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Abstract— A classical plane problem of the theory of elasticity about a crack in a stretched orthotropic elastic unbounded plane is considered, which leads to a singular solution for stresses in the vicinity of the crack edge. The relations of the generalized theory of elasticity, including a small scale parameter, are given. The equations of the generalized theory are of a higher order than the equations of the classical theory and allow eliminating the singularity of the classical solution. The scale parameter is determined experimentally. The results obtained determine the effect of the crack length on the bearing capacity of the plate and are compared with the experimental results for plates made of fiberglass and carbon fiber reinforced plastic.

The problem of stretching a plate with a central or lateral crack is considered. The previously obtained solution, which determines the stresses in the plate in the vicinity of the central crack, is used to predict the load at which plastic deformation appears in the plate with a lateral crack. The Mises condition is used as a criterion for plasticity. The calculation results are compared with the experiment carried out on plates made of aluminum alloy, brass and steel.

The problem of tension of a plate made of a brittle material with a central through crack is considered. The traditional approach to solving the problem of strength of brittle bodies, which is based on linear fracture mechanics, is discussed. The apparatus of a generalized theory of elasticity, which is based on analyzing the state of stress in a medium element having small but finite sizes, is used to solve the problem of crack.

Matrix photosensitive elements based on a HgCdTe semiconductor solid solution on silicon substrates with 640 × 512 elements at a pitch of 25 μm with a long-wavelength sensitivity of 5 μm at half maximum are designed and produced. The scheme and topology are developed according to which matrix multiplexers with 640 × 512 elements at a pitch of 25 μm, which ensure operating modes at a clock frequency up to 10 MHz, are manufactured. Using a hybrid assembly method on indium bumps, a matrix photodetector with 640 × 512 elements at a pitch of 25 μm is produced. The best photodetector specimens are characterized by the following parameters: average NETD value 99.5%.

—Design and fabrication of photosensitive array elements in the 384 × 288 element format with a step of 25 μm with a long wavelength limit of sensitivity at 0.5 to approximately 9.5 μm were performed. The circuit and topology were developed, according to which matrix high-speed multiplexers are manufactured in the form of 384 × 288 elements with a step of 25 microns, which provide operating modes at a clock frequency of up to 20 MHz. The 384 × 288 element hybrid photodetector (PD) format in 25 μm increments has an average Noise Equivalent Temperature Difference (NETD) of less than 30 mK, while the number of working elements was more than 97%. Examples are given of using the microscanning system to reduce defective pixels in an image frame and/or increase the frame format to 768 × 576. It is shown that as a result of the use of microscans in a thermal imaging channel based on the developed PD during the transition to the 768 × 576 format, an improvement in spatial resolution of 1.4 times was obtained for the same minimum resolved temperature difference (MRTD), while the MRTD at a frequency of 0.44 mrad-1 decreased from 1.6 to 0.9 K compared to the original 384 × 288 format.

The influence of characteristics of ligands and nickel complex compounds on the rate of the autocatalytic (chemical) deposition of nickel–phosphorus coating and the phosphorus content is considered. It has been established that the charge and complex of the ligand have the highest effect on the rate of process, and charge number and stability of the complex ion have the highest effect on the content of phosphorus in the coating. Mathematical models describing the relationship between the deposition rate, the composition of coatings, and the corresponding ligand parameters are obtained. Recommendations for the selection of the ligand composition of solutions for the chemical deposition of nickel–phosphorus alloy are proposed.

In this survey, some interesting generalizations of the theory of C0-semigroups and their applications are presented. The survey is divided into three parts: “Integrated semigroups,” “C-semigroups,” and “Applications.” Different approaches to the theory are discussed. The content presented is taken from articles of the last 20 years and also contains some results of the authors. Various applications are presented; most of them concern ill-posed Cauchy problems.

The results of the theoretical and experimental studies of the electric wind velocity and efficiency are considered. The experiments are carried out in air at atmospheric pressure using the electrode system as a flat multispike electrode–two parallel tube.

The impact of the presence of the near-surface graded-gap layers with an increased content of CdTe on the admittance of MIS structures based on MBE-grown n-Hg1–xCdxTe (x = 0.22–0.23) with the Al2O3 insulating coating has been experimentally studied. It has been shown that the structures with a gradedgap layer are characterized by a deeper and wider capacitance dip in the low-frequency capacitance–voltage (CV) characteristic and by higher values of the differential resistance of the space-charge region than the structures without such a layer. It has been found that the main features of the hysteresis of capacitance dependences typical of the graded-gap structures with SiO2/Si3N4 are also characteristic of the MIS structures with the Al2O3 insulator. The factors that cause an increase in the CV characteristic hysteresis upon formation of the graded-gap layer in structures with SiO2/Si3N4 or Al2O3 are still debatable, although it may be assumed that oxygen plays a certain role in formation of this hysteresis.

The requirements imposed on vertical-cavity surface-emitting lasers in a number of metrological problems in which optical pumping of alkali atoms is used are considered. For lasers produced by different manufacturers, these requirements are compared with the experimentally observed spectral characteristics at a constant pump current and in the microwave modulation mode. It is shown that a comparatively small number of lasers in the microwave modulation mode make it possible to obtain the spectrum required for atomic clocks based on the coherent population-trapping effect.

We consider two problems of elasticity, namely, the Boussinesq problem about the action of a lumped force on a half-space and the related problem about the interaction of the half-space with a cylindrical rigid punch with plane base. In the classical statement, these problems have singular solutions. In the Boussinesq problem, the displacement under the action of the force is infinitely large, and in the punch problem, the infinitely large variable is the pressure on the punch boundary. In the present paper, these problems are solved with the use of relations of generalized elasticity derived regarding a medium element of small but finite dimensions rather than a traditional infinitesimal element. The structure parameter of the medium contained in the solutions can be determined experimentally. The obtained generalized solutions of the problems under study are regular.

In a temperature range of 9–200 K, temperature dependences of the differential resistance of space-charge region in the strong inversion mode are experimentally studied for MIS structures based on CdxHg1–xTe (x = 0.22–0.40) grown by molecular-beam epitaxy. The effect of various parameters of structures: the working layer composition, the type of a substrate, the type of insulator coating, and the presence of a near-surface graded-gap layer on the value of the product of differential resistance by the area is studied. It is shown that the values of the product RSCRA for MIS structures based on n-CdHgTe grown on a Si(013) substrate are smaller than those for structures based on the material grown on a GaAs(013) substrate. The values of the product RSCRA for MIS structures based on p-CdHgTe grown on a Si(013) substrate are comparable with the value of the analogous parameter for MIS structures based on p-CdHgTe grown on a GaAs(013) substrate.

The composition of narrow fractions of shale gasoline extracted from LTC (low-temperature carbonization) tar is determined by rectification and gas chromatography–mass spectrometry. The LTC tar is derived from high-sulfur Mishor Rotem shale. The fractions considered are

We consider the classical problem of the theory of elastic plates, namely, the problem on the torsion of a square isotropic plane by forces applied at the corners. The traditional solution of this problem based on the classical theory of plates and Kirchhoff and Thomson–Tait transformations is compared with the solution obtained in the improved theory of plates and with experimental results. The solution, which does not exist in the classical theory of plates, of the problem on the torsion of a plate by torques uniformly distributed over the plate contour is presented as well.

A photodetector array chip for detection of the optical signal in a wave range of 0.4–1.0 μm; conversion of the optical signal into the electric signal; and its extraction in the analog form to 1, 2, 4, 8, or 16 outputs has been designed, fabricated, and studied. The main parameters of this chip are the following: the charge capacity is up to 200000 electrons, the frame rate is higher than 600 Hz at the maximum resolution, and the integrated sensitivity is up to 1000 V/(lx s).

A new technological process for the synthesis of composite materials based on carbon fibers and the combination of a thermoset and a thermoplastic matrix is described. The mechanical characteristics of a two-matrix composite are presented. The scope of its application is discussed.

The feasibility of producing high-quality acicular coke from heavy Yarega oil is studied. A scheme that involves deasphalting, hydrofining, delayed coking, demetallation, and thermal degradation or gasification is proposed for processing this oil. Also studied are the physicochemical properties and group hydrocarbon composition of the oil and the obtained heavy resid.

Carbon materials are widely used in metallurgy and in the power industry as fuels and reducing agents. Coal, although inexpensive, is difficult to use, on account of its high ash content. In the operation of industrial systems, the ash might melt, with the subsequent formation of buildup. In addition, coal ash must be stored in tailings. Therefore, fuel oil and natural gas are more commonly used. Ash tailings pose a significant environmental problem in Russia. Various methods are known for the use of ash in construction. However, their adoption has been slow, on account of the complications caused by the variability in ash composition and properties. The industrial applicability of ash may be assessed by studying the physicochemical processes that accompany ash heating and determining the relation between the properties and mineral composition of ash. An important property of ash is its fusibility, which may vary widely on account of its nonuniform mineral composition. Traditionally, the fusibility of ash is determined on the basis of State Standard GOST 32978–2014 (ISO 540:2008). As in any visual method, the results are highly inaccurate. Existing theoretical analyses employ fusibility values obtained on the basis of the international standard. In this context, there is a pressing need to develop and test new methods of determining the melting point of ash.

Gold(III) coordination compounds with three water-soluble porphyrins―5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (H2TSPP4–), 5,10,15,20-tetrakis(4-N-methylpyridyl)porphyrin (H2TMPyP4+), and 5,10,15,20-tetrakis(4-N,N,N-trimethylaminophenyl)porphyrin (H2TTMAPP4+)―have been studied. Complex [Au(TTMAPP)]5+ has been prepared for the first time. The analysis of coordination-induced shifts of proton signals in NMR spectra and intensities of Q bands in absorption spectra indicates the high degree of bond covalence in the studied metal porphyrins and a partial transfer of electron density from porphyrin to gold ion. The cationic complexes [Au(TMPyP)]5+ and [Au(TTMAPP)]5+ in aqueous solutions has been found to exist in monomeric form, while anionic complex [Au(TSPP)]3– undergoes dimerization upon growth of concentration and solution ionic strength. Equilibrium constant for dimerization has been calculated, the constant has been found to decrease when temperature rises. Thermodynamic parameters of dimerization process have been determined: ΔH° =–31.8 kJ/mol and ΔS° =–13.8 J/mol K.

The group chemical composition of oil fractions refined at Kinef Ltd. is shown to change with time. The oxidation rate and penetration index of asphalt obtained from heavy residual increase as the penetration increases. The extensibility of road asphalt decreases markedly as the paraffin content increases. Road asphalt meeting PNST 1-2012 specifications was produced by compounding asphalts oxidized to different degrees.

The thermochemical processing of high-sulfur shale from the Mishor Rotem deposit (Israel) is studied in terms of the material balance, in a Fisher retort and a larger-scale laboratory system. The properties of the products (tar, char, and gas) are determined. The shale tar has a high sulfur content, on account of the presence of a wide range of thiophene derivatives. In the fractions of semicoking tar from Mishor Rotem shale that boil at temperatures up to 250°C, 236 compounds are quantitatively identified. The content of thiophene and its homologs with the substituents C1–C5 and of benzothiophene with alkyl substituents C1–C3 is determined.

We consider the classical plane problem of elasticity about a crack in an isotropic elastic unbounded plane resulting in a singular solution for the stresses near the crack edge. Relations of generalized elasticity with a small parameter characterizing the medium microstructure are derived, and the higher order of these relations permits eliminating the singularity of the classical solution. An experimental method for determining the medium parameter is proposed, and the corresponding experimental results are given.

The solution of the problem on a circular membrane loaded at the center by a lumped force is a classical example of a singular solution of equations of mathematical physics. In this paper, the problem is solved by using relations of the generalized theory of elasticity, which contain a structural parameter and permit obtaining a regular solution. An experiment for determining the structural parameter in the problem of bending of a membrane is described.

The nature of the processes that occur when electrodes modified with complexes [M(Schiff)] (M = Ni, Pd, Pt; Schiff denotes four-dentate Schiff base ligands) are irradiated with visible light for the potential use of these electrodes in photoelectrochemical energy conversion devices is considered. The factors responsible for shifts in the electrode potential upon photoexcitation, i.e., the nature of the metal site, the nature of the substituents in the sensitizer, and the oxygen concentration are discussed. Tentative mechanisms of the photovoltaic effects observed for conventional and semiconductor electrodes modified with [M(Schiff)] complexes are determined.

The synthesis of modified solid resorcinol–formaldehyde resins based on resorcinol and a fraction of water-soluble shale alkylresorcinols (Tb > 270°C) was studied. Styrene was used as a modifier. Data on the quality of the target products depending on a molar ratio between the initial components were acquired.

We obtain elasticity equations of higher (in the general case, infinite) order than the equations of the classical theory. In contrast to the numerous known versions of the nonclassical theory (Cosserat, nonsymmetric, microstructure, micropolar, multipolar, and gradient), which also result in higher-order equations and contain elasticity relations for traditional and couple stresses with a large number of elastic constants, our theory, regardless of the order of the equations, contains only one additional constant, which can be expressed in terms of the microstructure parameter of the medium. The basic equations of the generalized theory are presented for one-, two-, and three-dimensional problems; these equations take into account the stress gradients and can be written in terms of generalized stresses, strains, and displacements. A boundary value problem that does not require the introduction of couple stresses is stated for the generalized theory of elasticity.

Metal–insulator–semiconductor structures based on n -Hg 1− x Cd x Te ( x = 0.19–0.25) were grown by molecular-beam epitaxy on the GaAs (0 1 3) substrates. Near-surface graded-gap layers with high CdTe content were formed on both sides of the epitaxial HgCdTe. Admittance of these structures was studied experimentally in a wide temperature range (8–150) K. It is shown that an increase in the composition of the working layer and a decrease in temperature lead to a decrease in the frequency of transition to high-frequency behavior of the capacitance–voltage characteristics. The differential resistance of space charge region in the strong inversion increases with the composition of the working layer and for x = 0.22 and 0.25, the differential resistance is limited by the Shockley-Read generation. The values of the differential resistance of space charge region at different frequencies and temperatures were found.

A new photocatalyst, water-soluble palladium(II) complex with meso-tetrakis(4-N,N,N-trimethylammoniophenyl) porphyrin, was suggested as a component of a photocatalytic system for water reduction to hydrogen. In the ternary system palladium(II) porphyrin-methyl viologen-triethanolamine, the metalloporphyrin phosphorescence is quenched only by methyl viologen by the mechanism of oxidative electron transfer. The reduced form of methyl viologen is accumulated in the solution, and hydrogen is evolved in the presence of colloidal platinum. The highest quantum yield of the formation of the reduced methyl viologen form and hydrogen in the system reaches 0.4. After 1-h irradiation of the system, 125 mol of hydrogen is evolved per mole of metalloporphyrin.

The characteristics of SWIR (1.6–3 μm) 320 × 256 and 1024 × 1024 focal plane arrays (FPA’s) based on n-type In-doped HgCdTe heteroepitaxial layers are reported. The HgCdTe layers were grown by molecular beam epitaxy on silicon substrates with ZnTe and CdTe buffer layers. p–n junctions were formed by arsenic ion implantation into HgCdTe film. Reverse current in the temperature range from 210 to 330 K was found to be limited by the diffusion mechanism. At the same time in the temperature range from 140 to 210 K the reverse current was dominated by the thermal generation of charge carriers through deep traps located in the middle of the band gap. At 170 K NETD was less than 40 mK.

Total conductance of MIS structures based on graded-gap p-Hg1–хCdхTe (x =0.22–0.23) grown by molecular beam epitaxy (MBE) is studied in a wide temperature range 8-300 K. It is found that for MIS structures based on graded-gap MBE p-Hg1–хCdхTe (x =0.23) doped with As to a concentration of 1017 сm–3, the differential resistance of space charge region in the temperature range 8–100 K is limited by the processes of tunnel generation of minority carriers. It is shown that for MIS structures based on graded-gap MBE p-Hg1–хCdхTe (x =0.22) with the hole concentration of (8–9)·1015 сm–3, the differential resistance of space charge region in the temperature range 30–90 K is limited by the processes of Shockley-Read generation, regardless of the presence of a graded-gap layer. At higher temperatures, the differential resistance of space-charge region is limited by processes of the minority carrier diffusion from the quasi-neutral bulk region.

3 Admittance of MIS structures based on graded-gap n-Hg1-хCdхTe (x = 0.31-0.32) grown by molecular beam epitaxy (MBE) is investigated in a wide temperature range (8-300 K). It is shown that the temperature and frequency dependences of the differential resistance of space charge region for structures with a graded-gap layer are qualitatively similar to those for structures without a graded-gap layer. It is found that for MIS structures based on MBE n-Hg1-хCdхTe (x = 0.31-0.32), regardless of the presence of a graded-gap layer, the differential resistance of space charge region is limited by the processes of Shockley-Read generation in the temperature range of 25-100 K.

Total conductance of MIS structures based on heteroepitaxial n-Hg1–xCdxTe (x = 0.23) grown by molecular beam epitaxy has been studied in the temperature range 8–150 K at frequencies of alternating test signal 2 kHz – 2 MHz. It is found that for structures with a near-surface graded-gap layer and an increased content of CdTe, the differential resistance of space charge region increases significantly, as the temperature decreases from 77 to 8 K, and for structures without a graded-gap layer, the changes in the differential resistance of space charge region are nonmonotonic and relatively small. These results can be explained by the fact that at 8–77 K, for structures without graded-gap layers, the differential resistance of the space charge region is limited by tunneling via deep levels, and for structures with graded-gap layers, it is limited by the Shockley-Read generation processes.

We consider a spherically symmetric static problem of general relativity whose solution was obtained in 1916 by Schwarzschild for a metric form of a special type. This solution determines the metric coefficients of the exterior and interior Riemannian spaces generated by a gravitating solid ball of constant density and includes the so-called gravitational radius rg. For a ball of outer radius R=rg, the metric coefficients are singular, and hence the radius rg is traditionally assumed to be the radius of the event horizon of an object called a black hole. The solution of the interior problem obtained for an incompressible ideal fluid shows that the pressure at the ball center increases without bound for R=9/8rg, which is traditionally used for the physical justification of the existence of black holes. The discussion of Schwarzschild’s traditional solution carried out in this paper shows that it should be generalized with respect to both the geometry of the Riemannian space and the elastic medium model. In this connection, we consider the general metric form of a spherically symmetric Riemannian space and prove that the solution of the corresponding static problem exists for a broad class of metric forms. A special metric form based on the assumption that the gravitation generating the Riemannian space inside a fluid ball or an elastic ball does not change the ball mass is singled out from this class. The solution obtained for the special metric form is singular with respect to neither the metric coefficients nor the pressure in the fluid ball and the stresses in the elastic ball. The obtained solution is compared with Schwarzschild’s traditional solution.

Modulation characteristics of absorption at the resonance D 1 line of cesium atoms in a cell with antirelaxation coating are studied. It is experimentally shown that the minimum of the response to harmonic modulation in a certain frequency band coincides with Maxwellian velocity distribution maximum, despite the line profile distortion observed during linear frequency scanning [1]. The effect is theoretically explained.

This paper gives the parameters of 320 × 256 element long-wavelength infrared photodetectors fabricated by a new improved technology based on heteroepitaxial mercury-cadmium-tellur structures. In these photodetectors, the variation of the photodiode bias voltage over the area of the array is minimized; inefficient photodiode regions related to both hybridization and spike-shaped growth defects of epitaxial films are eliminated; the current-voltage characteristics of the diodes in the resulting photodetectors are homogeneous and are limited by the diffusion current component up to −400 mV. The dark current is 0.25–0.45 nA, and R 0 A = (0.6–3) · 102 Ω · cm2. The voltage sensitivity, the threshold irradiance, and the average NETD at the maximum sensitivity are 11.8 · 108 V/W, 3.7 · 10−8 W/cm2, and 26.8 mK, respectively. The percentage of defective elements is 1.5%.

We study the peculiarities of the absorption spectra in D1,2-lines of Cs, caused by optical pumping in cells with antirelaxation coating. In these cells the internal state of the atom, which arose under optical pumping by a monochromatic laser field, is preserved with a high probability in a collision with the wall. As a result, the optical pumping action extends to the entire volume of the cell and to all the velocities of the atoms. This leads to the speed-dependent scanning distortions of the absorption line profile. The detected features should be considered when using laserpumped quantum magnetometers with antirelaxation-coated cells.

The plane elasticity problem of bending of a cantilever strip whose material is assumed to be incompressible in the transverse direction is solved. It is shown that, in the classical statement of of the boundary condition for the fixed edge of the strip, the solution has a singularity at the corner points of the edge. Several cases of the strip fixation and loading characterized by the presence or absence of the solution singularity are considered. The strength of glass beams of three types, for which the theory of elasticity predicts whether the normal stress has a singularity, is studied experimentally. It is shown that the limit stresses for the beams of the types under study are practically the same, which testifies that the solution singularity does not have any physical nature.

Results of the research aimed at improving the strength of hybrid photodetectors (PD) based on mercury-cadmium-telluride heteroepitaxial layers are presented. It is shown that annealing of silicon multiplexers at 157 °C in a hydrogen flow in vacuum changes the shape of indium bumps to hemispherical and levels off their mechanical properties over the plate. Controlled recovery of the natural curvature of silicon multiplexer plates and photosensitive element arrays in hybrid photodetectors at 120 °C extends their operation time. A sequence of technological operations on PD hybridization providing an increase in the efforts needed for separating photosensitive elements from silicon multiplexers at least by 75% compared to the PD with fused indium bumps is proposed.

The dependences of photo-emf of metal-insular-semiconductor structures based on n-Hg1–xCdxTe (x = 0.21–0.23) on bias voltage, frequency, and temperature are experimentally studied. The photoelectrical characteristics of the metal-insulator-semiconductor structures based on epitaxial n-Hg1–xCdxTe (x = 0.21–0.23), including those taking into account the presence of near-surface graded-gap layers having an increased content of CdTe at various temperatures are calculated. The calculated dependences are compared with experiment and it is shown that the differential resistance of the spatial charge region for the metal-insulatorsemiconductor structures based on n-Hg1–xCdxTe (x = 0.21–0.23) without a graded-gap layer is restricted by tunneling through deep levels, whereas the differential resistance of the same structures with graded-gap layers – by the charge-carrier diffusion.

A specialized architecture based on peer servers is suggested for the development of distributed control systems with advanced reliability and operating speed; implementation is used in the Novosibirsk subway automated traffic control system.

Boundary inverse problems occupy an important place among the inverse problems of mathematical physics. They are connected with the problems of diagnosis, when additional measurements on one of the borders or inside the computational domain are necessary to restore the boundary regime in the other border, inaccessible to direct measurements. The boundary inverse problems belong to a class of conditionally correct problems, and therefore, their numerical solution requires the development of special computational algorithms.The paper deals with the solution of the boundary inverse problem for one-dimensional second-order parabolic equations, consisting in the restoration of boundary regime according to measurements inside the computational domain. For the numerical solution of the inverse problem it is proposed to use an analogue of a computational algorithm, proposed and developed to meet the challenges of identification of the right side of the parabolic equations in the works P.N.Vabishchevich and his st...