1,720,992 research outputs found
Interstellar Detection of Vibrationally Excited Transitions of Organic Molecules. The Bologna Laboratory Support
No full textIn the ongoing effort to detect complex organic molecules (COMs) in star-forming regions, support from laboratory spectroscopy is essential. Several COMs contribute to the observed spectra, which are fairly crowded, and additional spectral complexity may result from the vibrational excitation of the more abundant species. Therefore a comprehensive characterization of the rotational spectra is needed to allow the identification of low-abundance COMs. This work reports the cases of two interstellar organics, cyanoacetylene (HC3N) and aminoacetonitrile (NH2CH2CN), whose accurate descritpion of the ro-vibrational energies, obtained from FT-IR, FIR and millimeter-wave spectra recorded in the laboratory, has given a contribution to the analysis of spectral line surveys with regards to the molecules in vibrationally excited states
The molecular structure of HBF+ by microwave spectroscopy
No full textThe millimeter- and submillimeter-wave spectra of the H11BF+, H10BF+, D11BF+, and D10BF+ isotopomers have been observed and analyzed. The derived moments of inertia have been used to determine an rs structure of this molecular ion. The average bond distances obtained are: rs(BH)=1.1736 A ̊rs(BF)=1.2102 A ̊ To our knowledge this is the first experimental determination of the HBF+ structure. © 1987
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
High-resolution molecular spectroscopy of open shell molecules: isotopologues of the imidogen (15ND) and amidogen (15ND2) radicals
No full textHigh-resolution molecular spectroscopy of open shell molecules: isotopologues of the imidogen (15ND) and amidogen (15ND2) radicals
Dore Luca 1, Bizzocchi Luca 2, Degli Esposti Claudio 1, Melosso Mattia 1, Tamassia Filippo 3
1 Dipartimento di Chimica “Giacomo Ciamician”, Università di Bologna, Via Francesco Selmi 2, I-40126 Bologna, Italy
2 Centre for Astrochemical Studies, Max-Planck-Institut für extraterrestrische Physik, Gießenbachstraße 1, D-85749 Garching bei München, Germany
3 Dipartimento di Chimica Industriale “Toso Montanari”, Università di Bologna, Via del Risorgimento 2, I-40136 Bologna, Italy
A wide number of studies have been carried out on the imidogen and amidogen radicals, which are thought to be involved in the ion-reaction scheme in which ammonia is produced from N+. The rotational spectrum of the main isotopologue of the imidogen radical NH has been investigated in the THz region as well as in the Far-Infrared-Region [1]. In addition, the less common isotopologues ND and 15NH have been studied by rotational spectroscopy [2,3,4]. The interest on this small free radical has increased, since both NH and ND have been detected is several astronomical sources [5,6]. However, no data on the rare isotopologue 15ND were available until now. In this work, 15ND radical has been produced by DC-glow discharge of 15ND3 and Ar and its pure rotational spectrum has been recorded up to 1.2 THz. The fine and hyperfine structure of the N = 1 ← 0 and N = 2 ← 1 transitions has been assigned and all the measured line frequencies have been analyzed, allowing to determine the rotational constant B, the centrifugal distortion term D and 9 fine and hyperfine parameters. A global analysis including ro-vibrational data of all the isotopologues of NH radical is in progress. While discharging ammonia, the spectrum of another radical, rapidly identified as 15ND2, appeared (Fig. 1). In fact, imidogen and amidogen radicals are usually obtained in the same conditions. Although the amidogen radical has been subjected to numerous studies [7,8,9], no spectroscopic data on 15ND2 are reported. In the second part of our work, the rotational spectrum of the 15ND2 radical has been observed in selected frequency regions between 264 GHz and 1.2 THz. A total of 164 transitions have been recorded and assigned, whose analysis allowed us to determine with high accuracy the rotational constants, some centrifugal distortion terms and 21 fine and hyperfine parameters.
References:
[1] Flores-Mijangos J. et al., J. Mol. Spectrosc., 225, 189-195 (2004).
[2] Saito S. et al., ApJ., 410, L53-L55, 1993.
[3] Dore L. et al., Mol. Phys., 109, 2191-2198 (2011).
[4] Bailleux S. et al., A&A, 538, A135 (2012).
[5] Meyer M.D. et al., ApJ., 376, L49-L52 (1991).
[6] Bacmann A. et al., A&A, 521, L42 (2010).
[7] Muller H.S.P. et al., J. Mol. Spectro., 195, 177-184 (1999).
[8] Kanada M. et al., AIP, 94, 3423 (1991).
[9] Margulès L. et al., A&A, 591, A110 (2016)
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