Spectra of discrete symplectic eigenvalue problems with separated boundary conditions

In this paper we consider a discrete symplectic eigenvalue problem with separated boundary conditions and obtain formulas for the number of eigenvalues on a given interval of the variation of the spectral parameter. In addition, we compare the spectra of two symplectic eigenvalue problems with different separated boundary conditions.     

Interaction of copper(II) oxide with monobasic mineral acids under model conditions and in the presence of metallic copper

It was determined that the heterogeneous heterophase interaction of copper(II) oxide with concentrated solutions of mineral acids occurs under diffusion control and involves dissolution of the product (rate-limiting stage), imitation of the behavior of homogeneous reactions of simple types, and self-termination once the liquid phase of the system transforms to a saturated solution of the dominant product. The forming basic and neutral copper(II) salts in acidified solutions or suspensions easily and rapidly oxidize copper and its alloys.     

Effect of amino acid sorption on formation of water clusters in ion-exchange membranes

The average size and number of water clusters inside ion-exchange membranes are calculated from experimental isotherms of water vapor sorption as a result of considering the sorption in terms of the clusterization theory. It is established that, in MK-40 heterogeneous cation-exchange membrane, water clusters are not formed, while, inside MF-4SK perfluorinated homogeneous membrane, intense cluster formation takes place. The effect of amino acid sorption on cluster water is considered. An increase in the membrane hydrophobicity as a result of the incorporation of amino acid ions leads to prevailing interaction of water molecules with one another rather than with the polymer phase, which is evident from an enlargement of water clusters.     

Defect modes and magnetooptical activity of a one-dimensional magnetophotonic crystal

The reflection spectrum of a periodic transverse-magnetized structure containing a finite number of ferromagnet-dielectric periods has been obtained. The influence of a substitutional defect on the reflection spectrum is analyzed for normal incidence of light on the structure. It is shown that the intensity and position of the defect miniband in the bad gap of the spectrum depend on the location of the defect layer in the structure and on its type (magnetic or nonmagnetic). It is found that magnetooptical activity of the defect structure is higher than in a defect-free structure.