简介:Theexactclassicallimitsforthecoefficientofvariationcforthenormaldistributionarederived.Thehand-calculatingapproximatedclassicallimitsforchavinghighaccuracyaregiventomeetpracticalengineeringneeds.UsingOdehandOwen’scomputationalmethodandBrent’salgorithm,thetablesforther-upperexactclassicallimitsofcoefficientofvariation.fornormaldistributionarecalculatedforthedifferentconfidencecoefficientγ,thesamplesizen=I(1)30,40,60,120,thesamplecoefficientofvariation(?)=0.01(0.01)0.20.Itisshownthatifn≤8,(?)≤0.20,thentheY-upperexactclassicallimitscuforcareslightlyhigherthantheexactfiduciallimitscu,Fforc.ifn>8,(?)≤0.20,thencu-cu,F<5×10-6.
简介:Basedonthetheoryofcomplexfunctionandtheprincipleofhomogenization,harmonicdynamicsstressofaradiallyinfiniteinhomogeneousmediumwithacircularcavityisinvestigated.Duetothesymmetry,wavevelocityisassumedtohavepower-lawvariationintheradialdirectiononly,andtheshearmodulusisconstant.TheHelmholtzequationwithavariablecoefficientisequivalentlytransformedintoastandardHelmholtzequationwithageneralconformaltransformationmethod(GCTM).Thedisplacementsandstressfieldsareproposed.Numericalresultsshowthatthewavenumberandtheinhomogeneityparameterofthemediumhavesignificanteffectsonthedynamicstressconcentrationaroundthecircularcavity.Thedynamicstressconcentrationfactor(DSCF)becomessingularwhentheinhomogeneityparameterofmediumisclosetozero.
简介:Ingranulation,fineparticlescombinetoformacoarsegranuleintheformofaparticlematrixpartiallyorfullysaturatedwithabinderliquid.Thefinalproductofgranulationpossessesawidevarietyofgranulesizedistributionswithsurfacemeandiameterswhichdifferwithoperatingconditions.Thefinalgranulesizedependsontheoperatingconditions,e.g.operatinggasvelocity,inletairtemperature,initialfeedparticlesize,andviscosityofthebinder.Theobjectiveofthispaperistofindouttheuniformityintherelationbetweenthegranulemassfractioninthefinalgranulesizedistributionandthenumberoffeedparticlespresentinthegranules.Thetotalnumberofgranulesobtaineddependsontheexperimentalconditionsbutthegranulemassfractionandthenumberoffeedparticlesformingasinglegranuleareindependentofoperatingvariables,feedmaterialandmethodofgranulation.Thepaperpurportsfurthertocomparetheuniformnatureofmassfractionofthegranulesinfinalgranulesizedistributionandtheprimaryparticlesrequiredtoformthatparticulargranulesizeirrespectiveofexperimentalconditionsofgranulation.
简介:Thispaperpresentsanexactsolutionofthecracktipfieldinfunctionallygradientmaterialwithexponentialvariationofelasticconstants.ThedimensionlessPoisson'sratiosv0oftheengineeringmaterials(iron,glass...)arefarlessthanone;therefore,neglectingthem,onecansimplifythebasicequationandtheexactsolutioniseasytoobtain.Althoughtheexactsolutionforthecasev0≠0isalsoobtained,itisverycomplicatedandthemainresultisthesamewiththecasev0=0(itwillbedealtwithinAppendixⅦ).Ithasbeenfoundthattheexponentialtermexp(ax+by)intheconstitutiveequationsbecomesexp(ax/2+by/2-kr/2)intheexactsolution.
简介:Inthisstudy,wedevelopedageneralmethodtoanalyticallytackleakindofmovableboundaryproblemfromtheviewpointofenergyvariation.Havinggroupedtheadhesionofamicro-beam,dropletandcarbonnanotube(CNT)ringonasubstrateintooneframework,weusedthedevelopedlineofreasoningtoinvestigatetheadhesionbehaviorsofthesesystems.Baseduponthederivedgoverningequationsandtransversalityconditions,explicitsolutionsinvolvingthecriticalparametersandmorphologiesforthethreesystemsaresuccessfullyobtained,andthentheparameteranalogiesandcommoncharacteristicsofthemarethoroughlyinvestigated.Thepresentedmethodhasbeenverifiedviatheconceptofenergyreleaserateinfracturemechanics.Ouranalysesprovideanewapproachforexploringthemechanismofdifferentsystemswithsimilaritiesaswellasforunderstandingtheunityofnature.Theanalysisresultsmaybebeneficialforthedesignofnano-structuredmaterials,andholdpotentialforenhancingtheirmechanical,chemical,opticalandelectronicproperties.