bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of THz-TDS Technology in on-line detection of vacuum degree of arc extinguishing chamber
Authors: Yang Yongxu , Dong Jinxiang , Yue Feng , Zhang Kun , Li Wei
Published: March 2021

Terahertz time-domain spectroscopy (THz-TDS) is a non-destructive detection technology for carrying information inside a sample through a wide-band terahertz pulse carrying medium information. This paper briefly describes the imaging principle, characteristics, development and application direction of THz-TDS technology. The theoretical basis of THz-TDS technology applied in vacuum degree on-line monitoring is analyzed and verified by experiments. The experimental results show that with the change of vacuum degree, the signal amplitude attenuation and time delay of THz spectrum will change regularly. It shows that the spectrum and absorption spectrum obtained by THz-TDS imaging technology can sensitively distinguish the change of pressure in vacuum environment, that is, the change of vacuum degree. At the same time, the related air environmental pollution information also has strong absorption characteristics in the terahertz band, which makes the use of terahertz spectroscopy technology to detect pollutants in the atmosphere have a good development prospect.
Effect of exogenous Selenium on the growth and Selenium accumulation of Talinum paniculatum (Jacq.) Gaertn
Authors: xia Tianqi , Peng Sihan , Ma Yaoqing , Zhong Yufeng , He Zhongqun
Published: March 2021

In this study, we added different Selenium (Se) concentrations (0 mg⋅kg−1, 2.5 mg⋅kg−1, 5.0 mg⋅kg−1, 10.0 mg⋅kg−1, 20.0 mg⋅kg−1) into soil to study the effect of Se on the growth, quality and Se content of Talinum paniculatum (Jacq.) Gaertn. The results show that different Se concentration has significant different influence on the growth of T. paniculatum. Low Se concentration can promote the growth of T. paniculatum, but high Se concentration would inhibit the growth of T. paniculatum. The chlorophyll content of T. paniculatum increased with the increase of Se concentration, which was beneficial to the photosynthesis of T. paniculatum. The Se content of T. paniculatum increased gradually with the increase of Se concentration, and the rule of Se content of T. paniculatum was root > leaf > stem. Taken together, the optimum concentration of Se in the soil of T. paniculatum cultivation was about 5.0∼10.0 mg⋅kg−1.
Research on Residual Strength Prediction Model of Corroded Pipeline Based on Improved PSO-BP
Authors: Tingke Li , Yuanchun Peng , Jiadi Li , Dulin  , Xingqin Lian
Published: March 2021

In this paper, an improved particle swarm optimization (PSO) BP neural network model is proposed. For standard particle swarm optimization algorithm (PSO) is the "premature" and lack of diversity in the late, this paper puts forward an improved particle swarm optimization algorithm (IPSO), using the improved particle swarm optimization algorithm to optimize the BP neural network, which improves the learning ability of the BP neural network and accelerates its convergence speed. The IPSO-BPNN prediction model was constructed by using the BP neural network optimized by improved particle swarm optimization, and was applied to the prediction of residual strength of corroded pipeline. The experiment was carried out by the real pipeline test blasting data set. The results show that the prediction accuracy of IPSO-BPNN is better than that of BPNN and PSO-BPNN.
Immobilization of soil Cd (II) by modified biochars
Authors: Li Ming , Fan Tingting , Huang Jianbo , Liu Qi , Ding Yifei , Zhang Han , Feng Zhiwang
Published: March 2021

Adsorption kinetics and isotherms of Cd2+ onto different types of biochar are studied in batch experiments. Three types of biochar (rice, wheat and corn straw biochar) and their phosphate or chitosan modified materials were used in this study. Results showed that Langmuir equation can better describe the adsorption isotherms of Cd2+ onto these biochars (r2 > 0.960). Among different types of biochars, rice straw biochar (RB) and its chitosan modified biochar (CRB) had highest adsorption capacity of Cd2+. RB, wheat straw biochar (WB) and their modified biochars were used to remediate Cd-contaminated soil. Soil pH values increased with the increasing of biochar dosage and chitosan modified biochar amended soil had the highest soil pH values. Contents of DTPA extractable Cd in soil decreased with the increase of biochar dosage and incubation time. Among different types of biochars, 5% CRB amended soil at 60 days of incubation had the lowest content of DTPA extractable Cd. This study showed that the application of modified biochars can effectively alleviate soil Cd contamination.
A review of bioremediation techniques for heavy metals pollution in soil
Authors: Jin Tuo , Shi Chenning , Wang Ping , Liu Jinpeng , Zhan Liuyang
Published: March 2021

Heavy metals polluted soil caused by sewage irrigation, industrial pollution, pesticides and fertilizers, and atmospheric deposition have a harmful effect on the environment, which is difficult to completely eliminate and will threaten the ecological environment, food safety, and human health. The treatment of soil heavy metals and soil safe utilization have become the top priority of the treatment of industrial land and farmland soil. The existing main methods of soil heavy metals remediation include physical remediation, chemical remediation and biological remediation. With changes in governance scenarios and technological innovations, the joint application of interdisciplinary technologies has become an important development direction for soil heavy metals remediation. Especially in the treatment of heavy metals polluted farmland, the combined use of multiple technologies can further improve the safe utilization of farmland. In this paper, the main bioremediation techniques of heavy metals were summarized based on the domestic and foreign literatures in order to provide reference for further research in this field.
The influence of population agglomeration on air pollution: An empirical study based on the mediating effect model
Authors: Yang Bin , Ding Lijin , Tian Yihao
Published: March 2021

With rapid urbanization and industrialization, the population of metropolis in China is increasing. Previous studies suggest that population agglomeration would have a significant impact on air pollution in cities. Using a panel dataset of 30 provincial capital cities during 2013-2017, as well as days of air quality equal to or above Grade II as air pollution indicators, the results show that an increase of population density will improve air quality in large cities. Through the mediation effect test, this paper found that tertiary industry is the mediation channel of population agglomeration to reduce air pollution. An increase of population density in big cities is conductive to increasing the proportion of tertiary industry, thereby reducing the proportion of seriously polluting secondary industry, and reducing air pollution.
Study on Temporal and Spatial Distribution of Biogenic Elements of Sediment in Baiyangdian Lake
Authors: Zhen Han , Xiaobo Liu , Shiyan Wang , Pengfei Yu
Published: March 2021

Baiyangdian Lake is the largest macrophyte-dominated shallow lake in North China and the most important ecological barrier area in the Xiong’an New Area. Since the 1980s, the surface water of Baiyangdian Lake has been in a state of eutrophication for a long time due to high nitrogen and phosphorus content. Under the background of the gradual implementation of the New Area Planning Outline, the load of nitrogen and phosphorus from exogenous sources into the lake has been gradually controlled, and the nitrogen and phosphorus enriched in the sediment has increasingly become the main factor affecting water quality. Therefore, this study focused on the vertical and lateral distribution differences of total organic carbon, total nitrogen and total phosphorus contents in Baiyangdian Lake sediments. Meanwhile, combined with sedimentary years, the enrichment characteristics of nitrogen and phosphorus in different ages and their consistency with the change of total organic carbon content were analyzed. The study can provide some scientific reference for controlling the accumulation of nitrogen and phosphorus in Baiyangdian sediment and scientifically and orderly dredging.
Classification and prediction of wear state based on unsupervised learning of online monitoring data of lubricating oil
Authors: Su Yongsheng , Li Dayang , Wang Heng , He Chen , Yang Kun
Published: March 2021

With the development of the times, the demand for high efficiency and reliability of machine performance in China’s industry has become higher than ever before, and the traditional equipment condition evaluation method has also encountered a huge challenge. As an important branch of machine learning, cluster analysis is widely used in fault diagnosis and other fields because of its advantages of no prior knowledge and massive data processing. This paper introduces the concept of principal component analysis and K-means method based on time series in the field of oil data analysis. Through the test data on the oil monitoring data of the steam turbine unit in the power plant, the condition evaluation and classification of the equipment are carried out, among which the classification effect of 6μm particles, dielectric constant and 4μm particles is very obvious, and the water content is relatively obvious, which can basically distinguish each state. At the same time, on the basis of feature extraction, use the special cyclic neural network (RNN) in deep learning-long and short-term memory network (LSTM) to build a model of data for data prediction, under the powerful ability of LSTM to process temporal data, they have unearthed more irregular and non-linear trends in a large amount of historical data, and achieved better prediction results than traditional methods (ARIMA). Through clustering and prediction of lubrication parameter data, it can realize early warning and abnormal diagnosis of lubrication status and reduce damage to machinery and equipment.
Research on the Impact of Policy Transmission on Pollution Control of Livestock Breeding
Authors: Yu Wensong , Cai Xiaoshen , Wang Shujun
Published: March 2021

Scientific policy transmission is the key for local governments to effectively control pollution from livestock breeding. This study collects the livestock manure treatment policy texts and livestock feeding data of 70 local governments, and uses data mining and related analysis methods to analyze the relationships between actions, actors and the effect of livestock breeding pollution control in local government policies. The results show that: the better the transmission of actions and the greater the number of actors involved in transmission of actions, the better effect of livestock breeding pollution control. It is necessary to strengthen collaboration with Department of Natural Resources in building a cycle of planting and breeding development mechanism as well as acceleration of the transformation and upgrading of animal husbandry. Meanwhile, the collaboration with Department of Science and Technology should be enhanced in strengthening fiscal and taxation policy support, and coordinating the solution of land and electricity use problems.
Dynamic Migration theory, put forward by Dongfang Yang, of Cd content in Jiaozhou Bay
Authors: Yang Dongfang , Li Haixia , Zhang Longlei , Wang Qi , Ling Weifeng
Published: March 2021

Based on the horizontal and vertical matter content changing models proposed by the author himself, this article calculates the horizontal loss amount, vertical disputed amount and vertical sediment amount, and determines the block diagram of horizontal and vertical Cd content changing model, applying the investigation matters about the Cd content of Jiaozhou Bay in May, August, and October, 1992. According to the calculation results of horizontal loss amount and horizontal increase amount of Cd content in the bottom layer and the vertical disputed amount and vertical sediment amount of Cd content in the surface and bottom layer, the author proposes the dynamic migration process of Cd content in Jiaozhou Bay, pinpoint the migration direction and route of Cd content from southeast waters to the center waters of the bay in May, August and October: sources→surface layer of southeast water→bottom layer of southeast water→bottom layer of center water→surface layer of center water, and get the dynamic changing process of absolute and relative migration amount of Cd content.
Evaluation of chloride diffusion in concrete using PSO-BP and BP neural network
Authors: Yao Ling , Ren Lixia , Gong Guoli
Published: March 2021

Chloride diffusion is the major causes of deterioration of concrete structures in engineering. Because chloride diffusion experiments are time consuming, it is desired to develop a model to predict the chloride diffusion in concrete. In this paper, the optimizing of particle swarm algorithm (PSO) on BP neural network is adopted to predict the chloride penetration in concrete. For purpose of building these models, training and testing pattern is gathered from the technical literature. PSO-BP neural network can improve BP disadvantage. PSO-BP neural network is better precision than BP neural network through the results of PSO-BP, BP and experiments. The research results demonstrate that PSO-BP neural network is an effective tool in the prediction of chloride diffusion.
Study on Soil Moisture Temporal-Spatial Variation and Stability in Loess Plateau of China
Authors: Wang Yanpeng , Zhou Ying , Liu Xueyong
Published: March 2021

Soil moisture temporal-spatial distribution and stability are important factors influencing soil pollutant transport, material migration, regional climate change, hydro-ecological environment as well as agricultural production patterns. According to soil moisture distribution features on the loess plateau, the paper selected three different kinds of surface slopes on the typical experiment sites to carry out soil moisture measurement. The variation coefficient and rank correlation method are proposed to calculate the longitudinal and vertical soil moisture distribution characteristics. The temporal-spatial dynamic features of soil moisture are studied. The present findings show that the soil moisture in the Loess Plateau varies greatly at different soil depths during the period from April to June. The maximum soil moisture appears at the depth of 40-60 cm. The variation coefficient of soil moisture increases with the soil depth. It was discovered that there exists temporal stability at the depth of 20-80cm. The correlation coefficient of soil moisture in different slopes is significant during the period of April-June. The results would play an important support in theoretical research and ecological environment planning, optimization of agricultural planting pattern and comprehensive management of Loess Plateau.
Preparation of nanoscale zero-valent iron and its application in coking wastewater treatment
Authors: Wu Shihong , Yu Le , Li Meiling
Published: March 2021

Nanoscale zero-valent iron (NZVI) was prepared by liquid phase chemical reduction method. The nanoparticles were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The effect of prepared three nanoscale materials was evaluated by degrading coking wastewater. Optimal experiments involved the effects of water sample initial pH and Fe/C of NZVI on COD removal efficiencies were also investigated. It indicated that NZVI showed more excellent COD removal efficiencies. Under the optimal condition of dosage 1 g in 300 mL wastewater, Fe/C 1:1, pH 4, 120-min reaction time, the COD removal rate by NZVI could reach 67%.
Research on Human Reliability Model of a Reservoir Dam
Authors: Dandan Li , Ji Wang , Huiwen Wang
Published: March 2021

The safety of reservoirs has a great impact on the social and economic life of the country, and human factors in modern life occupy an increasingly important position. This paper uses the prediction technology of human error probability, establishes the reliability model of human factor cognition based on Bayesian network, quantifies the influencing factors of human factor, and actually uses the calculation in a certain reservoir dam.
Preparation of Autoclaved Aerated Concrete from Construction Waste
Authors: Xia Jiageng , Chen Yongliang , Chen Junbao , Li Aojun , Chen Tiejun
Published: March 2021

This research focuses on the preparation of autoclaved aerated concrete (AAC) with construction waste as the main raw materials. The properties of dry density and compressive strength of AAC were tested to determine the optimum mix proportion of raw materials and the construction waste fineness. The results indicated that the optimum mix proportion of raw materials was consist of 55-65% construction waste, 15-21% cement and 18-22% quicklime, together with 2% gypsum and 0.1% aluminum powder, the construction waste was mechanically milled for 20 min, and cured in the conditions of autoclave pressure 1.5 MPa for 6 h, the compressive strength of AAC samples were higher than 5.0 MPa, and dry density value could reach 650-700 Kg/m3, which meet the requirements of A5.0 B07 grade in the Autoclaved aerated concrete blocks (GB11968-2006). The analysis of microstructure and phase compositions of the AAC samples showed that the tobermorite, calcite and CSH were formed in the process of autoclave curing, and CSH gels were combined through the skeletons formed by tobermorite crystals, the interconnected and porous microstructure contributed to the good properties of low density and high strength of AAC.
Uptake of polystyrene microplastics by marine rotifers under different experimental conditions
Authors: Lan Ruyi , Wei Yongpeng , Xue Runze
Published: March 2021

Marine microplastic pollution has become one of the global problems due to the adverse effects of microplastics on marine organisms. This study investigated the uptake of (Polystyrene, PS) microplastics by marine rotifers (Brachionus plicatilis) under different microplastic concentration, exposure time and type of containers. The results showed that the ingestion of microplastics by rotifers was positively correlated with microplastic concentration. The intake reached maximum (65±5 particles/individuals, 5 mg/L; 28±11 particles/individuals, 3 mg/L) at 24 h, and then decreased over time. Moreover, the intake of microplastics in the plastic well plates was much lower than that in the glass vial. This study demonstrated that the intake of microplastics by rotifers varied with microplastics concentration and exposure time. More importantly, microplastics-related experiments using plastic containers could influence the uptake results. This work provides useful information on the interaction of microplastics with marine organisms.
Preparation of orange peel loaded Zn/Al-HT and its adsorption for Cr(VI) in water
Authors: Zhang Chao , Zhou Xi , Gao Feng
Published: March 2021

The orange peel loaded Zn/Al Hydrotalcite (Zn/Al-HT) was prepared by coprecipitation method. The effects of calcination temperatures, initial concentrations and pH on the adsorption properties of Cr(VI) were investigated, and the results showed that the calcined orange peel loaded Zn/Al-HT at 300°C(Mod2-LDO-300) had best removal rate of Cr(VI), it can be 96%, and the adsorption capacity is 38.5-106.2mg/g in the range of Cr (VI) initial concentration of 20-80mg/L. The Mod2-LDO-300 has a good adsorption effect at pH 2-8. It is a kind of environmental protection and industrial adsorption material.
Experimental Study on The Oxidative Degradation of RO Concentrated Water by Ti/IrO2-RuO2 Electrode
Authors: Wang Tingfeng
Published: March 2021

Advanced treatment and reuse of wastewater is an effective way to solve the shortage of water resources in China. The advantages of RO Technology, such as better water quality and lower operating cost, have become the mainstream desalination technology for wastewater reuse. However, RO technology will produce a certain amount of concentrated water, which contains a large number of inorganic salts and soluble refractory organics. The efficient removal of refractory organics in this high salinity system has become the main bottleneck and problem faced by RO technology. In view of the difficulty of further biochemical treatment of the concentrated water in the RO unit of a sewage treatment plant, the electrochemical method is used to treat the concentrated water. The effects of electrode spacing, current density and reaction time on the treatment of RO concentrated water were discussed. The optimal operation parameters for the treatment of 300ml of the wastewater are as follows: plate spacing 1.5cm, current density 300A/m2, reaction time 20min. Under the above conditions, the COD removal rate can reach 95%, and the lower the initial COD value, the higher the degradation efficiency.
Microwave assisted rapid synthesis of glycerol carbonate from glycerol catalyzed by anhydrous sodium silicate
Authors: Luo Deyi , Xie Mengjiao , Zhou Xi
Published: March 2021

Glycerol carbonate, a value-added derivative of biomass glycerol, has been synthesized by the transesterification of dimethyl carbonate with glycerol using anhydrous sodium silicate (Na2SiO3) as highly efficient, green and available solid base catalyst. The yield of glycerol carbonate reached up to 93% in 10 minutes under microwave irradiation. The result of leaching test indicated Na2SiO3 was a well-defined heterogeneous catalyst for the reaction. In addition, Na2SiO3 could be reused in 4 runs without significant loss of its catalytic activity.
Study on the Compatibility of Carbon / Silicon Carbide Composite Ceramics with Dinitrogen Tetroxide
Authors: Wang Weiqing , Tong Wei , Zhao Bing , Yan Jiujuan , Cong Rimei , Zhang Liqing
Published: March 2021

In this paper, the compatibility of carbon/silicon carbide composite ceramic materials and propellant dinitrogen tetroxide was studied. Referring to similar standards, the test parameters and immersion test scheme were selected. The changes of dinitrogen tetroxide properties and mechanical properties of ceramics before and after the experiment were mainly investigated, which provided theoretical and data basis for the application of this ceramic material in the field of dinitrogen tetroxide.
Dynamic Migration Process of Cd to the Bay Center
Authors: Yang Dongfang , Li Haixia , Zhang Longlei , Wang Qi , Ling Weifeng
Published: March 2021

Based on the horizontal and vertical matter content changing models proposed by the author himself, this article calculates the horizontal loss amount, vertical disputed amount and vertical sediment amount, and determines the block diagram of horizontal and vertical Cd content changing model, applying the investigation matters about the Cd content of Jiaozhou Bay in May, August, and October, 1992. The calculation results show that the variation range of absolutely horizontal loss amount of Cd content in the bottom layer is 0.63-0.82μg/L and the variation range of relatively horizontal loss amount is 68.90-87.50% in May and October. In August, the absolutely horizontal increase amount and relatively horizontal increase amount of Cd content in the bottom layer are 0.94 μg/L and 87.03%, respectively. The Cd content in the surface and bottom layer of southeast waters in August all have the absolutely vertical disputed amount 0.61μg/L and relatively vertical disputed amount 81.33%. The Cd content in the surface and bottom layer of southeast waters in May and October have the absolutely vertical sediment amount within 0.49-0.68μg/L and relatively vertical sediment amount within 57.14-68.05%. In the center of the bay, the Cd content in the surface and bottom layer in August have the absolutely vertical sediment amount 0.96 μg/L and relatively vertical sediment amount 88.88%. In May and October, the absolutely vertical disputed amount and relatively vertical disputed amount of Cd content in the surface and bottom layer of bay center are 0.35-0.52μg/L and 58.42-79.54%, respectively.
Propulsion life prediction based on support vector machine
Authors: Tang Ran , Fang Gang , Liu Guangjia , Wang Heng
Published: March 2021

The advanced technology of the propulsion device is a national key research project, and PHM prediction and health management are among the core technologies. Our prediction of the remaining effective life (RUL) of the propulsion unit is a key part of the PHM technology. The data-driven method can effectively predict RUL. For example, the artificial intelligence method is widely used because it has certain advantages. Therefore, this paper uses machine learning algorithms to carry out RUL prediction research of propulsion devices. In addition, on the basis of support vector machine (SVM) regression theory, we combined the method of SBI (similarity-based interpolation), using Matlab program to build a prediction model. Both the practice samples and test samples of the model come from the engine simulation data, CMAPSS, provided by NASA. Finally, we use test samples to test the prediction model. The results show that the constructed model has good accuracy and robustness, and it can better predict the RUL of the propulsion unit.
Hyperspectral parameters and prediction model of soil moisture in apple orchards
Authors: Wang Wenqian , Gao Mingxiu , Wang Jiafan
Published: March 2021

In this study, the apple orchard of Shuangquan town in mountainous and hilly area of central Shandong Province was taken as the research area. The relationship between the ratio spectral index (RSI), difference spectral index (DI) and normalized difference spectral index (NDSI) and soil moisture content in the range of 400nm-2450nm was explored, and then a quantitative estimation model of soil moisture content was build. The results show that the correlation between soil moisture content and spectral reflectance can be improved by different spectral index calculation. The sensitive modeling areas determined by RSI, DI and NDSI are all near the third water absorption peak, among which RSI (R2304, R2081), RSI (R2306, R2080), RSI (R2306, R2081), RSI (R2307, R2079), RSI (R2307, R2080), RSI (R2307, R2081), RSI (R2308, R2080) and RSI (R2308, R2081) the PLSR regression equation constructed for independent variables has the best estimation effect, the largest determination coefficient (R2 = 0.7918), and the smaller Root Mean Square Error (RMSE = 0.0054). The selection of full band spectral index can better extract effective information, and significantly improve the accuracy and adaptability of soil moisture spectral estimation model.
Damage Detection of Transmission Tower Based on Stochastic Subspace and Statistic Model
Authors: Xingjie Wang , Tingting Yang , Meigen Cao , Chong Zheng , Wensong Zhou , Yutong Pang
Published: March 2021

During the long service period of the transmission tower, the severe environment, material aging and fatigue effects result in the damage accumulation and resistance fading of the transmission tower, which even lead to the structural failure. In this paper, a stochastic subspace-based damage detection algorithm combined with statistical model is proposed for the damage identification of transmission tower structures through processing and analysing its vibration signals. Based on the structural modal parameters identified from the structural vibration response, the nominal modal parameters are defined. Considering that the Hankel matrixes constructed by the system observability matrix and the system output covariance matrix have the same kernel space, the damage index sensitive to the modal parameters is constructed. In the manuscript, firstly, the damage index establishment method and process of the algorithm are presented; and then the vibration data of transmission tower structure simulation under different damage conditions are obtained through numerical simulations; finally, above data are analysed to obtain the damage identification results of transmission tower. The results show that the method proposed in this work can effectively identify the local damage of transmission tower structure.
Numerical Simulation of Natural Gas Hydrate Production with Multiple Fracturing Horizontal Wells
Authors: Tan Bijun , Guo Tiankui , Wang Jia , Yu Tianxi
Published: March 2021

Natural gas hydrate (NGH) has great development prospects as alternative energy source. However, the commercial extraction of hydrate never become reality by conventional depressurization. Hydraulic fracturing assisted depressurization has been proposed to promote gas production. In this work, we presented a 3D multiple fracturing horizontal wells model. Firstly, we compared it with conventional horizontal wells. Then, taking gas production rate and cumulative gas production as performance indexes, the sensitivity analysis of fracturing parameters was conducted. The best fracture parameters for multiple fracturing horizontal wells in this specific hydrate reservoir are the fracture number of 5, the fracture length of 100 m, and the fracture conductivity of 50 μm2·cm, respectively.
Experimental Investigation of Fatigue Quality of Structure Under Tensile Load with Unloaded Fasteners Which Rivet Bucktail Overrides Bend Radius (Parallel to Load) in Civil Aircraft
Authors: Zhirong Huang , jiayi Tu , Zixiong Chen , Chuntao Diao , Jie Wen
Published: March 2021

In the process of civil aircraft production, there will exist such a situation that the fasteners interfere with bend radius and it is hard to replace the structure element because of some limits of objective condition. This article investigates the fatigue quality of structure under tensile load with unloaded fasteners which rivet bucktail overrides bend radius (parallel to load) in civil aircraft by fatigue tests based on DFR method. The results show that the DFR value will not decrease if the fastener interferes with bend radius is not as serious as the situation that the No.6 rivet hole of the structure under tensile load with R5 invases bend radius 1.0mm.
Collaborative optimization of high proportion renewable energy system based on Improved PSO algorithm
Authors: Meng Yifeng
Published: March 2021

Due to the uncertainty of renewable energy, the high proportion of renewable energy system has low cooperative scheduling capability and high cost. Therefore, based on the improved PSO algorithm, a high proportion of renewable energy system collaborative optimization method is proposed. Firstly, the framework and decomposition mechanism of transmission and distribution collaborative scheduling of renewable energy system are set up. Then, based on the analysis of the improved PSO algorithm strategy, the reactive power optimization method of renewable energy system is designed based on MSI-PSO algorithm. Firstly, the mathematical model of high proportion renewable energy system is proposed and solved, so as to complete the collaborative optimization. Finally, the simulation analysis shows that the design method has higher collaborative scheduling ability and lower cost, which proves that the collaborative optimization method of high proportion renewable energy system based on Improved PSO algorithm is effective.
Operation principle analysis of multi-function SF6 insulating gas decomposition product field detector
Authors: Zhang Jiguo , Xu Yi , Peng Bo , Ma Yao , Wang Yu , Zhao Jinyu , Lin Xin , Chen Jingzhe
Published: March 2021

In recent years, SF6 gas insulated equipment is widely used in power system to meet the development needs of power industry. The change of CF4 content is of great significance for analyzing the insulation state of electrical equipment. In this paper, a new technology and equipment for on-site detection of CF4 in SF6 gas based on spectral absorption principle is studied. It provides reference and technical support for the operation and maintenance of SF6 gas insulated equipment and the condition based maintenance of equipment in the future.
Research on Business Model of Power Sharing Tower Based on Canvas Theory
Authors: Zou Lifang , Ye Minquan , Yu Jing , Lin Shiyuan
Published: March 2021

Sharing tower resources is an active response strategy of power grid companies in the face of power reforms, an effective way to revitalize power grid assets, improve quality and efficiency, and also an important carrier for the construction of Power Internet of Things. This article discusses the connotation and principles of shared towers, proposes a business model system of power sharing tower based on canvas theory, including nine elements such as value proposition, market demand, and operating mode. At the same time, this article uses economic comparison methods to evaluate the benefits of shared towers, analyzes the method of calculating lease expenses, and proposes targeted risk prevention and control to promote the healthy and orderly development of power shared tower resources.
Research progress of magnetic materials in microbial fuel cell applications
Authors: Yao-Zhao  , Jing-Zhang  , Yuqing-Peng  , Naiqing-Sha  , Yanhong-Li
Published: March 2021

As a new type of environmental protection technology that can treat sewage and generate electricity, microbial fuel cells (MFC) have broad research prospects. In recent years, MFC has made great breakthroughs, but its high internal resistance and low power generation efficiency have prevented its development. Researchers began to study the influence of magnetic fields on the MFC power generation efficiency to improve the power generation efficiency, and the results are gratifying. This shows that magnetic materials may be the solution to push MFC to practical applications. This article briefly introduces the research progress of magnetic materials as the additional structure of MFC and MFCs electrode materials, and discusses the role and influence of magnetotactic bacteria in MFC.
Small Signal Stability Analysis of Microgrid with Multiple Parallel Inverters
Authors: Han Yi , Qian Zhongmin , Shao Danlu , Lin Qiujia , Yin Shuangrui , Chen Minyu , Ai Qian
Published: March 2021

Microgrids are introduced into power grid for managing the high penetration of renewable energy sources(RESs). Based on the resistive characteristics of the microgrid line, this paper proposes an inverter control mode combining the outer power loop controller with anti-droop control and the inner voltage-current dual-loop controller. Meanwhile, a complete small signal model of single inverter including anti-droop control, dual-loop control, filter and branch is established. Then considering the coupling relationship of the output voltage phase angles of each inverter, the small-signal model of the microgrid with multiple parallel inverters is established under the global coordinate system. The static stability analysis of the complete microgrid is carried out by the root locus method. Results show that the anti-droop control is more conducive to the accurate distribution and fast response of the active power output by inverter units than the traditional droop control.
Research on Deep Generative Model Application for Shortterm Load Forecasting of Enterprise Electricity
Authors: Zhu Liwen , Huang Yujun
Published: March 2021

This paper mainly applies deep generative models for short-term load forecasting on the enterprise electricity consumption dataset. After data cleaning on the electricity use dataset with the help of related weather data, we complement missing data and improve the data quality to better implement neural network generative prediction models. We build DeepAR and Wavenet as the representative of deep generative models. The main result is that deep generative models perform better compared with other baseline models, such as ARIMA, machine learning and baseline neural networks, no matter what accuracy metric and prediction horizon. Further improvement is to test in higher frequency electricity dataset with better quality.
Preparation and Characteristics of Lithium Battery Separator Based on Cellulose Modification by Water-Soluble Polyimide Impregnated
Authors: Liu Xin , Wei Sun , Liang Jie , Ning Ruxia , Sun Zhonghua , Li Xiang
Published: March 2021

In order to improve the comprehensive performance of lithium battery separator, cellulose based on lithium battery separator (mCNS) was prepared by cellulose/nylon 6 with ionic liquid [Emim]Ac as solvent and enhanced with polyimide (PI) as the impregnated solution. The properties of modified separator were investigated. As could be discovered from the experimental results that the addition of PI endowed the separators with more uniform and dense micro-pores, and the ions can pass through better, which was conducive to improving the electrical conductivity of the separator. Remarkable tensile strength (69 MPa) and elongation at break (35.3%) can be obtained at PI concentration of 40%. Meanwhile, the electrolyte absorption and retention rate reached 238.7% and 69.4%. The value of maximum thermo-shrinkage stress was 1.38 N and the thermo-shrinkage rate could reach 1.5%, which guaranteed the thermal stability of the battery. The electrochemical voltage was attained to 4.7 V and the ionic conductivity was improved to 0.61×10−3 S⋅cm−1. The mCNS separator preparation process was simple and the performance was excellent, which provides a novel idea for the green development of lithium battery separator.
Research on key technologies and application scenarios of energy big data
Authors: Wang Haoyue , Liu Dunnan , Zhao Hongtao
Published: March 2021

Big data technology is a new concept in the development of today’s society. With the current development of the Internet and information technology, the increase in data volume has become a common feature of the development of many industries, which further highlights the need for big data technology applications. As the foundation of the national economy, the trend of changes in energy big data, to some extent, determines the development direction of the entire national economy. This article starts with the relevant concepts and characteristics of energy big data, conducts research on the key supporting technologies and application scenarios of energy big data, and draws corresponding conclusions and suggestions.
The Highly Efficient Degradation on Nitrobenzene by Using Nano-copper-cobalt Bimetallic Oxide as Heterogeneous Fenton Catalysts: Efficiency, Dynamic and Mechanism
Authors: Li Jinwei , Shen Jian , Liu Qiang , Jiang Chengchun
Published: March 2021

The nano-copper-cobalt bimetallic composite oxide (NCC) has been synthesized under hydrothermal conditions, which was further characterized by SEM, TEM-EDS, XRD, XPS and FTIR-ATR. NCC was used as heterogeneous Fenton catalyst to degrade nitrobenzene (NB). During the degradation process, H2O2 can be activated efficiently by NCC, and NB was degraded rapidly with high efficiency among wide pH range (3-9). In detail, NB with concentration of 10 mg/L (pH=7) can be completely degraded within 45min at room temperature, in which the amount of NCC was 2.5g/L, and that of H2O2 was 0.8mol/L. OH· was the main active reactive oxidation species (ROS), which was verified by free radical quenching experiments and benzoic acid (BA) probe experiments. The stability of NCC has been proved by executing four cycling experiments, and no obvious decrease can be found on its degradation ratio. Finally, the degradation mechanism was proposed in terms of their interface pictures. This work paves a new way for the application of NCC as heterogeneous Fenton catalysts.
Meso-numerical simulation of rock triaxial compression based on the damage model
Authors: Tiankui Guo , Zeming Du
Published: March 2021

The mathematical model of brittle rock triaxial compression simulation is established and solved by the secondary development of COMSOL, and the numerical model is verified by rock uniaxial compression experiment and triaxial compression experiment. The meso-damage evolution of brittle rock under triaxial compression is simulated, and the influence of heterogeneity coefficient, confining pressure and loading rate on stress-strain curve and ultimate failure mode are studied. The results show that: The enhancement of rock heterogeneity makes the core failure position more dispersed, and when the coefficient of heterogeneity decreases from 10 to 0.8, the young’s modulus decreases by 14.92%, and the peak strength decreases by 35.45%; The increase of confining pressure makes the failure events gather to the fault surface, and when the confining pressure increases from 0MPa to 40MPa, the young’s modulus increases by 22.57%, the peak strength increased by 94.47%, and the residual strength increased by 112 times; The increase of loading rate makes the rock failure unit relatively dispersed, resulting in two fault planes, and when the loading rate increases from 0.01 × 10−3 to 0.2 × 10−3, the peak strength increases by 7%. This paper provides a reference for more accurate, rapid and comprehensive study of rock triaxial compression numerical simulation.
Flotation Separation of Mercury (II) using Ammonium Sulfate-Potassium Iodide-Butyl rhodamine B system
Authors: Wen Xinrong , Tu Changqing
Published: March 2021

The flotation separation behavior and conditions of mercury (II) using ammonium sulfate-potassium iodide-butyl rhodamine B(Bu-RhB) system are investigated. In the presence of (NH4)2SO4, KI and Bu-RhB, Hg2+ can form ternary associate precipitate (Bu-RhB)2 (HgI4) which floated above the water phase and Hg2+ is floated quantitatively at pH 1.0. While Zn2+, Mn2+, Co2+, Ni2+, Cu2+, Fe3+ and Al3+ can not be floated in the same condition. Hence, the separation method of trace mercury (II) by flotation is established. This mothod is used to separate Hg2+ in the synthetic water samples, the results are satisfactory.
Optimal scheduling method of virtual power plant based on bi level programming
Authors: Dunnan Liu , Yuan Gao , Weiye Wang , Jiahao Liang
Published: March 2021

Virtual power plant controls various types of flexible loads through information integration to realize efficient utilization of energy, which is an important channel to absorb high proportion of renewable energy. In this paper, an optimal scheduling method of virtual power plant based on bi level fuzzy chance constrained programming is proposed. The bi level chance constrained programming is used to describe the power price incentive strategy and the price response of the virtual power plant. The interactive mechanism between the power grid and the virtual power plant is visually displayed. The example shows that this method can realize the distributed generation and active negative of the virtual power plant The effective scheduling of load.
The Effect of Longitudinal Ventilation System on Smoke Movement and People’s Evacuation in Tunnel Fire
Authors: Xiao Kunhua , Ji Yuyang
Published: March 2021

Smoke movement in a model tunnel controlled by longitudinal ventilation system was studied and in this paper. Smoke movement in a tunnel was studied numerically with some equations reviewed. A numerical experiment with Computational Fluid Dynamics (CFD) was carried out. At the initial stage of tunnel fire, the velocity of ventilation fans can be set up as critical speed to slow down smoke movement and high temperature diffusion. However, in evacuation stage, the ventilation speed should be decreased to prevent smoke transmit too fast and hurt people in the downstream. Without longitudinal ventilation system, smoke is distributed symmetrically in the tunnel. When the tunnel has longitudinal ventilation system, smoke will not distribute in the upstream of the tunnel but it will spread quickly to the downstream. If people still evacuate along the center line of the downstream, they may be threatened by the smoke. This study demonstrated both the advantages and disadvantages of longitudinal ventilation system and showed that the velocity of ventilation fans should be carefully chosen.
Research on electromagnetic disturbance characteristics of magnetic coupling resonant wireless energy transmission device and converter valve system
Authors: Hao Jianhong , Xiao Zhiren , Teng Wanyi , Li Fangyi
Published: March 2021

The IGBT device in the converter valve device will produce complex electromagnetic disturbance signals in the process of fast on and off, and the driving circuit is close to the device. In this paper, the wireless energy transmission system based on magnetic coupling resonance is used to replace the traditional driving power supply method, which makes the electromagnetic environment in the space where the driving circuit is located more complex. In this paper, firstly, the test is completed according to the relevant standards of the drive circuit, and then the electromagnetic simulation software is used to complete the modeling and simulation of the converter valve based on the wireless energy delivery system, which proves that the drive circuit can withstand the electromagnetic disturbance generated by the wireless energy delivery system and the converter valve, and there is no need to add additional shielding measures.
Study on sealing performance of bolted flange structure after creep based on ABAQUS
Authors: Zhou Wenbo , Wang Hehui
Published: March 2021

In this paper, a finite element analysis model is established based on ABAQUS software and DN600 bolted flange connection structure is the research object. The elastic-plastic constitutive relation is adopted for the flange and bolt materials, and the user subroutine of Creep is written in Fortran language according to the creep constitutive equations. Each component can meet the requirements of strength and seal evaluation, and it is found that after creep, the seal stress of gasket decreases significantly, and the stress increases almost linearly from the inside to the outside of the gasket. After cooling and heating, the stress is redistributed. The residual pre-tightening force of bolt is increased, and the flange deflection angle is slowed down, which improves the sealing performance. The study of gasket sealing performance in this paper has a positive guiding significance for preventing leakage accidents.
Research on Working Characteristics of Pre-combustion Plasma Igniter
Authors: Li Zhengqing
Published: March 2021

In the future, aircraft will definitely move towards a faster and higher goal, and the scramjet is the only way to go. For scramjet engines, reliable and effective ignition is a key to stable combustion in the combustion chamber. Plasma ignition is the research frontier of ignition-assisted combustion technology. This technology consumes low energy, can significantly reduce the minimum energy required for ignition, and increase the rate of chemical reaction. It has obvious advantages for aero engine combustion chambers. In this paper, the working principle of plasma fuel nozzle based on rotating sliding arc discharge is described, and the discharge characteristics of rotating sliding arc are studied on this basis.
The Application of WiFi 6 Technology in Underground Mine
Authors: Min Chen , Jinhao Zhang
Published: March 2021

Aiming at the problems of large power consumption of 5G communication technology equipment and short wireless transmission distance of wireless signal, the author designs the wireless network coverage scheme of WiFi 6 in coal mine to achieve the fully coverage of 5G communication. This paper makes an exposition of WiFi 6 technology from the aspects of technical principle, networking mode, antenna design and power consumption calculation. The WiFi 6 signal coverage scheme solves the problem of wireless network signal coverage in long-distance roadway underground coal mine by realizing the full coverage of wireless network. The data of laboratory experiments and coal mine roadway simulation show that with the characteristics of wide network communication coverage area, fast communication speed and low power consumption, WiFi 6 network scheme can fully meet the requirements of full wireless coverage in coal mine.