1,277 research outputs found

    Mamíferos del Wealdiense de Uña, cerca de Cuenca

    Get PDF
    En esta nota preliminar se dan a conocer los hallazgos realizados en el Wealdiense de Uña, en la provincia de Cuenca corresponidientes a diversos mamíferos niesozoicos que se integran dentro de los grupos de los Pantoterios y los Multituberculados. Este es el segundo yacimiento de España de mamíferos secutidarios, siendo el primero el de Galve, en la provincia de Teruel. La descripción definitiva de los materiales será realizada por cada cada uno de los dos firmantes; por el primero, el de Uña y por el segundo, el de Galve

    Circular dichroism of magneto-phonon resonance in doped graphene

    Full text link
    Polarization resolved, Raman scattering response due to E2g_{2g} phonon in monolayer graphene has been investigated in magnetic fields up to 29 T. The hybridization of the E2g_{2g} phonon with only the fundamental inter Landau level excitation (involving the n=0 Landau level) is observed and only in one of the two configurations of the circularly crossed polarized excitation and scattered light. This polarization anisotropy of the magneto-phonon resonance is shown to be inherent to relatively strongly doped graphene samples, with carrier concentration typical for graphene deposited on SiO2_2

    A high-current hollow cathode as a source of intense line radiation in the VUV

    Get PDF
    The VUV line emission of a high-current DC hollow cathode was investigated in the wavelength region 10 nm to 100 nm. Spectra of quadruply ionised atoms could be observed. The radiance in the Al IV lines at 13 nm and 16 nm and in the He II Lyman-series was determined by a comparison with the spectral concentration of radiant intensity of the synchrotron radiation emitted by the electron storage ring BESSY. The authors found the radiance of the lines to be reproducible within +or-25%

    Electronic excitations and electron-phonon coupling in bulk graphite through Raman scattering in high magnetic fields

    Full text link
    We use polarized magneto-Raman scattering to study purely electronic excitations and the electron-phonon coupling in bulk graphite. At a temperature of 4.2 K and in magnetic fields up to 28 T we observe KK-point electronic excitations involving Landau bands with Δn=0\Delta |n|=0 and with Δn=±2\Delta |n|=\pm2 that can be selected by controlling the angular momentum of the excitation laser and of the scattered light. The magneto-phonon effect involving the E2gE_{2g} optical phonon and KK-point inter Landau bands electronic excitations with Δn=±1\Delta |n|=\pm1 is revealed and analyzed within a model taking into account the full kzk_z dispersion. These polarization resolved results are explained in the frame of the Slonczewski-Weiss-McClure (SWM) model which directly allows to quantify the electron-hole asymmetry.Comment: 13 pages, 10 figure

    Cavity-enhanced optical Hall effect in two-dimensional free charge carrier gases detected at terahertz frequencies

    Full text link
    The effect of a tunable, externally coupled Fabry-P\'{e}rot cavity to resonantly enhance the optical Hall effect signatures at terahertz frequencies produced by a traditional Drude-like two-dimensional electron gas is shown and discussed in this communication. As a result, the detection of optical Hall effect signatures at conveniently obtainable magnetic fields, for example by neodymium permanent magnets, is demonstrated. An AlInN/GaN-based high electron mobility transistor structure grown on a sapphire substrate is used for the experiment. The optical Hall effect signatures and their dispersions, which are governed by the frequency and the reflectance minima and maxima of the externally coupled Fabry-P\'{e}rot cavity, are presented and discussed. Tuning the externally coupled Fabry-P\'{e}rot cavity strongly modifies the optical Hall effect signatures, which provides a new degree of freedom for optical Hall effect experiments in addition to frequency, angle of incidence and magnetic field direction and strength

    Mamíferos del Wealdiense de Uña, cerca de Cuenca

    Get PDF
    En esta nota preliminar se dan a conocer los hallazgos realizados en el Wealdiense de Uña, en la provincia de Cuenca corresponidientes a diversos mamíferos niesozoicos que se integran dentro de los grupos de los Pantoterios y los Multituberculados. Este es el segundo yacimiento de España de mamíferos secutidarios, siendo el primero el de Galve, en la provincia de Teruel. La descripción definitiva de los materiales será realizada por cada cada uno de los dos firmantes; por el primero, el de Uña y por el segundo, el de Galve

    Electron effective mass in Al0.72_{0.72}Ga0.28_{0.28}N alloys determined by mid-infrared optical Hall effect

    Full text link
    The effective electron mass parameter in Si-doped Al0.72_{0.72}Ga0.28_{0.28}N is determined to be m=(0.336±0.020)m0m^\ast=(0.336\pm0.020)\,m_0 from mid-infrared optical Hall effect measurements. No significant anisotropy of the effective electron mass parameter is found supporting theoretical predictions. Assuming a linear change of the effective electron mass with the Al content in AlGaN alloys and m=0.232m0m^\ast=0.232\,m_0 for GaN, an average effective electron mass of m=0.376m0m^\ast=0.376\,m_0 can be extrapolated for AlN. The analysis of mid-infrared spectroscopic ellipsometry measurements further confirms the two phonon mode behavior of the E1_1(TO) and one phonon mode behavior of the A1_1(LO) phonon mode in high-Al-content AlGaN alloys as seen in previous Raman scattering studies

    Measles viral load may reflect SSPE disease progression

    Get PDF
    Subacute sclerosing panencephalitis (SSPE) is a rare, slowly progressive neurological disorder caused by the persistent infection with measles virus (MV). Despite much research into SSPE, its pathology remains obscure. We examined autopsy tissues of eight SSPE patients by real time quantitative PCR, immunohistochemistry and immunoblotting to determine viral load. MV N, M and H gene RNA could be detected in the central nervous system (CNS) of all patients and in two non-CNS tissues of one patient. The viral burden between patients differed up to four-fold by quantitative PCR and corresponded with detection of MV protein. The level of both viral RNA and antigen in the brain may correlate with disease progression

    How to not induce SNAs: The insufficiency of directional force.

    Get PDF
    People respond faster to smaller numbers in their left space and to larger numbers in their right space. Here we argue that movements in space contribute to the formation of spatial-numerical associations (SNAs). We studied the impact of continuous isometric forces along the horizontal or vertical cardinal axes on SNAs while participants performed random number production and arithmetic verification tasks. Our results suggest that such isometric directional force do not suffice to induce SNAs. [Abstract copyright: Copyright: © 2023 Michirev et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
    corecore