简介:InordertoimprovethehydrogenationanddehydrogenationperformancesoftheMg2Ni-typealloys,MgwaspartiallysubstitutedbyLainthealloy,andmeltspinningtechnologywasusedforthepreparationoftheMg20-xLaxNi10(x=0,2,4,6)hydrogenstoragealloys.ThestructuresofthealloyswerestudiedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM)andhigh-resolutiontransmissionelectronmicroscopy(HRTEM).Itwasfoundthatnoamorphousphaseformedintheas-spunLa-freealloy,buttheas-spunalloyscontainingLaheldamajoramorphousphase.WhenLacontentx≤2,themajorphaseintheas-castalloyswasMg2Niphase,butwithfurtherincreaseofLacontent,themajorphaseoftheas-castalloyschangedintoLaNi5+LaMg3phase.Thermalstabilityoftheas-spunalloyswasstudiedbydifferentialscanningcalorimetry(DSC),showingthatspinningratewasanegligiblefactoronthecrystallizationtemperatureoftheamorphousphase.Thehydrogenabsorptionanddesorptionkineticsoftheas-castandas-spunalloysweremeasuredusinganautomaticallycontrolledSievertsapparatus,confirmingthatthehydrogenabsorptionanddesorptioncapacitiesandkineticsoftheas-castalloysclearlyincreasedwithrisingLacontent.ForLacontentx=2,theas-spunalloydisplayedoptimalhydrogendesorptionkineticsat200°C.
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.
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简介:ThemagneticpropertiesandthephasestructureofTb1-xPrxFe1.96(x=0,0.1,...,0.7)werestudied.ItisfoundthatthesaturationmagnetizationoneasyaxisisdecreasedwithincreaseofPrcon-tent,from77.24Am^2·kg^-1forx=0,reducestominimumvalueof11.84Am^2·kg^-1forx=0.5,andreturnesto37.14Am^2·kg^-1forx=0.7.Thenon-cu-bicphasesappearbeyondx=0.2andthematrixchangesfrom1:2phaseforx=0to1:3phaseforx=0.4,atlastto2:17phaseforx=0.7.Thecom-poundsstructurewouldturnmorecomplexasthePrcontentincreases.
简介:Theeffectofanexternalelectricfieldonthecrystallizationbehaviorofamorphous(Nd0.1Fe0.9)3Balloywasinvestigated.ThecrystallizationproductofNd2Fe23B3phasewasobtainedforthisamorphousalloyannealedat923Kfor300sinthepresenceofanexternalelectricfieldof300kV·m-1(50Hz);whilethecrystallizationproductsareNd1.1Fe4B4,α-Fe,andFe3Bphasesunderthesameannealingconditionexceptforfree-electricfield.Ontheotherhand,thesampleswereannealedat1023K,whichishigherthanthedecompositiontemperatureofmetastableNd2Fe23B3phase,for600s.Inthecaseofthepresenceofanexternalelectricfield,themetastableNd2Fe23B3phase,asamainphase,isstillstayedinthesample.ThisfactsuggeststhattheexternalelectricfieldenhancesthestabilizationofthemetastableNd2Fe23B3phase.Theeffectoftheexternalelectricfieldonthephaseselectionandstabilizationwasexplainedintermsofthespecificconductancedifferencebetweenthecrystallizationproducts.
简介:JCCY-6铲运机为金川集团公司矿山井下主力无轨采掘设备,该车装配的关键零部件驱动桥为80年代美国公司设计的产品,该型号驱动桥技术落后、故障率较高,行车性能无法满足安全生产需求,而且该型号驱动桥厂家已经停产淘汰,目前无法采购,严重制约金川集团公司矿山设备的正常运行。本文论述了通过技术改进.使用德国KESSLER公司的D106重型驱动桥替换现有车辆的美国公司生产的老式驱动桥的方案并成功应用。
简介:结合实例,分析数控车削加工中的基本工艺、机床坐标系和工件坐标系的建立问题;针对FANUC0i系统数控车床的对刀法,阐述了多把刀具的对刀步骤;并对零件进行了手动程序编制.
简介:AnovelsolidsolutionCe6MoO15wasachieved.Theirstructureandoxideionicconductivitywerestudied.BasedonCe6MoO15,rareearthelementsubstitutiononceriumsiteshowsthatallresultingoxidesenhancetheconductivityfurther,andhavehighoxide-ionconductivity,whichmaybeakindofpromisingmaterialforSOFCs.