简介：Measurementsofparticulatematter(PM),i.e.,PM10,PM2.5,andPMl,havebeenperformedontheCantonTower,alandmarkbuildinginGuangzhou,atheightsof121and454msinceNovember2010,usingaGRIMM180aerosolparticlespectrometer(Germany).AnalysesofdatafromNovember2010toMay2013showedthattheannualaveragevaluesofPM10,PM2.5,andPMlattheobservationheightof121mabovethegroundwere44.1,38.2,and34.9μg/m3,respectively,andthoseat454mabovethegroundwere35.7,30.4,and27.5μg/m3,respectively.ByconsideringthevaluesofthesecondaryconcentrationlimitsgivenintheAmbientAirQualityStandardsissuedin2012,itwasobservedthattheannualaveragevaluesofPM10attheobservationheightsof121and454m,aswellasthoseofPM2.5at454m,reachedthosestandards.Furthermore,theover-standardamplitudeoftheannualaveragevalueofPM2.5attheobservationheightof121mwas9.1%.Duringtheobservationperiod,themaximumdailyaveragevaluesofPM10,PM2.5,andPM1attheobservationheightof121mwere183.3,144.8,and123.8μg/m~3,respectively,andthoseat454mwere102.8,92.7,and86.4μg/m3.ThedailyaveragevaluesofPM10attheobservationheightof454mwerenotabovethestandards.Theover-standardfrequenciesofthedailyaveragevaluesofPM10andPM2.5attheobservationheightof121mwere0.6%and10.7%,respectively,andtheover-standardamplitudeswere9.0%and24.4%,respectively.Theover-standardfrequencyofthedailyaveragevalueofPM2.5attheobservationheightof454mwas2.0%,andtheover-standardamplitudewas10.4%.Accordingly,itcanbestatedthattheairattheobservationheight454mabovethegrounddidnotreachthesecondarylimitofthenewstandards.Thepollutionwasmostseriousduringwinter,andtheairwasrelativelycleanerduringsummer.Overall,theverticaldistributionsofPM10,PM2.5,andPMldecreasedwithheight.Thelapseratesshowedthefollowingsequence:PM10>PM2.5>PM1,whichindicatesthattheverticaldistributionoffineparticles

简介：Dropshaftsareverticalstructureswidelyusedinurbandrainagesystemsandbuildingsforwatertransportation.Inthispaper,aphysicalmodelstudywasconductedtoinvestigatetheairentrainmentinthedropshaftundervariousflowregimeswithandwithoutairventilation.Observedfromtheexperiments,theairentrainmentmechanismsvariedwiththewaterflowregimesinthedropshaft.Whentherewasnowaterplugformedinthedropshaft,aircouldbesupplieddirectlyfromdownstream.Oncethewaterplugwasformed,whilewithoutventing,theairwasreplenishedonlyfromdownstreamintermittentlyandthenintheformoflargeairbubbletravelingupwardstotheairspaceatthetop;whilewithventing,airwasmainlyreplenishedfromthedropshafttopandnolargeairbubblewasobserved.Theexperimentalresultsalsoshowedthattheamountofentrainedairinthedropshaftwithventingwasgreaterthanthatwithoutventing.

简介：Inordertoinvestigatetheinfluenceoftheverticalvibrationloadingontheliquefactionofsaturatedsand,onedimensionalmodelforthesaturatedsandwithaverticalvibrationispresentedbasedonthetwophasecontinuousmediatheory.Thedevelopmentoftheliquefactionandtheliquefactionregionareanalyzed.Itisshownthattheverticalvibrationloadingcouldinduceliquefaction.Therateoftheliquefactionincreaseswiththeincreaseoftheinitiallimitstrainorinitialporosityoramplitudeandfrequencyofloading,andincreaseswiththedecreaseofthepermeabilityorinitialmodulus.Itisshownalsothatthereisaphaselaginthesandcolumn.Whenthesandpermeabilitydistributionisnon-uniform,theporepressureandthestrainwillrisesharplywherethepermeabilityisthesmallest,andfracturemightbeinduced.Withthedevelopmentofliquefaction,thestrengthofthesoilfoundationbecomessmallerandsmaller.Inthelimitingcase,landslidesordebrisflowscouldoccur.

简介：AnanalysisispresentedwithmagnetohydrodynamicsnaturalconvectiveflowofaviscousNewtonianfluidsaturatedporousmediuminaverticalslot.TheflowintheporousmediahasbeenmodeledusingtheBrinkmanmodel.Thefully-developedtwo-dimensionalflowfromcappedtoopenendsisconsideredforwhichacontinuumofsolutionsisobtained.Theinfluenceofpertinentparametersontheflowisdelineatedandappropriateconclusionsaredrawn.Theasymptoticbehaviourandthevolumefluxareanalyzedandincorporatedgraphicallyforthethree-parameterfamilyofsolution.

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简介：Takingtheshort-fibercompositematerialsasengineeringback-ground,utilizingtheexistingbasicsolutionsofsingleinclusionandsinglecrack,theplaneproblemofverticalcontactinteractionsbetweenlinecrackandrigidlineinclusionininfiniteplane(matrix)fromtheviewpointofcrackfracturemechanicsisstudied.Accordingtoboundaryconditions,asetofstandardCauchy-typesingularintegralequationsoftheproblemisobtainable.Besides,singularindexes,stressesandstressintensityfactorsaroundthecontactpointareexpressed.Numericalexamplesaregiventoprovidereferencestoengineering.

简介：在现在的纸，我们讨论magnetohydrodynamic(MHD)在在零个雷纳兹数字和长波长近似下面的一条垂直不对称的隧道的一个夸张正切液体模型的蠕动的流动。当驱散术语不在时的温度方程的准确答案被计算了，为流功能和轴的压力坡度的分析表达式被建立。流动在与波浪的速度移动的一个波浪原则被分析。为压力上升的表示数字地被计算了。恰当的参数的物理特征被阴谋图分析并且详细讨论了。

简介：Young’sequationisafundamentalequationincapillarityandwetting,whichreflectsthebalanceofthehorizontalcomponentsofthethreeinterfacialtensionswiththecontactangle(CA).However,itdoesnotconsidertheverticalcomponentoftheliquid-vaporinterfacialtension(VCLVIT).ItisnowwellunderstoodthattheVCLVITcausestheelasticdeformationofthesolidsubstrate,whichplaysasignificantroleinthefabricationofthemicrofluidicdevicesbecauseofthewideuseofthesoftmaterials.Inthispaper,thetheoretical,experimental,andnumericalaspectsoftheproblemarereviewed.TheeffectsoftheVCLVIT-inducedsurfacedeformationonthewettingandspreading,thedeflectionofthemicrocantilever,andtheelasto-capillarityandelectroelasto-capillarityarediscussed.Besidesabriefreviewonthehistoricaldevelopmentandtherecentadvances,somesuggestionsonthefutureresearcharealsoprovided.

简介：Inthispaper,thebasicequationsgoverningtheflowandheattransferofanincompressibleviscousandelectricallyconductingfluidpastasemi-infiniteverticalpermeableplateintheformofpartialdifferentialequationsarereducedtoasetofnon-linearordinarydifferentialequationsbyapplyingasuitablesimilaritytransformation.Approximatesolutionsofthetransformedequationsareobtainedbyemployingtheperturbationmethodfortwocases,i.e.,smallandlargevaluesofthesuctionparameter.Fromthenumericalevaluationsofthesolution,itcanbeseenthatthevelocityfieldatanypointdecreasesasthevaluesofthemagneticandsuctionparametersincrease.Theeffectofthemagneticparameteristoincreasethethermalboundarylayer.Itisalsofoundthatthevelocityandtemperaturefieldsdecreasewiththeincreaseinthesinkparameter.

简介：Basedonaseriesofnumericalcalculations,thebehaviorofflowfieldinobstructedsquarebuoyantverticaljetissummarizedandanalyzed.Basedontheaxiallinevelocitydistribution,theflowafterthedisccanbedividedintothreeregions,i.e.,recirculationregion,transitionalregionandself-similarregionThecharacteristicofself-similarityofuprightvelocitywasvalidated.Thethreeregionscanalsobedistinguishedbasedontheaxialvelocity.Theaxialvelocityinself-similarregionwasfoundtoobeythesamelawandtheformulapresentedbyintroducingthevelocityexpressionusedbyChenandRodi.Theisolinesofpressureoncross-sectionsofdifferentheightsweredisplayedandtheproduction,expansion,breakinganddisappearingofnegativepressureregionswerefound.

简介：Experimentalresultsontheinstabilityoftheisothermalnatural-convectionboundarylayeraroundaverticalheatedflatplatearepresented.ItisdemonstratedthatthecharacteristicsoftheinstabilitywaveintheouterlayerisconsistentwiththecalculationofBrewster&Gebhart.Afteraninitialgrowthofitslowfrequencycomponentsatthedownstreamsideoftheturningpointoftheneutralcurve(Gr≈120)itscomparativelyhigherfrequencycomponentsdevelopandbecometurbulentsubsequentlywithabuoyancysubrangeinitspowerspectra.Simultane-ously,inthemeasurementattheinnerlayernearthewallaviscousinstabilitysignalthesameastheTollmien-Schlichtingwavesinordinaryboundarylaycranditssub-harmonicsinamuchhigherfrequencydomainisdiscoveredandaninertialsubrangecanbeobservedinthespectraatGr≈378.6.

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简介：Ananalysisisperformedtostudytransientfreeconvectiveboundarylayerflowofacouplestressfluidoveraverticalcylinder,intheabsenceofbodycouples.Thesolutionofthetime-dependentnon-linearandcoupledgoverningequationsiscarriedoutwiththeaidofanunconditionallystableCrank–Nicolsontypeofnumericalscheme.Numericalresultsforthesteady-statevelocity,temperatureaswellasthetimehistoriesoftheskin-frictioncoefcientandNusseltnumberarepresentedgraphicallyanddiscussed.Itisseenthatforallflowvariablesasthecouplestresscontrolparameter,Co,isamplified,thetimerequiredforreachingthetemporalmaximumincreasesbutthesteady-statedecreases.

简介：Someexperimentsweremadeforthebuoyantjetfromasquareorificewithasquarediscplacedonitinstaticambientandconcentrationalongtheaxisinself-similarareabehinddiscwasmeasured.Andatthesametimeathree-dimensionalmathematicalmodelwasestablishedtosimulatethewholeflowingunderdifferentconditions.Alltheresultspredictedbythenumericalcalculationweresubstantiatedbytheexperiments.Theresultswerecomparedwithexperientialformulaforobstructedroundbuoyantverticaljetsinstaticambientanditwasfoundthatthetwoconcentrationdistributionshadgoodaccordance.Starshapeoftemperatureisolinesoncross-sectionsinthenearareasfromthediscwasfoundanditwasaveryspecialfigureforobstructedsquarebuoyantverticaljetswithasquaredisc.Theshapewilltransformtoconcentriccirclesgraduallyaliketotheroundbuoyantverticaljetinself-similarareawithincreasingofthedistancefromthedisc.

简介：Thispaperstudiesmixedconvection,doubledispersionandchemicalreactioneffectsonheatandmasstransferinanon-Darcynon-Newtonianfluidoveraverticalsurfaceinaporousmediumundertheconstanttemperatureandconcentration.Thegoverningboundarylayerequations,namely,momentum,energyandconcentration,areconvertedtoordinarydifferentialequationsbyintroducingsimilarityvariablesandthenaresolvednumericallybymeansoffourth-orderRunge-Kuttamethodcoupledwithdouble-shootingtechn...

简介：这份报纸与可变的墙温度在一个垂直的可渗透的锥上讨论micropolarnanofluid的自然传送对流边界层流动。非类似的答案被获得。在管理流动的边界层近似下面的非线性地联合的微分方程用一个有效、反复的、tri斜的、含蓄的有限差别方法数字地被解决。为两nanofluid的不同试验性的关联有效粘性和nanofluid热电导率被考虑。作为旋涡粘性参数增加，两个都，速度介绍，这被发现并且本地Nusselt数字减少。在在这调查考虑的所有nanoparticles之中，另外，Cu给好传送对流。

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

简介：Thescatteringproblemofanti-planeshearwavesinafunctionallygradedmaterialstripwithanoff-centercrackisinvestigatedbyuseofSchmidtmethod.Thecrackisverticallytotheedgeofthestrip.ByusingtheFouriertransform,theproblemcanbesolvedwiththehelpofapairofdualintegralequationsthattheunknownvariableisthejumpofthedisplacementacrossthecracksurfaces.Tosolvethedualintegralequations,thejumpofthedisplacementacrossthecracksurfaceswasexpandedinaseriesofJacobipolynomials.Numericalexampleswereprovidedtoshowtheeffectsoftheparameterdescribingthefunctionallygradedmaterials,thepositionofthecrackandthefrequencyoftheincidentwavesuponthestressintensityfactorsofthecrack.

简介：Anewanalyticalmodelwasdevelopedtopredictthegravitywavedrag(GWD)inducedbyanisolated3-dimensionalmountain,overwhichastratified,non-rotatingnon-Boussinesqshearedflowisimpinged.Themodelisconfinedtosmallamplitudemotionandassumestheambientvelocityvaryingslowlywithheight.ThemodifiedTaylor-GoldsteinequationwithvariablecoefficientsissolvedwithaWentzel-Kramers-Brillouin(WKB)approximation,formallyvalidathighRichardsonnumbers.WiththisWKBsolution,genericformulaeofsecondorderaccuracy,fortheGWDandsurfacepressureperturbation(bothforhydrostaticandnon-hydrostaticflow)arepresented,enablingarigoroustreatmentontheeffectsbyverticalvariationsinwindprofiles.Inanidealtesttothecircularbell-shapedmountain,itwasfoundthatwhenthewindislinearlysheared,thattheGWDdecreasesastheRichardsonnumberdecreases.However,theGWDforaforwardshearedwind(windincreaseswithheight)decreasesalwaysfasterthanthatforthebackwardshearedwind(winddeceaseswithheight).Thisdifferenceisevidentwheneverthemodelishydrostaticornot.