简介：Surfaceeffect,whichisattributedtothedifferentenvironmentsurroundingthesurfaceornear-surfaceatomsfromthatembracingthebulkatoms,maybecomesignificantwhenthesurface-to-volumeratioofabodyislarge.Thispaperconsiderstheeffectofaplaneboundaryofapiezoelectricbodymodeledasathinlayerwithspecifiedmaterialproperties,forwhichatransferrelationbetweenthestatevectorsatthetopandbottomsurfacesisderivedbasedonthestate-spaceformulations.Theequationsofsurf...

简介：产生交通的逃亡者灰尘是在北京的城市的大气的微粒污染的来源。这篇论文介绍暂停方法，在AP-42文件由USEPA推荐了，为收集北京道路表面灰尘。分析为道路表面灰尘的集体尺寸分发在数字尺寸分发和一个双山峰模式显示出单个山峰的分布。一条高级道路上的道路灰尘的集体集中分发的中部的直径在一条低档道路上比那高。到PM10的PM2.5的比率与那为香港在类似的研究获得了一致。为二件选择道路样品，尺寸分发的平均相对偏差是10.9%和11.9%。所有结果显示有效地在这个论文罐头介绍的方法从交通决定逃亡者灰尘的尺寸分发。

简介：Thisletterpresentsananalyticalsolutiontothehydrodynamiclubricationofacircularpointcontactslidingoveraflatsurfacewithcavitation.ThesolutionisfoundbysolvingtheReynoldsequationwithReynoldsboundaryconditionforcavitation.Thecavitationboundaryisshowntobestraightlinesdirected108.4°againsttheslidingdirection.Theresultisexperimentallyverifiedinthelimitoflargevaluesofviscosity,slidingvelocityandradiusofasphericalball.Thesolutionraisesquestionsaboutthecouplingbetweencavitationandfilmruptureandcanbeusedasanindependentcheckonthevalidityofnumericalsolutions.

简介：Thebendingresponsesoffunctionallygraded(FG)nanobeamswithsimplysupportededgesareinvestigatedbasedonTimoshenkobeamtheoryinthisarticle.TheGurtin-MurdochsurfaceelasticitytheoryisadoptedtoanalyzetheinfluencesofsurfacestressonbendingresponseofFGnanobeam.ThematerialpropertiesareassumedtovaryalongthethicknessofFGnanobeaminpowerlaw.Thebendinggoverningequationsarederivedbyusingtheminimumtotalpotentialenergyprincipleandexplicitformulasarederivedforrotationangleanddeflectionofnanobeamswithsurfaceeffects.IllustrativeexamplesareimplementedtogivethebendingdeformationofFGnanobeam.Theinfluencesoftheaspectratio,gradientindex,andsurfacestressondimensionlessdeflectionarediscussedindetail.

简介：ThecaptureoforthophosphatesandtotalphosphorusfromthePudongCanalriverinthePudongDistrictofShanghaibyTiO2nanoparticlesisstudiedusingarotatingphotoreactorandthenano-TiO2photocatalystDegussaP25.TheeffectsofUVirradiationintensityinarangeof20-74mW/cm2.theloadingoftheTiO2nanoparticlesinarangeof0.05-0.1g/L,irradiationtimeupto4h,andpHvaluesinarangeof2-10.5onthecaptureefficiencyareinvestigated.TheresultsshowthatthecaptureoforthophosphatesandtotalParesignificantlyenhancedbyUVirradiation;ataloadingof0.1g/Landanirradiationintensityabove36mW/cm2,orthophosphatesandtotalphosphorusarerapidlycapturedbyTiO2nanoparticles,causinganobservedreductionfrom0.4mg/Ldownto0.02mg/L.pHvaluesinarangeof2-10.5havelittleeffectonthecaptureefficiencyoforthophosphatesandtotalphosphorus.

简介：Thebasicequationsoffreecapillary-gravitysurface-wavesinacircularcylindricalbasinwerederivedfromLuke'sprinciple.TakingGalerkin'sexpansionofthevelocitypotentialandthefreesurfaceelevation,thesecond-orderperturbationequationswerederivedbyuseofexpansionofmultiplescale.Thenonlinearinteractionswiththesecondorderinternalresonanceofthreefreesurface-waveswerediscussedbasedontheabove.Theresultsinclude:derivationofthecoupleequationsofresonantinteractionsamongthreewavesandtheconservationlaws;analysisofthepositionsofequilibriumpointsinphaseplane;studyoftheresonantparametersandthenon-resonantparametersrespectivelyinallkindsofcircumstances;derivationofthestationarysolutionsofthesecond-orderinteractionequationscorrespondingtodifferentparametersandanalysisofthestabilitypropertyofthesolutions;discussionoftheeffectivesolutionsonlyinthelimitedtimerange.Theanalysismakesitclearthattheenergytransformationmodeamongthreewavesdiffersbecauseofthedifferentinitialconditionsundernontrivialcircumstance.Theenergymayeitherexchangeamongthreewavesperiodicallyordamporincreaseinsinglewaves.

简介：Thisstudyaimsatthemechanismofdragreductioninturbulentboundarylayer(TBL)withsuperhydrophobicsurface.Comparingthetime-resolvedparticleimagevelocimetry(TRPIV)measurementresultswiththatofhydrophilicsurface,thedragreductionrateoverasuperhydrophobicsurfaceisapproximately10%.Toinvestigatethecharacteristicsofcoherentstructureinadrag-reducedTBLwithsuperhydrophobicsurface,amodifiedmulti-scalespatiallocally-averagedstructurefunctionisproposedfordetectingcoherentstructure.Theconditionalsamplingandspatialphase-lockaveragemethodsareemployedtoobtainthetopologyofphysicalquantitieslikethevelocityfluctuation,spanwisevorticity,andReynoldsstressduringejectandsweepprocess.Theresultsindicatethatthesuppressionofcoherentstructureburstinthenear-wallregionisthekeymechanisminreducingtheskinfrictiondragforTBLoversuperhydrophobicsurface.

简介：Insulatorsonhigh-voltageUansmissionlinesarealmosttheonlyman-madestructuresontheEarth'ssurfaceintendedforlong-termoperationunderstrongelectricfields.AftersamplesofnaturalcontaminantparticleswerecollectedfrominsulatorsurfacesinChina,itwasfoundthattheparticlediameterdistribution(PDD)wasmainlyconcentratedinthe5-50μmrange.Toanalyzethestatisticalcharacteristicsoftheseparticles,thisworkstudiesthephysicalprocessesofparticlecollisionandadhesionusingthetheoriesofhydrodynamicsandcollisiondynamics.Thephysicalmodelconsiderscouplingofthefluidfieldandtheelectricfield,introducesanadhesioncriterion,andestablishesaparticleandsurfacecollisionmodel.Theeffectsofrelativehumidity,windspeed,aerodynamicshape,electricfieldtype,andelectricfieldstrengthonparticleadhesionwereanalyzed.Theresultsshowthattherelativehumidityandwindspeedhaveverysignificanteffectsandtheinfluencesoftheelectricfieldtypeandtheelectricfieldstrengthareobvious,buttheinfluenceoftheaerodynamicshapeisrelativelyweak.Thesimulationresultssupportthestatisticalcharacteristicsdeterminedinthiswork.Thephysicalmodelestablishedhereprovidesreferencevaluesforstudyoftheadhesioncharacteristicsofparticlesonsurfacesunderelectricfields.

简介：Ananalyticalmodelisdevelopedtostudythesurfaceeffectsonthevibrationbehaviorincludingthenaturalfrequencyandthecriticalflowvelocityoffluid-conveyingnanotubesembeddedinanelasticmedium.TheeffectsofsurfaceelasticityandresidualsurfacestressareaccountedthroughthesurfaceelasticitymodelandtheYoung-Laplaceequation.AWinkler-typefoundationisemployedtomodeltheinteractionofnanotubesandthesurroundingmedium.Theresultsshowthatthesurfaceeffectshavemoreprominentinfluencesonthenaturefrequencywithsmallernanotubethickness,largeraspectratioandlargerelasticmediumconstants.Bothsurfacelayersandtheelasticmediumenhancethestabilityofnanotubes.Thisstudymightbehelpfulfordesigningthefluid-conveyingnanotubedevicesinNEMSandMEMSsystems.

简介：Thisletterreportsexperimentalobservationofadirectcorrelationbetweentheacousticnonlinearityparameter(NP)measuredwithnonlinearRayleighwavesandtheaccumulationofplasticitydamageinanAZ31magnesiumalloyplatespecimen.Rayleighwavesaregeneratedanddetectedwithwedgetransducers,andtheNPsaremeasuredatdifferentstresslevels.TheresultsshowthatthereisasignificantincreaseintheNPswithmonotonictensileloadssurpassingthematerial'syieldingstress.Theresearchsugge...

简介：BasedontheZufiriatheoreticalmodel,anewmodelregardingtheasymptoticbubblevelocityfortheRayleigh-Taylor(RT)instabilityispresentedbyuseofthecomplexvelocitypotentialproposedbySohn.TheproposedmodelisanextensionoftheordinaryZufiriamodelandcandealwithnon-idealfluids.Withthecontrolvariablemethod,theeffectoftheviscosityandsurfacetensiononthebubblegrowthrateoftheRTinstabilityisstudied.TheresultisconsistentwithCao’sresultifweonlyconsidertheviscouseffectandwithXia’sresultifweonlyconsiderthesurfacetensioneffect.TheasymptoticbubblevelocitypredictedbytheZufiriamodelissmallerthanthatpredictedbytheLayzermodel,andtheresultfromtheZufiriamodelismuchclosertoWhite’sexperimentaldata.

简介：Thispaperdealswiththefreevibrationanalysisofcircularalumina(Al2O3)nanobeamsinthepresenceofsurfaceandthermaleffectsrestingonaPasternakfoundation.ThesystemofmotionequationsisderivedusingHamilton'sprincipleundertheassumptionsoftheclassicalTimoshenkobeamtheory.Theeffectsofthetransversesheardeformationandrotaryinertiaarealsoconsideredwithintheframeworkofthementionedtheory.Theseparationofvariablesapproachisemployedtodiscretizethegoverningequationswhicharethensolvedbyananalyticalmethodtoobtainthenaturalfrequenciesofthealuminananobeams.TheresultsshowthatthesurfaceeffectsleadtoanincreaseinthenaturalfrequencyofnanobeamsascomparedwiththeclassicalTimoshenkobeammodel.Inaddition,fornanobeamswithlargediameters,thesurfaceeffectsmayincreasethenaturalfrequenciesbyincreasingthethermaleffects.Moreover,withregardtothePasternakelasticfoundation,thenaturalfrequenciesareincreasedslightly.Theresultsofthepresentmodelarecomparedwiththeliterature,showingthatthepresentmodelcancapturecorrectlythesurfaceeffectsinthermalvibrationofnanobeams.

简介：Nanoparticlescanprovideflameretardancetohostingpolymersandactasnanofireextinguishers.Hydroxyapatite（Ca5（OH）（PO4）3）（HA）isnothygroscopic,andisthermallystableupto800℃,with18.5wt%phosphorouscontent.ItisthishighphosphorouscontentthatcanprovideHAwithflameretardantproperties.Inthispaper,wereportonthecontinuoussynthesisofultrafineHAusingahydrothermalsynthesistechnique.TheHAsurfacepropertieswerechangedfromhydrophilictohydrophobicbypostsynthesissurfacemodification.TheratiooftheHAnanoparticlesandanintumescentagentknownasExolitAP750wasinvestigatedtoyieldaself-extinguishingmulti-componentepoxynanocompositeforextendedapplicationunderextremefireconditions.TheHA/AP750/epoxynanocompositewasabletoresistaflameat1700℃andself-extinguishaftertheflamehadbeenremoved.Thenanocompositeshowedanenhancedflammabilityperformanceinstandardconecalorimetrytestingandformedacompactandcohesiveprotectivecharlayerwitha50%decreaseinpeakheatreleasedcomparedwithvirginepoxy.OuraimwastoestablishtheuseofHAasaneffectivenanofillerwithphosphorous-basedflameretardantproperties.Thesurfaceofthisnanofireextinguisherwasmodifiedeffectivelywithdifferentsurfactantsforenhancedcompatibilitywithdifferentpolymericmatrices.

简介：Inthispaper,westudytheunsteadycoupledheatandmasstransferoftwo-dimensionalMHDfluidoveramovingoscillatorystretchingsurfacewithSoretandDufourefects.Viscousdissipationefectsareadoptedintheenergyequation.Auniformmagneticfieldisappliedverticallytotheflowdirection.Thegoverningequationsarereducedtonon-linearcoupledpartialdiferentialequationsandsolvedbymeansofhomotopyanalysismethod(HAM).Theefectsofsomephysicalparameterssuchasmagneticparameter,Dufournumber,Soretnumber,thePrandtlnumberandtheratiooftheoscillationfrequencyofthesheettoitsstretchingrateontheflowandheattransfercharacteristicsareillustratedandanalyzed.

简介：Thebubblesriseupandburstatthefreesurfaceisacomplextwo-phaseprocess.AfreeenergylatticeBoltzmannmethod(LBM)modelisadoptedinthispapertostudythisphenomenon.Theinterfacecapturingtechnique[Zhengetal.,2006]isusedtodealwiththehighdensityratioproblem.TheLaplacelawandtheair-waterinterfacecapturingabilityarevalidatedforthemultiphasemodel.Theinteractionbetweenthesinglebubbleormultiplebubblesandthefreesurfacearestudiedbythemultiphasemodel.Theforceactingonthebubbleandtheevolutionofthefreesurfaceisstudied.Meanwhile,effectoftheinitialdistancebetweentwoadjacentbubblesoninteractioneffectsofmultiplebubblesisinvestigatedaswell.

简介：在现在的工作，一个计算框架为多尺度的建模和稳固的燃料的分析被建立。一个收拾行李的算法，作为范围或磁盘认为铵高氯酸盐(AP)和铝(艾尔)是粒子被开发匹配尺寸分发和稳固的燃料的卷部分。一个homogenization理论被采用计算一个代表性的体积元素(RVE)的吝啬的压力和紧张。用吝啬的结果，RVE的一种合适的尺寸被决定。没有考虑在粒子和矩阵之间的接口，燃料的松驰的几数字模拟被执行。松驰效果和依赖于应用负担的燃料的非线性的机械行为被讨论。新技术说出基于表面的连贯的行为的A被建议描述由二成分组成的粒子dewetting的现象：一个损坏开始标准和一条损坏进化法律。就接触损坏行为而言的几个例子被计算，损坏接口引起的也非线性的行为在这份报纸被讨论。而且，损坏接口上的批评接触压力，起始的接触僵硬和接触失败距离的效果当模特儿被学习了。

简介：一个热水的方法准备的象花的SnO2nanopowders是经由受精与钯修改的表面。晶体结构，形态学，和样品的表面化学状态借助于X光检查衍射(XRD)被描绘，扫描电子显微镜学(SEM)，和X光检查光电子光谱学(XPS)分别地。煤气的察觉到表演也被调查。为220渠湡瑯'T獥?的热水的温度?呎?乔？

简介：Anumericalstudyofanon-Darcymixedconvectiveheatandmasstransferflowoveraverticalsurfaceembeddedinaporousmediumundertheefectsofdoubledispersion,melting,andthermalradiationisinvestigated.Thesetofgoverningboundarylayerequationsandtheboundaryconditionsistransformedintoasetofcouplednonlinearordinarydiferentialequationswiththerelevantboundaryconditions.ThetransformedequationsaresolvednumericallybyusingtheChebyshevpseudospectralmethod.Comparisonsofthepresentresultswiththeexistingresultsintheliteraturearemade,andgoodagreementisfound.Numericalresultsforthevelocity,temperature,concentrationprofiles,andlocalNusseltandSherwoodnumbersarediscussedforvariousvaluesofphysicalparameters.

简介：Analyticalsolutionsfortheflexural-gravitywaveresistancesduetoalinesourcesteadilymovingonthesurfaceofaninfinitelydeepfluidareinvestigatedwithintheframeworkofthelinearpotentialtheory.Thehomogenousfluid,coveredbyathinelasticplate,isassumedtobeincompressibleandinviscid,andthemotiontobeirrotational.ThesolutioninintegralformforthewaveresistanceisobtainedbymeansoftheFouriertransformandtheexplicitlyanalyticalsolutionsarederivedwiththeaidoftheresiduetheorem.Thedispersionrelationshowsthatthereisaminimalphasespeedcmin,athresholdfortheexistenceofthewaveresistance.NowaveisgeneratedwhenthemovingspeedofthesourceVislessthancminwhilethewaveresistancesfirstlyincreasetotheirpeakvaluesandthendecreasewhenVcmin.Theeffectsoftheflexuralrigidityandtheinertiaoftheplatearestudied.

简介：Westudythedynamicbehaviorofaquartzcrystalresonator(QCR)inthickness-shearvibrationswiththeuppersurfacecoveredbyanarrayofmicro-beams(MBs)underlargedeflection.ThroughtakingintoaccountthecontinuousconditionsofshearforceandbendingmomentattheinterfaceofMBs/resonator,dependencesoffrequencyshiftofthecompoundQCRsystemversusmaterialparameterandgeometricalparameterareillustratedindetailfornonlinearandlinearvibrations.Itisfoundthatthefrequencyshiftproducesalittleright(left)translationforincreasingelasticmodulus(length/radiusratio)ofMBs.Moreover,thefrequencyright(left)translationdistancecausedbynonlineardeformationbecomesmoreseriousinthesecond-ordermodethaninthefirst-orderone.