Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and reactions of (4,5-dicarbomethoxy-1,3-dithiolyl)tributylphosphonium tetrafluoroborateMasaru Sato, Nina C. Gonnella, and Michael P. CavaCite this: J. Org. Chem. 1979, 44, 6, 930–934Publication Date (Print):March 1, 1979Publication History Published online1 May 20…
The defect structure of Li3N (space group P6/mmm, a ≃ 3.65, c ≃ 3.88 Å) has been investigated with data sets measured at seven temperatures in the range 153 to 678 K. The data have been used for normal and high-order refinements and for the calculation of the corresponding difference electron densities. The final Rw r…
Results of polarized neutron experiments on SmCo5 at 4.2 K and 300 K are reported. To overcome the problem of the huge Sm absorption the measurements were made at short wavelengths, but on a single crystal containing natural samarium. The Co moments are close to those found in YCo5. The Sm form factor is very differen…
We present an ultrahigh vacuum study of the carbon monoxide–silver system using Raman scattering. Silver films deposited in UHV on a room-temperature substrate cooled close to 78 K and exposed to saturation doses of CO show Raman lines at 1995 and 2070 cm−1. These disappear upon warming to room temperture. Films fresh…
The G-200 glass of the glass-ionomer cement has two phases: a continuous calcium aluminosilicate matrix and partly crystalline calcium fluoride-rich droplets, the nature of which depend on the thermal history of the glass. The setting process of the cement takes place when the glass is mixed with poly(acrylic acid). I…
Abstract The marine nanoplankton of New Zealand has been examined for the first time by a combination of transmission and scanning electron microscopy. Of the c. 50 taxa found, practically all are known also from the Northern Hemisphere. As in this part of the world, the nanoplankton consists mainly of members of the…
Paracyanogenlike films – (CN)n– are prepared by reactive rf sputtering of carbon in nitrogen. The material is deposited on quartz, silicon, metals, sapphire, and mica from 20° to 450°C. Above 450°C, there is no film accumulation on the substrates. The sputtering process yields a deposition rate greater than ten times…
A method is described for measuring some of the shear properties of fabrics, a square test piece in cyclical biaxial extension being used. Shear stiffness and ‘coercive force’ may be quantified and other features of the hysteresis curve studied qualitatively.
We report the results of studies on AlN which precipitates during the γ-α phase transformation in high permeability grain-oriented silicon steel (HI-B). We examined the behavior of AlN in each stage of the process by means of chemical analysis, electron microscope observation and hydrogen hot extraction technique. The…
Summary The substitution of 2A1 3+ for Si 4+ + M 2+ ( M = Mg or Ni) has been studied by infra-red spectroscopy in 7 Å trioctahedral minerals over the composition range from Al = 0.00 to Al = 2.00. Significant differences are observed in the infra-red spectra and these make possible an estimation of the amount of Al in…
The magnetostriction (λ100) and the magnetic moment of single crystal HoFe2 were measured as a function of temperature down to T=4.2 K. HoFe2 forms a cubic (C15) Laves phase compound with the easy axis of magnetization along the [100] crystallographic direction. At room temperature the magnetostriction is rather small…
A continuum model is proposed to consider diffusion situations where distinct types of structural or point defects contribute to the overall diffusivity. With respect to structural defects, the analysis is motivated by diffusion in the presence of a continuous distribution of high-diffusivity paths, such as grain boun…
A model is developed for the failure time of a bundle of fibers subjected to a constant load. At any time, all surviving fibers share the bundle load equally while all failed fibers support no load. The bundle may collapse immediately or fibers may fail randomly in time, possibly more than one at a time. The failure t…
The periodic multilayers of dielectric materials such as polystyrene/collodion or polystyrene/polyvinyl alcohol were fabricated by means of alternately dropping these solutions onto a spinner. As these materials are slightly elastic, a large shift of the center of the Bragg reflection by 650 Å toward shorter wavelengt…
Some electron microscope observations are presented showing the dissociation of [100] tilt boundaries in thin-film welded bicrystals of gold. Boundaries near Σ9, Σ11, and Σ99 misorientations dissociate to give twins and lower energy boundaries. The boundaries produced are not always of higher coincidence (lower Σ) tha…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMolecular structure and magnetic properties of the chloro-bridged dimer chloro[hydrotris(1-pyrazolyl)borato]copper(II). Observation of a ferromagnetic ground stateStephanie G. N. Roundhill, D. Max Roundhill, Darrel R. Bloomquist, Christopher Landee, Roger D. Willett, David M…
The formation of Li 2 VX 2 ( X = S , Se ) in Li/Li + , propylene carbonate ( PC ) / LiVX 2 cells occurs near 1.0V. The selenide, Li 2 VSe 2 , has been previously described. Magnetic susceptibility and x‐ray powder diffraction data are presented for Li 2 VS 2 . The LiVX 2 / Li 2 VX 2 couples are reversible and two phas…
In the presence of carbon or silicon carbide, silica can be reacted to form a vapor of silicon monoxide. The rates of these reactions were explored at 1300° to 1550°C. For mixtures of carbon and silica, evidence supported a two‐step reaction: silicon carbide formed prior to reaction between silicon carbide and silica.
Abstract Silk fibroin films in the random‐coil and β‐form conformations were immersed in water at temperatures from 2 to 130°C, and conformational changes were followed by x‐ray diffraction, infrared spectroscopy and differential scanning calorimetry. On treatment with water below 60°C, the random‐coil conformation is…
Emission from argon saturated aqueous alkali metal salt solutions is observed during insonation at 460 kHz. It is postulated to arise from de-excitation of excited alkali metal atoms formed by free radical reduction processes. In addition to the emission resonance lines, diffuse bands are observed at ∼554 nm and ∼740…