bluuebunny/crossref_metadata_2025 huggingface dataset:
Do persons with low socioeconomic status have less access to greenspace? Application of accessibility index to urban parks in Seoul, South Korea
Authors: Heo Seulkee , Nori-Sarma Amruta , Kim Sera , Lee Jong-Tae , Bell Michelle L
Published: July 2021

Access to urban greenspace has many benefits such as improved health and social cohesion. If access differs by population, these benefits make access to greenspace an environmental justice issue, but little is known regarding accessibility of parks among different sub-groups in Seoul, South Korea. We explored potential socioeconomic inequities for access to parks in Seoul measuring two park provision metrics: total park area per capita (TPPC), and park accessibility index determined by size and proximity of parks. We assessed correlations between a deprivation index for the 25 Gus (administrative unit equivalent to the US borough) and each park provision metric. Regression analyses were applied for the associations between eight socioeconomic indicators of the 424 Dongs (equivalent to the US neighborhood) and each park provision metric. An interquartile range (IQR) increase in percent elderly (⩾65 years) (3.2%) was significantly associated with larger TPPC (1.6 m2/person, 95% CI: 0.8, 2.4). Park accessibility index was associated with more socioeconomic variables than was TPPC. An IQR increase in percent elderly and divorce rates (1.2/1000 population) was associated with increased park accessibility by 3571 km (95% CI: 1103, 6040) and decreased park accessibility by 1387 (95% CI: −2706, −67), respectively. An IQR increase in percentage of the population receiving social low-income support aid (2.2%) was associated with increased park accessibility (reflecting park size and proximity of parks) of residential parks near residential areas by 1568 (95% CI: 15, 3120). Results suggest higher park access for socioeconomically disadvantaged regions. Findings indicate that measures of detailed park access considering spatial proximity and park size may more accurately measure park inequity compared to more basic metrics (e.g. TPPC), which may bias estimation of park inequity by capturing only one characteristic of parks. Detailed park measures should be considered in urban planning and health studies of greenspace.
The sudden stratospheric warming in January 2021
Authors: Lu Qian , Rao Jian , Liang Zhuoqi , Guo Dong , Luo Jingjia , Liu Siming , Wang Chun , Wang Tian
Published: July 2021

Using the ERA5 reanalysis, sea surface temperature and sea ice observations, and the real-time multivariate Madden–Julian index, this study explores a sudden stratospheric warming (SSW) in January 2021, its favorable conditions, and the near surface impact. Wavenumbers 1 and 2 alternately contributed to the total eddy heat flux from mid-December 2020 to late January 2021, and the wavenumber 2 during the onset period nearly split the stratospheric polar vortex. In mid-December 2020 and during the 2021 New Year period (1–5 January 2021), a blocking developed over the Urals, which enhanced the local ridge and the climatological wavenumber 2. Composite results confirm that the Arctic sea ice loss in autumn and La Niña favor the deepening of the high latitude North Pacific low and the increase of the Urals height ridge, which together enhance the planetary waves and hence disturb the stratospheric polar vortex. However, the Madden–Julian oscillation (MJO) in the tropics was dormant in mid-to-late December 2020 and early January 2021, and the well-established statistical relationship between the MJO convection over the western Pacific and the SSW is not applicable to this special case. The cold air outbreak in China during the 2021 New Year period before the January 2021 SSW onset is not explained by the SSW signal which developed in the stratosphere. In contrast, the downward-propagating signal reached the near surface in mid-February 2021, which may contribute to the cold air outbreak in US and may help to explain the extreme coldness of Texas in middle February.
Prediction of CO2 hydrate formation in supercritical CO2 long-distance pipeline network by simulation
Authors: Chen Bing , Fang Qichao , Zhao Qiong
Published: July 2021

Various impurities are dissolved in industrially captured CO2, which will change the physical properties and phase characteristics of CO2, and bring many technical difficulties in CO2 pipeline transportation. In particular, the dissolved water may generate CO2 hydrate, which threatens the safety operation of the pipeline. In order to investigate whether the CO2 fluid with low water content will form hydrates in the pipeline, in this paper, the phase equilibrium curve of impurity-containing CO2 hydrate calculated by vdW-P hydrate phase equilibrium model, and import it into the OLGA multiphase flow software. Predict and analyze the hydrate formation conditions and possible hazards during the stable operation of the actual supercritical CO2 transportation pipeline network.
The effect of composite flux on the melting temperature of fly ash based wall insulation materials
Authors: Zhao Liang , Liu Zhuo , Pi Hao , Yao Shuang , Nan Yunxi
Published: July 2021

Fly ash was used as the main raw material, potassium feldspar and dolomite as fluxes to preparate wall insulation materials, the image sintering point tester was used to observe the changes in volume shrinkage, expansion passivation and globalization of the sample under high temperature conditions, and corresponding temperatures were recorded when the various situation occurred. The relationship between the adding ratio of the composite flux and the melting temperature was studied, and the basic formula for the preparation of fly ash foam ceramics was determined. The experimental results show that when the raw material composition is 60wt% fly ash, the total added amount of composite flux is 40wt%, potash feldspar: dolomite = 3:1, and the melting temperature range of the sample is 1150∼1365 °C, not only the initial melting temperature is lower, but the melting temperature range is also wider.
Study on formation mechanism of ground fissures and disaster prevention and reduction measures for buildings-- A case study of Qingxu area in Shanxi Province
Authors: Pan Chunjuan , Fan Yuhai , Wang Hui , Wang Junfeng , Cui Sheng
Published: July 2021

In recent years, Pingquan village of Qingyuan town and dongmayu village of Mayu Township in Qingxu area of Taiyuan City, under the action of regional tectonic stress, the plane distribution of ne60-80 has appeared one after another along the border mountains. There are many parallel ground fissures, which lead to serious damage to some villagers’ houses. Through field investigation and data analysis, the distribution characteristics and formation mechanism of Qingxu ground fissures are elaborated in detail, and the corresponding defense countermeasures are put forward.
Analysis of landslide disaster characteristics of Zugong highway (G4218) line
Authors: Fan Yuhai , Wang Hui , Pan Chunjuan
Published: July 2021

Landslide is a kind of common geological disaster in mountainous areas. The soil and rock mass on the slope have been scoured by rivers or artificially cut slope for a long time. Under the action of gravity, it will slide downward. Landslides are developed in the third section of the highway from Zhubarong to Bangda Bingzhan along G4218 line (Zuogong Highway), but the distribution of hazardous landslides is relatively concentrated. The landslide shear outlet is above the highway, then a large number of gravel and blocks of sliding bodies are piled up and buried on the road surface. Not only is the workload of cleaning up the earth and stones huge and takes a long time, but also after the slope foot is cleared, it will cause the slide of the upper body to further slide, causing the slope of the highway to be moved together with the highway, so that the highway is completely damaged. Therefore, it is of great significance to strengthen the research on the development and prevention of landslide disaster.
Study on the Identification Method of Pyrogenetic Rock Based on N -DP Intersection Graph
Authors: Hu Gang , Mao Zhiqiang , Yan Ping , Yin Qian , Wang Xiyu , Lai Fuqiang
Published: July 2021

Igneous rocks have the characteristics of “diversification of eruption mode, diversification of lithologic origin and multiple changes of mineral assemblages ", so it is difficult to identify fine. This study is based on a real case study of igneous carboniferous reservoir in Jinlong 10 block at Junggar basin. The distinguish of the reservoir-developed rocks are catalyzed to basalt, andesite, dacite, granite, tuff and volcanic breccia rock, based on a combination of core and thin sheet analysis data. Based on the characteristics of log response of different lithology, the basic basalt, neutral andesite and acidic granite are quickly distinguished by N-DP intersection map method, and the idea of “step by step stripping” is adopted in the interval, and tuff and volcanic breccia are identified by intersection map method. The results of lithology identification and the conclusion of core sheet analysis have a high degree of anastomosis, which effectively improves the accuracy of lithology identification.
Characteristics and evolution of the Paleogene overpressured top seal in Niuzhuang Sub-sag, Dongying Sag, Bohai Bay Basin
Authors: Zhang Tianjiao , Hu Yang , Feng Yuelin , Wang Yongshi , Han Hongwei , Yu Jingqiang , Zhang Weizhong , Shi Shilong , Li Xiaochen
Published: July 2021

The buried depth of overpressured top seal layer in Niuzhuang sub-sag is mainly 2700–3600m, which is characterized by deep center and shallow edge in plane. Its lithology is a combination of dark grey, grey mudstone and sandy mudstone. There are a large number of carbonate cements and clay minerals in the argillaceous rocks that form the top sealing layer. The diagenesis of mudstone occurs in the rapid transformation period of illite/smectite mixed layer minerals, and corresponds to a large number of carbonate cements. The displacement pressure, thickness and diagenetic intensity of overpressured top seal are important factors affecting its physical sealing ability. There are five evolution stages of overpressured top seal, namely, at the initial stage of settlement, the strata are normally compacted, and the development of overpressured top seal is not obvious; During the first stage of accumulation, the low-amplitude hydrocarbon generation in the deep sag was supercharged, and the overpressured top seal was initially formed. Intermittent period of reservoir formation, overpressure top seal uplift erosion; During the rapid subsidence period, the strata are undercompacted to form overpressure, and the overpressure top seal is re-formed. During the second stage of storage, the thickness of overpressure top seal increased to the maximum.
Experimental study on oil supply efficiency of under-race lubrication based on radial oil scoop
Authors: Qin Jingwen , Jiang Huiqing , Guo Hui , Wang Fuliang , Zhu Hui
Published: July 2021

Under-race lubrication is an efficient lubrication method of aeroengine bearings for achieving high DN values. In this paper, an experimental study on oil supply efficiency of under-race lubrication structure based on high rotation speed and small size radial oil scoop is carried out. The influence of rotation speed, nozzle diameter and oil temperature on oil supply efficiency are analysed. The research results can be used to guide the design of oil nozzle and under-race lubrication structure.
Discussion and application of establishing oil saturation model by stages
Authors: Liu Yanyu , Fu Xiaoliang , Zhao Zhi , Ma Hanying , Fu Xiaoli , Li Xuewei
Published: July 2021

Most of the old oilfields in China have entered the stage of ultra-high water cut development. In order to guide drilling wells and further exploitation, it is necessary to describe the remaining oil distribution at present accurately and quantitatively. At the same time, the focus of work should be shifted to the study of remaining oil distribution between wells. For the oilfields with wide area, large thickness, long history of production and many injection production wells, the calculation of numerical simulation is too large and the grid precision is coarse. Although the traditional modeling method of mixing new and old wells can ensure the grid precision, it cannot represent the current situation of the reservoir and play a guiding role in production, so it needs a new way, ensures the plane and vertical precision of the model (accuracy 10×10×0.5m), and through certain constraints, can accurately describe the current plane and vertical oil saturation distribution law of the oilfield, which provides a new direction for further exploitation of the oilfield.
Research on access efficiency and optimization of massive seismic data
Authors: Chen Fang , Wan Xiaolong , Wang Juan , Liu Feng , Yang Fenxiu
Published: July 2021

With the continuous development of exploration technology, the magnitude of seismic data is getting larger and larger, and the access efficiency of seismic data has become the main bottleneck in the process of seismic data processing. The cluster structure realizes the separation of computing and storage. The data is stored in the disk array, and the data is calculated in the computing node. The maximum network speed between each computing node and the management node is 1GB/s, and the total maximum network speed of all computing nodes is 5GB/S (peak value). In addition, for disk array, the maximum read speed can be ignored (more than 1GB/s) without considering the network bandwidth, while the maximum write speed is 350MB/s. In the process of data processing, it needs to flow between the disk array and the computing node, and its speed must be affected by the network bandwidth. Therefore, the theoretical maximum I/O speed of the system is 1GB/s for reading and 350MB/s for writing. To build a multi format seismic data model, the loading of the system before optimization can not support the original seismic data format, so the original seismic data (such as SEGY and SEGD) needs to be converted into the internal ATT format of the system. In this process, the whole original data needs to be read circularly, and the new file is written circularly, and then the new file is decompiled, Save the header part into the table in the database. Export is the opposite process, which needs to convert ATT format to SEGY or SEGD format.
Analysis on the geo-resistivity anomaly at Baoji Seismic Station of the Jiuzhaigou Ms7.0 earthquake
Authors: Sun Yu , Zhang Weichao
Published: July 2021

According to the geological structure and observation characteristics of Baoji Seismic Station, a variety of methods are used to process and analyze the geo-resistivity data of Baoji Seismic Station from 2014 to 2018, such as the fourier sliding method that removing annual variation, the anisotropic degree method of the geo-resistivity, the normalized monthly rate method and the difference method. The analysis of these geo-resistivity data was used to extract the precursory anomalies of the geo-resistivity at Baoji Seismic station before the Jiuzhaigou Ms7.0 earthquake, obtain the characteristics of the changes in the geo-resistivity data before and after the earthquake, find the possible causes of the data changes, and evaluate the observation efficiency of the geo-resistivity at Baoji Seismic Station.
Research on Coal Bolt Grouting and Solidification Technology for Increasing the Drainage Concentration of Along-bed Boreholes
Authors: Li Shengzhou
Published: July 2021

In order to increase the coal seam’s along-bed drilling concentration and to prevent roof leakage in roadways, the test has carried out research on coal bolt grouting and solidification to increase the along-bed drilling concentration. The results of the field investigation show that the coal After the body is grouted and solidified, it presents a shape similar to a cement block. The slurry enters the cracks of the coal body and forms a stronger whole after solidification. No roof leakage occurred in the coal roadway in the solidification section, and the roadway integrity was well controlled. After the anchor rod is grouted and solidified, the concentration of gas drainage in bedding boreholes is generally higher. The concentration of gas drainage in the initial drilling of the test group was 30% to 60%, and the average drainage concentration during the investigation was about 40%, and the attenuation was slower than that of the drilling in the control group. The effect of bolt grouting to solidify coal is obvious.
Experiment on formation mechanism of water film thickness in sandstone reservoir
Authors: Zhai Shuo , Li Yao , Gong Yufeng
Published: July 2021

In hydrophilic reservoirs, formation water exists in the rock void in the form of water film, and the existence of water film has a great influence on the oil and gas seepage in the formation. In this paper, based on Archie’s formula, the water film thickness in sandstone reservoir is tested, so as to study the formation mechanism of water film thickness. The results show that the larger the water saturation, the thicker the water film thickness and the smaller the gas flow channel.
Study on the design and forecast method of complex fracture in shale oil formation in at Da’anzhai Formation in the Sichuan Basin
Authors: Fan Yu , Zhou Changlin , Liang Jun , Zeng Ji , Zhang Dandan , Luo Le
Published: July 2021

The exploration of lacustrine shale oil and gas located at Da’anzhai Formation in the Sichuan Basin has entered into the development stage, and the horizontal well volume fracturing is the main stimulating technology for shale oil and gas development. To solve the problems of the accurate description of induced stress, complex fracture design, and poor match in geological engineering, the complex fracture design model is developed by the extended finite element method and augmentation Lagrange multiplicator method in consideration of the contact problem of natural crack. And the induced stress distribution characters and mechanism of complex fracture propagation are analyzed. It is found that as for the stimulation measure for the formation developed a natural crack, the fracturing fluid with lower injection rate are smaller viscosity is suggested to generate complex fracture due to the strong stress interference. Moreover, applying the proposed design method of complex fracture to a well in Da’anzhai Formation, it is shown that the results were basically close to the on-site results.
Study on Pouring Quality Evaluation of Mass Concrete Component
Authors: Xie Yalong
Published: July 2021

Mass concrete component pouring quality evaluation is an indispensable link in the construction of basic engineering. This article takes the Fuchun River bridge built during the construction of the Huzhou-Hangzhou high-speed railway as an example, using electronic temperature measurement and ultrasonic testing to assess the bridge the quality of the mass concrete components poured during the construction process is evaluated, and the detection results are transmitted to the smart construction site system in real-time. The real-time monitoring and evaluation of the casting quality has been achieved. The evaluation results are that the Fuchun River Bridge was poured during the construction process. The quality of mass concrete components meets the marking requirements. Suggestions on the later maintenance of concrete components are given for reference for other engineering projects.
Study on quality and safety monitoring scheme of tunnel construction based on 3D laser scanning
Authors: Qian Jin , Zhou Yanhui
Published: July 2021

In the process of railway tunnel construction, it is very important to monitor and predict the subgrade settlement. In order to solve the problems of low efficiency, high cost, low accuracy and hidden safety problems in the detection of tunnel construction quality and safety by manual hand-held radar, this paper studies the construction quality and safety detection scheme of Lushan Tunnel, a new railway connecting line of Huzhou-Hangzhou high-speed railway. Firstly, the settlement and deformation observation points are set up on both sides and near the middle of the tunnel invert. Secondly, the observation elements are buried according to the specified scheme. Then set the monitoring frequency of the original parts after different working procedures to monitor the settlement of the roadbed after tunnel construction. Finally, the curve regression method is proposed to predict and evaluate the tunnel foundation settlement. This scheme mainly solves the problems of low precision and low efficiency in the traditional monitoring scheme. It can continuously monitor the construction quality in real time and predict and monitor the subgrade settlement in the process of tunnel construction.
Study On the Influence of Micro-Steel Pipe Pile Reinforcement and Soil Structure on Landslide Stability in Geological Engineering
Authors: Xie Xiao , Wang Luyao
Published: July 2021

Micropile is a new type of supporting structure, which is characterized by rapid and convenient construction, flexible pile layout and significant reinforcement effect. In this paper, combined with a landslide case, the influence of micro steel pipe pile reinforcement on the displacement, stress, strain and stability of the landslide is preliminarily studied by using finite element analysis simulation software. The results show that the reinforcement of micro-steel pipe piles improves the slope stability, but it is still in an unstable state. In the later stage, the landslide can be effectively controlled by adjusting the reinforcement scheme and the parameters of piles, such as material grade and pile density.
Design And Implementation of Simultaneous Soil Excavation of Adjacent Deep Foundation Pits
Authors: Ren Dong
Published: July 2021

The horizontal distance between two adjacent deep foundation pits in soft soil area is about twice the excavation depth. After the two foundation pits are designed and monitored throughout, the inclination data of each foundation pit is analyzed and it is found that the mutual influence is small.
Formation age and geological environment of monzonitic granite from Qingshanpu pluton on the eastern margin of Longshou, Gansu
Authors: Zhu Quanlong , Guo Zhifeng , Wang Shengyun , Chen Jinyong , Qiu Ruizhao , Zhou Su
Published: July 2021

Zircon U–Pb dating, geochemistry, and Sr–Nd–Hf isotope data are reported for monzonite from the Qingshanpu pluton on the eastern margin of Longshoushan. The zircon LA-ICP-MS U–Pb age data showed that the emplacement age of the monzonite is 442.6 ± 4.8 Ma. The rocks are characterized by high SiO2contents (73.15%–73.85%), high K2O contents (3.67%–3.99%), and low P2O5contents (0.042%–0.049%). The aluminum saturation index was 1.03–1.05, and the molecular number of standard corundum was 0.58%–0.77%. Rocks are enriched in Rb, Sr, U, K, and Pb and depleted in Nb, Ti, Zr, P, and Eu, thereby indicating that they are weakly peraluminous I-type granites. The monzonite in the Qingshanpu pluton had lower ISrvalues, which ranged from 0.70850 to 0.70904, and the εNd(t) values ranged from -8.54 to -6.49. The εHf(t) values ranged from -9.75 to 0.42, and the two-stage model age TCDMranged from 1406 to 2043 Ma. This study concluded that the North Qilian subducted beneath the Alxa Plate at the end of the Early Paleozoic, causing elastic collision and eventually leading to closure. During elastic collision, several parts of the orogenic belt collapsed and were dismantled. The remelted ancient crust mixed with a small amount of mantle material during its ascent and finally formed the Qingshanbao pluton.
Shaking Table Test of Microbial Damping Layer of Tunnel Crossing Fault in Underground Soil Structures
Authors: Peng Shuquan , Zhou Qiwen
Published: July 2021

In this paper, relying on the East Africa Great Rift Valley Railway Tunnel Construction Project, based on the MICP (Microbial Induced Calcite Precipitation) technology, the microbial cemented tunnel shock-absorbing layer is made by using geogrid and rubber particles. Through the design of two sets of shaking table tests, the comparative analysis has The response characteristics of the cross-fault tunnel without microbial damping layer to seismic waves are simulated to study the anti-seismic effect of the microbial damping layer. The results show that the microbial damping layer can effectively reduce the peak acceleration intensity of the surrounding rock at the fault, with a reduction of 21.28% under the E1 wave and 54.92% under the Kobe wave. Both the peak acceleration and the strain of the tunnel lining decreased. At the same time, the microbial damping layer can reduce the acceleration difference between the left and right lining of the tunnel at the fault. The difference is reduced to 12.92% under the E1 wave; the difference under the Kobe wave is reduced to 8.82%, making the lining close to stability under vibration. The research results can provide a reference for the shock absorption of the Great Rift Valley Tunnel Project in East Africa and the application of microbial materials.
Research on Design and Construction Technology of Large Span T-Truss Suspension Beam
Authors: Meng Zhaohu , Wei Wanlong , Han Guangzhao , Yu Ziqiang , Lu Jianrong , Wu Minglei , Zhang Jun , Yu Jia , Jin Dongyang
Published: July 2021

Urban subway construction is often in the lower part of the city center road, and there are many municipal pipelines and pipelines in the lower part of the road. Because it involves the life of the surrounding residents, it is difficult to move and change. In the open excavation of foundation pit, the whole suspension construction measures are often used to solve this problem. Within the excavation area of the Yingmentan Station passageway of Lanzhou Rail Transit Line 1, there is a steel pipe municipal water supply pipeline. This municipal water supply pipeline needs integral suspension protection, with a suspension span of 22.5m. The design adopts T-shaped truss beams for overall suspension. This paper uses T-shaped beam design and force analysis research. Provide reference for similar projects.
Spatiotemporal Change Analysis of Annual Average NDVI in Qinling Mountains as Ecological Security Barrier and Dividing Line between Geography and Climate
Authors: Li Jianfeng , Zhang Lulu , Ye Huping
Published: July 2021

Based on Google Earth Engine cloud platform and MOD13Q1-NDVI images, this paper analyses the spatiotemporal variation characteristics of vegetation cover in Qinling area and its five watersheds from 2000 to 2020 from the perspectives of annual average NDVI. The results show that: 1) Since 2000, the vegetation cover in Qinling Mountains has shown a fluctuating growth trend, with annual average NDVI above 0.4, the maximum value in 2016 and the minimum value in 2001. There are obvious differences in the annual average NDVI of the five major basins, the fluctuation range of the Danjiang River Basin is the largest, the fluctuation trend of the Hanjiang River Basin and the Jialing River flow is similar, and the annual average NDVI of the Nanluo River Basin as a whole is the lowest. 2) The change characteristics of annual average NDVI in the four five-year periods from 2000 to 2020 are different, the decreasing area of annual average NDVI in the first two five-year periods is obviously larger than the increased area, and the degree of vegetation cover continues to worsen; in the third five-year period, the annual average NDVI increased almost in the whole study area, and the vegetation cover improved rapidly. The change range of annual average NDVI in the fourth five-year period is the smallest, and the proportion of unchanged area is more than half.
Evaluation of Low-Carbon Benefits of Smart Grid Based on Random Forest Algorithm
Authors: Chen Lingxuan , Xie Pengyang , Ma Shuaihua , Yang Chen
Published: July 2021

The eventual exhaustion of non-renewable fossil energy and the damage to the environment during its mining, processing, and consumption process have caused countries around the world to pay attention to how to improve energy efficiency, how to better develop clean energy, and how to optimize the energy structure. Electric energy is an indispensable secondary energy source of both industrial development and home life. How to convert clean energy into electric energy and improve the efficiency of electric energy used provides new ideas about solving energy shortages and environmental pressures. Smart grid is the application of advanced communication and information technology to all business links involved in the power grid. It is of great significance of the realization of information, automation and interaction of the power grid. It has become the development trend of the modern power grid. It can be seen that the construction of smart grids is an important way for countries around the world to alleviate the pressure on energy and environmental protection. This paper summarizes the current research status of smart grids at home and abroad, and combines the characteristics of smart grids with the problems existing on the research on low-carbon benefits of smart grids at home and abroad, and constructs a comprehensive evaluation index system suitable for low-carbon benefits evaluation of smart grids and low-carbon benefits of smart grids. Evaluate the model, use the analytic hierarchy process to preprocess the data, confirm the weight of each indicator system, and get the evaluation score; divide the processed data into a training set and a test set, and use the random forest algorithm to train the model; The evaluation model is used to evaluate the low-carbon benefits of smart grids. The evaluation results show that the model has high evaluation accuracy and certain practicability. Finally, based on the evaluation results and the status quo of smart grids in my country, corresponding suggestions are put forward to promote the further development of low-carbon smart grids.
Analysis of the Impact of AHP-based Power Grid Transmission and Transformation
Authors: Kang Yanfang , Guo Xiaohan , Xi Xiaojuan , Li Lingyun , Li Dapeng
Published: July 2021

In recent years, the changing trend and causes of power grid engineering are diversified and complicated. In view of this problem, it is impossible to determine the influencing factors by quantitative analysis. Selection in order to solve this problem, we collect relevant power transmission project data, since 2015. First, we determine the control index system, 20 factors affected substation project, 19 influence factors affected route project, and then use AHP method to establish the new situation under the background of grid engineering control model. Through the MATLAB software, we determine the weight of each influence factor. Finally, the factors that have great influence on power grid engineering control are obtained according to the order of weight. Thus, it lays the foundation for the orderly development of better control grid engineering in the future.
Numerical study on the influence of shroud cavity in the high-pressure centrifugal compressor for compressed air energy storage system
Authors: Meng Chong , Zuo Zhitao , Sun Jianting , Liang Qi , Guo Wenbin , Chen Haisheng
Published: July 2021

As a key energy equipment of the compressed air energy storage (CAES) system, the centrifugal compressor with shroud cavity is employed to avoid the leakage flow from the rotor, especially in the high-pressure stages. In order to clarify the leakage characteristics and its influences, the high-pressure centrifugal compressor with shroud cavity is taken as the research object in the present work. First, the leakage flow across the shroud cavity has been studied numerically, it’s found that there are negative effects on the high-pressure compressor’s aerodynamic performance by the shroud cavity. And then, the flow characteristics inside the shroud cavity are showed by finding several secondary flow regions and cavity vortices. In addition, through the entropy contours and streamlines, the influence on the main flow by the leakage are analysed in detail. By analysing the influence of the shroud cavity on the high-pressure compressor, this paper can provide a practical guidance for the design of the impeller in the CAES system.
Suggestions on efficient development and utilization of solar energy resources in Tibet
Authors: Pu Zewei
Published: July 2021

Tibet’s special geographical location makes it rich in clean energy resources, including renewable energy such as hydropower, solar energy, geothermal energy and wind energy. The advantaged clean energy resources not only provide advantaged resource advantages for the development and utilization of clean energy in Tibet, but also lay the foundation for accelerating the strategy of energy structure adjustment. By the end of 2020, the total installed power capacity of Tibet has reached 4.0185 million kilowatts, of which the clean energy sector is growing rapidly. The installed capacity of hydropower, wind power, geothermal power and solar photovoltaic power generation in the same period has reached 3.58 million kilowatts. Clean energy accounts for 89.09% of the total installed power generation capacity, while the installed capacity of photovoltaic power generation is about 1.5 million kilowatts, accounting for 37.33% of the total installed capacity, Second only to hydropower. However, there is still a lot of room to improve the utilization of solar photovoltaic.
Research on a Steel Stranded Molding Device for Distribution Network
Authors: Qian Yong , Ren Shuang , Zhai Guanyu , Wang Xiaobing , Shen Amei
Published: July 2021

There are many power grid upgrading and transformation projects in the system. The installation of cement poles is generally involved in the construction of power distribution lines, which involves the field production and cooperation of steel strands and composite fittings. The traditional method of making stay wire is to bend the steel strand (stay wire) by hand and to change its shape by hammering to adapt to the groove position of stay wire fittings. In order to improve the speed of drawing wire and improve the process standard, the author developed a steel stranded molding device, which is specially used to mold the steel strands.
Two-stage Optimal Dispatch of Multi-type Energy Coupling System Using Particle Swarm Optimization for Cool-Heat-Electricity
Authors: Zhang Xin , Jiang Jinpeng , Zhang Jihong , Zhang Zilei
Published: July 2021

As the larger error between the dispatch plan of the previous day and the actual operation of the community multi-type energy coupling system, the actual operation cannot be fully meet. A two-stage optimization dispatch method of the community multi-type energy coupling system based on the particle swarm algorithm is proposed in this study. Firstly, the optimal dispatch model of community multi-type energy coupling system on previous day is established. Minimizing the daily operation cost is the objective function. The optimal dispatch curve of community multi-type energy coupling system on previous day is obtained. Secondly, based on the optimal dispatch curve of community multi-type energy coupling system on previous day, an intraday correction model is constructed. The example results show that the proposed model can eliminate the dispatch error of the previous day and realize the optimal operation of community multi-type energy coupling system.
Research on Multi-Objective Optimization of Household Photovoltaic Energy Storage and Grid System
Authors: Zhou Zelong , Liu Meifeng
Published: July 2021

With the integration of large-scale photovoltaic systems, many uncertainties have been brought to the grid. In order to reduce the impact of the photovoltaic system on the grid, a multi-objective optimal configuration strategy for the energy storage system to discharge electricity into the grid is proposed. On the basis of the time-of-use electricity price, the total load variance and the user’s profits are taken as two objective functions. Constraints such as the maximum discharge power limit of the energy storage system are taken into account and a multi-objective optimal scheduling model for the centralized discharge of the energy storage system is established. A multi-objective genetic algorithm is used to solve the optimization model. The calculation results of MATLAB verify the feasibility and effectiveness of the strategy and the influence of different energy storage system capacities on the optimization results are also analyzed.
Short-Term Wind Speed Prediction of Wind Farms Based on Particle Swarm Optimization Support Vector Machine
Authors: Yu Xin , Zhang Zhongxuan , Song Mingxuan
Published: July 2021

With the large-scale integration of wind power into the grid, grid-side instability caused by fluctuations in wind speed is becoming more and more significant, and the topic of wind speed prediction for wind farms is urgent. Based on this, in order to solve the problem of low prediction accuracy of a single support vector machine, this paper proposes a wind speed prediction method that uses particle swarm optimization to optimize the support vector machine. Use particle swarm algorithm to optimize the selection of penalty factors and kernel function parameters of support vector machines, then conduct model training on the optimized parameters, and then apply the established prediction model to wind speed prediction of wind farms, and finally analyze the prediction results. The prediction results show that the support vector machine algorithm optimized by the particle swarm optimization algorithm has better accuracy in predicting the wind speed of wind farms, which is significantly higher than the prediction accuracy of a single support vector machine.
Study of thermal effect of lightning current on a metal roof
Authors: Zhang Biao , Zhou Junchi , Wang Yuzhi , Deng Daoyang
Published: July 2021

Metal roofs have often been seen as substitute of traditional materials such as concrete these years. Most metal roofs are made of AL-Mn-Mg alloy, which is lighter in weight, cost-effective in price and easier to construct. But it also has much higher probability of being struck by lightning due to its electrical conductivity. This work is dedicated to study the effect of lightning current on it. Firstly, we established a simplified Positive Cathode Voltage Drop model to calculate the fusion volumes and depth of lightning-burnt metal when it was struck by maximum lightning current of 200kA. Then in the lab, we introduced simulated lightning current with 10/350 waveform to a series of 1.17mm AL-Mn-Mg alloy samples, which are wildly used as power substation roofs in Jiangsu Province. The impulse current was set at 20kA,30kA and 50kA. When struck by a 50kA simulated current, the sample alloy had significant fusion marks, caused by electric arc between the metal surface and the discharge probe. But the alloy sample was not penetrated, which conformed to theoretical calculation. So we could come to the conclusion that a roof made of 1.17mm AL-Mn-Mg alloy will not be fused through by a typical lightning stroke.
Study on Wastewater Treatment Technology and Water Environment Protection Method
Authors: Yang Rongrong , Meng Qingjun
Published: July 2021

Water resources are very important for human beings, and water resources are indispensable for normal life and industrial production. With the population growth and industrialization in China, the shortage and pollution of water resources are becoming more and more serious, which not only restricts the further development of our society, but also has a serious impact on people’s lives. Emulsions are widely used in metal processing. Waste emulsions are hazardous wastes, which can cause serious harm to the ecological environment and need to be properly treated. The results show that the oil removal rate of different emulsion wastewater is over 85%, and the COD removal rate is between 36-97%. It shows that the vibrating membrane has good performance of preventing membrane fouling and concentration polarization. In this situation, only by strengthening the treatment of wastewater and focusing on the protection of water environment can we achieve sustainable development and promote the harmonious coexistence between man and nature.
The effect of different climatic conditions on the decomposition of wood by fungi and the interaction between fungal populations
Authors: Ren Yikang , Wang Chen , Li Huiying
Published: July 2021

This article mainly explores the process of decomposing wood that simulates the fungal community. Under the conditions of a given environmental temperature and humidity, the relationship between the decomposition rate of the fungus and the growth rate, moisture resistance, environmental temperature and humidity of the fungus is obtained. In the Logstic model, a competitive resistance term was introduced to describe the interaction between fungal communities. In the end, we get: The interaction between communities will mainly make the community evolve in two directions: multiple populations coexist and a single species survives. Community evolution is more sensitive to changes in humidity, while changes in temperature have a significant impact on the decomposition rate of fungal communities.. And through the analysis of climatic conditions in different regions, it is obtained that the fungal community prefers warm and humid environments. The diversity of the population causes the fungus community to have stronger resistance and resilience. The slow growth rate of the fungus will make the community more adaptable, and it also leads to the reduction of the overall decomposition efficiency of the community.
Analysis of energy consumption of a main machine hall for a thermal power plant with lead dampers
Authors: Wang Changshan
Published: July 2021

The lead damper is a kind of energy dissipating device with stable hysteretic performance, good shock absorption performance and simple structure. To study the lead damper damping effect in the main machine hall, the nonlinear finite element analysis software ABAQUS is adopted to analyze the seismic performance of a main machine hall with lead damper under the action of the rare earthquake and compare the elastic-plastic analysis results under the action of different seismic wave in this paper. The results show the structural seismic performance has been improved significantly, “no collapse under strong earthquake” can be achieved, A successful engineering case was provided for the application of lead damper in the damping design of main machine hall structures.
Analysis of Interaction between Fungi and Environment Based on Lotka-Volterra Model
Authors: Liu Chaoyi , Liu Zhourui , Chen Weifeng
Published: July 2021

The global carbon cycle is an important part of the earth’s life activities, and fungi play a very important role as an important participant in the earth’s carbon cycle. We used the Monod model combined with the Lotka-Volterra model to establish a model of the fungal degradation rate under the action of various fungi by studying the decomposition of the ground litter and wood fiber by fungi. We found that the degradation rate is very long when the ground litter and wood fiber are sufficient. After time, it will enter the dynamic balance and basically will not change. This is also an important reason for verifying that the earth carbon cycle can be stable for tens of thousands of years.
Electric Vehicle Load Prediction Method Based on Back-Propagation Neural Network
Authors: Liu Dunnan , Wang Lingxiang , Li Hua , Gao Yuan , Peng Xiaofeng , Liu Mingguang
Published: July 2021

The development of large-scale electric vehicles puts forward new requirements for safe and reliable operation of distribution network. Accurate and reliable EV load forecasting can effectively support large-scale EV load grid-connected operation and provide conditions for reasonable regulation of demand side resources. Firstly, this paper analyses the necessity and feasibility of electric vehicle load forecasting from the scale characteristics, regulation ability and informatization level of electric vehicle development. Then, a load forecasting method based on Back-Propagation neural network algorithm is proposed. Finally, the applicability of the model was verified based on the daily load of electric vehicles. The results show that the model can realize the effective load prediction of electric vehicles, and will support the smooth progress of related work.
Study on Response Surface Optimization of Hot-pressing of Multi-layer Plywood via Soy-based Adhesive
Authors: Deng Layun , Zhang Xi , Wu Qiao , Wang Dong , Wang Yong
Published: July 2021

Eucalyptus veneers were applied to fabricate multi-layer plywood with soy-based adhesives as the glue. Prior to optimization, single-factor experiments were performed to select the proper range of each factor. Furthermore, effects of adhesive amount, hot-pressing time, hot-pressing pressure, and hot-pressing temperature were investigated via response surface methodology (RSM). Through RSM optimization, optimum hot-pressing conditions were obtained. To verify the optimized conditions, validation test was carried out. The result presented that the error rate between the predicted value and the measured value was 1.2%, which was reasonable for prediction.
Study on the dynamic changes of potato microbes in soil affected by environmental pollution using high-throughput sequencing
Authors: Lin Qiao , Yan Dongmei , Li Jiayi , Liu Junhua , Li Cheng , Yang Jun , Cai Li , Shu Yimei , Hua Xubin
Published: July 2021

To analyse the dynamic changes of the microbial community and biodiversity in potato liquor, this experiment uses potato and corn as raw materials and uses solid fermentation method to obtain potato liquor to brew liquor. The fermentation of the 1st, 3rd, 5th, 7th, 9th, 11th, 13th and 15th days of wine samples and sent for inspection. The results show that potato liquor brews wine in the fermentation process, the bacterial community is more than fungi, and in the end of fermentation is mainly played by bacteria. Lactobacillus and Weissella accounted for the largest proportion of lactobacillus and Weissella, and found that the number of Lactobacillus (Lactobacillus) increased as fermentation progressed, but the number of Weissella continued to decrease. In the fungal community, the abnormal Wickerham yeast and the false silk yeast genus (Candida) account edged the largest proportion of the entire fermentation process. Aspergillus, on the other hand, plays a role in the early fermentation phase.
Research on the process of decomposing woody fibers for carbon cycle with different environmental factors
Authors: Zhang Xiaoduo , Liu Wenhao , He Shupeng
Published: July 2021

The decomposition process of wood fiber is an important part of carbon cycle, and fungi play a crucial role in the decomposition process of wood fiber. Therefore, it is of great significance to analyze the effect of fungi on the decomposition process of wood fiber and explore the factors affecting the decomposition process. Based on the useful attributes found in the data set, first, the paper put forward the log linear regression model, and draw the relationship curve of wood fiber decomposition rate with temperature and mycelium growth rate. At the same time, the reliability and significance of the model are analyzed, and the model is tested. Next, in order to combine the interactions between different fungal species, based on the influence data of humidity tolerance and growth rate on decomposition rate given in the topic, the paper establish a multiple linear regression model to explore the influence of environmental factors and the interaction between populations on decomposition rate.