Materials Literature
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Surface modes play an important role in a solid's response to external disturbances. A charged particle on approaching or leaving the surface may suffer inelastic scattering owing to its coupling with these modes. The scattering rate is calculated in the Born approximation for two instances: (i) in metals, where the s…
The linear-combination-of-atomic-orbitals (LCAO) model of the preceding paper for the cubic-SrTi${\mathrm{O}}_{3}$ band structure is applied to predict the effect of the 110 \ifmmode^\circ\else\textdegree\fi{}K phase transition on the SrTi${\mathrm{O}}_{3}$ conduction bands. In this cubic-to-tetragonal structural tran…
The temperature and frequency dependence of conductivity, dielectric properties, infrared absorption, and electron-paramagnetic-resonance data are presented for semiconducting phosphate glasses based on oxides of Ti, V, Mn, Fe, Co, Ni, Cu, Mo, and W. The vanadate system is examined in a range of compositions, most of…
The nonrelativistic augmented-plane-wave (APW) method has been applied to calculate the electronic band structures for several cubic perovskite-type compounds, including KNi${\mathrm{F}}_{3}$, SrTi${\mathrm{O}}_{3}$, KMo${\mathrm{O}}_{3}$, and KTa${\mathrm{O}}_{3}$. These calculations involve ad hoc crystal potentials…
A theory is outlined of the aligning action of sound on nematic liquid crystals. It is based on sound-induced stresses and forces and identifies four contributions to the transverse stress. Formulas for the threshold sound intensities of a few simple deformations are given.
Experiments to reveal the influence of water concentration in obsidian upon the annealing rate of fission tracks showed that a 2.2% H2O obsidian would lose 70% of its tracks in 1 m.y. if held at 30°C. Data obtained at three temperatures (227°, 253°, and 282°C) give the possibility of extrapolations to geologically sig…
The step cascade with side flow is defined as a step cascade where uranium of lower assays than that from the final stage is withdrawn, and where also, in addition to the major feed, reprocessed spent uranium is introduced as minor feed. A method of calculation is proposed for finding the exact total flow rate of the…
Abstract The cation exchange capacity (C.E.C.) of nontronite was determined by titrating the acid clay, prepared by the action of H-resin on nontronite, in water and some nonaqueous solvents. The base-titratable acidities of the acid nontronite, freshly prepared as well as aged, were found to be greater than the acidi…
New vapor pressure data for cobalt have been obtained in the temperature range 1519–1926°K from Knudsen effusion experiments. The derived third-law heat of vaporization of cobalt is Δ H298°=101.0± 0.6 kcal/mole. Plausible explanations are presented that account for the widely differing vapor pressure data and heats of…
In the AE-bearing lead deposit of Korsns, apatite is the most common REmineral, monazite is a widespread accessory and allanite is a rare constituent. The paper describes one type of each. Also, the physical properties and chemical composition of the minerals are presented. The chemical analyses contain determinations…
The stress-optic coefficient ( n 3 /2)( q 11 - q 12 ) has been determined for a series of 18 optical glasses of different compositions in the wavelength range 5700-3200 Å. The coefficients are negative for all the glasses except for a high-lead-content glass of density 6·7 and refractive index 1·89. The numerical valu…
The influence of heat treatment on the Si,Al-distribution in a sanidine of Volkesfeld, Eifel, was investigated by two complete crystal-structure analyses. Observed differences in the mean T–O distances are compared with simultaneous changes of the optic axial angle and give additional data to such correlations first p…
The mechanism of the reaction of UO 2 with carbon in the presence of N 2 at 1700°C and the rate of formation of the carbonitride product were determined. Uranium carbonitride forms at specific O 2 and N 2 chemical potentials by reactions such as (1) UO 2 ( s ) + 0.67HCN( g )→UO 1.33 N 0.45 ( s ) + 0.67CO( g ) + 0.11N…
Abstract The Raman effect in selenium–tellurium mixed crystals has been studied. Four first order Raman lines have been observed and associated with long wavelength lattice modes of the alloy system. The experimental results together with existing infrared data indicate that the long wavelength modes from three of the…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectron probe microdetermination of carbon in ferrous alloysJ. S. Duerr and R. E. OgilvieCite this: Anal. Chem. 1972, 44, 14, 2361–2367Publication Date (Print):December 1, 1972Publication History Published online1 May 2002Published inissue 1 December 1972https://pubs.acs.or…
An assignment of the 13 C‐NMR spectrum of the enzyme cofactor flavin‐adenine dinucleotide (FAD) is given by comparing it with the 13 C chemical shifts of the constituents of FAD, i.e. adenosine 5′‐diphosphate, riboflavin 5′‐monophosphate, riboflavin, adenosine and adenine. The 13 C‐NMR spectrum of FAD shows three grou…
Energy levels of Er3+ in three compounds: Er(OH)3, 1% Er3+:Y(OH)3, and 1% Er3+:Tb(OH)3 have been determined from optical absorption experiments on single crystals at 77 and 1.3°K and from far infrared absorption experiments at 1.3°K. For each material, the four crystal field parameters which specify the crystal field…
The shape of the two phase, β-Nb + β-Zr, monotectoid loop in the niobium–zirconium phase diagram has been re-investigated by X-ray analysis for alloys with controlled content of interstitial impurities.
1. A substantial portion of the axial filament of the spicules of silicious sponges is protein. 2. The axial filament protein lacks the hydroxylated amino acids that are characteristically abundant in collagen. 3. It is feasible to follow the course of silicious deposition in spicules using C14 or H3 in protein precur…
Abstract The structure of poly‐1,3‐dioxolane, [OCH 2 O(CH 2 ) 2 ] n was studied by x‐ray diffraction and infrared spectroscopy. Three crystal modifications were found. The crystal structure of modification II was determined: four molecular chains of glide type pass through the orthorhombic unit cell; Pbca‐D 2 h 15…