Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA novel total synthesis of (2R,4'R,8'R)-.alpha.-tocopherol (vitamin E). Construction of chiral chromans from an optically active, nonaromatic precursorNoal Cohen, Rocco J. Lopresti, and Gabriel SaucyCite this: J. Am. Chem. Soc. 1979, 101, 22, 6710–6716Publication Date (Print…
Magnetic susceptibility data for several Fe(II) coordination polymers containing oxalate or squarate dianions are reported in the temperature range 4.2-300 K. Low temperature magnetism of Fe(C2O4)(H2O)2 is dominated by intrachain ordering near 32 K followed by the onset of interchain long-range order slightly below th…
We consider the electrical resistivity due to the two-level systems which have been detected recently by ultrasonic saturation experiments. Using model parameters consistent with these experiments, we calculate a temperature-dependent resistivity. It is found that the scattering mechanism is too weak by at least three…
Electrolytic charging of austenitic stainless steels with hydrogen induces formation of two distinct alloy hydride phases, both being unstable under normal atmospheric conditions. One of the new phases denoted Hγ, has the same Bravais lattice as austenite (fcc), whereas another, denoted Hϵ, exhibits an hcp structure.…
Abstract Type I collagen fibrillogenesis in vitro has been studied by laser light scattering, and the results indicate that initiation of aggregation involves at least two steps. Step I of aggregation involves no change in the intensity of scattered light at an angle of 90° and is accompanied by a decrease in the diff…
The entrance and exit regions of 127 degrees cylindrical or 180 degrees spherical electron spectrometers with real apertures are approximated by a shielded parallel plate capacitor. By employing a resistor network, the fringing field resulting from a new arrangement of shielding electrodes is measured. It is shown tha…
The anodic behavior of 99.99% aluminum in nitrate and nitrate‐chloride solutions was examined over a wide range of concentrations. In solutions containing an excess of nitrate ions, the existence of an unusually high passive current was observed. The magnitude of this current was strongly affected by some kinetic fact…
An experimental program was conducted to determine the feasibility of reducing the chromium content in the widely used commercial Type 304 stainless steel and still maintain comparable corrosion resistance. Potentiodynamic anodic polarization characteristics in 1N H2SO4 and NaCl solutions were selected as the prime cr…
Subcontinuously cored from Hauterivian to recently deposited sediments, DSDP Site 398 was studied mineralogically and geochemically by routine and specific investigations. The whole series, lithologically quite diversified, contains minerals and associated chemical elements whose origin is chiefly detrital. The clay m…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntramolecular electron transfer from pentacyanoferrate(II) to pentaamminecobalt(III) mediated by various 4,4'-bipyridinesJing-Jer Jwo, P. L. Gaus, and Albert HaimCite this: J. Am. Chem. Soc. 1979, 101, 21, 6189–6197Publication Date (Print):October 1, 1979Publication History…
The symmetry-forbidden first-order Raman scattering in the paramagnetic phase of europium chalcogenides has been analyzed in terms of the Raman tensor components, their resonance enhancement, and the phonons involved. The most dominant scattering contribution is due to the antisymmetric ${\ensuremath{\Gamma}}_{15}^{+}…
A general expression for the light-scattering cross section in a magnetic semiconductor is developed in terms of a Raman tensor and a spin-correlation function. This expression is evaluated for the high-temperature, paramagnetic phase of the europium chalcogenides. In particular we show that the cross section can be a…
Abstract Raman spectra of single crystals TlGaS 2 and TlGaSe 2 are investigated in equilibrium conditions at room temperature under various hydrostatic pressures up to 7.25 and 9.27 kbar, respectively. Phase transitions at about 5 kbar are shown to occur in both the single crystals. Mode parameters γ i = (1/ v i ) (d…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure of [Rh2(CO)2(.mu.-Cl)((C6H5)2PCH2P(C6H5)2)2][BF4]. A binuclear "A-frame" complex showing the open "active" siteMartin Cowie and Stephen K. DwightCite this: Inorg. Chem. 1979, 18, 10, 2700–2706Publication Date (Print):October 1, 1979Publication History Published onl…
The glass transition temperature of nylon 6–inorganic salt mixtures has been investigated. Tg not only increases monotonically with the salt content but the rate of increase depends on the type of salt. Infrared measurements indicate that metal ions form adducts with the amide group, and, as a result, the nylon chains…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCyclodehydration reactions using molten sodium tetrachloroaluminateL. G. Wade Jr., K. J. Acker, R. A. Earl, and R. A. OsteryoungCite this: J. Org. Chem. 1979, 44, 21, 3724–3725Publication Date (Print):October 1, 1979Publication History Published online1 May 2002Published ini…
The dose rate effect on the mechanical and electrical properties of representative insulating and jacket materials has been studied. Crosslinked polyethylene (XLPE),thylene ethylene-propylene terpolymer (EPDM), and some chlorine containing polymeric materials are irradiated in air at several dose rates. XLPE degrades…
Abstract The equilibrium constants, enthalpy, and entropy of the reversible binding of nitrogen oxide to Fe(II)edta in an aqueous solution have been measured in the temperature range 38.5 to 70 °C. Experiments were carried out by absorbing NO under O2 free conditions. The results show that, in the absorption of NO wit…
Abstract It was found that the breakup‐time of jets formed by shaped charges of cylindrical symmetry is given very accurately by the formula: This formula is obtained from a general principal applied here for the first time which says that the breakup‐time of homogeneous ductile metals under very high strain rates is…
The precipitation process of nickel ferrite (NiFe2O4) from silicate glasses has been studied by electron spin resonance (ESR). The ESR linewidth ΔH1/2 and effective g value were measured as functions of heat-treatment temperature and time. Both the linewidth and effective g value change drastically near the glass tran…