最新刊期
卷 13 ， 期 2 ， 1992
- 摘要：Dimethyl sulfoxide complex of europium nitrate was synthesized. Its composition is Eu(NO3/)3·4(CH3)2SO. The crystal structure of this complex belongs to monoclinic system. Its lattice parameters are:α= 1.4806 nm, b= 1.0948nm, с= 1.5335nm. β= 108.07o and Z= 4. Space group is C2/c-C2k6. Coordination number of Eu3+ is 10. Its luminescence spectra weredetermined at liquid nitrogen temperature (Fig. 3). Argon laser was used for excitation. The excitation wavelength is 457.9nm.108|57|4更新时间：2020-08-11
- 摘要：30 layers of tapCuPc were deposited by LB technique onto tbe optical glass waveguide of K+ ion exchange. A four layer dielectric waveguide with a LB fi’m cladding was formed. It is reported for the first time, that the optical bistability in the optical waveguide coated with nonlinear LB films of copper tera-4-(2.4-ditert-ampylphenoxy) phthalo-cyanine (tapCuPc) has been observed using different laser pulse at room temperature.When LB film are removed, no optical bistability can be observed in the waveguide.99|60|1更新时间：2020-08-11
- 摘要：This letter presents the analysis of semiconductor laser arrays based on the Finite Element Method, with emphasis on non-uniform structures where the channel width and/or refractive index can vary across the array. The results show that the variation of the channel width (Fig. 2) will have the same effect on the near-field intensity profiles (or the supermode control) as the variation of the channel refractive index (Fig. 3). The variation of the separation layer refractive index(n2) can lead to a highly uniform intensity distribution in all elements for the fundamental mode (Fig. 4 ) and enhanced mode stability, indicating that it is highly important and difficult for us to control the separation layer refractive index. The results (Fig. 1) of the Finite Element Method show a good agreement with those obtained by E. Kapon et al.[7], based on the direct numerical solution of the equation (1). The results for example 2 show that the Finite Element Method can often overcome the limitations of more specialized methods (e. g. the coupled-mode theory).115|53|0更新时间：2020-08-11
- 摘要：The Finite Element Method (FEM) has been applied to the analysis of propagation characteristics of MQW planar waveguides. Effective indexes and intensity profiles for both TE and TM modes in MQW waveguides with an arbitrary number of wells are presented. The results show that the variation of r affects the number of modes, effective indexes, birefringence and intensity profiles of the propagating mode in the waveguides. Comparing the FEM with the RMS approach of Ohke et al., we found that the formulae of RMS were not correct in certain conditions.110|61|0更新时间：2020-08-11
- 摘要：In this paper the three-photon fluorescence phenomenon of Sm3+ induced by 1.06μm pulsed laser beam is reported. This can be explained as two-step processes: a single-photon absorption to 6F9/2 state and non-radiative relaxation to 8F1/2 state; and then a successive two-photon absorption to 6P1/2 state and nonradiative relaxation to 4G5/2 state. A brief discussion is given.115|66|5更新时间：2020-08-11
- 摘要：In the paper, we report the optical properties of CdS semiconductor ultrafine particles in hydrosols and those of CdS semiconductor ultrafine particles in organosols in which the surfaces of the particles are coated with a layer of organic surfactant molecules. The experimental results show that surface modification of the particles significantly affects their optical properties.CdS hydrosols and organosols were prepared through colloidal chemical method. The particle size and size distribution were determined by TEM and small angk X-ray scattering. The results show that the colloidal particle size is below 10nm.The absorption, excitation and emission spectra of CdS particles in the hydrosols and organosols were measured and discussed, we conclude that when the particle size is less than 5nm,the particles exhibit obvious quantum size effects.The surface modification of the particles effectively removes the surface defects of the particles, and strongly enhances the intensity of interband luminescence. On the other hand, a number of discrete electronic transitions due to quantum confinement effects are observed and explained by the effective mass approximation.108|95|5更新时间：2020-08-11
- 摘要：In the early 1970's, Ibach made the low energy electron diffracting experimentation on ZnO etc. semiconductor surface. Since then the surface polaron in the crystals have been of considerable interest. Many scholars have studied the surface polaron problem. The properties of the exciton in the surface layer of crystals influence the optical properties of the crystals very remarkably. X. X. Liang discussed the properties of weak-coupling surface exciton in polar crystals. Most polar crystals are diatomic. In these crystals there is only one mode of longitudinal optical (LO) phonon. The properties of crystals have bean studied by a great variety of techniques, in which discussions are limited only for the case of one LO phonon branch. However, a large number of polar crystals, with several atoms per unit cell, have more than one LO phonon.114|69|1更新时间：2020-08-11
- 摘要：InGaAsP/InP DH LEDs with planar buried ridge structure (PBRS) for single mode optical fiber communication system have been investigated.The design for materials and device is briefly descrbed. Heterostruc-ture crystals were grown by two-step LPE technology. The LED has a tilted back facet to suppress laser oscillation and a planar buried ridge stripe active region. The device was coupled with single mode fiber using laser welding and metallized fiber coupling and packaging technology. The launched power in single mode fiber was 35 microwatts. This result is reported for the first time in China.The bandwidth of the LED was 195MHz. In 140Mb/s single mode fiber transmission experiments, transmission distance without repeater was more than 20km.104|95|0更新时间：2020-08-11
- 摘要：GaxIn1+xAs1-ysby alloys in GaSb-rich conner have been grown on the GaSb and GaAs substrates by Metalorganic Chemical Vapor Deposition (MOCVD) in a horizontal, atmospheric pressure reactor. The reac-tants included trimethylgallium (TMGa), trimethylindium (TMIn),arsine (AsH3) and phosphine (PH3). The composition of epi-layer was determined by electron microprobe. It was observed that the composition y of solid depended on the ratio of PTMsb to (PTMsb + PASH3) in vapor phase, but also on the AsH3 flow rate of vapor source, and the growth rate for per molar Ⅲ group source increased with growth temperature below 620℃. It indicated that the growth is influenced by surface kinetics.113|62|2更新时间：2020-08-11
- 摘要：This paper deals with the investigation on the deterioration of powder ACEL phosphor using ion probe experiment.lt is found for the first time that copper ions migrate during the deterioration.This conclusion is in accordance with positron annihilation lifetime spectrum.It is also shown that the degree of copper ion migration was alleviated for annealed and quenched phosphor.The initial brightness of ACEL sample was 450cd/m2 under the excitation of 5kHz and 200 V. It decreased to 125.5cd/m2 after the aging of 4000 hours.The maximum of initial brightness for samples with improved phosphor is 766cd/m2.105|69|0更新时间：2020-08-11
- 摘要：The fluorescence lifetime of fluorescent materials in solution is often measured in the case of low concentration. But the medium of dye laser is always high concentration solution, generally in ihe range of 10-4~10-2mol·L-1. It is necessary to measure the parameters,such as quantum yield and fluorescence lifetime, of high concentration solution in order to studying the physical and chemical behaviors of the laser dye. However, it is difficult to accurately measure the fluorescence lifetime because of the existance of self-absorption and re-emission of the fluorescence molecules in high concentration solution.Recently, several authors have developed some methods for measuring the fluorescence lifetime of high concentration solutions.122|54|1更新时间：2020-08-11
- 摘要：In this paper we report the formation of stable and ordered Lang-muir-Blodgett(LB) film of natural porphyrins without long alkyl chains (Hematoporphyrin, protoporphyrin and porphyrin C). Monolayer and multilayers of porphyrins and porphyrins mixed with stearic acid or phos-phoilpid were studied on solid substrates. The utility of complementary experimental techniques such as UV-visible absorption spectroscopy, steady-state and time-resolved fluorescence spectroscopy in yielding information about stable solid-condensed LB films with the conjugated ring plane obliquely orientated on the substrate is highlighted. There is considerable interaction between porphyrin molecules in the same layer of the films and this leads to peak broadening, red shift, fluorescence lifetime shortening, fluorescence-quenching and so on. All these phenome-naare consistent with the formation of aggregate species in LB films studied.100|65|0更新时间：2020-08-11
- 摘要：In the present work we have studied erythrocyte membrane Na+, K+-ATPase activity in 32 cases with cardiovascular disease, before and efter the K+ Joad assay,by bioluminescence technique. The results show that the erythrocyte membrane Na+, K+-ATPase activity for negative K+ load assay patients, coronary heart plus hypertensive heart disease and serious myocardiac damage are significantly low (p<0.05). And the myocardiac function has relation to Na+, K+-ATPase.93|35|0更新时间：2020-08-11
- 摘要：Optical bistability of CdSλSe1-x doped glass with channel waveguide structure is first reported. Switching time of 23 ps of the bistability device of channel waveguide was observed. The average threshold power is about 3mW which is corresponnding to 2MW/cm2 power density in cross section of. channel waveguide. This enhancement effect of optical nonli-nearity based on limitation of waveguide boundary have been realized in channel waveguide.111|54|0更新时间：2020-08-11
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