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Abstract [(CH 3 ) 2 AIOCH 3 ] 3 has been studied by gas phase electron diffraction. The mainmolecular parameters are R(A1C) = 1.957(3) Å, R(A10) = 1.861(3) 8, R(0C)= 1.436(3) Å, <CAIC = ll7.3(0.8)°, <0A10 = 103.2(1.1)° and (AIOAl = 125.8(0.4)°. The three valences of the 0 atoms appear to be lying in one…
X-ray and neutron-diffraction techniques have been used to ascertain the structures of vanadium deuterides with compositions between V2D and V4D3 over a temperature range 5–425 °K. The β phase, V2D, has a monoclinic crystal structure at room temperature with a≃c = 4.46; b = 3.00 Å, β = 95.5°. The deuterium atoms prefe…
A new scanning transmission electron microscope has been built which uses a lanthanum hexaboride thermal cathode electron gun. Initial results indicate a beam diameter of 5 Å and point-to-point resolution of 7 Å. The vacuum level in the instrument is similar to that of standard commercially available electron microsco…
Summary A new variety of heterogenite was found in samples from Mindigi, Shaba, Zaïre. Photometric reflectance varies from 0·235 to 0·165 at λ 5890 Å in air. The bireflectance is 0·070, the degree of anisotropy is 0·7 and the main index in air is 2·7. A thermal weight-loss curve and a microprobe analysis are given and…
Separate plus and minus cultures of Blakeslea trispora synthesize small amounts of trisporic acids under specific conditions. These amounts are expressed as a percentage of the trisporic acids (50 mg/liter of medium) synthesized by mixed plus-minus cultures in 5 days. Plus cultures, without additives from minus cultur…
The elastic properties of polycrystalline monoclinic Gd 2 O 3 were determined by the sonic‐resonance method. Volume‐fraction porosity varied from 0.025 to 0.367 and temperature from room temperature to 1400°C. The Young's and shear moduli are linear functions of volume‐fraction porosity, but the rate of their decrease…
Seven T1u infrared active modes account for the pyrochlore structure. Decreasing A3+ cation size in the rare-earth zirconates increases disorder among the cations and the tendency to form the fluorite structure. There is a general trend of increasing absorption frequencies with smaller cell sizes for the higher-wave-n…
LiSn crystallizes monoclinic: a = 5.17 ± 0.02 Å; b = 7.74 ± 0.02 Å; c = 3.18 ± 0.02 Å; γ = 104.5° ± 0.3°, space group: P 2/m - C 2h 1 . LiSn is not isotypic with LiGe and LiPb, but there are many structural relations to LiPb.
Abstract A simple electrostatic model has been used to demonstrate that the inner surface hydroxyls in kaolinite, dickite and nacrite are responsible for the interlayer bonding in these minerals. The contribution to the interlayer bonding of an individual hydroxyl hydrogen depends on the orientation of the hydroxyl gr…
Abstract This article emphasizes the influence of crystal-chemical composition on the ease of transformation of micas to vermiculite or more smectite-like minerals. The swelling test, with glycerol, of Mg-saturated mineral is used to characterize the degree of transformation. The main structural factors of this evolut…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUnusual metalloporphyrins. XVI. Preparation and purification of tetrasodium meso-tetra(p-sulfophenyl)porphine. Easy procedureTapeshwari S. Srivastava and Minoru TsutsuiCite this: J. Org. Chem. 1973, 38, 11, 2103Publication Date (Print):June 1, 1973Publication History Publish…
It is shown that the correlation of the threshold stress for stress corrosion cracking (SCC) of plain specimens and of KISCC for precracked specimens in a Mg 7% Al alloy immersed in K2CrO4/NaCl solutions is explicable in terms of the formation of cracks that do not propagate to total failure in plain specimens stresse…
A mechanism believed responsible for the explosive vapor growth observed in Armstrong’s experiment with LMFBR materials (liquid sodium injected into molten UO2) is discussed. Basically, liquid sodium globules can be entrained and wet the liquid UO2 surfaces. The lack of nucleation sites in the liquid-liquid-like syste…
Abstract The small‐angle x‐ray scattering (SAXS) patterns of a number of linear polyethylene (PE) and polyoxymethylene (POM) samples have been measured and compared to the intensity functions of one‐dimensional paracrystalline lattices. It was found that the ratio of the angular positions of the second and first scatt…
Abstract The crystal structure of nylon 12 prepared by polymerization of dodecalactam has been determined by x‐ray diffraction. Nylon 12 fiber exhibits only the γ form as its stable crystal structure. The unit cell of nylon 12 was determined with the aid of the x‐ray diffraction pattern of a doubly oriented specimen.…
Abstract The intensities and other spectral parameters of the main components of infrared amide bands for the random and anti‐parallel pleated sheet forms have been determined for poly‐S‐carbobenzoxymethylcysteine, poly‐ S ‐carboxymethylcysteine, polylysine and silk fibroin of Bombyx mori in heavy water solutions and…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDecomposition of Hydrazine on Shell 405 Catalyst at High PresureStanley E. Wood and James T. BryantCite this: Ind. Eng. Chem. Prod. Res. Dev. 1973, 12, 2, 117–122Publication Date (Print):June 1, 1973Publication History Published online1 May 2002Published inissue 1 June 1973h…
The spontaneous electric polarization Ps has been measured for Gd2(MoO4)3 over the temperature range from 4.2 °K to the Curie point. Near 4 °K the maximum Ps is slightly less than 0.29 μC/cm2 with a very low temperature coefficient. An electric field enforced phase transition from paraelectric to ferroelectric at temp…
Oxidation states of palladium-loaded Y zeolites were measured by ESR and IR spectrometry. After treatment by oxygen at 500µC the Pd is almost in the Pd(II) form, and few Pd (1%) are found in the Pd(III) form. After reduction by hydrogen at room temperature the Pd at zero oxidation state is almost atomically dispersed.…
The elastic resistance to bending of woven fabrics has previously been considered in terms of the existence in the yarns of rigid and elastic sections. The difficulties inherent in such a model and the noticeable differences between the predicted and experimental findings are examined in this paper. Two models of a pl…