Abstract Results from experimental measurements of the electromagnetic field from a controlled source on the Rybachy and Sredny peninsulas are considered. The experimental work is performed as part of the FENICS-2019 project on electromagnetic sounding of Earth’s crust on the Baltic Shield using industrial power transmission lines. Geoelectric sections are constructed for the upper part of the lithosphere

Abstract An analysis is performed of the statistical relationship between coronal mass ejections and solar flares to establish the sequence of these events. Periods of delay in the occurrence of coronal mass ejections relative to the associated flare-like manifestations of solar activity are determined. It is found that situations in which flares occur several hours ahead of coronal ejections predominate

Abstract Small heterogeneities in the electron density of the F layer are studied in the mid-latitude atmosphere. A comparison to predictions of the HWM07 model indicates the orientation of cross-anisotropy of heterogeneities corresponds with direction of the horizontal wind, and heterogeneities are located at different altitudes of the F layer.

Abstract Data from the DMSP F6 and F7 satellites are used to show that during the magnetic calm the ion pressure in the region of the ionospheric projection of the low-latitude boundary layer does not depend on the Bz component of the interplanetary magnetic field but grows rapidly along with the dynamic pressure of the solar wind. A local increase in ion pressure in the midday sector is detected,

Abstract A database of more than 700 rockburst events in the mines of Russian North is analyzed over the period 1947–2004 to determine the possible role of cosmophysical factors in the occurrence of rockbursts. The analysis reveals similarity between the seasonal distributions of rockbursts and geomagnetic disturbances in the auroral zone. A 22-year periodicity in the occurrence of rockbursts and natural

Abstract Simultaneous disturbances of the total electron content and the horizontal component of geomagnetic field in the range of Pc6 are registered during periods of magnetospheric substorms. Such disturbances arise in intervals of interaction between Earth’s magnetosphere and the turbulent sheath of magnetic clouds. Wavelet analysis of disturbances in the interplanetary magnetic field and the velocity

Abstract A study of Herzberg kinetic states \({{c}^{1}}\Sigma _{{\text{u}}}^{ - }\), A'3Δu, \({{{\text{A}}}^{3}}\Sigma _{{\text{u}}}^{ + }\) is performed for molecular oxygen in the Earth’s middle atmosphere during the precipitation of high-energy protons and electrons into the atmosphere. It is shown for the first time that considering the transfer of energy from metastable molecular nitrogen N2(

Abstract A radiophysical technique is proposed for calculating mesospheric temperatures using experimental measurements of the frequencies of resonant atmospheric oscillations (the acoustic cutoff frequency and the Brunt–Väisälä frequency). The partial reflection method is used to measure temperatures at sunset and an altitude of 75 km for days when the planetary index of geomagnetic storms was Kp

Abstract Data from most neutron monitor stations show that the intensity of cosmic rays has not yet reached the level observed at them in 2009. At a number of stations (e.g., Barentsburg, Thule, Kerguelen, and Moscow), however, the intensity has already surpassed the 2009 level. This anomalous effect could be associated with the unusual behavior of solar activity in cycle 24.

Abstract Results are presented from the numerical modeling of two independent GLE events that occur at different times and have different energy characteristics of protons in primary particles. The resulting dependences are analyzed with allowance for features caused by characteristics of each spectrum.

Abstract A study is performed of ionospheric disturbances caused by an interplanetary shock wave on January 24, 2012, and its subsequent substorm. Results are presented from an analysis of how changes in the vertical electron density profile affect the amplitude and phase characteristics of signals with frequencies of the Beta time signal service, recorded at the Earth’s surface.

Abstract Results are presented from modeling two different conditions for parameterizing the geometry of Earth’s atmosphere and the spectrum of primary cosmic rays. In the first, the input data correspond to solar cosmic rays and calculations are made for all geographic latitudes and longitudes. The second is devoted to estimating the contribution from the nuclei of galactic cosmic rays while considering

Abstract A detailed study is performed of the spatial features of two very intense substorms (supersubstorms) during the magnetic storm of March 9, 2012, using global geomagnetic data from the SuperMAG and INTERMAGNET planetary networks and the Scandinavian IMAGE profile. Supersubstorms develop on a global scale in longitude, from before midnight, through the night and morning, and into the day sector

Abstract A way of calculating the field of solar radiation in Earth’s atmosphere is described that considers the thermodynamic non-equilibrium in the vibrational bands of CO2 and O3. The proposed technique allows calculations with high spectral resolution (line by line), along with parameterizations of the optical parameters of the Earth’s upper atmosphere that can be used in calculating the field

Abstract A way of processing images to obtain information about ionospheric–magnetospheric plasma is described. Data from regular observations of auroras are used. Examples are given of triangulation using data from pairs of cameras with low (several kilometers) spatial diversity to determine the energy of precipitated electrons and numerically estimate the complexity of the spatial–temporal auroral

Abstract An analysis is performed of the effect geomagnetic pulsations with frequencies of several millihertz (the Pi3/Pc5 range) have on the magnitude of geomagnetically induced currents (GICs) in the Severnyi Tranzit Electric Power Transmission Line (EPL) located at auroral latitudes. It is shown the characteristics of GICs depend not only on the amplitude of geomagnetic pulsations, but on their

Abstract Processes of the excitation and quenching of electronically excited state \({{{\text{A}}}^{{\text{3}}}}\Sigma _{{\text{u}}}^{ + }\) of molecular oxygen in the Earth’s atmosphere at the altitudes of nightglow are considered. The calculated integrated intensities of Herzberg I bands are compared to experimental data obtained from space shuttle Discovery (STS-53). It is shown that the best agreement

Abstract Results are presented from analyzing simultaneous observations of very low frequency bursts of the auroral hiss at separated places: Barentsburg (Spitsbergen Archipelago), Lovozero (Kola Peninsula, Russia), and Kannuslehto (Finland). The observations are compared to results from modeling the propagation of the auroral hiss from the region of generation to the ground and in Earth–ionosphere

Abstract Experimental data are presented on the effect geomagnetically induced currents have on a power transformer. An analytical solution is obtained for current harmonics via nonlinear inductance under dc bias. It is shown that the nonmonotonic dependence of the harmonic amplitude on the dc value is determined by the nonlinearity of the weber–ampere characteristic of inductor.

Abstract The correlation between the parameters of electromagnetic ion cyclotron waves in Earth’s magnetosphere and the parameters of trapped and precipitating ring current ions is analyzed using the example of a single event. It is shown that the observed energies and the degree of isotropy of proton fluxes at low altitudes correspond to the results from calculating the coefficient of pitch-angle

Abstract The nonlinear dynamics of positrons in modified theories is considered in light of new hypotheses regarding the mass of charged particles and the mass of the graviton. Laws of the vertical movement of positrons in a constant magnetic field, a Barnhill–Schiff electric field, and the Earth’s gravitational field are obtained on the basis of calculations. Experiments are proposed to test these

Abstract Neutral excitations in a two-dimensional electron system with an orbital and spin quantum number of 1 in the vicinity of filling factor v = 3/2 are studied experimentally. It is found that the rate of excitation relaxation to the ground state slows very strongly at v = 3/2, even though the number of vacancies in the ground state suitable for the relaxation of excitations is macroscopically

Abstracts A new experimental technique is proposed for studying bulk states under conditions of the fractional quantum Hall effect.

Abstract A study is performed of the relationship between the number (width) of channels of unphased coherent generation and the spectral separation between these channels within the line of amplification for a powerful laser diode with wide contacts. The reasons for this separation are discussed in connection with the transformation of parameters in the active medium in proportion to the operation

Abstract An algorithm is developed that allows automatic calculation of the number of gas bubbles seeping from a point source. The algorithm is based on an analysis of recorded acoustic signals generated by the bubbles. The algorithm is tested under field and laboratory conditions. It can be used to calculate gas flows during long-term sessions of monitoring natural methane seeps.

Abstract A spin-depolarized electron system with filling factor ν = 1 in a GaAs quantum well is investigated according to time-resolved Kerr rotation. A transition from a new spin-correlated state to one with the low spin stiffness characteristic of a single-particle electron system is observed at temperatures above 5 K. A nonlinear contribution to the Larmor oscillations decay is distinguished at

Abstract Two fundamentally different non-contact techniques are used to observe electronic paramagnetic resonance (EPR) in a two-dimensional system based on the ZnO/MgZnO heterotransition. Spin resonance is detected in the first geometry for the transmission signal in a broadband coplanar waveguide applied to the surface of a sample. In the second, EPR manifests in a change of the power of a radio

Abstract Characteristics of intermittent behavior are investigated at the interface between generalized synchronization in unidirectional dissipatively coupled systems with complex attractor topology. An example of Lorentz systems and Chua generators is used to show the distributions of both the duration of laminar phases and the average duration of laminar phases depend exponentially on the super

Abstract The possibility and conditions of recording and reading out two-quantum transient holograms on the exciton levels of CdSe/CdS/ZnS-type semiconductor quantum dots are studied theoretically.

Abstract Measurements are made of the spectra and degrees of circular polarization of radiation from single InAs quantum dots embedded in a planar GaAs waveguide of a semiconductor nanostructure, and an electrically pumped semiconductor laser based on an AlAs/AlGaAs microcavity with GaAs quantum wells in the active region. The upper layers of the microcavity are a square lattice of a photonic crystal

Abstract The thermodynamic stability of quantum Hall ferromagnets with filling factors ν = 1 and ν = 2 is studied via inelastic light scattering in strongly interacting two-dimensional electronic systems based on ZnO. For a ferromagnet with ν = 2, it is found that the Curie temperature is determined by the Coulomb energy of the formation of domain walls. For a ferromagnet with ν = 1, the thermodynamic

Abstract A study is preformed of the relationship between the spectrum of low-energy collective excitations in two-dimensional Fermi liquids and the paramagnet/ferromagnet phase transition in the quantum Hall state with filling factor v = 2. It is shown theoretically and experimentally that the softening of the energy of collective spin–flip excitations accompanies the spontaneous switching of the

Abstract An investigation is performed of the relaxation of plasma excitations in two-dimensional electron systems (2D-ESes) in GaAs/AlGaAs heterostructures. The effect radiational and incoherent collisional relaxation mechanisms have on the linewidth of cyclotron magnetoplasma resonance (CR) is studied. CR arises as a pure resonance that does not hybridize with dimensional magnetoplasma excitations

Abstract Microwave absorption of partially gated two-dimensional electron systems in GaAs/AlGaAs heterostructures is studied, and a new family of proximity plasma excitations is discovered. It is established that these plasma excitations are associated with a metallic gate that partially screens two-dimensional electron system. Laws of dispersion are determined for strip and disk gates. Experimental

Abstract Possible mechanisms of the emergence of exciton and trion traps at room temperature and the dynamics of relaxation processes occurring in them are discussed, based on an analysis of the results from experiments on photon echoes in thin films of zinc oxide and doped silicon. The current–voltage characteristics recorded for such films with traps displaying the memristor effect are studied, and

Abstract An analysis is performed for experimental data on the rates of reactions describing ethane pyrolysis. A 1–25% level of accuracy is obtained, which greatly exceeds the world value. A critical analysis is also performed for existing theoretical models of the rates of chemical reactions.

Abstract The theory of interferometric processing of hydroacoustic information is generalized to when intense nonlinear internal waves result in coupling of the sound field modes. A theoretical explanation is given for experimental data on the forming of a hologram in the presence of intense nonlinear internal waves. The error in transmitting unperturbed information through a perturbed ocean environment

Abstract A means of express gas analysis is developed that meets all necessary requirements for determining the partial composition of natural gas and derivatives of gas mixtures using a portable Raman spectrometer with an excitation wavelength of 532 nm, rigidly coupled to a hollow crystalline light guide and equipped with a gas inlet system.

Abstract A way is proposed for measuring the rate of degradation of a high-power continuous-wave laser diode with a wide contact by monitoring the state of its heterostructure every 50 h of operation. The number and structure of the channels of laser generation is used as a controlled parameter. The mechanism of the laser diode structure’s degradation is considered in the time dependence of the number

Abstract Procedures are developed for the quantitative determination of proteins, recombinant thrombin, and hemagglutinin on the influenza A virus, based on the SERS effect observed on aggregates of silver nanoparticles modified with aptamers to thrombin and hemagglutinin, respectively.

Abstract The problem of a unipolar electromagnetic pulse being diffracted by an ideally conducting cylinder is considered using a computational experiment. It is shown that the scattered field is bipolar for the chosen polarization, with which the magnetic component of the field is parallel to the cylinder axis. The shape of its temporal profile depends on the ratio of the cylinder’s radius and the

Abstract A study is performed for the propagation of optical vortices in quadratic nonlinear media with linear and nonlinear absorption. When such beams propagate in media with a quadratic nonlinearity without absorption, their vortex structure is destroyed and they break up into several nonvortex quasi-solitons. Nonlinear absorption allows the beam to keep its structure longer.

Abstract The amplitude and phase characteristics of spatial spectra are determined for wave beams whose initial field is described by complex fractal functions. It is shown that the observed asymmetry of the spectra and their resistance to the influence of noise can be used to improve the optical diagnostics of fractal formations.

Abstract It is shown that the intensity of magneto-optical effects is enhanced by structures containing photonic crystal layers and an iron garnet ferromagnetic dielectric as they support the excitation of quasi-surface Tamm modes at the boundary between the two. Such structures have high Q-factor resonances and can enhance the transverse magneto-optical Kerr effect. Up to 100% magneto-optical modulation

Abstract The authors consider the generation of correlated multiphoton quantum states using periodically poled nonlinear crystals with quadratic nonlinearity. The spatial and polarization characteristics of the generated correlated beams are studied. Statistical quantum polarization Stokes operators and coefficients of intermode correlation are calculated.

Abstract Vertical velocity profiles are obtained experimentally for the boundary layer of a flow with an inverse pressure gradient in different phases of the periodic process of fluid deceleration. At the greatest drop in velocity, the profile has a local minimum with two inflection points at the upper boundary of the viscous layer. Chains of vortices then form at this location, testifying to a loss

Abstract Results are presented from a theoretical study on optimizing the parameters of an electron gun of a powerful multicavity extended interaction klystron at a frequency of 95 GHz, ensuring the formation of a dense annular electron beam and its transport through interaction region with a current transmission coefficient of 99%, with taking into account of the thermal spread of electron velocities

Abstract A new way of modeling the self-organization of two-dimensional dendrites with randomly formed growth centers is proposed. Dendritic structures with different symmetries are obtained. The set of new original algorithms and programs allows a generalized analysis of the structure of dendrites and their fractal features.

Abstract— A noninvasive procedure for ultrasound imaging is developed to study the structure of fish embryos and measuring the speed of sound in their tissues. Loach (Misgurnus fossilis) eggs growing in the immersion cell of a device are examined using an acoustic microscope with a central frequency of 50 MHz. The speed of sound in the yolk and cell layer (blastula) of the embryo is measured at developmental

Abstract A way of using recurrence analysis to determine individual differences is developed using EEG data from subjects performing series of movements. The procedure is based on analyzing repeated activities to determine channels with patterns or increased frequency. The results from applying the technique to experimental data are presented.

Abstract Characteristics of a reference optical frequency spectrum formed in a circuit with a continuous laser and an amplitude modulator with a high modulation index are investigated via numerical modeling. The possibility of forming microwave oscillations of a desired frequency is demonstrated, and the generation of a broadband microwave oscillation at the modulation of two or more lines selected

Abstract Metal–dielectric–metal structures are considered promising candidates for efficient rectifying elements in terahertz band. A numerical model of such a structure is discussed in the basis of finite elements in a nonequilibrium Green function formalism.

Abstract An analytical model of the diffraction of quasi-monochromatic light beams on spatially inhomogeneous multilayer diffraction structures formed in a photopolymer material by holographic means is presented. This model allows for inhomogeneities in the amplitude profile of the first harmonic of the refractive index of each layer of the multilayer structure.

Abstract A theory is presented for a hybrid of a photocathode with a Travelling Wave Tube (TWT) and an amplifier with complex permittivity. A linear theory of an amplifier with complex permittivity is used in the section with complex permittivity, and the linear theory of TWT is used in the TWT section. Defined motion and the given current are used to construct a nonlinear theory.

Abstract A model of a superlattice consisting of alternating single and double layers of graphene is studied. The energy spectrum of the superlattice can be controlled by an external electric field perpendicular to a sample’s surface. It is shown that the energy spectrum of such a structure can be approximated by the Kane model. The coefficient of interband absorption for such a superlattice is calculated

Abstract The excitation and propagation of plasmon–polariton modes are considered at a single interface of a dielectric medium and metal in linear and nonlinear regimes. Physical mechanisms of the emergence of a nonlinear response of free electrons in the metal based on the quantum hydrodynamic model are described. It is shown that the period and profile of the envelope of a cnoidal wave of surface

Abstract An acoustic field scattered by an object can be presented as a multipole series. The set of values of every coefficient in this series is limited for objects with cylindrical symmetry when there are no internal sources of energy. Relations are presented for the phases and amplitudes of these coefficients, and between the powers of the absorbed and scattered fields.

Abstract A three-dimensional problem is considered for electromagnetic diffraction on a bound ideally conducting body containing a conical point. An asymptotic representation of the electromagnetic field is calculated in the vicinity of the conical point with the solution presented as the sum of singular and smooth parts.

Abstract An investigation is made of reducing the contrast in photosensitivity caused by photocurrents between inhomogeneities along n+ and p+ layers in a uniformly illuminated n+−p(n)−p+ silicon structure. Measurements and calculations are performed using a model that consists of two silicon solar cells with different photosensitivities and joined by a resistor. Agreement is achieved between measurements

Abstract Optical properties of dense plasma depend on electric fields inside it (the so-called microfield). A critical survey is made of existing theoretical models of plasma microfields. The most important models are verified using experiments in which dense plasma was created by powerful laser radiation. It is shown that the Quasi-Independent Particle model (QUIP) provides the best theoretical verification