简介:分析了影响45Mn17Al3钢磁导率性能的主要因素。通过工业试验确定了合理的化学成分、热处理工艺制度及试样表面加工要求等。试验结果表明,45Mn17Al3钢在800、4000及8000A/m三个磁场强度下,相对磁导率μr≤1.005,满足了某些特殊工程对磁性能的较高要求。
简介:微波合成因合成速度快、清洁和能效高而成为一种非常有前途的材料制备方法。与常规方法相比,很多材料可以在相对较低的温度和较短的时间内用微波加热合成。该文作者利用混合微波加热技术,在短时间内由镁粉、镍粉和石墨粉合成了具有立方钙钛矿结构的金属间化合物超导材料MgCNi3。利用微波加热合成的MgCNi3,镁的挥发和氧化程度明显减少。粉末X射线衍射显示合成的样品主相为MgCNi3,还含有少量未反应的石墨粉和微量的MgO杂相。金相显微镜和扫描电镜观察表明超导样品的晶粒大小一般为2~6μm。由标准的四探针电阻方法和磁测量技术测得样品的超导起始转变温度为6.9K,转变宽度约为0.8K。
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简介:ThephotoluminescencepropertiesofBiTaO4∶Pr3+andBiTaO4atroomtemperaturewerestudied,andtheinfraredtransmissionanddiffusionreflectionspectraofBiTaO4weremeasured.ThephotoluminescencespectrumofBiTaO4peaksatabout420,440and465nm.Therehasanobviousexcitationbandfrom330to370nm.ThephotoluminescencespectrumofBiTaO4∶Pr3+consistsofthecharacteristicemissionofPr3+,anditsmainpeakisat606nmfrom3P0→3H6transitionofPr3+.Itsexcitationspectrumconsistsofthewidebandwithmaximumat325nm,thewidebandintherangeof375~430nm,andthecharacteristicexcitationofPr3+.Thebandsat325nmand375~430nmmaybefromtheabsorptionofthechargetransfertransitionofthetantalategroupanddefectenergylevelsinitsforbiddenband,respectively.ThereisenergytransferfromhosttoPr3+.BecauseboththehostdensityandphotoluminescencepeakintensityofBiTaO4∶Pr3+aresuperiortoPbWO4,BiTaO4∶Pr3+maybeapotentialheavyscintillator.
简介:TheeuropiumionsdopedMMoO_4(M=Sr,Ba)nanophosphorsweresuccessfullysynthesizedviaafacilehydrothermalmethodusingisopropanol.Therelationshipbetweenphosphorcrystallinephase,morphology,photoluminescentpropertiesandhexadecyltrimethylammoniumbromide(CTAB)concentration,pHvalueinprecursorsolutionwasinvestigated.TheresultsindicatedthatthemorphologyandphotoluminescentpropertieswerestronglyinfluencedbyCTABconcentrationandpHvalueinprecursorsolution.InSrMoO_4:Eu~(3+)hosts,thephosphorsurfacetendedtobecomesmootherastheconcentrationofCTABwasincreased;whileparticlestendedtoagglomerateasincreasingpHvalue.TherelativeintensityratioofchargetransferbandtoEu~(3+)characteristicemissionpeaksofMMoO_4:Eu~(3+)(M=Sr,Ba)waschangedasCTABconcentrationandpHvaluechanged.TheemissionspectraofMMoO_4:Eu~(3+)(M=Sr,Ba)couldbeadjustedbyCTABconcentrationandpHvalueduetotheirimpactsonthestructure.ItwasimportantthatthedifferentmorphologiesandphotoluminescentpropertiesofMMoO_4:Eu~(3+)(M=Sr,Ba)couldbeobtainedbythefacilehydrothermalmethodandmodulatedbychangingCTABconcentrationandpHvalue.
简介:VariousaffectingfactorsanddegradationmechanismwerestudiedonultrasonicdegradationofmethylorangeadoptingY2O3dopinganataseTiO2catalystpreparedinlaboratory.Intheexperiment,theUV-VISspectrophotometerwasusedtofollowandinspectthedegradationprocessofmethylorange.TheresultsindicatethattheultrasonicdegradationratiosofmethylorangeinthepresenceofanataseTiO2catalystaremuchbetterthanthosewithoutcatalyst.Moreover,thecatalyticperformanceofY2O3dopinganataseTiO2catalystisobviouslyhigherthanthatofanataseTiO2catalystwithoutdoping.TheoptimalconditionswereadoptedinthisworkandthedegradationandCODeliminationratioofmethylorangegotto98%and99.0%in90min,respectively.