1,720,997 research outputs found
Prediction of soft X-ray photo-electron/absorption spectra by ab initio calculations
No full textWe present two different theoretical approaches used to predict the photoelectron and the photoabsorption and discuss their accuracy by comparison with new experimental data.
The first method has been developed specifically for molecular inner shell excitation and ionization by Nobuhiro Kosugi since 1980 and implemented in the GSCF3 code. [1] Here the core ionized states and core-to-excited states transitions are solved within the Hartree-Fock approximation by explicitly taking into account the core hole. The excited orbitals to be singly occupied by the core-electron excitations are optimized within the STatic EXchange (STEX) method by freezing the core and the occupied valence HF orbitals of the corresponding core hole state. The calculations have been run for several molecules of biological interest (tyramine, tryptamine, tryptophol, barbituric and thiobarbituric acid) and the obtained XPS and NEXAFS spectra have been compared with the experimental results. [2]
The second approach has been developed by Angela Acocella in order to investigate the onset of the ionization dynamics in photoelectron spectroscopy with a quantum-mechanical time-dependent propagator used to evolve the electronic wavefunction [3] with the aim to correlate it to the spectral analysis. In practice, the high energy of the incoming photon triggers a complicated re-organization of the wavefunction where the usually dominant one-photon contribution is combined with all the possible many-photon contributions of the same energy, together with the continuum states of the ionized electron. The presented model proved to reproduce with reasonable accuracy both XPS and UPS spectra of the coronene molecule. [4]
[1] N. Kosugi and H. Kuroda, Chem. Phys. Lett. 74 (1980) 490.
N. Kosugi and H. Kuroda, Chem. Phys. Lett., 94 (1983) 377.
N. Kosugi, Theor. Chim. Acta, 72 (1987) 149.
[2] M. Coreno, V. Feyer, O. Plekan, K. C. Prince, R. Richter; W. Caminati, L. Evangelisti, B. M. Giuliano, A. Maris, S. Melandri, manuscript in preparation.
[3] A. Acocella, G. A. Jones and F. Zerbetto, J. Phys. Chem. A 110 (2006) 5164-5172.
A. Acocella, F. Carbone and F. Zerbetto, J. Am. Chem. Soc., 132 (2010) 12166-12167.
[4] A. Acocella, M. De Simone, F. Evangelista, M. Coreno and F. Zerbetto, paper submitted
Scritture di immagini. Arti verbovisuali, dal secondo Novecento a oggi : Avanguardia, neoavanguardia, comunicazione di massa
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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
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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