简介：Electrospinning技术被用来制作PVP/Ce(NO3)3合成microfibers。不同词法CeO2nanofibers被PVP/Ce(NO3)的锻烧获得3合成microfibers并且被扫描电子描绘显微镜学(SEM)，传播电子显微镜学(TEM)，X光检查衍射(XRD)，热gravimetric和微分热分析(TG-DTA)，并且(FTIR)。SEM显微图显示合成纤维的表面是光滑的并且随锻烧温度的增加变得粗糙。CeO2空nanofibers的直径(在600点的300nm

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简介：TheCe-Fe-OmixedoxidewitharatioofCe/Fe=7:3,whichwaspreparedbycoprecipitationmethodandemployedasoxygencarrier,fordirectpartialoxidationofmethanetosyngasintheabsenceofgaseousoxygenwasexplored.ThemixedoxidewascharacterizedbyX-raydiffraction(XRD),X-rayphotoelectronspectroscopy(XPS)andscanningelectronmicroscopy(SEM),andthecatalyticperformanceswerestudiedinafixed-bedquartzreactorandathermogravimetricreactor,respectively.Approximately99.4%H2se...

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简介：LanthanidedopedNaYF4microcrystalsweresynthesizedviaafacilehydrothermalmethod.MulticolorupconversionluminescencewasobservedinNaYF4microcrystalsdopedwithYb3+/Er3+,Yb3+/Tm3+,andYb3+/Er3+/Tm3+undertheexcitationof980nminfraredlight.Importantly,theexcitationpowerdensitydependenceofupconversionemissionintensityindicatedclearlytheenergytransferfromTm3+toEr3+ionsundertheexcitationoflowpowerdensity(5×102–9×102W/cm2).Meanwhile,theinverseenergytransferfromEr3+toTm3+ionsundertheexcitationofrelativelyhigherpowerdensity(4.1×104–4.9×104W/cm2)wasalsorevealed.ThiswasadirectevidenceforreversibleenergytransferbetweenEr3+andTm3+ions.Undertheexcitationofhighpowerdensity(4.1×104–4.9×104W/cm2),darksensitizerswerealsomotivatedsothatthebottleneckeffectofhighconcentrationYb3+iondopingwasbroken.ThiswasthemainreasonforrealizinghighupconversionefficiencyofthesampleswithheavydopingofYb3+ion.

简介：Inthedirectfiredfurnaceofacontinuousannealingline,sealrollsaresusceptibletodeformationthatleadstosurfacedefectsofsteelstrips.Accordingtofailureanalysis,thereasonsincludeimproperstructuraldesignandheatimbalance.Animproveddesignhasbeenproposedtoreducestressconcentrationandthermalradiation.Aheattransfermodelhasbeenemployedtodeterminetheproperwaterflowrateforrollcooling.Industrialapplicationprovesthatsealrollswiththenewdesignhaslessdeformationandlongerservicelife.