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Stochastic identities for random isotropic fields
Physical Review Fluids. 2025. Vol. 10. No. 2. Article L022602.
This Letter presents nontrivial stochastic identities for random isotropic second-rank tensor fields. They can be considered as markers of statistical isotropy in turbulent flows of any nature. The case of axial symmetry is also considered. We confirm the validity of the identities using different direct numerical simulations of turbulent flows.
Gordin V. A., Efremenko D., Boundary-Layer Meteorology 2026 Vol. 192 No. 51
An inverse problem of reconstructing the turbulent exchange tensor from large archives of observed wind profiles within the Åkerblom–Ekman (A-E) model framework is investigated using high-vertical-resolution radiosonde observations. The reconstructed tensor provides improved agreement between modeled and observed wind profiles compared to classical formulations based on real turbulent exchange coefficient. Instead of the classical A-E ...
Added: October 16, 2026
Kuznetsov A. P., Sedova Y. V., Stankevich N., Chaos, Solitons and Fractals 2026 Vol. 213 No. 12 Article 119309
We analyze the interaction of a quasi-periodic subsystem, in which two-, three-, and four- frequency quasi-periodic oscillations are possible, with a chaotic subsystem. A discrete version is obtained via the Euler scheme from the corresponding flow model. The dynamics of individual subsystems are discussed, including quasi-periodic bifurcations of invariant tori and the occur rence of ...
Added: October 16, 2026
Aleksei Samarin, Nazarenko A., Nazarenko D. et al., Machine Learning and Knowledge Extraction 2026 Vol. 8 No. 10 Article 330
Automated microscopic image analysis is essential for quantitative microbiology, yet manual acquisition and generic recognition models struggle with morphological variability and scene artifacts. We address both ends of this pipeline. First, we present a low-cost, open-source acquisition system, based on an Arduino UNO R3 microcontroller and NEMA 17 stepper motors, that automates focusing, magnification, and ...
Added: October 14, 2026
Parkhomenko V., Kulikova S., Buzmakov A. V., Lobachevskii Journal of Mathematics 2026 Vol. 47 No. 6 P. 2979–2992
The stability of formal concepts and its generalization as robustness are considered in the paper. We use an approximation of stability in the form of Δ-measure for fast calculations. A computationally efficient method for calculating robustness based on subcontexts is presented. We also present a new method to analytically evaluate the number of preimages for ...
Added: October 14, 2026
Kuznetsov A. P., Sedova Y. V., Sataev I. R. et al., Mathematics and Computers in Simulation 2027 Vol. 2 P. 574–592
Universal bifurcation structures on the parameter plane of nonlinear systems, known as shrimps, are discussed. An overview of numerous examples from various fields of science is given. Shrimps are typical for both maps of different dimensions and flows. The varieties of shrimp are discussed and relevant examples are given. The similarity property on the parameter ...
Added: October 14, 2026
Dmitriev A., Kornilov V., Batienkov R., Lecture Notes in Civil Engineering 2026 Vol. 886 P. 249–255
Numerous studies have provided compelling evidence that the probability distribution of avalanche sizes follows a power law, and that 1/f noise is present in the stochastic dynamics of landslides. We present a theoretical explanation of these phenomena within the framework of self-organized criticality theory, proposing a discrete-time model in the form of a sandpile cellular ...
Added: October 13, 2026
Dmitriev A., Shulman I., Lebedev A., Studies in Computational Intelligence 2026 Vol. 1265 P. 266–273
A discrete-time model is presented for the self-organization of the X/Twitter social network to the edge of a phase transition, characterized by avalanche-like propagation of information in the network. The model is based on the analogy between the critical dynamics of the X social network and sandpile cellular automata with Manna rule on the Chung-Lu ...
Added: October 13, 2026
Arutyunov K., Kharitonov I. A., Petrosyants K. O., JETP Letters 2026 Vol. 124 No. 6 P. 1–16
Superconducting properties of metallic micro- and nanowires can be entirely different from those of bulk superconductors. Of particular interest is the nonequilibrium current-induced state of a quasi-one-dimensional superconducting channel. The most interesting phenomenon here is the stepped I–V characteristic, explained by a process known as phase slip center activation. If the origin of such step-like ...
Added: October 13, 2026
Makarov D. M., Kalikin N., Fashchevsky K. A. et al., Electrochimica Acta 2026 Vol. 579 Article 150159
Machine learning (ML) has become a powerful tool for accelerating the development of carbon-based supercapacitors;
however, most published models assume that a single predictive framework can describe both conventional
porous carbons and hybrid carbon electrodes. Here, we test this assumption using a comprehensive
benchmark dataset and an extended literature-curated dataset enriched with synthesis- and electrolyte-related
descriptors. Three ML algorithms ...
Added: October 13, 2026
Leon L. Ogorodnikov, Sergey S. Vergeles, Physical Review Fluids 2025 Vol. 10 No. 12 Article 124702
We study the spatial dependence of pair correlation functions of velocity field com ponents in a rotating turbulent fluid on a background of a coherent geostrophic vortex. The statistics of the turbulent pulsations are determined by their dynamics, which is the dynamics of inertial waves affected by the differential rotation in the vortex and a ...
Added: February 24, 2026
Kabalina V., Мондрус О. В., Cheglakova L., Организационная психология 2026 Т. 16 № 2 С. 66–98
Purpose: To study the mechanisms of interaction between organizational resources and employee resilience in the formation of such outcomes as well-being and burnout.
Methodology: Cross-sectional data were collected through questionnaires from 915 employees of an industrial company following multiple waves of the COVID-19 pandemic in February-March 2022. Quantitative data were analyzed using partial least squares structural ...
Added: February 10, 2026
Nikolay A. Ivchenko, Vergeles S. S., Physics of Fluids 2025 Vol. 37 No. 12 Article 126605
Interaction of inertial waves with geostrophic flow in a rapidly rotating fluid system is studied. In accordance with the experimental conditions [Tumachev et al., “Two dynamical regimes of coherent columnar vortices in a rotating fluid,” JETP Lett. 118, 426 (2023) and Tumachev et al., “Observation of a large stable anticyclone in rotating turbulence,” Phys. Fluids 36, 126620 (2024)], this ...
Added: December 17, 2025
Гаман-Голутвина О.В., Сморгунов Л. В., Полис. Политические исследования 2023 № 1 С. 7–10
The object of consideration in the article is the sources of global turbulence and the understanding of this topic within the framework of modern political science. Among the sources of turbulence are the natural environment and its pulsations, which can destabilize social systems; anthropogenic impact on nature, climate and large ecosystems; unstable demography and powerful ...
Added: December 8, 2025
Gaman-Golutvina O. V., Сравнительная политика 2024 Т. 15 № 3 С. 4–18
The article contains the description of the world political context that influences the evolution of the military-political sphere. The articles of the presented issue are devoted to this analysis. As a methodological framework, it is proposed to use the information introduced into scientific circulation by J. Rosenau in 1990, the concept of turbulence in world ...
Added: December 8, 2025
Sergunin A. A., В кн.: Перспективы развития Арктической зоны Российской Федерации в условиях геополитической турбулентности на Севере Европы и в Арктике.: Петрозаводск: Петрозаводский государственный университет, 2024. С. 83–96.
В данном исследовании изучаются возможности международного арктического сотрудничества в условиях текущего кризиса в отношениях
между Россией и «коллективным» Западом. Вопреки некоторым существующим стереотипам и мрачным прогнозам, сотрудничество в сфере энергетики,
развития транспортных коридоров и инфраструктуры Российской Арктики
вполне возможно с дружественными РФ государствами. Диалог со всеми заинтересованными сторонами возможен в таких областях, как выработка адекватных климатической и экологической ...
Added: January 7, 2025
Петрозаводск: Петрозаводский государственный университет, 2024.
В сборнике «Перспективы развития Арктической зоны Российской Федерации в условиях геополитической турбулентности на Севере Европы
и в Арктике» опубликованы выступления, доклады, научные статьи участников Первого научно-практического межрегионального форума с международным участием «Арктика — наш общий дом», которые соответствуют тематике форума, его целям и ключевым темам: Арктическая Карелия;
Внерегиональные игроки в Арктике (БРИКС и другие страны-партнёры
России); Возможные сценарии ...
Added: January 7, 2025
Bogachev V. A., I. V. Kolokolov, V. V. Lebedev et al., JETP Letters 2024 Vol. 120 No. 8 P. 573–579
The diffraction of a light wave by fluctuations in the refractive index in a turbulent medium leads to its distortions. Their analysis allows one to extract the main parameters of turbulence. In this paper, we propose a
new method based on measurements of the correlation function of the gradients of the light wave phase,
which allows us ...
Added: December 7, 2024
Sirota V. A., Ilyin A., Kopyev A. V. et al., Physics of Fluids 2024 Vol. 36 No. 2 Article 021701
A set of exact integrals of motion is found for systems driven by homogenous isotropic stochastic flow. The integrals of motion describe the evolution of (hyper-)surfaces of different dimensions transported by the flow and can be expressed in terms of local surface densities. The expression for the integrals is universal: it represents general geometric properties ...
Added: February 17, 2024
Ivchenko N., Vergeles S. S., Журнал экспериментальной и теоретической физики 2023 Т. 163 № 5 С. 724–733
We study statistical properties of the passive scalar advection in a 2D flow that consist of a steady-state shear flow and a relatively weak smooth random component taking into account the effects of finite weak diffusion. The model is closely related to the dynamics of passive scalar transfer inside coherent vortices emerging as a result ...
Added: February 15, 2024
Kolokolov I., Lebedev V., Журнал экспериментальной и теоретической физики 2024 Т. 165 № 1 С. 128–140
We examine fluctuations of vorticity excited by an external random force in two-dimensional fluid in the presence of a strong external shear flow. The problem is motivated by the analysis of big coherent vortices appearing as a consequence of the inverse energy cascade in a finite box at large Reynolds numbers. We develop the perturbation ...
Added: January 29, 2024
Pavlov D., Galigerov V., Kolotinskii D. et al., International Journal of High Performance Computing Applications 2024 Vol. 38 No. 1 P. 34–49
Fluid dynamics is a ubiquitous problem that arises in different branches of science and industry. It is usually tackled by numerically solving differential equations on a finite grid. Molecular dynamics was not a feasible tool to approach fluid dynamics until very recently due to its disproportional computational complexity. In this paper we propose a new ...
Added: July 18, 2023
Parfenyev V., Mogilevskiy E., Falkovich G., Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 2023 Vol. 107 No. 5 Article 054114
We suggest a new computer-assisted approach to the development of turbulence theory. It allows one to impose lower and upper bounds on correlation functions using sum-of-squares polynomials. We demonstrate it on the minimal cascade model of two resonantly interacting modes when one is pumped and the other dissipates. We show how to present correlation functions ...
Added: May 16, 2023
Leon L. Ogorodnikov, Vergeles S. S., Physics of Fluids 2022 Vol. 34 No. 12 Article 125111
We consider analytically velocity pair structure function of turbulent pulsations on the background of a coherent geostrophic vortex in a fast rotating fluid. The statistics of the turbulent pulsations is determined by their dynamics that is the dynamics of inertial waves affected by the differential rotation in the vortex and weak viscous damping. Our consideration ...
Added: December 14, 2022
Il'in A. S., Копьев А., Сирота В. А. et al., Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 2022 Vol. 105 No. 5 Article 9
We consider finite-dimensional systems of linear stochastic differential equations ∂txk(t)=Akp(t)xp(t), A(t) being a stationary continuous statistically isotropic stochastic process with values in real d×d matrices. We suppose that the laws of A(t) satisfy the large-deviation principle. For these systems, we find exact expressions for the Lyapunov and generalized Lyapunov exponents and show that they are determined in a precise way only by ...
Added: May 20, 2022