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41.
N. N. Peschanskaya V. V. Shpeizman A. B. Sinani B. I. Smirnov 《Physics of the Solid State》2004,46(11):2058-2062
Laser interferometry is used to study micrometer-scale creep-strain nonuniformities (jumps) that occur during compression of metals (Ag, Al, Bi, Cu, Pb, Sn, Zn) and LiF: Mg crystals. The strain rate is found to vary periodically. The average magnitude of deformation L over one period and the variation of L with the total strain are determined. Correlations are found to exist between L and the Mg content in the LiF crystals, between L and the grain size in the metals, and between the magnitude of small jumps and the Burgers vector in the metals. 相似文献
42.
Tatiana Sukhanova Vladimir Bershtein Mimi Keating Galina Matveeva Milana Vylegzhanina Victor Egorov Nina Peschanskaya Pavel Yakushev Edmund Flexman Stefan Greulich Bryan Sauer Kathleen Schodt 《Macromolecular Symposia》2004,214(1):135-146
Comparative WAXD/SAXS/SEM/DSC structural studies of a series of semi-crystalline poly(oxymethylene) (POM) engineering plastics, including the commercial products, homopolymer Delrin® and typical poly(oxymethylene-co-oxyethylene)s, and a few lab-made POM compositions, were performed. The latter differed in their content of functional additives (present in low concentrations) and POM molecular weight characteristics. In parallel, their densities, thermal behavior/laser-interferometric creep rate spectra (DSC/CRS) at 20-180 °C, as well as long-term creep resistance (LTCR) at 20 °C were studied. It has been found that introducing the nucleating agents and oxyethylene units resulted in formation of more fine spherulitic or practically non-spherulitic structure with close- or loose-packed lamellar stacks. The presence of both “thick” (5-10 nm) and “thin” (1.5-3 nm) lamellae in the weight ratio of ∼3:1 was shown in all cases. Close values of real POM crystallinities, not exceeding 50%, were obtained by WAXD and DSC. A predominant role of “straightened out” or slightly bent tie chains in disordered layers of isotropic POMs was presumed, resulting in segmental dynamics differently constrained by crystallites (DSC/CRS data). As a result, certain morphology - density - creep resistance correlations were found. 相似文献