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 250 毫秒
1.
1 Introduction  Themethodsthatcanmeasurethephaseandthe pulsedurationmainlyincludetheFROG[1] (frequency -resolvedopticalgating)andtheSPIDER[2 ] (spectral phaseinterferometryfordirectelectric fieldreconstruction) .FROG[1] usestheunknownpulseitselfasatime delayed ga…  相似文献   

2.
ButterflyinterconnectionnetworksandtheirapplicationsinWalsh-Hadamardtransform-basedinformationprocessingandopticalcomputingHE...  相似文献   

3.
1 Introduction  InrecentyearsLiNbO3crystalshavereceivedmuchattentionbecauseoftheirexcellentnonlinearproperties,andcanbeusedformanyapplicationsinthefieldsofelectro optics,laser physics,holographyandacoustics.Periodically poledcongruentLiNbO3 crystal (PPLN )h…  相似文献   

4.
FluorescenceandNonlinearOpticalPropertiesofOrganicDyeinInorganicGlasandXerogelMatricesZHANGQinyuanJIANGZhonghong(ShanghaiInst...  相似文献   

5.
Straightness Measurement Using Laser Diode and CCD Camera   总被引:4,自引:0,他引:4  
1IntroductionInmanufactureandasembleofmodernmachinesandinstruments,anindispensablerequirementisthecontrolofformandpositionero...  相似文献   

6.
1 Introduction  Two photonabsorption (TPA )isanimportantnonlinearabsorptionprocessinbothbasicandappliedresearches.Formanyyears,duetotherelativelysmallTPAcross sectionsofmostmaterials,two photonprocesseswerefoundlimitedapplications.Lately ,greatprogresseshav…  相似文献   

7.
EvanescentWavesandEnergyConservationCAOQing;DENGXiming(NationalLaboratoryonHighPowerLaserandPhysics,ShanghaiInstituteofOptics...  相似文献   

8.
1IntroductionThereareverystrongnonlinearopticalefectsduetothehighpowerdensityoftheoutputoflargelasersystemsandparticularlythe...  相似文献   

9.
1 Introduction  ThestudyontheYVO4crystalcanbetracedbackto 1 970′s.Howeverduetoitspoorheatconductivity ,ithasnotbeenconsideredasagoodcandidateforflashlamp pumpedlasersystem .Lately ,thedevelopmentofLDlaserandnarrowbandLD pumpingtechnologyaimedattheabsorption p…  相似文献   

10.
1 Introduction  Troposphericaerosolandcloudaretwoimportantfactorsaffectingearth atmosphereradiationbalanceandalsotwoofthelargestuncertaintiesintheclimateeffectsmodelingandevaluation ,sotheirobservationsbecomeveryimportant.Lidar (LightDetectionandRange)is…  相似文献   

11.
.NULL.     
Thenbutanemoleculeisthesmallesthydrocarbonwheremorethanonegeometricconformercanexist.Ithasbeenthesubjectofmanyspectroscopican?..  相似文献   

12.
Some interesting aspects of the temperature dependence of the Planck’s functionφ and heat capacities of metals exhibiting the h.c.p. ⇄ b.c.c. transformation have been brought to light by the use of reduced temperature (T*) and Planck’s function (-φ T*). It has been shown that tangents drawn to the -φ T* vsT* plots of these metals at any chosen value ofT* intersect at a point whose coordinates are defined by the slope and intercept ofφ vs entropy plots at any homologous temperature and the selectedT* value. A generalized expression obtained for the temperature dependence ofφ has been used to demonstrate that the heat capacity of these metals may be visualized to have structural and material components.  相似文献   

13.
Although several different groups have studied the photolysis of phosphorus ylides, none have utilized e. s. r. to support the postulated decomposition mechanisms. The fundamental question which awaits a definitive answer is which bond breaks first upon photolysis. Tschesche1 and de Silva2 utilizing the ylides (1) and (2) suggested that the carbon-phosphorus double bond was initially broken while Nagao3 using (3) proposed phenyl-phosphorus bond cleavage.  相似文献   

14.
The influence of the association of charged defects into intimate pairs on a.c. conduction is discussed in the light of the fundamental mechanism being that of the simultaneous hopping of two electrons over the barrier separating two oppositely charged defect centres, the barrier height being correlated with the intersite separation via the Coulomb interaction. The behaviour of chalcogenide glasses is discussed in terms of the present theory, and it is concluded that the existence of two classes of a.c. conductivity behaviour into which these materials generally fall can be simply explained by the predominance of either intimate pairs or non-intimate pairs of charged defect states according to the conditions of preparation.  相似文献   

15.
介绍了C.T.R.威耳逊的主要贡献和发明云室的过程.他由研究水滴的凝结规律入手,不断改进实验装置,拍摄了带电粒子的径迹照片,从而证明了康普顿效应;还分析了威耳逊取得成功的几个重要因素.  相似文献   

16.
The semidione radical anions derived from a variety of alicyclic ketones and α-hydroxyketones have been extensively investigated via esr by Russell and co-workers.1Studies of the chemistry and spectra of the 1, 2-cyclobutanediones derived from the tricyclo[4. 4. 2. 01,6] dodecane-11-o1-12-one system2suggested that an examination of the esr spectra of the related semidiones would be of considerable interest. The recent reports on the esr spectra of cyclobutanes emidione1cand several substituted cyclo-butanes emidiones1bfurther prompt this communication.  相似文献   

17.
凹叶厚朴各部位挥发油成分比较研究   总被引:1,自引:0,他引:1  
采用顶空固相微萃取(HS-SPME)提取凹叶厚朴不同部位的挥发油成分,气相色谱-质谱(GC-MS)分析其组成.结果显示:根鉴定出19个化合物,其中4(14),11-桉叶二烯(26.04%),(1S-顺)-1,4-二甲基-7-(1-甲基亚乙基)-奠(24.94%),石竹烯(9.41%),β-桉叶醇(7.28%)为主要成分...  相似文献   

18.
John Meurig Thomas 《哲学杂志》2013,93(31):3757-3765
Though known these days largely because he invented the fuel cell, Grove also had many other distinguished achievements to his credit. His monumental book On the Correlation of Physical Forces contained all the arguments that led to the enunciation of the first law of thermodynamics. He was also an extremely versatile natural philosopher who was, in addition, well versed in classical literature, particularly the works of the eminent scholars of ancient Greece and Rome. This article touches upon these qualities, but is predominantly concerned with the emergence and modern aspects of the H2/O2 fuel cell and its potential for the clean generation of energy.  相似文献   

19.
Locally rotationally symmetric (L.R.S.) Bianchi type V bulk viscous tilted stiff fluid cosmological model is investigated. To get the deterministic model of the universe, we have also assumed a condition A=Bn between metric potentials A, B where n is the constant. The behaviour of the model in presence and absence of bulk viscosity and singularities in the model are also discussed. In general, the models represent accelerating, shearing, tilted and non-rotating universe. The models have point type singularity in presence and absence of bulk viscosity both.  相似文献   

20.
A series ofc-axis oriented YBa2Cu3O x -films with different oxygen content were prepared by laser deposition. The oxygen contentx was determined by X-ray diffraction and by resonant Rutherford-back-scattering (RRBS) measurements. Thec-axis length in these films of YBa2Cu3O x is about 0.5% larger compared to bulk values. We describe transport measurements in magnetic fields up to 7 Tesla between room temperature andT c in samples with an oxygen content between the orthorhombic-to-tetragonal transition (x6.4) and full oxygenation (x7). The ratio /R H was investigated with respect to the two-dimensional Luttinger liquid theory and the model of the two-dimensional ionic metal. We report on deviations from the expected quadratic temperature behaviour of /R H , especially in films with high oxygen content.  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