Materials Literature
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1. A method is described for studying the peristaltic reflex in the guinea-pig or cat isolated colon, using a graded localized intraluminal stimulus consisting of a solid bolus.2. The method gives an easy evaluation of propulsive activity and makes it possible to record simultaneously the segmental activity of the cir…
The prospect that permanent magnets with previously unattainable coercivities and energy products might be made from cobalt-rare earth alloys has caused intense research efforts in the last three years. Alternative ways of preparing magnets from powders and by casting were demonstrated in several laboratories.(BH)_{\m…
Energy levels, linewidths, and oscillator strengths for trivalent neodymium ions in a commercial laser glass were determined from the fluorescence and absorption spectra. The spectra were composed of broad groups of overlapping lines and were deciphered from spectral variations produced by changes in glass temperature…
Epitaxial layers of ZnO have been deposited by chemical vapor transport on single-crystal sapphire substrates. The ZnO layers have been deposited up to thicknesses of 100μ. X-ray analysis showed that the c axis of the ZnO could be made to lie parallel to the (0112)-oriented sapphire substrate. Resistivities were gener…
Ceramic samples of SrTiO3, containing a wide range of solid substitution of trivalent rare-earth ions, have been fabricated and examined in detail. Well-developed dielectric relaxation was observed in samples containing lanthanum, praesodymium, neodymium, samarium, gadolinium, terbium, dysprosium, holmium, erbium, thu…
The effects of sintering temperature and cooling rate on the magnetic and crystallographic properties of lithium ferrite were studied. The magnetic moments and lattice parameters increased with increasing sintering temperature; these increases result from correlated oxygen and lithium oxide losses. Either annealing at…
Abstract The relative abilities of various solvents to dissolve crystalline polyvinylidene chloride were judged by comparing temperatures at which dilute suspensions became homogeneous. PVDC is not soluble in common solvents at ambient temperatures. It dissolves in solvents of matching solubility parameter only above…
The transfer of energy from $\mathrm{Yb}^{2}F_{\frac{5}{2}}$ to $\mathrm{Tb}^{5}D_{4}$ by the cooperative action of two ${\mathrm{Yb}}^{3+}$ ions has been observed in Y${\mathrm{F}}_{3}$. The correlation between the $\mathrm{Tb}^{5}D_{4}$ intensity and the $\mathrm{Yb}^{2}F_{\frac{5}{2}}$ and $\mathrm{Tb}^{5}D_{4}$ li…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStudies of surface reactions of nitric oxide by nitrogen-15 isotope labeling. I. Reaction between nitric oxide and ammonia over supported platinum at 200-250.deg.Klaus Otto, Mordecai Shelef, and J. T. KummerCite this: J. Phys. Chem. 1970, 74, 13, 2690–2698Publication Date (P…
A new type of spin ordering in a spin-pair system is theoretically investigated. In the system, the intra-pair exchange interaction is antiferromagnetic and is much stronger than the inter-pair exchange interaction. In an external magnetic field, the excited triplet of the pair splits, and the lowest component of the…
Abstract— The values of the absolute quantum yields of fluorescence and of intersystem crossing have been obtained for porphin and its derivatives by methods based on relative measurements involving flash photolysis. For a given compound the sum of these quantum yields is unity within experimental error which shows th…
After digestion of the murein-lipoprotein complex (rigid layer) of the E. coli cell wall with lysozyme the solubilized lipoprotein contained 2 disaccharide units of the murein per 1 lipoprotein molecule. From purely enzymatic degradation of the murein-lipoprotein complex with pronase and lysozyme the peptide GlcNAc-Mu…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNew fundamental type of inorganic complex: hybrid between heteropoly and conventional coordination complexes. Possibilities for geometrical isomerisms in 11-, 12-, 17-, and 18-heteropoly derivativesLouis C. W. Baker and Jane S. FiggisCite this: J. Am. Chem. Soc. 1970, 92, 12…
Three-terminal dielectric measurements of the weak-field permittivity have been carried out on single crystals of bismuth titanate (Bi4Ti3O12), which contained only ``narrow-angle'' twin walls. The pseudo-orthorhombic εa, εb, εc in these twinned monoclinic crystals show strong dispersion in the frequency range 100 Hz-…
Homoepitaxial growth of GaAs was studied in situ in an ultrahigh-vacuum high-energy electron diffraction (HEED) system. Two surface structures, GaAs(1̄1̄1̄)−(19)1/2 and GaAs(1̄1̄1̄)−2, were observed during growth. The transition from one surface structure to the other was found to be a function of the deposition rate…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemiluminescence arising from simultaneous transitions in pairs of singlet oxygen moleculesAhsan U. Khan and Michael KashaCite this: J. Am. Chem. Soc. 1970, 92, 11, 3293–3300Publication Date (Print):June 1, 1970Publication History Published online1 May 2002Published inissue…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTX-ray photoelectron spectroscopyJack M. Hollander and William L. JollyCite this: Acc. Chem. Res. 1970, 3, 6, 193–200Publication Date (Print):June 1, 1970Publication History Published online1 May 2002Published inissue 1 June 1970https://pubs.acs.org/doi/10.1021/ar50030a003htt…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT.pi.-Cation radicals and dications of metalloporphyrinsJack Fajer, Donald C. Borg, Arthur Forman, David Dolphin, and Ronald H. FeltonCite this: J. Am. Chem. Soc. 1970, 92, 11, 3451–3459Publication Date (Print):June 1, 1970Publication History Published online1 May 2002Publish…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrical properties of solid oxide electrolytesT. H. Etsell and Spyridon N. FlengasCite this: Chem. Rev. 1970, 70, 3, 339–376Publication Date (Print):June 1, 1970Publication History Published online1 May 2002Published inissue 1 June 1970https://pubs.acs.org/doi/10.1021/cr6…
Abstract The relative shear moduli of composites containing glass spheres in a rubbery matrix obey the Mooney equation, analogous to the relative viscosity of similar suspensions in Newtonian liquids. However, when the matrix is a rigid epoxy, the relative shear moduli are less than what the Mooney equation predicts b…