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Calculations of heat transport in crystalline materials have recently become mainstream, thanks to machine-learned interatomic potentials that allow for significant computational cost reductions while maintaining the accuracy of first-principles calculations. Moment tensor potentials (MTPs) are among the most efficient and accurate models in this regard. In this study, we demonstrate the application of MTP to the calculation of the lattice thermal conductivity of α and β - Ga 2 O 3. Although MTP is commonly employed for lattice thermal conductivity calculations, the advantages of applying the active learning methodology for potential generation are often overlooked. Here, we emphasize its importance and illustrate how it enables the generation of a robust and accurate interatomic potential while maintaining a moderate-sized training dataset. [ABSTRACT FROM AUTHOR]

The study focused on the nitrilo‐tris‐(methylene phosphonate) [K2ntpH4]2 and [(K1−yTly)2ntpH4]2 complexes, which are a series of isovalent substitutions. The crystals of [K2ntpH4]2 are monoclinic and belong to the space group of symmetry P21/c with Z=4. When thallium substitutes potassium, the molecular structure remains the same, but the symmetry of the crystal packing changes to a triclinic system, space group of symmetry P1‾ ${\bar{1}}$ , with Z=2. One coordination polyhedra maintains an isometric configuration, while the other undergoes significant distortions. Polarization‐selective coordination is observed, where the thallium(I) ion, which is easily polarizable, populates the highly distorted polyhedron. The low polarizable potassium ion populates the weakly distorted one. The crystal is formed with an average thallium fraction higher than the initial aqueous solution. This suggests that replacing potassium ions in the complex with thallium ions is energetically favourable. It could explain why thallium is toxic to intracellular enzymes and carriers of genetic information. The isovalent substitution of potassium made it possible to observe the step‐by‐step formation of a super‐strong hydrogen bond, a phenomenon that is rarely detected under normal conditions. The O...O interatomic distance in the hydrogen bond decreases gradually from 2.55 Å for [K2ntpH4]2 to 2.474 Å for [Tl2ntpH4]2. [ABSTRACT FROM AUTHOR]

Bifurcation analysis is an essential tool in nonlinear dynamics. Bifurcation diagrams help to discover subtle features of investigated dynamics such as chaotic and periodic regimes, hidden attractors and fixed points. However, plotting high-resolution bifurcation diagrams can be a computationally challenging task, especially in multiparametric evaluation. It should be noted that the bifurcation analysis is a task with natural parallelism and thus can be efficiently solved using hybrid central-graphics processing architectures. In this paper, we propose an advanced algorithm and special software for plotting bifurcation diagrams using calculations accelerated by graphics processing unit in combination with a highly efficient semi-implicit ordinary differential equation solver. Time series processing is based on the extraction of amplitude and phase features for the density-based spatial clustering of applications with noise to determine oscillation periodicity. We showcase the features of the application of proposed solutions on a set of test chaotic systems. The performance of the analysis algorithms is investigated in comparison with conventional solutions based on central processing unit and several approaches known from the literature. We explicitly show that the proposed algorithm outperforms known solutions in both calculation speed and precision. [ABSTRACT FROM AUTHOR]

The effect of the saturation of a current transformer (CT) on the operation of the starting elements of high-speed backup relay protection is examined. A method for selective detection of an external fault evolving into an internal fault with CT saturation is proposed. The method is applicable to both main and backup protections. [ABSTRACT FROM AUTHOR]

Application of metamaterial in realistic devices requires reliable approaches for effective material parameters. We demonstrate that a general homogenization procedure is non-versatile relative to the approach associated with the device functionality either inside or outside the structure. We exemplify it with internal and external treatments for the effective permittivity of a metamaterial in a lens consisting of dielectric rods. The dependence of the focal length on the permittivity and frequency of the incident field is determined, and the composite metalens with an ordinary lens are compared. The focal length is the same for both lens types. The approaches are compared to obtain effective permittivity values. The results show that different methods of homogenization are to be considered for a property description depending on the needs. [ABSTRACT FROM AUTHOR]

High-order harmonic generation (HHG) in solids opens new frontiers in ultrafast spectroscopy of carrier and field dynamics in condensed matter, picometer resolution structural lattice characterization and designing compact platforms for attosecond pulse sources. Nanoscale structuring of solid surfaces provides a powerful tool for controlling the spatial characteristics and efficiency of the harmonic emission. Here we study HHG in a prototypical phase-change material Ge2Sb2Te5 (GST). In this material the crystal phase can be reversibly changed between a crystalline and amorphous phase by light or electric current mediated methods. We show that optical phase-switching is fully reversible and allows for dynamic control of harmonic emission. This introduces GST as new addition to materials that enable flexible metasurfaces and photonic structures that can be integrated in devices and allow for ultrafast optical control. [ABSTRACT FROM AUTHOR]

Discrete chaotic maps are a mathematical basis for many useful applications. One of the most common is chaos-based pseudorandom number generators (PRNGs), which should be computationally cheap and controllable and possess necessary statistical properties, such as mixing and diffusion. However, chaotic PRNGs have several known shortcomings, e.g., being prone to chaos degeneration, falling in short periods, and having a relatively narrow parameter range. Therefore, it is reasonable to design novel simple chaotic maps to overcome these drawbacks. In this study, we propose a novel fractal chaotic tent map, which is a generalization of the well-known tent map with a fractal function introduced into the right-hand side. We construct and investigate a PRNG based on the proposed map, showing its high level of randomness by applying the NIST statistical test suite. The application of the proposed PRNG to the task of generating surrogate data and a surrogate testing procedure is shown. The experimental results demonstrate that our approach possesses superior accuracy in surrogate testing across three distinct signal types—linear, chaotic, and biological signals—compared to the MATLAB built-in randn() function and PRNGs based on the logistic map and the conventional tent map. Along with surrogate testing, the proposed fractal tent map can be efficiently used in chaos-based communications and data encryption tasks. [ABSTRACT FROM AUTHOR]

A prototype of a mobile device for measuring skin resistance on a patient's finger in the range of 0.75–5 MΩ was developed and assembled. Application of a patented method for the diagnosis of rejection using normalized skin resistance values obtained during systematic examination identified signs of kidney rejection in a series of patients, with confirmation by subsequent biopsy of grafts. [ABSTRACT FROM AUTHOR]

Inspired by pandemic-transformed instruction, this paper examines the digital accessibility of five tech tools used in information literacy sessions, specifically for students who use assistive technologies such as screen readers. The tools are Kahoot!, Mentimeter, Padlet, Jamboard, and Poll Everywhere. First, we provide an overview of the Americans with Disabilities Act (ADA) and digital accessibility definitions, descriptions of screen reading assistive technology, and the current use of tech tools in information literacy instruction for student engagement. Second, we examine accessibility testing assessments of the five tech tools selected for this paper. Our data show that the tools had severe, significant, and minor levels of digital accessibility problems, and while there were some shared issues, most problems were unique to the individual tools. We explore the implications of tech tools' unique environments as well as the importance of best practices and shared vocabularies. We also argue that digital accessibility benefits all users. Finally, we provide recommendations for teaching librarians to collaborate with campus offices to assess and advance the use of accessible tech tools in information literacy instruction, thereby enhancing an equitable learning environment for all students. [ABSTRACT FROM AUTHOR]

In this article, we consider designs of simple analog artificial neural networks based on adiabatic Josephson cells with a sigmoid activation function. A new approach based on the gradient descent method is developed to adjust the circuit parameters, allowing efficient signal transmission between the network layers. The proposed solution is demonstrated on the example of a system that implements XOR and OR logical operations. [ABSTRACT FROM AUTHOR]

Eigenmodes in equilateral and isosceles triangular trimers of infinite cylinders have been studied using the theory of multiwave scattering. Equations have been derived for the eigenfrequencies of the exceptional points where eigenfrequencies and eigenvectors are degenerate. The symmetry of the isosceles triangular trimer determines the separation of modes antisymmetric in the base direction. In the case of the equilateral triangular trimer, modes are separated into symmetric and double degenerate rotational modes. It has been found that damping symmetric modes in the trimer have a higher Q-factor compared to a dimer, which is of significant importance for applications of effects based on exceptional points. The behavior of complex eigenfrequencies in the isosceles triangular trimer has also been studied depending on the ratio of the lengths of its base and leg. At the point corresponding to the equilateral triangular trimer, the Q-factors of symmetric and antisymmetric modes have the local maximum and minimum, respectively. [ABSTRACT FROM AUTHOR]

The problem of taking into account the influence of air on the properties of distilled water is considered, namely the lack of a single generally accepted method for calculating such an influence. The sensitivity of the structure of water to the influence of external factors is described and the possibility of recording and studying such factors based on changes in the temperature coefficient of electrical conductivity of water is shown. The dependences of the temperature coefficient of electrical conductivity of distilled water on the rate of change in water temperature, the degree of filling of conductometric cells, as well as on the intensity of carbon dioxide exchange between water and air across their interface have been studied. It is noted that currently these exchange processes are studied insufficiently. A hardware-software measuring complex has been developed and manufactured to study the temperature coefficient of electrical conductivity of water in the temperature range of 20–55 °C. The temperature coefficient of electrical conductivity of water was measured in sealed conductometric cells at different degrees of filling with distilled water and various water heating and cooling rates. The degree of cell filling varied from 10 to 100%, and the water temperature variation rate—from 0.04 to 2.00 °C/min. With a constant heating and cooling time of 15 min in all experiments, the rate was varied by changing the temperature of the heating element. The integral temperature coefficient of electrical conductivity is calculated based on the initial and final values of electrical conductivity and water temperature in each measurement cycle. The dependences of the temperature coefficient of electrical conductivity on the water temperature variation rate at several constant values of the degree of cell filling were obtained. It was shown that at a constant water-to-air volume ratio in the cell and increased water heating rate, the temperature coefficient of electrical conductivity of water decreases by 19–22%. It has been established that at a constant water heating rate, the temperature coefficient of electrical conductivity of water decreases by 40–42% as the cellular water volume drops. The obtained results can be used to quantify the coefficient of carbonic acid dissociation, mobility of hydrogen ions, as well as intensity of the gas exchange process at various external conditions affecting water. Refinement of data on the electrical conductivity of water and processes occurring at the water/air interface is necessary for the development of models of atmospheric phenomena and climate changes, as well as for the creation of sensors capable of detecting weak changes in the environmental parameters for the purposes of environmental monitoring and medical diagnostics. [ABSTRACT FROM AUTHOR]

Computer simulation of continuous chaotic systems is usually performed using numerical methods. The discretization may introduce new properties into finite-difference models compared to their continuous prototypes and can therefore lead to new types of dynamical behavior exhibited by discrete chaotic systems. It is known that one can control the dynamics of a discrete system using a special class of integration methods. One of the applications of such a phenomenon is chaos-based communication systems, which have recently attracted attention due to their high covertness and broadband transmission capability. Proper modulation of chaotic carrier signals is one of the key problems in chaos-based communication system design. It is challenging to modulate and demodulate a chaotic signal in the same way as a conventional signal due to its noise-like shape and broadband characteristics. Therefore, the development of new modulation–demodulation techniques is of great interest in the field. One possible approach here is to use adaptive numerical integration, which allows control of the properties of the finite-difference chaotic model. In this study, we describe a novel modulation technique for chaos-based communication systems based on generalized explicit second-order Runge–Kutta methods. We use a specially designed test bench to evaluate the efficiency of the proposed modulation method and compare it with state-of-the-art solutions. Experimental results show that the proposed modulation technique outperforms the conventional parametric modulation method in both coverage and noise immunity. The obtained results can be efficiently applied to the design of advanced chaos-based communication systems as well as being used to improve existing architectures. [ABSTRACT FROM AUTHOR]

Josephson junctions (JJs) are superconductor-based devices used to build highly sensitive magnetic flux sensors called superconducting quantum interference devices (SQUIDs). These sensors may vary in design, being the radio frequency (RF) SQUID, direct current (DC) SQUID, and hybrid, such as D-SQUID. In addition, recently many of JJ's applications were found in spiking models of neurons exhibiting nearly biological behavior. In this study, we propose and investigate a new circuit model of a sensory neuron based on DC SQUID as part of the circuit. The dependence of the dynamics of the designed model on the external magnetic flux is demonstrated. The design of the circuit and derivation of the corresponding differential equations that describe the dynamics of the system are given. Numerical simulation is used for experimental evaluation. The experimental results confirm the applicability and good performance of the proposed magnetic-flux-sensitive neuron concept: the considered device can encode the magnetic flux in the form of neuronal dynamics with the linear section. Furthermore, some complex behavior was discovered in the model, namely the intermittent chaotic spiking and plateau bursting. The proposed design can be efficiently applied to developing the interfaces between circuitry and spiking neural networks. However, it should be noted that the proposed neuron design shares the main limitation of all the superconductor-based technologies, i.e., the need for a cryogenic and shielding system. [ABSTRACT FROM AUTHOR]

Developing efficient path-planning algorithms is an essential topic in modern robotics and control theory. Autonomous rovers and wheeled and tracked robots require path generators that can efficiently cover the explorable space with minimal redundancy. In this paper, we present a new path-planning algorithm based on the chaotic behavior of the Courbage–Nekorkin neuron model with a coverage control parameter. Our study aims to reduce the number of iterations required to cover the chosen investigated area, which is a typical efficiency criterion for this class of algorithms. To achieve this goal, we implemented a pseudorandom bit generator (PRBG) based on a Courbage–Nekorkin chaotic map, which demonstrates chaotic behavior and successfully passes all statistical tests for randomness. The proposed PRBG generates a bit sequence that can be used to move the tracked robot in four or eight directions in an operation area of arbitrary size. Several statistical metrics were applied to evaluate the algorithm's performance, including the percentage of coverage of the study area and the uniformity of coverage. The performance of several competing path-planning algorithms was analyzed using the chosen metrics when exploring two test areas of the sizes 50 × 50 cells and 100 × 100 cells, respectively, in four and eight directions. The experimental results indicate that the proposed algorithm is superior compared to known chaotic path-planning methods, providing more rapid and uniform coverage with the possibility of controlling the covered area using tunable parameters. In addition, this study revealed the high dependence of the coverage rate on the starting point. To investigate how the coverage rate depends on the choice of chaotic map, we implemented six different PRBGs using various chaotic maps. The obtained results can be efficiently used for solving path-planning tasks in both real-life and virtual (e.g., video games) applications. [ABSTRACT FROM AUTHOR]

The article discusses the characteristics of the joint operation of current transformers (CTs) of various accuracy classes with advanced algorithms for the differential protection of a microprocessor-based transformers. The issues of modern differential protection of transformer algorithms are presented, as well as means to address them, both using CTs with air gaps and improving their algorithms. [ABSTRACT FROM AUTHOR]

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The work highlights the results of a study into the dual wedge-shaped wear of composite brake pads for freight wagons. It has been found that the overnormative wear makes the area of a composite brake pad larger in the lower part up to a value directly proportional to the wagon mileage and smaller in the upper part. To assess the braking efficiency of a rail vehicle, a graphical analytical method has been developed; it allows determining the factor of dual wedge-shaped wear of pads depending on the wagon mileage. The results of calculation were verified by comparing two samplings obtained by mathematical and computer modelling. The results of calculation have proven that the hypothesis on the adequacy is not rejected. The results of the study conducted will allow more accurate assessment of the braking efficiency of freight rolling stock to be made, as well as contribute to improving the safety of train traffic. [ABSTRACT FROM AUTHOR]

Various discretization effects caused by applying numerical integration techniques to continuous chaotic systems are broadly studied in nonlinear science. Along with the negative impact on the precision of the various finite-difference schemes, such effects may have surprisingly fruitful practical applications, e.g. pseudo-random number generation, image encryption with improved diffusion and confusion properties, chaotic path planning, and many others. One such application is chaos-based communication systems which gained attention in recent decades due to their high covertness and broadband transmission capability. A crucial problem in the design of chaotic communication systems is the modulation of carrier signals. Due to the noise-like properties of chaotic signals, they can barely be modulated using the same methods as conventional harmonic signals. Thus, developing new modulation techniques is of great interest in the field of chaotic communications. In this study, we investigate the discrete model of the Lorenz oscillator obtained using controllable midpoint numerical integration and develop a novel modulation technique for chaos-based communication systems. We discover and analyze the multistability phenomenon in the dynamics of the investigated finite-difference Lorenz model through bifurcation, the basin of attraction, and Lyapunov spectrum analysis procedures. Using a specially designed testbench, we explicitly show that the proposed modulation method outperforms commonly used parametric modulation and is nearly equal to the state-of-the-art symmetry-based modulation in terms of covertness and noise resistivity. In addition, the proposed modulation technique is much easier to implement using computer arithmetics, especially in fixed-point hardware. The reported results may be efficiently applied to designing advanced chaos-based communications systems or improving the characteristics of existing communication system architectures. [ABSTRACT FROM AUTHOR]

Capabilities to monitor the purity and mixture composition of liquids with the aid of low-cost portable devices can grant essential advantages in maintaining personal health safety. The overwhelming majority of consumer wireless devices operate at relatively small operational bandwidth, thus not allowing for retrieving material composition via dispersion characteristics. To mitigate the bandwidth limitations, resonant methods, granting precision in a small frequency window, might be of use. Here, we demonstrate a liquid sensor able to provide 90.5 kHz/RIU sensitivities owing to a resonator, supporting high-quality factor quasi-bound states in the continuum. The sensor's architecture encompasses a high-permittivity ceramic resonator and a capillary wrapped around it. The volumetric design increases the overlap between the electromagnetic mode and the liquid under test while maintaining resonant conditions within a relatively narrow frequency band. To demonstrate the capabilities of the proposed method, the UHF RFID band was considered, and temperature dependence of the distilled water permittivity was retrieved. Interfacing standalone low-cost electromagnetic sensors with widely available consumer-level wireless devices offers promising opportunities that contribute to the paradigm shift toward IoT. [ABSTRACT FROM AUTHOR]

During spring 2020, emergency remote teaching became the norm for hundreds of higher education institutions in the United States due to the COVID-19 pandemic. Librarians were suddenly tasked with moving in-person services and resources online. For librarians with instruction responsibilities, this online mandate meant deciding between synchronous and asynchronous sessions, learning new technologies and tools for active learning, and vetting these same tools for security issues and ADA compliance. In an effort to understand our shared and unique experiences with emergency remote teaching, the authors surveyed 202 academic instruction librarians in order to answer the following questions: (1) What technology tools are academic librarians using to deliver content and engage student participation in emergency remote library sessions during COVID-19? (2) What do instruction librarians perceive as the strengths and weaknesses of these tools? (3) What digital literacy gaps are instruction librarians identifying right now that may prevent access to equitable information literacy instruction online? This study will deliver and discuss findings from the survey as well as make recommendations toward best practices for utilizing technology tools and assessing them for equity and student engagement. [ABSTRACT FROM AUTHOR]

In this work, feasibility tests of new two-stage approach of deposition of thick high-entropy alloy coatings were performed. At the first stage of this approach, metal composite coating is formed by detonation spraying of low-entropy metal powder blends. At the second stage, the composite precursor coating is heat treated in order to promote the synthesis of high-entropy phases. The tests were carried out using three different powder mixtures of Fe, Ni, Cu, Co, and Al powders. Experimental results showed that the detonation spraying allows formation of uniform metal composite coating. The microstructure analysis and microhardness measurements of the coating before and after heat treatments confirmed that the heat treatment enables element diffusion in the coating followed by formation of CoFeNi, CoCuFe0.8Ni, and Al0.05CoCu0.3FeNi alloys with uniform fcc structure after recrystallization. At the same time, the final composition of the coatings differed from the targeted ones due to different deposition efficiencies of the particles during detonation spraying process. [ABSTRACT FROM AUTHOR]

It is known, that coherent chaotic communication systems are more vulnerable to noise in the transmission channel than conventional communications. Among the various methods of reducing the noise impact, such as extended symbol length and various digital filtering algorithms, the optimization of the synchronization coefficient may appear as a very efficient and simple straightforward approach. However, finding the optimal coefficient for the synchronization of two chaotic oscillators is a challenging task due to the high sensitivity of chaos to any disturbances. In this paper, we propose an algorithm for finding the optimal synchronization parameter Kopt for a coherent chaos-based communication system affected by various noises with different signal-to-noise ratios (SNR). It is shown, that under certain conditions, optimal K provides the lowest possible bit error rate (BER) during the data transmission. In addition, we show that various metrics applied to the message analysis and demodulation task propose different noise immunity to the overall system. In the experimental part of the study, we simulated and physically prototyped two chaotic communication systems based on well-known Rössler and Lorenz chaotic oscillators. The microcontroller-based prototype of a wire chaotic communication system was developed to investigate the influence of noise in the physical data transmission channel. The experimental results obtained with the designed hardware testbench are in good correspondence with the theoretical propositions of the study and preliminary simulation results. The suggested evaluation metrics and optimization algorithms can be used in the design of advanced chaos-based communication systems with increased performance. [ABSTRACT FROM AUTHOR]

The results of the study of the effect of thermal annealing and diffusion on the structure of a porous silicon film formed by metal-assisted etching on a single-crystal silicon substrate are presented. The porous silicon film surface is studied by scanning electron microscopy and Raman scattering spectroscopy. It is shown that thermal treatment modes affect the morphology of porous silicon films on micro- and nanometer scales. [ABSTRACT FROM AUTHOR]

This industrial article focuses on the finishing machining of workpieces made of aluminium alloy EN AW 7075 with a freeform shape, utilizing minimal material stocks. These workpieces are widely used in sectors like aviation and the energy industry. In these sectors, there is a pressing demand for high-quality production in the initial attempt, eliminating the need for subsequent post-processing operations. The reason for this is to save material and reduce production time. The paper, therefore, deals with a method that involves analysing the shape of a spherical end mill in relation to surface roughness and quality, followed by a mathematical recalculation of the tool path. This approach allows to adjust the machining settings during the preparation phase in order to achieve satisfactory surface quality across the entire machined surface. This method was successfully validated during the final surface treatment of the turbine hubs. [ABSTRACT FROM AUTHOR]

The article describes the studies on the geomechanical behavior of the large pitwall rock mass using the seismic method. The on-site measurements of elastic wave velocities in rock mass enabled determining the elastic characteristics of rocks, which allowed an inference on the rock mass stability. It is shown that the seismic method provides sufficiently reliable data on the time history of the geomechanical behavior of the large-area pitwall rock mass, and enables the geomechanics and stability control. The long-term experience of using the seismic method to ensure pitwall rock mass stability is presented as a case-study of Zhelezny Open Pit Mine, Kovdor Mining and Processing Plant. The proposed approach is applicable at deep open pit mines. [ABSTRACT FROM AUTHOR]

In order to study the shot peening that occurs during the application of powder coatings, experiments are carried out on glass shot peening of steel test strips using a CCDS2000 detonation device. Experimental dependences of the shot peening depth and the residual stresses in a hardened layer on treatment parameters (particle size, density, and velocity, as well as the strength of the test strip material) are obtained. Engineering equations are proposed for calculating the values of and . [ABSTRACT FROM AUTHOR]

In this paper, the problem of scattering of a plane harmonic electromagnetic wave on a double wire array is solved accurately. The array consists of two identical infinite wire gratings arranged in a free space. Each of the grids consists of parallel thin, infinitely long metal cylinders of circular cross section. The study considers the case when the electric vector of the incident wave is parallel to the wires. The expression for the total reflection coefficient is obtained in the dipole approximation for the case of s -polarization. Analysis of the spectrum of the total reflection coefficient in the subwavelength part of the microwave frequency range was carried out. The paper proposes a new approach for determining the effective relative permittivity and permeability, as well as the effective refractive index of the grating. The approach does not depend on the number of grating layers and allows to taking into account near-field couplings in homogenizing the grating. This approach also allowed us to describe the behavior of the reflectivity and obtain expressions for the effective parameters of the grating at and near the resonant frequency. The validation of all the approximations obtained in the study was carried out using a finite-difference time-domain electromagnetic simulator. [ABSTRACT FROM AUTHOR]

We consider an optical dimer consisting of two particles having a resonance in the optical range, which might be used as a building block for photonic structures such as metamaterials. We find its eigenmodes that can be excited independently for symmetric and asymmetric dimers, and correlate them to the geometry of illumination that might be used to excite these modes. [ABSTRACT FROM AUTHOR]

The results of an experimental study of the surface morphology of zinc-oxide films and the electrical properties of structures based on a single-crystal Si/microcrystalline ZnO heterojunction are presented. An analysis of the structure of the zinc-oxide films grown in argon and oxygen atmospheres is carried out, and the size distribution of nanofibers grown on its surface is obtained. The capacitance–voltage characteristics of In/ZnO/n-Si/Al and Au/ZnO/n-Si/Al heterostructures are simulated. On the basis of calculations and comparison of the experimental and simulated dependences, the concentration of free charge carriers in the sample and the position of the Fermi level are determined, the presence of a fixed charge in the system is revealed, and the density of surface states is found based on the ratio of the voltage applied to the system and the surface potential at the interface between layers. The value of the built-in surface charge is calculated. The relationship between the material of the upper contacts and the capacitance–voltage and current–voltage characteristics of the system is studied. The resistance of the formed zinc-oxide films is calculated. The prevailing charge-transfer mechanisms are discussed. An empirical dependence of the surface potential of silicon on the voltage applied to the structure is revealed. The effect of technological modes for obtaining zinc-oxide films synthesized by spray pyrolysis on the surface structure, effective capacitance of the structure, density of electronic states, and processes of charge-carrier transfer in samples under the action of an electric field is analyzed. [ABSTRACT FROM AUTHOR]

We have numerically investigated the dynamics of charged microparticles in a "five-wire" surface radio-frequency trap. The period-doubling bifurcation conditions have been shown to depend on the particle, the trap, and the alternating voltage parameters. For a comprehensive study of the dynamics chaotization through a cascade of period doubling, we have used Fourier analysis of a particle trajectory as well as the calculations of a non-trivial Lyapunov exponent map. We have demonstrated that the period-doubling bifurcation is consistent with a Feigenbaum scenario. A new approach to particle property determination can, thus, be based on observing a period-doubling bifurcation. [ABSTRACT FROM AUTHOR]

Halide perovskites are a class of semiconductors with strong direct interband transition and high mobility of charge carriers resulting in bright luminescence, which can be easily tuned chemically in a broad spectral range. Moreover, perovskites can be synthesized by means of simple wet chemistry approaches on arbitrary surfaces, opening new avenues for perovskites integration with a plethora of other functional materials. Here, this work reports on a versatile platform for reversible switching of halide perovskite's optical properties enabled by high‐index phase‐change materials (Ge‐Sb‐Te) serving as an active subnanolayer, which controls the perovskite film's behavior. Based on this approach, this work demonstrates micro‐QR‐coding and switchable bright emission, whose wavelength can be adjusted in the whole visible range. [ABSTRACT FROM AUTHOR]

The publication presents the results of research into the strength of an improved tank container. The tare of a tank container can be reduced through application of composite material for the tank. In this case its mass can be 46% lower than that of a metal tank. The strength of the tank was calculated by computer simulation. The maximum stress occurs in its lower part and is about 295 MPa. The dynamic loading of a tank can be reduced by application of elastic elements in the fittings of a tank container. The reduction in dynamic load is achieved by the elastic friction forces generated in the fittings. The results of mathematical modelling of the tank container dynamics proved the effectiveness of this solution. [ABSTRACT FROM AUTHOR]