5,463 research outputs found

    Electric field tuning of a stop band in a reflection spectrum of synthetic opal infiltrated with nematic liquid crystal

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    This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Y. Shimoda, M. Ozaki, and K. Yoshino, Appl. Phys. Lett. 79, 3627 (2001) and may be found at https://doi.org/10.1063/1.1421080

    Ionization Source of a Minor-axis Cloud in the Outer Halo of M82

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    The M82 `cap' is a gas cloud at a projected radius of 11.6 kpc along the minor axis of this well known superwind source. The cap has been detected in optical line emission and X-ray emission and therefore provides an important probe of the wind energetics. In order to investigate the ionization source of the cap, we observed it with the Kyoto3DII Fabry-Perot instrument mounted on the Subaru Telescope. Deep continuum, Ha, [NII]6583/Ha, and [SII]6716,6731/Ha maps were obtained with sub-arcsecond resolution. The superior spatial resolution compared to earlier studies reveals a number of bright Ha emitting clouds within the cap. The emission line widths (< 100 km s^-1 FWHM) and line ratios in the newly identified knots are most reasonably explained by slow to moderate shocks velocities (v_shock = 40--80 km s^-1) driven by a fast wind into dense clouds. The momentum input from the M82 nuclear starburst region is enough to produce the observed shock. Consequently, earlier claims of photoionization by the central starburst are ruled out because they cannot explain the observed fluxes of the densest knots unless the UV escape fraction is very high (f_esc > 60%), i.e., an order of magnitude higher than observed in dwarf galaxies to date. Using these results, we discuss the evolutionary history of the M82 superwind. Future UV/X-ray surveys are expected to confirm that the temperature of the gas is consistent with our moderate shock model.Comment: 7 pages, 5 figures, 2 tables; Accepted for publication in Ap

    New stent technologies.

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    Fluctuation of spastic location in patients with vasospastic angina: A quantitative angiographic study

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    Objectives.: This study sought to determine whether the location of coronary spastic activity may change over time in patients with persistent variant angina. Background.: Although electrocardiographic studies have provided indirect evidence to indicate that the location of ischemia may change in patients with variant angina, it has not been tested by quantitative angiography whether the location of vasospastic activity may change over time. Methods.: Paired ergonovine provocation tests and coronary angiography were performed at a mean (±SD) interval of 43 ± 13 months apart in patients with persistent symptoms of vasospastic angina in the absence of significant atherosclerosis. A total of 87 spastic and nonspastic segments of 87 major vessels in 29 patients were analyzed by quantitative angiography at baseline, after the administration of ergonovine and after isosorbide dinitrate at the initial and follow-up tests. Results.: In 13 patients (group 1), coronary spasm was observed in the same 16 coronary segments at both the initial and follow-up ergonovine provocation tests. In 16 patients (group 2), the following angiographic changes occurred between the initial and follow-up tests in 48 major vessels: Of the 23 segments that developed spasm at the initial test, 10 did not have spasm at the follow-up test; of the 25 vessels that did not demonstrate spasm on the initial test, 12 demonstrated spasm on the follow-up test (a new site of spasm). Thus, in 22 (46%) of 48 vessels, fluctuation of spastic location was observed at follow-up. Conclusions.: Quantitative coronary angiography and repeated ergonovine tests revealed that some patients with persistent vasospastic angina demonstrate fluctuation of vasospastic location, whereas others exhibit a fixed location of vasospasm. Vasospastic angina may not only be a transient disease restricted in location, but may also be a persistent and variable condition involving multiple vessels over many years

    Evolution of superconductivity in LaO1-xFxBiS2 prepared by high pressure technique

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    Novel BiS2-based superconductors LaO1-xFxBiS2 prepared by the high pressure synthesis technique were systematically studied. It was found that the high pressure annealing strongly the lattice as compared to the LaO1-xFxBiS2 samples prepared by conventional solid state reaction at ambient pressure. Bulk superconductivity was observed within a wide F-concentration range of x = 0.2 ~ 0.7. On the basis of those results, we have established a phase diagram of LaO1-xFxBiS2.Comment: 11 pages, 6 figure

    Binary systems of discotic liquid crystalline semiconductors toward solution-processing thin film devices

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    SPIE OPTO, 2012, San Francisco, California, United StatesY. Shimizu, Y. Matsuda, F. Nekelson, Y. Miyake, H. Yoshida, A. Fujii, and M. Ozaki "Binary systems of discotic liquid crystalline semiconductors toward solution-processing thin film devices", Proc. SPIE 8279, Emerging Liquid Crystal Technologies VII, 82790G (10 February 2012). DOI: https://doi.org/10.1117/12.91354
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