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1.
In this work, the beam splitter with two input ports and two output ports in two-dimensional photonic crystals is studied through the finite-difference time-domain method. The beam splitter consists of two orthogonally cross line defects. The diameter of the two diagonal air holes at the intersection of the two line defects was modified. The input light can be identically divided into the two output ports. The beam splitters can be applied in the photonic crystal Mach-Zehnder interferometers or photonic crystal optical switches. 相似文献
2.
In the present paper, some new almost fixed point theorems and fixed point theorems for lower semicontinuous type multivalued mappings are obtained in metrizable H-spaces. 相似文献
3.
Dendritic nanocrystalline CdS film was deposited at liquid-liquid interface of surfactants and an electrolyte containing 4 mmol L−1 cadmium chloride (CdCl2) and 16 mmol L−1 thioacetamide (CH3CSNH2) with an initial pH value of 5 at 15 °C by electrochemical synthesis. The nanofilm was characterized by transmission electron microscopy (TEM), field emission scanning electron microscope (FE-SEM), atomic force microscopy (AFM), ultraviolet visible (UV-vis) absorption spectroscopy and fluorescence spectroscopy. The surface morphology and particle size of the nanofilm were investigated by AFM, SEM and TEM, and the crystalline size was 30-50 nm. The thickness of the nanofilm calculated by optical absorption spectrum was 80 nm. The microstructure and composition of the nanofilm was investigated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), showing its polycrystalline structure consisting of CdS and Cd. Optical properties of the nanofilm were investigated systematically by UV-vis absorption and fluorescence spectroscopy. A λonset blue shift compared with bulk CdS was observed in the absorption spectra. Fluorescence spectra of the nanofilm indicated that the CdS nanofilm emitted blue and green light. The nanocomposites film electrode will bring about anodic photocurrent during illumination, showing that the transfer of cavities produces photocurrent. 相似文献
4.
In this paper, by the use of a fixed point theorem, many new necessary and sufficient conditions for the existence of positive solutions in C[0,1]∩C1[0,1]∩C2(0,1) or C[0,1]∩C2(0,1) are presented for singular superlinear and sublinear second-order boundary value problems. Singularities at t=0, t=1 will be discussed. 相似文献
5.
PARAMETER ESTIMATION OF SPATIAL AR MODEL 总被引:1,自引:0,他引:1
Jiang Jiming 《数学年刊B辑(英文版)》1991,12(4):432-444
Consider a stable AR model of two parameter spatial series {X_t, t∈N~2}, i. e. {X_(t)t∈N~2} is homogeneous and satisfies the following difference equationX_t-sum from n=s∈相似文献
6.
理想气体的温度、体积和压强三个状态参量之间的关系由气体状态方程pV/T=恒量决定。当气体状态发生变化时,判断某一个参量的变化趋势是一个比较复杂的问题。如图1,为p—T图中的状态变化曲线,状态由A变化到B,判断体积的变化趋势。 相似文献
7.
We study notions of nondegeneracy and several levels of increasing degeneracy from the perspective of the local behavior of a local solution of a nonlinear program when problem parameters are slightly perturbed. Ideal nondegeneracy at a local minimizer is taken to mean satisfaction of second order sufficient conditions, linear independence and strict complimentary slackness. Following a brief exploration of the relationship of these conditions with the classical definition of nondegeneracy in linear programming, we recall a number of optimality and regularity conditions used to attempt to resolve degeneracy and survey results of Fiacco, McCormick, Robinson, Kojima, Gauvin and Janin, Shapiro, Kyparisis and Liu. This overview may be viewed as a structured survey of sensitivity and stability results: the focus is on progressive levels of degeneracy. We note connections of nondegeneracy with the convergence of algorithms and observe the striking parallel between the effects of nondegeneracy and degeneracy on optimality conditions, stability analysis and algorithmic convergence behavior. Although our orientation here is primarily interpretive and noncritical, we conclude that more effort is needed to unify optimality, stability and convergence theory and more results are needed in all three areas for radically degenerate problems.Research supported by National Science Foundation Grant ECS 90-00560 and Grant N00014-89-J-1537 Office of Naval Research 相似文献
8.
9.
VOCs控制催化剂的研制 总被引:5,自引:1,他引:5
以堇青石蜂窝陶瓷体为第一载体、γ-Al2O3为第二载体,制成的含稀土La和过渡金属元素的复合氧化物催化剂,在连续流动的反应体系上评价了催化剂对苯、氰氢酸、乙酸和氯苯等VOCs的氧化反应活性.结果表明: 采用LaCuMn组合制备的催化剂,La的含量在7%~10%左右、Cu的含量在5.5%左右、Mn的含量在7.5%左右时,第二载体γ-Al2O3的负载以采用半胶、pH值4~5、加入某些活性剂、负载量以7%~10%、活化温度为400~500 ℃时制成的催化剂的活性最好,研制的VOCs控制催化剂对各种VOCs均具有很高的催化活性. 相似文献
10.