19,923 research outputs found

    Towards the development of the maritime safety administration

    Get PDF

    Shape evolution and shape coexistence in Pt isotopes: comparing interacting boson model configuration mixing and Gogny mean-field energy surfaces

    Get PDF
    The evolution of the total energy surface and the nuclear shape in the isotopic chain 172−194^{172-194}Pt are studied in the framework of the interacting boson model, including configuration mixing. The results are compared with a self-consistent Hartree-Fock-Bogoliubov calculation using the Gogny-D1S interaction and a good agreement between both approaches shows up. The evolution of the deformation parameters points towards the presence of two different coexisting configurations in the region 176 ≤\leq A ≤\leq 186.Comment: Submitted to PR

    Discovery of a deep Seyfert-2 galaxy at z = 0.222 behind NGC 300

    Get PDF
    We report on the unveiling of the nature of the unidentified X-ray source 3XMM J005450.3-373849 as a Seyfert-2 galaxy located behind the spiral galaxy NGC 300 using Hubble Space Telescope data, new spectroscopic Gemini observations and available XMM-Newton and Chandra data. We show that the X-ray source is positionally coincident with an extended optical source, composed by a marginally resolved nucleus/bulge, surrounded by an elliptical disc-like feature and two symmetrical outer rings. The optical spectrum is typical of a Seyfert-2 galaxy redshifted to z=0.222 +/- 0.001, which confirms that the source is not physically related to NGC 300. At this redshift the source would be located at 909+/-4 Mpc (comoving distance in the standard model). The X-ray spectra of the source are well-fitted by an absorbed power-law model. By tying NHN_\mathrm{H} between the six available spectra, we found a variable index Γ\Gamma running from ~2 in 2000-2001 years, to 1.4-1.6 in the 2005-2014 period. Alternatively, by tying Γ\Gamma, we found variable absorption columns of N_H ~ 0.34 x 10−2210^{-22} cm−2^{-2} in 2000-2001 years, and 0.54-0.75 x 10−2210^{-22} cm−2^{-2} in the 2005-2014 period. Although we cannot distinguish between an spectral or absorption origin, from the derived unabsorbed X-ray fluxes, we are able to assure the presence of long-term X-ray variability. Furthermore, the unabsorbed X-ray luminosities of 0.8-2 x 1043^{43} erg s−1^{-1} derived in the X-ray band are in agreement with a weakly obscured Seyfert-2 AGN at z≈0.22z \approx 0.22.Comment: MNRAS, accepte

    Developmental effects in the online use of morphosyntactic cues in sentence processing: Evidence from Tagalog

    Get PDF
    Children must necessarily process their input in order to learn it, yet the architecture of the developing parsing system and how it interfaces with acquisition is unclear. In the current paper we report experimental and corpus data investigating adult and children's use of morphosyntactic cues for making incremental online predictions of thematic roles in Tagalog, a verb-initial symmetrical voice language of the Philippines. In Study 1, Tagalog-speaking adults completed a visual world eye-tracking experiment in which they viewed pictures of causative actions that were described by transitive sentences manipulated for voice and word order. The pattern of results showed that adults process agent and patient voice differently, predicting the upcoming noun in the patient voice but not in the agent voice, consistent with the observation of a patient voice preference in adult sentence production. In Study 2, our analysis of a corpus of child-directed speech showed that children heard more patient voice- than agent voice-marked verbs. In Study 3, 5-, 7-, and 9-year-old children completed a similar eye-tracking task as used in Study 1. The overall pattern of results suggested that, like the adults in Study 1, children process agent and patient voice differently in a manner that reflects the input distributions, with children developing towards the adult state across early childhood. The results are most consistent with theoretical accounts that identify a key role for input distributions in acquisition and language processin

    Thermalization and Cooling of Plasmon-Exciton Polaritons: Towards Quantum Condensation

    Get PDF
    We present indications of thermalization and cooling of quasi-particles, a precursor for quantum condensation, in a plasmonic nanoparticle array. We investigate a periodic array of metallic nanorods covered by a polymer layer doped with an organic dye at room temperature. Surface lattice resonances of the array---hybridized plasmonic/photonic modes---couple strongly to excitons in the dye, and bosonic quasi-particles which we call plasmon-exciton-polaritons (PEPs) are formed. By increasing the PEP density through optical pumping, we observe thermalization and cooling of the strongly coupled PEP band in the light emission dispersion diagram. For increased pumping, we observe saturation of the strong coupling and emission in a new weakly coupled band, which again shows signatures of thermalization and cooling.Comment: 8 pages, 5 figures including supplemental material. The newest version includes new measurements and corrections to the interpretation of the result
    • …
    corecore