Materials Literature
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Abstract The chemical equilibrium of a purified sample of hectorite was studied over a range of pH, silicic acid, and magnesium chloride concentrations. The quasi-equilibrium reached by about 6 weeks was reversible with respect to added magnesium ions but only partially so for added silicic acid. The free energy of fo…
Abstract The extent to which silicate minerals release Ca, Mg, Na, and K during the determination of exchangeable cations in soils by the ammonium‐acetate‐extraction procedure was evaluated. The method of exchangeable‐sodium evaluation used by the US Salinity Laboratory was employed for this study with the exception t…
Luminescence of complex ions is a general phenomenon; the number of such complexes in various electronic configurations found to show emission is increasing rapidly. For some it has been possible to assign the emission as phosphorescence or as fluorescence, for others the proper assignment is as yet not clear.
Abstract Four crystalline glyceroxides, that is, CaC 3 H 6 O 3 , Ca(C 3 H 7 O 3 ) 2 , Ca 3 (C 3 H 7 O 3 ) 6 · (C 3 H 8 O 3 ) 2 and Ca(C 3 H 7 O 3 ) 2 · (C 3 H 8 O 3 ) 4 were found in the system of calcium oxide‐glycerol in the temperature range from 10deg;C to 150°C. Phase equilibrium, solubilities, optical data, X‐ra…
The first order magnetic anisotropy constant K 1 of eight ferrites with inverse-type spinel structure and two ferrites with normal-type has been measured under hydrostatic pressure by the use of a torque method. The pressure dependence of K 1 , K 1 -1 ( d K 1 / d p ), in Li 0.5 Fe 2.5 O 4 is +4.1×10 -6 bar -1 , in NiF…
Abstract The relation between counter ion distribution, ion mobility and degree of contraction has been studied on hydrobiotite (2–5 µ size), equilibrated with mixed RbCl-SrCl 2 solutions. From X-ray data, isotopic exchange and chemical extraction, it appears that the counter ions of the contracted portions of the int…
Abstract Es wird über einleitende Untersuchungen an Nitrosodicyanmethanido‐Komplexen berichtet. Pyridin‐Komplexe der allgemeinen Formel [Me(ONC(CN) 2 ) 2 (C 5 H 5 N) 4 ] werden beschrieben. Spektralphotometrische Messungen im sichtbaren und ultraroten Spektralbereich an den oktaedrisch konfigurierten Komplexen führen…
Abstract The purpose of this paper is to clarify whether intramolecular energy transfer in europium chelates occurs via the triplet state of the ligand. It is attempted to excite the triplet state of europium dibenzoylmethide (EuD) by utilizing intermolecular triplet-triplet energy transfer from lanthanum dibenzoylmet…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLinear antiferromagnetism in dichloro(1,2,4-triazole)copper(II) and copper(II) benzoate trihydrateMotomichi Inoue, Shuji Emori, and Masaji KuboCite this: Inorg. Chem. 1968, 7, 7, 1427–1430Publication Date (Print):July 1, 1968Publication History Published online1 May 2002Publ…
The structure of the utricle, a special envelope investing the oogonium, characteristic of the Mesozoic Charophyte family Clavatoraceae, is described in Perimneste horrida Harris and allied species. It shows a three-rayed symmetry, being formed by three similar trifurcately branched ramules bearing antheridia. The typ…
Abstract— Fluorescence and phosphorescence spectra of lumiflavine, riboflavine, FMN and FAD have been measured by continuous and flash excitation techniques. The differences in emission characteristics observed, show that the flavine side‐chains afect the singlet‐triplet transitions on which chemical and biological ac…
Crystal and magnetic structures of antiferromagnetic Mn 2 N were studied by means of neutron diffraction at 290°K, 230°K, and 120°K. An orthorhombic arrangement of nitrogen atoms in the octahedral interstices of hcp manganese lattice was found. The crystal structure is ζ-Fe 2 N type whose space group is D 2 h 14 - P b…
Abstract Flint clay is defined as a sedimentary, microcrystalline to crystalline clay (rock) composed dominantly of kaolin, which breaks with a pronounced conchoidal fracture and resists slaking in water. Additional ceramic (refractory) properties are implied, but not expressed, in the definition. Flint clay first giv…
A lactate racemase [EC 5.1.2.1] was isolated and purified about 190 fold in specific activity from the sonic extract of Lactobacillus sake. The purified preparation was almost homogeneous by ultracentrifugal and electrophoretical analyses. Characteristic properties of the enzyme were as follows: (a) absorption spectru…
Abstract Polycondensations of 1,4,5,8‐naphthalenetetracarboxylic acid (NTCA) with both 3,3′‐diaminobenzidine (DAB) and 1,2,4,5‐tetraaminobenzene tetrahydrochloride (TAB) in polyphosphoric acid (PPA) were found to produce soluble polymers which exhibit excellent thermal stabilities. Polymer structures were deduced from…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFive-coordination with "hybrid" ligands. II. Nickel(II) complexes with polyfunctional arsenic-containing ligandsL. Sacconi, I. Bertini, and F. ManiCite this: Inorg. Chem. 1968, 7, 7, 1417–1420Publication Date (Print):July 1, 1968Publication History Published online1 May 2002…
The temperature dependence of the elastic constants of calcite have been investigated by the ultrasonic phase-comparison method from 25° to 375°C. The variation in the elastic constants and the elastic moduli of calcite is smooth and linear over the temperature range, and does not show the break in the variation of th…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotochromic fulgides. Spectroscopy and mechanism of photoreactionsAzucena Santiago and Ralph S. BeckerCite this: J. Am. Chem. Soc. 1968, 90, 14, 3654–3658Publication Date (Print):July 1, 1968Publication History Published online1 May 2002Published inissue 1 July 1968https://…
Abstract Polyimide films from 4,4′‐diaminodiphenyl ether and pyromellitic dianhydride were pyrolyzed at 400–600°C. in non‐oxidative systems. Major gaseous products were carbon monoxide and carbon dioxide; hydrogen evolution occurred above 525°C. A mobile n ‐imide‐isoimide equilibrium is in accord with the gas evolutio…
The theory of grain growth in the presence of a liquid phase is examined using modifications of equations derived for coalescence of solid particles widely dispersed in a liquid. Although the grain diameter‐time relation can still be represented by d 3 = kt , the absolute growth rates are increased as the amount of li…