期刊文献+
共找到893篇文章
< 1 2 45 >
每页显示 20 50 100
Selective Technology Importation and the Convergence in the Late Qing Dynasty: Evidence from Wired Telegraph
1
作者 Jiao Yinyi Cai Meng 《China Economist》 2024年第5期117-136,共20页
Using the adoption and expansion of wired telegraph in China during the late 19^(th) century,this paper investigates the effect of cost reductions for knowledge exchange on China’s industrial growth before the outbre... Using the adoption and expansion of wired telegraph in China during the late 19^(th) century,this paper investigates the effect of cost reductions for knowledge exchange on China’s industrial growth before the outbreak of the War of Resistance Against Japanese Aggression(1931-1945),thus testing Baldwin’s theory of“the Great Convergence”in which developing countries are empowered by information and communication technologies.Based on panel data of 1858-1937,we found that wired telegraph access had a significantly positive effect,as well as a long-term growth effect,on the entry of industrial enterprises.Our mechanism analysis indicates that wired telegraph access accelerated early-stage industrialization in localities by encouraging market integration,human capital accumulation,and auxiliary commercial organizations.Only a few countries firmly asserted their telegraph sovereignty and set up their own workforce educational system during telegraph adoption.This explains why the Great Convergence arising from technology importation only occurred in a small number of countries.Our findings contribute to understanding the source of China’s modern industrial progress,as well as why global inequities remain. 展开更多
关键词 wired telegraph entry of industrial enterprises the Great Convergence human capital
在线阅读 下载PDF
Improvement of Wired Drill Pipe Data Quality via Data Validation and Reconciliation 被引量:2
2
作者 Dan Sui Olha Sukhoboka Bernt Sigve Aadn?y 《International Journal of Automation and computing》 EI CSCD 2018年第5期625-636,共12页
Wired drill pipe(WDP)technology is one of the most promising data acquisition technologies in today s oil and gas industry.For the first time it allows sensors to be positioned along the drill string which enables c... Wired drill pipe(WDP)technology is one of the most promising data acquisition technologies in today s oil and gas industry.For the first time it allows sensors to be positioned along the drill string which enables collecting and transmitting valuable data not only from the bottom hole assembly(BHA),but also along the entire length of the wellbore to the drill floor.The technology has received industry acceptance as a viable alternative to the typical logging while drilling(LWD)method.Recently more and more WDP applications can be found in the challenging drilling environments around the world,leading to many innovations to the industry.Nevertheless most of the data acquired from WDP can be noisy and in some circumstances of very poor quality.Diverse factors contribute to the poor data quality.Most common sources include mis-calibrated sensors,sensor drifting,errors during data transmission,or some abnormal conditions in the well,etc.The challenge of improving the data quality has attracted more and more focus from many researchers during the past decade.This paper has proposed a promising solution to address such challenge by making corrections of the raw WDP data and estimating unmeasurable parameters to reveal downhole behaviors.An advanced data processing method,data validation and reconciliation(DVR)has been employed,which makes use of the redundant data from multiple WDP sensors to filter/remove the noise from the measurements and ensures the coherence of all sensors and models.Moreover it has the ability to distinguish the accurate measurements from the inaccurate ones.In addition,the data with improved quality can be used for estimating some crucial parameters in the drilling process which are unmeasurable in the first place,hence provide better model calibrations for integrated well planning and realtime operations. 展开更多
关键词 Data quality wired drill pipe (WDP) data validation and reconciliation (DVR) DRILLING models.
原文传递
Sealing of Ejection Hole at the Bottom of Projectile for Wired Transmission System of Penetration Data
3
作者 Huiming Ma Ya Zhang Shizhong Li 《Journal of Beijing Institute of Technology》 EI CAS 2017年第3期318-323,共6页
It is difficult to find the projectile when people want to get the penetration data in a hard recovery method,so a recovery system of penetration data is designed based on an ejection mode from the projectile base and... It is difficult to find the projectile when people want to get the penetration data in a hard recovery method,so a recovery system of penetration data is designed based on an ejection mode from the projectile base and a method of wired transmission,at the same time,the system was sealed with a designed sealing device,the working principle of which was introduced.Using Fluent as the simulation platform,the transient pressure of seal cavity was simulated based on the change of chamber pressure,and steady-state pressure of seal clearance and seal cavity were simulated based on the maximum chamber pressure.The sealing performance was tested by apressure test system.The results of simulation and experiment show that the maximum pressure of seal cavity is 139.4kPa when the maximum chamber pressure is 242.9MPa and the maximum temperature of gunpowder explosive gas is2 166.5K,so the sealing performance can be assured.The sealing device can be taken as a reference in sealing research on gunpowder gas at the bottom of projection. 展开更多
关键词 SEALING projectile base PENETRATION data recovery wired transmission Fluent
在线阅读 下载PDF
SEM-Based Method for Performance Evaluation of Wired LANs
4
作者 Qi Xiaogang Xu Chunxia Liu Lifang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2018年第3期403-412,共10页
For wired local area networks(LANs),their effectiveness and invulnerability are very critical.It is extraordinarily significant to evaluate the network performance effectively in the design of a reasonable network top... For wired local area networks(LANs),their effectiveness and invulnerability are very critical.It is extraordinarily significant to evaluate the network performance effectively in the design of a reasonable network topology and the performance improvement of the networks.However,there are many factors affecting the performance of the networks,and the relation among them is also complicated.How to evaluate the performance of the wired LANs more accurately has been a heavy challenge in the network research.In order to solve the problem,this paper presents a performance evaluation method that evaluates the effectiveness and invulnerability of the wired LANs.Compared to traditional statistical methods,it has the distinct advantage of being able to handle several dependent variables simultaneously and tolerates the measurement errors among these independent variables and dependent variables.Finally,the rationality and validity of this method are verified by the extensive experimental simulation. 展开更多
关键词 wired local area networks(LANs) structural equation model(SEM) node contribution performance prediction network topology
在线阅读 下载PDF
A DYNAMIC TRANSMISSION CAPACITY ALLOCATION SCHEME FOR WIRED/WIRELESS ATM NETWORKS
5
作者 Wang Jie Li Lemin(National Key Lab of Broadband Optical Fiber Transmission and Communication Networks, University of ELectronic Science & Technology of China, Chengdu 610054) 《Journal of Electronics(China)》 2000年第3期225-233,共9页
The previous research on administration of the transmission capacity in the wired/ wireless ATM networks only focuses on wired part or wireless part. There are very few people do the work extending to the links associ... The previous research on administration of the transmission capacity in the wired/ wireless ATM networks only focuses on wired part or wireless part. There are very few people do the work extending to the links associating with handoff in the whole network. This paper develops the algorithms of transmission capacity administration on the link connecting the base station and base station controller (including the air interface of the base station) and the VPs among the base station controllers in the wired/ wireless ATM networks, which adapt to the traffic state of each service in every cellular cell to allocate (provision) transmission capacity and to reserve handoff guard capacity on these links, respectively. By simulating and analyzing the performance of the algorithm, it is found that it does well for the multimedia communication in which the transmission capacity requirement of each service may be widely different, so that the network bandwidth resource can be used efficiently. 展开更多
关键词 wired/wireless ATM networks Capacity ALLOCATION HANDOFF Service classification
在线阅读 下载PDF
Brief Discussion on the Application of Fiber-optic Wired Communication Technology in Modern Communication Engineering
6
作者 ZHANGZhen 《外文科技期刊数据库(文摘版)工程技术》 2022年第2期033-037,共5页
Communication engineering is often referred to as "information engineering", which itself is an important branch of electronic engineering, in the environment of the information age, communication engineerin... Communication engineering is often referred to as "information engineering", which itself is an important branch of electronic engineering, in the environment of the information age, communication engineering as an important medium of information transmission, its construction has practical and far-reaching positive significance for the development of the country and society. Based on the importance of communication, improve the quality of data transmission speed of communication engineering, obviously is a path in the field of communication in the future and most important, and the application of optical fiber cable communication technology can effectively realize the data transmission speed and quality in communication engineering, information interaction under the information age speed and productivity are directly related. Therefore, the research on the application of fiber optic wired communication technology can lay a solid information foundation for the future development of our country to a certain extent, and it will have a huge impact in the field of information engineering and other fields. 展开更多
关键词 optical fiber wired communication communication engineering application
原文传递
Sensing Thermal Underground Transients of Buried Wired Structures 被引量:1
7
作者 Ira Kohlberg William Szymczak Camille D'Annunzio 《Journal of Earth Science and Engineering》 2013年第11期730-743,共14页
Mathematical investigations of the dynamic response of buried systems to thermal and/or electromagnetic stimulation continues to be of great importance. The size of such systems can range from the microelectronic scal... Mathematical investigations of the dynamic response of buried systems to thermal and/or electromagnetic stimulation continues to be of great importance. The size of such systems can range from the microelectronic scale to large underground structures. Stimulation can occur from unwanted electromagnetic signals entering the buried system, and for assessing the operating state of a buried system that is not usually physically accessible. In both cases detecting damage or status can be accomplished by examining the time dependence of the resultant surface temperature. This study shows how to determine surface temperature for a hypothetical thermal-plus-systems using a combination of Fourier-space and Laplace-time transform techniques. The hypothetical model can be generalized from scaling the relevant relationships. 展开更多
关键词 Electromagnetic heating buried wire surface temperature Laplace transform.
在线阅读 下载PDF
Battery Charging Method for Electric Vehicles:From Wired to On-Road Wireless Charging 被引量:2
8
作者 Kishore Naik Mude 《Chinese Journal of Electrical Engineering》 CSCD 2018年第4期1-15,共15页
Recent fossil fuel shortages and global warming related problems have caused a substantial shift from internal combustion engine vehicles towards EVs.This paper explores the thorough review of battery charging infrast... Recent fossil fuel shortages and global warming related problems have caused a substantial shift from internal combustion engine vehicles towards EVs.This paper explores the thorough review of battery charging infrastructure from wired connection to on-road wireless charging for an EV.The initial part of the paper deals with the wired charging and its power electronics infrastructure.The later portion deals with the wireless charging where both static and On-Road types are discussed.Furthermore,various aspects of wireless power transfer are also discussed.The Market scenario and future growth prospects are reviewed and presented in last section of the paper. 展开更多
关键词 wired charging static WPT on-road WPT
原文传递
Macro-and Microphysical Characteristics of Freezing Rain and Their Impacts on Wire Icing Mechanisms in the Southwestern Mountainous Areas of China 被引量:1
9
作者 Yue ZHOU Chunsong LU +3 位作者 Jingjing Lü Xiaoyun SUN Lingli ZHOU Hui XIAO 《Advances in Atmospheric Sciences》 2025年第8期1620-1635,共16页
Based on comprehensive observations of 20 wire icing events during winter from 2019 to 2021,we investigated the characteristics of the icing properties,the atmospheric boundary layer structure,the raindrop size distri... Based on comprehensive observations of 20 wire icing events during winter from 2019 to 2021,we investigated the characteristics of the icing properties,the atmospheric boundary layer structure,the raindrop size distribution,and their associated effects on the ice accretion mechanism in the mountainous region of Southwest China.The maximum ice weight was positively correlated with the duration of ice accretion in the mountainous area.The duration of precipitation accounted for less than 20%of the icing period in the mountainous area,with solid-phase hydrometeors being predominant.Icing events,dominated by freezing rain(FR)and mixed rain–graupel(more than 70%),were characterized by glaze or highdensity mixed icing.The relationship between the melting energy and refreezing energy reflected the distribution characteristics of the proportion of FR under mixed-phase precipitation.The intensity of the warm layer and the dominant precipitation phase significantly affected the variations in the microphysical properties of FR.The melting of large dry snowflakes significantly contributed to FR in the mountainous areas,resulting in smaller generalized intercepts and larger mass-weighted mean diameters in the presence of a stronger warm layer.Under a weaker warm layer,the value of the massweighted mean diameter was significantly smaller because of the inability of large solid particles to melt.Finally,FR in the mountainous area dominated the ice weight during the rapid ice accumulation period.A numerical simulation of FR icing on wires effectively revealed the evolution of disaster-causing icing in mountainous areas. 展开更多
关键词 freezing rain wire icing macro-and microphysical characteristics mountainous area
在线阅读 下载PDF
Robust interface and excellent as-built mechanical properties of Ti–6Al–4V fabricated through laser-aided additive manufacturing with powder and wire
10
作者 Fei Weng Guijun Bi +5 位作者 Youxiang Chew Shang Sui Chaolin Tan Zhenglin Du Jinlong Su Fern Lan Ng 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第1期154-168,共15页
The feasibility of manufacturing Ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully ci... The feasibility of manufacturing Ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully circumvent defects in Ti-6Al-4V deposits for LAAM_(p) and LAAM_(w),respectively.With the optimized process parameters,robust interfaces were achieved between powder/wire deposits and the forged substrate,as well as between powder and wire deposits.Microstructure characterization results revealed the epitaxial prior β grains in the deposited Ti-6Al-4V,wherein the powder deposit was dominated by a finerα′microstructure and the wire deposit was characterized by lamellar α phases.The mechanisms of microstructure formation and correlation with mechanical behavior were analyzed and discussed.The mechanical properties of the interfacial samples can meet the requirements of the relevant Aerospace Material Specifications(AMS 6932)even without post heat treatment.No fracture occurred within the interfacial area,further suggesting the robust interface.The findings of this study highlighted the feasibility of combining LAAM_(p) and LAAM_(w) in the direct manufacturing of Ti-6Al-4V parts in accordance with the required dimensional resolution and deposition rate,together with sound strength and ductility balance in the as-built condition. 展开更多
关键词 laser-aided additive manufacturing powder deposition wire deposition interfacial characteristic mechanical behavior
在线阅读 下载PDF
Formulation and Characterization of Functionally Graded Materials Comprising SS316L and Inconel625 for Enhanced Performance in High-Pressure Pneumatic Tools
11
作者 Sainath Krishna Mani Iyer Karuppasamy Ramasamy Prabagaran Subramaniam 《稀有金属材料与工程》 北大核心 2025年第2期363-376,共14页
SS316L alloy coupled with Inconel625 alloy were combined with Ti6Al4V or Inconel718 alloy through wire arc additive manufacturing technique to manufacture functionally graded materials(FGMs).Two FGMs,namely 60%SS316L+... SS316L alloy coupled with Inconel625 alloy were combined with Ti6Al4V or Inconel718 alloy through wire arc additive manufacturing technique to manufacture functionally graded materials(FGMs).Two FGMs,namely 60%SS316L+20%Inconel625+20%Ti6Al4V composite and 60%SS316L+20%Inconel625+20%Inconel718 composite,were prepared.The tensile strength,elongation,yield strength,hardness,cross section area of the parent material,and composition were analysed.Results illustrate that the 60%SS316L+20%Inconel625+20%Inconel718 composite has better mechanical properties than 60%SS316L+20%Inconel625+20%Ti6Al4V composite,and the comprehensive properties of 60%SS316L+20%Inconel 625+20%Ti6Al4V composite are better than those of the parent material SS316L.Hence,the composite of 60%SS316L+20%Inconel625+20%Inconel718 is optimal.Due to its high strength,the 60%SS316L+20%Inconel625+20%Inconel718 composite has great application potential in the field of high pressure pneumatic tool and defence tool. 展开更多
关键词 MICROSTRUCTURE tensile strength functionally graded material additive manufacturing Inconel alloy TITANIUM stainless steel wire arc additive manufacturing
原文传递
Exploring the evolution of texture and properties of ultrafine copper wire during high strain drawing process
12
作者 LIU Jin-song ZHOU Yan +3 位作者 WANG Song-wei CHEN Shuai-feng SONG Hong-wu ZHANG Shi-hong 《Journal of Central South University》 2025年第6期1973-1994,共22页
The ultrafine copper wire with a diameter of 18μm is prepared via cold drawing process from the single crystal downcast billet(Φ8 mm),taking a drawing strain to 12.19.In this paper,in-depth investigation of the micr... The ultrafine copper wire with a diameter of 18μm is prepared via cold drawing process from the single crystal downcast billet(Φ8 mm),taking a drawing strain to 12.19.In this paper,in-depth investigation of the microstructure feature,texture evolution,mechanical properties,and electrical conductivity of ultrafine wires ranging fromΦ361μm toΦ18μm is performed.Specially,the microstructure feature and texture type covering the whole longitudinal section of ultrafine wires are elaborately characterized.The results show that the average lamella thickness decreases from 1.63μm to 102 nm during the drawing process.Whereas,inhomogeneous texture evolution across different wire sections was observed.The main texture types of copper wires are comprised of<111>,<001>and<112>orientations.Specifically,the peripheral region is primarily dominated by<111>and<112>,while the central region is dominated by<001>and<111>.As the drawing strain increases,the volume fraction of hard orientation<111>with low Schmid factor increases,where notably higher fraction of<111>is resulted from the consumption of<112>and<001>for the wire ofΦ18μm.For drawn copper wire of 18μm,superior properties are obtained with a tensile strength of 729.8 MPa and an electrical conductivity of 86.9%IACS.Furthermore,it is found that grain strengthening,dislocation strengthening,and texture strengthening are three primary strengthening mechanisms of drawn copper wire,while the dislocation density is the main factor on the reducing of conductivity. 展开更多
关键词 copper wires ultrafine wire DRAWING texture evolution tensile strength
在线阅读 下载PDF
Experimental Study and a Modified Model for Temperature-Recovery Stress of Shape Memory Alloy Wire under Different Temperatures
13
作者 Zhi-Xiang Wei Wen-Wei Wang +2 位作者 Yan-Jie Xue Wu-Tong Zhang Qiu-Di Huang 《Structural Durability & Health Monitoring》 2025年第2期347-364,共18页
To investigate the performance of utilizing the shape memory effect of SMA(Shape Memory Alloy)wire to generate recovery stress,this paper performed single heating recovery stress tests and reciprocating heating-coolin... To investigate the performance of utilizing the shape memory effect of SMA(Shape Memory Alloy)wire to generate recovery stress,this paper performed single heating recovery stress tests and reciprocating heating-cooling recovery stress tests on SMA wire under varying initial strain conditions.The effects of various strains and different energized heating methods on the recovery stress of SMA wires were explored in the single heating tests.The SMA wire was strained from 2%to 8%initially,and two distinct heating approaches were employed:one using a large current interval for rapid heating and one using a small current interval for slower heating.The experimental outcomes reveal that during a single heating cycle,the temperature-recovery stress relationship of SMA wire exhibits three distinct stages:the martensite phase stage,the transition stage from martensite to austenite phase,and the austenite phase stage.Notably,the choice of heating method does not influence the maximum recovery stress value,and the correlation between initial strain and maximum recovery stress is predominantly linear.Moreover,conducting the reciprocating temperature rise and fall performance test is important to better simulate the scenario in practical engineering where multiple recovery stress in SMA wires for structural repair.In this test,two temperature cycling methods were studied:interval rise and fall,as well as direct rise and fall.In the case of utilizing the interval temperature rise and fall method,it was observed that the recovery stress associated with cooling was significantly higher than that corresponding to heating at the same temperature.Furthermore,the recovery stress was lower upon subsequent heating than that measured during the previous heating cycle.Based on the experimental results,a prediction model for the temperature-recovery stress relationship has been proposed to simplify numerical calculations.It is hoped that an approximate temperaturerecovery stress curve can be obtained from the parameters of the SMA wire.The calculated values derived from this model show good alignment with the measured values,indicating its reliability. 展开更多
关键词 SMA wire TEMPERATURE recovery stress modified model phase transition
在线阅读 下载PDF
Mass spectrometry for non-destructive detection of the average diameter of micro copper wires
14
作者 Rui Su Xiaowei Fang +5 位作者 Peng Zeng Yong Qian Xuanzhu Li Huiyu Xing Jiamei Lin Jiaquan Xu 《Chinese Chemical Letters》 2025年第10期474-477,共4页
The performance and price of copper-based micro linear products are determined by the diameter uniformity.How to accurately detect the wire diameter of long-length copper based micro linear products without cutting or... The performance and price of copper-based micro linear products are determined by the diameter uniformity.How to accurately detect the wire diameter of long-length copper based micro linear products without cutting or damage has always been a technical concern for production enterprises.Herein,a novel approach was developed for nondestructive detection of the average diameter at any given segment of a long copper wire by assessing the adsorption capacity of arginine on its surface.The amount of adsorbent on the surface of the copper wire exhibits a positive correlation with the area,which can be detected by extractive electrospray ionization mass spectrometry(EESI-MS)after online elution with ammonia.The experimental results demonstrated that the analysis can be completed within 15 min,with a good linear relationship between copper wires with different diameters and the adsorption capacity of arginine.The linear correlation coefficient R2was 0.995,the relative standard deviation was 1.10%-2.81%,and the detection limit reached 2.5μm(length of segment=4 cm),showing potential applications for facile measurement of the average diameter of various metal wires. 展开更多
关键词 Measurement of diameter Mass spectrometry Non-destructive detection Copper wire Average diameter Measurement of diameter Mass spectrometry Non-destructive detection Copper wire Average diameter
原文传递
Research on Birdcage Buckling in the Armor Wire of A Damaged Umbilical Cable Under Compression and Bending Cyclic Load
15
作者 CHEN Si-yuan DENG Yu +2 位作者 LIANG Xu DENG Xue-jiao WANG Zhen-kui 《China Ocean Engineering》 2025年第1期86-99,共14页
Buckling failure in submarine cables presents a prevalent challenge in ocean engineering.This work aims to explore the buckling behavior of umbilical cables with damaged sheaths subjected to compression and bending cy... Buckling failure in submarine cables presents a prevalent challenge in ocean engineering.This work aims to explore the buckling behavior of umbilical cables with damaged sheaths subjected to compression and bending cyclic loads.A finite element model is devised,incorporating a singular armor wire,a rigid core,and a damaged sheath.To scrutinize the buckling progression and corresponding deformation,axial compression and bending cyclic loads are introduced.The observations reveal that a reduction in axial compression results in a larger number of cycles before buckling ensues and progressively shifts the buckling position toward the extrados and fixed end.Decreasing the bending radius precipitates a reduction in the buckling cycle number and minimizes the deformation in the armor wire.Furthermore,an empirical model is presented to predict the occurrence of birdcage buckling,providing a means to anticipate buckling events and to estimate the requisite number of cycles leading to buckling. 展开更多
关键词 umbilical cable armor wire birdcage buckling bending cycle damaged sheath
在线阅读 下载PDF
A Dynamic Prediction Approach for Wire Icing Thickness under Extreme Weather Conditions Based on WGAN-GP-RTabNet
16
作者 Mingguan Zhao Xinsheng Dong +5 位作者 Yang Yang Meng Li Hongxia Wang Shuyang Ma Rui Zhu Xiaojing Zhu 《Computer Modeling in Engineering & Sciences》 2025年第2期2091-2109,共19页
Ice cover on transmission lines is a significant issue that affects the safe operation of the power system.Accurate calculation of the thickness of wire icing can effectively prevent economic losses caused by ice disa... Ice cover on transmission lines is a significant issue that affects the safe operation of the power system.Accurate calculation of the thickness of wire icing can effectively prevent economic losses caused by ice disasters and reduce the impact of power outages on residents.However,under extreme weather conditions,strong instantaneous wind can cause tension sensors to fail,resulting in significant errors in the calculation of icing thickness in traditional mechanics-based models.In this paper,we propose a dynamic prediction model of wire icing thickness that can adapt to extreme weather environments.The model expands scarce raw data by the Wasserstein Generative Adversarial Network with Gradient Penalty(WGAN-GP)technique,records historical environmental information by a recurrent neural network,and evaluates the ice warning levels by a classifier.At each time point,the model diagnoses whether the current sensor failure is due to icing or strong winds.If it is determined that the wire is covered with ice,the icing thickness will be calculated after the wind-induced tension is removed from the ice-wind coupling tension.Our new model was evaluated using data from the power grid in an area with extreme weather.The results show that the proposed model has significant improvements in accuracy compared with traditional models. 展开更多
关键词 Wire icing thickness instantaneous wind transmission lines WGAN-GP-RTabNet dynamic tension
在线阅读 下载PDF
Mixing behavior and mass transfer of liquid-liquid two-phase flow in an annular microchannel with helical wires
17
作者 Min An Chengxiang Wang +6 位作者 Qing Liu MengyaWang Zhirong Yang Wenpeng Li Guoli Zhou Jingtao Wang Jinli Zhang 《Chinese Journal of Chemical Engineering》 2025年第1期42-56,共15页
Combining the advantages of high efficiency,low-pressure drop,and large throughput,the pore arrayenhanced tube-in-tube microchannel(PA-TMC) is a promising microreactor for industrial applications.However,most of the m... Combining the advantages of high efficiency,low-pressure drop,and large throughput,the pore arrayenhanced tube-in-tube microchannel(PA-TMC) is a promising microreactor for industrial applications.However,most of the mass transfer takes place in the upstream pore region,while the contribution of the downstream annulus is limited.In this work,helical wires were introduced into the annulus by adhering to the outer surface of the inner tube.Mixing behavior and mass transfer of liquid-liquid twophase flow in PA-TMC with different helical wires have been systematically studied by a combination of experiments and volume of fluid(VOF) method.The introduction of helical wires improves the overall volumetric mass transfer coefficient KLa by up to 133% and the mass transfer efficiency E by up to 117%.The simulation results show that the helical wire brings extra phase mixing regions and increases the specific interface area,while accelerating the fluid flow and expanding the area of enhanced turbulent dissipation rate.Influences of helical wires in various configurations are compared by the comprehensive index I concerning the pressure drop and mass transfer performance simultaneously and a new correlation between KLa and specific energy consumption φ is proposed.This research deepens the understanding of the mixing behavior and mass transfer in the PA-TMCs and provides practical experience for the process intensification of microchannel reactors. 展开更多
关键词 Microchannels Helical wires Volume of fluid(VOF) Mass transfer Optimization
在线阅读 下载PDF
Simultaneous enhancement of tensile strength and electrical conductivity of drawn Cu–20 wt.% Fe wire through intermediate annealing
18
作者 Fei Yang Can-hui Wu +7 位作者 Yuan-fang Wang Rui-feng Li Feng-jian Shi Wen-yi Huo Li-ming Dong Jun Zhou Yan-xin Qiao Feng Fang 《Journal of Iron and Steel Research International》 2025年第10期3410-3425,共16页
The deformation of Cu–20 wt.%Fe alloy wires leads to a significant improvement in mechanical properties and a decrease in electrical conductivity.Simultaneous improvements in strength and conductivity were achieved b... The deformation of Cu–20 wt.%Fe alloy wires leads to a significant improvement in mechanical properties and a decrease in electrical conductivity.Simultaneous improvements in strength and conductivity were achieved by intermediate annealing of drawn Cu–20 wt.%Fe wires.As the annealing temperature increased,the strength of Cu–20 wt.%Fe alloy wire decreased monotonically,but the electrical conductivity first increased and then decreased,reaching its peak value after annealing at 500℃.The decrease in strength is related to dislocation recovery and static recrystallization of Cu and Fe phases,and the increase in electrical conductivity mainly results from the aging precipitation of solid solution Fe.After annealing at 500℃,there was no obvious recrystallization of Cu phase,and many of the nano-Fe particles precipitated from Cu matrix.An annealing temperature of 600℃ induced the recrystallization of Cu matrix and an increase in Fe solid solubility,resulting in a decrease in strength and electrical conductivity.Subsequently,the wires annealed at 500℃ were drawn to 2 mm.Compared with those of the continuously drawn Cu–20 wt.%Fe alloy wires,the deformation ability,strength,and electrical conductivity of Cu–20 wt.%Fe alloy wires subjected to intermediate annealing treatment are significantly greater.This is mainly related to the sufficient precipitation of Fe in Cu matrix and the strengthening of refined Fe fibers parallel to the drawing direction. 展开更多
关键词 Cu-Fe alloy wire Drawing deformation Intermediate annealing Electrical conductivity Mechanical property
原文传递
A novel wire arc additive and subtractive hybrid manufacturing process optimization method
19
作者 GUO Yiming ZHANG Wanyuan +2 位作者 XIAO Mingkun SONG Shida ZHANG Xiaoyong 《Journal of Southeast University(English Edition)》 2025年第1期109-117,共9页
A reasonable process plan is an important basis for implementing wire arc additive and subtractive hybrid manufacturing(ASHM),and a new optimization method is proposed.Firstly,the target parts and machining tools are ... A reasonable process plan is an important basis for implementing wire arc additive and subtractive hybrid manufacturing(ASHM),and a new optimization method is proposed.Firstly,the target parts and machining tools are modeled by level set functions.Secondly,the mathematical model of the additive direction optimization problem is established,and an improved particle swarm optimization algorithm is designed to decide the best additive direction.Then,the two-step strategy is used to plan the hybrid manufacturing alternating sequence.The target parts are directly divided into various processing regions;each processing region is optimized based on manufacturability and manufacturing efficiency,and the optimal hybrid manufacturing alternating sequence is obtained by merging some processing regions.Finally,the method is used to outline the process plan of the designed example model and applied to the actual hybrid manufacturing process of the model.The manufacturing result shows that the method can meet the main considerations in hybrid manufacturing.In addition,the degree of automation of process planning is high,and the dependence on manual intervention is low. 展开更多
关键词 wire arc additive manufacturing hybrid manufacturing process optimization MANUFACTURABILITY
在线阅读 下载PDF
Elevated temperature tensile properties of wire arc additively manufactured 308L austenitic stainless steel
20
作者 A.Rajesh Kannan Yasam Palguna +2 位作者 Hafiz Muhammad Rehan Tariq N.Siva Shanmugam Tea-Sung Jun 《International Journal of Minerals,Metallurgy and Materials》 2025年第9期2164-2176,共13页
Wire arc additive manufacturing(WAAM)presents a promising approach for fabricating medium-to-large austenitic stainless steel components,which are essential in industries like aerospace,pressure vessels,and heat excha... Wire arc additive manufacturing(WAAM)presents a promising approach for fabricating medium-to-large austenitic stainless steel components,which are essential in industries like aerospace,pressure vessels,and heat exchangers.This research examines the mi-crostructural characteristics and tensile behaviour of SS308L manufactured via the gas metal arc welding-based WAAM(WAAM 308L)process.Tensile tests were conducted at room temperature(RT,25℃),300℃,and 600℃in as-built conditions.The microstructure con-sists primarily of austenite grains with retainedδ-ferrite phases distributed within the austenitic matrix.The ferrite fraction,in terms of fer-rite number(FN),ranged between 2.30 and 4.80 along the build direction from top to bottom.The ferrite fraction in the middle region is 3.60 FN.Tensile strength was higher in the horizontal oriented samples(WAAM 308L-H),while ductility was higher in the vertical ones.Tensile results show a gradual reduction in strength with increasing test temperature,in which significant dynamic strain aging(DSA)is observed at 600℃.The variation in serration behavior between the vertical and horizontal specimens may be attributed to microstructural differences arising from the build orientation.The yield strength(YS),ultimate tensile strength(UTS),and elongation(EL)of WAAM 308L at 600℃were(240±10)MPa,(442±16)MPa,and(54±2.00)%,respectively,in the horizontal orientation(WAAM 308L-H),and(248±9)MPa,(412±19)MPa,and(75±2.80)%,respectively,in the vertical orientation(WAAM 308L-V).Fracture surfaces revealed a transition from ductile dimple fracture at RT and 300℃to a mixed ductile-brittle failure with intergranular facets at 600℃.The research explores the applicability and constraints of WAAM-produced 308L stainless steel in high-temperature conditions,offering crucial in-sights for its use in thermally resistant structural and industrial components. 展开更多
关键词 wire arc additive manufacturing austenitic stainless steels microstructure mechanical properties elevated temperatures
在线阅读 下载PDF
上一页 1 2 45 下一页 到第
使用帮助 返回顶部