Materials Literature
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The aim of this paper is to show how van der Waals forces may account for profound changes in the IR spectra of alkylammonium saturated montmorillonite and the effect of adsorbed water molecules. IR spectra recorded on alkylammonium montmorillonite films submitted to vacuum and after exposure to water vapour show, in…
X-ray diffraction analyses of polycrystalline samples of Ca3TeO6 and Ca3WO6 have shown these compounds to be isostructural with Ca3UO6 (space group P21).
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCationic isomerization and oligomerization of isocyanideTakeo Saegusa, Naotake Takaishi, and Yoshihiko ItoCite this: J. Org. Chem. 1969, 34, 12, 4040–4046Publication Date (Print):December 1, 1969Publication History Published online1 May 2002Published inissue 1 December 1969h…
Summary Clinoptilolite-heulandite is reported from Jurassic, Cretaceous, and Palaeocene sediments in south-east England. It occurs mainly in 1–20 μm size fractions, and is associated with abundant montmorillonite and often also with glauconite and amorphous silica or low-temperature disordered cristobalite-tridymite.…
Soda‐alumina‐silica glass fibers were ion‐exchanged in potassium nitrate at 400°C; their strength was measured before and after exchange. The potassium concentration distribution and the optical retardation were also measured. The results for unetched fibers are consistent with the premise that the kinetics of exchang…
The motile species of diatoms in a largely non-motile association on grains of sand travel to the surface of the sand when buried, although they move more slowly and less often than species living in silt, and ascend each grain in turn. Diatoms on sand grains from a freshwater lake are found to migrate daily to and fr…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal structure of tetraamminezinc octahydrooctaborate(-2), Zn(NH3)B8H8Lloyd J. GuggenbergerCite this: Inorg. Chem. 1969, 8, 12, 2771–2774Publication Date (Print):December 1, 1969Publication History Published online1 May 2002Published inissue 1 December 1969https://doi.org…
The different sources of nonlinearity in elastic structures undergoing large displacements are identified, and a general matrix formulation of the theory of nonlinear elastic structures is developed. It is shown that the nonlinearity results from the nonlinearity of the transformations relating member deformations to…
Abstract The acid dissolution of 8 chlorites in 2N Si-saturated HCl showed that there was no preferential dissolution of Al in octahedral positions and that the octahedral and tetrahedral sheets in the chlorite structure were equally attacked. An analysis of chemical data suggested a simple two-dimensional diffusion m…
Abstract Samples of smectites and vermiculites were evaluated to (1) determine the effects of source and amount of charge, (2) determine if a continuum of properties exists, and (3) improve the basis for differentiating criteria for identification. The montmorillonites expanded to the equivalent two-layer complex upon…
The unrestricted Hartree–Fock theory is used to investigate bond alternation in C4N+2H4N+2 cyclic polyenes. The possible ground states are examined as functions of the parameters in the Pariser–Parr–Pople model Hamiltonian. We show that charge-density-wave ground states do not exist for physical values of the input pa…
The sorption, permeation and diffusion of water in polydimethyl-siloxane (DMS), polydimethylmethylphenylsiloxane (PMS), and poly-3,3,3-trifluoropropylmethylsiloxane (FMS), and of methanol in FMS have been measured at a number of temperatures in the range 20°-50°C. For water, satisfactory agreement is obtained between…
Abstract Sr 2 PbO 4 , Ca 2 PbO 4x , Ca 2 SnO 4 und Cd 2 SnO 4 kristallisieren in orthorhombischen Gittern der wahrscheinlichen Raumgruppe Pbam—D . Wie Wie im Pb 3xO 4 liegen Ketten von PbO 6 ‐Oktaedern vor, die über gemeinsame Kanten verknüpft sind. Die zweiwertigen Atome sind von sieben Sauerstoffatomen in einer Anor…
The luminescence of pure alkali halide crystals induced by the excitation with UV-light in the fundamental absorption region at low temperature is observed in NaCl, KCl, RbCl, NaBr, KBr, RbBr and KI. In KCl, RbCl and NaBr one emission band, in NaCl, KBr and RbBr two emission bands and in KI three emission bands are in…
Ferromagnetic resonance has been observed in single crystals of the family La 1−x Pb x MnO 3 with 0.25 < x < 0.45 from 13 to 25 GHz and in the temperature range from 77 to 430 °K. The line width, ΔH, exhibits a sharp minimum accompanied by an isotropic shift in the resonance line at a critical temperature, T c .…
The paramagnetic resonance spectrum of Tb 4+ in zircon shows that Tb 4+ ions enter the tetragonal lattice substitutionally for zirconium. The 8 S 7/2 ground-state splittings are 23 times as large as those for Gd 3+ in this mineral, totalling nearly 10 cm −1 .
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrical properties and crystal structure of barium tantalum sulfide, BaTaS3Richard A. Gardner, Marcus Vlasse, and Aaron WoldCite this: Inorg. Chem. 1969, 8, 12, 2784–2787Publication Date (Print):December 1, 1969Publication History Published online1 May 2002Published iniss…
Abstract Sediment samples from cores taken in the Gulf of Mexico were subjected to normal laterally confined loads of 0.5, 4.0, 32.0, and 64.0 kg per cm 2 . Electron micrographs of their microstructure show the progressive change in particle orientation during the laboratory consolidation of a sediment sample. A predo…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStereochemistry of asymmetric silicon. XVII. Synthesis, resolution, and stereochemistry of the 1,2,2,2-tetraphenyl-1-methyldisilane systemLeo H. Sommer and K. T. RosboroughCite this: J. Am. Chem. Soc. 1969, 91, 25, 7067–7076Publication Date (Print):December 1, 1969Publicatio…
Abstract Infrared spectroscopy studies were undertaken to determine the effects of ultraviolet light radiation on a methylsiloxane resin. The results indicate that SiCH 2 Si linkages were formed as a result of irradiation at wavelengths above 281 mμ from a xenon are lamp; on the other hand, SiOH and SiCH 2 CH 2 Si li…