bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on navigation and positioning Technology based on opportunity signal of low orbit satellite
Authors: Li Shenyang , Wang Haitao 
Published: June 2021

AbstractGlobal Navigation Satellite System (GNSS) signals to the Earth’s surface are weak, vulnerable to interference, and require significant infrastructure investment to keep them operating. In order to get rid of the dependence on GNSS navigation system and overcome the problems such as shadow occlusion and malicious interference, opportunity signal is used to realize positioning to make up for the shortcomings in this aspect. Aiming at the limitation of coverage and availability of land-based opportunity signals at present, the opportunity signals of low-orbit satellites have the advantages of high signal power, wide coverage and no need to build additional infrastructure, etc. Therefore, space-based opportunity signal positioning by using low-orbit satellite system can be used as an effective backup or supplement to GNSS system. In this paper, the signal communication system of low orbit satellite is studied deeply, and the Doppler frequency information is obtained by using the single tone signal of the pilot frequency of low orbit satellite, and the mathematical model of instantaneous Doppler positioning and its geometric factor of accuracy is established, so as to realize the positioning ability of opportunity signal of low orbit satellite. The simulation results show that the positioning accuracy is better than 200 m using the actual low orbit satellite signals. The research results have reference significance for the theoretical research and application of location technology based on opportunity signal. By studying the communication system of low orbit satellite signal, the mathematical model of instantaneous Doppler positioning is established, and the method of obtaining Doppler frequency information by using the single tone signal of low orbit satellite signal and combining the satellite orbit information calculated by the orbit prediction model to realize low orbit satellite positioning is proposed. The measured data verification results show that the positioning accuracy of 100 meters can be achieved by using the LORB opportunity signal, and the research results have reference significance for the theoretical research and application of positioning technology based on the LORB opportunity signal.
Performance Analysis of GNSS Receiver allied in High-Orbit Based on SoC Platform
Authors: Liu Xianyang , Tian Xiaobin , Pei Dongbo , Liu Lei , Yu Qian 
Published: June 2021

Abstract
GNSS receiver technologies allied in high orbit altitudes has developed rapidly in recent years and has been used in orbit on many spacecraft. In this paper, TJS-5 Satellite is taken as an example to illustrate the design scheme of the high orbit navigation receiver based on the SoC platform, which takes the characteristics of the weak signals of GEO orbit navigation into consideration, and adopts the high sensitivity acquisition technology and the fast signal acquisition technology. Finally, the 19-day in-orbit data of TJS-5 Satellite are analyzed. The number of available satellites is between 4 and 8, the position accuracy of orbit determination is 15.8133m and the velocity is 0.012108m/s, which meets the needs of autonomous positioning and precise orbit determination in the whole orbit period of the satellite. The calculated results are compared with those of TJS-2 satellite.
Data Collection of Digital Monitoring System for Agricultural Facilities Environment
Authors: Li Feifei , Wang Hongling , Sun Lu , Wang Zilin , Ran Yuting , Xia Yingjun 
Published: June 2021

Abstract
In order to realize the intelligent control of the agricultural facility greenhouse environment cluster, the paper designs and implements an agricultural facility greenhouse environment cluster monitoring system based on RS485 bus and Modbus protocol. The system consists of on-site data acquisition and control part, remote monitoring centre monitoring software part and communication protocol part. We use the RS485 bus with Modbus protocol to realize the communication between the monitoring centre host and the microcontrollers of each greenhouse. The paper uses the BP neural network PID control algorithm to achieve the intelligent control of the agricultural greenhouse environment. Use Qt software to design a human-computer interaction interface to realize remote control of the greenhouse cluster. The experimental results show that the system can correctly collect the temperature, humidity and light intensity of the agricultural greenhouse environment, and can effectively control the environmental parameters of each greenhouse through the action of the control relay.
Surface heating control during low-temperature plasma treatment
Authors: Brzhozovsky B , Martynov V , Zinina E , Permyakov S 
Published: June 2021

Abstract
The main features of the process reflecting product surface heating during low-temperature plasma treatment have been established, and the necessity of managing this process has been substantiated. A control method has been developed that makes it possible to determine the moment of termination of the plasma effect on the product surface using a logistic curve as a data model on the temperature recorded outside the zone of thermal plasma effect (lagged temperature).
Surface hardening of 35KhGSA steel samples on the MAK-10 plasma modification machine
Authors: Ilinykh S A , Krivorogova A S , Ilinykh N I , Ignat’eva E V , Korolev O A , Marshuk L A , Krashaninin V A , Gelchinsky B R , Leontiev L I 
Published: June 2021

Abstract
The plasma modification unit UPM MAK-10 developed in IMET UrO RAS was used for surface hardening samples of 35KhGSA steel. As a result, it leads to an increase in the tribological characteristics of products (hardness and wear resistance, etc.) and, consequently, increases the service life of various machines and mechanisms.
Microstructure and properties of a silicon coating deposited on a titanium nickelide substrate using molecular-beam epitaxy equipment
Authors: Krukovskii K V , Kashin O A , Luchin A V , Kohanenko A P , Dirko V V , Lozovoi K A , Kashina O N , Bobrov D I 
Published: June 2021

Abstract
The microstructure and properties of a silicon coating on a titanium nickelide substrate were studied to assess the possibility of using such a coating to improve the biocompatibility of medical implants. The silicon coating with thickness of 4.0±0.5 microns was applied to the TiNi substrate on a molecular beam epitaxy unit. The coating had a submicrocrystalline structure with a crystallite size of 0.1…0.2 microns, a developed surface, and high crack resistance.
Effect of annealing on the morphology and mechanical properties of phosphorus-doped nickel coatings obtained by cathodic arc evaporation
Authors: Lapitskaya V A , Kuznetsova T A , Khabarava A V , Trukhan R E , Chizhik S A , Delendik K I , Voitik O L , Kuprin A S , Kudin D V , Koneru A , Bortnitskaya M A 
Published: June 2021

Abstract
The results of an atomic force microscopy study of the surface of nickel coating doped with phosphorus of 2 μm thick obtained by cathodic arc evaporation after the annealing at temperatures from 100 to 500 °C are presented. The surface morphology changes significantly with an increase in the annealing temperature. A negative high correlation between the specific surface energy and the coating roughness after the annealing was established. The mechanical properties (microhardness, elastic modulus and plastic deformation) were determined by nanoindentation. A decrease in the elastic modulus of the nickel coating with an increase in the annealing temperature was found.
Microstructure, mechanical and hydrophilic properties of two-layer nanostructured TaN/Ta2O5 coatings
Authors: Petrovskaya A S , Lapitskaya V A , Khabarava A V , Melnikova G B , Kuznetsova T A , Chizhik S A , Zykova A V , Safonov V I 
Published: June 2021

Abstract
The microstructure, mechanical and hydrophilic properties of two-layer TaN/Ta2O5

coatings on stainless steel and silicon wafers were studied using atomic force microscopy (AFM), nanoindentation (NI) and sessile drop method. It was found that the two-layer films are characterized by a granular structure with low roughness values. The average values of the elastic modulus and microhardness for TaN/Ta2O5 were 130 GPa and 8.7 GPa, respectively. The contact angles for the two-layer coatings were 95.1° 90.0° on the steel and silicon substrates, respectively.
Formation of droplets in a heterophasic amorphocrystalline nanopowder Bi2O3 produced by pulsed electron beam evaporation in vacuum
Authors: Sokovnin S Yu , Ilves V G , Murzakaev A M 
Published: June 2021

Abstract
In the present work, a mesoporous multiphase amorphous crystal nanopowder Bi2O3 with a specific surface area of up to 23 m2/g was produced by pulsed electron beam evaporation in vacuum. Influence of thermal annealing (200-500 °C) of powders in air is investigated. The formation of droplets with a size of 3-5 nm on the surface of all large nanoparticles constituting the framework 3D nanopowder agglomerates was found due to extrusion of liquid bismuth from the volume during cooling.
Application of complex niobium nitrides as heat-protective and wear-resistant coating materials for cutting tools
Authors: Tabakov V P , Chikhranov A V , Dolzhenko Y A , Vlasov S N 
Published: June 2021

Abstract
The results of investigations of the contact temperatures on the front surface and the thermal state of cutting wedge of carbide tool using coatings based on complex niobium nitrides are presented. The efficiency of using carbide tools with developed wear-resistant coatings is shown. Further use of the developed coating compositions for creating multilayer coatings is proposed.
The impact of fintech on the profitability of state-owned commercial banks in China
Authors: Wu Guo , Yuan Hongfei 
Published: June 2021

Abstract
Fintech is the innovative use of technology in the design and delivery of financial products and services. This study aims to statistically investigate the fintech and other determinants that affect the profitability of six state-owned commercial banks (SOBs) in China using the data from the 2014-2019 period. Theoretically, fintech serves as a disruption for its banking services through adverse impacts on asset business, liquidity business and intermediary business. Empirically, the result shows that the development of fintech has a negative impact on the profitability of SOBs and the regression results from the OLS estimation, the FGLS estimation, the Prais-Winsten estimation and the FE estimation are compared to ensure the validity of the statistical inference.
Improved High Precision Aircraft Target Detection Method of YOLT
Authors: Mao Jiaxing , Zhang Xinyu , Ji Yang , Zhang Zhen , Guo Zihao 
Published: June 2021

Abstract
The first remote sensing dataset that can be used for aircraft target detection is created and a 3D model simulation method for data augmentation is proposed. After statistical analysis of aircraft sizes, a high-precision improved YOLT method for target detection is proposed. YOLT is the first light algorithm focusing on target detection in remote sensing images. We improve its network structure, design a creative method based on receptive field improvement and adopt an optimized non-maximum suppression strategy. The results show that our method has better performance than other main target detection algorithms, especially for small targets and cross-scale samples.
Performance Analysis and Optimization of Nginx-based Web Server
Authors: Wang Jundi , Kai Zhao 
Published: June 2021

Abstract
Performance optimization and analysis of Web server is one of the key technologies of Web server. Through the analysis of the work flow and working principle of the Web server, some influencing factors that are in line with the current environment and have feasibility are selected for targeted optimization, such as value of a thread or process, live time, cache size. Through optimization, the comprehensive performance of Web server based on Nginx has been greatly improved.
Applications Research of Blockchain Technology in Accounting System
Authors: Zheng Ruirui 
Published: June 2021

AbstractAccounting is the business language of social economy. The in-depth application of blockchain technology in the accounting industry can promote the development of the accounting industry itself, and also further promote the blockchain technology to play a higher role in the whole social economy. This paper studies the necessity and feasibility of the application of blockchain technology in the accounting industry, discusses the working principles of the accounting information system of the seller and the buyer, and constructs the vertical and horizontal application models of blockchain technology in the accounting system. Finally, this paper points out that we can strengthen the promotion of applications of blockchain technology in the accounting system by strengthening policy guidance, improving legislative protection, and cultivating compound talents.
COVID-19 Propagation Prediction Model Based on Machine Learning
Authors: Liu Yunxiang , Xiao Yan 
Published: June 2021

Abstract
The continuous spread of COVID-19 virus around the world has exerted a great impact on the world’s economy and security. China took the lead in responding to the epidemic with a positive attitude and contributed valuable experience to the fight against the epidemic for people around the world Based on the COVID-19 epidemic data published by the National Health Commission, this study established a time series of the number of newly diagnosed patients on a daily basis. The SIR model of transmission dynamics was used to determine the trend and inflection point of the epidemic, and the SVR algorithm was used to reasonably predict and analyze the number of newly diagnosed patients on a daily basis.
Evolution of Global EV Battery Technology Based on the Main Path of Patent Citation
Authors: Yan Duanwu , Deng Xiaocong , Mei Xirui 
Published: June 2021

Abstract
Based on the patent data collected from European patent database search, this paper firstly analyzes the general situation of electric vehicle battery field in terms of patent application trend, regional distribution and technology field distribution, then constructs patent citation networks in different development stages and identifies the main path of patent citations by SPC algorithm. Finally, the technological evolution process in the field of electric vehicle battery is analyzed by combining visualization mapping and patent texts. The research results show that the evolution direction of electric vehicle battery technology gradually converges, and fuel cell technology is the most critical technology in the whole technology development process.
The dynamics mode of production structure in the Patorani community in Takalar district
Authors: Halik H A , Salman D , Darma R , Arief A A 
Published: June 2021

Abstract
Business activities of torani fish eggs as an integral part of the rural economic system influenced by the presence of the capitalist system. The values of capitalism are absorbed and practiced by some people in their economic activities so as to give birth to more than one mode of production. The presence of more than one mode of production makes one dominate the other. This collision of production modes encourages the articulation of production modes, resulting in a new social formation. This study aims to describe the structure and articulation mode of production that takes place in the Patorani community in Takalar district. This research was conducted using a qualitative approach with a case study strategy. The results of this study indicate that the mode of production structure that takes place is more characteristic of the capitalist mode of production. The capitalist mode of production dominates the non-capitalist mode of production, resulting in articulation of the means of production to meet market demands.
Comparison of Viability and Efficacy of an Immobilized Bacterial Consortium in Four Different Carriers to Degrade Oil
Authors: Darmayati Y , Wiranata Y , Afianti N F , Manurung B 
Published: June 2021

AbstractThis research aimed to evaluate the storage system’s effect on immobilizing bioremediation agents’ performance in four different carriers (Perlite, Silica, Vermiculite, and Zeolite). Measured parameters were the viability and efficacy of artificial bacterial consortium (Bacillussp.,B. licheniformis, andEnterobacter cloacae) immobilized in the four porous rock carriers by lyophilization. They were stored at room temperature (25-27°C) for three months. The experiment was taken place in a microcosm system with three replicates for 28 days. The results indicate that storage of immobilized bacteria for three months at room temperature will affect their viability. The efficacy of immobilized bacteria in Vermiculite and Perlite reached the highest rate until the first week, 61.44% and 60.18 %, respectively. However, the efficacy in decreasing oil concentration of immobilized cells in the four carriers was almost similar (90.53 – 91.63%), with no significant difference between each other in the late stage. This is very different with control, decreasing oil in only 10.85 - 13.57%, except in control with fertilizer (Cp) supplemented (90.63%). We conclude that bioremediation will improve oil removal. However, storage at room temperature for three months will decrease the performance of these immobilized cells.
Ecosystem biotechnologies for the enhancement of ecohydrological potential of the catchments – Water, Biodiversity, Ecosystem Services, Resilience, Culture and Education
Authors: Zalewski M 
Published: June 2021

Abstract
One of the threats for biosphere sustainability in the face of climatic changes is the amplification of water and nutrient cycling stochasticity, which means intensive floods, droughts, and pollution. This is largely due to the increase of industrial agriculture and random urbanization, which results in a cumulative impact. To reverse the effect of cumulative intermediate impacts, which often are major factors of degradation of the ecological potential at catchments, a profound understanding of the water-biota interplay is most important. This is because water has been the major determinant of ecosystem structure as it drives carbon, phosphorus, and nitrogen cycling and determines ecosystem services for society. Thus the fundamental for the development of innovative Ecohydrological Nature Based Solutions (EH NBS) for water is the profound understanding of water–biota interplay from molecular to catchment scale. The above Ecohydrological framework serves not only to mitigate intermediate forms of impact but also to increase the ecological potential of a river basin expressed by a multi-dimensional goal – Water, Biodiversity, ecosystem Services for society, Resilience to climatic changes, Culture, and Education (WBSRCE), which helps to harmonize the enhanced ecosystem potential with social needs and, in turn, achieve sustainability of river basins. As far as Ecohydrology is empirical science, international advanced study courses where scientists, and pro-activists can share experience at UNESCO IHP Demosites should also be an important tool for dissemination.
Research on the mechanical properties of reinforced steel fiber concrete column under impact loading
Authors: Yantao Jiang , Chuanyun Xiong , Peiding Wang 
Published: June 2021

Abstract
In order to study the effect of different slenderness ratio and axial compression ratio on the lateral impact resistance of reinforced steel fiber reinforced concrete columns, the impact models with different slenderness ratio and continuously varying axial compression ratio were established to analyze the lateral impact resistance of the components. The results show that the proper axial compression ratio is helpful to improve the anti-impact ability of the components. Under normal working conditions, columns with a slenderness ratio of less than 6.5 are recommended to not exceed the axial compression ratio 0.6, for columns with slenderness ratio greater than 12, the axial compression ratio should not be less than 0.3. For columns that may be subjected to impact, the slenderness ratio should not exceed 14.
Causes of Work Safety Accidents in Railway Construction Engineering
Authors: Du Zhuoqun , Liu Yisheng 
Published: June 2021

Abstract
Work safety accidents that occurred in railway construction engineering could cause casualties and economic losses. Analyzing the trends and causes of accidents is helpful to reduce the occurrence of an accident. In this paper, the 108 work safety accident cases from 2005 to 2020 are collected and analyzed by statistical method. The complex network theory is used to construct causation model in collapse accident. The analysis results show that from 2015 to 2020 the largest number of accidents that occurred during railway construction are in lines, followed by tunnels and bridges-culverts. The occurrence frequency of work safety accidents from May to July is significantly higher than other months. The results also show that the nodes (construction personnel operate in violation of rules and regulations and inadequate management in construction site) are of high value.
Study on early basic mechanical properties of inorganic polymer-based fast-hardening concrete
Authors: Xia Wei , Xu Jinyu , Luo Xin , Yao Ao 
Published: June 2021

Abstract
In order to predict the application effects of inorganic polymer-based fast-hardening concrete (IPFC) in pavement emergency repair, the slag, fly ash and silica fume were used as solid cementitious materials, and sodium hydroxide and sodium silicate were used as alkali-activators to prepare IPFC specimens. The change rules of the basic mechanical properties of the specimens with different slag, fly ash and silica fume contents in early stage were studied by experiments. The results show that, the early compressive strength of each group of specimens is more than 20 MPa and that of slag-based fast-hardening concrete (SFC) specimens is the highest. SFC specimens have the highest bending strength when they are cured for 2 h, while the silica fume/slag-based fast-hardening concrete (SSFC) specimens have the highest bending strength when the curing time is up to 3 h.
The design and implementation of the auxiliary calculation system for geotechnical engineering index and parameters
Authors: Xu YR , Zhou YM , Liu YH , Yin YB 
Published: June 2021

Abstract
A program based on Visual Basic for the auxiliary calculation and statistical analysis of geotechnical engineering index and parameters is introduced in this paper. The application methods and skills of the program are illustrated with examples. This program contains 10 main calculation modules of geotechnical, a total of 23 different index calculation methods were integrated in it. Through this program, users only need to input the original data of geotechnical engineering tests of different projects and plots, and can quickly conduct the statistical analysis of geotechnical engineering parameters in a certain area, and can also compare the significance of differences among various factors. It is simple to operate, and the results are accurate and reliable, which can greatly improve the efficiency of parameter calculation and calibration in the practice of geotechnical engineering, and ensure the accuracy and precision of the calculation results.