1,721,069 research outputs found
Dynamic stark splitting in a Morse oscillator
No full textWe have show that in the spirit of the Jaynes-Cummings model a Morse oscillator interacting with a single mode electromagnetic field can be solved within the rotating wave approximation. The model exhibits dynamic Stark splitting which is reminiscent of Rabi doublets in two-level atoms and Autler-Townes doublets in three-level systems
2π-"Pulse" for three-wave mixing
No full textThe classical three-wave mixing equations have been recast in the form of Maxwell-Bloch equations which admit of hyperbolic secant soliton solutions for the pump wave similar to the case of self-induced transparency
Three-wave mixing and nonlinear optical transients in the space domain
No full textThree-wave mixing equations under parametric approximation have been recast in the form of Bloch equations for optical modes and a new echo analog of optical transient in the space domain is predicte
Inhibition of chaos in bistable Hamiltonian systems by a critical external resonance
No full textWe have shown that, depending on some critical values of the phase and amplitude, an external periodic resonant driving field can inhibit classical deterministic stochasticity in a bistable Hamiltonian system. Our analysis is based on a coupled oscillator model describing a harmonic oscillator quadratically coupled to a nonlinear oscillator with a double-well potential
Optical bistability with interacting atoms
No full textThe effect of interatomic interaction (dipole-dipole) on optical bistability has been analysed. It has been shown that for certain ranges of interaction the van der Waals loop diminishes or completely disappears
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Quantum equilibrium factor in the decay of a metastable state at low temperature
No full textThe Kramers factor is the key nonequilibrium contribution to the decay rate of a metastable state of a system in contact with a thermal bath. In the 1980s Wolynes introduced a quantum equilibrium correction to the overall rate. This is responsible for tunnelling and quantum enhancement of rate at low temperature. Based on a quantum formulation of a system-reservoir model and a Wigner canonical thermal distribution function for the harmonic oscillator bath we suggest a generalization of the quantum equilibrium factor and a consequent rate expression which are valid in the deep tunnelling region
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