Effect of the degree of extension on the phase composition and tendency toward mesomorphism of UHMWPE in gel-spun oriented fibers

Structural transformations of UHMWPE-based fibers prepared by orientational drawing have been studied by the combination of SAXS and WAXS methods, photo- and diffractometry, and isometric DSC measurements in a wide temperature range. A sequence of phase transformations and other structural changes has been followed and identified during the orientational deformation of the fibers in a wide range of draw ratios from 1 to 85 within the temperature interval from room temperature to the melting temperature of the polymer.     

Water-vapor absorption spectrum in the 0.59-μm region

The paper gives the results of investigation of the water-vapor absorption spectrum in the range of 586.9–596.6 nm. In the given range, 282 water-vapor absorption lines were recorded and were identified as belonging to the bands 4ν₁ + ν₃, 3ν₁ + 2ν₂ + ν₃, 3ν₁ + 2ν₃. Theoretical justification of the technique for interpreting the observed spectrum was made. The values of more vibration-rotation levels of energy were determined: for state (401) up to J = 10, for state (321) up to J = 10, and for state (302) up to J = 8. The rotational and centrifugal constants of the reduced Watson's Hamiltonian for the vibrational states (401), (321), (302), and (222) and constants of Fermi resonance (401)-(321), (302)-(222), and Coriolis resonance between the states (401), (321), and (302), (222) were determined.     

The new lead vanadylphosphate Pb2VO(PO4)2

The structure of dilead vanadium oxide bis­(phosphate) contains corrugated layers formed by VO₅ square pyramids oriented in opposite directions in a chessboard fashion. The pyramids are connected by tetra­hedral PO₄ groups. The layers are separated by the Pb atoms and isolated PO₄ tetra­hedra.     

Rotational instability of filamentary crystals undergoing plastic deformation

We investigated the kinetics of spontaneous torsion in filamentary crystals during plastic deformation by a tensile load. The nature of the observed effect is discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 76–81, August, 1988.     

Carbonylation of m-fluoronitrobenzene in the presence of selenium-containing catalysts

Conclusions The additives triethylamine, pyridine, imidazole,-aminopyridine, and tris (hydroxy-methyl)aminomethane exert a promoting effect on the carbonylation of m-fluoronitrobenzene in the presence of selenourea.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1427–1428, June, 1984.