首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
AimsandscopeHIGHENERGYPHYSICSANDNUCLEARPHYSICScoversthefieldsofHighEnergyPhysics,Cosmic RayPhysics,HighEnergyAstrophysics,IntermediateEnergyPhysics,NuclearPhysics,HeavyIonPhysics,Accelerator,Detec torandSynchrotronradiationintheaspectsofexperiments,theori…  相似文献   

2.
Multiplephotonlaserphotochemistry¥V.S.Letokhov(InstituteofSpectroscopy,USSRAcademyofSciences,Troitzk,MoscowRegion,142092,Russ...  相似文献   

3.
1 Introduction  StimulatedRamanscattering(SRS)isanimportantnonlinearprocess.WiththeaidoftheSRS,wecanturnopticalfibersintobroadb?..  相似文献   

4.
HIGHENERGYPHYSICSANDNUCLEARPHYSICSisascienceperiodicalfocusingonspecializedfieldswithitsfirstissuepublishedin 1 977.ItissponsoredbytheInstituteofHighEner gyPhysicsandtheInstituteofModernPhysics,theChineseAcademyofSciences.Itisamonthlyjournal,distributedbo…  相似文献   

5.
ChineseJournalofLasersisaspecializedperiodicalonlaserscienceandtechnology,whichissponsoredbytheChineseOpticalSociety,undertakenbyShanghaiInstituteofOpticsandFineMechanics,ChineseAcademyofSciences,andpublishedbySciencePressofChina .TheEnglisheditionisiss…  相似文献   

6.
1 Introduction  StimulationRamanscattering(SRS)ingaseshasbeenusedinmanyfields,suchasfrequencyconversion[1],beamcleanup[2]andpulsecompression[3].InahighpowerSRSsystem,thewindowsoftheRamancellareusuallydamagedbyhighintensitypumpingbeams[4].Ingeneral,th…  相似文献   

7.
ChineseJournalofLasersisaspecializedperiodicalonlaserscienceandtechnology ,whichissponsoredbytheChineseOpticalSociety ,undertakenbyShanghaiInstituteofOpticsandFineMechanics ,ChineseAcademyofSciences ,andpublishedbySciencePressofChina .TheEnglisheditionisi…  相似文献   

8.
1 Introduction  Self propagating high temperaturesynthesis (SHS )wasfirstdiscoveredandbroughtforwardbyMerzhanovandBorovinskayawhentheystudiedrocketsolidfuelsfromthereactionoftransitionalmetalswithboron ,carbonandnitrogenetc.SHS′smaterialbeginstocontinuous…  相似文献   

9.
TheLightTracksintheOpticalFiberswithTwoTypesofParabolicRefractiveIndices¥SHENWenda(DepartmentofPhysics,ShanghaiUniversity,Sha...  相似文献   

10.
1 Introduction  Intheearly 1970s ,PhilipsCo .Ltd .(Netherlands)broughtforthanovelmounttechnology—SMT (SurfaceMountTechnology ) ,whichistostickcomponentsandsolderingpasteonaprintedboardwithoutperforation .SMT basedintegratedcircuitchip ,namelySMIC ,includingBGA(Bal…  相似文献   

11.
两种新卟啉的FT-SERS光谱周光明,盛蓉生,徐知三,王霆,熊亚,王小华,曾云鹗(武汉大学化学系武汉大学分析测试中心武汉430072)(北京Bruker公司北京100871)FT-SERSSpectraofTwoNovelPorphyrins¥Zho...  相似文献   

12.
The influence of pH and anions on the adsorption mechanism of rifampicin on colloidal silver nanoparticles has been analysed by electronic absorption, resonance Raman (RR) and surface‐enhanced resonance Raman spectroscopy (SERRS). Rifampicin is a widely used antibiotic with a zwitterionic nature. SERRS spectra of rifampicin adsorbed on silver sols, prepared using hydroxylamine hydrochloride as reducing agent, undergo dramatic changes upon lowering the pH. The spectral form changes progressively from that characteristic of chemisorbed rifampicin (at pH > 7) to one very similar to the rifampicin RR spectrum (at lower pH), indicative of a modification of the adsorption mechanism on the surface of the Ag nanoparticles. The RR‐type SERRS spectrum is proposed to result from formation of an ion pair between rifampicin and Cl anions, which, deriving from the colloid preparation, are adsorbed on the Ag surface. The addition of anions to the hydroxylamine hydrochloride sol facilitates conversion from the chemisorbed to ion pair form and leads to an order of magnitude increase in the SERRS signal. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

13.
本文用表面共振增强Raman方法,研究了菌紫质在不同条件下吸附在镀银玻璃上的Raman光谱,结果表明菌紫质吸附在银膜上,代表菌紫质分子循环中间体M412特征谱带的1565cm-1Raman位移明显增强,说明银膜对M412态有一定表面共振增强作用。  相似文献   

14.
吸附在银溶胶颗粒上的品成像染料的拉曼散射增强刘春艳,王宇杰,李楠,臧泠,张振宗(中国科学院感光化学研究所北京100101)StudiesonTheInteractionofImagingDyeandSilverCilusterbySERS¥Chuny...  相似文献   

15.
The evidence for the existence of a chemical mechanism in surface‐enhanced resonance Raman scattering (SERRS) of rhodamine 6G (R6G) adsorbed on colloidal silver excited at 1064 nm is reported on the basis of experimental and theoretical analyses. A weak absorption peak at around 1060 nm for R6G‐functionalized silver nanoparticles was observed, which is not present in the individual spectra of R6G or silver nanoparticles. Theoretically, the charge difference density reveals that this weak absorption is a metal‐to‐molecule charge transfer excited state. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

16.
We describe quantum‐size and binding‐site effects on the chemical and local field enhancement mechanisms of surface‐enhanced resonance Raman scattering (SERRS), in which the pyridine molecule is adsorbed on one of the vertices of the Ag20 tetrahedron. We first investigated the influence of the binding site on normal Raman scattering (NRS) and excited state properties of optical absorption spectroscopy. Second, we investigated the quantum‐size effect on the electromagnetic (EM) and chemical mechanism from 300 to 1000 nm with charge difference density. It is found that the strong absorption at around 350 nm is mainly the charge transfer (CT) excitation (CT between the molecule and the silver cluster) for large clusters, which is the direct evidence for the chemical enhancement mechanism for SERRS; for a small cluster the strong absorption around 350 nm is mainly intracluster excitation, which is the direct evidence for the EM enhancement mechanism. This conclusion is further confirmed with the general Mie theory. The plasmon peak in EM enhancement will be red‐shifted with the increase of cluster size. The influence of the binding site and quantum‐size effects on NRS, as well as chemical and EM enhancement mechanisms on SERRS, is significant. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

17.
The problem of the chemical enhancement of rhodamine 6G (R6G) adsorbed on silver cluster has been theoretically investigated by charge difference densities (CDDs) to show the direct charge transfer (CT) evidence. For surface‐enhanced resonance Raman scattering (SERRS) of R6G excited at 514.5 nm, the enhancements of v(151) and v(154) result from weak intermolecular (from Ag to R6G) CT and the strong intramolecular CT [similar to that of resonance Raman scattering (RRS) of R6G], respectively. The possibility of the SERRS of R6G contributed from pure intermolecular CT is also discussed, when the incident light is close to the new metal–R6G CT excited state at 1571.4 nm. Meanwhile compared with the absorption process the fluorescence yield of R6G is investigated by transition densities and CCDs. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

18.
光谱增感技术可使卤化银感光材料实现对全波段感光,同时光谱增感技术在现代光信息记录与存储、光电器件、太阳能转换与存储等领域具有重要的应用.应用微波吸收介电谱技术研究了立方体氯化银吸附感绿菁染料后的光电子衰减特性,建立了氯化银光电子衰减动力学模型,根据此模型结合光电子衰减实验结果对光谱增感染料吸附在卤化银表面的电子陷阱效应进行了分析.研究结果表明:当染料以单分子态吸附在卤化银表面时,染料起浅电子陷阱效应;染料以J聚集体吸附在卤化银表面时,染料起到了深电子陷阱效应.浅电子陷阱与深电子陷阱效应的临界浓度为每40g 关键词: 感绿染料 氯化银 光电子衰减 电子陷阱效应  相似文献   

19.
赵新新  陶向明  宓一鸣  季鑫  汪丽莉  吴建宝  谭明秋 《物理学报》2012,61(13):136802-136802
采用密度泛函理论研究了Ru(0001) /BaO表面的原子层结构和氮分子的吸附性质. 研究结果表明, 在低覆盖度下氧化钡倾向于以相同的构型形成Ru(0001) 表面原子层. 在此构型中, 氧原子位于表面p(1× 1) 结构的hcp谷位, 而钡原子则位于同一p(1× 1) 结构的顶位附近. 钌氧键键长等于0.209 nm, 比EXAFS的实验值大0.018 nm. 在Ru(0001) /BaO表面氮分子倾向吸附于钡原子附近. 相应位置的氮分子吸附能位于0.70到0.87 eV之间, 大于氧原子附近的氮分子吸附能. 钡原子附近的钌原子对氮分子具有更强的活化性能. 相应位置的氮分子拉伸振动频率等于1946 cm- 1, 比氧原子附近的最大分子振动频率小约130 cm-1. Ru(0001) /BaO表面氮分子键强度介于清洁Ru(0001) 和Ru(0001) /Ba表面之间. Ru(0001)/BaO表面不同位置的氮分子吸附性质差异是由钡和氧原子化学性质不同造成的. 表面钡原子的作用能够减少吸附氮分子的σ*轨道电子密度, 增加π*轨道电子密度, 从而增强氮分子和钌原子间的轨道杂化作用, 弱化氮分子键.  相似文献   

20.
金硫氢原体模拟成矿的拉曼研究程光煦(南京大学现代分析中心及固体微结构物理国家实验室,微结构科学技术高等研究中心南京210093)蔡元吉,周茂(地矿部南京地质矿产研究所南京210002)RamanInvestigationforTheSolutiono...  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号