1,721,045 research outputs found
The high-resolution infrared spectrum of DC4H from 450 to 1100 cm−1: overtone, combination and hot bands.
No full textThe high-resolution infrared spectrum of monodeuterated diacetylene has been recorded in the 450–
1100 cm−1 spectral region by Fourier transform infrared spectroscopy. Seven new bands have been
identified: the ν3 fundamental (C–C stretch), and the ν8 + ν9, ν7 + ν8, 2ν7, 2ν8, ν8 + ν9 − ν9, and
ν6 + ν9 − ν9 combination, overtone, and hot bands. The assigned transitions, together with those
previously reported for the fundamental bands [F. Tamassia, L. Bizzocchi, C. Degli Esposti, L. Dore,
M. Di Lauro, L. Fusina, M. Villa, and E. Canè, Astron. Astrophys. 549, A38 (2013)], form a comprehensive
data set which comprises more than 2500 ro-vibrational transitions, and involves all singly
and most doubly excited vibrational states of DC4H lying below 1000 cm−1. Rotational and vibrational
l-type resonance effects among the sub-levels of excited bending states were considered in the
analysis, which also included a careful treatment of the various anharmonic interactions coupling
many vibrational states lying above 600 cm−1. Reliable and unambiguous spectroscopic parameters
were obtained for each investigated state, including the rotational and centrifugal distortion constants
Bv and Dv, the l-type doubling parameter qt, the anharmonicity constants xL(89), xL(69), and the vibrational
l-type terms r89, r69 for the v8 = v9 = 1 and v6 = v9 = 1 bend-bend combination states
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
High-sensitivity detection of the rotation spectrum of HCl in the v = 1 state by tunable FIR spectroscopy
No full textCommunication: Observation of homonuclear propensity in collisional relaxation of the 13C12CD2 (v2 = 1) isotopologue of acetylene by stimulated Raman spectroscopy
No full textWe report the first experimental observation of homonuclear propensity in collisional relaxation of
a polyatomic molecule. A pump-probe stimulated Raman setup is used to pump population to a
single rotational level of the v2 = 1 vibrationally excited state in 13C12CD2 and then monitor the
redistribution of the rotational population that has taken place after a fixed delay. The Q-branch of
the 2ν2–ν2 band shows a pattern of intensity alternation between the even and the odd rotational
components, with the greater intensities always corresponding to the rotational levels with the same
parity as the one where all the population was initially deposited. The effect can be explained by the
existence of a propensity rule that favors collisional relaxation between rovibrational levels of the
same parity
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
High resolution infrared study of SbHD2: The ground state and the Sb-H stretching bands nu1 and 2nu1
No full textHigh resolution infrared spectra of (SbHD2)-Sb-121 and (SbHD2)-Sb-123 have been studied in the region of nu(1), the Sb-H stretching fundamental, from 1780 to 1990 cm(-1). The 2 nu(1) stretching overtone band of (SbHD2)-Sb-123, located in the 3640-3790 cm(-1) range, has also been investigated. The SbHD2 molecule is an asymmetric rotor of C-s symmetry with the asymmetry parameter kappa = 0.61. The nu(1) band is of hybrid type, formed by strong C-type and weak B-type transitions, and almost unperturbed. For (SbHD2)-Sb-123, 2092 transitions have been assigned: 70% of these belong to the C component, the other 30% are of B-type. The assigned transitions have been fitted using a Watson type S-reduced Hamiltonian in the lilt representation, with a standard deviation of the fit sigma = 0.45 x 10(-3) cm(-1). In order to determine the ground state parameters all possible ground state combination differences (GSCD) have been generated from the v, transitions. In total, 3942 GSCD up to J '' = 27, K ''(a) = 25, and K ''(c) = 20 have been fitted with sigma = 0.52 x 10(-3) cm(-1). Only C-type transitions have been observed in the weak 2 nu(1) overtone band. The 556 assigned transitions have been fitted with sigma = 2.6 x 10(-3) cm(-1) using the same Hamiltonian as for nu(1). In the nu(1) band of (SbHD2)-Sb-121 771 C-type transitions have been assigned, and the nu(1) = 1 spectroscopic constants obtained from a fit with sigma = 0.70 x 10(-3) cm(-1). Using 618 GSCD the ground state spectroscopic constants of (SbHD2)-Sb-121 have been derived with a = 1.0 x 10(-3) cm(-1). The molecular parameters for the ground and the nu(1) = 1 states of the two isotopologues agree well. The quartic theoretical ab initio force field of SbH3 has been used to predict all relevant spectroscopic parameters for (SbHD2)-Sb-123, (SbHD2)-Sb-121, (SbHD2)-Sb-123, and (SbH2D)-Sb-121. Relations between the harmonic frequencies and between the anharmonicity constants obtained in the expanded local mode theory, for the XH3 -> XH2D/XHD2 isotopic substitution, have been compared with those obtained in the present study. (C) 2010 Elsevier Inc. All rights reserved
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
The rotational spectrum of12C2HD in the ground and excited bending states: an improved ro-vibrational global analysis
Full text linkRotational transitions of 12C2HD were recorded in the range 100–700 GHz for the vibrational ground state and for the bending states v4 = 1 (Π), v5 = 1 (Π), v4 = 2 (Σ+ and Δ), v5 = 2 (Σ+ and Δ), v4 = v5 = 1 (Σ−, Σ+ and Δ), v4 = 3 (Π and Φ) and v5 = 3 (Π and Φ). The transition frequencies measured in this work were fitted together with all the infrared ro-vibrational transitions involving the same bending states available in the literature. The global fit allowed a very accurate determination of the vibrational, rotational, and l-type interaction parameters for the bending states up to v4 + v5 = 3 of this molecule. The results reported in this paper provide a set of information very useful for undertaking astronomical searches in both the mm−wave and the infrared spectral regions. The parameters from the global fit can be used to calculate accurate rest frequencies for rotational transitions in the ground state or in excited vibrational states involving the bending modes. Pure rotational transition frequencies up to 1 THz are listed
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
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