Materials Literature
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The C form of La2O3 has been prepared and its transformation to the A form is found to take place at ∼590°C. The C→A transformation of Nd2O3 takes place at 550°C. The temperatures as well as the energies of activation of the phase transformations of the rare earth sesquioxides vary with the size of the cation. Y2O3 un…
Abstract The Raman spectrum of a NaNO 2 single crystal in the ferroelectric phase is obtained and the polarization of the lines is investigated. The forms of normal vibrations are considered on the basis of symmetry coordinates and the intensity of lines. Formulae for translational vibrations are derived and numerical…
Fe1,15Ga0,85O3 est piézoélectrique et magnétoélectrique et cristallise dans le groupe orthorhombique non centrosymétrique Pc21n. Les paramètres de la maille sont a = 8,75 Å ; b = 9,40 Å ; c = 5,07 Å ; Z = 8. Le composé est aussi dense que α — Fe2O3 (type corindon α — Al2O 3), comme le montre la comparaison avec la mai…
1-Bromo-1,19-dideoxy-19-methyl(or ethyl)biladiene-ac dihydrobromides are prepared by condensation of the hydrobromide of a 5-bromo-5′-bromomethyldipyrromethene with that of a 5-unsubstituted 5′-methyl(or ethyl)-dipyrromethene in presence of stannic chloride. The 1,19-dideoxybiladiene-ac salts are cyclised to the corre…
The heats of fluorination of germanium and of hexagonal and tetragonal germanium dioxide have been determined calorimetrically by reacting them with fluorine gas. The heat of transition of vitreous into hexagonal germanium dioxide has been determined by solution calorimetry in hydrofluoric acid. The following data hav…
Abstract The thermogravimetric method is shown to offer a simple but valid and meaningful method for assessing the degree of humification of organic soils. Heights of the 280C maxima in the differential thermogravimetric (DTG) curves of 22 organic soil samples, ranging from peats, mucky peats, peaty mucks to mucks, we…
In a number of aqueous environments the increase in the corrosion rate ( i c ) of magnesium with an increase in impressed anodic current ( i ) is expressed by d i c di = τ a where τ a is the transport number of the anions of the electrolyte. This adds confirmation to the viewpoint that film damage by anions rather tha…
Abstract Zircons from different localities show considerable variation in physical properties, and it is generally accepted that these variations are the result of α‐radiation damage due to the presence of radioactive impurities, in particular, uranium and thorium. Transmission electron microscopy has been used to stu…
Abstract The core structure and Peierls barrier for an edge dislocation lying in the {110} plane with Burgers vector along 〈111〉 in body‐centered cubic iron were investigated numerically with the aid of a high speed computer using an anharmonic potential. The core radius is about 5 Å and the corresponding core energy…
Abstract Viscosities of samples of poly(vinyl chloride) in cyclohexanone were measured over a wide range of concentrations, up to polymer weight fractions of the order of 0.4. Polymers with molecular weight from 10,000 to 230,000 and with different molecular weight distributions were studied. The effect of concentrati…
As one of the steps that lead to an understanding of the secretion of magnesian calcite in skeletal parts of marine organisms, the laboratory synthesis of the mineral from aqueous solutions was carried out at low temperatures and pressures. The conditions of the laboratory synthesis of magnesian calcites are shown in…
Improved methods of preparing salts of the oxopentachlororhenate(V) ion, [ReOCl5]2–, are given and the magnetic properties of Cs2ReOCl5 are discussed. The hydrolysis of rhenium pentachloride in the presence of triphenylphosphine leads to the formation of rhenium(III) complexes. The reaction products of trans-dioxobis(…
High‐purity aluminum sheet was anodized in eleven different acidic electrolytes: boric, chromic, phosphoric, sulfuric, oxalic, malonic, succinic, tartaric, fumaric, glutaric, and adipic acids. These anodic coatings were analyzed by infrared to determine the composition and nature of each. We found, aside from alumina…
Very pure monoclinic prepared from recrystallized zirconium oxy‐chloride and activated with 0.08% Ti 4+ responds well to 2537Aå and cathode‐ray excitation. A room temperature quantum efficiency of 70%, relative to , has been attained with 2537Aå excitation. The emission band extends from below 4000 to above 6500Aå, pe…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Thermal Degradation Mechanism of Polystyrene1Leo A. Wall, Sidney Straus, Joseph H. Flynn, Donald McIntyre, and Robert SimhaCite this: J. Phys. Chem. 1966, 70, 1, 53–62Publication Date (Print):January 1, 1966Publication History Published online1 May 2002Published inissue…
Electric, magnetic, and optical properties of the rocksalt form of titanium monoxide (TiO0.80 to TiO1.25) have been studied. TiO is metallic, exhibiting weak paramagnetism. Properties of TiO-phase samples are determined primarily by the relative concentration of titanium and oxygen atoms and to a lesser extent by samp…
A theoretical expression is presented to relate the effective thermal conductivity of statistically describable two-phase systems to the conductivities of the pure phases, the volume concentrations of the phases, and a shape factor. Auxiliary equations to relate bulk gas conductivity and small interparticle distance a…
It is proved that if two structures differing only in their initial internal stresses are subject to the same loading history, the distributions of internal stress will approach one another in regions of creep and plasticity as the loading proceeds. This theorem is used to prove the existence and uniqueness of steady…
If an intermediate generated on the disc electrode decomposes homogeneously in the solution, then the collection efficiency at the ring electrode will be reduced. This paper examines the effects of such a decomposition which takes place by first-order kinetics. For thin-ring, thin-gap electrodes, two limiting solution…
The transmittance and reflectance of CuO0.67 and CuO films ranging in thickness from 392 to 2335 Å have been measured in the wavelength region of 400 to 800 mμ. These data were used to obtain the wavelength dependence of the optical constants of these materials. Differences between the optical properties of CuO0.67 an…