简介:用滚镀的方法在金刚石表面镀Ni层和纳米Si3N4/Ni复合镀层,用扫描电子显微镜观察金刚石镀前和镀后的表面形貌,用DKY-1型单颗粒抗压强度测定仪测量金刚石单颗粒的抗压强度。用热压烧结的方法得到铁基结合剂金刚石节块,在INSTRON-5569型万能材料试验机上测量节块的抗弯强度,在NMW-1立式万能摩擦磨损试验机上测试节块的耐磨性。结果表明:在金刚石表面镀Ni层和纳米Si3N4/Ni复合镀层后,表面镀层均匀,纳米Si3N4/Ni复合镀层比纯Ni层更致密,更平滑,晶粒更细小;纳米Si3N4/Ni复合镀层金刚石单颗粒有更高的抗压强度;纳米Si3N4/Ni复合镀层金刚石铁基结合剂节块有更高的抗弯强度和更优良的耐磨性。
简介:Organicsubstancesuchassolventandresin'seffectonluminescentcapabilityofSrAl2O4:Eu2+,Dy3+phosphorwasstudied.Someorganicsolventsandresinswereselectedforexperimentation.TheresultsindicatethatthoseorganicsolventswillnothavenegativeeffectontheappliedcapabilityofSrAl2O4:Eu2+,Dy3+phosphor.Adoptingtheorganicresinsandcoveringmethod,theafterglowluminanceofSrAl2O4:Eu2+,Dy3+phosphorwasincreasedby85.01%and82.51%.
简介:Er3+-Tm3+-Yb3+tri-dopedBaMoO4phosphorsweresynthesizedbyco-precipitationtechniqueandcharacterizedbyX-raydiffractionanalysis,absorptionstudyandfieldemissionscanningelectronmicroscopyanalysis.Upconversionaswellasdownconversionluminescencestudieswereperformedbyusingnearinfrared(980nm)andultraviolet(380nm)excitations.Energyleveldiagram,pumppowerdependenceandcolourcoordinatestudywereutilizedtodescribethemulticolorupconversionemissionproperties.Undersingle980nmdiodelaserexcitationthedualmodesensingbehaviourisrealizedviaStarksublevelsandthermallycoupledenergylevelsoftheTm3+andEr3+ionsinthepreparedtri-dopedphosphors.AcomparativefluorescenceintensityratioanalysisforintegratedemissionintensitiesarisingfromtheStarksublevels{1G4(a)and1G4(b)}andthermallycoupledenergylevels{2H11/2and4S3/2}oftheTm3+andEr3+ions,respectivelywascarriedoutinthepreparedtri-dopedBaMoO4phosphors.ThemaximumsensitivityforthermallycoupledenergylevelsoftheEr3+andStarksublevelsoftheTm3+ionwasreported.Thedevelopedphosphorscouldbeusefulinthedisplaydevicesandopticalthermometricapplications.
简介:Hydrogen,asatemporaryelementintitaniumalloys,isverygoodincontrollingmicrostructure.ThemicrostructureandphasetransformationofTi6A14ValloyareaffectedbytheamountofTiH,addedintothemeltofTi6A14Valloyduringtheinductionskullmelting(ISM)process.Thisprocess,calledmelthydrogenation,wasstudiedinthispaperthroughtheuseofopticalmicroscopy,scanningelectronmicroscopy(SEM)andtransmissionelectronmicroscopy(TEM).Theresultsareasfollows:aftermelthydrogenation,boththesolidificationmacrostructureandmicrostructureofTi6A14Valloyarerefined;theαphaseprecipitatesinalamellarformwiththeresidualβphasefromthegrainboundaries;δ-hydridesprecipitateduringthesolidificationprocessasaresultoftheexistenceofhydrogen.TheSphasewithanF.C.C.structurecanbeobservedbyTEMintheαphaselaminaeofspecimenswith1.25%TiH2.Inaddition,thedependenceofthemicrohardnessofspecimensontheweightpercentageofTiH,addedtothemeltduringtheISMprocesswasalsostudied.
简介:RE-dopedNi-basedcatalystswerepreparedbysol-gelmethod.ThesecatalystswereappliedtothereactionofCO2reformingCH4tosyngas.ThestudiesrevealthatRE-doped(RE=La,Ce,Sm,Yb)Ni-basedcatalystsshowhighercatalyticactivitythanundopedNi-basedcatalyst,andwiththeincreasingofRE-dopedquantity,thecatalyticactivityofcatalystsexhibitsregularchanges.WhenRE-dopedquantityis0.2%(molarratio),thecatalystsshowthebestcatalyticactivity.
简介:ThestructureandhydridingperformanceofLa0.6Nd0.4Ni4.8Mn0.2Cux(x=0~0.4)alloyswereinvestigatedinordertodevelopsuitablematerialsformetalhydrideairconditioner.TheeffectofCuadditiononthecrystalstructure,equilibriumpressure,hydrogencapacityandhysteresisaswellashydrogenabsorption/desorptionkineticsweresystematicallystudiedbyusingthemeasurementofP-Cisotherms,X-raydiffractionandscanningelectronmicroscopy.AstheamountofCuincreases,theplateaupressureincreasesandhydrogenabsorption/desorptionkineticsisimproved,buttheeffectivehydrogenstoragecapacitydecreases.Itisshownthatvariationsinthebasalplaneparameteracanbeusedasanindicationfortheplateaupressurechanges.Withtheincreaseofparametera,theplateaupressuredecreases.ForLa0.6Nd0.4Ni4.8Mn0.2Cux(x=0~0.4)alloysthereisarelationshipbetweentheeffectivehydrogenstoragecapacitiesandtheratiosoftheirunitcellparameterscanda.Theeffectivehydrogenstoragecapacitydecreaseswithincreaseofa/c.
简介:有一致形态学的新奇红射出的K2(Ge,Si)F6:Mn4+黄磷被一起沉淀方法综合。纯K2有P636阶段>除P3m1空间组以外的mc空间组就被Si的加入在K2在房间温度的GeF6根据XRD描述。薄片状的显示出的SEM图象和为K2GeF6:Mn4+和K2(Ge,Si)F6:Mn4+黄磷分别地。光致发光刺激(PLE)和光致发光(PL)在K2GeF6:Mn4+和K2(Ge,Si)F6:Mn4+系统。并且K2有Si的GeF6:Mn4+显示出一座强壮的山峰。同时水晶的地包围Mn4+变化能在这个氟化物系统影响腐烂时间。带的设备的颜色范围基于K2(Ge,Si)F6:Mn4+和K2分别地,GeF6:Mn4+到达了多达94.58%NTSC(国家电视标准委员会)和94.386%NTSC那基于氮化物红黄磷比那高得多。在K2(Ge,Si)F6:Mn4+黄磷的所有这些原来的特征作为为改善灯光和常规白LEDs的显示质量的红黄磷为潜在的应用是合乎需要的。
简介:PolycrystallineGd2(MoO4)3:Dy3+phosphorshavebeensynthesizedbyhightemperaturesolid-statereactionmethod.ThephosphorswerecharacterizedwithX-raydiffractometer,thermogravimetricanalysisanddifferentscanningcalorimeter,scanningelectronmicroscopy,andphotoluminescencespectrofluorimeter.Severalpeaksat351,389,425,452,and472nmappearedinphotoluminescenceexcitationspectrum,whichmatchedwellwiththeemissionoftheultraviolet(UV)andblue-lightemittingdiode(LED)chips.Uponexcitationat389nmUVlight,intenseemissionscenteredat484,575and668nmwereattributedtothetransitionsof4F9/2→6H15/2,4F9/2→6H13/2and4F9/2→6H11/2ofDy3+,respectively.ThechromaticitycoordinatesandcorrelativecolortemperatureshavebeencalculatedandpresentedintheCommissionInternationaldeI'Eclairage(CIE)diagrams.TheresultsindicatedthatGd1.9(MoO4)3:Dy0.13+withCIEcoordinatesof(x=0.38,y=0.41)andthecorrelativecolortemperatureof4134KisapotentialcandidateforwhiteLEDs.
简介:采用高分子网络凝胶法合成Sm^3+掺杂YPO4纳米荧光材料,利用X射线衍射(XRD)、透射电镜(TEM)、傅里叶红外光谱(FT-IR)和荧光光谱等对合成产物的晶体结构、颗粒尺寸、形貌和光学性能进行分析与测试,并研究Sm^3+掺杂浓度(n(Sm)/n(Y+Sm))的影响。结果表明,采用高分子网络凝胶法合成的YPO4:Sm^3+为单一的四方晶系磷钇矿结构的YPO4晶体,颗粒尺寸约为20nm。其激发光谱在405nm处有一最强激发带,属于Sm^3+的6H5/2-4K11/2跃迁,发射光谱在603nm^处有一最强峰,属于Sm3+的4G5/2-6H7/2跃迁。激发和发射光谱测试结果表明,Sm3+掺杂YPO4荧光材料可以被405nm波长的光有效地激发,发射出强烈的Sm3+特征橙红色光。当Sm3+掺杂浓度高于2%时观察到浓度猝灭现象,浓度猝灭机理为电多极-电多极相互作用。