24 research outputs found

    Three-Particle Correlations in Simple Liquids

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    We use video microscopy to follow the phase-space trajectory of a two-dimensional colloidal model liquid and calculate three-point correlation functions from the measured particle configurations. Approaching the fluid-solid transition by increasing the strength of the pair-interaction potential, one observes the gradual formation of a crystal-like local order due to triplet correlations, while being still deep inside the fluid phase. Furthermore, we show that in a strongly interacting system the Born-Green equation can be satisfied only with the full triplet correlation function but not with three-body distribution functions obtained from superposing pair-correlations (Kirkwood superposition approximation).Comment: 4 pages, submitted to PRL, experimental paper, 2nd version: Fig.1 and two new paragraphs have been adde

    The Spitzer High Redshift Radio Galaxy Survey

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    We present results from a comprehensive imaging survey of 70 radio galaxies at redshifts 1<z<5.2 using all three cameras onboard the Spitzer Space Telescope. The resulting spectral energy distributions unambiguously show a stellar population in 46 sources and hot dust emission associated with the active nucleus in 59. Using a new restframe S_3um/S_1.6um versus S_um/S_3um criterion, we identify 42 sources where the restframe 1.6um emission from the stellar population can be measured. For these radio galaxies, the median stellar mass is high, 2x10^11 M_sun, and remarkably constant within the range 13, there is tentative evidence for a factor of two decrease in stellar mass. This suggests that radio galaxies have assembled the bulk of their stellar mass by z~3, but confirmation by more detailed decomposition of stellar and AGN emission is needed. The restframe 500 MHz radio luminosities are only marginally correlated with stellar mass but are strongly correlated with the restframe 5um hot dust luminosity. This suggests that the radio galaxies have a large range of Eddington ratios. We also present new Very Large Array 4.86 and 8.46 GHz imaging of 14 radio galaxies and find that radio core dominance --- an indicator of jet orientation --- is strongly correlated with hot dust luminosity. While all of our targets were selected as narrow-lined, type 2 AGNs, this result can be understood in the context of orientation-dependent models if there is a continuous distribution of orientations from obscured type 2 to unobscured type 1 AGNs rather than a clear dichotomy. Finally, four radio galaxies have nearby (<6") companions whose mid-IR colors are suggestive of their being AGNs. This may indicate an association between radio galaxy activity and major mergers.Comment: 31 pages, 125 figures. Accepted for publication in the Astrophysical Journa

    Triplet correlations in two-dimensional colloidal model liquids

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    Three-body distribution functions in classical fluids have been theoretically investigated many times, but have never been measured directly. We present experimental three-point correlation functions that are computed from particle configurations measured by means of video-microscopy in two types of quasi-two-dimensional colloidal model fluids: a system of charged colloidal particles and a system of paramagnetic colloids. In the first system the particles interact via a Yukawa potential, in the second via a potential Γ/r3\Gamma/r^{3}. We find for both systems very similar results: on increasing the coupling between the particles one observes the gradual formation of a crystal-like local order due to triplet correlations, even though the system is still deep inside the fluid phase. These are mainly packing effects as is evident from the close resemblance between the results for the two systems having completely different pair-interaction potentials.Comment: many pages, 8 figures, contribution to the special issue in J.Phys. Cond. Mat. of the CECAM meeting in LYON ''Many-body....'

    女子ハンドボール選手の心理的競技能力に関する研究 : 経験年数および大会参加経験別による比較

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    The purpose of this study was that belonging (member of senior, university, and high school woman handball players), the experience as players and the event participation experience of the woman handball players clarified the relation to the psychological-competitive ability. Four hundred twenty two woman handball players were inspected by the Diagnostic Inventory of Psychological-Competitive Ability for Athlete (DIPCA.2)", which Tokunaga had developed. The result were as follows: (1) According to belonging, it was clarified that all items by which the university players excluded the volition for winning indicated a high value, and the psychological-competitive ability was excellent. (2) According to the experience as players, the player who had experienced for ten years the psychological-competitive ability was excellent. (3) An experienced player became and no ability height became clear in the prefecture and each district event participation experience. (4) In each the National Athletic Event participation experience, it became clear the possession of the player with rich experiences of ability, and especially it was excellent in confidence, decision, predictive ability, and the judgment. These results suggested that the standard and the environment of the team, which belongs, influenced the woman handball player\u27s psychological-competitive ability. In addition, being influenced by the experience of players and the event participation experience become clear. However, it is thought that it is necessary to pile up the research from a preceding research

    Compact-2D FDTD for Waveguides Including Materials with Negative Dielectric Permittivity, Magnetic Permeability and Refractive Index

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    An efficient compact-2D finite-difference time-domain method is presented for the numerical analysis of guided modes in waveguides that may include negative dielectric permittivity, negative magnetic permeability and negative refractive index materials. Both complex variable and real variable methods are given. The method is demonstrated for the analysis of channel-plasmon-polariton guided modes in triangular groves on a metal surface. The presented method can be used for a range of waveguide problems that were previously unsolvable analytically, due to complex geometries, or numerically, due to computational requirements of conventional three-dimensional finite-difference time-domain methods. A 3-dimensional finite-difference time-domain algorithm that also allows analysis in the presence of bound or free electric and equivalent magnetic charges is presented and an example negative refraction demonstrates the method

    Manifestations of Rheumatoid Arthritis on Imaging of The Chest

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