bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of SiC/ graphene nanosheet composites by helicon wave plasma*
Authors: Chen Jia-Li , Ji Pei-Yu , Jin Cheng-Gang , Zhuge Lan-Jian , Wu Xue-Mei
Published: February 2021

We report an approach to the rapid, one-step, preparation of a variety of wide-bandgap silicon carbide/graphene nanosheet (SiC/GNSs) composites by using a high-density helicon wave plasma (HWP) source. The microstructure and morphology of the SiC/GNSs are characterized by using scanning electron microscopy (SEM), Raman spectroscopy, x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and fluorescence (PL). The nucleation mechanism and the growth model are discussed. The existence of SiC and graphene structure are confirmed by XRD and Raman spectra. The electron excitation temperature is calculated by the intensity ratio method of optical emission spectroscopy. The main peak in the PL test is observed at 420 nm, with a corresponding bandgap of 2.95 eV that indicates the potential for broad application in blue light emission and ultraviolet light emission, field electron emission, and display devices.
HeTDSE: A GPU based program to solve the full-dimensional time-dependent Schrödinger equation for two-electron helium subjected to strong laser fields*
Authors: Zhao Xi , Zhang Gangtai , Bai Tingting , Wang Jun , Yu Wei-Wei
Published: February 2021

Electron–electron correlation plays an important role in the underlying dynamics in physics and chemistry. Helium is the simplest and most fundamental two-electron system. The dynamic process of helium in a strong laser field is still a challenging issue because of the large calculation cost. In this study, a graphic processing unit (GPU) openACC based ab initio numerical simulations package HeTDSE is developed to solve the full-dimensional time-dependent Schrödinger equation of helium subjected to a strong laser pulse. HeTDSE uses B-spline basis sets expansion method to construct the radial part of the wavefunction, and the spherical harmonic functions is used to express for the angular part. Adams algorithm is employed for the time propagation. Our example shows that HeTDSE running on an NVIDIA Kepler K20 GPU can outperform the one on an Intel E5-2640 single CPU core by a factor of 147. HeTDSE code package can be obtained from the author or from the author’s personal website (doi: 10.13140/RG.2.2.15334.45128) directly under the GPL license, so HeTDSE can be downloaded, used and modified freely.
Structure-based simulations complemented by conventional all-atom simulations to provide new insights into the folding dynamics of human telomeric G-quadruplex*
Authors: Bian Yun-Qiang , Song Feng , Cao Zan-Xia , Yu Jia-Feng , Wang Ji-Hua
Published: February 2021

The hybrid atomistic structure-based model has been validated to be effective in investigation of G-quadruplex folding. In this study, we performed large-scale conventional all-atom simulations to complement the folding mechanism of human telomeric sequence Htel24 revealed by a multi-basin hybrid atomistic structure-based model. Firstly, the real time-scale of folding rate, which cannot be obtained from the structure-based simulations, was estimated directly by constructing a Markov state model. The results show that Htel24 may fold as fast as on the order of milliseconds when only considering the competition between the hybrid-1 and hybrid-2 G-quadruplex conformations. Secondly, in comparison with the results of structure-based simulations, more metastable states were identified to participate in the formation of hybrid-1 and hybrid-2 conformations. These findings suggest that coupling the hybrid atomistic structure-based model and the conventional all-atom model can provide more insights into the folding dynamics of DNA G-quadruplex. As a result, the multiscale computational framework adopted in this study may be useful to study complex processes of biomolecules involving large conformational changes.
Time-dependent diffusive interactions between dark matter and dark energy in the context of k-essence cosmology
Authors: Bandyopadhyay Abhijit , Chatterjee Anirban
Published: February 2021

We investigated the scenario of time-dependent diffusive interaction between dark matter and dark energy and showed that such a model can be accommodated within the observations of luminosity distance-redshift data in Supernova Ia (SN Ia) observations. We obtain constraints on different relevant parameters of this model from the observational data. We consider a homogeneous scalar field ϕ(t) driven by a k-essence Lagrangian of the form L = V(ϕ)F(X) with constant potential V(ϕ) = V, to describe the dynamics of dark energy in this model. Using the temporal behaviour of the FRW scale factor, the equation of state and total energy density of the dark fluid, extracted from the analysis of SN Ia (JLA) data, we have obtained the time-dependence of the k-essence scalar field and also reconstructed the form of the function F(X) in the k-essence Lagrangian.
Search for age pattern across spiral arms of the Milky Way
Authors: He Zhi-Hong , Xu Ye , Hou Li-Gang
Published: February 2021

The age pattern across spiral arms is one of the key observational features utilised to study the dynamic nature of the Galaxy’s spiral structure. With the most updated samples of high-mass star formation region (HMSFR) masers, O stars and open clusters, we investigated their distributions and kinematic properties in the vicinity of the Sun. We found that the Sagittarius-Carina Arm traced by HMSFRs, O stars (≲ 10 Myr) and young open clusters (<30 Myr) seem to deviate gradually towards the Galactic Anticenter (GAC) direction. The Local Arm traced by HMSFRs, O stars, young clusters and also medium-young clusters (30–100 Myr) are inclined to gradually deviate toward the Galactic Center (GC) direction. The properties for the Local Arm are supported by a simplified simulation of cluster motions in the Galaxy. Indications of systematic motions in the circular and radial velocities are noticed for the old open clusters (>200 Myr). These results are consistent with the idea that star formation can be triggered by spiral shocks of density waves, and indicate that the corotation radius of the Galaxy is located between the Sagittarius-Carina Arm and the Local Arm, close to the Solar circle.
Towards engineering in memristors for emerging memory and neuromorphic computing: A review
Authors: Sokolov Andrey S. , Abbas Haider , Abbas Yawar , Choi Changhwan
Published: February 2021

Resistive random-access memory (RRAM), also known as memristors, having a very simple device structure with two terminals, fulfill almost all of the fundamental requirements of volatile memory, nonvolatile memory, and neuromorphic characteristics. Its memory and neuromorphic behaviors are currently being explored in relation to a range of materials, such as biological materials, perovskites, 2D materials, and transition metal oxides. In this review, we discuss the different electrical behaviors exhibited by RRAM devices based on these materials by briefly explaining their corresponding switching mechanisms. We then discuss emergent memory technologies using memristors, together with its potential neuromorphic applications, by elucidating the different material engineering techniques used during device fabrication to improve the memory and neuromorphic performance of devices, in areas such as I
ON/I
OFF ratio, endurance, spike time-dependent plasticity (STDP), and paired-pulse facilitation (PPF), among others. The emulation of essential biological synaptic functions realized in various switching materials, including inorganic metal oxides and new organic materials, as well as diverse device structures such as single-layer and multilayer hetero-structured devices, and crossbar arrays, is analyzed in detail. Finally, we discuss current challenges and future prospects for the development of inorganic and new materials-based memristors.
A revew of in situ transmission electron microscopy study on the switching mechanism and packaging reliability in non-volatile memory
Authors: Yang Xin , Luo Chen , Tian Xiyue , Liang Fang , Xia Yin , Chen Xinqian , Wang Chaolun , Liang Steve Xin , Wu Xing , Chu Junhao
Published: February 2021

Non-volatile memory (NVM) devices with non-volatility and low power consumption properties are important in the data storage field. The switching mechanism and packaging reliability issues in NVMs are of great research interest. The switching process in NVM devices accompanied by the evolution of microstructure and composition is fast and subtle. Transmission electron microscopy (TEM) with high spatial resolution and versatile external fields is widely used in analyzing the evolution of morphology, structures and chemical compositions at atomic scale. The various external stimuli, such as thermal, electrical, mechanical, optical and magnetic fields, provide a platform to probe and engineer NVM devices inside TEM in real-time. Such advanced technologies make it possible for an in situ and interactive manipulation of NVM devices without sacrificing the resolution. This technology facilitates the exploration of the intrinsic structure-switching mechanism of NVMs and the reliability issues in the memory package. In this review, the evolution of the functional layers in NVM devices characterized by the advanced in situ TEM technology is introduced, with intermetallic compounds forming and degradation process investigated. The principles and challenges of TEM technology on NVM device study are also discussed.
Neutron irradiation-induced effects on the reliability performance of electrochemical metallization memory devices
Authors: Tao Ye , Li Xuhong , Wang Zhongqiang , Li Gang , Xu Haiyang , Zhao Xiaoning , Lin Ya , Liu Yichun
Published: February 2021

In this work, electrochemical metallization memory (ECM) devices with an Ag/AgInSbTe (AIST)/amorphous carbon (a-C)/Pt structure were irradiated with 14 MeV neutrons. The switching reliability performance before and after neutron irradiation was compared and analyzed in detail. The results show that the irradiated memory cells functioned properly, and the initial resistance, the resistance at the low-resistance state (LRS), the RESET voltage and the data retention performance showed little degradation even when the total neutron fluence was as high as 2.5 × 1011 n/cm2. Other switching characteristics such as the forming voltage, the resistance at the high-resistance state (HRS), and the SET voltage were also studied, all of which merely showed a slight parameter drift. Irradiation-induced Ag ions doping of the a-C layer is proposed to explain the damaging effects of neutron irradiation. The excellent hard characteristics of these Ag/AIST/a-C/Pt-based ECM devices suggest potential beneficial applications in the aerospace and nuclear industries.
Methodological foundations of scaling in modern Measurement Theory. Classification of measurement scales and their application under uncertainty based on Bayesian Intelligent Technologies
Authors: Prokopchina S V
Published: February 2021

Measurement theory is currently being actively developed due to its relevance in modern information technologies that implement the principles and algorithms of DATA SCIENCE, BIG DATA, Internet of Things, Business Intelligence, and DATA MINING. One of the most important applications of measurement theory methods and tools is implemented in artificial intelligence technologies. This is due to the need to use a variety of measurement data in these technologies. The conditions for obtaining such measurement information are associated with uncertainty, which necessitates the use of special methods and tools for obtaining measurement data. This, in turn, determines the need to develop and apply new types of scales focused on uncertainty conditions. The article offers a classification of measurement scales for the implementation of classical and intelligent measurement algorithms. The principles of implementing scales with dynamic constraints for measurement intellectualization based on Bayesian intelligent technologies are considered. Examples of using smart measurement scales are given.
Metrological parameters of information and measurement systems for the study of a kinematic portrait of a person
Authors: Romantsova N V , Suloeva E S , Tsareva A V
Published: February 2021

When developing measurement procedures and means, it is necessary to carry out an analytical description of errors and their characteristics. The report discusses the methods of metrological analysis when creating a portable information and measurement system for evaluating walking techniques. The paper describes the metrological analysis of estimates of total error components of the measurement results of informative parameters for the task.
Hybrid intelligent system of rules extraction for decision making
Authors: Averkin A N , Yarushev S A
Published: February 2021

This article attempts to give an overview of several algorithms for extracting rules from an artificial neural network. The goal of this article is to find critical links three important parts of artificial intelligence – production models, fuzzy logic and deep learning. Such an approach will stimulate researchers in the field of soft computing to develop applied systems in the field of explanational artificial intelligence and machine learning.
Application of the fractional-order model in the problems of identification and order reduction for the controlled processes
Authors: Ayazyan G K , Tausheva E V
Published: February 2021

In the paper, the problems of an identification and order reduction of the dynamics models of controlled processes are solved by applying of fractional-order transfer functions of the form an aperiodic (non-oscillatory) system of the nth order with time delay, and an aperiodic system of the nth order with an integrator and delay, where n generally is a positive fractional constant. The solution of the problem is based on the method of moments. The problem is reduced to solving four polynomial equations with respect to the four coefficients of the model. In the symbolic computing environment Maple, an identification and order reduction program has been developed that implements the described algorithm. The efficiency of the algorithm was tested on test models.
Evaluation of the effectiveness of geographic information systems adaptation to destabilizing factors
Authors: Burlov V G , Gryzunov V V
Published: February 2021

Formulation of the problem. Geographic information systems are becoming an integral part of many automated control systems. The quality of the made management decision depends on their ability to work. At the same time, geoinformation systems operate in conditions of destabilizing factors reducing the quality of services provided. The existing indicators of the efficiency of the functioning of geoinformation systems do not allow to quickly and comprehensively assess the ability of geoinformation systems to adapt to the action of destabilizing factors, and therefore, to understand how the system is able to satisfied the requirements of its users.

Purpose. To propose performance indicators that allow assessing the “usefulness” of geoinformation systems for the consumer in conditions of destabilizing factors.

Results. Non-stochastic indicators of efficiency have been developed: integral and differential, a theorem has been formulated and proved about the independence of events in solving tasks for any directed graph, examples are given and conditions for the expediency of using the proposed indicators for the evaluating of the effectiveness of geographic information systems adaptation are given to the destabilizing factors action.

Practical significance. The proposed indicators can be used to synthesize the structure and functions of geographic information systems in real time.
Software model of a highly undetectable stegosystem – ⊕HUGO model
Authors: Kustov V N , Krasnov A G
Published: February 2021

The article is devoted to the research of a software model of the hidden message transmission process using one of the new methods of steganography proposed by the authors. The presented model implements a hard-to-detect method for embedding hidden messages in digital still images used as covering objects (containers). The main principle of using the model is to minimize adequately specified distortion using a new efficient encoding algorithm. Distortion is defined as an operation ⊕ (excluding OR - XOR) between the next half-byte of the hidden message and the right half-byte of the specially selected byte of the covering object, which is selected from the condition for minimizing the penalty function calculated on some selected neighbourhood of this byte. This allows authors to keep the original image almost unchanged and make it indistinguishable from the original, even after large payloads are embedded in it. Thus, the embedded hidden message may not be visible when the steganalysis even for the experienced steganalytic. The ⊕ operation has the property of bijectivity (it is reversible), which makes quite easy to use it to extract a hidden message on the recipient’s side, if the recipient has key information. The stegosystem model is called the ⊕Highly Undetectable SteGOsystem model. In short, it can be referred to as the ⊕HUGO model.
Dark energy as the information field of the universe
Authors: Bogomolov A I
Published: February 2021

Using modern theories of the origin and expansion of the Universe, recent discoveries in astronomy and quantum physics, the article proposes the hypothesis to add to attributes of the nascent universe such as “space” and “time” of the attribute “information,” which finds its embodiment from a physical point of view in the form dark energy. With the development of the Universe, the volume of information grows and, accordingly, the mass of dark energy increases, turning into an information field or noosphere, which provides for the expansion of the Universe. An analogy is made between the Big Bang and the expansion of the Universe in the process of its evolution, due to the increase in the amount of dark energy and between the birth of Man from singularity (egg) and the growth of his information and knowledge in the process of his life.
The use of a neural network model for the analysis of tourism development in the regions of the country
Authors: Kazak A N , Oleinikov N N , Chetyrbok P V , Shamaeva N P , Alexandrova E V
Published: February 2021

Neurocomputer and neural network technologies are one of the most effective artificial intelligence strategies. A neural network model has been developed, designed to assess the prospects of tourism development in certain regions of the Russian Federation. In particular, the Krasnodar Territory was chosen for analysis as one of the most popular resorts in terms of the level of domestic tourism development. Using the neural network model built in Matlab, the impact of individual economic indicators on the number of tourist visits to this resort was evaluated. This kind of analytical activity is important for adjusting regional policies in the field of tourism and recreational activities and will allow relevant experts to improve the quality of management decisions and strategies being developed. Thus, the competitiveness of the regions increases and a new approach to the development of the recreational sphere is introduced.
Recognition of emotions in human speech with deep learning models
Authors: Shchetinin E Yu
Published: February 2021

The paper investigates the architecture of deep neural networks for recognizing human emotions from speech. Convolutional neural networks and recurrent neural networks with an LSTM memory cell were used as models of deep neural networks. An ensemble of neural networks was also built on their basis. Computer experiments on the use of the proposed deep learning models and basic machine learning algorithms for recognizing emotions in human speech contained in the RAVDESS audio database were conducted. The results obtained showed high efficiency of neural network models, and accuracy estimates for individual emotions were 92%.
Possible directions in the development of Russian low-cost airlines
Authors: Melekhina T L , Pozdeeva S N
Published: February 2021

Having carried out a comparative analysis of the development of low-cost airlines in European and Asian countries, the authors used a correlation-regression analysis for financial forecasting of the activities of the “Pobeda” air carrier. The article defines the factors that affect the profit and built a multi-factor regression model that allowed to calculate the forecast value of revenue. There are prospects for development and stable functioning in the market, and this is only the beginning of the transition to a new level of development in the field of transport services.
Validation of an image-analysis-based method of measurement of the overall dimensions of seeds
Authors: Gierz Ł , Markowski P , Chmielewski B
Published: February 2021

Due to agricultural producers’ increasing awareness and the introduction of increasingly restrictive crop protection standards, producers have to use new technologies that are safer for consumers and the environment. In order to meet the requirements of these standards, it is necessary to take the physical properties of crops and agricultural raw materials (basic geometric parameters, shape factors, and equivalent spherical diameters) into account when designing machinery for the harvesting, transport, and processing of agricultural produce. When designing machinery, methods used for calculating the strength of the machine construction and the discrete element method (DEM) used in computer simulations of processes involving seeds or particles require the provision of the exact geometrical dimensions of particles and seeds. The aim of the study was to develop a universal method of measurement of the overall dimensions of granular material particles using a widely available application based on image analysis. The study presents the possibility of using a new method of measuring overall dimensions by means of the widely available ImageJ application on a specially designed test facility.
Analysis of the influence of gear tooth friction on dynamic force in a spur gear
Authors: Jedliński Ł
Published: February 2021

The main objective of this paper is to investigate the influence of tooth friction on the dynamic force of the gearbox. This is one of the most insignificantly investigated aspects of the gearbox work, despite both experimental and theoretical research conducted. For this reason, it is not entirely possible to establish the friction force determining the friction coefficient due to the complexity of the process. Currently, various approaches are taken in calculating dynamic models, among others excluding friction, Coulomb models, models in which the value of the friction coefficient depends on the sliding velocity, and the application of complex elastohydrodynamic models. Due to such different approaches, it was decided to examine the influence of tooth friction on the dynamic force for the stationary work conditions of the gearbox. Moreover, a new gear tooth friction model was developed, based on the Coulomb model of friction and rolling friction. The results were obtained for four friction models and, in the fifth case, without including it. Furthermore, the influence of torsional vibration on the friction lever arm was analysed.
Detection of measurement noise in surface topography analysis
Authors: Podulka P
Published: February 2021

Various types of measurement noise detection from the results of surface topography measurements are presented and compared. The types of considered surface textures are: honed, turned, ground, laser-melted, milled, composite, ceramic and isotropic topographies. The measurements are carried out using the stylus (Talyscan 150) or non-contact – optical (white light interferometer Talysurf CCI Lite) equipment. It was assumed that for certain stratified textures, power spectral density assessment would be sufficient, otherwise, the multi-threaded analysis was required. It was also found that certain frequency errors in measurement can be readily detected with profile analysis. Nonetheless, when measurement noise amplitudes are relatively small, e.g. root mean square height (Sq) < 10%, then the isometric view detection is nearly impossible. For the detection of high-frequency measurement noise, the power spectral density analysis is required; for this type of texture, the high-frequency measurement noise surface (HFNS) is described using the regular spline filter. It is indicated that the HFNS should be observed if the machining marks are visible in the isometric view. Secondly, accurately defined HFNS should contain only the high-frequency rather than low-frequency details.
Calculation of the production of exhaust emissions in the laboratory conditions
Authors: Šarkan B , Hudec J , Sejkorova M , Kuranc A , Kiktova M
Published: February 2021

In the past, the type approval of road vehicles with regard to the production of pollutants was carried out exclusively in the form of laboratory tests. Laboratory tests determined the course of the vehicle’s driving cycle and the methodology for quantifying pollutants depending on the distance passed. The revision of EU legislation in 2016 brought changes in the field of type approval, in particular a change in the driving cycle and an additional driving test in the form of real drive emission. The paper discusses a matter of the possibility of using Commission Regulation (EU) 2017/1151 for the purpose of calculating emissions of road vehicles in their operation by applying the methodology of real drive emission. The research task was performed on a roller dynamometer on two vehicles in the simulation of the original New European Driving Cycle (NEDC) in laboratory conditions with the application of the methodology for calculating emissions from real drive emission. During the test, the method of calculating the exhaust flow by sensing the amount of fuel consumed and the amount of intake air was used. Significant data, such as mass air flow, air temperature, engine speed, vehicle speed was recorded via the electronic control unit. Recorded data obtained from emission tester, roller dynamometer and On Board Diagnostic (OBD) tool must be synchronised. Test results should be used in the field of comparison of the type approval emission level and the emission level in operation.
Artificial neural network model of hardness, porosity and cavitation erosion wear of APS deposited Al2O3 -13 wt% TiO2 coatings
Authors: Szala M , Awtoniuk M , Łatka L , Macek W , Branco R
Published: February 2021

The aim of the article is to build-up a simplified model of the effect of atmospheric plasma spraying process parameters on the deposits’ functional properties. The artificial neural networks were employed to elaborate on the model and the Matlab software was used. The model is crucial to study the relationship between process parameters, such as stand-off distance and torch velocity, and the properties of Al2O3-13 wt% TiO2 ceramic coatings. During this study, the coatings morphology, as well as its properties such as Vickers microhardness, porosity, and cavitation erosion resistance were taken into consideration. The cavitation erosion tests were conducted according to the ASTM G32 standard. Moreover, the cavitation erosion wear mechanism was presented. The proposed neural model is essential for establishing the optimisation procedure for the selection of the spray process parameters to obtain the Al2O3-13 wt% TiO2 ceramic coatings with specified functional properties.
Surface quality simulation with statistical analysis after milling AZ91D magnesium alloy using PCD tool
Authors: Kulisz M , Zagórski I , Korpysa J
Published: February 2021

Machined surface quality is one of the key indicators of a correctly conducted milling process. This paper reports on the results from numerical and statistical analysis of the condition of AZ91D Magnesium Alloy after milling using the PCD Tool. Three surface roughness indicators were of interest - average roughness (Ra), maximum height of profile (Rz) and mean width of profile elements (RSm). The surface quality, described by Ra/Rz, shows negligible deterioration at higher speeds vc
. Two artificial neural networks, MLP (Multilayer Perceptron) and RBF (Radial Basis Function), modelled with Statistica package, were employed to simulate the effects that individual process variables have on the 2D surface roughness parameters. The statistical significance of the results was assessed using the one-way ANOVA technique. Given the successful validation of the numerical and empirical data (R2 > 0.85), it may be inferred that our ANNs are an accurate predicting tool that models milling parameters ensuring that the surface is of suitable quality. The surface roughness indicators are generated from the corresponding technological parameters. Simulations save time, effort and costs that would be incurred by additional machining tests.
Mechanical design of a low-cost ABS hand prosthesis using the finite element method
Authors: Bastarrechea A , Estrada Q , Zubrzycki J , Torres-Argüelles V , Reynoso E , Rodríguez-Mendez A , Coutiño E
Published: February 2021

Many hand accidents are reported around the world resulting in a necessity to perform a procedure of amputation of the hand. For this consideration, a large number of hand prostheses have been designed. However, the mechanical design of these prostheses present challenges such as kinematic functionality, strength, and cost. The present article analyses the mechanical design of a low-cost practical hand prosthesis using the finite element method with the help of Abaqus commercial software. Functional and technical requirements were considered to consider the biomechanics of the human hand. The hand prosthesis was conferred with 14-degrees-of-freedom (DOF), which gives it the capacity for grips associated with security, stability, dexterity, and sensibility. Additionally, due to practicality and low-cost manufacturing techniques, fused deposition modelling with acrylonitrile butadiene styrene (ABS) is proposed. The evaluation of the hand prosthesis was carried out by tensile, flexural, and torsional load conditions. Finally, the mechanical effectiveness of the designed prosthesis was demonstrated since maximum stresses close to 13 MPa were computed, which are less than the yield stress of ABS.
The test-bed research of a low power low-temperature PEM fuel cell
Authors: Dubeński K , Czarnigowski J , Durakiewicz P , Szewc S
Published: February 2021

The article presents the results of testbed research of Horizon H-300 PEM Fuel Cell. It is a Polymer Electrolyte Membrane Fuel Cell (PEMFC) which reaches 300 Watt output power. It is a power source for hyper-light prototype vehicles taking part in the Shell Eco-Marathon competition. The aim of the research was to develop the load characteristics of a PEM type cell. The tests were carried out in a steady state of operation and included developing the characteristics of the output voltage concerning the load current. The current load was carried out by a programmable electronic load with the ability to accurately determine the load current. It also allows for measuring the output voltage. The tests were carried out in the load current range 0.2 - 7A, which is a significant range of the cell’s operating parameters which is used in the vehicle. During the tests, hydrogen consumption was also measured at individual points of the cell’s operation using a flow meter. This has also allowed the development of the characteristics of fuel consumption and power generated by the cell. The developed characteristics are presented in this article. A linear characteristic of power and fuel consumption in the function of the current loading on the cell was obtained for practically the whole range of the tested loads. Also, the specific fuel consumption is linearly dependent on the load power, and the lowest values (in the example the highest efficiency) were obtained at the lowest value of load power.
Study of inertinite components by IR spectroscopy
Authors: Fedorova N I , Malysheva V Yu , Ismagilov Z R
Published: February 2021

The paper presents the results of a study by IR spectroscopy of inertinite concentrates isolated from humus coals of various stages of metamorphism. It was revealed that in the studied samples there is a rather significant intensity of absorption bands characteristic of aromatic structures (D3040, D1620, D900-750 cm−1). To characterize the chemical maturity of inertinites, we used the parameter D3040/D2920 (the ratio of the optical densities of CH unsaturated and CH aliphatic bonds). It was found that the D3040/D2920 parameter increases with an increase in the vitrinite reflectance. The data obtained showed that the components of the inertinite group are characterized by a reduced number of aliphatic groups and a more developed spatial polyconjugation system.
Study of the structure and morphology of carbon sorbents
Authors: Zykov I Yu , Dudnikova Y N , Fedorova N I , Ismagilov Z R , Mihaylova E S
Published: February 2021

The paper presents the results of a study of the morphology of carbon sorbents from Kuzbass coal. Carbon sorbents were obtained by chemical activation of the initial coal with potassium hydroxide at a temperature of 800 °C and a KOH/coal ratio of 1 g/g. It was shown that alkaline activation has no significant effect on the ash content of the obtained carbon sorbents. The elemental composition of the obtained carbon sorbents practically does not differ and remains constant when the elemental composition of the initial coal changes. The morphology of the surface of the initial coal and sorbents was studied by the SEM method, and the different nature of the surface of carbon sorbents based on coal was shown. For carbon sorbents from bituminous coals of low stages of metamorphism, a spongy structure is characteristic, for carbon sorbents from bituminous coals of high stages, it is layered. The physicochemical characteristics of carbon sorbents were determined. A study was carried out for the content of total and water-soluble iron for the amount of water-soluble ash.
Industrial scale gasification of T-grade coal via fixed bed technology
Authors: Slyusarskiy K V , Matveev A S , Yankovsky S A , Gubin V E
Published: February 2021

The gasification of solid fuel is known technology suitable for many purposes which has found quite limited applications worldwide. The one of the major reasons is deficiency of practical operation experience of industrial scale units. The paper reports the data on T-grade coal gasification by air via 4 ton per hour pilot scale VTI gasifier situated in Tomsk polytechnic university (Tomsk, Russia). The tests were carried out for bituminous coal of Kuznetsk basin. The results presented were obtained in nonstationary regime for single 4 t load of fuel. The characteristics temperatures into gasifier as well as generator gas composition were determined. Obtained results allowed to conclude that T-grade coal is suitable fuel for VTI gasification technology.
Complex research of the components of the coal tar pitch
Authors: Popova A N , Lyrshchikov S Yu , Sotnikova L V , Dudnikova Yu N
Published: February 2021

The composition, structure and morphology of particles of β-and α2-fraction powders of medium-temperature coal tar pitch were studied using the methods of electron microscopy, adsorption porosimetry, NMR, IR-EPR spectroscopy, X-ray diffractometry, thermal analysis, and chromatography-mass spectrometry. The morphology and structure of coke residues were investigated depending on the heating temperature. It has been established that polyaromatic hydrocarbons in the composition of volatile products of thermolysis of coal tar pitch are formed mainly during the decomposition of the β-fraction components. The results obtained are of interest from the point of view of the directions of using the isolated fractions of coal tar pitch as precursors for obtaining functional carbon materials.
Case study of an effective system of process synchronization within the framework of the development of an integrated scientific and technical programme
Authors: Ganiyeva I A , Petrick N A , Dooginov D V , Remizov S V
Published: February 2021

Implementation of the outputs of intellectual activity related to manufacture of high added value products may be complicated due to the lack of additional resources of industrial enterprises in the context of the economy stagnation. The given Integrated Programme is the programme of a complete innovation cycle formed on the basis of the priority scientific and technological areas highlighted in the R&D Strategy. For the successful implementation of the Programme, it is necessary to identify the needs of large enterprises of the operating sector of the economy in high-tech production processes and to coordinate the potential of implementation with scientific organizations.
Initial results from a simplified sub-sampling approach for Distributed Acoustic Sensing
Authors: Ellwood R. , Godfrey A. , Minto C.
Published: February 2021

Recently, interest has risen in the use of Distributed Acoustic Sensing (DAS) to monitor the condition of sub-sea cables connecting off-shore windfarms. Certain failure modes of these cables develop gradually, over the course of weeks to months, in response to external environmental factors. DAS provides a wealth of information on physical processes occurring over a long linear length. A significant challenge in acquiring all this information is in managing the volume of data captured (in excess of 1TB a day). This paper presents results from an investigation into an approach to adapt the way the data is acquired and stored, whilst not inherently biasing the process. The approach combines a range of traditional techniques, as well as a simplified implementation of the already well established sparse sampling technique. This approach is applied to the collection of data from a windfarm export cable over a period of 876 hours. Analysis of this data demonstrates the systems capability to practicably capture long term trends in the data due to environmental factors.
Excitation power density and temperature dependence of photoluminescence study on electron-irradiated GaAs middle cell of GaInP/GaAs/Ge triple-junction solar cell
Authors: Yan G , Liu Y Y , Wu R , Liu J , Wang J L , Wang R
Published: February 2021

Excitation power density (2.603-9.196 W/cm2) and temperature (10-300 K) dependence of photoluminescence (PL) measurements have been presented and discussed in detail for the carrier recombination mechanism and quenching of the GaAs middle cell in 1.0 MeV electron-irradiated GaInP/GaAs/Ge triple-junction solar cell. When the excitation power density increases, the PL intensity increases. The dependence of PL intensity on excitation power density is observed to be linear below 40 K, and becomes increasingly superlinear with increasing temperature and eventually quadratic at 300 K. The observed phenomenon revealed a competing mechanism between radiative and non-radiative recombination process of photogenerated carriers. However, with the increase of temperature, the PL intensity decreases, and strong thermal quenching phenomenon of PL intensity can be observed above 40 K. By analyzing with multiple centre model, it is due to the presence of thermally activated non-radiative recombination centres named E4 electron trap with an activation energy of ∼0.76 eV and named E5 electron trap with an activation energy of ∼0.96 eV.
Interfacial interaction mechanism of graphene/phenolic resin composites: A molecular dynamics study
Authors: Bian C , Yan N , Zhu G W , Qu H J , Guan Y W , Li H Y , Luan T , Gong J L
Published: February 2021

The outstanding thermal and mechanical properties of graphene/phenolic resin (G/PR) composites are largely related with the interfacial interactions. The interfacial properties of the G/PR composites were studied with molecular dynamics method, based on dozens of G/PR and graphene oxide/PR (GO/PR) interface models. The results showed that, p-π/π-π and hydrogen bond interactions are the main interactions between the G/PR and GO/PR interfaces, respectively. Strong interfacial interactions were formed between the crosslinked PRs and GO layer grafted with oxygen-containing groups. The obtained results will be beneficial to guide the design and preparation of G/PR composites with special performances.
Tensile properties of Z-pinned composite laminates with low damage insertion technique
Authors: Ma C Y , Li Y L , Chen W , Li X Q , Teng X B , Xu Y J , Liu W W
Published: February 2021

In this paper, the effects of Z-pin diameter and Z-pin length on the tensile properties of carbon fiber reinforced laminates were studied. A new Z-pin insertion technique which causes less microdamage damage than the original method was developed. Experimental testing reveals that the in-plane tensile strength of Z-pin specimens is 96.98%-105.32% of the control group. The best performance of in-plane tensile properties is TF18 group which pinned by full-depth Φ0.18mm diameter. The tensile strength increases by 5.32%, and the Young’s modulus increases by 4.71% relative to the control group. Compared with the group of large diameter Z-pin, the in-plane performance of the ultra-fine diameter group is better due to the less in-plane damage. In the half-depth group, delamination occurred between the middle Z-pin sublayer and the upper and lower layers, thus reducing the in-plane tensile property. The Poisson’s ratio increases in both full depth and half depth after Z-pinned and it is only related to insertion depth.
Investigation of structure and ionic conductivity of (PEO)12-SiO2-LiClO4 nanocomposite electrolyte for all solid-state lithium-ion battery
Authors: Li Y Z , Yang Y P , Lei R Y , Fu S D , Wan R G , Li J
Published: February 2021

Solid polymer electrolytes (SPEs), based on poly ethylene oxide (PEO) matrix and nano-sized SiO2, are prepared by solution-casting method. The morphology, crystallinity, thermostability and ionic conductivity of nanocomposite polymer electrolyte are systematically investigated by field-emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), thermogravimetric analysis, and AC impedance spectroscopy. The result reveals that SiO2 is uniformly dispersed in the SPE. Furthermore, the incorporation of nano-sized SiO2 can restrict the crystalline behaviour of PEO effectively, leading to the improvement in amorphous state of PEO. With increasing the mass loading of SiO2, the ionic conductivity of SPEs increase to a maximum value, about 3.03 × 10−4 S·cm−1 (χ(SiO
2/PEO) = 6.85%), and then fall down. Meanwhile, the initial decomposition of SPE reaches 335 °C, showing the good thermal stability and potential application of SPEs for the next-generation all solid-state lithium-ion battery (LIB) with enhanced safety.
Evaluation of the potential anti-alcoholism activity of chitosan grafted with gallic acid
Authors: Lu S T , Yu J Y , Hu Z , Zhang L Y , Huang D J , Liao M N
Published: February 2021

In order to broaden the application of chitosan (CS) in the anti-alcoholism, gallic acid (GA) was grafted onto the CS molecular chain by 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride (EDC)-mediated coupling, and the structure of gallic acid grafted chitosan (CS-GA) was characterized by using UV-Vis spectroscopy (UV-Vis) and Fourier transform infrared spectroscopy (FTIR). The potential anti-alcoholism activity of CS-GA was preliminarily evaluated with ethanol adsorption rate and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rate. The results showed that GA was grafted onto the CS successfully and CS-GA was obtained. CS-GA could adsorb a large amount of alcohol and reach a peak within 15 min after contact with alcohol in vitro. The DPPH radical scavenging ability of CS-GA was 57.5%, which was 2.4 times of CS. In summary, CS-GA had vigorous potential anti-alcoholism activity and is expected to be developed as a promising antidote.
Study on preparation of amphiphilic silane and its modification on copper surface
Authors: Liu M G , Zhao R
Published: February 2021

The amphiphilic polymers monosilane and disilane were synthesized in this sdudy. The pretreated copper plates were modified by the synthesized silane. The copper plates after silane treatment were characterized by measuring total reflection fourier infrared spectroscopy (ATR-FTIR), electrochemical impedance, X-ray photoelectron spectroscopy, and contact angle. ATR-FTIR and XPS confirmed that the amphiphilic polymer silane was successfully grafted onto copper surfaces; the contact angle measurement results showed that the contact angle of the surface of the copper plate after grafting the silane was reduced from 83°to 50°; the electrochemical impedance results showed that the electrochemical transfer resistance on the surface of the copper plates after grafting the silane was increased from 702.8 to 6452.. This study has important reference significance for inhibiting the corrosion of copper plates.
Isolation of a protein-polysaccharide complex from brown algae biomass
Authors: Bogolitsyn K , Parshina A , Druzhinina A , Shulgina E
Published: February 2021

This article presents new comparative data on the chemical composition of Arctic brown algae and algae from the Yellow sea. The effectiveness of the use of the extraction scheme to obtain the protein-polysaccharide complex (which has a double effect: enterosorption and immunomodulating) is estimated.
The design of bridge between structures based on the concept of "building on cable-stayed bridge”
Authors: Biyu Bao
Published: February 2021

Based on the concept of "building houses on cable-stayed bridges", a 4-storey bridge is set up in the first and second phase of the project, which makes the structural design interpret the architectural concept in a unique structural form. This paper focuses on the selection concept, structural layout, and the analysis of the rigidity, displacement, internal force and bearing capacity of the bridge structure. The experience can be used for reference in similar projects.
Influence of collapse width on the effect of geotextile in controlling subgrade collapse based on symmetrical semisection model tests
Authors: Wu Di , Liang Yihuai , Luo Chen , Wu Jianjian
Published: February 2021

Subgrade collapse is a frequent geological hazard all over the world, which seriously threatens safety of human life and economic development. Compared with conventional methods of collapse, employing geotextile basal reinforcement with the features of reinforcement and filtration can achieve better treatment. In this paper, four symmetrical semi-section model tests with different width of collapse treated by geotextile and one full-section model test were carried out. Data acquisition instruments and particle image velocimetry (PIV) equipment were applied to research soil pressure, vertical displacement of filling and tensile force of geotextile. The following results were achieved: the results obtained from symmetric semi-section and full-section model test was proximal so that the symmetrical semi-section model test had certain feasibility; the laying of geotextile basal reinforcement had good effect on collapse treatment; the width of collapse area was an crucial factor affecting the collapse treatment using geotextile and the geotextile with high tensile strength and enough buried depth should be employed when dealing with large scale collapse problems.
Finite Element Analysis of 3D Printed Steel-fiber RC Beam for Mechanical Performance
Authors: Wang Yue , Li Ming
Published: February 2021

In this study, by referring to the existing test data and numerical simulation parameters of Bos, using the compression constitutive relationship of concrete proposed by Thorenfeldt and the tensile constitutive model proposed by Petersson, the numerical simulation of the flexural toughness of steel fiber notched beam by pouring and 3D printing is carried out by using the finite element software ABAQUS, and the load deflection curve is obtained, which is compared with the test curve of BOS to verify The rationality of the research model. Based on the verified model parameters, ABAQUS is used to simulate the four point bending test of steel fiber reinforced 3D printing concrete and plain concrete, focusing on the influence of steel fiber content and notch depth on the load deflection curve.