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The paper presents the results of research in which powdered cellulose technologies are considered using commercial hardwood bleached sulfate pulp as a raw material. The morphological and chemical properties of powdered and fibrillar cellulose samples are given. The dependence of the properties of the obtained products on the manufacturing method is shown. For comparison and evaluation of the effectiveness of the process of dispersion and hydrolysis, the properties of commercial fibrillar and microcrystalline cellulose have been studied.

The article provides a scientific and methodological analysis of the mechanisms of psychophysical development of student youth by means of physical culture. The undoubted importance of regular physical activity, complexes of general developmental exercises, as well as special training complexes for the main sports included in the curriculum for the discipline “Physical culture” at the university is revealed. This material forms the basis of a theoretical lecture course on physical culture, and can also be used for the introductory part of practical exercises.

Based on fundamental research of above-threshold-power laser radiation by C. Townes (laser beam splitting) and G. A. Askaryan (self-focusing and sublimation evaporation), a new highperformance technology for growing nanowhiskers of metal and their oxides, semiprecious crystals, and composite materials based on polycarbonate in open air is developed. Some possibilities of its practical applications are shown.

A new technology is suggested for crystallizing arbitrary materials at temperatures of 3000-4000ºC and pressures of 20-100 thousand atmospheres. First experimental results were obtained in a foil-coated polycarbonate that comprised diffraction gratings. It was established that a laser beam reflected from the diffraction gratings is self-focused inside polycarbonate and becomes a seed, which changes the polycarbonate structure and leads to vitrification and growth of ordered structures from symmetrically arranged whiskers. This results in a light dispersion effect in composites. The results concerning whiskers formed with sharp tips are presented. We used data obtained in these experiments for developing a model of crystallization with the rates of 80-100 m/s. In this case, not only crystals grow, but nanowhiskers also. A new phenomenon of nanowhiskerography was discovered, which can be used for developing the defence against falsification that cannot be reproduced by polygraphic methods. A fundamental data, obtained in this article is allowed us to use technology for crystallisation any materials (glass, quartz, semiconductors, whisker graphite). The term “coherent nanowhiskerography” - is introduced for the first time by us, because the whisker crystallization occurs with a delay in reflection from two diffraction gratings, which are situated at the different depths. Thus, each whisker repeats in structure a retarded whisker during the crystalization. Due to this, unique optical and electrophysical properties arise. Since at the ends of whiskers there is only 1-2 atoms with dangling chemical bonds, therefore, the technology is extremely promising for the new direction of creating a new direction of terahertz technology and also up to date generations of the computing technology.

In this paper, a layout of an electric power plant that uses the gas turbine engine as a source of energy is presented. We give also the numerical analysis of this power plant and show its high efficiency.

Different classes of compounds with imidazoline radicals were studied by EPR spectroscopy. The effects of light and atmospheric oxygen on the stability of these compounds in alcoholic solutions were investigated. The study of the photochemical stability of rhodium complexes with imidazoline radicals in oxygen-containing and oxygen-free media demonstrated that the photolysis of these compounds in the absence of oxygen causes the disappearance of paramagnetism. The reaction is reversible, and the observed effects are due to the formation of hydroxylamine groups via the interaction between excited nitroxyl radicals and the solvent in the absence of oxygen. When present in this system, oxygen deexcites the nitroxyl groups. A similar effect of oxygen is observed for nitroxyl derivatives of the fullerenes C60 and C70. A quite different photolytic behavior is shown by copper complexes with bidentately bonded nitroxyl radicals. These compounds are stable to photolysis in both oxygen-containing and oxygen-free media. It was demonstrated using phenyl-tert-butylnitrone (PBN) as the spin trap that photolysis in the absence of the trap results in the decomposition of the copper complex to copper metal. It is assumed that PBN incorporates into the complex at free coordination sites and competes with the copper ion in its reaction with the earlier formed radical of the ligand.

The photosensitivity of conducting polymer films with newly synthesized polymethine dyes is investigated. It is demonstrated that the photosensitivity of polymer films based on poly(o-hydroxyamide) with transport indole molecules forming intermolecular complexes with dyes is two or three times higher than the photosensitivity of the polymer films containing indole as a structural component of the dye. The introduction of the indole-containing dye into the photoconducting poly(vinylcarbazole) leads to an increase in the photo-conductivity by one and a half orders of magnitude. In this case, the quantum yield increases to η = 0.085. A correlation is revealed between the electronic structure of the dyes, the characteristics of the photoconduction in the materials under investigation, and the mechanisms of charge relaxation in the samples. An increase in the photoconductivity of the films results in the crossover from the drift mechanism of charge relaxation to the relaxation mechanism associated with intrinsic electrical conduction.

Comblike polymers (copolymers) of methacrylates with nonlinear optical photochromic chromophores in the side chains are synthesized. An increase in the induced birefringence under laser radiation is studied in poly-n-(fluoroalkyl methacrylates) and their hydrocarbon analogs. It is demonstrated that the chemical structure and composition of polymers (copolymers) affect the rise and decay of the photoinduced birefringence and the stability of the second-harmonic generation signal.

The dielectric relaxation and molecular motion in polymers and copolymers of methacrylates and methacrylamides with π-conjugated anisodiametric chromophoric groups in the side chains are investigated in the temperature range from −170 to 120–150°C at frequencies of 0.1–100 kHz. It is shown that the motion of chromophoric groups and relaxation transitions in these systems are similar to those in liquid-crystal polymers with side mesogenic chains. The chromophoric groups execute orientational motion of two types: orientational rotations about the long axes in the glass state and orientational rotations about the short axes at temperatures above T g . The π-conjugation excludes local motion within the chromophoric group.

Effect of the formation procedure on the structure and transport characteristics of poly(2,2,3,3,4,4, 5,5-octafluoro-n-amyl acrylate)-polyamidoimide composite membranes in separation of O2/N2 gas mixture (air) over a wide temperature range is studied.

New amphiphilic photosensitive three-component random copolymers of octafluoropentylmethacrylate (OFPM), methacrylic acid (MA) and o -chlorophenylpyrimidine containing chromophore 6-[ N -(4,6-dimethyl-2-pyrimidyl)- N -(2-chlorophenyl)amino]hexylmethacrylate or 2-( N -allyl-2-chloroaniline)-4,6-dimethylpyrimidine are described. By means of 1 H NMR and electron spectroscopy, it was found that the main photoreaction of these copolymers is cyclization with the participation of heterocycle nitrogen atom of o -chlorophenylpyrimidine chromophore resulting in its conversion into N -substituted pyrimido-[1,2- a ]-benzimidazolium chloride. Efficiency of charge carriers photogeneration in polymeric films of macroscopic thickness was determined with the method of photoinduced decay of surface potential. One of the copolymers was shown to form monomolecular layers on aqueous subphase and conditions for formation of Langmuir–Blodgett (LB) films were determined. Bilayer spacing of these films was evaluated from X-ray reflectivity data.

The third-order nonlinear optical susceptibility χ(3)(3ω; ω, ω, ω) of two types of copolymer films containing optically nonlinear N-substituted nitroazobenzene in the side (methacrylic series copolymers) and main (copolyimidoamido esters) polymer chains is investigated using the third harmonic generation method at a wavelength of 1.064 µm.

New comblike copolymers of methacrylic acid esters with an optically nonlinear chromophore—a derivative of the 4′-(4-nitrobenzylideneamino)phenol—in a side chain were obtained. Processes of forced orientation of nonlinear optical chromophores covalently bonded with the main chains in an electric field and the effects of the conditions of orientation on the nonlinear second-order optical activity of the polymer films were studied in some detail. The existence of a correlation between the chemical structure and the composition of the copolymers with the magnitude and the stability of the surface electron potential of the corresponding films was shown. It was established that a maximum extent of orientation of chromophores in the bulk of the polymer and, as a consequence, a high intensity of the second-harmonic signal were achieved when the thickness of the region of the uniform electric field maximally approached the thickness of the sample.

This review summarizes the results of studies on complexation of fullerene C60 with transition metals. The structural background for metal-fullerene interaction is discussed. Much attention is focused on the compounds MnC60. Methods of their preparation, structure, and properties are considered in detail. The nature of their catalytic activity is discussed.

Experimental and theoretical investigations were made of the active-medium gain and of the parameters of the radiation emitted by an rf-pumped slab CO2 laser. The average output power was 160 W and the efficiency was 10%. Near-diffraction-limited divergence was achieved. In the pulse-periodic regime, the pulse power was twice the average power in the cw regime. When external correcting optics was used, the total divergence of the laser radiation was 2–3 mrad at 0.8 of the total power. A suite of programs for numerical simulation of the physical processes in an rf-pumped slab CO2 laser with diffusion cooling was developed. The experimental and theoretical results were compared.

The 2,2,5,5-tetramethyl-3-imidazoline-3-oxy-1-oxyl-4-(azidophenyl) derivatives of the C60 fullerene with one (compound I), two (compound II), and three (compound III) nitroxyl groups are synthesized and studied by EPR spectroscopy. It is demonstrated that successive addition of nitroxyl radicals to C60 leads to a decrease in the rotational mobility of molecules. Chromatographically inseparable isomers are found for compounds II and III.

The thermal stability of submicron films of an amylmethacrylate-amylacrylate copolymer containing chemically bound fullerene C60 was studied by mass spectrometry. The thermal stability of this composition depends on the film thickness δ. For δ>10 nm, a low-temperature stage of the thermal degradation was observed. The intensity of this process increases with the film thickness. The energy parameters of the two stages of thermal degradation kinetics were determined. A decrease in the thermal stability with increasing film thickness is explained by the chemical activity of fullerene in the course of heating the polymer-based composition.

Second-harmonic generation was used to investigate nonlinear optical properties and the structure of multilayer Langmuir — Blodgett films of a copolymer of fluoroalkylmethacrylate with methacrylates containing an azo dye and a cinnamoyl group inside a chain. Quantum-chemical calculations were made of the components of the molecular hyperpolarisability tensor in which the intermolecular interactions were taken into account. The orientation of nonlinear optical fragments of a polymer chain relative to the substrate and components of the quadratic optical susceptibility tensor of the film were determined.

We compared the efficacy of a routine sulphosalycilic acid method and a new technique of pirogallolic red staining for urine protein assay in children with metabolic nephropathy, crystal-calcium crystaluria. The former method was found ineffective in proteinuria diagnosis in children with metabolic nephropathy. The pirogallolic method appeared more effective as it detects microproteinuria and therefore allows accurate diagnosis, control of its treatment and finally to improve the results of therapeutic and prophylactic measures.

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This review summarizes the results of studies on complexation of fullerene C60 with transition metals. The structural background for metal-fullerene interaction is discussed. Much attention is focused on the compounds MnC60. Methods of their preparation, structure, and properties are considered in detail. The nature of their catalytic activity is discussed.

The polarization properties of second harmonic and sum-frequency signals generated by femtosecond laser pulses in films of polymers containing covalent groups of an azobenzothiazole chromophore polarized by an external electric field are investigated. It is shown that the methods of polarization nonlinear optics make it possible to determine the structure of oriented molecular dipoles and reveal important properties of the motion of collectivized π electrons in organic molecules with strong optical nonlinearities. The polarization measurements show that the tensor of quadratic nonlinear optical susceptibility of chromophore fragments oriented by an external field in macromolecules of the noted azopolymers has a degenerate form. This is indicative of a predominantly one-dimensional character of motion of collectivized π electrons along an extended group of atoms in such molecules.

Results are presented of a numerical investigation of the axisymmetric flow around a family of bodies with a pointing angle for which the shock is detached. It is shown that the supersonic part of the stream remains the same for all bodies of the family for a fixed value of M∞ despite the fact that the shaper of the subsonic zone is related quite strongly to the pointing angle Β*. The dependence of the shock standoff and its radius of curvature on the spreading line on the body shape is studied. Effects inherent in flows around sharply pointing bodies are discussed. A dimensionless parameter characterizing each body of the family under consideration is introduced and used to establish general flow regularities. Data illustrating the possibility of applying such parametrization are analyzed for a wider class of pointing bodies.

An analysis is made of the conditions for cw operation of a dye laser subject to thermooptic inhomogeneities which appear in the active medium under the action of pump radiation. Calculations allow for the inhomogeneous distribution of the gain across a cell containing the dye solution. The spatial distribution of the laser radiation on the exit mirror of the resonator is accounted for. It is shown that the gain inhomogeneity has a considerable influence on the suppression of lasing in the case of pulses of microsecond duration.

We have investigated the 1H and 19F spin-spin relaxation behavior in the melts and swollen gels of cross-linked polyfluoroalkyl acrylates PFA-nR where n is the number of CF2 groups in the side chain (n = 2, 3, 4). It was found that in the strands the anisotropic motion of the main chain units and the side groups lead to the non-zero degree of averaging of magnetic dipole-dipole interactions (Q). Q of side groups was estimated to depend on the degree of cross-linking Q ≈ blx, where x is the number of persistent lengths in the strand, b was found to decrease with increasing n. In opposite to PFA-3F and PFA-2H networks, the dangling ends in PFA-4R network were shown to influence the relaxation behavior, indicating the growth of motional anisotropy of dangling ends with chain diameter.

The oxidation of the products of the reaction of dialkylphosphorylacetaldehydes with aryldiazonium salts gives tetrazonyl radicals.

Condensation of thiophene-2-aldehyde with p-aminobenzoic and barbituric acids gives 2-thenylidene -p-aminobenzoic acid and 2-thenyl-idenebarbituric acid. Similarly, 5-nitro-thiophene-2-aldehyde gives 5-nitro-2-thenylidene-p-aminobenzoic acid and 5-nitro-2-thenyl-idenebarbituric acid. Condensation of thiophene-2-aldehyde with nitroethane gives 1-(2-thienyl)-2-nitroprop-1-ene; and 1-nitro-2-(2-thienyl-5-nitro) ethene is synthesized by nitrating thienylnitroethylene.