简介:TheRamanspectraofthenaturalendmembersofthegarnet-groupminerals,whichincludepyrope,almandineandspessariteofFe-Algarnetseriesandgrossularite,andraditeanduvaroviteofCa-Fegarnetseries,havebeenstrdied.MeasuredRamanspectraofthesemineralsarereasonablyandqualitativelyassignedtotheinternalmodes,translationalandrotatorymodesofSiO4tetrahedra,aswellasthetranslationalmotionofbivalentcationsintheXsite.ThestretchandrotatoryA1gmodesfortheFe-AlgarnetseriesshowobviousRamanshiftsascomparedwiththosefortheCa-Fegarnetseries,owingtothecationsresidingintheXsiteconnectedwithSiO4tetrahedrabysharingthetwoedges.TheRamanshiftsofallmemberswithineitheroftheseriesareattributedmainlytothepropertiesofcationsintheXsitefortheFe-AlgarnetseriesandintheYsitefortheCa-Fegarnetseries.
简介:Theso-called"phasedifference"iscommonlyintroducedasaphenomenologicalparameterinRamantensortheory,soastofittheexperimentaldatawell.Althoughphasedifferenceiswidelyrecognizedasanintrinsicpropertyofcrystals,itsphysicsstillremainsambiguous.Recently,Kranertetal.havepresentedanewformalismtoexplaintheoriginofphasedifferencetheoretically.Here,wesystematicallyconductedexperimentalresearchwithpolarphononsinwurtzitecrystals,theresultsofwhichstronglysurestthatthephasedifferenceshouldbepredeterminedinaRamantensor,ratherthanbetreatedasRamantensorelementstraditionallyorasanintrinsicproperty.OnthegroundsofpinpointingexistinglogicalflawsinRamantensorstudy,weprovidealogicallyclearparadigm.
简介:TheangledependenceofopticalphononmodesofanAlNbulksinglecrystalfromthem-plane(1100)andc-plane(0001)surfaces,respectively,isinvestigatedbypolarizedRamanspectroscopyinabackscatteringconfigurationatroomtemperature.CorrespondingRamanselectionrulesarederivedaccordingtomeasuredscatteringgeometriestoillustratetheangledependence.Theangle-dependentintensitiesofphononmodesarediscussedandcomparedtotheoreticalscatteringintensities,yieldingtheRamantensorelementsofA1(TO),E22,E1(TO),andA1(LO)phononmodesandtherelativephasedifferencebetweenthetwocomplexelementsofA1(TO).Furthermore,theRamantensorofwurtziteAlNiscomparedwiththatofwurtziteZnOreportedinpreviouswork,revealingtheintrinsicdifferencesoflatticevibrationdynamicsbetweenAlNandZnO.
简介:Asmid-infrared(MIR)lasersshownumerousapplicationsinthefieldofdefense,medical,materialsprocessing,andopticalcommunications.InvestigationonMIRRamanfiberlasers(RFLs)increasinglybecomesahottopic.Comparedwiththetraditionalsilicafibers,fluorideandchalcogenideglassfiberspossesshighernonlinearcoefficientsandexcellentMIRtransmittances.Inthisarticle,thelatestdevelopmentsoftheMIRRFLsusingfluorideandchalcogenideglassfibersasgainmediaareintroduced,respectively.ThisreviewarticlemainlyfocusesonthedevelopmentsofMIRRFLsinaspectsofoutputwavelength,outputpower,andopticalefficiency.Besides,theprospectofMIRRFLsisalsodiscussed.
简介:O433.597052890研究表面光学和热学特征的一种新方法—光热位移光谱=Anewmethodforthestudyofopticalandthermalpropertiesofsurfaces:photothermaldisplacementspectroscopy[刊,中]/张振杰(西北大学物理系.陕西,西安(710069))//光子学报.—1996,25(7).—585—588介绍研究固体、表面及薄膜的光学和热学特性的一种十分灵敏的探测技术。这一探测技术—光热位移光谱,是基于对样品表面吸收电磁辐射后所引起的热膨胀的测量。该技术亦适用于那些要求高真空和温度变化范围较大条件的实验研究工作。这种光谱技术还能将面吸收和体吸收很好的区分开来,入射功率面的
简介:O433.42006064868基于超短脉冲的癌细胞荧光光谱=Fluorescencespectrastudyofcancercellsbasedollultrashortpulseslasertech-nique[刊,中]/刘天夫(中国计量学院信息工程系,浙江,杭州(310018)),陈碧芳…//发光学报.—2006.27(1).—113-117研究用于癌症诊断与治疗的光敏剂血卟啉(HPD))的超快光动力学过程。采用超短脉冲激光光谱技术和皮秒时间相关单光子计数系统,测量了经血卟啉培养的活体癌细胞与正常细胞的荧光光谱、荧光寿命特性及荧光峰值强度随时间的变化。对测量所得的荧光光谱曲线及时间分辨荧光衰减曲线分析,计算出在癌细胞内部血卟啉浓度增大了约2个数量级,结果确认了荧光光谱技术诊断与治疗癌症的可行性。图6表1参4(于晓光)
简介:O433.42005031664芳香杂环聚合物紫外-可见光谱性质的理论研究=Atheo-reticalstudyofUV-Visabsorptionspectraofheterocyclicaromaticpolymers[刊,中]/冯东东(华东理工大学材料科学与工程学院,超细材料制备与应用教育部重点实验室.上海(200237)),庄启昕…∥高等学校化学学报.-2005,26(3).-522-526在AM1方法优化构型的基础上,用ZINDO/CI方法计算了系列芳香杂环聚合物的紫外-可见光谱,探索分子结构与其光学性质之间的关系。理论计算结果表明,模型
简介:TheRamanspectrafromleukemiccellline(HL60)andnormalhumanperipheralbloodmononuclearceils(PBMCs)areobtainedbyconfocalmicro-Ramanspectroscopyusingnear-infraredlaser(785nm)excitation.Thescanningrangeisfrom500to2000cm-1.ThetwoaverageRamanspectraofnormalPBMCsandcarcinomacellshavecleardifferencesbecausetheirstructureandamountofnucleicacid,protein,andothermajormoleculesarechanged.Thespectraarealsocomparedandanalyzedbyprincipalcomponentanalysis(PCA)todemonstratethetwodistinctclustersofnormalandtransformedcells.Thesensitivityofthistechniqueforidentifyingtransformedcellsis100%.更多还原
简介:Theobjectiveofthestudywastoelucidateopticalcharacteristicsofthechromophorestructuresoffluorescentproteins.RamanspectraofcommonlyusedGFP-likefluorescentproteins(FPs)withdiverseemissionwavelengths(green,yellow,cyanandred),includingtheenhancedhomogenousFPsEGFP,EYFP,andECFP(fromjellyfish)aswellasmNeptune(fromseaanemone)weremeasured.High-qualityRamanspectrawereobtainedandmanymarkerbandsforthechromophoreoftheFPswereidentifiedviaassignmentofRamanspectrabands.WereportthepresenceofapositivelinearcorrelationbetweentheRamanbandshiftofCs=C6andtheexcitationenergyofFPs,demonstratedbyplottingabsorptionmaxima(cm-1)againstthepositionoftheRamanbandCs=C6inEGFP,ECFP,EYFP,theanionicchromophoreandtheneutralchromophore.ThisstudyrevealednewRamanfeaturesinthechromophoresoftheobservedFPs,andmaycontributetoadeeperunderstandingoftheopticalpropertiesofFPs.
简介:NormalHamanSpectra(NRS)ofsolidPMT(1-phenyl-5-mercaptotetrazole)andMBT(2-mercaptobenzothiazole)andtheirsurfaceenhancedRamanspectra(SERS)adsorbedonthesurfaceofthesilversubcolloidalparticlesarereportedandcompared.ItissupposedthatPMTadsorbedonsilverwithbothNandSatomswhereasMBTmaybeadsorbedonsilverthroughSatom.
简介:Ramanspectroscopyisaversatiletoolwidelyusedforcomprehensiveprobingofcrystalinformation.However,generallywhenappliedinnarrow-band-gapvanderWaalscrystals,itisliabletoforma'bug,'especiallyintransition-metal-dichalcogenides(TMDs).Thatis,severalresonantRaman-scattering(RS)modeswillinevitablyappearintheRamanspectrawithstrongintensity,interferingwiththedesiredsignalofoptical-phononmodes.Here,weproposecross-sectionalpolarizedRamanscatteringcapableofregulatingtheintensityofRSmodesinaccordancewithquasi-sinusoidalrules.Typically,forMoS2andWS2,whenthepolarizationvectorofexcitedlightisalongthecaxisofthecrystal,allRSmodesarenearlycompletely'expunged'fromtheRamanspectra.ThemechanismisthattheabsorptionofmostTMDswithaspacegroupofR3mforthelightpolarizedalongthecaxisisinfinitesimal,thusformingasmallcouplingintensityofelectronicstatesexcitedopticallyandacoustic-phononmodesatpointM,whichinturnrestraintheappearanceofRSmodes.TheregulatingstrategyproposedcanbeappliedtoothervanderWaalscrystalssoastoobtainahighsignal-to-noiseratioRamanspectrum.
简介:TH744.12006064901直接数字频率合成技术在声光单色系统中的应用=Appli-cationofdirectdigitalfrequencysynthesistechnologyina-cousto-opticmonochromaticsystem[刊,中]/万峰(天津大学精密仪器及光电子工程学院.天津(300072)),范世福//分析仪器.—2006.(3).—38—40介绍了直接数字频率合成技术的工作原理和由直接数字频率合成器、数字信号处理器、非共线TeO2红外声光器件等组成的声光单色系统及其性能测试,实验结果表
简介:调查在上植入Ge在氨下面轧了由MOCVD成年然后在1100点退火的电影周围被执行了。与增加Ge培植剂量,四座另外的山峰在260的波浪数字产生,314,428并且在Ramam系列的670cm-1。在PL系列,与在2.66eV和黄乐队集中的PL乐队相比的乐队边排放的相对紧张随植入Ge的剂量的增加减少。260的模式和314cm-1被归因于散布的激活混乱的拉曼,而428的模式和670cm-1被分到空缺和空缺相关的建筑群的本地颤动。在2.66eV和黄乐队集中的PL乐队也与这些空缺缺点有关。在为样品的301cm-1的新拉曼山峰退火了仅仅5min由于缺乏的退火从Ge簇发源。
简介:A31kmlongrangedistributedopticalfiberRamanphotontemperaturesensor(DOFRPTS)systemhavebeendevelopedbasedontemperatureeffectoftheamplifiedspontaneousRamanscatteringinfiber,andusingfiberlaserasapumpedsource.Theresultsshowthattemperaturemeasuringuncertaintyis±2°C,temperatureresolutionis0.1°C,measurementtimeis432s,spatialresolutionislessthan4m.