Research subject. The Dodo and Puiva quartz crystal deposits in the Neroiskiy mineral province (Subpolar Urals) were studied. Although these deposits have received sufficient research attention, a number of issues remain to be elucidated, including the age of crystal-bearing mineralization and the age of host rocks. Aim . In this work, we aim to determine the age of the metasomatites that bear quartz crystal mineralization and to develop a model of the formation of the Dodo and Puiva deposits. Materials and Methods. 40 Ar/ 39 Ar dating was carried out according to the method described by A.V. Travin et al. The argon isotope composition was measured on a Micromass 5400 mass spectrometer (IGM SB RAS). Results . Microprobe studies of the mineralogy of the Dodo and Puiva quartz crystal deposits were carried out. The temperatures of meta-somtaite formation were determined to range within 339–364°C. Six main structural and morphological types of quartz veins were identified and described. The 40 Ar/ 39 Ar ages of mica of quartz crystal deposits and host metamorphic schists were determined. Reliable plateaus were obtained, the values of which ranged within 251–257 Ma and agreed with each other within the deviation (average for 4 dates is 255 ± 2 Ma). Conclusion . A new model for the formation of quartz crystal deposits in the Subpolar Urals is proposed. The obtained 40 Ar/ 39 Ar ages correspond to the period of the post-orogenic extension of the Urals. At that time, a system of meridional grabens and rifts was formed in the Urals and in the West Siberian Plate. At the same time, and as a result of the same stretching impulse, large blocks of the middle crust (granite, schist, etc.) were brought to the Earth’s surface in the Urals. During the rise of deep blocks, at a depth of 10 km, a sharp, approximately 3-fold drop in fluid pressures (from lithostatic to hydrostatic) and a strong decrease in temperatures due to adiabatic expansion and the throttling effect occurred. The obtained 40 Ar/ 39 Ar ages (255 Ma) reflect not only the age of the quartz crystal deposits of the Subpolar Urals, but also place the moment of rise of the entire Central Ural uplift above a depth of 10 km, i.e., to the level of the upper cortex.

Poly(siloxane-urethane)s are an unique class of organosilicon copolymers that combine valuable properties of both silicones and polyurethanes. In this study a series of polymer films based on poly(siloxane-urethane) was prepared and fully characterized. A modern synthetic route developed by our group earlier based on utilization of organoeuropiumsiloxanes as luminescent agents for the preparation of luminescent polymers was used. The effect of the nature of phenyleuropiumsiloxanes of different structures on mechanical, thermal as well as optical properties of composites was studied. It was shown that oligomeric phenyleuropiumsiloxane in combination with β-diketone ligand provides the most prospect composite materials with intense luminescence.

Natural silicates are potential sources of divalent cations, which are necessary for the mineralization of CO2 in the form of carbonates. The kinetics study of the natural talc dissolution was carried out in flow-through reactors at 25 °C in the presence and absence of organic ligands — oxalate and citrate, at pH 3. Increasing of the rate of talc dissolution in the presence of citrate and oxalate, approximately 3–4 times, is typical only for the initial stage of mineral dissolution. The steady-state dissolution rates of talc were established approximately 30–40 hours after the beginning of the experiment and were equal to 3E–10–16 mol/cm2s.

Dating of zircons from eclogites and amphibolite in metamorphic rocks of the Eastern Mugodzhar zone (terminal south of the Urals) is conducted. Of four eclogite samples, close (and the oldest ones of 520 ± 4 Ma) concordant age values are obtained in three samples, and these ages probably correspond to the age of the protolith. Concordant dates of 472 ± 3 and 379 ± 3 Ma correspond to the main stages of metamorphism in the East Mugodzhar Range: the former marks the time of high-pressure metamorphism, whereas the latter corresponds to the metamorphism of amphibolite facies. The presence of ancient and at the same time varied-age zircons (probably carrying rounding signatures) indicates the primary sedimentary nature of the amphibolites studied. The youngest zircons from eclogites of the Mugodzhar Range are of 282 ± 2 Ma in age, corresponding to the stage of collision. The obtained data show that the metamorphic complexes of the Mugodzhar Range are not units of Early Proterozoic or Riphean age (as was previously believed), but represent Lower–Middle Paleozoic complexes from the middle of the Earth’s crust. Thus, these metamorphic rocks belong to the deep part of an island-arc system that had been located in the eastern sector of the Urals, which later was drawn to the near-surface level when some regions of the Urals underwent uplift and erosion.

Natural sheet magnesium silicates are potential sources of divalent cations, which are necessary for the mineralization of CO2 in the carbonates. In order to study the influence of inorganic (HCO3−) and organic (oxalate and citrate) ligands on the kinetics of dissolution of talc and serpentine, experiments were performed in a flow-through reactor at 25°C. Dissolution rates of natural silicates r (mol cm−2 s−1) in solutions of various compositions were calculated at the stationary stage of dissolution after a rapid initial stage, which is characterized by the formation of a surface leached layer depleted in magnesium. The presence of ligands increases the dissolution rate of magnesium silicates due to the formation of surface complexes, which leads to separation of magnesium from the surface and transition into solution. Initial incongruent stage may be the most promising for the development of carbonation technologies, since the minimum removal of the network-forming elements prevents the undesirable formation of secondary minerals (for example, clays), which exclude divalent cations from the carbonation process and greatly reduce the permeability of rocks.

A series of poly[dimethyl(methylbenzyl)siloxanes] with different content of the methylbenzylsiloxane fragments have been synthesized. Structure of the polymers has been confirmed by means of 1Н and 29Si NMR spectroscopy. Thermal properties of the polymers have been investigated by means of differential scanning calorimetry and thermogravimetric analysis. It has been found that the copolymer crystallization is suppressed at the content of the methylbenzylsiloxane fragments on the copolymer of 3 mol

Natural Mg phyllosilicates are potential sources of divalent cations, which are necessary for the mineralization of CO2 into carbonates. The influence of inorganic ( HCO_3^ - ) and organic (oxalate and citrate) ligands on the dissolution kinetics of talc and serpentine was studied in experiments in a flow-through reactor at 25°C. The dissolution rates of natural silicates r (mol cm–2 s–1) in solutions of various composition were calculated at the stationary stage of dissolution after a rapid initial stage, which is characterized by the formation of a surface leached layer depleted in magnesium. The presence of ligands increases the dissolution rate of magnesium silicates due to the formation of surface complexes, which leads to magnesium separation from the surface and transfer into solution. The initial incongruent stage may be the most promising for the development of carbonation technologies, because the minimum removal of the network-forming elements prevents the undesirable formation of secondary minerals (for example, clays), which exclude divalent cations from the carbonation process and greatly reduce the permeability of rocks.

New titanium(+4) and vanadium(+5) 8-oxyquinolinate complexes were synthesized. Their structures were determined by X-ray diffraction. The synthesized compounds catalyze the polymerization of ethylene in the presence of Al/Mg activators, Et2AlCl/Bu2Mg and Et3Al2Cl3/Bu2Mg (up to 3400 kg of PE (mol of [M] h atm)−1), to form ultrahigh-molecular-weight polyethylene with a molecular weight up to 5.3•106 Da. The synthesized compounds are shown to be efficient precatalysts for the synthesis of ethylene-octene copolymers. A high insertion of 1-octene into the copolymer composition, up to 9.5

Nowadays organosilicon luminescent materials are of increasing interest due to the variety of their synthetic or modification techniques and application fields. Ladder polyphenylsilsesquioxanes (L-PPSQ) are a unique class of organosilicon polymers, which can be ideal matrices for the luminescent composites due to their high thermal stability, optical transparency and mechanical strength. In this work, new mechanically strong, heat-resistant, transparent and sensitive to ammonia vapor luminescent composite films based on L-PPSQ have been obtained. As the source of Europium ions oligophenyleuropiumsiloxane was used, demonstrating perfect compatibility to the matrix due to the similar nature. To improve luminescent properties of the films, new organosilicon ligands were introduced into the composites and their influence on the properties of the materials was studied. Valuable properties of described composites may allow their further application as multifunctional coatings.

Nowadays, the synthesis and investigation of the properties of new fluorescent polymers based on polysiloxanes and organic fluorophores is an actual topic of research. These polymers find application in various fields of science and technology, in particular, as sensors, fluorescent covers, and optical materials. This work describes the method for obtaining new naphthalene end-capped and side-chain modified polydimethylsiloxanes. The physicochemical, optical, and thermal properties of the resulting polymers are thoroughly studied.

The synthesis of novel stereoregular carborane-containing phenylcyclosiloxanes (4, 5, 6, 8, and 12 –SiO– units in the ring) has been developed.

Cross-linked polyurethanes (PUs) were obtained by curing with MQ resins bearing oxymethyldimethylsiloxane or oxyethoxymethyldimethylsiloxane groups, their mixtures with 1,4-butanediol, and neat 1,4-butanediol and studied for their physico-mechanical properties. The MQ resins with functional hydroxy groups were found to act as polyols during curing of a urethane prepolymer. The network PU, obtained by curing with the MQ resins, represents a hybrid organic–inorganic polymer with bulk cross-links of inorganic nature, the surface groups of which are chemically bound to the polymer matrix. At a concentration of the MQ resins of 0.5 ppm, the properties of hybrid polyurethanes are comparable to those of the polyurethane obtained using 0.63 ppm of 1,4-butanediol.

New data are reported on composition and morphology of wulfenite—stolzite-range minerals in oxidized ores at the Novoburannoe (Gumbeyskoe) scheelite deposit in the Southern Urals (Russia). Supergene stolzite and W-bearing wulfenite occur as veinletlike complex-zoned aggregates along the cracks in Mo-bearing scheelite at the point of contact with calcite, dolomite, chalcopyrite, and tennantite. The mineral composition varies from Mo-bearing stolzite (Pb0.98Ca0.02)(W0.78Mo0.22)О4 and W-rich wulfenite (Pb0.93Sr0.05Ca0.02)(Mo0.59W0.41)О4 to pure wulfenite. W-bearing wulfenite is predominant in the studied samples. W-free wulfenite forms pseudomorphs after molybdenite inclusions in galena.

Siloxane star-shaped polymers have been obtained by sequential hydrothiolation and hydrosilylation of vinyl- and hydride-containing tetracyclosilsesquioxane. The mild conditions of these reactions avoid ring isomerization, opening the way to star-shaped polymers based on a stereoregular silsesquioxane ring. Monofunctional telechelic PDMS and a mixture of polymer star-shaped stereoisomers were synthesized as reference materials. All resulting compounds bore the same functional groups and were analyzed by GPC, TGA, DSC and NMR. The study of monolayers of these compounds on the Langmuir trough allowed to evaluate the influence of stereoregularity and pre-organization of the star PDMS on the parameters of the formed monolayers.

Crosslinked polysiloxanes with boron bis(dibenzoylmethanate) complexes used as crosslink junctions of polymer networks are first synthesized, and their physicochemical, mechanical, thermal, and fluorescent properties are studied. It is shown that the polymers under study feature the elastic behavior, possess high thermal and thermo-oxidative stability, and exhibit intense fluorescence in a wide wavelength range (400‒700 nm).

New network poly(siloxane–propylene oxide–urethane–ureas) based on α,ω-bis[(3-aminopropyl)diethoxy]oligodimethylsiloxanes, oligo(propylene oxide), and cycloaliphatic diisocyanates are synthesized. The resulting polymers are studied by differential scanning calorimetry and thermogravimetric analysis; their stress–strain characteristics are elucidated. These polymers are found to feature microphase separation and, consequently, two glass transition temperatures, defined by the chemical structures of the microphases. It is shown that an increase in the molecular weight and mass content of siloxane blocks leads to a decrease in the elastic modulus and tensile strength.

The chemical composition of 42 samples of raw glass from the Komarov settlement on the Middle Dniester was studied by means of SEM-EDS, EPMA and LA-ICP-MS analyses. We singled out groups of colourless glass of Levantine and Egyptian origin, the chronology of which indicates that the workshop could be dated to the 4 th – early 5 th century. The data on the chemical composition of the raw glass do not confirm that glassmaking industry existed here in an earlier period, as was previously believed. The manufacturing in Komarov combines the use of high-quality perfectly decolourized raw glass with intensive use of cullet, which might point out either different levels of the glassware manufactured here, or selective recycling. The characteristic features of the workshop's raw glass supply are the absence of the HIMT glass and late spread of antimony-decolourized glass.

Development of new microporous organic polymers attracts significant attention due to a wide scope of promising applications. In addition, the synthesis of soluble, non-crosslinking polymers of high surface area and uniform microporosity is very challenging, and the methods for soluble microporous polymers formation are rather limited. In this work, we report a new approach to construct porous polyphenylenes which employs the Diels–Alder polycondensation of multifunctional ethynyl-containing monomers of different spatial architecture with bis(cyclopentadienone)s. The resulting polymers were soluble in common organic solvents, and their structure and properties were assessed by NMR, TGA, DSC, and SEC studies. The polymers demonstrated a specific surface area up to 751 m2·g−1 and ultramicroporous (pore size ≤ 0.6 nm) structure. N2 and CO2 adsorption–desorption data revealed that porosity parameters, e.g., specific surface area and pore sizes, can be tuned selectively by varying the type of monomers and reaction conditions.

The composition of 139 samples of red enamel items from different regions of Eastern and Central Europe was studied using the SEM-EDS method. Most of the enamels were made following the “recipe” of provincial Roman enamellers; in some cases “ordinary” red glass was used. The high degree of standardization of the “recipes” for the manufacture and colouring of Roman glass and enamel does not make it possible to distinguish between the products of different manufacturing centres in most cases. At the same time, the peculiarities of the composition of spurs suggest the existence of specialized centres for their production, while specific features of penannular brooches suggest the possibility of distinguishing some types originating from the Baltic region. The heterogeneity of enamels with the “classical” composition indicates the functioning of numerous enamel workshops, rather than a centralized production.