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简介：Inthepresentwork,aparametricnumericalstudyisconductedinordertoassesstheeffectofairfoilcamberingontheaerodynamicperformanceofrigidheavingairfoils.TheincompressibleNavier-Stokesequationsaresolvedintheirvelocity-pressureformulationusingasecond-orderaccurateinspaceandtimefinite-differencescheme.Totackletheproblemofmovingboundaries,thegoverningequationsaresolvedonoverlappingstructuredgrids.ThenumericalsimulationsareperformedataReynoldsnumberofRe=1100andatdifferentvaluesofStrouhalnumberandreducedfrequency.Theresultsobtainedshowthattheairfoilcamberinggeometricparameterhasastronginfluenceontheaverageliftcoefficient,whileithasasmallerimpactontheaveragethrustcoefficientandpropulsiveefficiencyofheavingairfoils.

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简介：Inthispaper,astructuralanalysisisperformedtogaininsightsonthesynergisticmechanicalamplificationeffectthatCampaniformsensillahavewhencombinedinanarrayconfiguration.Inordertosimplifytheanalysisperformedinthispreliminaryinvestigation,anarrayoffourholesinasingleorthotropiclaminaisconsidered.Firstly,aFiniteElementMethod(FEM)analysisisperformedtodiscretelyassesstheinfluencethatdifferentgeometricalparametershaveonthemechanicalamplificationpropertiesofthearray.Secondly,anartificialneuralnetworkisusedtoobtainanapproximatedmulti-dimensionalcontinuousfunction,whichmodelstherelationshipbetweenthegeometricalparametersandtheamplificationpropertiesofthearray.Thirdly,anoptimizationisperformedtoidentifythegeometricalparametersyieldingthemaximummechanicalamplification.Finally,resultsarevalidatedwithanadditionalFEMsimulationperformedbyvaryinggeometricalparametersintheneighborhoodoftheidentifiedoptimalparameters.ThemethodproposedinthispapercanbefullyautomatedandusedtosolveawiderangeofoptimizationproblemsaimedatidentifyingoptimalconfigurationsofstrainsensorsinspiredbyCampaniformsensilla.

简介：Poly(vinylalcohol)(PVA)/hydroxyapatite(HA)compositehydrogelspecimenswerepreparedwith15%PVAand1%,2%,3%,4%and5%HAbyrepeatedfreezing-thawing.ThetestsofstaticanddynamicmechanicalpropertieswerecarriedouttodiscusstheinfluenceofdifferentcontentsofHAandfreezing-thawingcyclesonthemechanicalpropertiesofPVA/HAcompositehydrogel.TheresultsofstaticmechanicaltestsshowedthatthePVA/HAcompositehydrogelwith3%HAandninefreezing-thawingcycleshadexcellentstressrelaxationproperties,higherrelaxationratio,lowerstressequilibriumvalueandpresentedbetterpropertiesofcreepandrecovery.TheresultsofdynamicmechanicaltestshowedthatthePVA/HAcompositehydrogelwithninefreezing-thawingcycleshadhigherstoragemodulusandlossmodulus,sowasthePVA/HAcompositehydrogelwith3%HA.

简介：Inthispaperweinvestigatedhowtherunningspeedwouldaffectthedynamicsofbodypitching,andwhetherbodyinertiaisimportantforanimals.Passivetrottingofspring-massmodelandpassiveboundingofspring-beammodelwerestudiedatdifferentspeedsfordifferentsetsofbodyparametersrespectively.Furthermore,differentbodyinertiaswereusedinbounding.Wefoundthatrunningspeedexertseffectonlegperformancebymeansofcentrifugalforce.Thecentrifugalforcecanbeunderstoodasanenhancementtothenaturalfrequencyofthespring-masssystem.Thedisadvantageofbodypitchingmaybeoffsetbythegreatincreaseincentrifugalforceathighspeed.Theresultsalsorevealthatbodymassdistributionmightnotbethemainreasonforthedifferenceinmaximalrunningspeedsofdifferentanimals.

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简介：Thispaperaddressesthedesignofabiomimeticfishrobotactuatedbypiezoceramicactuatorsandtheeffectofartificialcaudalfinsonthefishrobot'sperformance.Thelimitedbendingdisplacementproducedbyalightweightpiezocompositeactuatorwasamplifiedandtransformedintoalargetailbeatmotionbymeansofalinkagesystem.Caudalfinsthatmimictheshapeofamackerelfinwerefabricatedforthepurposeofexaminingtheeffectofcaudalfincharacteristicsonthrustpro-ductionatanoperatingfrequencyrange.Thethicknessdistributionofarealmackerel'sfinwasmeasuredandusedtodesignartificialcaudalfins.ThethrustperformanceofthebiomimeticfishrobotpropelledbyfinsofvariousthicknesseswasexaminedintermsoftheStrouhalnumber,theFroudenumber,theReynoldsnumber,andthepowerconsumption.Forthesamefinareaandaspectratio,anartificialcaudalfinwithadistributedthicknessshowsthebestforwardspeedandtheleastpowercon-sumption.

简介：Biomimeticsurfaceisaneffectivewaystopromotetheperformancegradeandappliedrangeofmaterialswithoutalteringtheirsubstrate.Manyimprovedpropertiessuchasresistingfatigue,enduringwear,etc,havebeenachievedbyapplyingbiomimeticmorphologyorstructuretosomeengineeringmaterialsurfaces.Inthispaper,aimingtorevealtherelationshipbetweenthermalcrackingbehaviorandmechanicalpropertiesofengineeringmaterialswithbiomimeticsurface,biomimeticspecimenswerefabricatedusinglasertechniquebyimitatingtheheterogeneousstructureonthesurfaceofplantleaves.TheeffectofthermalfatiguecyclingonthetensilepropertiesofH13diesteelspecimenswithdifferentsurfaces(severaltypesofbiomimeticsurfacesandasmoothsurface)wascomparedandinvestigated.Asaresult,duetothecouplingeffectsofthemorphologicalfeaturesonthesurfaceandthemicrostructurecharacteristicswithinunitzone,thesespecimenswithbiomimeticsurfaceexhibitremarkablyenhancedUltimateTensileStrength(UTS)and0.2%YieldStrength(YS)comparedwithreferencespecimenswhilecorrespondingductilityremainslargelyunaffectedevenheightened,whetherthethermalfatigueloadsornot.Therelativemechanismsleadingtotheseimprovementshavebeendiscussed.

简介：ThispaperreportstheadsorptionofBovineSerumAlbumin(BSA)ontoDielectricBarrierDischarge(DBD)processedPoly(methylmethacrylate)(PMMA)surfacesbyaQuartzCrystalMicrobalancewithDissipationmonitoring(QCM-D)tech-nique.ThepurposeistostudytheinfluenceofDBDprocessingonthenatureandscaleofBSAadsorptiononPMMAsurfaceinvitro.ItwasobservedthatDBDprocessingimprovesthesurfacewettabilityofPMMAfilm,afactattributabletothechangesinsurfacechemistryandtopography.ExposureofthePMMAtoPhosphateBuffedSaline(PBS)solutionintheQCM-Dsystemresultedinsurfaceadsorptionwhichreachesanequilibriumafterabout30minutesforpristinePMMA,and90minutesforprocessedPMMAsurface.SubsequentinjectionofBSAinPBSindicatedthattheproteinisimmediatelyadsorbedontothePMMAsurface.ItwasrevealedthatadsorptionbehaviourofBSAonpristinePMMAdiffersfromthatonprocessedPMMAsurface.AsloweradsorptionkineticswasobservedforpristinePMMAsurface,whilstaquickadsorptionkineticsforprocessedPMMA.Moreover,thedissipationshiftofproteinadsorptionsuggestedthatBSAformsamorerigidstructureonpristinePMMAsurfacethatonprocessedsurface.ThesedatasuggestthatchangesinwettabilityandattendantchemicalpropertiesandsurfacetextureofthePMMAsurfacemayplayasignificantroleinBSAadsorptionprocess.