7,536 research outputs found

    OECD\u27s FDI Regulatory Restrictiveness Index: Revision And Extension To More Economies

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    This paper provides a revised measure of regulatory restrictions on inward foreign direct investment (FDI) for OECD countries and extends the approach to 13 non-member countries. The methodology is largely similar to that adopted in the previous version of the OECD indicator and covers three broad categories of restrictions: limitations on foreign ownership, screening or notification procedures, and management and operational restrictions. The FDI restrictiveness indicator captures statutory deviations from national treatment , i.e. discrimination against foreign investment. When combined with other factors having an influence on foreign investment decisions, it has proven to be a good predictor of countries\u27 inward FDI performance

    Structure and growth process of vapor-grown carbon fibers

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    The structure, effect of heat, and growth process of vapor-grown carbon fibers are investigated. The growth process of the carbon fibers could be divided into three stages; nucleation, elongation, and thickening processes. Also, a multi-layered structure can be produced as well as graphitization

    Joule heating generated by spin current through Josephson junctions

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    We theoretically study the spin-polarized current flowing through a Josephson junction (JJ) in a spin injection device. When the spin-polarized current is injected from a ferromagnet (FM) in a superconductor (SC), the charge current is carried by the superconducting condensate (Cooper pairs), while the spin-up and spin-down currents flow in the equal magnitude but in the opposite direction in SC, because of no quasiparticle charge current in SC. This indicates that not only the Josephson current but also the spin current flow across JJ at zero bias voltage, thereby generating Joule heating by the spin current. The result provides a new method for detecting the spin current by measuring Joule heating at JJ.Comment: 3 pages, 2 figure

    Theory for Photon-Assisted Macroscopic Quantum Tunneling in a Stack of Intrinsic Josephson Junctions

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    We propose a theory for photon-assisted macroscopic quantum tunneling (MQT) in a stack of capacitively-coupled intrinsic Josephson junctions in which the longitudinal Josephson plasma, i.e., longitudinal collective phase oscillation modes, is excited. The scheme of energy-level quantization in the collective oscillatory states is clarified in the NN-junction system. When the MQT occurs from the single-plasmon states excited by microwave irradiation in the multi-photon process to the uniform voltage state, our theory predicts that the escape rate is proportional to N2N^2. This result is consistent with the recent observation in Bi-2212 intrinsic Josephson junctions.Comment: 5 pages, 2 figure

    Scalar perturbations in braneworld cosmology

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    We study the behaviour of scalar perturbations in the radiation-dominated era of Randall-Sundrum braneworld cosmology by numerically solving the coupled bulk and brane master wave equations. We find that density perturbations with wavelengths less than a critical value (set by the bulk curvature length) are amplified during horizon re-entry. This means that the radiation era matter power spectrum will be at least an order of magnitude larger than the predictions of general relativity (GR) on small scales. Conversely, we explicitly confirm from simulations that the spectrum is identical to GR on large scales. Although this magnification is not relevant for the cosmic microwave background or measurements of large scale structure, it will have some bearing on the formation of primordial black holes in Randall-Sundrum models.Comment: 17 pages, 7 figure

    Voltage-biased I-V characteristics in the multi-Josephson junction model of high Tc_c superconductor

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    By use of the multi-Josephson junction model, we investigate voltage-biased I-V characteristics. Differently from the case of the single junction, I-V characteristics show a complicated behavior due to inter-layer couplings among superconducting phase differences mediated by the charging effect. We show that there exist three characteristic regions, which are identified by jumps and cusps in the I-V curve. In the low voltage region, the total current is periodic with trigonometric functional increases and rapid drops. Then a kind of chaotic region is followed. Above certain voltage, the total current behaves with a simple harmonic oscillation and the I-V characteristics form a multi-branch structure as in the current-biased case. The above behavior is the result of the inter-layer coupling, and may be used to confirm the inter-layer coupling mechanism of the formation of hysteresis branches.Comment: 12 pages, Latex, 4 figure

    The X-ray Structure of A399 and A401: A Pre-Merging Cluster Pair

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    We present {\em ASCA} results of the pair clusters A399 and A401. The region between the two clusters exhibits excess X-rays over the value expected with a simple superposition of the two clusters. We see, however, no temperature rise at the merging front; the temperature is near the average of those in the inner regions of the two clusters. These indicate that the two clusters are really interacting but it is not strong at present. The inner regions of the two clusters show no radial variations of temperature, abundance and absorption values. We set upper-limits of mass deposition rate of cooling flow to be M˙<35  Myr1\dot{M}<35\;\rm M_{\odot}yr^{-1} and M˙<59  Myr1\dot{M}<59\;\rm M_{\odot}yr^{-1} for A399 and A401, respectively. A hint of azimuthal variation of the temperature is also found.Comment: 17 pages, 13 postscript figures, 2 external tables, accepted for publication in PAS
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