bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on braking energy recovery technology of electric vehicle in underground coal mine based on road condition recognition technology
Authors: Zhang Fan , Zhao Yuan , Hao Zhijun 
Published: November 2022

Abstract
Electric explosion-proof trackless rubber-wheeled vehicles in coal mines usually use braking energy recovery technology to improve cruising range. In order to improve the efficiency of vehicle braking energy recovery and improve vehicle braking safety performance, this paper proposes a braking energy recovery control strategy for electric vehicles in coal mines based on road condition recognition. This strategy is based on the coal mine underground positioning technology, and adopts different braking energy recovery control strategies for different road conditions, while improving the braking energy recovery ratio of the vehicle, it ensures a good feeling of the brake pedal and ensures the safety performance of the vehicle braking. Finally, the feasibility of the control strategy is verified by simulation.
Design and Kinematics Model of Autonomous Wheel-Claw Reconfigurable Amphibious Robot
Authors: Bai Bing , Song Meili , Bao Wei , Xiao Zhen 
Published: November 2022

Abstract
In order to improve the adaptability of traditional wheeled robots to complex environments, a passive wheel-claw reconfigurable amphibious robot is proposed in this paper. This robot has strong mobility when moving on the ground. In complex scenes, if there are obstacles, it will automatically switch to claw mode. By studying the motion mechanism of the wheel-claw reconstruction process, the kinematics model of the robot under multiple working conditions is established by using the coordinate transformation method, and the wheel-claw transformation process is analysed in detail. Based on the virtual prototype of Adams, the dynamic simulation under the conditions of flat ground and obstacle crossing is carried out, the established dynamic mathematical model is verified. The simulation results provide theoretical data basis for the actual design of the robot. The experimental results of the prototype platform show that the designed passive wheel claw robot has the ability to work in complex scenes.
Non-singular terminal extended sliding mode control of permanent magnet synchronous motor based on variable exponential reaching law
Authors: Zheng Chuanxi , Gu Yuandong 
Published: November 2022

Abstract
A non-singular terminal extended sliding mode control method based on variable exponential reaching law is presented because the permanent magnet synchronous motor speed control system is subject to parameter disturbance, external disturbance, and end effect. In order to accomplish global rapid convergence and get rid of singularity, a non-singular terminal extended sliding mode surface is first created. After the system reaches the sliding mode surface, a new extended state variable is constructed in accordance with the first-order angular velocity model, and a new better exponential reaching law is utilized to eliminate chattering. Finally, a disturbance observer is designed to detect the disturbance during motor operation in real-time and add it to the speed control loop as a compensation. The simulation findings demonstrate that, in comparison to the conventional sliding mode control strategy, the suggested variable-parameter non-singular terminal sliding mode control strategy lowers the effect of disturbance on the motor’s real operation and has the benefits of rapid convergence speed, good resilience, minimal speed overshoot, and high control precision.
Design and implementation of IoT gas meter based on security chip
Authors: Xu Xiaoqing , Liang Xiaowei , Shen Cheng 
Published: November 2022

Abstract
IoT gas meter is facing the challenge of information security. This paper designs and implements a scheme of gas meter based on security chip. The scheme uses stm32l073 as MCU to collect gas metering data, cooperates with Hua Hong’s security chip, and uses NB_IoT as the communication module. The business data is pushed to the gas meter business management system through China Telecom Tianyi IoT platform CTWing, so as to realize the remote safety management of gas meters.
Development and Engineering Application of the Measurement System Based on the Miniaturized Ultrasonic Transducer
Authors: Kong YouDi , Zhao JianRui , Wang HaiTao , Wang XinPeng , Wang GuangJie , Wu YuHua , Zhang WeiXing 
Published: November 2022

Abstract
The iron terminals are mostly used in the small ultrasonic transducers which are connected to the circuit board by the direct or indirect welding method. Although the method is considered to be firm and reliable, the ultrasonic transducer or the whole system is easy to be damaged when the ultrasonic transducer is replaced or maintained. Moreover, the terminals of the ultrasonic transducer are easy to be oxidized. The miniaturized ultrasonic transducer with the electroplated copper terminals is innovatively designed to enhance the oxidation resistance of its terminals. Then the ultrasonic transducers are installed on the circuit board by the copper claw spring instead of welding. In addition, the waterproof miniaturized ultrasonic transducer is replaced by the fully covered waterproof sound permeable membrane and the non waterproof miniaturized ultrasonic transducer. The experimental results demonstrate that the quality of the signal transmission of the ultrasonic transducer is not affected, and the convenience of replacement and maintenance of the ultrasonic transducer is improved. With this design process, the overall waterproof performance of the system is also significantly enhanced while the system cost is reduced, market future is wide prospect.
Application of On-line Digital Radiographic Inspection for Pipeline with Insulation
Authors: Li Xu-Feng , Sun Jie , Lu Shengzi , Wang Lei 
Published: November 2022

Abstract
Pipes with insulation are widely used in the industrial field. The traditional nondestructive testing technology for on-line pipes with insulation often requires the removal of a large number of insulation layers and the forcing of the owner to stop for testing. The traditional testing mode not only has low detection efficiency, but also forces the owner to spend a lot of manpower, material resources and financial resources. In recent years, a series of new nondestructive testing (NDT) technologies have different advantages for in-service pipeline testing with coated layers. However, Digital radiographic (DR) testing can satisfy the integrity inspection of on-line pipeline with insulation well. In this paper, the basic principle of DR testing and the configuration of instrument parameters are introduced. Based on the analysis and discussion of the actual testing cases, it is proved that digital ray testing can effectively solve the quality testing of on-line insulation pipeline, and it is a new nondestructive testing technology worthy of further study and popularization.
Research on test and evaluation of Li-MnO2 primary battery under high temperature stress storage
Authors: Deng Jin , Jiang Jinghong , Ming Zhimao 
Published: November 2022

Abstract
This paper mainly studies the influence of high temperature conditions on Li-MnO2 primary battery, and analyzes the influence of high temperature conditions on the performance of Li-MnO2 primary battery by testing the capacity, voltage and internal resistance of the product. Through impedance test, the different polarization differences between products stored at high temperature and normal temperature were analyzed. The effects of high temperature environment on the internal macro structure and micro material components of the battery were analyzed by means of electronic computed tomography (CT), scanning electron microscope and X-ray energy spectrometer (SEM-EDS) and X-ray photoelectron spectroscopy (XPS). Finally, through various test data, the internal reaction mechanism of the battery at high temperature was analyzed to deepen the research on the performance of Li-MnO2 primary battery.
A Design of Indoor Air-Quality Monitoring System
Authors: Wang Chao , Liu Hongli , Ji Jiawen , Wu Yangshuang 
Published: November 2022

Abstract
With the deepening of people’s understanding of the harm of air pollution, indoor air quality is getting more and more attention. This paper designs an indoor air quality monitoring system based on sensor technology and Internet of things technology, the system function includes air quality detection, real-time data display, server transfer, remote display throught Wechat mini programe and others, the system can detect six important environmental parameters and allows users to view the data on mobile phone. Based on the data collected, this paper also designs an air quality evaluation algorithm.
Detection method of water channel defects in engine block based on deep learning
Authors: Deng Yaohua , Li WeiJie , Lin ShengYu , Lu Qiwen , Liu Xiali 
Published: November 2022

Abstract
Aiming at the low efficiency of manual detection in the detection of water channel defects of engine cylinder block and the poor generalization ability of traditional machine vision in manual design features, an improved water channel defect detection model of cylinder block based on fast RCNN network is proposed. Restnet50 is selected as the feature extraction network of waterway defects, and feature pyramid network (FPN) is introduced to improve the detection ability of small defects; The anchor box is optimized by k-means++ clustering algorithm to improve the positioning of the target box. Experiments show that the map of the improved network in the engine cylinder block waterway defect data set reaches 88.74%, the accuracy is increased by 4% compared with the original fast RCNN, and the recall rate is increased by 1.67%. The recognition and detection effect in real samples is good, and it can be effectively used for the engine cylinder block waterway defect detection.
Research on Online Monitoring and Analyze of Hydraulic Turbine Based on Low Cost, Fast and Internet of Things Technology
Authors: Bai Liang , Zhang Yin , Liang Wuke , Luo Jiawang 
Published: November 2022

Abstract
In view of the problems such as difficulty in and high cost of vibration signal collection of rotating mechanical rotating shaft, this paper proposes a low-cost, fast, stable and reliable hydraulic turbine rotating wheel vibration signal online monitoring scheme specially designed to the imbalance and dynamic balance counterweight of hydraulic turbine rotating shaft. Three high-frequency wireless acceleration sensors are installed on the rotating shaft to monitor the vibration signals of the three directions in real time. Vibration signals are sent to the cloud platform to facilitate data storage. The acceleration signal is decomposed by WOA-VMD. The time domain signal shows the running track of the shaft to guide the dynamic balance counterweight of the rotor. The frequency domain signal is used to analyze the machine vibration in the shaft frequency domain and predict the health status of the shaft according to the frequency change. According to this system, completed the experiment of a hydraulic turbine experiment, proved the feasibility and rationality of the system, and has good application prospect and practical value.
A Non-contact Heart Rate Measurement Approach Based on Modified EEMD Algorithm with Updated White-noise Iterating
Authors: Shi Yingli , Qiu Jian , Peng Li , Han Peng , Luo Kaiqing , Liu Dongmei 
Published: November 2022

Abstract
At present, Imaging Photoplethysmography (IPPG) has attracted extensive attention on heart rate measurement, because of its non-contact, non-invasive and safe characteristics. However, in reality, the IPPG signal is extremely feeble and susceptible to be submerged by ambient interference such as illumination. To this end, we propose a new IPPG signal processing approach to enhance the anti-interference capability of measuring heart rate through a modified EEMD algorithm with updated white-noise iterating. In the modified EEMD algorithm, based on the standard deviation of the input IPPG signal, zero-mean white noises are generated randomly for iterative ensemble averaging. Through this new method, the fault caused by the residual white noise of traditional EEMD is solved. Lastly, through the comparative experiments of our own acquisition statistics, the approach proposed by this paper has significantly improved the performance in terms of accuracy, timeliness and anti-interference under various scenarios. The mean absolute error reaches 1.4 beats per minute and the correlation coefficient r reaches 0.8089. In addition, the modified EEMD algorithm reduces the running time by more than 10 times compared to the original method, approximately 0.16s per time.
Matlab/Simulation of Brushless DC motor vector control
Authors: Tan Zi-Xi , Ding Li-Bo 
Published: November 2022

Abstract
Based on improving the dynamic and static performance of the brushless DC motor control system, a speed current closed-loop brushless DC motor control scheme is designed by using SVPWM. In the light of the environment of matlab/simulink, the vector control model of BLDCM is established by using the control strategy of id=0 and the idea of modularization. The simulation results show that the system has good dynamic and static performance and stable operation, which proves the reliability and effectiveness of the simulation model.
A new compact linear beam-plasma discharge simulator BPD-PSI
Authors: Sergeev N.S. , Sorokin I.A. , Podolyako F.S. 
Published: November 2022

Abstract
A new BPD-PSI line-type plasma simulator is introduced.
The device features two vacuum units: a target unit and an electron gun unit, connected to each other by a water-cooled electron beam transport channel.
The Pierce-type electron gun is used to generate stationary or pulsed electron beam, utilized for beam-plasma discharge generation. The plasma electron density can be varied in the range of
n
e = 1 × 1016 - 1 × 1018 m-3
with electron temperature in the range of
T
e = 1-20 eV. The ion flux of 1 × 1021 m-2 s-1 and heat fluxes up to 5 MW m-2 are obtained. A set of utilized plasma and plasma-surface interaction diagnostics are described. Five demonstration experiments are presented: 1) high vs low power beam-plasma operation, 2) beam-plasma discharge with/without presence of an external magnetic field, 3) incident ion flux composition analysis, 4) incident ion energy distribution function measurement, 5) in-situ target surface temperature control and in-vacuo thermal desorption spectroscopy measurement.
All of the technical features of the setup described in this paper make it a new tool for studying plasma-surface interactions.
Local resetting with geometric confinement
Authors: Miron Asaf 
Published: November 2022

Abstract
‘Local resetting’ was recently introduced to describe stochastic resetting in interacting systems where particles independently try to reset to a common ‘origin’. Our understanding of such systems, where the resetting process is itself affected by interactions, is still very limited. One ubiquitous constraint that is often imposed on the dynamics of interacting particles is geometric confinement, e.g. restricting rigid spherical particles to a channel so narrow that overtaking becomes difficult. We here explore the interplay between local resetting and geometric confinement in a system consisting of two species of diffusive particles: ‘bath’ particles, and ‘tracers’ which undergo local resetting. Mean-field (MF) analysis and numerical simulations show that the resetting tracers, whose stationary density profile exhibits a typical ‘tent-like’ shape, imprint this shape onto the bath density profile. Upon varying the ratio of the degree of geometric confinement over particle diffusivity, the system is found to transition between two states. In one tracers expel bath particles away from the origin, while in the other they ensnare them instead. Between these two states, we find a special case where the MF approximation is exact.
Tunable metamaterial absorber based on VO2-graphene
Authors: Gong Dagang , Mei Jinshuo , Li Nianchao , Shi Yuanchao 
Published: November 2022

Abstract
In this paper, a tunable multilayer metamaterial absorber is proposed, which is composed of VO2-graphene mixed structure layer, PDMS dielectric layer, VO2 layer, PDMS dielectric layer and bottom metal film layer. The simulation results show that when VO2 is in the insulating phase and the Fermi level of graphene is 0.9 eV, the absorption peak of 0.75–1.15 THz is generated by the interaction resonance of graphene and bottom metal. When VO2 is in metal phase and the Fermi level of graphene is 0 eV, the absorption peak of 2.5–4.5 THz is generated by the resonance of vanadium dioxide. Therefore, the tunable switching between two different frequency bands can be realized. Moreover, the dual regulation of both vanadium dioxide conductivity and graphene Fermi energy level can also modulate the absorption amplitude and broaden absorption band. In order to explain the mechanism of VO2-graphene on the absorption performance, the electric field distribution and equivalent impedance of the absorber are discussed and analyzed in this paper. In addition, the absorption performances at variable incidence angles for both TE and TM polarizations are investigated and the absorber is insensitive to polarization. Therefore, the absorber has potential application value in the terahertz field.
Effect of 4He2+ ion irradiation on the optical, electrical, morphological, and structural properties of ZnO thin films
Authors: López-Suárez Alejandra , Acosta Dwight , Magaña Carlos 
Published: November 2022

Abstract
A study of the effect of 2.5 MeV 4He2+ ion irradiation on the optical, electrical, morphological and structural properties of ZnO thin films is presented. Polycrystalline zinc oxide thin films were deposited on soda lime glass substrates using the spray pyrolysis technique. During the process, the substrates’ surfaces were kept at 400, 450 and 500 °C. The samples were analyzed by different techniques and the optical results showed a red shift in the energy band gap after irradiation. It was also confirmed that the wurtzite-type hexagonal structure of the ZnO films remained after irradiation, the crystallite size increased and the lattice parameters decreased due to He2+ irradiation. SEM micrographs revealed that ion irradiation favors the nucleation and the formation of grains in the films. Micrographs showed nanometric particles with spherical and flake-like forms, which depend on the deposition temperature. A decrement in the average particle size of the samples deposited at 400 and 450 °C was observed after irradiation; meanwhile, an increase in the particle size was detected in the film deposited at 500 °C. The resistivity values increased with He2+ ion irradiation.
Thermoelectric properties variation in antimony telluride nanofilm using molecular dynamics
Authors: Lai Tang-Yu 
Published: November 2022

Abstract
In recent years, thermoelectric materials that have the advantage of directly converting heat into electricity, have become a hot research topic. In this study, we designed a series of Sb2Te3 nanofilms using molecular dynamics simulation to explore the effects of structural defects on the phonon transport properties of thermoelectric materials. We predicted that temperature variations and structural defects can greatly increase the transfer of energy invalid and decrease thermal conductivity. Designing thermoelectric materials as composite interfaces, multilayer films, and defect structures is an effective way to achieve this goal.
Relativistic toroidal light solitons in plasma
Authors: CHENG Zhongming , DENG Dachao , YU Mingyang , WU Huichun 
Published: November 2022

Abstract
In the laser–plasma interaction, relativistic soliton formation is an interesting nonlinear phenomenon and important light mode convection in plasmas. Here, it is shown by three-dimensional particle-in-cell simulations that relativistic toroidal solitons, composed of intense light self-consistently trapped in toroidal plasma cavities, can be produced by azimuthally-polarized relativistic laser pulses in a near-critical underdense plasma.
A review of COVID vaccines: success against a moving target
Authors: Chong S H , Burn L A , Cheng T K M , Warr I S , Kenyon J C 
Published: November 2022

Abstract

Background
Multiple vaccine platforms against COVID-19 have been developed and found safe and efficacious at a record speed. Although most are effective, they vary in their ease of production and distribution, their potential speed of modification against new variants, and their durability of protection and safety in certain target groups.

Sources of data
Our discussion is based on published reports of clinical trials and analyses from national and global health agencies.

Areas of agreement
The production of neutralizing antibodies against the viral spike protein is protective, and all vaccines for which published data exist have been found to be effective against severe disease caused by the viral strain they target.

Areas of controversy
The degree to which vaccines protect against emerging variants, moderate disease and asymptomatic infection remains somewhat unclear.

Growing points
Knowledge of the duration of protection and its decay is increasing, and discussions of booster frequency and target strains are ongoing.

Areas timely for developing research
The global effort to combat transmission and disease continues to rely upon intense epidemiological surveillance, whilst real-world data and clinical trials shape vaccination schedules and formulae.
Distinct brain pathologies associated with Alzheimer’s disease biomarker-related phospho-tau 181 and phospho-tau 217 in App knock-in mouse models of amyloid-β amyloidosis
Authors: Hirota Yu , Sakakibara Yasufumi , Ibaraki Kyoko , Takei Kimi , Iijima Koichi M , Sekiya Michiko 
Published: November 2022

Abstract
Phospho-tau 217, phospho-tau 231 and phospho-tau 181 in cerebrospinal fluid and plasma are promising biomarkers for the diagnosis of Alzheimer’s disease. All these p-tau proteins are detected in neurofibrillary tangles in brains obtained post-mortem from Alzheimer’s disease patients. However, increases in p-tau levels in cerebrospinal fluid and plasma during the preclinical stage of Alzheimer’s disease correlate with amyloid-β burden and precede neurofibrillary tangles in brains, suggesting that these p-tau proteins are indicative of amyloid-β-mediated brain pathology. In addition, phospho-tau 217 has greater sensitivity than phospho-tau 181, though it is unclear whether each of these p-tau variants contributes to the same or a different type of neuropathology prior to neurofibrillary tangle formation. In this study, we evaluated the intracerebral localization of p-tau in App knock-in mice with amyloid-β plaques without neurofibrillary tangle pathology (AppNLGF), in App knock-in mice with increased amyloid-β levels without amyloid-β plaques (AppNL) and in wild-type mice. Immunohistochemical analysis showed that phospho-tau 217 and phospho-tau 231 were detected only in AppNLGF mice as punctate structures around amyloid-β plaques, overlapping with the tau pathology marker, AT8 epitope phospho-tau 202/205/208. Moreover, phospho-tau 217 and phospho-tau 202/205/208 colocalized with the postsynaptic marker PSD95 and with a major tau kinase active, GSK3β. In contrast and similar to total tau, phospho-tau 181 signals were readily detectable as fibre structures in wild-type and AppNL mice and colocalized with an axonal marker neurofilament light chain. In AppNLGF mice, these phospho-tau 181-positive structures were disrupted around amyloid-β plaques and only partially overlapped with phospho-tau 217. These results indicate that phospho-tau 217, phospho-tau 231 and a part of phospho-tau 181 signals are markers of postsynaptic pathology around amyloid-β plaques, with phospho-tau 181 also being a marker of axonal abnormality caused by amyloid-β burden in brains.