简介:AmeshlessapproachtoanalysisofarbitraryKirchhoffplatesbythelocalboundaryintegralequation(LBIE)methodispresented.Themethodcombinestheadvantageousfeaturesofallthethreemeth-ods:theGalerkinfiniteelementmethod(GFEM),theboundaryelementmethod(BEM)andtheelement-freeGalerkinmethod(EFGM).Itisatrulymeshlessmethod,whichmeansthatthediscretizationisinde-pendentofgeometricsubdivisionintoelementsorcells,butisonlybasedonasetofnodes(orderedorscat-tered)overadomaininquestion.Itinvolvesonlyboundaryintegration,however,overalocalboundarycen-teredatthenodeinquestion;Itposesnodifficultiesinsatisfyingtheessentialboundaryconditionswhileleadingtobandedandsparsesystemmatricesusingthemovingleastsquare(MLS)approximations.Itisshownthathighaccuracycanbeachievedforarbitrarygeometriesforclampedandsimply-supportededgeconditions.Themethodisfoundtobesimple,efficient,andattractive.
简介:Thestabilityofthethinliquidfilminacapillaryisimportanttothephase-changeheattransferprocessinminiatureofmicrostructures.Fromthebasicequationsformotionandheattransferattheinterfaceofthefilm,itsstabilityistheoreticallystudied.Withevaluationoftheeffectsandrelativemagnitudesofvariousdrivingforcesandwiththeuseoflong-wavetheoryinadditiontolinearstabilityanalysis,thecontrollingequationsaresimplifiedandanevolutionequationforthefilm'sthicknessisobtained.Detailedanalysisontheevolutionequationshowsthatinstabilityoccursfirstinthemeniscusregionandtheinstabilityconditionvarieswithboundaryconditions,geometricalscalesandthermalproperties.Thenumericalresultsagreewellwithearlieroneswithsomefavorableextensionsandimprovements.
简介:Theeffectofdiffusiononthermoelasticthinplatesisinvestigated.Thegoverningequationsforthinthermoelasticdiffusionplatesunderthreedifferentlawsofheatanddiffusiontransmissionarederived.BytheC0-semigrouptheory,thewell-posednessoftheproposedequationsisshown.
简介:ItiswellknownthatthephotocatalyticactivityofTiO2thinfilmsstronglydependsonthepreparingmethodsandpost-treatmentconditions,sincetheyhaveadecisiveinfluenceonthechemicalandphysicalpropertiesofTiO2thinfilms.Therefore,itisnecessarytoelucidatetheinfluenceofthepreparationprocessandpost-treatmentconditionsonthephotocatalyticactivityandsurfacemicrostructuresofthefilms.ThisreviewdealswiththepreparationofTiO2thinfilmphotocatalystsbywet-chemicalmethods(suchassol-gel,reversemicellarandliquidphasedeposition)andthecomparisonofvariouspreparationmethodsaswellastheiradvantageanddisadvantage.Furthermore,itisdiscussedthattheadvancementofphotocatalyticactivity,super-hydrophilicityandbactericidalactivityofTiO2thinfilmphotocatalystinrecentyears.
简介:Theelectroluminescencethinfilmsdopedwitherbium,fabricatedbythermalevaporationwithtwoboats,areanalyzedbyX-raydiffraction(XRD).Therelationshipbetweenelectroluminescencebrightnessandmicrostructureofthethinfilmsisobtained.Theresultsrevealthatthelargegrainsizeinhighindexplaneofdepositedmicrocrystallinefilmhasaneffectonelectroluminescencecharacteristicsofthefilmdevices.
简介:Effectsofdepositionlayerpositionandnumber/densityonlocalbendingofathinfilmaresystematicallyinvestigated.Becausethedepositionlayerinteractswiththethinfilmattheinterfaceandthereisanoffsetbetweenthethinfilmneutralsurfaceandtheinterface,thedepositionlayergeneratesnotonlyaxialstressbutalsobendingmoment.Thebendingmomentinducesaninstantout-of-planedeflectionofthethinfilm,whichmayormaynotcausethesocalledlocalbending.Thedepositionlayerismodeledasalocalstressor,whoselocationanddensityaredemonstratedtobevitaltotheoccurrenceoflocalbending.Thethinfilmrestsonaviscouslayer,whichisgovernedbytheNavier-Stokesequationandbehaveslikeanelasticfoundationtoexerttransverseforcesonthethinfilm.Theunknownfeatureoftheaxialconstraintforcemakesthegoverningequationhighlynonlinearevenforthesmalldeflectioncase.Theconstraintforceandfilmtransversedeflectionaresolvediterativelythroughthegoverningequationandthedisplacementconstraintequationofimmovableedges.Thisresearchshowsthatinsomespecialcases,thedepositiondensityincreasedoesnotnecessarilyreducethelocalbending.Bycomparingthethinfilmdeflectionsofdifferentdepositionnumbersandpositions,wealsopresenttheguidelineofstrengtheningorsuppressingthelocalbending.
简介:Thebucklingofthingelfilmhasattractedmuchattentionduetoitsapplicationsinthedesignofthreedimensionalstructurefromtwo-dimensionaltemplate.Wehaveestablishedananalyticalmodeltostudytheswelling-inducedbucklingofathingelstripwithoneedgeclampecdandtheothersfree.Theclosed-formsolutionsfortheamplitudeandwavelengthofthebuckledshapeareobtainedbyenergyminimizationofthetotalpotentialenergy.Theanalyticalresultsagreewellwithfiniteelementanalysisbasedontheinhomogeneousgeltheorywithoutanyparameterfitting.Themodelprovidesaroutetostudycomplexpostbucklingbehaviorsofthingelfilmsandguidelinestodesignthebuckledconfigurationquantitativelybycontrollingtheswellingratio.
简介:Thepreparation,currentstatusandtrendsareinvestigatedforsiliconthinfilmsolarcells.Theadvantagesanddisadvantagesofamorphoussiliconthinfilm,polycrystallinesiliconthinfilmandmono-crystallinesiliconthinfilmsolarcellsarecompared.Thefuturedevelopmenttrendsarepointedout.Itisfoundthatpolycrystallinesiliconthinfilmsolarcellswillbemorepromisingforapplicationwithgreatpotential.
简介:Inthispaper,anumericalmodelof2Dweaklycompressiblesmoothedparticlehydrodynamics(WCSPH)isdevelopedtosimulatetheinteractionbetweenwavesandthinstructures.Anewcolordomainparticle(CDP)techniqueisproposedtoovercomedifficultiesofapplyingtheghostparticlemethodtothinstructuresindealingwithsolidboundaries.Thenewtechniquecandealwithzero-thicknessstructures.Toapplythisenforcingtechnique,thecomputationalfluiddomainisdividedintosubdomains,i.e.,boundarydomainsandinternaldomains.Acolorvalueisassignedtoeachparticle,andcontainstheinformationofthedomainsinwhichtheparticlebelongstoandtheparticlescaninteractwith.Aparticle,nearbyathinboundary,ispreventedfrominteractingwithparticles,whichshouldnotinteractwithontheothersideofthestructure.Itispossibletomodelthinstructures,orthestructureswiththethicknessnegligiblewiththistechnique.TheproposedWCSPHmoduleisvalidatedforastillwatertank,dividedbyathinplateatthemiddlesection,withdifferentwaterlevelsinthesubdomains,andisappliedtosimulatetheinteractionbetweenregularwavesandaperforatedverticalplate.Finally,thecomputationiscarriedoutforwavesandsubmergedtwin-horizontalplateinteraction.Itisshownthatthenumericalresultsagreewellwithexperimentaldataintermsofthepressuredistribution,pressuretimeseriesandwavetransmission.
简介:Inthispaper,thespin-coatedthinfilmsofphthalocyaninedyearepresented.Absorptionspectrumofthethinfilmshowsacomparativelybroadabsorptioninthewavelengthrange630-770nm.Opticalparametersofthethinfilmweremeasuredbyaspectroscopicellipsometersystem.5-inCD-RdiscsmadeofthisdyeexhibitgoodperformancewithYamaha20-speedrecorder.Jittersoflandandpitarelessthan30ns,andthe3T-11T'ssignalsshowverygoodquality.ThisdyeisapromisingrecordingmediumforCD-Rwithmuchhigherrecordingspeed.
简介:AnalyzedandstudiedthecharactersofhighstrengthlowalloysteelwhichcontainMo,Cr,NbandNi.etc.Followingactualrolling,combiningthefeatureofrollingmode,andexploitingtheequipmentadvantageof5mHeavyPlateMill,optimizedthematerialdesign,heatingtemperatureandrollingmethod,stabilizedrollingprocessofthinalloyedsteel,thequalityindexwasadvanced.
简介:Photovoltaicsarecurrentlyrecognizedasatoprankingtechnologyamongthenewenergies.Photovoltaicshavethepotentialtoeventuallymakeaconsiderablecontributiontothepowergenerationcapacityintheworl,especially,intheindustrializedcoutries.GoodaccomplishmenthasbeenobtainedinthecostreductionofPVsystems,forexamplein1974,systemscost(100-150)$/W.In1981,suchsystemscostlessthan(10-30)$/W,andnowtheycostlessthan5$/W.However,moreR&Deffortsarestillnecessary,toachievelarge-scalecost-effectiveprouctionofPVsystemstomakeitcompetitivewithdieselgenerationofelectricity,althoughPVsystemshaveproventobecompetitiveinruralandremoteareas.Inthispaper,anoverviewonhighefficiencysolarcelltechnologicswilllbepresented.