999 resultados para Covariant spectator theory
Resumo:
Dy3+ doped oxyfluoride silicate glass was prepared and its optical absorption, 1.3 mu m emission, and upconversion luminescence properties were studied. Furthermore, the Judd-Ofelt [Phys. Rev. 127, 750 (1962); J. Chem. Phys. 37, 511 (1962)] intensity parameters, oscillator strengths, spontaneous transition probability, fluorescence branching ratio and radiative lifetime were calculated by Judd-Ofelt theory, while stimulated emission cross section of H-6(9/2)+F-6(11/2)-> H-6(15/2) transition was calculated by McCumber theory [Phys. Rev. A. 134, 299 (1964)]. According to the obtained Judd-Ofelt intensity parameters Omega(2)=2.69x10(-20) cm(2), Omega(4)=1.64x10(-20) cm(2), and Omega(6)=1.64x10(-20) cm(2), the radiative lifetime was calculated to be 810 mu s for 1.3 mu m emission, whose full width at half maximum and sigma(e) were 115 nm and 2.21x10(-20)cm(2), respectively. In addition, near infrared to visible upconversion luminescence was observed and evaluated. The results suggest that Dy3+ doped oxyfluoride silicate glass can be used as potential host material for developing broadband optical amplifiers and laser applications.
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Many social relationships are a locus of struggle and suffering, either at the individual or interactional level. In this paper we explore why this is the case and suggest a modeling approach for dyadic interactions and the well-being of the participants. To this end we bring together an enactive approach to self with dynamical systems theory. Our basic assumption is that the quality of any social interaction or relationship fundamentally depends on the nature and constitution of the individuals engaged in these interactions. From an enactive perspective the self is conceived as an embodied and socially enacted autonomous system striving to maintain an identity. This striving involves a basic two-fold goal: the ability to exist as an individual in one's own right, while also being open to and affected by others. In terms of dynamical systems theory one can thus consider the individual self as a self-other organized system represented by a phase space spanned by the dimensions of distinction and participation, where attractors can be defined. Based on two everyday examples of dyadic relationship we propose a simple model of relationship dynamics, in which struggle or well-being in the dyad is analyzed in terms of movements of dyadic states that are in tension or in harmony with individually developed attractors. Our model predicts that relationships can be sustained when the dyad develops a new joint attractor toward which dyadic states tend to move, and well-being when this attractor is in balance with the individuals' attractors. We outline how this can inspire research on psychotherapy. The psychotherapy process itself provides a setting that supports clients to become aware how they fare with regards to the two-fold norm of distinction and participation and develop, through active engagement between client (or couple) and therapist, strategies to co-negotiate their self-organization.
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Novas tecnologias, entendidas como parte integrante dos ambientes midiáticos contemporâneos, ajudam a conformar novos modelos perceptivos. O surgimento e a proliferação de tecnologias de síntese e de modelagem de sons por meios eletrônicos recria a relação entre o espaço presente no filme e as referências significantes que possuímos desse espaço. Os sons destacam-se dos objetos empíricos, alargando o campo de significações e de afetações sensoriais. Ao criar novas relações entre o corpo do espectador e uma inédita paisagem sonora eletrônica, novas tecnologias de som, como parte de um processo mais amplo das mídias, demandam um maior envolvimento da plateia. Dispositivos de imersão, efeitos especiais, uma nova distribuição espacial do ambiente sonoro, maior fidelidade e potência, reproduzem o encantamento físico despertado pelos primeiros cinemas. Para analisar o surgimento de novas audibilidades, novas formas de investigar o mundo a partir dessas tecnologias e dessa atual paisagem sonora, este trabalho procura uma abordagem tríplice. Inicialmente, procuramos fazer uma descrição de cunho fenomenológico da experiência cinematográfica. Em seguida, utilizamos propostas da Teoria das Materialidades para falar das afetações físicas induzidas pelo espaço sonoro eletrônico. Por último, utilizamos a perspectiva das ciências cognitivas que nos diz que corpo, cérebro e ambiente neste caso um ambiente extremamente tecnológico fazem parte de um mesmo processo dinâmico
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131 p.
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A new formulation derived from thermal characters of inclusions and host films for estimating laser induced damage threshold has been deduced. This formulation is applicable for dielectric films when they are irradiated by laser beam with pulse width longer than tens picoseconds. This formulation can interpret the relationship between pulse-width and damage threshold energy density of laser pulse obtained experimentally. Using this formulation, we can analyze which kind of inclusion is the most harmful inclusion. Combining it with fractal distribution of inclusions, we have obtained an equation which describes relationship between number density of inclusions and damage probability. Using this equation, according to damage probability and corresponding laser energy density, we can evaluate the number density and distribution in size dimension of the most harmful inclusions. (c) 2005 Elsevier B.V. All rights reserved.
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We construct an F(R) gravity theory corresponding to the Weyl invariant two scalar field theory. We investigate whether such F (R) gravity can have the antigravity regions where the Weyl curvature invariant does not diverge at the Big Bang and Big Crunch singularities. It is revealed that the divergence cannot be evaded completely but can be much milder than that in the original Weyl invariant two scalar field theory. (C) 2014 The Authors. Published by Elsevier B.V.
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133 p.