45,552 research outputs found

    Formation of Non-reciprocal Bands in Magnetized Diatomic Plasmonic Chains

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    We show that non-reciprocal bands can be formed in a magnetized periodic chain of spherical plasmonic particles with two particles per unit cell. Simplified form of symmetry operators in dipole approximations are used to demonstrate explicitly the relation between spectral non-reciprocity and broken spatial-temporal symmetries. Due to hybridization among plasmon modes and free photon modes, strong spectral non-reciprocity appears in region slightly below the lightline, where highly directed guiding of energy can be supported. The results may provide a clear guidance on the design of one-way waveguides

    First-principles calculations of a high-pressure synthesized compound PtC

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    First-principles density-functional method is used to study the recently high-pressure synthesized compound PtC. It is confirmed by our calculations that the platinum carbide has a zinc-blende ground-state phase at zero pressure and the rock-salt structure is a high-pressure phase. The theoretical transition pressure from zinc-blende to rock-salt is determined to be 52GPa. Furthermore, our calculation shows the possibility that the experimentally synthesized PtC by Ono et al. under high pressure condition might undergo a transition from rock-salt structure to zinc-blende after the pressure quench to ambient condition.Comment: A revised versio

    Conformal or Walking? Monte Carlo renormalization group studies of SU(3) gauge models with fundamental fermions

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    Strongly coupled gauge systems with many fermions are important in many phenomenological models. I use the 2-lattice matching Monte Carlo renormalization group method to study the fixed point structure and critical indexes of SU(3) gauge models with 8 and 12 flavors of fundamental fermions. With an improved renormalization group block transformation I am able to connect the perturbative and confining regimes of the N_f=8 flavor system, thus verifying its QCD-like nature. With N_f=12 flavors the data favor the existence of an infrared fixed point and conformal phase, though the results are also consistent with very slow walking. I measure the anomalous mass dimension in both systems at several gauge couplings and find that they are barely different from the free field value.Comment: 26 pages, 11 figure

    Development of National Assessment Criteria for Green Schools in China

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    In the Peoples' Republic of China, a green schools programme was initiated in 1996. It has promoted both education reform and socially sustainable development. Recently, the assessment criteria for green schools have become an obstacle to the rapid development of the green school initiative, mainly due to the cultural and social system in Mainland China. Because there are many district criteria which mainly focus on green schools construction and evaluation, it is necessary to have new criteria to replace them. However, the requirements of the existing national criteria arenā€™t detailed, and the requirements donā€™t satisfy evaluation needs after the provincial criteria are replaced. Hence, the new national criteria should include a more comprehensive set of indices and requirements. This paper firstly examines the experiences from other countries and areas, and then analyses weaknesses of the existing green schools assessment process in China. Finally, someĀ Ā  understanding about green schools, and principles to establish new national criteria in China, are discussed in the paper. Since new national criteria are being established, they will be applied to the evaluation of theĀ  national green schools project in Mainland China in 2006
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