简介:TheauthorsestablishtheHilbertianinvarianceprinciplefortheempiricalprocessofastationaryMarkovprocess,byextendingtheforward-backwardmartingaledecompositionofLyons-Meyer-ZhengtotheHilbertspacevaluedadditivefunctionalsassociatedwithgeneralnon-reversibleMarkovprocesses.
简介:AMarkovianriskprocessisconsideredinthispaper,whichisthegener-alizationoftheclassicalriskmodel.ItisproperthatariskprocesswithlargeclaimsismodelledastheMarkovianriskmodel.Insuchamodel,theoccurrenceofclaimsisdescribedbyapointprocess{N(t)}_(t≥0)withN(t)beingthenumberofjumpsduringtheinterval(0,t]foraMarkovjumpprocess.TheruinprobabilityΨ(u)ofacompanyfacingsuchariskmodelismainlystudied.AnintegralequationsatisfiedbytheruinprobabilityfunctionΨ(u)isobtainedandtheboundsfortheconvergencerateoftheruinprobabilityΨ(u)aregivenbyusingageneralizedrenewaltechniquedevelopedinthepaper.
简介:Magnetohydrodynamicsisoneofthemajordisciplinesinsolarphysics.Vigorousmagnetohydrodynamicprocessistakingplaceinthesolarconvectionzoneandatmosphere.Itcontrolsthegeneratingandstructuringofthesolarmagneticfields,causestheaccumulationofmagneticnon-potentialenergyinthesolaratmosphereandtriggerstheexplosivemagneticenergyrelease,manifestedasviolentsolarflaresandcoronalmassejections.Nowadaysdetailedobservationsinsolarastrophysicsfromspaceandonthegroundurgeagreatneedforthestudiesofmagnetohydrodynamicsandplasmaphysicstoachievebetterunderstandingofthemechanismormechanismsofsolaractivity.Ontheotherhand,thespectacularsolaractivityalwaysservesasagreatlaboratoryofmagnetohydrodynamics.Inthisarticle,wereviewedafewkeyunresolvedproblemsinsolaractivitystudiesanddiscussedtherelevantissuesinsolarmagnetohydrodynamics.
简介:Inthispaper,anewprocesstofabricateanelectromagneticsteppingmicromotorusingsurfacescarificiallayertechnology(SSLT)isillustrated,andtheSEMphotoofthesteppingmicromotorisshowed.Thetorqueofthesteppingmicromotorwithmaxsimumtorqueof60μNmisdirectlycalculatedbyusingelectromagneticslawsandthelawofconservationofenergy.ThestatorandtheshaftandtherotorofthemicromotorwiththematerialofnickelarefirstallfabricatedbynormalLIGAprocessatthesametime.ThesacrificiallayerstructurewiththematerialofAZresistismadeonthesurfaceoftherotorbyusingSSLT.ThestatorandtheshaftarefixedtogetherwithcoppersubstrateinsteadoftheoldTisubstratebyelectroplating.AfterremovingtheTisubstrate,PMMAresistandthesacrificiallayerstructure,therotorisseparatedfromthestatorandnewcoppersubstrate,andcanrotateonthenewsubstratedrivenbymagneticforce.Thefourcoilswith300turnseacharewoundonironbarsbyhandusingmicroscopeandsteppingmotor.Thebarsareassembledbyhandintothestatorholesfromrearofnewcoppersubstratetofromamagneticcircuitwiththestatorandtherotor.Apowersupplywithfourconsecutivepulsesprovidesthecurrentforthecoilswoundontheironbarsadnproducesthemagneticforcetodrivetherotortorunwiththespeedof60rpm.
简介:InthispaperareversibleMarkovprocessasachemicalpolymersreactionoftwotypesofmonomersisdefined.Byanalyzingthepartitionfunctionsoftheprocessweobtainthreedifferentdistributionsoftheaveragemolecularweight,dependingofthevalueofstrengthofthefragmentationreaction,andprovethatagelationoftheprocesswilloccurinthethermodynamiclimit.
简介:SinceitserliestyearsofR&D[1],theGEANT4simulationtoolkithasbeendevelopedfollowingsoftwareprocessstandardswhichdictatedtheoverallevolutionoftheproject.Thecomplexityofthesoftwareinvolved,thewideareasofapplicationofthesoftwareproduct,thehugeamountofcodeandCategorycomplexity,thesizeanddistributednatureoftheCollaborationitselfareallingredientswhichinvolveandcorrelatetogetherawidevarietyofsoftwareprocesses.Althoughin"production"andavailabletothepublicsinceDecember1998,theGEANT4softwareproduct[1]includesCategoryDomainswhicharestillunderactivedevelopment.Thereforetheyrequiredifferenttreatmentalsointermsofimprovementofthedevelopmentcycle,system,testingandusersupport,ThisarticleismeanttodescribesomeofthesoftwareprocessesastheyareappliedinGEANT4forbothdevelopment,testingandmaintenanceofthesoftware.
简介:Supernovaexplosionisapeculiarastronomicalphenomenon,whichhasarousedgreatinterestandextensiveresearchbyastronomers.Atpresent,however,itiserroneouslybelievedthatthesupernovaexplosionisasplendidfuneralofadyingstar.Infact,newastronomicalobservationsandtheauthor’stheoreticalstudieshaveshownthatintheprocessofastar’snever-endingevolution,numeroussupernovaexplosionsmayoccur,andsupernovaexplosionwillrunthroughmanystagesofstellarevolution.Whenevertheatmosphereofthestarbecomesverydenseanditssurfaceiscoveredwithathicklayerofmaterialagain,athermonuclearreactioncanbeignitedagain,causingasupernovaexplosion.Especially,whenthestarhasundergoneanumberofsupernovaeexplosionsanditssurfaceiscoveredwithmultiplelayersofsupernovaexplosionremnants,thecoreofthemassivestarmayundergosuddengravitationalcollapse,causingaviolentsupernova;whenastarisimpactedbyafallingcelestialbody,italsoproducesviolentsupernovaexplosions.
简介:Theelectrochemicalreductionbehaviorofbilirubin(BR)atplatinumelectrodeinDMFwasinvestigatedbycyclicvoltammetry,insituelectronspinresonancespectroscopyandinsiturapidscanningthinlayerspectroelectrochemistry.ExperimentalresultsrevealedthatthereductionofBRfirstlyundergoesanECEprocess:BR-+eBR-dimerize(BR)22-+e(BR)23-.Thegenerated(BR)23-canbere-oxidizedtoBRandthentopurpurin(Pu)byaseriesofoxidationprocesses:(BR)23--e(BR)22--2e2BR,BR--2eBV--2ePu.However,there-reductionreactionsofPuarenotthereverseprocesses.Thedifferentreductionmechanismsarediscussedindetail.
简介:Ultrasound(US)-inducedcavitationisaneffectivewayinoxidizingorganiccontaminantsinwastewatereitherastheindependentoperationunitorincombinationwithotheroxidationmethods.Inthispaper,blackliquorandfiltrateafteracidifyingandsettlingweresonicated.Theeffectofworkingparametersonultrasonicdegradationofblackliquor,suchasdifferentcombinationmethods,frequency,powersupply,initialconcentration,pH,durationtime,ionicstrengthandcatalystwerestudied.Theresultswereasfollows:(1)Attheconditionsof40kHz,100W,4h,pHat6andtemperature30±2℃,utilizingUS/US-H2O2/US-Fenton,weak-orangefiltrateturnedtocolloidwiththeincreaseoftimeandlittlesedimentproducedaftersettling.EspeciallyfiltratecametobemilkwhitecollidesandupperwaterapproachedtonearlyachromaticbyUS-Fenton.ComparedwiththeUS,US-H2O2/US-FentonCOD(Chemicaloxidationdemand)removalratiocanincrease15%,30%respectively.Becauseofmorehydroxylradicalsproducedinthereactionprocess;(2)Attheconditionof100Wand4h,thedegradationefficiencyofblackliquorwasbetterat40kHzoverat20kHz.Moreoverblackliquorcanbebiodegradedeasily.Thosebasedonthatthebigmoleculeofcontaminantsinaqueoussolutioncanbechangedintothelittlemoleculewithultrasound(3)Attheconditionof40kHzand4h,theCODremovalratioofblackliquorwasmorehigherat60Wthanat80W,whiletheremovalratioofCODat60Wwasnearlyclosetotheratioat100W;(4)Theinitialconcentrationofblackliquorinfluencedtheeffectofsonochemicaldegradation;(5)ThevariationofpHhadnoeffectondegradation;(6)Thelongerthedurationtime,thegreatertheremovalratioofCOD.Butthisratioincreasedslowlyafter4h;(7)Adding0.2g/LNaCltochangetheionicstrengthoftheblackliquor,theCODremovalratiocanincrease10%;(8)ThedegradationratesincreasedbythecoexistentcatalystsofTiO2,Co2+andAg+.
简介:OneofthemostchallengingissuesfacedinHEPinrecentyearsisthequestionofhowtocapitaliseonsoftwaredevelopmentandmaintenanceexperienceinacontinuousmanner.Tocapitaliseinourcontextmeanstoevaluateandapplynewtechnologiesastheyarise,andtofurtherevolvetechnologiesarlreadywidelyinuse,Italsoimpliesthedefinitionandadoptionofstandards,whileensuringreproducibilityandqualityofresults.TheCMSprocessimprovementeffortistwo-pronged.ItaimsatcontinuousimprovementofthewayswedoObjectOrientedsoftware,aswellascontinuousimprovementintheefficiencyoftheworkingenviuronment.Inparticulartheuseandcreationofde-factosoftwareprocessstandardswithinCMShasproventobekeytooursuccessfulsoftwareprocessimprovementprogram.WedescribethesuccessfulCMSimplementationofasoftwareprocessimprovementstrategy,followingISO15504sincethreeyears.WegivethecurrentstatusofthemostimportantprocessesfamiliesformallyestablishedinCMS,andprovidetheguidelineswefollowedbothfortooldevelopment,andmethodologyestablishment.
简介:Inordertounderstandthebreakupperformanceofcoaxialporousinjectors,thespraysofcoaxialporousinjectorswithtwodifferentporousmaterialcylinderlengthswerecomparedwiththoseofconventionalshearcoaxialinjectors.Toallowcomparison,thewallinjectionlengthsweredesignedtobeequivalenttothevalueoftherecessdepth.Coldflowsprayswerevisualizedusingback-litphotographymethodsandanalyzedquantitativelywithalaserdiffractionapparatus,inordertostudytheeffectsofthemomentumfluxratioandWebernumberonthebreakupforeachtypeofinjector.Incaseoftheshearcoaxialinjector,thelargeliquidcorewasobservedinlowairmassflowratecondition.However,thedestabilizationoftheliquidjetfromthecoaxialporousinjectorisalmostcompletewithintheinnerregion,neartheinjectorfaceplate.Additionally,betterbreakupperformanceinlowgasflowrateconditionwasobtainedwhentheporouscylinderlengthdecreased,whiletheshearcoaxialinjectorsshowedbetterbreakupefficiencywhentherecesslengthincreased.Inconclusion,thedifferentbreakupprocesscausedbytheradialmomentumintheinnerregionoftheporousinjectordisintegratedtheliquidcore.
简介:Acetonediffusioninpolycarbonatewasinvestigatedbyspin-echo1HNMRimagingmethodatroomtemperature.TheresultshowsthatthediffusionprocesssatisfiesCaseⅡdiffusion.Thevelocityofdiffusionfrontis13.8nmsec-1(0.05mm/h).
简介:Thedefinitionsandpurposesofenergysystemsandprocesssystemsarecomparedinthispaperbyconsideringtheroleofenergyinsystemswithemphasisonthedifferencesinthemethodsusedtooptimizetheexergoeconomicbenefitsofbothtypesofsystems.TheprocesssystemexergoeconomicrelationshipprimarilyincludetheestablishmentoftheThree-linkmodelofprocesssystems,thecompositionofobjectivefunctions,andthecorrespondingboundaryconstraintconditionsforoptimization.TheThree-Link-Method(TLM)whichisbasedonexergoeconomics,canbeusedtoeffectivelyoptimizeprocesssystems.TheTLMusedtooptimizeprocesssystemsisoutlinedinthispaper,Someaspectswhichneedfurtherdevelopmentarealsoidentified.
简介:Theeffectofresinstructureondesalinationofligninsolutionwasinvestigated,theoptimalstructureofresinisasfollows;crosslinkingdegreeas4%,ratioofcationogentoanionogenisnear1.withsuchresinthedesalinationofligninwasproducedverywellbecausetheresinhasbothmoleculesievingandionretardationproperties.Thesulfonationdegressofligninandtotalsaltcontentofligninsolutionweredeterminredwithionexchangetechnique,therelativeerrorlessthan1%.Thesaltcontentofsmallmoleculeintheligninsolutionwascalculatedfromsulfonationdegreeofligninandtotalsalt.Amonggelandmacroporousresinsthebestseparationofligninfromreducingsugarwasachievedwithinterpenetratingsulfonatedresin2×1.5×1.Theseparationofligninwithinterpenetratingresinwascarriedoutsimultaneouslywithfractionationoflignin,theeffectoffractionationwithmacroporoussulfonatedresinisbetterthanthatwithinterpenetratingresin,buttheformerhasadefinitesorptionofligninwhichdecreasedtherecoveryoflignin.