Modified method of round Gaussian rings. Application to the two-planetary problem
Modified method of round Gaussian rings. Application to the two-planetary problem
B. P. Kondratyev$^{1,2,3}$, V. S. Kornoukhov$^1$, E. V. Basova$^2$
A scheme of the extended method of round Gaussian rings, designed to study the secular evolution of orbits in systems consisting of a central star and two planets, is presented. The reason for the secular evolution of the nodes and inclinations of the orbits of the planets is their mutual gravitational attraction. The orbits of the planets are modeled by homogeneous round Gauss rings, onto which the masses, sizes and inclinations of the orbits, as well as the orbital angular momenta of the planets are transferred. The method takes into account the fact that, in the general case, the ascending nodes of the orbits may not coincide. The mutual gravitational energy of the rings is presented as a series in powers of small tilt angles including terms up to second order. With the help of this function, a closed system of 4 differential equations is compiled that describes the secular evolution of planetary orbits. The solution of the equations is obtained in the final analytical form, which greatly simplifies the interpretation of the studied motions. The method has been tested on the example of the Sun-Jupiter-Saturn system. For the first time, the new approach is used to study the exoplanetary system Kepler-36. Graphs are constructed for all unknown quantities. It has been established that in the course of evolution the mutual inclination angle of the orbits remains constant, and the librations of the orbits in the inclination angle and in the motion of the nodes occur synchronously.
Show AbstractMagnetic hysteresis of Sm$_{1-x}$Gd$_x$Co$_3$Cu$_2$ alloys
Magnetic hysteresis of Sm$_{1-x}$Gd$_x$Co$_3$Cu$_2$ alloys
V. E. Sevryukov, O. B. Degteva, A. Yu. Karpenkov, A. I. Ivanova, E. M. Semenova
In work the results of a comprehensive study of hysteresis parameters of Sm$_{1-x}$Gd$_x$Co$_3$Cu$_2$ (x=0.1–0.9) alloys, taking into account the real microstructure presents. It is shown that in the state as-cast, all alloys of this series are significantly heterogeneous and inclusions of up to three phase components contain. The use of high temperature annealing at 1050$^\circ$C for 4 hours the microstructure of the alloys changes. However, the single-phase state was achieved only for alloy samples with x = 0.1. The high-coercivity state of the samples arises due to the regular microstructure by the pinning mechanism. The maximum coercive force of the magnitude 0.94 T was obtained with the composition Sm$_{0.4}$Gd$_{0.6}$Co$_3$Cu$_2$.
Show AbstractSeparation of Quark and Gluon Jets in Heavy Ion Collisions at High Energies
Separation of Quark and Gluon Jets in Heavy Ion Collisions at High Energies
S. V. Obraztsov, O. L. Kodolova
The possibility of separation of quark and gluon jets in heavy ion collisions, both in the presence of the effect of quenching of jets and in its absence, was investigated. Using machine learning methods, a method for reconstruction of quark and gluon jet fractions has been developed using variables characterizing the shape, multiplicity, and charge of the jet. The possibility of using these variables to study the characteristics of a dense medium arising from the collision of high energy ions is shown
Show AbstractDispersive element of the compact spectrometer based on photonic crystal with modulated photonic band gap
Dispersive element of the compact spectrometer based on photonic crystal with modulated photonic band gap
N. I. Pyshkov$^1$, S. E. Svyakhovskiy$^2$
A compact dispersive element based on a photonic crystal with a modulated period has been experimentally demonstrated. The position of the photonic band gap of this crystal gradually shifts with depth towards long waves, so different spectral components are reflected from different depths of the structure. At inclined incidence, this provides a significant Goos-Henchen shift and its strong spectral dependence and contributes to the spatial separation of the spectral components.
Show AbstractMOLECULAR MODELING OF GLYPROLINE PRO-GLY AND ITS COMPLEXES
MOLECULAR MODELING OF GLYPROLINE PRO-GLY AND ITS COMPLEXES
L. I. Ismailova, G. A. Akverdieva, S. D. Demukhamedova, N. A. Akhmedov
In the present work, glyproline Pro-Gly and its biologically active complexes with heparin and with the antithrombin-heparin protein complex were studied using molecular modeling methods. This molecule is used as a drug, exhibits immunomodulatory, antiulcer, antidiabetic, antithrombotic and anticoagulant effects. Within the molecular mechanics framework its conformational profiles were studied, the geometry and energy of intra- and interresidual interactions were estimated for the most stable states of the studied dipeptide. A comparative analysis of the extended and folded structures of this molecule optimized by the DFT/B3LYP/6-31+G(d,p) method was carried out, the frontier molecular orbitals were calculated, the surface of the molecular electrostatic potential was studied, the effective charges on the atoms were determined, and the dipole moment and polarizability values were calculated. Subsequent molecular docking revealed that the folded structure of Pro-Gly glyproline showed a higher affinity value for both heparin and the antithrombin-heparin protein complex than the extended one. A model of the pharmacophore of the Pro-Gly molecule for its interaction with a specific receptor was proposed. The obtained data form the basis for the development of effective analogs of glyprolines in complex with heparin, which are more specific with respect to their putative target - antithrombin.
Show AbstractInfluence of the spatial dispersion in metal on the optical characteristics of the layered magnetoplasmonic nanoparticle cluster
Influence of the spatial dispersion in metal on the optical characteristics of the layered magnetoplasmonic nanoparticle cluster
Yu. A. Eremin$^1$, A. S. Penzar$^2$
In this paper, the diffraction problem of a plane electromagnetic wave on a cluster of two layered nanocylinders consisting of a magnetoplasmonic core and a golden shell is considered. The resulting influence of spatial dispersion in the golden shell is taken into account within the framework of the Generalized Nonlocal Optical Response theory. Based on the scheme of the discrete source method, the influence of the relative position of particles, their deformation and the effect of spatial dispersion on the behavior of the absorption cross section and the near-field gain is analyzed. It is shown that the position of the plasmon resonance can be shifted to the transparency of biological tissues due to variations in the distance between the particles and the core material. It has been established that account for the spatial dispersion in the golden shell leads to a decrease in the intensity and a slight shift in the position of the plasmon resonance in the short-wave region, without taking it beyond the tissue transparency region.
Show AbstractThe effects of underwater relief on the dynamics of the autumnal thermal bar
The effects of underwater relief on the dynamics of the autumnal thermal bar
B. O. Tsydenov
Results of numerical modeling of effects of underwater slope on the dynamics of the thermal bar circulations during the autumn cooling are presented. Cases of the bottom relief geometry corresponding to the configurations "gentle slope", "stepped profile", "trench" , and "steep slope" are considered. It was found that the flow structure, the time of formation, and the speed of propagation of the thermal bar significantly depend on morphological characteristics of lakebed topography in autumn.
Show AbstractOn the stability of the dislocation structure of speckle fields
On the stability of the dislocation structure of speckle fields
A. M. Zotov, P. V. Korolenko
The features of propagation in free space of light beams with a dislocation structure of the wave front are considered. The resistance to the influence of diffraction a of small-scale dislocation system providing spatial superresolution is analyzed. Based on a comparison of the characteristics of various types dislocation formations, a conclusion is made about the highest structural stability of systems with screw edge dislocations. Such dislocations can be obtained by azimuthal rotation of edge dislocations, which are characterized by a sharp jump in the phase along a singular line. The results obtained can be used to optimize the characteristics of optical devices with ultrahigh spatial resolution, as well as to develop software for the operation of spatial light modulators that form beams with a given amplitude-phase profile.
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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