简介:FluorescencespectraofSm2+andEu2+→Sm2+energytransferwerestudiedinSrB4O7.Thereappearsonlyfluorescencefrom5D0transitionofSm2+at77K.Thevibroniclinesassociatedwith5D0→7F0transitionwereobserved.Thethermalpopulationtoupperstatesof5D1and4f5dlevelsfrom5D0givesriseto5D1→7FJand5d→4fradiativetransitionsofSin2+athighertemperature.
简介:黄磷(Bi1-xSmx)2ZnB2O7(x=0.01,0.03,0.05,0.07,和0.09)被常规稳固的州的反应综合。所有样品的纯净被X光检查粉末衍射(XRD)检查。XRD分析证明所有这些混合物具有Bi2ZnB2O7的一个单个阶段,显示在Bi2ZnB2O7的双性人(3+)能被没有晶体结构的变化的Sm(3+)部分代替。在房间温度的刺激和排放系列显示出Sm(3+)的典型4f-4f转变。主导的刺激线在404nm附近由于(6)H5/2→(4)K11/2和排放光谱在563,599,646,和704nm由一系列线组成由于(4)G5/2→(6)H5/2,(6)H7/2,(6)H9/2,并且(6)H11/2分别地。在Bi2ZnB2O7的Sm(3+)的最佳的集中关于3mol%(相对1mol双性人(3+))并且批评距离Rc作为2.1nm被计算。Bi1.94Sm0.06ZnB2O7的排放紧张的温度依赖在在100和450K之间的温度范围被检验。紧张下降了到起始的紧张的一半的熄灭的温度是280K。为在Bi1.94Sm0.06ZnB2O7的Sm(3+)的一生作为0.29和1.03ms的价值被适合。
简介:利用粉末冶金方法研制了Sm(CobalFe0.24Cu0.08Zr0.027)7.0,Sm(CpbalFe0.27Cu0.05Zr0.027)7.0,Sm(CobalFe0.26Cu0.05Zr0.026)7.03种高温永磁,并对其磁性能、温度稳定性和显微结构进行了分析.结果表明:样品Sm(CobalFe0.27Cu0.05Zr0.027)7.0具有最高的内禀矫顽力(2165.6kA·m-1)和最大磁能积(212.0kA·m-3);3种磁体的温度系数都较低,最高使用温度均在400℃以上,大大高于一般商用磁体;增加Sm,Co,Cu的含量和减少Fe的含量可以提高材料的温度稳定性.X射线分析表明,合金中含有Sm2(Co,Fe)17主相,Sm(Co,Cu)5相,含Zr化合物等.Sm(Co,Cu)5相、单质Zr、晶粒边界等钉扎畴壁,使合金具有较高的矫顽力.
简介:Thecrystalandmolecularstructuresof[(C3H7O)2PS2]2(CCDCNo.217201)weredeterminedbymeansofX-raycrystallography.ItcrystallizedinatriclinicsystemwithspacegroupP1^-andlatticeparametersa=0.82794(3)nm,b=0.84764(2)nm,c=0.85034(3)nm,α=97.78(3)°β=110.77(3)°,γ=94.95(3)°,V=0.54701(9)nm^3,Z=1.Inthismolecule,thetwodiisopropyldithiophosphategroups,[(C3H7O)2PS2]2,whichareparalleltoeachother,arelinkedbyanS--Sbondandthereexistinversioncentersinthemolecule,Inthestructure,theP=Sbondsinthetwodithiophosphateunitsaretrans-orientedtoeachother.
简介:Lifetimemeasurementsoflow-lyingexcitedstatesin^87Zrhavebeenperformedviaβ-γcoincidences.The127MeV^32SbeamwasdeliveredfromtheSector-FocusingCyclotron(SFC)oftheHeavyIonResearchFacilityinLanzhou(HIRFL).Theparentnuclei^87Nbwereproducedbythereaction58Ni(32S,2p1n),atabeamenergy127MeVthrougha8umAldegrader.A200ug/cm^2layerof58Nievaporatedontoa200ug/cm^2thickcarbonfoilwasemployedasthetarget.Afterevaporationresidueswereseparatedfromtheprojectilebeamsbythegas-filledrecoilseparatorSHANS[1],thenucleiofinterest87Zrcanbeobtainedwithahigherpurityandthenwereimplantedintoa300umsilicondetector.
简介:Gasphasereductionofcarbonmonoxidetoformaldehydeandethylenewasfoundinelectrochemicalcellwithaninorganicionexchangerα-Zr(HPO4)2·H2Ousedassolidproton-conductingelectrolyteatroomtemperatureandatmosphericpressure.ThetypeandamountoftheelectroreductionofCOdependonthedifferentmetalelectrodesandcurrentdensities,whichgivesalankbetweenheterogeneouscatalysisandelectrochemistry.
简介:Nd_2Zr_2O_7isbeingexploredasanalternatethermalbarriercoating(TBC)materialforoperatingabove1300°C,andgreatefforthasbeenmadetoenlargeitsthermalexpansioncoefficient(TEC)andimproveitstoughness.Inthisstudy,Sc_2O_3wasdopedtoNd_2Zr_2O_7.Thephasestructure,TECsandtoughnessof((Nd_(1-x)Scx))_2Zr_2_O7(x=0,0.025,0.05,0.075,0.1)compoundswereinvestigated.((Nd_(1-x)Scx))_2Zr_2_O7(x=0,0.025,0.05,0.075)exhibitedpyrochlorestructure,while((Nd_(0.9)Sc_(0.1)))_2Zr_2O_7consistedofpyrochloreandfluoritephases.WiththeincreaseoftheSc_2O_3content,theorderingdegreeofthepyrochloreinthecompoundsdecreased.In((Nd_(1-x)Scx))_2Zr_2O_7series,((Nd_(0.925)Sc_(0.075)))_2Zr_2O_7exhibitedthelargestTEC,whilethetoughnessofthecompoundsincreasedwithincreasingtheSc_2O_3content.Therelatedmechanismswerediscussedbasedonthecrystalstructureanalysis.ConsideringtheTECandtoughness,10mol%Sc_2O_3wassuggestedastheoptimaldopingcontentforNd_2Zr_2O_7ceramic.
简介:Atacertainhightemperature,thiscyclewillbedominantandendtherp-processtoheavierregion[2].Itprovidesanuppertemperaturelimitforrp-processalongtheprotondriplinetoproducenuclidesbeyondA=84,includingthelightpnuclidesof92;94Mo,96;94Ru.TheexistenceofZr-Nbcycleisanimportantquestioninrp-process[2].α-separationenergy(Sα)of84Moplaysanimportantroleintheformationofthiscycle.Astrongenhancementof83Nb(p,α)reactionrateisduetoaverylowSαof84Mo[1].
简介:研究了YBaCu3O6~7超导催化剂上CO2的加氢制醇反应。考察了温度、压力和空速等条件对催化剂反应性能的影响。反应的主要产物是甲醇、CO和少量甲醚。利用XPS、XRD和AFM等技术对催化剂的结构、铜的存在状态和反应活性位进行表征发现,在反应过程中,YBa2Cu3O6~7由orthombic相转变为tetragonal相。反应活性位可能是Cu(I)物种。反应后催化剂颗粒的分散程度明显提高