53 research outputs found

    Superconductivity and Rattling under High Pressure in the beta-Pyrochlore Oxide RbOs2O6

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    Rattling-induced superconductivity in the beta-pyrochlore oxide RbOs2O6 is investigated under high pressures up to 6 GPa. Resistivity measurements in a high-quality single crystal show that the superconducting transition temperature Tc increases gradually from 6.3 K at ambient pressure to 8.8 K at 3.5 GPa, surprisingly remains almost constant at 8.8 \pm 0.1 K in a wide pressure range between 3.5 (Po) and 4.8 GPa, and suddenly drops to 6.3 K at Ps = 4.9 GPa, followed by a gradual decrease with further pressure increase. Two anomalies in the temperature dependence of the normal-state resistivity are observed at Po Ps, revealing the presence of two high-pressure phases corresponding to the changes in Tc. The rattling of the Rb ion inside a cage made of Os and O atoms may be slightly and seriously modified in these high-pressure phases that probably have cages of reduced symmetry, respectively, so that electron-rattler interactions that govern the superconducting and transport properties of beta-RbOs2O6 are significantly affected.Comment: arXiv admin note: text overlap with arXiv:1009.035

    Nonlinearity and disorder: Classification and stability of nonlinear impurity modes

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    We study the effects produced by competition of two physical mechanisms of energy localization in inhomogeneous nonlinear systems. As an example, we analyze spatially localized modes supported by a nonlinear impurity in the generalized nonlinear Schr\"odinger equation and describe three types of nonlinear impurity modes --- one- and two-hump symmetric localized modes and asymmetric localized modes --- for both focusing and defocusing nonlinearity and two different (attractive or repulsive) types of impurity. We obtain an analytical stability criterion for the nonlinear localized modes and consider the case of a power-law nonlinearity in detail. We discuss several scenarios of the instability-induced dynamics of the nonlinear impurity modes, including the mode decay or switching to a new stable state, and collapse at the impurity site.Comment: 18 pages, 22 figure

    Flattening effect of four wave mixing on multiwavelength Brillouin-erbium fiber laser.

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    A multiwavelength Brillouin-erbium fiber laser with enhanced output uniformity is demonstrated and its performance with and without the assistance of four wave mixing (FWM) is compared. The presence of FWM effect is proven by the generation of anti-Stokes wave and higher-order Stokes wave. This scheme is successful in flattening the multiwavelength output. At Brillouin pump wavelength of 1,550 nm, between the first and the last output channel, peak power differences of 4.59 and 8.32 dB are recorded for the scheme with and without the assistance of FWM, respectively. This represents 3.73 dB improvement in the multiwavelength output power uniformity

    Sex differences in self-construal and in depressive symptoms: predictors of cross-national variation

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    Sex differences in aspects of independent versus interdependent self-construal and depressive symptoms were surveyed among 5,320 students from 24 nations. Men were found to perceive themselves as more self-contained whereas women perceived themselves as more connected to others. No significant sex differences were found on two further dimensions of self-construal, or on a measure of depressive symptoms. Multilevel modeling was used to test the ability of a series of predictors derived from a social identity perspective and from evolutionary theory to moderate sex differences. Contrary to most prior studies of personality, sex differences in self-construal were larger in samples from nations scoring lower on the Gender Gap Index, and the Human Development Index. Sex differences were also greater in nations with higher pathogen prevalence, higher self-reported religiosity, and in nations with high reported avoidance of settings with strong norms. The findings are discussed in terms of the interrelatedness of self-construals and the cultural contexts in which they are elicited and the distinctiveness of student samples

    Need for approval from others and face concerns as predictors of interpersonal conflict outcome in 29 cultural groups

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    The extent to which culture moderates the effects of need for approval from others on a person's handling of interpersonal conflict was investigated. Students from 24 nations rated how they handled a recent interpersonal conflict, using measures derived from face-negotiation theory. Samples varied in the extent to which they were perceived as characterised by the cultural logics of dignity, honour, or face. It was hypothesised that the emphasis on harmony within face cultures would reduce the relevance of need for approval from others to face-negotiation concerns. Respondents rated their need for approval from others and how much they sought to preserve their own face and the face of the other party during the conflict. Need for approval was associated with concerns for both self-face and other-face. However, as predicted, the association between need for approval from others and concern for self-face was weaker where face logic was prevalent. Favourable conflict outcome was positively related to other-face and negatively related to self-face and to need for approval from others, but there were no significant interactions related to prevailing cultural logics. The results illustrate how particular face-threatening factors can moderate the distinctive face-concerns earlier found to characterise individualistic and collectivistic cultural groups

    Is an emphasis on dignity, honor and face more an attribute of individuals or of cultural groups?

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    This study compares the individual-level and sample-level predictive utility of a measure of the cultural logics of dignity, honor, and face. University students in 29 samples from 24 nations used a simple measure to rate their perceptions of the interpersonal cultural logic characterizing their local culture. The nomological net of these measures was then explored. Key dependent measures included three different facets of independent versus interdependent self-construal, relevant attitudes and values, reported handling of actual interpersonal conflicts, and responses to normative settings. Multilevel analyses revealed both individual- and sample-level effects but the dignity measure showed more individual-level effects, whereas sample-level effects were relatively more important with the face measure. The implications of this contrast are discussed

    Study of molten pig iron flow in the blast furnace hearth by numerical analysis and model experiments

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    46.50; Translated from Japanese (Nisshin Seiko Giho 1987 (56) p. 1-9)Available from British Library Document Supply Centre- DSC:9022.06(BISI-Trans--26556)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo
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