316 research outputs found

    Superhyperfine interactions in Ce3+ doped LiYF4 crystal: ENDOR measurements

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    The first observation of the resolved Mims electron-nuclear double resonance (ENDOR) spectra from the nearby and remote nuclei of 19F and 7Li nuclei on impurity Ce3+ ions in LiYF4 crystal is reported. It shows that LiYF4:Ce3+ system can be exploited as a convenient matrix for performing spin manipulations and adjusting quantum computation protocols while ENDOR technique could be used for the investigation of electron-nuclear interaction with all the nuclei of the system and exploited for the electron-nuclear spin manipulations.Comment: 4 pages, 2 figures, 1 Table. Reported on Theor-2017 (Kazan, Russia) Conferenc

    Improved Randomization Tests for a Class of Single-Case Intervention Designs

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    Forty years ago, Eugene Edgington developed a single-case AB intervention design-and-analysis procedure based on a random determination of the point at which the B phase would start. In the present simulation studies encompassing a variety of AB-type contexts, it is demonstrated that by also randomizing the order in which the A and B phases are administered, a researcher can markedly increase the procedure’s statistical power

    An Improved Two Independent-Samples Randomization Test for Single-Case AB-Type Intervention Designs: A 20-Year Journey

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    Detailed is a 20-year arduous journey to develop a statistically viable two-phase (AB) single-case two independent-samples randomization test procedure. The test is designed to compare the effectiveness of two different interventions that are randomly assigned to cases. In contrast to the unsatisfactory simulation results produced by an earlier proposed randomization test, the present test consistently exhibited acceptable Type I error control under various design and effect-type configurations, while at the same time possessing adequate power to detect moderately sized intervention-difference effects. Selected issues, applications, and a multiple-baseline extension of the two-sample test are discussed

    Crystal electric field parameters for Yb3+ ion in YbRh2Si2

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    The tetragonal crystal electric field parameters for Yb3+ ion in YbRh2Si2 are determined from the analysis of the literature data on angle-resolved photoemission, inelastic neutron scattering and electron paramagnetic resonance.Comment: 8 pages, 3 figures, 4 table

    Influence of Al on the structure and in vitro behavior of hydroxyapatite nanopowders

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    Nanopowders of aluminum-substituted (0-20 mol %) hydroxyapatite (HA) with the average size of 40-60 nm were synthesized by the precipitation method from nitrate solutions. A series of samples were studied by various analytical tools to elucidate the peculiarities of al introductio

    Inhomogeneity of the intrinsic magnetic field in superconducting YBa2Cu3OX compounds as revealed by rare-earth EPR-probe

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    X-band electron paramagnetic resonance on doped Er3+ and Yb3+ ions in Y0.99(Yb,Er)0.01Ba2Cu3OX compounds with different oxygen contents in the wide temperature range (4-120)K have been made. In the superconducting species, the strong dependencies of the linewidth and resonance line position from the sweep direction of the applied magnetic field are revealed at the temperatures significantly below TC. The possible origins of the observed hysteresis are analyzed. Applicability of the presented EPR approach to extract information about the dynamics of the flux-line lattice and critical state parameters (critical current density, magnetic penetration depth, and characteristic spatial scale of the inhomogeneity) is discussedComment: 17 pages, 5 Figures. Renewed versio

    Inhomogeneity of the intrinsic magnetic field in superconducting YBa 2Cu3OX compounds as revealed by a rare-earth EPR probe

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    X-band electron paramagnetic resonance experiments on doped Er 3+ and Yb3+ ions in YBa2Cu3O X (6<X<7) compounds with different oxygen contents in a wide temperature range (4-120 K) have been performed. In the superconducting species at temperatures significantly below TC, strong dependences of the linewidth and resonance line position on the sweep direction of the applied magnetic field are revealed. The possible origins of the observed hysteresis are analysed. The applicability of the presented EPR approach to extract information about the dynamics of the flux-line lattice and critical state parameters (critical current density, JC, magnetic penetration depth, λ, and characteristic spatial scale of the inhomogeneity) is discussed. © 2005 IOP Publishing Ltd

    Conventional electron paramagnetic resonance of Mn<sup>2+</sup> in synthetic hydroxyapatite at different concentrations of the doped manganese

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    © 2018 Institute of Physics Publishing. All rights reserved. Powders of synthetic hydroxyapatite doped with Mn2+ ions in concentrations from 0.05 till 5 wt. % were investigated by conventional electron paramagnetic resonance (EPR). The parameters of the spin-Hamiltonian are derived. Partially resolved hyperfine structure in the magnetic fields corresponding to g ≈ 4.3 and g ≈ 9.4 is observed. The narrowing of the central peak with concentration is reported. A possibility to use the linewidth and intensity of the central peak for concentration measurements are discussed. The results could be used for the identification and qualification of Mn2+ in oil, mining and ore formations

    A DFT, X- and W-band EPR and ENDOR study of nitrogen-centered species in (Nano)hydroxyapatite

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    © Springer-Verlag Wien 2014. Incorporation of the nitrogen-containing impurities in hydroxyapatite (HAp) powders with the sizes of the crystallites of (20–50) nm was studied using first-principles modeling combined with the multi-frequency (9 and 94 GHz) electron paramagnetic resonance (EPR) methods. It is shown that the observed EPR spectra are undoubtedly due to the presence of the bulk radiation-induced NO3 2- radicals. This conclusion is based on spin-polarized density functional theory calculations of spectroscopic parameters within gauge-including projector augmented wave framework followed by the exact comparison of the simulated EPR and electron–nuclear double resonance spectra with the experimental findings. In addition, a comprehensive analysis of the simulated properties allows us to suggest that the paramagnetic centers preferably occupy PO4 3- sites in the HAp structure
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