bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research and application of gas drainage technology by downward drilling holes
Authors: Qin Muguang 
Published: March 2021

Abstract
Aiming at the undesirable phenomenon of low drainage concentration and poor effect in the downward boreholes in Panjiang mining area, the gas drainage technology of “full casing, two plugs and one injection, sealed hole under pressure” and pressurized air and water was proposed. And the on-site implementation was carried out in 21126 transportation jacking lanes of Tucheng mine. The research results show that the pressurized air blowing water technology effectively solves the problems of down-drilling slag and water accumulation, improves the gas drainage effect of the down-draining drilling, effectively solves the problem of regional outburst prevention, improves the efficiency of excavation, and promotes the safety of mine production.
Evaluation of Local Scour Calculation Equations for Bridge Piers in Sandy Riverbed
Authors: Cao Jin , Chen Juxiang , Zhu Dayong , Wei Song 
Published: March 2021

Abstract
Local scour depth is the key index of foundation design of bridge across river. At present, there are many equations to calculate the scour depth of bridge piers, but the results of different equations vary greatly. It is still a difficult problem for bridge designers how to choose the appropriate equation for calculating local scour depth. Six typical equations for calculating local scour depth were selected to compare and analyze the influences of pier width, velocity, water depth in front of piers and bed sand particle size on the local scour depth. The results showed that bed sand particle size and geometric non-uniformity coefficient had the most significant influence on the scour depth. It was proposed that the prediction equation should be selected according to the size range and uniformity of bed sand.
Effect of Mechanochemical Activation on Peat Humic Acid
Authors: Ge Lei , Yang Chenxi , Wang Jian 
Published: March 2021

Abstract
Mechanochemical method is an efficient processing method that uses mechanical means to change the structure and physical and chemical properties of objects. This article takes peat from Erlintu Town, Yuyang District, Yulin City, Shaanxi Province as an example. It is activated by mechanochemical method, and then humic acid and fulvic acid are extracted by alkali-soluble acid purification technology. The results show that mechanochemical the method can improve the extraction rate of humic acid and fulvic acid in peat. Among them, the mechanochemical method with percarbonamide as the oxidant and sodium hexametaphosphate as the grinding aid has the best effect of activating peat. Mechanochemical methods can increase the molecular condensation degree and molecular relative mass of humic acid, but reduce the molecular condensation degree and molecular relative mass of fulvic acid.
Research on the current situation and Development Countermeasures of Wenzhou digital agriculture
Authors: Tang Wenjie , Lin Chanjuan , Cui Xiaojun 
Published: March 2021

Abstract
Research on the current situation and Development Countermeasures of digital agriculture in Wenzhou the development level of county digital agriculture in Zhejiang province leads the whole country. As one of the important cities in Zhejiang Province, the development level of digital agriculture in Wenzhou does not match its status. This paper analyzes the current situation of digital agriculture in Wenzhou, and thinks that the digital agriculture in Wenzhou is relatively weak and unbalanced. It is necessary to further consolidate the foundation of digital transformation in Wenzhou agriculture and rural areas, comprehensively improve the digital level of Wenzhou agriculture industry chain, actively explore the new mode of Wenzhou digital agriculture integration, and build a digital skills popularization system for rural areas
The mechanism underlying grazing shaping stoichiometry of plant community on a grassland of Guizhou subtropical plateau
Authors: Ding Leilei , Zhang Yujun , Liu Jiajia , Zhang Wen , Wang Zhiwei , Ruan Xirui , Shu Jianhong , Wang Puchang , Liu Xiufeng 
Published: March 2021

Abstract
Livestock grazing is a traditional and major use of grassland in China subtropics. However, plant stoichiometry and how it was affected by grazing in these ecosystems have been poorly explored. Here, the responses in plant nutrition and stoichiometry as well as soil nutrition and stoichiometry under representative grazing intensities (i.e., moderate grazing and heavy grazing) compared with no-grazing were characterized, the drivers of plant stoichiometry were explored in a subtropical artificial grassland, SW China. Wilcoxon test showed that grazing intensity significantly changed the response of soil OC, TN, AN, AP, AK, pH, OC: TN, AN: AP, AN: AK, AP: AK, and AP: AK. Grazing intensity changed the response in N, ASH, EE, ADF, P, N: P, N: P, N: Ca and P: Ca of plant. Path analysis showed the effect of grazing intensity on the stoichiometric ratio of nitrogen and phosphorus in plant community was achieved through the removal of herbivores. Our research provides some mechanistic understanding of grazing management of subtropical grassland, and also provides new insights and useful reference for the protection and utilization of grassland in Guizhou Plateau.
Performance analysis and optimized design of a certain frame
Authors: Deng Shiping 
Published: March 2021

Abstract
In recent years, energy shortages and environmental pollution have become increasingly prominent, and automobile lightweight has become an important field in the development of the automobile industry. This paper analyses the frame performance of an all-terrain single-seat off-road vehicle and optimizes the structure design. The weight of the new structure has been reduced by 4.084 kg, and the weight reduction rate has reached 12.83%. The statics analysis and modal analysis of the new frame structure show that the new structure still meets the requirements of usage.
Fractal characteristics of soil particle size in loess hilly areas with different years of conversion
Authors: Meng Tingting , Jin Minghui , Cheng Jie 
Published: March 2021

Abstract
The purpose of this study was to investigate the change of soil particle composition and its effect on the fractal dimension of grassland under different years of conversion. The changes of soil particle composition and soil fractal dimension were analyzed by taking the 8-year grassland and 31-year grassland in the Yuanzegou watershed of the loess hilly region as the research objects, and taking the sloping farmland as the control. The results showed that the clay content of soil was increased by 69.6%, 47.6% and 8.80%, 8.7%, respectively, in the 31-year grassland and the 8-year grassland in the 0-20cm, 20-40cm. The decrease of sand content was 38.7%, 18.2% and 15.6%, and 13.5%, respectively, which were significantly different from that of the 31-years grassland (P<0.05). The contents of particles in the 40∼60cm soil layer did not change significantly. fractal dimension range from 2.6 to 2.7, the expression for the conversion of 31 years grassland>grassland>changing slope farmland 8 years, the fractal dimension of soil particles increased along with the increasing length of the grass farmland, in 0∼20, 20∼40cm soil layer, the conversion of 31 years grassland soil particles fractal dimension D and slope have significant difference (P<0.05). The fractal dimension of soil particle volume was positively correlated with soil clay (P<0.01), and positively correlated with soil particle size on farmland and grassland after 31 years of conversion (R2=0.6970, 0.6701), but not on grassland after 8 years of conversion. There was a negative correlation between soil sand content and fractal dimension of soil particles in the three plots, but there was only a significant difference in slope farmland.
Study on EOR method in high water cut stage of low permeability A Oilfield
Authors: Shi Yuhui 
Published: March 2021

Abstract
By using coring, logging, testing data and dynamic data of oil and water wells, the geological recognition, drive system evaluation and remaining oil research after infilling adjustment of different well patterns are carried out, the dominant channel of water drive and the existing position of remaining oil in different well pattern periods. It can be used for reference to improve development effect and oil recovery of other low permeability oilfields in high water cut stage A Oilfield is a typical low-permeability oilfield, which has the characteristics of poor physical properties, start-up fracture gradient and natural fracture development. After more than 30 years of waterflooding development, the oilfield has achieved good development results through multiple rounds of comprehensive adjustment of water injection wells and oil well measures. But at present, the oil field has entered the high water cut stage, the remaining oil is more scattered, the effect of adjustment means is poor, and the oil recovery rate is reduced, so it is necessary to explore the technical methods to improve the development effect and further enhance the oil recovery. In this paper, the recovery of oil field is evaluated by using the results of indoor core, empirical formula method and reservoir engineering method, and the potential of readjustment of oil field is clarified. Secondly, the reservoir geological recognition and multi-disciplinary remaining oil recognition are carried out, the dominant channel of water drive is identified, the type, existing position and formation reason of remaining oil are clarified, and the comprehensive treatment countermeasures based on the corresponding adjustment and plugging at both ends of oil and water wells are put forward; the application means of periodic water injection is developed, and the cooperation with deep water adjustment and flooding is explored, so as to further expand the affected volume, Methods of EOR. The typical application well area effect has been obviously improved, which provides reference for other low permeability oil fields to improve development effect and enhance oil recovery.
Organic reconstruction and application of soils
Authors: Lei Na , Zhang Yang , He Jing , Dong Qiguang 
Published: March 2021

Abstract
The organic reconstruction of soil generally means that human beings adopt engineering methods to give full play to their subjective initiative under the premise of respecting the laws of nature, so that the process of soil formation is accelerated, slowed down or reversed, and the organic process is driven by inorganic means or promoted by organic development. In actual operation, the soil can be reconstructed by using physical, chemical and biological reconstruction methods through technical means such as replacement, compounding, addition and reduction. The soil construction can increase the area of arable land, relieve the shortage of land in our country, and at the same time improve soil quality, ensure regional food security, build a new ecosystem, and ensure regional sustainable development.
A Prediction-Based Truck Scheduling Method for Open-Pit Mines and Its Numerical Study
Authors: Tian Fengliang , Sun XiaoYu , Gu XiaoWei , Chen Yu 
Published: March 2021

Abstract
In this paper, we proposed a two-stage approach to use real-time prediction for truck scheduling in open-pit mines. We studied the truck scheduling problem using two economic concepts: risk and utility. To schedule trucks by computer, a recursive formula of the truck loading time has been established in this paper. The utility is used to measure the benefit that may be gained by using a particular scheduling strategy. The risk is used to measure the difficulty for a truck to be loaded in time. Inspired by Occam’s razor, we noted the relationship between the risk and the number of factors considered in the algorithm. On this basis, how to reduce the risk of scheduling when the prediction is inaccurate is studied. To verify these methods, we performed simulation experiments based on real data. The experimental results show that our approach can balance the efficiency of trucks and shovels. The impact of the inaccurate prediction on the output can be reduced by risk reduction.
Research on the Path of Cultural Integration of Landless Farmers in Weifang City Based on New Urbanization
Authors: Yu Yuan 
Published: March 2021

Abstract
Based on the current situation that culture integration is difficult in the social integration of land-losing farmers, focusing on the improvement of culture, literacy and knowledge and skills of land-losing farmers, aiming at the problems such as the imbalance between cognitive level and modern development level, the great difference between urban and rural lifestyles, and the disconnection between knowledge and skills and the employment market demand, this paper takes the cultural adaptation in the city and the creative transformation and inheritance of rural culture as the foothold, deeply analyzes the cultural root of the cultural integration dilemma, and tries to provide a feasible path to solve the exploration and research on the cultural integration of land-losing farmers in Weifang based on new urbanization.
Exploration on Reform of Materials Forming and Control Engineering for Intelligent and Additive Manufacturing
Authors: Chen Zezhong 
Published: March 2021

Abstract
With the development of new technologies such as intelligent manufacturing and additive manufacturing, it is necessary to reform and upgrade traditional major of materials forming and control engineering. In 2019, the major of materials forming and control engineering in University of Shanghai for Science and Technology successfully passed China engineering education certification. In order to meet the requirements of continuous improvement, new courses on intelligent manufacturing and additive manufacturing are added into the new training program of the major, and new major orientations are designed in the curriculum system, which can better fit the training demand of excellent talents from advanced manufacturing industries of Shanghai and Yangtze River Delta.
Analysis of Iterative Deepening A* Algorithm
Authors: Jiang Wenrong 
Published: March 2021

Abstract
The A* algorithm is a direct search method. It can effectively solve the shortest path problem in static routing networks. It is also an effective method to deal with a large number of search problems. The closer the artificially estimated distance value in the algorithm is to the actual value, the faster the final search speed will be. This article focuses on the heuristic A* algorithm and discusses the problem of out-of-order Rubik’s Cube searching the shortest feasible solution. It discusses the implementation ideas, advantages and disadvantages, and practical application value of the A*(IDA*) algorithm based on iterative deepening. The development of heuristic algorithms presents some personal insights.
A Fuzzy Comprehensive Evaluation Approach for the 3D Modeling Accuracy of UAV Oblique Photogrammetry
Authors: Zhang Zhaohu , Zhang Yongzhi , Yong Zhaojun , Liang Jinzheng , Ye Xinyang , Zhang Qiuwen 
Published: March 2021

Abstract
3D modeling is the important foundation of virtual reality and scene simulation. The technology of UAV oblique photogrammetry provides a new way for 3D modeling, and the accuracy becomes the key of its application. Since there are a lot of uncertainties in 3D modeling of UAV oblique photogrammetry, this paper proposed a fuzzy comprehensive evaluation approach to deal with this uncertain problem. Firstly, according to the composition of 3D modeling system based on UAV oblique photogrammetry, the main impact factors of 3D modeling accuracy are determined, and the indicator system of accuracy evaluation is therefore constructed. Secondly, by using the method of analytic hierarchy process, the weights and membership degrees of each indicator are calculated. Finally, the proposed approach is applied and validated in the case study. After the fuzzy mapping by the dot multiplication performance between the indicator weights and membership degrees, the comprehensive evaluation sets of different cases are obtained, and their corresponding 3D modeling accuracies can be determined based on the maximum membership degree principle. It is concluded that the fuzzy comprehensive evaluation approach proposed in this paper can quickly and correctly assess the 3D modeling accuracy of UAV oblique photogrammetry.
Analysis of Maximum and Minimum Temperature in Qilian Mountainous, Northwest China
Authors: Zhao Chuancheng , Gao Hongkai , Yao Shuxia , Zhou Jiaxin 
Published: March 2021

AbstractAs one of the key elements of climate change, the temperature changes can affects the energy balance and hydrological cycle. The variations and trend of mean annual maximum temperature (Tmax) and minimum temperature (Tmin) were analyzed by using linear regress for 44 stations inside and surrounding the Qilian Mountains for period of 1960-2017. The results have shown that the variations of mean annual Tmaxand Tminhave significant increasing in whole study regions. The warming trend of mean annual Tmixis higher than that of Tmax. Both the trend of mean annual Tmaxand Tminin the southern slope is warmer than those in the northern slope of Qilian Mountains. In spring, the warming trend of Tmaxis significantly weaker inside than that outside the Qilian Mountains. For all seasons, the trend of Tmaxand Tminis the highest in winter, and is weakest in spring.
Aspect-Based Sentiment Analysis Based on Multi-Channel and Dynamic Weight
Authors: Cheng Jin , Yi Huixiong 
Published: March 2021

Abstract
With the wide use of graph convolution network (GCN) in various NLP tasks, researchers introduce GCN to aspect-based sentiment analysis. They utilize GCN over dependency tree to capture the syntactic information and obtain the final representation by modeling the interaction between the semantic and syntactic information. However, due to the unreliability of the construction of dependency tree, these interaction-based models may suffer from the side effect of unreliable syntactic information. To tackle the problem, we propose a multi-channel aspect-specific attention mechanism to ease the possible side effect by retaining and exploiting the original semantic information, which is not affected by the syntactic information. We also propose a dynamic weighted concatenation mechanism to sufficiently utilize the multi-channel information by dynamically assigning weights to the multi-channel information. The extensive experiments on five benchmark datasets indicate the effectiveness of the proposed mechanisms.
Error Analysis and Process Parameter Optimization of Impeller Model Manufactured by FDM Process
Authors: Zhou Huiqun , Zhao Guoxiang 
Published: March 2021

Abstract
Through the process of making impeller model by Fused Deposition Modeling (FDM), the error of 3D printing forming process was analyzed, including principle error, forming error and post-processing error. The error caused by measurement is analyzed, and the causes of the error and the solving methods are expounded in detail. By analyzing the errors in the size of impeller models, the possible causes of errors can be analyzed. Combining the forming conditions and the actual situation, the optimization method of process parameters is analyzed, which can provide a certain reference for 3D printing production and testing the best process parameters.
The Effect of Turbidity on Functional Responses of European Shore Crab
Authors: Wang Ning 
Published: March 2021

Abstract
Understanding the mechanisms of the natural environment that affect the interaction between consumers and resources is the key to understanding the stability and function of ecosystems. Although the effects of many environmental factors on predator-prey interactions have been well studied, turbidity in aquatic ecosystems is not one of them. Turbidity is ubiquitous and can be important because it is related to water pollution and can significantly reduce visibility of both predator and prey. In this study, the effect of turbidity on the interaction between the shore crab Carcinus maenas and the gammarid amphibians Echinogammarus marinus is studied. The functional response of the predator (crab) under different turbidity levels (consumption rate under different prey (shrimp) densities) was quantified, and it was found that turbidity increased the search speed and handling time. In zero turbidity, that is, completely clear water, the performance of the predator (crab) is not as good as the performance under low turbidity conditions. This may be caused by many reasons, such as the crab is get used to low turbidity conditions because they live at the bottom of intertidal and they will stir up sand at the bottom when they are moving. However, in order to better understand how the interaction between consumers and resources responds to turbidity, more research is needed.
The Research on Traffic Assignment Method Based on the Urban Road Network Topology
Authors: Zhang Qiang , Wang Bin , Liu Yan 
Published: March 2021

Abstract
As our country urbanization and economic development accelerating, traffic problems become increasingly serious. In urban road network, the intersection delay has a major influence on road impedance even the choice of the path. In order to reflect the actual situation of traffic flow distribution more accurately, the transportation network assignment model was established based on the intersection flow of delays and traffic control.
By comparing delay models of signal control and analyzing the intersection impedance, the intersection optimization model was built based on delay, queuing and traffic capacity. Then, we analyzed the structure of the road network topology and traffic assignment models, researched the advantages and disadvantages of the allocation algorithm in detail. Finally, the balanced allocation algorithm for FW algorithm convergence slowly was improved. The feasibility of the algorithm was verified by examples.
Research on Baseflow Separation Based on Single Parameter Digital Filtering Method
Authors: Zhou Jiaxin , Zhao Chuancheng , Li Qingfeng , Yang Ruiqi 
Published: March 2021

Abstract
Baseflow is the main source of supplement for rivers during dry seasons. The reliable separation methods play an important role in baseflow research and water resources management and utilization. Based on the daily runoff data of Changmabao hydrological station in the upper reaches of Shule River from 1957to 2016. Based on the parameter calibration of the single-parameter digital filter method, the single-parameter digital filter method is used to study the baseflow separation of the study area. The results show that that the optimal parameter combination is when the filtering parameter is 0.975 and the filtering times is 3. The multi-year average BFI value obtained by the single-parameter digital filtering method is 0.742. The high Nash-Sutcliffe efficiency coefficient and the average relative error is less than 10%, indicating that the baseflow estimation results of this method is stable, reliable and accurate.
Quantitative Analysis and Prediction of the Worldwide COVID-19 Pandemic
Authors: Pan Xiaohui 
Published: March 2021

Abstract
At present, the novel coronavirus disease 2019 (COVID-19) has spread rapidly worldwide. As COVID-19 impacts societies, governments, communities, and individuals, we want to provide information for governments and people to understand the situation better. In this paper, we perform quantitative analysis and prediction of the global COVID-19 pandemic. First, we summarize worldwide confirmed, recovered, death, and active cases. Second, we select eight representative countries and analyze their confirmed and death cases with considering their populations. Third, we exploit the AR model in machine learning to predict the cases of these representative countries for the next 30 days. Our analysis and prediction show that some countries, including the United States, Spain, and Brazil, are in and will still be in the severe COVID-19 outbreak. This work can provide reference information for the prevention and control of COVID-19.