Materials Literature
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RNA synthesis, one of the early events in spore germination, is underway by the 2nd min. During the first 10 min of germination, RNA synthesis can proceed in the absence of exogenous nutrients at the expense of previously existing RNA. Salvage pathways for bases, nucleosides, and nucleotides are operative during this…
Abstract A pyrolysis–gas chromatographic–mass spectrometric technique for analyzing the pyrolysis products from polymers in an inert atmosphere is described. Initial studies encompassing the pyrolysis of poly(vinyl chloride) homopolymer and a series of PVC plastisols (based on o ‐phthalate esters) have provided a comp…
An electron microscope equipped with conventional electron optics can be used as a `diffractometer' for structure research on individual aperiodic objects. The resolution limit of the electron microscope is not the resolution limit of the `diffractometer' and electron structure research with atomic resolution is possi…
Th e " low te mperature stru cture type" of Ta, O. has bee n found to occur in two di stin c t forms with th e lowes t te mp e rature form hav in g a unit cell 14 tim es th e s ub ce ll a nd an inte rm ed ia ,e te mlJe ra ture form with a unit ce ll 11 tim es the subcell. Th e two t ypes form inte rm ediate partially…
Abstract Poorly crystalline inorganic materials were removed from soil clays of different origin and mineral composition by successive treatments with sodium dithionite, 2 % Na 2 CO 3 and 0·5 N NaOH. Techniques are described whereby difference spectra representing the infrared absorption of the materials removed by th…
1. Mass spectra of the trimethylsilyl derivative and the methyl ester of the N-trifluoroacetyl derivative of bacilysin indicated that the antibiotic had a molecular weight of 270. Several peaks in the spectrum of the methyl ester were consistent with the presence of an N-terminal alanine residue in the molecule. 2. Th…
A theory of cubic-to-tetragonal transformations occurring in spinels containing octahedrally coordinated ($B$ site) ${d}^{9}$ and ${d}^{4}$ transition-metal ions in high concentration is developed. The problem is treated in the spirit of the molecular field approximation. For each Jahn-Teller (JT) susceptible ion in t…
We have found that the lifetime of aluminum films subjected to high current densities at elevated temperatures can be increased by the addition of copper. Previous studies have indicated that the failure mechanism is a combination of electromigration-induced phenomena, including nucleation and growth of voids, which a…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSpin label studies of oriented smectic liquid crystals (a model system for bilayer membranes)Joachim SeeligCite this: J. Am. Chem. Soc. 1970, 92, 13, 3881–3887Publication Date (Print):July 1, 1970Publication History Published online1 May 2002Published inissue 1 July 1970http…
Abstract Two octyl-ammonium vermiculite complexes with different 001 periodicities have been studied by i.r. spectroscopy. In each case i.r. spectroscopy affords information on the orientation of the — NH 3 + groups and the strength of the hydrogen bond between these groups and the silicate oxygen surfaces. Also a per…
An exciton is a quantum of electronic excitation energy travelling in the periodic structure of a crystal; it is electrically neutral and hence its movement through the crystal gives rise to the transportation of energy but not charge. This is a concise description of the ideal exciton. The authors give a more physica…
Abstract The ability of selected phosphorus‐containing compounds and nitrogen‐containing compounds to act as flame retardants for cotton cellulose was investigated using flame tests, thermal gravimetric analysis (TGA), and differential thermal analysis (DTA). The effectiveness of the organophosphorus compounds was fou…
ADVERTISEMENT RETURN TO ISSUEPREVArticleRuthenium complex having both linear and bent nitrosyl groupsCortlandt G. Pierpont, Donald G. Van Derveer, William Durland, and Richard EisenbergCite this: J. Am. Chem. Soc. 1970, 92, 15, 4760–4762Publication Date (Print):July 1, 1970Publication History Published online1 May 200…
Abstract The weathering of biotite in a sedentary soil profile developed on biotitehornblende- rock near Rehiran, Inverness-shire has been investigated by optical, X-ray, chemical, infrared and differential thermal methods. In the C horizon a direct transformation to hydrobiotite was observed. This involves oxidation…
Measurements of the solubility of calf-skin tropocollagen in neutral phosphate buffers in the temperature range 20-37 degrees C show that native collagen fibril formation is an endothermic process made thermodynamically favourable by a large positive entropy of precipitation associated with structural changes in the s…
Measurements have been made of magnetization curves obtained by applying stresses to various polycrystalline magnetic materials in the presence of a small, constant, magnetic field. The materials examined were nickel, mild steel, and both isotropic and cube textured silicon iron. Residual stray fields were carefully c…
Abstract Recently developed techniques permit the estimation of the surface free energy of polymers and the separation of this free energy into dispersion and hydrogen‐bonding components. These techniques have been used to calculate the thermodynamic reversible work of adhesion of a vinylidene chloride copolymer coati…
In x-ray photoe lectro n spectrosco py (XPS), a sample is exposed to low energy x rays (a pp rox im ately keY), and th e res ultant photoelectrons a re analyzed with hi gh precis ion for kin eti c energy. Aft er co rrection for in e las ti c scatt erin g, th e measured ph otoe lectron spectrum s hould refl ect th e va…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTANNUAL REVIEW Solids MixingL. T. Fan, S. J. Chen, and C. A. WatsonCite this: Ind. Eng. Chem. 1970, 62, 7, 53–69Publication Date (Print):July 1, 1970Publication History Published online1 May 2002Published inissue 1 July 1970https://pubs.acs.org/doi/10.1021/ie50727a009https://…
Compression-annealed pyrolytic graphite and single-crystal graphite specimens were irradiated with neutrons for total exposures of 3 to 71×1017 neutrons/cm2 (nvt) at 50°C, 3 to 8×1019 nvt at 650°C and 1.2×1020 nvt at 1000°C. The elastic constants of the materials were determined before and after irradiation by ultraso…