bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling of shock-wave loading of carbides as mixtures of components
Authors: Maevskii K K
Published: November 2021

The results of numerical experiments on the modeling of shock wave loading of solid and porous carbides with various stoichiometric compositions are presented. The model is based on the assumption that all the components of the mixture, including gas, have similar pressure, velocity and temperature. The model allows describing the behavior of porous materials and mixes in a wide range of porosity and pressures with precision of experiment. The behavior of complex materials such as carbides is considered as a mixture. The model accurately describes the behavior of the carbides with equal shares of the components of WC, TiC, TaC, NbC and the behavior of boron carbide B4C. Comparison for data of calculation and experimental data was held for carbides with different porosity.
Studying the effect of monochrome light on the photocatalytic activity of tungsten oxide
Authors: Derbasova N M , Gavrish V M , Oleynik A
Published: November 2021

The paper presents studies of the photocatalytic activity of tungsten oxide nanopowder agglomerates under the action of monochrome light in the decomposition reactions of an organic pollutant (methylene blue). It is determined that the radiation of 470 nm (blue) provides the highest values of the rate constant of phototransformation of methylene blue
Developing methods for mathematical modeling of a two-phase dielectric-electrolyte microsystem
Authors: Gorbacheva E V , Kalaidin E N
Published: November 2021

In this paper, we propose a numerical solution to the problem of stability of a two-phase dielectric / electrolyte system under direct and alternating electric fields. The lower wall adjacent to the electrolyte is assumed to be a charged surface, while the upper one is electrically insulated. The charge on the lower surface is supposed to be stationary, and the surface charge on the free interface between liquids is assumed to be mobile. The model is described by a system of Nernst-Planck-Poisson-Stokes equations. The mathematical model is closed by the corresponding boundary conditions. The linear stability of the one-dimensional flow is investigated. At a constant electric field, and the presence of two types of instabilities is found: short-wave and long-wave.
Experimental study of the effect of adding nanoparticles on the rheological properties of oil-based drilling fluids
Authors: Mikhienkova E I , Minakov A V , Matveev A V , Lysakov S V
Published: November 2021

A systematic study of the effect of nanoparticles of various concentrations and sizes on the rheological properties of various oil-based drilling fluids with nanoparticle additives has been carried out. The concentration of nanoparticles in drilling emulsions varied from 0.25 to 2 wt%, and the average size of nanoparticles ranged from 18 to 100 nm. As a result of numerous laboratory experiments, formulations and technology for the preparation of stable oil-based drilling fluids with additives of nanoparticles have been developed. The effect of nanoparticles on the viscosity and rheological properties of these drilling fluids has been studied.
Heat and mass transfer in a metal hydride reactor: combining experiments and mathematical modelling
Authors: Dunikov D O , Borzenko V I , Blinov D V , Kazakov A N , Romanov I A , Leontiev A I
Published: November 2021

Heat transfer in porous metal hydride (MH) beds determines efficiency of MH devices. We present a COMSOL Multiphysics numerical model and experimental investigation of heat and mass transfer in a MH reactor filled with 4.69 kg of AB5 type alloy (Mm0.8La0.2Ni4.1Fe0.8Al0.1). To achieve an agreement between the model and experiments it is necessary to include a flow control device (inlet valve or flow regulator) into the model. We propose a simplified and easy-to-calculate boundary condition based on a porous domain with variable permeability at reactor inlet. The permeability of the domain is connected with hydrogen mass flow by a PID controller. Thus, boundary conditions for the inlet pressure and mass flow are coupled and heat transfer inside the reactor could be calculated without additional assumptions applied to heat and mass transfer in the MH bed.
Heat transfer under conditions of operation of a gas infrared emitter and an air exchange system
Authors: Borisov B V , Kuznetsov G V , Maksimov V I , Nagornova T A , Vyatkin A V
Published: November 2021

In this work, the processes of heat transfer in a premise heated by a gas infrared emitter (GIE) are studied on the basis of numerical solution of the heat and mass transfer equations in a two-dimensional formulation. Calculations are carried out taking into account the presence of supply and exhaust ventilation in the considered area. Ventilation is required during the operation of high-intensity type GIE. The analysis of the main heat and mass transfer parameters by radiant and convective flows is carried out.
The influence of wood processing waste on the technical and energy characteristics of the Maikuben coal-based mixed fuels
Authors: Kuznetsov G V , Cherednik I V , Galaktionova A A , Yankovsky S A
Published: November 2021

The manuscript presents the results of experimental studies of the energy and technical characteristics of mixed fuels based on lignite from the Maikuben basin of the Republic of Kazakhstan and wood processing waste, pine sawdust from the Tomsk LPC. The addition of wood biomass to coal is found to result in a significant reduction in the ash content of the mixed fuel (by 73.1 %) with a wood fraction equal to 50 % and a moderate reduction in calorific value (by 8.2 %) with the same concentration of biomass in the mixed fuel.
Developing the operating principle and mathematical model of the downhole device for injecting scCO2 in productive formations
Authors: Pavlova P L , Guzei D V
Published: November 2021

Traditional technologies are not economically efficient in term of processing heavy and extra-heavy oils. Technologies based on the use of supercritical fluids (SCF) may become one of the innovative directions in the production and processing of heavy and extra-heavy oils. Therefore, in this paper the operation principle of the downhole device for pumping scCO2 into a productive reservoir is developed. The mathematical model is developed either. Calculations with different heat flux densities on the channel wall are carried out. The dependences of the temperature distribution along the length of the heated section are obtained. The calculation results are compared with experimental data.
Representativeness of monitoring station readings in the context of urban environment
Authors: Meshkova V D , Dekterev A A , Litvintsev K Yu
Published: November 2021

In this paper, a comprehensive analysis of the interaction of the urban environment elements with the natural environment components is carried out. The assessment of the complex impact of meteorological parameters on the human body is analyzed based on data obtained from monitoring stations. The readings of monitoring stations concerning both wind speed and directions are found to significantly deviate in different parts of the city due to urban development. A numerical study of the neighborhood with the monitoring station also shows a very complex mechanism for determining the pollution intensity of the area and the relevance of the data obtained, especially concerning pollutants.
Analysis of the influence of dust formation on technological processes in the production of PET
Authors: Geller Yu A , Antanenkova I S , Aparushkina M A
Published: November 2021

Possible methods of dust formation during the production of polyethylene terephthalate granulate and its preparation for molding are considered. The features and patterns of dust formation during drying in an active hydrodynamic layer at different speeds and temperatures are revealed.
The Application of Brain-computer Interface (BCI) based Functional Electrical Stimulation (FES)
Authors: Liu Tianhang
Published: November 2021

Rehabilitation medicine has developed rapidly in recent years. Brain computer interface and functional electrical stimulation are very cutting-edge technologies in this field. Because brain computer interface provides a real-time operation platform for patients to operate their limbs according to their intention for functional electrical stimulation, the research on BCI based FES has gradually increased in recent years. This paper discusses the current development status and technical application of FES and BCI. The research status of BCI based FES is discussed, and the existing problems of various research are summarized. According to the research findings, this field is a new technology with great application prospects in the field of modern rehabilitation engineering.
A Triple-threshold-based Load Event Detection Algorithm for Non-intrusive Load Monitoring
Authors: Chen Mingming , Fang Kaijie , Huang Qifeng , Yang Shihai , Cheng Hanmiao , Liu Tianchang , Huang Yixuan
Published: November 2021

Event detection is an important foundation of non-intrusive load monitoring algorithm. In this paper, the common household appliance load events are classified, and a new triple-threshold event detection algorithm is proposed aimed at solving the problems of false detection and missing detection in the practical application. Firstly, a low power threshold is used to realize high-sensitive detection of the load events, and secondly the detected events are spliced according to the time threshold to get the complete events. Thirdly, the high threshold is used to discriminate the complete event set to filter out the disturbance caused by load fluctuation. Finally, the results are modified with a correction logic. The test results carried with static data show that, the algorithm proposed in this paper is more accurate for positioning the time of putting into and cutting off load, which is conducive to improve the accuracy of transient interval interception of load events, and has advantages in detecting slow rising load events. In addition, the algorithm proposed in this paper has a small amount of calculation, which can meet the requirements of application in the hardware of smart meter.
Investigation of Base Transport Mechanism in Silicon-Germanium Heterojunction Bipolar Transistor Operating over Wide Temperature Range
Authors: Yu Guofang , Cui Jie , Zhao Yue , Fu Jun , Ren Tian-Ling
Published: November 2021

A high breakdown voltage silicon-germanium heterojunction bipolar transistor operated over a wide temperature range from 300 K to 10 K has been investigated. The measured Gummel characteristics illustrate that the collector current and base current both shift to the higher voltage as the temperature decreases. The fT/fmax are extracted to be 23/40 GHz at 300K, 28/40 GHz at 90 K, and 25/37GHz at 10K, respectively. The effective amplification range becomes narrow as the temperature decreases. And the ideality factor of base current in the low current region is shown to be temperature-dependent and its value is much larger than 2 at cryogenic temperatures. This phenomenon indicates that the base current is not only contributed by drift, diffusion, and Shockley-Read-Hall recombination, but also by trap-assisted tunneling. The Hurkx local trap-assisted tunneling has been used to analyze the non-ideal base transport mechanism. And a calibrated TCAD device model is developed to further verify this non-ideal transport mechanism.
Tunable mid-infrared laser sources for trace-gas analysis
Authors: Kolker D B , Sherstov I V , Boyko A A , Nyushkov B N , Erushin E Y , Kostyukova N Y , Akhmathanov A I , Kiryakova A Y , Pavluck A V
Published: November 2021

We demonstrate advanced experimental approaches to photoacoustic gas detection with tunable mid-infrared (mid-IR) laser sources of different types. A gas analyzer for registration of various gas components based on a tunable narrow-linewidth optical parametric oscillator (OPO) was designed and investigated. Using this OPO, the possibility of measuring the trace concentration (∼2÷3 ppm) of methane (CH4) in air was experimentally shown. The gas detection capability was enhanced by introducing injection seeding into the OPO. Another gas analyzer was based on a quantum cascade laser (tunable within the range ∼7.6 ÷7.7 μm) and a resonant differential photoacoustic detector. Detection of the ultra-low concentration (∼0.3 ppm) of methane in air was achieved (the standard dispersion was (1σ) ≍ (10–11) ppb with an integration time of 10 s). We compare the presented approaches and outline their further development.
Effect of terahertz radiation on intermolecular interactions of albumin under aerobic and anaerobic conditions
Authors: Nemova E A , Dultseva G G , Nikolaev N A , Cherkasova O P
Published: November 2021

The effect of THz radiation on coupling between albumin molecules under aerobic and anaerobic conditions is assessed through an EPR-quantified procedure. Rearrangements induced by terahertz radiation are found to affect the hydrogen bonding network causing an increase in the rate of bimolecular interactions. Molecular mechanism of the observed effect is considered involving the interactions between the functional groups of albumin molecules. Irradiation causes conformational changes in albumin molecules, which involves changes in the steric states of molecules. These rearrangements hinder or simplify the adsorption of specific agents on the reactive sites of albumin molecules.
Theoretical bases of combined nonlinear optical demodulator-amplifer for broadband microwave photonics system
Authors: Nikolaev G N , Mikerin S L
Published: November 2021

Our demodulator is based on the use of a strong light pump wave along with a signal modulated light wave. The demodulator is linear in terms of the modulation signal, which makes it possible to obtain a demodulated signal without harmonic distortion. The modulator conversion efciency and signal gain increase with increasing microwave baseband.
Controlled Fractional Order Processes with Distributed Parameters
Authors: Mamatov Mashrabjon , Alimov Xakimjon
Published: November 2021

This work is devoted to the study of the problem of pursuit in systems controlled with distributed parameters of fractional order. Derivatives with respect to spatial variables are ordinary, integer, and even of arbitrary order. Designed and studied sampling schemes. A numerical method is constructed for finding strategies in suitable classes and for constructing the corresponding control laws. Theorems are proved for the possibility of completing the pursuit by the finite difference method, and they can be used to solve finite-difference optimal control problems or numerical solutions of differential games of fractional order. Problems of the type under study are encountered in modeling the processes of economic growth and in problems of stabilizing dynamic systems.
The Mathematical Analysis and Classification Research of an Iris Data Set Using Binary Tree and Grey Relation Grade
Authors: Feng Chiang Ling
Published: November 2021

The data from an Iris flower database is studied. The Iris database is the most commonly used database for machine learning algorithms. The Iris database was developed by Ronald Aylmer Fisher in 1936. The Iris database has 150 records in three categories: Iris Sentosa, Iris Versicolor and Iris Virginic. The database has four attributes: sepal length, sepal width, petal length and petal width. For the machine learning algorithm, 150 Iris flower databases are used. Of the 150 Iris in the Iris database, 80% are used as the training set and the remaining 20% Iris as the test set. In machine learning, to perform classification and discrimination is a complicated and difficult thing. In this study, a grey relation grade is used to extract the main features of the Iris flower and a Binary Tree [1] is used to classify the Irises. The results show that for the same specific attributes, grey relation grade extracts the main attributes and can be used in combination with a binary for classification.
Discrete Schemes for a Class of Semilinear Hyperbolic Eqution
Authors: Xu Jing , Jiang Xiaoli
Published: November 2021

This paper focuses on the numerical algorithm of a class of semilinear hyperbolic equation. The dissipation term and external force source term existing in the equation enhance the nonlinearity of the model and make the nonlinear effect complicated. However, this nonlinear effect has a great influence on the discrete scheme, which cannot be neglected. Discretizing the nonlinear terms to ensure the validity of the scheme is the core issue in this paper. An effective scheme based on linearization techniques and iteration theory is proposed. It is based on the finite difference method. The efficiency of the proposed schemes was verified via some numerical examples showing that they compare well with existing methods.
A Classification Algorithm: Data Mining and Mathematical Model
Authors: Cheng R , Kong X , Yu M , Wang N
Published: November 2021

In this paper, we propose a classification algorithm based on Recency-Frequency-Monetary (RFM) model and K-means data mining method. In addition, the designed algorithm is verified by the experiments on the member data in a large shopping mall. The experiments results show that the proposed algorithm can provide an accurate classification of the members. Finally, some marketing strategies for different classes of members are given according to the classification results.
The Uniqueness of Solution to the Inverse Eigenvalue Problem for an Arrow-shaped Generalised Jacobi Matrix
Authors: Huang Hongliang , Wang Qike , Li Zhibin , Wang Lidong
Published: November 2021

This paper studies the inverse eigenvalue problem for an arrow-shaped generalised Jacobi matrix, inverting matrices through two eigen-pairs. In the paper, the existence and uniqueness of the solution to the problem are discussed, and mathematical expressions as well as a numerical example are given. Finally, the uniqueness theorem of its matrix is established by mathematical derivation.
Design of Fuel Supply Curves for Aircraft Center of Gravity Balance Based on DCT Compression
Authors: Wei Yawen , Su Bo , Wang Xuru , Li Zhen , Wang Pengfei , Feng Xiangchao
Published: November 2021

The center of gravity (CG) has a significant influence on the controllability, stability, and fuel efficiency of the aircraft. For the aircraft with multiple fuel tanks, the CG position can be controlled by the fuel quality of different fuel tanks during flight. In this paper, an optimization method based on discrete cosine transform (DCT) compression is proposed to solve the optimization strategy of aircraft multi-tank fuel supply according to the current aircraft mission and engine working requirements. The transform coefficients of the low frequency components are used as design variables to represent the fuel supply curves. The improved KS function is proposed to deal with constraints. The numerical example is demonstrated to verify the effectiveness of the proposed method.
Finite Analysis of Support Time for Tunnels in Strain-softening Rock Mass in Consideration of Fictitious Support Pressure
Authors: Cui Lan , Sheng Qian , Niu Zhenzhen
Published: November 2021

This study considers that the support time is quantitatively determined by the production limit of the displacement reduction factor and the support force under the extrusion conditions of the strain-softening rock mass. Therefore, the two indicators of the downlines under the support time are the displacement reduction factor of the support force and the yield limit. Based on the solution of the fictitious pressure proposed in an existing paper, the finite difference method is adopted to investigate the variations of the support force and displacement reduction factor versus the delayed distance considering different support types, initial stresses, and post-peak behaviours. The results show that on the one hand, the delay distance is suggested within 1 R0 in most tunnel cases; on the other hand, the factors have greater impact on rock-support interactions are rock mass and in-situ stress. Relatively contrast, softening and expansion behavior was not significant enough. Furthermore, it is also very important in composite support systems to assess the proportion of loads shared with the weakest part.
A Novel Route Planning Scheme Based on Dynamic Time Variables
Authors: Zhang Jinghe , Li Lei , Zhang Yuechao , Cheng Shaofeng , Fang Weidong
Published: November 2021

In this paper, the processing method of dynamic time variables in the route planning nodethat we designed involves the field of route planning, including determining the route time and stay time, combining the floating reserved time to determine the redundancy; after the entity has visited a node, the current value is calculated Redundancy: According to the calculated redundancy value, combined with the preset redundancy threshold, the entity’s route and stay time are reminded. By converting the dynamic time variable into a fixed value, the model can complete the search for the optimal path within a limited time. At the same time, the concept of reserved floating time is introduced, thereby retaining the dynamic characteristics of time, so that visitors can have sufficient time stay, and can complete the stay according to the fixed time requirements, can effectively track the stay time and make corresponding processing in the corresponding situation to ensure the stay ability. The proposed scheme has better performance.
Research on Modeling and Power Algorithm of Photovoltaic Cells for Solar Cars
Authors: Zhong Yan , Yang Qing , Zhang Yanzhong
Published: November 2021

Solar photovoltaic cells will be an effective supplement to electric vehicle batteries. In order to make the photovoltaic system of the solar car provide reliable power, this paper models the photovoltaic cell and designs the maximum power point (MPP) tracking algorithm based on three-point sampling with a fixed voltage. In addition, considering that the output power will change when the voltage and radiation intensity change under the peak power of the solar vehicle, the prediction of the peak output power of the photovoltaic array considering the influence of the radiation intensity and battery voltage is put forward for the first time. Experiments show that the designed power algorithm runs stably, and the power generation power prediction error is less than 1%. The peak output power prediction of the photovoltaic array takes into account the effects of real-time radiation intensity and battery voltage fluctuations, making the peak power prediction of the vehicle more accurate.
Modeling and Analysis of Different Architecture for Civil Aircraft Hydraulic System
Authors: He Xunan , Kang YuanLi , Hui Yannian
Published: November 2021

For the evaluation of civil aircraft hydraulic system, Fuel Consumption is a very important index. However, there is no effective method to perform analysis for different architecture. This paper proposes that taking fuel weight penalty as a major mathmatical modeling method to analysis traditional architecture and more electric architecture. The result shows that the fuel consumption of more electric architecture is less than traditional architecture.
Modeling and Finite Analysis of Overall Structure Mechanical Behavior of Steel Frame—Cold-formed Thin-walled Steel Composite Wall
Authors: Liang Huqing , Tang Mengxiong , Huang Ruicong , Jiang Zhengrong , Qiu Junming , Cai Jian
Published: November 2021

Based on the finite element method, the typical layout and parameters were selected to establish the overall structure model of steel frame—cold-formed thin-walled steel composite wall and their influence on the mechanical properties and the economic steel amount was analyzed. The results show that the screw spacing, purlin section and purlin spacing have little effect on the lateral stiffness and the amount of steel used in the overall structure, while the width of wall opening has obvious effect. It is suggested that the screw spacing should be consistent with the relevant provisions in the cold-formed thin-walled steel structure specification, the purlin section should be selected relatively small according to the wall thickness and the purlin spacing should be properly amplified. The applicable height of this structure system is higher than that of pure cold-formed thin-wall steel structure system in ordinary residential buildings. The amount of steel used in this structure system is obviously less than that of pure steel frame structure system.
A Failure Propagation Analysis Method Based on 3 X 3 Hierarchical Model
Authors: Pang Shujie , Jiao Jian
Published: November 2021

In recent years, with the increasing complexity of equipment, system design and safety analysis for the equipment are becoming more and more difficult. In this paper, we make a more comprehensive analysis of the hierarchical relationship of the system from the vertical and horizontal angles and put forward the 3 × 3 Hierarchical Model. Then, we propose a failure propagation analysis method based on 3 × 3 Hierarchical Model. At the same time, SysML is used to build the models, which is convenient for different people to learn and modify the models. Finally, a hydraulic transmission system is taken as an example to illustrate the feasibility of the method.
Numerical simulation of wave phenomena using FreeFEM
Authors: Hasanah U , Pudjaprasetya S R
Published: November 2021

In this research free surface motion governed by the shallow water equations is considered. A numerical scheme based on the finite element method, which is incorporated in the open source FreeFEM, was used to simulate several wave phenomena. By carefully setting the corresponding initial condition as well as boundary conditions, several numerical computations were conducted. Numerical simulations presented here are standing wave in a closed basin, progressive wave over a flat bottom, as well as wave shoaling over a decreasing depth and wave refraction. In all cases above, the existing analytical formula are used to validate the numerical results. These computations suggest that explicit-implicit scheme is appropriate for varying water wave simulations.
Basic analysis on heat transfer phenomena in natural circulation for liquid sodium
Authors: Wulandari R , Permana S , Suprijadi
Published: November 2021

Natural convention, the heat transfer on fluid due to density differences that can be caused by differences in fluid temperature. One example application of natural convection is cooling system, such as nuclear reactor cooling system. The purpose of this study is to analysis the basic characteristic heat transfer of sodium liquid in the natural circulation system for steady state analysis and transient characteristic with Finite Element Method. The selected module is the Non-Isothermal FLow (NITF) module. This module is a combination of three basic equations, namely the continuity equation, the Navier-Stokes equation, and the dynamic equation of heat transfer in fluid. The simulation model measures 1.5 x 2 (m) with sodium liquid (Na) as a fluid.
Research and practice on optimal design method of the oilfield water injection system pipeline network
Authors: Qu Fengjiao , Liu Tingting , Zhang Zhiming , Xie Weiyi , Wang Yansong , Wu Zanmei , Liu Yuhan , Liu Yun
Published: November 2021

The efficiency of oilfield water injection system is generally low and energy consumption is high. With the deepening of oilfield exploitation, the water cut of the oilfield is increasing, the power consumption of the water injection system is increasing year by year, the oilfield exploitation cost is increasing, and energy conservation and consumption reduction are very important. In order to improve oilfield water injection efficiency and reduce water injection energy loss, this paper puts forward the pipe network optimization design method of partial pressure water injection, establishes the mathematical model of partial pressure water injection pipe network and throttling loss calculation model, compiles the calculation software of partial pressure water injection mathematical model, optimizes the partial pressure interval, calculates the partial pressure points, effectively reduces the energy loss of water injection system and improves the efficiency of water injection system.
Study on the impact of confining pressure on gas permeability of tight sandstone cores
Authors: Tong Jianxiang , Wang Hengyang , Wang Yuyi , Zhang Ya , Huang Xiaohe
Published: November 2021

Taking the tight sandstone core of Shengli Oilfield as the experimental sample, this paper studies the permeability variation of the tight sandstone under different confining pressures. The experimental results show that when the pore pressure is constant, the measured gas permeability of core decreases with the increase of confining pressure. Power function is more reasonable to describe the influence of confining pressure on permeability of tight sandstone between power function and exponential function. Analyze the impact of confining pressure on gas permeability of tight sandstone cores by using permeability change rate coefficient D and coefficient S.
An Improved Particle Swarm Optimization algorithm for Optimal Control of ASP Flooding
Authors: Lang Meiling , Ge Liang
Published: November 2021

An optimization for injection of alkali/surfactant/polymer (ASP) flooding in oil recovery is considered in this paper. This optimal control problem (OCP) is formulated as a parameter identification system, where the objective function is revenue maximization and the governing equation is multiphase flow in porous media. We use the ASP concentrations and slug size as the control and give the pointwise constraint for the control. An improved particle swarm optimization (IPSO) which is a particle swarm optimization (PSO) with second-order oscillatory in velocity, is applied to solve the OCP. Finally, an example of the OCP for ASP flooding is exposed and the results show that the IPSO method is effective and feasible.
Photovoltaic Direct Drive Water-saving irrigation System and Its Optimization Design Method
Authors: Zhu Junfeng , Wang Xingtian , Liu Wenbing , Wang Shifeng , Wang Qiujun
Published: November 2021

Photovoltaic irrigation has been widely used in many areas without conventional energy sources. In order to solve the problem of unstable operation and poor irrigation uniformity caused by the diurnal variation of solar radiation, a photovoltaic direct-drive water-saving irrigation system with automatic regulation was proposed. By using automatic control technology and the method of zonal rotation irrigation, all the electric energy generated by solar panels can be converted into irrigation energy under different light intensities, so that the water-saving irrigation equipment can work stably in different regions and the irrigation uniformity is ensured in different regions. According to the characteristics of solar energy resources and photovoltaic water-pumping units, the optimum design method of photovoltaic water-saving irrigation system is put forward. The minimum capacity of solar panels can meet the irrigation demand of a certain area, which can guide the engineering design of solar water-saving irrigation, greatly improve the engineering quality and energy utilization rate. It has the advantages of simple design, low cost, stable operation and energy-saving ring.
Optimal dispatching of integrated energy system considering flexible load
Authors: Guo Jinrui , Zhang Zhijun , Xu Lei , Wang Hao , Wang Hui , Niu Yifan
Published: November 2021

Demand response, as an effective dispatching method, has been widely used in the optimization research of integrated energy system (IES). In this article, first, the mathematical model of flexible loads including shiftable electric, heat, and cooling load are established in line with their characteristics. Second, an optimal scheduling model of the IES is built, where the minimum sum of system operation and maintenance and the environmental protection costs comprise the objective function. Furthermore, the alternating direction multiplier method is used to solve the optimal scheduling model in a fully distributed manner. Finally, simulation results show that the proposed model and algorithm can efficiently solve the IES optimal dispatching problem, reduce the peak-valley difference, and improve the stability of the system.
Study on Oil-water Two-phase Migration Mechanism of Low Permeability Fractured Core based on the Online NMR Testing
Authors: Zheng Xiaomin , Li Ning , Li Dong , Li Nan
Published: November 2021

Understanding the dynamic migration mechanism of oil-water two-phase is the key to improve the effect of water injection development in low permeability fractured reservoir. Based on artificial fracturing of core and basic physical parameter testing, the online NMR displacement experiments of cores with different fracture widths are conducted to analyze the oil-water dynamic distribution characteristics and migration mechanisms. The experimental results show that when water breaks through at the outlet, oil volume in the small pores is basically unchanged. In the large pores it decreases to a certain extent, while in the fracture it decreases greatly. When the displacement is over, oil volume in the small pores still changes little, while it decreases greatly in the large pores, and it is almost zero in the fracture. With the decrease of fracture width, the recovery ratio when waterflooding front breaks through and the final recovery ratio after displacement increase gradually. The contribution proportion of recovery ratio in the fracture decreases as a whole, while in the large pores it increases gradually, and in the small pores it decreases slightly. The research results lay a foundation for the optimal design of fracture parameters and the adjustment of water injection development technology policy in low permeability fractured reservoir.
A Study on the Characteristics of the Concentrated Solar Photovoltaic/thermal Integrated System
Authors: Ai Dengxin , Wang Guilin , Li Ye , Gan Zhiyong
Published: November 2021

This paper mainly introduces a comprehensive solar energy utilization system with low-CPC and polycrystalline silicon solar photovoltaic components. Outdoor experiments have been made to test the electrical efficiency, heat efficiency and their changes of the system with fixed temperature of outlet water and different sunshine conditions. Besides, this paper also compares the effects of outlet water at various temperatures on the efficiency of the whole system as well as the temperatures and flow rate responses with different PID parameters. Through analysis of these experimental data, the most desirable temperature of outlet water and PID parameters have been obtained in CPC-PV/T Hybrid Thermal-electric System, thus providing references for relevant experimental research.
Preparation and absorption performance of CNTs/PUR honeycomb composite absorbing material
Authors: Zhao Yankai , Bi Song , Hou Genliang , Liu Zhaohui , Li Hao , Song Yongzhi , Hou Zhiling
Published: November 2021

In this paper, a carbon nanotubes/polyurethane resin (CNTs/PUR) honeycomb composite absorbing material was prepared, and the influence of the content of carbon nanotubes on the absorbing performance of single-layer and double-layer honeycomb composite absorbing materials was investigated. The mechanical properties of single-layer and double-layer materials are discussed. The honeycomb core and carbon nanotubes are compounded together by the impregnation method to form a CNTs/PUR honeycomb composite absorbing material. The microstructure shows that the carbon nanotubes are uniformly dispersed in the water-based polyurethane resin, and the impregnated layer and the honeycomb wall are well combined. The reflectivity of the material shows that as the content of carbon nanotubes increases, the absorption performance of the material first increases and then decreases; when the content of carbon nanotubes is 5.6%, the single-layer honeycomb composite absorbing material has the best absorption performance. The effective absorption bandwidth is 10.6 GHz (2~18GHz), and the maximum absorption strength is -24.5 dB; when the combination mode is 2-4, the double-layer honeycomb composite absorbing material has good absorption performance, and the maximum absorbing strength is -32.2dB, the bandwidth is 13.7GHz (2~18GHz).
Simple and accurate calculation model of viscosity for supercritical CO2
Authors: Deng Jia , Zhao Guangjie , Zhang Lan , Ma Huizhong , Song Fuquan , Cao Qing , Zhang Xueling
Published: November 2021

The high-precision calculation method suitable for the viscosity of supercritical CO2 is reported. The modified LBC model, modified DS model and Ehsan empirical formula are selected to calculate viscosity. The error analysis result shows that the average absolute error of the modified DS model is the lowest, which can be applied to the engineering calculation. The LBC model is suitable at 7.5–25MPa and the Ehsan empirical formula has high accuracy at 25–60MPa. Then the viscosity plate is drawn at temperature range of 310–800K and pressure range of 7.5–60MPa, which can be applied in carbon dioxide resources recovery and utilization of technology.
Investigation of the phase transformation characteristics of Fe-Co elastrocalaric refrigeration alloy
Authors: Li Xianfa , Shi Yongjun , Wang Shuyao
Published: November 2021

Mechanical alloying (AM) and powder metallurgy(PM) have been widely used in many fields especially in the development of new alloy materials due to the advantages of simple process, high material utilization rate and accurate material ratio. In this investigation, experimental procedures were proposed to explore the phase transformation characteristics, elastrocalaric refrigeration effect of Fe-Co alloys synthesized by AM and PM. The samples of Fe-Co elastrocalaric refrigeration alloy with different phase transformation temperatures and different enthalpy changes have been successfully prepared by changing the initial ratio of Co element. The results show that the phase transformation characteristics have changed with the increase of Co content and showed different changing trends.
Study of the corrosion of stainless steel with fatty acid/paraffin/graphite composite phase change materials
Authors: Yan Quanying , Ma Guangyuan , Wang Wei
Published: November 2021

The corrosion performance of phase change materials on stainless steel was studied using single fatty acid, fatty acid/paraffin mixed phase change materials and fatty acid/paraffin/graphite composite phase change materials as corrosion media. The results show that the corrosion of fatty acid, paraffin and graphite composite phase change materials to stainless steel is very small; among them, stearic acid series of phase change materials are the least corrosive and can be used as the ideal energy storage medium for stainless steel phase change heat storage and heat exchange devices.
The Mass and Heat Transfer Characteristics Study of the Natural Convection Evaporation of an LNG Droplet in BOG
Authors: Fei Zhengyang , Deng Jiajia , Lu Jinshu , Wang Bin , Xue Dawen
Published: November 2021

The evaporation process of LNG droplets in BOG is closely related to the cooling down process of the LNG tank, but there isn’t an available droplet evaporation model at present. Been prepared based on the conservation of mass, momentum, and energy, a CFD model of natural convection evaporation of a single LNG saturated droplet in the BOG was developed and applied. The results show that:①There are two distinguished zones around the droplet surface, where the local temperature boundary layer of the droplet gradually thickens and rapidly thickens with the increase of the angle of inflow from 0 ° to 90 ° and from 90 ° to 180 °, respectively; ② With the increase of droplet size, the average thickness of temperature boundary layer increases gradually, which leads to the decrease of relative evaporation rate;③“blowing effect” remains almost unchanged with the increase of droplet size.
On the tensile fracture behavior of Cr coating for ATF cladding considering the effect of pre-oxidation
Authors: Pan Ziyan , Yuan Mingduo , Zou Zhenyu , Zhang Weijian , Du Mingyue , Jiang Jishen , Ma Xianfeng
Published: November 2021

In this study, the fracture mechanisms of Cr-coated Zr4 alloy samples were studied by in-situ tensile testing with high-resolution observations. Both original sample and pre-oxidized sample were studied to study the effects of pre-oxidation on the cracking and failure behavior. For the Cr-coated Zr4 sample, with the increase of tensile strain, multiple surface cracks were dominant and less interfacial cracks were formed, indicating good interfacial strength of Cr coating. For the pre-oxidized samples, there was a thin oxide layer formed on the Cr coating surface, revealing improved oxidation resistance and protection effects. However, a brittle ZrCr2diffusion layer was formed in the same while at the Cr/Zr4 interface underneath the Cr coating, which would lead to earlier micro-cracks formed under tensile stress and evidently degrade the interfacial strength. The findings in the study indicated the importance of optimizing coating microstructure in future study to avoid forming the above-mentioned brittle diffusion interlayer and the associated premature failure.
Study on anode material of CoδFe1-δOx-Sm0.2Ce0.8O1.9 for solid oxide fuel cell
Authors: Dong Runze , Yang Pu , Shao Tianqi , Wang Ruochen , Li Ping , Fu Dong
Published: November 2021

This paper mainly explores the anode properties of CoδFe1-δOx-Sm0.2Ce0.8O1.9 (SDC) (δ=0, 0.2, 0.5, 0.8, and 1) for solid oxide fuel cell (SOFC). The composite anode materials were synthesized by sol-gel method, and the XRD technique was used to characterize structural properties. After H2 reduction at 700 oC, the CoδFe1-δOx oxides were reduced to Co, Fe metal or Co-Fe alloy. The symmetric cells were fabricated with CoδFe1-δOx-SDC as the electrodes and SDC-carbonate as the electrolyte. At 700 oC, the symmetric cell with Co0.5Fe0.5Ox-SDC electrodes showed the lowest polarization resistance and the symmetric cell with Co0.2Fe0.8Ox-SDC showed the largest polarization resistance.
Preparation of Binary Mixed Inorganic Hydrate
Authors: Yan Quanying , Lv Yifan , Wang Chenyu
Published: November 2021

In this paper, 54 binary mixed inorganic hydrates composed of Na2SO4·10H2O, Na2CO3·10H2O, CH3COONa·3H2O and MgSO4·7H2O were prepared, and try to research their reasonable and feasible preparation methods. The results show that the thermogravimetric ratio of binary mixtures varies with the composition and proportion of binary mixtures. There is evaporation of water in the mixtures preparation process, so appropriate deionized water should be added to supplement the evaporated water in the mixtures preparation of phase change materials.
Research on Control Method of Wet Desulfurization System for Coal-fired Boiler
Authors: Zhang Xingchao , Liu Jianhong , Hu Peng
Published: November 2021

In wet flue gas desulfurization technology, the key factor affecting flue gas SO2 absorption is the control of slurry pH value in the absorption tower. However, most of the commonly used pH value control methods have some defects and cannot fully meet the system control requirements. On the basis of the analysis for the problems in the control process, this paper discussed a control strategy based on internal model control algorithm. The system simulation test showed that this control method had good dynamic performance, robustness and anti-interference, which could realize the relatively accurate control of pH value for wet flue gas desulfurization system, and achieve the control goal.
Influence of friction coefficient on mechanical properties of braided wire rope in winding traction state
Authors: Cui Weihua , Gu Weilin , Li Xiaoyang , Wang Hui
Published: November 2021

In the construction of cable erections, when passing through the reel of the tractor, the braided wire rope used for traction in the state of winding traction is subjected to the composite action of tensile, bending, extrusion, friction and other forces, of which the stress condition is the most complicated, and the wear is the most likely to occur. The Friction coefficient is an important factor which directly affects the mechanical and wear properties of wire ropes. Therefore, according to the cable traction condition, the influence of friction coefficient on the rope tension attenuation during the winding traction process is analyzed. Because the wear of wires between braided wire rope strands is the most serious, this paper focuses on the influence of the friction coefficient between the rope strands on the mechanical properties of wire ropes. Regarding YS9-8×19 braided wire rope as the research object, a solid model of “rope-wheel” winding traction system is established. Based on the actual conditions, the finite element simulation model of winding traction system is established by setting load and constraint conditions. The influence of friction coefficients on the stress and deformation of braided wire rope strands is researched, by setting different friction coefficients between rope strands and analyzing the simulation results, in order to provide theoretical instructions of braided wire ropes used for traction.
Research on edge controller based on industrial furnace
Authors: Deng Yi , Gao Jiapeng , Zhang Xuewen
Published: November 2021

Traditional control instruments and DCS control systems are limited by shortcomings such as single control function, independent controlled elements, inability to close-loop control on site, and ineffective communication. Aiming at these problems, this paper proposes a kind of industrial furnace edge controller which has the functions of acquisition, calculation, control, storage, output and communication in one. The edge controller structure, edge computing and the control method applied to edge computing are designed. The fuzzy PID control method is compared with the conventional PID control method by taking the temperature control of resistance furnace as an example. The simulation shows that the control effect of fuzzy PID on resistance furnace temperature is obviously better than that of conventional PID. The test results also show that the performance indices for the fuzzy PID control are better, which again proves that the fuzzy PID control outperforms. The research results of this paper are of reference value for engineering applications.
Effects of Pitching Motion Elements on Aerodynamic Characteristics of Airfoil
Authors: Yin Rui , Huang Jing , He Zhi-Yuan
Published: November 2021

The aerodynamic characteristics of NACA4412 airfoil with different pitching motion elements were compared and analyzed based on CFD in this research. The results are acquired as follows: the difference between the lift and drag coefficients of the airfoil during pitch up and pitch down motions becomes larger with the increase of the pitching amplitude or initial angle of attack; as the pitching amplitude increases, the lift coefficient grows slightly greater and the drag coefficient grows much greater; as the initial angle of attack increases, the lift coefficient grows much greater and the drag coefficient grows slightly; the smaller the attenuation frequency is, the larger the lift-to-drag ratio of the airfoil will be.