Materials Literature
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The electronic band structures of the beta , epsilon and gamma polytypes of GaSe are studied by the tight-binding method. The calculation takes into account interlayer interactions and the generally neglected lowest excited atomic states. The energy levels of the three polytypes differ from each other by 0.3 eV at mos…
Generalisations of the two apparently rational eigenvalues found by Thorson and Moffitt for the Jahn-Teller system Gamma 8 (X) tau 2 are studied. Equations of finite order are established for determining the strength D of the Jahn-Teller interaction of which an eigenvalue lies on a baseline. (A baseline is the line th…
A new fundamental radiation-induced defect in high-purity synthetic silica has been identified by electron-spin-resonance studies of $^{17}\mathrm{O}$-enriched Si${\mathrm{O}}_{2}$ as a peroxy radical ${\mathrm{O}}_{2}^{\ensuremath{-}}$ bonded to one Si in the glass matrix. The precursors of these defects are envision…
Abstract. — With Mossbauer effect and X-ray diffraction on magnetically aligned ErFe3 it has been shown that the easy axis of magnetization turns from the crystallographic c-axis to the 6-axis at 50 K with increasing tempe-rature. In the Er(Fei_:sCox)3 series from x = 0 up till x = 0.4 almost the same spin reorientati…
Abstract In a preceding paper the diffraction theory on this subject has been worked out by using far less approximations than those which had been involved in earlier tratments, arriving at more general and exact results. The approach used to obtain the expressions for the variance and integral breadth of reflections…
The depolarized light scattering from a phase-separated borosilicate glass was experimentally measured. The theory predicts that the internal stress field around the second-phase particles gives rise to a depolarized four-leaf-clover scattered-intensity pattern. The phase-separated and annealed specimen showed practic…
The permanent magnets which can be manufactured from rare earth base alloys have magnetic properties which substantially exceed the values obtained before with the Alnico and Ferrite magnets where the specific energy (from 3 to 6 times) and the resistance to de-magnetization (from 30 to 4 times) are concerned, but at…
Abstract The strain‐induced crystallization phenomenon of a crosslinked polymer network was studied using statistical, thermodynamics. The basic approach was essentially that used by Flory (1), but in this work Flory's assumption of only a single crystalline phase (the extended‐chain crystalline structure with chain p…
The ternary system Y6(Fe1-xMnx)23 exhibits unusual magnetic behavior. Although both Y6Mn23 and Y6Fe23 are magnetically ordered, these ternaries show a striking reduction in both Curie temperature and magnetization. In the compositional range of x = 0.5 to 0.75, there exists no magnetic ordering at liquid helium temper…
A simple mathematical model that includes (a) uniform liquor flow through a package and (b) Fickian diffusion of a dye within the fibres is described. The distribution of a dye within the package and the degree of levelness are calculated for constant dyeing conditions (e. g., constant temperature) and a dye with a li…
Abstract Wholly aromatic polysulfonamides of high molecular weight were prepared by the solution poly‐condensation of aromatic disulfonyl chlorides with aromatic diamines in tetramethylene sulfone and substituted pyridines as the acid acceptor. Polysulfonamides with inherent viscosities as high as 1.2 were readily obt…
Abstract Factors affecting the formation of hard elastic polypropylene and nylon 6,6 are described. In the case of polypropylene, it is shown that the morphology of the stress spin‐oriented fibers depends on the molecular weight, the molecular weight distribution, and the cooling rate. Narrow molecular weight distribu…
The authors' previous work on the fractography of cotton has been extended to include a comparison of cotton varieties, differences between individual fibers of different strength, fracture of mercerized cotton in water, fracture of crosslinked cotton (including tests in water, and at and between reversals), fractures…
Abstract The objective of this study was to develop a test which can accurately predict the contribution of coating characteristics to the control of rates of release of urea from SCU granules. It was assumed that product quality is a function of average coating thickness and uniformity of coating thickness. To achiev…
Photoelectron spin polarizations of 50 and 17% have been obtained with the chalcopyrite-structure semiconductors ZnSiAs2 and ZnGeAs2, respectively, by irradiation with circularly polarized light. A comparison is made with the results obtained from GaAs, which has a zinc-blende structure. An analysis of the chalcopyrit…
Using Auger electron spectroscopy, the region near the front contact of cuprous oxide front-wall solar cells was investigated. In cells showing large photovoltages, a maximum of the copper concentration being by about 4 at.% percent higher than the bulk concentration was observed at a distance of 70 Å from the metal-s…
Abstract. The prevalence of a chlamydial infection in hatchery‐reared adult hard clams Mercenaria mercenaria (L.) from Great South Bay, Long Island, New York was relatively high and seasonally stable. Infection occurred early in life while juvenile clams were still within the hatchery. Fluorescent antibody tests sugge…
Tables of calculated balloon parameters are given for a range of unwinding conditions when conical packages are used. Both single and double balloons are considered. Empirical formulae for estimating the yarn tension at the eye are deduced.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSpin-inversion and orbital symmetry conspiracy in type A lumiketone rearrangementsSason S. ShaikCite this: J. Am. Chem. Soc. 1979, 101, 10, 2736–2738Publication Date (Print):May 1, 1979Publication History Published online1 May 2002Published inissue 1 May 1979https://pubs.acs…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSerendipitous synthesis of a sila-.alpha.-pyran - convenient, penultimate precursor to dimethylsilanoneT. J. Barton and W. D. WulffCite this: J. Am. Chem. Soc. 1979, 101, 10, 2735–2736Publication Date (Print):May 1, 1979Publication History Published online1 May 2002Published…