Materials Literature
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The electrical conductivity of sintered specimens of nonstoichiometric was measured as a function of temperature from 1000°−300°C and composition from . These results are described in terms of a high temperature and low temperature region. In both temperature regions the conductivity for fixed values of x exhibits an…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrically conducting metal dithiolate-perylene complexesLuis Alcacer and August H. MakiCite this: J. Phys. Chem. 1974, 78, 3, 215–217Publication Date (Print):January 1, 1974Publication History Published online1 May 2002Published inissue 1 January 1974https://pubs.acs.org/…
An i.r. study of nitric oxide adsorption on high area MgO (previously degassed at 800°C) at room temperature is reported. The adsorption of NO onto MgO produces i.r. bands at 800–900 cm–1, 1100–1250 cm–1, and 1350–1450 cm–1. These absorption bands were assigned to several surface species: NO–2 ions with various config…
Positron annihilation has been used in a study of the annealing of molybdenum irradiated at 60°C to the low dose of 1·5 × 1018 fast neutrons cm−2. On the basis of changes observed in positron lifetimes and intensities, it was possible to identify the defect mechanisms responsible for the various annealing stages. In p…
The critically branched state of matter (close to a gel point) is further explored theoretically and experimentally. Fluctuations and effects due to cutting the high molecular weight tail of the distribution are examined in terms of asymptotic formulae derived from the Flory-Stockmayer distribution for random ƒ-functi…
Abstract Die Photoelektronen (PE)‐Spektren der mono‐ und disubstituierten Chlor‐ und Bromäthylene zeigen bis zu 9 isolierte Banden. Die Zuordnung anhand qualitativer MO‐Modelle wird durch Spektrenvergleich, Perfluor‐Effekte und Schwingungsfeinstrukturen gesichert. Aus den zugeordneten Spektren lassen sich MO‐Parameter…
The variety of supported metal catalysts utilized in the operations of the petroleum and chemical industries emphasizes the importance of metal-catalyzed reactions. As a result, many scientific investigators have attempted to characterize and follow closely the changes in the crystallite size and shape of supported me…
The calculation of the principal polarizabilities of nematic compounds with reference to the two approaches using either the Vuks formulae or the Neugebauer's relations is discussed. The polarizabilities and internal field constants have been calculated from the birefringence data in the nematic phase of seven compoun…
Abstract The development of impact polystyrene and types of processes used is traced from its inception. Our accidental discovery of the process has resulted in the process being termed unique in that no other commercial polymerization has a like phenomenon that occurs in the shearing agitation step. The prior art and…
University of Michigan, Ann Arbor, Yale University, and The Conneclicut Agricultural Experiment Station, New Haven
Electron spectroscopic (XPS and UPS) studies of the interaction of CO, CO2, O2 and H2O with Mo, and H2O and CO2 with Au are reported. The object was first to explore how far one could distinguish and between different states of chemisorption; whether there was any relation between bond strength and electron binding en…
The known amino acid sequence of the α1 chain of collagen enables the distribution of electric charges along the molecule to be predicted (with the assumptions that the residues, including those in the telopeptides, are uniformly spaced and that the charge distribution in the α2 chain is similar to that in the α1). By…
The diffractometric method has more advantages than the camera technique for X-ray diffraction analysis of the crystalline components of human dental calculus. With the use of this crystallographic method and infrared absorption techniques, it was found that the magnesium content of human dental calculus is the result…
New mesogens have been prepared and studied by differential thermal analysis and optical microscopy to elucidate the effects on mesomorphic properties of replacing a benzene ring by differnt hiterocyclic rings. Earlier workers have assessed the effects on nematic properties arising from such changes in the terminal gr…
The densification behavior of Si 3 N 4 containing MgO was studied in detail. It was concluded that MgO forms a liquid phase (most likely a magnesium silicate). This liquid wets and allows atomic transfer of Si 3 N 4 . Evidence of a second‐phase material between the Si 3 N 4 grains was obtained through etching studies.…
The compositions M II M 2 III ( S , Se ) 4 where M II = Eu , , Ca , Sr , Ba and M III = Al , Ga , In were prepared by reaction of the elements in evacuated silica tubes with iodine as a mineralizer. All members except Ba ( Ga , Al ) 2 S 4 , which is cubic, exhibit the pseudo‐orthorhombic PbGa 2 Se 4 type structure. Th…
Abstract The reaction H 2 → 2 H (dissolved) on thin Pd and Pd‐Ag foils (2.5–5 μm) was studied, with the aid of resistance measurements, in a flow apparatus at temperatures in the range 20–150°C. The rate determining step is the dissociation of the H 2 ‐molecule on the metal surface. It is assumed that in the formation…
Mutants requiring threonine plus methionine (or homoserine), or threonine plus methionine plus diaminopimelate (or homoserine plus diaminopimelate) have been isolated from strains possessing only one of the three isofunctional aspartokinases. They have been classified in several groups according to their enzymatic def…
A group of photoluminescent materials, which may have great influence on future fluorescent lamp development, is surveyed. The materials are based on hexagonal aluminates and gallates which are structurally related to the magnetoplumbites and (β‐alumina. When activated with Mn 2+ , Eu 2+ , Tl 2+ , Ce 3+ , and Tb 3+ ,…
Polyvinyl chloride) (PVC) is undoubtedly among the most frequently used plastics; it is widely applied in many branches of the national economy, including industry and building [1]. Its advantages are comparatively high chemical resistance, low production costs, and an almost universal possibility of application as pa…