Reaction of peroxydisuccinic acid with salts of metals of variable valence

Conclusions A study was made of the effect of the salts FeSO₄, MnSO₄, and CoSO₄ on the decomposition of peroxydisuccinic acid in aqueous medium. Both the composition and the yield of the reaction products are determined to a large degree by the nature of the metal ion.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2060–2062, September, 1971.     

Nonlinear stability analysis of a two-layer thin liquid film: dewetting and autophobic behavior

The nonlinear stability analysis of a liquid film composed of two superposed thin layers of immiscible liquids resting on a solid substrate is performed. It is shown that the coupling of van der Waals interactions in the two layers can lead to an autophobic behavior in the form of spinodal decomposition of two planar liquid layers into a system of localized drops divided by almost planar wetting layers. The results of the weakly nonlinear analysis near the instability threshold are confirmed by the numerical solution of a system of two strongly nonlinear evolution equations for the liquid-liquid and liquid-gas interfaces. The kinetics of the drop coarsening at late stages is studied and is found to be close to that reported for a one-layer film. It is also shown that gravity effects can become significant even for very thin two-layer films.     

Angular electron distribution in photoionization of spatially oriented linear molecules for different geometries of the experiment

Starting from the general expression for the angular distribution of electrons produced through photoionization of spatially oriented molecules, simpler formulas for photoionization of linear molecules with an inversion center found in the Σ state, accompanied by the production of molecular ions in Σ and Π states, are obtained. For different geometric arrangements of the vectors determining the angular distribution, simple formulas are derived and their comparative analysis is made. It is shown that one can determine for different conditions of the experimental measurement of the angular dependences of ejected electrons the values of matrix elements and phase differences and separate the processes responsible for the production of ions in states with different symmetries.     

Effect of a pulsed magnetic field on the microhardness of C60 single crystals

Magnetic-field pulses with induction greater than 10 T were observed to influence the microhardness of C₆₀ single crystals. It was established that the magnetic field reversibly alters the bulk properties of the material. Pis’ma Zh. éksp. Teor. Fiz. 69, No. 2, 110–113 (25 January 1999)     

Intracavity amplitude isolator of a ring solid-state laser

An aperture in a ring laser with plane mirrors is shown to be a major source of rescattering of oppositely directed waves. An aperture with nonparallel surfaces is a nonreciprocal element of a ring laser and acts in much the same way as a passive isolator providing quasi-unidirectional lasing. It is shown that the realization of single-frequency oscillations in the regime of twisting modes in a ring laser does not ensure the elimination of inverse population gratings.     

A new type of magnetoplastic effects in linear amorphous polymers

A new type of magnetoplastic effects in polymers is revealed. This effect cannot be explained by the reorientation of macromolecular units that possess a magnetic susceptibility anisotropy. It is shown that the joint action of magnetic and electric fields and the rotational mobility of side groups in macromolecules are factors of crucial importance in changing the plasticity of polymers in pulsed magnetic fields.     

Motion of a pair of bubbles in a liquid of low viscosity

Lagrange's equations are used to examine the long-range interaction of bubbles. The Lagrange function equals the kinetic energy of an ideal liquid flowing around a bubble. The generalized external forces include the upthrust and the viscous resistance to flow around each buble. The azimuthal angle is increased by the long-range interaction. The locus for the relative motion is calculated for: 1) the case in ~hieh the relative speed is fairly high, which allows one to neglect the effects of viscosity on the collision time. 2) low relative speed, where the viscous forces determine the motion. Estimates are given for the differential effective cross-section for elastic scattering and the coalescence cross-section.We are indebted to V. G. LevichandV. V. Tolmachev for discussions.     

Transfer of energy from an evaporating drop in a vapor medium

The article considers the temperature distribution around an evaporating drop in a vapor medium. The transfer of energy is effected by molecular thermal conductivity, convection, and radiation. The mean length of the free flight path of the radiation considerably exceeds the characteristic distance at which the temperature changes. The times required for relaxation of the temperature to a steady-state value are determined, as well as the characteristic distances at which the temperature distribution changes.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 1, pp. 74–78, January–February, 1972.The authors thank V. G. Levich for his evaluation of the results obtained.