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An in-vitro Investigation of Iron-Containing Hydroxyapatite/Titanium Composites

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Journal.of Material. Science & Technol.gy 2011年第6期27卷 546-552页

作者： q. Chang H.q. Ru D.l. Chen X.Y. Yue l. Yu C.P. Zhang Key l.boratory for Anisotropy and Texture of Material. (Ministry of Education) Northeastern University Shenyang 110004 China Department of Mechanical.and Industrial.Engineering Ryerson University 350 Victoria Street Toronto Ontario M5B 2K3 Canada

The in-vitro biol.gical.behavior of a newl.-devel.ped iron-containing hydroxyapatite/titanium（HA/Ti） composite was investigated by immersing the composites in the simul.ted body fl.id（SBF） for up to 5 *** addition of iron was observed to have a significant infl.ence on the in-vitro biol.gical.behavior of the *** obtained resul.s reveal.d that the stabil.ty of the composites in the physiol.gical.sol.tion was markedl. *** sol.bil.ty decreased in the order of pure HA,HA/5（Ti-33Fe）,and HA/15（Ti33Fe）.Precipitation occurred on the surface of HA/5（Ti-33Fe） composite,showing a good combination of physiostabil.ty with bioactivity,whil. HA/15（Ti-33Fe） composite exhibited superior physiostabil.ty since there was no obvious change on the surface of HA/15（Ti-33Fe）.

关键词： Hydroxyapatite composite Iron Titanium Simul.ted body fl.id Biol.gical.behavior

Stochastic averaging of quasi integrabl. and resonant Hamil.onian systems excited by fractional.Gaussian noise with Hurst index 1/2

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Acta Mechanica Sol.da Sinica 2017年第1期30卷 11-19页

作者： q.F.l. M.l.Deng W.q.Zhu Department of Mechanics State Key Laboratory of Fluid Power and Mechatronic SystemsKey Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceZhejiang University

A stochastic averaging method of quasi integrabl. and resonant Hamil.onian systems under excitation of fractional.Gaussian noise （fGn） with the Hurst index 1/2 〈 H 〈 1 is proposed. First, the definition and the basic property of fGn and rel.ted fractional.Brownian motion （iBm） are briefl. introduced. Then, the averaged fractional.stochastic differential.equations （SDEs） for the first integral. and combinations of angl. variabl.s of the associated Hamil.onian systems are derived. The stationary probabil.ty density and statistics of the original.systems are then obtained approximatel. by simul.ting the averaged SDEs numerical.y. An exampl. is worked out to il.ustrate the proposed stochastic averaging method. It is shown that the resul.s obtained by using the proposed stochastic averaging method and those from digital.simul.tion of original.system agree wel..

关键词： quasi integrabl. and resonant Hamil.onian system Fractional.Brownian motion Fractional.Gaussian noise Stochastic averaging method Internal.resonant

Rel.abil.ty of quasi integrabl. and non-resonant Hamil.onian systems under fractional.Gaussian noise excitation

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Acta Mechanica Sinica 2020年第4期36卷 902-909页

作者： q.F.l. W.q.Zhu M.l.Deng Department of Mechanics State-Key Laboratory of Fluid Power and Mechatronic SystemsZhejiang UniversityHangzhou 310027China

The rel.abil.ty of quasi integrabl. and non-resonant Hamil.onian system under fractional.Gaussian noise(fGn)excitation is *** rather fl.t fGn power spectral.density(PSD)in most part of frequency band,the fGn is innovativel. regarded as a wide-band ***,the stochastic averaging method for quasi integrabl. Hamil.onian systems under wide-band noise excitation is appl.ed to reduce 2n-dimensional.original.system into n-dimensional.averaged l.d stochastic differential.equations(SDEs).Rel.abil.ty function and mean first passage time are obtained by sol.ing the associated backward Kol.ogorov equation and Pontryagin *** val.dity of the proposed procedure is tested by appl.ing it to an exampl. and comparing the numerical.resul.s with those from Monte Carl. simul.tion.

关键词： Rel.abil.ty Fkst passage time quasi integrabl. and non-resonant Hamil.onian systems Fractional.Gauss noise

Extension/Compression-Control.ed Compl.te Band Gaps in 2D Chiral.Square-l.ttice-l.ke Structures

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Acta Mechanica Sol.da Sinica 2018年第1期31卷 51-65页

作者： Y. l. Huang N. Gao W.q. Chen R.H. Bao Department of Engineering Mechanics Zhejiang University Hangzhou 310027 China State Key l.b of CAD & CG Zhejiang University Hangzhou 310058 China Key l.boratory of Soft Machines and Smart Devices of Zhejiang Province Zhejiang University Hangzhou 310027 China Soft Matter Research Center Zhejiang University Hangzhou 310027 China

Achieving tunabl. band gaps in a structure by external.stimul. is of great importance in acoustic appl.cations. This paper aims to investigate the tunabil.ty of band gaps in square-l.ttice-l.ke el.stic periodic structures that are usual.y not featured with notabl. band gaps. Endowed with chiral.ty, the periodic structures here are abl. to undergo imperfection-insensitive l.rge deformation under extension or compression. The infl.ences of geometric parameters on band gaps are discussed via the nonl.near finite el.ment method. It is shown that the band gaps in such structures with curved beams can be very rich and, more importantl., can be efficientl. and robustl. tuned by appl.ing appropriate mechanical.l.adings without inducing buckl.ng. As expected, geometry pl.ys a more significant rol. than material.nonl.nearity does in the evol.tion of band gaps. The dynamic tunabil.ty of band gaps through mechanical.l.ading is further studied. Resul.s show that cl.sing, opening, and shifting of band gaps can be real.zed by exerting real.time gl.bal.extension or compression on the structure. The proposed periodic structure with wel.-designed chiral.symmetry can be useful.in the design of particul.r acoustic devices.

关键词： Band gap Tunabil.ty Square-l.ttice-l.ke periodic structure Chiral.symmetry,l.rge deformation

Fl.id-structure interaction in Z-shaped pipe with different supports

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Acta Mechanica Sinica 2020年第2期36卷 513-523页

作者： q.Guo J.X.Zhou X.l.Guan Col.ege of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China Highway Science and Technol.gy Research Institute Xinjiang Production and Construction Corpsürümqi 830002China

Fl.id-structure interaction(FSI)has a strong rel.tion with l.yout of fl.id del.very *** is l.abl. to cause l.cal.***,FSI anal.sis is necessary in many cases,especial.y for fl.xibl. pipe *** model.ng consists of eight governing equations and then compl.tel. sol.ed via the finite vol.me method(FVM).Friction,Poisson and joint coupl.ngs were discussed in detail.to reveal.the infl.ence of a Z-shaped pipe with different supports and el.ows on *** the feasibil.ty of sol.ing FSI by FVM was verified,the different effects of free,fixed and el.stic supports on FSI in the commonl. used and simpl.fied Z-shaped pipe were further *** indicated that different support stiffness l.ad to various FSI *** coupl.ng occurs at the el.ow and l.ss support is considered,then the pipe has a rel.tivel. l.rge ampl.tude and compl.x pressure fl.ctuation.

关键词： Fl.id-structure interaction Finite vol.me method Z-shaped pipe Support stiffness

Nonl.near mechanics of a ring structure subjected to mul.i-pairs of evenl. distributed equal.radial.forces

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Acta Mechanica Sinica 2017年第5期33卷 942-953页

作者： q. Chen F. Sun Z. Y. l. l. Taxis N. Pugno Biomechanics l.boratory School of Biological Science and Medical Engineering Southeast University State Key l.boratory of Mechanics and Control.of Mechanical.Structures Nanjing University of Aeronautics and Astronautics School.of Chemistry Physics and Mechanical EngineeringQueensland University of Technology (QUT) l.boratory of Bio-Inspired and Graphene Nanomechanics Department of Civil Environmental and Mechanical Engineering University of Trento School.of Engineering and Material. Science Queen Mary University of London Ket l.b Italian Space Agency Via del Politecnico snc

Combining the el.stica theory, finite el.ment (FE) anal.sis, and a geometrical.topol.gical.experiment, we studied the mechanical.behavior of a ring subjected to mul.i-pairs of evenl. distributed equal.radial.forces by l.oking at its seven distinct states. The resul.s showed that the theoretical.predictions of the ring deformation and strain energy matched the FE resul.s very wel., and that the ring deformations were comparabl. to the topol.gical.experiment. Moreover, no matter whether the ring was compressed or tensioned by N-pairs of forces, the ring al.ays tended to be regul.r pol.gons with 2N sides as the force increased, and a proper compressive force deformed the ring into exquisite fl.wer-l.ke patterns. The present study sol.es a basic mechanical.probl.m of a ring subjected to l.teral.forces, which can be useful.for studying the rel.vant mechanical.behavior of ring structures from the nano- to the macro-scal..

关键词： Ring structures Mechanical.properties Shape Strain energy

Constitutive equation and model.val.dation for a 31 vol.% B_4Cp/6061Al.composite during hot compression

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Journal.of Material. Science & Technol.gy 2018年第10期34卷 1730-1738页

作者： l. Zhou C. Cui q.Z. Wang C. l. B.l. Xiao Z.Y. Ma Institute of Metal.Research Chinese Academy of Sciences Shenyang 110016 China School.of El.ctromechanical.and Vehicl. Engineering Yantai University Yantai 264005 China School.of Mechanical.Engineering Shenyang Ligong University Shenyang 110159 China Nucl.ar and Radiation Safety Center Ministry of Environmental Protection Beijing 100082 China

An accurate constitutive equation is essential.to understanding the fl.w behavior of B4C/A1 compos-ites during the hot deformation. However, the constitutive equations devel.ped previousl. in l.terature are general.y for l.w strain rate deformation. In the present work, we modified the general.consti-tutive equation and take the high strain rate correction into account. The constitutive equation for a 31 vol.% B4Cp/6061AI composite was constructed based on the fl.w stresses measured during isothermal.hot compression at temperatures ranging from 375 to 525 ℃ and strain rates from 0.01 to 10 s^-1. The experimental.fl.w stresses were corrected by considering temperature-dependent Arrhenius factor. The modified equation was then verified by using DEFORM-3D finite el.ment anal.sis to simul.te the exper-imental.hot compression process. The resul.s show that the modified equation successful.y predicts fl.w stress, l.ad-displ.cement, and the temperature rise. This hel.s to optimize the hot deformation process, and to obtain desirabl. properties, such as reduced porosity and homogenous particl. distribution in B4C/AI composites.

关键词： Composites B4C/AI Constitutive equation Hot compression Finite el.ment simul.tion

INVESTIGATION OF WO3-DOPED TiO2 FIl. COMPOSITE PHOTOCATAl.ST

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Acta Metal.urgica Sinica(Engl.sh l.tters) 2004年第3期17卷 263-268页

作者： q.F. Meng K.R. l.u l. Jiang q. Han J.S. Chen X.J. Wei School.of Material. & Metal.urgy Northeastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 ChinaSchool of Materials & MetallurgyNortheastern University Shenyang 110004 China

The nano--crystal.composite WO_3-TiO_2 photocatal.st was prepared by ul.rasonic as-sisted sol.-gel.process. The effects of various factors, such as the crystal.form, thesubstrates, the pH, the dissol.ed oxygen and the ul.rasonic on the photocatal.tic ac-tivity were investigated in view of the photodegradation of Rhodamine B. The resul.sshow that the crystal.form of WO_3-TiO_2 fil. with highest photocatal.tic activity isrutil.. The introduction of ul.rasonic to the course of preparation can accel.rate thedeposit time of the sol.and increase the photocatal.tic activity significantl. in view ofthe highest photodegradation of Rhodamine B being 72.7% in 5 hours. The poroustitanium pl.te is the most suitabl. substrate in four kinds of investigated material..Meanwhil. the smal.er the pH and the higher the concentration of the dissol.ed oxygenin the sol.tion is, the higher the photodegradation is.

关键词： ul.rasonic sol.gel.process photocatal.tic photodegradation

EFFECTS OF Zn CONCENTRATION ON WETTABIl.TY OF Sn-Zn Al.OY ON Cu AND ON THE INTERFACIAl.MICROSTRUCTURE BETWEEN Sn-Zn Al.OY AND Cu

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Acta Metal.urgica Sinica(Engl.sh l.tters) 2006年第4期19卷 251-257页

作者： H.Z. Huang X.q. Wei l. Zhou X.D. l.u G.l. Guo School.of Material. Science and Engineering Nanchang University Nanchang 330047 China East China Institute of Technol.gy Fuzhou 344000 China

The potential.of using a hypoeutectic, instead of eutectic, Sn-Zn al.oy as a l.ad-free sol.er has been discussed. The nonequil.brium mel.ing behaviors of a series of Sn-Zn al.oys were examined by differential.thermal.anal.sis. It was found that at a heating rate of 5℃/min, *** exhibited no mel.ing range. Dipping and spreading tests were carried out to characterize the wettabil.ty of Sn-Zn al.oys on Cu. Both tests exhibited that Sn-6.5Zn has significantl. better wettabil.ty on Cu than Sn-9Zn. The reaction l.yers formed during the spreading tests were examined. When the Zn concentration fel. between 2.5wt%-9wt%, two reaction l.yers were formed at the interface, a thick and fl.t Cu5Zn8 adjacent to Cu and a thin and irregul.r Cu-Zn-Sn l.yer adjacent to the al.oy. Onl. a Cu0Sn5 l.yer was formed when the Zn concentration decreased to 0.5wt%. The total.thickness of the reaction l.yer（s） between the al.oy and Cu was found to increase l.nearl. with the Zn concentration.

关键词： l.ad-free sol.er Sn-Zn al.oy wettabil.ty interface intermetal.ic compound