1,721,018 research outputs found
The syntheses and structures of organoaluminum amides and imides with polydentate amines.
No full textThis thesis deals with the syntheses and structures of organoaluminum amides and imides using polydentate amines. Various bidentate and tridentate amines were reacted with trimethylaluminum to yield complexes with uncommon structural features. The reaction between trimethylaluminum and N-phenylethylenediamine produces a monomeric dialkylaluminumamido complex and a trimeric monoalkylaluminumamido complex. The structures of \rm Me\sb2Al(NH\sb2,CH\sb2CH\sb2NPh), 2.1, and \rm (MeAl(NHCH\sb2CH\sb2NPh))\sb3, 2.2 are presented. The reaction between trimethylaluminum and 8-aminoquinoline in a 1:2 ratio affords a monomeric monoalkylaluminumamido complex, while in a 2:1 ratio a tetranuclear imido complex is formed. Reaction of this tetranuclear complex with one equivalent of molecular oxygen converts a methyl group to a methoxy group and results in the formation of a new tetranuclear species. The structures of MeAl(8-amidoquinoline)\sb2 3.1, \rm Me\sb8Al\sb4(\mu\sb3-8-imidoquinoline)\sb2 3.2, and \rm Al\sb4(\mu\sb3-8-imidoquinoline)\rm\sb2(CH\sb3)\sb7(OCH\sb3) 3.3 are presented. The reaction between 2-(aminomethyl)pyridine and trimethylaluminum affords a chelated dimeric dialkylaluminumamido complex. The analogous reaction with 4-(aminomethyl)pyridine also produces a dimeric dialkylaluminumamido complex but in this species the pyridine group does not chelate. The structures of (Me\sb2Al(2-(amidomethyl)pyridine)) \sb2 3.4, and (Me\sb2Al(4-(amidomethyl)pyridine)) \sb2 3.5 are presented. The reactivity of some tridentate amines was also investigated. The reaction between trimethylaluminum and tetraethyldiethylenetriamine (tedtaH) in a 1:1 ratio produces a mononuclear dialkylaluminumamido chelate complex, while a 3:1 ratio affords a trinuclear species. The structures of Me\sb2Al(tedta) 4.1, and \rm Me\sb8Al\sb3(tedta) 4.2 are presented. The reaction between trimethylaluminum and di(2-pyridylmethyl)amine (dpaH) produces a mononuclear complex similar to 4.1. The structure of Me\sb2Al(dpa) 4.3 is presented.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1994 .T735. Source: Masters Abstracts International, Volume: 34-02, page: 0764. Adviser: Suning Wang. Thesis (M.Sc.)--University of Windsor (Canada), 1994
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
Heterometallic and homometallic complexes containing bifunctional ligands and their application in high-temperature oxide superconductor materials.
No full textWe have been interested in the development of soluble precursors for the production of YBa\sb2Cu\sb3O\sb{7-\delta} and Bi\sb2(Ca,Sr)\sb{\rm n+1}Cu\sb{\rm n}O\sb{\rm (2n + 4) + \delta}, superconductor materials. Several heterometallic and homometallic complexes containing the constituent metals of these superconductors and bifunctional ligands such as aminoalcohols, acetates and thioethers have been isolated and structurally characterized. The thermal decomposition properties and magnetic properties of some of these compounds have been investigated. The first ligand system investigated involved 1,3-bis(dimethylamino)-2-propanol (bdmapH). By varying the ratio of bdmapH, Cu(OCH\sb3)\sb2, and M(O\sb2CCF\sb3)\sb2 (M = Ca, Sr) several heterometallic complexes have been obtained, including Sr\sb2Cu\sb2(bdmap)\sb4(O\sb2CCF\sb3)\sb4, CaCu(bdmap)\sb2(O\sb2CCF\sb3)\sb3(H\sb2O), Sr\sb2Cu\sb4(bdmap)\sb6-(O\sb2CCF\sb3)\sb4(\mu\sb 3-OH)\sb2(THF)\sb2 and SrCu\sb2(bdmap)\sb3(O\sb2CCF\sb3)\sb3(THF). With the exception of Sr\sb2Cu\sb4(bdmap)\sb6(O\sb2CCF\sb3)\sb4(\mu\sb 3-OH)\sb2(THF)\sb2, these compounds thermally decompose to form mixtures of fluorides and oxides. An analogous acetate compound SrCu\sb2(bdmap)\sb3(O\sb2CCH\sb3)\sb3(THF) has been produced, which forms the corresponding oxide at high temperature. A bismuth dimer, Bi\sb2(bdmap)\sb2(O\sb2CCH\sb3)\sb4(H\sb2O), has also been obtained. Superconducting powder of the Bi\sb2Sr\sb2CaCu\sb2O\sb{8 + \delta} and epitaxial superconducting films of the YBa\sb2Cu\sb3O\sb{7-\delta} superconductor have been produced using the bdmap and acetate ligands as cross-linking reagents. The second ligand system investigated involved di-2-pyridylmethanediol. Only homonuclear complexes have been obtained by using this ligand, including the mononuclear compound Cu ((2-py)\sb2CO(OH)) \sb2(HO\sb2CCH \sb3)\sb2\cdotCH\sb2Cl\sb2, the tetranuclear compound Cu\sb4 ((2-py)\sb2CO(OH)) \sb2(O\sb2CCH\sb 3)\sb6(H\sb2O)\sb2\cdotCH\sb2Cl\sb2, and the bismuth dimer Bi\sb2 ((2-py)\sb2CO(OH)) \sb2(O\sb 2CCF\sb3)\sb4\cdot(THF)\sb2. The tetranuclear Cu\sb4 compound was found to be dominated by ferromagnetic exchanges. The third ligand system examined involved 2,2\sp\prime-thiodiethanol (tdeH\sb2). Heterometallic complexes Pr\sb2Cu\sb4(tde)\sb3(tdeH)\sb2(hfacac)\sb4(\mu\sb6 -O) and Ba\sb2Cu\sb2(tdeH)\sb4(hfacac)\sb4 have been obtained using this ligand. The six metal centers in Pr\sb2Cu\sb4(tde)\sb3(tdeH)\sb2(hfacac)\sb4(\mu\sb6-O) are arranged in a octahedron and are linked by \mu\sb6-oxide and 2,2\sp\prime-thiodiethanolato ligands. A metallomacrocyclic Cu\sb4 compound, Cu\sb4(tde)\sb2(hfacac)\sb4 has been produced. Attempts have been made to produce bismuthine complexes with an amino or pyridyl functional group that can coordinate to copper. The reaction of 4-Li-C\sb6H\sb4CH\sb2N(2-PY)\sb2 with BiCl\sb3 produces the compound Bi\sp{\rm III} (p-C\sb6H\sb4CH\sb2N(2-py)\sb2\rbrack\sb3. The ability of this compound to coordinate CuCl\sb2 has been investigated. The complex Bi\sp{\rm V} (p-C\sb6H\sb4CH\sb2N(2-py)\sb2\rbrack\sb3(O\sb2CCH\sb3)\sb2 has also been produced.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1997 .B725. Source: Dissertation Abstracts International, Volume: 59-08, Section: B, page: 4100. Adviser: Suning Wang. Thesis (Ph.D.)--University of Windsor (Canada), 1997
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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