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The global structure of astrospheres: Effect of Knudsen number
Publications of the Astronomical Society of Australia. 2024. Vol. 41. Article e074.
Корольков С. Д., Vladislav Izmodenov
The interaction between stellar winds and the partially ionized local interstellar medium (LISM) is quite common in astrophysics. However, the main difficulty in describing the neutral components lies in the fact that the mean free path of an interstellar atom, l, can be comparable to the characteristic size of an astrosphere, L (i.e. the Knudsen number, which is equal to l/L, is approximately equal to 1, as in the case of the heliosphere). In such cases, a single-fluid approximation becomes invalid, and a kinetic description must be used for the neutral component. In this study, we consider a general astrosphere and use a kinetic-gas dynamics model to investigate how the global structure of the astrosphere depends on the Knudsen number. We present numerical results covering an extremely wide range of Knudsen numbers (from 0.0001 to 100). Additionally, we explore the applicability of single-fluid approaches for modelling astrospheres of various sizes. We have excluded the influence of interstellar and stellar magnetic fields in our model to make parametric study of the kinetic effects feasible. The main conclusion of this work is that, for large astrospheres (with a distance to the bow shock greater than 600 AU) a heated rarefied plasma layer forms in the outer shock layer near the astropause. The formation of this layer is linked to localized heating of the plasma by atoms (specifically, ENAs) that undergo charge exchange again behind the astropause. This process significantly alters the flow structure in the outer shock layer and the location of the bow shock, and it cannot be described by a single-fluid model. Additionally, this paper discusses how atoms weaken the bow shocks at near-heliospheric conditions.
Melentiev P. N., Калмыков А. С., Гритченко А. С. et al., Успехи физических наук 2024 Т. 194 № 11 С. 1130–1145
Представлен краткий обзор достигнутого уровня оптических методов детектирования единичных молекул в биомедицинских приложениях. Показано, что регистрация флуоресценции единичных молекул красителей, ковалентно связанных с антителами (биомолекулами), совместно с использованием современных методов нанофотоники может быть применена для решения различных задач в биологии и медицине: визуализации биомолекул, токсинов, вирусных частиц, определения ультранизких концентраций аналитов напрямую во взятой пробе, ...
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Antsiferov P.S., Stepanov L.V., Matiukhin N. D., Review of Scientific Instruments 2025 Vol. 96 No. 12 Article 123506
The article presents the discharge plasma based source of extreme ultraviolet (EUV) radiation. The discharge circuit has been driven by means of stripe line storage with working voltage 10.5 kV. The main feature of the proposed source is that plasma electrons acquire the energy, necessary for the production of multiply charged ions with ionization potentials ...
Added: May 20, 2026
Анциферов П. С., Степанов Л. В., Матюхин Н. Д., Оптика и спектроскопия 2026 Т. 134 № 2 С. 214–218
Сообщено о разработке системы регистрации спектров на ПЗС-линейке для уникального ВУФ спектрометра, построенного на основе сферической дифракционной решетки с радиусом 6.65 m. Была использована линейка HAMAMATSU S11156-2048-02, которая устанавливалась по касательной к окружности Роуланда с возможностью механического перемещения для сканирования спектра. Были получены спектрограммы в диапазоне длин волн 2130-2270 Angstrem. Описана методика сшивки регистрируемых спектральных ...
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Shipilov F., Barnyakov A., Ivanov A. et al., / Series Physics "arxiv.org". 2026.
A fast simulation of the detector response is a vital task in high-energy physics (HEP). Traditional Monte-Carlo methods form the backbone of modern particle physics simulation software but are computationally expensive. We present a machine-learning-based approach to fast simulation of the Focusing Aerogel Ring Imaging Cherenkov (FARICH) detector response. Given a particle track and momentum, ...
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Malinovsky A. M., Пилипенко С. В., Mikhalchenko A. O. et al., Astronomy Reports 2026 Vol. 70 P. 1–6
Radiation from rotational transitions of CO molecules in distant galaxies creates a chaotic background with an intensity reaching 1000 Jy/sr at a wavelength of approximately 1 mm. This background will pose a serious problem, when measuring spectral distortions of the cosmic microwave background, in particular, the mu-distortion, which presumably has an intensity of less than ...
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Kaveev A. K., Fedorov V. V., Pavlov A. V. et al., Journal of Materials Chemistry C 2026 Vol. 14 No. 7 P. 2697–2705
Bismuth nanostructures represent a promising material platform for semiconductor nanooptoelectronics and colorimetry owing to the multi-colored light reflection and quantum confinement. In this work, we study the photoluminescent properties of bismuth nanostructures grown using molecular beam epitaxy on the planar CaF2/Si(111) surface. We demonstrate the different surface morphologies of Bi, ranging from planar films obtained ...
Added: May 19, 2026
Pavlova T., V.M. Shevlyuga (Шевлюга В. М., Applied Surface Science 2026 Vol. 736 P. 166813–166813
The objective of miniaturizing doped areas in silicon, with the ultimate goal of achieving atomic-precision doping, requires a fundamental understanding of the dopant incorporation process at the atomic level. We present a combined scanning tunneling microscopy (STM) and density functional theory (DFT) investigation of single phosphorus atom incorporation into the Si(100) surface. Phosphorus was supplied ...
Added: May 19, 2026
Pasternak D., Romshin A., Khmelnitsky Р. et al., Carbon 2026 Vol. 256 Article 121655
A single-photon source (SPS) is a key component required for quantum communication devices. We report the
discovery of bright diamond-based SPS created by nature. It is shown that narrow (≤2 nm) lines observed in the
500-800 nm range in photoluminescence (PL) spectra of the surface layer of untreated Yakut diamonds rich in
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A.M. Smirnov, Kurtina D. A., Saitov S. R. et al., Optical Materials: X 2026 Vol. 30 Article 100441
Chiral semiconductor nanostructures and nanoparticles are promising materials for applications in biological sensing, enantioselective separation, photonics, and spin-polarized devices. Here we performed a detailed analysis of optical properties of chiral CdSe nanoplatelets with thickness of 2 and 3 monolayers (ML) with Nacetyl-L-cysteine ligands. We studied the absorption spectra peculiarities, analyzed time-resolved photoluminescence and investigated circular ...
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Smirnov A., Mantsevich V. N., Saitov S. R. et al., Journal of Applied Physics 2026 Vol. 139 Article 185702
This work presents a comprehensive investigation into the temperature-dependent thermally stimulated conductivity and photoconductivity of vacuum-annealed thin films based on core–shell CdSe/CdS nanoplatelets passivated with oleic acid ligands. Controlled thermal annealing under vacuum conditions leads to a substantial increase in both dark and photoinduced conductivity, which is primarily attributed to partial desorption of the ligands. ...
Added: May 18, 2026
Масютин Д. А., Moiseev E., Komarov S. et al., Письма в Журнал технической физики 2026 Т. 52 № 7 С. 27–30
Исследованы инжекционные полупроводниковые микролазеры с кольцевым резонатором радиусом 15 мкм с несимметричным расположением внутреннего отверстия резонатора. Показано, что асимметрия обеспечивает формирование в диаграмме направленности двух лепестков излучения, разориентированных на 50° относительно оси смещения внутреннего отверстия. Измеренная добротность резонаторов сопоставима с добротностью дисковых резонаторов и находится на уровне ∼ 10^6. ...
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Rathish S., Andrey S. Vasenko, Thazhathenair A. et al., The Journal of Physical Chemistry Letters 2026 Vol. 17 No. 18 P. 5386–5394
We demonstrate and rationalize the effect of Au nanoparticles (NPs) on the hierarchical g-C3N4/CeO2 heterojunction. g-C3N4/CeO2 decorated with monodispersed plasmonic Au NPs was synthesized. Detailed analyses showed that CeO2 nanocubes and monodispersed Au NPs were evenly distributed over the 2D g-C3N4 surface, forming a robust interface enriched with abundant active sites. The structure enabled efficient separation of photogenerated charge ...
Added: May 16, 2026
Das A., Paul R., Sharma N. et al., Colloids and Surfaces A: Physicochemical and Engineering Aspects 2026 Vol. 728 P. 138830
Niobium-doped TiO2 (Nb-TiO2), demonstrates dual functionality as an efficient photocatalyst for dye degradation and a promising photoelectrocatalyst for water oxidation. Nb incorporation via a facile hydrothermal method was confirmed by XRD (Rietveld refinement), XPS, TEM, FT-IR, Raman, and BET analyses, indicating successful lattice doping and structural modification. Photocatalytic dye degradation experiments were conducted using a model ...
Added: May 16, 2026
I. V. Kolokolov, V. V. Lebedev, Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 2026 Vol. 113 No. 5 Article 054117
We theoretically investigate the correlation functions of the phase of a light wave propagating through a
turbulent medium. We use an equation for the logarithm of a wave packet envelope, which includes a secondorder
nonlinear term. Based on this equation, we develop a diagrammatic technique to calculate corrections
to the correlation function obtained in the linear approximation. We ...
Added: May 15, 2026
Гущина В. А., / Series chemrxiv-2023-vpzhz-v2 "ChemRxiv". 2023.
All-inorganic perovskite CsPbBr3 and Cs4PbBr6 nanoparticles are being intensively studied due to their unique properties and wide range of applications; however, however, the nature of their optical properties is not yet fully understood due to the difficulty of synthesis of singlephase nanoparticles. In this article we describe the features of the synthesis of single-phase particles ...
Added: May 14, 2026
Гущина В. А., Mendeleev Communications 2025 Vol. 35 No. 2 P. 193–195
All-inorganic perovskite CsPbBr3 and Cs4PbBr6 nanoparticles are intensively studied for their unique optical properties, though synthesizing single-phase nanoparticles has posed challenges. Detailed synthesis method of CsPbBr3 and Cs4PbBr6 single-phase nanoparticles and their chemical and phase analysis are described. Distinctive optical characteristics, such as photoluminescence, optical band gap and the Urbach tail region, are revealed and explained within the current ...
Added: May 14, 2026
Гущина В. А., Physics of Complex System 2026 Vol. 7 No. 1 P. 3–15
Heterostructures based on ZnO nanorods and CsPbBr3 nanocrystals were investigated for their potential as semiconductor SERS substrates. We found that ZnO morphology governs the efficiency of interfacial energy transfer, leading to enhanced photoluminescence under 390 nm excitation and a noticeable reduction of the bandgap in the composites. Raman analysis revealed a pronounced intensity enhancement and ...
Added: May 14, 2026
Sergey D. Korolkov, Igor I. Baliukin, Opher M., Advances in Space Research 2026 Vol. 77 No. 6 P. 7443–7454
Global ideal magnetohydrodynamic models of the heliosphere typically predict a greatly exaggerated magnetic field pile-up in the inner heliosheath (IHS), the region between the termination shock and heliopause. However, Voyager 1 and 2 observations show only a gradual increase throughout this region. This mismatch is largely attributed to the simplified assumption of a unipolar solar ...
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Li H., Yang Z., Wang C. et al., Journal of Deep Space of Exploration 2025 Vol. 12 No. 5 P. 489–502
In this paper, the main scientific objectives, observational requirements, and expected scientific returns of boundary exploration missions in different directions, such as the heliospheric nose and tail, were briefly introduced; the current research status at home and abroad was reviewed, including ongoing and proposed missions and their scientific payload configurations; several major scientific questions related ...
Added: February 11, 2026
A. V. Titova, S. D. Korolkov, V. V. Izmodenov, Lobachevskii Journal of Mathematics 2025 Vol. 46 No. 9 P. 4526–4533
The stability of the heliopause, the tangential discontinuity separating the solar wind from the interstellar medium, is influenced by various processes, including the Kelvin–Helmholtz instability. This study investigates the role of charge exchange collisions between protons and hydrogen (H) atoms in reduction of the Kelvin–Helmholtz growth rate at the heliopause. Using a two-dimensional gasdynamic model ...
Added: January 12, 2026
Sergey Korolkov, Vladislav Izmodenov, Publications of the Astronomical Society of Australia 2025 Vol. 42 Article e123
Recently, there have been discussions about the shape of the heliopause. Some scientists question the classical form, which is close to a paraboloid. They suggest that the heliopause may have a two-jet collimated shape. While we disagree with this view of the heliopause shape, it seems likely that for stars with stronger stellar magnetic fields ...
Added: September 4, 2025
Baliukin I., Izmodenov V., Advances in Space Research 2025 Vol. 76 No. 3 P. 1917–1938
One of the most remarkable discoveries by the Interstellar Boundary Explorer (IBEX) is the ribbon – a narrow band of enhanced energetic neutral atom (ENA) fluxes observed in the sky. The prevailing explanation attributes the IBEX ribbon to the secondary ENA mechanism. In this process, “primary” hydrogen ENAs, produced via charge exchange between solar wind protons and interstellar hydrogen ...
Added: August 12, 2025
Viktor A. Frantsuzov, Artemyev A., Shi X. et al., Astrophysical Journal 2024 Vol. 963 No. 1 Article 16
The investigation of mechanisms responsible for the heating of cold solar wind electrons around the Earth’s bow shock is an important problem in heliospheric plasma physics because such heating is vitally required to run the shock drift acceleration at the bow shock. The prospective mechanism for electron heating is magnetic pumping, which considers electron adiabatic ...
Added: April 25, 2025
A.V. Titova, V.V. Izmodenov, S.D. Korolkov, Publications of the Astronomical Society of Australia 2025 Vol. 42 Article e045
Interstellar hydrogen atoms (H atoms) penetrate into the heliosphere through the region of the solar wind interaction with the interstellar plasma due to their large mean free path. Resonant charge exchange of H atoms with protons has been considered as the main interaction process between the components. In the majority of models, other processes like ...
Added: April 22, 2025