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Abstract Tl 4 Ge 4 Se 10 crystallizes in space group C2/c with a = 15.602(6), b = 15.549(5), c = 9.052(3) Å, β - 107.10(3)° and Z = 4. The compound was prepared by fusion of a stoichiometric mixture of Tl 2 Se and GeSe 2 . The crystal structure is characterized by adamantane-like anions [Ge 4 Se 10 ] 4- and Tl + catio…
The nomenclature of replacement deposits is reviewed in terms of two processes, namely those involving the reaction between: (a) carbonate and siliceous rocks and (b) carbonate and unusual solutions, commonly, but not always, related to granitoids. ‘Wrigglite’ skarn is an example of a replacement deposit produced by p…
Abstract The new isotypic compounds BaGe 2 P 2 and BaGe 2 As 2 crystallize in the tetragonal system (P4 2 mc) with the following lattice constants: BaGe 2 P 2 : a = 761.8 ± 0.5 pm, c = 850.0 ± 0.5 pm, c/a = 1.12, BaGe 2 As 2 : a = 778.6 ± 0.5 pm, c = 866.4 ± 0.5 pm, c/a = 1.11. Fourbonded Ge atoms and twobonded P (As)…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructural and ligand field parameters of some trigonally distorted tetrahedral cobalt(II) and nickel(II) complexesMalcolm Gerloch and Mark R. ManningCite this: Inorg. Chem. 1981, 20, 4, 1051–1056Publication Date (Print):April 1, 1981Publication History Published online1 May…
Abstract The rate of dissolution of phlogopite in an open system was measured at low temperature and pressure and at pH 3–5. The maximum dissolution rate was achieved by maintaining extremely low ionic concentrations in the solution using a cation-exchange resin (hydrogen form) as a trap for released cations. The resi…
Abstract Die erstmals dargestellten isotypen Verbindungen Ba 4 SiAs 4 , Ba 4 GeAs 4 , Sr 4 SiAs 4 und Sr 4 GeAs 4 kristallisieren kubisch, Raumgruppe P 4 3n, mit 8 Formeleinheiten in der Elementarzelle: In den Strukturen liegen isolierte, d.h. nur von Ba‐Ionen umgebene SiAs ‐ bzw. GeAs ‐Tetraeder vor. Die Verbindungen…
In Bacillus subtilis, conditions causing partial deprivation of guanine nucleotides initiated sporulation and caused the synthesis of citrate synthase, aconitase, and alpha-ketoglutarate dehydrogenase. Alpha-ketoglutarate dehydrogenase could also be induced by acetate, and the specific activity of this enzyme was elev…
An experimental investigation of the morphological stability of the planar solid-liquid interface was carried out in which, for the first time, all pertinent solidification parameters were determined quantitatively and the effect of convenction was evaluated. The microscopic growth rate and interface morphology were d…
Methods for measuring various storage moduli and damping factors of glassy polymers in the frequency range 10−2 to 10−7 Hz are critically reviewed. At frequencies between about 10−2 and 200 Hz, components of the complex tensile modulus E∗ and complex Poisson's ratio ν∗ have been determined at 21 °C for polymethyl meth…
Abstract The structure of a lepidolite-2 M 1 from Biskupice, Czechoslovakia, has been redetermined. Violations of systematic extinctions and of monoclinic equivalences plus the results of a second harmonic generation test indicate that the true symmetry most likely is C 1̄. The deviation of the data set from C 2/ c sy…
Abstract A process that uses terephthalic acid and excess 1,4‐butanediol for the production of polybutylene terephthalate was investigated and the reaction conditions were maximized for fast reaction and minimal loss of butanediol by dehydration to tetrahydrofuran. For best results a mixed catalyst was selected: butyl…
Abstract The crystal structures of Eu2B5O9X (X=Cl and Br) were determined by the method of X-ray diffraction analysis and refined by the least-square method to give R=0.054 for 1967 observed reflections of Eu2B5O9Cl and R=0.047 for 1979 observed reflections of Eu2B5O9Br. These haloborates are isostructural and belong…
Abstract In this article, the polycondensation of terephthaloyl chloride and p ‐phenylenediamine was systematically studied, including the liquid–crystalline state of the solution and the spinning of poly(1,4‐phenyleneterephthalamide) (PPTA). High‐molecular‐weight PPTA with ε inh = 5–7 was prepared and the main factor…
Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter Facebook Reddit LinkedIn Tools Icon Tools Reprints and Permissions Cite Icon Cite Search Site Citation H. W. Gao, S. Ramachandran, E. B. Christiansen; Dependency of the Steady‐State and Transient Visc…
Magnesium metal immersed in thionyl chloride solutions becomes covered by a passivating layer which has properties of solid electrolyte. The buildup and the electrochemical properties of this layer were studied. Tafel slopes measured on freshly immersed Mg electrodes depend linearly on the apparent thickness of the SE…
The current theoretical formulations of optical absorption by small metal particles are critically reviewed. Several inconsistencies of the usual dielectric-function calculations are noted, and an improved expression is proposed. The results indicate that optical spectra should have a bearing on the difficult question…
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Abstract Pairs of four thermoplastic resins, polystyrene, poly(methyl methacrylate), acetal homopolymer, and nylon‐12, were intensively melt‐blended in nine proportions from 0 to 100 percent. Capillary rheometry at 210°C was done on each blend; melt densities were also measured on most of them. The dependence of shear…
The structure of a bartonite crystal from Coyote Peak, Humboldt County, California, has been solved and refined in anisotropic mode to a conventional R = 0.068for 504 observed reflections. The tetragonal unit cell [space group 14/mmm, a = 10.424(1), c = 20.626(1)A] contains 2 formula units, which were found by site-oc…
A large enough DC or low frequency AC field couples to the permanent polarization P and unwinds the helical texture of a smectic C* liquid crystal.′ From the measurement of the unwinding critical field, one can deduce the value of P. We present here a general model to compute the unwinding critical field; this model t…