Fourier lived and worked in an era when, in the studies on mathematical analysis, the first, heroic period and began a long period of ordering, improvement and strict presentation initial ideas. During this period, new and wonderful ideas were formulated, but the spirit of the era defined The form and style of the presentation of those classical textbooks on mathematical analysis, according to which we now teach students. In the modern era, classical mathematics increasingly interacts with the mathematics of the computer age. This forces us to introduce new elements into seemingly well-established sections of mathematical analysis
Show AbstractIn this work were obtained estimated cross sections of photoneutron reactions on $^{124}$Sn based on the theoretical-experimental approach. Calculations of the used multiplicity transition fuctions were based on the calculations of combined model of photonucleon reactions and the TALYS program. The Influence of the parameters of selected models on the estimated cross sections of the photoneutron reactions was evaluated.
Show AbstractWe obtain the perturbative expression for the Green function of the massless scalar field in a curved background being the tensor product of (d − 2)-dimensional Minkowski space-time and two-dimensional conical space. For d > 4 such a spacetime is considered as the simplest model for higher-dimensional cosmic string with (d − 3) flat extra dimensions. To the lowest perturbativetheory order on the angle deficit, one computes the renormalized vacuum mean values of ⟨ϕ2(x)⟩ren and ⟨TMN(x)⟩ren, valid for arbitrary dimensionality d > 3 and curvature coupling ξ. The old results for the vacuum mean values, corresponding to the infinitely thin straight cosmic string in four dimensions, are revised.
Show AbstractThe paper describes a new numerical algorithm that allows to simulate tsunami wave in a uniform manner throughout the entire its propagation zone, starting from the initial surface perturbation over the deepwater zone up to the shoreline, including the flooding and drying of a coastal zone. The algorithm is based on the regularized shallow water equations in conjunction with the adaptive choice of the regularization parameter. As an example, the tsunami wave propagation near the coast of Japan in 2011 is shown.
Show AbstractA new method is considered for the separation of extensive air shower events according to the masses of primary particles on the basis of the directly measurable spatial-angular characteristics of Cherenkov light which is capable of distributing the showers between the three groups with small error probability in the framework of event-by-event approach in 1-100 PeV energy range. The results are described of the application of the method to the processing of the data of the optical part of the would-be detector setup of «Pamir-XXI» project. Quantitative indicators are given for the optimal and universal separation criteria, weak dependence of the latter on the night sky background and nuclear interaction model at super high energies and its superiority over the widely used Xmax parameter are demonstrated. The revealed characteristics of the method should be considered as the upper limits to approach to while constructing real detectors.
Show AbstractIt has been proposed a technique for selecting EAS from ultrahigh energy γ-rays against the background of protons with imaging Cherenkov telescopes. This technique has been developed within the framework of «Pamir- XXI» project but it may be useful for other mountain projects as well as for EAS method in general. The specific variant of optical detector configuration for EAS Cherenkov light measurement and the methods of processing of the data and attainable uncertainties of the selection of γ-rays against the background of protons. The EAS from protons and γ-quanta of energy E≥30ТeV are considered.
Show AbstractThe monitoring system of the electromagnetic calorimeter (ECAL) of the BM@N (Baryonic Matter at Nuclotron) spectrometer is presented. The system is based on a plastic scintillator with wavelength shifter Fibers. Detection of light is carried out by silicon photodetectors MPPC (Multi-Pixel Photon Counter), insensitive to the magnetic field. The efficiency of minimal ionizing particles registration is close to 100%. Work has been performed at the Veksler and Baldin Laboratory of Physics High Energies, Joint Institute for Nuclear Research.
Show AbstractInformation on the masses of atomic nuclei is becoming more accessible every year, both due to the increase in the number of open isotopes, and due to the refinement of the available data. Consequently, the phenomenological approach to the study of the properties of atomic nuclei through mass ratios is becoming more and more appropriate. Mass relations are considered and their relationship with the properties of the atomic nucleus is shown in this article. This approach can be effectively used for educational purposes due to its simplicity. A large number of mass relations, as well as a significant amount of the constantly updated base of atomic nuclei, require the automation of the calculation and visualization of mass characteristics in various nuclear chains. The MaRel program designed to solve this problem is described in this article.
Show AbstractDuring study of cosmogenic background sources in EXO-200 experiment we obtained a list of 1689 isotopes, produced by passing of cosmic muons. Here we describe a method that allowed to estimate which isotopes from the list don't have a significant impact on a low-background data from the detector. Using this method we excluded more than 98~\% from the list with reasonable consumption of computing resources. This method might be useful in other cases of study of processes of material activation.
Show AbstractQuantum-chemical ab initio Hartree-Fock method using the 6-31G+(d) basis was used to calculate the spatial and electronic structure of the PEG5 polyethylene glycol oligomer complex consisting of five repeating units with the KCl ion pair. A comparative analysis of the structural and energy changes that occur during the formation of the PEG5+KCl complex with the previously studied PEG5 complexes with potassium, sodium, chlorine and ionic NaCl pairs were carried out. The investigated models of the complexes were obtained as a result of preliminary modeling on the basis of calculations carried out by the molecular dynamics method. The calculation of the energy and geometric parameters of the complexes was carried out. The main structural rearrangements and changes in the electronic structures at the formation of all studied The calculation confirmed that the stabilization of such complexes is ensured by the formation of coordinating interactions of potassium or sodium cations with oxygen atoms, and the chlorine anion with the terminal hydrogen of the polyethylene glycol chain. The theoretical vibrational spectra of the PEG5+KCl complex was studied by the ab initio Hartree-Fock method using 6-31G + basis. Theoretical interpretation of the obtained theoretical vibrational spectrum in the distribution of potential energy in vibrational coordinates was carried out using the VEDA-4 program.
Show AbstractThe effect of prolonged illumination of CH3NH3PbI3 films on their conductivity and spectral dependences of photoconductivity is studied. A significant influence of ambient medium (vacuum, air) on the results of measurements is found. It is shown that prolonged illumination does not change the interband photoconductivity, but leads to a metastable increase in photoconductivity near 1.2 eV quantum energy. The obtained result indicates the photoinduced creation or filling of localized states located in the forbidden gap of CH3NH3PbI3 at an energy distance of 1.2 eV from the level of nonequilibrium carriers charge transfer.
Show AbstractIn this paper, the electrical and photoelectric properties of thin films of polyphenylquinoline containing the phenylamine bridging group and 2,1,3-benzothiadiazole moiety are studied. An analysis of the conductivity and photoconductivity temperature dependences indicates hopping mechanism of conductivity over localized states, which are separated from Fermi level by an energy 0.85-1.0 eV. The activation energy of the charge carriers mobility is 0.2 eV. From the analysis of the photoconductivity and the absorption coefficient spectral dependences, estimate of the optical width of the investigated material band gap was obtained equal to 1.8-1.9 eV, and an exponential behavior of the density distribution function of states within the band gap near the zones edges was determined. The analysis of the photoconductivity lux-ampere dependences indicates a bimolecular recombination of nonequilibrium charge carriers in the investigated material at room temperature.
Show AbstractAn approach to the quantitative assessment of the degree of chirality in the hierarchical structures of macromolecular systems is developed. Earlier, the authors revealed a phenomenological regularity: beginning with the level of the "left" asymmetric carbon in the amino acid residues of the primary structure of proteins, the chiral character of the L-D-L-D structural levels alternates: the "right" α-helices of the secondary structure forming a left supercoiling, the quaternary structure of microfilaments – the "right". The proposed approach makes it possible in general to quantify the sign and degree of chirality of the secondary protein structures. A sufficient condition for the method for determining the sign of the chirality of the secondary structure is the choice of the relative arrangement of α-carbons, which allows one or two orders to reduce the amount of information processed compared with the complete description of the system. As a result of the analysis of right and left spiral secondary structures, it is shown that the angle between the direction vector and the sum of vector products reveals the direction of twist of the spiral. Along with the right α-helices and the left polyproline helices, which, forming themselves, form the right super-spirals in the collagen, β-structures were analyzed. Data on the spatial structure are displayed on special "chirality maps", which demonstrate the existence of isolated regions of existence for different types of helicity. The method is implemented as a computer program in Python 3.6 using the SciPy library and can be applied to nucleic acids.
Show AbstractThe complexes of nanoparticles - promising photosensitizers that are used for diagnostics and photodynamic therapy of oncological diseases, were synthesized by the combination of inorganic nanostructures with polymerization of organic monomer method based on porphyrazines and phthalocyanines of aluminum, magnesium, zinc and polyvinylpyrrolidone as a polymer. As a result of the circulation of nanoparticles in the bloodstream, they passively accumulate in the tumor tissues due to the EPR effect. One of the key conditions for observing this effect is the particle size, which in most cases should not exceed 200 nm. The dynamic light scattering method was used to determine for the first time the values of the hydrodynamic radii of biocompatible micellar forms and the most stable complexes of these nanoparticles were established. The tendency to increase the size of the photosensitizer with an increase in the relative concentration of the polymer is revealed, which makes it possible to form a well-established technology for the synthesis of nanoparticles of the required size, to implement targeted delivery to tumor tissues using the "passive targeting" method.
Show AbstractA method for estimation of extensive air shower (EAS) primary particle parameters with the help of particle detectors of high mountain setups was developed. The results were obtained in the framework of “Pamir-XXI” project. A configuration of charged particle detector network was proposed capable of evaluating the primary particle energy and direction in the energy range 1-10 PeV in the best way. A new method of EAS event separation by primary particle mass on the basis of muon angular distribution is described. A muon tracker of area 400 m2 is to be used for this purpose. The obtained accuracy estimates should be considered as the upper limits of real experimental accuracy.
Show AbstractThe paper presents results of studying total electron content (TEC) variations during the intense tropical cyclones occurred in late August-early October 2016 in the North-Western Pacific Ocean. An increase in the intensity of TEC variations within internal gravity waves periods is observed at stations located near the cyclone region. The most significant growth in the amplitude is registered for small- and medium-scale variations (2-50 min) mainly at the daytime. The intensity of variations with longer periods (up to 4 hours) changes only in the morning and evening local time hours, during the passage of the solar terminator. We assume the interaction of ionospheric disturbances generated by tropical cyclones and solar terminator passage. A possible mechanism for the interaction is briefly discussed
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