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The features of the solvatochromic effects of absorption (Ab) and photoluminescence (PL) spectra, as well as the quantum yield of emission (QYE) of carbon nanoparticles (CNPs) synthesized by various methods from a mixture of citric acid and nitrogen-containing precursors, in protic and aprotic solvents have been studied. It has been shown that the parameters of the spectra Ab, PL and the QYE value of particle solutions to a large extent depend on the method, conditions and modes of synthesis, the method of modification and separation of CNPs, the types and composition of precursors, and also the fundamental properties and pH of solvents. In solvents with a dielectric constant of 4.5 – 109.5, the QYE value of particles varies in a wide range from 10.8 to 100.0 %, and the PL band peak shifts from 466.4 to 536.8 nm. The presence of strong solvatochromic effects in the spectra of Ab and PL particles was shown, and the important role of the processes of protonation and deprotonation of surface groups of CNPs was established. The influence of universal and specific interactions on the spectroscopic parameters of CNPs has been investigated, and a significant contribution to the solvatochromic effects of specific interactions has been demonstrated.

The effect of pH of the medium on the optical, luminescent, and emission parameters of various types of carbon nanoparticles (CNPs) in aqueous solutions is studied. It is shown that the parameters of the optical absorption and photoluminescence spectra, as well as the value and stability of the quantum yield of emission, significantly depend on the value of pH of the medium and the properties of the functional groups and carbon cores of the carbon nanoparticles. The main contribution to the change in the specified parameters of carbon nanoparticles is made by their functional groups. The strongest and most vivid change in the optical and luminescent parameters of all the types of carbon nanoparticles is observed in the ranges of pH of an aqueous solution of 10–13 and 0.1–3. The change in the parameters of carbon nanoparticles is closely related to the processes of protonation and deprotonation of the functional groups of the particles of the CNPs–COOH, CNPs–OH, and CNPs–NH2 types as well as to photostimulated processes. A growth and a decline in the absorption and emission, appearance and disappearance of absorption bands, change in the symmetry and width of the contours, and also the bathochromic and hypsochromic shifts of the absorption and photoluminescence bands are often observed in the absorption and photoluminescence spectra with the change in pH of the medium of carbon nanoparticles. It is shown that the mechanism of the effect of nitrogen and oxygen heteroatoms of the functional groups on the photoluminescence and quantum yield of emission is associated with the complex interactions of the electrons of the unshared pairs of the N and O atoms with the π-system of the aromatic rings of the carbon core of the nanoparticles.

The important features of the optical, luminescent, and emission properties of aqueous solutions of carbon nanoparticles (CNPs) of various types in the interaction of particles with electromagnetic radiation have been studied and analyzed. It is shown that the functional groups of CNPs play the dominant role in the spectra of optical absorption and photoluminescence (PL) of particles. Hydrothermal (HT) treatment of CNPs in the presence of ammonia and thermal treatment of particles in a solution of hydrogen peroxide have a strong influence on the absorption spectra, PL, and quantum yield (QY) of emission. It was found that the main PL bands of CNP samples are formed by superposition of several separate PL bands associated with electronic transitions of various types of radiative centers, and their excited states are located in the band gap of the carbon core of the particles. It was established that this circumstance is the reason for the dependence of the position of the PL band peak of most types of CNPs on the excitation wavelength. Linear dependences of the position of the PL band maximum and the emission QY magnitude on temperature and an exponential dependence on the time of HT treatment were revealed. The method of exposure to exciting radiation showed that the change in the PL intensity and the emission QY value under the influence of electromagnetic radiation is due to the photostimulated change in the surface recombination rate and diffuse particle processes in the region of excitation of CNP solutions. The possibility of investigating the stability of PL and QY by exposure of CNPs solutions to excitation radiation was demonstrated.

Methods are considered of generating signals in a radar sensor receiver provided with a colocated antenna system of Multiple Input Multiple Output (MIMO) configuration when synthesizing virtual antenna arrays. Review of the basic spectral methods used in beamforming with digital automobile radars, such as Capon method, MUSIC and ESPRIT was carried out. Spatial spectra obtained by various methods were constructed for a radar signal model, and comparative spectra characteristic by angular resolution is provided. Output heatmaps in the angle-distance coordinate were constructed to represent methods operation according to the real target situation based on data sampling from the front-mounted automobile radar. Advantages of decomposition methods based on MUSIC and ESPRIT algorithms in solving the problem of a signal emitter localization are presented

Luminescent carbon nanoparticles (CNPs) having a high mass yield of carbon material and emission quantum yield are synthesized from lentil grain flour via thermal carbonization, followed by treatment in nitric acid, and by the hydrothermal method. The luminescent and optical properties, solubility, and stability of solutions of various CNPs during interaction between particles and electromagnetic radiation are studied and analyzed by photoluminescence and optical absorption methods. When carbonization temperatures are 400 and 500°C, the mass yields of carbon materials are 34.6 and 29.7%, respectively. The amount of CNPs whose sizes are less than 50 nm is 7.2–12.5%, whereas the proportion of particles soluble in pure water is no more than 0.8% of the weight of a carbon material. New particles having a mass yield of 81–104% and high solubility of CNPs in water are formed as a result of special treatment of carbon material powders in HNO3. The solubility of CNP powders is strongly dependent on temperature and pH of a solvent; some samples achieve 30.3 g/L at 96.9°C. The energy of the direct band gap of CNPs is 3.325–3.445 eV, and the carbon nuclei of the particles contain structural defects and various surface groups of high concentration. Some absorption bands, including those at 271 (NH1) and 370 nm (NH2), appear in the optical absorption spectra after hydrothermal treatment of all CNPs in the presence of ammonia or urea. The structural features of the NH1 and NH2 bands, the photoluminescence spectra, and the magnitudes and the stability of quantum yields of different CNPs are thoroughly studied depending on temperature and duration of hydrothermal treatment. The maximum quantum yield of the best CNP samples during excitation with 406 nm laser radiation is 39.3%, which is a promising indicator for practical use.

The paper discusses methods for the direction of arrival estimation (DOA) in MIMO radar sensors with a small antenna array with colocated elements. An algorithm for processing a data array in the “channel-range-speed” coordinates is presented in the context of signal sources localization with the main digital beamforming methods, such as conventional beamforming (CBF), minimum variance distortion-less response (MVDR) or Capon method, multiple signal classification MUSIC and its modification. Their comparative analysis is given. The application of the methods in frequency-modulated continuous wave (FMCW) radar is shown and a technique for improving their characteristics is considered.

Theoretical research is performed on isolated nanoparticles (NPs) and NP-containing composite films with establishing analytically the concentration of nonequilibrium charge carriers and luminescence intensity as functions of surface recombination rate s, radius, diffusion length, lifetime of minority charge carriers, and other parameters. A hyperbolic dependence of the photoluminescence intensity (PL) on the parameter s is found. It is shown theoretically and experimentally that the photostimulated rise of s of NPs brings about quenching, while its decline favors amplification of PL. The microphotoluminescence PL intensity is established as a function of exciting laser exposure time for powdered carbon nanoparticles (CNPs), solutions of CNPs, and composite films based on PVOH polymers and CNPs with average particle diameters of 1.3 and 1.7 nm. Furthermore, the PL signal intensity of films processed at temperatures of 100–200°C decreases upon their exposure to a high-power-density 532-nm excitation radiation and rises in the case of films treated at 220–340°C. Almost always, the PL intensity of exposed dry CNP powders abruptly drops. The study allows putting forward a new method for contactless and rapid measurement of the parameters of luminescent NPs.

Studying the processes occurring in biological systems under irradiation is critically important for understanding the principles of working of biological systems. One of the main problems, which stimulate interest to the processes of photo-induced excitation and ionization of biomolecules, is the necessity of their identification by various mass spectrometry (MS) methods. While simple analysis of small molecules became a standard MS technique long time ago, recognition of large molecules, especially carbohydrates, is still a difficult problem, and requires sophisticated techniques and complicated computer analysis. Due to the large variety of substances in the samples, as far as the complexity of the processes occurring after excitation/ionization of the molecules, the recognition efficiency of MS technique in terms of carbohydrates is still not high enough. Additional theoretical and experimental analysis of ionization and dissociation processes in various kinds of polysaccharides, beginning from the simplest ones, is necessary. In our work, we extent previous theoretical and experimental studies of saccharides, and concentrate our attention to protonated glucose. In this article we paid the most attention to the cross-ring dissociation and water loss reactions due to their importance for identification of various isomers of hydrocarbon molecules (for example, distinguish α- and β-glucose).

The polymeric matrix prepared by the solution procedure from a 1: 1 blend of polyvinylidene fluoride and polyamidobenzimidazole and its composite filled with NTsTS-1 piezoelectric ceramic exhibiting high thermal and ferroelectric properties were studied by Fourier IR spectroscopy. In this matrix, polyvinylidene fluoride crystallizes with the formation of a polar β-phase, imparting enhanced ferroelectric properties to the material. Determination of the particle size distribution in the polymeric matrix by optical microscopy and IR spectroscopy gave consistent results.

Our previous data suggest that depression-like behavior of rats, which is induced by the 14-daylong unpredictable influence of stress factors, is accompanied by a sustained increase in the contents of L-arginine and nitric oxide (NO) and its stable metabolites, as well as stimulation of the inducible isoform of NO synthase (iNOS) and suppression of the activity of its constitutive NOS isoforms (cNOS) in the cytosol and mitochondria of the prefrontal cortex (PFC) and striatum. A single intraperitoneal injection of GABA lithium salt (at a dose of 0.9 mg/kg) on the second day of the post-stress period normalized the levels of L-arginine and active forms of nitrogen in cellular compartments from the PFC and striatum. Although this treatment did not influence the stress-induced shifts in the activity of cNOS, it prevented stimulation of the iNOS/NO system of mitochondria due to blockage of NO hyperproduction and nitrosative stress, whose development results in the disturbance of energetic processes in these brain areas.

The work is devoted to the study of the problems of management, the activities of international companies in solving urgent problems of risk assessment, international cooperation of companies in the development and use of software and the applications of the Business Intelligence class, Data Quality and Business Analytics, the role of SAS in the domestic market. The first part is devoted to the activities of international companies in the field of risk assessment. The second part is devoted to the review of analytical products of SAS. Keywords: audit, risk assessment, in-depth analytics, business intelligence

The changes in spike activity of single neurons of the compact part of the substantia nigra, evoked by nucleus caudatus stimulation under conditions of long-term registration of the single and multiple, isolated and combined actions of GABA, GABA-amide, glutamine, and ethanolamine-O-sulfate (EOS) were studied in albino rats. Inhibition of poststimulus activity under GABA action was recorded and the inhibitory effect of GABA-amide was revealed. Primary excitatory and subsequent inhibitory effects of glutamine in combination with EOS were shown. The subsequent administration of bacterial melanin, synthesized by a mutant culture of Bacillus thuringiensis (BT-M) evoked a clear-cut and prolonged excitatory reaction during all the combined actions of GABA, GABA-amide, glutamine, and EOS. Preliminary administration of BT-M abolished the inhibitory poststimulus effects of GABA, GABA-amide, and EOS, as well as glutamine-induced excitation.

In a situation when the level of risk increases every day, and regulatory requirements are becoming more stringent, to monitor illegal activities, it is necessary to use advanced analytical tools. Automation of the processes for risk assessment in the era of the digital economy is the key of success for any audit firm, as this will reduce labour and time costs and constantly improve its system for the risk detection of any kind and the submission of reliable information as a result of its activities. SAS offers the best-of-a-kind solution that includes high-performance analytics and combination of detection methods of irregularities, which help to monitor a larger number of risk factors, particularly analyzing large data volumes – in minutes instead of hours.

A preparative method of synthesis of 2-substituted thieno[2,3-d]pyrimidin-4-ones involving deamination of the corresponding 3-amino derivatives, by sodium nitrite in acidic medium is proposed. A possible reaction mechanism is considered.

Optical properties of various fullerene matrices based on C60 were studied by scanning microphotoluminescence in the range of 660–2300 nm. Variations observed in the photoluminescence spectra at room temperature after prolonged exposure to focused He−Ne laser irradiation directly after implantation of ions of rare-earth elements (Yb+ Nd+, or Er+) or after an isochronal thermal annealing of ion-implanted samples in the temperature range of 50–150°C are attributed to changes in the ratio of the generation and recombination rates of native lattice defects. Photoluminescence of fullerene matrices implanted with Yb+ ions has an intracenter origin at liquid-nitrogen temperature. A variation in the photoluminescence of fullerene matrices following dissolution of the samples in toluene and subsequent recrystallization indicates that Yb atoms are involved in the formation of fullerene-based endohedral or more intricate cluster complexes. The results obtained make it possible to identify a number of technological factors that are important for the production of new photoluminescent media, including those for laser operation.

The synthesis was carried out to obtain choline and thiocholine esters of N-protected and non-protected amino acids and peptides. As the N-protecting group the benzyloxycarbonyl group was applied, which was then removed by CH3COOH/HBr after the synthesis of β-amino esters. Choline and thiocholine esters are obtained by the interaction of the corresponding β- amino esters with iodic methyl. The pharmacological studies have indicated that choline esters of both N-protected amino acids and peptides, and non-protected derivatives possess slight radioprotective activity.

The synthesis of ethyl esters of 2-salicylidene derivatives of tyrosine, γ-amino butyric acid (GABA), and glycyl-glycine was carried out. These Schiff base ligands present themselves as pale-yellow crystals. These Schiff bases have been used to prepare Mn (II) complexes by allowing them to react with Mn (II) ion. Their possible structures were determined using several analytical and physical-chemical techniques. These Mn (II) complexes are obtained as gray crystals. Cytogenetic studies of bone marrow cells from whole-body 4.2 Gy (0.42 Gy/min dose rate) irradiated white inbred rats revealed that prior administration of 10mg/kg of the Mn chelate of the ethyl ester of the 2-salicylidene derivative of tyrosine was radioprotective. Compared to two control groups: (I) — animals exposed to irradiation only and (II) — animals treated with vehicle before irradiation, there was a 7-fold decrease in number of chromosome aberrations. Mn-chelates of 2-salicylidene GABA and glycyl-glycine were less radioprotective. The studies compounds have just as superoxide scavanging activity.

A preparative method of synthesis of 2-substituted thieno[2,3-d]pyrimidin-4-ones involving deamination of the corresponding 3-amino derivatives, by sodium nitrite in acidic medium is proposed. A possible reaction mechanism is considered.

Bistable luminescence was observed experimentally when a quantum-well gallium arsenide layer was excited with laser radiation. The bistability appeared at a specific concentration of titanium atoms, which were used to dope the quantum-well layer and the substrate. The luminescence bistability was not observed when the investigated samples were doped with chromium or vanadium.

The paper contains the results of the research of the mechanism of "shuttle" self-discharge determined by the manganese and titanium ions in the electrolyte of a PbO 2 |H 2 SO 4 |C heterogeneous electrochemical supercapacitor (HES). Research was made with respect to the effect of the shuttle self-discharge determined by the manganese and titanium ions on the energy, capacity parameters, and the charge and discharge voltage of HESs. Using the methods of the research of the energy, capacity parameters, self-discharge of the capacitors, and optical spectra of their electrolytes, it was established that, in the process of the shuttle, self-discharge of the capacitors with the electrolytes containing manganese and titanium, mostly MnO - 4 , Mn 2+ and Ti 3+ and TiO 2+ ions, respectively, is involved. It is shown that the shuttle self-discharge determined by the manganese ions brings about the self-discharge of an HES down to the minimal allowable voltage, and the titanium ions to the voltage of 1.62 V. It was established experimentally that the self-discharge current and the power of energy losses during the self-discharge related to the manganese ions in the electrolyte depend nonlinearly on the concentration of the manganese ions. When the concentrations of iron, titanium, and manganese are identical in the electrolyte of HES, the value of the capacitors' self-discharge decreases during the transition from the iron to the manganese. In the spectra of the optical density of HESs electrolyte containing manganese and titanium in the wave band of 200-1100 nm, absorption bands are discovered which are related to the ions of the manganese, titanium, and the level of the capacitors' state of charge. During the charge and discharge of an HES with the electrolyte which contains the titanium, Ti 2+ ions whose concentration is substantially lower than the concentration of Ti 3+ ions are also formed in the electrolyte.

This work contains the results of research on the mechanism of the shuttle self-discharge determined by Fe 2+ and Fe 3+ ions in the electrolyte of a heterogeneous electrochemical supercapacitor (HES) of a PbO 2 |H 2 SO 4 |C system, as well as the results of the measurements of the effect of the shuttle self-discharge current on the energy, capacity, and operation parameters of HES capacitors. It is shown that the presence of the iron ions in the electrolyte of a HES capacitor brings about shuttle self-discharge, which continues until the voltage decreases to the value of 1.05 V. The shuttle mechanism is related to oxidation and reduction of Fe 2+ and Fe 3+ ions in the positive and negative electrodes, respectively. An analytical expression is obtained for the calculations of the shuttle self-discharge current determined by different types of impurity ions in the electrolyte of HES capacitors. Analysis is made with respect to the obtained experimental and theoretical data of the self-discharge current, energy, and capacity parameters, as well as their dependence on the concentration of iron ions in the electrolyte, the separator's thickness, and modes of the capacitors' charge. It is established that the processes of oxidation and reduction of iron ions take place in the near-surface layers of the capacitor electrodes. It is shown that the linear increase of the separator thickness does not bring about any linear decrease of the shuttle self-discharge current determined by Fe 2+ and Fe 3+ ions.

A mathematical model of heterogeneous electrochemical supercapacitors (HES) is proposed which makes it possible to develop capacitors with optimal designs and make calculations of their energy, capacity, and power parameters. Special attention is paid to the processes which occur in electrodes with double electric layer (DEL) of HES capacitors during their charge and discharge by different currents. It is demonstrated theoretically that in the efficiency of HES capacitors' operation, an important role is played by distribution of the potential along the thickness of electrodes with DEL. In order to build capacitors with improved parameters and optimal design, it is of paramount importance to take account of the type and value of conductivity of the material of the electrode with DEL and conductivity of the electrolyte in its pores. Analysis is performed to determine the efficiency of PbO 2 |H 2 SO 4 |C system capacitors' operation subject to thickness, conductivity, and specific capacitance of the electrode with DEL. It is established that energy and capacity parameters of the capacitors depend to a great extent on conductivity of their negative electrodes and electrolytes. It is demonstrated that there are different mechanisms of losses of energy and charge of the capacitors during their charge, discharge, and storage.

1. It has been established that HCl is capable of H-bond formation with carbonyl π-complexes of transition metals via the oxygen of the carbonyl group in the presence of a metal atom in liquid xenon at low temperatures. 2. The protonation of carbonyl complexes of transition metals via the metal atom may occur through a stage of hydrogen bond formation via the oxygen atom of the CO group.

1. Using the example of the complex [η5-C5H5Fe(CO)2]2, it has been shown that the bridging carbonyl groups are able to form hydrogen bonds with donor protons. 2. Protonation of the complex [η5-C5H5Fe(CO)2]2 has been detected in its reaction with perfluoro-tert-butanol and with HCl at the metal-metal bond in solution in liquid xenon.

1. Perfluoro-tert-butanol forms H bonds of the OH...OC-M type with transition metal carbonyl π complexes: CpM(CO)3 (Cp=η5-C5H5 and η5-Et5C5, M=Mn, Re), MezM(CO)3 (Mez = η6-Me3H3C6, M=Cr, Mo, W), (η5-C5H5)M(CO)2PR3 (R=Ph, i-Pr, M=Mn, Re) at low temperatures in liquid xenon and at ∼20‡C in CCl4. 2. For isostructural complexes, the basicity of the O atom of the CO group increases on substitution of one of the CO groups by a phosphine ligand, introduction of alkyl substituents in the π ring, and in going from Mn to Re. 3. Hexacarbonyls M(CO)6 (M=Cr, Mo, W) do not form an H bond with perfluro-tert-butanol.