1,720,969 research outputs found
Notes On The Philosophical Status Of Nuclear Physics
No full textIn our paper we propose a philosophical analysis, based on the notion of phenomenological model, of Nuclear Physics. In this way, we will show some peculiarities of this branch of physics
Multilevel Structures in a Surface Coupling Model
No full textA surface coupling model, able to generate intermediate structures in the nucleon-nucleus scattering is dealt with. Particular emphasis is given to the case of several interfering resonances, with the aim of reconsidering, on the grounds of a physical model, the R- and S-matrix approach to the problem. In the case of two interfering levels, the pole collision has been investigated by variation of some meaningful parameters of the model. Some examples of actual cross-section analyses are finally given
Nuclear Astrophysics
No full textIn this report I will try to illustrate some of the main research themes and hot topics in nuclear astrophysics. The particular aim of the present report is to briefly illustrate the research activities, in the field of nuclear astrophysics, performed by the Italian nuclear physicist community within the "Programma di Ricerca di Interesse Nazionale su Fisica Teorica del Nucleo e dei Sistemi a Molti Corpi''.
(National Research Program on Theoretical Physics of Nuclei and Many Body Systems)
supported by the ``Ministero dell'Istruzione dell'Universita` e della Ricerca'
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Spin observables for the p d --> \pi^+ t reaction around the Delta resonance
No full textThe proton analyzing power Ay0 and the deuteron tensor analyzing power T20 are evaluated for the pd↔π+t process, in the energy region around and above the Δ resonance. These calculations extend a previous analysis of the excitation function and differential cross section, based on a model embodying one- and two-body p-wave absorption mechanisms and isobar excitation. The three-nucleon bound state and the pd scattering state are evaluated through Faddeev techniques for both the Bonn and Paris potentials. The spin variables exhibit a greater sensitivity to the number of included three-nucleon partial waves than the cross sections, while the role played by the initial- or final-state interactions appears to be small. The results for the tensor analyzing power at backward angles show a non-negligible dependence on the potentials employed, consistently with what has been previously found for the cross sections. The calculation of spin observables gives a clear indication that other reaction mechanisms (presumably s-wave two-body absorption) have to be included in the model, in order to reproduce the experimental data below the Δ resonance, in analogy with the simpler pp↔πd process
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe 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
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