1,720,966 research outputs found
NO+center dot O-2 versus NO3+ - which is the more stable?
No full textThe geometries of the lowest stationary points on the triplet and singlet 'NO3+' potential energy surfaces are investigated. It is found that the skewed T-shaped NO+ . O-2((X) over tilde(3)A ") state has the lowest energy, with a linear ((A) over tilde(3)Sigma(-)) minimum lying similar to 1 kcal mol(-1) higher in energy. About 1 eV higher in energy lie the cis and trans isomers of the closed-shell state ties the D-3h (X) over tilde(1)A'(1) state of NO3+ - the cation of the nitrate radical. It is found that the MPn series is rather oscillatory; for NO3+ and so is probably unreliable. The binding energy, enthalpy and and compared to available values. Ionospheric entropy of complexation of the (X) over tilde(3)A " NO+ . O-2 complex are calculated implications are noted
A first study of diastatides: BeAt2, BAt2 and CAt2
No full textEffective core potentials (ECPs) augmented with large, flexible valence basis sets (tested on HAt) have been used to obtain the geometries and harmonic vibrational frequencies of the diastatide compounds BeAt2, BAt2 and CAt2 for the first time. For CAt2, the ground electronic state is calculated to be the (A) over tilde (1)A(1) state, and the lowest singlet-triplet gap is calculated to be larger than that of CI2, which is against expectations based upon electronegativity
The ionization energy and Delta H-f (0 K) of CP, PCP and PCCP
No full textBy employing high-quality ab initio methods [RCCSD(T)/cc-pV5Z//UQCISD/6-311G(2d)I, the adiabatic ionization energies of CP, PCP and PCCP are calculated, yielding values of 10.92 +/- 0.05, 8.78 +/- 0.05, and 9.43 +/- 0.05 eV. In addition, DeltaH(f) (0 K) for CP, PCP and PCCP are derived, giving values of 124 +/- 2, 96 +/- 2 and 103 +/- 4 kcal mol(-1), respectively. Some notable discrepancies with literature values are highlighted. The ground state of CP+ is confirmed to be the X(3)Pi state arising from a (...)pi (3)sigma (1) configuration, with the (...)pi (4)sigma (0)((1)Sigma (+)) state lying 0.75 eV higher in energy
The interaction energies of the Rg.NO+ cationic complexes: Rn.NO+
No full textThe equilibrium geometry and harmonic vibrational frequencies of Rn . NO+ are calculated at the QCISD level of theory, employing an effective core potential augmented by a large, flexible diffuse and polarization valence space. The interaction energy is then calculated at the CCSD(T) level using a larger basis set based on a different ECP. The trends in the bonding in the Rg . NO+ complexes (Rg = rare gas) are then noted, and it is confirmed that the major interaction in these species is the charge/induced-dipole interaction
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
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