838 research outputs found

    Integration of Poland into EU global industrial networks: the evidence and the main challenges

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    In this paper, we attempt to identify the achievements of one decade of transformation of the Polish economy in effecting the integration of its manufacturing sector with those of the broader European and global economy, using the automotive industry as an illustrative example. We begin with a broad picture of the current situation in Poland, looking particularly at the motivations of EU-based investors. We then discuss the automobile industry, again examining the motives of foreign investors and the effects of policy on their behavior. Next, we examine the chief public and private actors in the integration process, with a particular focus on their roles in trying to push Poland's integration in the direction of high value added and high innovation. Finally, we briefly discuss the impact of Poland's accession to the EU on industrial networking, and then summarize our conclusions and suggest a research framework for testing the hypothesis (formulated on the basis of our observations of the Polish case) that the market orientation of a given industry, measured by the ratio of the trade balance in that industry to its total domestic output, depends among other things on ownership structure, with the domestically-owned sector tending to use locally developed technologies and the foreign-owned sector tending to transfer in technology from abroad

    Energy-level quantization in YBa2Cu3O7-x phase-slip nanowires

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    Significant progress has been made in the development of superconducting quantum circuits, however new quantum devices that have longer decoherence times at higher temperatures are urgently required for quantum technologies. Superconducting nanowires with quantum phase slips are promising candidates for use in novel devices that operate on quantum principles. Here, we demonstrate ultra-thin YBa2Cu3O7-x nanowires with phase-slip dynamics and study their switching-current statistics at temperatures below 20 K. We apply theoretical models that were developed for Josephson junctions and show that our results provide strong evidence for energy-level quantization in the nanowires. The crossover temperature to the quantum regime is 12-13 K, while the lifetime in the excited state exceeds 20 ms at 5.4 K. Both values are at least one order of magnitude higher than those in conventional Josephson junctions based on low-temperature superconductors. We also show how the absorption of a single photon changes the phase-slip and quantum state of a nanowire, which is important for the development of single-photon detectors with high operating temperature and superior temporal resolution. Our findings pave the way for a new class of superconducting nanowire devices for quantum sensing and computing

    Non-adiabatic spin torque investigated using thermally activated magnetic domain wall dynamics

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    Using transmission electron microscopy, we investigate the thermally activated motion of domain walls (DWs) between two positions in permalloy (Ni80Fe20) nanowires at room temperature. We show that this purely thermal motion is well described by an Arrhenius law, allowing for a description of the DW as a quasi-particle in a 1D potential landscape. By injecting small currents, the potential is modified, allowing for the determination of the non-adiabatic spin torque: the non-adiabatic coefficient is 0.010 +/- 0.004 for a transverse DW and 0.073 +/- 0.026 for a vortex DW. The larger value is attributed to the higher magnetization gradients present

    Generalised Ordinary vs Fully Simple Duality for <i>n</i>-Point Functions and a Proof of the Borot–Garcia-Failde Conjecture

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    We study a duality for the n-point functions in VEV formalism that we call the ordinary vs fully simple duality. It provides an ultimate generalisation and a proper context for the duality between maps and fully simple maps observed by Borot and Garcia-Failde. Our approach allows to transfer the algebraicity properties between the systems of n-point functions related by this duality, and gives direct tools for the analysis of singularities. As an application, we give a proof of a recent conjecture of Borot and Garcia-Failde on topological recursion for fully simple maps..</p

    Direct measurement of the charge distribution along a biased carbon nanotube bundle using electron holography

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    Nanowires and nanotubes can be examined in the transmission electron microscope under an applied bias. Here we introduce a model-independent method, which allows the charge distribution along a nanowire or nanotube to be measured directly from the Laplacian of an electron holographic phase image. We present results from a biased bundle of carbon nanotubes, in which we show that the charge density increases linearly with distance from its base, reaching a value of similar to 0.8 electrons/nm near its tip. (C) 2011 American Institute of Physics. [doi:10.1063/1.3598468

    Hypercommutative operad as a homotopy quotient of BV

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    We give an explicit formula for a quasi-isomorphism between the operads Hycomm (the homology of the moduli space of stable genus 0 curves) and BV/Δ\Delta (the homotopy quotient of Batalin-Vilkovisky operad by the BV-operator). In other words we derive an equivalence of Hycomm-algebras and BV-algebras enhanced with a homotopy that trivializes the BV-operator. These formulas are given in terms of the Givental graphs, and are proved in two different ways. One proof uses the Givental group action, and the other proof goes through a chain of explicit formulas on resolutions of Hycomm and BV. The second approach gives, in particular, a homological explanation of the Givental group action on Hycomm-algebras.Comment: minor corrections added, to appear in Comm.Math.Phy
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