Vol 64, No 8 (2019)

Stimulated Raman scattering in magnesium silicate Ca₂MgSi₂O₇, which enters the family of \(D_{{2d}}^{3}\)‑tetragonal acentric crystals with a melilite structure, has been observed. The recorded components of Stokes and anti-Stokes χ⁽³⁾-nonlinear lasing are identified with two SRS-active modes, ω_SRS1 ~ 908 cm^–1 and ω_SRS2 ~ 668 cm^–1, which also manifest themselves in the generation of combined phonon modes ω_SRS3C ~ 170 cm^–1 and ω_SRS4C ~ 1270 cm^–1.

The problem of generation of waves on the surface of a water layer placed on an elastic base is considered. It is assumed that the generating source is located inside the elastic half-space. The Podyapolskii approach is used which is based on study of the solutions to the common linear system of equations of the theory of elasticity in the half-space and the theory of water waves linked at the interface by the corresponding boundary conditions. The previously obtained simplified dispersion relation for the water mode with account for the elastic base effect is used to derive a simple integral formula which associates the initial perturbation of a special kind in the elastic half-space and the amplitude of the surface water waves generated by this source. The obtained solutions are compared with the solutions based on the well-known piston model of long wave generation.

This paper demonstrates the integrability of some classes of seventh-order partially homogeneous dynamic systems, in which a system on the tangent bundle to three-dimensional manifolds can be distinguished. In this case, the force fields have dissipation of different signs and generalize those previously considered.

The responses of an aluminum multilayer composite to dynamic loading are described using the relaxation model of plasticity. The relations between the strain-rate sensitivity of a multilayer composite, the dynamic-loading parameters, and the strain-rate sensitivity of its components are established. The estimates of the strain-rate sensitivity are shown to be higher for the GLARE composite as compared to those for the rate sensitivity for its component—Al 2024-T3 sheet metal.