244 research outputs found
SYNTHESIS OF MAGHEMITE BY THERMAL ANNEALING
The paper considers the preparation of a nanostructured maghemite powder as a result of thermal magnetite (Fe3O4) treatment. Methods of scanning electron microscopy, energy dispersive analysis, and X-ray analysis were used to analyze the obtained results. X-ray diffraction analysis has showed that as a result of the thermal treatment of the initial powder, γ-Fe2O3 phase (the space group P4132), as well as the phase transition of the crystal structure from Fe3O4 to γ-Fe2O3 with a preferential crystallite orientation for the γ-Fe2O3 phase from the texture plane with Miller indexes (220) are noticed.Данная работа выполнена в рамках реализации научного гранта «Разработка технологии получения нанопорошков железа методом поверхностной оксидации нелегированной стали» финансируемого Комитетом науки Министерства образования и науки Республики Казахстан согласно договору №45 от 12 февраля 2015 года
Rates of convergence for empirical spectral measures: a soft approach
Understanding the limiting behavior of eigenvalues of random matrices is the
central problem of random matrix theory. Classical limit results are known for
many models, and there has been significant recent progress in obtaining more
quantitative, non-asymptotic results. In this paper, we describe a systematic
approach to bounding rates of convergence and proving tail inequalities for the
empirical spectral measures of a wide variety of random matrix ensembles. We
illustrate the approach by proving asymptotically almost sure rates of
convergence of the empirical spectral measure in the following ensembles:
Wigner matrices, Wishart matrices, Haar-distributed matrices from the compact
classical groups, powers of Haar matrices, randomized sums and random
compressions of Hermitian matrices, a random matrix model for the Hamiltonians
of quantum spin glasses, and finally the complex Ginibre ensemble. Many of the
results appeared previously and are being collected and described here as
illustrations of the general method; however, some details (particularly in the
Wigner and Wishart cases) are new.
Our approach makes use of techniques from probability in Banach spaces, in
particular concentration of measure and bounds for suprema of stochastic
processes, in combination with more classical tools from matrix analysis,
approximation theory, and Fourier analysis. It is highly flexible, as evidenced
by the broad list of examples. It is moreover based largely on "soft" methods,
and involves little hard analysis
Quantum walks: a comprehensive review
Quantum walks, the quantum mechanical counterpart of classical random walks,
is an advanced tool for building quantum algorithms that has been recently
shown to constitute a universal model of quantum computation. Quantum walks is
now a solid field of research of quantum computation full of exciting open
problems for physicists, computer scientists, mathematicians and engineers.
In this paper we review theoretical advances on the foundations of both
discrete- and continuous-time quantum walks, together with the role that
randomness plays in quantum walks, the connections between the mathematical
models of coined discrete quantum walks and continuous quantum walks, the
quantumness of quantum walks, a summary of papers published on discrete quantum
walks and entanglement as well as a succinct review of experimental proposals
and realizations of discrete-time quantum walks. Furthermore, we have reviewed
several algorithms based on both discrete- and continuous-time quantum walks as
well as a most important result: the computational universality of both
continuous- and discrete- time quantum walks.Comment: Paper accepted for publication in Quantum Information Processing
Journa
Разработка и внедрение технологии изготовления малолитражных баллонов высокого давления с использованием операции обжима
Разработка и внедрение технологии изготовления малолитражных баллонов высокого давления с использованием операции обжима / А. Д. Кирицев [и др.] // Вісник Приазовського державного технічного університету : зб. наук. праць / ПДТУ. – Маріуполь, 2001. – Вип. 11. – С. 154–158.По результатам исследований, проведенных кафедрой КШП, разработана и внедрена на Мариупольском ЗАО «Пожзащита» новая технология изготовления малолитражных баллонов высокого давления с использованием операции обжима с предварительным дифференцированным нагревом очага деформации
Measurements of , , p and spectra in Be+Be collisions at beam momenta from 19A to 150A with the NA61/SHINE spectrometer at the CERN SPS
The NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS) studies the onset of deconfinement in hadron matter by a scan of particle production in collisions of nuclei with various sizes at a set of energies covering the SPS energy range. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of π ±
π±
, K ±
K±
, p and p ¯
p¯
produced in the 20% most central 7
7
Be+ 9
9
Be collisions at beam momenta of 19A, 30A, 40A, 75A and 150A GeV/c
GeV/c
. The energy dependence of the K ±
K±
/π ±
π±
ratios as well as of inverse slope parameters of the K ±
K±
transverse mass distributions are close to those found in inelastic p+p reactions. The new results are compared to the world data on p+p and Pb+Pb collisions as well as to predictions of the Epos, Urqmd, Ampt, Phsd and Smash models
Erratum to: Measurements of , , p and spectra in Be+Be collisions at beam momenta from 19A to 150A GeV/c with the NA61/SHINE spectrometer at the CERN SPS – NA61/SHINE Collaboration
Measurements of production in Be + Be collisions at beam momenta from 19A to 150 in the NA61/SHINE experiment at the CERN SPS
The NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS) studies the onset of deconfinement in hadron matter by a scan of particle production in collisions of nuclei with various sizes at a set of energies covering the SPS energy range. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of , , p and produced in the 20% most centralBe+Be collisions at beam momenta of 19A, 30A, 40A, 75A and 150A . The energy dependence of the / ratios as well as of inverse slope parameters of the transverse mass distributions are close to those found in inelastic p+p reactions. The new results are compared to the world data on p+p and Pb+Pb collisions as well as to predictions of the Epos, Urqmd, Ampt, Phsd and Smash models
Spectra and mean multiplicities of π- in central 40 Ar+ 45 Sc collisions at 13A, 19A, 30A, 40A, 75A and 150 AGeV/c beam momenta measured by the NA61/SHINE spectrometer at the CERN SPS: NA61/SHINE Collaboration
The physics goal of the strong interaction program of the NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS) is to study the phase diagram of hadronic matter by a scan of particle production in collisions of nuclei with various sizes at a set of energies covering the SPS energy range. This paper presents differential inclusive spectra of transverse momentum, transverse mass and rapidity of π mesons produced in central Ar45Sc collisions at beam momenta of 13A, 19A, 30A, 40A, 75A and 150A Ge V /c. Energy and system size dependence of parameters of these distributions – mean transverse mass, the inverse slope parameter of transverse mass spectra, width of the rapidity distribution and mean multiplicity – are presented and discussed. Furthermore, the dependence of the ratio of the mean number of produced pions to the mean number of wounded nucleons on the collision energy was derived. The results are compared to predictions of several models
Spectra and mean multiplicities of in central collisions at 13A, 19A, 30A, 40A, 75A and 150A Ge V/c beam momenta measured by the NA61/SHINE spectrometer at the CERN SPS
International audienceThe physics goal of the strong interaction program of the NA61/SHINE experiment at the CERN Super Proton Synchrotron (SPS) is to study the phase diagram of hadronic matter by a scan of particle production in collisions of nuclei with various sizes at a set of energies covering the SPS energy range. This paper presents differential inclusive spectra of transverse momentum, transverse mass and rapidity of mesons produced in centralAr+Sc collisions at beam momenta of 13A, 19A, 30A, 40A, 75A and 150. Energy and system size dependence of parameters of these distributions – mean transverse mass, the inverse slope parameter of transverse mass spectra, width of the rapidity distribution and mean multiplicity – are presented and discussed. Furthermore, the dependence of the ratio of the mean number of produced pions to the mean number of wounded nucleons on the collision energy was derived. The results are compared to predictions of several models
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