Materials Literature
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ABSTRACT The action of buffered potassium permanganate as a fixative for electron microscopy has been investigated. Electron contrast has been shown to be produced by the deposition of granular material in the tissue. The particles are about 50 A in diameter. Actual fixation of the tissue is performed by the dehydrati…
Abstract Detailed physical, chemical, and mineralogical studies were made on profiles representative of the McBride, Isabella, and Nester series. These are soils that were formed in calcareous sandy loam, sandy clay loam, and clay loam tills, respectively, in northern Michigan. They are bisequal profiles representativ…
The optical absorption edge of WO 3 single crystal has been measured with polarized light over the temperature range from -100°C to 900°C. From 0°C to about 700°C, the absorption edge shifts linearly toward red with increasing temperature, the temperature coefficients being -9.0×10 -4 ev/deg for the case of light pola…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIonic Polymerization. XVI. Reactions of 1-Cyclopropylethanol-Vinylcyclopropane1-3C. G. Overberger and A. E. BorchertCite this: J. Am. Chem. Soc. 1960, 82, 18, 4896–4899Publication Date (Print):September 1, 1960Publication History Published online1 May 2002Published inissue 1…
In disordered magnetic materials such as the ferrites, the dominant source of resonance linewidth can be attributed to processes involving only two elementary excitations: the destruction of a magnon with the creation either of another magnon or a phonon. We here consider only the primary magnon-magnon scattering proc…
The infrared absorption spectra of LiNO3, NaNO3, KNO3, RbNO3, CsNO3, NaNO2, and KNO2 above and below the melting point have been obtained by supporting the salts in the interstices of a fine mesh platinum screen. The frequencies observed have been assigned values according to the symmetry classification. The effects o…
Abstract The changes in relative viscosity which occur when nylon 66 is irradiated with 2 m.e.v. electrons under an oxygen‐free atmosphere under various conditions have been observed. A mechanism is proposed which reconciles all of these observations, and on the basis of this postulated mechanism yields of chain break…
Experimental investigations of subsolidus phase relations in the ternary system gold-silver-tellurium are discussed in the light of their significance for interpretation of the mineralogy and conditions of formation of telluride deposits, particularly those of Kalgoorlie, Western Australia, and Vatukoula, Fiji. Calave…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Compressibilities of Certain Molten Alkali Silicates and BoratesJ. O'M. Bockris and E. KojonenCite this: J. Am. Chem. Soc. 1960, 82, 17, 4493–4497Publication Date (Print):September 1, 1960Publication History Published online1 May 2002Published inissue 1 September 1960htt…
Oxygen diffusion coefficients have been determined for polycrystalline samples of NiCr 2 O 4 and α‐Fe 2 O 3 by exchange measurements with oxygen gas containing the stable isotope 18 O, using mass spectrometer analysis. Oxygen diffusion in NiCr 2 O 4 can be represented by the equation D = 0.017 exp (‐65,400/RT); oxygen…
The use of the mass-action law in connection with solid-state equilibria involving conduction electrons or holes assumes that the chemical potential of the species is related to its concentration by μ=μ0(T)+kT lnn. This approximation can fail at concentrations which are still very small by ordinary chemical standards.…
It is shown that the Yafet-Kittel triangular spin-configurations in the cubic spinel do not minimize the classical Heisenberg exchange energy. (Only nearest-neighbor $A\ensuremath{-}B$ and $B\ensuremath{-}B$ interactions, ${J}_{\mathrm{AB}}$ and ${J}_{\mathrm{BB}}$, are included; one spin-magnitude ${S}_{A}$ for the $…
Abstract The changes that are observed under magnification when a single polyvinyl chloride particle is immersed in a drop of diluent and slowly heated have been explained on the basis of a three‐dimensional network system in which the polymer crystallites act as junction points for the network. The existence of a tem…
Using the technique of zone melting by electron bombardment, $\frac{3}{8}$-in. diameter single crystals of vanadium were grown in a high vacuum. Two crystals were prepared from seeds such that their lengths were parallel to the [100] and the [110] crystal directions. With these orientations, the elastic moduli ${C}_{1…
Abstract By means of the method of electron paramagnetic resonance a demonstration is given of the occurrence of macroradicals during the degradation of glassy polymers whether of organic (polystyrene, polyethylene, polymethyl methacrylate) or of inorganic (quartz) nature.
The thermal expansion characteristics of polycrystalline delta (face-centered-cubic) zirconium hydride and epsilon (body-centered-tetragonal) zirconium hydride were determined between room temperature and 362°C and 300°C, respectively, by means of x-ray diffraction techniques. The average linear thermal expansion coef…
A phase diagram is proposed for the system UO 2 ‐ZrO 2 on the basis of earlier work and the results of new studies in which the mixed oxides were melted in a solar furnace to avoid contamination. X‐ray diffraction measurements were made on specimens melted in helium and on the same specimens after heating to 1350°C. i…
The phase transitions in PbNb 2 O 6 and in compositions of the type Pb 1+x (B x Nb 1‐x )O 6 , where B = Ti 4+ , Zr 4+ , or Sn 4+ , have been investigated between 25° and 650°C. using X‐ray and dilatometric techniques. The modified PbNb 2 o 6 compositions possess orthorhombic PbNb 2 O 6 ‐type structure, with the additi…
An apparatus is described for the direct measurement of torque-twist relationships for single wool fibers. Calculation of the rigidity of a dry fiber (0% relative humidity) agrees with results obtained by Speakman, who used a torsion pendulum technique. However, this latter technique is shown to give an underestimatio…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHYDROGEN SORPTION ON GRAPHITE AT ELEVATED TEMPERATURES1,2J. P. Redmond and P. L. Walker Jr.Cite this: J. Phys. Chem. 1960, 64, 9, 1093–1099Publication Date (Print):September 1, 1960Publication History Published online1 May 2002Published inissue 1 September 1960https://pubs.a…