1,721,096 research outputs found
Role of the Laboratory in monitoring platelet function in patients with aspirin treatment
No full textPreparation of Mono- and Binuclear Complexes of Copper(II), Nickel(II), Cobalt(II), Iron(III), and Vanadyl(V) with 2,2' - Dyhydroxy-3,3'- Dyacetyl-5,5'-Dichlorodiphenylmethane.
No full textThe synthesis of mononuclear complexes M(HL)2.nS [M = copper(II), nickel (II) and cobalt(II), S = solvent] and M'(HL)2OH.nS [M' = iron(III) and vanadyl(V)] and of the binuclear complexes M2L2.nS [M = copper(II), nickel(II) and cobalt(II)] and Fe2L2(OH)2.H2O and (VO)2L2SO4.4H2O derived from 2,2'-dihydroxy-3,3'-diacetyl-5,5'-dichlorodiphenylmethane (H2L) is reported. Their coordination geometry is discussed on the basis of physico-chemical data. Magnetic measurements at room temperature suggest that no interactions between metal ions are present in the binuclear chelates. Iron(III) and vanadyl(V) complexes were used as catalysts for the oxidation of 3,5-di-t-butyl-1,2-dihydroxybenzene (3,5-DBTC). From the oxidative cleavage, 3,5-di-t-butyl-o-quinone (3,5-DTBQ), 3,5-di-t-butyl-1-oxacyclohepta-3,5-diene-2,7-dione (3,5-DTBODD), 3,5-di-t-butyl-5-carboxymethyl-2-furanone (3,5-DTBCF) and 4,6-di-t-butylpyrone-2-one (4,6-DTBP) were isolated and identified by mass, IR and H-1 NMR data. The title compound was reacted to give a hexaketone by application of the Wittig method. A polymeric Schiff base was obtained by reaction of the diacetyl derivative with ethylenediamine, also in the presence of nickel(II) perchlorate or boric acid
Studies on the ligand-receptor interaction in the biological systems. Part I: A new mathematical model and its application by curve fitting methods
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A crystallographic study of disorder in titanium trichloride, a component of Ziegler-Natta catalysts for stereospecific polymerization
No full textThe profiles of X-ray diffraction patterns have been examined for several powder samples of δ-TiCl3, obtained by mechanical activation of γ-TiCl3 and presenting different catalytic activities in the Ziegler-Natta stereospecific polymerization of propylene to isotactic polypropylene. Particular attention has been paid to the δ-TiCl3 samples showing the best catalytic properties.
On the basis of a previous investigation by Allegra, a mathematical treatment has been developed and a disorder function has been elaborated taking into account, in calculating the profiles of the X-ray diffraction intensities, not only the disorder effects but also the sizes of the δ-TiCl3 crystallites. The selected experimental pattern (δ-TiCl3, highly activated) has been well reproduced in this way and fitted by overlapping the calculated spectra of two disordered forms, labelled ε1 and ε2, which differ in the relative amounts cubic and hexagonal sequences of the Cl-Ti-Cl layers constituting the violet forms of TiCl3. The best fit was achieved by introducing into the calculations crystallite sizes of about 70 Å.
The results of the structural investigation are also discussed in terms of activity of the δ-TiCl3 based catalyst for the stereospecific polymerization of propylene
Powder XRD and TG studies on MgCl2 supported Ziegler-Natta catalysts: Activation of the a-MgCl2 support with ethyl formate and related structural modifications
No full textSynthesis, characterization and ionic conductivity of poly[(oligo ethylene oxide) ethoxysilane]/EuCl3
No full textGoing 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
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