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46 个结果
  • 简介:Asanimportantmulti-functionalmaterialappliedinsurfaceacousticwavedevices,opticalcommunications,laserandoptoelectronicsduetoitsgoodphotoelectricandpiezoelectricproperties,lithiumtantalate(LiTaO3)hasdrawnextensiveinterests[1].NumerousphysicalpropertiesofLiTaO3,suchasacoustical,electronicstructures,opticalpropertiesandeffectivemass,thermodynamicproperties,havebeenreportedinseveralpapers.Pointdefectswillaffecttheelectronicstructurewhichshouldberesponsibleformanyphysicalproperties,especiallyopticalproperties.

  • 标签: FIRST-PRINCIPLE INVESTIGATION LITAO3
  • 简介:CaF2:Ho3+/Yb3+nano-particleswithintensegreenup-conversion(UC)luminescencearesuccessfullysynthesizedviaafacilehydrothermalapproachbyusingNH4FasthefluoridesourceandNa2EDTAasachelatingreagent.PowderXraydiffraction(XRD),transmissionelectronmicroscopy(TEM),fieldemissionscanningelectronmicroscopy(FE-SEM),andUCemissionspectraareusedtocharacterizethestructures,shapes,andluminescentpropertiesofthesamples.TheeffectsfromfluoridesourcesandchelatingreagentsontheformationsofCaF2nano-particlesareinvestigated,andtheformationprocessisalsodeduced.Undertheexcitationofa980-nmlaserdiode,thesampleseachshowagreenup-conversionemissioncenteredat540nmcorrespondingtothe5S2/5F4→5I8transitionsofHo3+.Moreover,theUCmechanismsofHo3+/Yb3+co-dopedCaF2nano-particlesarealsodiscussed.

  • 标签: 上转换发光 水热合成 氟化钙 共掺杂 场发射扫描电子显微镜 乙二胺四乙酸二钠
  • 简介:采用燃烧法合成了La1.6(MoO_4)_3:Eu_0.4^3+纳米晶末,研究了其声子一掺杂-晶格相互作用和发光性质。x射线粉末衍射(XRD)分析表明,在500~900℃退火后,La1.6(MoO_4)_3:Eu_0.4^3+样品为单一晶相。对样品进行了光致发光(PL)测量,激发Mo^6+-O^2-电荷迁移带,观察到Eu^3+的系列发光,表明Mo^6+-O^2-带和Eu^3+间存在能量传递,中心波长分别在λ1=469nm和λ2=426nm处的两个one-phonon边带,相应的声子能量分别为767和1202cm^-1,分别对应于Mo=0和Mo-0-Mo伸缩振动。同时,计算了两个局域模电子一声子耦合强度的黄昆因子分别为S1=0.055和S2=0.037,为揭示其三价离子高传导特性及其负热膨胀物理特性提供了实验基础。

  • 标签: 发光特性 燃烧法 La1.6(MoO_4)_3:Eu_0.4^3+纳米晶 局域模 one-phonon边带
  • 简介:Theeffectofpromotercobaltandthesequencesofaddingcobaltandmolybdenumprecursorsontheperformanceofsulfur-resistantmethanationwereinvestigated.AllthesesampleswerepreparedbyimpregnationmethodandcharacterizedbyN2-adsorption,X-raydiffraction(XRD),temperature-programmedreduction(TPR)andlaserRamanspectroscopy(LRS).TheconversionsofCOforMo-Co/Al,Co-Mo/AlandCoMo/Alcatalystswere59.7%,54.3%and53.9%,respectively.Amongthesecatalysts,theMo-Co/AlcatalystpreparedstepwiselybyimpregnatingMoprecursorfirstlyshowedthebestcatalyticperformance.Meanwhile,theconversionsofCOwere48.9%forMo/Alcatalystand10.5%forCo/Alcatalyst.TheadditionofcobaltspeciescouldimprovethecatalyticactivityofMo/Alcatalyst.TheN2-adsorptionresultsshowedthatCo-Mo/Alcatalysthadthesmallestspecificsurfaceareaamongthesecatalysts.CoMoO4speciesinCoMo/AlcatalystweredetectedwithXRD,TPRandLRS.Moreover,crystalMoS2whichwasreportedtobelessactivethanamorphousMoS2wasfoundinbothCo-Mo/AlandCoMo/Alcatalysts.Mo-Co/Alcatalystshowedthebestcatalyticperformanceasithadanappropriatesurfacestructure,i.e.,nocrystalMoS2andverylittleCoMoO4species.

  • 标签: PROMOTER COBALT MOLYBDENUM IMPREGNATION sequence sulfur-resistant
  • 简介:Inthepresentwork,theLEDchipwasirradiatedbyusing59.6MeVNionsinaterminalchamberoftheSector-focusedcyclotron(SFC)intheNationalLabortaryofHeavy-ionAcceleratorsinLanzhou.The63MeVNionspenetratedthroughagoldfoilandscatteredinalargearea.Theenergyofionwasreducedto59.6MeVafterscatteringofthegoldfoil.TheLEDwasprovidedbytheSemiconductorLightingCenterinInstituteofSemiconductorinBeijing.TheluminencesoftheLEDbefore/afterirradiationweretestedthroughaintegratingsphereinSemiconductorLightingCenterinInstituteofSemiconductorinBeijing.Theluminancewastestedunderacurrentof350mA.Fig.1showstherelationshipbetweentheluminencesandtheirradiationfluences.Theirradiationledto

  • 标签: CHARACTERISTICS LUMINESCENCE IRRADIATED
  • 简介:TheprogressofresearchgoingoninGroupofEnergyMaterials(GEM),MaterialResearchCenter,in2014isinthefollowingthreeaspects.1.FacilitydevelopmentInordertopushforwardourstudyonfusionreactormaterials,weupgradedtheirradiationterminal(128#)ofthesectorfocusedcyclotron(SFC)atHIRFL,bydevelopinganewspecimenstagespecificforirradiationwithlow-fluencescatteredions.Sofartheterminaliscapableofirradiationtobothverylowfluences(106ions/cm2)andveryhighfluences(typically1016ions/cm2)forvariousmaterials.SpecimentemperaturecanbereadilycontrolledusingtheL-N2coolingstageorthethehigh-Tstage(upto600oC).Ourrecentinvestigationwithtransmissionelectronmicroscopy(TEM)ofthedefectsproducedbyhigh-energyNeionsinsteelspecimensprovidesaclearevidencethatdefectswereproduceduniformlyalongthedepthinthespecimen,indicatingthattheenergydegraderoftheterminalworkseffectivelytodispersetheionenergyinawiderange.AphotooftheterminaltogetherwithaSRIMestimateofdepthprofilesofdamageinan8%Crreducedactivationferritic/martensiticsteel(RAFMS)isshowninFig.1.

  • 标签: RESEARCH PROGRESS ENERGY
  • 简介:Heavyionbeamsaregenerallyrecognizedasoneofpowerfulmutagensinplantbreedingtogeneratenewmutantswithidealorusefulagronomiccharacters[1].12C6+ionbeams(80MeV/u)acceleratedbyHeavyIonResearchFacilityinLanzhou(HIRFL)wereusedtoirradiatewheatsamples,oneofthemajorwheatvarietiesinQinghaiprovince,namedGaoyuan448.Theradiationdosesrangedfrom10to200Gy.Theirradiatedsamples,controls,andanothermajorwheatvarietynamedAbowereplantedinfarmlocatinginLeducountyofQinghaiprovincein2014.

  • 标签: MUTATION BREEDING IRRADIATED
  • 简介:Arabidopsisthalianaisacommonresearchplantofmolecularandcellbiologicalresearchwhichhasshortlifecycleandhugeamountofseeds[1].Gammarayisoneoftheimportantphysicalmutagenswhichiswidelyusedinplantgeneticsandbreedingresearch[2].Thepurposeofthisstudyistoinvestigatethedose-effectofrayradiationsontherootdevelopmentofArabidopsis.Dryseedswereirradiatedbyrayswiththedoserangefrom100to1600Gy.

  • 标签: EFFECT IRRADIATION GROWTH
  • 简介:Nanostructuredγ-Al2O3withhighsurfaceareaandmesoporousstructurewassynthesizedbysol-gelmethodandemployedascatalystsupportfornickelcatalystsinmethanereformingwithcarbondioxide.ThepreparedsampleswerecharacterizedbyXRD,N2adsorption-desorption,TPR,TPO,TPH,NH3-TPDandSEMtechniques.TheBETanalysisshowedahighsurfaceareaof204m2g-1andanarrowpore-sizedistributioncenteredatadiameterof5.5nmforcatalystsupport.TheBETresultsrevealedthatadditionoflanthanumoxidetoaluminumoxidedecreasedthespecificsurfacearea.Inaddition,TPRresultsshowedthatadditionoflanthanumoxideincreasedthereducibilityofnickelcatalyst.Thecatalyticevaluationresultsshowedanincreaseinmethaneconversionwithincreasinglanthanumoxideto3mol%andfurtherincreaseinlanthanumcontentdecreasedthecatalyticactivity.TPOanalysisrevealedthatthecokedepositiondecreasedwithincreasinglanthanumoxideto3mol%.SEMandTPHanalysesconfirmedtheformationofwhiskertypecarbonoverthespentcatalysts.AdditionofsteamandO2todryreformingfeedincreasedthemethaneconversionandledtocarbonfreeoperationincombinedprocesses.

  • 标签: 甲烷二氧化碳重整 镍催化剂 纳米结构 氧化镧 合成气 NH3-TPD
  • 简介:Spallationtargetrepresentsoneofthemostchallengingcomponentsinacceleratordrivensystems(ADS)sinceitisthecomponentcouplingtheacceleratorandthesub-criticalcore.Itissubjectedtobombardmentofintenseprotonbeamandveryhighthermalloadinastrongradiationfield.TheirradiatedLBEtargetposesseverehandlingproblemsforthemaintenancestaffandotherscientistsduetoitsresidualactivity[1].ToassistthedesignofADS,thegeneralradiologicalsafetyaspectsoflead,lead-bismutheutectic(LBE)andtungstenspallationtargetwerestudiedwithMCNPX2.7code[2].Thespallationtargetwasirradiatedbya250MeV,10mAprotonbeamproducedbyalinearprotonaccelerator.Theneutronyield,neutronspectrum,residualproductionandtimeevolutionfortheirradiatedtargetwereanalyzed.

  • 标签: Designed China ADS
  • 简介:FK01isanewstrainofoil-sunflowerwithcytoplasmicmalesterilelineHAasfemaleparentandcytoplasmicmalesterilerestorerline19540asmaleparent.19540isamutantirradiatedbycarbonionwhichseedoilcontentincreases.FK01joined2014Gansuprovinceregionaltestofoil-sunflowerandplantedinsixsites:Jingyuanagriculturaltechniquespreadingcenter,Minqinagriculturaltechniquespreadingcenter,Jingtaiagriculturaltechniquespreadingcenter,Jiuquanagriculturalsciencesresearchinstitute,Tianshuiagriculturalsciencesresearchinstitute,andHuanxianseedcontrolstation.

  • 标签: OIL-SUNFLOWER NEW STRAIN FK01
  • 简介:Asoneofcandidatesforthefuelcladdingorstructurematerialusedinfourthgenerationfissionandfusiondemonstratereactor,MAXphasehasthepropertiesofbothceramicandmetal,suchashighmeltingpoint,hightemperaturestability,gooderosionresistanceandradiation-damagetolerance[1;2].Maxphaseisaseriesofceramicsofnanolamellarandhexagonalstructure.Mrepresentstransitionelement.Arepresentsthethirdorfourthmaingroupelement.XrepresentNandC.Inthedesignoflead-cooledfastreactor,itisrequiredthatthematerialshouldendurethecorrosionofliquidPb-Bialloy.Therefore,understandingoftheoxidelayersandtheirgrowthmechanismsinLBEisfundamentallyimportantforthedevelopmentofcandidatematerials.

  • 标签: LIQUID Pb-Bi ALLOY
  • 简介:AlNthinfilmsirradiatedwith100MeVU,95MeVArand84MeVCionsfromtheHIRFL-SFC(HeavyIonResearchFacilityinLanzhou)wereinvestigatedbyInfraredspectraandRamanspectra.ItappearedA1(TO),A1(LO),E1(To)andE2PhononvibrationabsorptionmodetoirradiatedsamplesinFig.1.652cm??1isvibrationabsorptionpeakofAlN,withtheincreaseofirradiationdose,thevibrationabsorptionbandappearacertainbroadeningphenomena.Lightercarbonionirradiationonthevibrationabsorptionbandbroadeningoftheimpactisnotbig.670cm??1isthetransverseopticalphononabsorptionpeakoftheE1(TO),afterirradiation,thevibrationabsorptionpeakandthebroadenAl-Nkeyintoanorganicwhole.249and660cm??1istheE2(low)andE2(high)

  • 标签: Characteristics IRRADIATED ENERGY
  • 简介:Arabidopsisthalianahasmanyadvantagesforplantresearch,includingashortgenerationtime,smallsize,largenumberofoffspring,andarelativelysmallnucleargenome.TheseadvantagespromoteddeepenscientificinvestigationforvariousbiologicalissuesandcharacterizedmanygenesusingArabidopsisthaliana[1].Inthisstudy,dryseedsofArabidopsisthalianawereirradiatedbyneonionbeamsfrom100to500Gy.Thenabout10dryseedsweresownonMurashigeandSkoogmedium,eachtreatmentgrouprepeatedforthreetimes,andalltheculturedishesweregrowninthecultureroomswiththeconditionof22?Cunder18h-light/6h-darkcycle.ImageJsoftwarewasusedtomeasurethelengthofrootsandhypocotylfromthedigitalphotostakenonthe7thdayaftersowing.

  • 标签: DOSE EFFECTS IRRADIATION
  • 简介:Inordertodeepentheunderstandingofthedifferencebetween0!1and1!0sinleeventupset(SEU)cross-sectioninanovelactivedelayelement(ADE)SRAM(StaticRandomAccessMemory)cell,theirradiationwascarriedoutatHeavyIonResearchFacilityinLanzhou(HIRFL).Usingthe86Kr26+ionsirradiatedthedeviceundertest(DUT)adoptedpartiallydepleted(PD)siliconofinsulator(SOI)technology.ThefeaturesizeofDUTfabricatedbyinstituteofmicroelectronic(IME)was180nm.TheschematicdiagramofSEUhardenADE-SRAMcellisshowninFig.1.TheADEisessentiallyaNMOSconnectedinonlyoneofthefeedbackpathsbetweenthetwoinventorsofthememorycell.Itplaysaroleasswitchingtransistor.Exceptduringawriteoperation,whentheswitchtransistoristurnedon(soasnottocompromisethewritespeed),theoff-ADEprovidesamuchgreaterRCdelaybetweenthetwoinventorsofthememorycelltoachievemuchimprovedSEUhardness[1].

  • 标签: SINGLE EVENT Upset
  • 简介:QuantumdynamicscalculationsforthetitlereactionH(2S)+S2(X3-Σg)→SH(X2Π)+S(3P)areperformedbyusingagloballyaccuratedoublemany-bodyexpansionpotentialenergysurface[J.Phys.Chem.A1155274(2011)].TheChebyshevrealwavepacketpropagationmethodisemployedtoobtainthedynamicalinformation,suchasreactionprobability,initialstate-specifiedintegralcrosssection,andthermalrateconstant.Itisfoundnotonlythatthereisareactionthresholdnear0.7eVinbothreactionprobabilitiesandintegralcrosssectioncurves,butalsothatboththeprobabilityandcrosssectionincreasefirstlyandthendecreaseasthecollisionenergyincreases.Theexistenceoftheresonancestructureinboththeprobabilityandcrosssectioncurvesisascribedtothedeeppotentialwell.Thecalculationoftherateconstantrevealsthatthereactionoccurringonthepotentialenergysurfaceoftheground-stateHS2isslowtotakeplace.

  • 标签: 反应概率 动力学计算 上海 量子 表面 截面曲线
  • 简介:Singlecrystal(100)InPsamplesand(0001)GaNepitaxiallayerswereirradiatedattheHeavyIonResearchFacilityinLanzhou(HIRFL)with86Krionsatroomtemperature.Theionfluencewasvariedfrom5×1010to1×1012cm?2.Additionally,thinaluminumfoilswithdifferentthickness(sometensofmicrometers)wereplacedinfrontofsomesamplestodeceleratetheSHI's.Ionbeamscanningwasusedtoirradiatethewholesamplesurfaceinauniformwayandmaintainednormalincidence.Topreventsampleheatingduringhigh-energyirradiation,thefluxwaskeptconstantbelow1.3×1010cm?2s?1.ThemodificationsofthesampleswereinvestigatedbyXRD.

  • 标签: INP Single CRYSTAL