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A series of symmetrical dibenzylidene derivatives of cyclohexanone were synthesized with the goal of studying the physicochemical properties of cross-conjugated dienones (ketocyanine dyes). The structures of the products were established and studied by X-ray diffraction, NMR spectroscopy, and electronic spectroscopy. All products had the

A series of symmetrical dibenzylidene derivatives of cyclobutanone were synthesized with the goal of studying the physicochemical properties of cross-conjugated dienones (ketocyanine dyes). The structures of the products were established and studied by X-ray diffraction and by NMR and electronic spectroscopy. All the products had E,E-geometry. The oxidation and reduction potentials of the dienones were determined by cyclic voltammetry. The potentials were shown to depend on the nature, position, and number of substituents in the benzene rings. A linear correlation was found between the difference of the electrochemical oxidation and reduction potentials and the energy of the long-wavelength absorption maximum. This correlation can be employed to analyze the properties of other compounds of this type. Quantum chemistry was used to explain the observed regularities in the electrochemistry, absorption, and fluorescence of the dyes. The results are in good agreement with the experimental redox potentials and spectroscopy data.

New stationary phases for hydrophilic chromatography (HILIC) with functional layers formed by the multicomponent Ugi reaction have been obtained. Acetone, glycolic acid, ethyl isocyanacetate, and 3‑aminopropyl silica, which also act as adsorbent matrices, were used as reaction components. The study of the effect of solvent on the reaction yield showed that a high degree of coverage of the matrix was achieved when the reaction was carried out in ethanol. The new adsorbents’ chromatographic properties compared with the initial matrix were assessed using the Tanaka tests for hydrophilic phases and by studying the retention of polar analytes from various classes. The synthesized adsorbents have demonstrated high efficiency and selectivity in separating model mixtures of sugars, amino acids, and water-soluble vitamins in the HILIC mode.

The hydrodynamic action on long thin beams executing bending resonance vibrations in a fluid near a plane rigid surface (surface) is investigated. The model of quasi-two-dimensional interaction between the fluid and the beam is used, according to which the hydrodynamic action on any beam cross-section can regarded as a result of plane flow around it. The fluid flow in the planes orthogonal to the beam plane is modeled using the time-dependent system of Navier—Stokes equations, whose solution is determined numerically on the basis of the finite volume method. The solutions are determined in a wide range of the governing parameters of the oscillation process, namely, the dimensionless frequency, the vibration amplitude, and the distance to the surface. The dependences for the hydrodynamic forces thus obtained are used to assess the surface effect on the vibrations of cantilevers with actual physical parameters.

The problem of generation of steady streaming by an oscillating circular cylinder is considered. For the case of a finite oscillation frequency, the asymptotic expansion of the solution in terms of a small oscillation amplitude is constructed. In the leading steady term the two possible regimes of secondary streaming are analyzed. The fluid pumping effect of secondary streaming is studied. Energy efficient pumping regime is determined. The limits of applicability of high-frequency asymptotic solutions are established.

A new efficient method was proposed for the synthesis of (18-crown-6)stilbene; the structure of the product was confirmed by X-ray diffraction analysis. In MeCN, this compound forms pseudodimeric complexes with

Spectral, luminescent, and time-resolved properties of 2,4-dibenzylidenecyclobutanone and its diethylamino, methylthio, methoxy, and dimethoxy derivatives have been studied. The electron-donating substituents shift bathochromically the absorption band maximum by 45–140 nm relative to unsubstituted dienones and the fluorescence maximum by 50–125 nm relative to the methoxy derivative. Upon the laser pulse, dienones convert to the triplet state with a lifetime of 0.15–3.5 μs and a stable photoproduct is formed.

Spectral, luminescent, and time-resolved properties of 2-bezylidene-5-(pyridin-3-ylmethylene)cyclopentanone and its derivatives with electron-donating substituents (diethylamino, methoxy, methylthio, and dimethoxy) on the benzene cycle have been studied in acetonitrile at room temperature. The presence of substituents causes a long-wavelength shift of the absorption band maximum by 26–114 nm in comparison with the unsubstituted dienone and a long-wavelength shift of the fluorescence maximum by 43–125 nm in comparison with the methoxy derivative. Under laser irradiation of oxygen-free dienone solutions, intersystem crossing to the triplet state occurs with a half-life of 0.7–1.5 μs. A stable photoproduct is formed for the methoxy, methylthio, and dimethoxy derivatives of dienone.

Photoprocesses of bis(15-crown-5)-1,4-distyrylbenzene (DSB) and its complexes with barium and lead perchlorates in MeCN were studied by absorption, luminescence, and laser kinetic spectroscopies. Triplet DSB complexes are involved in the degradation of electronic excitation energy along with the trans—cis-isomerization and fluorescence processes. The most effective intersystem crossing was observed for the complex with lead perchlorate. The process is accompanied by a decrease in the quantum yield of DSB fluorescence and no trans—cis-isomerization is observed in this case. Shifts of spectral bands observed in the absorption and fluorescence spectra and the changes in the band intensities as well as the ability of DSB to form the 2: 2 bisandwich complex with barium perchlorate were explained using the results of quantum chemical calculations.

The paper is devoted to the study of the problem of high-frequency low-amplitude harmonic oscillations of a circular cylinder in a viscous incompressible fluid. The study develops the classical method of successive asymptotic expansions of a solution into internal and outer, steady and oscillating components in terms of a small parameter. The case of finite streaming Reynolds numbers is considered. Using the original method for calculation of the hydrodynamic force components from external flow characteristics, analytical expressions for four terms of the force expansion were found. The obtained results allow to evaluate not only a linear response to perturbations of flow caused by oscillations of the cylinder, but also the effect of the non-linear interaction of harmonics in the boundary layer.

Photoprocesses in 1,4-diazadistyrylbenzene (1) and 1,3-diazadistyrylbenzene derivative (2) diperchlorates in MeCN were studied by absorption, luminescence, and kinetic laser spectroscopies. For compound 1, trans-cis-photoisomerization and intersystem crossing to a triplet state are observed. For compound 2, photoelectrocyclization is suggested. Quantum chemical calculations of diazadistyrylbenzene structures in the ground and excited states were carried out. The schemes for photoreactions were proposed.

The paper is devoted to the study of the periodic rectilinear motion of an elliptic cylinder at an arbitrary angle of attack in a viscous incompressible fluid according to an arbitrary multi-harmonic law. The study develops the classical method of inner and outer asymptotic expansions of a solution in a small parameter, which is taken as the ratio of the thickness of the Stokes boundary layer to the semi-major axis of the elliptic cylinder. Another parameter of the problem, which is the Reynolds number calculated based on the thickness of the boundary layer, is considered to be of the order of unity. The selected range of values of parameters describes the low-amplitude high-frequency oscillations of the cylinder in a fluid. The asymptotic solution of the problem built in the study allows us to determine the first three terms of the expansion of the hydrodynamic force acting on the cylinder. For the detailed analysis of the obtained solution, several cases of the periodic motion of cylinders with different axis ratios for different oscillation parameters according to harmonic and multi-harmonic laws were considered. In these cases, the asymptotic dependencies of the hydrodynamic forces were compared with the data of direct numerical simulations and with known results of previous asymptotic and experimental research. The results of the analysis allow us to establish the limits of applicability of the asymptotic theory and to determine the structural changes of the hydrodynamic forces when transition to the zone of moderate oscillation amplitudes occurs.

Modern solar power stations traditionally use lumped elements to convert electrical energy. This approach is simple and affordable for small power plants; however, the cost of such controllers increases significantly for power of several kilowatts. It is also necessary to place other lumped conversion elements such as MPPT (maximum power point tracking) controller, inverter and the sine filter. Presented control system allows to combine all these devices into one distributed system per moving to a modular multilevel conversion topology. In order to ensure the flexibility and the ability to operate in any network configurations, the proposed article also considers the use of a proportional-resonant regulator to abandon the use of phase-locked loop frequency and, as a consequence, simplify the control system. The presented article will consider a model of a 10 kW power station for a standard mains voltage of 220 V.

Photoprocesses in bis(18-crown-6)-1,4-distyrylbenzene (DSB) and its complexes with potassium, barium, and lead perchlorates have been studied in MeCN solutions by absorption, luminescent, and laser kinetic spectroscopy. The DSB molecules in the triplet state participate in the degradation of electron excitation energy, cis–trans isomerization, and fluorescence. The triplet–triplet absorption spectrum has several maximums in the range of 500–700 nm. The most efficient intersystem crossing to the triplet state is observed for the lead perchlorate complex, which is accompanied by a drop in the fluorescence quantum yield and the absence of trans–cis isomerization.

Spectral, luminescent, and kinetic properties of 2,5-bis(4-diethylaminobenzylidene)cyclopentanone (ketocyanine, A) in air-saturated and oxygen-free acetonitrile have been studied. The ns-Laser and continuous photoexcitation of A results in a product B undergoing in the oxygen-free solution the intersystem crossing into the triplet state with the lifetime of 1 µs. The photoinduced conversion of A into B occurs within a time shorter than 1 µs and is manifested in a decrease in both the fluorescence intensity of A and absorbance at 457 nm and in the appearance of a new absorption at λ > 535 nm. The product B undergoes photoinduced conversion to the parent A via both the excited singlet and triplet states of B.

Photonics of tetramethoxy-1,4-distyrylbenzene in MeCN was studied by absorption, luminescence, and laser kinetic spectroscopies. Photoinduced transformations of the compound in question involve cis–trans-isomerization, intersystem crossing, fast and delayed fluorescence, and electron transfer. The ground-state structure and vibrational spectrum, as well as the energies and structures of excited singlet and triplet states were calculated by the DFT/PBE and TDDFT/PBE0 methods. The assignment of vibronic bands in the absorption spectra was made and the energies of corresponding transitions were calculated.

The paper is devoted to study of the aerodynamic forces acting on flat cantilever beams performing flexural vibrations in a viscous fluid. Original method for the force evaluation is presented based on analysis of experimental measurements of a logarithmic decrement of vibrations and relative variation in frequency of duralumin test specimens. The theoretical core of the method is based on the classical theory of bending beam oscillations and quasi-two dimensional model of interaction between a beam and a gas. Using the proposed method, extensive series of experiments for a wide range of oscillations parameters were carried out. The processing of the experimental data allowed to establish the global influence of the aerodynamic effects on beam oscillations and the local force characteristics of each cross-section of the beam in the form of universal functions of dimensionless amplitude and dimensionless frequency of oscillation. The obtained estimates of the drag and added mass forces showed a good correspondence with the available numerical and experimental data practically in the entire range of the investigated parameters.

This paper considers methods for controlling secondary flows near an oscillating circular cylinder by changing two process control parameters: the dimensionless amplitude and the vibrational Reynolds number. A direct numerical modeling study is performed. It is shown that by varying the indicated parameters in a relatively small range, it is possible not only to intensify mass transfer processes, but also to change the direction of the main secondary flows.

The reaction of tetraethyl [1,3-phenylenedi(methylene)]bis(phosphonate) with formyl derivatives of benzocrown-ethers or formyl derivatives of o-dimethoxybenzene lead to high yield formation of the respectful bis(crown ether) containing 1,3-distyrylbenzenes or tetramethoxy-substituted 1,3-distyrenebenzenes. NMR spectra and quantum-chemical calculations showed the prevalence of unsymmetrical syn/anti,(syn,anti),syn/anti-conformations in 1,3-distyrylbenzenes. 1,3-Distyrylbenzenes absorb in shorter wavelength spectral region and have a weaker fluorescence than 1,4-distyrylbenzenes. The difficulty in the electrochemical reduction of 1,3-distyrylbenzenes comparing with 1,4-distyrylbenzenes is due to a less effective conjugation system in the metaderivatives.

In the paper the vibration-driven motion of a spherical body in a viscous fluid at finite Reynolds numbers is considered. Based on the direct numerical simulation the structure of hydrodynamic forces acting on the body from the fluid and their influence on the efficiency of propulsion are studied.

Photoprocesses in bis(15-crown-5)-1,3-distyrylbenzene (DSB) and its complexes with barium and lead perchloatewere studied in MeCN by absorption, luminescence, and laser kinetic spectroscopy. The triplet DSB molecules are involved in the degradation of electronic excitation energy, together with fluorescence processes. The most efficient intersystem crossing accompanied by a decrease in the DSB fluorescence quantum yield, occurs for the lead perchlorate complex. Using quantum chemistry methods (DFT and TDDFT), the geometry, structure, and transition energies to the S1 state were calculated for trans- and cis-isomers of DSB in the gas phase and with allowance for the solvent and for 1:1 and 2:2 DSB complexes with barium cation in the ground and excited states. The orbital structures of the 2:2 complexes were calculated by ab initio method, and conclusions were drawn about the possibility of [2 + 2]- photocycloaddition reaction.

Spectral, luminescent and time-resolved characteristics of 2,5-dibenzylidenecyclopentanone and its symmetrical derivatives (bis(N,N-diethylamino-), dimethoxy-, tetramethoxy-, dimethylthio-, and bis-18- crown-6 derivative) have been studied in media of different polarity (cyclohexane, toluene, acetonitrile, DMSO, and methanol) at room temperature. The absorption maximum of dibenzylidenecyclopentanone shifts bathochromically by 15 nm with an increase in polarity of the medium (cyclohexane–methanol). The introduction of electron-donating substituents in the aromatic rings of dibenzylidenecyclopentanone also results in a bathochromic shift of the absorption maximum by 100–130 nm in the media of different polarity and shifts the fluorescence maximum by 130 nm relative to the maximum of the dimethoxy derivative. Upon laser irradiation of oxygen-free solutions of dibenzylidenecyclopentanone and its tetramethoxy- and bis-18-crown-6 derivatives in acetonitrile, the triplet state with a half-life time of 0.3–1 μs is generated. For dimethoxy-, dimethylthio-, tetramethoxy-, and bis-18-crown-6 derivatives of dibenzylidenecyclopentanone, the isomers with a lifetime of ~50 ms are formed.

The relevance of the article is that it examines the provisions of the criminal procedure law on a reasonable time of preliminary investigation, the consequences of violation of a reasonable period of preliminary investigation. A formula is proposed that makes it possible to make a clearer idea of a reasonable time as a border in the criminal procedural time between conditionally permitted and absolutely unacceptable. In the Author's opinion, the consequences of a violation of a reasonable period is the person's moral and (or) property damage. The Author recommends that in the Federal Law of April 30, 2010, No. 68-FZ, replace the concept of “significance of consequences” with the notion of “harm”.

Photoinduced processes in bis(diethylaminobenzylidene)cyclohexanone (CH1) and its bis(aza-18-crown-6) derivative (CH2) in acetonitrile at ambient temperature and 77 K have been studied. The absorption, fluorescence, and phosphorescence spectra of CH1 and CH2 are similar. The probability of the formation of the triplet state is higher for CH2 molecules (λT-Tmax = 660 nm, lifetime τT ~ 20 μs). The lifetime of the CH1 molecule in the triplet state is estimated at τT ~ 2–3 μs. Photoisomers of CH1 and CH2 are formed along with the triplet state. According to DFT calculation results, the formation of trans–cis photoisomers of CH1 and CH2 is the most energetically favorable.

An improved method for the synthesis of two symmetric biscrown-containing and one model tetramethoxy-substituted 1,4-distyrylbenzenes was suggested. The structures of compounds were established by 1H and 13C NMR spectroscopy and X-ray diffraction analysis. Spectrophotometric and fluorescent titration were used to determine spectral properties, stoichiometry, and stability of complexes of biscrown-containing 1,4-distyrylbenzenes with alkali and alkaline-earth metal cations. The stability of the complexes was found to depend on the metal cation size and charge, as well as on the size of the crown ether fragment. The electrochemical oxidation and reduction potentials of the biscrown-containing 1,4-distyrylbenzenes and the model compound in solution were determined and their basic differences from the corresponding characteristics of biscrown-containing stilbenes were identified.

A series of cross-conjugated dienones was synthesized to study the dependence of physicochemical characteristics on the nature of substituents in the aromatic groups of symmetric cyclopentanone dibenzylidene derivatives. The structure of compounds was established by electronic, IR, and NMR spectroscopy and X-ray diffraction study. All the compounds obtained possess the E,E-geometry. In the crystalline state, the arrangement of the dienone molecules is unfavorable for the intermolecular [2+2] photocycloaddition to take place. The low-temperature phases transition for unsubstituted diphenyl derivative of cyclopentanone was detected using variable-temperature X-ray diffraction and differential scanning calorimetry. Oxidation and reduction potentials of the dienones were measured by cyclic voltammetry. Their dependence on the nature and placement of substituents in the benzene rings was demonstrated. A linear correlation (R = 0.9343) between the difference of electrochemical oxidation and reduction potentials and the energy of the long-wavelength absorption maximum was found, that allows us to recommend the use of the data obtained in the correlation analysis of other compounds of this class.

The paper is devoted to the study of hydrodynamics around long cantilever beams that perform flexural vibrations in first natural mode in a viscous incompressible fluid. The study is based on the numerical three-dimensional simulation of flows induced by vibrations. The fluid motion is described by the full non-stationary system of Navier–Stokes equations and the oscillation profile of the beam is determined according to the Euler–Bernoulli theory. In the framework of the research, the analysis of the changes of hydrodynamics around the beams that are caused by an increase of the relative length, dimensionless frequency and amplitude of oscillations is made, in particular, the applicability of a quasi-two-dimensional theory is considered. According to the results of the study, the dynamic processes of vortex formation in a wide range of vibration frequencies and amplitudes are described, the map of the observed flow regimes is constructed, and analysis of the dependence of hydrodynamic forces on the vibration parameters is carried out.

Photoprocesses of bis(18-crown-6)-1,3-distyrylbenzene (DSB) and its complexes with barium and lead perchlorates in a MeCN–CH2Cl2 (9:1, v/v) mixture were studied by absorption, luminescence, and laser kinetic spectroscopies. Unlike its strongly conjugated 1,4-isomer, 1,3-derivative shows almost independent behavior of its chromophoric subunits and is capable of phototransformations not observed in 1,4-distyrylbenzenes. Triplet DSB complexes are involved in the radiationless deactivation of the excited state along with the fluorescence processes. The most effective intersystem crossing was observed for the complex with lead perchlorate. The process is accompanied by a drastic decrease in the quantum yield of DSB fluorescence. Quantum chemistry (DFT and TDDFT) is used to calculate the geometric structure and absorption spectra of DSB and its complexes with barium and lead cations and to explain the observed results.

Spectral, luminescent, and time-resolved properties of 2,6-dibenzylidene cyclohexanone and its symmetric derivatives in the para-position of benzene ring (dimethoxy, dimethylthio, and bis-N,N-diethylamino groups) have been studied in media of different polarity (cyclohexane, acetonitrile, dimethylsulfoxide, and methanol). Introduction of electro-donating substituents to dibenzylidene cyclohexanone results in the red shift of the absorption maximum by 81–138 nm upon passing from the nonpolar to polar medium. Bis(N,N-diethylamino)dibenzylidene cyclohexanone fluoresces in polar solvents, acetonitrile, dimethylsulfoxide and methanol. The bathofluoric shift on passing from acetonitrile to methanol is 39 nm. The relative quantum yield of fluorescence in acetonitrile is seven times that in methanol. An intermediate species absorbing in the range of 400–560 nm with a maximum at 430–460 nm has been observed under the action of the laser pulse on dibenzylidene cyclohexanone solutions in acetonitrile. The intermediate species has a lifetime of 40, 20, and 7 μs for dibenzylidene cyclohexanone and its dimethylthio and dimethoxy derivatives, respectively.

Dienones (ketocyanine dyes) containing two aza-18-crown-6 ether residues were synthesized. The complex formation of these dyes with the EtNH3+ and +H3N(CH2)nNH3+ ions (n = 2–10, 12) in MeCN was studied by electronic and 1H NMR spectroscopy, including spectrophotometric and 1H NMR titration. It was found that homoditopic bis-azacrown dienones and alkanediammonium ions with a short polymethylene chain form 1:1, 2:2, and 1:2 complexes, whereas alkanediammonium ions with a long polymethylene chain form only pseudocyclic 1:1 complexes. The stability constants of the resulting complexes were determined (logK1:1 varies in the range from 2.74 to 5.62 [M–1], logK2:2 = 2.1 [M–1], and logK1:2 varies in the range from 2.03 to 2.96 [M–1]). The most stable complexes are formed by diammonium ions with a long polymethylene chain owing to simultaneous binding of both NH3+ groups to the azacrown ether residues of the dye. The structure of supramolecular complexes was confirmed by quantum chemical calculations.

The acylation of unsymmetrical N-benzylbispidinols in aromatic solvents without an external base led to the formation of supramolecular gels, which possess different thicknesses and degrees of stability depending on the substituents in para-positions of the benzylic group as well as on the nature of the acylating agent and of the solvent used. Structural features of the native gels as well as of their dried forms were studied by complementary techniques including Fourier-transform infrared (FTIR) and attenuated total reflection (ATR) spectroscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and small-angle X-ray scattering and diffraction (SAXS). Structures of the key crystalline compounds were established by X-ray diffraction. An analysis of the obtained data allowed speculation on the crucial structural and condition factors that governed the gel formation. The most important factors were as follows: (i) absence of base, either external or internal, (ii) presence of HCl, (iii) presence of carbonyl and hydroxyl groups to allow hydrogen bonding, and (iv) presence of two (hetero)aromatic rings at both sides of the molecule. The hydrogen bonding involving amide carbonyl, hydroxyl at position 9, and, very probably, ammonium N-H+ and Cl&minus, anion appears to be responsible for the formation of infinite molecular chains required for the first step of gel formation. Subsequent lateral cooperation of molecular chains into fibers occurred, presumably, due to the aromatic &pi, &minus, &pi, stacking interactions. Supercritical carbon dioxide drying of the organogels gave rise to aerogels with morphologies different from that of air-dried samples.

The acylation of unsymmetrical N-benzylbispidinols in aromatic solvents without an external base led to the formation of supramolecular gels, which possess different thicknesses and degrees of stability depending on the substituents in para-positions of the benzylic group as well as on the nature of the acylating agent and of the solvent used. Structural features of the native gels as well as of their dried forms were studied by complementary techniques including Fourier-transform infrared (FTIR) and attenuated total reflection (ATR) spectroscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and small-angle X-ray scattering and diffraction (SAXS). Structures of the key crystalline compounds were established by X-ray diffraction. An analysis of the obtained data allowed speculation on the crucial structural and condition factors that governed the gel formation. The most important factors were as follows: (i) absence of base, either external or internal; (ii) presence of HCl; (iii) presence of carbonyl and hydroxyl groups to allow hydrogen bonding; and (iv) presence of two (hetero)aromatic rings at both sides of the molecule. The hydrogen bonding involving amide carbonyl, hydroxyl at position 9, and, very probably, ammonium N-H+ and Cl− anion appears to be responsible for the formation of infinite molecular chains required for the first step of gel formation. Subsequent lateral cooperation of molecular chains into fibers occurred, presumably, due to the aromatic π−π-stacking interactions. Supercritical carbon dioxide drying of the organogels gave rise to aerogels with morphologies different from that of air-dried samples.

The oxidation of 3,7-disubstituted hexahydroindazoles with potassium hexacyanoferrate(III) afforded previously unknown tetrahydro-2H-indazole derivatives. A novel ring contraction reaction leading to 2,3-diazaspiro[4.4]non-3-en-1-one derivatives was discovered. The product structure was proved by NMR spectroscopy, mass spectrometry, and X-ray analysis.

The patterns of static equilibrium sorption of Pb2+ and Mn2+ ions from solutions simulating a composition of industrial liquid waste, onto modified bentonite and zeolite were researched. Na-bentonite and Na-clinoptilolite demonstrate high sorption activity with respect to Pb2+ and Mn2+ ions are recommended instead of a commercial synthetic KU-2-8 for a sorption after-treatment of liquid wastes from toxic Pb2+ and Mn2+ ions.

Photoprocesses in bis(diethylaminobenzylidene)cyclopentanone (D1) and its bis(aza-18-crown-6) derivative (D2) have been studied in acetonitrile. The absorption, fluorescence, and phosphorescence spectra of D1 are similar to those of D2. Laser excitation of oxygen-free solutions of D1 and D2 leads to generation of a triplet state with a lifetime of ∼1 μs and two intermediate species with lifetimes of ∼100 μs and longer than 1 s.

In the paper a method for determining of the aerodynamic influence on oscillating cantilever beams based on gyroscope measurements is presented. The developed method allow to establish the global influence of the aerodynamic effects on oscillation process and the local force characteristics in each cross-section of the beam. The obtained estimates of drag and added mass forces acting on the beams show a good agreement with the known numerical and experimental data.

The aerodynamic component of damping of a vibrating plate in the range of parameters characteristic of damped flexural vibrations of test specimens is investigated. On the basis of a large series of numerical simulations in the dynamics of two-dimensional flow of gas around a plate, we managed to suggest a unified approximating equation for the damping constant in terms of dimensionless parameters of the process considered.

The challenges of the modern society and the growing demand of high-technology sectors of industrial production bring about a new phase in the development of organic synthesis. A cutting edge of modern synthetic methods is introduction of functional groups and more complex structural units into organic molecules with unprecedented control over the course of chemical transformation. Analysis of the state-of-the-art achievements in selective organic synthesis indicates the appearance of a new trend — the synthesis of organic molecules, biologically active compounds, pharmaceutical substances and smart materials with absolute selectivity. Most advanced approaches to organic synthesis anticipated in the near future can be defined as 'atomic precision' in chemical reactions. The present review considers selective methods of organic synthesis suitable for transformation of complex functionalized molecules under mild conditions. Selected key trends in the modern organic synthesis are considered including the preparation of organofluorine compounds, catalytic cross-coupling and oxidative cross-coupling reactions, atom-economic addition reactions, methathesis processes, oxidation and reduction reactions, synthesis of heterocyclic compounds, design of new homogeneous and heterogeneous catalytic systems, application of photocatalysis, scaling up synthetic procedures to industrial level and development of new approaches to investigation of mechanisms of catalytic reactions. The bibliography includes 840 references.

The paper presents the synthesis of a series of adamantyl phosphate esters. Five compounds (oxo and hydroxy substituted adamantyl phosphates) were tested for their inhibitory activity with respect to myo-inositol monophosphatase.

Possibility of performing sorption-coagulation purification of model wastewater to remove cationactive dyes (Rhodamine G, Methylene blue, thionine, and fuchsine) with bentonite sorbents and Gyanja flocculant-coagulant was studied. The effect of the nature and charge of exchange cations on the sorptioncoagulation capacity of bentonite samples was examined.

Four (2R,3S)-N-benzoylphenylisoserine esters with substituted bicyclo[3.3.1]nonanes are synthesized. The compounds are found to be unable to promote tubulin polymerization, but cause a weak tubulin aggregation (oligomerization).

2-(endo-7-Hydroxybicyclo[3.3.1]non-exo-3-ylmethyl)propane-1,3-diol was synthesized in seven steps starting from endo-7-hydroxybicyclo[3.3.1]nonane-exo-3-carboxylic acid. The title compound attracts interest as intermediate product for the synthesis of potential tubulin ligands.