237 research outputs found

    Shifted convolution and the Titchmarsh divisor problem over F_q[t]

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    In this paper we solve a function field analogue of classical problems in analytic number theory, concerning the auto-correlations of divisor functions, in the limit of a large finite field.Comment: 22 pages, updated versio

    Resonance-like piezoelectric electron-phonon interaction in layered structures

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    We show that mismatch of the piezoelectric parameters between layers of multiple-quantum well structures leads to modification of the electron-phonon interaction. In particular, short-wavelength phonons propagating perpendicular to the layers with wavevector close to 2πn/d2\pi n/d, where dd is the period of the structure, induce a strong smoothly-varying component of the piezo-potential. As a result, they interact efficiently with 2D electrons. It is shown, that this property leads to emission of collimated quasi-monochromatic beams of high-frequency acoustic phonons from hot electrons in multiple-quantum well structures. We argue that this effect is responsible for the recently reported monochromatic transverse phonon emission from optically excited GaAs/AlAs superlattices, and provide additional experimental evidences of this.Comment: 6 pages, 7 figure

    Author as a corporal subject of a. Huxley’s works

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    The relevance of the problem studied in the article is conditioned by the fact that A. Huxley’s works are regarded in the context of the modern theory of mimesis for the first time. The aim of the article is to analyze the author’s problem as a corporal subject of Huxley’s works in the context of the modern theory of mimesis. The leading method for studying this problem is the analytical anthropology of literature which allows describing mimetic features and the author’s image as a corporal subject of Huxley’s works. The main attention in the article is paid to the artistically embodied forms of the author’s corporality. The article may be useful for philologists, philosophers, for developing courses and seminars on the history of the English literature, and also within courses on the anthropology of literature. © 2016 Falaleeva et al

    Fukushima plutonium effect and blow-up regimes in neutron-multiplying media

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    It is shown that the capture and fission cross-sections of 238U and 239Pu increase with temperature within 1000-3000 K range, in contrast to those of 235U, that under certain conditions may lead to the so-called blow-up modes, stimulating the anomalous neutron flux and nuclear fuel temperature growth. Some features of the blow-up regimes in neutron-multiplying media are discussed.Comment: 15 pages, 8 figures. (v2: numerous corrections and style improvements). arXiv admin note: substantial text overlap with arXiv:1207.369

    Electron-phonon interaction via Pekar mechanism in nanostructures

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    We consider an electron-acoustic phonon coupling mechanism associated with the dependence of crystal dielectric permittivity on the strain (the so-called Pekar mechanism) in nanostructures characterized by strong confining electric fields. The efficiency of Pekar coupling is a function of both the absolute value and the spatial distribution of the electric field. It is demonstrated that this mechanism exhibits a phonon wavevector dependence similar to that of piezoelectricity and must be taken into account for electron transport calculations in an extended field distribution. In particular, we analyze the role of Pekar coupling in energy relaxation in silicon inversion layers. Comparison with the recent experimental results is provided to illustrate its potential significance
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