21,685 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Headquarters of Hawaiian Department
No full textWritten by . What appears to be an official document, addressed to the adjutant general of the War Department by O. H. McDole, Lt. Col., Assistant Adjutant General, about deporting people in Hawaii of Japanese descent to Japan. The document mentions Kenzi Kimura, Torataro Onoda, Ryoichi Tanaka.These materials are from box 73 and 74 of the Frank Chin Papers. The Frank Chin Papers contain personal and professional correspondence between Frank Chin and Michi Weglyn relating to particular projects on which either author was working as well as files related to the Day of Remembrance Tribute to Michi Weglyn
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
Prandtl number effects on the decaying and the forced turbulence in stratified fluids
No full textEffects of high-Prandtl number density-stratifying scalar, i.e., active scalar, on decaying and forced turbulence in stratified fluids are investigated by numerical simulations. In decaying turbulence, potential energy spectrum of the high-Prandtl number active scalar (Pr=6) agrees with the kinetic energy spectrum even at small scales. In forced steady turbulence, these two spectra again approach each other at small scales. These phenomena, which are in disagreement with the Batchelor scaling for a high-Schmidt number passive scalar, occur at scales even smaller than the Ozmidov scale, suggesting that these effects would not be negligible in general
CONFORMATIONAL ANALYSIS OF SEROTONIN-(HO) AND (HO) CLUSTERS
No full textAuthor Institution: Department of Chemistry, Purdue University, West Lafayette, IN 47907Serotonin (5-hydroxytryptamine) has many functions in the human body. Previous studies of serotonin have determined the inherent conformational preferences of the isolated molecule, and mapped out the energy thresholds to conformational isomerization between particular conformational isomers. Since biological processes occur in aqueous solution, it is of interest to understand how the conformational preferences of serotonin are changed by its interactions with water. Since both the flexible side chains of serotonin (OH and ethylamine) have good H-bonding sites, we anticipate a significant interplay between the ways in which water binds to serotonin and the conformations that are thereby stabilized. While there are eight observed conformations of serotonin monomer, UV-UV hole-burning spectroscopy was used to prove the presence of three conformations of SERO-(HO) and one conformation of SERO-(HO). Resonant ion-dip infrared spectroscopy in the OH and CH stretch regions provides powerful diagnostics of the H-bonding present and its effect on serotonin conformation. In particular, one of the SERO-(HO) conformers and the SERO-(HO) conformer possess a water bridge between the amino group on the ethylamine side chain and the 5-OH group on the indole ring. The corresponding spectra for the remaining two conformers of SERO-(HO) are nearly identical to that found in the tryptamine-HO complex, in which water binds as H-bond donor to the most stable conformation of serotonin. The two conformers differ in the orientation of the 5-OH group (\textit{syn} or \textit{anti}), producing a 5 \wn shift in the absorption frequency of the 5-OH stretch transition
WEAK C--HO INTERACTIONS AND HO INTERNAL ROTATION IN THE HCClF--HO AND HCBrF--HO DIMERS
No full textAuthor Institution: Department of Chemistry, Eastern Illinois University, 600 Lincoln; Ave., Charleston, IL 61920; Department of Chemistry, University of Missouri - Kansas City, Kansas City, MO 64110; Department of Chemistry, University of Virginia, McCormick Rd., PO, Box 400319, Charlottesville, VA 22904The polarity of the C-H bond involved in a weak C-HX interaction may be tuned by introducing different combinations of \hbox{halogen} substituents on the carbon atom. In this study, the structures of the HCClF--HO and HCBrF--HO dimers have been studied by rotational spectroscopy and theoretical methods, with the hope of observing weak C-HO interactions. Ab initio calculations \hbox{(MP2/6-311++G(2d,2p))} predict cyclic structures for both dimers, with a C-HO and an O-HX (X = Cl or Br) interaction present in each complex. Fourier-transform microwave spectroscopic investigations of both species have confirmed that this structural motif is present, although the experimental results display some significant differences from the theoretical predictions. \vspace{1em} The spectra of both HCClF--HO and HCBrF--HO were doubled due to internal rotation of the water molecule within the weak complex (with the higher frequency state about three times the intensity of the lower frequency state, as expected for exchange of equivalent hydrogen nuclei). Ab initio potential energy scans have been performed to estimate the barrier to rotation of the water molecule in both dimers, and for HCClF--HO a global fit using ERHAM, {\bf 107}, (1997), 4483-4498.} has also provided an experimental determination of the energy difference between the tunneling states ( GHz) and barrier to rotation () \wn). Remarkably, the more intense higher frequency transitions belong to the lower energy internal rotation state
Adsorption and diffusion of H(2)O molecule on the Be(0001) surface: A density-functional theory study
No full textUsing first-principles calculations, we systematically study the adsorption behavior of a single molecular H(2)O on the Be(0001) surface. We find that the favored molecular adsorption site is the top site with an adsorption energy of about 0.3 eV, together with the detailed electronic structure analysis, suggesting a weak binding strength of the H(2)O/Be(0001) surface. The adsorption interaction is mainly contributed by the overlapping between the s and p(z) states of the top-layer Be atom and the molecular orbitals 1b(1) and 3a(1) of H(2)O. The activation energy for H(2)O diffusion on the surface is about 0.3 eV. Meanwhile, our study indicates that no dissociation state exists for the H(2)O/Be(0001) surface. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved
H-tailored surface conductivity in narrow band gap In(AsN)
No full textWe show that the n-type conductivity of the narrow band gap In(AsN) alloy can be increased within a thin (similar to 100 nm) channel below the surface by the controlled incorporation of H-atoms. This channel has a large electron sheet density of similar to 10(18) m(-2) and a high electron mobility (mu > 0.1 m(2)V(-1)s(-1) at low and room temperature). For a fixed dose of impinging H-atoms, its width decreases with the increase in concentration of N-atoms that act as H-traps thus forming N-H donor complexes near the surface. (C) 2015 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License
VIBRATIONAL PREDISSOCIATION DYNAMICS OF THE (HO) DIMER
No full textAuthor Institution: Department of Chemistry, University of Southern California, Los Angeles, CA, 90089The state-to-state vibrational predissociation dynamics of the (HO) dimer were studied by resonance-enhanced multiphoton ionization (REMPI) and velocity-map imaging (VMI) to obtain pair-correlated product energy distributions. The 2+1 REMPI spectra of the HO photofragments were recorded via the \~{C}B (000) \~{X}A (000 and 010) transition following a vibrational excitation of the dimer's bound-OH stretch fundamental. The fragment' center-of-mass translational energy (c.m. {\em E}) distributions were determined from VMI of selected rotational states of the detected HO photofragments. The c.m. {\em E} distributions were then converted to pair-correlated HO cofragment rotational level distributions. This is the first experiment in which HO products with bend () excitation were observed by REMPI. The dissociation energy of the dimer was determined from the images with spectroscopic accuracy. The predissociation mechanism of (HO) will be discussed and compared with the corresponding hydrogen bonded dimers of an acid (HCl-HO) and a base (NH-HO)
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