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V. I. Selikhova N. P. Bessonova E. V. Konyukhova Ya. I. Odarchenko E. A. Sinevich S. N. Chvalun B. Rieger 《Polymer Science Series A》2008,50(10):1071-1081
The structure, thermophysical, and thermomechanical characteristics of metallocene-synthesized isotactic PPs of different molecular masses containing different amounts of stereodefects have been studied. The degree of crystallinity and the content of a and g modifications in slowly cooled and melt quenched films are estimated by three independent methods, i.e., X-ray analysis, DSC, macroscopic density measurements, and changes in their phase structure upon annealing and orientation are analyzed. As the content of stereodefects increases, the fraction of g crystallites in the films increases, while the degree of crystallinity decreases (down to 5%). The formation of the g phase is assumed to be related to the epitaxial crystallization; this process is assisted by stresses induced on chains upon slow melt crystallization and after annealing of the oriented samples. This evidence allows the analysis of structural and thermodynamic characteristics of thermoplastic and elastic samples of the isotactic PP. 相似文献
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B. I. Petrov G. A. Abakumov A. V. Arapova E. V. Sharova O. I. Artiushin I. L. Odinets N. M. Lazarev Yu. A. Bessonova 《Russian Journal of General Chemistry》2011,81(11):2231-2234
The synthesis and the studies of properties of diphenyl[dialkyl(alkyl)carbamoylmethyl]phosphine oxides by differential scanning
calorimetry, mass spectrometry and Knudsen effusion method were performed. The thermodynamic parameters of melting and vaporization
were calculated. 相似文献
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Z. Karimov I. A. Bessonova M. R. Yagudaev S. Yu. Yunusov 《Chemistry of Natural Compounds》1980,15(6):712-716
A complete x-ray structural investigation has been made of the alkaloid anhydroperforine. The crystals are rhombic: a=17.425(5) Å, b=8.166 Å, c=11.284(5) Å, z=4, space group P212121 (diffractometer, 1000 reflections, MLS in the anisotropic approximation, R=0.11). The investigation has unambiguously demonstrated the conformation of the anhydroperforine molecule and has confirmed its structure. The lengths of the bonds and the values of the valence angles are the usual ones. The conformations of rings B and C are planar, ring D has a chair, and ring A, a distorted half-chair conformation.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 805–810, November–December, 1979. 相似文献
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From the roots ofHaplophyllum dauricum (L) G. Don., collected on the territory of the Uvur-Khangai aimak, Mongolian People's Republic, in the fruit-bearing stage have been isolated robustine, dictamnine, -fagarine, haplopine, skimmianine, 4-methoxy-N-methyl-2-quinolone, folimine, robustinine, and the new alkaloid daurine the structure of which has been established as 8-(,-dimethylallyloxy)-4-methoxy-N-methyl-2-quinolone.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 73–76, January–February, 1984. 相似文献