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Lithium cobaltate with stoichiometric composition (LiCoO2) is synthesized by the sol–gel method. The physical parameters (particle size, specific surface area, and specific static conductivity) of studied samples are found and their dependence on the calcination temperature is revealed. The following three conduction mechanisms are shown to contribute to the conductivity value: frequency-independent σ0, ionic transport in the sample bulk σsv, and ionic transport at the electrode/ionic conductor interface σdl. The optimal modes of thermal treatment that allow the highly developed specific surface of LiCoO2 to be retained are determined.

An influence of hyper-hardening on structure and mechanical properties of ceramic solid solutions (SS) Li0.12Na0.88TayNb1–yO3 with tantalum concentrations у = 0.05; 0.25; 0.4 has been revealed. The...

LiTaO3 ceramics has been produced from a fine powder synthesized by a sol-gel method from a Li,Ta-containing citrate precursor, and its microstructure and mechanical and electrical properties have been studied. Young’s modulus and microhardness of the ceramic lithium tantalite have been determined. The critical stress intensity factor of mode I KIC, which is a criterion for the crack resistance of a material, has been evaluated, and the effective fracture energy of the LiTaO3 ceramics has been determined. The complex impedance dispersion Z*(ω) has been studied, and temperature dependences of dielectric constant and conductivity have been measured in the temperature range ~300–705 K, which is crucial for the acoustoelectronic applications of ceramic lithium tantalate. In the temperature range studied, the static conductivity and relaxation time of LiTaO3 ceramics have been determined. The charge transport activation enthalpies for various temperature ranges have been estimated.

Solutions of poly(acrylic acid) mixtures with poly(sodium styrenesulfonate) in water and in decimolar hydrochloric acid are studied by potentiometry, viscometry, and rotational rheometry. It is shown that, in a wide range of mixture compositions, thermosensitive polyelectrolyte complexes are formed via ion–dipole interactions of functional groups of polymers. The formation of complexes in the semidilute solution regime is accompanied by a significant increase in viscosity as compared with solutions of the initial polymers, which makes it possible to obtain systems with high viscosity without using large concentrations of polyelectrolytes. The dependence of viscosity on the composition of the mixture passes through a maximum corresponding to the most complete binding of the components of the complex, and the position of the maximum does not depend on the molecular weight of poly(sodium styrenesulfonate) and is determined by the ratio of the concentrations of the functional groups of the polymers. The frequency dependences of the storage modulus and the loss modulus demonstrate that the system experiences strong structuring in the process of complex formation.

The electrical properties and phase states of Li0.17Na0.83NbуТа1 –уO3 (y = 0.1–0.5) ferroelectric perovskite solid solutions prepared by high-pressure, high-temperature synthesis have been studied using impedance spectroscopy. The e'(T) and σsv(T) curves of the solid solutions have been shown to have anomalies due to phase transitions of the materials. Their Curie temperature has been found to decrease with increasing Ta concentration. The static electrical conductivity of the solid solutions has been measured as a function of temperature and the enthalpies of activation of charge carriers in them have been evaluated. The Li0.17Na0.83Nb0.1Та0.9O3 solid solution has been shown to be a high-temperature superionic conductor. Possible mechanisms of the observed phenomena are discussed.

The manufacture of LiNbO3 and LiNbO3:Zn fine-grained powders by two variants of the sol–gel process was studied. The microstructure, mechanical and electric properties of LiNbO3 and LiNbO3:Zn ceramics prepared from powders of various origins were studied. The ceramics prepared from powders that had been fractionated by elutriation had uniform micro- and submicrostructure, improved strength characteristics, and ionic grain-boundary conductivity. Doping LiNbO3 with Zn2+ reduced the electronic conductivity of LiNbO3:Zn ceramics, and this allowed the ceramics to be efficiently polarized and their piezoelectric properties to be improved.

Ordered defective structures in lithium niobate crystals have been established. The phenomenon is a result of non-equilibrium processes of a different nature: photo-induced light scattering, laser ablation, and creation of cracks during relieving mechanical stresses. The shape of such structures depends on the nature and energy that affect a crystal. A number of concentric areas with a different density of laser-induced defects with a changed refractive index appear during photoinduced light scattering. Concentric clusters of microdomains appear in a macrodomain of another sign at laser ablation as a result of local switching under impulse laser radiation. A number of microcracks with a fractal structure appear near main macro-crack during cracking under mechanical stress. Thus, appearance of ordered defective structure occurs not only in the local spot of direct exposure to laser radiation, mechanical stress, etc., but also in some volume of a crystal around it.

В учебном пособии изложены современные взгляды на проблему эпилепсии и эпилептических синдромов, рассмотрены вопросы этиологии и патогенеза, подробно изложена международная классификация эпилепсии и эпилептических синдромов, приведена клиника и диагностика, базирующаяся на современных методах исследования, описаны основные клинические формы эпилепсии и эпилептических синдромов. Особое внимание уделено личностным изменениям, имеющих решающее значение при реабилитации и реадаптации больных эпилепсией. Подробно излагаются современные подходы в лечении эпилепсии и эпилептических синдромов. Прилагаются контрольные тесты и разбор клинических случаев, а также перечень художественных и кинематографических произведений, создавших образы больных эпилепсией. Учебное пособие предназначено для клинических ординаторов и аспирантов, осваивающих основную образовательную программу по специальностям «Психиатрия» и «Неврология», представляет интерес для врачей-психиатров, неврологов и клинических психологов, а также будет полезным для врачей общей практики и терапевтов. Утверждено на заседании центральной методической комиссии ФГБОУ ВО РостГМУ Минздрава России. Протокол No 1 от 10 ноября 2020 г. Одобрено на заседании кафедры психиатрии ФГБОУ ВО РостГМУ Минздрава России. Протокол № 5 от 23 сентября 2020 г. Одобрено на заседании кафедры нервных болезней и нейрохирургии ФГБОУ ВО РостГМУ Минздрава России. Протокол № 2 от 30 сентября 2020 г.

Microstructure and elastic properties of ferroelectric ceramic solid solutions Li0,17Na0,83NbyTa1-yO3 with a perovskite structure were investigated, obtained by thermobaric synthesis at high pressures and temperatures. The electrical characteristics and phase states of a series of ferroelectric high-pressure solid solutions Li0,17Na0,83NbyTa1-yO3 ( y = 0,1 — 0,5 ) were investigated by the impedance spectroscopy method. Some anomalies are revealed in ε'(T) and σsv(T) dependencies associated with phase transitions in the studied ceramic samples. The values were established of the static conductivity as a function of the temperature and enthalpy of activation of charge carriers. It was found that Li0,17Na0,83NbyTa1-yO3 is a high-temperature superionic.

Fine crystalline GdNbO4 powders have been synthesized by sol-gel method. Usual ceramic technology and hot pressing have been applied to obtain GdNbO4 ceramic samples. Morphological particularities have been studied in GdNbO4 ceramics microstructure. Ceramics strength characteristics (strength, Young’s modulus) have been evaluated for the first time. A mode I stress intensity factor KIC have been determined (note that the factor is a crack resistance criterion). Photoluminescence characteristics have been compared in GdNbO4 ceramics before and after vacuum annealing in the visible region.

One of the fundamental tasks of modern computer information systems is processing of symbol information, the amount of which prevails in the total amount of information. At present, rules-based approach is effectively applied to the tasks of processing symbol information. The paper deals with the peculiarities of text search applying rules-based approach. The main essence of the approach is to find pattern occurrences in the text and possible implementation of substitution (text modification). Meanwhile, when implementing search for occurrences, various kinds of collisions may arise. They should be taken into account to solve the set tasks correctly. For example, algorythms of sequential word matching can run into collisions which involve the possibility of skipping positions of pattern occurrence in a word with some structural peculiarities. The paper presents a method of searching taking into account possible collisions developed by the authors, as well as algorithmic and automatic models of the method. The developed method involves patterm markup and setting a sequence of its viewing in the form of algorithm diagram. Three algorythms (implementation variants) of the method have been developed. Algorithms differ in the possibility to carry out transition to this oк that position of the pattern and the text depending on the result of matching (equality or inequality of the current symbols of the patten and text). An automation model of the method has been developed. The proposed method of sequential matching with the pattern with collisions elimination increases the effectiveness of the computer system when implementing search procedures and symbol information processing. The method can be used in the systems of symbol information processing.

A method is developed for the preparation of mixed pentoxide Nb2(1–y)Ta2y O5 by rapid coprecipitation of a mixture of hydroxides of niobium and tantalum from a solution of hydrofluoric acid by ammonia water, followed by purification and calcination of the precipitate. The proposed method allows obtaining a homogeneously mixed pentoxide of niobium and tantalum Nb2(1–y)Ta2y O5, in contrast to the method of obtaining Nb2(1–y)Ta2y O5 from a mechanical mixture of individual pentoxides of niobium and tantalum. The temperature dependences of the real part of the permittivity (e′) of ceramic samples of Nb2(1–y)Ta2y O5 at various frequencies were investigated and the magnitude of dielectric loss (tan(δ)) versus frequency measurement of the electric field and temperature was evaluated. On the basis of analysis of the data of impedance spectroscopy, the temperature dependence of the static conductivity σ dс of the ceramic Nb2(1–y)Ta2y O5 was determined. From the temperature dependence of σ dс , the enthalpies of activation of charge transport for different temperature ranges were evaluated.

We have studied the electrical properties of ceramic Nb2(1–y)Ta2yO5 samples, examined the dispersion of the real part of their dielectric permittivity e′ at room temperature, and assessed their lattice dielectric permittivity e′∞ The temperature dependences e′(T) have been obtained at different frequencies, and the dielectric loss tan δ has been evaluated as a function of measuring electric field frequency and temperature. The direct-current conductivity (σdc) of the solid solutions has been determined at room temperature. Using impedance spectroscopy data, we have obtained temperature dependences of σdc for the Nb2(1–y)Ta2yO5 ceramics and evaluated the activation enthalpy for charge transport in these materials in different temperature ranges.

We have studied the detailed structure and mechanical properties of the Nb2O5 and Ta2O5 pentoxides after ultrarapid quenching in comparison with the properties of Nb2O5 and Ta2O5 ceramics prepared by a conventional ceramic processing technique and using high-intensity light (HIL) in an optical furnace. The results demonstrate that high-energy processing (HIL and ultrarapid quenching) improves the hardness and strength of Nb2O5 and Ta2O5. At the same time, HIL processing and quenching lead to structural disordering of the Nb2O5 and Ta2O5 pentoxides.

LiNbO3:MgO crystals, representing important materials for nonlinear optics, laser optics, integrated optics, and optical electronics owing to their high resistance with respect to optical damage, are studied. The crystals of LiNbO3:MgO were grown from a granulated charge mixture of lithium niobate synthesized using homogeneously doped Nb2O5:Mg precursors of different origin. The effect of organic substances used in the technology of lithium niobate charge mixture on the properties of LiNbO3:MgO single crystals is studied. It is found that the physicochemical and optical characteristics of LiNbO3:MgO crystals grown from charge mixtures synthesized from Nb2O5:Mg precursors obtained using organic solvents and without them differ to a considerable extent. It is suggested that the difference in the properties of LiNbO3:MgО crystals of different origin is caused by change in the structure of the ion complexes in the melt owing to the presence of traces of organic impurities. Change in the structure of ion complexes in the melt leads to change in crystallization mechanisms and, accordingly, in the chemical composition and the properties of LiNbO3:MgO crystals. Furthermore, it is shown that the use of homogeneous doping methods as opposed to the method of direct doping provides the distribution coefficient K eef > 1. That is, the method of homogeneous doping allows one to introduce a substantially greater concentration of an impurity element in the LiNbO3:MgO crystal compared with the direct method for doping the charge mixture at the same impurity concentration in the starting material.

The preparation conditions for the homogeneously doped precursor Nb2O5:Mg for the synthesis of granulated lithium niobate batch was studied. The effect of non-metallic impurities in the Nb2O5:Mg precursors and the lithium niobate batch on the characteristics of the melt–crystal system and the physicochemical and optical characteristics of the LiNbO3:Mg crystals was established.

Ceramic solid solutions GdNbx[Formula: see text]O4 ([Formula: see text]–1) were synthesized by sol–gel. Morphological particularities of microstructure were studied, strength characteristics (Young’s modulus) and stress intensity factor for mode I [Formula: see text] were evaluated. The latter is a criterion of crack resistance of the material. Luminescent properties of solid solutions GdNbx[Formula: see text]O4 were researched under UV exciting radiation. A comparatively small addition of Ta ([Formula: see text]) was shown to increase luminescence intensities of centers [Formula: see text]–O−. An addition of Ta to GdNbO4 leads to creation of solid solution [Formula: see text][Formula: see text]O4. Intensity of these centers is 3–6.5 times larger than that of GdNbO4 and GdTaO4.

The sol–gel technique is used to study synthesis of lithium–lanthanum titanate Li3xLa2/3–xTiO3 (x = 0.167 and 0.11) using water–soluble salts of LiNO3 · 3H2O, La2O3 and a citrate Ti(IV) complex. This process allows obtaining single–phase crystalline compounds of Li0.5La0.5TiO3 and Li0.33La0.56TiO3 with a perovskite structure after precursor sintering at 1000°C. The synthesized Li3xLa2/3–xTiO3 powders are described using the methods of XRD, DTA/TG, and SEM microscopy. Conductivity of Li3xLa2/3–xTiO3 by the Li+ ion is determined using the impedance spectrometry technique in the range of 1–2 × 106 Hz and is 8 × 10–4 S/cm at the room temperature. The temperature dependence is studied and the activation energy of ion conductivity of Li0.33La0.56TiO3 is studied in the range of 25–200°C.

The structural, mechanical, and electrical properties of ceramics based on coprecipitated Nb2(1 − y)Ta2yO5 pentoxides have been studied by scanning probe microscopy, Raman spectroscopy, and impedance spectroscopy. We have examined the effect of high-intensity light processing on the structure and properties of the Nb2(1 − y)Ta2yO5 ceramics.

We have studied conditions for the growth of LiNbO3〈Zn〉 crystals in the composition range ≃4.0–8.91 mol % ZnO. It has been shown that, in the composition range ≃4–6.8 mol % ZnO in the melt, compositionally and optically homogeneous LiNbO3〈Zn〉 crystals can be grown. Above 6.8 mol % ZnO, imperfect crystals consisting of two distinct phases grow. We have accurately determined threshold impurity concentrations corresponding to significant changes in LiNbO3〈Zn〉 crystallization conditions.

We have studied the structural and electrical properties of the Li0.125Na0.875NbO3 solid solution prepared by a conventional ceramic processing technique and high-temperature, high-pressure synthesis. The synthesis of the Li0.125Na0.875NbO3 solid solution at high pressure and temperature (p = 6 GPa, T = 1400–1800 K) allows one to achieve a higher degree of structural order and better microhomogeneity. This is accompanied by a considerable increase in dielectric permittivity and ionic conductivity, because ion transport is contributed by the grain boundaries of the ceramic, which have a considerably larger area than those in the Li0.125Na0.875NbO3 solid solution prepared by conventional ceramic processing.

Results of X-ray diffraction, dielectric, and Raman studies of the ferroelectric Li0.125Na0.875NbO3 solid solution obtained under hot-pressing conditions (6 GPa, 1400 and 1800 K) are compared with those of the same compound synthesized by conventional ceramics technology. The thermo-barometric synthesis is found to improve the ordering of cations and to increase the value of dielectric permittivity and ion conductivity of the ceramics.

We investigated how the type of an extraction system affects the characteristics of precursors Nb2O5:Mg produced at the stage of extraction processing of niobium-containing HF-H2SO4 and HF-HCl solutions with an extractant comprising a mixture of dimethylamides of carboxylic acids of the C10–C13 fraction and 1-octanol in Escaid diluent. We also studied the optical properties of homogeneously doped crystals LiNbO3:Mg grown from a batch synthesized with the use of pentoxide Nb2O5:Mg obtained from various extraction systems. On Z-cut LiNbO3:Mg crystal wafers, such mechanical characteristics as Young’s modulus and microgravity were measured.

The structure and mechanical characteristics of ceramic Nb2O5 and ceramic materials produced from coprecipitated Nb2(1 − y)Ta2yO5 pentoxides by a conventional ceramic processing technique and exposure to high-intensity light have been studied by scanning probe microscopy and Raman spectroscopy.

Synthesis from aqueous peroxide solutions provides lithium-aluminum titanophosphate Li1.3Al0.3Ti1.7(PO4)3 (LATP) with particles of submicron size and conductivity of (4–5) × 10−4 S/cm at the room temperature. LATP were characterized using the methods of XRD, DTA/TG, measurement of specific surface area, ionic and electronic conductivity. According to XRD, a single-phase crystalline product with the specific surface area of 8.2 m2/g is formed as a result of precursor sintering at 700°C (the average particle size of electrolyte was 250 nm). Sizes of coherent-scattering region were calculated on the basis of the values of intrinsic broadening of diffraction maximums. Analysis of broadening of diffraction maximums indicates that the size of primary LATP crystallites after sintering at 700°C was 90 nm according to peak (113) (2θ = 24.5°) and 110 nm according to peak (104) (2θ = 20.9°). The synthesized submicron LATP powders are suitable for formation of solid electrolyte films using the method of aerosol deposition.

Experimental data demonstrate that LixNa1 − yTayNb1 − yO3 (y ≠ 0) ferroelectric solid solutions near special concentration points (x = 0.125 and 0.25), which have increased degrees of short- and long-range order, undergo a superionic transition. In the Raman spectra of Li0.12Na0.88TayNb1 − yO3, the superionic transition shows up as a predominant “melting” of the alkali metal sublattice and broadening of the corresponding lines into a Rayleigh line wing, whereas the other sublattices in the structure remain relatively “rigid.” The temperature of the superionic transition can be tuned by varying the degree of static disorder of structural units in the Nb5+/Ta5+ sublattice.

We have analyzed conditions for the growth of large (≥80 mm in diameter) LiNbO3〈Mg〉 crystals in a wide range of dopant concentrations in the melt (2.9–5.8 mol % MgO). We have established conditions for the growth of large LiNbO3〈Mg〉 crystals uniform in doping level from melts containing magnesium concentrations above a certain threshold (Cmelt 5.0–5.8 mol % MgO) and optimized the high-temperature electrodiffusion annealing process, which allowed us to obtain single-domain, microstructurally homogeneous, large LiNbO3〈Mg〉 crystals containing 4.9–5.15 mol % magnesium.

We compare the microstructure, electrical properties, and Raman spectra of ceramic samples of the Li0.03Na0.97Ta0.05Nb0.95O3 ferroelectric solid solution prepared by a conventional ceramic processing technique using ceramic powders with different particle sizes. The Li0.03Na0.97Ta0.05Nb0.95O3 solid solutions prepared from the powders of different particle sizes are shown to differ only slightly in average grain size, pore size, and porosity, but the particle size of the ceramic powder has a significant effect on their electrical properties. The difference in properties between the samples is due not so much to the difference in particle size between the parent ceramic powders as to the fact that the diffusion processes involved in solid-state synthesis may give rise to composition gradients, and grains that differ in size may differ in microstructure and composition.

The aim of the study was the research of clinical and molecular phenotypes in the generalized form of myasthenia with optimized treantment, which includes the application of basic mode of the treatment and meglumine sodium succinate, and also the combined mode of the treatment, which includes the mode of the treatment and meglumine sodium succinate and ozonotherapy. The most epressed improvement of indicators of the clinical and neurologic status (the eliminaton of motoring breakdown, eye movement disrders, the weaknesses of mimic, respiratory and chewing muscles, bulbar syndrome, the doubling in eye and ptosis, pharyngeal violations and increase in volume of movement of eyes) was observed in the group of patients receiving the combined therapy. The reduction of the epressiveness of the defeat of the neuromotor device and the decrement of the amplitude of the various degree of M-answer in patients with myasthenla is revealed in the application of the combined therapy in the comparison with the application of the basic and optimized therapy. For the first time we have investigaed the dynamics of the intensity of the expression of specfic peptides and proteins in blood serum in patients with the application of basic therapy, reamberin and ozonotherapy, which have allowed to open the new mechanisms of the efficiency ofthe combined therapy of the disease.

We have studied the mechanical properties of niobium pentoxide and tantalum pentoxide ceramics prepared by a conventional ceramic processing technique and by exposure to high-intensity light (HIL). The results demonstrate that, after HIL exposure in an optical furnace, the niobium pentoxide and tantalum pentoxide ceramics possess enhanced microhardness and improved mechanical properties (strength, fracture toughness, and brittle microstrength) owing to the formation of fractal micro- and nanostructures. With increasing exposure intensity, the strength of the Nb2O5 and Ta2O5 ceramics increases.

The microstructure and electrical properties of two samples of the ferroelectric Li0.03Na0.97Ta0.05Nb0.95O3 ceramic solid solution prepared from initial charge stocks of different dispersity by conventional ceramics technology are compared. The average size of grains and concentration of pores in the samples are found to be of little difference while the electrical properties of the ceramics are strongly affected by the grain size of the initial mixture. The difference in properties is due to conditions at the diffusion stage of the solid-phase synthesis caused by differences in composition of larger grains rather than the grain size itself.

The effects of the temperature of synthesis and component concentration on microstructure of high-pressure LixNa1-xTayNb1-yO3 solid solution perovskite ceramics (х = 0.12, 0.17; у = 0; у ≥ 0.5) were studied. Original results of elastic properties of high-pressure LixNa1-xTayNb1-yO3 (х = 0.17; 0 ≤ у ≤ 0.5) solid solutions measured by contact probe techniques are reported. The observed decrease of the modulus of elasticity with increasing the sintering temperature of Li0,17Na0,83TayNb1-yO3 solid solutions is assumed to be related to conditions of re-crystallisation of disordered solid solutions at synthesis under high pressure.

The dielectric properties and electrical conductivity of the ferroelectric perovskite solid solutions Li0.07Na0.93Ta0.1Nb0.9O3 and Li0.07Na0.93Ta0.111Nb0.889O3 have been studied at temperatures from 290 to 700 K and frequencies from 25 Hz to 1 MHz. In this temperature range, the solid solutions undergo a first-order ferroelectric phase transition. Li0.07Na0.93Ta0.111Nb0.889O3 (prepared from coprecipitated Ta2yNb2(1 − y)O5 pentoxides) has a markedly lower Curie temperature (by ∼75 K) and higher ionic conductivity and high-frequency dielectric permittivity in comparison with Li0.07Na0.93Ta0.1Nb0.9O3 (prepared from a mechanical mixture of Ta2O5 and Nb2O5).

The microstructure and elastic properties of ceramic samples of high-pressure LixNa1 − xTayNb1 − yO3 perovskite solid solutions have been studied for the first time in relation to their composition and the synthesis temperature. The results demonstrate that, with increasing sintering temperature, the Young’s modulus of the Li0.17Na0.83TayNb1 − yO3 solid solutions decreases, which can be understood in terms of the recrystallization behavior of the disordered solid solutions under high-pressure synthesis conditions.

This paper examines the effect of exposure to high-intensity light on the structure, thermal expansion, mechanical properties, and Raman spectrum of ceramic Nb2O5. We demonstrate that such exposure creates fractal micro- and nanostructures in ceramic Nb2O5, has a significant effect on its thermal expansion, increases its elastic moduli and the anisotropy in its mechanical properties, and produces isolated polyhedra in its crystal structure.

Results of studies of dielectric properties and conductivity in 290–700 K range of temperature and frequencies from 25 to 106 Hz in ferroelectric perovskite solid solutions Li0.07Na0.93Ta0.1Nb0.9 O3 and Li0.07Na0.93Ta0.111Nb0.889 O3 are reported. A first-order ferroelectric phase transition proceeds in both studied compositions within the observed range of temperature. The co-precipitated Ta2yNb2(1-y)O5 pentoxides being used for synthesis of Li0.07Na0.93Ta0.111Nb0.889O3 the Curie point shifts by ∼75 K to a lower temperature while compared with Li0.07Na0.93Ta0.1Nb0.9O3 synthesised from mechanical mixture of the Ta2O5 and Nb2O5 oxides the high-frequency dielectric permittivity and ion conductivity of relatively low value of activation enthalpy increases.

We have studied the dielectric properties and electrical conductivity of LixNa1 − xTa0.1Nb0.9O3 (x = 0.03−0.135) ferroelectric solid solutions at temperatures from 290 to 700 K and frequencies from 25 to 106 Hz. The results demonstrate that charge transport in these materials is due to the Li+ ion and that their conductivity is dominated by volume ion transport. In the temperature range studied, the LixNa1 − xTa0.1Nb0.9O3 solid solutions undergo a first-order ferroelectric phase transition close to second order. Increasing the lithium content enhances features characteristic of second-order transitions.

The microstructure of ceramic samples of high-pressure ferroelectric Li x Na1 − x NbO3 (x = 0.17, 0.25) perovskite solid solutions has been studied in relation to synthesis temperature and composition. The elastic properties (Young’s modulus) of the high-pressure Li x Na1 − x NbO3 (x = 0.125, 0.17, 0.25) solid solutions have been studied for the first time by a contact technique. The results demonstrate that, with increasing sintering temperature, the Young’s modulus of the high-pressure Li x Na1 − x NbO3 solid solutions at singular concentration points (x i = 0.125 and 0.25, Li/Na = 1/7 and 1/3) increases considerably, whereas that of Li0.17Na0.83NbO3 decreases markedly, which seems to be related to the recrystallization behavior of ordered and disordered solid solutions at high pressures.

Innovative nuclear energy system (INSS) designed to ensure effective use of uranium 238 and thorium 232 to produce energy. Maintain the neutron balance of this process requires the development and use of new types of nuclear fuel and structural materials. This requires the development of models to predict changes in their properties under the action of fields of different radiation, temperature, stress and exposure to various chemical substances. It is important achievement is not the limiting parameters, and the optimal combination of the properties of materials and their working conditions. In this paper parameters such as the fluence of fast neutrons, the reaction rate in the fuel rod cladding and the change of nuclide composition, in particular, developments of hydrogen and helium, influencing the change of the strength properties of steels, are calculated.

Gd-doped lithium niobate single crystals having a regular domain structure with a period from 100 to 1 μm have been grown under highly unsteady thermal conditions. Examination by atomic force microscopy shows that such lithium niobate single crystals contain periodic nanostructures with a period from 10 to 100 nm in the region of regular domain structures. Raman scattering data suggest that the cation sublattice of the lithium niobate crystals contains a superstructural sublattice of defect clusters with a step of 1–2 nm. We conclude that lanthanide-doped lithium niobate single crystals contain periodic fractal structures in a range of length scales, from ≃ 1 nm to 100 μm.

We have studied the electrical and elastic properties of LixNa1 − xTa0.1Nb0.9O3 (x = 0–0.16) ferroelectric ceramic solid solutions. The results demonstrate that these properties of the LixNa1 − xTa0.1Nb0.9O3 solid solutions are rather sensitive to the lattice distortions resulting from compositional structural phase transitions. The elastic constants determined by acoustic and contact techniques agree well.

Thermal behaviour and dispersion of dielectric permeability and thermal behaviour of conductivity measured in ferroelectric ceramic solid solutions of Li x Na 1−x NbO 3 (x = 0.17, 0.25) synthesized at high pressure and possessing extended region of homogeneity are reported. The Li x Na 1−x NbO 3 (x = 0.17, 0.25) solid solutions of perovskite structure are found to be super-ionic conductors at rather low temperatures O ≥ 400 K. Dielectric dispersion and anomalous behaviour of dielectric permeability are observed in the thermal range of super-ionic conductivity corresponding to structural transformations in the high-pressure solid solutions.

Allozyme variation of chum salmon Oncorhynchus keta was examined in the populations from nine rivers of the Russian Far East. A total of 12 loci were tested, and eight of these were shown to be polymorphic. The greatest contribution to the samples differentiation was made by the EST-D1* and sIDHP-2* loci. Most of the allele diversity was distributed among the individuals within the samples. The among-sample differences within races were statistically significant and accounted for slightly more than 7% of total variation. The differences between the races constituted 0.1% and were statistically nonsignificant. Genetic similarity of seasonal races within single locality allowed suggestion on their secondary formation after settling of founder population into a certain region.