Materials Literature
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Abstract Luminescence centres connected with Bi 3+ and Pb z+ ions are investigated in CaO, SrO, CaS, and SrS crystals at 5 to 300 K. It is found that the ground state and the two lowest excited states of the Bi 3+ as well as the Pb 2+ centres correspond to the energy levels of the free impurity ions and have A 1g , 3…
The nature of the residual stress in steel after uniaxial plastic deformation was investigated magnetically. The B - H curve measured in the residual stress state after elongation was similar to the one under compressive stress, and the induced magnetic anisotropy was uniaxial with the easy axis at right-angles to the…
Elastic moduli of spinel phases in the system Mg(Al, Cr, Fe) 2 O 1 were determined from sonic analyses of porous, polycrystalline specimens prepared by hot‐pressing. A special iterative least‐squares technique (ILS) and standard curve‐fitting techniques were used to obtain moduli at zero porosity by extrapolation. A m…
Calculates the full width at half maximum (FWHM) of the phonon broadening function for Li, Na, K and Al at different temperatures. A theory is used which employs the ionic pseudopotential, rather than, as in Bergersen et al's (1971) theory, a bare Coulomb potential. Despite the fact that a pseudopotential in a general…
This report lists nomenclature recommendations resulting from a six-year study of problems common to the disciplines of mineralogy and crystallography. The recommendations include definitions of polytypism, topotaxy, syntaxy, and epitaxy, certain criteria for mineral names, preferred format for chemical formulae, and…
Pressure-sintered LixNa1−xNbO3 in the range 0.015⩽x⩽0.15 exhibits electromechanical properties amenable to high-frequency device applications with radial-frequency constants fR(r) between 1.75 and 1.95 kHz m, coupling coefficients up to 0.4, and permittivities between 100 and 200. The temperature and time dependencies…
Several aspects of the secondary emission avalanche along an insulator surface (which is believed to play a role in insulator flashover) are addressed theoretically. The saturation condition for the two extremes of supply-limited and space-charge-limited current are obtained in analytic form, and comparison with the c…
The principal Hugoniot of molybdenum has been determined at a pressure of 2.0 TPa by measuring directly both the shock velocity and the particle velocity behind the shock. Neutrons from an underground nuclear explosion were used to generate a high-pressure shock in a slab of molybdenum by rapidly fission heating an ad…
Differential-scanning-calorimetry measurements and optical-microscopy observations are reported on mixtures of two stable liquid crystalline compounds, one of which has the nematic, smectic-$A$ and smectic-$C$ phases, while the other has only nematic and smectic $C$. The phase diagram for this system is found to have…
A new theory is developed to explain superplastic flow in two-phase materials. It is postulated that boundary-dislocations, piled up in dislocation-Interphase-Boundaries (IPBs) climb away into disordered regions of the IPB. Sliding then occurs at an IPB as dislocations glide toward the head of the pile up to replace t…
Using the generalized oscillator-strength formulation of the Born approximation, electron ionization cross sections were calculated for 20 elements with $19\ensuremath{\le}Z\ensuremath{\le}54$. For Kr and Xe, good agreement (30%) is found for the total ionization cross section above 300 eV. Comparison with measured cr…
Yvonne A. Begg, Janette N. Whyte, Bruce A. Haddock; The identification of mutants of Escherichia coli deficient in formate dehydrogenase and nitrate reductase a
The purpose of this article is to examine current hypotheses about the optical and electrical properties of the amorphous chalcogenide semiconductors, and to examine whether they can be extended to explain some of the properties of amorphous silicon dioxide. For the selenides and tellurides we assume the validity of t…
The first member of a new family of materials for nonlinear optics, methyl- (2,4-dinitrophenyl) -amino-2 propanoate (MAP), has been prepared and its linear and nonlinear optical properties have been investigated. High nonlinear coefficients result from the favorable electronic properties of the MAP molecule, as well a…
Scattering from a multielectron target by a heavy particle is approximated in terms of amplitudes for scattering from individual target electrons. By treating the motion of the projectile classically and ignoring correlations, the wave function for the system is expressed as a product of single-electron wave functions…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEquilibrium Data for Wet-Air Oxidation. Water Content and Thermodynamic Properties of Saturated Combustion GasesRobert A. Heidemann and John M. PrausnitzCite this: Ind. Eng. Chem. Proc. Des. Dev. 1977, 16, 3, 375–381Publication Date (Print):July 1, 1977Publication History Pu…
The spin-reorientation phase transition in SmCr${\mathrm{O}}_{3}$ at $T\ensuremath{\simeq}33\ifmmode^\circ\else\textdegree\fi{}$K is studied using acoustic-velocity and specific-heat measurements. Although the reorientation occurs within a narrow temperature region (\ensuremath{\sim} 1\ifmmode^\circ\else\textdegree\fi…
Ellipsometric measurements have been performed at room temperature on arc-evaporated carbon films between 0.6 and 3.8 eV. Previously published data on evaporated carbon films are reviewed and a comparison made between the present data and those for glassy carbon over the same energy range.
The electrochemical behavior of the magnesium electrode in thionyl chloride (TC) solutions was studied. It was found that this electrode is covered by a passivating layer which consists of some insoluble magnesium salt, probably . The properties of this layer determine the chemical and electrochemical behavior of the…
A study was made to determine whether a magnetic field, such as that associated with a thermonuclear reactor, might adversely affect the corrosion behavior of metallic surfaces in contact with a flowing electrolyte. In metal/ flowing‐electrolyte systems, electrochemical reactions dependent on the metal/ electrolyte in…