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Flexible piezoelectret film sensor for noncontact mechanical signal capture by multiple transmission media

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Nano Research 2024年第8期17卷 7643-7657页

作者： Xingchen Ma Qianqian Hu Lian Zhou Xinhao Xiang Yi Qin Ke Zhang pengfei he Ying Dai Wenxin Niu Xiaoqing Zhang Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology School of Physics Science and EngineeringTongji UniversityShanghai 200092China Shanghai Yangzhi Rehabilitation Hospital(Shanghai Sunshine Rehabilitation Center) School of MedicineTongji UniversityShanghai 201619China Department of Rehabilitation Sciences Tongji University School of MedicineShanghai 200092China School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092China

Mechanical signal capture without physical contact has emerged as a highly promising research field and attracted tremendous attention due to its prosperous applications in household medical care,lifestyle monitoring and remote operation,offering users high level of safety,convenience and ***,noncontact sensing is ideal to maximize the immersive user experience in the human–machine interaction(HMI),eliminating interference to human activities and mechanical fatigue to the sensor,***,we report a self-powered flexible sensor integrated with irradiation cross-linked polypropylene(IXPP)piezoelectret film for noncontact sensing,featuring multi-functions to detect mechanical signals transmitted through solid,liquid and gaseous media and would facilitate their versatile practical *** folded-structure configuration of the sensor facilitates the improvement of the noncontact sensing *** solid media,such as the rectangular wooden stick used in this study,the sensor can detect mechanical stimulus exerted at a distance of 100 cm.A system detection sensitivity up to 57 pC/kPa with a low detection limit of 0.6 kPa is achieved at a noncontact distance of 10 *** when partly or completely immersed in water,the sensor effectively traces movement signals of human bodies underwater,demonstrating great advantages for non-inductive aquatic fitness training ***,due to the low acoustic impedance of piezoelectret film,speech recognition through gaseous medium is also *** further introduce application demonstrations of the developed film sensors to monitor exercise postures and physiological signals without direct contact between human body and the sensor,displaying great potential to be incorporated into future smart *** study commendably expands the application scope of piezoelectret materials,which will have profound implications for exploring novel intelligent human–machine interactions.

关键词： noncontact sensing piezoelectret multiple transmission media mechanical signal capture

High speed laser cladding as a new approach to prepare ultra-high temperature ceramic coatings

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Journal of Advanced Ceramics 2024年第2期13卷 143-154页

作者： Qiyao Deng pengfei he Chuan Sun Yang Li Yue Xing Yujie Wang Jinglong Li Xiubing Liang Xin Wang Yujie Zhou Yujun Cai National-Local Joint Engineering Laboratory of Intelligent Manufacturing Oriented Automobile Die&Mould Tianjin University of Technology and EducationTianjin 300222China Defense Innovation Institute Academy of Military ScienceBeijing 100071China School of mechanical engineering Tianjin University of Technology and EducationTianjin 300222China Scientific and Technological Innovation Center Beijing 100012China

Ultra-high temperature ceramic(UHTC)coatings are used to protect the hot-end components of hypervelocity aerocrafts from thermal *** study provides a new approach to fabricate UHTC coatings with high speed laser cladding(HSLC)technology,and places more emphasis on investigating the formation mechanism,phase compositions,and mechanical properties of HSLC-UHTC *** show that a well-bonded interface between the coating and the tantalum alloy substrate can be *** coating is mainly composed of(Zr,Ta)C ceramic solid solution phase with a content of higher than 90% by volume and Ta(W)metal solid solution *** a relatively high powder feeding rate,the ZrC ceramic phase appears in the coating while a dense ZrC UHTC top layer with a thickness of up to~50μm is successfully *** for the mechanical properties of the HSLC coatings,the fracture toughness of the coating decreases with the increase of powder feeding *** increase of carbide solid solution phase can significantly improve the high temperature microhardness(552.7±1.8 HV0.5@1000℃).The innovative design of HSLC ZrC-based coatings on refractory alloys accomplishes continuous transitions on microstructure and properties from the substrate to the UHTC top layer,which is a very promising candidate scheme for thermal protection coating.

关键词： high speed laser cladding(HSLC) ultra-high temperature ceramic(UHTC) thermal protection coating microstructure mechanical properties

Experimental investigation on acoustic emission precursor of rockburst based on unsupervised machine learning method

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Rock Mechanics Bulletin

Rock Mechanics Bulletin 2024年第2期3卷 63-77页

作者： Jie Sun Dongqiao Liu pengfei he Longji Guo Binghao Cao Lei Zhang Zhe Li State Key Laboratory for GeoMechanics and Deep Underground Engineering China University of Mining and TechnologyBeijing100083China School of Mechanics and Civil Engineering China University of Mining and TechnologyBeijing100083China Institute for Deep Underground Science and Engineering China University of Mining and TechnologyBeijing100083China Department of Earth Sciences University of FlorenceFirenze 50121Italy School of Science China University of Mining and TechnologyBeijing100083China School of Energy and Mining Engineering China University of Mining and TechnologyBeijing100083China

The key to achieving rockburst warning lies in the understanding of rockburst *** the cor-relation characteristics of rockburst acoustic emission(AE)parameters,a self-organizing map neural network(SOMNN)based method for rockburst precursor inversion was *** feature of this method lies in a cyclic data segmentation iteration process based on the thinking of“interference signal screening”,“key signal extraction”,and“precursor signal inversion”.The rationality of this method has been verified in three groups of rockburst *** results revealed that rockburst AE precursor signals consist of a series of signals characterized by long duration,high energy,low average frequency,high energy amplitude,and low peak ***,potential value in long term rockburst warning of the precursor obtained in this study was shown via the comparison of conventional ***,a preliminary interpretation for rockburst pre-cursor was proposed under the framework of AE parameters physical significance,and it is revealed that AE precursor signals are likely linked to the creation of large-scale tensile cracks before rockburst.

关键词： Rockburst Acoustic emission Precursor Machine learning

熔滴复合电弧增材制造2219铝合金组织与性能

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浙江大学学报（工学版） 2024年第8期58卷 1585-1595页

作者：王勇超魏正英贺鹏飞西安交通大学机械制造系统工程国家重点实验室陕西西安710000

为了提高铝合金电弧增材制造的质量和效率,采用新型的电弧增材制造工艺——熔滴复合电弧增材制造(DAAM)技术来制造铝合金样品.采用全新的熔滴生成系统(DGS)代替传统的送丝系统,使得材料的添加与电弧能量相互独立.成形的材料为2219铝合金... 详细信息

为了提高铝合金电弧增材制造的质量和效率,采用新型的电弧增材制造工艺——熔滴复合电弧增材制造(DAAM)技术来制造铝合金样品.采用全新的熔滴生成系统(DGS)代替传统的送丝系统,使得材料的添加与电弧能量相互独立.成形的材料为2219铝合金,通过熔滴系统添加了微量Mg元素.利用熔滴复合电弧增材制造设备沉积了薄壁结构,沉积速率较传统电弧增材制造技术大幅提升(约为160 mm^(3)/s).观察和分析薄壁结构截面的微观组织表明,薄壁结构的晶粒形态以柱状晶为主,呈现层内柱状晶和层间等轴晶的周期性分布规律.经过T6热处理后,试样水平和垂直方向的平均抗拉强度分别为455.4和417.0 MPa,屈服强度分别为342.4和316.4 MPa.较之前的研究结果对比表明,Mg元素的添加提升了2219铝合金的屈服强度,但导致延伸率降低.

关键词： 2219铝合金电弧增材制造熔滴微观组织力学性能

岩石强度理论及不同拉压应力状态下岩石强度试验研究现状

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岩石力学与工程学报 2024年第4期43卷 890-906页

作者：何鹏飞何满潮李鑫陶志刚刘冬桥中国矿业大学(北京)隧道工程灾变防控与智能建养全国重点实验室北京100083 中国矿业大学(北京)力学与土木工程学院北京100083 中国矿业大学(北京)深地空间科学与工程研究院北京100083

岩石强度理论对不同尺度的岩石工程稳定性分析具有重要的理论意义与工程价值,其发展与岩石在不同拉压应力状态下的强度试验研究息息相关。尽管岩石在拉压应力的作用下强度特性差异很大,但目前对其强度理论及不同应力状态下强度试验的研... 详细信息

岩石强度理论对不同尺度的岩石工程稳定性分析具有重要的理论意义与工程价值,其发展与岩石在不同拉压应力状态下的强度试验研究息息相关。尽管岩石在拉压应力的作用下强度特性差异很大,但目前对其强度理论及不同应力状态下强度试验的研究多关注三向受压应力状态。进行了如下系统综述:在阐述金属和土体相关强度理论的基础上,介绍岩石强度理论的发展历程及研究进展;与岩石强度理论发展相协调的不同拉压应力状态下岩石强度试验的研究现状;进而分析了现有岩石强度测试所覆盖的应力状态分区及9种岩石强度理论所定义的3个特征拉伸强度的区别;最后对岩石强度理论及不同拉压应力状态下岩石强度试验研究中尚未解决的问题进行讨论总结并对未来研究工作进行了展望。

关键词：岩石力学强度理论应力状态破坏拉伸

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预充氢金属疲劳损伤研究进展

同济大学学报（自然科学版） 2024年第7期52卷 1118-1125页

作者：贺鹏飞赵晟炜李文晓同济大学航空航天与力学学院上海200092

在高压氢环境和疲劳荷载作用下,金属承载件会出现材料疲劳性能减损,甚至失效。对临氢构件开展原位氢疲劳损伤研究存在氢安全方面的困难,因此近年来多采用对预充氢金属进行疲劳性能研究的替代方式。简要概述了氢损伤机理,介绍了金属预充... 详细信息

在高压氢环境和疲劳荷载作用下,金属承载件会出现材料疲劳性能减损,甚至失效。对临氢构件开展原位氢疲劳损伤研究存在氢安全方面的困难,因此近年来多采用对预充氢金属进行疲劳性能研究的替代方式。简要概述了氢损伤机理,介绍了金属预充氢试验方法,总结了预充氢情况下氢对金属高、低周疲劳性能影响的实验结果;归纳了建立预充氢金属的疲劳寿命模型,对金属氢损伤开展定量分析的研究现状;最后讨论了通过改变临氢材料内氢的渗入量和存在形式来抑制氢对金属的影响来提高临氢材料疲劳寿命的几种方法。

关键词：金属疲劳预充氢氢损伤疲劳寿命模型

基于连续小波变换和模型无关元学习的压燃式活塞发动机气门故障诊断研究

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内燃机工程 2024年第1期45卷 57-63,71页

作者：何鹏飞黄国勇阮爱国昆明理工大学民航与航空学院昆明650500 中国广核新能源投资有限公司云南分公司昆明650200

针对压燃式活塞发动机缸盖表面振动信号样本少及传统故障诊断方法特征提取和选择困难的问题,提出了一种基于连续小波变换(continuous wavelet transform,CWT)和模型无关元学习(model agnostic meta learning,MAML)的压燃式活塞发动机气... 详细信息

针对压燃式活塞发动机缸盖表面振动信号样本少及传统故障诊断方法特征提取和选择困难的问题,提出了一种基于连续小波变换(continuous wavelet transform,CWT)和模型无关元学习(model agnostic meta learning,MAML)的压燃式活塞发动机气门间隙异常故障诊断方法。通过将CWT的特征提取能力和MAML的快速学习能力相结合搭建故障诊断模型。试验结果表明该方法能有效识别气门间隙故障,并且其准确率高于传统基于CWT和卷积神经网络(convolutional neural network,CNN)的故障诊断方法。通过跨域故障对比试验,研究了不同气门故障类型对模型诊断能力的影响,验证了该方法在解决小样本和跨域故障问题时具有更高的准确率和泛化能力。

关键词：压燃式活塞发动机故障诊断连续小波变换元学习

经长时服役的超临界锅炉T91/TP347H异种钢接头性能分析

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热加工工艺 2024年第9期53卷 87-90页

作者：何朋非张仁魁周梦保湖南省湘电锅炉压力容器检验中心有限公司湖南长沙410004

对某超临界锅炉运行7.5万小时的T91/TP347H异种钢接头,采用金相显微镜、万能材料试验机和扫描电镜等仪器设备,研究长时服役后T91/TP347H异种钢接头的性能。结果表明:该异种钢接头薄弱区在T91熔合线处,该位置链状孔洞和脱碳层的形成大大... 详细信息

对某超临界锅炉运行7.5万小时的T91/TP347H异种钢接头,采用金相显微镜、万能材料试验机和扫描电镜等仪器设备,研究长时服役后T91/TP347H异种钢接头的性能。结果表明:该异种钢接头薄弱区在T91熔合线处,该位置链状孔洞和脱碳层的形成大大弱化了力学性能,氧化缺口的形成加速了接头的开裂。异种钢接头各区域的冲击性能显著降低,其中焊缝冲击性能最低,实测仅为66 J。

关键词：异种钢接头 T91 TP347H 脱碳层长时服役

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氯碱生产系统仪表及自控阀异常的分析及处置

氯碱工业 2024年第8期60卷 23-25页

作者：贺鹏飞陕西金泰氯碱化工有限公司陕西榆林718100

针对烧碱装置运行过程中自控系统仪表及自控阀出现的问题,进行了分析,并给出解决措施。

关键词：氯气总管氯气缓冲罐螯合树脂塔压力表自控阀