How the Hubble flow in an anisotropic Universe looks like?
How the Hubble flow in an anisotropic Universe looks like?
A. V. Toporensky$^1$, I. V. Stepanyan$^2$, R. V. Ivanov$^3$
Using formulae for light propagation, redshift and photometric distance in a Bianchi I anisotropic Universe, we create a picture of the Hubble flow that could be observed by a hypothetical observer in the anisotropic Universe. The algorithm used can be applied (after some modification) for more complicated visualizations of a sky seen by an observer in strong gravitational fields.
Show AbstractMonitoring of methane bubble emission and hydrological parameters in Laspinskaya Bay (Crimea)
Monitoring of methane bubble emission and hydrological parameters in Laspinskaya Bay (Crimea)
A. A. Budnikov$^1$, I. N. Ivanova$^1$, A. I. Khurchak$^2$, T. V. Malakhova$^2$
This work is devoted to studies of the shallow methane seepages temporal variability in the coastal area of Laspi Bay and high-frequency monitoring of the hydrological parameters daily dynamics in this area. The paper presents results obtained during the summer months of 2016, 2018-2021, and early February 2023. Using the passive acoustic method, it is shown that the intensity and periodicity of bubble gas emission by individual point sources can vary during the day and from season to season. It was obtained that a decreased content of dissolved oxygen and its saturation is observed above the active site of the seepages as compared to the distant (background) site. Moments of sharp decrease in oxygen content not accompanied by changes in temperature and other hydrological parameters were noted.
Show AbstractEffect of fluorination on properties of thiophene-phenylene co-oligomers with annulated core: a DFT study
Effect of fluorination on properties of thiophene-phenylene co-oligomers with annulated core: a DFT study
S. N. Korchkova$^1$, A. Yu. Sosorev$^2$
Organic light-emitting transistors are a new type of optoelectronic devices that combine the functionality of OLED and a transistor that controls it. The working layer of these devices requires organic semiconductors that combine high charge mobility with a high photoluminescence quantum yield. One of the promising classes of such materials are thiophene-phenylene co-oligomers, the properties of which can be tuned over a wide range by adding various substituents. In this work, we address the effect of fluorination on the properties of two model thiophene-phenylene co-oligomers with an annulated central fragment, P-TTA-P and P-BTBT-P. It is shown that fluorination of both molecules lowers their frontier orbitals energy levels, and this should enable electron transport in their crystals and films. At the same time, fluorination has a qualitatively different effect on the delocalization of frontier orbitals, the width of the optical gap, the oscillator strength, the exciton binding energy, and the Raman spectrum, which is explained by the difference in the equilibrium geometry of fluorinated molecules. It is expected that the revealed relationships between the structure and properties of the studied compounds will contribute to the rational design of organic semiconductors for efficient light emitting devices.
Show AbstractDrift flow on the water surface with a film of hydrophobic particles in a uniform and decelerating air flow
Drift flow on the water surface with a film of hydrophobic particles in a uniform and decelerating air flow
I. N. Ivanova, O. N. Melnikova
The effect of a film of hydrophobic dust particles on the water surface on the development of a drift current under the influence of wind is studied. In a uniform air flow on a flat water surface, the drift current is caused by viscous forces and increases along the fetch. The formation of stationary waves on a drift current is found if the drift velocity is > 0.23 m/s. In a decelerating air flow in the presence of wind waves, the total component of the drift velocity cyclically increases and drops to a viscous component when a steep wind wave breaks up into longer linear waves. As the particle settling time Ts increases, the maximum ratio the wave part of the drift velocity to the total decreases from 0.6 for pure water to 0.3 for Ts = 4 days
Show AbstractOn one conjugate object in the symmetric tensor C*-category and the statistics of superselection sectors
On one conjugate object in the symmetric tensor C*-category and the statistics of superselection sectors
A. S. Sitdikov, A. S. Nikitin
In this work, a model of a symmetric tensor $C^*$-category with conjugation is constructed for the dimension of the object $d=3$. It is proved that the constructed conjugate object of the category satisfies the conjugation equations. The classes of morphisms between objects of the modeled category are considered and studied, and the algebra of observables in the presence of such an conjugate object is introduced. As an application of the model, we consider the theory of quantum information transfer, where it is necessary to take into account the constraints associated with the superselection rules.
Show AbstractPattern analysis of fractal-like systems
Pattern analysis of fractal-like systems
Yu. V. Ryzhikova, S. B. Ryzhikov$^2$
The features of the Fourier spectra of fractal-like systems are studied. On the basis of theoretical studies, the features of the scaling invariants of the objects under consideration in light fields are determined, which manifest themselves in the form of stable local formations - patterns. Particular attention is paid to the problem of stability of the ratios of the scaling characteristics of the analyzed systems and their Fourier transforms. The possibility of identifying and systematizing various fractal systems based on the estimation of their scaling parameters is considered. An analysis of the stability of the scaling parameters of the probing radiation to changes in the parameters of the systems under study indicates that the pattern approach to improving the methods of optical diagnostics is promising.
Show AbstractInfluence of dispersion on dynamics of the anti-Stokes broadening of the femtosecond pulse spectrum during filamentation in fused silica
Influence of dispersion on dynamics of the anti-Stokes broadening of the femtosecond pulse spectrum during filamentation in fused silica
I. Yu. Geints$^1$, E. D. Zaloznaya$^{1,2}$, A. E. Dormidonov$^2$, V. P. Kandidov$^1$
Numerical simulation methods are used to study the spectral transformation of a femtosecond wave packet during filamentation in fused silica under conditions of normal, zero, and anomalous group velocity dispersion. It is shown that during plasma generation that causes phase modulation of the light field, a rapid anti-Stokes broadening of the spectrum occurs. It was established that the short-wavelength shift of the broadband supercontinuum spectrum is much larger in case of anomalous group velocity dispersion than in case of normal and zero dispersion. The influence of the wave packet energy on the spectrum broadening dynamics is considered. Estimates of the numerical scheme parameters are obtained based on the dispersion analysis of the process of broadband supercontinuum propagation in a medium.
Show AbstractElectrophysical Properties of Methylammonium Alum Single Crystals: The Role of the Hydrogen Bond Network in the Formation of Temperature Anomalies
Electrophysical Properties of Methylammonium Alum Single Crystals: The Role of the Hydrogen Bond Network in the Formation of Temperature Anomalies
N. D. Gavrilova$^1$, I. A. Malyshkina$^1$, O. D. Novik$^2$
Pyroelectric, dielectric properties, and thermodepolarization currents of methylammonium alum crystallohydrate single crystals were studied in temperature range 120–200 K. Temperature dependences of these quantities demonstrated peaks at ~143, ~160, and 176.4 K (Curie point). The behavior, which is typical to many crystals with a network of hydrogen bonds with an O–H...O distance of ~2.7 ± 0.1 Å, is considered from the point of view of a quantum chemical model of a hydrogen bond network containing water clusters in addition to individual H2O molecules. The movement of bridging protons in molecular clusters in electric fields is coherent and correlated, and all bridging protons of the system are involved in it. These displacements are associated with oscillations of the oxygen frame of the compression-tension type. The discreteness of the temperature peaks of the electrophysical properties is associated with the discreteness of the energy levels of the double-well potential, caused by the splitting of the excited levels.
Show AbstractStudy of light element activation in human blood during 20 MeV linac operating
Study of light element activation in human blood during 20 MeV linac operating
M. V. Zheltonozhskaya$^1$, P. D. Remizov$^1$, M. V. Lenivkin$^1$, E. N. Lykova$^1$, A. P. Chernyaev$^1$, V. N. Yatsenko$^2$, O. V. Iatsenko$^2$
A series of experiments have been performed to study the activation of chemical macronutrients in human venous blood throughout radiation treatment with the 20 MeV linac. Some elements in the human blood can be activated as positron-emitting radionuclides by (γ, n)-reaction. We calculated the 11C, 13N, 15O, 30P, 34mCl, and 38K activities in irradiated human venous blood samples for the first time. As a result, we concluded that the main contribution to the internal dose from positron-emitting nuclides activated in human blood provides three nuclides: 15O, 34mCl, and 38K. The 34mCl and 38K contribution to the total dose can be comparable with 15O due to the high boundary energy of positrons, a longer half-life, and the presence of high-energy gamma quanta.
Show Abstract3D theoretical study of resonant charge exchange between H- ion and adsorbate-covered metal surface Cu(111)/Cu(110) with adsorbates Li+/Na+
3D theoretical study of resonant charge exchange between H- ion and adsorbate-covered metal surface Cu(111)/Cu(110) with adsorbates Li+/Na+
I. A. Melkozerova, I. K. Gainullin
The influence of the surface type on resonant charge exchange between H- ion with a metal surfaces Cu(111) and Cu(110) covered by adsorbate Li+/Na+ has been studied. A model static problem was considered. For modeling, a three-dimensional realization of the wave-packet propagation method was used. The Cu(110) and Cu(111) surfaces were described by a pseudopotential, derived from a density functional theory (DFT). An occupation of H- ion, an electron density dynamics and an ion level width were analyzed. As a result, we obtained that an electron oscillates more in case of the surface Cu(111). Furthermore, the resonant charge exchange is more efficient for Cu(111) surface.
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