学科分类
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255 个结果
  • 简介:TheRamanspectraofthenaturalendmembersofthegarnet-groupminerals,whichincludepyrope,almandineandspessariteofFe-Algarnetseriesandgrossularite,andraditeanduvaroviteofCa-Fegarnetseries,havebeenstrdied.MeasuredRamanspectraofthesemineralsarereasonablyandqualitativelyassignedtotheinternalmodes,translationalandrotatorymodesofSiO4tetrahedra,aswellasthetranslationalmotionofbivalentcationsintheXsite.ThestretchandrotatoryA1gmodesfortheFe-AlgarnetseriesshowobviousRamanshiftsascomparedwiththosefortheCa-Fegarnetseries,owingtothecationsresidingintheXsiteconnectedwithSiO4tetrahedrabysharingthetwoedges.TheRamanshiftsofallmemberswithineitheroftheseriesareattributedmainlytothepropertiesofcationsintheXsitefortheFe-AlgarnetseriesandintheYsitefortheCa-Fegarnetseries.

  • 标签: 拉曼光谱 石榴石 榴子石 铁铝榴石 晶体结构
  • 简介:新课改正如火如茶的开展,落实素质教育成为初中思品教学改革的重要环节。传统的教学已无法适应当前学生发展需求,初中思品教学改革势在必行。所谓“抓住‘圆心’散射教学”是指在教学过程中抓住重点,以重点为核心延伸教学内容,在丰富课堂知识的同时,活跃课堂氛围。因此,在初中思品教学中如何做到环环紧扣、突出重点是当前每一位初中思品教师亟需解决的问题。

  • 标签: 教学改革 散射 圆心 课堂氛围 学生发展 教学过程
  • 简介:Theso-called"phasedifference"iscommonlyintroducedasaphenomenologicalparameterinRamantensortheory,soastofittheexperimentaldatawell.Althoughphasedifferenceiswidelyrecognizedasanintrinsicpropertyofcrystals,itsphysicsstillremainsambiguous.Recently,Kranertetal.havepresentedanewformalismtoexplaintheoriginofphasedifferencetheoretically.Here,wesystematicallyconductedexperimentalresearchwithpolarphononsinwurtzitecrystals,theresultsofwhichstronglysurestthatthephasedifferenceshouldbepredeterminedinaRamantensor,ratherthanbetreatedasRamantensorelementstraditionallyorasanintrinsicproperty.OnthegroundsofpinpointingexistinglogicalflawsinRamantensorstudy,weprovidealogicallyclearparadigm.

  • 标签: 晶体 拉曼张量 通讯技术 发展现状
  • 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.

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  • 简介:Asmid-infrared(MIR)lasersshownumerousapplicationsinthefieldofdefense,medical,materialsprocessing,andopticalcommunications.InvestigationonMIRRamanfiberlasers(RFLs)increasinglybecomesahottopic.Comparedwiththetraditionalsilicafibers,fluorideandchalcogenideglassfiberspossesshighernonlinearcoefficientsandexcellentMIRtransmittances.Inthisarticle,thelatestdevelopmentsoftheMIRRFLsusingfluorideandchalcogenideglassfibersasgainmediaareintroduced,respectively.ThisreviewarticlemainlyfocusesonthedevelopmentsofMIRRFLsinaspectsofoutputwavelength,outputpower,andopticalefficiency.Besides,theprospectofMIRRFLsisalsodiscussed.

  • 标签: 拉曼光纤激光器 中红外 硫系玻璃光纤 输出功率 红外透过率 激光显示
  • 简介:针对光散射中的样品颗粒浓度改变时出现复散射的现象,设计探究颗粒浓度与复散射关系实验。得出结论为颗粒浓度很稀时,光强与浓度成正比,复散射基本不表现。

  • 标签: 颗粒浓度 复散射 光强 粒径
  • 简介:阐述了拉曼散射的原理,重点介绍了表面增强拉曼散射(SERS)的特点,增强原理、衬底特点以及最新进展.指出目前普遍接受的增强机理是电磁增强机制和化学增强机制同时存在,只是两者在不同实验体系中所占的比重不同.

  • 标签: 表面增强拉曼散射 增强机理 活性衬底
  • 简介:TheRamanspectrafromleukemiccellline(HL60)andnormalhumanperipheralbloodmononuclearceils(PBMCs)areobtainedbyconfocalmicro-Ramanspectroscopyusingnear-infraredlaser(785nm)excitation.Thescanningrangeisfrom500to2000cm-1.ThetwoaverageRamanspectraofnormalPBMCsandcarcinomacellshavecleardifferencesbecausetheirstructureandamountofnucleicacid,protein,andothermajormoleculesarechanged.Thespectraarealsocomparedandanalyzedbyprincipalcomponentanalysis(PCA)todemonstratethetwodistinctclustersofnormalandtransformedcells.Thesensitivityofthistechniqueforidentifyingtransformedcellsis100%.更多还原

  • 标签: 光谱学 黎曼光谱 白血病细胞 激光
  • 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.

  • 标签: RAMAN SPECTRA FLUORESCENT protein CHROMOPHORE
  • 简介:NormalHamanSpectra(NRS)ofsolidPMT(1-phenyl-5-mercaptotetrazole)andMBT(2-mercaptobenzothiazole)andtheirsurfaceenhancedRamanspectra(SERS)adsorbedonthesurfaceofthesilversubcolloidalparticlesarereportedandcompared.ItissupposedthatPMTadsorbedonsilverwithbothNandSatomswhereasMBTmaybeadsorbedonsilverthroughSatom.

  • 标签: SILVER adsorbed SERS SURFACE supposed SALTS
  • 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.

  • 标签: RAMAN SPECTROSCOPY der RS
  • 简介:一九○九年及后来一段时间,英国物理学家卢瑟福和他的同事做了用α粒子轰击重金属箔的实验。实验结果是绝大多数α粒子穿过金属后偏转角度不大,但还有一部分偏转角度较大,并且有极少数偏转角超过了90°,有的甚至被弹回,偏转角几乎达到了180°。这种现象叫做α粒子的散射。限于条件,中学难于做这个实验。若我们利用微机的作图功能进行模拟,也是能够形象地再现α粒子的散射现象。我们从α粒子散射的理论得知,α粒子散射的路径是双曲线,偏转角θ与瞄准距离b有如下关系ctg(θ/2)=4πε0((Mv2)/(2Ze2))b,即距离

  • 标签: Α粒子 偏转角 英国物理学家 金属箔 粒子轰击 散射现象
  • 简介:材料,体积或平面波导的有弹性、震动的性质,被Brillouin和拉曼光谱学学习在眼镜陶艺跟随nanocrystals生长的过程。nanoparticles原因外观在低频率拉曼光谱,典型山峰,谁的放,取决于晶体的尺寸。同时,由于光声子,锋利的水晶山峰出现在拉曼系列,允许起核心作用的阶段,和Brillouin山峰的频率移动的决心被观察。CLC数字TB383现在的工作与MIUR-FIRBRBNE012N3X的金融支持部分被资助了,MIURPRIN,轻拍FAPVU2004鈥?006。

  • 标签: 拉曼光谱 布里渊光谱 光子材料 诊断技术
  • 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。

  • 标签: GAN 锗离子植入 拉曼散射 光致发光
  • 简介:A31kmlongrangedistributedopticalfiberRamanphotontemperaturesensor(DOFRPTS)systemhavebeendevelopedbasedontemperatureeffectoftheamplifiedspontaneousRamanscatteringinfiber,andusingfiberlaserasapumpedsource.Theresultsshowthattemperaturemeasuringuncertaintyis±2°C,temperatureresolutionis0.1°C,measurementtimeis432s,spatialresolutionislessthan4m.

  • 标签: 照片 传感器 光纤元件 纤维分布
  • 简介:Aclearlight-yellowsilversolwhichhasthevisiblespectralabsorptionat390nm,whenadsorbedphenylmercaptotetrazole(PMT)ormercaptobenzothiazole(MBT),hasanewabsorptionat510-550nm.ItwasfoundthattheadsorptionofhalideionscompeteswithPMTandMBT.However,halideionshaveacompletelydifferentinfluencefromPMTandMBTonthespectralabsorptionofthesilversol.Thedifferencesmayresultfromthechangeofthepropertiesofthesurfaceofthesilversubcolloidalparticlesandfromthebondformscombiningadsorbateswiththesubstrates.

  • 标签: SILVER adsorbed VISIBLE HALIDE SURFACE AGGLOMERATION
  • 简介:Thestructureanddynamicsofelectrode/liquidinterfacesplayanincreasinglyimportantroleinelectrochemistry.Ramanspectroscopyiscapableofprovidingdetailedstructuralinformationatmolecularlevelandnewinsightintotheinterfacialstructure,adsorption,reaction,electrocatalysisandcorro-sion.InthisaccountwewillsummarizesomeprogressesofsurfaceRamanspectroscopyinthestudyofelectrochemicalinterfaces,mainlybasedonourgroup’swork,layingemphasisonthedetectionsensitivity,spectralresolution,timeresolutionandspatialresolutionaswellasthehyphenatedtechnique.

  • 标签: RAMAN SPECTROSCOPY surface enhanced RAMAN SPECTROSCOPY
  • 简介:TheStokesspectruminthestimulatedRamanscattering(SRS)isverycomplicated.Inthisarticle,weusebothGaussianandLorentzapproximationtoinvestigatethegainpropertiesofmulti-pumpingbroadbandRamanamplifier,andpresentsomeschemesforflatteningthegain.Alltheresultsshowthattheflatnessofthegainspectrumiscloselyrelatedtothepumpingfrequencygrid.ByresearchingthegainpropertiesofRamanamplifiersofsuchITU-TfibersasG.652,G.653,G.655andlargeeffectiveareanon-zerodispersionflatteningfiber,wefindthattheRamangainisassociatedwiththefibertypeanditstransmissioncharacteristics,especiallyitdecreaseswiththeincreaseoftheeffectivecorearea.

  • 标签: 光纤通信 多波长抽运 RAMAN放大器 SRS