Multilayer metallization of ferrite Mg<Subscript>0.54</Subscript>Zn<Subscript>0.46</Subscript>Fe<Subscript>2</Subscript>O<Subscript>4</Subscript>

The character of interatomic interaction in ferrite Mg_0.54Zn_0.46Fe₂O₄ was studied using the x-ray spectroscopy technique and theoretically. It was found that the electronic structure of samples is rearranged during annealing at high temperatures (1280°C, 0.5–0.8 h). The electronic structure rearrangement was shown to be associated with multilayered ferrite metallization in which alternating layers with metallic and ionic-covalent bonds form.     

N. N. Bogolyubov's research in mathematics and theoretical physics

Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 41, No. 9, pp. 1156–1164, September, 1989.     

Oleksandr Ivanovych Stepanets' (On His 60th Birthday)

Ukrainian Mathematical Journal -     

Fading Markov Random Evolution

We introduce the notion of fading Markov random evolution and study the properties and characteristics of this process.     

Unbounded self-adjoint operators connected by algebraic relations

Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 41, No. 12, pp.1664–1668, December, 1989.     

Investigation of the ηη system in π − p interactions at a momentum of 32.5 GeV/c at the GAMS-4π spectrometer

The ηη system produced in charge-exchange π ^? p interaction at a momentum of 32.5 GeV/c is studied in an experiment performed with the GAMS-4π spectrometer at the 70-GeV accelerator of the Institute for High-Energy Physics (IHEP, Protvino). A partial-wave analysis is performed in the mass range between 1.1 and 3.9 GeV for ?t <0.2 (GeV/c)², S, D, G, and J waves being taken into account in this analysis. The S wave has a complicated structure, displaying peaks at about 1.5 and 1.7 GeV. These peaks are associated with the f ₀(1500) and f ₀(1710) mesons. One of the solutions (preferable one) involves the f ₀(2200) and f ₂(1950) resonances. The mass region above 2.4 GeV is dominated by the G wave. A broad state of mass about 3 GeV and width 0.7 GeV is found in the J wave. The parameters of the resonances in question and their production cross sections are measured.     

Dynamics of conflict interaction between systems with internal structure

We investigate a dynamical system of conflict between two systems each of which, in turn, has an internal conflict. The external conflict and the internal one have different natures. The external conflict is described by an alternative interaction between nonannihilating adversaries. The internal conflict is similar to a conflict between interrelated populations of different biological nature (“predator-prey” model). We construct a computer model of this system and describe a typical behavior, illustrated by diagrams, which can be interpreted, in particular, as a migration of labor and investments between countries. __________ Translated from Neliniini Kolyvannya, Vol. 9, No. 4, pp. 435–450, October–December, 2006.     

Lyapunov–Schmidt Approach to Studying Homoclinic Splitting in Weakly Perturbed Lagrangian and Hamiltonian Systems

We analyze the geometric structure of the Lyapunov–Schmidt approach to studying critical manifolds of weakly perturbed Lagrangian and Hamiltonian systems.     

Construction of an Integral Manifold of a Multifrequency Oscillation System with Fixed Times of Pulse Action

We determine a class of multifrequency resonance systems with pulse action for which an integral manifold exists. We construct a function that determines a discontinuous integral manifold and investigate its properties.     

On the smoothness of the Green function for the problem of bounded invariant manifolds

We investigate the smoothness of the Green function for the problem of bounded invariant manifolds of linear extensions of dynamical systems. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 50, No. 4, pp. 570–584, April, 1998.