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61.
Nishaanthan Nadarajah Elaine Wong Ka Lun Lee Ampalavanapillai Nirmalathas 《Optics Communications》2007,273(1):246-251
A scheme for upstream transmission and local area network emulation in passive optical networks using a single reflective semiconductor optical amplifier placed at the customer premises is proposed and experimentally demonstrated. In this scheme, two optical carriers are delivered to the optical network units from the central office for the transmission of upstream and local area network signals, respectively. 相似文献
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大型台车式电阻炉预测模糊温度控制系统 总被引:1,自引:1,他引:0
针对大型台车式电阻炉具有大滞后,大惯性,严重非线性的特性,提出了由预测控制和模糊控制相结合的预测模糊控制算法,同时也介绍了预测模糊控制算法在电阻炉计算机控制系统中的应用,实际运行效果良好. 相似文献
64.
Platinum nanoclusters (Pt-NCs) were synthesized on the surface of a gold electrode that was modified with cysteamine to form a kind of self-assembled monolayer via in-situ cyclic voltammetry (CV). Scanning electron microscopy, electrochemical impedance spectroscopy, and CV were used to characterize the properties of the electrode. The Cys monolayer induces the aggregation of platinum nanoparticles due to electrostatic interaction between the positive amino groups of the cystein monolayer and the negative charge of the hexachloroplatinate ions and causes the formation of Pt-NCs on the surface of the electrode. The resulting electrode exhibits high elecrocatalytic activity towards the oxidation of methanol. 相似文献
65.
Haiyan Wang Fuqiang Zhang Zhian Tan Qiongfang Chen Lun Wang 《Electrochemistry communications》2010,12(5):650-652
CdS nanocrystals (NCs) usually exhibit very weak electrochemiluminescence (ECL) emission. It is showed that when CdS NCs were treated by heating in the presence of ammonia (heated-CdS–NH3), greatly enhanced ECL was observed. The ECL of the heated-CdS–NH3 modified glassy carbon electrode (heated-CdS–NH3/GCE) in phosphate buffer solution (pH 7.0) containing 0.1 M K2S2O8 was ca. 310 times higher than that of CdS/GCE. The treatment caused the changes in the morphology and surface electronic structure of CdS NCs, which facilitated the reduction process of CdS, consequently improved the quantity of the excited states (CdS*), leading to enormous enhancement in ECL. 相似文献
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We present an iterative method for the solution of the exterior all-space electrostatic problem for nonlinear dielectric media. The electric potential is specified on interior boundaries and the electric field decays at infinity. Our approach uses a natural variational formulation based on the total energy of the nonlinear dielectric medium subject to boundary conditions. The problem is decomposed into an exterior calculation and an interior calculation with the boundary-specified electric potentials imposed as constraints between them. Together, these enable an iterative method that is based on the variational formulation. In contrast to direct solution of the electrostatic problems, we avoid the construction, storage and solution of dense and large linear systems. This provides important advantages for multiphysics problems that couple the linear electrostatic Poisson problem to nonlinear physics: the latter necessarily involves iterative approaches, and our approach replaces a large number of direct solves for the electrostatics with an iterative algorithm that can be coupled to the iterations of the nonlinear problem. We present examples applying the method to inhomogeneous, anisotropic nonlinear dielectrics. A key advantage of our variational formulation is that we require only the free-space, isotropic, homogeneous Greens function for all these settings. 相似文献
68.
Theseparationofopticalisomersisarapidlygrowingareaincapillaryelectrophoresis(CE),andmostchiralseparationbyCEhavebeenperformedinaqueousbackgroundelectrolyte.Organicsolventssuchasmethanolandacetonitrilehavebeenappliedasbuffermodifiersatconcentrationtypicallynothigherthan40%inordertoincreasehydrophobicanalytesolubilityandtoimproveselectivity,resolution,ortoaltertheelectroosmoticflow(EOF)andelectrophoreticmobilityofanalyte.Buttherehavebeenonlyafewreportsonthechiralseparationusingpurenonaqueousme… 相似文献
69.
随着互联网上交易的增多,多单位同质产品销售的拍卖机制成为了一个新的研究方向.针对易逝性服务产品的收入管理问题,提出将产品销售分为多个拍卖期的MMV(Multi-period and Multi-unit Vickrey(Auction with Reserve Pricing)动态拍卖机制,给出每期最优拍卖单位数和保留价格的确定方法,证明了最优拍卖单位数分别关于剩余存量和销售时间单增的性质,以及保留价格关于剩余存量的单降性.最后证明MMV机制的每期实际成交价格将高于Vulcano(2002)提出的MSP(Modified Second-Price)机制,根据易逝性服务产品的需求特点得到MMV机制优于MSP机制的结论. 相似文献
70.
将二茂铁甲酰丙酮与异菸肼缩合,生成金属有机多齿新配体,该配体(FCR)与闭式-十二氢十二硼酸稀土化合物反应,得到分子式为[Ln(FcR)2]2(B12H12)3·XH2O(Ln=La,Nd,Eu,Gd,Dy,Ho,Er,TmandLu)的9个配位化合物,经元素分析、红外光谱、紫外光谱对其组成、结构进行了表征,通过TG-DTA研究了它们的热行为. 相似文献