1,721,035 research outputs found
The problem of the characterization of Sn-based corrosion products in bronzes: a Raman approach
No full textHigh-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
High Resolution Infrared Spectroscopy of H12C13CD and H13C12CD: The bending states up to v4 +v5 =2
No full textThe high-resolution infrared spectrum of two partially deuterated isotopologues of acetylene, (HCCD)-C-12-C-13 and (HCCD)-C-13-C-12, has been recorded by Fourier transform spectroscopy in the range 450-1850 cm(-1). The bending fundamental bands and a number of overtone, combination and hot bands have been identified for both isotopomers. In total, 17 vibrational bands for (HCCD)-C-12-C-13 and 18 bands for (HCCD)-C-13-C-12 were analyzed, involving all the I-vibrational components of the excited bending states up to v(t)= v(4) + v(5) = 2. The data pertaining to each molecule were analyzed together with the pure rotational transitions recorded in the millimeter- and sub-millimeter-wave frequency ranges and the v(5) <- v(4) band available in the literature. The model Hamiltonian adopted for the analysis takes into account the usual vibration and rotation l-type resonances. The ground state and 9 vibrationally excited states have been characterized for each isotopomer. The spectroscopic parameters obtained from the fits reproduce 1617 transitions for (HCCD)-C-13-C-13 and 1613 transitions for (HCCD)-C-13-C-12, with standard deviations of the fit equal to 0.00038 cm(-1) and 0.00032 cm(-1), respectively. (C) 2011 Elsevier Inc. All rights reserved
High resolution infrared and Raman spectroscopy of ν2 and associated combination and hot bands of 13C12CD2
No full textInfrared and Raman spectra of dideuterated acetylene containing one 13C atom, 13C12CD2, have been recorded
and analysed to obtain detailed information on the fundamental 2 band and associated combination and hot
bands. Infrared spectra were recorded at 4103cm1 resolution in the region 11502900cm1, which contains
combination and hot bands from the ground and the bending v41⁄41 and v51⁄41 states. The Q-branches of the 2
fundamental and associated hot bands (2þ44, 2þ55, 2þ2424, 2þ2525 and
2þ4þ5(4þ5)) were recorded using inverse Raman spectroscopy, with an instrumental resolution of
about 3103cm1. In addition, the observation of the 222 Raman band was carried out populating the
v21⁄41 state by stimulated Raman pumping. In total, 11 Raman and 9 infrared bands were analysed, involving all
the l-vibrational components of the excited stretchingbending manifolds up to vt1⁄4v4þv51⁄42.
A simultaneous analysis of all infrared and Raman assigned transitions has been performed on the basis of a
theoretical model which takes into account the rotation and vibration l-type resonances within each vibrational
manifold and the DarlingDennison anharmonic resonance between the 2þ24 and 2þ25 states. The
parameters obtained reproduce the assigned transition wavenumbers with a standard deviation of the same order
of magnitude as the experimental uncertainty
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
Improved sensitivity of tunable far-infrared spectroscopy: application to the detection of HBr in the ν = 1 state
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