偶氮染料掺杂高分子薄膜的光学常数

在单晶硅片上 ,以旋涂 (Spin- Coating)法制备了推 -拉型偶氮染料掺杂高分子 (PMMA)薄膜 ,其中二甲基胺基 [N(CH3 ) 2 ]作为推电子基团 ,羧基 (COOH)作为拉电子基团。利用椭圆偏振光谱和吸收光谱 ,研究了薄膜的复折射率、复介电函数和吸收系数 ,分析了影响薄膜电子光谱的因素。结果表明 ,该薄膜在 40 0～ 60 0 nm波长范围内 ,存在强而宽的吸收 ,并发现染料分子的聚集状态对其吸收光谱有较大的影响     

Beam scanning of array using ferroelectric phase shifters

The beam scanning characteristics of a two-element array utilising a ferroelectric phase shifter are presented for the first time. Applying a DC voltage across the ferroelectric material changes the velocity of the input signal, a beam scan of 26° being achieved. The S₁₁ performance and the radiation patterns of the array at two frequencies are presented     

The Voltammetry and Electroanalysis of Some Estrogenic Compounds at Modified Diamond Electrodes

The voltammetry of some estrogenic compounds (estradiol, nonylphenol, bisphenol A, ethynylestradiol, estrone, estriol) in aqueous solution at boron doped diamond electrodes is reported. For oxidised (hydrophilic) electrodes electrochemically irreversible kinetics were observed for the diffusing molecules allowing the inference of diffusion coefficients and transfer coefficients. In contrast for hydrogen terminated (hydrophobic) surfaces significant adsorption was observed. A limit of detection of 1–100 µM for the estrogenic compounds was found using the oxidised diamond electrode. Surface modification of the oxidised diamond with nano‐Carbon (so‐called Carbon Black) allowed preconcentration of the target by adsorption onto the Carbon Black prior to analysis and a corresponding reduction of the limit of detection by ca three orders of magnitude to 5–100 nM.     

Efficient threshold public key encryption with full security based on dual pairing vector spaces

Most robust and noninteractive threshold public key encryption (PKE) schemes have only been proven secure against chosen‐ciphertext attacks under the static corruption model; yet, the dynamic corruption model is more reasonable. In this paper, on the basis of bilinear groups of prime order and dual pairing vector spaces, we propose a threshold PKE scheme that is noninteractive, robust and, secure against adaptive chosen‐ciphertext attacks under the dynamic corruption model without random oracles. Moreover, our scheme is shown to be more efficient than currently existing fully secure threshold PKE schemes. Copyright © 2013 John Wiley & Sons, Ltd.