Temperature changes in the mesopause region under climate changes in recent decades (1960−2024)
Temperature changes in the mesopause region under climate changes in recent decades (1960−2024)
I. I. Mokhov$^1$, V. I. Perminov$^2$, I. A. Fomina$^4$
The results of an analysis of temperature variations in the mesopause region based on long-term measurements of hydroxyl airglow at the Zvenigorod Scientific Station of the A.M. Obukhov Institute of Atmospheric Physics RAS (ZSS IAP RAS) in 1960–2024 in comparison with variations of surface temperature characterizing global-scale climate changes are presented. Along with temperature variations in the mesopause region, two versions of temperature variations in the mesopause region, normalized to the same level of solar activity, were analyzed. Quantitative estimates of a strong decrease of temperature in the mesopause region over the past decades in winter against the background of a global increase of surface temperature have been obtained. It was noted that significant coherence of long-term variations of the mesopause region temperature with the surface temperature in the Northern Hemisphere with the use of cross-wavelet analysis, which was not previously evident in data for a shorter time interval. The possibility of such coherence was predicted in (Mokhov et al., 2017) under the continuation of global warming based on the results of model simulations for the 20−21st centuries, taking into account anthropogenic forcing. It was not previously manifested from observational data for a shorter time interval. Along with long-term trends, features of a sharp decrease of temperature in the mesopause region for the 1970s with its synchronicity with the known shift in surface climate regimes associated with El Niño events were analyzed. The results of cross-wavelet analysis using data obtained at the ZSS IAP RAS for the time interval 1960−2024 indicate a more significant connection between temperature variations in the mesopause region and El Niño indices in recent decades.
Show Abstract{Features of the formation of β-carboxymethyl cyclodextrin complexes on the surface of lipid monolayers
{Features of the formation of β-carboxymethyl cyclodextrin complexes on the surface of lipid monolayers
I. V. Grigoryan$^1$, A. M. Adelyanov$^1$, G. B. Khomutov$^1$, A. P. Parkhaeva$^3$, E. Yu. Simonenko$^1$, A. G. Mironova$^5$, V. A. Pigareva$^2$, A. V. Sybachin$^2$
In this work, the interaction of β-carboxymethyl cyclodextrins (CMCD) with monomolecular layers of a mixture of electroneutral and cationic lipids on the surface of an aqueous subphase was studied.Monolayers were transferred to mica substrates using the Langmuir-Blodgett method and studied by atomic force microscopy. Analysis of monolayer compression isotherms and AFM images showed that CMC adsorption on the cationic Langmuir lipid monolayer is accompanied by the formation of supramolecular ensembles of similar morphology, regardless of the concentration of added oligosaccharides.
Show AbstractMolecular-dynamic simulation of structural transformations in the conducting channel of memristors based on nostichometric and ion-irradiated silicon oxides
Molecular-dynamic simulation of structural transformations in the conducting channel of memristors based on nostichometric and ion-irradiated silicon oxides
E. V. Okulich$^1$, V. I. Okulich$^2$, I. G. Kamilevich$^3$, D. I. Tetelbaum$^1$, A. N. Mikhaylov$^1$
The molecular dynamics method was used to simulate the processes of structural changes occurring over a time of about 100 ns in the region of the memristor filament formed in non-stoichiometric silicon oxides, including those subjected to ion implantation, during forming and/or switching. At the same time, the influence of the high temperature at which the filament region is located at certain stages of memristor operation was studied. It is shown that during the indicated periods of time, significant structural rearrangements occur, consisting in the formation and disintegration of various complexes, which is confirmed by calculations of radial distribution functions of distances between atoms in various combinations.
Show AbstractDynamics of Faraday rotation in hybrid magnetophotonic metasurfaces
Dynamics of Faraday rotation in hybrid magnetophotonic metasurfaces
A. M. Chernyak$^{1,2}$, A. I. Musorin$^{1,2}$, A. A. Fedyanin$^2$
The behavior of Faraday rotation on the femtosecond timescale in Mie-resonant magnetophotonic metasurfaces formed by a two-dimensional array of silicon nanodisks coated with a thin nickel film is studied. It is shown that in the static case the maximum of polarization plane rotation is 14◦ at the resonant wavelength for spectrally overlapped electric and magnetic dipole modes. When a single femtosecond laser pulse passes through the designed metasurface, it splits into two, the durations of which are half as long as the initial one, and the polarization planes are rotated in opposite directions, forming almost orthogonal replicas.
Show AbstractInfluence of annealing on magnetooptical properties of nanocrystalline films Fe$_{72.4}$Ti$_{5.4}$B$_{19.2}$O$_{3.0}$
Influence of annealing on magnetooptical properties of nanocrystalline films Fe$_{72.4}$Ti$_{5.4}$B$_{19.2}$O$_{3.0}$
N. N. Perova$^1$, E. A. Gan'shina$^1$, P. I. Mikhailovich$^1$, D. M. Gridin$^1$, E. V. Harin$^2$, V. A. Tejetov$^2$, E. N. Sheftel$^2$, A. B. Granovsky$^{1,3}$
The results of a study of the magnetic properties of Fe$_{72.4}$Ti$_{5.4}$B$_{19.2}$O$_{3.0}$ nanocrystalline films subjected to annealing in vacuum at 200°, 300° and 400°C are presented. Films with a mixed (nanocrystalline + amorphous) structure with a thickness of 0.52 μm were obtained by magnetron deposition on glass substrates. Hysteresis loops were measured on a vibrating magnetometer, field and spectral dependences of the transverse Kerr effect (TKE), and magnetization reversal processes were visualized on a magneto-optical Kerr magnetometer. It is shown that the processes of partial crystallization of the initially amorphous phase and the redistribution of Ti and B, respectively, within crystal grains and grain boundaries, resulting in the formation of new phases, which occur as a result of annealing, manifest themselves in a two-stage process of magnetization reversal and in modification of the TKE spectra.
Show AbstractVacuum polarization in the point impurity background
Vacuum polarization in the point impurity background
Yu. V. Grats, P. -. Spirin
We consider the vacuum polarization effect near the point delta-like source. The corresponding interaction is introduced within a technique of self-adjoint extension for the Laplace operator. Such a technique was widely discussed within Quantum Mechanics; we propose it for the investigation of vacuum field effects. It allows to compute the renormalized Hadamard function and the renormalized vacuum energy density for massive real scalar field with minimal curvature coupling. The dependence of the vacuum polarization effect upon the fields's mass is analyzed.
Show AbstractThe effect of dimensional quantization effects on the effective mass of the main charge carriers in LED heterostructures with InxGa1-xN/GaN multiple quantum wells
The effect of dimensional quantization effects on the effective mass of the main charge carriers in LED heterostructures with InxGa1-xN/GaN multiple quantum wells
E. R. Burmistrov$^1$, L. P. Avakyants$^2$
The zone diagrams of LED heterostructures with multiple quantum wells InxGa1-xN/GaN are calculated by numerically self-consistent solution of the system of Schrodinger equations and Poisson electroneutrality. The effect of the electron-phonon interaction, the nonparabolicity of the dispersion law and the hybridization of the wave function on the values of the effective mass of the main charge carriers in InxGa1-xN/GaN quantum wells has been studied. The redshift of 2D plasmon resonances is associated with the temperature renormalization of the effective mass of two-dimensional carriers. To describe the temperature dependence of the effective mass, the function of displacement of the 2D plasmon resonance frequency is used.
Show AbstractCross section evaluation of the exclusive K+Λ and K+Σ0 electroproduction channels off proton with CLAS detector
Cross section evaluation of the exclusive K+Λ and K+Σ0 electroproduction channels off proton with CLAS detector
A. V. Golda$^1$, A. A. Golubenko$^{1,2}$, M. M. Davydov$^1$, E. L. Isupov$^2$, V. I. Mokeev$^3$, S. A. Savkin$^1$, V. V. Chistyakova$^1$
We report the tool for evaluation of the cross section for K+Λ and K+Σ0 electroproduction channels off proton. Within the framework of this work, we interpolated and extrapolated the structure functions of the K+Λ and K+Σ0 electroproduction channels using various algorithms for predicting the behavior of the studied observables. A set of algorithms for estimating systematic errors in the differential cross section prediction result is implemented. The program has been developed for estimating the differential cross section and structural functions using the C++ and Python libraries. For interactive work with the program, a web site was developed that allows you to visually analyze one-dimensional and two-dimensional distributions of structural functions and differential cross section.
Show AbstractUsing gamma distribution to obtain Maxwell - Renyi statistics and other generalized distributions
Using gamma distribution to obtain Maxwell - Renyi statistics and other generalized distributions
D. V. Nakashidze$^1$, A. M. Savchenko$^1$, T. N. Bakiev$^2$
We propose a universal method for performing calculations within the framework of generalized statistics generated by the parametric Tsallis, Renyi, and Sharma–Mittal entropies. The essence of the approach lies in the use of an auxiliary gamma distribution whose parameters correspond to a particular variant of the statistics. Equations are derived that allow the generalised partition function and the mean energy to be expressed in terms of canonical quantities. The effectiveness of the proposed method is demonstrated using the example of Renyi statistics. The Maxwell - Renyi distribution is obtained and its properties are calculated, on the basis of which assumptions about the possible nature of the generalised parameter are formulated.
Show AbstractModification of the surface relief of additive materials under irradiation with Ar+ ions
Modification of the surface relief of additive materials under irradiation with Ar+ ions
D. S. Kireev$^1$, K. F. Minnebaev$^2$, V. A. Kiselevskiy$^3$, A. E. Ieshkin$^4$
Additive manufacturing (AM) is a modern, developing group of technologies based not on the removal of material, but on the layer-by-layer growth and synthesis of an object according to a CAD (Computer-Aided Design) model. The main disadvantages of objects manufactured using AM technologies are a high degree of porosity and surface roughness. This work examines the possibility of modifying the surface of additive materials Ti6Al4V and AlSi10Mg using irradiation with Ar+ ions with energies in the range from 2 to 9 keV. Using SEM, the surface topography was obtained before and after irradiation and mechanical polishing. A decrease in surface porosity and roughness, as well as the influence of beam energy on the final surface topography, was demonstrated.
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