Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDiffusion of bis(2-ethylhexyl) phthalate above and below the glass transition temperature of poly(vinyl chloride)Robson F. Storey, Kenneth A. Mauritz, and Brian B. ColeCite this: Macromolecules 1991, 24, 2, 450–454Publication Date (Print):January 1, 1991Publication History P…
The complexes [Co(pc)(NO2)(py)]·dce, [Co(pc)(NO2)(py)]·thf, and [Fe(pc)(NO2)(py)](pc = phthalocyaninate, py = pyridine, dce = 1,2-dichloroethane and thf = tetrahydrofuran) have been isolated as stable crystalline materials. Their molecular and electronic structures have been investigated by IR and UV/VIS spectra, X-ra…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydrodynamic properties of polystyrene in dilute n-butyl chloride solutionMichael E. Lewis, Shouyan Nan, and Jimmy W. MaysCite this: Macromolecules 1991, 24, 1, 197–200Publication Date (Print):January 1, 1991Publication History Published online1 May 2002Published inissue 1 J…
Various organocobalt(III) porphyrins have been synthesized in good yields through the hydrometallation of a hypothetical hydridocobalt(III) porphyrin intermediate.
The state of CuO deposited on alumina depends on the copper loading: at low loadings (CuO content smaller than 6 wt%), copper is present in the form of Cu2+ ions formed by exchange with the hydrogen atoms of the alumina hydroxyl groups, whereas at high loadings, the formation of bulk copper oxide is observed and the h…
Gastropod apertures reflect expanded states of their mantle edge under variable boundary conditions. The apertures are divided into two groups: apertures without distinct overlap zones (e.g., whorl overlap) and those with overlap zones. Each group follows a unique morphological rule. Apertures without overlap zones ar…
5,10,15,20-Tetrakis(para-substituted phenyl)porphyrinatoiron(III) chloride complexes catalyse the reduction of styrene with NaBH4 to ethylbenzene and 2,3-diphenylbutane and the precursor is assumed to be the σ-alkyl complex (Xtpp)FeIII–PhCHMe.
Present works describe the improvement of the magnetic properties of Sm(Fe, Ti)12 melt-spun ribbons with ThMn12-type structure. In order to increase the remanence, the Ti content was decreased and the heat treatment temperature and time were lowered and shortened, respectively. As a result, the maximum energy products…
Abstract Samples of polyaromatic amines were synthesised by chemical and electrochemical methods, using different amounts of electrolytes for the purpose of doping the polymer. These polymers were found to show electrical conductivity in the range 10 −12 –10 −6 S/cm. A study of conductivity at various temperatures ind…
Abstract Crystallization behaviour of isotactic polypropylene/linear low density polyethylene (iPP/LLDPE) blends has been investigated by optical microscopy and DSC. Crystallization of iPP depends upon blend composition and thermal history. When blended with LLDPE, the crystallization temperature of iPP, T c , decreas…
Abstract Relying on a semiempirical Pariser‐Parr‐Pople (PPP) model, it is shown that classical valence bond (VB) theory, using only a few covalent structures, can provide highly correlated energies and wave functions and thus a useful description of a molecular electronic structure, assuming that it is based on approp…
Abstract The technique of dynamic mechanical thermal analysis (DMTA), operated in the dual cantilever mode, was used to characterize the effects of frequency, crystallinity, molecular weight (MW) and the extent of thermal oxidation on the dynamic mechanical response of poly(ethylene oxide) (PEO). The glass transition…
A new interpretation of the reflectance spectra of weathered or silica-coated soda-lime glass between 1250 and 900 cm<sup>-1</sup> is suggested. Traditionally, the presence and intensity of each spectral band observed were attributed to the concentration of a given chemical species in the film. Contributions due to th…
This report describes the results of VAMAS international round robin test for evaluating fracture toughness of ceramics. Thirteen laboratories in Japan, France, Germany, UK, Canada, Belgium and CEC (JRC Petten) took part in the test. The values of fracture toughness obtained by the SEPB, the IF and the IS methods were…
Results published previously [ J. Opt. Soc. Am.57, 610 ( 1967)] concerning the focusing properties of Fresnel zone plates were obtained by implicitly invoking the Fraunhofer approximation. A comparison of these results with those derived from Fresnel diffraction theory shows that the focusing properties of Fresnel zon…
An extensive comparative structural analysis of lactate dehydrogenase (LDH) sequences from thermophilic, mesophilic and psychrophilic bacilli revealed characteristic primary structural differences. These specific amino-acid substitutions were found in the entire LDH molecule. However, in certain regions of the LDH an…
Abstract The oxidation of several compositions (5, 9 and 14% Mn) of polycrystalline Ag‐Mn alloys from room temperature to 650 °C in high vacuum and in 5 m Torr O 2 has been investigated by x‐ray photoelectron spectroscopy (XPS). The behavior of the oxidation and the nature of the oxide films are controlled by tempeara…
The present work describes the process of grain growth during secondary recrystallization, which develops the 〈100〉 texture in Fe–Cr–Co–Mo hard magnets. The secondary recrystallization was caused by heat-treating the alloys in the sequence of α, α+γ, α+γ+σ, α phase regions of Fe–Cr–Co–Mo alloys (HTSR). This heat treat…
The laminated or composite bacterial cellulose (BC) membrane is very useful not only for ultrafiltration but also for evapomeation of membrane separation techniques. BC membranes laminated with β-chitin or deacetylated chitin sulfonate (S-DAC) show high solute rejection, 85% rejection in the former, 90% rejection in t…
Abstract Simultaneous K exchange with Ca, Mg, and Na occurs in soils, but most of the published information is obtained from binary systems. The theoretical question of whether selectivity coefficients obtained in binary systems are valid for ternary systems has not yet been clarified; however, no significant differen…