13,350 research outputs found

    Deflection microwave amplifier with field‐emitter arrays

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    A new class of microwave and millimeter‐wave amplifiers, based on the deflection of collimated microscopic electron beams with high‐current density and low voltage from field‐emitter arrays, was analyzed. The deflection concept may be applied in two ways; as microelectronic amplifiers or as bunched beam cathodes to power conventional amplifier configurations such as klystrodes and traveling wave tubes. We found that the frequency fT, at which the short‐circuit current gain attains unit magnitude, depends only on the electron beam energy, current density, and emittance, and is independent of beamwidth and total current. The results indicate that field‐emitter arrays have the potential of making wideband deflection amplifiers at frequencies up to tens of GHz. © 1994 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69885/2/APPLAB-65-22-2881-1.pd

    Hybrid exciton-polaritons in a bad microcavity containing the organic and inorganic quantum wells

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    We study the hybrid exciton-polaritons in a bad microcavity containing the organic and inorganic quantum wells. The corresponding polariton states are given. The analytical solution and the numerical result of the stationary spectrum for the cavity field are finishedComment: 3 pages, 1 figure. appear in Communications in Theoretical Physic

    Entangling two superconducting LC coherent modes via a superconducting flux qubit

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    Based on a pure solid-state device consisting of two superconducting LC circuits coupled to a superconducting flux qubit, we propose in this paper that the maximally entangled coherent states of the two LC modes can be generated for arbitrary coherent states through flux qubit controls.Comment: 5 pages, 2 figure

    Power system transient stability assessment based on quadratic approximation of stability region

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    This paper presents an approach to estimate the Critical Clearing Time (CCT) of the multi-machine power systems based on the quadratic surface which approximates the boundary of stability region relating to the controlling unstable equilibrium point. A decomposition method is developed to obtain the coefficients of the quadratic approximation surface. The CCT is determined by the crossing point of the quadratic surface and the continuous faulted trajectory. Simulations in IEEE 9-bus and New England system show the effectiveness of the proposed approach. © 2005 IEEE.published_or_final_versio

    Mott physics, sign structure, ground state wavefunction, and high-Tc superconductivity

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    In this article I give a pedagogical illustration of why the essential problem of high-Tc superconductivity in the cuprates is about how an antiferromagnetically ordered state can be turned into a short-range state by doping. I will start with half-filling where the antiferromagnetic ground state is accurately described by the Liang-Doucot-Anderson (LDA) wavefunction. Here the effect of the Fermi statistics becomes completely irrelevant due to the no double occupancy constraint. Upon doping, the statistical signs reemerge, albeit much reduced as compared to the original Fermi statistical signs. By precisely incorporating this altered statistical sign structure at finite doping, the LDA ground state can be recast into a short-range antiferromagnetic state. Superconducting phase coherence arises after the spin correlations become short-ranged, and the superconducting phase transition is controlled by spin excitations. I will stress that the pseudogap phenomenon naturally emerges as a crossover between the antiferromagnetic and superconducting phases. As a characteristic of non Fermi liquid, the mutual statistical interaction between the spin and charge degrees of freedom will reach a maximum in a high-temperature "strange metal phase" of the doped Mott insulator.Comment: 12 pages, 12 figure

    Coarse-grained reconfigurable array architectures

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    Coarse-Grained Reconfigurable Array (CGRA) architectures accelerate the same inner loops that benefit from the high ILP support in VLIW architectures. By executing non-loop code on other cores, however, CGRAs can focus on such loops to execute them more efficiently. This chapter discusses the basic principles of CGRAs, and the wide range of design options available to a CGRA designer, covering a large number of existing CGRA designs. The impact of different options on flexibility, performance, and power-efficiency is discussed, as well as the need for compiler support. The ADRES CGRA design template is studied in more detail as a use case to illustrate the need for design space exploration, for compiler support and for the manual fine-tuning of source code

    THE EFFECT OF SUPPLEMENTATION GARLIC OIL AS AN ANTIBACTERIAL ACTIVITY AND SALTING TIME ON THE CHARACTERISTICS OF SALTED EGG

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    This study has been done to examine the influences of garlic oil, salting time in the characteristics of salted egg. Typical bacterial used in this study were Escherichia coli, Salmonella enteritidis, and Staphylococcus aureus. They were obtained from the culture collection of National R&D Center for Egg Processing Laboratory, Food Science and Technology College, Huazhong Agricultural University, Wuhan, China. The experimental design was completely randomized design with factorial factor A x B (3 x 5) for three replications. Factor A were supplementation of garlic oil with different concentration (0%; 0.1%; 0.5%) and factor B were different time for salting process (0; 7; 14; 21; 28 days). The research was done through several activities, the determination of garlic oil as an antibacterial activity and making salted eggs in the presence of garlic oil are performed.  The results showed that garlic oil had antibacterial activity on the three bacteria used in this study. The minimum inhibitory concentration (MIC) of garlic oil was used as a determination of the concentration in salted egg presence of garlic oil. Egg white and yolk of duck eggs with different salting time and concentration of garlic oil showed slight differences in chemical composition and textural properties as salting proceeded. Both of treatment could induce solidification of yolk accompanied by oil exudation and the development of gritty texture. Thus both of treatment somehow affected the characteristics of the resulting egg white and egg yolk
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