bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on application of real-time database for air quality automatic monitoring system
Authors: Sun Peiwen , Liu Wenfeng , Xu Yijin , Wang Lingyun 
Published: March 2021

Abstract
With the increase of city air monitoring sites and monitoring project, monitoring instruments and monitoring data are increasing rapidly. When using the traditional relational database in processing huge real-time data, the throughput and timeliness of monitoring system has been unable to meet the needs of the business. In order to solve this problem, this paper introduces the real-time database into the air quality automatic monitoring system. According to the design principles, the paper outlines the four aspects of the design: the composition of the system, the overall structure of the system, the data flow and the network topology. Aim at assembling the embedded system architecture, distributed system, database technology, network browser/server computing mode, client/server network computing technology, and large-scale computer application system of virtual private network connection based on public network. In the specific design, this paper design substation and central station architecture based on the real-time databases and complete the function of field data collection and storage, equipment control, data transmission, human-computer interaction, data exchange interface with third party system and other function. Finally, according to the observation results of the city air quality automatic monitoring system, the project realizes the functions of the system and improve the real-time quality of environmental air monitoring and the capacity of instrument supervision.
Application of diffusive gradients in thin-films in sediments and soils
Authors: Weng Hongsheng , Hei Liang , Huang Xu , Cai Mingxuan 
Published: March 2021

Abstract
Diffusive gradients in thin-films (DGT) is an in situ passive sampling technique that can measure heavy metals, nutrients and organics in the environment. It has the advantages of species selectivity, high resolution and getting the average concentration during the monitoring period, and it has been widely used in sediments and soils. This paper introduced the device and principle of DGT, and reviewed the application progress of DGT in sediments and soils. It was suggested that DGT was an efficient and available method for the in situ high resolution measurement and prediction of the bioavailability of heavy metals. Finally, the future development of the DGT was prospected.
Carbon emission evaluation of heavy equipment on dam construction site using discrete event simulation
Authors: Liu Chunna , Wu Qiong , Tang Wenzhe , Liu Yi 
Published: March 2021

Abstract
The construction industry is considered to be one of the largest contributors to greenhouse gas (GHG) emissions globally, accounting for around one-third of the total in world. Carbon emissions generated from heavy equipment on dam construction site are normally estimated without distinguishing the working modes, which may not represent on-site situations. Thus, this paper aims to evaluate carbon emissions of heavy equipment on dam construction sites, by establishing a methodology and applying the Discrete Event Simulation (DES) model. The case study demonstrates that DES model is validated to simulate the working models accurately, and the idling time of heavy equipment can influence carbon emissions a lot. It is suggested that dam project stakeholders should develop appropriate equipment management plans by using DES and improve the working efficiency, realizing the carbon reduction.
Research on power-communication coordination recovery strategy based on grid dividing after extreme disasters
Authors: Lu Jianqiang , Xie Xiangpeng , Zhou Xia , Bu Chengjie 
Published: March 2021

Abstract
Extreme natural disasters will cause great damage to the power and communication systems of the distribution network. During the restoration process of the distribution network, the power and communication systems interact and restrict each other. The coordination of the two can make the distribution network restore effectively and quickly. To improve the recovery speed and efficiency of the distribution network after disasters, power-communication coordination recovery strategies based on gridding method after disasters are proposed. Firstly, according to the corresponding relationship between mobile base stations and power nodes, multi-level grids of distribution networks are divided, and power-communication coordinated recovery models of distribution networks are respectively established aiming at short rush repair time and small power outage loss. On this basis, a coordinated recovery strategy of power-communication is proposed in combination with the gridding method. Finally, the IEEE33-node distribution network system is taken as an example to verify the necessity of the gridding method and coordinated power-communication recovery and the effectiveness of the proposed method.
A bibliometric analysis of measures for controlling slope and watershed erosion from 2010 to 2019
Authors: Gu Yanping , Lu Fangchun , Zhang Jinjuan 
Published: March 2021

Abstract

The bibliometric method is a scientific method that uses mathematical and statistical methods to quantitatively analyze all knowledge carriers, which can effectively grasp the subject knowledge context. Controlling slope and watershed erosion has received wide attention from scholars from various countries. So the bibliometric method was employed to evaluate the global scientific production of measures for controlling slope and watershed erosion from 2010 to 2019 and sought the characteristics of publication outputs and tendencies from the articles. The basic data were obtained from the Science Citation Index Expanded from the Web of Science. The several aspects were analysed including document language, annual outputs and distribution of journals, subject, authors, highly cited papers as well as frequency of author keywords. The results showed that annual output of the related scientific articles kept a steady rise from 2013 to 2019. Chinese Academy of Sciences, Northwest A&F University and Ministry Water Resources were mainly research institutes, which have published a lot of articles. In addition, Jean Poesen, from University of Mekelle, was the most productive author who has published 28 articles in the field of controlling slope and watershed erosion. The keywords of articles on controlling slope and watershed erosion were also analysed by using scientometric indexes. By analysing frequency of keywords in 10 periods, the current research emphases were discovered. The result showed that “Soil erosion”, “Runoff” and “Erosion” are the top 3 author keywords in this field. And the “soil-erosion” always was the top 1 keywords in the research of watershed erosion. Through analysis of the keywords, it can be known that soil erosion in the plains, simulation of erosion, and the impact of climate change on erosion are research hotspots.
Effects of coastal reclamation on the storm surge in the Bohai Bay
Authors: Yue Xinyang , Li Cheng , Miao Qingsheng , Yang Jinkun , Dong Mingmei , Yang Yang 
Published: March 2021

Abstract
In recent years, the Bohai Bay has experienced frequent reclamation activities and significant changes in the coastline with the rapid development of economy. Coastline changes will influence the propagation of tide and ocean waves, and the storm surges may get worse as well. Based on the ADCIRC storm surge model, an unstructured triangular grid model driven by tide and wind was established to simulate the storm surge in Bohai Sea. The numerical simulation of hydrodynamic environment during typhoon NO.9711 under four coastline scenarios which are 1980, 2004, 2008 and 2015 had been carried out to investigate how coastal reclamation affects storm surges. The results reveal that the storm surge level and hazard risk in the reclamation areas has increased along with the changes of the coastline.
Design and implementation of air pollution management system and an application case in Beijing
Authors: Huang Songbo , Chang Zhanqiang , Wang Yanqiao , Zhang Yanxin , Yang Qing 
Published: March 2021

Abstract
In recent years, the air pollution in China is becoming more and more serious, especially in Beijing. In this paper, an air pollution information management system was established by using ComGIS component of ArcEngine and Visual C# .NET platform and SQL Server technology. The system consists of three modules, including basic function, spatial analysis and early warning. It can monitor air pollution from different angles. In order to realize the simulation of pollution diffuse and the visual management of air pollution, we developed this system to monitor and analyse the air pollution situation in Beijing in quasi real time. Air pollution concentration data recorded by the monitoring station in Beijing on May 23, 2015 was obtained. The results showed that the severe atmospheric pollution in Beijing was mainly distributed in Chaoyang, Xicheng, Dongcheng and Fengtai districts. The area with severe PM2.5 exceeding the standard was located near the Monitoring station of Yizhuang Development. However, it indicated that the severely polluted areas extended from Daxing and Tongzhou districts to Xicheng, Dongcheng and Chaoyang districts when simulating the diffusion of PM2.5 pollutants by adding wind power and wind direction data on the same day.
Precipitation forecast over China for different thresholds using the multimodel bias-removed ensemble mean
Authors: Lv Yang , Zhi Xiefei , Zhu Shoupeng 
Published: March 2021

Abstract
Based on the daily accumulated precipitation data obtained from the ensemble forecasts by three meteorological agencies and the CMORPH observational data, the experiments of bias-removed ensemble mean (BREM) towards classified samples of different precipitation thresholds are carried out with results as follows: (1) The Classified BREM (CBREM) is characterized by higher skill in precipitation forecast in contrast to BREM. Most visible improvements can be observed for light precipitation, but there is a negative impact for a moderate threshold. (2) The CBREM after choosing optimal grading thresholds for each grid point further improves forecast skill of precipitation, which shows greatest advancement for moderate precipitation with the threat score improving percentage of over 20% on average.
Effect of Mg content on microstructure and properties of Zn-Al-Cu Alloy
Authors: Wang Hongxing , Wu Canhui , Zhang Yan , Zhan Henghui , Li Yu , Lu Qianyi , Xu Yajun 
Published: March 2021

Abstract
Zn-Cu-Al-xMg (x=0,0.25,0.5) zinc alloy was prepared by metal mould casting. The effects of Mg addition on the structure, electrical conductivity and mechanical properties of Zn-Al-Cu alloy were studied. The results show that without Mg addition, the alloy consists of Zn solid solution(ƞ phase) containing of Cu and Al and layered α+η eutectic structure. With the addition of Mg, the η phase grains were refined, the layered eutectic structure disappeared, and the intermetallic compound Mg2Zn11 appeared, and its content increased with the increase of Mg content. The hardness of the alloy increases with the increase of Mg content. When the content of Mg is 0.5wt.%, the hardness reaches the maximum value of 151HV. Tensile strength and electrical conductivity first increase and then decrease. When the addition of Mg is 0.25wt.%, the maximum tensile strength and electrical conductivity are 270 MPa and 26.4% IACS, respectively. The wear mechanism of zinc alloy is a mixture of adhesive wear and abrasive wear, and the adhesive wear is dominant.
Correlation between the distribution of solar energy resources and the cloud cover in Xinjiang
Authors: Wan Xiaozhong , Qin Fang , Cui Fang , Chen Weidong , Ding Huang , Li Chaohui 
Published: March 2021

Abstract
In order to study the influence of cloud cover on solar energy resources, it provides scientific basis for the development and utilization of solar radiation resources. Based on the Cloud and the Earth’s Radiant Energy System (CERES) and European Centre for Medium-Range Weather Forecasts (ECWMF) data from 2014-2018, the correlation between the temporal and spatial distribution of solar energy resources and the cloud cover in Xinjiang was studied and analyzed. The results show that solar energy resources have generally shown an upward trend in the past five years, with an average annual radiation of 7206.5 MJ/m2 and very stable. The overall distribution of solar radiation is mainly dominated by latitude, decreasing from south to north, and the change is relatively uniform. The maximum value of annual total radiation in the southern area of Xinjiang is about 9000 MJ/m2, which is 1.5 times of that in the northern area. The maximum daily total radiation is 28.88 MJ/m2 in July, which is 3.3 times of that in December. The total radiation in summer can reach up to 2200 MJ/m2, which is 2.2 times of that in winter. Summer radiation is high but fluctuating, and winter radiation is small but relatively stable. The autumn is the period with the least amount of total cloud during the year, the cloud cover in the northern area is about 40%, and the winter in the northern area is the highest along the foothills of the Tianshan Mountain, up to 70%. The fitting effect of radiation attenuation and cloud cover in the northern area is higher than that in the southern area, and the maximum correlation coefficient is 0.98 in summer and the minimum is 0.571 in winter. The fitting effect of radiation attenuation and cloud cover in the northern area is higher than that in the southern area, and the maximum correlation coefficient is 0.98 in summer and the minimum is 0.571 in winter. The solar radiation is mainly affected by clouds in summer, while in winter, there are other factors such as aerosols.
Effects of electromagnetic interference and crevice on corrosion of natural gas pipelines
Authors: Luo Yanlong , Lin Nan , Zhou Shaokun , Li Shili , Wang Haitao 
Published: March 2021

Abstract
Pipeline transportation is the main method of natural gas transportation. The intrinsic safety of natural gas pipelines has always been the focus of attention. During the transportation process, pipelines are affected by many factors. Existing studies have little research on the destruction of natural gas pipelines under the coupling of high-voltage transmission lines with electromagnetic interference and crevice corrosion. However, in actual inspections, it was found that this working condition caused very serious damage to the natural gas pipelines. Therefore, studying the corrosion law of natural gas pipelines under the coupling effect of electromagnetic interference and crevice corrosion can provide a theoretical basis for the safety management of natural gas pipelines. In this paper, through the electromagnetic interference simulation and corrosion test, the corrosion rate of natural gas pipelines under general corrosion, crevice corrosion and coupling of crevice corrosion and electromagnetic interference were analyzed.
Thermal performance of naturally stratified water storage tank in a power plant: a comparative study
Authors: Han Yuchen , Bai Ning , Wang Han , Li Jinghao , Zhang Jinyi 
Published: March 2021

Abstract
Thermal storage is one of the key technology in the transformation of thermal power flexibility. A model of naturally stratified water storage tank is established, and CFD analysis of heat release process is made. As can be seen from experimental results in a power plant, in the thermocline thickness in the tank increased from 0.43 m to 0.66 m, with an average hourly thickness of 0.06m, which has well agreement with the CFD analysis results. The effective height of the tank is 29.836m, from which we can calculate that its thermal storage efficiency is as high as 96.7%.
Impact of DG on short circuit current detected by protection
Authors: Gong Jing 
Published: March 2021

Abstract
DG (distributed generation) access causes the change of current detected by the protection, and then affects the sensitivity of the original protection. In order to solve the problem, the influences of DG capacity, DG access location and short-circuit location on short circuit current are analysed in this paper. When the DG capacity and grid-connected position remain unchanged, the unit current method is used to solve the short-circuit current by solving the transfer impedance. The relationship between the change of short circuit position and the impact degree of DG is discussed in detail, and the calculation formula of extreme point is derived. When the DG capacity and short circuit location remain unchanged, the impact of DG grid-connected position on the upstream and downstream current is analysed. The characteristic curve of the impact of DG position change on protection current detection is given, and the impact of DG grid-connected position on protection sensitivity is explained clearly. The conclusion provides an important reference for the selection of DG grid-connected position and the calculation of relay protection in distribution network with DG.
Analysis and design of energy storage capacity of AC-DC hybrid power distribution unit with energy storage to improve the reliability of power grid
Authors: Zhao Haibo , Zhang Zhi , Hu Ende , Li Qi , Zhao Guopeng , Zhang Youbo , Wang Dong 
Published: March 2021

Abstract
Based on the development of AC-DC distribution network, a new AC-DC distribution device with energy storage structure is designed in this paper. This paper first analyzes the existing AC-DC power distribution equipment and network reliability assessment methods. On this basis, the design is put forward, the energy storage link is placed at the DC high voltage side. The constraints of energy storage as an critical load backup power supply are defined and the mathematical model is established. In this paper the timing Monte Carlo method is used to calculate the reliability of the device and the power grid. The model in this paper can be applied to a variety of distribution network structure and energy storage scenarios, with high accuracy. It is concluded that the AC-DC distribution unit has remarkable effect in improving reliability.
Power flow calculation of AC / DC hybrid distribution network considering energy router
Authors: Rong Xiuting , Zhang Hui , Jia Chenyiyang , Zhao Jie , Ma Gaoyuan , He Yuqin 
Published: March 2021

Abstract
Energy router (ER) is the key equipment in the construction of AC / DC hybrid distribution network in the future. Based on the characteristics of AC and DC ports and topological structure of ER, a steady-state model of ER with multi ports access was established, and a power flow model of AC / DC hybrid distribution network considering ER was constructed. Newton Raphson method combined with alternating iteration method was used to solve the problem. IEEE-33 was selected to calculate and compare the circular distribution network considering ER and the traditional AC distribution network. The results show that ER can improve the voltage level of nodes and reduce network loss in hybrid distribution network.
The application of ultrasonic phased array technology in wind turbine blade defect detection system
Authors: Zhang Ningning , Bian Wentong , Pan Binbin 
Published: March 2021

Abstract
Start The working environment of wind turbines is complex and harsh. If the early damage of blades is not found in time, it may develop into mechanical failure under bad working conditions. Once an accident occurs, the consequences will be serious. In this paper, we study the non-destructive testing of ultrasonic phased array technique in the application of wind turbine blade defect detection, and analysis all kinds of common defects of blade production stage. According to these defects, the corresponding test device is selected, and the fault library is accumulated through defect test blocks. The original data of blade ultrasonic detection were identified, compared and finally the defect type was determined.
Optimal power and energy sizing of compressed air energy storage in distribution network using multiparametric programming
Authors: Chen Fan , Guo Zhongjie , Lin Qiyou , Xue Xiaodai , Xie Yuguang , Mei Shengwei 
Published: March 2021

Abstract
As a new type of mechanical energy storage, compressed air energy storage (CAES) has attracted wide attention in recent years. This paper studies the optimal sizing problem of CAES in power distribution network (PDN). CAES plays a role in shaving the peak and filling the valley at demand side and thus reduces the operation cost of PDN to purchase electricity from the main grid. A multi-parametric linear programming (MP-LP) model is formulated where the power and energy capacities of CAES are regarded as parameters; the parameterized optimal value function (OVF) provides a graphical tool to describe the impact on operation cost of CAES configuration, which helps determine the planning strategy in a visual manner. The visualized results reveal not only the optimal solution, but also some useful information, like the sensitivity of operation cost to parameters. Case studies conducted on the IEEE 33-bus distribution system verifies the effectiveness of the proposed method.
Phase delay solution based on instantaneous reactive power theory
Authors: Zhao Mengzhen , Zhang Jie , Zhang Xin , Zhou Wandong , Xu Anfei 
Published: March 2021

Abstract
According to the theoretical detection method of instantaneous reactive power, the paper proposes a harmonic current detection method based on the combination of synchronous rotating coordinate system and PI control. This method adds PI adjustment after the filtering link to accurately track the current amplitude, realizes zero error control, and performs phase compensation on the rotating coordinate system to compensate the fixed phase delay time of the filter, so as to achieve the accuracy of the harmonic detection link. The analysis of the experimental results shows that the improved harmonic detection method is equally effective under the three-phase symmetrical load and three-phase asymmetrical load. Under three-phase symmetrical load conditions, the improved harmonic detection method reduces the THD of the grid current by 0.72% compared with the original method. Under three-phase asymmetrical load conditions, the improved method reduces the THD of the grid current by 0.11% compared to the original method.
Research on the hybrid energy system of electric vehicle
Authors: Zhou Shiqiong , Sun Jing , Kang Longyun 
Published: March 2021

Abstract
In order to solve the negative problems of environment and energy caused by fuel vehicles, the application of new energy sources in the field of automobiles has gradually become the focus of attention. A hybrid energy system of electric vehicle was studied, which is composed of ultracapacitors(UCs), solar panel (namely PV) and lead-acid battery set. Through the research, it was found that the maximum power tracker can track the maximum power point of the solar panel, and the ultracapacitors with high power density and the battery with high energy density can be complementary by each other, shorten the discharge time of high current and improve the dynamic performance of the vehicle.
The impact of load transfer on transmission and distribution costs
Authors: Gan Zishen , Jing Zhaoxia 
Published: March 2021

Abstract
This article analyses the impact of the load transfer on the transmission and distribution costs from the N-1 security check of the distribution network and the total supply capacity, and proposes a capacity expansion planning model for the distribution network to obtain the best investment time for the generator, and then further studys the impact on the cost of transmission and distribution after the expansion of the distribution network.