bluuebunny/crossref_metadata_2025 huggingface dataset:
Scenario modeling and operation path planning of autonomous driving tower cranes
Authors: Du Xuan , Yu Xian-Zhe , Yun Xing-Yu
Published: November 2022

Combined with the operation specification of building tower cranes, the three-dimensional path planning technology of tower cranes and the optimization of path points are studied. The improved RRT-Connect algorithm is proposed. By introducing heuristic information in the path search, the path search efficiency and quality of the algorithm are improved. By eliminating invalid points in the path, the control burden of tower crane is reduced, and the optimized lifting point movement path is transformed into tower crane joint movement, and finally the calculation result is uploaded to PLC through LAN. The running trajectory of the tower crane lifting point is visually displayed in the scene model, and the validity and safety of the path are verified. The real tower crane is controlled. The operation is completed and the automatic driving of the tower crane is realized.
Path Planning Method of Rolling Brush of Car Washing Machine Based on Fractional Differentiation
Authors: Yan Hao , Qiu Yafeng , Hou Xiaoming , Jin Zhao
Published: November 2022

The roller brush cleaning path of the gantry reciprocating automatic car washing machine is the key to determining the quality of the car wash. For the issue that the traditional method cannot accurately and reliably calculate the roller path, a rolling brush path planning scheme combined with fractional differential algorithm is proposed. By analysing the working form of the car washing machine and the appearance characteristics of the car, a multi-view car detection system is designed, and the car images are collected by using multiple cameras. The possibility of the path of each roller brush of the car washing machine is extracted from the contour information, and the contour curve is converted into the roller brush path in the form of coordinate points through software. Finally, the actual size of the car to be washed is calculated by the multi-view camera, and the average error between the calculation result and the actual result is 2.63%, which meets the operating conditions of the gantry reciprocating automatic car washing machine.
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

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

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

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

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

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

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

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

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

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

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

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

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.
Comparisons of I- and Cl- concentrations on the corrosion behavior of TA4 titanium alloy in azeotropic acetic acid solutions
Authors: Deng Cong , Zhao Zhongxun , Hu Huasheng , Li Xufeng , Luo Weijian
Published: November 2022

The corrosion problems of TA4 titanium alloy trays were urgent to be solved in the safe and steady production process of the acetic acid distillation column. According to the real corrosion environment of the distillation column, the corrosion behavior of TA4 titanium alloy in simulated azeotropic acetic acid solutions with a series of I- and Cl- concentrations was investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. The experimental results showed that the TA4 titanium alloy was much easier to be corrosive with I- and Cl- in the test solution, the passive film resistance R
f, the charge transfer resistance R
ct, and Warburg impedance W decreased obviously with the increasing concentration of I- and Cl-. The corrosion rate of Cl- was 1.79 times higher than I- on average when the I- and Cl- concentration increased from 0.1 wt.% to 5 wt.%. The inhibition of passive film formation on the surface of TA4 titanium alloy by Cl- is stronger than that of I-.
Effect of support settlement on ultimate bearing capacity of Zhoukoudian steel structure
Authors: Li Y , Zheng B , Ding T Y , Qu W X , Ju J S , Zhang Y S
Published: November 2022

In order to study the effect of non-uniform support settlement on global stability ultimate bearing capacity of lattice shell structure, combining with the project of first site protective building in Zhoukoudian Ruins, the finite element software ANSYS is employed to conduct geometric nonlinear and double nonlinear global stability analysis of the single-layer lattice shell respectively based on consistent mode imperfection method and advanced consistent mode imperfection method, thus the global stability ultimate bearing capacity under different settlement cases is obtained and compared. Analysis results show that non-uniform support settlement is beneficial to increase the elastic global stability ultimate bearing capacity of the structure by a small margin, but excessive settlement may have adverse effects on the bearing capacity of the structures with initial imperfections. When considering material nonlinearity, small non-uniform support settlement is conducive to a slight increase in the elastoplastic global stability ultimate bearing capacity of the structure that decreases and is lower than that without settlement with the increase of non-uniform settlement. In addition, non-uniform support settlement will not affect the instability path of the lattice shell.
Analysis on progressive collapse resistance of Zhoukoudian single-layer latticed shell structure
Authors: Li Y , Zhang Y S , Ding T Y , Qu W X , Ju J S , Zheng B
Published: November 2022

The progressive collapse of the spatial grid structure is the focus and difficulty of the current research. The stability problem of the single-layer latticed shell structure is more prominent due to its low redundancy. In this paper, the dynamic nonlinear analysis of the Zhoukoudian large-span single-layer latticed shell structure is carried out to study its progressive collapse process by the finite element software ABAQUS. The results show that the structure eventually collapse under 7 times the gravity load. The mid-span zone on the left side of the structure is the weak point of the structure where the earliest failure members appear. After the failure members appear for the first time in the structure, the vertical displacement increases faster, and then the failure members develop along the longitudinal and transverse directions of the structure starting from the mid-span zone on the left side, which eventually leads to the failure of the structure.
Enhancement of oxidation resistance in titanium by plasma treatment for high temperature applications
Authors: Alhammadi J , Mohanta A , Shymanski V I , Matras G , Vega F , Kasmi C
Published: November 2022

Titanium metal has many uses in various industries and applications due to its unique and distinctive properties, making it an important and effective material in daily use in many fields. However, they cannot be used for high-temperature applications for a long time due to their poor oxidation resistance at high temperatures. This study used compression plasma flows (CPFs) treatment to enhance the oxidation resistance of pure titanium samples in high-temperature environment. X-ray diffraction (XRD) was used to characterize air-annealed pure titanium samples with and without CPFs treatment. Without CPFs treatment, the XRD spectra of the samples annealed at 700 °C for 10 minutes and above consist of additional diffraction lines of (110), (101), and (211), representing the rutile TiO2 phase, indicating the occurrence of oxidation. However, TiO2 phases were absent in the XRD spectra of the samples treated with CPFs and then annealed under similar conditions. This indicates the effectiveness of the treatment and its ability to prevent oxidation at high temperatures. Moreover, the XRD investigation showed insignificant changes in the crystal structure of the samples annealed after plasma treatment. Thus, titanium and its alloys with CPFs treatment show potential for high-temperature applications.
A spatiotemporal registration method between roadside lidar and camera
Authors: Zhu Jianguo , Dong Yanyan , Xu Xiaobin , Wang Jiewen , Wu Jianqing
Published: November 2022

With the rapid development of intelligent transportation, it is of great significance to improve road traffic safety and traffic efficiency by tracking road users in real time. In this paper, a roadside multi-source data acquisition platform is designed based on two main sensors, lidar and camera, to perform time synchronization between lidar data and camera data. The point cloud data and image data of the same frame are the research objects. Based on Zhang Zhengyou’s calibration method and the plane target model theory, the camera internal parameters and the joint external parameters of the lidar and camera are respectively calibrated to obtain the internal and external parameter matrix. The error is 0.09 pixels, and the external parameter calibration error is 0.22 pixels. The registration test of lidar and camera under different roadside layout conditions is designed to verify the adaptability of the registration method. When the camera is arranged and installed, the distance between the horizontal and vertical directions should not exceed 90 cm.
Study on the Characteristics of FSRD with a Corrugated Anode and p+ Adjustment Region at Cathode
Authors: Wang Cailin , Yu Li , Yang Wuhua , Guan Lei
Published: November 2022

The reverse recovery characteristic of the power diode will directly affect the reliability of the inverter application. In order to improve the reverse recovery characteristics of the fast and soft recovery diode (FSRD), a new FSRD structure with Corrugated Anode and P+ adjusting Cathode (CA-PC-FSRD) is studied by the Sentaurus-TCAD simulator and compared with the characteristics of conventional FSRD. The influence of key parameters, such as the height and width of anode corrugation and the width of the p+ adjusting region at the cathode, on the characteristics are discussed. Simulation results show that the CA-PC-FSRD has excellent soft recovery characteristics compared with the conventional FSRD at the same voltage level.
Effect of H/F Adsorption on the Electronic Structure of TH-Ge0.5Si0.5C2-zz
Authors: Luo GuiHong , Yang Ying , Li RuKun , Zhang MengYang , Zhao WenJing
Published: November 2022

A new material TH-Ge0.5Si0.5C2-zz has been discovered, which has a direct bandgap and has a broad application prospect in photoelectric devices. The effect of H/F atom adsorption on the structural parameters and electrical properties of TH-Ge0.5Si0.5C2-zz was studied in this paper. In a nutshell,bandgap of TH-Ge0.5Si0.5C2-zz can be notable increased by H atom adsorption, and the work function and electron affinity energy are decreased. While the bandgap of TH-Ge0.5Si0.5C2-zz cannot be opened by the full adsorption of the F atom.
A low supply voltage sensitivity low power oscillator design
Authors: Shi Hao , Guo Zhongjie , Bai Ruokai , Li Mengli , Qiu Ziyi
Published: November 2022

With the rapid development of social economy, the integrated circuit industry has developed rapidly. At the same time, people’s requirements for the cost, power consumption, integration, stability and other aspects of integrated circuit chips have increased. Oscillators, as an important module for providing clocks to chips, have higher requirements for on-chip oscillators. The purpose of this paper is to achieve a low supply voltage sensitive and low power oscillator. Based on this research purpose, this paper proposes a power adjustment oscillator circuit of the flip level technique, which realizes that the clock signal duty cycle is 50% under the typical case of a supply voltage of 4 V. The center frequency is 512 KHz, of which the process angle trimming range of the capacitor trim circuit is 52.37%-211.28%. With the supply voltage range of 2.5 V to 5.5 V, the clock signal has a frequency variation of 0.299%/V, has low supply voltage sensitivity, and consumes only 400 nA with low power dissipation.
Research on the Mechanism of Sensing Signal Processing
Authors: Ning Chuanpeng , Yu Xin
Published: November 2022

The speed sensor is an important support for the development of modern industrial automation. It plays a great part in automobiles, machinery manufacturing, and aerospace, and is widely used in CNC machine tools, cutting laser machines, industrial transmission, and other mechanical equipment. In this paper, a sensor is designed, which uses the signal generated by the body’s rotation as a sine wave signal to transmit frequency information. The sinusoidal signal is transmitted to the signal processing circuit, and two voltage dividers are used to reduce the signal amplitude to the applied voltage of the MCU below 5V. After processing the circuit, the sinusoidal signal can be converted into the square wave signal with the same frequency. The square wave signal is transmitted to the microcontroller to read the square wave’s pulse frequency, and the body’s rotational speed can be output after the formula is calculated in the program read by the microcontroller in advance.
Optimization of Planar Array Electrostatic Sensor for Metal Surface Defect Detection
Authors: Xue Qian , Chen Xijuan
Published: November 2022

Static electricity is usually generated in the damage area of the metal surface due to contact friction, and the charge distribution density can reflect the size, shape, and relative position of the damage area. Based on this, a planar array electrostatic sensor is designed to detect metal surface defect in this paper, and the shielding method, number of electrodes, electrode shape, and arrangement of the sensor are optimized taking account of the induced charge value, the uniformity of sensitivity and the image correlation coefficient. Different image reconstruction algorithms (e.g. Landweber algorithm, conjugate Gradient algorithm, Tikhonov regularization and primary dual interior point method) are utilized to evaluate the performance of the designed electrostatic sensor. The results demonstrated that the sensor with hexagonal electrode shape, integrated shielding, a new arrangement, a duty cycle of 80%, and a peripheral shielding electrode, has better image quality for all the tested damage models. When using the PDIPA algorithm for image reconstruction, the image correlation coefficient can exceed 0.9.
N-buffer design and optimization in 4500V class IGBT
Authors: Nie Ruifen , Jin Rui , Wang Yaohua , Li Li , Gao Mingchao , Liu Yueyang , He Feng , Liu Jiang , Li Cui , Sun Wanru , Tian Baohua
Published: November 2022

In this paper, the effects of doping structure of multi-proton injection (MPI) buffer layer on static and short circuit characteristics of IGBT were studied, and the relationship between donor concentration of the buffer layer and injection dose and annealing temperature was studied. The MPI buffer layer suitable for 4500V IGBT was optimized by comparative experiments. This MPI buffer layer can solve the problem of high-temperature activation of the traditional IGBT buffer layer and lower thermal budget and can be fabricated on large wafers for better parameter consistency.
The electric transport properties of iridate Sr2-x
Bi
x
IrO4 and Sr2-y
Dy
y
IrO4
Authors: Xiong Yanfei , Zu Hao , Liu Hui
Published: November 2022

Sr2IrO4 is predicted to be a new superconductor in theory, and its electric transport properties have attracted much attention in the field of physics. Here we prepared a series of polycrystalline samples doped with Sr2-xBixIrO4 (x=0,0.02,0.04,0.06,0.08) and Sr2-yDyyIrO4 (y=0,0.02,0.04,0.06) respectively. The influence of the two ions on the lattice structure and electronic structure after the substitution of the Ir site is very similar, which makes the overall reduction trend of IrO6 octahedron and Ir-O1-Ir bond angle. The resistivity shows a non-monotonic change with doping and still maintains the insulation. The low-temperature section, medium-temperature section, and high-temperature section conform to three-dimensional variable range hopping (3D-VRH), thermal activation model, two-dimensional weak localization model respectively.
A new compact linear beam-plasma discharge simulator BPD-PSI
Authors: Sergeev N.S. , Sorokin I.A. , Podolyako F.S.
Published: November 2022

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

‘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

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

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

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

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

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

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.
APOBEC3B expression is promoted by lincNMR collaborating with TGF-β–Smad pathway
Authors: Ota Kosuke , Sakai Satoshi , Ohhata Tatsuya , Suzuki Takahito , Uchida Chiharu , Niida Hiroyuki , Kitagawa Masatoshi
Published: November 2022

Long non-coding RNAs (lncRNAs) participate in carcinogenesis and cancer malignancies. Transforming growth factor-β (TGF-β) is involved in various cellular processes including cancer progression. We performed comprehensive RNA sequencing analyses to identify lncRNAs regulated by TGF-β and found that lincNMR (long intergenic noncoding RNA–nucleotide metabolism regulator, also identified as MAP3K9-DT) was induced by TGF-β in various cell lines. There are several variants of lincNMR (hereafter lincNMRs) in the lincNMR/MAP3K9-DT locus, and their expression was increased by TGF-β. TGF-β-mediated induction of lincNMRs was decreased by depletion of Smad2/3 in Huh7, suggesting that the TGF-β–Smad pathway is involved in lincNMRs expression. We also found that APOBEC3B but not other APOBEC family members were a target gene of lincNMRs. APOBEC3B, a cytidine deaminase, promotes C to U mutation and highly expressed in various human cancers. Although it is associated with cancer progression, regulatory mechanisms of APOBEC3B expression have not been fully elucidated. We performed RNA immunoprecipitation assays and proved that lincNMRs bound to endogenous Smad2 in Huh7 cells. The increased activity of the promoter of APOBEC3B induced by overexpression of Smad2/3 was inhibited by depletion of lincNMRs. These data suggest that lincNMRs participate in APOBEC3B expression by collaborating with TGF-β–Smad pathway. High expression of lincNMRs was positively correlated with high expression of APOBEC3B in various cancer cell lines. Overexpression of APOBEC3B as well as lincNMR was found in human cancers such as hepatic and lung cancers and was associated with their poor prognosis, suggesting that lincNMR may contribute to tumor malignancy via enhanced expression of APOBEC3B.
MGTdb: a web service and database for studying the global and local genomic epidemiology of bacterial pathogens
Authors: Kaur Sandeep , Payne Michael , Luo Lijuan , Octavia Sophie , Tanaka Mark M , Sintchenko Vitali , Lan Ruiting
Published: November 2022

Multilevel genome typing (MGT) enables the genomic characterization of bacterial isolates and the relationships among them. The MGT system describes an isolate using multiple multilocus sequence typing (MLST) schemes, referred to as levels. Thus, for a new isolate, sequence types (STs) assigned at multiple precisely defined levels can be used to type isolates at multiple resolutions. The MGT designation for isolates is stable, and the assignment is faster than the existing approaches. MGT’s utility has been demonstrated in multiple species. This paper presents a publicly accessible web service called MGTdb, which enables the assignment of MGT STs to isolates, along with their storage, retrieval and analysis. The MGTdb web service enables upload of genome data as sequence reads or alleles, which are processed and assigned MGT identifiers. Additionally, any newly sequenced isolates deposited in the National Center for Biotechnology Information’s Sequence Read Archive are also regularly retrieved (currently daily), processed, assigned MGT identifiers and made publicly available in MGTdb. Interactive visualization tools are presented to assist analysis, along with capabilities to download publicly available isolates and assignments for use with external software. MGTdb is currently available for Salmonella enterica serovars Typhimurium and Enteritidis and Vibrio cholerae. We demonstrate the usability of MGTdb through three case studies — to study the long-term national surveillance of S. Typhimurium, the local epidemiology and outbreaks of S. Typhimurium, and the global epidemiology of V. cholerae. Thus, MGTdb enables epidemiological and microbiological investigations at multiple levels of resolution for all publicly available isolates of these pathogens.

Database URL: https://mgtdb.unsw.edu.au
NEMAR: an open access data, tools and compute resource operating on neuroelectromagnetic data
Authors: Delorme Arnaud , Truong Dung , Youn Choonhan , Sivagnanam Subhashini , Stirm Claire , Yoshimoto Kenneth , Poldrack Russell A , Majumdar Amitava , Makeig Scott
Published: November 2022

To preserve scientific data created by publicly and/or philanthropically funded research projects and to make it ready for exploitation using recent and ongoing advances in advanced and large-scale computational modeling methods, publicly available data must use in common, now-evolving standards for formatting, identifying and annotating should share data. The OpenNeuro.org archive, built first as a repository for magnetic resonance imaging data based on the Brain Imaging Data Structure formatting standards, aims to house and share all types of human neuroimaging data. Here, we present NEMAR.org, a web gateway to OpenNeuro data for human neuroelectromagnetic data. NEMAR allows users to search through, visually explore and assess the quality of shared electroencephalography (EEG), magnetoencephalography and intracranial EEG data and then to directly process selected data using high-performance computing resources of the San Diego Supercomputer Center via the Neuroscience Gateway (nsgportal.org, NSG), a freely available web portal to high-performance computing serving a variety of neuroscientific analysis environments and tools. Combined, OpenNeuro, NEMAR and NSG form an efficient, integrated data, tools and compute resource for human neuroimaging data analysis and meta-analysis.

Database URL: https://nemar.org
Segmental volumetric analysis with a ventilated or perfused area: identifying the intersegmental plane
Authors: Kitazume Mai , Tane Shinya , Shimizu Nahoko , Kitamura Yoshitaka , Maniwa Yoshimasa , Nishio Wataru
Published: November 2022

OBJECTIVES

Two methods are available to identify the intersegmental plane during segmentectomy: the inflation-deflation method, based on the ventilation area, and injection of indocyanine green, based on the pulmonary arterial distribution. However, whether the intersegmental plane created by these 2 methods matches remains unknown. Our goal was to identify the demarcation lines based on bronchial and arterial territories using 3-dimensional computed tomography-based volumetry.

METHODS

We collected data from patients who underwent thoracoscopic segmentectomy in our hospital between April 2012 and May 2021. Three-dimensional images were reconstructed from the preoperative contrast-enhanced computed tomography data using the SYNAPSE VINCENT software program. The volume of the affected area and the distance of the tumour from the intersegmental plane were calculated based on each affected artery and bronchus. Each calculated volume was compared to each affected segment using a paired t-test.

RESULTS

Of 195 patients, 114 underwent upper lobe segmentectomy, and 81 underwent lower lobe segmentectomy. In upper lobe segmentectomy, the affected arterial segmental volume was smaller than the bronchial volume (505.0 ml vs 539.4 ml, P < 0.001). In lower lobe segmentectomy, there was no significant difference between arterial and bronchial volumes (234.6 ml vs 236.9 ml, P = 0.607). The volume of the affected arterial segmental lung and the distance of the tumour from the intersegmental plane were significantly smaller than the bronchial volume in upper lobe segmentectomies.

CONCLUSIONS

As per the results, the affected segmental volume delineated by the indocyanine green method would be underestimated in upper lobe segmentectomy.
State-of-the-art management of dysplastic Barrett's esophagus
Authors: Vantanasiri Kornpong , Iyer Prasad G
Published: November 2022

Endoscopic eradication therapy (EET) has become a standard of care for treatment of dysplastic Barrett’s esophagus (BE) and early Barrett’s neoplasia. EET mainly consists of removal of any visible lesions via endoscopic resection and eradication of all remaining Barrett’s mucosa using endoscopic ablation. Endoscopic mucosal resection and endoscopic submucosal dissection are the two available resection techniques. After complete resection of all visible lesions, it is crucial to perform endoscopic ablation to ensure complete eradication of the remaining Barrett’s segment. Endoscopic ablation can be done either with thermal techniques, including radiofrequency ablation and argon plasma coagulation, or cryotherapy techniques. The primary end point of EET is achieving complete remission of intestinal metaplasia (CRIM) to decrease the risk of dysplastic recurrence after successful EET. After CRIM is achieved, a standardized endoscopic surveillance protocol needs to be implemented for early detection of BE recurrence.