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Benchmarking density functionals and Gaussian basis sets for calculation of core-electron binding energies in amino acids
No full textA variety of density functionals and Gaussian basis sets has been studied for performance in calculations of core-electron binding energies of the carbon, nitrogen, and oxygen nuclei in the gaseous amino acids glycine, alanine, proline, threonine, and methionine. The main goal of this study is the identification of methods that will be sufficiently accurate and efficient to be used for analysis of experimental X-ray photoelectron spectra of amino acids, large polypeptides, and DNA nucleosides in various environments. The various methods studied are evaluated based on consideration of their performance for calculation of relative conformer energies, core-electron binding energies, and chemical shifts of the binding energies, using common popular density functionals with small basis sets
Comparative study of Gaussian basis sets for calculation of core electron binding energies in first-row hydrides and glycine
No full textPerformance of density functionals for computation of core electron binding energies in first-row hydrides and glycine
No full textMonocarbon cationic cluster yields from N-2/CH4 mixtures embedded in He nanodroplets and their calculated binding energies
No full textThe formation of monocarbon cluster ions has been investigated by electron ionization mass spectrometry of cold helium nanodroplets doped with nitrogen/methane mixtures. Ion yields for two groups of clusters, CHmN2+ or CHmN4+, were determined for mixtures with different molecular ratios of CH4. The possible geometrical structures of these clusters were analyzed using electronic structure computations. Little correlation between the ion yields and the associated binding energies has been observed indicating that in most cases kinetic control is more important than thermodynamic control for forming the clusters. (C) 2014 AIP Publishing LLC
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
Ab Initio Calculation of Some Parent Quinone Structures
No full text44 p.There has been considerable biological interest through the last few years in the chemical nature of semiquinones. Semiquinones are alicyclic compounds with conjugated bond systems provided by two double bonds in a six membered ring and two carbon-oxygen double bonds. Their uniqueness comes in part from their ability to function as electron acceptors and to form charge transfer complexes. This study was undertaken, attempting to search for chemical trends in the parent compounds of these structures. As well as these hydrogen species, a study of the effect of fluorination upon these compounds Is expedient owing to the interesting influence fluorine atoms have upon transient species. Much experimental evidence on these semiquinones and their fluorine derivatives has been accumulated and this project Intends to compare theoretical values with those of experiment. Finally some conclusions will be drawn to compare with the evidence given by others.Radiation Laboratory. University of Notre Dame. South Bend, Indiana
Theoretical Studies of the C3H3 Radical
No full textv, 46 p.A specific
aim of this work is to define the energy barrier to
internal conversion of the cyclopropenyl radical. This study serves to compare and contrast the
geometrical parameters, energy values, and hyperfine
coupling constants of the propargyl and cyclopropenyl
radicals with previous studies.Radiation Laboratory. University of Notre Dame. South Bend, Indiana
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
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