Magnetic and electric properties are studied of an organic ferromagnet of pyrolysed polyacrylonitrile (PAN) and of its composites with an epoxy which are of great interest for practical use. Possible models of the pyro‐PAN ferromagnetic macromolecules are presented. Unusual magnetic properties of the composites obtained such as sign inversion of their magnetic susceptibility with increasing strength of the external magnetizing field are found. Dependences of their dielectric and magnetic constants on the electromagnetic wave frequency are obtained.

The formation of systems of globular star clusters around galaxies has been studied in the framework of a nonlinear-nonstationary model of collapsing galaxies. Instabilities of the model with respect to four perturbation modes are analyzed, with the mode order determining the average number of clusters in the system. Critical diagrams for the dependence of the initial value of the virial ratio on the rotation degree of collapsing model are plotted. The instability growth rates are calculated, and the obtained instability parameters are compared. K e y w o r d s: systems of globular star clusters. gravitational instabilities, pulsation model of self-gravitating system, cosmology of globular clusters.

No abstract

No abstract

We study strongly non-stationary stochastic processes which take place in the phase space of disk-like self-gravitating systems at the early stage of their evolution. Numerical calculations were carried out based on the model of chaotic effects according to which the selected phase volume is experienced by random pushes that have diverse and complicated character.