bluuebunny/crossref_metadata_2025_split huggingface dataset:
Blockchain periodic storage space recovery method based on blockchain consensus algorithm
Authors: Cao Hongping 
Published: August 2021

Abstract
Decentralized encryption digital cash has been proved to be a successful application mode, and the users of the application can also be the maintainers of this application. To solve the problem of fast growth of blockchain data on Ethereum platform, this paper proposes a method to recycle the periodic storage space of blockchain deployed on blockchain based on blockchain consensus algorithm. On the principle of decentralization, the problem of mutual trust between nodes is solved. And that stability value of the update storage node is recorded, and the high-stability node is selecte to store the newly generated data copy, so that the stability of data storage is improved. Finally, some bytecode fragments are replaced by a suitable algorithm. Tests show that the massive small file system supporting file deletion has no obvious decline in file reading and writing performance compared with the original one, and the storage space of smart contracts can be saved by nearly 46%.
Research on an Adaptive Heterogeneous Database Middleware and Visualization Technology
Authors: Zhou Bin , Yang Mingling 
Published: August 2021

Abstract
In order to improve the efficiency of MIS development based on heterogeneous data sources, an adaptive heterogeneous database middleware and key visualization technology are proposed to realize the automatic creation of data access layers through visualization operations on the basis of heterogeneous databases. This research focused on the general access mode of various data sources in middleware, the interface of data and operation mapping between entity classes and object-oriented virtual heterogeneous databases, the associated interface technology between associated entity classes and corresponding data tables, the interface technology of cross-table and cross-database operation, the algorithm model for optimizing data access, the visualized operation interface, with the purpose is to provide a universal, powerful and easy-to-use middleware for the development of WEB-based MIS software. It will enable program developers to complete the development of data access layers (library building, entity class creation, data access operation method establishment, etc.) through simple visualized operations, and generate program code for the data access layer, which will greatly reduce the development workload and time of the MIS software in this procedure and improve the efficiency of software development.
Framework design of sports image analysis system based on three-dimensional image technology
Authors: Chen Xianming 
Published: August 2021

AbstractSports image analysis system based on computer vision image processing technology is a hot project in urgent need of society at present. Due to various objective and subjective factors, the application environment of intelligent module in sports image analysis system is limited, and there is still a certain gap from the social requirements. In this paper, the hardware selection of the system is focused on the applicability and cost. Based on the idea of the inherent hardware of the organizers of the grass-roots sports meeting, the system combining camera, video capture card and PC is selected, which has a high ratio of information to price. A fuzzy enhancement system of 3D digital image based on data mining is designed. Analyze the motion information in video stream to a certain extent, extract the physical characteristics and behavioral characteristics of moving objects, and use the fusion of the two to complete the dynamic target analysis in video surveillance images. The sports image analysis system based on 3D image technology designed in this paper has good universality and good application and popularization value.
Simulation study of turbulent mixing characteristics of tight lattice with triangular arrangement under blockage condition
Authors: Li Yunxiang , Luo Dongmei , Yang Xinyu , Zhang Chuyun 
Published: August 2021

Abstract
The study of turbulent mixing in the gaps of fluid sub-channels in the tight lattice under blockage conditions is of great significance to the prediction of the thermal-hydraulic behavior of fuel assemblies under accident conditions. The CFD method was used to simulate the fluid flow phenomenon in the blockage condition in the tight lattice, and the velocity field and the turbulent mixing coefficient distribution in the section and downstream of the blockage under different blockage conditions were further compared and analyzed. The analysis results show that the blockage mainly affects the flow field of the sub-channel where it is located and the adjacent sub-channels. The turbulent mixing coefficient in these channels will increase significantly; when the sub-channel blockage rate is small, the turbulent mixing coefficient downstream of the blockage will be reduced; the short length will make the flow field near the top of blockage segment more complicated. The obtained changes of transverse and axial turbulent mixing coefficients under different blockage conditions can provide a reference for the parameter setting of the sub-channel analysis program.
Introduction on Research and Application of Exothermic Welding Technology
Authors: Fan Pingcheng , Liu Xiao , Sun Zengwei , Gong Weiwei 
Published: August 2021

Abstract
With the development of society, the welding process presents the trend of diversification, high efficiency and specialization. A variety of advanced modern welding processes begin to replace the traditional welding technology. Exothermic welding is one of them, which is widely used in all kinds of engineering construction due to a lot of advantages. However, exothermic welding also has its own shortcomings, this paper mainly expounded the main shortcomings of exothermic welding, and put forward some improvement methods. Aiming to deepen the understanding of exothermic welding and make better use of this modern welding process.
Analysis on the lubrication performance of spiral-grooved journal bearing using CFD technique
Authors: Chen Yu , Wu Kai , Zhong Taisheng , Wang Yu 
Published: August 2021

Abstract
As the main element, the lubrication characteristics of spiral-grooved journal bearing would decide the stability of mechanical systems. And, a effectivee model will represent the hydrodynamic characteristics of spiral-grooved journal bearing effectively. Based on the CFD technique, this work presents the simulation methodology for analyze the effects of spiral-grooved parameters on the lubrication performance of journal bearing. Compared with the published data, the proposed method is demonstrated effectiveness. Moreover, the influences of eccentricity ratio, groove number, spiral angle, groove width and groove depth are discussed by the orthogonal design method, which provide a reference for the optimized design of spiral-grooved journal bearing.
An improved splashing model for supercooled large droplets based on minimum mass loss ratio
Authors: Ma Honglin , Li Weibin , Wang Yuejun , Zhao Fan , Wang Yingyu 
Published: August 2021

Abstract
Supercooled large droplets widely exist in clouds, which have poor aerodynamic follow-up and strong dynamic characteristics, making the relevant experiments and numerical simulation more difficult. Splash is the main influencing factor of droplet collection efficiency, and it is easier to be recorded and quantified. In the LEWICE model, little or no splash happened around stagnation point. Focus on this problem, an improved large droplet splashing model is proposed based on the idea of minimum mass loss ratio. In the numerical simulation part, the advantages and disadvantages of the proposed model are analyzed by comparing with several classical splashing models and experimental data. Based on the experimental data of airfoil MS317, the validity of the model is verified. Moreover, airfoil NACA23012 and ARJ cruise configuration are chosen to obtain the droplet collection efficiency, which shows the feasibility of the proposed model.
Research Situation of Welding Performance for P92 Heat Resistant Steel
Authors: Zhang Zhihao , Han Kuo , Zhao Xiaochun , Gao Yunpeng 
Published: August 2021

Abstract
In this paper, the welding performance of P92 ferritic heat resistant steel in recent years was introduced. P92 steel was a ferritic/martensitic steel, which had been brought to commercial maturity during the last decade due to its excellent high temperature performances. However, the welding related problems of P92 steel was gradually exposed with the wide application, causing a serious impact on the production and operation of boiler unit. Therefore, Strengthening research and development of suitable welding process and post weld heat treatment process that can lead P92 heat-resistant steel to being better serve in the power industry for our country will be the focus of metal workers in the next step.
Analysis on Two-phase Heat Transfer Characteristics in Horizontal Mini-tubes
Authors: An Tong , Zhang Beichen , Wang Yuan , Pan Yulong , Chen Haishan 
Published: August 2021

Abstract
The two-phase heat transfer characteristics of degassed water flow boiling in horizontal mini-tubes are experimentally investigated in this paper. The inner diameters (di) of the tubes are 1.2mm, 1.6mm, and 2.0mm. Experiments are conducted with heat fluxes between 1.5kW/m2 and 155.75kW/m2 at mass fluxes of 21.19, 42.39, and 84.77kg/(m2s). The boiling curves of the three tubes are obtained. Incipient hysteresis is observed only in the tube with di = 1.2mm. Two-phase dominant heat transfer mechanisms are analyzed in the tubes with di = 1.2mm and di = 2.0mm based on the curves of local heat transfer coefficient versus vapor quality and the visualization results. The trend of peak value of the local heat transfer coefficient versus heat flux at different mass fluxes in the tube with di = 1.2mm is discussed in accordance with the thickness variation of the liquid film in annular flow.
Design and analysis of a Ventral Diverterless Supersonic Inlet
Authors: Ge Changjie , Shang Yinhui , Xiao Lianghua 
Published: August 2021

Abstract
The diverterless supersonic inlet (DSI) has the advantages of good stealth performance and light structure weight. In this paper, the Bump surface is designed based on the flow field obtained by Taylor-Maccoll equation solving the supersonic conical flow, and a ventral diverterless supersonic inlet is given by the method. Numerical simulation is used to study the mechanism of the Bump surface for diverting the boundary layer. Results indicates: (1) the lateral pressure gradient created by the shock wave at the leading edge of the Bump surface is the main reason of pushing the boundary layer away; (2) the total pressure loss due to the shock wave will be small for better combination of the Bump surface and the lip; (3) it is necessary to design the duct of the DSI inlet with refinement to achieve low distortion.
Simulation on the Influence of Type-S Current-limiting Railing on the Passenger Flow at the Entrance
Authors: Zhang Bosi 
Published: August 2021

Abstract
The type-S current-limiting railing is usually set in front of the entrance of stations to relief the backlog of passengers and the congestion at the entrance. The influences of type-S current-limiting railing on the passenger flow at entrance were investigated through numerical simulation. Results showed that the type-S current-limiting railing increased the walking distance of passengers to the entrance. Therefore, it resulted in the decrease of the passenger flow rate and pedestrian density in front of the entrance, as well as the increase of the interval time between passengers went through the entrance. The passenger flow rate at the entrance increased with the total number of passengers. When the number of passengers that queueing up at the entrance was large, the congestion would be formed even the type-S current-limiting railing was set, while the passengers inside the railings were well-organized under the effects of current-limiting railing. The influence of railing number on the passenger flow rate at entrance was not significant, while the pedestrian density in the railings decreased with the railing number. When the railing width was large, the pedestrians might walk abreast and speed up to surpass the passengers ahead of them in the railings. The passenger flow rate at the entrance increased linearly, and the interval time between passengers decreased linearly with the railing width. Therefore, limiting the railing width could decrease the passenger flow rate at the entrance and relief the operation pressure of stations.
Hurricane Ball Movement Analysis
Authors: Long Ruilin 
Published: August 2021

Abstract
The problem addressed in this paper originates from IYPT 2019 Question 6: By starting with hand rotation and using a tube to blow up towards it, two steel balls connected together can be rotated at a very high frequency and explain to explore this phenomenon. It is found in the pre-experiment that even without the use of the tube blowing, the two-steel-ball system can maintain a fairly long rotation, the kinetic energy decreases slowly, which leads to the steel ball system and the table between the pure roll without friction. The equation of motion of the steel ball system is then derived from the pure roll condition analytically, and the equation illustrates that the angle 9 of buckling of the steel ball system is related to the angular velocity of rotation co and the radius of the ball r. The experimental results are verified with good agreement with the expected results.
Research on Orbit Optimization of Manned Spacecraft Based on Dynamics
Authors: Gong Yanxiang , Wu Xiaomei 
Published: August 2021

Abstract
Based on the dynamics angle, the paper finds a suitable launch window based on the pork-chop diagram, and then uses the conic splicing method to carry out the preliminary design of the orbit. The two-body model is used to design the orbit at each stage, and finally under the precise mechanical model, using differential correction method, accurate track design based on B plane parameters.
Analysis of stress relaxation of paper tube
Authors: Long Ruilin 
Published: August 2021

Abstract
Roll a long paper strip into a tight tube and put it vertically on a table. Why does it often unwind in jerks? What determines the period of the jerks? In the following work, we explain the fact of why the paper tubes unwind in jerks by researching mechanical structure of paper tube theoretically and analyze the data of experiments. Finding that the basic cause of paper tube motion in jerks is stress relaxation. Successfully prove our theory by our experiments. Then we investigate the influence of several physical quantities on period of jerks, such as humidity, friction factor of paper layers. All of these factors determine the period of jerks.
Study on frequency domain response characteristics of straight pipe conveying fluid
Authors: Long Jun , Wu Ji , Wang Zixin 
Published: August 2021

Abstract
In this paper, a transfer matrix method (TMM) for solving the frequency domain response of the straight pipe conveying fluid is established based on 14-equation model by Laplace transformation. The reliability of the method is verified by the frequency domain response results of fluid velocity and structural axial stress in the pipe under free boundary conditions. Then, based on the transfer matrix method, the influence of boundary conditions and fluid density on the frequency domain response characteristics of pipeline vibration is analyzed. The numerical results show that the boundary conditions have a significant effect on the amplitude of the vibration response of the pipeline, but the amplitude changes little under the fixed and simply supported boundary conditions. The vibration frequency is inversely proportional to the density, while the axial vibration response amplitude increases with the increase of fluid density, and the change of density has little effect on the transverse vibration response.
An Improved Hybrid Cartesian/Immersed Boundary Method for Flow Simulation with Moving Boundaries
Authors: Su Guanting , Zheng Mengzong , Li Qiushi 
Published: August 2021

Abstract
To simulate flow problems with moving fluid-solid interfaces, a boundary treatment technique based on a hybrid Cartesian/immersed boundary method is presented. In the vicinity of the immersed boundary, a forcing term is added into the governing flow equations to modify the discretization scheme for the viscous term during its spatial discretization. Addition of such a term enforces desired boundary condition on the immersed boundary. A one-dimensional linear interpolation scheme is used to obtained required information for the modified discretization scheme when dealing with a moving boundary. The present method is essentially second-order accurate and can obtain results that are in good agreement with benchmark references when simulating the flow induced by the in-line oscillation of a circular cylinder.
Balance between poverty alleviation and air pollutant reduction in China
Authors: Li Ruoqi , Shan Yuli , Bi Jun , Liu Miaomiao , Ma Zongwei , Wang Jinnan , Hubacek Klaus 
Published: August 2021

Abstract
Key targets of the sustainable development goals might be in contradiction to each other. For example, poverty alleviation may exacerbate air pollution by increasing production and associated emissions. This paper investigates the potential impacts of achieving different poverty eradication goals on typical air pollutants in China by capturing household consumption patterns for different income groups and locations, and linking it to China’s multi-regional input-output table and various scenarios. We find that ending extreme poverty, i.e. lifting people above the poverty line of USD 1.90 a day in 2011 purchasing power parity (PPP), increases China’s household emissions by only less than 0.6%. The contribution increases to 2.4%–4.4% when adopting the USD 3.20 PPP poverty line for lower-middle-income countries. Technical improvements in economic sectors can easily offset poverty-alleviation-induced emissions in both scenarios. Nevertheless, when moving all impoverished residents below the USD 5.50 PPP poverty line for upper-middle-income countries, household emissions in China would increase significantly by 18.5%–22.3%. Counteracting these additional emissions would require national emission intensity in production to decrease by 23.7% for SO2, 13.6% for NO
x
, 82.1% for PM2.5, and 58.0% for PM10. Required synergies between poverty alleviation and emission reduction call for changes in household lifestyles and production.
Temporal scaling of long-term co-occurring agricultural contaminants and the implications for conservation planning
Authors: Liang Xiuyu , Schilling Keith E , Jones Christopher S , Zhang You-Kuan 
Published: August 2021

Abstract
Stemming the export of agricultural contaminants such as nitrogen, phosphorus, sediment, and bacteria in rivers is needed to improve water quality in agricultural regions. However, patterns and trends of these co-occurring agricultural contaminants are relatively unexplored owing to the lack of long-term and high-frequency data sets needed to capture their fluctuations over different time scales. Using a dataset measured at the Raccoon River in west-central Iowa for more than 17 years, spectral analyses were used to characterize the variability and temporal scaling of co-occurring nutrients, sediment, and bacteria in long-term monitoring data in a water-supply river draining a highly agricultural watershed. Results showed that scaling exponents of pollutant concentrations gradually increased from bacteria (0.27) to sediment (0.64), chloride (1.02), orthophosphate (0.75), and nitrate (1.73). The smaller scaling exponents of bacteria and sediment indicate transport primarily by surface water runoff whereas the larger exponents of nutrients indicate transport by groundwater and subsurface tile drainage. Nitrate export exhibits a chemostatic behavior whereas the other constituents deviate from the chemostatic behavior, indicating that the agricultural watershed has a large reservoir of nitrogen relative to the other pollutants. The results are seen to provide guidance for implementation of conservation practices in agricultural watersheds by helping watershed managers more correctly match the appropriate practice to the dominant hydrologic transport pathway.
Distinct East Asian precipitation variability and predictability in coupled and uncoupled El Niño events
Authors: Liu Yunyun , Wu Renguang , Ding Yihui 
Published: August 2021

Abstract
Previous studies have shown different impacts of eastern (EP) and central (CP) Pacific El Niños on the East Asian precipitation. This study reveals distinct precipitation anomalies over East Asia in coupled and uncoupled El Niños. The uncoupled warm events in 1979, 2004, 2014, 2018, and 2019, which occurred in the autumn–winter transition, represent an unusual form of El Niño diversity. The sea surface temperature anomalies (SSTA) in the western North Pacific (WNP) appear to be an important factor leading to the different distribution of precipitation anomalies over East Asia and the WNP. In coupled El Niños, anomalous lower-level anticyclone over the WNP is a result of combined effects of warm SSTAs in the equatorial CP and EP and cold SSTAs in the WNP. The cold SSTAs are attributed to surface heat flux anomalies that in turn are associated with convection and wind anomalies. The lack of cold SSTAs in the WNP in the uncoupled El Niños leads to a weaker anomalous anticyclone with a northwestward location. The different features of an anomalous anticyclone over the WNP induce discrepancy in the distribution of precipitation anomalies and the associated predictability over East Asia between coupled and uncoupled El Niños. The prediction skill tends to be lower for the uncoupled El Niño events than the coupled ones, which further indicates the necessity to distinguish uncoupled from coupled warm events.
Changes in the implementation of concrete in situ work method to a precast method
Authors: Birowo JB Wowok , Suangga Made , Harimawan  
Published: August 2021

Abstract
Sulfur Jetty Development Project and TUKS Oil and Gas Dredging Project The Balikpapan RDMP RU V Project is located in Balikpapan City, East Kalimantan. In this project there are 2 (two) main work scopes, namely sulfur jetty work and dredging work. Like other projects, an engineering review of the design drawings, work volumes, work methods, and work schedules is also carried out. The purpose of this engineering review is to evaluate whether the change in the method of implementation of concrete works in Situ to Precast can maximize the work in accordance with the concepts of quality, time and cost. For this reason the submission of the amendment to PERTAMINAwas accompanied by several technical reasons that affected the work. For the method change, a number of processes were carried out such as the submission of design changes, changes in work methods, the process of calculating the structure and several other matters related to the quality of the structure due to changes in the method of implementation. From the results of the calculation of the structure has adjusted to the needs in accordance with the initial plan, by changing the installation method but still maintaining the strength of the structure in accordance with the initial plan. With this Precast method, the construction process is relatively safer and measurable in terms of cost and time.