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Coherent terahertz radiation has been generated in p–n heterostructures based on a-Si:H/a-SiC:H/c-Si excited by 800-nm femtosecond laser pulses at room temperature. Terahertz radiation is generated when a reverse bias voltage is applied to heterostructures. The properties of the generated terahertz radiation strongly depend on the bias voltage, which reflects the dynamics of nonequilibrium charge carriers produced by femtosecond laser pump in the heterostructure.

The operation of the TiN/HfO2/Pt bipolar memristor has been simulated by the finite elements method using the Maxwell steady state equations as a mathematical basis. The simulation provided knowledge of the effect of conductive filament thickness on the shape of the I–V curve. The conductive filament has been considered as the highly conductive Hf ion enriched HfOx phase (x < 2) whose structure is similar to a Magneli phase. In this work a mechanism has been developed describing the formation, growth and dissolution of the HfOx phase in bipolar mode of memristor operation which provides for oxygen vacancy flux control. The conductive filament has a cylindrical shape with the radius varying within 5–10 nm. An increase in the thickness of the conductive filament leads to an increase in the area of the hysteresis loop of the I–V curve due to an increase in the energy output during memristor operation. A model has been developed which allows quantitative calculations and hence can be used for the design of bipolar memristors and assessment of memristor heat loss during operation.

The problem of determining the moment of formation of normal cracks in bending reinforced concrete elements with a complex cross-sectional shape, clamped at one end in brickwork and operating under the action of a negative bending moment is considered. A technique for testing prototypes of hollow-core slabs without formwork is presented. The purpose of the experiment is to determine the angles of rotation of the support nodes of hollow-core slabs without formwork, embedded in brickwork. The design of an installation for testing experimental specimens until the moment of cracking is presented. A diagram of the arrangement of measuring instruments is given to determine the deformation of the support unit at the place where the slab is embedded in the masonry, the defl ection of the prototype at the place of load application, the deformation of the brickwork simulating the wall of a multi-storey building.

The article examines the features of the calculation of large-span structures for covering religious buildings using the example of covering the middle part and the refectory of the church in honor of the holy unmercenaries Kosma and Domian of Asi, located in the village of Sezzhee, Bogatovsky district, Samara region. At the time of the work, the facility was undergoing a largescale reconstruction. Based on the data of the detailed examination of the technical condition of the building structures of the church roofi ng, calculations were made in a physically nonlinear sett ing, allowing to fully assess the stress-strain state of the monolithic reinforced concrete structure of the cover of the middle part and the refectory, which is a complex single continuous system of thin-walled spatial structures of various along the outline of the median surfaces.

It is shown that the introduction of cellulose ester mixed with acetotrimethyl acetate into films of organometallic perovskite CH3NH3PbBr3 significantly increases their stability while maintaining the optical and photoelectric properties of perovskite. It is found that, upon the introduction of 10–20 wt % mixed cellulose ester in CH3NH3PbBr3, the resistivity of the composite increases by a factor of 5–10 during 60–70 days, whereas in pure perovskite films such changes are observed within 10–15 days. When the films are illuminated with a simulated solar light, the resistance of the samples drops by 2–3 orders of magnitude, and the effect of photosensitivity persists for more than 2 months. The formation of hydrogen bonds between mixed cellulose ester and organometallic perovskite is, in our opinion, the main factor that increases the stability of the composite film in comparison with pure perovskite. The composite films been under study are promising for creating degradation-resistant perovskite solar cells and light-emitting diodes.

Introduction. The introduction of the bodies of zemstvo self-government in the Russian Empire led to the need to form the system of zemstvo budgets with their own income items, often falling on the same objects of taxation as state taxes. Most of the income came from taxation of land (state, private and peasant). In addition, the items of income were receipts from the taxation of real estate, trade and industrial enterprises, trade documents, etc. The zemstvo extended not only to Great Russian provinces but also to foreign ones, in so doing the functions of zemstvo had their own characteristics, since it was necessary to take into account ethnic and religious characteristics in provinces with a predominance of the non-Russian population. The purpose of the article is to clarify the comparison of the main sources of income of the zemstvo budget in ethnically different regions of the Russian Empire. Materials and Methods. The solution of research problems was provided by a complex of complementary theoretical (analysis of scientific literature, comparative analysis, comparison, generalization, systematization) and empirical (study and generalization of published and archival sources, hermeneutic) methods. Results. A comparative analysis of the principles and objects of taxation between the provinces of these groups (Kursk and Ufa) showed the similarity of approaches and priority of land taxation as the simplest and covering most of the payers. Discussion and Conclusions. The principles of forming zemstvo budgets throughout the Empire were unchanged, focused on the property approach of taxation, which was rather archaic due to the introduction of income taxation in the advanced countries, as the fairer one, while in Russia the main burden of taxation still fell on the shoulders of the peasantry, and led to the deficit of the zemstvo treasury. This brings the problem of forming zemstvo budgets to a further level of research into social, political and economic history.

The mechanisms of radiative recombination and electroluminescence in the structures based on the films of perovskite nanocrystals CsPbBr3 in the matrix of a semiconductor polymer MEH-PPV have been considered. It has been shown that two mechanisms determine the electroluminescence intensity in light-emitting field-effect transistors with active layers based on the MEH-PPV films:CsPbBr3 (nanocrystals): recombination of the charged carriers injected into the polymer matrix and recombination at the interface polymer/perovskite nanocrystals. The results of theoretical and experimental studies have shown that the superlinear dependence of the electroluminescence intensity on the level of electrical excitation in the light-emitting field-effect transistors based on MEH-PPV:CsPbBr3(nanocrystals) is due to the mechanism of electron tunneling through a potential barrier at the electrode.

A brief overview is presented for means of severe plastic deformation during the formation of gradient structure from the viewpoint of physical mesomechanics. An analysis of the results on the impact of the means of drawing with shear on steel; severe plastic deformation by high pressure torsion on steel, titanium, and copper; and alternating bending by applying a ECAP-Conform stand on copper. It is shown that structures with different degrees of gradient form in the materials as a result of these actions.

Composite films based on CH3NH3PbI3 organometallic perovskite and mixed cellulose ester (CE) were studied using terahertz (THz) spectroscopy in the time domain. It is established that the introduction of CE into CH3NH3PbI3 precursor significantly modifies the parameters of perovskite in the THz range and improves stability of the composite films. In particular, CE addition to the perovskite composite film leads to significant weakening of absorption bands in the region of 1–2 THz related to the excitation of low-frequency oscillatory modes in CH3NH3PbI3 molecules. This can be explained by damping of these modes on CE molecules enveloping the perovskite molecules.

Thin films of a composite based on CH3NH3PbI3 perovskite and graphene oxide (GO) particles were studied by the terahertz time domain spectroscopy method in the 0.2-2.9 THz spectral range. A significant increase in the terahertz absorption coefficient and the real part of the optical conductivity of the CH3NH3PbI3/GO composite was found with an increase in the content of GO particles in the composite. At the same time, it was established that the contribution of low-frequency vibrational modes in the perovskite molecule to the absorption and optical conductivity of the composite significantly decreases with an increase in the GO concentration.

Fiber-forming polymer composites filled with carbon nanoparticles of three types (carbon black is a spherical filler; carbon nanofibers and carbon nanotubes are anisotropic nanoparticles) were produced by melt technology. Electrical conductivity of the fiber-forming polymer composites was measured; a function of the filler concentration and the percolation thresholds were determined. It was found that an increase in the aspect ratio of carbon nanoparticles leads to a decrease in the percolation threshold. The correlation between the axial ratio, stiffness, filler concentration and electrical conductivity of the percolation cluster in fiber-forming polymer composites was analysed.

It is shown based on the structural analysis by reciprocal space mapping and the experimental secondary ion mass spectrometry and transmission electron microscopy data that, along with lateral compressive stress, vertical compressive stress is induced in a multilayer epitaxial heterostructure with a metamorphic step-graded buffer. The reason for this stress is that interphase boundaries hinder complete stress removal at strain relaxation. The analysis carried out within the linear elasticity theory showed that the elastically strained state of the heterostructure layers is similar to the state arising during a two-stage deformation process (bulk and biaxial compression). It is shown that the free energy of the system in the metastable state is minimal in this case.

Current–voltage characteristics of composite field-effect transistors with active layers based on inorganic perovskites, nanocrystals of cesium halides CsPbBr3, embedded into the matrix of a semiconductor polymer PFO (PFO:CsPbBr3) have been analyzed. An increase in current gain β in current–voltage characteristics of structures of this kind with increasing negative gate voltage was found and considered. It was shown that, if there is additional injection of minority carriers from electrodes into the transistor channel, composite light-emitting field-effect transistors with improved characteristics can be developed.

The article reveals the content of the concept of imaginary competition and its negative impact on real competition. The formal normative approach to the interpretation of the constitutional ban on monopolization and monopolistic activity is criticized. The necessity of legislative consolidation of prohibition (prohibitions) on imaginary competition form (forms) of monopolistic activity is substantiated.

On the basis of data on X-ray structural analysis performed by the method of reciprocal-space mapping and investigations using secondary-ion mass spectrometry and transmission electron microscopy, it is shown that vertical compressive stresses also arise in a multilayer epitaxial heterostructure comprised of a step-graded metamorphic buffer along with lateral compressive stresses. The cause of the appearance of vertical stresses is the effect of interlayer hardening, which arises due to the deceleration of fragments of glide dislocations by interphase boundaries. Analysis performed within the framework of the linear theory of elasticity shows that the elastically stressed state of the buffer steps is similar to the state that can be achieved as a result of a two-stage deformation process: bulk and biaxial compression. Bulk compression leads to large energy expenditures in the formation of the structure of the buffer steps, which is reflected, in particular, in violation of the coherence between the dislocation-free and the underlying layers.

The thermodynamic and kinetic regularities of processes occurring during heat treatment in silicon layers implanted with oxygen and carbon ions have been considered. We have analyzed the regularities of silicon deformation, impurity distribution and defect formation after different annealing modes. Diffusion smearing of implanted impurities in these layers has not been observed during carbon and oxygen implantation. As-annealed carbon does not occupy sites of the silicon lattice, in contrast to the implantation behavior of other impurities, e.g. boron and phosphorus. Phase formation regularities in implanted layers during subsequent heat treatment have been analyzed. Changes in the free energy of the system during heterogeneous and homogeneous precipitate nucleation have been compared. Sequential implantation with carbon and oxygen ions has been found to initiate diffusion flows of carbon and oxygen toward the center of the ion doped layer (the uphill diffusion phenomenon). The possibility of uphill diffusion has been analyzed from the standpoints of the Onsager theory. We show that the contribution of the chemical interaction between oxygen and carbon is far greater than the entropy contribution to the diffusion flux. We have demonstrated the high efficiency of ion doping with oxygen and carbon for gettering of uncontrolled impurities from active regions of silicon structures. The efficiency of this gettering process has been assessed for epitaxial structures in which layers had been grown on silicon wafers implanted with these impurities. Uphill diffusion in the layers after double doping with carbon and oxygen has led to the formation of more defects which may provide for efficient gettering. We have found the optimal oxygen and carbon implantation dose ratio for maximal gettering efficiency.

The electrical properties of composite films based on conductive polymer PEDOT: PSS, graphene oxide (GO), and titanium dioxide nanoparticles (TiO2) (PEDOT: PSS– TiO2 and GO–TiO2) used as contact layers of organic and perovskite photovoltaic structures have been studied. As a result of the study of morphology by atomic force microscopy, it was found that the PEDOT: PSS–TiO2 and GO–TiO2 films have a globular structure with a grain size of ~200–300 nm. The current–voltage characteristics of the PEDOT: PSS–TiO2 and GO–TiO2 films are measured in the temperature range of 80–300 K, the dependences of the resistivity versus temperature, ρ(T), which have an activation character, are obtained. It is established that as the temperature decreases, the ρ(T) dependences show a transition from large values of the activation energy (570 meV and 329 meV) to lower values (25 meV and 2.2 meV) for the PEDOT: PSS–TiO2 and GO–TiO2 films, respectively. The mechanisms of transport of charge carriers in the materials studied are discussed.

Problem Statement (Relevance): The paper describes some features and prospective benefits of deformation by methods of drawing with shear (SD) and high pressure torsion (HPT) in a temperature range of dynamic strain aging (DSA) effect, which allow receiving a high complex of physical and mechanical properties. Objectives: The study aims to investigate and analyze features of the structure formation with the combined application of severe plastic deformation (SPD) and the DSA effect during deformation by drawing with shear and high pressure torsion, to establish patterns of the gradient structure formation. Methods Applied: 1. Computer simulation in Deform 3D software to investigate the stress-strain state on materials with various types of a crystalline lattice: copper grade M1 (FCC), Steel 10 (BCC) and titanium VT1-0 (HCP) and a further comparison with experimental results. 2. Microhardness measurement 3. Scanning and transmission electron microscopy. Originality: This research resulted in investigation of the combined effect of the DSA effect and SPD on the gradient structure formation and mechanical properties of metals with various crystalline lattices. Findings: the paper presents the results of the study of the structure formation during non-monotonous plastic deformation of the alloys (steel 10, copper and titanium) with various crystalline lattice types by SD, as well as ECAP and HPT of low-carbon steel in the temperature range of the DSA effect. Deformation mechanisms and features of the deformation behavior on a mesoscopic scale under various deformation treatment modes are analyzed. The temperature range of the DSA effect in steel 10 under ECAP and the fact of the gradient structure formation under HPT are established. Practical Relevance: The study helped to obtain data that can be used to choose the optimal deformation treatment mode with the DSA effect.

Light-emitting organic field-effect transistors (LE-FETs) on the basis of composite films that consist of perovskite nanocrystals (CsPbBr3) embedded in a matrix of conjugated polymer—polyfluorene (PFO)—have been obtained, and their electrical and optical properties have been investigated. Output and transfer current-voltage characteristics (I-Vs) of FETs based on PFO : CsPbBr3 films (component ratio 1 : 1) have a slight hysteresis at temperatures of 100–300 K and are characteristic of hole transport. The hole mobility is ∼3.3 and ∼1.9 cm2/(V s) at the modes of the saturation and low fields, respectively, at 250 K and reaches ∼5 cm2/(V s) at 100 K. It has been shown that the application of pulsed voltage to LE-FETs based on PFO : CsPbBr3 can reduce the ionic conductivity and provide electroluminescence in this structure at 300 K.

The electrical properties of the films of organometallic perovskites CH3NH3PbBr3 and CH3NH3PbI3 were studied. Current–voltage characteristics for the CH3NH3PbBr3 and CH3NH3PbI3 samples were measured in a temperature range of 300–80 K, from which the temperature dependences of resistivity ρ(T) having characteristic points of inflection in a range of 160–240 K were determined. The activation energies of charge carriers prior to and after points of inflection were determined. It is assumed that the observed features in the temperature dependences of resistivity (temperature at the points of inflection) correlate with the temperatures of tetragonal-to-orthorhombic phase transitions for two studied organometallic perovskites (CH3NH3PbBr3 and CH3NH3PbI3).

Changes in surface energy and electrical conductivity of polyimide (PI)-based nanocomposite films filled with carbon nanotubes (CNTs) induced by UV exposure are gaining considerable interest in microelectronic, aeronautical, and aerospace applications. However, the underlying mechanism of PI photochemistry and oxidation reactions induced by UV irradiation upon the surface in the presence of CNTs is still not clear. Here, we probed the interplay between CNTs and PIs under UV exposure in the surface properties of CNT/PI nanocomposite films. Changes in contact angles and surface electrical conductivity at the surface of CNT/PI nanocomposite films after UV exposure were measured. The unpaired electron intensity of free radicals generated by UV exposure was monitored by electron paramagnetic resonance. Our study indicates that the covalent interactions between CNTs and radicals generated by UV irradiation on the PI surfaces tailor the surface energy and surface conductivity through anchoring radicals on CNTs. Surprisingly, adding CNTs into PI films exposed to UV leads to antagonistic contributions of dispersion and polar components to the surface energy. The surface electrical conductivity of the CNT/PI nanocomposite films has been improved due to an enhanced hopping behavior with dense π-conjugated CNT sites. To explain the observed changes in surface energy and surface conductivity of CNT/PI nanocomposite films induced by UV exposure, a qualitative model was put forward describing the covalent interactions between UV-induced PI free radicals and CNTs, which govern the chemical nature of surface components. This study is helpful for characterizing and optimizing nanocomposite surface properties by tuning the covalent interactions between components at the nanoscale.

One of the most significant stages of building a supply chain is the analysis of the criticality of the elements that make up it. When assessing the criticality of functional elements of adaptive supply chains, it is proposed to use the corresponding integral indicators. The introduced indicators, in addition, allow calculating the structural significance taking into account fluctuations in demand, based on the idea of a parametric genome of the structure of complex systems. This article presents the results of evaluating the significance of the functional elements of a certain supply chain with varying intensities of customer orders.

Films of CH3NH3PbI3 organometallic perovskite, which is currently considered as a promising basic material for new-generation solar cells, as well as films containing CsPbI3 inorganic lead–halid perovskite nanocrystals, have been studied in the spectral range of 0.2–2.9 THz at room temperature by terahertz time-domain spectroscopy. Several low-frequency vibrational modes previously attributed exclusively to vibrations of Pb–I bonds have been observed in the perovskite films under investigation in this spectral range. The comparison of terahertz characteristics of perovskites under study has shown that vibrations associated with a cation (CH3 NH3+, Cs+) make a significant contribution to the formation of the observed low-frequency vibrational modes in perovskites under consideration.

The problems of interpretation of criminal law and administrative law institutes of active repentance (“leniency programmes”) in relation to cartels are considered.The definition of the effectiveness of the institution of active repentance is given as the ability of this institution to achieve the goals stipulated by law (in the aggregate or in a particular combination): 1) termination of the committed offense (crime) (“surrender”),2) assistance in investigating the relevant administrative offense (crime), 3) compensation for the harm caused by his offense (crime), 4) refusal to commit such offenses (crimes) in the future.The condition of the quadunity of these goals is investigated. It is noted that among the main factors reducing the effectiveness of administrative law and criminal law institutions of active repentance (“leniency programmes”) in relation to a cartel is the legal inconsistency of these institutions.Proposals are being made to amend par. 3 of the Notes to Art. 178 of the Criminal Code of the Russian Federation and Note 1 to Art. 14.32 of the Code of the Russian Federation Code of Administrative Offenses iin order to bring together the relevant institutions of active repentance.The necessity of legislative consolidation of general procedural rules for the implementation of the person who participated in the conclusion of the cartel, the law granted him the right to active repentance is substantiated.

Solution-processed hybrid perovskite materials are attracting considerable attention as active layers of solar cells and hybrid light-emitting diodes (LEDs). Introducing perovskite CsPbBr3 nanocrystals (NCs) into light-emitting polymer (MEH-PPV) matrix can improve the processability and stability of such hybrid LEDs. In this work we investigate experimentally and consider theoretically the nonradiative excitation energy transfer from perovskite CsPbBr3 NCs to organic conjugated polymer MEH-PPV matrix along with experimental investigation of optical properties of such MEH-PPV:CsPbBr3 hybrid thin film structures. The theoretical analysis is carried out based on the Forster theory. The relative photoluminescence (PL) intensity of the MEH-PPV matrix is calculated as a function of the embed CsPbBr3 NC concentration. The decrease of the PL intensity with the increase of the CsPbBr3 NC concentration is found both theoretically and experimentally. It was found that the PL decay obtained experimentally is stronger with respect to that found theoretically. The reasons for the quantitative distinctions between the experimental data and as a result of the theoretical consideration are discussed.

This paper presents a modified nonlinear model of the Fujii transistor that incorporates the gate capacitance values obtained by capacitance-voltage measurements. It is shown that the proposed model allows us to correctly determine the operating frequency of the transistor, taking into account the effect of charged dislocation lines in the barrier layer of the heterostructure. The operating frequency values obtained with this modified model are in good agreement with the measured values.