57,259 research outputs found

    An annotated checklist of Wisconsin Mordellidae (Coleoptera)

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    A three-year survey of Wisconsin Mordellidae (Coleoptera) encompassing a compilation of data from literature records and local collections as well as field work including trapping, hand-collecting, and rearing yielded 68 species comprising 14 genera in three tribes. Sixty-three species (92% of Wisconsin fauna) represent new state species records, not previously recorded from the state in the literature. Plant-associations and state-specific temporal and spatial distribution data for larvae and adults are noted as available. Distributional records suggest 16 additional species and one additional genus are likely to occur in Wisconsin

    A dipolar droplet bound in a trapped Bose-Einstein condensate

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    We study the statics and dynamics of a dipolar Bose-Einstein condensate (BEC) droplet bound by inter-species contact interaction in a trapped non-dipolar BEC. Our findings are demonstrated in terms of stability plots of a dipolar 164Dy droplet bound in a trapped non-dipolar 87Rb BEC with a variable number of 164Dy atoms and the inter-species scattering length. A trapped non-dipolar BEC of a fixed number of atoms can only bind a dipolar droplet containing atoms less than a critical number for the inter-species scattering length between two critical values. The shape and size (statics) as well as the small breathing oscillation (dynamics) of the dipolar BEC droplet are studied using the numerical and variational solutions of a mean-field model. We also suggest an experimental procedure for achieving such a 164Dy droplet by relaxing the trap on the 164Dy BEC in a trapped binary 87Rb-164Dy mixture

    Mixing, demixing, and structure formation in a binary dipolar Bose-Einstein condensate

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    We study static properties of disk-shaped binary dipolar Bose-Einstein condensates of 168^{168}Er-164^{164}Dy and 52^{52}Cr-164^{164}Dy mixtures under the action of inter- and intra-species contact and dipolar interactions and demonstrate the effect of dipolar interaction using the mean-field approach. Throughout this study we use realistic values of inter- and intra-species dipolar interactions and the intra-species scattering lengths and consider the inter-species scattering length as a parameter. The stability of the binary mixture is illustrated through phase plots involving number of atoms of the species. The binary system always becomes unstable as the number of atoms increases beyond a certain limit. As the inter-species scattering length increases corresponding to more repulsion, an overlapping mixed state of the two species changes to a separated demixed configuration. During transition from a mixed to a demixed configuration as the inter-species scattering length is increased for parameters just below the stability line, the binary condensate shows special structures in density in the form of red-blood-cell-like biconcave and Saturn-ring-like shapes, which are direct manifestations of dipolar interaction

    Statics and dynamics of a binary dipolar Bose-Einstein condensate soliton

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    We study the statics and dynamics of a binary dipolar Bose-Einstein condensate soliton for repulsive inter- and intraspecies contact interactions with the two components subject to different spatial symmetries −- distinct quasi-one-dimensional and quasi-two-dimensional shapes - using numerical solution and variational approximation of a three-dimensional mean-field model. The results are illustrated with realistic values of parameters in the binary 164Dy-168Er mixture. The possibility of forming robust dipolar solitons of very large number of atoms make them of great experimental interest. The existence of the solitons is illustrated in terms of stability phase diagrams. Exotic shapes of these solitons are illustrated in isodensity plots. The variational results for statics (size and chemical potential) and dynamics (small oscillation) of the binary soliton compare well with the numerical results. A way of preparing and studying these solitons in laboratory is suggested

    Magnetic studies of the lightly Ru doped perovskite rhodates Sr(Ru,Rh)O3_3

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    The solid solution between the ferromagnetic metal SrRuO3_3 and the enhanced paramagnetic metal SrRhO3_3 was recently reported [K. Yamaura et al., Phys. Rev. B 69 (2004) 024410], and an unexpected feature was found in the specific heat data at xx=0.9 of SrRu1−x_{1-x}Rhx_xO3_3. The feature was reinvestigated further by characterizing additional samples with various Ru concentrations in the vicinity of xx=0.9. Specific heat and magnetic susceptibility data indicate that the feature reflects a peculiar magnetism of the doped perovskite, which appears only in the very narrow composition range 0.85<<xx≤\le0.95.Comment: Accepted for publication in a special issue of Physica B (the proceedings of SCES04

    Scaling of data communications for an advanced supercomputer network

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    The goal of NASA's Numerical Aerodynamic Simulation (NAS) Program is to provide a powerful computational environment for advanced research and development in aeronautics and related disciplines. The present NAS system consists of a Cray 2 supercomputer connected by a data network to a large mass storage system, to sophisticated local graphics workstations and by remote communication to researchers throughout the United States. The program plan is to continue acquiring the most powerful supercomputers as they become available. The implications of a projected 20-fold increase in processing power on the data communications requirements are described

    Laser-Doppler gas-velocity instrument

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    Three-D instrument using a laser light source measures both turbulence and mean velocity of subsonic and supersonic gas flows. This instrument is based on the measurement of the Doppler frequency shift of light waves scattered by moving particles in the gas stream

    A List of Wisconsin Springtails With New Records and Annotations (Hexapoda: Parainsecta: Collembola)

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    Twenty Collembola species new to Wisconsin were collected from soil at two agricultural sites in southern Wisconsin, including an undescribed species of Isotomidae. The state faunal list now contains 52 species representing seven families
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