Радиофизика, электроника, акустика

Background and Objectives: Metasurfaces are coatings consisting of elementary resonators that reemit incident UHF electromagnetic waves. By varying the parameters and arrangement of these resonators, it is possible to tune the electrical properties of the metasurface as a whole. This produces a number of practically important characteristics that are difficult to achieve with conventional attenuation coatings, and therefore prospective in the tasks of shielding of electronic devices and attenuation of the reflected signal.

Background and Objectives: Layered structures based on ferrite and metal films are actively studied in magnonics. Usually, the effects associated with the finite conductivity of the metal are not taken into account. The aim of this work was to investigate the influence of the thickness of a metal with finite conductivity on the dispersion and damping of a magnetostatic backward volume wave (MSBVW) in the ferrite-metal and ferrite-insulator-metal structures.

Background and Objectives: The Josephson effect is widely used for both generating and receiving very high frequency signals. The approaches and methods of nonlinear dynamics are commonly used: construction of phase portraits, bifurcation analysis, Kuramoto model approach, etc. Usually large arrays of identical junctions are considered. However, the non-identity of junctions leads to new and interesting effects. A very popular model is a chain of junctions connected via an RLC circuit.

Background and Objectives: Quasi-periodic oscillations are widespread in nature and technology. In the phase space, quasi-periodic oscillations with a different number of incommensurable frequencies correspond to invariant tori of different dimensions. Multiparametric analysis of high-dimensional systems is quite difficult. The way out of this situation can be the transition from systems with continuous time to discrete maps.

Background and Objectives: The purpose of the study carried out in the article is to obtain analytical expressions for calculating the gas (liquid) flow rate in the turbulent gas (liquid) flow regime. A method is presented for the mathematical description of a three-dimensional profile (hodograph) of the flow velocity in a turbulent flow regime based on two known velocity values in the pipeline cross section. The article analyzes the physical processes occurring in the turbulent flow.

Background and Objectives: The study of complex collective dynamics in networks of coupled oscillators and its control is an important task for many scientific disciplines. Networks of nonlinear oscillators are capable of demonstrating a wide variety of spatiotemporal regimes of collective dynamics.