Origin and spectral composition of the luminescence associated with the fatigure fracture of polymers

The nature of the luminescence associated with the fatigue fracture of polymers, accompanied by intense cracking, and with the growth of an artificial crack has been subjected to analysis. As a result of a comparison of the spectral composition of the luminescence associated with fracture with that of the luminescence produced by other modes of excitation it is concluded that the emission is chiefly attributable to gas-discharge phenomena.Institute of Chemical Physics, Academy of Sciences of the USSR, Moscow. Translated from Mekhanika Polimerov, No. 3, pp. 515–518, May–June, 1972.     

Crystallization of X-type zeolite from concentrated sodium silicate and aluminate solutions

Crystallization of an X-type zeolite from concentrated solutions of sodium aluminate (Al₂O₃ 90–330 g l^?1) and silicate (SiO₂ 110–180 g l^?1) was studied.     

Experiment on the chemical modeling of the action of alcohol dehydrogenase

Summary Certain chelate compounds, containing nickel and zinc, can serve as chemical models of alcohol dehydrogenase in the dehydrogenation of ethyl alcohol.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimisheskaya, No. 7, pp. 1273–1274, July, 1965     

High precision delta(17)O isotope measurements of oxygen from silicates and other oxides: method and applications

The use of infrared laser-assisted fluorination to release oxygen from milligram quantities of silicates or other oxide mineral grains is a well-established technique. However, relatively few studies have reported the optimisation of this procedure for oxygen-17 isotope measurements. We describe here details of an analytical system using infrared (10 μm) laser-assisted fluorination, in conjunction with a dual inlet mass spectrometer of high resolving power ( approximately 250) to provide (17)O and (18)O oxygen isotope measurements from 0.5-2 mg of silicates or other oxide mineral grains. Respective precisions (1) of typically 0.08 and 0.04 per thousand are obtained for the complete analytical procedure. Departures from the mass-dependent oxygen isotope fractionation line are quantified by Delta(17)O; our precision (1) of such measurements on individual samples is shown to be +/-0.024 per thousand. In turn, this permits the offset between parallel, mass-dependent fractionation lines to be characterised to substantially greater precision than has been possible hitherto. Application of this system to investigate the (17)O versus (18)O relationship for numerous terrestrial whole-rock and mineral samples, of diverse geological origins and age, indicates that the complete data set may be described by a single, mass-dependent fractionation line of slope 0.5244+/- 0.00038 (standard error). Copyright 1999 John Wiley & Sons, Ltd.     

Preparation of silyl derivatives of unsaturated carbocyclic compounds by the Diels-Alder reaction of 1,2-dimethylenecyclobutane and vinylsilanes

The Diels-Alder reactions of 1,2-dimethylenecyclobutane with vinyltrichlorosilane and vinylmethyldichlorosilane give the corresponding trichlorosilyl and methyldichlorosilyl derivatives of cyclobutene. Methylation of these derivatives gave 4-trimethylsilylbicyclo[4.2.0]oct-1-ene, which underwent thermal isomerization to 4-trimethylsilyl-1,2-dimethylcyclohexane.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 943–945, April, 1991.