bluuebunny/crossref_metadata_2025 huggingface dataset:
High precision MI sensor with low energy consumption driven by low-frequency Wiegand pulse
Authors: Yao Ruixuan , Takemura Yasushi , Uchiyama Tsuyoshi
Published: February 2023

This study introduces a new method to drive high-precision magneto-impedance (MI) sensors with low power consumption using a Wiegand sensor to replace the oscillator circuits of the MI sensor. We studied the characteristics of an MI sensor driven by low-frequency pulses and concluded that pulses with a fast rise time and small excitation current are necessary to induce a significant MI effect. The Wiegand sensor induced 10 Hz low-frequency pulse voltages of approximately 12 V and a constant width of 20 μs when an alternating magnetic field of 5 mT/μ0 alternating magnetic field was applied. A fast rise-time-shaping circuit was designed to shape the Wiegand pulses with a fixed amplitude and rise time of less than 100 ns. The MI sensor exhibited a good output linearity of 0.04 mV/μ0T for detecting magnetic field in the range of ±150 μT when Wiegand pulses of amplitude 1 V were supplied. The power consumption of the MI sensor was reduced from milliwatts (mW) to microwatts (μW) and its usage time was extended by 300% compared to that of the previous design. This newly designed MI sensor is suitable for use in bio-magnetic field measurements, constant vehicle detection devices, and other applications.
Time-domain computing for Boolean logic using STT-MRAM
Authors: Zhou Rong , Cai Hao
Published: February 2023

With the development of artificial intelligence, the separation of memory and processor in the traditional von-Neumann architecture has led to the bottleneck of data transmission hindering the development of energy efficient computing. The computing-in-memory (CIM) paradigm is expected to solve the problems of memory wall and power wall. In this work, we propose a time-domain (TD) computing scheme based on the spin transfer torque magnetic random access memory (STT-MRAM). Basic Boolean logic operations, such as AND/OR/Full-adder (FA), are implemented through converting the bit-line voltage to time delay and time-to-digital converter (TDC). The proposal is simulated using the 28 nm CMOS process and 40 nm MTJ compact model. Monte-Carlo simulations show that 94.2% to 100% computation accuracy can be obtained and the delay of AND/OR and FA is 2.5 ns and 3.5 ns. The energy consumption of AND/OR and FA achieve 59.43 fJ and 97.56 fJ, respectively.
Low magnetic damping constant in half-metallic Co2FeAl Heusler alloy thin films grown by molecular beam epitaxy
Authors: Hojo Takayuki , Tezuka Nobuki , Nakano Takafumi , Tsunoda Masakiyo , Oogane Mikihiko
Published: February 2023

Half-metallic Co2FeAl Heusler alloy thin films with various thickness were prepared by MBE method and its magnetic and crystalline properties were investigated. At the thickness of 20 nm and above, good magnetic properties and high B2-order parameter was obtained. In addition, magnetic damping constant was evaluated from peak-to-peak linewidth measured by FMR and ultra-low magnetic damping constant below 0.001 was obtained at the film thickness of 30 nm. These results are thanks to the excellent half-metallicity in the Co2FeAl films prepared by MBE.
Iron loss evaluation method for SiFe sheet material under PWM inverter excitation
Authors: Matsumori Hiroaki , Yamaguchi Taisei , Shimizu Toshihisa , Kosaka Takashi , Matsui Nobuyuki
Published: February 2023

This study proposed an iron loss evaluation method for SiFe sheet material under high-frequency current ripple caused by pulse width modulation (PWM) inverter switching. The PWM inverter switching results in dynamic minor loops on the BH plane, leading to iron loss. Furthermore, in magnetic material with wide major loops, such as SiFe sheet material, the iron loss caused by one dynamic minor loop differs based on the flux density bias difference even for the same magnetic field bias. A previous study reported an iron loss calculation error because the conventional iron loss calculation method neglected the iron loss of the flux density bias characteristic in the same magnetic field bias. Therefore, we modified the previously developed iron loss measurement system to collect the iron loss of the flux density bias characteristic and proposed an iron loss calculation method for SiFe sheet material.
Neighboring stars shaped a planetary nebula
Authors: Hill Heather M.
Published: February 2023

Early images from the JWST reveal previously unseen fingerprints of stellar interactions with a dying star.
Consulting can be stimulating and lucrative for physicists
Authors: Feder Toni
Published: February 2023

Skills from physics training transfer well to a career that comes in many flavors.
Malaysian physics and the maker ethos
Authors: Lee Clarissa Ai Ling
Published: February 2023

Far removed from traditional research centers, Malaysian physicists forged a scientific culture that prioritized innovation and reuse.
Understanding the Mayans on their own terms
Authors: Freire Olival
Published: February 2023

Calculating Brilliance: An Intellectual History of Mayan Astronomy at Chich’en Itza, Gerardo Aldana y Villalobos, U. Arizona Press, 2022, $75.00
Factors influencing the adaptability and habitat use of rescued Malayan sun bears (
Authors: Abidin Kamaruddin Z. , Mansor Mohammad Saiful , Husna Izzat , Nazri Nabilah , Farinordin Farah Ayuni , Izam Nur Amalina Mohd , Magintan David , Nor Shukor Md
Published: February 2023

Context The lack of documentation and detailed assessment of previous sun bear (Helarctos malayanus) release programs raises concerns about bears’ capacity to adapt to their new habitats and key elements of release success. Aims We evaluated the influence of the sun bears’ individual profiles and environmental factors on their adaptability, and investigated their habitat use and movements in the wild. Methods We released 13 rescued sun bears (four wild-caught and nine rehabilitated) to natural habitats between December 2015 and August 2017, and inferred adaptability process by analysing their pre- and post-release data. Key results Post-release monitoring showed that sun bears required at least a month to acclimatise to their release area. No nuisance cases were reported, and bears were observed avoiding monitoring teams in a series of encounters. Principal-component analysis identified a previous history of ill health (e.g. malnutrition), low avoidance of humans prior to release and low potential of release sites as significant factors associated with poor adaptability of released bears. Rehabilitated bears also showed lower adaptability to hilly topography with an average elevation of more than 500 m. Individual profiles of adult physically fit wild-caught bears with high avoidance of humans prior to release were associated with high adaptability. Binary logistic regression indicated that habitat type was the main factor influencing bear movement. Bears had a high affinity for oil palm plantations adjacent to the forest edge. Most habitat use of released bears was close to the forest edge. Conclusions In terms of competition, predation, food availability, and adaptability, the selection of forest edges adjacent to other favourable habitats is perceived as a more opportunistic survival strategy, as long as the bears do not rely on humans to survive and endure with the natural interactions in the wild. Implications This study emphasises the importance of improving the likelihood of survival of rehabilitated bears, especially in the early release phase. Reducing human–bear interaction in rehabilitation centres by practising a buddy system and minimal human contact in captivity considerably enhances release effectiveness.
Effect of Fuel Injection Timing on Marine Diesel Engine Blended with Isoamyl Alcohol
Authors: Lin Hang , Huang Zhaoxia , Huang Jialiang , Li Pinfang , Wang Qiwei , Zhang Feifei , Fan Jinyu
Published: February 2023

In order to study the problem that the pressure in the cylinder decreases significantly after diesel is mixed with isopentanol, which leads to the reduction of power performance, the software of AVL-FIRE is used for simulation, and the angle of start injection is adjusted to improve cylinder pressure. It turns out that in terms of combustion, The maximum burst pressure is reduced after mixing isoamyl alcohol. By increasing fuel injection timing, maximum burst pressure can rise to 87.8%-94.5% of the original engine respectively. The indicated power can be increased to 91.92%-95.62% of the original. In terms of emissions, after mixing, with the increase of fuel injection timing, NO does not change significantly, Soot shows a downward trend.
Effect of Radial Clearance on the Secondary Motion and Tribological Performance of Stirling Engine Piston-Crosshead
Authors: Sun Sicong , Yang Xin , Li Hailiang , Jia Jiao , Han Chener , Zeng Jia , Xiao Ruixue
Published: February 2023

The cylinder radial clearance is a significant influencing factor for secondary motion and frictional power consumption of Stirling engine piston-crosshead structure. In this paper, a piston-crosshead dynamical model of the Stirling engine considering the surface tribological characteristics is established, and the correctness of the model is verified on the piston rod sealing test bench. The influence of the clearance on the dynamics and the tribology of the Stirling engine piston-crosshead is analysed based on this model, and it is shown that the crosshead knocking force and the frictional force reach equilibrium when the clearance is 0.06 mm.
Dynamic Analysis of Hydraulic Pipeline Based on Substructure Method
Authors: Jiang Hongxuan , Yang Qingjun , Liu Hu , Liu Yang , Cui Xiaofeng
Published: February 2023

The vibration problem of hydraulic system is related to the normal operation of vehicles. The research methods of hydraulic system mainly include finite element simulation and vibration test. The vibration test is not repeatable because of the great influence of the environment, and the computer simulation provides the possibility for the analysis of the complex hydraulic system. However, in the process of local refinement design of the system, the simulation calculation of the whole structure is still needed to modify the local parameters, and the simulation time is long. Based on the substructure method in structural analysis, the substructure method for fluid structure coupling is derived to reduce the time cost in the simulation process of hydraulic system. In this paper, pointing at the particular vibration region of the pipeline, the structure is divided into substructures. The dynamic characteristics of each substructure are obtained by dynamic analysis, and the overall characteristics of the system are obtained according to the boundary coordination.
Semi-physical Simulation Model for Leakage of Prediction Aviation Pipeline
Authors: Ye Xiangrui , Luo Bin , Deng Lichuan
Published: February 2023

The high stability and tightness of modern aviation hydraulic pipelines require them to have a very low leakage rate under variable pressure environments. Once the leakage of the hydraulic pipeline is likely to cause an irreversible air disaster. Flaring straight pipe joint is one of the most widely used in aircraft hydraulic pipelines. The establishment of the simulation model is an effective method to accurately predict the annular gap leakage of the pipe joint. The ring gap of the pipe joint is located inside the threaded sleeve, which cannot be directly observed. The existing leakage prediction methods usually only focus on the microscopic interface contact and ignore the leakage prediction of real complex structures. Therefore, this article is based on ideas, semi-physical simulation through experimental data calibration tightening torque and annular gap width and the mathematical relationship between void ratio, and then established the flaring type straight pipe joint circular aperture leakage prediction simulation model, the ability to different tightening torque and hydraulic pressure conditions for predicting the pipe joint leakage rate, finally, the simulation experiments have been carried out to verify prediction model, The validity of this method is proved.
Study on Combustion and Emission Performance of Dual Injection Strategy for Ammonia/Hydrogen Dual-Fuel Engine
Authors: Wang Binbin , Yang Chuanlei , Wang Hechun , Hu Deng , Duan Baoyin , Wang Yinyan
Published: February 2023

To realize zero carbon emission in internal combustion engines and boost the growth of ammonia fuel, we mixed a few hydrogens into ammonia fuel to boost the atomization and combustion performance in the combustion chamber. We study hydrogen and ammonia mixed and injected directly through two injectors, the intake temperature is 551k, to find the best injection advance angle combination to ensure the overall working performance of the ammonia Dual fuel engine. The investigation shows that when the main/auxiliary fuel injection timing is 704°CA, the knock value is less than 2, the combustion in the cylinder is gentle, and the negative work phenomenon of knock combustion is avoided. The engine power is the highest and the best economy. The emissions of soot, CO, HC, and CH2O are at a very low level, the CO2 content before and after combustion increases to zero, and the NOx emission is slightly higher than the original engine. We will improve engine NOx emission through SCR Technology in the future. The investigation results will boost the development of an ammonia and hydrogen compression ignition engine and boost the internal combustion engine to zero carbon combustion mode.
Selective Separation of Arsenic from Arsenic-bearing Copper Dust by Vulcanization Reduction
Authors: Li Xuepeng , Wang Juan , Chang Jun
Published: February 2023

Arsenic is removed from arsenic-bearing copper dust by vulcanizing reduction. Vulcanizing reduction conditions and kinetics of arsenic volatilization are studied. Different temperatures, sulfur additions and vulcanizing reduction times are studied to obtain the conditions of separating arsenic from arsenic-bearing copper dust. Arsenic was selectively removed with a volatilization rate of 94.54% under the conditions of temperature of 400°C, sulfur addition of 10wt% and 60min vulcanizing reduction time. Arsenic was prepared to As2O3with a purity of 95.3% which can be used as raw material to prepare elemental arsenic. The kinetic study showed that the process of arsenic volatilization conformed to the SCM model; the arsenic volatilization process was controlled by diffusion control in the first 60 minutes and switched to chemical reaction in the 70-120 minutes.
Effect of Zn Transition Layer on Properties of Vacuum Deposited Zn-Mg Coating
Authors: Liu Qiuyuan , Qiu Xiaopan , Liu Xin , Zhao Xingyuan , Jiang Sheming , Zhang Qifu
Published: February 2023

Zinc coatings have been served as a barrier and a galvanic protection for steel products for over a century. However, with the depletion of zinc resources, it becomes an urgent issue to obtain a new type of zinc coating that uses less zinc and has higher corrosion resistance. In order to develop Zn/ZnMg coatings with better corrosion resistance than traditional galvanized steel and suitable for advanced high strength steel, the vacuum thermal evaporation technique was used to simultaneously deposit Zn/ZnMg coating onto interstitial free steel plates and single-crystal silicon wafers in a high vacuum environment. The microstructure, morphology, adhesion and corrosion resistance behavior of the Zn/ZnMg coating were studied by scratch test, salt spray test and electrochemical method. The results shows that the grain size in the Zn/ZnMg coating tended to increase with the increase of the substrate temperature. After deposited the pure Zn transition layer, the adhesion of the coating has been obviously improved. When the substrate temperature was increased to 200°C, the obtained coating exhibited strong corrosion resistance.
Effect of Crystallinity on Properties of Autoclaved Aerated Concrete Matrix Materials
Authors: Pan Yunfeng , Jiang Yaqing , Liu Zongqi , Xiang Qiudi , Gao Chao
Published: February 2023

The properties of Autoclaved Aerated Concrete (AAC) are related to the crystallinity of hydration products of matrix materials. This study describes the effects of tobermorite and C-S-H gel contents in hydration products of AAC matrix materials on mechanical and drying shrinkage properties. In this study, the mass contents of tobermorite and C-S-H gel were semiquantitative calculated By XRD and nitrogen adsorption method respectively. According to the data obtained from the orthogonal design, the influences of the contents of tobermorite and C-S-H gel on the mechanical properties and drying shrinkage were analyzed, and the optimum mass ratio of tobermorite to C-S-H gel was determined. The factors affecting the crystallization of AAC matrix materials were investigated. The results manifest that the matrix material has higher compressive strength, higher flexural strength and smaller drying shrinkage when the tobermorite content is 0.18~0.23, and the C-S-H gel content is 0.440~0.500. The fineness of quartz sand is the primary factor affecting the performance of AAC matrix materials, followed by constant temperature time, calcium-silica ratio and cement-lime ratio. The research results provide a reference for predicting or designing the performance of AAC.
Prediction Model for Microstructure Evolution of 610L during Hot Rolling Process
Authors: Zhang Siyuan , Jiang Haitao , Xin Jiangping , Zhang Yefei , Yang Zhenyu , Tian Shiwei
Published: February 2023

The microstructure evolution of steels through the whole process method can guide steel production at a lower cost. In this paper, the stress-strain curves of 610L under different deformation conditions are studied using a Gleeble-3500 testing machine. This work combines dynamic recrystallization, static recrystallization, and sub-dynamic recrystallization models to predict the recrystallization fraction and grain size during the rolling process. Through linear fitting, the parameters m1
, Q, and A are 0.15, 9030.19, and 0.062, respectively. Comparing the experimental results with the fitted model, it is found that the grain size calculated by the model is close to the experiment, proving the model’s accuracy.
Compressive Strain Sensing Elastic Foam Based on Sericin Dispersed Carbon Nanotubes
Authors: Li Ming , Xiao Ming , Jiang Weidong , Ran Jianhua , Min Yuhuan , Yang Tong , Bi Shuguang , Xia Long
Published: February 2023

The flexible strain sensor can transform the micro or macro deformation into the visual electrical signals for monitoring the physiological and motor characteristics of human body. However, the current commercial strain sensors generally have some shortcomings such as large stiffness and small strain range. In this work, a flexible compressive strain sensor with the 3D conductive network was fabricated by using biomacromolecule sericin protein dispersed carbon nanotubes (SSCNTs) as the conductive material and melamine foam (MF) as the elastic matrix. The results showed that the sensitivity of MF/SSCNTs elastic foam was 1.36 in the strain range of 0-70% with the CNTs content of 10 wt% and the cyclic compressive sensing performance was stable for at least 1600 cycles. This kind of flexible compressive strain sensor is environmentally friendly, low cost, simple process, and provides a new method for the preparation of green flexible sensor.
Determination and Application of Similar Materials in a Subway Excavation and Support Model Test
Authors: Jian Xiuwen , Wang Zhongrong , Wang Yang
Published: February 2023

In order to study the mechanical response of strata during the construction of a subway, it is crucial to develop similar materials suitable for indoor model tests. Therefore, based on the similarity theory, combined with the uniaxial compressive test results of similar materials, the similar materials and their ratios of advanced small pipes, shotcrete and steel frames were determined. Then, they were applied to the model test of a subway excavation and support. The variation laws of surface displacement, stress distribution around the tunnel and internal force of the steel frame during tunnel excavation and support were obtained to verify the reliability of similar materials. The results show that the aluminum arch frame with width of 4.87 mm and thickness of 5.00 mm can be used to simulate the grid steel frame. Nine fine steel wires in a ring are taken to simulate the advanced small pipes, and gypsum with elastic modulus of about 1.12 GPa are prepared to simulate the initial shotcrete. They are proven to accurately simulate the physical characteristics of supporting materials in practical engineering, and the variation is similar to that obtained from the field test, which improves the authenticity of the model test results.
Numerical and Experimental Study on Axial Feed Skew Rolling of Small-Diameter GH4169 Alloy Bars
Authors: Zhang Huibo , Wang Baoyu , Feng Pengni , Wang Jiapeng , Liu Wei
Published: February 2023

This study relates to an innovative method for forming small-diameter GH4169 superalloy bars by Axial Feed Skew Rolling (AFSR). The finite element (FE) model was established to reveal the deformation characteristics and rolling force parameters of GH4169 superalloy bar in AFSR process. The distribution of stress field reveals that in the deformation area, the stress state in the center of the workpiece is radial compression, axial and tangential tension. In the deformation area, the core temperature of the workpiece rises due to plastic deformation, but after leaving the deformation area, the temperature of workpiece decreases significantly. Therefore, for small-diameter long bars, especially temperature-sensitive materials, auxiliary heating equipment is required when using AFSR technology. Furthermore, the roller with clamping sections was designed, and the rolling experiments were carried out on a double-rotating-arm skew mill. The rolled pieces obtained have no helical grooves on the surface, and the diameter deviations are less than 0.1 mm. The actual rolling process is stable and highly consistent with the FE simulation, which verifies the reliability of the FE model and the feasibility of forming superalloy bars by the AFSR method.
Construction of Conductive Network in Carbon-Nanotube-Based Nanocomposites for Electromagnetic Wave Absorption via Diameter and Composition Regulation
Authors: Fang Yuan , Wang Wenjian , Wang Shuai , Xue Weidong , Zhao Rui
Published: February 2023

Nitrogen-doped carbon nanotubes (NCNTs) and their composites are promising electromagnetic wave absorbers for their strong dielectric polarization and tunable conductivity. However, further investigation is needed to understand the relationship between diameter, composition, and absorption performance. Herein, using the Trojan catalyst strategy in which the catalyst emerged in-situ from a solid solution, the diameter of NCNTs and the composition of the absorber composite were regulated to achieve an effective absorption bandwidth of 4.4 GHz at 1.6 mm. This study showed that the diameter of NCNTs plays a critical role in the formation of conductive network, and an insulating phase can act as a modulator of impedance.
Influence of Solvothermal Reaction Temperature on Hydroxyapatite Nanowires
Authors: Wu Jinan , Nan Xiangkai , Qi Liang , Zhao Yanwei , Zhang Haijun , Qi Mei-li
Published: February 2023

Nowadays, nanomaterials have become the focus of many scientific researchers. As one of the mostly used biomaterials, the special structure and good performance of hydroxyapatite (HA) nanowires is a research hotspot. However, the synthesis of ultralong HA nanowires with highly efficiency and relatively low-cost is still a great challenge. In this work, HA nanowires are successfully synthesized through a simple solvothermal route, with calcium oleate and sodium hexametaphosphate as the calcium and phosphorus source, respectively. Influence of the solvothermal reaction temperature on the HA products are investigated. As the solvothermal temperature increases, the morphology of the HA crystals become nanowires and the length increases. This method is one-step and environmentally friendly without any pollution, since no organic solvent is allowed to be used in the whole experiment. The as-synthesized ultralong HA nanowires have enhanced mechanical properties and can be used in bone tissue engineering, drug delivery, adsorbents, and many other applications.
Study on TIG Process of AZ31 Magnesium Alloy
Authors: Liang Chunping , Li Ming , Peng Huining , Chen Yanyun , Li Guochao
Published: February 2023

In this paper, manual argon tungsten arc welding is used to weld AZ31 magnesium alloy plate with thickness of 2.5mm on both sides. The welding current parameters are changed. The best welding current is explored by analyzing the performance of welding joint; The corrosion resistance of welded joint was studied in the same medium. The results show that the microstructure of base metal zone is α- Mg solid solution, and the microstructure of the weld seam is mg solid solution α- Mg solid solution and β- Mg17Al12 intermetallic compound. When the welding current increases from 80A to 120A, the welding heat input increases gradually, and the grain size of HAZ increases gradually. The results of microhardness test show that the microhardness of weld zone is the largest, that of base metal is moderate, and that of heat affected zone is the lowest. The corrosion resistance of AZ31 magnesium alloy welded joint shows that the corrosion resistance of the weld zone is better than that of the base metal zone.
Modelling EPS Beads Distribution in 2D and 3D and Its Compressive Strength
Authors: Li Qiang , Xie Dongbai , Jiang Weiguo
Published: February 2023

The paper aims to build a distribution model for the EPS beads distribution in 2 and 3 dimensions. An EPS distribution model is built firstly, in which the calculated 2D distribution with volume fraction of 10%,20%,30% and the radius of 1.35mm and 3.5 mm are compared with the real experimental image of EPS distribution, and the calculated results match the real EPS bead distribution well. Secondly, the 3D distribution model is presented, and then the 3D model is incorporated into the finite element model to calculate the stress distribution. Finally, the failure of EPS concrete is predicted under different volume fraction and the radius of EPS bead according to the calculated stress distribution. From the simulated results of 3D stress distribution, it can be found that under the same volume fraction condition, reducing the radius of EPS bead can improve the compressive strength of EPS concrete.
Effect of Particle Size and Concentration of Nanocellulose on Thermal Properties of Nanocellulose Aerogel
Authors: Yang Xue , Wang Ziyang
Published: February 2023

Traditional building thermal insulation materials are mostly from petrochemical materials or high energy consumption processing process, which seriously restricts the sustainable development of the economy. Therefore, it is urgent to develop high-performance green insulation materials with high efficiency, energy saving, light weight and environmental protection. In this paper, nanocellulose aerogels made from cellulose nanocrystal (CNC) and cellulose nanofibril (CNF) with different concentrations were prepared by freeze-drying process. The effect of the concentration of nanocellulose on the thermal properties of aerogel was fully studied by infrared thermal imager, thermogravimetric analyser, and thermal conductivity meter. The study found that the overall thermal insulation performance of CNF aerogel was better than that of CNC aerogel. The concentration had a significant effect on the thermal insulation performance and thermal conductivity of the two aerogels. Among all the prepared nanocellulose aerogels, CNF aerogel with a concentration of 1% showed the best thermal insulation performance, which had a temperature difference of 24.1°C and a thermal conductivity of 0.030 W/mK.
Optimization of Trunk Phase Difference for Seeking Maximum Bidirectional Green Wave Bandwidth
Authors: Zhang Jie , Zhang Junyou , Zhu Qinglin , Luo Yuqiu , Lv Fengfei , Gao Han
Published: February 2023

This paper first analysis the shortcomings of the existing traditional numerical solution algorithm to solve the two-way green wave bandwidth problem, then improves the traditional numerical solution algorithm, constructs the objective function, proposes a trunk phase difference optimization method to seek the maximum two-way green wave bandwidth, constructs the model and solves it using Lingo optimization software, which can overcome the disadvantages of artificially fixed speed and common signal period and the lack of connection between green wave speed and common signal period. It can overcome the disadvantages of artificially fixed speed and common signal period and the lack of connection between green wave speed and common signal period, and optimize the signal period, phase difference, green signal ratio and green wave speed simultaneously. Meanwhile, the simulation analysis by VISSIM software verifies that the method can significantly reduce the stopping delay and improve the intersection capacity.
Structural Design and Analysis of an Airborne Equipment
Authors: Zheng Xiaodong , Su Zhiqiang , Wang Cangcang
Published: February 2023

The airborne electronic equipment has high requirements in high temperature resistance, vibration resistance, humidity and heat resistance and salt spray resistance, and the technical indexes of heat dissipation, vibration resistance and three-proof performance are determined through reliability analysis and the working characteristics of the components themselves. This paper introduces the design process of an airborne electronic equipment structure scheme. Under the conditions of meeting the structural size requirements and three-proof performance, the mainframe and antenna structure scheme is designed by analyzing the heat generation and vibration resistance requirements of components, and the temperature and mechanical simulation is verified by using ANSYS software. The design scheme meets the requirements of environmental adaptability.
Control Performance of Tuned Liquid Dampers for Construction Platform and Super Tall-Rise Building
Authors: Sun Haoding , Cao Qing , He Haoxiang , Zhou Daxing
Published: February 2023

To meet the engineering demand for vibration control of a super-tall integral jacking platform moulding system, a tuned liquid damper (TLD) is used for the tuned control device of the construction steel platform. An experimental method for isolating the substructure is proposed, and the effectiveness of the TLD for vibration damping control of the steel platform is verified by shaking table tests. The test results show that the dynamic response of the construction steel platform and the main body of the structure under earthquake can be suppressed simultaneously by controlling the mass ratio of TLD to the construction platform within 5%, and the displacement damping effect is good.
A Health Assessment Technique Based on WPD and Multiple Linear Regression Analysis
Authors: Lv Saige , Hu Xiong
Published: February 2023

A health assessment technique based on WPD and multiple linear regression analysis is studied in this paper. Firstly, the Temperature-Vibration function model is established by analyzing the mechanism of vibration and temperature of the gearbox. Secondly, the vibration and temperature signals and ambient temperature of the quayside crane lifting gearbox were decomposed by wavelet packet, and the total energy after wavelet packet reconstruction was calculated respectively. Thirdly, multiple linear regression analysis is carried out to obtain the multiple linear regression model of the lifting gearbox based on the established function model. Finally, the absolute error between the total energy of the wavelet packet of the actual and the calculated temperature is calculated to judge the health status of the gearbox during 2009-2015 according to the model. The results show that the judged health state of the quayside crane lifting gearbox is consistent with the actual situation, indicating that the technique can be effectively applied to the health assessment of the gearbox.
Health Status Characterization and RUL Prediction Method of Escalator Bearing Based on VMD-GRU
Authors: Zhang Yi , Guan Peng
Published: February 2023

In order to solve the problem of life index extraction and prediction of rolling bearings in the case of small samples, a bearing health index extraction and prediction method based on variational mode decomposition (VMD) and Gate Recurrent Unit (GRU) network is proposed. First, in view of the scarcity of bearing fault life data of field equipment, the sample data is expanded, and the one-dimensional data is decomposed into multi-dimensional data by VMD decomposition; Then, the multi-dimensional features are extracted and normalized in time domain; Finally, the normalized features are used as the input and the bearing life percentage are used as the output to train the GRU network, which is used to extract the bearing health index and predict the remaining useful life. The test-bed data verification shows that the bearing health index based on VMD-GRU method has better trend, monotonicity, robustness and the predicted residual life is more accurate. The analysis results based on escalator motor bearing fault cases show that: in the case of small samples, the health index performance of GRU network is better based on the features used VMD decomposition and feature extraction.
Study on the External Skeletal Power System Transmission Institution
Authors: Bao Jinfeng , Li Xiang
Published: February 2023

The power exoskeleton system can effectively extend the working hours of firefighters and improve the efficiency of work in the fire field. When firefighters are facing danger, the auxiliary device that comes with the system will greatly ensure the safety of the lives and reduce the casualties of personnel. Research projects first understand the hazards, causes, and solutions of forest fires. Secondly, the analysis of human skeletal structure and sports, and provide theoretical basis for the structural design of the power exoskeleton system. The pre -plan is designed according to the principles of simplicity, non -imitation, and quasi -imitation simulation design, and optimized the pre -planning plan in combination with sports and dynamics. Based on the limited element analysis, the structure, transmission principle, and transmission method of the power exoskeleton system were combined with the analysis of the power exoskeleton system. Finally, according to the use environment for power exoskeleton with auxiliary tools, build power exoskeleton sample machines to verify theoretical models and control planning. This topic conducts a variety of research on the exoscoligoral power system, the theoretical research, theoretical research, the simulation experiments, the manufacturing process, and the prototype production, which provides theoretical reference and technical support for the research of the exoskeleton dynamic system.
Indigenous peoples and the COVID-19 pandemic: a systematic scoping review
Authors: Pickering Kerrie , Galappaththi Eranga K , Ford James D , Singh Chandni , Zavaleta-Cortijo Carol , Hyams Keith , Miranda J Jaime , Arotoma-Rojas Ingrid , Togarepi Cecil , Kaur Harpreet , Arvind Jasmitha , Scanlon Halena , Namanya Didacus B , Anza-Ramirez Cecilia
Published: February 2023

Past influenza pandemics including the Spanish flu and H1N1 have disproportionately affected Indigenous Peoples. We conducted a systematic scoping review to provide an overview of the state of understanding of the experience of Indigenous peoples during the first 18 months of the COVID-19 pandemic, in doing so we capture the state of knowledge available to governments and decision makers for addressing the needs of Indigenous peoples in these early months of the pandemic. We addressed three questions: (a) How is COVID-19 impacting the health and livelihoods of Indigenous peoples, (b) What system level challenges are Indigenous peoples experiencing, (c) How are Indigenous peoples responding? We searched Web of Science, Scopus, and PubMed databases and UN organization websites for publications about Indigenous peoples and COVID-19. Results were analyzed using descriptive statistics and content analysis. A total of 153 publications were included: 140 peer-reviewed articles and 13 from UN organizations. Editorial/commentaries were the most (43%) frequent type of publication. Analysis identified Indigenous peoples from 19 different countries, although 56% of publications were centered upon those in Brazil, United States, and Canada. The majority (90%) of articles focused upon the general adult population, few (<2%) used a gender lens. A small number of articles documented COVID-19 testing (0.04%), incidence (18%), or mortality (16%). Five themes of system level challenges affecting exposure and livelihoods evolved: ecological, poverty, communication, education and health care services. Responses were formal and informal strategies from governments, Indigenous organizations and communities. A lack of ethnically disaggregated health data and a gender lens are constraining our knowledge, which is clustered around a limited number of Indigenous peoples in mostly high-income countries. Many Indigenous peoples have autonomously implemented their own coping strategies while government responses have been largely reactive and inadequate. To ‘build back better’ we must address these knowledge gaps.
Investigating atmospheric nitrate sources and formation pathways between heating and non-heating seasons in urban North China
Authors: Yan Xiao , Hu Beibei , Li Yilan , Shi Guitao
Published: February 2023

In urban North China, nitrate (

NO

3
−

) is a primary contributor to haze formation. So far, the production processes and source apportionments of atmospheric

NO

3
−

during the heating season (i.e. the wintertime) have not yet been well understood. This study determined δ15N–

NO

3
−

, δ18O–

NO

3
−

, and Δ17O–

NO

3
−

of aerosol samples to compare the potential sources and formation pathways of atmospheric

NO

3
−

during heating (November to March) and non-heating (April to May) seasons. Combining stable isotope composition with the MixSIAR model based on Δ17O–

NO

3
−

showed that NO3 + DMS/HC (dimethyl sulfate/hydrocarbon) pathway was the dominant process of atmospheric nitrate formation during the heating season (mean = 52.88 ± 16.11%). During the non-heating season, the contributions of NO3 + DMS/HC (mean = 37.89 ± 13.57%) and N2O5 + H2O (mean = 35.24 ± 3.75%) pathways were comparable. We found that Δ17O–

NO

3
−

was negatively correlated with wind speed and positively correlated with relative humidity during the heating season, possibly associated with the sources and production of atmospheric

NO

3
−

. In specific, in a dust storm event, the very low Δ17O–

NO

3
−

is likely associated with particles from land surface. Under the premise of considering 15N fractionation, the constraint-based on δ15N–

NO

3
−

illustrated that coal combustion was the major source of NO
x
emission during the heating season, and the relative contribution of coal combustion decreased rapidly from the heating season (mean = 42.56 ± 15.50%) to the non-heating season (mean = 21.86 ± 4.91%). Conversely, the proportion of NOx emitted by soil microbes rose significantly from the heating (mean = 9.67 ± 5.99%) to non-heating season (mean = 24.02 ± 11.65%). This study revealed differences in the sources and formation processes of atmospheric

NO

3
−

during the heating and non-heating seasons, which are of significance to atmospheric nitrogen oxide/nitrate pollution mitigation.
On the asymptotic Plateau problem in hyperbolic space
Authors: Lu Siyuan
Published: February 2023

In this paper, we solve the asymptotic Plateau problem in hyperbolic space for constant

σ

n
−
1

\sigma _{n-1}

curvature, i.e. the existence of a complete hypersurface in

H

n
+
1

\mathbb {H}^{n+1}

satisfying

σ

n
−
1

(
κ
)
=
σ
∈
(
0
,
n
)

\sigma _{n-1}(\kappa )=\sigma \in (0,n)

with a prescribed asymptotic boundary

Γ
\Gamma

. The key ingredient is the curvature estimates. Previously, this was only known for

σ
0

>
σ
>
n

\sigma _0>\sigma >n

, where

σ
0

\sigma _0

is a positive constant.
Removal From Grandmother’s.
Authors: Douglass Frederick
Published: February 2023

Author’s early home — Its charms — Author’s ignorance of ‘old master’ — His gradual perception of the truth concerning him — His relations to Col. Edward Lloyd — Author’s removal to ‘old master’s’ home — His journey thence — His separation from his grandmother — His grief.
Troubles of Childhood.
Authors: Douglass Frederick
Published: February 2023

Col. Lloyd’s plantation — Aunt Katy — Her cruelty and ill-nature — Capt. Anthony’s partiality to Aunt Katy — Allowance of food — Author’s hunger — Unexpected rescue by his mother — The reproof of Aunt Katy — Sleep — A slave-mother’s love — Author’s inheritance — His mother’s acquirements — Her death.
A Slaveholder’s Character.
Authors: Douglass Frederick
Published: February 2023

Increasing acquaintance with old Master — Evils of unresisted passion — Apparent tenderness — A man of trouble — Custom of muttering to himself — Brutal outrage — A drunken overseer — Slaveholder’s impatience — Wisdom of appeal — A base and selfish attempt to break up a courtship.
A Child’s Reasoning.
Authors: Douglass Frederick
Published: February 2023

The author’s early reflections on Slavery — Aunt Jennie and Uncle Noah — Presentiment of one day becoming a freeman — Conflict between an overseer and a slave woman — Advantage of resistance — Death of an overseer — Col. Lloyd’s plantation home — Monthly distribution of food — Singing of Slaves — An explanation — The slaves’ food and clothing — Naked children — Life in the quarter — Sleeping-places — not...
Characteristics of Overseers.
Authors: Douglass Frederick
Published: February 2023

Austin Gore — Sketch of his character — Overseers as a class — Their peculiar characteristics — The marked individuality of Austin Gore — His sense of duty — Murder of poor Denby — Sensation — How Gore made his peace with Col. Lloyd — Other horrible murders — No laws for the protection of slaves possible of being enforced.
Change of Location.
Authors: Douglass Frederick
Published: February 2023

Miss Lucretia — Her kindness — How it was manifested — ‘Ike’ — A battle with him — Miss Lucretia’s balsam — Bread — How it was obtained — Gleams of sunlight amidst the general darkness — Suffering from cold — How we took our meal mush — Preparations for going to Baltimore — Delight at the change — Cousin Tom’s opinion of Baltimore — Arrival there — Kind reception — Mr. and Mrs. Hugh Auld — Their son...
Growing in Knowledge.
Authors: Douglass Frederick
Published: February 2023

My mistress — Her slaveholding duties — Their effects on her originally noble nature — The conflict in her mind — She opposes my learning to read — Too late — She had given me the ‘inch,’ I was resolved to take the ‘ell’ — How I pursued my study to read — My tutors — What progress I made — Slavery — What I heard said...
The Last Flogging.
Authors: Douglass Frederick
Published: February 2023

A sleepless night — Return to Covey’s — Punished by him — The chase defeated — Vengeance postponed — Musings in the woods — The alternative — Deplorable spectacle — Night in the woods — Expected attack — Accosted by Sandy — A friend, not a master — Sandy’s hospitality — The ash-cake supper — Interview with Sandy — His advice — Sandy a conjuror as well as a Christian — The magic root — Strange meeting with Covey — His manner — Covey’s Sunday...
Escape From Slavery.
Authors: Douglass Frederick
Published: February 2023

Reasons for not having revealed the manner of escape — Nothing of romance in the method — Danger — Free papers — Unjust tax — Protection papers — ‘Free trade and Sailors’ rights’ — American eagle — Railroad train — Unobserving conductor — Capt. McGowan — Honest German — Fears — Safe arrival in Philadelphia — Ditto in New York.
Recollections of Old Friends.
Authors: Douglass Frederick
Published: February 2023

Work in Rhode Island — Dorr War — Recollections of old friends — Further labors in Rhode Island and elsewhere in New England.
One Hundred Conventions.
Authors: Douglass Frederick
Published: February 2023

Anti-slavery conventions held in parts of New England, and in some of the Middle and Western States — Mobs — Incidents, etc.
John Brown and Mrs. Stowe.
Authors: Douglass Frederick
Published: February 2023

My first meeting with Capt. John Brown — The Free-Soil movement — Colored Convention — Uncle Tom’s Cabin — Industrial School for colored people — Letter to Mrs. H. B. Stowe.
Increasing Demands of The Slave Power.
Authors: Douglass Frederick
Published: February 2023

Increased demands of slavery — War in Kansas — John Brown’s raid — His capture and execution — My escape to England from United States marshals.
Vast Changes.
Authors: Douglass Frederick
Published: February 2023

Satisfaction and anxiety — New fields of labor opening — Lyceums and colleges soliciting addresses — Literary attractions — Pecuniary gain — Still pleading for human rights — President Andy Johnson — Colored delegation — Their reply to him — National Loyalist Convention, 1866, and its procession — Not wanted — Meeting with an old friend — Joy and surprise — The old master’s welcome, and Miss Amanda’s friendship — Enfranchisement debated and...
A Grand Occasion.
Authors: Douglass Frederick
Published: February 2023

Inauguration of President Garfield — A valuable precedent — An affecting scene — The greed of the office-seekers — Conference with President Garfield — Distrust of the Vice-President.
President Cleveland’s Administration.
Authors: Douglass Frederick
Published: February 2023

Circumstances of Cleveland’s election — Political standing of the District of Columbia — Estimate of Cleveland’s character — Respect for Mr. Cleveland — Decline of strength in the Republican Party — Time of gloom for the colored people — Reason for the defeat of Blaine.
The Supreme Court Decision.
Authors: Douglass Frederick
Published: February 2023

Action of the Supreme Court — Its effect on the colored people — Address at Lincoln Hall.
European Tour.
Authors: Douglass Frederick
Published: February 2023

Revisits Parliament — Changes in Parliament — Recollections of Lord Broughan — Listens to Gladstone — Meeting with old friends.
Minister to HaÏTi.
Authors: Douglass Frederick
Published: February 2023

The Môle St. Nicolas — Social Relations — Sympathy for Haïti — The facts about the Môle St. Nicolas — Conference with the Haïtian Government — Negotiations for the Môle St. Nicolas — Close of the interview.
Amour Dure
Authors: Lee Vernon , Worth Aaron
Published: February 2023

PART I

Urbania,* August 20th, 1885. — I had longed, these years and years, to be in Italy, to come face to face with the Past; and was this Italy, was this the Past? I could have cried, yes cried, for disappointment when I...
THE LEGEND OF MADAME KRASINSKA
Authors: Lee Vernon , Worth Aaron
Published: February 2023

It is a necessary part of this story to explain how I have come by it, or rather, how it has chanced to have me for its writer.

I was very much impressed one day by a certain nun of the order calling themselves...
CHAPTER III
Authors: Austen Jane , Mullan John
Published: February 2023

Mr. Woodhouse was fond of society in his own way. He liked very much to have his friends come and see him; and from various united causes, from his long residence at Hartheld, and his good nature, from his fortune, his house, and his...
CHAPTER V
Authors: Austen Jane , Mullan John
Published: February 2023

‘I do not know what your opinion may be, Mrs. Weston,’ said Mr. Knightley, ‘of this great intimacy between Emma and Harriet Smith, but I think it a bad thing.’

‘A bad thing! Do you really think it a bad thing? — why so?’

‘I think they...
CHAPTER VI
Authors: Austen Jane , Mullan John
Published: February 2023

Emma could not feel a doubt of having given Harriet’s fancy a proper direction and raised the gratitude of her young vanity to a very good purpose, for she found her decidedly more sensible than before of Mr. Elton’s being a remarkably handsome man,...