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Using the focused ion beam probe method, cross-section sample of a single functional device of micron dimensions were cut out for STEM and TEM studies. The use of analytical methods of transmission electron microscopy made it possible to obtain accurate data on the geometric parameters of nanoscale functional devices, the phase and elemental composition of functional element material, as well as on the concentration of free electrons at the Fermi level in the nanoelement material. [ABSTRACT FROM AUTHOR]

The interconnection between the destructive and stabilizing effects of ultrasmall gold nanoparticles (GNPs) synthesized by the Duff method in relation to the internal structure of the particles of DNA liquid-crystalline dispersions (LCDs), depending on the degree of their ordering, was studied. It is shown that "stabilization" of the particles' ordered structure is, in fact, a consequence of its "destruction." The dominance of one or another effect depends in a complex way on the distance between neighboring DNA molecules within the particles of its LCD, determined by osmotic conditions, and the efficiency of penetration of GNPs into these particles. [ABSTRACT FROM AUTHOR]

The paper describes a method developed in National Research Centre "Kurchatov Institute" for creating different functional nanostructures using ion beam irradiation. As an example, the formation of an integrated resistive elements in a low-temperature NbN superconductor nanowire is demonstrated. The possibility of producing an insulating layer of aluminum oxide with a thickness of 15 nm on the aluminum surface at room temperature under 0.2 keV oxygen ions irradiation was shown. [ABSTRACT FROM AUTHOR]

The characterization system and automated database on vitrified high-level waste (VHLW) accumulated at the Mayak Production Association were developed for assessing and substantiating the waste disposal safety. All the available analytical data on VHLW are accumulated in the database. Calculations based on the developed integral algorithm for estimating the content of radiologically significant radionuclides (RSRNs) in containers with VHLW were made. [ABSTRACT FROM AUTHOR]

The creation of antibacterial nanocomposites that provide prolonged release of encapsulated drugs is of great interest for various fields of medicine (dentistry, tissue regeneration, etc.). This article demonstrates the possibility of creating such nanocomposites based on sodium alginate and drug-templated mesoporous silica nanocontainers (MSNs) loaded with two bioactive substances. Herein, we thoroughly study all stages of the process, starting with the synthesis of MSNs using antiseptic micelles containing the hydrophobic drug quercetin and ending with assessing the activity of the resulting composites against various microorganisms. The main emphasis is on studying the quercetin solubilization in antiseptic micelles as well as establishing the relationship between the conditions of MSN synthesis and micelle morphology and capacity. The effect of medium pH on the release rate of encapsulated drugs is also evaluated. It was shown that the MSNs contained large amounts of encapsulated drugs and that the rate of drug unloading depended on the medium pH. The incorporation of such MSNs into the alginate matrix allowed for a prolonged release of the drugs. [ABSTRACT FROM AUTHOR]

This paper presents the results of the studies of refractory materials produced by the company Keralit, the Borovichi Refractories Plant, and Scientific and Technical Center Bakor (STC Bakor) and intended for the roof of an EP-6 electric furnace for high-level waste vitrification. These studies determined the strength properties and acid resistance of these materials when exposed to nitric-acid in vapor and solution forms. The results of the studies show that the optimum materials for constructing the melter roof are MKRTU-50 and MKV-65 produced by the Borovichi Refractories Plant and STC Bakor, respectively. [ABSTRACT FROM AUTHOR]

The correlation between the time of preliminary storage of ultrasmall gold nanoparticles (GNPs) synthesized according to the Duff method and the structural aspects of their interaction with the particles of cholesteric liquid-crystalline dispersions (CLCDs) of DNA were studied. It has been established that the "age" of GNPs significantly affects the magnitude of their destructive action on the ordered organization of the DNA CLCD particles. The observed effect may be caused by both the gradual perfecting of the crystal lattice of the studied GNPs (i.e., their metallization) and the change in the chemistry of their surface over time. [ABSTRACT FROM AUTHOR]

The unique properties of metal nanoparticles (NPs) resulting from their localized surface plasmon resonance have led to the emergence and rapid development of promising scientific areas. One of these areas is thermoplasmonics, which is based on the ability of such NPs to effectively transform optical radiation into heat. We discuss the optical properties of noble metal NPs, the main approaches to their synthesis, as well as the latest advances of thermoplasmonics in the field of biomedicine. The focus of this review is on photothermal diagnostics and therapy (theranostics) of various diseases. Note that, in addition to theranostics of tumors, the prospects for the use of plasmonic NPs in cardiology, ophthalmology, the fight against bacterial and viral infections, and other biomedical fields have been analyzed. [ABSTRACT FROM AUTHOR]

Results of experimental measurements of mechanical and physical characteristics of refractory materials are presented: LTEC, thermal conductivity, heat capacity, dynamic and static elasticity moduli. The study is conducted to select material for the manufacture of a glass furnace arch for solidifying radioactive waste. It is shown that materials of the MKRV-53 and AZS-60SB grades are superior with respect to properties compared with material of the BMKrF grade. The results obtained are used for mathematical modeling of electric furnace arch operating regimes. [ABSTRACT FROM AUTHOR]

The study investigates hydrogenation of CO2 over mono- and bimetallic catalysts supported on biochar. In this reaction, bimetallic iron–cobalt catalysts were shown to surpass monometallic iron and cobalt catalysts in terms of catalytic performance. The optimal combination of performance parameters was reached at an iron to cobalt ratio of 3 : 1. The composition and genesis of the active phase in the bimetallic Fe–Co catalyst were identified, and the CO2 hydrogenation mechanism was suggested for an iron-dominated bimetallic catalyst. Using biochar as a support was found to provide an active phase composition favorable for CO2 hydrogenation. [ABSTRACT FROM AUTHOR]

The results of two different ways of introducing SYBR Green I (SG) and PicoGreen (PG) cyanine dyes, as well as ultrasmall gold nanoparticles (GNPs) in a cholesteric liquid-crystalline dispersion (CLCD) of DNA, are compared: preliminary incubation with DNA and introduction in a ready-made dispersed system. In the absence of dyes and in the presence of SG, the preliminary incubation of GNPs in a DNA solution leads to an increase in the destruction of its cholesteric phase. At the same time, more efficient quenching of SG fluorescence was observed upon the injection of GNPs in a ready-made dispersed system. For the case of PG, the order of introduction of the components does not affect either the properties of the DNA CLCD or the fluorescence of the dye. [ABSTRACT FROM AUTHOR]

Specific features of the seedless synthesis of gold nanoparticles in micellar solutions of both individual alkyltrimethylammonium bromides with different hydrocarbon chain lengths and their mixtures have been studied. The main attention has been focused on studying the possibility of controlling the shape and, consequently, the position of the localized surface plasmon resonance of the nanoparticles in the presence of octadecyltrimethylammonium bromide (OTAB). It has been found that its use leads to the formation of monodisperse gold nanorods with a larger aspect ratio than that in the case of cetyltrimethylammonium bromide, which is commonly used for this purpose. Moreover, it has been shown that the introduction of OTAB into micellar solutions of its homolog with a noticeably shorter alkyl chain (dodecyltrimethylammonium bromide) promotes a change in the shape of the formed gold nanoparticles from spherical to rodlike one. [ABSTRACT FROM AUTHOR]

Gold nanoparticles (GNPs) are promising radiosensitizers for cancer radiotherapy. Moreover, they can be used in the same way for radiation processing and sterilization. Such application of GNPs is of practical interest since it may significantly reduce the dose load and expand the application of radiation treatment. In the present study, the high radiosensitization effect of GNPs in relation to viral particles is demonstrated for the first time. The preparations of tobacco mosaic virus (TMV) are used as an experimental model, insofar as this virus has the same properties as animal and human ones but is safe for humans. Irradiation with 45 kVp X‐ray to the doses of 4 and 7 kGy leads to a decrease in the infectious activity of TMV virions up to 1.92‐ and 2.70‐fold, respectively. At the same time, irradiation in the presence of 0.4 mg mL−1 of 12 nm spherical GNPs increases the efficiency of virus inactivation up to 15‐ and 22‐fold. The GNPs enhance both the damage to capsid protein due to the enhanced generation of reactive oxygen species and genome RNA due to the emission of secondary radiation. These results show the great prospects of the application of high‐Z nanoparticles in radiation treatment. [ABSTRACT FROM AUTHOR]

Chamberprotection of metals from atmospheric corrosion is a variety of vapor-phase inhibition. It is based on the effect of adsorption films formed in the vapors of low-volatile corrosion inhibitors at elevated temperatures. The paper analyzes the specific features of the chamber protection of a magnesium alloy with chlorobenzotriazole. It has been found that the protective properties of surface films formed in hot vapors of this compound increase upon exposure of the metal to air. The processes of structuring of protective films that occur in this case have been studied by a set of corrosion, electrochemical and physical methods. It has been shown that chamber treatment of the alloy is accompanied by chlorobenzotriazole adsorption and uniform thickening of the surface oxide-hydroxide layer. In this case, the corrosion processes slow down by a factor of up to 10. Prolonged exposure of the samples in air after the chamber treatment results in additional oxidation of magnesium and hydroxylation of the oxide. However, the oxide-hydroxide layer does not grow on the entire surface, but as separate islets. Such a change in the structure of the surface films results in an additional 10-fold increase in the corrosion resistance of the magnesium alloy. [ABSTRACT FROM AUTHOR]

The features of the formation of organosilica shells from γ-mercaptopropyltrimethoxysilane on the surface of gold nanorods and the possibilities of using the prepared composite particles as means of combined tumor therapy are discussed. It is shown that the presence of SH functional groups, which are able to coordinate platinum ions, in the shells makes it possible to load rather large amounts of an anticancer drug, cisplatin, into them. Quantitative data are obtained on the regularities of the sorption of this drug and the influence of the pH and ionic strength of a solution on the kinetics of its desorption. [ABSTRACT FROM AUTHOR]

It has been found that the addition of ammonia water to a gold sol obtained by the Duff method induces the growth of the gold particles. The growth kinetics of such particles in alkaline solutions of ammonia and sodium hydroxide has been investigated. Using the modified Kolmogorov–Johnson–Mel–Avrami model, the aggregative mechanism of nanoparticle growth has been revealed for a system with the maximum NH3⋅H2O concentration, while a mixed mechanism, which includes the Ostwald ripening, has been found for other systems. It has been shown that the sizes and dispersity of the final particles can be controlled by varying the concentration of ammonia water and the time of preliminary incubation of an initial sol, while sodium hydroxide does not exhibit such ability. It has been assumed that the decomposition of gold–phosphine complexes, which stabilize the ultrafine particles, followed by the formation of gold–ammonia complexes is the most probable explanation for the action of ammonia water on the Duff sols. [ABSTRACT FROM AUTHOR]

The features of the synthesis of SiO2 mesoporous container particles (MCPs) using a hybrid template represented by miramistin micelles with curcumin solubilized in them have been studied. Miramistin is an antiseptic, whereas curcumin is a hydrophobic biologically active compound of a broad range of action. The effects of reaction system pH on the structure and morphology of MCPs and on the content of the biologically active compounds in them have been investigated. It has, in particular, been found that spherical and rodlike MCPs are formed in neutral and alkaline media, respectively. Quantitative data have been obtained on the kinetics of releasing the encapsulated compounds from the container particles into an ambient medium with a given pH value. It has been determined that the rate of this process can additionally be controlled by forming a shell a biocompatible polymer, polydopamine, on the MCP surface. Using MCPs synthesized in an alkaline medium as an example, it has been shown that such containers are highly efficient antiseptics with respect to both gram-positive and gram-negative microorganisms. [ABSTRACT FROM AUTHOR]

Structural changes in particles of cholesteric liquid crystal dispersion (CLCD) of DNA during the formation of complexes of the cyanine dyes SYBR Green I (SG) and PicoGreen (PG) with negatively charged gold nanoparticles (NPs) have been studied using circular dichroism spectroscopy. It has been shown that in the presence of the dyes, the degradation of the cholesteric DNA packing by the action of gold NPs increases by a factor of ~1.6 (SG) or ~2.7 (PG). Gold NPs have been found to prevent the formation of the reentrant cholesteric DNA phase during the quenching of DNA CLCD—its heating to 80°C and cooling to 20°C. Pretreatment of the DNA dispersion with SG or PG in this case facilitates the restoration of the circular dichroism signal. A greater effect is noted for PG, which can be explained by stronger electrostatic interaction of this dye with Au NPs, since its charge is +3, whereas the charge of SG is +2. [ABSTRACT FROM AUTHOR]

It is shown by the example of hydrogen (in hydrides ZrH), helium (in pores after implantation), and nickel (in G-phase precipitates) that the application of electron energy-loss spectroscopy within the scanning transmission electron microscopy method makes it possible to analyze the distribution of different chemical elements in the microstructure of reactor materials. The advantages of electron energy-loss spectroscopy (in comparison with energy-dispersive spectroscopy) for studying irradiated materials and important experimental conditions of the formation of energy loss spectra are discussed. [ABSTRACT FROM AUTHOR]

The perspectives of using γ-mercaptopropyltrimethoxysilane as a precursor for creating multifunctional composite nanoparticles (CNPs) with a rodlike gold core and an organosilica shell have been analyzed. It is shown that the presence of thiol groups, which are capable of specific interactions with metal ions and atoms, in the shell makes it possible to "directly" (i.e., without any additional modification) load rather large amounts of an anticancer drug, cisplatin, into it. In addition, preliminary data have been obtained that indicate the possibility of nitrosation of the SH-groups of the shells, which is very important from the viewpoint of creating container CNPs for NO, with such containers providing not only its delivery to tumors, but also its controlled release under the action of laser radiation. [ABSTRACT FROM AUTHOR]

The review analyzes the general trends of the studies devoted to the encapsulation of various functional compounds (from drugs to corrosion inhibitors) in silica mesoporous container particles (MCPs). The main focus is on discussing new approaches to creating such structures. Primarily, they are approaches that allow one to combine the stages of the synthesis of MCPs and their loading with one or several targeted substances. The data available from the literature have been used to show the advantages and promises of such one-stage approaches to solving problems relevant to providing MCPs with high content of encapsulated substances and controlling the rate of their release. [ABSTRACT FROM AUTHOR]

The peculiarities of the synthesis of silica-based mesoporous container particles with the use of sodium oleate as a templating agent have been discussed. Sodium oleate is an anionic surfactant and an efficient corrosion inhibitor. It has been shown that the container particles obtained as a result of combining the stages of their synthesis and loading contain a very large amount of the inhibitor. The effect of dispersion medium composition and temperature on the structure of surfactant associates and, hence, the morphology of the obtained particles has been analyzed. [ABSTRACT FROM AUTHOR]

A comparative analysis has been performed for the structure of ring deposits resulting from the evaporation of droplets of aqueous dispersions of gold nanorods and composite nanoparticles with a gold core/organosilica shell structure based thereon. The nature of the particles has been shown to have a key effect on the character of their packing near a three-phase contact line. The study of the conductivity of the ring deposits obtained from dispersions of the composite particles has shown that it is realized via over-barrier electron emission. [ABSTRACT FROM AUTHOR]

Basic information on the physicomechanical and stress-strain properties of polymer composites based on a wide assortment of adhesive preforms and glass and carbon reinforcing fillers is presented. The main advantages of composites with adhesive binders over those with melted binders are discussed. Information about the technological specifics for fabricating construction elements of adhesive binder polymer composites is included. Data from promising research on the design of new polymer composites based on adhesive binders and glass and carbon reinforcing fillers are given. [ABSTRACT FROM AUTHOR]

The effect of the properties of modifying additives (Mg and Ca) introduced into nanosized catalytic dispersions on the occurrence of three-phase Fischer–Tropsch synthesis has been studied. It has been found that the introduction of Mg and Ca into the catalytic dispersion composition contributes to a redistribution of oxygen-containing products; namely, it provides a decrease in the yield of the main byproduct—CO2—and an increase in the yield of alcohols dissolved in water. [ABSTRACT FROM AUTHOR]

The possibility, in principle, of high-temperature three-phase Fischer-Tropsch synthesis, which is implemented in the presence of iron-containing catalytic dispersions in a bubble column reactor, is demonstrated. The catalytic system is activated in situ in a CO stream. It is proved that the particle size of the iron-containing dispersion used as the catalyst for this process depends on the precursor solution injection technique and in no case does it exceed 50 nm. It is shown that the described three-phase high-temperature Fischer-Tropsch synthesis method makes it possible to achieve high process parameters, such as target products yield up to 138 g/m3 with 90% selectivity of products formation. The properties of the developed catalyst enable it to perform for a prolonged period with high conversions without impairment of process selectivity. [ABSTRACT FROM AUTHOR]

The effect of the plasmonic enhancement of dye fluorescence in poly(vinyl butyral) films containing Ag/SiO2 core-shell nanoparticles has been thoroughly studied. It has been shown that the magnitude of this effect can be quite large (up to 5 times) even for a dye having a very high quantum yield (coumarin 7). Therewith, it substantially depends on the size and concentration of Ag/SiO2 particles and the quantum yield of a dye. The results obtained are discussed with involvement of mechanisms reported in the literature for plasmonic enhancement of fluorescence of dyes characterized by high and low quantum yields. [ABSTRACT FROM AUTHOR]

The features of (γ-mercaptopropyl)trimethoxysilane (MPTMS) hydrolytic condensation in alkaline aqueous solutions have been studied. The interrelation between the process time, MPTMS concentration, and structure-related morphological characteristics of the obtained organosilica (silsesquioxane) particles has been determined. It has been shown that toroidal particles are mainly formed at low precursor concentrations (≤2.5 mM) in a solution. The formation kinetics of such nanotoroids has been analyzed, and preliminary data have been obtained on the mechanism of this process. These data have been discussed taking into account the information available from the literature on the structure of silsesquioxanes and the role of disulfide bonds in the formation of anisotropic particles of these compounds. [ABSTRACT FROM AUTHOR]

The most significant results of Russian studies in the field of atmospheric electricity in 2015–2018 are reviewed. The review is a part of the Russian National Report on Meteorology and Atmospheric Sciences to the International Association of Meteorology and Atmospheric Sciences (IAMAS). It was presented and approved at the 27th General Assembly of the International Union of Geodesy and Geophysics (IUGG)1. The review is followed by a list of the main Russian works on atmospheric electricity published in 2015–2018. [ABSTRACT FROM AUTHOR]

The solubilization of a water-insoluble biologically active compound, curcumin, in micelles of amphiphilic antimicrobial agents, such as miramistin, ethonium, and cetalkonium, is investigated, and the thermodynamic characteristics of this process are determined. It has been shown that the sol–gel synthesis of multifunctional mesoporous silica containers can be realized using these surfactants' micelles, which contain solubilized curcumin, as "hybrid" templates. [ABSTRACT FROM AUTHOR]

Abstract—Data on the most frequently mentioned systems consisting of bimetallic nanoparticles, one of the components of which are gold nanoparticles, are generalized and systematized. Methods of their preparation affecting their structural characteristics are described. Optical and other properties and advantages in their directed application in various fields are shown. [ABSTRACT FROM AUTHOR]

Supported polymetallic catalysts (5–15% wt% of active phase) for deep oxidation and hydrogenation were successfully prepared by Self-propagating Surface Synthesis (SSS) using metal nitrates as oxidants and urea as a fuel. Commercial granules of γ-Al2O3; NaA, NaX, ZSM-5 zeolites; and silica gel were used as supports. The synthesized catalysts were characterized by XRD, BET, and SEM/EDS. Catalytic behavior of the catalysts in a flow reactor was determined by gas–liquid chromatography, chemical analysis, and tested in deep oxidation of CO and propane as well as in hydrogenation of CO2 to methane. [ABSTRACT FROM AUTHOR]

Abstract: Topochemical transformations occurring during the reduction of low-concentrated catalytic dispersions used for Fischer-Tropsch synthesis in a three-phase slurry reactor are investigated. As evidenced by dynamic light scattering and transmission electron microscopy, catalyst systems containing nanoparticles with sizes of 91 and 3 nm, respectively, are formed in systems containing cobalt at concentrations of 5 and 1 wt %. After catalyst activation via the reduction of cobalt-containing particles by hydrogen, the size of the dispersed phase is 2-3 nm regardless of the content of cobalt in the suspension. The study of magnetic properties of suspension samples in situ indicates that metallic cobalt is formed during the process of catalyst activation, as confirmed by X-ray powder diffraction analysis. [ABSTRACT FROM AUTHOR]

Abstract: The experimental data on the hydrogenolysis of long-chain alkanes over suspended cobalt Fischer-Tropsch catalysts are presented which demonstrate the specific character of the molecular-mass distribution of its products (the combination of excess methane, local minimum at С3-С7 carbon chain lengths, and local maximum at С12-С16 carbon chain lengths). These results provide the experimental verification for the model of the mentioned distribution previously advanced by the authors which includes the hypothesis that the probability of С-С bond cleavage in an alkane molecule increases from the chain center to its ends. These distribution features are observed in the conversion of both alkanes of the suspension medium and individual n-alkanes (n-С16Н34) at different temperatures for in situ synthesized nanosized catalysts and commercial oxide samples and for n-С16Н34 after distillation of the hydrocarbon medium of the preliminarily suspended nanosized catalyst. [ABSTRACT FROM AUTHOR]

Abstract: The laws governing the formation of nanoscale iron-containing disperse systems with a dispersed-phase particle size of 2-256 nm have been studied. The main features of the Fischer-Tropsch (FT) synthesis of synthetic hydrocarbons (HCs) in the presence of these systems have been revealed; the effect of the active phase concentration in the slurry on the selectivity for products with the C11+ chain length has been determined. It has been shown that a decrease in the particle size of the disperse system leads to an increase in the resistance of the iron carbide phase to oxidation by oxygen-containing products formed in the HC synthesis reaction. [ABSTRACT FROM AUTHOR]

The influence of integrated resistors formed under irradiation in a nanowire on its superconducting transitions has been investigated. Niobium nitride nanowires with widths of 75–20 000 nm fabricated from a 5-nm-thick NbN film on single-crystal silicon substrates coated with a 0.3-μm-thick thermal silicon oxide layer and on sapphire substrates have been considered. The influence of a built-in resistive region on the critical current of transition from the superconducting to normal state is described. [ABSTRACT FROM AUTHOR]

Abstract: The effect of the degree of anisotropy (axial ratio) of gold nanoparticles on the structure and conductivity of ring deposits formed on a planar substrate upon evaporation of droplets of aqueous dispersions with different particle number concentrations has been studied. A nontrivial phenomenon of a decrease in the specific conductivity of the deposits with an increase in particle concentration in case of gold nanorods dispersions has been revealed. [ABSTRACT FROM AUTHOR]

Seedless synthesis of gold nanorods with the use of sodium borohydride and hydroquinone as reductants of metal ions has been systematically studied. The effect of reaction system composition on the morphology and optical characteristics of the formed particles has been determined. It has been found that the position of the band of the longitudinal surface plasmon resonance of the nanorods varies nonmonotonically with variations in the concentration of hydroquinone or silver nitrate. The seedless synthesis has been shown to yield high-quality gold nanorods, with the tunable position of their longitudinal surface plasmon resonance in a wide spectral range (from 700 to ~1050 nm). Therewith, the conversion of metal ions is no lower than 78 wt %. [ABSTRACT FROM AUTHOR]

It has been shown that silica container particles can be loaded with large amounts of an anionic corrosion inhibitor, sodium N-oleyl sarcosinate, at the stage of the sol−gel synthesis of the particles by using its micelles as a template. When incorporated into paint and varnish coatings, such containers efficiently protect low-carbon steel and D16 aluminum alloy from corrosion under severe conditions of neutral salt spray. [ABSTRACT FROM AUTHOR]

Abstract: Several years ago the photoinduced reaction of mixed phosphonium‐iodonium ylides (1) with acetylenes (2) to give λ5‐phosphinolines (3) and substituted furans (4) was described. This reaction is one‐pot, metal‐free synthesis of heterocycles 3 and 4 with the yields of 40% to 80%. The reaction proceeds only in dichloromethane (DCM) at the high ylide concentrations (>0.01 mol/L). The product analysis by 31P NMR, electrospray ionization mass spectrometry, UV‐vis spectrophotometry, and the dynamic light scattering study of the self‐aggregation of the ylide in DCM showed a dual role of the solvent in the photoinduced reactions of mixed phosphonium‐iodonium ylide: (i) at the low ylide concentrations (<0.01 mol/L), the conjugated photoinitiation of the chain reaction in DCM results in the formation of chlorine‐containing products and (ii) at the high ylide concentrations (>0.01 mol/L), the photolysis mechanism is determined by self‐organization of the ylide molecules to give large stable aggregates in DCM, in which the target heterocycles are synthesized. Two important issues follow from the study. First, the annulation reaction between mixed phosphonium‐iodonium ylide and acetylenes occurs only when the reactive intermediates are in close proximity to one other, and, second, DCM is not inert reagent in reactions occurring with participation of radicals and in one form or another can participate in photoinduced radical reactions of various solutes. [ABSTRACT FROM AUTHOR]

Kinetic models are developed for the molecular-mass distribution of the products of hydrogenolysis of mixed long-chain n-alkanes experimentally studied in the three-phase slurry reactor over nanosized cobalt-containing Fischer-Tropsch catalysts. The models are based on different hypotheses pertaining to the ratios of probabilities for the cleavage of C-C bonds as a function of their position in n-alkane chains with allowance made for the occurrence of secondary transformations of products and the vapor-liquid equilibrium in the mixture of n-alkanes in a hydrogen medium. It is demonstrated that the experimentally observed features of this distribution cannot be described in terms of the known theories of C-C bond cleavage in the hydrogenolysis of long-chain alkanes (terminal methane splitting and uniform or normal distribution of product composition). The hypothesis of a regular increase in the probability of C-C bond cleavage on going from the center of the carbon chain to its ends is advanced. Calculations performed using combinations of the distribution following this hypothesis and the normal distribution make it possible to solve the problems mentioned above. [ABSTRACT FROM AUTHOR]