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Preflare Fluctuations of Radio Emission from Active Regions of the Sun According to Observations at RSTN
Geomagnetism and Aeronomy. 2024. Vol. 64. No. 7. P. 1054–1058.
Abramov-Maximov V. E., Bakunina I. A.
For the first time, several flare events are analyzed based on multifrequency observations using the
Radio Solar Telescope Network. The purpose of the analysis is to identify signs of flare preparation. In all
considered cases, preflare quasi-periodic fluctuations (QPFs) of radio emission were detected. The duration of
preflare wavetrains is 6–20 min. Wavetrains consist of 3–5 pulses. QPFs at lower frequencies (200–600 MHz)
begin later than those at high frequencies by 2–6 min. QPFs at frequencies of 2695–8800 MHz occur almost
synchronously. The highest amplitude of QPFs is observed at a frequency of 4995 MHz. The observed QPFs
can be explained by the force-free magnetic rope model (Solov’ev and Kirichek, 2023).
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
Махлуф М., Ozhegov R., Elezov M. et al., Фотоника 2026 Vol. 20 No. 6 P. 414–423
This paper compares the ranging precision of direct time-of-flight (dToF) and non-line-of-sight (NLOS) LiDAR architectures, both using a superconducting nanowire single-photon detector (SNSPD). Both systems operate at 1550 nm with a 50 ps pulsed laser and time-correlated single-photon counting (TCSPC). The dToF configuration achieved approximately 100 µm precision at 10 m, while the NLOS configuration achieved 500 µm precision for ...
Added: October 12, 2026
Singapore: Springer, 2026.
This volume presents the Proceedings of the 34th IUPAP Conference on Computational Physics (CCP2023), held in Kobe, Japan on August 4–8, 2023. It offers a collection of peer-reviewed articles that highlight recent developments in computational and simulation research across various areas of physics. Key topics include the use of data science, quantum computing, and machine ...
Added: October 12, 2026
Goncharov A., Chibisov A., Advanced Theory and Simulations 2023 Vol. 12 No. 13 Article 2200816
Designing stable quantum computers with the ability to correct errors responsibly requires a detailed understanding of the physical processes that underlie these devices. In this study, detailed quantum mechanical simulations of the atomic structure, charge distribution of electron density, and distribution and orientation of magnetic and quantum states as a function of applied external pressure ...
Added: October 11, 2026
Chibisov A., Gnidenko A., Chibisova M. et al., FlatChem 2023 Vol. 41 Article 100533
Manufacturing precise quantum computers with small errors in quantum operations, long coherence times, and low power consumption is the most important challenge in modern nanoelectronics. To understand the operating modes of such calculators in detail, both the optimal arrangement of the qubit system within the structure and changes in its magnetic properties must be comprehensively ...
Added: October 11, 2026
Bakunina I. A., Мельников В. Ф., Шаин А. В. et al., Геомагнетизм и аэрономия 2025 Т. 65 № 9 С. 1363–1373
Рассмотрена связь особенностей положения и ориентации магнитных жгутов в активной области (АО) с источниками микроволнового (17 ГГц) излучения и излучения в крайнем ультрафиолетовом диапазоне (EUV) при возникновении эруптивных вспышек, сопровождающихся корональными выбросами массы, и вспышек с "запертой" эрупцией. Приведены примеры эруптивных событий, демонстрирующие пространственное совпадение микроволновых источников с расположением магнитных жгутов в АО, восстановленных при ...
Added: June 22, 2026
I. A. Bakunina, Melnikov V. F., Shain A. V. et al., Geomagnetism and Aeronomy 2024 Vol. 64 No. 8 P. 1237–1249
Using statistics from 15 X-ray class M flare events, the features of the position and orientation of magnetic flux ropes in the general spatial structure of the magnetic field of the active region (AR) during flares and coronal mass ejections (CME) were studied by reconstructing the coronal magnetic field from the photosphere to the corona ...
Added: February 17, 2025
Bakunina I. A., Мельников В. Ф., Шаин А. В. et al., В кн.: XXVIII всероссийская ежегодная конференция «Солнечная и солнечно-земная физика-2024», Труды.: СПб.: Главная (Пулковская) астрономическая обсерватория РАН, 2024. С. 25–28.
It is shown on a sample of 15 M-class X-ray flares that CMEs occur in events with «open» magnetic ropes reconstructed in the NLFFF approximation. Magnetic ropes coincide with radio brightness maxima at 17 GHz. Several hours before the flare, in the region of magnetic ropes, a glow of loops in the EUV (94, 131 ...
Added: December 1, 2024
СПб.: Главная (Пулковская) астрономическая обсерватория РАН, 2024.
Сборник содержит доклады, представленные на XXVIII Всероссийскую ежегодную конференцию по физике Солнца «Солнечная и солнечно-земная физика – 2024» (7 – 11 октября 2024, ГАО РАН, Санкт-Петербург). Конференция проводилась Главной (Пулковской) астрономической обсерваторией РАН при поддержке секции «Солнце» Научного совета по астрономии РАН и секции «Физика солнечной плазмы» Научного совета «Солнце-Земля». Тематика конференции включала в себя ...
Added: December 1, 2024
I. A. Bakunina, Melnikov V. F., Kuznetsov S. A. et al., Geomagnetism and Aeronomy, Netherlands 2023 Vol. 63 No. 8 P. 1154–1166
The dynamics of the magnetic field reconstructed in the nonlinear force-free approximation in the pre-flare and post-flare phases of M-class X-ray flares in seven active regions is considered: two flares with a coronal mass ejection (CME), two flares with eruption but no CMEs, and three flares without eruption. Extrapolation of the magnetic field to the ...
Added: February 3, 2024
Abramov-Maximov V. E., I. A. Bakunina, Geomagnetism and Aeronomy, Springer, Switzerland 2023 Vol. 63 No. 7 P. 916–919
We present a study of the frequency of occurrence of quasi-periodic fluctuations (QPFs) of microwave
radiation from solar active regions at the pre-flare stage. We used correlation curves obtained with the
Nobeyama Radioheliograph (NoRH). We analyzed 529 flares of classes X, M, and C (according to the GOES
classification). In a significant number of considered events (approximately 75% ...
Added: December 28, 2023
P.A.Bespalov, O.N.Savina, Geomagnetism and Aeronomy 2023 Vol. 63 No. 7 P. 910–915
According to modern concepts, Type I noise storms in the meter wavelength range (30–400 MHz), consisting of a large number of narrow-band short bursts, are excited in the rarefied solar corona. These radiations are characterized by a high brightness temperature and circular polarization. Despite many advances in theory and confidence that the mechanism of radiation ...
Added: December 22, 2023
Bakunina I. A., Мельников В. Ф., Шаин А. В. et al., В кн.: Труды XXVII Всероссийской ежегодной конференции по физике Солнца “Солнечная и солнечно-земная физика - 2023”, 9-13 октября 2023 года, Санкт-Петербург, ГАО РАН.: СПб.: ГАО РАН, 2023. С. 23–26.
It is shown that the positions of the flux ropes in the general spatial structure of the active region magnetic field reconstructed in the NLFFF approximation for flares with and without CME are different: magnetic flux ropes are located quasi-parallel to the overlying magnetic field lines in the events with CME, and quasi-perpendicular in the ...
Added: December 3, 2023
I. A. Bakunina, Melnikov V. F., Shain A. V. et al., Geomagnetism and Aeronomy 2022 Vol. 62 No. 8 P. 1066–1072
The dynamics of the preflare phase of microwave and ultraviolet emission for M-class X-ray flares in three active regions (ARs), two flares with coronal mass ejections (CMEs) and one flare without a CME, were considered. Extrapolation of the magnetic field in the AR corona showed that eruptive events were associated with the formation of a ...
Added: February 16, 2023
Abramov-Maximov V. E., I. A. Bakunina, Geomagnetism and Aeronomy 2022 Vol. 62 No. 7 P. 895–902
We present a study of the spatial distribution of quasi-periodic oscillations (QPOs) of microwave emission in three solar active regions before flares. The following events are considered: SOL2011-09-06T01:50M5.3, SOL2011-09-25T02:33M4.4, and SOL2012-07-08T04:19C6.6. Daily observations on the Nobeyama Radioheliograph at a frequency of 17 GHz are used. In all three cases, pre-flare trains of the QPOs of ...
Added: February 16, 2023