10,884 research outputs found

    Gaps below strange star crusts

    Full text link
    The gap caused by a strong electric field between the quark surface and nuclear crust of a strange star is studied in an improved model including gravity and pressure as well as electrostatic forces. The transition from gap to crust is followed in detail. The properties of the gap are investigated for a wide range of parameters assuming both color-flavor locked and non color-flavor locked strange star cores. The maximally allowed crust density is generally lower than that of neutron drip. Finite temperature is shown to increase the gap width, but the effect is significant only at extreme temperatures. Analytical approximations are derived and shown to provide useful fits to the numerical results.Comment: 12 pages incl. 14 figures. To appear in Physical Review

    The effect of height and density of sex pheromone traps on captures of male fruittree leafroller, Archips argyrospilus and threelined leafroller, Pandemis limitata (Lepid.: Tortricidae)

    Get PDF
    When sex pheromone traps in the upper third of a standard apple tree were compared with traps at head height, the upper traps captured far more fruittree leafroller moths (<i>Archips argyrospilus</i> (Walker) than the lower traps. The results with threelined leafroller (<i>Pandemis limitata</i> (Rob.) were reversed: traps at head height captured nearly twice as many moths as traps in the upper portion of a tree. Trap captures increased with trap/area up to 1 trap/ha. This density is probably sufficient for monitoring purposes

    High-order harmonic generation from polyatomic molecules including nuclear motion and a nuclear modes analysis

    Full text link
    We present a generic approach for treating the effect of nuclear motion in the high-order harmonic generation from polyatomic molecules. Our procedure relies on a separation of nuclear and electron dynamics where we account for the electronic part using the Lewenstein model and nuclear motion enters as a nuclear correlation function. We express the nuclear correlation function in terms of Franck-Condon factors which allows us to decompose nuclear motion into modes and identify the modes that are dominant in the high-order harmonic generation process. We show results for the isotopes CH4_4 and CD4_4 and thereby provide direct theoretical support for a recent experiment [Baker {\it et al.}, Science {\bf 312}, 424 (2006)] that uses high-order harmonic generation to probe the ultra-fast structural nuclear rearrangement of ionized methane.Comment: 6 pages, 6 figure

    Angular Normal Modes of a Circular Coulomb Cluster

    Full text link
    We investigate the angular normal modes for small oscillations about an equilibrium of a single-component coulomb cluster confined by a radially symmetric external potential to a circle. The dynamical matrix for this system is a Laplacian symmetrically circulant matrix and this result leads to an analytic solution for the eigenfrequencies of the angular normal modes. We also show the limiting dependence of the largest eigenfrequency for large numbers of particles

    Charge order in Magnetite. An LDA+UU study

    Full text link
    The electronic structure of the monoclinic structure of Fe3_3O4_4 is studied using both the local density approximation (LDA) and the LDA+UU. The LDA gives only a small charge disproportionation, thus excluding that the structural distortion should be sufficient to give a charge order. The LDA+UU results in a charge disproportion along the c-axis in good agreement with the experiment. We also show how the effective UU can be calculated within the augmented plane wave methods

    High Q Cavity Induced Fluxon Bunching in Inductively Coupled Josephson Junctions

    Get PDF
    We consider fluxon dynamics in a stack of inductively coupled long Josephson junctions connected capacitively to a common resonant cavity at one of the boundaries. We study, through theoretical and numerical analysis, the possibility for the cavity to induce a transition from the energetically favored state of spatially separated shuttling fluxons in the different junctions to a high velocity, high energy state of identical fluxon modes.Comment: 8 pages, 5 figure
    • …
    corecore