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基于Twin Builder的110kV油浸式变压器3维磁场降阶模型及损耗分析
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作者 张重远 刘迪程 +2 位作者 高成龙 刘云鹏 刘刚 《高电压技术》 EI CAS CSCD 北大核心 2024年第3期941-951,共11页
为解决3维变压器磁场有限元仿真计算效率低的问题,提出基于本征正交分解法的磁场降阶模型与基于二次多项式的损耗响应面模型。以1台110 kV变压器为算例,首先建立了考虑绕组涡流损耗的变压器磁场仿真模型,通过仿真分析了其在额定工况下... 为解决3维变压器磁场有限元仿真计算效率低的问题,提出基于本征正交分解法的磁场降阶模型与基于二次多项式的损耗响应面模型。以1台110 kV变压器为算例,首先建立了考虑绕组涡流损耗的变压器磁场仿真模型,通过仿真分析了其在额定工况下的磁场及损耗分布;其次,通过仿真试验设计获取了多组工况下的磁场与损耗数据,在Twin Builder中训练得到变压器磁场的各降阶模块;最后,搭建面向数字孪生应用的变压器3维磁场降阶模型,实现了变压器磁场损耗的快速计算与云图分布的可视化。与计算单数据相比,仿真结果考虑了涡流效应的绕组损耗在靠近端部时有明显升高,最大值分别出现在高、低压绕组两端,约为绕组中部损耗的1.3~1.65倍。基于该磁场结果建立的降阶模型在计算效率方面较全阶模型有显著提升,将实际仿真时间缩短至0.76s,可满足数字孪生应用场景下的磁场快速计算需求。 展开更多
关键词 油浸式变压器 数字孪生 twin Builder 本征正交分解 响应面法 降阶模型
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Twin-block在骨性Ⅱ类错[牙合]下颌后缩患儿中的应用
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作者 陈菁菁 王密 +2 位作者 刘芳 乔柱 赵虎 《中国美容医学》 CAS 2024年第9期53-57,共5页
目的:探讨Twin-block在骨性Ⅱ类错[牙合]下颌后缩患儿中的应用效果。方法:选取2019年1月-2021年1月笔者医院接收的84例骨性Ⅱ类错[牙合]下颌后缩患儿设置为研究对象,按随机抽签法分为对照组、研究组,各42例,对照组采用直丝弓矫治器,研... 目的:探讨Twin-block在骨性Ⅱ类错[牙合]下颌后缩患儿中的应用效果。方法:选取2019年1月-2021年1月笔者医院接收的84例骨性Ⅱ类错[牙合]下颌后缩患儿设置为研究对象,按随机抽签法分为对照组、研究组,各42例,对照组采用直丝弓矫治器,研究组采用Twin-block矫治器。比较两组治疗前后咀嚼功能、牙齿咬合力、下颌骨变化、软组织面型变化、上气道矢状径,并统计家属治疗满意度。结果:治疗后,研究组咀嚼功能、牙齿咬合力、下颌骨变化指标、软组织面型变化指标均优于对照组(P<0.05);治疗后,研究组上气道矢状径高于对照组(P<0.05);研究组家属治疗满意度(95.24%)明显高于对照组(73.81%)(P<0.05)。结论:Twin-block应用于骨性Ⅱ类错[牙合]下颌后缩患儿治疗中,能改善咀嚼功能,增强牙齿咬合力,促进下颌骨生长,提高面型美观度,扩大上气道矢状径,利于改善呼吸功能,获得家属对治疗效果的高度评价。 展开更多
关键词 twin-BLOCK 直丝弓矫治器 骨性Ⅱ类错[牙合] 下颌后缩 软组织面型变化 上气道矢状径
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Twin-Block双期矫治与单纯直丝弓矫正技术在早期下颌后缩矫正患儿中的疗效对比
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作者 田华 邓刚 郝天喜 《中国医疗美容》 2024年第1期66-70,共5页
目的探讨Twin-Block双期矫治与单纯直丝弓矫正技术在替牙及恒牙早期错(牙合)畸形矫正患儿中的疗效对比。方法选取我院2020年9月到2023年9月收治的60例恒牙早期错(牙合)畸形患儿作为研究对象,按照治疗方法不同分为观察组与对照组,各组均... 目的探讨Twin-Block双期矫治与单纯直丝弓矫正技术在替牙及恒牙早期错(牙合)畸形矫正患儿中的疗效对比。方法选取我院2020年9月到2023年9月收治的60例恒牙早期错(牙合)畸形患儿作为研究对象,按照治疗方法不同分为观察组与对照组,各组均为30例。所有患儿均采取矫正治疗,对照组患儿采取直丝弓矫正技术进行治疗,观察组患儿采取Twin-Block矫治器及直丝弓矫治技术进行双期治疗。对比两组患儿临床疗效,及矫治时间,治疗前头影测量及关节改建情况,采用口腔锥形束扫描成像进行检测两组患儿关节窝宽径、关节前间隙、关节后间隙、关节上间隙、髁突前后径、髁突高度相关参数表达水平,最后对比两组患儿治疗前后上下齿槽座(ANB)角、下齿槽座(SNB)角、上齿槽座(SNA)角、下颌平面角(Mp-SN)、下颌综合长度(Ar-Po)、下颌升支高度(Ar-Go)、下颌体长(Go-Gn)、上中切牙-SN平面角(U1-SN)、下中切牙-下颌平面角(L1-Mp)、上唇审美平面距(Ls-E)、下唇审美平面距(Li-E)、鼻唇角。结果观察组治疗总有效率96.67%明显高于对照组76.67%(P<0.05);治疗后,观察组矫治时间长于对照组(P<0.05);治疗前,两组患儿关节窝宽径、关节前间隙、关节后间隙、关节上间隙、髁突前后径、髁突高度对比无明显差异(P>0.05),治疗后,两组患儿关节窝宽径对比无明显差异,关节前间隙减小,观察组(1.21±0.28)mm高于对照组,关节后间隙、关节上间隙、髁突前后径、髁突高度均增加,且观察组高于对照组(P<0.05);治疗前,两组患儿ANB角、SNB角、SNA角、Mp-SN、Ar-Po、Ar-Go、Go-Gn、U1-SN、L1-Mp、Ls-E、Li-E、鼻唇角对比无明显差异(P>0.05),治疗后,两组患儿SNB、Mp-SN、Ar-Po、Ar-Go、Go-Gn、鼻唇角均增大,ANB、U1-SN、L1-Mp、Li-E、Ls-E减小,且观察组变化大于对照组(P<0.05)。结论Twin-Block矫治器配合直丝弓矫治技术双期矫治器与单纯直丝弓矫正技术相比治疗替牙及恒牙早期错(牙合)畸形疗效显著,可作为儿童恒牙早期错(牙合)畸形的首选治疗方案。 展开更多
关键词 twin-BLOCK矫治器 直丝弓矫正 恒牙早期 错(牙合)畸形 咀嚼功能
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螺旋扩弓器联合Twin-block矫治器早期矫治在青少年下颌后缩中的应用效果及对气道形态的影响研究
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作者 张静 刘全惠 《中国医学工程》 2024年第2期70-73,共4页
目的探讨螺旋扩弓器联合Twin-block矫治器早期矫治在青少年下颌后缩中的应用效果及对气道形态的影响研究。方法将河南大学赛思口腔医院2021年5月至2022年5月收治的63例青少年下颌后缩患者,根按照随机数字表法分为两组,对照组(32例)、观... 目的探讨螺旋扩弓器联合Twin-block矫治器早期矫治在青少年下颌后缩中的应用效果及对气道形态的影响研究。方法将河南大学赛思口腔医院2021年5月至2022年5月收治的63例青少年下颌后缩患者,根按照随机数字表法分为两组,对照组(32例)、观察组(31例),对照组早期给予Twin-block矫治器治疗,观察组早期给予螺旋扩弓器联合Twin-block矫治器矫治治疗,观察两组牙齿角度相关指标、气道形态指标及舌骨位置变化。结果矫治前,两组上下齿槽座角(ANB)、颅底-下齿槽座角(SNB)、前下中切牙下颌平面(T-MP)、颅底-上齿槽座角(SNA)比较差异无统计学意义(P>0.05),矫治后3个月,观察组ANB、SNB、T-MP、SNA均大于对照组(P<0.05);矫治前,两组后鼻脊-咽顶点距(PNS-R)、软腭后-软腭后咽壁距(SPP-SPPW)、后鼻脊-上咽壁距(PNS-UPW)、会厌骨-下咽壁距(V-LPW)比较差异无统计学意义(P>0.05),矫治后3个月,观察组PNS-R、SPP-SPPW、PNS-UPW、V-LPW均大于对照组(P<0.05);矫治前,两组舌骨-眶耳平面距(H-FH)、舌骨-下颌平面距(H-MP)、舌骨-颈椎前平面距(H-VL)、舌骨-颅底平面距(H-S)比较差异无统计学意义(P>0.05),矫治后3个月,观察组H-FH、H-MP、H-VL、H-S均大于对照组(P<0.05)。结论螺旋扩弓器联合Twin-block矫治器早期矫治可以有效改善青少年下颌后缩患者牙齿角度、气道形态,纠正舌骨的位置,改善通气功能。 展开更多
关键词 早期矫治 下颌后缩 气道形态 螺旋扩弓器 twin-BLOCK矫治器
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Origin of nucleation and growth of extension twins in grains unsuitably oriented for twinning during deformation of Mg-1%Al 被引量:1
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作者 Biaobiao Yang Javier LLorca 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第3期1186-1203,共18页
A large number of anomalous extension twins,with low or even negative twinning Schmid factors,were found to nucleate and grow in a strongly textured Mg-1Al alloy during tensile deformation along the extruded direction... A large number of anomalous extension twins,with low or even negative twinning Schmid factors,were found to nucleate and grow in a strongly textured Mg-1Al alloy during tensile deformation along the extruded direction.The deformation mechanisms responsible for this behaviour were investigated through in-situ electron back-scattered diffraction,grain reference orientation deviation,and slip trace-modified lattice rotation.It was found that anomalous extension twins nucleated mainly at the onset of plastic deformation at or near grain boundary triple junctions.They were associated with the severe strain incompatibility between neighbour grains as a result from the differentbasal slip-induced lattice rotations.Moreover,the anomalous twins were able to grow with the applied strain due to the continuous activation ofbasal slip in different neighbour grains,which enhanced the strain incompatibility.These results reveal the complexity of the deformation mechanisms in Mg alloys at the local level when deformed along hard orientations. 展开更多
关键词 Magnesium Extension twinning In-situ electron back-scattered diffraction basal slip Deformation mechanisms.
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Natural Disaster Risk Monitoring for Immovable Cultural Relics Based on Digital Twin 被引量:1
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作者 LI Bolun DONG Youqiang +2 位作者 QIAO Yunfei HOU Miaole WEN Caihuan 《Journal of Geodesy and Geoinformation Science》 CSCD 2024年第1期90-104,共15页
Natural disaster risk monitoring is an important task for disaster prevention and reduction.In the case of immovable cultural relics,however,the feedback mechanism,risk factors,monitoring logic,and monitoring indicato... Natural disaster risk monitoring is an important task for disaster prevention and reduction.In the case of immovable cultural relics,however,the feedback mechanism,risk factors,monitoring logic,and monitoring indicators of natural disaster risk monitoring are complex.How to achieve intelligent perception and monitoring of natural disaster risk for immovable cultural relics has always been a focus and a challenge for researchers.Based on the analysis of the concepts and issues related to the natural disaster risk of immovable cultural relics,this paper proposes a framework for natural disaster risk monitoring for immovable cultural relics based on the digital twin.This framework focuses on risk monitoring,including the physical entities of natural disaster risk for immovable cultural relics,monitoring indicators,and virtual entity construction.A platform for monitoring the natural disaster risk of immovable cultural relics is proposed.Using the Puzhou Ancient City Site as a test bed,the proposed concept can be used for monitoring the natural disaster risk of immovable cultural relics at different scales. 展开更多
关键词 immovable cultural relics natural disaster risk digital twin risk monitoring
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基于TwinCAT3的一种开源机器人控制系统设计 被引量:1
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作者 黄睿 张新 +2 位作者 朱华炳 张涛 曾亿山 《科学技术与工程》 北大核心 2024年第4期1561-1569,共9页
目前主流工业机器人为封闭式控制结构,存在不开源、二次开发难的问题,因此设计一种基于TwinCAT3(the windows control and automation technology)的跨平台、可移植性好的机器人控制系统架构。该架构包含视觉、运动控制和算法集成与仿... 目前主流工业机器人为封闭式控制结构,存在不开源、二次开发难的问题,因此设计一种基于TwinCAT3(the windows control and automation technology)的跨平台、可移植性好的机器人控制系统架构。该架构包含视觉、运动控制和算法集成与仿真控制模块,采用倍福自动化设备规范(automation device specification,ADS)通信技术和实时工业以太网总线技术(ethernet for control automation technology,EtherCAT),建立以计算机(personal computer,PC)和倍福控制器为EtherCAT主站,控制多组从站执行器的一主多从工作模式。该模式结合离线与在线控制、集成数字孪生技术,完成虚拟样机与物理样机的联动;采用开源可扩展架构,便于视觉算法、智能算法等算法集成。经实验验证,此架构具有拓展性好、实时性强的特点。 展开更多
关键词 twinCAT3 开源机器人 控制系统 视觉 数字孪生
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U型Twin-PBL剪力键极限承载力的数值分析 被引量:1
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作者 李志勇 王银辉 +1 位作者 张乾坤 王松林 《城市道桥与防洪》 2024年第1期209-213,220,M0018,共7页
根据端部承压混凝土可提高Twin-PBL剪力键承载能力的特点,提出一种新型的可用于装配式钢混组合结构的间断式U型Twin-PBL剪力键。通过3组推出试验试件的非线性数值模拟分析,研究了这种新型剪力键的极限承载特点和承载力。结果表明:U型Twi... 根据端部承压混凝土可提高Twin-PBL剪力键承载能力的特点,提出一种新型的可用于装配式钢混组合结构的间断式U型Twin-PBL剪力键。通过3组推出试验试件的非线性数值模拟分析,研究了这种新型剪力键的极限承载特点和承载力。结果表明:U型Twin-PBL剪力键极限承载能力较普通承压型Twin-PBL剪力键有显著提高,且提高主要来源于端部混凝土承压面积增大,所以混凝土强度的提高对该剪力键承载能力影响明显,而孔中混凝土榫和贯穿钢筋两部分对承载力贡献无明显变化,故而通过修正端承压混凝土面积得到了这种剪力键承载力计算公式。研究结果为装配式钢-混凝土组合梁桥的间断式剪力键提供了新的思路。 展开更多
关键词 U型twin-PBL剪力键 钢-混组合结构 数值模拟 极限承载力
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Twinning aspects and their efficient roles in wrought Mg alloys:A comprehensive review
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作者 S.S.A.Shah Manping Liu +5 位作者 Azim Khan Farooq Ahmad M.R.Abdullah Xingquan Zhang Shiwei Xu Zhen Peng 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第6期2201-2230,共30页
Twinning is widely recognized as an effective and cost-efficient method for controlling the microstructure and properties of wrought magnesium(Mg)alloys.Specifically,twins play a crucial role in initiating dynamic rec... Twinning is widely recognized as an effective and cost-efficient method for controlling the microstructure and properties of wrought magnesium(Mg)alloys.Specifically,twins play a crucial role in initiating dynamic recrystallization(DRX),while twin regions experience rapid recrystallization during static recrystallization(SRX).The activation of twinning can lead to changes in lattice orientation,significantly impacting the final texture in Mg alloys.The active roles of twinning are influenced by various factors during the activation process,and the mobility of twin boundaries(TB)can be amplified by stress effects,dislocation interactions,and thermal effects.Conversely,annealing treatments that involve proper segregation or precipitation on TBs serve to stabilize them,restraining their motion.Events such as segregation may also alter the twinning propensity in Magnesium-rare earth(Mg-RE)alloys.While{10–11}contraction twins(CT)and{10–11}-{10–12}double twins(DT)can promote dynamic recrystallization(DRX),they also pose a risk as potential sources of voids and cracks.Additionally,understanding the nucleation and growth mechanisms of twinning is crucial,and these aspects are briefly reviewed in this article.Considering the factors mentioned above,this article summarizes the recent research progress in this field,shedding light on advancements in recent eras. 展开更多
关键词 Mg alloys twinNING RECRYSTALLIZATION TEXTURE Mechanical properties
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Digital twin driven and intelligence enabled content delivery in end-edge-cloud collaborative 5G networks
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作者 Bo Yi Jianhui Lv +2 位作者 Xingwei Wang Lianbo Ma Min Huang 《Digital Communications and Networks》 SCIE CSCD 2024年第2期328-336,共9页
The rapid development of 5G/6G and AI enables an environment of Internet of Everything(IoE)which can support millions of connected mobile devices and applications to operate smoothly at high speed and low delay.Howeve... The rapid development of 5G/6G and AI enables an environment of Internet of Everything(IoE)which can support millions of connected mobile devices and applications to operate smoothly at high speed and low delay.However,these massive devices will lead to explosive traffic growth,which in turn cause great burden for the data transmission and content delivery.This challenge can be eased by sinking some critical content from cloud to edge.In this case,how to determine the critical content,where to sink and how to access the content correctly and efficiently become new challenges.This work focuses on establishing a highly efficient content delivery framework in the IoE environment.In particular,the IoE environment is re-constructed as an end-edge-cloud collaborative system,in which the concept of digital twin is applied to promote the collaboration.Based on the digital asset obtained by digital twin from end users,a content popularity prediction scheme is firstly proposed to decide the critical content by using the Temporal Pattern Attention(TPA)enabled Long Short-Term Memory(LSTM)model.Then,the prediction results are input for the proposed caching scheme to decide where to sink the critical content by using the Reinforce Learning(RL)technology.Finally,a collaborative routing scheme is proposed to determine the way to access the content with the objective of minimizing overhead.The experimental results indicate that the proposed schemes outperform the state-of-the-art benchmarks in terms of the caching hit rate,the average throughput,the successful content delivery rate and the average routing overhead. 展开更多
关键词 Digital twin IoE Content delivery CACHING ROUTING
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Digital Twin Modeling Enabled Machine Tool Intelligence:A Review
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作者 Lei Zhang Jianhua Liu Cunbo Zhuang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第2期29-54,共26页
Machine tools,often referred to as the“mother machines”of the manufacturing industry,are crucial in developing smart manufacturing and are increasingly becoming more intelligent.Digital twin technology can promote m... Machine tools,often referred to as the“mother machines”of the manufacturing industry,are crucial in developing smart manufacturing and are increasingly becoming more intelligent.Digital twin technology can promote machine tool intelligence and has attracted considerable research interest.However,there is a lack of clear and systematic analyses on how the digital twin technology enables machine tool intelligence.Herein,digital twin modeling was identified as an enabling technology for machine tool intelligence based on a comparative study of the characteristics of machine tool intelligence and digital twin.The review then delves into state-of-the-art digital twin modelingenabled machine tool intelligence,examining it from the aspects of data-based modeling and mechanism-data dual-driven modeling.Additionally,it highlights three bottleneck issues facing the field.Considering these problems,the architecture of a digital twin machine tool(DTMT)is proposed,and three key technologies are expounded in detail:Data perception and fusion technology,mechanism-data-knowledge hybrid-driven digital twin modeling and virtual-real synchronization technology,and dynamic optimization and collaborative control technology for multilevel parameters.Finally,future research directions for the DTMT are discussed.This work can provide a foundation basis for the research and implementation of digital-twin modeling-enabled machine tool intelligence,making it significant for developing intelligent machine tools. 展开更多
关键词 Machine tool Digital twin Smart manufacturing SYNCHRONIZATION
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A survey on blockchain-enabled federated learning and its prospects with digital twin
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作者 Kangde Liu Zheng Yan +2 位作者 Xueqin Liang Raimo Kantola Chuangyue Hu 《Digital Communications and Networks》 SCIE CSCD 2024年第2期248-264,共17页
Digital Twin(DT)supports real time analysis and provides a reliable simulation platform in the Internet of Things(IoT).The creation and application of DT hinges on amounts of data,which poses pressure on the applicati... Digital Twin(DT)supports real time analysis and provides a reliable simulation platform in the Internet of Things(IoT).The creation and application of DT hinges on amounts of data,which poses pressure on the application of Artificial Intelligence(AI)for DT descriptions and intelligent decision-making.Federated Learning(FL)is a cutting-edge technology that enables geographically dispersed devices to collaboratively train a shared global model locally rather than relying on a data center to perform model training.Therefore,DT can benefit by combining with FL,successfully solving the"data island"problem in traditional AI.However,FL still faces serious challenges,such as enduring single-point failures,suffering from poison attacks,lacking effective incentive mechanisms.Before the successful deployment of DT,we should tackle the issues caused by FL.Researchers from industry and academia have recognized the potential of introducing Blockchain Technology(BT)into FL to overcome the challenges faced by FL,where BT acting as a distributed and immutable ledger,can store data in a secure,traceable,and trusted manner.However,to the best of our knowledge,a comprehensive literature review on this topic is still missing.In this paper,we review existing works about blockchain-enabled FL and visualize their prospects with DT.To this end,we first propose evaluation requirements with respect to security,faulttolerance,fairness,efficiency,cost-saving,profitability,and support for heterogeneity.Then,we classify existing literature according to the functionalities of BT in FL and analyze their advantages and disadvantages based on the proposed evaluation requirements.Finally,we discuss open problems in the existing literature and the future of DT supported by blockchain-enabled FL,based on which we further propose some directions for future research. 展开更多
关键词 Digital twin Artificial intelligence Federated learning Blockchain
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Numerical study on the cavity dynamics for vertical water entries of twin spheres
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作者 Xu Wang Xujian Lyu +1 位作者 Ruisheng Sun Dongdong Tang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期459-472,共14页
In this study, a three dimensional(3D) numerical model of six-degrees-of-freedom(6DOF) is applied to simulate the water entries of twin spheres side-by-side at different lateral distances and time intervals.The turbul... In this study, a three dimensional(3D) numerical model of six-degrees-of-freedom(6DOF) is applied to simulate the water entries of twin spheres side-by-side at different lateral distances and time intervals.The turbulence structure is described using the shear-stress transport k-ω(SST k-ω) model, and the volume of fluid(VOF) method is used to track the complex air-liquid interface. The motion of spheres during water entry is simulated using an independent overset grid. The numerical model is verified by comparing the cavity evolution results from simulations and experiments. Numerical results reveal that the time interval between the twin water entries evidently affects cavity expansion and contraction behaviors in the radial direction. However, this influence is significantly weakened by increasing the lateral distance between the two spheres. In synchronous water entries, pressure is reduced on the midline of two cavities during surface closure, which is directly related to the cavity volume. The evolution of vortexes inside the two cavities is analyzed using a velocity vector field, which is affected by the lateral distance and time interval of water entries. 展开更多
关键词 twin water entries Side-by-side CAVITY Numerical simulation
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安氏Ⅱ类错[牙合]畸形佩戴Twin-block矫治器时上颌骨的应力分布
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作者 李帅 刘桦 +3 位作者 商永慧 刘义琮 赵启航 刘文 《中国组织工程研究》 CAS 北大核心 2025年第5期881-887,共7页
背景:Twin-block矫治器常用于安氏Ⅱ类错[牙合]畸形的矫治,其刺激下颌骨生长的作用机制已得到许多研究证实,但对上颌骨生长的影响尚不清楚。目的:通过有限元法分析安氏Ⅱ类错[牙合]畸形患者佩戴Twin-block矫治器时上颌骨复合体、周围骨... 背景:Twin-block矫治器常用于安氏Ⅱ类错[牙合]畸形的矫治,其刺激下颌骨生长的作用机制已得到许多研究证实,但对上颌骨生长的影响尚不清楚。目的:通过有限元法分析安氏Ⅱ类错[牙合]畸形患者佩戴Twin-block矫治器时上颌骨复合体、周围骨缝及上颌牙列的应力分布。方法:选择在山东省康复大学青岛医院/青岛市市立医院口腔正畸科进行正畸治疗的安氏Ⅱ类错[牙合]畸形患者1例,测量患者佩戴Twin-block矫治器时的咬合力数据,采集其锥形束CT数据,建立包含上颌骨复合体、周边各骨缝、Twin-block矫治器及上颌牙列在内的有限元模型,通过ABAQUS软件模拟患者戴入Twin-block时上颌骨、骨缝及上颌牙列的应力分布与位移。结果与结论:①上颌前牙受到的等效应力明显小于后牙,两侧牙齿的最大等效应力分别为4.7975 MPa和8.7161 MPa,均位于第一前磨牙处;最大位移呈现在两侧上颌切牙处,分别为0.0805 mm和0.0810 mm;②骨缝的最大等效应力为1.284 MPa,主要集中在两侧翼腭缝及额颌缝,其余骨缝受力情况几乎无差异;骨缝的最大位移为0.07 mm,其中翼腭缝的位移量最大,其次是额颌缝;③上颌骨复合体受到的最大等效应力为27.18 MPa,主要集中在上颌骨前面梨状孔两侧、鼻额缝周边及颚骨后部翼腭缝附近;上颌骨的最大位移值为0.07 mm,主要集中于上颌牙槽骨;④结果显示,咬合力通过Twin-block矫治器作用于上颌骨复合体,导致上颌骨顺时针旋转、牙合平面变陡,应采取相应措施补偿这种趋势,例如建牙合过程中考虑上颌磨牙伸长、下颌磨牙压低,不仅能够将牙合平面整平,同时有利于下颌前伸,这将进一步提高Ⅱ类错[牙合]正畸治疗效果。 展开更多
关键词 错牙合畸形 组织构建 骨组织工程 twin-BLOCK矫治器 功能矫治 有限元分析
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Mechanical Behavior and Microstructure Evolution during Tensile Deformation of Twinning Induced Plasticity Steel Processed by Warm Forgings
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作者 王文 ZHAO Modi +2 位作者 WANG Xingfu 汪聃 韩福生 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第2期417-424,共8页
The mechanical behavior and microstructural evolution of an Fe-30Mn-3Al-3Si twinninginduced plasticity(TWIP)steel processed using warm forging was investigated.It is found that steel processed via warm forging improve... The mechanical behavior and microstructural evolution of an Fe-30Mn-3Al-3Si twinninginduced plasticity(TWIP)steel processed using warm forging was investigated.It is found that steel processed via warm forging improves comprehensive mechanical properties compared to the TWIP steel processed via cold rolling,with a high tensile strength(R_(m))of 793 MPa,a yield strength(R_(P))of 682 MPa,an extremely large R_(P)/R_(m)ratio as high as 0.86 as well as an excellent elongation rate of 46.8%.The microstructure observation demonstrates that steel processed by warm forging consists of large and elongated grains together with fine,equiaxed grains.Complicated micro-defect configurations were also observed within the steel,including dense dislocation networks and a few coarse deformation twins.As the plastic deformation proceeds,the densities of dislocations and deformation twins significantly increase.Moreover,a great number of slip lines could be observed in the elongated grains.These findings reveal that a much more dramatic interaction between microstructural defect and dislocations glide takes place in the forging sample,wherein the fine and equiaxed grains propagated dislocations more rapidly,together with initial defect configurations,are responsible for enhanced strength properties.Meanwhile,larger,elongated grains with more prevalently activated deformation twins result in high plasticity. 展开更多
关键词 TWIP steel twinNING mechanical property deformation mechanism MICROSTRUCTURE
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Analyzing topics in social media for improving digital twinning based product development
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作者 Wenyi Tang Ling Tian +1 位作者 Xu Zheng Ke Yan 《Digital Communications and Networks》 SCIE CSCD 2024年第2期273-281,共9页
Digital twinning enables manufacturers to create digital representations of physical entities,thus implementing virtual simulations for product development.Previous efforts of digital twinning neglect the decisive con... Digital twinning enables manufacturers to create digital representations of physical entities,thus implementing virtual simulations for product development.Previous efforts of digital twinning neglect the decisive consumer feedback in product development stages,failing to cover the gap between physical and digital spaces.This work mines real-world consumer feedbacks through social media topics,which is significant to product development.We specifically analyze the prevalent time of a product topic,giving an insight into both consumer attention and the widely-discussed time of a product.The primary body of current studies regards the prevalent time prediction as an accompanying task or assumes the existence of a preset distribution.Therefore,these proposed solutions are either biased in focused objectives and underlying patterns or weak in the capability of generalization towards diverse topics.To this end,this work combines deep learning and survival analysis to predict the prevalent time of topics.We propose a specialized deep survival model which consists of two modules.The first module enriches input covariates by incorporating latent features of the time-varying text,and the second module fully captures the temporal pattern of a rumor by a recurrent network structure.Moreover,a specific loss function different from regular survival models is proposed to achieve a more reasonable prediction.Extensive experiments on real-world datasets demonstrate that our model significantly outperforms the state-of-the-art methods. 展开更多
关键词 Digital twinning Product development Topic analysis Social media
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Temperature effect on nanotwinned Ni under nanoindentation using molecular dynamic simulation
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作者 何茜 徐子翼 倪玉山 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期603-612,共10页
Temperature effect on atomic deformation of nanotwinned Ni (nt-Ni) under localized nanoindentation is investigated in comparison with nanocrystalline Ni (nc-Ni) through molecular simulation.The nt-Ni exhibits enhanced... Temperature effect on atomic deformation of nanotwinned Ni (nt-Ni) under localized nanoindentation is investigated in comparison with nanocrystalline Ni (nc-Ni) through molecular simulation.The nt-Ni exhibits enhanced critical load and hardness compared to nc-Ni,where perfect,stair-rod and Shockley dislocations are activated at (111),(111) and (111) slip planes in nt-Ni compared to only SSockley dislocation nucleation at (111) and (111) slip planes of nc-Ni.The nt-Ni exhibits a less significant indentation size effect in comparison with nc-Ni due to the dislocation slips hindrance of the twin boundary.The atomic deformation associated with the indentation size effect is investigated during dislocation transmission.Different from the decreasing partial slips parallel to the indenter surface in nc-Ni with increasing temperature,the temperaturedependent atomic deformation of nt-Ni is closely related to the twin boundary:from the partial slips parallel to the twin boundary (~10 K),to increased confined layer slips and decreased twin migration(300 K–600 K),to decreased confined layer slips and increased dislocation interaction of dislocation pinning and dissociation (900 K–1200 K).Dislocation density and atomic structure types through quantitative analysis are implemented to further reveal the above-mentioned dislocation motion and atomic structure alteration.Our study is helpful for understanding the temperature-dependent plasticity of twin boundary in nanotwinned materials. 展开更多
关键词 NANOINDENTATION twin boundary plastic deformation molecular dynamics simulation
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Survey on digital twins for Internet of Vehicles:Fundamentals,challenges,and opportunities
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作者 Jiajie Guo Muhammad Bilal +3 位作者 Yuying Qiu Cheng Qian Xiaolong Xu Kim-Kwang Raymond Choo 《Digital Communications and Networks》 SCIE CSCD 2024年第2期237-247,共11页
As autonomous vehicles and the other supporting infrastructures(e.g.,smart cities and intelligent transportation systems)become more commonplace,the Internet of Vehicles(IoV)is getting increasingly prevalent.There hav... As autonomous vehicles and the other supporting infrastructures(e.g.,smart cities and intelligent transportation systems)become more commonplace,the Internet of Vehicles(IoV)is getting increasingly prevalent.There have been attempts to utilize Digital Twins(DTs)to facilitate the design,evaluation,and deployment of IoV-based systems,for example by supporting high-fidelity modeling,real-time monitoring,and advanced predictive capabilities.However,the literature review undertaken in this paper suggests that integrating DTs into IoV-based system design and deployment remains an understudied topic.In addition,this paper explains how DTs can benefit IoV system designers and implementers,as well as describes several challenges and opportunities for future researchers. 展开更多
关键词 Internet of vehicles Digital twin Simulation Traffic systems
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Digital Twins for Wastewater Treatment:A Technical Review
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作者 Ai-Jie Wang Hewen Li +6 位作者 Zhejun He Yu Tao Hongcheng Wang Min Yang Dragan Savic Glen TDaigger Nanqi Ren 《Engineering》 SCIE EI CAS CSCD 2024年第5期21-35,共15页
The digital twins concept enhances modeling and simulation through the integration of real-time data and feedback.This review elucidates the foundational elements of digital twins,covering their concept,entities,domai... The digital twins concept enhances modeling and simulation through the integration of real-time data and feedback.This review elucidates the foundational elements of digital twins,covering their concept,entities,domains,and key technologies.More specifically,we investigate the transformative potential of digital twins for the wastewater treatment engineering sector.Our discussion highlights the application of digital twins to wastewater treatment plants(WWTPs)and sewage networks,hardware(i.e.,facilities and pipes,sensors for water quality and activated sludge,hydrodynamics,and power consumption),and software(i.e.,knowledge-based and data-driven models,mechanistic models,hybrid twins,control methods,and the Internet of Things).Furthermore,two cases are provided,followed by an assessment of current challenges in and perspectives on the application of digital twins in WWTPs.This review serves as an essential primer for wastewater engineers navigating the digital paradigm shift. 展开更多
关键词 Digital twins Urban water systems Wastewater treatment
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Strengthening effect of prefabrication(10-12)tensile twinning on AZ80+0.4%Ce magnesium alloy and inhibition mechanism of discontinuous precipitation
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作者 Zhen Wang Xi Zhao +5 位作者 Zhimin Zhang Yaojin Wu Kai Chen Xianwei Ren Dengkui Wang Wei Wang 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第5期1918-1930,共13页
This paper provided an effective method to further improve the mechanical properties of the AZ80+0.4%Ce magnesium alloy wheel spoke.The effect of high strength and ductility was obtained with a yield strength of 295.3... This paper provided an effective method to further improve the mechanical properties of the AZ80+0.4%Ce magnesium alloy wheel spoke.The effect of high strength and ductility was obtained with a yield strength of 295.36 MPa,an elongation of 10%,by the combination of pre-deformation(7%deformation)and two-stage aging treatment(120℃/9 h+175℃/24 h).The evolution of the microstructure and properties of the alloy was explored under the coupling conditions of different pre-deformation degrees and multi-stage aging.The results show that,pre-deformation introduced a large number of(1012)tensile twinning and dislocations,which greatly promoted the probability of continuous precipitates(CPs)appearing.On the contrary,the discontinuous precipitates(DPs)were limited by the vertical and horizontal twin structure.As a result,the pre-nucleation method of two-stage aging increased the proportion of CPs by 34%-38%.Owing to the DPs was effectively suppressed,the alloy's yield strength has been greatly improved.Besides,under multi-stage aging,the twin boundaries induce protruding nucleation to form static recrystallization by hindering the migration of dislocations,and the matrix swallows the twins,then the texture gradually tilts from the two poles to the basal plane.As an important supplement,the grain refinement and oblique texture promoted the improvement of the yield strength of the component. 展开更多
关键词 Magnesium alloy Pre-deformed Two-stage aging Tensile twinning Continuous precipitates Texture
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