简介:济钢对闲置的M84100/5M轧辊磨床的改造,既满足了宽厚板生产的需要,还节约了资金,同时也为轧辊磨床的改造积累了经验。
简介:Thecrackingandaromatizationofn-hexaneoverH-ZSM-5modifiedbyvariousrareearthswereinvestigatedbymeansofcontinuousflowmicro-reactor.ThesurfacepropertiesofmodifiedH-ZSM-5catalystswereobtainedfromIR,XRDandXPS.Theresultsshowthattherareearthsenhancethearomatizingpropertiesofthecatalystswhicharepreparedbymechanicalmixturemethod.Theresultsofn-hexanecrackingandaromatizationarecorrelatedwiththeacidity.TheBrnstedacidicsitesaretheactivesitesofn-hexanearomatization,whileLewisacidsiteplaysanimportantroleinn-hexanecracking.
简介:ThemeasurementsoftemperaturedependenceofthemagneticsusceptibilityofLa1-xSrxCoO3perovskiteoxidesatdifferentSrdoping(0≤x≤0.5)andannealingtemperaturewerepresented.Forthesamplewithx=0.1,ashoulderwasobservedaround150K,andapeakwhichisonefeatureofspinglassappearedaround50Kinthecurveofsusceptibilityversustemperature.Thehigh-temperature(250~420K)susceptibilityfitswellwithCurie-Weisslawforallsamples.WeissconstantandeffectivemagneticmomentweredeterminedandtheirvariationswithSrdopingandoxygenannealingconditionwereobtained.TheWeissconstantincreasesmonotonouslywithSrcontentforx>0.2.Thevaluesofeffectivemomentswereinterpretedwiththespinstateofcobaltions.Studiesonthesusceptibilitiesofthesampleswithx=0.2underdifferentpreparationtemperaturesandannealingtemperaturesshowthattherisingofsinteringtemperatureandannealingtemperaturewillincreasethepara-ferromagnetictransitiontemperature,andreducetheeffectivemomenttonormalvalue.OurresultshowsthatbothCo3+andCo4+ionsshouldbeinISstateafterannealingandtheoxygenannealingcausesthetransitionofCo3+spinstatefromHStoIS.
简介:探讨了在大生产条件下4Cr5MoSiV1钢的脱碳层测定原则。结果表明,金相法测定结果较准确且操作简便
简介:NanosizedBaCeo.95Yo.o5O3-δpowderswiththehomogeneouscompositionweresynthesizedbyanewcombustionprocessbasedonthePechinimethod.Apolymericprecursorsolwasformedbyuseofcitricacidandethyleneglycolasthechelatingagentsofmetalions.Theperovskite-typeBaCeo.95Yo.o5O3-δpowderswithuniformshapeandsmallerthan40nminsizedwereobtainedthroughthecombustionofthepolymericprecursorsolattheexistenceofnitricacidandammoniumhydroxide.Itwasfoundtheparticlesizecouldbecontrolledbymodulatingthequantitiesofnitricacidandammoniumhydroxide,thequantitiesoftheresidue,carbonateionswerealsoaffectedbythequantitiesofthecitricacidandethyleneglycol.
简介:ThesinglecrystalgrowthofstoichiometrichostluminescentcrystalNa5Eu(WO4)4hasbeeninvestigated.UsingNa2WO4asaflux,theoptimumconditionstogrowapuresinglecrystalbyflux-slow-coolingmethodhavebeendetermined.Ahighopticalqualitysinglecrystalofdimention4.5mmhasbeengrown,whichisthelargestoneasweknowsofar.Themicro-hardnessofNa5Eu(WO4)4singlecrystalis3.46×103MPa.Itsrefractiveindexis1.81inwhitelightwavelengthregionandthespecificgravityis5.65g/cm3.Thefluorescentandexcitationspectrahavebeendeterminedandthereasonofthefluorescentquenchof5D2and5D1to7FjofEu3+canbeexplainedasmulti-phononnon-radiationtransition.
简介:LuminescencelifetimeofCe(Ⅲ)forCe0.9RE0.1P5O14,whereREdenotesrareearthionsotherthanCe(Ⅲ),wasmeasuredbymeansofthetime-correlatedsinglephotoncountingtechnique.Ithasbeenfoundthatthelifetimedataarecapableofelucidatingtheenhancementorquenchingofcerium(Ⅲ)luminescencebyalienREions(otherthanCe)indoublydopedceriumpentaphosphatecrystal.