Materials Literature
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An electron microscopic study was made of a uterine leiomyosarcoma, and this lesion was compared with normal myometrium and with uterine leiomyomas, one of which was of the cellular type. The leiomyomas had abundant myofilaments, well-developed pinocytic activity, a well-defined basement membrane, and an abundant extr…
The hydrolysis of the borohydride ion according to the equation (i) is catalysed by nickel–boron and cobalt–boron, BH4–+ 3H2O → H2BO3–+ 4H2(i) alloys. The metal-catalysed hydrolysis has been studied at 22·0 °C by measurement of the hydrogen gas evolved. Analysis of the gas evolved when the reaction is carried out in d…
Abstract
On analyse les propriétés de fluorescence de l'ion Bi3+ incorporé dans les oxydes et orthovanadates de terres rares LnVO4 (Ln = Sc, Y, Gd), La2O 3 et Ln2O3 (Ln = Sc, Lu, Y, Gd). Les transitions électroniques responsables de l'absorption et de l'émission sont attribuées aux niveaux de l'ion libre du premier état excité…
The total electrical conductivity and the electronic conductivity in silver beta alumina have been determined between 23° and 800°C over a wide range of oxygen partial pressure using a‐c and d‐c techniques. The ionic transference number was found to be very close to unity under all conditions. Comparison of these meas…
The stretching vibrations of water (H2O, HDO and D2O) in montmorillonite, hectorite, saponite and vermiculite are split into two components, similar to those seen in perchlorate solutions. Examination of lower hydrates and pyridine complexes of the layer silicates shows that the higher frequency component corresponds…
Spin-lattice (T1) and, where appropriate, tranverse (T2) relaxation times are reported for the protons in DMSO + water mixtures over a range of temperature and composition. Self-diffusion coefficients are also measured. A minimum in T1 for a d6-DMSO + H2O sample enables rotational correlation times for water molecules…
Abstract The stability of a capillary liquid bridge of given volume between two small, solid, equal, separated spheres is investigated by formulating and treating a minimum energy problem in the calculus of variations and by experiment. A conjecture is made that in the case of two solutions one and only one is minimiz…
A thermogravimetric system is described for the determination of the total oxygen consumption, sample weight‐change, and vaporization rate during the oxidation of . The results show an increasing deviation from parabolic kinetics with increasing temperature at 250 mm oxygen pressure. The following equation is used to…
The nature of oxygen adsorbed on slightly reduced TiO2 has been investigated using oxygen enriched with 17O2. On anatase, the oxygen adsorbs as O–2 with a hyperfine splitting Axx about g3 of 77 G; no structure could be resolved for Ayy and Azz. On rutile, oxygen adsorbs as O–2 on two sites of different thermal stabili…
There has been speculation in the past about the extent to which space charge formed by the flow of prebreakdown current affects the electric strength of polythene. In the present work, conduction and absorption-current measurements up to about half the breakdown field have given clear evidence of space-charge effects…
Interdiffusion in the aluminum-copper system was investigated in the temperature range of 400° to 535°C with diffusion couples of pure aluminum and copper metals.In the aluminum-copper equilibrium phase diagram there are five intermediate phases in this temperature range, namely γ2, δ, ζ2, η2 and θ. Electron probe mic…
A theory of orientation polarization in nematic liquid crystals is developed for a molecular dipole moment parallel to the long axis of the molecule. The theory is essentially an extension of the Debye model for normal polar liquids to take into account the strong intermolecular potential which is responsible for the…
The well‐known susceptibility of austenitic stainless steels to intergranular corrosion after heat‐treatment in the temperature range of 550°–800°C ( i.e. , "sensitization") has long been attributed to depletion of Cr from regions of the alloy matrix adjacent to grain boundaries in which had precipitated. Those region…
The literature was examined to relate ambient silica concentrations to numerical dominance of specific freshwater planktonic diatoms. Mean silica concentrations (mg/liter) during dominance are: Stephanodiscus astraea, 0.6; Tabellaria flocculosa asterionelloides, 0.9; Asterionella formosa, 1.7; Melosira granulata, 13.4…
Abstract not Available.
We present an extension of the Helfrich theory of hydrodynamic instabilities to the case of alternating electric fields. The electrohydrodynamic effects are described by two coupled equations for the charge density (q) and the local curvature of the molecular alignment (ψ). The relaxation time for q is the dielectric…
Simple derivations of the elastic theory of liquid crystals with uniaxial molecular order are given using a molecular Cauchy-like approach and a more general phenomenological approach. In a second-order approximation, both methods lead to the same expression for the elastic energy density, except for the existence of…
Abstract not Available.
The ionic conductivity of the solid electrolyte NaAl11O17 has been measured from − 150 to + 820°C using a novel nonpolarizing solid electrode, reversible to sodium ions. The resistivity at 25°C was found to be 72 Ω-cm, the lowest value reported for any ionically conducting oxide ceramic. The enthalpy of motion is 3.79…