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Introduction. One of the diseases most frequently occurring in the representatives of the feline family (Felidae) is feline panleukopenia. Feline panleukopenia is a highly contagious disease of viral etiology with high (up to 90%) mortality. It affects representatives of the feline as well as the raccoon (Procyonidae) and the kunih (Mustelidae) families.Despite the preventive measures taken, the virus continues to circulate actively in the population of susceptible animals.The aim of the work is to analyse the epizootic situation and to review the domestic and foreign scientific publications.Materials and methods. The data obtained from the record books of a number of veterinary clinics of the cities of Ivanovo and Vladimir on the primary veterinary outpatient visits of sick animals within the period from 2020 to 2022 has become the subject of the research. Additionally, the brief description of feline panleukopenia and the epizootological data referring to the various cities of the Russian Federation available in the similar publications for the period from 2012 to 2022 is provided in the article. The data from the foreign sources on seasonal manifestation of the disease is also presented.Results. The analysis of the feline panleukopenia epizootic situation in the certain districts of the cities of Ivanovo and Vladimir has been carried out. The data on the panleukopenia permanently adverse situation in a number of the Russian Federation cities has been obtained, its share among other nosological units in cats reaches 3.6-27%. The data analysis results for the Russian cities located in the various federal districts, as well as for the cities of Ivanovo and Vladimir, has shown that the feline panleukopenia cases detection throughout the country is subject to seasonality, the peaks of cases detection fall on spring-autumn. It has also been confirmed that the main age group susceptible to panleukopenia includes kittens under the age of one year (3-6 months old). The need for more comprehensive understanding of the disease epizootic situation is pointed out as well as the need for phylogenetic studies of the new feline panleukopenia virus isolates which would enable carrying out the efficient preventive measures.Discussion and conclusions. Understanding the real epizootic situation in the Russian Federation regions and obtaining the new isolates of the feline panleukopenia virus for diagnostic, production and control purposes will make it possible to determine more efficient measures for combating this infection.

The search for fluorescent proteins with large two-photon absorption (TPA) cross-sections and improved brightness is required for their efficient use in bioimaging. Here, we explored the impact of a single-point mutation close to the anionic form of the GFP chromophore on its TPA activity. We considered the lowest-energy transition of EGFP and its modification EGFP T203I. We focused on a methodology for obtaining reliable TPA cross-sections for mutated proteins, based on conformational sampling using molecular dynamics simulations and a high-level XMCQDPT2-based QM/MM approach. We also studied the numerical convergence of the sum-over-states formalism and provide direct evidence for the applicability of the two-level model for calculating TPA cross-sections in EGFP. The calculated values were found to be very sensitive to changes in the permanent dipole moments between the ground and excited states and highly tunable by internal electric field of the protein environment. In the case of the GFP chromophore anion, even a single hydrogen bond was shown to be capable of drastically increasing the TPA cross-section. Such high tunability of the nonlinear photophysical properties of the chromophore anions can be used for the rational design of brighter fluorescent proteins for bioimaging using two-photon laser scanning microscopy.

Introduction. To assess SIRS and organ dysfunction in children with abdominal trauma using generally accepted scales is an actual issue for today. Purpose. To verify clinical criteria for SIRS and organ dysfunction in children with abdominal injuries in the perioperative period. Material and methods. 18 patients, aged 6 -12, with injury of their abdominal organs were treated at the Kusch Pediatric Surgery Clinic ( Republican Children’s Clinical Hospital) in Donetsk in 2014-2019. 11 (61.1%) patients with isolated blunt abdominal trauma and injuries of parenchymal organs were taken into Subgroup 1; 7 (38.9%) patients with open abdominal organ trauma and multiple injuries of internal organs - into Subgroup 2. Assessment of mechanical injury severity and prognosis were made using Pediatric Trauma Score (Tepas J.J., 1985) and Revised Trauma Score (Fitzmaurice L.S. 1997). Shock syndrome gradations were made by the FEAST criteria (Fluid Expansion as Supportive therapy) (2017). Results. Nosological configuration of the injury (closed or open, isolated or multiple) as well as the volume and character of surgical intervention were used for defining SIRS severity in children with abdominal injuries. In the perioperative period, parameters characterizing the degree of disorders of vital organs served as unified criteria of organ dysfunction in children with abdominal trauma. Conclusion. Before surgery, the most informative indexes were: tachypnea RR > 18.0 per min, SpO2/FiO2 < 264, HR > 130.0 beats per min, total leukocyte count > 13.5∙109/L or 50% FiO2 to maintain SpO2> 92%, SpO2 / FiO2

The light-driven sodium-pump rhodopsin KR2 exhibits ultrafast photoisomerization dynamics of its all-trans protonated Schiff-base retinal (PSBR). However, the excited-state decay of KR2 also shows slow picosecond time constants, which are attributed to nonreactive states. The mechanism that produces long-lived states is unclear. Here, by using molecular dynamics simulations and large-scale XMCQDPT2-based QM/MM modeling, we explore the origin of reactive and nonreactive states in KR2. By calculating the S0-S1 vibronic band shapes, we gain insight into the early-time excited-state dynamics of PSBR and show that the protein environment can significantly alter vibrational modes that are active upon photoexcitation, thus facilitating photoisomerization from all-trans to 13-cis PSBR. Importantly, we reveal structural heterogeneity of the retinal-binding pocket of KR2, characterized by three distinct conformations, and conclude that the formation of a strong hydrogen bond between the retinal Schiff base and its counterion is essential for the ultrafast reaction dynamics.

The control landing problem for an aircraft-type unmanned aerial vehicle (UAV) in the vertical plane is considered. In this paper we propose a discrete method of controlling a continuous object, called the method of optimized delta-transformations, which is based on the choice of the control parameters at each step of discretization, which allow minimizing the time duration of the transient process when deviating from the program trajectory, taking into account the restrictions imposed on the control signals. We also made a comparison with the classical method of control generation in the proportional-derivative control circuit. The goal of both methods is to compensate the deviation of the center of mass of the unmanned aerial vehicle from the program flight trajectory. Comparative results of the numerical simulation of the flight of an unmanned aerial vehicle at the landing stage with ideal and noisy measurements of the flight parameters are given.

Nanometer Ce0.8(Sm0.75Sr0.20Ba0.05)0.2O2 – δ powder with mean nanoparticle size of 15 nm has been obtained by laser evaporation of a solid-phase target followed by condensation. The nanopowder has been used to prepare suspensions for electrophoretic deposition in a mixed isopropanol : acetyl acetone = 50 : 50 vol % disperse medium offering the unique property of self-stabilization. Optimal conditions for electrophoretic deposition have been found, and uniform thin-film electrolytic coatings have been formed on a La2NiO4 cathodic carrier substrate (12–15% porosity). It has been shown that the resulting electrolyte offers a high adhesivity and has, after sintering at 1400°C, a compact granular structure with grains from 1 to 8 μm in size. The conductivity of the 2-μm-thick electrolyte equals 0.1 S/cm at 650°C.

Potentialities of the method of electrophoretic deposition of thin-film coatings based on micrometer powders of multidoped barium cerate BaCe0.8Sm0.19Cu0.01O3–δ (BCSCuO) and BaCe0.89Gd0.1Cu0.01O3–δ (BCGCuO) were considered. Micrometer powders of BCSCuO and BCGCuO were produced by the methods of solid-phase and citrate-nitrate syntheses, respectively. The dispersity, fraction composition, and electrokinetic potential of nonaqueous suspensions of these powders and the electrokinetic parameters of the electrophoretic deposition process were examined. An ultrasonic treatment and ultracentrifugation produced aggregatively stable suspensions of BCGCuO and BCSCuO micrometer particles in a mixed (70/30 vol %) isopropanol–acetyl acetone medium. These suspensions are characterized by high positive values of the zeta potential (+24 and +28 mV, respectively). Thin film coatings of the electrolyte materials BCSCuO and BCGCuO, which are of interest for the technology of medium-temperature solid-oxide fuel cells, were produced by the electrophoretic deposition onto a dense model cathode.

The assessment of land management practices according to their impact on soil water and solute balance is of great importance for crop yield potentials and sustainable development of the territory of Altai Krai (Russia). This contribution presents the results obtained from automatic weather stations, soil-hydrological measuring stations and a weighable gravitation lysimeter station established in the framework of the German—Russian KULUNDA project (2012–2016). It was shown that No-Till technology gradually formed soil conditions close to the natural background (steppe). For the first time, data regarding the amount of actual evapotranspiration (Eta) for the environmental conditions of the Kulunda dry steppe have been produced based on sophisticated lysimeter measurements.

The study of the water balance is not only of great practical importance, but also of interest from the standpoint of basic science for the researchers of the steppe zone, which has traditionally attracted people for its climate and soil resources. The article presents the results obtained from a network of automatic stations deployed in the framework of the Russian-German scientific cooperation in the field of climate, soil, and hydrological monitoring for 2012-2015. The instrumental data were obtained and the method of soil water balance calculation was performed on the basis of data of automatic weather station observations and lysimetric stations of new generation in the conditions of Western Siberia.

The study of the water balance is not only of great practical importance, but also of interest from the standpoint of basic science for the researchers of the steppe zone, which has traditionally attracted people for its climate and soil resources. The article presents the results obtained from a network of automatic stations deployed in the framework of the Russian-German scientific cooperation in the field of climate, soil, and hydrological monitoring for 2012-2015. The instrumental data were obtained and the method of soil water balance calculation was performed on the basis of data of automatic weather station observations and lysimetric stations of new generation in the conditions of Western Siberia.

A high-speed multichannel system for measuring the current density distribution of a completed pulsed corona discharge, which is based on a 32-bit microcontroller, was developed. The system allows the current-density distribution on a grounded electrode-collector to be determined for both negative and positive (back) coronas. The measurement results are transmitted to a personal computer, where they are processed and visualized. The device provides the possibility of measuring the current-density distribution for a single pulse and operating in the mode of storing the measurement results. The sampling time in one measurement channel does not exceed 1 μs, which allows measurements at a current-pulse repetition frequency of a few kilohertz with 64 operated channels. The number of measuring channels is multiple of 16 and limited by the type of the used microcontroller. When appropriate sensors are used, the system can be used to measure the current-density distribution of charged-particle beams with large cross-sectional areas.

The nature of absorption bandshapes of dibenzoylmethanatoboron difluoride (DBMBF2) dye substituted in ortho-, meta-, and para-positions of the phenyl ring is investigated using DFT and TDDFT with the range-separated hybrid CAM-B3LYP functional and the 6-311G(d,p) basis set. The solvent effects are taken into account within the polarized continuum model. The vibronic bandshape is simulated using a time-dependent linear coupling model with a vertical gradient approach through an original code. For flexible chromophores, the spectra of individual conformers are summed up with Boltzmann factors. It is shown that the long-wavelength absorption bandshape of DBMBF2 derivatives is determined by three factors: the relative statistical weights of conformers with different electronic absorption patterns, the relative position and intensity of the second low-energy electronic transition, and the vibronic structure of individual electronic peaks. The latter is governed by the relationship between the hard vibrational modes, which contribute to vibronic progression, and soft modes, which provide broadening of the peaks. The simulated spectra of the dyes in the study are generally consistent with the available experimental data and explain the observed spectral features.

Results from theoretical studies on the structureless luminescence spectra of Mn2+ impurity ions in matrices of calcite (CaCO3) and smithsonite (ZnCO3) are reported. The positions of the maxima and the width of the 4 T 1(4 G) → 6 A 1(6 S) emission bands of the indicated luminophors are calculated using a combined approach based on the periodic and cluster methods of quantum chemistry, and on well-known models of the vibrational broadening of electronic transition bands of impurity centers in crystals. The calculated parameters of the spectral bands are compared with the known experimental data and discussed in terms of the structural features of the investigated matrices and the contribution from lattice vibrations in the mechanism of broadening.

Existing high-accuracy aircraft navigation systems are based on inertial navigation systems integrated with aiding systems. An aiding system can be represented by an RGB color vision-based correlationextremal navigation system (CENS). The article describes the algorithm for consideration of air condition when making the color photos for reference images and the algorithm for synthesizing the reference images of one season using the color photos of the other season to be applied in color vision-based CENS.

Th is article presents th e results of crop yield in areas with different technologies of cultivation based on the network of automatic stations that provide data on climatic and soil-hydrological monitoring in the dry steppe during the vegetation period of May – September 2013 – 2016 . These data on regional ecological and climatic parameters are of great interest to the ecologists, plant physiologists, and farmers working in the Kulunda Plain (Altai Territory). We compared the following options for cropping technologies: the modern system, which is the "no-till", technology without autumn tillage; the intensive technology of deep autumn tillage by plough PG-3-5 at a depth of 22 – 24 cm. Cultivation of crops was carried out using the following scheme of crop rotation: the modern system: 1 – 2 – 3 – 4 (wheat – pea s – wheat – rape); the intensive system: 5/6 – 7/8 – 9/10 ( fallow – wheat – wheat). We believe that the use of modern technology in these conditions is better due to exchange between the different layers of soil. When the ordinary S oviet system , the so-called "plow sole" , was used , at a depth of 24 cm , we observed that this creates a water conductivity barrier that seems to preclude the possibility of lifting water from the lower horizons. Results of the study of infiltration of soil moisture at the depth of 30 and 60 cm have shown in some years the advantages of the modern technology over the ordinary S oviet system: in the version with the use of modern technology we can trace better exchange between the various horizons and , probably , moisture replenishment from the lower horizons. Differences in individual observation periods are comparatively large due to the redistribution of soil moisture, depending on the weather conditions, the crops used in the crop rotation s , and cultivation techniques. Moreover, the average moisture reserves within the one meter layer did not show any significant differences during the growing season s of 2013 – 2016 . In terms of soil moisture usage and produc tive grain yield according to the four year experiment, the application of the modern technology with crop rotation "wheat – rape – wheat – pea s " was more effective than the ordinary S oviet system with crop rotation "wheat – fallow – wheat – wheat". The four-year observation period is clearly insufficient to identify the advantages of the modern system, as during this time it is impossible to significantly improve soil quality indicators, which will continue to determine its water-retaining properties and moisture accumulation.

Рассмотрена оценка риска эмболизации венозного тромба при флеботромбозе и выявлены факторы, приводящие к возникновению тромбоэмболии легочной артерии (ТЭЛА). В качестве материала для построения статистической модели использованы результаты общедоступных клинических исследований. С помощью метода доверительных интервалов Неймана выполнен поиск статистически значимых различий выборок пациентов с четырьмя различными диагнозами. Выявленные статистически значимые отличия были использованы в дальнейших исследованиях в качестве априорной информации при формировании профилей опасности наличия ТЭЛА. Дальнейшие исследования выполнялись с помощью дискриминантного анализа и позволили выявить комплекс факторов, обладающих максимальными дискриминирующими возможностями при определении ТЭЛА для разных категорий пациентов. Достоверность полученных результатов определялась путем решения выявленных систем линейных классификационных уравнений, с определением часто применяемых в медицинской статистике таких параметров, как чувствительность и специфичность, являющихся аналогами ошибок первого и второго рода.DOI 10.14258/izvasu(2016)1-33, In this paper, the risk assessment of venous thrombus embolization under phlebothrombosis and factors that lead to pulmonary embolism (PE) has been considered. The statistical model has been constructed using the results of non-specific clinical trials. The Neumann’s method of confidence intervals is utilized for selection of statistically significant differences among four data samples of patients with different diagnoses. Revealed statistically significant differences are used in further studies as a priori information for the development of PE risk profiles. Further studies are carried out using discriminant analysis. A complex of factors is revealed that has a maximum discriminating efficiency in PE determination for different categories of patients. The reliability of the results is evaluated by solving the identified systems of classification linear equations. Parameters commonly used in medical statistics, such as sensitivity and specificity, being the analogues of the first and second kind of errors are also evaluated.DOI 10.14258/izvasu(2016)1-33

A sequential, fully first-principle theoretical study of the Mn2+ green emission bands in the Zn2SiO4:Mn2+ phosphor is presented for the first time. A combined approach is developed based on the modern periodic density-functional theory and cluster ab initio wave-function-based electronic structure methods, the linear response theory for lattice phonons, and generating function formalism of vibronic spectra within the displaced multi-mode harmonic oscillator model. We obtain fairly good agreement between the calculated low- and high-temperature emission band positions, widths, zero-phonon lines and phonon wings and the available experimental emission studies, with special emphasis on Mn2+ distribution over two non-equivalent Zn2+ sites in the Zn2SiO4 material. An interpretation for vibronic structure observed in the low-temperature emission spectrum of this phosphor is suggested based on the present first-principle study.

The interaction of small analyte molecules (NH3, C2H5OH, and (CH3)2CO) in the gas phase with the 9-(diphenylamino)acridine dye adsorbed on an amorphous silica surface is studied by density functional theory (DFT) calculations using the cluster approach. Two cluster models for the silica surface are considered: a small SiH3OH model and an extended Si10O11(OH)18 one, constructed using classical molecular dynamics simulations. The electronic absorption spectra of the adsorbed dye are calculated within the time-dependent density functional theory (TDDFT) formalism and the effects of dye–analyte interactions are investigated. The spectral line broadening due to vibrations is estimated within the Pekar model. A computationally efficient procedure is proposed for the prediction of changes in the absorption spectra of organic dyes adsorbed on silica on their interaction with analytes. © 2012 Wiley Periodicals, Inc.

An ab initio approach is developed for calculation of low-lying excited states in Ln(3+) complexes with organic ligands. The energies of the ground and excited states are calculated using the XMCQDPT2/CASSCF approximation; the 4f electrons of the Ln(3+) ion are included in the core, and the effects of the core electrons are described by scalar quasirelativistic 4f-in-core pseudopotentials. The geometries of the complexes in the ground and triplet excited states are fully optimized at the CASSCF level, and the resulting excited states have been found to be localized on one of the ligands. The efficiency of ligand-to-lanthanide energy transfer is assessed based on the relative energies of the triplet excited states localized on the organic ligands with respect to the receiving and emitting levels of the Ln(3+) ion. It is shown that ligand relaxation in the excited state should be properly taken into account in order to adequately describe energy transfer in the complexes. It is demonstrated that the efficiency of antenna ligands for lanthanide complexes used as phosphorescent emitters in organic light-emitting devices can be reasonably predicted using the procedure suggested in this work. Hence, the best antenna ligands can be selected in silico based on theoretical calculations of ligand-localized excited energy levels.

Cluster ab initio quantum chemistry approach is developed to simulate the charge-transfer-to-solvent (CTTS) absorption band and satellite ligand field bands of hexaammineruthenium(II) ion in aqueous solution. Several cluster models, including 16, 21, and 38 water molecules, are explored for this purpose. TDDFT method with long-range corrected BLYP (LC-BLYP) functional is used to obtain the vertical transition characteristics, and DFT B3LYP is used for calculation of the ground state geometry and vibrational frequencies of the solvated complex. A simple harmonic bath model is employed to estimate the absorption bandwidths and coherence decay times with the parameters taken from the quantum chemistry calculations. The present approach provides rather reasonable estimates for the CTTS band position and shape, also giving an additional insight for the mechanism of the CTTS band broadening.

A multiscale method is proposed for modeling elements of optical chemosensors based on photonic crystals. The method is based on the first-principles quantum-chemical and electrodynamic calculations. A technique is proposed that takes into account electromagnetic emission sources in the framework of the finite-difference time-domain method. An end-to-end simulation of fluorescence in a photonic crystal is performed: the absorption and emission spectra of a dye on a substrate are calculated by quantum chemistry, and it is shown how the dye emission spectra are modified in a three-dimensional photonic crystal.

The extremely high scintillation efficiency of lutetium iodide doped by cerium is explained as a result of at least three factors controlling the energy transfer from the host matrix to activator. We propose and theoretically validate the possibility of a new channel of energy transfer to excitons and directly to cerium, namely the Auger process when Lu 4f hole relaxes to the valence band hole with simultaneous creation of additional exciton or excitation of cerium. This process should be efficient in LuI3, and inefficient in LuCl3. To justify this channel, we perform calculations of density of states using a periodic plane-wave density functional approach. The second factor is the increase of the efficiency of valence hole capture by cerium in the row LuCl3–LuBr3–LuI3. The third one is the increase of the efficiency of energy transfer from self-trapped excitons to cerium ions in the same row. The latter two factors are verified by cluster ab initio calculations. We estimate either the relaxation of these excitations and barriers for the diffusion of self-trapped holes (STH) and self-trapped exciton (STE). The performed estimations theoretically justify the high LuI3:Ce3+ scintillator yield.

The results of the theoretical investigation of Yb charge transfer luminescence (CTL) in sesqiuoxide matrices involving ab initio cluster calculations are presented in this paper. Different parameters such as Stokes shift, excitation and emission wavelengths, bandwidths and radiative lifetimes are derived from the calculations and compared with the results of the spectroscopic measurements. The best agreement between the calculated and the measured parameters is obtained for the case of the hole localized on a single oxygen ion in the Yb first coordination sphere.

Theoretical description of the charge-transfer state arising in Y 2 O 3 –Yb crystal after excitation is proposed on the basis of ab initio embedded cluster calculations. The best agreement with experimental data was obtained for a hole localized on a 2p orbitals of one of the oxygen ions surrounding the Yb 3+ ion. Parameters of the charge-transfer luminescence such as Stokes shift, maxima of the absorption and emission bands and radiative lifetime obtained from the ab initio calculations are in fair agreement with the experimental data.

The equilibrium geometries of the cylinder-like lithium hydrocarbon complexes Li[Cn]1 (n = 7–12) are calculated within Density Functional Theory(DFT) with PBE0 exchange-correlation potential. The 6-31 G* basis was set on carbon and lithium atoms while STO-3G one was chosen for hydrogens. The tendencies found for complexes with n = 7–12 gets broken and transforms to asymptotic behavior in range of n > 13. The large complexes possess the structure where lithium is placed at the carbon hexagon center area and close to C2v symmetry. Opposite, for n = 5–6 lithium is placed on the high symmetry axis of initial hydrocarbon. Several stationary points of complexes with n = 8–21, defined by lithium location under the hexagon center (1), under the CC bond center (2) and at the hydrocarbon skeleton center (3) were found. The migration barriers between stationary points (1)–(3) were estimated. The type (3) structures are distinctly higher of energy than (1) and (2), at that the difference is increased according to growing of n. The complexes with n < 13 are characterized by usual charge transfer from metal to hydrocarbon skeleton, for n ≥ 13 the molecular-like solution is occurred. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008

Ab initio quantum chemical strategies for quantitatively predicting the lowest (1Ag 1T1g) vertical d-d excitation energy of hexaammineruthenium(II) ion in aqueous solution are discussed. The scalar-relativistic ECP/valence basis set on Ru atom developed by the Stuttgart group in a combination with the state-average CASSCF(d) approach, followed by multiconfigurational quasi-degenerate second-order perturbation theory (MCQDPT2) to account for differential correlation effects is proved to be an adequate tool to reproduce the experimental absorption spectrum of the complex for a variety of AO basis sets on ligand atoms. In addition, different ab initio methodologies are examined in order to predict the ground state geometry which is consistent with the follow-up excitation spectrum calculations. It is observed that the use of the optimized structures of a hypothetical gas-phase complex lead to substantial underestimation of excitation energies. Solvent effects strongly influence the excitation energy though indirectly, mainly by means of changing the ground state geometry of the solvated complex when compared with the vacuum one. In particular, the ground state structure of the complex surrounded by effective fragments simulating water molecules provides the lowest CASSCF/MCQDPT excitation energy estimate to be within 25,500–26,400 cm−1, in a fair agreement with the experimentally measured value of 25,600 cm−1. At the same time, direct incorporation of solvation effects causes only minor change in the estimated transition energies, within several hundred cm−1. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008

Hydrogen atom in a cylindrical cavity is the simplest model for describing electronic states of the atom encapsulated into the nanotube. In the present work, simple analytical estimates for the electronic energy change under longitudinal and transversal shifts of the nucleus are made, using the first-order perturbation theory with the radius of the cavity as a perturbation parameter. Predicted signature of the electronic energy for the variety of atomic states agrees in essential details with the direct numerical estimations by finite difference and collocation procedures. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008

The electron accelerator URT-1М-300 for mobile installation was created for radiation disinfecting of clothes, footwear, documents and personal belongings from pathogenic microorganisms in field conditions to correct drawbacks that were found the URT-1M electron accelerator operation (the accelerating voltage up to 1 МV, repetition rate up to 300 pps, electron beam size 400х100mm, the pulse width about 100 ns).

Iteration method for transcendental equation solution and Leontovich boundary conditions are applied to research the effect of surface impedance on the electric waves in a circular waveguide. Calculation expressions and graphical results are obtained for the field distribution in a waveguide.

The dielectric model for an arctic soil both thawed and frozen has been developed. The model is based on the soil dielectric measurements carried out in the ranges of gravimetric moisture from 0.01 to 0.43 g/g, dry soil density from 1.25 to 1.83 g/cm3, and temperature from 25 to −30°C (cooling run), in the frequency range 0.05–15 GHz. To fit the results of measurements of the soil complex dielectric constant as a function of soil moisture and wave frequency, the refractive mixing dielectric model in conjunction with the Debye multi-relaxation equations were applied. As a result, the spectroscopic parameters of dielectric relaxations for the bound, transient bound, and unbound soil water components were derived, being further complimented with the thermodynamics parameters to ensure a complete set of parameters of the temperature dependent multi-relaxation spectroscopic dielectric model for moist soils proposed. To calculate complex dielectric constant of soil, the following input variables have to be assigned: 1) density of dry soil, 2) gravimetric moisture, 3) wave frequency, and 4) temperature. The error of the dielectric model was evaluated in terms of RMSE, yielding the values RMSE of 0.53 and 0.43 for the soil dielectric constant and loss factor, respectively. These values appeared to be in the order of the dielectric measurement error itself. The dielectric model suggested can be applied in the active and passive remote sensing techniques in microwave to develop algorithms for retrieving soil moisture and freeze/thaw state of the topsoil in the Arctic regions.

In this paper numerical solution of electromagnetic pulse scattering by dual layered dielectric structure has been considered. For calculation convenience propagation in two-dimensional rectangular area bounded perfectly conducting walls has been treated. Numerical algorithm has been developed using finite difference in time-domain with NVIDIA CUDA technology implementation. A finite difference method implementation for the case of computation by graphical processor has been considered. The results of numerical modeling Gaussian function pulse scattering has been shown. Comparative analysis of the CPU and GPU performance has been retrieved out. As shown, the FDTD method computation by graphical processor allows to achieve a sufficient gain of the performance.

Рассмотрено численное решение задачи распространения электромагнитного импульса в двумерной прямоугольной области, ограниченной идеально проводящими стенками, содержащей идеально проводящий объект произвольной формы. Вычислительный алгоритм реализован на основе метода конечных разностей во временной области с использованием программно-аппаратной технологии NVIDIA CUDA. Исследованы особенности реализации метода конечных разностей для расчетов на графическом процессоре, в частности рассмотрен способ организации хранения в видеопамяти массивов значений компонент поля в точках дискретизированного пространства. Представлены численные результаты моделирования рассеяния импульса с плоским фронтом в квадратной области, содержащей цилиндрический объект. Проведен сравнительный анализ производительности разработанного алгоритма при выполнении на центральном и графическом процессорах. Показано, что для данного алгоритма применение вычислений на графических процессорах обеспечивает существенный прирост производительности.DOI 10.14258/izvasu(2015)1.1-06, In this paper, a numerical solution of electromagnetic pulse propagation for the case of two-dimensional rectangular area bounded by perfectly conducting walls with included perfectly conducting various-shape object has been considered. A numerical algorithm has been developed using finite difference in time-domain with NVIDIA CUDA technology implementation. A finite difference method implementation for the case of computation by graphical processor has been considered. The results of numerical modeling of a plane wave pulse scattering in the square waveguide with included cylindrical object has been shown. Comparative analysis of the performance for CPU and GPU has been carried out. It is shown, that the FDTD method computation by graphical processor provides a sufficient gain in the performance.DOI 10.14258/izvasu(2015)1.1-06

In this study, the shape and material of the high-voltage electrode of an atmospheric pressure plasma generation system were optimised. The research was performed with the goal of achieving maximum uniformity of plasma treatment of the surface of the low-voltage electrode with a diameter of 100 mm. In order to generate low-temperature plasma with the volume of roughly 1 cubic decimetre, a pulsed volume discharge was used initiated with a corona discharge. The uniformity of the plasma in the region of the low-voltage electrode was assessed using a system for measuring the distribution of discharge current density. The system's low-voltage electrode - collector - was a disc of 100 mm in diameter, the conducting surface of which was divided into 64 radially located segments of equal surface area. The current at each segment was registered by a high-speed measuring system controlled by an ARM™-based 32-bit microcontroller. To facilitate the interpretation of results obtained, a computer program was developed to visualise the results. The program provides a 3D image of the current density distribution on the surface of the low-voltage electrode. Based on the results obtained an optimum shape for a high-voltage electrode was determined. Uniformity of the distribution of discharge current density in relation to distance between electrodes was studied. It was proven that the level of non-uniformity of current density distribution depends on the size of the gap between electrodes. Experiments indicated that it is advantageous to use graphite felt VGN-6 (Russian abbreviation) as the material of the high-voltage electrode's emitting surface.

Electronic states of the cylindrically confined hydrogen atom are studied numerically by the finite difference (FD) approach. Energies of the low-lying states of the system are estimated vs. the radius R and length Z of the cylinder, as well as the position of the nucleus at the axis. Under the isotropic stretch of the cylinder with the constant ratio R = Z/2, the energy level picture reminds us that in the spherically confined atom: the energies of all states regularly grow up when decreasing the size of the cavity, and the states with the same principal n, but higher values of the angular l quantum number correspond to lower energies almost everywhere. Anisotropic stretch of the cylinder from prolate to the oblate one with constant volume causes numerous level intersections and avoided crossings, with the levels ordered as 1σ, 2π, 3δ, 2σ,…, in the prolate limit case, and as 1σ, 2π, 2σ, 3δ, 3π, 3σ,…, in the oblate limit case. The results of numerical calculations are in excellent agreement with qualitative consideration of the one-electron system in the impenetrable cavity by using both variational and perturbative approaches. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006

Spatial confinement effects on the energy states of the beryllium atom and the electronic states of the beryllium dimer molecule are studied. Confinement effects are modeled by systems of point charges. Electronic structure calculations are carried out on the basis of the frozen core full configuration interaction method. Atomic states are treated within the even-tempered basis set 17s13p9d consisting of 110 primitive Gaussians. The valence and the Rydberg states of the spherically confined Be atom exhibit different behavior under the compression. Inversions of the atomic terms are discussed. The potential energy curves of the cylindrically confined Be2 molecule are calculated within the cc-pVTZ basis set. The employed cylindrical point charge environment model is shown to introduce significant end effects which are diminishing as the length of the cylinder increases. In very short tubes the above end effects may introduce additional changes into the molecular energy level picture. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004

Rovibronic states and transitions of one-electron atom in an impenetrable spherical cavity of radius R are studied. Independent estimations for the electronic wave functions and energies of the system are obtained on the basis of different numerical methods, and the follow-up solution of the nuclear motion problem is performed for cavities of different size (R from 2–8 a.u.). The corresponding transition probabilities are evaluated within the dipole approximation. A qualitative analysis of the structure of the energy spectrum, the transition frequencies, and intensities is presented. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004

The classical counterpart of the well-known quantum mechanical model of a spherically confined hydrogen atom is examined in terms of the Lenz vector, a dynamic variable featuring the conventional Kepler problem. It is shown that a conditional conservation law associated with the Lenz vector is true, in fair agreement with the corresponding quantum problem previously found to exhibit a hidden symmetry as well.

The splitting of a degenerate energy level under external perturbation is one of the oldest quantum-chemical problems. The changes in the energy level structure under the modifications of environment are of the fundamental importance for a large number of problems from the solid state theory to astronomy and high pressure chemistry and physics. The modeling of properties of simple nanoscale objects may be realized by accurate analysis of the simplest spherically symmetric one-electron system placed in an impenetrable cavity of a complex shape. We consider the numerical methods which may be used to solve the problem of confined one-electron atom in a cavity of a polyhedral type and qualitative constructions for the energy levels splitting. The classical polyhedral cavities are considered (cube, octahedron and tetrahedron) and some modifications of that ones by truncation or smoothing of some vertexes. In particular the continuous modifications of the cavity to the other ones are considered. To some extent this problem is similar to that one of the Crystal Field Theory, but the effects of the point charges and impenetrable boundaries are essentially different, just as the resulting levels splitting. Special attention is paid to the case of the cavities of large size, where a large number of qualitative conclusions may be done by analysis of the behavior of exact wave-functions for a free system in the neighborhood of the cavity boundary. In particular, the splitting in the case of large polyhedral cavities was considered analytically, and numerically. The compact forms of the proofs of the known and new theoretical statements are presented. The unsolved theoretical problems in the description of simple confined one-electron systems are described.

The problem of a hydrogen atom in an impenetrable spherical cavity of small radius R is considered on the basis of the first-order perturbational treatment of the electron-nucleus interaction taking explicit account of the boundary condition. An approximate analytic expression is derived for the electronic energy as a function of the shift of the nucleus off the centre. The estimations obtained are in good qualitative and semiquantitative agreement with the results of the finite-difference calculations. Some general features of the energy dependences are discussed qualitatively.

A general asymptotic estimate is derived for the molecular energy level shifts caused by the encapsulation of the system into a spherical impenetrable box of a large radius R. The value of the shift is proved to be exponentially small with respect to both R and Bi = 2(2Ii)1/2, where Ii is the lowest ionization potential in the ith state of the non-confined `free' system.

A general criterion for the degeneracy of states of the hydrogen atom placed in a spherical impenetrable box of radius R is formulated on the basis of the Lenz vector formalism. The reasons for the elimination of the Coulomb degeneracy typical of the conventional hydrogen atom problem and for the non-conservation of the Lenz vector are discussed. The explanation of the simultaneous degeneracy of some energy levels (e.g. 2s and 3d, 3s and 4d, etc. at R =2 au) is given.

The approach based on the multiplicative form of a trial wave function within the framework of the variational method, initially proposed by Kirkwood and Buckingham, is shown to be an effective analytical tool in the quantum mechanical study of atoms and molecules. As an example, the elementary proof is given to the fact that the ground state energy of a molecular system placed into the box with walls of finite height goes to the corresponding eigenvalue of the Dirichlet boundary value problem when the height of the walls is growing up to infinity.

In this paper the maximum reachable value of directivity of the surface wave along the impedance flange of antenna array are discussed. As shown by numerical experiment usage, single-directional surface wave can be achieved in very rare array characteristics combination. However, high surface wave directivity (over the 90% of surface wave power) can be achieved in many cases. It makes possible to construct surface wave antennas without any emerging parts over the surface.