bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on mutual test method and strategy of bi-directional power grid connected invertert
Authors: Tian Shuowen , Yin Zhongdong 
Published: July 2021

Abstract
In order to improve the utilization rate of grid connected inverter and expand its auxiliary service capacity for power grid, the demand of grid connected inverter supporting V2G, V2B, V2H and other technology applications is increasingly obvious. However, due to its detection technology has not yet carried out systematic research, if the existing detection technology is applied, it will not only follow the shortcomings of the current technology, but also abandon the advantages of bi-directional power control topology. In order to solve this problem, this paper proposes a test method and control strategy for multiple bi-directional power grid connected inverters: Taking two bi-directional power grid connected inverters as examples, the circuit topology of back-to-back mutual test is proposed, and its working mode is analyzed; PID control with coupling inner membrane control is introduced to improve the dynamic response ability; The MATLAB simulation model is built and verified. The results show that the proposed test method and control strategy can effectively realize the test of bi-directional charging facilities, and provide a certain reference for the corresponding industry.
A design of intelligent delivery drone based on BeiDou navigation and visual processing
Authors: Xu Xiaohao 
Published: July 2021

Abstract
This article used automatic control, 5G real-time communication, visual processing and other technologies to design a carbon fiber intelligent delivery drone, based on BeiDou satellite navigation and face recognition. And we proposed a semi-autonomous delivery mode to achieve real-time control of the drone. This mode can reduce flight risks and ensure the safety and accuracy of distribution. The drone can be powered by microcrystalline silicon thin film solar cells. The BeiDou satellite navigation system is used for autonomous positioning, combined with binocular stereo vision technology to observe the surroundings, automatically plan the flight path. On the way, personnel can intervene in real time as needed. Finally, when the drone arrives at the destination, facial recognition technology is used to confirm the identity of the recipient to complete the delivery.
Performance of 2-D inlets with curved compression surface formed by segments with controllable compression angle
Authors: Pan Jin , Jin Feng 
Published: July 2021

Abstract
Suppose that curved surface consists of tiny polylines. Two 2-D inlets with curved surfaces formed by equal compression angles of the micro-element segments and a slight increase in the compression angle of the micro-element segments are designed respectively. The numerical simulation method is used to compare the performance of two curved surface 2-D inlets with the reference three-wedge compression 2-D inlet. Select NASA classic test data, in order to determine the turbulence model and calculation method chosen by the numerical simulation Fluent software. Numerical simulation results show: the pressure ratio of the curved compression system at the place corresponding to the wedge compression second shock wave is only 0.55 of the wedge compression pressure ratio, which is much smaller than the critical pressure ratio of the boundary layer separation; at design point, the performance of three inlets is similar; at non-design points, the 2-D inlets with the curved surface have a higher flow coefficient and total pressure recovery coefficient. The configuration of the small segments compression angles is the key to the performance of the curved surface compression two-dimensional inlet.
Research on cavitation pulsation characteristics under liquid breakdown mechanism
Authors: Huang Xin , Zong Siguang , Liu Tao , Liang Shanyong 
Published: July 2021

Abstract
The SGR series solid-state laser system with adjustable pulse energy is adopted. The system uses solid-state Nd: YAG laser to generate laser cavitation in distilled water, High speed camera is used to observe the pulsation process of laser cavitation in distilled water, and candy algorithm is used to detect the edge of cavitation, extract the edge features of cavitation, calculate the circumference of the edge of cavitation, and analyze the pulsation characteristics of cavitation in distilled water. The results of laser acoustic signal collected by hydrophone, high-speed photography and MATLAB image analysis are compared, and the initial expansion of cavitation is in different stages It is concluded that the initial expansion rate and the final pulsation rate of the cavity are faster.
Design of online laser marking system by vision guided based on template matching
Authors: Zhang Weichao , Xiao Zhongjun , Yan Zhiguo 
Published: July 2021

Abstract
Industry 4.0 has put forward the requirements of improving the marking efficiency and accuracy of the laser marking industry, and manual placement has been unable to meet the production needs. In this paper, laser marking technology is combined with image recognition technology, and the automation of marking production process is realized by controlling the stepper motor to drive the conveyor belt, and accurate marking of arbitrarily placed workpiece is realized on the conveyor belt. The test results show that this marking system designed by us has high precision, and the yield of finished products reaches 99.5%, which provides a set of efficient and reliable solution for small and medium power laser marking production line to realize online positioning function.
A servo control method of bolt tightening robot for power transmission lines
Authors: Zhang Mingda , Sun Yihui , Wang Sijin , Yang Quan 
Published: July 2021

Abstract
This paper discusses a control method of bolt tightening robot automatically search and tighten. Because of the influence of the wind in the search process, so this paper adopt the servo system to determine the position of the target to complete the bolt docking[1]. Due to the bolt by weathering, corrosion, etc have different situation, so for different years of bolt, the fastening work done by corresponding torque control.
Research on impact characteristics of a new graphite composite earthing device
Authors: Zhao Jianli , Li Yuanjie , Le Wang , Pan Zhuohong 
Published: July 2021

Abstract
For the new type of graphite composite grounding material, there is a lack of generally accepted rules and standards. In this paper, the impact properties of a new type of graphite composite earthing material are studied. The test results show that the new type of composite grounding device always has spark discharge effect. With the increase of impulse current amplitude, the value of impulse coefficient decreases, and the rate of decrease decreases. Increasing the amplitude of the shock current may only increase the electric field strength in the region, but not increase the spark discharge range in the soil, so the shock coefficient tends to be flat. The test results can provide guidance for the selection and application of new grounding materials.
Study on influencing factors of sulfur particle size in chelated iron in oxidation process
Authors: Zhang Wu , Liu Qishong , Liu Ke , Fan Rui , Liu Bo , Xue Jingwen 
Published: July 2021

Abstract
The insoluble elemental sulfur with particle size less than 10 μm is produced in the solution through chelated iron-based method, while the sulfur recovery is generally through the aggregation sedimentation filtration method. In this paper, the influence of desulfurization solution parameters on the size of sulfur are investigated, and the indispensable conditions for the formation of large-size sulfur are discussed. Meanwhile, in order to obtain the conditions for large sulfur particles generation, the influence of the concentration of sulfur modifier on the Zeta potential of desulfurization solution and the change of sulfur particle size were studied.
Research on preparation of low bulk density Claus tail gas hydrogenation catalyst
Authors: Zhang Xiaoxue , Li Jinjin , Liu Zongshe , Zhu Hongyang , Duan Ting 
Published: July 2021

Abstract
With the continuous improvement of national energy conservation and emission reduction requirements, oil and natural gas production industry has increasingly strict requirements for SO2 emission from tail gas. Nowadays, most of large and medium-sized natural gas purification plants and refineries adopt hydrogenation reduction tail gas treatment process to achieve ultra-low SO2 emission, which puts forward high requirements for the activity, stability and economy of tail gas hydrogenation catalyst. In recent years, due to the high price of hydrogenation catalyst, it has become a research hot spot to reduce the cost of catalyst by reducing the bulk density. Traditional catalyst preparation process focused on the types and properties of support and active components, while the influence of alumina powder properties and preparation conditions have not been paid enough attention. With the extensive application of fine characterization methods and the further understanding of catalyst micro-structure, the influence of alumina powder properties and preparation conditions on the performance of catalyst are more and more obvious. In this paper, the Pseudo boehmite was investigated. TG, SEM, XRD and other characterization methods were used to study the preparation method of low bulk density Claus tail gas hydrogenation catalyst.
Design and optimization on training management system of professional classroom
Authors: Sun Xuwen , Qi Lei , Li Shixiong , Shan Hongyan , Ma Siming 
Published: July 2021

Abstract
In order to further enrich the practical guarantee conditions of training theory teaching simulation in the university and improve the level of digital, scientific and information management of professional classrooms, this paper, through analyzing the ideas of system construction, explaining the system composition, structure and system function, designs a professional classroom training management system which integrates the functions of training design, training implementation, training assessment, etc., focally analyzes the key system technology and gives the technology as can be adopted next to further perfect the system function. The research is of great practical significance to improve the level of training information management system development and training management informatization subsequently.
The extended Kano model based on moderated regression analysis: A case study of express delivery service
Authors: Li Zhen , Meng Qingliang 
Published: July 2021

Abstract
Not all product and service quality are equally important to customers. Several studies have applied regression analysis to identify the key elements affecting customer satisfaction. This paper used an extended Kano model based on the moderated regression analysis to improve the defects of the traditional Kano model. The model is validated using data collected from express delivery service. And the empirical results show that the method produces more accurate classification. Overall, this study makes contributions to both Kano model improvement and express delivery service quality optimization.
Effect of fiber reinforcement on mechanical properties of flow solidification of silt
Authors: Ding Jihui , Wang Haochen , Han Shouxin , Yu Zenghui , Yan Shengkang 
Published: July 2021

Abstract
In order to solve the brittle failure of cement flowing solidified sludge, basalt fiber and cement are mixed to prepare flowing solidified sludge. The fluidity and unconfined compressive strength tests of fluid solidified sludge with different cement and fiber content have been carried out. The results show that mixing basalt fiber into cement solidified fluid sludge will reduce its fluidity and increase its unconfined resistance Compressive strength; there is an optimal amount of basalt fiber, and its optimal amount is affected by the amount of cement; with the increase of curing age, the compressive strength of the sludge solidified with fiber cement increases gradually; the solidified sludge is unconfined for 14d and 28d The unconfined compressive strength has a linear relationship with the 7d unconfined compressive strength.
Molecular dynamics study on the deformation of void single crystal magnesium under uniaxial stress
Authors: Tang Jinqi , Yao Junping 
Published: July 2021

Abstract
The uniaxial tension and compression process of single crystal magnesium model with voids along [0001] direction was simulated by using embedded atom potential and molecular dynamics method, and the micro plastic deformation mechanism of voids under tension and compression was studied. The results show that the elastic modulus of the single crystal magnesium model under compression is greater than the elastic modulus under tension, indicating that compression deformation is more difficult; In the process of plastic deformation, the dislocation, stacking fault and twin will be produced in the single crystal magnesium model under tension and compression, but the emission mechanism of dislocation is different. Tension will make the dislocation slip to the edge of the model along the direction of 45 ° and produce four symmetrical slip bands, while compression will produce an annular defect band near the cavity; In addition, the stacking fault area and twin type produced are also different. This asymmetry is mainly caused by the different initial deformation mechanisms under the two loading conditions.
The existence of underground gas storage causes geomagnetic anomaly in this area?
Authors: Wang Zhendong , Su Shupeng , Yuan Jiehao 
Published: July 2021

Abstract
When the stress state of the rock changes, its permeability will also change accordingly, which is the so-called piezomagnetic effect. The piezomagnetic characteristics of rocks are an important and reliable physical basis for the seismomagnetic effect. Based on the experiments of rock magnetism, many scholars have carried out targeted experiments on the relationship between stress and rock magnetism, and achieved many important experimental understandings. As the largest underground gas storage (UGS) in operation in China, the Hutubi UGS has a design storage capacity of 10 billion cubic meters. It is operated periodically every year by gas injecting in summer and gas extracting in winter. During the process of gas injection and gas extraction in Hutubi UGS, the gas well pressure changes up to more than 10 MPa. Periodic injection and extraction operations will induce variations in the in-situ stress field in local areas. Whether these variations can cause local crustal magnetic anomalies is the focus of this paper. An observation network composed of 63 total geomagnetic intensity measuring stations was established in the Hutubi UGS and its surrounding areas, and the geomagnetic anomalies have been systematically observed. Based on the two phases of field observation data in October 2016 and October 2018, a polynomial fitting method was used to obtain the crustal magnetic anomalies in the UGS area. Results show that the existence of the Hutubi UGS has indeed caused the geomagnetic anomaly changes in this areas, the maximum value of the magnetic anomaly is 19 nT. The results of this field observation further confirmed the existence of the piezomagnetic effect in the laboratory and established the internal connection between the meso-scale crustal magnetic anomalies and the underground stress variations.
Study on the stability of artificial vibration points with internal resonance in solar sail dynamics
Authors: Diao Zhenbao 
Published: July 2021

Abstract
In this paper, the linear and stability of solar sail spacecraft at the libration point of artificial balance is studied. The stability has been analyzed for the linear cases and nonresonance cases. The changing law of artificial balance point is found when the attitude angle of solar sail is fixed. The linear stability region of the solar sail spacecraft at L4 was found. Based on the circular restricted three-body problem, the dynamic model of the continuous solar sail spacecraft is established. The variation law of the position of manual translational point with the β parameters is analyzed. The condition and existence range of linear stability of artificial translational point are given. The influence of thrust parameters on the system and manual translational point is analyzed. The dynamics equation of the solar sail spacecraft near the linearly stable artificial translational point and the nonlinear vibration theory, the range of the system mass parameters and thrust parameters when the system has 1:2 and 1:3 internal resonance is obtained. Using the multi-scale method, the stability of the long and short period motion of the detector is analyzed, and the boundedness of motion is proved.
First-principles study of the effect of vacancies on the interface stability of 3C-SiC/Mg composites based on theoretical physical method
Authors: Lv Zhao , Yao Junping 
Published: July 2021

Abstract
In this paper, the first principles calculation method based on theoretical physics method was used to optimize the structure of 3C-SiC(111)/Mg(0001) interface model with vacancies. The interface adhesion work, vacancy formation energy and electronic structure were calculated and analyzed. The results show that the interface adhesion work of 3C-SiC/Mg-VMg
−1、3C-SiC/Mg-VMg
−2、3C-SiC/Mg-VMg
−3 is greater than that of 3C-SiC/Mg which indicates that Mg vacancy have a certain promoting effect on the interface bonding of 3C-SiC/Mg, and the interface adhesion work of 3C-SiC/Mg- VMg
−
1 is the largest. Because after the presence of Mg vacancy, the number of wavelet peaks increases and the pseudo-energy gap increases, so that the covalent bond increases and the interface adhesion work increases. Their vacancy defect formation energies are not much different, which are 1.1057eV, 1.0584eV, 1.2299eV, respectively. After the presence of C vacancy and Si vacancy, the interface adhesion work of 3C-SiC-VC
−
1/Mg 、3C-SiC-VC
−
3/Mg、3C-SiC-VSi
−
2/Mg and 3C-SiC-VSi
−4/Mg is smaller than that of 3C-SiC/Mg, which indicates that C vacancy and Si vacancy have no effect on the interface bonding. Among them, the interface adhesion work of 3C-SiC-VC
−1/Mg is greater than that of 3C-SiC-VC
−3/Mg, and the interface adhesion work of 3C-SiC-VSi
−4/Mg is greater than that of 3C-SiC-VSi
−2/Mg. After the presence of vacancy, the number of small wave peaks in the density of states map becomes less, the distribution of the density of states near the Fermi level becomes narrower, the metallicity is enhanced, and the bond strength decreases. In terms of the formation energy of vacancy defects, the formation energy of 3C-SiC-VC
−
1/Mg is less than that of 3C-SiC-VC
−
3/Mg, and the formation energy of 3C-SiC-VSi
−
2/Mg is less than that of 3C-SiC-VSi
−
4/Mg.
Vibration characteristic analysis for emulsion droplet excited by chaotic frequency pulsed electric field
Authors: Peng Y , Zhang Y Y , Liao Z X 
Published: July 2021

Abstract
In this paper, taking single emulsion droplet as the research object, the vibration characteristics of emulsion droplet in chaotic electric field is explored. The fixed amplitude and equal pulse width chaotic frequency pulsed electric field is constructed by using the Chaotic-Pulse-Position Modulation method, the vibration dynamics model of emulsified oil droplet in chaotic electric field is established, and the chaotic electric field parameters and vibration response of droplet are solved. Results show that the optimal pulse width is 0.009s, the optimal chaotic boundary of pulse electric field frequency is 170 rad/s to 690 rad/s, the droplet is excited into chaotic vibration, and there is resonance. Besides, the droplet vibration in chaotic pulsed electric field is unsteady, but the droplet will enters the steady state vibration from the second same pulse.
Study on enlarging chaos frequency in two coupled lasers using both optoelectronic cross-feedback and self-feedback
Authors: Chen Mengmeng , Yan Senlin 
Published: July 2021

Abstract
This paper presents an optoelectronic delayed time cross-feedback and self-feedback method to enlarge chaotic frequencies of two semiconductor lasers as two chaotic signal oscillators and to enhance the oscillation behaviours of the lasers. The technical solution of enlarging-frequency of two lasers is that the light from one laser is converted into a photocurrent by the photoelectric converter, and then the delayed time photocurrent is divided into two currents. One is cross fed to another laser while the other photocurrent is fed to self-laser, which can result in enhancing chaos oscillation to realize enlargement of chaotic frequency of two semiconductor lasers. We adjust the feedback levels or the delayed time to realize enlargement of chaotic frequency of two semiconductor lasers. When the feedback level increased, enlargement of the chaotic frequency of the two semiconductor lasers is obviously enhanced. When a feedback is performed, enlargement of chaotic frequency of one laser is obviously enhanced. When the two feedbacks are performed, enlargements of chaotic frequencies of two lasers are obviously enhanced. These results illustrate that enlargement of chaotic frequency of two laser can be effectively obtained via the optoelectronic delayed time cross-feedback and self-feedback method. The research result of this paper is a reference value for enlargement of chaotic frequency, chaos communization, and laser technology etc.
A numerical method for the solid mechanics with Euler variables
Authors: Liu Junchen , Li Shihai , Wang Ling , Feng Chun , Qian Feng , Wang Junfu , Zhu Xinguang 
Published: July 2021

Abstract
Based on the requirement of field engineering, we proposed a new numerical method for analyzing the solid mechanics with Euler variables. By replacing the Lagrange variables with the Euler variables, there will be three new items appearing in the equation. We use the fixed Euler grid to calculate solid mechanics, and use the boundary of material regiment to describe the movement of the boundary of material, after the boundary of material regiment moves beyond the Euler element grid size, new Euler element grids will appear and the corresponding old Euler element grids which have been out of the region of material will disappear. By this way, the movement of solid could be calculated in the Euler fixed grids. Then we did some test cases, we get the result that the new method is right and could be used to calculate the solid mechanic problems.
US residential heat pumps: the private economic potential and its emissions, health, and grid impacts
Authors: Deetjen Thomas A , Walsh Liam , Vaishnav Parth 
Published: July 2021

AbstractTo explore electrification as a climate change mitigation strategy, we study US residential heat pump adoption, given the current US housing stock. Our research asks (a) how the costs and benefits of heat pump adoption evolve with increased penetration, (b) what rate of heat pump adoption is economic given today’s housing stock, electric grid, energy prices, and heat pump technology, and (c) what effect changing policies, innovations, and technology improvements might have on heat pump adoption. We answer these research questions by simulating the energy consumption of 400 representative single-family houses in each of 55 US cities both before and after heat pump adoption. We use energy prices, CO2emissions, health damages from criteria air pollutants, and changes in peak electricity demand to quantify the costs and benefits of each house’s heat pump retrofit. The results show that 32% of US houses would benefit economically from installing a heat pump, and 70% of US houses could reduce emissions damages by installing a heat pump. We show that the potential for heat pump adoption varies depending on electric grid, climate, baseline heating fuel, and housing characteristics. Based on these results we identify strategic, technology, and policy insights to stimulate high heat pump adoption rates and deep electrification of the US residential heating sector, which reduces CO2emissions and the impacts of climate change.