bluuebunny/crossref_metadata_2025_split huggingface dataset:
BLUES iteration applied to nonlinear ordinary differential equations for wave propagation and heat transfer
Authors: Berx Jonas , Indekeu Joseph O 
Published: December 2020

Abstract
The iteration sequence based on the BLUES (Beyond Linear Use of Equation Superposition) function method for calculating analytic approximants to solutions of nonlinear ordinary differential equations with sources is elaborated upon. Diverse problems in physics are studied and approximate analytic solutions are found. We first treat a damped driven nonlinear oscillator and show that the method can correctly reproduce oscillatory behavior. Next, a fractional differential equation describing heat transfer in a semi-infinite rod with Stefan–Boltzmann cooling is handled. In this case, a detailed comparison is made with the Adomian decomposition method, the outcome of which is favourable for the BLUES method. As a final problem, the Fisher equation from population biology is dealt with. For all cases, it is shown that the solutions converge exponentially fast to the numerically exact solution, either globally or, for the Fisher problem, locally.
Semiclassical treatment of quantum chaotic transport with a tunnel barrier
Authors: Bento Pedro H S , Novaes Marcel 
Published: December 2020

Abstract
We consider the problem of a semiclassical description of quantum chaotic transport, when a tunnel barrier is present in one of the leads. Using a semiclassical approach formulated in terms of a matrix model, we obtain transport moments as power series in the reflection probability of the barrier, whose coefficients are rational functions of the number of open channels M. Our results are therefore valid in the quantum regime and not only when M ≫ 1. The expressions we arrive at are not identical with the corresponding predictions from random matrix theory, but are in fact much simpler. Both theories agree as far as we can test.
Research on Cleansing and Drying System of Rice Husk before Pyrolysis
Authors: Luan Zhenhui , Chen Tao , Zhang Liming 
Published: December 2020

Abstract
Rice husk gasification technology has been concerned by many scholars at home and abroad. Because the rice husk contains too much impurities and dust, too much air is mixed into the combustion, which affects the purity of pyrolysis gas, causing difficulties in gas purification, blockage and corrosion of pipelines and other problems. In order to improve the quality of rice husk pyrolysis gas, the authors designed a cleansing and drying system of rice husk before pyrolysis. This paper analyzed the design principle of the system, designed the structure of screw conveyor and the dryer, determined the structure parameters of the system. The study indicates that the system can cleanse and dry the rice husk into the system, and can be used as a pretreatment device for rice husk pyrolysis.
Study on the Quantitative Measurement Technique of the Micro Fracture Surface
Authors: Liu Xiaolan , Zheng Yong , Ma Yongqian 
Published: December 2020

Abstract
The quantitative study on the distribution of cracks and micro cracks is a major problem in the study of reservoir properties of tight and lithologic regions In view of this problem, the present study is to evaluate the cracks by indirect method, and the direct evaluation method is lack of micro cracks This paper tries to combine the results of electronic scanning electron microscopy and image data processing method, which can directly test the density of micro cracks The test results prove that the method is convenient and feasible, and has a strong reference value for engineering practice and scientific research.
Theoretical and Empirical Analysis on the Transformation of Energy Consumption New Mode
Authors: Zhao Liujun , Wang Yinan , Lin Liu , Jie Li 
Published: December 2020

Abstract
The innovation of energy consumption modes plays an important role in solving energy development problems of China. This paper proposes a theoretical system for the transformation of energy consumption modes. Through the analysis of four elements of energy consumption mode, and their internal and external influence factors, four types of energy consumption new mode are derived, namely, integrated, sharing, intelligent and green patterns. These new modes present the features of digitalization, marketization, high efficiency, electrification and cleaning in the future. Finally, a transformation analysis index system is built to evaluate and prospect the future energy consumption modes. The new energy consumption modes in the future show the features of ‘technology before the market’. The main features of energy consumption modes are digital and efficient in the early stage. In the later period, the characteristics of cleaning, marketization and electrification are obvious.
Optimization of Heavy Metal Cu(II) Adsorption by Cotton Straw Biochar Using Response Surface Methodology
Authors: Hu Xuefei , Liu Chong , Yue Shengru , Li Fayong , You Yongjun , Wang Shan 
Published: December 2020

Abstract
Box–Behnken response surface optimization design was used to improve the process of Cu(II) removal from water by cotton straw biochar (CSBC). The pH of the solution, and the dosage and temperature of the CSBC were set as the three influencing factors. The Cu(II) equilibrium adsorption amount was taken as the response value. The quadratic polynomial model between the equilibrium adsorption amount and the above factors was established, optimal adsorption conditions were determined, and model fitting on the thermodynamic adsorption process was conducted under optimal conditions. The results showed that the amount and temperature of CSBC were the significant factors. When the pH was 6.00, the amount of CSBC was 0.20 g/l, the temperature was 45 °C, and adsorption capacity of CSBC to Cu(II) was the largest. The adsorption model conformed to the Freundlich isotherm equation. The adsorption of Cu(II) by CSBC belonged to a multimolecular layer adsorption, and the adsorption effect was significant. As a green, efficient, and cheap adsorbent, CSBC can be used to remove Cu(II) from wastewater.
Plugging Performance Evaluation of Nanoemulsion in Ultrafine Drilling and Completion Fluid by Pressure Conduction Method
Authors: Ye Yan , Sheng Yong , Zhang Qingwen , Luo Wei , Zhou Fujian 
Published: December 2020

Abstract
The paper is proposed to introduce nanoemulsion into the ultra-drilling completion fluid system to improve the plugging performance. The pressure conduction method was used to evaluate the plugging properties of tight sandstone, the evaluation results showed that the fluid loss of ultrafine drilling and completion fluid with nanoemulsion was reduced to 6.3 mL, and the pressure difference between the upstream and downstream reaches 0.29 MPa Plugging Property of ultrafine drilling and completion fluid with nanoemulsion is double higher than without nanoemulsion, and was 2.96 times higher than only nanoemulsion. The nano-emulsion and micro-nano solid particles in the ultrafine drilling fluid can seal the plugging layer after entering the pore throat, it can play a role in retarding pressure transmission and filtrate intrusion, and enhancing the plugging effect. The experimental results provide a certain reference value for the follow-up study of the sealing properties of the nanoemulsion.
Wellbore Stabilization Technology for Fractured Formation in Shunbei No.5 Fault
Authors: Li Shuanggui , Liu Jingtao , Yu Yang , Zhong Wenjian 
Published: December 2020

Abstract
Basic geological background, drilling fluid formulation optimization and field application were carried out aiming at the technical problems of multiple blocks in Shunbei Oilfield when collapsing strata and collapsing and blocking frequently. The lithology of the fracture zone is non-clay minerals. After the drilling fluid or filtrate is eroded, the self-developed pore network is easily pressurized and connected, which reduces the adhesion of the bedding interface, which in turn induces large-scale spalling and slump stuck. Based on the mechanism of the instability of the borehole wall, a submicron-micron (0.1-100μm) comprehensive and effective plugging is proposed to prevent drilling fluid or filtrate from invading the formation pores and fractures around the well, and at the same time ensure that the drilling fluid has an efficient rock-carrying solution. The technical achievements carried out on-site tests at Shunbei No. 5, based on the original Sikai high-temperature polysulfonate drilling fluid, optimized the indoor formulation, and developed a wellbore stable drilling fluid suitable for broken formations. During the application process, there were no drilling accidents such as block blockage, which was the shortest record of drilling time in the reservoir section of the block.
Evaluation and Improvement of the Coupled Effect of High-temperature Corrosion-erosion on Water Wall Tubes
Authors: Qin Ming , Jin Jun , Yan Mingqi , Tan Yaping , Liu Hui 
Published: December 2020

Abstract
Low-alloy and heat-resistant steel generally shows good anti-corrosion performance. Also unlike CFB boiler, there is little serious erosion happening in furnace of the pulverized coal boiler due to the low particle concentration. But when subjected to the coupled effect of high-temperature corrosion-erosion, serious failures would occur. This study analyzed the reason for eroded failure of water wall tubes of a 660 MW supercritical boiler with pulverized coal combustion, concluding that such failure resulted from the coupled effect of high-temperature corrosion-erosion. Analysis of the failed sample determined that failure was caused by the combination of high-temperature corrosion-erosion and the rate of failure was faster than that occurring solely by erosion. The numerical simulation result also showed that the H2S concentrations of the fault areas are much higher than others which are coincide with the fact. Furthermore, the study proposed the way of improving the situation for the special four-wall tangential firing through numerical simulation.
Emergy Analysis of Agricultural Ecosystem in Shouguang City, Shandong Province
Authors: Mu Lin , Wang Yan , Zhao Tianhong , Ma Jian 
Published: December 2020

Abstract
By using the method of emergy analysis, this paper analyzed agricultural industrial structure and the emergy input, output and emergy index of agricultural ecosystem in Shouguang City from 2007 to 2016, which reflected the development trend of agricultural ecosystem. The results showed that the total emergy input of agricultural ecosystem in Shouguang City from 2007 to 2016 was in a downward trend, and the change trend of total emergy output was in a downward and then upward trend. From the emergy index, the economic input of agricultural ecosystem in Shouguang City was large, the environmental utilization was not sufficient, but the pressure on the environment was small, and the agricultural ecosystem in Shouguang City was in a sustainable state Continuous development status.
Market Status and Development Prospects of Virtual Power Plants
Authors: Ying Zhiwei , Yu Tao , Huang Yupeng , Liu Dunnan , Jia Heping , Chen Chunyi 
Published: December 2020

Abstract
With the development of new energies and smart grids, virtual power plants (VPPs) have gradually attracted the academia and industries all over the world. VPPs, which are expected to become the supporting framework of smart grid technologies considering new energy integration, break the boundary between power generation side and power consumption side in traditional power systems and makes full use of advanced technical means such as network communication, intelligent measurement and intelligent decision. The concept and characteristics of VPPs are first introduced as well as the market status and demonstration projects of VPPs in different countries. Then, the development prospects of VPPs are pointed out from the aspects of market scope, smart grid construction, demand side response, power trading curve and market potential. Finally, in terms of the unification of the concept, profit model, market potential, and market mechanism, the corresponding solutions to the urgent challenges of VPPs are proposed.
Simulation Research on Performance of Synchronous DC Converter Considering Temperature Rise Effect
Authors: Zhou Ke , Yang Qianwen , Wang Xiao 
Published: December 2020

Abstract
In this paper, the effect of temperature rise of MOSFET on output performance of synchronous dc converter is studied. Firstly, the power loss calculation method and thermal resistance equivalent circuit of switching devices are analyzed, and mathematical modeling is carried out for the conduction mode and change rule of junction temperature, housing temperature and radiator temperature of switching devices, and the MOSFET temperature rise model is built in Matlab environment, and the temperature rise curves of different parts of MOSFET switching devices are obtained. By means of the model, the effect of temperature rise on the output and control signal of the synchronous DC converter is studied. The simulation results show that the effect of temperature rise on the switching device will increase the internal resistance of the switching device, decrease the gate opening voltage and reduce the output voltage. In the real circuit design, it is necessary to leave a margin for the above parameters to ensure an ideal output.
Assessment of the Impact of the Forecast Uncertainty of Wind and Photovoltaic Generation on Large-scale Power Transmission
Authors: Dai Sai , Ding Qiang , Yuan Kaiming , Hou Yanqiu , Lin Jikeng 
Published: December 2020

Abstract
In this paper, we proposed a method to assess the impact of the uncertainty of forecast error of wind and photovoltaic generation on power transmission. First, we proposed a probabilistic model to characterize the uncertainty of the forecast error and established an index system to assess the performance of the transmission system in various aspects. Second, we adopted the Latin hypercube sampling technique to obtain the expectation and the variance of the assessment indices. Third, we introduced a sensitivity method to measure the variation of the probabilistic characteristics of the assessment indices propagated from the variation of the forecast error. Finally, we used a stochastic multi-attribute decision-making method to make the ranking of all renewable power plants by the comprehensive influence of the uncertainty of forecast error on them. With this ranking, it is able to judge which renewable power plant’s forecast accuracy should be improved in order to most effectively control the error of the power transmission. The effectiveness of the proposed models and methods are briefly verified by a case.
Adaptability Analysis and Optimization of Oil Well Energy Saving Motor
Authors: Zheng Yong 
Published: December 2020

Abstract
Motor is the core energy consumption node of mechanical mining system, and also the key point of energy saving potential of mechanical mining system. At present, there are two main problems in the use of matching motor of mechanical oil production system: one is that the types of oil well motor are complex and the performance index is uneven; the other is that the oil well working conditions are complex and diverse, and there is no basis for motor selection.
In view of the above problems, in order to reduce the power consumption of high energy consumption motor, improve the rationality and scientificity of oil well energy-saving motor selection and matching work, effectively improve the operation efficiency of mechanical production system and reduce energy consumption, the adaptability of oil well energy-saving motor is carried out. Taking the energy-saving motor of oil pumping unit as the research object, through no-load, locked rotor, pumping unit simulated load, field calibration and other testing means This paper evaluates the comprehensive quality of the energy-saving motor of oil well from the systematic point of view, and studies the optimization method of the matching between the energy-saving motor and the pumping unit.
Effect of Wind Turbine Blade Profile Surface Roughness on Ice Accretion – A Numerical Case Study
Authors: Jin Jia Yi , Virk Muhammad S. 
Published: December 2020

Abstract
A parametric numerical study of wind turbine blade profile surface roughness has been carried out to investigate its effects on boundary layer characteristics and accreted ice growth. DU96-W-180 blade profile is used in this paper. Multiphase numerical analysis has been performed at glaze ice conditions for three different surface roughness values: Shin et al. surface roughness model and two specific roughness values (0.03m and 0.0003m). Study shows that surface roughness considerably effects the shear stresses as well as heat fluxes, which results a variation of ice accretion in rate and shape. Results show that accreted ice mass and ice thickness increases with the increase of surface roughness.
Traveling-Wave-Based Fault Location Method for Hybrid Distribution Network Mixed with Three-Phase and Phase to Phase Supply Lines
Authors: Xinyu Zhang , Yu Nie , Chuanzong Zhao , Wei Du , Yanan Wang , Zhigang WANG , Yanbing LIU 
Published: December 2020

Abstract
In China, a hybrid distribution network mixed with three-phase main lines and phase to phase supply lines can be found in many MV distribution networks due to lower cost of using two lines from three-phase main lines as well as lower cost of phase to phase transformer. For such a hybrid distribution network it is a challenge for traditional fault location techniques. This paper presents a traveling wave fault location method based on double-terminal measurement techniques. The proposed method analyses the traveling wave propagation mechanism of both aerial mode and zero mode components for a fault. The method then determines which mode component is used for the fault location according to fault types. The method has been developed and assessed on a typical distribution network using ATP power network simulation tool. The tests were conducted under various fault scenarios. The results show that zero mode component is more effective for a fault on the phase of three-phase main lines which is not linked to the phase to phase supply lines. However for a phase-to-phase fault, aerial mode component is more effective. For the remaining fault types, either aerial or zero mode component can be used.
A Novel Electromagnetic Flowmeter for Liquid Metal of Nuclear Reactors
Authors: Li Xuejing 
Published: December 2020

Abstract
Electromagnetic flowmeters (EMFM) play an important role in the cooling process of nuclear reactors, especially when the coolant is liquid metal. According to the working principle of the electromagnetic flowmeter, it is necessary to use a large-sized magnet to provide a uniform magnetic field, but this is very difficult for a core with limited space. This paper proposes a novel electromagnetic flowmeter with a single cylindrical permanent magnet. Compared with the conventional flowmeter, the volume of this electromagnetic flowmeter is greatly reduced. This paper perfects the theory of this single magnet flowmeter and compares it with the experimental results.
Study on Mechanical Performance of Connection jointsIn Novel Modular Steel Structure Buildings
Authors: Hu Qi , Lin Bing , Xie Yonglan , Chen Wenqiang 
Published: December 2020

Abstract
The overall mechanical performance of modular steel structure buildings are largely determined by the mechanical performance of the connection joints between the adjacent modules. In this paper, a novel connection joints between the adjacent modules is taken as research object, which has the advantages of convenient construction and assembly. By means of FEA, three models including the joint model, the model of adding ribs and the model of increasing beam height are calculated, and the experimental results were compared. The finite element model uses solid elements to simulate the detail structure of joints and contact elements to the contact relationship between components. The research results show that the results of finite element analysis are in good agreement with the experimental results in terms of deformation state and bearing capacity, and the accuracy of the finite element model is verified. The finite element model established in this paper can simulate the stress state of various parts of the joint which can make up for the shortage of the experimental measurement.
Portable Soil Electrical Conductivity Sensor System Based on Electromagnetic Pulsed Eddy Current method
Authors: Zhang Qi , Fu Yingchun 
Published: December 2020

Abstract
Soil salinization is one of the major environmental geological concerns around the world. The rapid survey of soil conductivity is urgent to reflect the salinization degree in time, while current methods rely on lab-test or electronic probe-based ones, which are not efficient on saving cost and improving efficiency. In this paper, a new electrical conductivity sensor based on electromagnetic pulsed eddy current strategy is proposed to meet the purpose of rapid and efficient survey of soil conductivity. Relevant software was also designed and tested. To facilitate the in-field test, a portable system was constructed.
Research on Outburst Prevention Method in Deep Coal Road Strip Area
Authors: Wang ZHonghua 
Published: December 2020

Abstract
Aiming at the prevention of outburst in the strip area of deep coal roadways with high geostress, it proposed a method for prevention of outburst in the strip area of coal roadways in which the pressure relief floor roadway is pre-excavated, and it is applied in Fengcheng mining area. The application shows that the method has obvious anti-outburst effects, technical and economic benefits, and broad application prospects.
Peculiarities of the floristic composition and phytocenotic spectra of the prospective conservation area “Siverga” (Tyumen Oblast, Russia)
Authors: Kapitonova O A , Lysenko T M 
Published: December 2020

Abstract
The coastal zone of the Lake Siverga (Tyumen Oblast, Russia) is characterized by a high level of floristic and phytocenotic diversity, which significantly increases the conservation status of the prospective protected area “Siverga”, limited by the coastline of the lake. Twelve vascular plants species included into the Red List of the Tyumen Oblast have been found on the surveyed territory. The plant communities, which are extremely rare in the region, have been observed on the coastal salt marshes; these communities have been previously noted only in the southern areas of the European part of Russia. Taking into account these results, we argue for expanding the boundaries of the protected natural area, which must include the floodplain areas and slopes of the floodplain terrace adjacent to the lake water area.