5,412 research outputs found

    Process for the production of metal nitride sintered bodies and resultant silicon nitride and aluminum nitride sintered bodies

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    A process for the manufacture of metal nitride sintered bodies, in particular, a process in which a mixture of metal nitrite powders is shaped and heated together with a binding agent is described. Of the metal nitrides Si3N4 and AIN were used especially frequently because of their excellent properties at high temperatures. The goal is to produce a process for metal nitride sintered bodies with high strength, high corrosion resistance, thermal shock resistance, thermal shock resistance, and avoidance of previously known faults

    Berry's phase in the multimode Peierls states

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    It is shown that Berry's phase associated with the adiabatic change of local variables in the Hamiltonian can be used to characterize the multimode Peierls state, which has been proposed as a new type of the ground state of the two-dimensional(2D) systems with the electron-lattice interaction.Comment: 2 pages, 2 figure

    Possible ability of bovine follicular fluid to attract migrating bull spermatozoa

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    AimTo examine the potential of bovine follicular fluid (BFF) to attract bull spermatozoa. MethodsThe ability of the BFF to attract bull sperm was evaluated by observing changes in sperm migration after being placed in a cross-column chamber. The movement parameters of the heads and flagella of the sperm that were attracted to the BFF were analyzed by using the Computer Assisted Sperm Analysis system. ResultsIt was observed that 61.6% of the bull sperm migrated toward the BFF when the BFF was used at a concentration of 0.1%, but 67.2% of the sperm did not migrate toward the BFF at a concentration of 10%. Relatively larger numbers of both precapacitated and postcapacitated bull sperm migrated toward the BFF (0.1%). The ability of the 0.1% BFF to attract sperm probably affected both the normal artificial insemination (AI) fertility sperm and the poor AI fertility spermatozoa. The flagellar curvilinear ratio of the sperm winding to the 0.1% BFF was significantly higher than that of the prewinding sperm. ConclusionThese results could suggest that BFF potentially attracts bull sperm at a certain concentration, irrespective of the capacitation status of the sperm. Although the mechanism by which this attraction occurs remains unclear, these data imply that it could be related to BFF-dependent changes in the sperm flagellar curvilinear ratio.ArticleREPRODUCTIVE MEDICINE AND BIOLOGY.16(2):133-138(2017)journal articl

    Monetary policy, firm heterogeneity, and product variety

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    This study provides new insights on the allocative effect of monetary policy. It shows that contractionary monetary policy exerts a non-trivial reallocation effect by cleansing unproductive firms and enhancing aggregate productivity. At the same time, however, reallocation involves a reduction in the number of product variety that is central to consumer preferences and hurts welfare. A contractionary policy prevents the entry of new firms and insulates existing firms from competition, reducing aggregate productivity. Under demand uncertainty, the gain of the optimal monetary policy diminishes in firm heterogeneity and increases in the preference for product variety. We provide empirical evidence on US data, which corroborates the relevance of monetary policy for product variety that results from firm entry and exit, and provides limited support to the cleansing effect of monetary policy

    Multi-Modes Phonon Softening in Two-Dimensional Electron-Lattice System

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    Phonon dispersion in a two-dimensional electron-lattice system described by a two-dimensional square-lattice version of Su-Schrieffer-Heeger's model and having the half-filled electronic band is studied theoretically at temperatures higher than the mean field critical temperature of the Peierls transition. When the temperature is lowered from the higher region down to the critical one, softening of multi phonon modes which have wave vectors equal to the nesting vector \vv{Q}=(\pi/a,\pi/a) with aa the lattice constant or parallel to \vv{Q} is observed. Although both of the transverse and longitudinal modes are softened at the critical temperature in the case of the wave vector equal to \vv{Q}, only the transverse modes are softened for other wave vectors parallel to \vv{Q}. This behavior is consistent with the Peierls distortions at lower temperatures.Comment: 10 pages, 5 Figure

    Star Formation Activity Beyond the Outer Arm II: Distribution and Properties of Star Formation

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    The outer Galaxy beyond the Outer Arm represents a promising opportunity to study star formation in an environment vastly different from the solar neighborhood. In our previous study, we identified 788 candidate star-forming regions in the outer Galaxy (at galactocentric radii RGR_{\rm G} \ge 13.5 kpc) based on Wide-field Infrared Survey Explorer (WISE) mid-infrared (MIR) all-sky survey. In this paper, we investigate the statistical properties of the candidates and their parental molecular clouds derived from the Five College Radio Astronomy Observatory (FCRAO) CO survey. We show that the molecular clouds with candidates have a shallower slope of cloud mass function, a larger fraction of clouds bound by self-gravity, and a larger density than the molecular clouds without candidates. To investigate the star formation efficiency (SFE) at different RGR_{\rm G}, we used two parameters: 1) the fraction of molecular clouds with candidates and 2) the monochromatic MIR luminosities of candidates per parental molecular cloud mass. We did not find any clear correlation between SFE parameters and RGR_{\rm G} at RGR_{\rm G} of 13.5 kpc to 20.0 kpc, suggesting that the SFE is independent of environmental parameters such as metallicity and gas surface density, which vary considerably with RGR_{\rm G}. Previous studies reported that the SFE per year (SFE/yr) derived from the star-formation rate surface density per total gas surface density, HI plus H2_2, decreases with increased RGR_{\rm G}. Our results might suggest that the decreasing trend is due to a decrease in HI gas conversion to H2_2 gas.Comment: 40 pages, 26 figures, 5 tables, accepted for publication in Ap

    Seronegative Sjogren syndrome with asymptomatic autoimmune sclerosing pancreatitis

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    The original publication is available at www.springerlink.com.ArticleCLINICAL RHEUMATOLOGY. 26(1): 117-119 (2007)journal articl

    High prevalence of hypothyroidism in patients with autoimmune pancreatitis

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    ArticleDIGESTIVE DISEASES AND SCIENCES. 50(6): 1052-1057 (2005)journal articl
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