bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of listening to music on emotional state of programmers: Preliminary study
Authors: Tarasau Herman , Thapaliya Ananga
Published: December 2020

The performance of programmer is crucial in software developing process. The performance can be influenced by the number of external factors, such as noise, illumination etc. These work uses Electroencephalography to understand the influence of music on programmers mental state. Several(n=8) programmers were given the task according to their proficiency. They were asked to solve different tasks with music and without. The arousal-valence coefficients were calculated in order to understand emotional state of programmers. As results, the mean Arousal and Valence levels are lower and higher respectively, while listening to music. Further researches may use the proposed methods as baseline. Also, we strongly advice to increase the number of samples and asses other factors that could potentially influence the emotional state.
Integrated Navigation System of Single-Axle Wheeled Robot With Two Degrees of Freedom Rotating Platform
Authors: Aleshin B.S. , Kuris E.D. , Lelkov K.S. , Miheev V.V. , Chernomorsky A.I.
Published: December 2020

A complex navigation system for a uniaxial wheeled robot with a two degrees of freedom rotating platform, which is a carrier of environmental monitoring equipment, is proposed. The navigation system includes an odometric subsystem, a block of inertial sensors, laser altimeters, and a receiver of the global navigation satellite system. Integration is carried out based on the use of the Kalman filter, taking into account the possibility of deformation of the wheels and their slippage when the robot moves relative to the non-horizontal underlying surface. The results of semi-natural modeling confirmed the effectiveness of the decisions made.
Development and modeling of the weighting algorithm of the passenger vehicle transportation quality
Authors: Aleksandrovich Zhuravlev Aleksandr , Petrovna Aksyonova Olga , Evgenevna Ziomkovskaia Polina
Published: December 2020

At the moment, the role of passenger vehicles (PV) in human life is quite large. People use PV almost every day. Recently, however, the roads are becoming more overloaded due to the increase in the number of vehicles. Consequently, the likelihood increases of less quality transportation. And the indicator of the quality of transportation is key in its assessment. One way to solve this problem is to develop an application that allows users to provide better information on how to get to their destination. However, for such an application to work, it is necessary to develop an algorithm by which it will work. This article proposes a weighting algorithm for assessing the quality of transportation of passenger vehicles. This algorithm works according to the following principle: the destination enters; the user assigns weight values to the characteristics of transportation (for example, convenience, safety, etc.); there is a comparative characteristic of vehicles going to the destination for each of the criteria (places are assigned for each of the criteria); at the end, the rating of each vehicle is compiled on the basis of multiplying the weight values of the vehicle seat by the criterion and the weight coefficient of the transportation criterion and further summing up the resulting terms.
Preliminary result on how to enhance online education during the COVID-19 pandemic
Authors: Fawaz Imam Muwaffaq Mohammad
Published: December 2020

In 2020 and because of COVID-19 pandemic, all institution transformed into online education is well established that there was no face to face teaching anymore and some institute and teachers were not ready to deal with, moreover students didn’t adapt to start the learning process online, This study shows aims to determine the best methods and technique we can use to give the best online education experience for both students and teachers in all institution wither if it’s academic, business or an individual. To test the hypothesis that we can enhance online education for all students an online survey was distributed to 115 students who study bachelor computer science and were taking online classes through Zoom and Youtube, the result showed that students prefer to digital pen and vLogs over slides, they care about video’s sound quality and prefer to watch 10 - 15 min video duration also they welcomed the Youtube chapters new technique to divided the long video into sections plus they prefer the audience engaging, energetic teaching style. The result showed that students are adapting to online learning and some of our technique were well received and some had no effect, On this basis, the concept of enhancing online education through new tools and practising new methods and trying them can taking into account when creating an online class in any educational institution.
Developing a Mobile Application Using Open Source Parking Management System on Etherium Smart Contracts
Authors: Imbugwa Gerald , Mazzara Manuel , Distefano Salvatore
Published: December 2020

In this paper, we envision to illustrate the process to be used in developing a mobile application on the smart contract. We start by looking at what other researchers have accomplished and how we can improve on what already exists. The paper highlights the requirement gathering process, the methodology for data collection to streamline and validate the requirement, the architecture and implementation phase by analyzing the technological stack to achieve the business goal.
Dynamical systems analysis using many-task interactive cloud computing
Authors: Popov Stefan N. , Vostokin Sergei V. , Doroshin Anton V.
Published: December 2020

The article states an approach for developing a distributed application architecture for dynamic systems analysis in a hybrid cloud. The problem that was posed as an example is based on the calculation of the Lyapunov characteristic exponents for trajectories of dynamical systems in phase space. Parallelization of the computational process is achieved by supplying the list of running tasks for computing Lyapunov characteristic exponents, depending on the result of finished tasks during calculations. We have implemented a distributed application to make this experiment automated. The architecture of application elements is established on the principles of the enterprise desktop grid and cloud systems. A vital detail of the application architecture is the deployment process based on a cloud hybrid computing environment using the Jupyter server running on the DigitalOcean cloud platform and the Everest cloud platform simultaneously with the Maple package.
A Survey of Blockchain Solutions for Autonomous Vehicles Ecosystems
Authors: Megha Swati , Salem Hamza , Ayan Enes , Mazzara Manuel
Published: December 2020

Since the beginning of the 2010s major car manufacturers progressively started to invest in Autonomous Vehicles(AV). Notable examples are Tesla, Ford, and Toyota. Small startups and tech giants like Google and Yandex are now also entering the competition to propose new solutions. Most of them have already developed their prototypes of driverless vehicles that you can normally observe in the streets of New-York, USA, or Innopolis, Russia. Despite the significant hype on this technology, current solutions are not always optimal and multiple challenges are left open in a domain such as security, data integrity, privacy, and communication. Blockchain is one of the most appealing technologies to be used in this domain since it provides solutions for some of these challenges. In this paper, we describe, categorize, and evaluate different solutions of the Autonomous Vehicles Industry that makes use of Blockchain. We use a software engineering approach to organize the existing work in multiple categories such as challenges addressed, quality attributes promoted. This work is intended to provide researchers in the field with a well-defined and structured categorization, plus insights into the existing literature.
Usage of a BART algorithm and cognitive services to research collaboration platforms
Authors: Voronkov I A , Saradgishvili S E
Published: December 2020

This article examines the possibility of extending the collaborative filtering method in shared information systems. The need to build recommendations dictates the volume and the intensity of the emergence of more and more new information. In the scientific world, the possibilities of building recommendations are widely explored, and this work presents the authors’ vision of a possible direction of development, which is based on a preliminary iteration with the highlighting of keywords.
Numerical simulation of focused ultrasonic waves in soft biological tissues with subsequent generation of shear waves
Authors: Lisin A. , Demin I.
Published: December 2020

Numerical simulation of the propagation of ultrasonic waves is carried out based on the numerical solution of the Westervelt equation by the pseudospectral method with visualization. The modeling conditions are selected in accordance with the physical model of a soft biological environment. A comparison of physical and numerical modeling of the evolution of shear waves is carried out, and the elastic characteristics of polymer phantoms are determined.
Application of Data-Oriented Design in Game Development
Authors: Fedoseev K , Askarbekuly N , Uzbekova A E , Mazzara M
Published: December 2020

Game development is a big, human resource intensive industry. Object-Orientated Design (OOD) is the most popular software design paradigm in game development. However, it is not the optimal choice whet it comes to performance and resource utilization. To solve this problem, Data-Oriented Design (DOD) can serve as an alternative for resource-intensive games where performance is the highest priority. The latter approach is often perceived as something exclusive to highly qualified specialists. Thus, a question arises whether DOD can suit and be useful for smaller companies and projects, and what are the trade-offs of using the approach compared to more wide-spread object-orientation.

This paper examines the experience of a small game development team implementing two similar case study projects, one using OOD and another using DOD. After an overview of both implementations, the authors analyze and compare the two projects in regards to performance and maintainability. Recommendations are given on when each of the two design approaches should be applied and what are the corresponding skill sets for developers to use them.
Optical transparency and conductivity of oriented platinum nanonetworks on a glass surface
Authors: Nizameeva G R , Nizameev I R , Nefedev E S , Kadirov M K
Published: December 2020

The work is aimed at creating an optically transparent conductive coating based on platinum nanowires which can become an alternative to the existing indium tin oxide. This coating can be used as transparent electrodes in solar panels, organic LEDs and many areas of modern electronics and optoelectronics. In work, the dependence of the sheet resistance of oriented platinum nanowires network on the amount of metal used is investigated. Oriented platinum nanowires are obtained by chemical deposition from an aqueous solution of hexachloroplatinic acid on a glass surface. The topography of the deposited metal layer on the glass is visualized by atomic force microscopy. It has been established that the platinum layer has good optical transparency. The synthesized coating would be of interest in terms of applicability as an optically transparent electrode.
The effect of plasma immersion ion implantation of Ne+ or Ar+ or Kr+ on the forming voltage of the resistive switching in the structure Ni/Pt/HfO2(10nm)/TaN(5nm)/TiN
Authors: Permyakova O O , Miakonkikh A V , Rudenko K V , Rogozhin A E
Published: December 2020

The effect of ion implantation on the characteristics of resistive switching in the structure of Ni/Pt/HfO2/TaN/TiN with an oxide layer thickness of 10 nm is considered. It was shown that after implantation of Ne+ ions, the forming voltage decreases by 0.5 V, while after implantation of Ar+ ions, the share of the forming-free cells increased from 0.1 to 0.6. Resistive switching after implantation of Kr+ ions is entirely absent.
Effect of the Al content in the substrate on the In nanodroplets growth by droplet epitaxy
Authors: Chernenko N E , Balakirev S V , Eremenko M M , Solodovnik M S
Published: December 2020

The paper presents the results of an experimental study of the effect of Al content in the epitaxial surface layer on the growth of In nanostructures formed by droplet epitaxy. We have shown that an increase in the Al content leads to a decrease in the droplet density and an increase in their size. We also showed that the influence of the Al content on the droplet characteristics is much less significant than that in case of the Stranski-Krastanov growth. The increase in the critical thickness of droplet formation on Al-containing surfaces when the temperature decreases is not significant. It allows us to control quantum dot emission wavelength almost independently of their geometric characteristics.
Characterization of nanocrystalline ZnO thin films prepared by new pyrolysis method
Authors: Volkova M G , Storozhenko V Yu , Petrov V V , Bayan E M
Published: December 2020

To obtain high-quality nanocrystalline transparent ZnO films, a new pyrolysis synthesis method was used. The resulting material was investigated by x-ray diffraction, scanning electron microscopy. Structural analysis of the films shows that they are polycrystalline and have a wurtzite structure. The film structure consists of nanocrystallites about 10–20 nm in size, uniformly distributed over the surface of the substrate and over the thickness of the film. The temperature dependence of the resistance of the obtained films was also investigated. The activation energies of conductivity are determined by the donor conductivity levels existing in zinc oxide, and temperature hysteresis is determined by the effect of charging oxygen adsorbed on the surface of zinc oxide.
Controlled Ultra-Thin Suboxide Films Generation in Metal-Oxide Systems by Ar+ Ion Irradiation
Authors: Lubenchenko A V , Lukyantsev D S , Pavolotsky A B , Ivanov D A , Lubenchenko O I , Ivanova I V , Iachuk V A , Pavlov O N
Published: December 2020

A method of controlled generation of metal suboxide films is proposed, basing on low-current ion sputtering of native oxides of ultra-thin metallic films and XPS chemical and phase depth profiling. Niobium suboxide ultra-thin films are generated and controlled using this approach.
Light-emitting hexagonal 9R-Si phase obtained by implantation of Kr+ ions in Si and SiO2/Si
Authors: Nikolskaya A A , Korolev D S , Konakov A A , Mikhaylov A N , Belov A I , Marychev M O , Murtazin R I , Pavlov D A , Tetelbaum D I
Published: December 2020

To study the mechanism of a 9R-Si hexagonal phase formation upon ion irradiation of the SiO2/Si system, three types of experimental samples have been investigated by photoluminescence (PL) spectroscopy and transmission electron microscopy (TEM): SiO2/Si system irradiated by Kr+, silicon irradiated by Kr+ and silicon irradiated by (Kr+ + O+) ions. All the samples were annealed after irradiation. The first type sample shows the presence of the 9R-Si phase and PL band at ∼ 1240 nm; the third type sample shows the same PL band and twin defects; for the second type sample, the PL at 1240 nm is not detected. Based on the results, the role of mechanical stresses, radiation defects and oxygen in the formation of the hexagonal silicon phase is discussed.
Influence of thermal treatment on the morphology and composition of Ge Nanowires
Authors: Lipilin F S , Gavrilin I M , Trifonov A Y
Published: December 2020

In this work we studied influence of thermal treatment on the morphology and composition of Ge nanowires (GeNW) obtained by electrochemical deposition using In nanoparticles. The obtained results showed that thermal treatment can be used for control the composition of GeNW, what is important for technologies, where the presence of In may negatively affect the operation of the device.
Structure and spectral-luminescent properties of Er3+:ZnO optical ceramics
Authors: Gorohova E , Basyrova L , Venevtsev I , Alekseeva I , Khubetsov A , Dymshits O , Baranov M , Tsenter M. , Zhilin A , Eron’ko S , Oreschenko E , Rodnyi P. , Loiko P
Published: December 2020

Transparent zinc oxide ceramics, undoped and doped with 0.1-2.0 wt% Er3+ ions were fabricated by uniaxial hot pressing of commercial oxide powders. The ceramics were characterized by X-ray diffraction, SEM, EDX, Raman, X-ray and optical spectroscopy. The analysis of morphology of Er3+:ZnO ceramics reveals that the main components of texture are hexagonal prism planes similar to those for undoped ceramic. The ZnO grain size decreases with addition of Er2O3. The Er3+ ions are distributed between the ZnO grains and the Er2O3 crystals and do not enter the zinc oxide structure. The luminescence spectra of Er3+:ZnO ceramics contain emission bands originating from the intra-4f shell transitions of Er3+ ions and bands assigned to defect states at ZnO. The X-ray luminescence spectra indicate the possible energy-transfer between the ZnO grains and Er3+ ions. The defect luminescence band becomes weaker and the X-ray luminescence decay time decreases as the erbium concentration is increased.
Perovskite nanoparticles and films: photoluminescent properties and lighting stability
Authors: Son A G , Krivogina E V , Kozyukhin S A , Shapovalov S S
Published: December 2020

In this paper, we obtained nanoparticles based on ABX3 type of metal halide perovskites at room temperature. The development of technological processes allowed us to synthesize the studied nanoparticles with room temperatures. Perovskite materials problem is degradations in moist environment, by light and unsteadiness to differential temperature. We studied perovskite degradation phenomena from light exposure. And were select the optimal layers for perovskite solar cell stability.
Characterization of an RNase III mutant of Rhodobacter sphaeroides
Authors: Boerner J M
Published: December 2020

In this work an RNase III deletion mutant of the facultative phototrophic α-proteobacterium Rhodobacter sphaeroides was characterized. The aim of this study was to identify differences in phenotype and RNA physiology between wild type and mutant, which can be explained by a loss of RNase III activity. We analyzed the growth behaviour of the mutant and the wild type under different growth conditions, including microaerobic and phototrophic mode of growth. As Rhodobacter sphaeroides is known for its metabolic versatility, we were also interested in regulation of the transcriptome. The results suggests that the deletion of the RNase III coding gene (rnc) strongly impacts phenotype and transcriptome of Rhodobacter sphaeroides.
Revealing a possible sensor mechanism of DNA - based silver nanoclusters
Authors: Kapitonova M A , Reveguk Z V , Kononov A I
Published: December 2020

The mechanisms underlying the sensory activity of silver clusters (Ag NCs) synthesized on oligonucleotide matrices are not understood yet. It is known that close proximity of cytosine and guanine rich sequences causes colour changes in the luminescence of Ag NCs. We studied two types of fluorescence activation of Ag NCs due to close proximity of two DNA strands. We concluded that the activation phenomenon could be explained by the same mechanism, namely by the reassembling of the silver atoms on the double-stranded DNA formed upon hybridization. Our results could be useful for further Ag NCs-based sensors development.
Multichamber hybrid microfluidic chips for nucleic acids detection by qPCR assay
Authors: Afonicheva P , Zubik A , Bulyanitsa A , Rudnitskaya G , Evstrapov A
Published: December 2020

The efficiency of silicon-glass chips for the nucleic acids analysis with a concentration of 106-102 copies/µl using various algorithms of searching threshold cycles is shown. Hypotheses that explain the observed PCR efficiency decrease for microfluidic chips compared to polymer test tubes are discussed.
On the possibility of analysis using the wavelet transform of the pulse waveform from the bloodstream
Authors: Davydov R V , Rud V Yu , Yushkova V V
Published: December 2020

A method has been developed using wavelet transform to describe the dynamics of the pulse wave shape during the diagnosis of human health. The pulse wave signal, in contrast to the previously discussed diagnostics, is considered an unsteady signal, in which there may be no periodicity. We found that this method is useful for diagnosing the properties of arterial vessels of patients with coronary heart disease, arterial hypertension and other diseases. Pulse wave research results are presented.
Analytical complex for study of the oxygen status of tissues of the human organism
Authors: Mazing M S , Zaitceva A Yu , Kislyakov Yu Ya , Davydov V V , Kondakov N S , Avdyushenko S A
Published: December 2020

An automated complex for the study of the oxygen status of human body tissues using an artificial trained analytical system is presented. It includes sensory, electronic and computer modules for measuring and analyzing data. System training is implemented according to the principle of dividing the subjects into groups using mathematical methods of data processing and comparing them with data on the degree of adaptive responses obtained in the course of independent biomedical research. After analytical system training, subsequent recognition of the “image” of the test subject and its assignment to one or another group of the type of reaction to the functional load was possible.
Development of a hydraulic system for bridge amplification
Authors: Kruglov V A , Reznik V S , Davydov V V , Glinushkin A P
Published: December 2020

In this paper, we consider the features of creating a hydraulic system with the goal of conducting bridge amplification, which is part of the Illumina/Solexa method. The result of the work is an automated system with all the necessary functional qualities.
Establishing the applicability of the laser diffraction technique for the graphene oxide platelets lateral size measurements
Authors: Rabchinskii M K , Saveliev S D , Ryzhkov S A , Nepomnyashchaya E K , Pavlov S I , Baidakova M V , Brunkov P N
Published: December 2020

In this paper, basing on the thorough comparison of the size measurement results obtained by Laser Diffraction (LD) and microscopic methods, we demonstrate the LD method to provide reliable and accurate data on the lateral size of two-dimensional graphene oxide (GO) platelets. Taking cue from the experimental study and theoretical calculations of scattering patterns, model accounting for arising of diffraction pattern that can be correctly processed with common LD instrumentation is suggested.
Photoelectric properties of heterostructures based on InAsSbx solid solutions (0.3 ˂x ˂0.35)
Authors: Kunkov R. E. , Klimov A. A. , Lebedeva N. M. , Lukhmyrina T. C. , Matveev B. A. , Remennyy M. A.
Published: December 2020

The results of a study of multilayer p-n heterostructures based on InAsSbx solid solution (0.3 ˂ x ˂0.35), with a long-wavelength photosensitivity boundary of λ0.1 ≈ 9.5 μm at room temperature are presented. The current-voltage and spectral characteristics of photosensitivity and electroluminescence were analyzed in the temperature range 80 ÷ 300 K. It is shown that the photoelectric properties are determined by the diffusion mechanism of current flow, and experimental samples of photodetectors are characterized by a quantum efficiency of Si ⩾ 1 A / W.
Study of SiNx based antireflection coating for GaP/Si heterojunction solar cells
Authors: Anokhina E V , Uvarov A V , Gudovskikh A S
Published: December 2020

This paper presents the results of a research of the optical properties of SiNx layers with various compositions obtained by plasma-enhanced chemical vapor deposition (PECVD). The growth rate and optical properties of SiNx obtained using SiH4 and N2 at low temperature were determined. A strong dependence of the optical properties of SiNx on concentration of silane in the gas mixture during deposition was demonstrated. Antireflection coatings for GaP/Si solar cells were fabricated based on developed SiNx layer.
Development of front contact grid for GaP/Si solar cells
Authors: Bogdanova M V , Morozov I A , Gudovskih A S
Published: December 2020

A scalable technology for applying metallization to GaP/Si photovoltaic structures for mass production was explored. The study of Ag-based contacts, which are obtained by screen-printing of silver past followed by subsequent annealing, are presented in this paper. Contact resistance measurements are done using the TLM method. The developed contacts have demonstrated excellent performance even in comparison with the vacuum deposition technology, which is the basis for using the developed technology of forming contacts in industry.
Optical properties of dry etched vertically aligned silicon structures with different geometry
Authors: Vyacheslavova E A , Morozov I A , Gudovskikh A S , Uvarov A V , Baranov A I , Kudryashov D A
Published: December 2020

In this paper, we study the effect of the height and diameter of vertically aligned silicon structures on their optical properties. Structures with different geometry were formed using nanosphere lithography and dry etching. Nanosphere lithography was realized with 0.9 and 2 μm latex spheres. The etching process was carried out through a formed mask (template) composed of 0.9 and 2 μm latex spheres, respectively. The diameter of the spheres and the etching time determined the size of the formed structures and their optical properties. A significant reduction of the total reflection with height as well as blue shift of the minimum with diameter decrease were observed.
Carbon nanotubes and wolfram oxide nanoparticles spray coating on polymer photoactive layer
Authors: Romashkin A V , Polikarpov Yu A , Alexandrov E V , Nevolin V K
Published: December 2020

The spray-coating technique to form top transparent conductive and buffer uniform layers of carbon nanotubes (CNTs) and tungsten oxide nanoparticles (nWO3) from the solvents mixture on MEH-PPV layer, providing minimal underlying layer dissolution and acceptable interface quality, was proposed and can be used for solar cells (SC). The effect of neighboring layers mixing on the electrical characteristics of organic SC and methods for minimizing this mixing by optimizing solution composition, which was selected based on the MEH-PPV solubility and the stability of CNT dispersion, were studied. The dipping degree of CNTs and nWO3 in MEH-PPV and the interface quality was studied by measuring the CNT layer surface resistance and the nWO3 diameter on the surface, as well as analyzing the CVC hysteresis, photoresponse, and current drop time with forward bias after light off.
Development of a method for adjusting the coordinates of the center of attention in the absence of fixation of the head
Authors: Kiseleva E S , Isaeva O L , Boronenko M B , Zelensky V I
Published: December 2020

In this paper, the movement of the pupils is a biometric indicator that analyzes the emotional state of a person. Eyetracking using infrared illumination based on the determination of the displacement vector between the centers of the pupil and the shine of the cornea gives results with high accuracy, provided that the human head is fixed. A method for determining the coordinates of the center of attention in the absence of fixation of the head without using infrared illumination is proposed. The accuracy of determining the coordinates of the center of attention is improved by moving from a coordinate system associated with a fixed head to a coordinate system associated with a moving center of the pupil.
Physico-mechanical properties and SEM of sol–gel plates based on chitosan L-(D-)ascorbate
Authors: Zhuravleva Yu Yu , Malinkina O N , Zudina I V , Shipovskaya A B
Published: December 2020

In our previous studies, it was shown that the isomeric form of ascorbic acid (L-or D-AscA) used to obtain the salt form of chitosan had a significant effect on the total space charge, size and general chirality of chitosan ascorbate macromolecules in solution, their stereomeric ordering in lyophilically isolated solid phase, as well as the kinetics of sol–gel synthesis of materials based thereon. This study examines the effect of L- and D-AscA on the physico-mechanical and morphological properties of thin-film sol–gel plates based on chitosan L-or D-ascorbate without and with Aloe Vera juice added. It has been established that the AscA isoform has a significant effect on the elastoplastic characteristics of the samples and the surface relief of their solid phase. The addition of Aloe Vera also leads to significant texturing of the surface relief. The latter could be used to design specific optical sensors and optodes of medico-biological purposes.
Optical spectra of titanium modificated surfaces with LIPSS and gold nanoparticles
Authors: Khankaev A , Tcibulnikova A , Bryukhanov V , Samusev I , Demin M , Lyatun I
Published: December 2020

This paper presents the reflection spectra of s - and p-polarized light and the refractive index spectra of anodized titanium surfaces modified by laser-induced periodic structures with gold nanoparticles. It is shown that these surfaces generate surface plasmons in the visible region of the spectrum, which leads to the formation of a negative values region in the refractive index.
Photoemission from p-GaAs(Cs,O) under transition from negative to positive electron affinity
Authors: Protopopov D E , Khoroshilov V S , Zhuravlev A G , Kazantsev D M , Alperovich V L
Published: December 2020

The evolution of the electron escape probability from p-GaAs(Cs, O) to vacuum was measured under the transition from the state of negative to the state of positive electron affinity. The transition was induced by the deposition of excess cesium or oxygen on the p-GaAs(Cs, O) surface activated to the state of negative electron affinity. Under deposition of excess cesium, the escape probability was significantly lower as compared to excess oxygen, presumably, due to reflection and scattering of electrons on two-dimensional cesium metal clusters. Under Cs-induced transition, at positive values of affinity, a new peak was observed below the band gap in the photoemission quantum yield spectra. The peak stems, presumably, from: (i) the effective capture of sub-bandgap light in the structure, which consists of the heavily doped p
+-GaAs epilayer grown on the semi-insulating GaAs substrate, due to diffuse backside reflection from the rough back surface of the substrate; (ii) absorption of the captured light near the emitting p
+-GaAs surface due to the Franz-Keldysh effect in the strong surface electric field; (iii) emission of the electrons generated near the surface.
Optical method for determination of fatigue damage in organic glass
Authors: Sinicyna E A , Nagornaya A I , Kulikova M E , Davydov V. V. , Glinushkin A P
Published: December 2020

The features of nucleation, start, and propagation of a crack inside a transparent organic sample are investigated. The distribution of the refractive index and density around the crack was studied by changing of speckle images and ellipsometry method. It was found that the maximum value of the relative change in density is near the crack. This value before the crack start is greater than 0.003. It is proved that the speckle method we offer can be the basis for the creation of various techniques. Using these techniques will allow us to estimate the time before the crack start by the rate of change of physical quantities in small areas of the order of 50 μm and their limiting values. The results of experimental investigations are presented.
Simulation of the super-Gauss beam abrupt focusing in the near diffraction zone using high-performance computer systems
Authors: Savelyev D A , Volotovskiy S G
Published: December 2020

We investigated the change in the type of focal spot when laser radiation passed through the diffraction axicon and the optical element matched with the circular Airy distribution having abrupt focusing properties. Modelling of near zone diffraction is numerically investigated by the finite difference time domain (FDTD) method. The abrupt formation of a light needle was shown for the optical element matched with the circular Airy distribution and for axicon.
Wave-vector direction-sensitive photocurrent in laser-induced graphene
Authors: Mikheev K G , Fateev A E , Zonov R G , Bulatov D L , Mikheev G M
Published: December 2020

Porous graphene film structures were formed in the process of line-by-line scanning by a focused laser beam of cw CO2 laser on polyimide film. It was shown that at a power density of 8 W/cm2 and a scanning speed range of 200-260 mm/s, porous graphene is formed on the surface of a 120-μm-thick polyimide film. The results of the investigation of the longitudinal photocurrent generation in LIG film are presented. Photocurrent excitation was carried out by nanosecond laser pulses at wavelength range of 266-1064 nm. It was found that the photocurrent depends on the direction of the wave-vector of the incident radiation according to the odd law characteristic of the photon drag effect (PDE). It is also shown that the presented method of the LIG film formation leads to anisotropy of its photovoltaic properties.
Study of microheater’s phase modulation for on-chip Kennedy receiver
Authors: Venediktov I O , Elezov M S , Prokhodtsov A I , Kovalyuk V V , An P P , Golikov A D , Shcherbatenko M L , Sych D V , Goltsman G N
Published: December 2020

In this work we describe phase modulators for several Mach-Zehnder interferometers (MZI) on silicon nitride platform for telecomm wavelength (1550 nm). We obtained current-voltage and phase-voltage curves for these modulators. MZI are needed for experimental realisation of various quantum receivers that can distinguish weak coherent states of light with extremely low error. Thermo-optical (TO) modulation is ensured by microheaters on one of the arms of MZI, which enables the change of the refractive index of the material with temperature. This approach allows to apply the necessary voltage to the golden microheaters to obtain the required phase change. For the on-chip microheaters we demonstrate the dependence of the phase shift on the voltage applied to our on-chip microheaters.
Intercept-resend attack on passive side channel of the light source in BB84 decoy-state protocol
Authors: Babukhin D , Sych D
Published: December 2020

Quantum key distribution (QKD) promises unconditionally secure communication based on fundamental laws of physics, though practical realizations of QKD may have loopholes and side channels, thus their security can be compromised. We analyze the intercept-resend attack on the BB84 decoy-state protocol under the presence of a passive side channel of the light source. We derive an upper bound for the secret key rate and show that it does not significantly deviate from the ideal side-channel-free case.
Formation of silver nanoparticles in ion-exchanged glass with nanosecond laser irradiation
Authors: Morozova O , Babich E , Kaasik V , Raskhodchikov A , Raskhodchikov D , Zhurikhina V , Lipovskii A
Published: December 2020

We studied the irradiation of silver enriched soda-lime glass slides by 6 nanosecond long laser pulses at the wavelengths of 1064 and 532 nm. The extinction spectra of the irradiated glass regions after the laser exposition and after chemical and reactive ion etching (RIE) were compared. Independently on the wavelength, the irradiation resulted in the formation of silver nanoparticles demonstrating localized surface plasmon resonance (LSPR), which gradually disappeared with the etching of the samples. The dependence of the spectral position of LSPR on the etching time was significantly different for chemical etching and RIE. We relate this to the chemical interaction of silver with the gases used in RIE.
Dielectric surrounding bleaches the optical bond between a microdisk resonator and a straight optical waveguide
Authors: Raskhodchikov A V , Scherbak S A , Kryzhanovskaya N V , Lipovskii A A , Zhukov A E
Published: December 2020

We performed a numerical study of a surrounding medium influence on coupling efficiency between a microdisk resonator supporting optical whispering gallery modes and a straight optical waveguide. Quality factors of the modes and relative optical power coupled to the waveguide were calculated using COMSOL Multiphysics environment. It was shown that the most efficient coupling takes place when propagation constants of the modes of the microdisk and the waveguide match. The coupling can be significantly strengthened by increasing the index of the surrounding medium.
To the issue of the second harmonic generation in poled silicate glasses
Authors: Reshetov I V , Kaasik V P , Lipovskii A A , Tagantsev D K
Published: December 2020

Thermal relaxation of the second harmonic generation (SHG) observed in thermally poled soda-lime silicate glass is studied. At least two relaxation processes could be distinguished. Determined activation energy of the fastest SHG relaxation process is equal to about 0.5 eV. This SHG relaxation occurs at temperatures essentially below ones, at which the thermally stimulated depolarization current (TSDC) measurements show the relaxation of the spatial charge formed in thermal poling of the glasses. This confirms that SHG in poled glasses is not mostly conditioned by the “frozen” spatial charge and electric field of this charge.
Enhance of the superconducting properties of the NbN/Au bilayer bridges
Authors: Simonov N O , Korneeva Yu P , Korneev A A , Goltsman G N
Published: December 2020

We experimentally demonstrate strong temperature dependence of the critical current of the superconducting 600-nm-wide and 5-μm-long bridge made of NbN/Au bilayer. The result is achieved due to the proximity effect realized between the highly disordered superconducting NbN layer and low resistive normal-metal Au layer.
Calculation of a binary diffractive optical element to increase the imaging system depth of field in the task of classifying images by a neural network
Authors: Dzyuba A P , Khonina S N , Nikonorov A V , Serafimovich P G
Published: December 2020

Using an example of a real-world data set, it is shown that the accuracy of the image classifier based on a convolutional neural network does not deteriorate when using only one color channel. The binary diffractive optical element was calculated, which allows to increase the imaging system depth of field by several times. This is achieved by using the different color channels for various defocus values. A comparison of the MTF curves of the original and apodized imaging systems for a given minimum acceptable value of image contrast is presented.
Sensitivity Features of Double-Resonance Plasmonic Sensor
Authors: Tomilin S V , Karavaynikov A V , Tomilina O A , Berzhansky V N
Published: December 2020

The paper presents the results of a model investigation about the temporal dynamics of changes in the resonance excitation conditions of surface plasmon-polariton waves in a double-resonance plasmonic sensor at different thicknesses of the sensitive ligand layer. It was shown that the maximum sensor reaction rate to the emergence of analyte is observed at a ligand layer with 40–50 nm thickness. When the ligand layer thickness is less than 40 nm, the sensitivity of the sensor decreases sharply, and when the ligand thickness is increase over 60 nm, a delay in the sensor reaction is observed which due to the limited diffusion rate of the analyte into the ligand. The most effective mode of a plasmon sensor operation is the mode in which the angle of the exciting beam incidence is somewhat different from the resonance angle at condition when the analyte is absent.
The Influence of Dielectric Environment on Spectral Shift of Localized Plasmonic Resonance
Authors: Tomilina O A , Berzhansky V N , Tomilin S V
Published: December 2020

In paper the investigation results of dielectric environment influences on spectral shift of localized plasmonic resonance in a system of self-assembled metallic nanoparticles was introduced. It was shown, that the value of spectral shift of localized plasmonic resonance has a linear proportion towards the changes of environment refractive index. For investigated plasmonic system of self-assembled Au nanoparticles the coefficient of proportionality was determined.
Peculiarities of the synthesis of GST films by magnetron sputtering for nonvolatile optical memory cells
Authors: Korolev D S , Sidorenko K V , Nikolskaya A A , Mikhaylov A N , Chigirinsky Y I , Minnullin R T , Makarov M E , Sapegin A A , Barabanenkov M Yu
Published: December 2020

The structure and optical properties of thin films of the chalcogenide semiconductor Ge2Sb2Te5, deposited by magnetron sputtering, was studied. A significant change in the topology and optical properties of the films is demonstrated with varying deposition conditions. It is shown that an increase in the deposition time leads to an increase in the surface roughness. Doping with nitrogen during deposition leads to a smoothing of the film surface, and also provides a strong change in the band structure and optical properties.
Peculiarities of the electronic and magnetic characteristics in Co2
YSi (Y = Ti, V, Cr, Mn, Fe, Co, Ni) Heusler alloys close to the half-metallic ferromagnets and spin gapless semiconductors
Authors: Perevozchikova Yu A , Semiannikova A A , Korenistov P S , Marchenkov V V
Published: December 2020

The Hall Effect and magnetization of Heusler alloys Co2YSi (Y = Ti, V, Cr, Mn, Fe, Co, Ni) were measured at T = 4.2 K and 300 K in magnetic fields of up to 100 kOe as well as the temperature dependence of the electroresistivity from 4.2 to 300 K. The normal and anomalous Hall coefficients, saturation magnetization, residual resistivity, type and concentration of current carriers and their mobility were obtained. It was demonstrated that there is a clear correlation between the electronic and magnetic parameters obtained, depending on the number of valence electrons z, at the transition from Co2TiSi (z=26) to Co2NiSi (z=32). The observed peculiarities of electronic and magnetic parameters may be due to the appearance of the states of the half-metallic ferromagnet and/or spin gapless semiconductor.
Anomalous Nernst-Ettingshausen effect in diluted magnetic semiconductors
Authors: Kuznetsov Y , Dorokhin M , Kudrin A. , Ved M , Lesnikov V
Published: December 2020

The magnetic field dependences of the Hall and Nernst-Ettingshausen effects in (In, Fe)Sb, (Ga, Fe)Sb, (Ga, Mn)As diluted magnetic semiconductors were investigated. The samples were fabricated on a semi-insulating GaAs substrates by pulsed laser deposition in vacuum. The manifestation of the anomalous Nernst-Ettingshausen effect along with the anomalous Hall effect in manganese-containing structures was shown experimentally. It is demonstrated that the difference in the magnetic field dependences of the Hall and Nernst-Ettingshausen effects in systems with Mn and Fe is due to the different nature of ferromagnetism.
An artificial neural network as a predictor of electrical characteristics of nanoelectronic device channel based on a low-dimensional heterostructure
Authors: Vetrova N A , Pchelintsev K P , Shashurin V D
Published: December 2020

In this paper a computational algorithm for calculating current density of low-dimensional semiconductor heterostructures based on an artificial neural network is proposed. The neural network training is performed using the quantum-mechanical model of Green’s Functions.
Test element for high voltage SiC Schottky diodes quality control
Authors: Sedykh S V , Rybalka S B , Kulchenkov E A , Demidov A A , Drakin A Yu , Bryukhno N A , Kuftov I V
Published: December 2020

The test element for quality control of SiC Schottky type high voltage diodes has been constructed at first in this study. It is shown that proposed test element give possibility for determination of important parameters for testing diode before Schottky contact formation and therefore can be decrease production costs in production of SiC Schottky type high voltage diodes.
Planar Schottky diode with a Γ-shaped anode suspended bridge
Authors: Shurakov A , Mikhailov D , Belikov I , Kaurova N , Zilberley T , Prikhodko A , Voronov B , Vasil’evskii I , Goltsman G
Published: December 2020

In this paper we report on the fabrication of a planar Schottky diode utilizing a Г-shaped anode suspended bridge. The bridge maintains transition between the top and bottom level planes of a 1.4 µm thick GaAs mesa. To implement the profile of a suspended bridge and inward tilt of a mesa wall adjacent to it, we make use of an anisotropic etching of gallium arsenide. The geometry proposed enables the fabrication of a diode with mesa of an arbitrary thickness to mitigate AC losses in the diode layered structure at terahertz frequencies of interest. For frequencies beyond 1 THz, it is also beneficial to use the geometry for the implementation of n-GaAs/n-InGaAs heterojunction Schottky diodes grown on InP substrate.
Efficiency of a microwave reflectometry for readout of a THz multipixel Schottky diode direct detector
Authors: Shurakov A , Prikhodko A , Mikhailov D , Belikov I , Kaurova N , Voronov B , Goltsman G
Published: December 2020

In this paper we report on the results of investigation of efficiency of a microwave reflectometry for readout of a terahertz multipixel Schottky diode direct detector. Decent capabilities of the microwave reflectometry readout were earlier justified by us for a hot electron bolometric direct detector. In case of a planar Schottky diode, we observed increase of an optical noise equivalent power by a factor of 2 compared to that measured within a conventional readout scheme. For implementation of a multipixel camera, a microwave reflectometer is to be used to readout each row of the camera, and the row switching is to be maintained by a CMOS analog multiplexer. The diodes within a row have to be equipped with filters to distribute the probing microwave signal properly. The simultaneous use of analog multiplexing and microwave reflectometry enables to reduce the camera response time by a factor of its number of columns.
Features of signal transmission through a fiber-optic system for an interference compensation module for an active phased array antenna
Authors: Moroz A V , Davydov V V , Malanin K Yu
Published: December 2020

The article describes the operation of the X-band radar under the influence of active and passive interference. The rationale for using the interference compensation module in a radar station with a small-sized active phased array antenna is presented. A fiber-optic system has been developed for transmitting a signal from a compensation module. The results of experimental studies of the transmission system are presented. The advantages of using a fiber-optic system in a radar station in comparison with a coaxial cable are shown.
The spin-filtering properties in two coupled Rashba quantum rings
Authors: Smolkina M O , Popov I Ju , Blinova I V
Published: December 2020

The spin-dependent electron transport in two coupled quantum rings with Rashba spin-orbit interaction and magnetic flux was studied by using quantum waveguide theory. We show the dependence of spin-polarization on system parameters such as the Rashba coupling constant, the radius of the rings, the angles between the leads and the attachment point of the rings. The spin-polarization can be controlled and changed from -1 to +1 by using a magnetic flux. Also it was shown that this model is a limiting case of double Rashba quantum ring when the length of the middle lead between rings vanishes. The same study for spin-filtering properties in two coupled quantum rings with Dresselhaus spin-orbit interaction was also obtained and the results were compared.