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991.
为了满足日益增加的集成光子器件设计的需求,本文研究了一种铌酸锂/钠表面等离子体波导(Li Nb O3/Na surface plasmonic waveguide, LNSPW),并利用LNSPW构成电光可调的定向耦合器(directional coupling,DC).利用有限元方法 (finite element method, FEM)对波导的模式特性和耦合器的耦合特性进行了分析.结果表明,随着波导尺寸的增大,传播长度可达约200μm,归一化有效模场面积小于0.4.通过调节耦合间距(Wgap)、耦合长度(LC)和工作波长(λ)等参数,铌酸锂钠表面等离子体波导构建的定向耦合结构可实现3 d B耦合.当Wgap=100 nm和LC=17μm时, DC在V0=53 V时可实现3 d B耦合,且具有较好的方向性和隔离度.LNSPW的研究为实现可调的DC提供了一种可行的方案,在集成电光可调器件研究领域有潜在的应用前景.除此之外, LNSPW还可广泛应用于非线性光学、光信号处理及光全... 相似文献
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Preparation of a novel P/Si polymer and its synergistic flame retardant application on cotton fabric
Liu Jian Kong Dezheng Dong Chaohong Zhang Zheng Wang Shuai Sun Heng Lu Zhou 《Cellulose (London, England)》2021,28(13):8735-8749
Cellulose - Cotton fabrics have been extensively used in our lives, but their flammable properties caused much potential harm. The purpose of our work is to give cotton fabrics certain flame... 相似文献
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Poly(perylene‐alt‐phenyleneethynylene)s with multiple pendant ester groups in various lengths: Synthesis,photophysics and selective hydrolysis
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Heng Zhang Ya Shao Hong Chen Kesong Miao Li‐Juan Fan 《Journal of polymer science. Part A, Polymer chemistry》2017,55(11):1880-1886
Five fluorescence polymers with poly(perylene‐alt‐phenyleneethynylene)s (PPPEs) backbone and multiple side chains containing ester‐groups were synthesized via Sonogashira coupling reaction. These polymers were soluble in common organic solvents to form red‐orange solution. The polymer powders had dark red color. The absorption/emission spectra of these polymers were similar, with absorption bands between 300 and 600 nm and an emission peak between 520 and 700 nm. Furthermore, the ester groups of the side chains were partially or completely hydrolyzed, resulting in the fluorescence PPPEs with tunable density of carboxylic acid functional groups on the polymer chains as interaction/reaction sites for further applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1880–1886 相似文献
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Da‐Sen Huang Wei‐Dong Zhang Yue‐Hu Pei Xiao‐Yang Peng Zheng‐Sheng Huang Hui‐Liang Li Yun‐Heng Shen 《Helvetica chimica acta》2009,92(8):1558-1561
Two new alkaloids, incarvines E ( 1 ) and F ( 2 ), were isolated from the EtOH extract of the whole plant of Incarvillea sinensis. Their structures were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR. 相似文献
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The mechanism of reaction between 3‐hydroxy‐3‐methyl‐2‐butanone and malononitrile for the synthesis of 2‐dicyanomethylene‐4,5,5‐trimethyl‐2,5‐dihydrofuran‐3‐carbonitrile catalyzed by magnesium ethoxide was investigated by density functional theory (DFT). The geometries and the frequencies of reactants, intermediates, transition states, and products were calculated at the B3LYP/6–31G(d) level. The vibration analysis and the IRC analysis demonstrated the authenticity of transition states, and the reaction processes were confirmed by the changes of charge density at bond‐forming critical point. The results indicated that magnesium ethoxide is an effective catalyst in the synthesis of 2‐dicyanomethylene‐4,5,5‐trimethyl‐2,5‐dihydrofuran‐3‐carbonitrile from malononitrile and 3‐hydroxy‐3‐methyl‐2‐butanone. The activation energy of reaction with magnesium ethoxide decreased by 102.37 kJ mol?1 compared with that of the reaction without it. The mechanism of reaction with catalyst magnesium ethoxide differs from that of reaction without it. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 41: 227–235, 2009 相似文献