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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
Study of the catalytic mechanism of enzyme catalase on organic hydroperoxides in non-polar organic solvent
No full textpi-conjugated poly(monosubstituted) acetylenes containing Sn(II) and Sn(IV) species: investigation with laser ionization mass spectrometry
No full textPolyenes [HC=CR](n) (R = Ph, C13H9O), namely polyphenylacetylene (PPA) and polyethynylfluorenol (PEFI) containing Sn(II) and Sn(IV) in the polymer matrix, have been investigated using laser ionization mass spectrometry. The positive ion mass spectra show that carbon clusters linked to Sn, i.e. SnCnH+ (n = 1-25) are formed for PPA, while a higher degree of fragmentation occurs for PEFI which gives SnCnH+ (n = 1-8). The species SnCl3- is found in the negative ion patterns of the two polymers, regardless of whether the dopant was SnCl2 or SnCl4. This result suggests a lower stability of the tin complexes, formed by interaction with the polymer matrix, with respect to the iron chlorides or polyiodides species found in the LMS spectra of PPA/FeCl3 and PPA/I-2, respectively, previously studied
Fecl3-doped Poly(phenylacetylene) Investigated By Means of Laser Ionization Mass-spectrometry
No full textThe laser ionization mass spectrometry technique has been used for the study of FeCl3-doped poly(phenylacetylene) (FeCl3-PPA). Assessment of the ionic fragments has been exploited by comparison of the spectra of FeCl3-PPA with those of reference compounds. Evidence of carbon clusters bonded to iron or to the FeCl moiety is reported; interaction of the chain C=C double bonds with iron leads to stable complexes where the allenic or acetylenic chains can be considered as macro ligands. The negative-ion patterns give evidence of the charge-transfer reaction also occurring between FeCl3 and PPA
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