Graphite is a semimetal and thus has no bandgap;photoluminescence is not expected from relaxed charge carriers. Here, however, an ultralow threshold optically pumped random lasing behavior in highly oriented pyrolytic...
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Graphite is a semimetal and thus has no bandgap;photoluminescence is not expected from relaxed charge carriers. Here, however, an ultralow threshold optically pumped random lasing behavior in highly oriented pyrolytic graphite (HOPG) was observed under 488 nm Ar+ laser excitation at room temperature. In addition, this lasing behavior differs from the conventional random lasing process, i.e., the emission exhibits an ultra-low lasing threshold and a linear dependence on the laser excitation intensity in a low power range, and it saturates at high excitation densities. The theoretical model which accounts for the optically pumped random lasing behavior in HOPG has been proposed. (C) 2013 Elsevier B.V. All rights reserved.
In this paper, a quantized H∞ control problem for networked control systems (NCSs) subject to randomly multi-step transmission delays is investigated. A quantizer is used before the measurement signal enters the comm...
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In this paper, a fault detection problem is considered for a class of systems with unknown-but-bounded noises by a set-membership filtering approach. The measurement and the process noises are both considered as unkno...
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In this paper, a fault detection problem is considered for a class of systems with unknown-but-bounded noises by a set-membership filtering approach. The measurement and the process noises are both considered as unknown-but-bounded. Two ellipsoidal sets, which are one-step-ahead prediction ellipsoid and estimation ellipsoid, are proposed for the state estimation. The fault signal is detected by intersecting the two ellipsoids to check whether the intersection set is empty or not. Recursive algorithms for calculating the two ellipsoids and for detecting whether the fault occurs in the system are developed. Simulation results are provided to illustrate the effectiveness of the proposed method.
Hard disk protection cards with a network clone function are widely used in universities at present to protect hard disk data. In this article, the working principle and optimized settings of the protection card has b...
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A low temperature growth method based on an electron cyclotron resonance plasma-enhanced metal organic chemical vapor deposition system (ECR-PEMOCVD) was proposed for the growth of GaN (Gallium nitride) films on ordin...
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A low temperature growth method based on an electron cyclotron resonance plasma-enhanced metal organic chemical vapor deposition system (ECR-PEMOCVD) was proposed for the growth of GaN (Gallium nitride) films on ordinary amorphous soda-lime glass substrates. To alleviate the large lattice mismatch between GaN film and glass substrate and improve the heat dissipation performance for potential optoelctrical device application, five intermediate layers (Cu, Ni, Ti, Ag, and ITO) were deposited-on the glass substrate before the growth of GaN. A comparative study was performed through structural analysis of the as-grown GaN films with various intermediate layers investigated by means of in-situ reflection high energy electron diffraction (RHEED), X-ray diffraction (XRD), and atomic force microscopy (AFM). The results indicate that the Ti intermediate layer has a great advantage over other intermediate layers in view of crystalline quality and smooth surface, therefore is more suitable and preferred for the potential application in optoelectronic devices. (C) 2014 Elsevier Ltd. All rights reserved.
In this paper, a linear unbiased minimum-variance filtering problem is considered for a class of systems with randomly multi-step sensor delays. A new mathematical model is established for the multi-step sensor delays...
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