Home – Home – Jornals – Chemistry for Sustainable Development 2013 number 1

Results of modeling of the formation of the Vilyui sedimentary basin are presented. We combine backstripping reconstructions of sedimentation and thermal regime during the subsidence with a numerical simulation based on the deformable solid mechanics. Lithological data and stratigraphic sections were used to “strip” the sedimentary beds successively and calculate the depth of the stratigraphic units during the sedimentation. It is the first time that the evolution of sedimentation which is nonuniform over the basin area has been analyzed for the Vilyui basin. The rift origin of the basin is proven. We estimate the spatial distribution of the parameters of crustal and mantle lithosphere extension as well as expansion due to dike intrusion. According to the reconstructions, the type of subsidence curves for the sedimentary rocks of the basin depends on the tectonic regime of sedimentation in individual basins. The backstripping analysis revealed two stages of extension (sediments 4–5 km thick) and a foreland stage (sediments >2 km thick). With the two-layered lithosphere model, we conclude that the subcrustal layer underwent predominant extension (by a factor of 1.2–2.0 vs. 1.1–1.4 in the crust). The goal of numerical experiments is to demonstrate that deep troughs can form in the continental crust under its finite extension. Unlike the oceanic rifting models, this modeling shows no complete destruction or rupture of the continental crust during the extension. The 2D numerical simulation shows the possibility of considerable basement subsidence near the central axis and explains why mafic dikes are concentrated on the basin periphery.

The Junggar basin contains an almost continuous section of Late Carboniferous–Quaternary terrigenous sedimentary rocks. The maximum thicknesses of the stratigraphic units constituting the basin cover make up a total of 23 km, and the basement under the deepest part of the basin is localized at a depth of 18 km. Both the folded framing and the basin edges have undergone uplifting and erosion during recent activity. These processes have exposed all the structural stages of the basin cover. Considering the completeness and detailed stratigraphic division of the section, we can determine the exact geologic age of intense mountain growth and erosion periods as well as estimate the age of orogeny periods by interpolating the stratigraphic ages. During the Permian orogeny, which included two stages (255–265 and 275–290 Ma), the Junggar, Zaisan, and Turpan–Hami basins made up a whole. During the Triassic orogeny (210–230 Ma), the Junggar and Turpan–Hami basins became completely isolated from each other. During the Jurassic orogeny (135–145 and 160–200 Ma), the sedimentation took place within similar boundaries but over a smaller area. During the Cretaceous orogeny (65–85 and 125–135 Ma), the mountain structures formed mainly at the southern boundaries of the basin and along the Karamaili–Saur line. The Junggar and Zaisan basins were separated at that time. The Early and Middle Paleogene were characterized by relative tectonic quiescence. The fifth orogenic stage began in the Oligocene. The recent activity consists of two main stages: Oligocene (23–33 Ma) and Neogene–Quaternary (1.2–7.6 Ma to the present).

High-Mg metabasalts and metapicrites discovered within the Urtagol Formation in the central zone of the Tunka bald mountains (East Sayan) are studied. In geochemistry the high-Mg metavolcanics are similar to subductional rocks. We have established that the Nb-rich recycled material of oceanic crust (RSC) was a source of elements for high-Ti metabasalts, and subductional fluid rich in LREE and Th relative to Nb was the source of these elements for high-Ti metapicrites. The enrichment of low-Ti metavolcanics, formed, probably, at the early stages of the basin opening, was due to the contamination of melt with continental-crust material. A comparison of the metavolcanics with nonmetamorphosed analogs is made, and some genesis aspects are considered. The results obtained led to the conclusion that the metavolcanics mark the paleospreading of the back-arc basin.

The petrology and ore potential of the Talazhin massif located in northwestern East Sayan are studied. The internal structure of the intrusion, the petrographic composition of its rocks, and their metallogenic, petrostructural, and petrogeochemical features are considered. The probable temperature and chemical composition of the parental magma of the pluton were computed using the KOMAGMAT-3.52 program on the modeling of equilibrium crystallization. The obtained data indicate that the Talazhin massif is a rhythmically layered plagiodunite–troctolite–anorthosite–gabbro intrusion formed from low-Ti high-alumina olivine–basalt melt. It is promising for Cu–Ni–PGE mineralization.

The role of overpressures in thermochemical processes in the South Caspian basin is considered. The studies, which take the world experience into account, suggest that the South Caspian basin (mainly its deep-water part), as well as other basins with abnormally high fluid pressures, is characterized by retarded kerogen and oil cracking and reaction of clay-mineral transformation. These processes can be periodically intensified by the development of diapirs and mud volcanoes, which are centers of pulsed hydrocarbon discharge from the system. The conclusion is made that deeply buried deposits in basins with fluid overpressure are promising for hydrocarbon pools.

We present the results of tectonophysical reconstruction of natural stress of the Earth’s crust in the Altai-Sayan mountain region using cataclastic analysis of fault slips and seismic data on the focal mechanisms of earthquakes. This method allows one to obtain the parameters of the total stress tensor by invoking additional data: generalized experimental data on the brittle fracture of rocks, seismic data on the released stress of strong earthquakes, and data on the topography and density of rocks. The results of the tectonophysical reconstruction of stresses showed significant heterogeneity of the stress state, which is manifested not only in the variation of the strike and dip of the principal axes of the stress tensor, determining changes in the geodynamic regime of the Earth’s crust, but also in the close location of the regions of high and low isotropic tectonic pressure in relation to the lithostatic pressure. The variance of the ratio of tectonic pressure to lithostatic pressure is in the range of 0.59–1.31, with an average value for the region close to unity. This paper discusses internal or external mechanisms capable of generating the stress field obtained by the tectonophysical reconstruction.

The acceleration response spectra of earthquakes with M = 4.0—6.5 in the southwestern part of the Baikal Rift Zone have been studied. The absorption properties of the medium and the attenuation of seismic signals in the study region were determined. Average acceleration response spectra were obtained for regional earthquakes. A comparative analysis of the acceleration response spectra was made for earthquake’s focal mechanisms with different senses of motions: reverse faults, reverse slip, strike slip, and oblique slip. The effect of the sense of fault motion in the seismic source on acceleration response spectra was determined.

Samples of marble and granite with different grain sizes were subjected to impact fracturing under laboratory conditions. The acoustic-emission (AE) signals generated by growing cracks were recorded at 10 ns intervals. Synchronically, the fractoluminescence (FL) resulting from the breakage of interatomic bonds on the sample surface was recorded. The duration of the intervals between the AE signals was shown to be a power-low function typical of correlated (self-similar) processes. However, the FL signals did not follow this law, because the duration of free-radical formation is much shorter than the intervals at which they appear when chemical bonds break down. The AE data indicate that new cracks appear more often in materials with a smaller grain size.

A two-mode method of measuring permeability and electroacoustic constant in the course of borehole logging is considered. The first mode is the Stoneley wave with its electroacoustic ratio; the second mode is the radial wave in the formation around the borehole with the electric field it generates. The radial wave enables one to measure the electroacoustic constant and the Stoneley wave, the electroacoustic ratio, linearly dependent on permeability. Using these measurements jointly enables one to find permeability of the porous medium. All formation evaluation can be reduced to an additional measurement of electric conductivity.

Geophysical and geochemical data have been analyzed jointly in order to gain better understanding of subduction-related active volcanism in Kamchatka. The velocity structure of lithosphere beneath volcanic arcs has been imaged on three scales. Regional tomography to distances of thousands of kilometers has allowed constraints on slab geometry, which changes markedly in dip angle and thickness beneath the Kuriles-Kamchatka arc, possibly, because of a change in the interplay of the subduction driving forces. Intermediate-scale regional tomography (hundreds of kilometers) has been applied to the cases of Toba caldera in Sumatra, Mount Merapi in Java, and volcanoes in the Central Andes and provided evidence of magma conduits marked by low-velocity zones that link the suprasubduction volcanic arcs with clusters of earthquake hypocenters on the slab top. Local tomography resolves the shallow structure immediately under volcanoes and the geometry of respective melting zones. An example time-lapse (4D) seismic model of the crust beneath the Klyuchevskoy group of volcanoes has imaged a decade-long history of anomalous velocity zones and their relation with the activity cycles of Bezymyanny and Klyuchevskoy Volcanoes. As modeling shows, andesitic Bezymyanny and basaltic Klyuchevskoy Volcanoes have different feeding patterns during their eruption cycles: The former feeds directly from the mantle, while the material coming to the latter passes through a complicated system of intermediate chambers. The local tomography model has been applied as reference to interpret the available major- and trace-element data from the Klyuchevskoy and Bezymyanny Volcanoes. The lava compositions of the two volcanoes have becoming ever more proximal since 1945 in many major and trace elements, while some parameters remain different. Paroxysmal eruptions of Bezymyanny for several recent decades correlate with the time when Klyuchevskoy erupted lavas with high percentages of high-Mg basalts. The difference in the evolution trends of the Kamchatka volcanic rocks may be due either to fractional crystallization or to the presence of concentrator minerals in the source, titanomagnetite, orthopyroxene, rutile, garnet, and plagioclase being especially active as to uptake of some elements. The natural compositions of rocks have been compared in this context with published experimental data. According to the seismic-velocity structure and lava compositions analyzed jointly, there are five levels of crystallization beneath the studied volcanoes, while the number and spatial patterns of magma sources are different for two types of andesitic volcanoes.

The integrated geological and geophysical studies carried out in recent years in the Lomonosov Ridge and at its junction with the Eurasian shelf revealed evidence for thinned (reduced) crust in the ridge (20–25 km) and its genetic relationship with shelf structures. We compared the parameters of deep seismic cross-sections of the shelf and Lomonosov Ridge, thus proving the existence of continental crust in the latter. Also, we analyzed the deep structure of the junction between the Lomonosov Ridge and the shelf and established a genetic geologic relationship, with no evidence that the Lomonosov Ridge moved as a terrane with respect to the shelf. In addition, seismological studies independently confirm the genetic relationship between the Lomonosov Ridge and the adjacent shelf. The Lomonosov Ridge is a continental-crust block of a craton. The craton was reworked during the Caledonian tectonomagmatic activity with the formation of a Precambrian–Caledonian seismically unsegmented basement (upper crust) and an epi-Caledonian platform cover. Afterward, the block subsided to bathyal depths in the Late Alpine. This block and the adjacent areas of the Eastern Arctic shelf developed in the platform regime till the Late Mesozoic.

The paper presents data on high-grade silicate-carbonate rocks (calciphyres) from the Irkut block (Sharyzhalgai uplift, southwestern Siberian craton). Their origin and age were determined from the rock characteristics, U–Pb dating, REE content, and Hf isotope composition of zircon. The calciphyres occur both as independent section fragments and as interbeds within Paleoproterozoic garnet-bearing and alumina-rich (cordierite- and sillimanite-containing) gneisses. They were produced by metamorphism of terrigenous-carbonate sediments. The terrigenous component ranges in maturity from arenites and wackes to argillaceous rocks; this is consistent with the reconstruction of the sedimentary protoliths of paragneisses, which are predominant in the metasedimentary unit. The geochemical features of the calciphyres, their LREE enrichment relative to “pure” carbonate rocks, and a distinct Eu anomaly were inherited from the terrigenous component of calc-silicate sediments. The Nd model age (2.4–2.7 Ga) of the calciphyres and the value T_Hf(DM-2st) = 2.5–3.0 Ga for zircon from these rocks indicate that carbonate accumulation was accompanied by the supply of terrigenous material, which formed during the erosion of Archean and Paleoproterozoic crust. Zircon from the calciphyres is similar to metamorphic zircon in REE patterns and Th/U ratios. It might have been of detrital origin and then recrystallized during high-temperature metamorphism. Terrigenous-silicate rocks were metamorphosed at ~1.87 Ga. This is close to the previous age estimates for the terrigenous-rock metamorphism (1.85–1.86 Ga) and the age of baddeleyite from apocarbonate metasomatic rocks (1.86 Ga).

The petrography, major element, and trace element (TE) compositions of minerals from two types of modal metasomatites (metasomatized peridotites and pyroxenites) from the Udachnaya and Komsomol’skaya-Magnitnaya kimberlite pipes, Yakutia, have been studied. It is shown that texturally and chemically equilibrated metasomatites A consist of a set of superimposed minerals: phlogopite + diopside ± ilmenite ± apatite ± sulfides ± graphite. Their major and trace element compositions have specific features. The contents of TEs in garnet and clinopyroxene from these metasomatites are close to those in garnet and clinopyroxene from low-temperature coarse-grained peridotites richest in TEs. The distribution of a significant portion of TEs between garnet and clinopyroxene from A -type metasomatites and from coarse-grained lherzolites rich in TEs is close to experimental values reported for minerals coexisting with carbonatitic and basaltic fluids. We assume that this metasomatic process was nearly synchronous with the global metamorphism and cratonization of the mantle lithosphere and that high-density silicate–carbonate fluid melts were metasomatizing agents.
Another large mantle metasomatism process in the lithosphere of the Siberian craton was associated with the Middle Paleozoic kimberlite magmatic event, induced by the Yakutian thermochemical plume. Metasomatic minerals (Mg phlogopite + Cr diopside + chromite ± sulfides ± graphite) intensely replaced the minerals of the primary paragenesis, particularly, garnet. These reaction metasomatites show a sine-shaped REE pattern in garnet and disequilibrium between garnet and clinopyroxene. It is supposed that the reaction metasomatism in the mantle lithosphere of the Siberian craton was associated with ingress of reduced asthenospheric fluids at the early stages of the kimberlite formation cycle. Metasomatic graphite formed in metasomatites of both types, and this fact evidences for two diamond formation epochs in the history of the mantle lithosphere of the Siberian craton.

By the example of the Ingoda basin (Transbaikalia) including a system of small lakes, the role of two leading processes of concentration of trace elements in small reservoirs (water–rock interaction and evaporation) has been estimated. It is shown that the accumulation of U, As, Se, Sb, and Ge does not depend on the kind of concentration. Their contents increase linearly with total dissolved solids in both lake and feeding waters. Accumulation of Sc, V, Y, Th, REE, and W is mainly due to evaporation, with their maximum concentration by three to four orders of magnitude. Only U, W, and REE, whose contents in the lakes reach n·100 μg/l, are of practical interest.

Several active fault zones were studied in the southern Siberian Platform along the Kovykta–Sayansk–Irkutsk gas pipeline. Late Cenozoic seismogenic faults are observed here. The fault zone in the Biliktuika River valley shows the strongest displacements and deformations. The radiocarbon dating of buried soil horizons for this fault was compared with seismological data on the earthquakes observed in this area. The comparison permitted attributing the latest slip along the fault to the 25 May 1887 earthquake.

Large earthquakes took place in southern Cisbaikalia in the first half of 1912. They might have caused a mass release of large amounts of gas (methane?) into the water of Lake Baikal and the atmosphere near Sharyzhalgai station of the Circum-Baikal Railroad. This phenomenon was observed in August 1912 by the residents as rising water columns several meters high and reported in the regional press.

We present results of mineralogical and crystallochemical studies of the Holocene carbonate sediments of a small saline lake localized in the Borgoi dry-steppe region, western Transbaikalia. Mg-calcites with a varying Mg content are predominant in the assemblage of endogenic carbonate minerals from bottom sediments. Mathematical modeling of the XRD spectra of carbonates permitted us to identify excess-Ca dolomites, which are an indicator of a shallow (playa) lake. The studies showed that the lacustrine Mg-calcites do not form a continuous series from low- to high-Mg varieties. We discuss the cause of this phenomenon and also consider the existing viewpoints of the structure of low-temperature Mg-calcites and excess-Ca dolomites and their formation conditions in lacustrine sediments. Juxtaposing the carbonate record with the data of lithological analysis, determined stable isotopes (δ¹⁸O and δ¹³C), and distribution of some geochemical indicators of climatic changes, we reconstructed the intricate evolution of Lake Verkhnee Beloe, which was controlled by the regional climate since the postglacial period till the present day.

Results of paleoclimatic analysis of geothermal data in the Middle and Southern Urals for different time intervals are presented. Climate reconstruction for the past millennium was made using data from 44 boreholes, and the magnitude of the Wurm–Holocene warming event was estimated based on data from two deep boreholes. The method of functional space inversion was used. The resolution of the method for reconstruction of various climatic events in the past was investigated. Parameters specified a priori and the required duration of the period to be reconstructed were chosen from the results of numerical modeling. According to the inversion results, the ground surface temperature at the maximum of the Medieval Warm Period in 1100–1200 was approximately the same as the present temperature, and at the minimum of the Little Ice Age around 1720, it was 1.2–3 ºC lower than at present. The subsequent temperature rise was more pronounced in the past century. The magnitude of the Wurm–Holocene warming event, reconstructed using data from two deep boreholes, is 10–11 ºC.

Based on the experimentally measured parameters of elemental composition, average molecular masses, and PRM spectrometry data, we calculated the average structural parameters of resin and asphaltene molecules in Paleozoic oils of some oilfields in the Timan–Pechora petroliferous basin. The values of the structural parameters of cyclic and aliphatic fragments in the molecules of resin–asphaltene components of the crudes studied here are within the ranges established earlier for high-molecular compounds of crudes from other petroliferous basins.
The average structural-group characteristics of resins in crudes from carbonate reservoirs vary over narrow ranges of values independently of the age and depth of occurrence of the reservoir.
The resinous fractions of crudes from terrigenous horizons show symbatic enrichment with paraffin fragments and depletion with naphthene fragments of molecules with depth. This points to the presence of a paragenesis of petroleum hydrocarbons and heteroatomic compounds in the Earth’s interior.

The heating of the wall of a reactor at the third ignition limit was measured during induction and explosion. It is shown that the heat released during induction is approximately equal to the heat released during explosion. It is established that in the induction period and below the limit, the reaction rate changes by a factor of about 10 with a change in the order of consecutive supply of hydrogen and oxygen to the reactor. This means that in these cases, the reaction occurs mainly on the wall of the reactor. The total amount of hydrogen peroxide and the peroxide radical HO₂ below the third ignition limit was measured. It is shown that these intermediate products are formed in an autocatalytic heterogeneous reaction. It is established from the sum of the data from the experiments and the literature that an detonating gas explosion at the third limit is degenerate. The explosion is the result of accumulation and decay of the intermediate product in the gas, which is hydrogen peroxide produced mainly in the wall of the reactor.

The structures of three laminar premixed stoichiometric flames at low pressure (6.7 kPa): a pure methane flame, a pure ethanol flame, and a methane flame doped by 30% of ethanol, have been investigated and compared. The results consist of mole fraction profiles of CH₄, C₂H₅OH, O₂, Ar, CO, CO₂, H₂O, H₂, C₂H₆, C₂H₄, C₂H₂, C₃H₈, C₃H₆, CH₃–C≡CH (propyne), CH₂=C=CH₂ (allene), CH₂O, and CH₃HCO, measured as a function of the height above the burner by probe sampling followed by on-line gas chromatography analyses. Flame temperature profiles have been also obtained by using a PtRh thermocouple. The similarities and differences between the three flames have been analyzed. The results show that, in these three flames, the mole fraction of the intermediates with two carbon atoms is much larger than that of the species with three carbon atoms. In general, the mole fraction of all intermediate species in the pure ethanol flame is the largest, followed by the doped flame, and finally the pure methane flame.

Operation of a pulse aerosol system of extinguishing fires caused by ignition of a methane–air mixture in drifts and coalfaces of coal mines is modeled. A computational experiment shows that such a system can cut off the shock wave propagating over the coal mine drift filled by a combustible methane–air mixture, suppress burning, and protect people and equipment in the mine from the shock wave action.

Results of studying the effect of K₂CO₃ additives on the grain size of the products of combustion of a gas suspension of Al particles (with the mean particle diameter of 4.8 mm) in a laminar diffusion flame are reported. An extreme character of the dependence of the mean size of Al₂O₃ particles on the additive concentration is experimentally observed. For the concentration of the K₂CO₃ additive equal to 0.5%, the mean diameter of Al₂O₃ particles is 30 nm; for the additive concentration of 5%, the mean particle size increases to 67 nm. It is demonstrated that the change in the mean size of A₂O₃ particles as a function of the concentration of the readily ionized additive is caused by interaction of the dusty and ionic subsystems of the plasma of the combustion products in the reaction zone in the flame. At a high concentration of ions (above 10²⁰ m^-3), this interaction increases the rate of coagulation of Al₂O₃ particles.

A model is proposed for the steady-state combustion of a mixture of a pyrolyzed solid fuel and an inert material in a countercurrent gaseous oxidizer. The chemical scheme includes the pyrolysis of the original fuel with the formation of a coke residue and gaseous products (pyrolysis tar), oxidation of pyrolysis tar, and oxidation of the coke residue. The process in an infinite nonadiabatic reactor is considered. The one-dimensional single-temperature model includes the energy conservation equation for the system and the mass conservation equations for each species. The original system of equations is solved for each type of thermal structure of the combustion wave (normal and inverse) using an asymptotic method and assuming a narrow combustion zone. Analytical relations between the main macrokinetic parameters of the process are obtained. It is shown that at la ow content of the inert components (in the parametric domain of inverse waves), pyrolysis completely proceeds in a zone distant from the combustion front. In the region of normal waves, more complete combustion of the fuel is observed, which is provided by oxidation of part of pyrolysis tar.

Modeling of the combustion of cyclic nitramines (CNAs) has shown that their combustion proceeds by the same mechanism with the joint effect of the processes in the condensed and gas phases. The combustion characteristics of the pure substances can be changed only at low pressures by using catalysts acting in the condensed phase, and at high pressures, this problem is difficult to solve. The combustion of binary compositions [CAN + fuel (F), CAN + ammonium perchlorate (AP)] and ternary compositions (AP + CAN + F) is considered. It is shown that the combustion mechanism and characteristics are determined by the chemical interaction and heat exchange between the reactants, which depend on the characteristic particle size in the system.

A pointwise semi-empirical mathematical model is proposed, which ensures a reasonably accurate description of experimental data on the ignition delay of iron particles as a function of ambient temperature with allowance for the dependence of the limiting ignition temperature on pressure.

A two-dimensional unsteady gas-dynamic mathematical model of continuous spin detonation in a non-stoichiometric hydrogen–oxygen mixture in an annular combustor of a rocket-type engine is formulated. An analysis of the governing parameters shows that this model is an eigenvalue problem, where the eigenvalue is the problem period, which cannot be arbitrarily prescribed, but which has to be sought in the course of solving the problem. Numerical modeling of the dynamics of transverse detonation waves is used to elucidate the influence of the fuel-to-oxidizer equivalence ratio on the wave structure and specific impulse, and the eigenvalue (minimum period of the problem) is determined as a function of the specific flow rate of the mixture. These eigenvalues are demonstrated to agree with experimental data. In the case of continuous spin detonation, addition of an expanding nozzle to a constant-section channel is shown to increase the specific impulse.

Loose packed PETN initiation by a hot gas flow generated by an explosion of an active charge separated by an air gap is studied. Experimental data obtained by means of synchrotron radiography are compared with simulations employing a two-phase two-velocity two-temperature model. Reasonable agreement is reached by taking into account two processes accelerating the reaction: particle fragmentation during powder compaction and combustion intensification due to instability of the evaporating surface layer excited by a high-velocity gas flow around the particles.

A model of a wide-range semi-empirical equation of state for metals is presented. The specific heat and Grüneisen coefficients of ions and electrons are functions of temperature and density. At low temperatures, the heat capacity varies according to Debye theory. The removal of the degeneration of the electron gas with increasing temperature is taken into account. The effect of ionization on the thermodynamic functions is effectively taken into account. The equation of state allows the calculation of states in a two-phase liquid–vapor region. This model was used to develop the equations of state for Ta, W, Al, and Be. For its range of applicability, the equation of state contains a relatively small number of free parameters, most of which have a physical meaning. Comparison of calculations of various isolines using equations of state with experimental data and calculations based on other models show that the equations of state for Ta, W, Al, and Be, describe most experimental data for these substances. At ultrahigh pressures and temperatures, calculations using the equations of state are in good agreement with calculations using the Thomas–Fermi model with corrections.

The relation between the parameters of mixed explosives [combinations of Al(NO₃)₃ × 9H₂O powder, RDX powder, and/or polyethylene foaming particles] and the phase and dimension of ultrafine Al₂O₃ is studied in this paper. Experimental results indicate that mixed explosives with a high density of 1.8 g/cm³ are adapted to prepare high-temperature α-A₂O₃. Ultrafine (α + γ)-Al₂O₃ with α-phase dominance is synthesized by the detonation of charges with a medium-high density of 1.3 g/cm³. Explosives with a medium-low density of 0.8 g/cm³ synthesize low-temperature pure γ-Al₂O₃.

This paper presents experimental data on the penetration of shaped charges with porous liners into metal targets located at distances smaller than or comparable to the diameter of the charge and some experimental data on the velocity of the jets from the investigated charges with liners of metal powders.

Combustion of furazanotetrazine dioxide (FTDO) was studied in a constant-pressure bomb in the range of pressures 0.1 ÷ 10 MPa. The thermal decomposition kinetics of FTDO in melt under non-isothermal conditions at temperatures 153 ÷ 179 °C was measured. The rate constants of the non-isothermal decomposition are described by an equation with an activation energy of 26.5 kcal/mol. It is concluded from the studies performed that the combustion of FTDO in the entire investigated pressure range obeys the gas-phase model, i.e., the leading combustion reaction is located in the flame.

The brightness temperature of shock-compressed EC141 NF epoxy resin was measured by a pyrometric method in the pressure range of 19 ÷ 42 GPa. The experimental points are in good agreement within the error with the calculation performed in the work. From the results of experiments, it follows that the presumed phase-transition region is not apparent in the pressure –temperature plane. Particle velocity records at the epoxy–water interface suggest the absence of a chemical reaction in EC141 NF epoxy compound at a pressure of 22.5 GPa during the observation time.

We discuss the tasks and methodological problems of molecular absorption spectrometry as a method for the analysis of unseparated mixtures of organic compounds (petroleum products, pharmaceuticals, and others), which method in some cases can successfully compete with chromatography. Using the chemometric algorithms, in particular the method of projection to latent structures, allows successfully solving three major problems: to eliminate the influence of inter–reference spectral overlapping, to take into account a non-additive character of absorption, to level the detection sensitivity with respect to similar analytes. A brief review of relevant studies carried out within recent years in the Omsk State University is reported.

Despite the abundance of available experimental techniques, the X-ray absorption spectroscopy often remains the only acceptable means for solving a number of problems: studying X-ray amorphous substances, determining the phase composition at a lower concentration limit for impurity samples, determining the valence state of a chemical element in the case of a low content thereof in the sample (mass percent quota). The present review reports the theory and examples of successful applying the methods of EXAFS and XANES to solve complicated problems.

Results are reported on studying the interaction of Pt (IV) anionic chloride complexes with layered magnesium-aluminum hydroxides in the course of synthesizing Pt/MgAlO_x catalysts. As the oxide precursors there were layered hydroxides used with different nature of interlayer anions (and ОН^–) and with Mg/Al ratio ranging within 2–4. The nature of an interlayer of anion is an important parameter affecting the amount of fixed platinum, the composition of surface species and the sites of location thereof in the structure of layered material. In the case of using a hydroxide carrier with the carbonate counterion the fixation of platinum occurs with the participation of the OH groups of hydroxide layers, via adsorbing the hydrolyzed forms of the complexes on the surface. The reduction thereof leads to the formation of isometric platinum particles of 2–4 nm in size. When attaching the platinum complexes to aluminum-magnesium hydroxide with interlayer anions ОН^–, the precursor of the active component is mainly located in the interlayer space, with further forming the particles of flat morphology 50 nm long and the thickness close to the interlayer distance in the layered carrier (0.75 nm). In the case of varying the Mg/Al ratio, an increase of triply charged aluminum cation causes changing the structural characteristics and adsorption properties of aluminum-magnesium hydroxide to result in the formation of an oxide phase with a more developed surface area and higher pore volume. Increasing the positive charge density and enhancing the electrostatic interaction promote the adsorption of a greater amount of platinum (IV) anionic complexes and a stronger interaction thereof with the hydroxide layers. In the case of changing the Mg/Al ratio from 4 to 2, one can observe increasing the dispersity level of the supported platinum particles and increasing the activity of Pt/MgAlO_x catalysts in the propane dehydrogenation reaction.

Zirconium sulphate catalysts applied onto SiO₂ and Al₂O₃ were prepared and investigated. Phase composition inherent in the catalysts, acidic properties according to the adsorption of CO and textural characteristics thereof were investigated. Catalytic activity level in the isomerization reaction of n–hexane was determined. It has been demonstrated that the most active catalytic system is presented by a catalyst based on Al₂O₃ carrier. The yield of hexane isomers wit the use of this catalyst amounts up to 75 mass % within the temperature range of 200–220 °C. It has been found that in the case of using alumina as a carrier the catalysts exhibit forming strong acid centers with the absorption bands of adsorbed CO being at 2210 and 2224 cm^–1.

Equilibrium was investigated concerning the sorption of palladium from the H₂PdCl₄ and Pd(NH₃)₄Cl₂ solutions onto B₂O₃–Al₂O₃ carrier. It is demonstrated that the sorption equilibrium is described by Langmuir equation. According the results of testing the Pd/B₂O₃–Al₂O₃ samples in the course of oligomerization it has been found that the optimum content of palladium in the catalyst should be equal to 0.5 mass %, whereas the optimum precursor of palladium should be presented by palladium chloride complex. The catalytic properties of Pd–Re₂O₇/B₂O₃–Al₂O₃ system in the one-stage propylene synthesis from ethylene were studied. It has been demonstrated that it is possible to obtain propylene with the yield equal to 77–83 % with respect to the theoretically determined one.

The effect of chemical composition on the formation of the crystal structure and texture characteristics of the oxide system B₂O₃–Al₂O₃ obtained through impregnation of pseudoboehmite with the solutions of ortho-boric acid was studied. It was shown that the modification with boron oxide slows down the crystallization of aluminium oxide. According to the high-resolution TEM data, borate-containing aluminium oxides are composed of amorphous and crystalline primary particles. It was established by means of ²⁷Al MAS NMR and ¹¹В MAS NMR that aluminium atoms in the samples occur in octahedral, tetrahedral and penta-coordination, while boron atoms occur in trigonal and tetrahedral coordinations; their relative content depends on chemical composition. The dependence of the specific surface of B₂O₃–Al₂O₃ system on its composition has an extremal character; the maximum is achieved with B₂O₃ content 5 mass %.