The scientific thought and advances of Academician Yaroslav Stepanovich Podstrigach of the Ukrainian Academy of Sciences

This article enumerates the basic areas of scientific activity of Academician Yaroslav Stepanovich Podstrigach and discusses new advances made by representatives of the scientific school founded by him which are a development of his ideas on interaction of fields of different natures in application to problems of mechanics and modern engineering.Translated fromMatematicheskie Melody i Fiziko-Mekhanicheskie Polya, Issue 35, 1992, pp. 3–8.     

Emitter lifetime and velocity distribution in the collisionless IR multiphoton excitation of chromyl chloride

The collisionless infrared multiphoton exeitation of chromyl chlonde is studied systematically. An attempt is made to find the parentage of the induced visible emission.     

Crystal structure of two oximes incis-pinane series

The structures of racemic 2-hydroxy-4-hydroxyiminopinan-3-one (1) and 3-hydroxyimino-cis-pinan-4-one monohydrate (2) have been determined by X-ray diffraction. The crystals of1 are monoclinic:P2₁/c, a=7.838(2),b=10.776(3),c=12.025(3) Å, =105.09(1)°,Z=4, room temp.; the crystals of2 are orthorhombic;P2₁2₁2₁,a=8.181(3),b=9.250(3),c=14.085(6)Å,Z=4, T=80K. Both structures were solved by direct methods, and refined toR=0.037 for 1920 reflections (1) and 0.032 for 1776 reflections (2). The absolute configuration of2 was not established. The hydroxyimine groups in both crystals and water molecules in2 participate in the network O–H...O of hydrogen bonds.     

Multiphoton vibrational pumping on optically prepared NO2 molecules

Reported is the collisionless infrared multiphoton excitation of NO₂ molecules initially prepared in an electronically excited state. From the shape of the infrared induced blue-shifted fluorescence spectrum the probability distribution P(n) for the net absorption of n photons has been deduced.     

Through-space interaction in non-conjugated acyclic dienes studied by photoelectron spectroscopy

The He (I) PE-spectra of the non-conjugated acyclic dienes 1 (n), n = 5, 6, 7, 8, 9 are reported. The π-level splitting in the molecules amounts respectively to 0·34, 0·46 (or 0·31), 0·41, 0·21 and 0·14 eV. Arguments based on the observed fine structure of the first two bands suggest there is no crossing of the π-levels, and EHT calculations on different conformations of 1 (5) and 1 (6), as well as comparisons with other available data, indicate a through-space dominated interaction throughout the series 1 (n).     

Segmental dynamics of poly(methyl acrylate)-d3 adsorbed on anopore: a deuterium NMR study

The segmental dynamics of poly(methyl acrylate-d3) (PMA-d3) adsorbed in the pores of anopore membranes has been investigated using deuterium NMR over the temperature range 25-80 degrees C. The onset of the NMR glass-transition temperature (Tg) for the adsorbed samples was approximately 15 degrees C higher than that for the bulk sample. The adsorbed polymer contained segments with restricted mobility (glassy), even at the highest temperatures studied, at which the bulk polymer showed only mobile segments. The spectra from samples with different adsorbed amounts of PMA-d3, between 1.1 and 4.2 mg/m2, were similar in their temperature-dependent mobilities. Neither was there much difference in the spectra of PMA-d3 on anopore samples with pore sizes of 0.2 and 0.02 microm. However, for a solvent-washed sample with an adsorbed amount of 0.7 mg/m2, additional restriction in PMA-d3 mobility was observed.