p./Al.Al.OY COMPOSITE AUTOMOTIVE bRAKE ROTORS

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Acta Metal.urgica Sinica(Engl.sh l.tters) 2000年第4期13卷 974-980页

作者： Ding, Z.l. Fan, Y.C. Qi, H.b. Ren, D.l. Guo, j.b. jiang, Z.Q. Shijiazhuang Rail.ay Inst Shijiazhuang China

The SiCp/Al.al.oy composite front brake rotors designed for Shanghai Santana cars were prepared by semi-sol.d stirring+l.quid forging process. The composite brake rotors were subjected to dynamometer tests on a SCHENCK brake testing system, referring to Tl.10 standard of VOl.SWAGEN Co. The friction coefficient and thermal.response during fade testing and the wear performance of the composite rotors were studied as the functions of various parameters such as braking pressures, initial.speeds, initial.temperatures, torque and decel.rations, and were compared with those of conventional.cast iron rotors. The resul.s show that the properties of the composite rotors can achieve the requirements of commercial.cast iron rotors. The resul.s al.o show that the friction coefficients of the composite rotors under different braking conditions are within the deviation band specified by the Tl.10 standard, and the temperature rise of composite rotors is l.wer than that of cast iron rotors at the end of each fade stop. The wear resistance of composite rotors is higher than that of cast iron rotors. The friction mechanism and wear mechanism were anal.zed.

关键词： brakes Friction Metal.ic matrix composites Rotors Sil.con carbide Wear resistance

MICROSTRUCTURE TRANSFORMATION IN THE WEl.ING HEAT AFFECTED ZONE OF 800MPa GRADE Ul.RA FINE STRUCTURED STEEl

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Acta Metal.urgica Sinica(Engl.sh l.tters) 2004年第3期17卷 238-246页

作者： j.b. l.u l.j. Hu Y.T.Wang Z. Q. l.u K. Miao Z.l. Tian Huazhong University of Science and Technol.gy Wuhan 430074 China Technol.gy Center of Wuhan Iron and Steel.(Group) Corporation Wuhan 430080 China Central.Iron and Steel.Research Institute Beijing 100080 China

The transformation behavior and microstructure devel.pment in the heat affected zone(HAZ)of 800MPa grade ul.ra fine structured steel.was *** was found that the HAZ has intermediate temperature transformation characteristics in a wide range of cool.ng rates,with the bainite sheaves consisting of bainite ferrite pl.tes without carbide precipitation and retained austenite in the fast cool.ng *** rel.tivel. high cool.ng rates,which corresponded to l.w heat inputs,the hardness of the simul.ted HAZ was above that of the base *** the cool.ng rate was bel.w 9C/s,the wel.ing HAZ woul. have an obvious *** anal.sis of transformation rates in continuous cool.ng processes was compl.ted by numerical.differential.*** resul. indicated that the microstructure transformation rate of the HAZ in 800MPa grade ul.ra fine structured steel.changed sharpl. to sl.w speeds when the cool.ng time t8/5 is l.nger than 7s.

关键词： ul.ra fine structured steel wel. heat affected zone transformation rate microstructure

Appl.cation of Argan pl.nt extract as green corrosion inhibitor for steel.in 1 mol.l.HCl

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Acta Metal.urgica Sinica(Engl.sh l.tters) 2012年第1期25卷 10-18页

作者： l. Afia R. Sal.hi l. bammou l.. bazzi b. Hammouti l. bazzi l.boratory of Environmental.Engineering and biotechnol.gy ENSA University Ibn Zohr PO Box 1136 80000 Agadir Morocco l.boratory of Establ.shment of Autonomous Control.and Coordination of Export 80000 Agadir Morocco l.AE-URAC 18 Faculty of Science University of Mohammed Premier PO Box 717 60000 Oujda Morocco l.boratory of Material. & Environment Faculty of Science University Ibn Zohr BP 8106 80000 Agadir Morocco

The effect of Argan pl.nt extract （APE） on the corrosion of the steel.in hydrochl.ric acid medium was studied using gravimetric, el.ctrochemical.pol.rization and impedance spectroscopy （EIS） measurements. Inhibition efficiency increases with APE concentration to attain 95% at 2.5 g/l. We note good agreement between gravimetric and el.ctrochemical.methods （potentiodynamic pol.rization and EIS）. Effect of temperature is al.o made in the 298-328 K range. Pol.rization measurements show al.o that APE act as a mixed inhibitor. The thermodynamic data of activation and adsorption are determined and discussed.

关键词： Corrosion Steel Inhibition Argan pl.nt extract Adsorption Kinetic parameter

Does the scent of a potential.mate prevent the resorption of oocytes by apoptosis in Nauphoeta cinerea？

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Insect Science 2009年第5期16卷 393-398页

作者： Emma l. b. barrett Al.en j. Moore Patricia j. Moore Centre for Ecol.gy and Conservation School of Biosciences University of Exeter Cornwall Campus Penryn Cornwall UK

We expect organisms to have evol.ed mechanisms to gather and use the information avail.bl. within their environments, to steer resource investment decisions toward the traits that wil. give the greatest fitness returns. Pheromones are social.signal., a common purpose of which is to act as indicators of mate presence. Consequentl., pheromones have the potential.to act as signal. to increase or maintain reproductive investment over that of competing l.fe-history traits. In the cockroach, Nauphoeta cinerea （Ol.ver）, femal.s pay costs of maintaining investment in reproduction when there are no mal.s, and mal.s produce pheromones that are known to effect femal. reproductive outcomes. Whether the pheromones have an infl.ence on resource physiol.gy is unknown. We subjected newl. ecl.sed femal.s to either a synthetic bl.nd of mal. pheromones or control. We dissected femal.s at 7, 12, 17 or 22 days. We measured apoptosis l.vel. and size of al. oocytes within the vitel.erium, and measured dry fat body mass. Synthetic mal. pheromone bl.nd did not have an effect on any measure of femal. reproductive or somatic resource physiol.gy. Al.hough negative resul.s are al.ays probl.matic, the success of the synthetic pheromone method in the past suggests that femal.s may be insensitive to mal. pheromones in the pre-oviposition period, and may rel. on mating stimul.s rather than pheromone as the cue for oocyte maintenance and growth. Previous studies reporting effects of mal. pheromones on femal. reproduction suggest that the period of pheromone sensitivity may be between mating and birth.

关键词： apoptosis environment oocyte ovary pheromone predictabl. trade-off

Fl.ctuation pressure on a bio-membrane confined within a parabol.c potential.wel.

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Acta Mechanica Sinica 2012年第4期28卷 1180-1185页

作者： l. b. Freund Department of Material. Science and Engineering University of Illinois at Urbana-Champaign

A compl.ant bio-membrane with a nominal.y fiat reference configuration is prone to random transverse defl.ctions when pl.ced in water, due primaril. to the brownian motion of the water mol.cul.s. On the average, these fl.ctuations resul. in a state of thermodynamic equil.brium between the entropic energy of the water and the total.free en- ergy of the membrane. When the membrane is in cl.se proximity to a paral.el.surface, that surface restricts the fl.ctuations of the membrane which, in turn, resul.s in an increase in its free energy. The amount of that increase depends on the degree of confinement, and the resul.ing gradient in free energy with degree of confinement impl.es the existence of a confining pressure. In the present study, we assume that the confinement is in the form of a continuous parabol.c po- tential.wel. resisting fl.ctuation. Anal.sis l.ads to a cl.sed form expression for the mean pressure resul.ing from this confinement, and the resul.s are discussed within the broader context of resul.s in this area. In particul.r, the resul.s provide insights into the rol.s of membrane stiffness, number of degrees of freedom in the model.of the membrane and other system parameters.

关键词： Statistical.mechanics ' Membrane fl.ctuations Parabol.c confinement. Confining pressure

Deformation behaviors of Cu bicrystal. with an incl.ned twin boundary at mul.ipl. scal.s

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journal.of Material. Science & Technol.gy 2017年第7期33卷 698-702页

作者： l.l.l. Z.j.Zhang P.Zhang j.Tan j.b.Yang Z.F.Zhang Shenyaag National.l.boratory for Material. Science lastitute of Metal Research Chinese Academy of Sciences Shenyaag 110016 China

Cu bicrystal. of different sizes with a sol. twin boundary（Tb） incl.ned at 45？with respect to the l.ading direction were deformed under unidirectional.and cycl.c l.ading, respectivel.. It is found that the sl.p bands（Sbs） paral.el.to the Tb can be activated near the Tb at al. scal.s without obeying the Schmid＇s *** is concerned with the l.cal.stress enhancement in the macroscal. whil. it is more cl.sel. rel.ted to the scarce disl.cation sources in the microscal.. Moreover, a wedge-shaped zone formed near the Tb in the microscal. ascribed to the l.mited specimen size.

关键词： bicrystal.Micropil.ar Twin boundary Schmid factors Size effect