bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Primary Frequency Control of Power Grid Based on Flywheel Energy Storage Technology
Authors: Li Jun
Published: May 2020

The frequency regulation of power grid is the most valuable application direction of energy storage technology in the auxiliary services field. Through the analysis and comparison of different energy storage technologies, the energy storage principle of flywheel energy storage (FES), the design of motor controller and capacity selection method of FES system are introduced and analyzed in detail. With its strong short-time power capacity and easy change of adjustment direction, combined with conventional frequency modulation technology, it can be used as an effective auxiliary means of primary frequency control (PFC) to ensure grid frequency stability.
Analysis of fire failure of wind turbine in a wind farm in Northwest China
Authors: Wang Huai-Xiang , Ma Dang-Guo , Chun Zhou , Bin Niu
Published: May 2020

The accident fan is the first-stage wind farm unit. From 2011 to 2019, the transformation of low-voltage crossing, lightning protection, grid switch, engine room grid cabinet and frequency converter cabinet are gradually carried out, and the original main control system is updated. One day in 2019, a fire accident happened to the generator, most of the engine room covers were burnt, the top section of the tower tube had traces of oil overflow after combustion, and a large area of combustion damaged parts scattered around the tower base. The cause of the accident is that the two phases of the stator contactor are not completely disconnected when the network is disconnected, and the main circuit breaker of the tower base is not tripped when the stator contactor is in fault, and the fault current is not cut off in time, which is a design defect.
Study on calculation model of wind deflection response of transmission line
Authors: Xie Yan , Li Mu , Liao Yane
Published: May 2020

The wind deflection angle is directly related to the electric gap and the construction cost of the transmission line, so the accuracy of the wind deflection calculation method and the reasonable value of the relevant parameters are very important for the safe operation and economic rationality of the transmission line. In this paper, based on the nonlinear transient analysis method, the characteristics of aerodynamic damping on the transient response of transmission line wind deflection are revealed. At the same time, according to the code of transmission line design in China, the static wind deflection calculation method is used to solve the static wind deflection angle of transmission line, and the dynamic and static calculation models of wind deflection angle are compared.
State of Charge Effects on the Parameters of Electrochemical Impedance Spectroscopy Equivalent Circuit Model for Lithium Ion Batteries
Authors: Xiao Haiqing , Tao Ziqiang , Bai Hong , Wang Hongwei , Fu Yanling , Si Nianpeng , Bai Hua
Published: May 2020

It is essential to know the behavior of the battery at all relevant internal and external conditions when the battery cell is in the new and the aging state. Electrochemical impedance spectroscopy (EIS) is a viable approach that can be used in lithium ion batteries (LIBs) to investigate the electrochemical behavior. In this paper, in order to investigate the state of charge effects on the LIBs, three types of commercial LIB cells were used, and the EIS measurements were performed under 100%, 80%, 50%, 20% and 0% SOC, respectively. An equivalent circuit model (ECM) including two constant phase angle elements in parallel with resistor elements is established to study the impedance characteristics for LIBs. The influence of the state of charge on the parameters of the ECM was analyzed. Based on the results we think EIS combined with ECM simulation tool can be used to derive useful information for improving battery design and state of health prediction.
Research on the policy of renewable energy development in China
Authors: Pan Xiaodie , Zhong Hongsen
Published: May 2020

The 19th National Congress of the Communist Party of China once again stressed the task requirements of establishing and improving the economic system of green and low-carbon circular development and promoting the reform of energy system and the development of renewable energy. In the face of the new requirements of the new era, it is urgent for China to not only master the basic laws of the world’s renewable energy development, comply with the trend and trend of energy reform, but also promote the development of renewable energy based on national conditions and regional conditions, so as to achieve higher quality development of economy and society.
CO2 Hydrate Formation Promoted by a Bio-friendly Amino Acid L ‐ Isoleucine
Authors: Liu Zhengwen , Zeng Yanxian , Wang Weixing
Published: May 2020

We prove that L-isoleucine, a bio-friendly amino acid, can be used to greatly increased CO2 uptake kinetics in the formation of CO2 hydrate without stirring. As far as we know, L-Isoleucine is an accelerator that can effectively promotes the formation of CO2 hydrate (the gravimetric capacity achieved to 331 mg g−1 in 1000 min at a concentration of 0.2 wt%). We also provided a preliminary explanation for this promotion mechanism of L-isoleucine by comparing the structure-performance. Our results will provide a reference for exploring the promotion mechanism of CO2 hydrate.
Theoretical study on the structure and sensitivity of fused aza-cyclic nitro-containing compounds
Authors: Wang Linyuan , Pu Keyu , Liu Jian , Liu Yujing
Published: May 2020

As the heterocyclic compound with high detonation properties and low sensitivity, fused aza-cyclic energetic compounds have shown great research value and application prospect in recent years. In this paper, two series (30 kinds) of new fused aza-cyclic nitro-containing compounds were designed to be the research target, with good fused aza-cyclic molecules as the basic structure and nitrogen-containing high energy groups of nitro group (-NO2) and amino group (-NH2) as substituents. The DFT-B3LYP/6-31G (d) method was used to optimize the molecular geometry and analyze the vibration frequency. The calculation results show that all derivatives have no virtual frequency, and they are stable structures on the potential energy surface; The nitro group charge of compounds was obtained. The structure-activity relationship between molecular structure and sensitivity was studied. And change relation of the sensitivity and the parent structure of molecule, the type and number of substituting group and configuration was summarized, providing references for relevant researchers.
Research and application of fracturing process for low permeability reservoir of Triassic in Junggar Basin
Authors: Yang Hong , Ni Hongjian , Wu Tao
Published: May 2020

Baikouquan formation of Triassic in the northwest margin of Junggar Basin has long been regarded as the synonym of “alluvial fan, ultra-low permeability and no benefit”. Moreover, the effect of Triassic conglomerate reservoir reconstruction in Mabei oilfield is not obvious, which leads to ineffective production and benefit development. In this paper, based on the research results and practical production application of Triassic conglomerate reservoir fracturing reconstruction technology in Junggar Basin in recent years, four kinds of adaptive reservoir reconstruction technology for low permeability conglomerate reservoir are explored, which effectively improves the single well production and realizes the increase of reserves and productivity in conglomerate reservoir exploration. (a) In view of the three reservoir conditions of multiple sets of sand layers, large vertical oil and gas display span and large difference of stress between each set of sand layer and surrounding rock, in order to ensure that multiple sets of sand layers are effectively reconstructed, the separate layer fracturing technology is implemented. Before fracturing, the process can realize circulation fluid replacement, and after fracturing, it can realize combined production; (b) For the reservoir with poor physical properties and high formation pressure, which cannot realize the stratified fracturing of tubing packer, the casing bridge plug layered fracturing technology is adopted; (c) In view of the fact that the oil and gas reservoirs are mostly located in the upper part of the thick sand layer and the fractures extend downward to easily connect the water layer, the reservoir reconstruction technology of secondary sand addition is implemented; (d) In view of the poor physical properties of the reservoir, the oil and gas production after the vertical well fracturing is not high, or the initial oil and gas production is high, but the production decline is fast, unable to stabilize the production for a long time, the horizontal well multi-stage fracturing technology is implemented. The successful field application of the open hole packer ball sliding sleeve fracturing technology and the bridge plug perforation combined fracturing technology in horizontal wells is realized. The research and practical application of adaptive reservoir reconstruction technology further promote the reconstruction of Triassic low permeability conglomerate reservoir and single well production increase in Junggar Basin. It can be used for reference in other basins for low permeable conglomerate reservoir fracturing, and it presents good application value.
Study on the spatial distribution characteristics of urban innovation power in Yangtze River Delta urban agglomeration
Authors: Liu Jing , Dou Yitao , Lu Yanwen , Yang Li
Published: May 2020

Based on the evaluation index panel data of innovation capacity of 26 cities in the Yangtze River Delta urban agglomeration from 2013 to 2017, the global entropy method and exploratory spatial data analysis method (ESDA) were used to evaluate and analyze the spatial characteristics of urban innovation capacity. The results show that: (1) From 2013 to 2017, the innovation capacity of the Yangtze River Delta urban agglomeration has an obvious regional difference, showing a distribution pattern of “Strong In The East And Weak In The West” on the whole. (2) From 2013 to 2017, the innovation capacity of the Yangtze River Delta urban agglomeration shows significant positive agglomeration characteristics in space. (3) The spatial agglomeration evolution of the innovation capacity of each city has obvious spatial locking characteristics. Based on the research conclusion, this paper puts forward some suggestions on strengthening urban innovation connection, improving innovation structure, increasing innovation investment and strengthening scientific and technological strength.
Airfoil shape optimization based on Non Uniform Rational Bspline and optimization algorithm
Authors: Sun Zhaocheng , Li Zengliang , Fan Menghao
Published: May 2020

In this article, we propose an innovation method of airfoil shape optimization, on the premise of ensuring the fitting accuracy; try to improve the smoothness of the airfoil. Non Uniform Rational B-Spline and quadratic penalty function are employed to parametric modelling and smoothness optimization. The monotone curvature variation is used to design smooth curves and least squares method ensuring high fitting accuracy. This program has been tested for a standard NACA 2415 and S825 airfoil and optimized to improve its smoothness. The results of optimization examples show that this method has high efficiency and precision.
Summary of Key Performance and Testing Methods for Thermal Storage Materials
Authors: Chang Liang , Zhang Gaoqun , Tan Hui , Deng Zhanfeng , Xu Guizhi , Song Xiaoyun , Cai Linhai
Published: May 2020

The development and application status of the key performance testing technology of heat storage materials in the application process are reviewed. According to the practical application requirements in terms of heat storage capacity, heat exchange capacity, material strength, service life, etc., the key performances of thermal storage materials that need to be focused on are sorted out, and the relevant testing techniques for each performance are sorted out and summarized. The specific test methods applicable to high-temperature heat storage materials are analyzed, and the related test technologies and evaluation methods for future heat storage materials are prospected.
A Novel Electronic Component Classification Algorithm Based on Hierarchical Convolution Neural Network
Authors: Hu Xiaomei , Xu Jun , Wu Jun
Published: May 2020

In the paper, the author proposes a recognition and classification algorithm of electronic components based on hierarchical convolutional neural network (NH-CNN) that reduces the computational complexity on the drawbacks of traditional image classification method based on deep learning such as the failure of effectively combining multiple deep characteristics, the poor performance of classifier, the difficulty of parameter adjustment and the long training time. The algorithm is trained through the Convolutional Automatic Coding (CAE) layer to obtain relevant feature maps, which reduces the input parameters of the designed convolutional neural network. Since the CAE model and the convolutional neural network have similar convolution and pooling operations, the feature maps obtained from the CAE model are put into the designed neural network based on the transfer learning method. Finally, the feature fusion method is used to output the obtained features to the fully connected layer, which is used to better express the depth information contained in the electronic component images and improve the accuracy of classification. The experimental results show that the proposed algorithm can effectively extract depth features with high precision of 94.26% and less complexity and overcome the defects of traditional image classification algorithms such as manual image extraction and low classification efficiency.
Study on High-temperature Erosion Resistance of Precursor Ceramic Coatings
Authors: Yang Songjie , Wang Jinqing , Wang Guangxin , Tong Shiqi , Wang Zhimeng , Zhang Mu’an , Lin Zixiang , Feng Zhi , Xiong Yunhao
Published: May 2020

Given the high-temperature chlorine corrosion in the process of waste incinerators, polysilazane was used as the precursor, and glass powder and zirconia were added as fillers to prepare composite ceramic coating on TP347 substrate. In this paper, the effect of temperature on the formation of voids in the coating was studied by microscopic analysis. The high-temperature erosion wear resistance of the coating was also tested. The results show that the coating sintered at 500°C and 700°C has the best microstructure. To make the coating have higher hardness, the sintering temperature should be increased as much as possible at the allowable temperature of the substrate. The high-temperature erosion test shows that the erosion resistance of the coating is slightly lower than that of the substrate at room temperature and 400°C, but with the increase of temperature, the high-temperature erosion wear resistance is gradually enhanced, even exceeding the substrate, which is because the substrate is subjected to severe oxidation at high-temperatures, and its mechanical strength decreases with increasing temperature, while the coating is brittle at low temperatures, the erosion mechanism gradually becomes plastic as the temperature increases. The development of the shape erosion results in a much lower erosion wear at high-temperatures than the substrate.
Numerical Simulation and Structure Optimization of the Sudden Expansion and Contraction Flow In Fracturing Tubing
Authors: Chen Wenjun
Published: May 2020

For serioius erosion of the sudden expansion and contraction (SEC) in fracturing tubing, numerical simulation of SEC flow field is carried out using CFD and reynolds tress model. The velocity flow field and sand concentration in calculation region is achieved. The flowfields indicate that a large recirculation zone exists and sand concentration increases in the SEC, which causes the mixture of fluid and sand to impact upon the wall at the certain angle, and aroused erosion. Based on the obtained erosion reason, the structure optimization of the SEC are proceeded. Which improved the flow in SEC, reduced the erosion of SEC, and extended the service life of the tool.
Study on the influence of glass encapsulating on the hygroscopicity of high temperature phase change heat storage materials
Authors: Zhang Gaoqun , Deng Zhanfeng , Lu Yunkun , Hao Junjie , Ren Zhongkai , Chang Liang , Tan Hui , Cai Linhai , Xu Guizhi , Wang Tianhao
Published: May 2020

In this paper, Na2CO3-K2CO3 / MgO phase change composite was coated on the surface of glass by spray plating, which solved the problem of absorbing moisture and pulverizing of molten salt / MgO phase change thermal storage material in high humidity environment, and reduced the absorbing moisture and pulverizing rate from 31% to 19% without affecting the latent heat of phase change thermal storage material.
Efficient and convenient pretreatment to enhance waste activated sludge anaerobic hydrolysis by iron porphyrin biomimetic enzyme
Authors: Ruan Min , Zhang Jian , Niu Cheng-Gang , Huang Jing , Zhang Wei , Zeng Zhi-Hao , Zhou Kang , Li Xue
Published: May 2020

A novel biomimetic enzyme was applied in the pretreatment of waste activated sludge (WAS) for enhancing the hydrolysis properties. An iron porphyrin complex was efficiently synthesized and purified. In comparison with the blank test, iron porphyrin complex used as biomimetic enzyme could significantly improve the sludge disintegration. Hydrogen peroxide was not the main influencing factor. During the pretreatment process, concentrations of the ammonia nitrogen (NH4
+-N) and reducing sugar (RS) both almost increased, which indicated that the protein and polysaccharide in sludge were effectively decomposed. Results demonstrated that the optimum treatment time and temperature of this biomimetic enzyme was at 7 hours and 40 °C, respectively. The efficient and economical dosage of the biomimetic enzyme used in treatment sludge digestion was 1%. Under the optimal treatment condition, the SCOD/TCOD ratio, the rate of VSS reduction, the concentrations of NH4
+-N and RS reached the values of 65.3%, 38.4%, 215.9 mg/L and 65.9 mg/L, respectively. And the possible mechanism of iron porphyrin biomimetic enzyme to promote anaerobic hydrolysis of WAS had been proposed. Therefore, the application of biomimetic enzyme was a desirable method in the WAS pretreatment.
Non-Intrusive Load Monitoring based on Deep Neural Network and Differential Current
Authors: Ding Shaokang , Zhu Hongwei
Published: May 2020

In daily life, it is easy to obtain the power consumption information of a house by installing an energy meter at the entrance. The non-intrusive load monitoring method can decompose the power consumption and the working state of a specific load according to the aggregated information of the power inlet, and then help people to save electricity. Here, we present a novel and complete non-intrusive load identification algorithm based on deep neural network and differential current. The algorithm includes several modules for data preparation, event detection, feature extraction and load identification, and uses the BLUED dataset to test the feasibility of the proposed algorithm.
Innovative research on refrigeration technology of cold chain logistics
Authors: Han Zhi , Hua Linhui , Fang Yunrui , Ma Qingwen , Li Yan , Wang Jing Xing
Published: May 2020

With the increasing demand for frozen food in China, the need for better cold chain logistics is also becoming more urgent, promoting the development of related new technologies. This paper focuses on the research of ice slurry and intelligent temperature control technology in cold chain logistics, expounds on the research background, present situation and innovation research, and finally discusses the problems existing in cold chain logistics technology and corresponding solutions.
Distributed control system for catalysing the formation of artificial rainfall and snow using charged particles
Authors: Yang Z , Wu Q , Zhang M , Zheng W , Wang Y , Ai X
Published: May 2020

In order to solve the limitations and shortcomings of the traditional artificial rainfall technology, researchers all over the world are actively researching new artificial rainfall technologies. The charged particle catalytic artificial rainfall technology is one of the new artificial rainfall technologies. This method uses a charged particle generator set up in the wild to produce charged particles to catalyse rainfall. It is necessary to control all equipment in the experiment site remotely during the experiment. Thus, a control system needs to be implemented. There are many kinds of controlled equipment in this control system, such as high-voltage power supply, meteorological data acquisition devices, and various experimental auxiliary equipment. In this paper, we design and implement a comprehensive control system based on the characteristics of the charged particle catalysed artificial rainfall field experiment and the controlled equipment in the experiment site. The software interface connected to different types of equipment in the system is developed based on the large-scale experimental control system framework CFET, which can easily add equipment and view measurement data. The system is designed as a distributed system connected through a network, which can meet the needs of centralized control of multiple experimental sites.
Stability Analysis of Slope and Nearby TransmissionTowers in a Hub project Based on Flac3D
Authors: Wu Gu , Chen Shanxiong , Li Jian , Dai Zhangjun , Guo Jianhua
Published: May 2020

Aiming at the problem that the construction process of a water conservancy and hydropower project will affect the stability of the slope and its surrounding buildings, a numerical simulation method is used to carry out a numerical analysis of the displacement and stress diffusion of a junction engineering slope and its nearby transmission tower. The results show that: the deeper the excavation depth of the slope, the greater the rebound of the excavated surface; after excavation, the horizontal displacement of the facing surface of the slope under the support of the continuous wall is small, and the slope can maintain stability. The stress ratio method determines the distance between the excavation surface and the tower foundation, and the slope excavation can be carried out smoothly while ensuring the stability of the tower foundation.
Optimization of microelectrolysis process for treatment ofPNP wastewater by response surface methodology
Authors: Ban Fuchen , Zheng Xueting , Zhang Haoyu
Published: May 2020

The simulated p-nitrophenol (PNP) wastewater was treated by micro-electrolysis. The Box-Behnken experimental design model in response surface method was adopted with iron-carbon as a micro-electrolytic filler. Factors such as iron chip dosage, initial pH value of solution and reaction time were used as investigation indexes to study the influence of single factors and their interactions on the PNP wastewater removal rate. The final optimization results show that the experiment has a good removal rate of PNP, with only a small difference from the predicted value. It can be seen that the response surface method is feasible and suitable forthe process optimizion of p-nitrophenol wastewatertreatment by micro-electrolysis, which can be applied to engineering practice through further research and improvement.
Modelling and Application of Urban Drainage Based on Mike Urban Model
Authors: Liu Yin , Zhang Shuanghu , Su Huidong , Wang Dan , Gu Qihao
Published: May 2020

To alleviate the drainage pressure of urban pipeline network and reduce flood disaster, for the problem of non-convergence of design standards caused by inconsistency of design rainstorm duration between urban construction and water conservancy departments, this paper takesa residential district in Wenzhou City of Zhejiang Province as an example, andanalyze the relationship of recurrence periods between pipeline network drainage and waterlogging drainage under the regulation and storage capacity of rivers. Mike Urban was used to establish the drainage model of pipeline network to simulate the drainage situation when facing different river water levels at the outlet. The results are as follows: (1) when the recurrence period of pipeline design is 1 year, 3 years and 5 years respectively, the corresponding design rainstorm recurrence period of waterlogging drainage is about 5 years, 15-20 years, 20-30 years; (2) when meeting the high the water level at the outlet, the once a year rainfall of pipeline network encountering is equivalent to that of the pipeline network encountering the once a year to once in three years rainfall when the water level of the outlet is constant; (3) when the water level at the outlet is high, the once in three years rainfall of the pipeline network encountering is equivalent to that of the pipeline network encountering the once in three years to once in five years rainfall when the water level of the outlet is constant. Relevant research can provide reference for the design standard of pipeline network.
Groundwater Chemical Characteristics and Mining Potential Evaluation of the Quaternary in the Boxing Section of Shandong Province in the Lower Yellow River
Authors: Qin Peng , Yao Yingqiang , Liu Hongliang , Liang Zhihao
Published: May 2020

Boxing is located in the lower reaches of the Yellow River, all of which are covered by loose rock layers. Quaternary loose rock pore water mainly exists in aqueous media such as medium sand, medium coarse sand and fine sand, forming multiple layers of loose rock pore water. Water-containing structure is interlayer confined water development. From the southeast to the northwest, the aquifer formation gradually becomes thinner with the Quaternary overburden, the thickness of the single-layer sand layer gradually becomes thinner, and the water richness gradually weakened. The chemical types of groundwater are mainly HCO3 and HCO3·Cl. The pore water of loose rocks in the middle and deep layers is decreasing from south to north, and the content of Cl- is increasing. From west to east, the percentage of HCO3
-mg equivalent decreases gradually, and the percentage of Cl-mg equivalent increases gradually. The area enclosed by the groundwater level buried depth 40m is the controlled mining area.
Study on Hydrochemical Ion Characteristics in the Upper Reach of Tao River
Authors: Zhu Zhaoxia , Liu Jinqi , Cao Yuting
Published: May 2020

In this paper, the water in the upper reach of the Tao River was selected as the research object, the chemical characteristics of water environment in the upper reach of Tao River were studied and the water quality was evaluated based on the comparative analysis of the data of two monitoring stations for one year. The results show that the contents of HCO3-, SO4
2- and Ca2+are high in the upper reach of the Tao River, and the water quality belongs to alkaline medium salinity water, and the salinity increases with the increase of HCO3
-.
Test-loading Capacity Estimation of Slip-lined RCPs using a plastic approach
Authors: He Yuting , Fu Xinsha , Li Baijian
Published: May 2020

As many reinforced concrete pipes (RCPs) need to be rehabilitated due to the reconstruction, expansion of highways and structural damage. Inserting a corrugated steel pipe (CSP) into the existing RCP is an economical rehabilitation technique in China, the current research seeks to better understand the performance of the RCP rehabilitated with grouted CSP by using the reinforced concrete pipes (RCPs) as the host pipes. Experiments were conducted to (1) determine the test-loading capacity of five specimens; (2) understand the role of the liner (CSP); (3) understand the influence of eccentric rehabilitation on the test-loading capacity of the slip-lined pipe; (4) explore an approach to estimate the load-carrying capacity of the rehabilitated pipes. The test-loading capacity of an RCP rehabilitated with grouted CSP mainly depends on the RCP and the grout before the first peak value of the applied versus diameter change curve, CSP improved the maximum test-loading capacity and ductility of rehabilitated pipe. The test-loading capacity of an eccentric rehabilitated pipe was lower than that of a concentric rehabilitated pipe. The comparison of the calculated results showed that the plastic approach was reasonable for an RCP rehabilitated grout CSP. Meanwhile, an approach for analyzing a vertical eccentric rehabilitated pipe was proposed based on the plastic approach. The errors between the theoretical results and experimental results were basically less than 30%.
Influence of Dredge Reamer Operating Parameters on Pollutant Diffusion in Reservoir Dredging
Authors: Tang Deyi , Weng Haoxuan , Ye Xuewei
Published: May 2020

In order to study the influence of pollutant diffusion in the process of reservoir environmental dredging, this paper took the Tongji-bridge reservoir environmental dredging project as an example to analyze the relationship among the reamer rotating speed, traverse speed and slurry absorption concentration, and thus determined the optimal reamer operation parameters. Besides, this paper also monitored and analyzed the impact of pollutant diffusion dispersion in environmental dredging under the condition of the optimal reamer operating parameters. The results turn out: (1)When the reamer rotating speed and traverse speed were set to 15 r/min and 15∼20 m/min, the slurry absorption concentration was higher and the efficiency of dredging was optimal at the moment. (2)Under the optimal reamer operation parameters condition, the pollutant diffusion in the horizontal direction was obviously affected by water depths. The horizontal diffusion distance was about 20m when the water depth was 15m to 20m and the horizontal was increased to be 40m in the depth of 10m to 15m. (3)Under the optimal reamer operation parameters condition, the pollutant diffusion in the vertical direction was little affected by different water depths. The peak of pollutant concentration from high to low was 1.0m above the bottom, intermediate water depth and 1.0m below the water surface.
Study on the Mapping of Rainfall Contour in Pu’er, Yunnan
Authors: Ling Zhen , Ye Tengfei , Li Liang , Chen Fan
Published: May 2020

This paper briefly introduces the development of GIS and its application in hydrologic analysis. The paper interpolates the predicted rainfall of pu’er city in 2017 and draws the rainfall contour line by using kriging method, inverse distance weight method, obstacle spline function and geostatistics kriging method in the deterministic interpolation method. The results show that the interpolation results are of high accuracy and the interpolation errors are ranked from small to large as inverse distance weight interpolation < including obstacles interpolation < kriging interpolation. The inverse distance interpolation method can be used to draw the rainfall contour map of pu’er city.
Analysis of Heterogeneous Settlement of Connecting Sections of Embankment on Deep Soft Ground Based on PLAXIS
Authors: Tang Mingli , Sha Yonghua , Chai Yucheng , Zhang Yidi
Published: May 2020

The article analyzes the uneven settlement of the dam gate connection section of a reclamation project along the coast of eastern Zhejiang by PLAXIS finite element software, and compares and analyzes the in-situ monitoring results to understand the settlement development law of the dam gate connection section during operation and the location of the largest uneven settlement. Through analysis, after the sluice and the seawall are connected, the sluice settlement in the first year of the operation period is 5.51 mm, the settlement at the seawall is 105.30 mm, and the settlement difference is 99.79 mm; the cumulative settlement of the sluice is 9.01 mm, and the cumulative settlement at the seawall is 214.00 mm and the settlement difference is 204.99 mm. The uneven settlement of the connecting section of the dyke is mainly manifested at the junction of the empty box of the sluice and the riprap area of the seawall. When the uneven settlement is large, it will cause road cracks.
Slope Stability Analysis of Levee
Authors: Su Kai
Published: May 2020

The stability of levees can be affected during fluctuations in the water table. It is also possible for the flood caused by the typhoon to have an influence on the position of the water table in an earth levee. This paper compares the traditional methods methodology with a combination of transient seepage and slope stability analysis for analyzing rapid drawdown scenarios. Firstly the stability of a levee was calculated by conventional methods, then considering the effect of water level changes in the seepage area, the simulated transient pore-water pressure response from a finite element SEEP / W analysis was used for levee stability simulation. The Silt Solidified Piles have a positive effect on the stability of the levee. The result s provide design basis for the projects.
Study on Static and Dynamic Release Characteristics of River Sediment Pollutants
Authors: Xu Xiaolong , Zhan Xinjie , Yang Shouhua , Li Wenwei
Published: May 2020

As the main accumulation reservoir of various pollutants, the sediment plays a very important carrier role in the process of migration and transformation of pollutants. In this paper, based on the test device such as the annular water tank developed, the pollutant release characteristics of the river sediment under still water and moving water conditions were studied. The experimental results show that the content of pollutants nitrogen and phosphorus in river sediments in Nanjing is higher and the content of heavy metals is lower. The static release of pollutants in the sediment reached an equilibrium state in about 60 hours, and the release was faster in the early stage, and the release rate in the later stage gradually slowed down and tended to the equilibrium state. The velocity of river water flow directly affects the release characteristics of sediments. As the water flow velocity increases continuously, the sediments have three states: “not started”, “small amount of movement” and “general movement”. The ratio of pollutants (total nitrogen, total phosphorus, heavy metals) release to total pollutants in the sediment of the river under still water conditions is 0.96%, 0.09%, 0.01-0.06%, about 18.46%, 15.43%, and 0.05-4.55% under hydrodynamic conditions, which are much higher than the amount of pollutants released under hydrostatic conditions, and the release amount of heavy metals Zn and total phosphorus is more affected by hydrodynamic conditions than other pollutants.
Reservoir Construction Effect on the Fish Spawning Events
Authors: Zhang Lina , Wang Xu , Lei Xiaohui , Wang Hao , Wang Jia , Zhang Cheng , Li Ting
Published: May 2020

The process of rising flow and the water temperature are the important factors affecting the richness of fish seedlings after the construction of the reservoir. The changes of ecologically significant environmental flow components in the lower reaches of the Hongshui River before and after the construction of the reservoir are compared and analyzed. The study analyses and compares the changes of environmental flow components of spawning period before and after the spawning period in order to find out the distribution characteristics of environmental flow components of during the main spawning period before and after the construction of the reservoir. Using the ZSN to standardize the flow and water temperature, and then analyzing whether to cooperate between the flow and water temperature, and whether it is beneficial for fish spawning and reproduction of fish under the combined effect of the rising water and water temperature.
Evaluation of river connectivity based on TOPSIS model: Taking the North District Expansion Zone of Zhangjiagang Economic Development Zone in Jiangsu Province as an Example
Authors: Yu Genting , Xu Haibo , You Aiju , Hu Keke , Hu Lin
Published: May 2020

The river system connectivity has become an important indicator of current river health assessment. The proper connectivity of river systems has the functions of allocating resources, improving water and soil environment, and preventing floods and droughts. However, it will be affected by many factors. In this paper, take Zhangjiagang, Jiangsu Province as an example, the influence degree of the structural connectivity index (expressed as static indicators) and hydroconnectivity index (expressed as static and dynamic indicators) on the connectivity of river flow system is analyzed based on the TOPSIS model. The study finds that the order of influence of each index on the connectivity of water system in the study area is: The structure connectivity index (α、 γ) is greater than hydrological connectivity index (R

b
、 W

p
、 R

d
、 E

p
、 C

EN
), and the Closeness T

j
=(0.546, 0.546, 0.471, 0.479, 0.506, 0.519, 0.463). when analyzing the regional scale, we should consider the local conditions and consider comprehensively from the perspectives of structural connectivity and hydrological connectivity. The results of the study hope to provide theoretical basis for water system planning and management.
Research on the computer system of train set shunting plan safety optimization of the hub type high-speed railway station
Authors: Guo Bin , Zhu Xiaoning , Wu Wanjing
Published: May 2020

Because the high-speed railway lines have connected into a network in China, the research of safety optimization of train set shunting plan of the hub type high-speed railway station is of great practical significance. To solve this problem, a time-space conflict resolution algorithm is proposed to minimize the total wait time of the train set on the station track, to optimize the timing and route of the train set shunting operation in two dimensions, and thus eliminate the route conflict. A computer system is developed based on the algorithm, a real world case study shows that the algorithm can eliminate the train route conflicts, ensure the safety of the plan, and the total wait time of the train set on the track is significantly decreased, and the utilization efficiency of the track is improved.
Study on Asymmetric Closure Scheme of Rigid Frame-Continuous Beam Composite System Bridge
Authors: Sun Hao , Zhang Xiao , Sun Jimei
Published: May 2020

The rigid frame-continuous beam composite system bridge has many spans, and the pier layout is different, and the demolition of temporary anchorage of pier and beam needs to undergo system transformation. Therefore, different closure sequence and the demolition time of temporary anchorage of pier and beam will have certain influence on the internal force and alignment of the main girder after completion of the bridge. Based on the practical engineering of the rigid frame-continuous beam composite system bridge constructed by asymmetric closure, four closure schemes were designed from two aspects: asymmetric closure sequence and temporary anchorage and demolition sequence. Based on the finite element model, the internal force and alignment of the main girder of the four closure schemes were compared and analyzed, and the general rules of closure of this type of bridge construction were summarized. The analysis and comparison results showed that the internal forces of the main girders are basically the same with different closure schemes, and the final linear shape of the main girders is different with different closure sequence. The results of this study can provide technical reference for sunhao2006@foxmail.com similar bridge construction decision-making and closure scheme determination.
Contribution of RC slabs to progressive collapse resistance of RC frame structures
Authors: Hou Jian , Sun Xiaoguang
Published: May 2020

The present study investigated the contribution of RC (reinforced concrete) slabs to progressive collapse resistance of RC frame structures based on experiment and numerical calculation. During the progressive collapse of a RC frame structure under a center column removal, the damage of floor slabs was obviously observed. This indicates that the RC slabs have a significant effect to the progressive collapse performances of the frame structures. Based on the failure phenomenon of RC slabs and its resistance mechanism of progressive collapse, a simplified calculation model of progressive collpase resistance of RC slabs was proposed. The contribution to collapse resistance and the proposed model of RC slab were verified using experimental and numerical calculation results with and without slabs.
Discussion on Monitoring Method for Horizontal Displacement of Supporting Pile Top of Deep Foundation Pit in Urban Rail Transit Project
Authors: Xu Yiteng , Yuan Fanglong , Wang Dayong , Yu Zhifa , Li Lixin
Published: May 2020

The horizontal displacement monitoring of the supporting piles plays a vital role in the safety judgment of deep foundation pit excavation and construction of main structure. In urban rail transit engineering, the monitoring of horizontal displacement of retaining pile top of deep foundation pit should be carried out according to the characteristics of the project, formulated a scientific monitoring plan, and selected a reasonable monitoring method. If necessary, the monitoring methods should be optimized and integrated, so as to get the real and effective monitoring data, which can reflect the change of the horizontal displacement of the foundation pit support structure to the greatest extent. By analyzing several common methods of deep foundation pit monitoring in current urban rail transit projects, the advantages and disadvantages of each method are summarized, and reasonable suggestions are proposed for accurate monitoring.
Influence of the pier heights on the seismic response of large rigid frame bridges in mountain regions
Authors: Li Xiaoqiong , Hung Lam Louis Chi
Published: May 2020

In recent years, several large rigid frame bridges with piers over 100 meters have been built in mountain regions in China. However, few studies are focused on the influence of the height of piers on the seismic performance of these bridges. Based on the sizes of piers of the existing large continuous rigid frame bridge in the world, finite element models with different pier heights of the bridges are established and dynamic analysis are conducted subjected to three-dimensional multi-support excitation. The seismic response of the structures is studied with the change of pier heights and natural periods. The results show that in actual engineering designs, it is strongly recommended that the adjacent piers with similar heights or very different heights should be avoided. The conclusion also provides suggestion to the design of large rigid frame bridges afterwards.
Effect of Carbon Nanofibers on Strength and Pore Structural Characteristics of Concrete
Authors: Zhang Hengbo , Xu Jinyu , Nie Liangxue
Published: May 2020

In order to investigate the influence of carbon nanofibers (CNFs) on the strength and internal pore structural characteristics of concrete, the carbon nanofibers reinforced concrete (CNFC) specimens with the content of 0%, 0.1%, 0.2%, 0.3% and 0.5% were prepared. The characteristics of the internal pore structure of specimens in each group were analyzed by the method of mercury intrusion porosimetry (MIP). The results show that the appropriate amount of CNFs has a significant enhancement effect on the strength of concrete, but the excessive amount of CNFs (0.5%) will weaken the performance of concrete; CNFs can effectively reduce the total pore volume and average pore size of concrete, and the internal pore structure of concrete can be improved reasonably.
Analysis of Urban Landscape Planning Based on Haze Environment
Authors: Zhang Yaoyao
Published: May 2020

With the acceleration of the urbanization process, the domestic economy has achieved rapid growth, but with the deterioration of the atmospheric environment, especially in cities with rapid industrial development, haze has been the primary air pollutant in recent years. All cities have been hit by haze. Frequent haze weather has seriously affected the lives of urban people, which makes us have to pay attention to how to deal with the haze problem. This article starts with the dangers of haze, analyzes the design principles of urban landscape planning, the active role of plant greening in the management of haze, and the method of arranging landscape plants. It shows that whether from the perspective of aesthetics, or from the function of anti-haze and environmental protection, the selection of a landscape design method that suits local conditions in the design will definitely be one of the major trends in urban landscape planning.
Energy Method on Dynamic Buckling of Elastic Bar with Clamped-Free boundary Condition subjected to Impact of Rigid Mass
Authors: Zhi Chaoyuan , Han Zhijun
Published: May 2020

Considering the effect of stress wave, the dynamic buckling problem of elastic bar with clamped-free boundary condition subjected to impact of rigid mass is studied using the energy method. The Lagrange function is built. Both of the trial function that satisfy the boundary conditions and the Lagrange function are substituted into the second Lagrange equation. After that an analytical expression of critical impact velocity can be deduced. By the analytical expression, it is obtained that the critical impact velocity is related to the impact mass of rigid block, the critical length and the inertia radius of the bar. The result show that the critical velocity decreases by increasing the impact mass and critical length, while increases by the increasing of inertia radius.
Characteristics of spontaneous commercial spaces in urban villages: a case study of three urban villages along Wuhe Avenue, Shenzhen City, China
Authors: Chen Shan , Zeng Qingyou
Published: May 2020

The mode of urban village renewal has changed from large-scale demolition and construction to organic renewal. The renewal of urban villages, especially commercial spaces, needs to be studied. Taking three urban villages along Wuhe Avenue in Longgang District, Shenzhen City, as examples, this study analyzed the characteristics of spontaneous commercial spaces and their existing problems. The study suggests that, for urban village renewal, the spontaneity and vitality of urban village businesses should be maintained and the environments of public spaces should be improved.
Sustainable Renewal of Recent-Past Detached House Based on Dynamic Development
Authors: Chen Wenchao , Yang Yifan
Published: May 2020

Through the analysis on the concept and characteristics of the recent-past detached houses, the necessity of sustainable renewal was expressed. On this basis, it analyzes the specific objects and technical routes of sustainable renewal of recent-past detached houses from multiple levels. Based on the aspects of building entities, external environment, and living form, this paper proposes a preliminary sustainable renewal strategy for the recent-past detached house.
Experimental study on static and dynamic mechanical properties of slag concrete
Authors: Chen Zhenfu , Li Shengbin
Published: May 2020

The slag concrete with 15%, 30% and 45% admixtures was prepared by the equal displacement cement method. The quasi-static mechanical properties of slag concrete were studied using a TYE-2000B pressure testing machine, and the dynamic mechanical properties of slag concrete under different strain rates were studied using a Φ100mm split Hopkin, and compared with ordinary concrete. Studies have shown that under quasi-static loading conditions, the compressive strength of slag concrete increases with the increase of slag content. Under dynamic load conditions, the strain rate sensitivity of slag concrete is significant. As the strain rate increases, the peak stress, strength enhancement factor and peak strain of slag concrete are significantly improved. In addition, the amount of slag is in the range of 0% to 45%. As the amount of slag increases, the dynamic compressive strength of the slag concrete increases.