4,139 research outputs found

    Fano resonance in the nonadiabatic pumped shot noise of a time-dependent potential well

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    We use the Floquet scattering theory to study the correlation properties of the nonadiabatic pumped dc current and heat flow through a time-dependent potential well. Oscillator induced quasibound states of electrons can transit to the Floquet states leading to resonant tunneling effect. Virtual electron scattering processes can produce pumped heat flow, pumped shot noise and pumped heat flow noise, with presence of time and spatial reversal symmetry. When one of the Floquet levels matches the quasibound level there strikes a "Fano" resonance

    Aligned Graphene Nanoribbons and Crossbars from Unzipped Carbon Nanotubes

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    Aligned graphene nanoribbon (GNR) arrays were made by unzipping of aligned single-walled and few-walled carbon nanotube (CNT) arrays. Nanotube unzipping was achieved by a polymer-protected Ar plasma etching method, and the resulting nanoribbon array was transferred onto any substrates. Atomic force microscope (AFM) imaging and Raman mapping on the same CNTs before and after unzipping confirmed that ~80% of CNTs were opened up to form single layer sub-10 nm GNRs. Electrical devices made from the GNRs (after annealing in H2 at high temperature) showed on/off current (Ion/Ioff) ratios up to 103 at room temperature, suggesting semiconducting nature of the narrow GNRs. Novel GNR-GNR and GNR-CNT crossbars were fabricated by transferring GNR arrays across GNR and CNT arrays, respectively. The production of ordered graphene nanoribbon architectures may allow for large scale integration of GNRs into nanoelectronics or optoelectronics.Comment: published in Nano Researc

    Development and construction of China

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    Libraries in China's higher education institutions have been developing in keeping pace with the flourishing development of China's higher education. This article aims to make an introduction to the construction of China's higher education libraries, especially the recent three decades' achievements since China's reform and opening-up in 1978. In this article, the authors draw a general picture of the development of libraries in China's higher education institutions, covering such eight aspects as management, types and positioning, organizational structure and personnel, expenditure and buildings, reader service, building and sharing of resources as well as automation system.</p
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