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The formation of a set of filaments and plasma channels in a femtosecond optical vortex has been studied experimentally and numerically. A longitudinal distribution of color center tracks with a length of 1 cm written in a LiF crystal by an axially asymmetric beam in the single-pulse regime has been detected experimentally for the first time. It has been shown that, at a sufficient excess of the peak power over the critical value, two hot points on the annular profile of vortex beam separated by the phase dislocation region form sequences of color center tracks; each sequence in the cross section of the beam is localized near the initial hot point. Secondary filaments and the corresponding tracks appear with an increase in the pulse energy. The parameters of femtosecond filaments in LiF have been numerically estimated.

The aim of the study was to identify ethnic differences in the number of CAG repeats of the androgen receptor gene (AR), anthropometric and hormonal indicators in men of three ethnic groups (Slavs, Buryats and Yakuts) living in the Russa. The androgen receptor mediates the effects of androgens on a wide range of organs and tissues in men. The AR is characterized by polymorphism of CAG repeats, which can be an ethno-dependent trait and determine functional and morphogenetic effects of testosterone. The study established the ethnic differences in the length of CAG repeats between the Slavs, Buryats and Yakuts (23, 24, 25 triplets, respectively), as well as in anthropometric and hormonal indicators. LH concentrations were higher in Buryats than in Slavs or Yakuts, but the testosterone level was the lowest in Buryats compared to Slavs or Yakuts.

Abstract— A classical plane problem of the theory of elasticity about a crack in a stretched orthotropic elastic unbounded plane is considered, which leads to a singular solution for stresses in the vicinity of the crack edge. The relations of the generalized theory of elasticity, including a small scale parameter, are given. The equations of the generalized theory are of a higher order than the equations of the classical theory and allow eliminating the singularity of the classical solution. The scale parameter is determined experimentally. The results obtained determine the effect of the crack length on the bearing capacity of the plate and are compared with the experimental results for plates made of fiberglass and carbon fiber reinforced plastic.

A series of multiblock polyurethane-ureas (PUU) based on polycaprolactone diol (PCL) with a molecular mass of 530 or 2000 g/mol, as well as hard segments of different lengths and structures, were synthesized by the step-growth polymerization method. The chemical structure of the synthesized multiblock copolymers was confirmed by IR- and NMR-spectroscopy. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were used to determine the relaxation and phase transition temperatures for the entire series of the obtained PUU. The X-ray diffraction (XRD) method made it possible to identify PUU compositions in which the crystallizability of soft segments (SS) is manifested due to their sufficient length for self-organization and structuring. Visualization of the crystal structure and disordering of the stacking of SS with an increase in their molecular mobility during heating are shown using optical microscopy. The change in the size of the hard phase domains and the value of the interdomain distance depending on the PCL molecular mass, as well as the length and structure of the hard block in the synthesized PUU, were analyzed using small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS). The evolution of the domain structure upon passing through the melting and crystallization temperatures of PUU soft blocks was studied using SANS. The studies carried out made it possible to reveal the main correlations between the chemical structure of the synthesized PUU and their supramolecular organization as well as thermal and mechanical properties.

Bi4–xPrxTi3O12 (x = 0.4, 0.8, 1.2, 1.6) solid solutions have been prepared by solid-state reactions, via multistep firing of stoichiometric mixtures of their constituent oxides in air at temperatures from 1003 to 1323 K. Their crystal structure has been determined using X-ray diffraction, and their luminescence spectra have been measured at room temperature. High-temperature heat capacity of polycrystalline substituted bismuth titanate samples has been determined by differential scanning calorimetry. The Cp(T) curves of the solid solutions with x = 0.4 and 0.8 have extrema related to phase transitions. Experimental data have been used to calculate the main thermodynamic functions of the solid solutions.

Bi4–xNdxTi3O12 (x = 0.4, 0.8, 1.2, 1.6) bismuth neodymium titanate solid solutions have been prepared by solid-state reactions, via firing of mixtures of their constituent oxides in air at temperatures from 1003 to 1323 K. The crystal structure of the synthesized phases has been determined by X-ray diffraction. The results demonstrate that increasing the neodymium concentration leads to a morphotropic phase transition from the orthorhombic structure (sp. gr. B2cb) of the parent phase Bi4Ti3O12 (which persists at x = 0.4 and 0.8) to a tetragonal structure (sp. gr. P42/ncm) at x = 1.2 and 1.6. The heat capacity of the synthesized bismuth neodymium titanate samples has been determined by differential scanning calorimetry in the temperature range 320–1000 K. The Cp(T) curves of the Bi4 – xNdxTi3O12 samples with x = 0.4 and 0.8 have been shown to have extrema due to their ferroelectric phase transition.

In this paper the effect of parameters such as concentration of glycine, succinic acid and bath pH on the technological parameters of the electroless deposition of nickel-phosphorus alloy coatings (deposition rate, specific pH change during deposition), the composition of the coatings and their properties (microhardness after heat treatment) was studied. Experimental design of 23 central composite design (CCD) was used to evaluate the appearance of coating, rate, specific pH change, the chemical composition of alloys, and microhardness, as well as to optimize the electroless process of the alloy using Response Surface Methodology (RSM) associated with experimental design. The microhardness of the deposited coatings was 4.6 - 6.8 GPa and after heat treatment at 400 °C for 0.5 h increased to 9.7-11.6 GPa, which corresponds to hard chromium coatings obtained by electrodeposition from solutions of chromic acid. The Harrington desirability function was applied for optimization. The optimal composition of bath (in mol/l) and electroless conditions are proposed: NiSO4·6H2O – 0.12, NaH2PO2·H2O– 0.36, NH2CH2COOH – 0.30, (CH2)2(COOH)2 – 0.20, Pb(CH3COO)2 - 10-5; pH – 5.8. Temperature – 70 – 96 ºС. An acceptable rate deposition of 8 (70 ºС) and 34 (95 ºС) mg/(cm2∙h) was observed for an alloy obtained under optimal conditions from an solution of optimal composition. Under these conditions, the coating contained 6 wt.% of phosphorus. Therefore, the results of this work show the importance of using optimization techniques to obtain metallic coatings with controlled properties for different types of applications.

Electron-based dissociation (ExD) produces uncluttered mass spectra of intact proteins while preserving labile post-translational modifications. However, technical challenges have limited this option to only a few high-end mass spectrometers. We have developed an efficient ExD cell that can be retrofitted in less than an hour into current LC/Q-TOF instruments. Supporting software has been developed to acquire, process, and annotate peptide and protein ExD fragmentation spectra. In addition to producing complementary fragmentation, ExD spectra enable many isobaric leucine/isoleucine and isoaspartate/aspartate pairs to be distinguished by side-chain fragmentation. The ExD cell preserves phosphorylation and glycosylation modifications. It also fragments longer peptides more efficiently to reveal signaling cross-talk between multiple post-translational modifications on the same protein chain and cleaves disulfide bonds in cystine knotted proteins and intact antibodies. The ability of the ExD cell to combine collisional activation with electron fragmentation enables more complete sequence coverage by disrupting intramolecular electrostatic interactions that can hold fragments of large peptides and proteins together. These enhanced capabilities made possible by the ExD cell expand the size of peptides and proteins that can be analyzed as well as the analytical certainty of characterizing their post-translational modifications.

In the earlier developed method of direct cutting-out, we take into account the anisotropy of material. This method is based on the procedure of modeling of finite or bounded bodies with thin structural defects of any type and boundary conditions on its contour by an infinite space with the same inhomogeneities as in the original problem and additional thin inhomogeneities (cracks or absolutely rigid inclusions), which form the boundary of the investigated body. Thus, loaded cracks are used to model boundary conditions of the first kind, whereas absolutely rigid inclusions embedded in the matrix with certain tension model boundary conditions of the second kind. The developed approach is verified for several problems of longitudinal shear of an anisotropic half space, a layer, and a wedge in the presence of an internal crack under given boundary conditions of the first kind.

In the context of the life-extension program for the No. 3 unit of the Smolensk NPP, the life-exhausted RBMK-1000 control and protection system, the safety control systems of the power unit, and the analog-relay control apparatus of the technological equipment of the block control board (reactor and turbine departments) have been replaced with systems and software-hardware suites (SHS) developed by NIKIET. NIKIET has completed the full cycle of work from the structural development of the systems and SHS to implementation followed by follow-up support services. Based on experience in modernization of special RBMK CPS and SCS-T systems and the process control and protection systems of the technological equipment of reactor installations developed by NIKIET, a unique automated digital control system with a single multi-level and decentralized structure of a complex of technical means was created, which secures not only safe and reliable operation of the entire power unit but also the fulfillment of key requirements of the system. Currently, the fundamental solutions implemented in this system are used as standards for the development of automated monitoring and control systems for other facilities, specifically, reactor installations with fast reactors (BREST, MBIR).

The mesostructure of segmented poly(urethane imide) containing 4–10 wt % CoFe2O4 or Al3Fe5O12 nanoparticles was experimentally studied by small-angle polarized neutron scattering, which can analyze the nuclear and magnetic subsystems of the obtained composites. The transformation of the domain structure of the magnetic elastomers based on poly(urethane imide) was investigated at various concentrations, chemical compositions, and localizations of ferrite nanoparticles in polymer chains. The dynamics of the change in the segmental mobility of soft blocks during heating of samples was characterized by magnetic–nuclear interference scattering. The experiments detected changes in the supramolecular structure of the multiblock copolymer, which depended on the percentage and type of nanoparticles. The correlation radii were determined in the magnetic subsystem of ferrite nanoparticles embedded in hard aromatic blocks of poly(urethane imide) as nodes of intermolecular crosslinkers and chain extenders. The temperature dependence was analyzed for the intensity of small-angle nuclear scattering by poly(urethane imide) and magnetic elastomers based on it, under the conditions of the transition of soft aliphatic segments from the glassy to the highly elastic state.

The theory of the lag modeling approach to optimizing design capacity of an open pit gold mine by the criterion of maximized integrated economic performance over the mine life is given. The geology of Brekchia gold field in the Altai Krai is described, and the open pit mine design is shown. The optimization results on the open pit mine design capacity by the integral criterion of maximum economic indices using the lag modeling approach are given. The influence of the market prices of gold on the optimized design capacity of the open pit mine is analyzed.

A brief description of the very-short-range numerical weather prediction technology based on the WRF-ARW nonhydrostatic model is presented. Skill scores are provided for the short- and very-short-range forecasts of temperature, precipitation and wind of various intensity, which were calculated with this model as a result of its integration on the nested grid with a spacing of 3 km, with the direct simulation of deep convection and the assimilation of radar and ground-based weather station data. The forecasts for a location were verified for the central part of European Russia using radar and weather station data for the summer of 2020. It is demonstrated that the model adequately simulates mesoscale convective systems and the related zones of heavy precipitation, strong winds, and thunderstorms. Possible reasons for forecast biases and the ways to reduce the value of spatial and temporal errors are discussed. Keywords: numerical very-short-range forecasting, mesoscale meteorological model, radar data assimilation, precipitation, severe weather events, active convection

It is shown that the Snyder–Bergles model seems to be the best phenomenological one while describing the process of forced boiling of the liquid considerably subcooled relative to the saturation temperature. This model most likely (without contradictions) accounts for the main physical subprocesses that accompany subcooled liquid boiling (liquid microlayer evaporation below the bubble, vapor condensation at the bubble dome, liquid inflow to the microlayer), meets modern concepts on the boiling mechanism, and agrees with the experimental data. Based on experiments at the Joint Institute for High Temperatures, Russian Academy of Sciences (JIHT RAS) using high-speed video recording (at a rate of up to 100 thousand frames per second) and other studies, some subprocceses incorporated into the model are refined. They are as follows: deactivation of the nucleation sites, heat removal from the bubble dome via unsteady heat conduction, and the bubble size evolution in time as the balance of masses of the evaporated and condensed vapor. It is shown that the main mechanism through which heat from the bubble dome is transferred to the surrounding liquid is unsteady heat conduction, the intensity of which is inversely proportional to the square root of the bubble existence time. The evolution of bubble sizes is caused by the balance of masses of the evaporating liquid microlayer and steam condensing on the bubble dome. With high heat flux densities supplied to the heating surface and low liquid subcooling values, the imbalance shifts toward the evaporation side, as a result of which conditions may emerge for a growth of large bubbles and their subsequent merging and occurrence of large vapor agglomerates in the coolant flow.

Introduction. The selected research topic urgency is due to the need for a quick assessment of the condition and reliability of materials used in various designs. The work objective was to study parameters of the influence of the defect on the response of the surface of the medium to the shock effect. The solution to the inverse problem of restoring the radius of a defect is based on the combination of a computational approach and the use of artificial neural networks (ANN). The authors have developed a technique for restoring the parameters of a defect based on the computational modeling and ANN. Materials and Methods. The problem is solved in the flat setting through the finite element method (FEM). In this paper, we used the linear equations of the elasticity theory with allowance for energy dissipation. The finite element method implemented in the ANSYS package was used as a method for solving the boundary value problem. MATLAB complex was used as a simulation of the application process (ANN). Results. A finite element model of a layered structure has been developed in a flat formulation of the problem in the ANSYS package. The problem of determining unsteady vibrations under pulsed loading for different radius variations of the defect is solved. Positional scanning of the research object is applied. Graphical dependences of the vibration amplitudes of points on the surface on the defect radius are plotted. Discussion and Conclusions. As a result of studying the dependences of vibration responses on the defect radius, the authors have developed an approach to restore this parameter in a flat structure based on a combination of the FEM and ANN. The research has shown that the amount of data used is sufficient for successful training of the constructed ANN model and identification of a hidden defect in the structure.