Materials Literature
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Photochemical decomposition of matrix-isolated carbon suboxide at 4.2°K with 1470-Å light produces highly reactive carbon atoms, presumably from an observed CCO intermediate. Reactions of carbon atoms with nitrogen lead to the observation of the infrared absorptions of the NCN and CNN radicals. Attempts to form methyl…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSulfoxide-Carbodiimide Reactions. III.1 Mechanism of the Oxidation ReactionA. H. Fenselau and J. G. MoffattCite this: J. Am. Chem. Soc. 1966, 88, 8, 1762–1765Publication Date (Print):April 1, 1966Publication History Published online1 May 2002Published inissue 1 April 1966htt…
Abstract The preparation of five samples of poly(methyl methacrylate) covering a wide range of tacticity and their electron irradiation to produce series of varying molecular weight are described. The glass transition temperature T g of each polymer was determined by DTA techniques. Plots of T g and the reciprocal of…
The influence of cell age, cell size, cell shape, and mode of colony formation on diatom sinking rates was investigated in 26 experiments with Skeletonema costatum (Grev.) Cleve and Rhizosolenia setigera Brightwell. The mean sinking rate of S. costatum ranged from 0.30 to 1.35 m/day; the absolute minimum and maximum r…
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 Alexander E. Karu, Michael Beer; Pyrolytic Formation of Highly Crystalline Graphite Films. J. App…
Numerical calculations of the powder pattern of the central component shifted by the second-order nuclear quadrupole interaction in solids have been performed for various values of the asymmetry parameter, η. Shape functions have been obtained in units of (νQ2/6νL) (a—¾) for η=0.1, 0.2, ···, 1.0, at 0.1 intervals. Als…
Abstract Intercrystalline links in polyethylene have been revealed by crystallizing from the melt mixtures of fractionated polymer and the linear hydrocarbon n ‐C 32 H 66 , the latter constituent being removed later by washing at room temperature in an organic solvent. These fibrous links measure up to 15,000 A. in le…
Earlier experimental work (J. Ferguson, H.J. Guggenheim and Y. Tanabe, J. appl. Phys. 36 (1965) 1046, Phys. Rev. Letters 14 (1965) 737) on the Mn pair spectrum of KZnF 3 :Mn and the spectrum of KMnF 3 has been extended. The narrow bands of KMnF 3 and RbMnF 3 have been assigned and their abnormally high intensities est…
Article Notizen: Zur Defokussierungsabhängigkeit des Phasenkontrastes bei der elektronenmikroskopischen Abbildung was published on April 1, 1966 in the journal Zeitschrift für Naturforschung A (volume 21, issue 4).
To explain the large isotope effect on the transition temperature in KH2PO4, the tunneling motion of the protons in hydrogen bonds is considered and a theory of the phase transition is developed under the assumption that the ferroelectric behavior of this substance is due to cooperation of the ionic displacements, the…
Samples of tellurium-doped indium antimonide that exhibited solute banding when solidified in a horizontal boat under ordinary conditions showed no bands when solidified in the presence of a vertical dc magnetic field. The effect of the field was to damp the thermal convection in the molten sample to the point of supp…
The theory of particle coarsening kinetics under control by diffusion through the matrix and by phase-boundary reaction is reviewed, and extended to the case of diffusion control when the particles are closely spaced and for impurity control at the interface. For the first case, d̄=f(T,φ)t⅓, Nv=f(T,φ)t−1, where d̄ is…
The effect of volume exclusion on the mean-square radius of gyration s2 is treated by use of the empirical expression W0(s)=const s6exp[−(7/2)〈s2〉0−1s2] for the statistical distribution of s for a system of linear chain molecules unperturbed by volume exclusion. Segment interactions within the perturbed molecule are t…
Paramagnetic Fe3(PO4)2·4H2O is monoclinic, with lattice constants a=10.541±0.005, b=4.646±0.004, c=9.324±0.005 Å and β=100°25.8′±1.0′ at 298°K, with two formula weights in the unit cell. The space group is P21/a. The positions of the iron, phosphorus, and oxygen atoms, determined by Ito and Mori in 1951, together with…
The crystal structure of tetramethylammonium hydroxide pentahydrate has been determined at 25°C by an analysis of the three-dimensional x-ray-diffraction data. The unit cell is orthorhombic with a=12.57, b=10.96, c=7.91 Å and contains four formula units. The OH− ions and H2O molecules form a hydrogen-bonded framework…
The process of cratering in materials is described in terms of four phases: transient, primary, secondary, and recovery. Rod projectiles were used in an experimental study of the relative importance of each phase and its influence on final crater dimensions. Aluminum and steel rods with aspect ratios of 1/6 to 25 were…
Several aspects of x-ray scattering from thin films have been studied. A relation is presented which correctly gives the positions of the interference maxima in the scattered radiation and is shown to reduce to the Kiessig (specular) interference equation under the appropriate conditions. In particular, it is shown ex…
The gyromagnetic factor appropriate to a transition-metal salt such as KNi${\mathrm{F}}_{3}$, is inspected in detail, with emphasis on extracting information concerning $3d$-electron covalent mixing from experiment. The necessary spin-orbit and orbital Zeeman matrix elements are evaluated within the framework of Hund-…
The absorption and reflection spectra of ZnO crystals have been studied in the region of intrinsic absorption, and the data have been interpreted in terms of the wurtzite model given by Birman. Three intrinsic exciton transitions have been observed, one associated with each of the three valence bands. Several bound-ex…
The indirect optical absorption edge in silicon and germanium has been studied in the presence of shear strain. The splitting observed in the transmission spectrum is dependent on the direction and magnitude of the applied stress and on the polarization of the light with respect to the stress axis. The results have be…