bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uncertainty Evaluation of Wind Speed Sensor in Automatic Weather Station
Authors: Yang Zhen , Zhang Husheng , Wang Qiang , Li Cuicui , Xu Wenlong , Chen Shengyuan 
Published: May 2021

Abstract
Uncertainty is a description of the degree of uncertainty of measurement results affected by measurement errors. This article completes the repeatability test of the verification results according to “JJG (Meteorology) 004-2011 Automatic Weather Station Wind Speed and Direction Sensor Verification Regulations”. The author establishes a mathematical model to determine the source of uncertainty, calculates the uncertainty components item by item, and completes the analysis of the verification results of the anemometer standard device. This helps to ensure the reliability of the observation data of the meteorological wind speed sensor.
Study of Hydraulic Disturbance of Pumped Storage Unit
Authors: Li Gaohui , Wu Xumin , Cui WeiJie , Qiu WeiXin , Zhou Tianchi 
Published: May 2021

Abstract
The analysis of hydraulic disturbance is an important part of the analysis of the hydraulic transient process of a hydropower station. This paper introduces the relationship between the grid-connected operation mode of the power station and the hydraulic disturbance by the power station system, and performs simulation calculations under the same boundary conditions according to the hydraulic disturbance test cases, and predicts the extreme control conditions which provides the basis for the safe operation of the power station. It also provides reference for the design and calculation of similar projects.
The Study on Hydrodynamic Characteristics of Qianhai Bay in Shenzhen
Authors: Yang Yugui , Gao Shiyou , Tong Xiaolei 
Published: May 2021

Abstract
Based on the fixed-point observation data in Qianhai Bay of Shenzhen in May 2020, the horizontal and vertical distribution characteristics of tidal current, wave in summer near Qianhai Bay of Shenzhen are analyzed. The results show that the correlation coefficient of high and low tide level between the Qianhai Bay and Chiwan hydrological station is 0.98. The former Bay is dominated by irregular semidiurnal tidal current, which basically rotates anticlockwise. Due to the special shape of Qianwan Bay, the average velocity in the bay is small, but the maximum velocity of flood tide is 0.48m/s, the maximum velocity of ebb tide is 0.45m/s, the possible maximum velocity is 0.64m/s at the bay mouth. The average wave height is 0.07m, the normal wave direction is southwest West (WSW), and the average period is 2.9s.
Multi-time-scale nested optimal scheduling model for cascaded hydropower reservoirs
Authors: Shen Keyan , Qin Hui , Zhou Jianzhong 
Published: May 2021

Abstract
As more hydropower plants are in operation, it is difficult to balance the medium-and long-term benefits with the short-term benefits when developing an optimal scheme for power generation from cascaded hydropower reservoirs. And traditional models have difficulty making full use of the latest runoff forecast information. To overcome these problems, a multi-time-scale nested optimal scheduling model for cascaded hydropower reservoirs is developed. This model analyzes the level-by-level control strategy and rolling update mechanism between upper and lower level submodels. An efficient algorithm for solving the model is also given. In this study, the model is applied to four cascaded hydropower reservoirs located at the Yangtze River. The case study shows that the developed model can better coordinate the medium- and long-term benefits with the short-term benefits, make full use of the latest forecast information, and enhance the power generation efficiency of the cascaded hydropower reservoirs. Compared with the results of the existing scheduling model, the total power generation from the proposed model is improved under the same boundary conditions.
Characteristics of NDVI Temporal and Spatial Variation in the Source Area of the Yangtze River and Its Response to Hydrothermal Conditions
Authors: Dai Xitong , Yao Liqiang , Yuan Zhe , Sun Keke 
Published: May 2021

Abstract
vegetation cover change monitoring is the basis of regional resources and environmental carrying capacity research. Based on the data set MODIS-NDVI 2001∼2018, this paper analyzes the spatial and temporal characteristics of annual NDVI in the Yangtze River source area by using maximum synthesis method and various statistical methods. The effects of surface hydrothermal conditions on space and time were discussed. The results show that:1) the NDVI of the source area of the Yangtze River shows a significant increase trend, and only some areas of Dongyuan NDVI show a downward trend. In spatial distribution, the vegetation coverage in the source area of the Yangtze River is mainly low and medium vegetation coverage, the vegetation coverage increases gradually from northwest to southeast, and the vegetation coverage of Yushu Tibetan Autonomous region is generally higher than that of Hercynian Mongolian Tibetan Autonomous region. At above 4000 m, the vegetation coverage increases more obviously with the increase of altitude. 2) precipitation in the source area of the Yangtze River decreases gradually from southeast to northwest, the low value area is located in the north of the source area of the Yangtze River, and the high value area is located in the eastern part of the Yushu Tibetan Autonomous region. However, the spatial trend of annual mean temperature and precipitation in the source area of the Yangtze River is opposite. The precipitation tendency rate in the source area of the Yangtze River shows obvious spatial difference, the precipitation in the south source generally shows a decreasing trend, and the precipitation in the north source generally shows an increasing trend. The southwest source and east source NDVI of 3) Yangtze River source area are negatively correlated with precipitation, while NDVI and temperature are positively correlated in most areas of the Yangtze River source area, and the effect of temperature on interannual variation is stronger than that of temperature. With the increase of temperature and precipitation, the NDVI also shows an increasing trend in spatial distribution, but precipitation has a stronger effect on the spatial heterogeneity of NDVI. From this we can see that the influence of hydrothermal conditions on the interannual variation of NDVI depends on the temperature, while the effect on spatial distribution mainly depends on the precipitation.
Relationship between chloride diffusion coefficient and ASTM C1202 electric flux under different environments and durability evaluation
Authors: Dong Wenxiu , Zhou Ming 
Published: May 2021

Abstract
The relationship of the diffusion coefficient and charge passed is developed employing the analysis of the traditional model and 244 groups of experimental data. The differences in the types of concrete were considered to determine the variation coefficient of the diffusion coefficient in the models. Results revealed that the different environmental conditions of the concrete chloride diffusion coefficient cannot be described solely by the existing maturity method. Reasonably good agreement is observed between the experimental and computational model of this paper, thus indicating that the proposed prediction model can be successfully used to estimate the chloride diffusion coefficient. An example of a durability assessment is performed to verify the applicability of the concrete durability assessment method. The concrete durability assessment method can control the durability quality and direction of the production of concrete.
Case analysis of in-situ stress coal and gas outburst and prevention countermeasures
Authors: Wang ZHonghua 
Published: May 2021

Abstract
The coal and gas dynamic disasters in Fengcheng mining area are serious. There are currently 6 pairs of coal and gas outburst mines. In view of the increase in the proportion of in-situ stress-oriented outbursts in the mining area as the mining depth increases, the establishment of classified disaster control measures is proposed. Stereo gas drainage system, and proposed to explore the use of deep hole pre-splitting blasting, roof strike long drilling, hydraulic reaming, hydraulic fracturing and other new technical measures. It is of great significance to safe and efficient production in mining areas.
Influence of rare earth elements on microstructure and strengthening mechanisms of Mg-12Gd-3Y-0.5Zr magnesium alloy
Authors: Yang Xiaoming 
Published: May 2021

Abstract
Mechanical properties of Mg-12Gd-3Y-0.5Zr (GW123K) including tensile strength and isothermal fatigue limit were tested by MTS810 system. Experimental results show that it has higher mechanical properties at different temperatures than other magnesium alloys without rare earth elements addition. Influence of rare earth elements on its microstructure and strengthening mechanisms are disscussed in this paper. SEM and TEM analysis indicates that rare earth elements additon leads to grain refinement and restricts grain boundary sliding and fatigue crack propogation.
Ba, Co modified activated clay and their adsorption performance characterization
Authors: Yang Jie , Wang Yajun , Tian Changan , Lai Shikang , Liu Yang , Si Xiaoqiang , Zhang Qing 
Published: May 2021

Abstract
A series of modified activated clay composite materials were prepared by solvothermal method. The modified samples were tested and characterized by a series of instrument methods. The modified activated clay materials with good adsorption effect, simple process and low cost were synthesized by doping different metal ions. The adsorption properties of the modified activated clay materials were investigated. The results show that the (Ba, Co)-activated clay modified samples can be used as adsorbents to remove Congo red organic dye wastewater, and the activity is greatly improved compared with the activated clay, the adsorption capacity is greatly enhanced. The particle size is small, and it has good thermal stability. When the initial Congo red concentration is 100 mg/L and the adsorption time is 140 minutes, the maximum adsorption capacity of Ba-activated clay is 371 mg/g, and that of Co-activated clay is 338 mg/g.
Research on Anti-reflection Measures of Hydraulic Reaming of Low Permeability Soft Coal Seam in Goutou Coal Mine
Authors: Reng Feng 
Published: May 2021

Abstract
According to the C5 coal seam of gully head coal mine complex geological conditions Poor permeability gas pressure is big Coal seam gas content is high Soft coal extraction from standard time is long, etc., combined with high pressure water jet force reaming technology principle and characteristics of the gully head coal mine is put forward using the method of integration of bottom hole drill wear layer expansion technical measures to increase coal seam permeability, and within the scope of the field to carry out the experimental study. In soft coal seam through field experiment research shows that the drilling construction process, through the integration of enlarging anti-reflection technology measures, can effectively improve the exposed area of a single layer of bore, change of coal seam and the stress distribution state of joints, thus improve the wear layer drilling drainage concentration and smoke volume, shorten the wear layer drilling extraction from standard time to the success of the test for the mine and similar mine to improve coal seam permeability is to provide the basis.
Research on characteristics of coal and gas outburst in deep mines
Authors: Wang ZHonghua 
Published: May 2021

Abstract
The single B4 coal seam mined in Fengcheng mining area is a gently inclined medium-thick coal seam, with high gas pressure and high content, soft coal seam, low air permeability, and serious coal and outburst disasters. According to the gas occurrence characteristics of Fengcheng mining area, the characteristics and laws of 186 outburst accidents in the mining area are statistically analyzed, and the characteristics of in-situ stress coal and gas outburst are obtained. It provides theoretical guidance for the prevention and control of gas dynamic disasters in mining areas, which is of great significance to safe and efficient production in mining areas.
Experimental investigation of dynamic shear behavior of typical silt sand in Rudong Offshore Wind Farm
Authors: Xiao Xian-bo , Xu Hai-yan , Yang Xiao-nan , Xu Xue-yong 
Published: May 2021

Abstract
The dynamic properties of typical silt sand in offshore wind farm are closely related to the stability of offshore wind farm foundations. This study investigates the dynamic behavior of typical silt sand in Rudong offshore wind farm of Jiangsu province based on dynamic triaxial testing and resonant column testing. Specifically, the dynamic properties including dynamic modulus, damping ratio, dynamic strength, dynamic strain, dynamic pore water pressures and stress-strain relationship of the silt sand are studied. It is found that the accumulated strain and pore pressure continuously increase with the increased cyclic number, which eventually leads to liquefaction failure. Soil specimen with a higher confining pressure is more likely to reach liquefaction with a lower number of loading cycles. It is also found that the Hardin-Drnevich model can be used to reflect the mechanism of the effect of confining pressure on the dynamic behavior of the silt sand. The dynamic shear modulus and damping ratio decrease and increase exponentially with the increase of shear strain, respectively.
Adaptability Analysis for Sand Proppant to Conglomerate Oil Reservoir in Well-block MA 131 of Xinjiang Oil Field
Authors: Chen Ang , Zhang Zhao , Tang Wei , Wang Lei , Yu Huiyong 
Published: May 2021

Abstract
SRV (Simulated Reservoir Volume) in horizontal well is a main instrument for exploiting dense conglomerate oil reservoir in Ma Lake. The expenses of proppant are about 25% to 30% of the total SRV costs. In order to reduce costs and improve efficiency, it is inevitable to replace ceramic proppant with quartz sand, because the price of quartz sand is significantly lower than ceramic proppant. With Well-block Ma 131 as an object, this paper analyzes post-SRV production result of the existing alternative sand well; creates simple fracture and curved fracture model based on features of conglomerate oil reservoir; plots required conductivity of the target area through simulation and calculation; and analyzes adaptability of sand proppant to the target area based on conductivity data of sand proppant. The results indicate that the required conductivity of Well-block Ma 131 changes within 10 and 35 D·cm; quartz sand can accommodate production demands completely when closure pressure is low; and required conductivity can be realized through improving sanding concentration when the closure stress is high.
Sediment Transport and Diffusion in the Yellow River Estuary in 2018 Based on Numerical Analysis
Authors: Liangchao Ma , Caodong Jiang , Dongfeng Li , Hongwu Zhang , Zihao Li 
Published: May 2021

Abstract
As the river with the highest sediment concentration in the world, the Yellow River carries a huge amount of sediment in the Yellow River estuary every year. The Yellow River estuary extends and forms a forward extension zone of land-sea interaction. It is of great significance to fully understand the movement and diffusion law of the sediment from the Yellow River to the sea and keep the balance of scouring and silting. A two-dimensional mathematical model from Luokou to the Yellow River estuary and Bohai Bay was established, and the diffusion law of sediment movement in the Yellow River flood and dry season was obtained by simulation calculation. The influencing factors of sediment movement and diffusion mainly include flood magnitude, sea level tide fluctuation and tidal current direction. The analysis of the movement range and diffusion rate of sediment under different conditions provides a reference basis for the control of the sand bar in the Yellow River estuary and the balance of scouring and silting in the lower reaches of the Yellow River.
Research on Biological Protection Engineering Construction on Downstream Levee of the Yellow River
Authors: Zhanjun Yuan , Feng Zhang 
Published: May 2021

Abstract
As an integral part of flood control engineering system, biological protection measures have always been attached great importance to by management units at all levels. Taking the calculation of the width of the breaktide belt in the lower reaches of the Yellow River as an example, this paper studies the great role of the protection works in ensuring the safety of the Yellow River project protection and the construction of water ecological civilization.
Evaluation and variation trend of groundwater quality in the area around Poyang Lake
Authors: Hu Binlong , Fu Shasha , Zhao Fengyao 
Published: May 2021

Abstract
Aiming to study the current situation and variation trend of groundwater quality in the area around Poyang Lake, the single factor index method was used to systematically analyze 19 indicators of 242 groundwater samples in the study area. Results showed that the overall quality of groundwater in the area around Poyang Lake is poor, with Type III water accounting for 19.01 %, Type IV water accounting for 36.36 % and Type V water accounting for 44.63 %, without Type I and Type II water. The Ammonia Nitrogen index of groundwater in Poyang Lake showed a trend of improvement. The Nitrate and Sulfate index showed a trend of deterioration year by year, on the contrary. And the Hardness, Mineralization degree, Oxygen Consumption and Chloride index showed a trend of stability year by year.
Analysis on the influence of reservoir group on the runoff of Datong station in dry season
Authors: Zeng Ming , Li Jiqiong , Min Yaowu , Yang Shanshan , Li Jie 
Published: May 2021

Abstract
Datong Station is an important controlling station in the lower reaches of the Yangtze River. Analysis on the influence of upstream reservoir group on the runoff change characteristics can provide theoretical support for the utilization and sustainable development of water resources in the lower reaches of the Yangtze River and the Yangtze River Estuary. Based on in-situ observation and mathematical statistics, this paper analyzes the runoff composition of Datong Station and the influence of reservoir group on the runoff of Datong Station in dry season. The main conclusions are as follows: the water inflow from Yichang and above is the main component of Datong Station runoff. The operation of upstream reservoir group adjusts the water inflow distribution of Datong Station to a certain extent. The water replenishing of reservoir group increases the runoff of Datong station obviously from November to March of the following year (dry season), which has a positive effect on resisting the saline water intrusion in the Yangtze River estuary.
Performance evaluation of Tanh and AWBM rainfall-runoff models
Authors: Li Yining 
Published: May 2021

Abstract
The present study compares the performance of two rainfall-runoff models including Tanh model and AWBM model for streamflow simulation. The Tanh model is a 2-parameter empirical model, and the AWBM is a 9-parameter conceptual model. The Tullaroop Creek sub-catchment at central Victoria is selected as the study area. Rainfall and streamflow data measured from the catchment are the major inputs to these models. The Tanh function is used as a simple rainfall-runoff relationship for the Tullaroop Creek catchment and it estimates annual runoff by using curve fitting of the rainfall runoff plot. The AWBM model is calibrated and validated for two periods: 1974-1987 and 1987-2000, respectively. The Nash–Sutcliffe Efficiency is computed to evaluate the efficacy of model predictions. From the results obtained, it is found that the AWBM model can provide adequate estimates of annual runoff at the study catchments than Tanh model.
Finite element analysis of u-shaped reinforced concrete column
Authors: Li Jiuyang , Wang Xiaoyu , Ma Weinan 
Published: May 2021

Abstract
Special shaped column is called frame column with special-shaped section. Under the condition of fully considering the strength and stiffness requirements of the whole structure, the U-shaped column is used in the new structural system of contemporary subway architectural pattern, which mainly uses special-shaped column instead of ordinary rectangular column to form the so-called “explicit frame”, so as to promote the interaction between steel and concrete, and greatly improve the bearing capacity of components power. In this paper, the bearing capacity, bending deformation and failure mode of U-shaped reinforced concrete column are analyzed through the finite element software ABAQUS under the change of wall thickness and height, which provides a theoretical basis for the future research on the performance of U-shaped reinforced concrete column.
Finite Element Simulation of Distressed Prestressed Concrete Cylinder Pipes Embedded in Soils
Authors: Guan Wei , Shang Feng , Nan Li Nan , Yao Meng Lu 
Published: May 2021

Abstract
Durability problems often occur to the prestressed concrete cylinder pipe embedded in aggressive soil environment. The residual performance assessment of damaged pipes is the basis of the maintenance strategy. This study proposes a soil-pipe interaction framework to simulate the limit states of the pipe with path-dependent modelling of each part of the pipe structure, surrounding soil and the contact state between them. Based on the analytical results, the limit states of the pipe can be ranked. Further sensitive analyses showed significance of the nonlinear soil-pipe interactions and the exact deformation is recognized as the aim of the future study.
Research on Application of MMA Super-solid Seal in Preventive Maintenance of Bridge Deck
Authors: Li Tao , Xu Jianhui , Wang Jie 
Published: May 2021

Abstract
In order to solve the problems of minor cracks, insufficient slip resistance, and lightening of the asphalt concrete bridge deck, the self-developed MMA super-solid seal is used to preventive maintenance of Yulong River Bridge and Baisha Viaduct of G65 Yangshuo to Pingle and G65 Guilin to Yangshuo expressways. The road performance of the MMA super-solid seal was evaluated. Engineering application results show MMA super-solid seal has a good preventive maintenance effect. The various road performance indicators (water permeability coefficient, bonding strength, sliding resistance, structural depth, etc.) meet the design requirements. MMA super-solid seal has a short maintenance time and excellent road performance, which is conducive to the sustainable development of road engineering. It can not only guarantee the service quality of the bridge deck, but also prolong the life of the bridge deck.