A simple, high efficiency and mini-sized surface plasmon polariton (SPP) modulator based on electro-optic polymer is proposed. The modulator is constructed by metallic stripes of Mach-Zender (M-Z) interferometric structure and with electro-optic polymer surrounding the stripes. The reflectivity index of the eleetro-optic polymer is modulated when the modulating voltage is applied to the two arms of the M-Z interferometer. Through the M-Z interferometer, the modulation of the reflectivity index can be transferred into the modulation of the SPP intensity. By calculating the electric field near the metallic stripes and taking the distribution of SPP field into account, the working principle of the SPP modulator is demonstrated in detail and the half-wave modulating voltage is evaluated as 2.8 V.
An electroluminescent polymer was synthesized by Wittig condensation and characterized by the measurements of H-1-NMR, IR, gel permeation chromatography (GPC), UV-Vis, PL, and cyclic voltammetry (CV). The polymer can be dissolved in common organic solvents such as tetrahydrofuran (THF), chloroform, and dichloromethane. The electroluminescent investigation showed that the non-doped devices with a double-layer configuration (ITO/PEDOT:PSS/Polymer/Mg:Ag) have a stable green emission property. The maximum luminance of the annealed device reaches 2317 cd/m(2). The emission maximum and the CIE 1931 coordinate values are respectively stabilized at 552 nm and near (x, y) =(0.43, 0.55) with different voltages. Copyright (C) 2008 John Wiley & Sons, Ltd.
Two phenothiazine-based polymers were synthesized by the Heck reaction of 3,7-divinyl-N-octylphenothiazine with 3,7-diiodo-N-octyl-phenothiazine and 5,8-dibromo-2,3-diethylquinoxaline. The polymers were characterized by the measurements of (1)H-NMR, IR, TG, GPC, CV, UV–Vis, and FL. The results indicated that the introduction of quinoxaline group makes the absorption, PL, and EL emission maxima red-shifted. The EL emission maximum and the CIE 1931 coordinate value are stabilized at a constant value with the increase in operating voltages. Therefore, the polymers have a stable electroluminescent emission property. Copyright (c) 2008 John Wiley & Sons, Ltd.
Wang Y, Sun J, Ma S, Gao W. Theoretic Analysis of Inter Frame Dependency in Video Coding, in Advances in Multimedia Information Processing - PCM 2008, 9th Pacific Rim Conference on Multimedia, Tainan, Taiwan, December 9-13, 2008. Proceedings.; 2008:935–939. 访问链接
Three different models are developed to calculate the thermodynamic product size distribution in a nucleation-elongation polymerization between a pair of A-A and B-B typed comonomers. These monomers are designed to undergo a single step of nucleation prior to an isodesmic chain elongation, namely, a cooperative, step-growth polymerization with dimerization being an energetically less favored process. Particularly, emphasis is laid on analyzing product distribution under conditions of imbalanced functionality stoichiometry. Consistent results are obtained from independent approaches, mechanistic and statistical, demonstrating that when the mole ratio of the comonomers deviates from unity, at polymerization equilibrium such a nucleation-elongation polymerization generates products of substantially higher molecular weights than those from a corresponding isodesmic system having an identical energetics for chain propagation yet without the nucleation process. This higher molecular weight is shown achieved by retaining a large portion of the excess monomer unreacted at equilibrium and selectively compose product chains with comonomers at a roughly stoichiometric ratio. Essentially, such a polymer-monomer coexisting bimodal distribution is a result from destabilization of the oligomeric species due to the nucleation effect.