bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal conductivity of h-BN monolayers using machine learning interatomic potential
Authors: Zhang Yixuan , Shen Chen , Long Teng , Zhang Hongbin 
Published: December 2020

Abstract
Thermal management materials are of critical importance for engineering miniaturized electronic devices, where theoretical design of such materials demands the evaluation of thermal conductivities which are numerically expensive. In this work, we applied the recently developed machine learning interatomic potential (MLIP) to evaluate the thermal conductivity of hexagonal boron nitride monolayers. The MLIP is obtained using the Gaussian approximation potential method, and the resulting lattice dynamical properties and thermal conductivity are compared with those obtained from explicit frozen phonon calculations. It is observed that accurate thermal conductivity can be obtained based on MLIP constructed with about 30% representative configurations, and the high-order force constants provide a more reliable benchmark on the quality of MLIP than the harmonic approximation.
Minimal length effects on motion of a particle in Rindler space *
Authors: Guo Xiaobo , Liang Kangkai , Mu Benrong , Wang Peng , Yang Mingtao 
Published: December 2020

Abstract
Various quantum theories of gravity predict the existence of a minimal measurable length. In this paper, we study effects of the minimal length on the motion of a particle in the Rindler space under a harmonic potential. This toy model captures key features of particle dynamics near a black hole horizon and allows us to make three observations. First, we find that chaotic behavior becomes stronger with increases in minimal length effects, leading predominantly to growth in the maximum Lyapunov characteristic exponents, while the KAM curves on Poincaré surfaces of a section tend to disintegrate into chaotic layers. Second, in the presence of the minimal length effects, it can take a finite amount of Rindler time for a particle to cross the Rindler horizon, which implies a shorter scrambling time of black holes. Finally, the model shows that some Lyapunov characteristic exponents can be greater than the surface gravity of the horizon, violating the recently conjectured universal upper bound. In short, our results reveal that quantum gravity effects may make black holes prone to more chaos and faster scrambling.
Production Performance Analysis of Su-6 Well Block in Sulige Gas Field, Ordos Basin, China
Authors: Sun Lin , Li Xianwen , Chen Baochun , Gu Yonghong , Wang Wenxiong , Zhao Jinsheng 
Published: December 2020

Abstract
As a tight sandstone gas reservoir of Su-6 well block in Sulige gas field, part of the gas wells have a poorer production performance with a faster decline rate of formation pressure and production, which is inconsistent with static reservoir parameters of gas well. In order to improve the productivity of gas well, on the base of static and dynamic classification of 232 gas wells, the reasons of inconformity between production performance and static reservoir parameters are analyzed from the four aspects of sand body connectivity, reservoir heterogeneity, gas saturation and fluid accumulation in wellbore. The results show that the main reasons causing the inconformity are the strong heterogeneity and poor sand body connectivity, and the secondary reasons are fluid accumulation in wellbore and low gas saturation. The results of this paper is of great significance to improve the productivity of gas wells and guide the development of ultra-low permeability gas reservoir.
Situation Analysis on the Price Formation Mechanism of New Energy in China
Authors: Mi Ning , Liu Dunnan , Qiao Ning , Wang Liyang , Li Qiang , Zhang Chao , Xu Xiaofeng , Yin Guolong 
Published: December 2020

Abstract
With the rapid development of China’s economy, the energy shortage is becoming more and more serious. In order to realize the sustainable development of society, Chinese government has strengthened its support for the development of new energy industry. At present, the total installed capacity of new energy in China has reached 37.2%. Compared with the initial period, the scale of new energy industry has been greatly increased. However, the problem of pricing mechanism of new energy benchmarking in China is increasingly prominent, which not only increases the gap of financial subsidies, but also fails to realize the reasonable optimal allocation of resources. For this purpose, according to the current domestic electricity market environment, this article proposes a new energy price formation mechanism which is more conformed to China’s national conditions. Firstly, the article summarizes the existing international new energy pricing mechanisms and analyses the countries in which they are applied. Secondly, through the analysis of the problems and challenges of new energy price in China, the formation mechanism of new energy price in this environment is proposed according to the current situation and future development trend of power market construction in China. Finally, the article summarizes the whole text and proposes relevant policy recommendations as a useful reference for the government to promote the construction of electricity market.
Well loss Risk Real-time Monitoring and Simulation Analysis of Key Parameters
Authors: Ma Yongqian , Shao Ru , Dong Guanghua , Liu Xiaolan 
Published: December 2020

Abstract
The downhole engineering parameters measurement system(EPMS) can show the actual state in wellhole more intuitively, and significantly improve the accuracy of drilling construction decision. However, there was a big gap between domestic and foreign countries in the comprehensive management, analysis and processing of underground and surface drilling engineering parameters. For the well loss risk, the characteristic parameters were internal and external pressures, and the threshold limit values of well loss risk levels was selected, so the assessment system was established. Then through real-time processing and analysis of underground and surface engineering parameters, the characteristic parameters of the well loss risk was calculated real-time, according to the comparison of the calculated value and the measured value, and the assessment system, the wellhore risk level was monitored real-time. Beside the well loss depth could be calculated by these measured parameters, which was important for the well loss treatment. This technology was used in G1 well in GX blocks of Shengli oilfield, in which the well loss occurd frequently. The application result shows that well loss can be monitored at an early stage, reducing the cost of materials and processing the complex time.
Study of a Novel High-Density Module with Triangled Light Redirecting Ribbons
Authors: Huang Guoping , Zhuang Hao , Jiang Yashuai , Sun Guan , Bai Xueliang , Li Jingnan 
Published: December 2020

Abstract
Light redirecting ribbons (LRR) have recently been applied in high-density crystalline silicon modules in PV industry. The adoption of this LRR may bring additional reliability risk, which may probably lead to higher power loss after aging. Therefore, damp heat (DH), thermal cycle (TC), UV irradiation and humidity freezing (HF) test were employed in this work to investigate the reliability of LRR-based high-density crystalline silicon modules. The obtained results show that this novel high-density modules with specially designed triangle ribbons have outstanding reliability both in damp heat and dry heat environment as well as under UV irradiation.
Off-design Characteristics for Expansion Power Generation Process of Liquid Air Energy Storage System
Authors: Xu Guizhi , Deng Zhanfeng , Cui Shuangshuang , Shi Xingping , Lu Chang , Liang Lixiao , He Qing 
Published: December 2020

Abstract
In order to study the off-design conditions of energy storage system due to the grid load requirements and the fluctuation of external environmental factors in the process of grid-connected operation and the off-design performance of energy storage system, the dynamic model of expansion power generation of 500kW liquid air energy storage (LAES) system is established. Considering the change characteristics of the adiabatic efficiency and pressure ratio of the expander with flow rate, the dynamic changes of rotor speed, electric power, and valve opening size of LAES system under complex conditions of increasing/decreasing load are simulated. The results show that the stability time of electric power is shorter when the variable load is lower when the load change rate of the energy storage system is kept constant under the condition of increasing/decreasing load. On the contrary, the stability time of electric power is longer when the variable load is higher. The stability time of electric power is 12s when the energy storage system changes from 100% rated condition to 90% working condition. The stability time of electric power is 34s when the energy storage system changes from 100% rated working condition to 60% working condition. Under the condition of variable load, the fluctuation of rotor speed is very small and remains unchanged.
Problem and Countermeasure Analysis of IGCC Combustion Gas Turbine Fueled with Low Heating Value Syngas
Authors: Liu Hongtao , Xue Li , Wang Xueqing , Zhang Huanxiang 
Published: December 2020

AbstractIGCC technology is recognized as one of the cleanest and most efficient power generation technologies. Inferior fuel is gasified into clean syngas by IGCC gasification reaction. Syngas is then sent to combustion gas turbine and combusted to generate power. Problem and countermeasure of IGCC combustion gas turbine fueled with low heating value syngas is analyzed in this paper. Main fuel components and combustion characteristics of syngas are significantly different with that of conventional natural gas. Diffusion combustion mode is adopted to match syngas combustion characteristics. The gas turbine will trip due to unstable combustion if direct burning syngas at low load case. Alternative fuels should be used at low gas turbine load case. There is an appropriate load window for fuel switching. Fuel switching at 50% load within 10 minutes is selected in this paper.
Study on Guided Wave Characteristics of Waveguide Rod
Authors: Meng Xiangjun , Li Wenfeng , Sun Peng , Zhang Xiaofei , Wu Jialing , He Qing 
Published: December 2020

Abstract
Waveguide rod is currently used as an auxiliary tool in ultrasonic testing. Because the waveguide rod can isolate high-temperature workpiece from ultrasonic sensor, it is often used in monitoring of high-temperature equipment. However, there are dispersion and attenuation when ultrasonic guided wave propagates in waveguide rod, which is not conducive to the monitoring of equipment. In order to improve the monitoring accuracy, the effects of diameters and lengths on the guided wave characteristics of the waveguide rod were analyzed through numerical calculation and experimental research. The results show that the larger the diameter of the waveguide rod, the smaller the attenuation of the ultrasonic guided wave and the weaker the dispersion; the increase in the length of the waveguide rod has no effect on the dispersion of the guided wave, but it will increase the attenuation.
Design of Power and Energy System for a Small Garbage Cleaning Ship
Authors: Zhang Wei , Jiang Dezhi , Li Pinfang 
Published: December 2020

Abstract
Port garbage and dirty oil will cause pollution to the marine environment, and the sea area of port is narrow and not easy to clean, which limits the use of conventional cleaning ships. There is a need for an environmentally friendly and flexible small garbage cleaning ship. This study introduces the composition and principle of the ship propulsion system, analyzes and calculates the characteristics of the motor and the power of the ship shaft, determines the type of the motor and the composition of the energy system, and further analyzes and calculates the solar power generation system. The results show that the mode of using lithium battery as main energy and solar energy as auxiliary energy can meet the power needs of the small cleaning ship and meet the relevant environmental protection requirements.
Double Rotary Valve Engine Design
Authors: Deng Baoqing , Liu Zhuoya , Gao Zengfa , Li Shihang , Deng Mengqi 
Published: December 2020

Abstract
This paper proposes a new type of dual-rotation valve engine, which uses the intake rotary valve and the exhaust rotary valve to control the intake and exhaust of the engine, replacing the intake and exhaust valves and camshafts of the conventional engine. The basic mechanism and working principle of the machine are discussed. In this paper, the combustion chamber structure and lubrication method of the machine are also designed. The compression ratio of the machine is calculated, the gas distribution phase is designed, and the ventilation passing ability is analyzed. It is concluded that the machine has the advantages of simple structure, few parts and strong ventilation capacity, that is, it is suitable for port injection and can also carry out in-cylinder injection.
Study on the Mechanism of High-Silicon Manganese Fume Dust Precipitation under Pressure by Acid Pickling
Authors: Li Kaifeng , Xie Hongyan , Jin Huixin , Zhang Qiang , Zhang Yaqing , Li Xiaohui , Bao Chongjun 
Published: December 2020

Abstract
Via the thermodynamic analysis of high silicon manganese soot precipitation process. Potential-oxidation state-ΔG diagram, E-pH diagram, micro-region morphology of manganese soot and X-ray energy spectrum analysis, we can know: under high temperature leaching conditions, the leaching system needs to maintain a relatively high initial acid concentration in order to achieve leaching of Mn2+ and increase the pressure leaching rate.
Numerical Simulation of the Effect of Combustion Process on Flue Gas Thermal Deviation in 660MW Boiler
Authors: Yang Xianbiao , Gao Yuan , Wang Shutao , Shi Renqiang , Liang Shaohua , Sun Rongyue 
Published: December 2020

Abstract
In order to analyze the effect of the air volume on the combustion side and the non-uniformity of pulverized coal on the temperature distribution of the boiler outlet flue gas, and then analyze the thermal deviation characteristics of the steam heating surface, the following five different working conditions are calculated and analyzed in a 660MW boiler. Results show that the deviation of pulverized coal content of each burner and the deviation of primary air volume are the important factors that cause the temperature deviation of flue gas outlet in the furnace. Therefore, it is an important way to improve the temperature distribution and reduce the thermal deviation of flue gas outlet by improving the uniform combustion and air distribution of the burner in the furnace.
Research and Development of Fire Alarm Detection Device for Lithium Ion Battery Based on Strain Measurement
Authors: Xiaobai Li , Xiaopeng Liu , Yingcong Zhang 
Published: December 2020

Abstract
In order to realize the fire alarm of lithium ion battery, a fire alarm detection device is developed based on the principle of strain measurement. This paper makes a study of the detection principle and application circuit. Firstly, according to characteristic rule of thermal runaway process of lithium ion battery, the correlation between battery deformation, temperature and released gas is analyzed and a battery fire warning method based on strain measurement is proposed. Then, the strain measuring circuit is designed and circuit working principle is analyzed. In the end, the application effect of the battery fire warning method based on strain measurement is verified through thermal runaway experiment of lithium ion battery. The experimental results show that the method based on strain measurement can identify fire risks at the early stage when the lithium ion battery thermal is out of control, preventing fire from spreading. Basically it can meet the needs of lithium-ion battery fire warning.
Effect of the surfactants on hydrate formation during methane storage process
Authors: Zhang Panfeng , Diao Yuqian , Dong Zhao , Pei Shufeng , Wang Qiaobo , Ren Shaoran , Zhang Liang 
Published: December 2020

Abstract
Enhanced hydrate formation rate by adding surfactant for achieving hydrate-based methane storage and transportation has drawn much attention in recent years. In this study, the effect of cocamidopropyl dimethylamine (CPDA), Sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium bromide (DTAB), and hexadecyl trimethyl ammonium bromide (HTAB) on induction time, the formation rate, water conversion ratio, and dissociation rate of methane hydrate have been investigated. And all the results have been compared with the water system without any additives. After adding surfactant into the aqueous solution, the hydrate formation is promoted, which lead to higher the hydrate formation rate and more water converted to be hydrate. 69.96wt% water was converted to be hydrate and its formation rate is 31.58mmol/min in 1.0wt%CPDA aqueous solution, in water without any additives system, it is 29.44wt%, 11.45mmol/min, respectively. Besides, the highest dissociation rate is also found in CPDA aqueous solution system, it is 42.2mmol/min and is 2.16 times than that of the pure water system.
Study on variational assimilation in chemical hazard leakage accidents
Authors: Jiang Jinli , Han Chaoshuai , Zhu Xuezheng , Gu Jin 
Published: December 2020

AbstractIn this paper, the problem is studied and analyzed by introducing variational assimilation method and combining with the gaussian plume model.Through the analysis and study of background error covariance, observation error covariance and diffusion parameters, the variational assimilation scheme of chemical hazards was designed and the mathematical modeling was carried out.Then, through Matlab platform programming, numerical experiments are carried out on the established model and an example analysis is made. The results show that the concentration prediction field after assimilation can effectively reduce the prediction error and achieve convergence.
Research on Application of Image Enhancement Technology in Automatic Recognition of Rock Thin Section
Authors: Xu Yuxuan , Dai Zongyang , Luo Yixin 
Published: December 2020

Abstract
Artificial intelligence technology has rapidly emerged in various new industries due to its high efficiency and has been successfully used in many fields. However, it has been slow to start in the field of petroleum exploration, under the background of the need for more efficient exploration and development in the petroleum field. In this paper we used the ResNet-18 convolutional neural network to make an attempt to automatically identify rock thin section, and finds that this method can efficiently identify rock thin section and has a higher accuracy rate. In addition, we adopted appropriate image enhancement technology, which can significantly improve the recognition accuracy of the model. It proves that related machine learning technology has broad application prospects in the fields of petroleum exploration and petroleum geology.
Study on the Law of the Influence on Slag Blocking in Combustors Produced by Coal Blending Combustion Strategy of Slag-tap Boiler
Authors: Xiang Ma , Hao Zhou 
Published: December 2020

Abstract
Slag blocking and slagging of combustors are influenced by the coal blending combustion strategy of slag-tap boiler. this paper studies these influence factors, analyzes the problems of slag blocking and slagging of combustors from the perspective of fuel, and examines the calorific value, ash content, ash melting point, ash melting characteristics of coal quality and slag captured rate of boiler. Based on the above researches, the writer summarizes the effects on slag blocking and slagging in the combustors produced by different coal combustion of slag-tap boiler, and forms coal blending combustion strategy suitable for the slag-tap boiler.
Analysis on factors that influence concentration of PM2.5 expelled in vehicle exhaust in underground parking lots of large shopping centers in Changchun
Authors: Bai Li , Fu Jia-Qian , Sun Yu-Tong 
Published: December 2020

Abstract
Our goal is to find out how the passenger number, vehicle type and vehicle displacement influence the PM2.5 concentration in underground parking lots of large shopping centers. To this end, we collected data of PM2.5 concentration in several underground parking lots in CBDs of Changchun. We have some findings from the conducted experiments. First, PM2.5 concentration rises as the the number of passengers carried in the vehicle increases. As for vehicle type and displacement, high-displacement sedans and moderate-displacement SUVs contribute most to PM2.5 concentration inside the parking lots, among which vehicles of older age cause even greater pollution, with PM2.5 concentration averaging 208 μg/m³and 241μg/m³respectively. And high-displacement MPVs have greater influence on PM2.5 concentration than low-displacement ones.
Pyrogenic transformation of old pine forests in the Middle Volga Integrated Biosphere Reserve and its effect on the nesting birds
Authors: Bykov E V , Golovatyuk S A 
Published: December 2020

Abstract
The effects of the pyrogenic transformation of old pine forests of the Middle Volga Integrated Biosphere Reserve on the nesting birds were studied, based on the original surveys performed in 2006-2009. The changes of the breeding ornithological fauna’s parameters were traced during the restoration of the lower tiers of vegetation after local lower fires. The response of particular species and guilds of nesting birds to the changes in nesting conditions due to a single bottom fire was determined, as well as the changes in the total number of nesting birds and in the number of particular guilds of nesting birds during the vegetation recovery after the fire. The bird species vulnerable to the changes in nesting conditions were identified. The relationship between post-pyrogenic vegetation restoration processes in old pine forests and the species composition and ecological preferences of birds nesting was shown.
Taxonomic composition of the bacteriobenthos of the littoral and pelagic zones of the Lake Kandry-Kul in June and September 2010 (Natural Park “Kandry-Kul”, Republic of Bashkortostan, Russia)
Authors: Sherysheva N G , Rakitina T A , Povetkina L P 
Published: December 2020

Abstract
The taxonomic composition of the bacteriobenthos of the littoral and pelagic zones of the Lake Kandry-Kul’ was analyzed by gas chromatography-mass spectrometry (microbial markers). The studied communities comprise 39 taxa of the Bacteria domain. Two dominant taxa were a characteristic of bacteriobenthos in the littoral zone in June, one dominant taxon, in September. The taxonomic structure of bacteriobenthos of the pelagic zone was characterized by two dominant taxa both in June and September. There were common dominants in the littoral and pelagic biotopes, namely, representatives of the genera Butyrivibrio, Spirochaeta, and of the group of iron-reducing bacteria (FeRB). The species Clostridium difficile, Geothrix fermentans, and the genus Thiobacillus were specific to the littoral bacteriobenthos community. The bacterial community of the pelagic zone was characterized by a change of dominant taxa in autumn. The increase of bacteriobenthos biomass and its particular taxa was significantly affected by the water temperature, redox potential, and the content of humic substances.