bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on the Community Group Buying Marketing Model of Fresh Agricultural Products in Jilin Province from the Perspective of Internet Marketing and Retail
Authors: Liu Lili , Zhang Fan , Li Hengyu , Wen Conggao
Published: May 2021

Under the “Internet +” environment, fresh food operators in Jilin Province are facing new opportunities. The new retail model has obvious advantages in the sale of fresh agricultural products. There are mainly two models of “community store + platform shopping” and “community group buying + centralized pickup.” There are still some problems in the community marketing of fresh agricultural products in Jilin Province. The business model can be improved by improving the logistics and distribution system of fresh agricultural products, promoting fresh agricultural products standards, strengthening supervision and management, actively introducing talents, broadening financing channels, and cultivating markets. Improve measures such as guiding the establishment of new consumption habits.
Design and Implementation of the Inner Mongolia Meteorological Service Intranet APP
Authors: Zhang Delong , Liu Yang , Liu Tianqi
Published: May 2021

The new media platform based on internet, like WeChat and other mobile phone applications (APPs), can provide meteorological information to users more conveniently and efficiently than the traditional platforms, such as TV, telephone, short message, etc. Therefore, an intranet APP is developed in Inner Mongolia Meteorological Information Center to realize the rapid acquisition of meteorological information in the 70th anniversary celebration of the Inner Mongolia Autonomous Region. Based on user experience and user demands, the APP offers multiple meteorological service products covering meteorological observations and forecasts. It quickly displays the data from the critical regional automatic stations and mobile meteorological stations for relevant users. In this way, it provides seamless, all-round, refined and targeted meteorological services throughout the celebration.
A new type of superhydrophobic membrane seawater desalination device
Authors: Huang Shudi , Li Yuqi , Li Zongjing
Published: May 2021

In response to the existing problems of the current seawater desalination equipment, this project designed a new type of super-hydrophobic membrane tangential distillation seawater desalination device with simple structure, low energy consumption, high seawater conversion rate, operation and reduced maintenance costs. The successful implementation of the project will not only provide economical and applicable freshwater equipment for the living water of island residents, but also have potential application value for China’s coastal defense construction and offshore development.
Cropland Extraction Using Water Mask and Phenological Features based on Landsat-8 Imagery
Authors: Xiao Wenjuan , Wang Jiasheng
Published: May 2021

Accurate cropland information is crucial for food security assessment. At present, Landsat-8 remote sensing imagery and Google Earth Engine (GEE) cloud platform provide favorable conditions for mapping cropland. Despite the improved mapping conditions, the existence of mixed pixels is still one of the main difficulties in the cropland extraction. Especially in paddy fields, the influence of water bodies on farmland extraction should not be ignored. Also, the lack of time series data with temporal-spatial resolution impedes the accurate cultivated land mapping. Aiming at these problems, we proposed an effective method to extract cropland precisely based on the Landsat-8 imagery and GEE platform. First, we created cloud-free images and masked out water based on Landsat-8 images. Second, we constructed the normalized difference vegetation index time series data with 30-m resolution from Landsat-8 and MODIS images to obtain accurate phenological information. Third, other cropland features such as texture features, tasseled cap transformation features, terrain features and spectral features were acquired. Finally, we applied the Random Forest algorithm and obtained the cropland for 2015 in Qinzhou. The results show that terrain characteristics and phenological characteristics have the greatest influence on cropland extraction. Based on water mask, the overall accuracy of cropland improved by 6.9%. Overall, the product has high accuracy with the mean overall accuracy (OA) of 97.9%. Compared with MCD12Q1 and GFSAD30 cropland products, it is 6.2% and 24.3% higher in OA respectively. In brief, our method is helpful for the cropland extraction.
Research on Material Workshop System under Intelligent Sorting Manufacturing in Digital Workshop
Authors: Zhang Teng
Published: May 2021

With the continuous development of science and technology level and management thought, the current manufacturing enterprises are also undergoing a change involving technological processes and management methods. With the rapid introduction of scientific and technological means, it is transforming from the traditional experience-based management mode to the information-based management mode, that is, the integration mode of two industries supported by informationization, pursuing sustainable development and adhering to scientific development. Digital workshop technology is one of the key technologies of digital manufacturing technology, which is an important application of digital manufacturing technology in manufacturing field, and has become the realization basis of advanced manufacturing technology in the actual manufacturing process. In this paper, an integrated management system structure of digital manufacturing workshop under networked manufacturing environment is proposed. According to the management requirements of modern digital workshop, wireless mobile communication technology is introduced, and a digital workshop intelligent sorting and manufacturing cutting workshop system is constructed.
Simulation System of Coal Mine Mechanical and Electrical Equipment Maintenance Based on Virtual Reality Technology
Authors: Meng Long
Published: May 2021

Aiming at the problem of cumbersome disassembly and assembly of large-scale equipment in coal mines and high cost, this article takes coal shearers, hydraulic supports, road headers and hoists as the research objects, and uses virtual reality technology to design and implement a set of virtual assembly subsystems., Virtual assembly and simulation system composed of scene simulation and roaming subsystems. The article uses Maya to model large-scale equipment, through VS programming, interactive control in Unity, and realizes the virtual assembly and maintenance of equipment and the virtual simulation roaming function of coal mining face. The test shows that the training and use of the simulation system effectively improves the actual assembly and maintenance capabilities of the equipment, while reducing the cost, and has a significant practical application effect.
The overall process of high-deck float-over for the large platform in paralic zones
Authors: Zhang Xiaochun , Yin Qingguo , Jiang Xiaobo , Yang Ling , Jin Song , Dong Yuezhou , Zhu Yan , Wang Xiaoyan
Published: May 2021

As the demand for oil and gas resources continues to grow, the development of oil and gas resources in paralic zones is also increasing. Because the water depth is very shallow in paralic zones, large construction equipment cannot enter the construction area, so the offshore installation of large platforms is facing a great challenge. The float-over installation method has the advantages of large lifting capacity, short operation period, and low construction cost. At the same time, it can effectively reduce the amount of dredging work and is more suitable for the offshore installation of large platforms in paralic zones. In this paper, the installation process and key technologies of hi-deck float-over for the large platform in paralic zones are emphatically introduced. The key technologies include the barge motion response analysis technology, the barge ballast adjustment technology, the positioning and buffering technology and motion monitoring technology, etc.
Fault diagnosis and analysis of compressor fracture problem
Authors: Su Jintao , Lou Jianping , Jiang Xiaolu
Published: May 2021

Fault diagnosis of fracture problems has always been a difficult point in fatigue analysis, and there is no good solution at present. Aiming at the nonlinear problem of fracture problems, this paper studies the pre-critical technology. According to the compressor cover local cracking problem, respectively by finite element analysis software MSC. Patran and Nastran to cover components were nonlinear analysis, through the comparison and fault diagnosis method of the fatigue damage final cover cracking reasons, the improving measures are put forward in this paper, the solution is verified the effectiveness of the improved reliability calculation..
Research on The Relationship between Residential Space Pattern and Traditional Culture based on Space Syntax: Taking Kejia House as an Example
Authors: Zou Han , Chen Chen , Xiao Wei
Published: May 2021

This article uses the space syntax theory to analyze the space diagram of the typical traditional houses and houses in Southeast Hubei, and discusses the characteristics of the spatial pattern of the traditional houses. Using Depthmap software to analyze the spatial pattern of traditional dwellings, and calculating data indicators of integration, connectivity, and integration of horizons. Through analyzing the characteristics of spatial pattern, it reflects the characteristics of moral concepts, clan concepts, and living habits in Southeast Hubei.
Computer Image Recognition Technology and Application Analysis
Authors: Yang Nan , Wang Zhiyi , Wang Shihao
Published: May 2021

In recent years, with the continuous development of science and technology, the application range of computer image processing and recognition technology, which improves image quality and plays an important role in practical application, has been gradually expanding. Based on this fact, this article first introduces computer image processing and recognition technology and analyzes its application advantages and characteristics, then analyzes and introduces its application principles and application process, and finally discusses its practical application. It can provide some help to related technicians to promote the application and innovation of computer image processing and recognition technology.
Construction Key Technology of Cast-In-Place Prestressed Box Girder for Bridge Engineering
Authors: Chen YongKang
Published: May 2021

Research topics: Based on the working platform of school-enterprise Cooperation Council, the exploration and research on the path of school-enterprise cultural inheritance and co-construction. Cast-in-place prestressed box girder construction in bridge engineering can reflect the continuous development of construction materials, box girder for higher strength concrete and steel composition, the construction process, the need to first raise the structure and apply the corresponding compressive stress, so as to make the structure work to withstand the tensile stress to be offset, to achieve the effective application of the tensile strength of steel, in this case, can promote the overall structural durability and stiffness to improve, so that the structure of the self-weight has been significantly reduced.
Numerical analysis of earth pressure of foundation pit adjacent to composite foundation
Authors: Guo Yuancheng , Gu Shaochuang , Lv Chenyu
Published: May 2021

It is necessary to consider the influence of the surcharge load of the existing building and the displacement of the retaining structure when excavating the foundation pit adjacent to the existing composite foundation. FEM analysis work were conducted with two working conditions (condition of loading and condition of translation). The distribution and diffusion mechanism of lateral earth pressure acting on the retaining structure adjacent to composite foundation was investigated. It was found that, when there is no displacement of the retaining structure, the magnitude of additional lateral earth pressure acting on retaining structure adjacent to the natural ground and the composite foundation in the shallow area is almost the same. Moreover, compared with the natural ground, the composite foundation can block the horizontal diffusion of the load, resulting in the reduction of lateral earth pressure acting on the shallow area of retaining structure adjacent to the composite foundation is larger than that of adjacent to natural ground when retaining structure translation outwards.
High-Efficiency and Energy-Saving Thermostat Combining Peltier Effect and Air Vortex Characteristics
Authors: Song Fei , Yang Chenglong , Zhou Lin
Published: May 2021

This project uses the Peltier effect to optimize the temperature control system of the thermostat, uses semiconductors to generate temperature differences, and then forms a heat pump, uses the conversion between high and low taste energy to replace the compressor for refrigeration and temperature adjustment, and at the same time uses the gas vortex characteristics to exchange gas and Adapt and improve the heat dissipation and other aspects. The incubator designed in this project is more excellent in terms of energy saving, low noise and service life, and improves the utilization of energy and resources. At the same time, the temperature control of the incubator has the advantages of stability and accuracy, which can effectively solve the problem of food and medical the deterioration and loss of supplies.
Load Prediction and Control of Capillary Ceiling Radiation Cooling Panel Air Conditioning System Based on BP Neural Network
Authors: Pi Gang , Xu Linghong , Ye Qiming , Hu Pingfang
Published: May 2021

Compared with traditional air conditioning system, capillary ceiling radiation cooling panel (CCRCP) air conditioning system has the characteristics of low energy consumption, low noise and can provide comfortable indoor thermal environment. However, there are two problems: (1) the traditional PID control has slow feedback and lag due to the non-linearity, hysteresis and many uncertain interference factors of radiation panel air conditioning system; (2) At the start-up time, the sharp drop of temperature of the capillary ceiling radiant panel surface always cause the condensation problem. The solution adopted in this paper is showed as follows: At first, CCRCP air conditioning system model is established in TRNSYS, and the BP neural network is applied to the real-time load prediction control of the model. Secondly, fresh air pre-dehumidification system is adopted in the model to ensure that the panel condensation will not occur in the start-up stage. The results show that: 1. the correlation coefficient R of BP neural network for load prediction of working day is as high as 0.97, and the MSE is only 0.00425; 2. The temperature difference between the indoor temperature that is adjusted by BP neural network load prediction and the indoor design temperature during working hours doesn’t exceed 1°C; 3. Under the most unfavorable conditions with 1 h pre-dehumidification time, when the fresh air volume of pre-dehumidification is 100m3/h, the panel condensation will be prevented in the start-up stage.
A Technology of Surface Defects for the Solar Wafer by Dual Vision
Authors: Huang Yuanmin , Yi Ming , Yang Weihang , Yang Man
Published: May 2021

For overcoming the defects of the existing method of surface defect for the solar wafer.A automatic measurement technology by dual vision is presented. Frist the principle and flow of the automatice measurement technology are introduced. Second the technique of camera calibration, technique of center extraction of edge and technique of automatic matching are researched. At the end, using the technology realized the rapid defects detection including crack, cavern, smudge and broken so on and so forth which can be concluded that the application of this technology helps to enhance the inspection efficiency.
Optimizing Scheduling Method for Distribution Network Considering Distributed Power Supply Flexibility
Authors: Xin Lv , Li Shunxin , Dong Shaoqiao , Zhao Min , Yang Min
Published: May 2021

In the construction of distribution network, low voltage distribution can ensure the stability of the whole power transmission, but it will also lead to poor operation because of the low voltage. When the operation of the operation and inspection system is unstable, the processing function of the data will decrease, and when the power problem is encountered, it will not react at the first time, so that the operation of the whole system will produce certain danger. The high permeability distributed power supply is connected to the distribution network, which exacerbates the volatility and instability of the distribution network. Therefore, it is necessary to improve the immunity of the distribution network while ensuring the function of the high permeability distributed power supply.
Research on Energy Management Strategy Based on Fuel Cell Health Status
Authors: Ren Xueshuang , Zhang Xin , Liu Dewang , Lv Qinyang
Published: May 2021

Energy management control strategy is one of the key technologies in the development of extended-range fuel cell vehicles. During the use of vehicles, fuel cell performance will decline, which limits the power output of the stack and the life of the stack. In order to control the power output of the fuel cell more reasonably, in this paper, the lumped parameter model of fuel cell is built based on Matlab/Simulink, and the vehicle model is built by AVL/Cruise simulation software. Combined with the fuel cell health state (SOH: State of Health) estimation method, the vehicle demand power and the state of charge (SOC: State of Charge) value of the power battery are used as input, and an energy management control strategy architecture based on the performance degradation of the fuel cell is designed. The simulation results show that the designed energy management can improve dynamic performance, and avoid frequent start and stop of the fuel cell, prolong the service life of the fuel cell, and further improve the economy of the vehicle.
Research on Cost Prediction of Power Transmission and Transformation Project Based on Combination Prediction Model
Authors: Ma Li , Wang Qixin , Liao Shuang , Guo Ting , Xiong Yi , Ming Yue , Zou Yuxin
Published: May 2021

Based on the project division of power transmission and transformation projects, this paper analyzes a large number of practical engineering cases, and summarizes the influencing factors of substation and overhead line project cost combined with the practical engineering experience of many experts, A number of cost control indicators are extracted, and a combination prediction model of project cost based on neural network and support vector machine is constructed. The actual project data are taken as samples for empirical research. The results show that the combination prediction model is feasible and accurate for the prediction of power transmission and transformation project cost, which provides a new idea and implementation method for the prediction of power transmission and transformation project cost.
Research on High Voltage Online Monitoring System for Dielectric Loss of Capacitive Equipment in Substation
Authors: Xu Minhu , Guo Yun , Zhang Dewen , Cao Rong , Shen Yubo , Han Siwei
Published: May 2021

The paper introduces the principle of on-line monitoring of the dielectric loss factor of capacitive equipment and the composition of the monitoring system. It explains the software-based mathematical analysis method and harmonic analysis method, and uses DSP for digital filtering. At the same time, the paper establishes an intelligent auxiliary monitoring terminal in the substation, uses the equipment ADP+ equipment protocol library to dynamically connect to various auxiliary monitoring equipment, uses signal frequency conversion sampling, alarm recording and other acquisition strategies to extract key equipment operation information, and hierarchically redundant storage data. Improve the real-time monitoring level of operating equipment and reduce the cost of operation and maintenance.
Research on the Improved Neural Network of Coal Price Forecast Based on Co-integration Theory
Authors: Gao Luhui , Wang Guoqing
Published: May 2021

China is a big coal consumer, and changes in coal prices will have a huge impact on the entire market economy system. In this paper, aiming at the prediction of coal price, the grey correlation analysis method is firstly used to describe the correlation degree between the main factors and the coal price, and the main influencing factors are sorted according to the correlation coefficient. Finally, it is determined that a coal price prediction system needs to be established on such indicators as coal reserves, raw coal production, total coal consumption, the proportion of coal in the energy mix, coal road traffic volume, coal imports, etc. Next, the quantitative indicators are combined with the economic cycle and cointegration theory to study, with the help of cointegration theory to improve the traditional neural network, so that it is more suitable for the prediction of coal prices. Finally, this paper obtains an effective coal price prediction model, which can better predict and analyze the future coal price and can play an important reference role in the formulation of government policies.
Factors Influencing Strategic Change of New Energy Enterprises: An Analysis Based on Time Perspective
Authors: Zhang Chunhong
Published: May 2021

New energy enterprises are important production and operation units engaged in the nature of new energy in the national economy. With the development of modern society, it is crucial to have a deep understanding of new energy enterprises, especially in the face of changing environment, and how to carry out strategic transformation of new energy enterprises. In a constantly changing environment, strategic change is a key issue and a central issue in the field of management and strategy. Time is the foundation of all research on strategic change, whether or not it is recognized by existing research. In this paper, the factors that influence strategic change in new energy companies are critically reviewed from a temporal perspective. Firstly, the development status of new energy enterprises is analyzed, the strategic change is defined, and then the influencing factors are obtained by integrating the relevant studies of the time dimension in the change activities. Based on the time perspective, the dynamic understanding of the strategic change process of new energy enterprises can be improved.
Influence of typical composite insulators defects on axial temperature based on simulation analysis
Authors: Luo Simin , Luan Le , Cui Yiping , Xu Shuo , Guo Qianwen , Liu Tian
Published: May 2021

In this paper, the finite element analysis software comsol is used to design two different defect models on the short-string composite insulator model, namely, the air gap defect and the mandrel-damp defect. The thermal field of composite insulators with two kinds of defects is simulated, and comparing the axial temperature gradient changes of mand-sheath interface under normal condition and under the condition of defects. The results show that local heating does not occur when the composite insulator contains an air gap defect without partial discharge.
Research and Analysis of Finite Difference Method and Least Square Method Identification Algorithm Based on CO2 Environmental Monitoring
Authors: Zhang WanJun , Zhang Feng , Zhang Jingxuan , Zhang Jingyi
Published: May 2021

According to the physical process of convection and diffusion followed by CO2 and the working principle of HVAC, a PDE model of indoor CO2 concentration is proposed according to the working conditions of indoor air flow in and out. The physical significance and selection principle of each component, initial and boundary conditions in the model are analyzed in detail. In order to prove the validity of the model, this paper, based on the different conditions of initial value and boundary value, puts forward the PDE model of indoor CO2 concentration The model is solved and simulated, and the results show that the dynamic evolution process of the model is consistent with the actual physical process; for the unknown parameters in the model, the finite difference method and the least square method are combined to realize the identification of the unknown parameters of the model, and the effectiveness of the identification method is verified by simulation.
Overview of intelligent vehicle core technology and development
Authors: Su Jintao , Lou Jianping , Jiang Xiaolu
Published: May 2021

This paper introduces the key technology progress of intelligent vehicle, and analyzes the sensing technology, recognition and decision technology of intelligent vehicle. Then the tracking technology of intelligent vehicle, vehicle attitude and path planning are reviewed. Finally, the research status of intelligent vehicle is summarized, and the research direction of intelligent vehicle in the aspect of integrated control is pointed out, which lays a theoretical foundation for the further solution of intelligent vehicle control.
Improving Thermal Comfort in Aircraft Cockpit Based on Optimization of Supply Air Grille
Authors: Hu Xianglong , Liu Yudi
Published: May 2021

Pilot’s thermal comfort and performance are directly affected by air flow field and temperature field in cockpit. A three-dimensional cockpit model of a certain civil aircraft is established, and the distribution of air velocity and temperature is obtained with the method of computational fluid dynamics (CFD). Aiming at the problems of high local air speed and uneven temperature distribution in the cockpit, two new supply air grilles are proposed. The results show that one of the grilles can obviously optimize air flow field and temperature in the cockpit and improve the thermal comfort of the pilots.
Thermal Assessment of Aircraft Fixed Leading Edge Compartment with Simulink and CFD Simulation
Authors: Hu Xianglong , Liu Yudi
Published: May 2021

Fixed leading edge is an important part of aircraft wing, and its design should consider the influence of temperature. The temperature of the fixed leading edge compartment is affected by the high temperature and high pressure gas inside the bleed air duct and the ambient temperature outside the skin. The temperature, pressure and velocity of the gas inside and outside the compartment are quite different, so it is difficult to converge by computational fluid dynamics (CFD) analysis directly. In this study, the method of combining Simulink with CFD is proposed to solve the temperature of fixed leading edge compartment in a certain civil aircraft. The calculation method is easy to converge, and the obtained temperature can be directly used in the design of fixed leading edge structures to ensure aircraft safety.
Energy Function Based Transient Stability Analysis of Power System Integrated with DFIG
Authors: Peng Kaiqin , He Anqi
Published: May 2021

The access of large-scale wind power seriously threatens the safe and stable operation of the power system. In this paper, a novel energy function based transient stability analysis approach is proposed for the power system integrated with Double Fed Induction Generator (DFIG). First, the network structure-preserving model of power system integrated with DFIG is established, where generators adopt 3th order electromechanical model, and its energy function is deduced. Next, the energy function of post-fault system is approximately calculated by trapezoidal integral path, and energy function based transient stability criteria are put forward to access the stability of the post-fault system. Finally, the New England-39 bus system integrated with DFIG is used as test system to investigate the validity of the proposed approach.
Safety Analysis of Flooding Accident in Shallow Water for Offshore Floating Nuclear Power Plant
Authors: Gong Daxin , Ye Ranling , Wangjiang E
Published: May 2021

The Offshore Floating Nuclear Plant (FNPP) integrates a nuclear reactor into a floating facility. A typical FNPP developed to supply desalinated water and electric power is analysed in this paper. Flooding accident is a postulated ship accident which should be considered in designing the FNPP in order to reduce harmful radiation impacts on the crew and environment. The integrity of the containment, the safety of spent fuel assemblies and the safety of the reactor core are the key factors to evaluate the accident consequences. Flooding accident in shallow water is investigated in this paper. For FNPP, the containment has sufficient strength to resist pressure from outside induced by seawater. Meanwhile, the seawater supplies enough heat sink for the cooling of the spent fuel assemblies. In order to investigate the safety of reactor core, a RELAP5 model with Passive residual heat removal system(PRHR) is used. The results suggest that the natural circulation in the primary system can be established and the residual heat can be carried out efficiently. The reactor core can keep safe during the flooding accident.
Design of an Intelligent Inspection Robot for Underwater Pipelines
Authors: Zhang Zhiyue
Published: May 2021

This paper will introduce the design of an intelligent inspection robot for underwater pipelines. The whole device is divided into detection module, control module, drive module and housing. Among them, the detection module is the camera and the head, the control module is mainly the Raspberry Pi motherboard, the drive module includes the battery, motor, motor driver. The device through the camera module feedback to the Raspberry Pi to make decisions, and this decision through the IO port output, and then through the motor drive module to drive the motor, the motor to make speed and direction of adjustment. This device is proposed to use stepper motor for robot movement method.
Research and analysis on the dustproof structure of low voltage switchgear
Authors: Sun Wei , Wang Bin
Published: May 2021

This study improves the dustproof effect by changing the appearance structure of the low voltage switchgear. The exterior structure of the low-voltage switchgear adopts S profile to prevent dust from entering the cabinet body and make dust proof treatment at the connection of the cabinet board parts. Through the dust experiment, compare the protective effect of low-voltage switchgear with common appearance structure, low-voltage switchgear with common appearance structure after dust-proof processing and the new type of structure. Finally, it is concluded that the low-voltage switchgear can effectively reduce the entry of dust by increasing the complexity of dust entry channels, and the S-shaped appearance structure can reduce more than half of the dust entering compared with the ordinary appearance structure.
Assessment and Analysis of the Global Development of Integrated Energy
Authors: Zhang Zhongping , Wang Jianguang , Zhou Yuhao , Wang Jing , Cao Chunlan , Li Xinxuan
Published: May 2021

With the acceleration of the transformation of global energy structure, in order to meet the demand for safer, more efficient and cleaner energy in the new era of our country, it is imperative to build a modern energy transformation and system, and integrated energy services gradually play an increasingly important role in the supply side and consumption side. Integrated energy service is a kind of energy supply and service mode to meet the diversified energy production and consumption of end customers. It focuses on the planning, design, construction, operation and service of cold, hot, electric, gas and other systems in three aspects of energy supply, energy use and service, deeply integrates the Internet of things, big data, artificial intelligence and other technologies with energy to form a dynamic level of source, network, load and storage Balanced integrated energy supply and service integration of modern energy system. Based on the analysis of the current situation of foreign and domestic integrated energy, this paper puts forward suggestions and prospects for the development of integrated energy services.
Research on Power Line Carrier Communication Based on HVDC
Authors: Chen Dong , Miao Wei , Li Long
Published: May 2021

This paper mainly studies the control of LED lamps under the condition of centralized DC power supply by power carrier mode, and modifies the mature power carrier scheme in AC system to adapt to the DC system environment and realize reliable communication in DC system. Through the analysis of system functional requirements and the comparison of existing communication technologies, the overall architecture of DC tunnel lighting system is proposed. The system adopts two-tier structure, including monitoring center, communication controller and HVDC tunnel lighting control terminal. This system realizes the master-slave monitoring of the communication controller to the control terminal of HVDC tunnel lamps, and puts forward the modification scheme to the conventional power carrier scheme, and verifies the improved power carrier scheme of DC system through the Qijiashan tunnel lighting project.
Research on Electric Vehicle Battery On-line Management System
Authors: Qi Yanxing , Yang Xueyin
Published: May 2021

This paper takes STM32 MCU as the control core to make deep research on the electric vehicle battery online management system. The internal resistance detection method and Kalman filter method are used to estimate the SOC value, and the equalization control circuit is used to make the SOC value of each single battery tend to be consistent, and the equalizing protection circuit is used to effectively protect the battery. Debugging and experimental results show that the system can accurately estimate the SOC value, solve the problem of inconsistent SOC value of each single battery, and effectively improve the efficiency of the battery.
Research on the Source of Subsidies Funds for Power Demand Response
Authors: Liu Junhui , Hua Jun , Fu Han , Li Hujun , Yang Qinchen
Published: May 2021

With the upgrading of residents’ consumption and the continuous improvement of electrification level, Henan’s power consumption has maintained rapid growth. There is a shortage of power supply under the constraints of time, structure, and environmental protection. The implementation of power demand response can smooth peak loads, promote supply and demand balance and operational efficiency. The basis for the successful implementation of power demand response is to have a stable and full source of subsidy funds. The feasibility of three subsidy sources of demand response under the current business model is discussed in order to provide useful reference for provincial power grid enterprises to organize and carry out demand response work.
Application of BIM Technology in Cost Control during the Stage of Production and Transportation of Assembly Building
Authors: Zhang Xinyu
Published: May 2021

Green building has become an important evaluation criterion for house construction. Prefabricated buildings are an effective means to achieve the goal of green building. However, the high cost during the construction process hinders the popularization and application of prefabricated buildings. Based on the current research, Building Information Modeling (BIM) Technology is an advanced technology in the construction industry, which has high efficiency in cooperation with prefabricated buildings. Based on BIM technology, it has better development in cost control of prefabricated buildings. Compared with traditional buildings, it has fast construction speed, high safety level, environmental protection, and other advantages. This paper analyzes the cost of influencing factors in the production and transportation stage, and establishes the cost management process of prefabricated buildings based on BIM technology. It analyzes the application of BIM technology from cost control, cost accounting, and cost analysis at this stage and finally verifies the feasibility of cost management based on BIM technology by taking a prefabricated building as the research object.
Research on Temperature Monitoring Method and System Design for Key High Voltage Equipment of Wind Farm
Authors: Xie Baoyu
Published: May 2021

This paper focuses on the temperature detection of high-voltage equipment in wind power plant, puts forward the surface acoustic wave measurement method, and deeply studies the design process of surface acoustic wave sensor device and the design scheme of monitoring system. In different process materials of piezoelectric substrate and antenna design mode, there will be great differences in the transmission efficiency and anti-interference ability of surface acoustic wave. Therefore, the influence of surface acoustic wave on the performance of surface acoustic wave sensor device is possible Testing and setting the surface measurement parameters can improve the measurement performance. In the aspect of detection system, the typical key temperature monitoring equipment of high voltage switch cabinet in wind farm is selected to form a practical deployment scheme, which realizes the integrated functions of automatic temperature measurement, parameter optimization and adjustment, alarm and so on. The research and design method in this paper has great practical application value in the operation and control of new energy system.
Stress-strain state of rock mass and lining when constructing underground turbine hall of hydropower plant
Authors: Abdulloev NM , Baryshnikov DV , Gakhova LN , Khmelinin AP
Published: May 2021

Numerical modeling was performed for stress-strain state of the rock mass and lining of underground turbine hall of Rogun hydropower plant. The hall is located in a rock mass at great depths. Numerical modeling was conducted using the method of boundary integral equations based on the model of linearly elastic quasi-isotropic medium. The character and features of forming inelastic deformation zones near the contour of turbine hall cross-section are found. The regularities of distribution of rock mass and lining stress-strain state are determined as well.
Investigation of hydraulic fracture growth near a mine opening
Authors: Azarov AV , Patutin AV
Published: May 2021

The behavior of a hydraulic fracture near the mine opening in a plane-parallel formulation has been investigated. The case was considered, when the rock was under hydrostatic pressure, and the initiating crack was oriented in the direction of mine opening. It is found that the fracture path is greatly influenced by the ratio of hydrostatic pressure and critical tensile stress of rock. It is shown that when the hydrostatic pressure increases with respect to critical tensile stress, the fracture begins to deviate from the mine opening earlier and does not reach its surface. It is also shown that under various conditions, fractures cannot bypass the mine opening completely due to the occurrence of severe strains in the area between the opening and fracture.
Stress-strain state of a rock mass with a fracture in opening roof
Authors: Krasnovsky AA
Published: May 2021

The influence of a fracture formed in the opening roof on stress-strain state of the rock mass is considered. The relationships determining displacement and stress components at the boundary of an opening with rectangular shape, on contact lines of the layers and on the line containing fracture are written. The examples of numerical implementation are given. The analysis of the obtained results is carried out.
Mechanical compression effect on gas filtration through the crack filled with acrylate composition
Authors: Rybalkin LA , Shilova TV
Published: May 2021

Hydraulic fracturing is a promising method used for increasing the permeability of a coal seam. Formation of an extensive network of drainage cracks contributes to increased gas recovery of coal. In this case, a negative factor is the breakthrough of cracks formed in the mine workings. In order to challenge this problem, it is proposed to screen mine workings with an additional crack filled with acrylate polymer containing solid inclusions, which prevents the closure of crack edges under the impact of rock pressure. The paper presents the results of experimental studies of acrylate screen gas permeability dependence on rock pressure.
A downhole uniaxial pressure gauge to determine elastic properties of hard rocks
Authors: Serdyukov SV , Drobchik AN
Published: May 2021

The paper presents experimental equipment meant for determination of elastic properties in hard rocks by means of creation of adjustable uniaxial pressure on open well walls perpendicular to the well axis, measurement of deformations in a wide range of loads and for automatic recording of the observed data.
Laboratory study of core samples. Porosity determination by different methods
Authors: Usoltseva OM , Serdyukov SV , Tsoi PA , Rybalkin LA , Semenov VN
Published: May 2021

This study presents the series of experiments to determine porosity of coal samples using three methods: connected porosity based on the fluid saturation method, surface porosity from the surface of polished sections under ultraviolet light using Mineral-7 analyzer; total porosity by tomographic method with the MST-05 NMR relaxometer. The porosity analysis reveals that the conventional method yields essentially lower results. Correct estimation of porosity (connected and total) requires integration of the above-listed methods, with an emphasis laid on one of them depending on further applications of these characteristics.
Laboratory modeling of deformation of specimens with discontinuity under direct shear in constant normal stiffness conditions
Authors: Usoltseva OM , Tsoi PA , Semenov V. N.
Published: May 2021

This study presents tests of specimens with discontinuity made of artificial geomaterial (concrete-sand mixture) having triangular profile of surface roughness under shear loading with the boundary “constant normal stiffness” condition, with three values of normal compressive load: 0.5, 0.9 and 1.2 MPa. The patterns of deformation were determined at each stage of loading diagrams: linear, nonlinear, peak load and residual strength. The empirical dependences of the ultimate shear stress on normal stress were constructed for different values of roughness.
Reamer design variables for curved path drilling
Authors: Cheshchin DO , Danilov BB
Published: May 2021

The paper presents the algorithm for assessment of design variables for a warm reamer in curved path drilling. The value of soil deformation by the reamer casing versus its length in the curved path drilling is determined in mathematical modeling. The formula of the maximum length of the reamer casing versus the casing diameter and the guide parameters is obtained/.
Circular models of air distribution due to piston effect in subways
Authors: Lugin IV , Kiyanitsa LA , Oshchepkov TS
Published: May 2021

Subways as places of stay of many people are imposed with higher standards of microclimate at platforms and in tunnels, including the dust criterion. To reduce dust concentrations in tunnel air to MAC values, the authors suggest installation of filters at ventilation connections nearby platforms. Aimed to find operational parameters of the filtering facilities, the authors determine the air velocities at ventilation connections. An original approach is proposed to the air distribution analysis using circular models as they considerably diminish the subway test area size without the loss of the computational accuracy and reduce the computation time.
Modernization of two-stage main fans at the end of the service life
Authors: Krasyuk AM , Lugin IV , Kosykh PV
Published: May 2021

The authors analyze air velocities in the inlet of the installation composed of two-stage axial fans (aerodynamic design OV-84 of the Central Aerohydrodynamic Institute) and in the inlet elements of the fan. It is shown that air flow is considerably nonuniform at the fan inlet, and the nonuniformity reduces in the air passage of the fan. The fan can be modernized by replacing the two-stage rotor by a high-rate single-stage rotor as per the inlet guide vanes– impeller–flow straightener design. This modification allows the required uniformity of air flow at the impeller inlet and ensures a longer service life of the rotor bearing assembly owing to considerable decrease n the weight of the rotor.
Soil improvement and mixture preparation in construction of protective cushion
Authors: Kiselev VV , Khokholov YuA
Published: May 2021

The authors discuss soil improvement and and mixture preparation for the construction of a protective cushion on the bottom of a mined-out kimberlite surface mine of ALROSA in order to extract ore reserves under the pit bottom using the mining systems with caving. The paper briefly describes overburden dumps at kimberlite surface mines, lists the main requirements for the protective cushion material, and presents the process flow chart and the machine chain for the production of the wanted mixture. The proposed technology makes it possible to prepare the mixture with the required composition and to construct the protective cushion up to enhanced safety of underground mineral mining.
Modeling separation of mineral particles in the upward flow
Authors: Matveev IA , Yakovlev BV , Eremeeva NG , Kulichkina TP
Published: May 2021

The paper presents a new tested and approved physico-mathematical model which sufficiently accurately and reliably describes the path of mineral particles in the upward flow along the inclined surface. The Mineral Dressing Laboratory at the Institute of Mining of the North has developed the separation method in the upward flow of hydraulic fluid and the high-angle concentrator design. The modeling results can be used to control separation in the working zone of the high-angle concentrator.
Study of permissible dynamic load on high-pressure gas pipe laying site in connection with blasting operations during open-pit mining
Authors: Kutuev VA , Zharikov SN
Published: May 2021

The paper presents the results of a study of permissible dynamic load on high-pressure gas pipe laying site of the II category located within the mining lease boundaries, in connection with carrying out blasting operations at the open-pit mine of JSC Sukholozhsktsement. The procedure of IM UrB RAS for calculating the permissible distances from the technological explosion in the mine to the protected object (gas pipeline) depending on the explosive weight in the stage, coefficient of soil conditions and permissible velocity of seismic vibrations is presented. It is found that depending on the explosion depth in the mine and using corresponding geological data, by changing the weight in the delay stage, it is possible to completely eliminate the negative effect of explosion on pipe laying area. A calculation scheme is also proposed to determine the safe distances to high-pressure gas pipeline depending on the angle of open pit side and blasting depth.
‘Dismay’ at global standards for school geoscience
Authors: Allen Michael
Published: May 2021

Despite growing demand for geo-scientists around the world, the attainment achieved in school-level earth-science education is bleak.
MIT scientist backed over China links
Authors: Gwynne Peter
Published: May 2021

More than 200 researchers at the Massachusetts Institute of Technology (MIT) have signed a letter supporting nanotechnologist Gang Chen, who was arrested and indicted in January on charges related to his links with research institutions funded by the Chinese government.
Supporting science in difficult times
Authors: Duffy Caitlin
Published: May 2021

With COVID-19 fostering anti-science conspiracies, Caitlin Duffy says that scientists have a duty to speak up and challenge misinformation
Grounds for optimism
Authors: McKenzie James
Published: May 2021

The solution to climate change could be lying beneath our feet. James McKenzie examines the potential of pumps that warm our homes and offices by extracting heat from the ground below
Digging up magnetic clues
Authors: Brazil Rachel
Published: May 2021

Analysing magnetic information stored in ancient artefacts is revealing the recent history of the Earth’s magnetic field and providing clues to the changes we might expect in the future. Rachel Brazil explains