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Improved Multi-Bandwidth Mode Manifold for Enhanced Bearing Fault Diagnosis

Chinese Journal of Mechanical Engineering 2022年第1期35卷 179-191页

作者： guifu du Tao Jiang Jun Wang Xingxing Jiang Zhongkui Zhu School of Rail Transportation Soochow UniversitySuzhou 215131China

Variational mode decomposition(VMD) has been proved to be useful for extraction of fault-induced transients of rolling bearings. Multi-bandwidth mode manifold(Triple M, TM) is one variation of the VMD, which units multiple fault-related modes with different bandwidths by a nonlinear manifold learning algorithm named local tangent space alignment(LTSA). The merit of the TM method is that the bearing fault-induced transients extracted contain low level of in-band noise without optimization of the VMD parameters. However, the determination of the neighborhood size of the LTSA is time-consuming, and the extracted fault-induced transients may have the problem of asymmetry in the up-and-down direction. This paper aims to improve the efficiency and waveform symmetry of the TM method.Specifically, the multi-bandwidth modes consisting of the fault-related modes with different bandwidths are first obtained by repeating the recycling VMD(RVMD) method with different bandwidth balance parameters. Then, the LTSA algorithm is performed on the multi-bandwidth modes to extract their inherent manifold structure, in which the natural nearest neighbor(Triple N, TN) algorithm is adopted to efficiently and reasonably select the neighbors of each data point in the multi-bandwidth modes. Finally, a weight-based feature compensation strategy is designed to synthesize the low-dimensional manifold features to alleviate the asymmetry problem, resulting in a symmetric TM feature that can represent the real fault transient components. The major contribution of the improved TM method for bearing fault diagnosis is that the pure fault-induced transients are extracted efficiently and are symmetrical as the real. One simulation analysis and two experimental applications in bearing fault diagnosis validate the enhanced performance of the improved TM method over the traditional methods. This research proposes a bearing fault diagnosis method which has the advantages of high efficiency, good waveform symmetry and enhanced in-band noise removal capab

关键词： Variational mode decomposition Manifold learning Natural nearest neighbor algorithm Rolling bearing Fault diagnosis Time-frequency signal decomposition

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Residual current compensation for single-phase grounding fault in coal mine power network

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International Journal of Mining Science and Technology 2014年第2期24卷 213-218页

作者： Jia Chenxi Wang Chonglin du guifu School of Information and Electrical Engineering China University of Mining & Technology

The way of neutral point to earth via full compensation arc suppression coil can solve the problem of residual current compensation in coal mine power network effectively. Based on the analysis on the grounding current detection results of Xieqiao coal mine, the conclusion that harmonic component of grounding current is dominated by higher harmonics with complex harmonic sources in coal mine power network system was obtained. The influences of harmonic source type and fault point position on harmonic voltage and harmonic current were analyzed theoretically. The influences of earthed fault feeder detection result and the estimation errors of parameters to earth on residual current compensation were analyzed. A new thought of residual current prediction and the selections of model method and control method were proposed on this basis. The simulation results prove that harmonic amplitudes of zero sequence voltage and zero sequence current are determined by harmonic source type as well as fault point position in coal mine power network, and also prove that zero sequence voltage detection can avoid the unstable problem of coal mine power network system caused by undercompensation of capacitive current. Finally, the experimental device of full compensation arc suppression coil is introduced.

关键词：单相接地故障电流补偿煤矿电网剩余电流高次谐波消弧线圈检测结果接地电流

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Cyclic-acyclic monomers metathesis polymerization to access photodegradable polydicyclopentadiene and polyethylene-like materials

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Science China Chemistry 2024年第4期67卷 1311-1315页

作者： Wu Li Daohong Liao Yougui Li guifu Si Changle Chen School of Chemistry and Chemical Engineering Hefei University of TechnologyHefei 230009China Key Laboratory of Precision and Intelligent Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China

The development of degradable and recyclable polymers is an attractive strategy to tackle the post-consumption pollution issue of commercial plastics.Cyclic-acyclic monomers metathesis polymerization(CAMMP)has been recently reported to produce degradable thermoset,thermoplastic and elastomeric polymers,and their degradability is enabled with addition of various chemicals.In this contribution,we demonstrate that the utilization of diene comonomers containing photodegradable moiety can give access to thermoset and thermoplastic materials bearing photo-degradation capabilities.The copolymerization of a series easily accessible diene comonomers bearing photodegradable ortho-nitrobenzyl moieties with dicyclopentadiene(DCPD)or cyclooctene(COE)leads to the formation of photodegradable p DCPD thermosets and p COE thermoplastic polymers with mechanical properties comparable to their non-degradable counterparts.Most importantly,their photo-degradation properties can be efficiently tuned with the addition of ultraviolet absorber during in-situ polymerization.

关键词： metathesis polymerization photodegradable polydicyclopentadiene polyethylene-like materials

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Highly elastic and degradable vitrimeric elastomers using polycondensation

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Chinese Chemical Letters 2024年第3期35卷 434-438页

作者： Yue Liu Yongshuang Huang Chao Li guifu Si Min Chen Institutes of Physical Science and Information Technology Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationAnhui UniversityHefei 230601China CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China

Introducing covalently crosslinked network to polymer matrix can merge the advantages in reprocessing and durability of polymers.In this contribution,a series of high-performance vitrimeric elastomers were achieved via polycondensation.The topological structures of polymers were tuned by varying the feeding ratios of bisacetoacetate,hex–substituted bisacetoacetate,bisamine and tris(2-aminoethyl)amine.With these structural manipulations,the vitrimeric elastomers presented great elastic recovery properties(strain recovery value up to 80%)benefiting from the introduction of long chain branch.Furthermore,the elastomers exhibited excellent reprocessing property,water vapor/oxygen barrier and adhesive properties.Specially,the elastomers could be degraded into monomer under acid conditions which enabled the elastomer synthesis again in closed loop recycling system.The ease of the polycondensation in this work to prepare highly elastic and recyclable vitrimeric elastomers demonstrated exciting opportunities for the synthesis of sustainable polymers.

关键词： Polycondensation Vitrimeric elastomers Highly elastic Degradable polymers

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Insight into structure evolution of carbon nitrides and its energy conversion as luminescence

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Carbon Energy 2024年第2期6卷 37-60页

作者： Hao Zhang Jingwei Zhang Wenjie Chen Minjia Tao Xianguang Meng Yuanjian Zhang guifu Zuo Hebei Provincial Key Laboratory of Inorganic Nonmetallic Materials College of Materials Science and EngineeringNorth China University of Science and TechnologyTangshanHebeiChina 2College of Clinical MedicineNorth China University of Science and TechnologyTangshanHebeiChina 3Hebei Iron and Steel LaboratoryTangshanHebeiChina 4Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and DeviceJiangsu Province Hi-Tech Key Laboratory for Bio-Medical ResearchState Key Laboratory of BioelectronicsSchool of Chemistry and Chemical EngineeringMedical SchoolSoutheast UniversityNanjingJiangsuChina

A series of carbon nitride(CN)materials represented by graphitic carbon nitride(g-C3N4)have been widely used in bioimaging,biosensing,and other fields in recent years due to their nontoxicity,low cost,and high luminescent quantum efficiency.What is more attractive is that the luminescent properties such as wavelength and intensity can be regulated by controlling the structure at the molecular level.Hence,it is time to summarize the related research on CN structural evolution and make a prospect on future developments.In this review,we first summarize the research history and multiple structural evolution of CN.Then,the progress of improving the luminescence performance of CN through structural evolution was discussed.Significantly,the relationship between CN structure evolution and energy conversion in the forms of photoluminescence,chemiluminescence,and electrochemiluminescence was reviewed.Finally,key challenges and opportunities such as nanoscale dispersion strategy,luminous efficiency improving methods,standardization evaluation,and macroscopic preparation of CN are highlighted.

关键词： carbon nitride chemiluminescence electrochemiluminescence energy conversion photoluminescence structural evolution

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A review on ultra-small undoped MoS_(2) as advanced catalysts for renewable fuel production

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Carbon Energy 2024年第2期6卷 92-112页

作者： Guoping Liu Lingling Ding Yuxuan Meng Ahmad Ali guifu Zuo Xianguang Meng Kun Chang Oi Lun Li Jinhua Ye Hebei Provincial Laboratory of Inorganic Nonmetallic Materials College of Materials Science and EngineeringNorth China University of Science and TechnologyTangshanChina College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjingChina School of Materials Science and Engineering Pusan National UniversityBusanKorea International Center for Materials Nanoarchitectonics(WPIMANA) National Institute for Materials Science(NIMS)1-1 NamikiTsukubaIbarakiJapan

Molybdenum disulfide(MoS_(2))has garnered significant attention in the field of catalysis due to the high density of active sites in its unique two-dimensional(2D)structure,which could be developed into numerous high-performance catalysts.The synthesis of ultra-small MoS2 particles(duction.Through a systematic review of their synthesis,structural,and spectral characteristics,as well as the relationship between their catalytic performance and inherent defects,we aim to provide insights into catalysis over this matrix that may potentially enable advancement in the development of high-performance MoS_(2)-based catalysts for sustainable energy generation in the future.

关键词： applications catalytic MoS_(2) structure synthesis

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基于GOOSE通信的地铁多变流器智能优化控制方法研究

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都市快轨交通 2022年第2期35卷 42-49页

作者：何斌杜贵府郑子璇中铁第四勘察设计院集团有限公司武汉430063 苏州大学轨道交通学院江苏苏州215031

当前地铁线路各牵引所变流器独立运行,无法实现实时信息交互、精准调整和协调控制。为解决这一问题,提出基于GOOSE通信的地铁多变流器智能优化控制方法。基于GOOSE通信网络搭建多变流器分层控制结构,以系统网损最小和钢轨电位幅值最小... 详细信息

当前地铁线路各牵引所变流器独立运行,无法实现实时信息交互、精准调整和协调控制。为解决这一问题,提出基于GOOSE通信的地铁多变流器智能优化控制方法。基于GOOSE通信网络搭建多变流器分层控制结构,以系统网损最小和钢轨电位幅值最小为目标,提出基于NSGA-II算法的多变流器双目标优化控制算法。搭建地铁牵引供电系统动态潮流仿真平台进行仿真验证,结果表明:基于GOOSE通信的多变流器智能优化控制方法能够实现多个变流器的动态管理和协调控制,降低线路网络损耗以及钢轨电位。与传统的无通信优化控制相比,多变流器智能优化控制方法能够实时优化各变流器的输出特性,实现线路节能、安全运行的目标。

关键词：城市轨道交通 GOOSE通信多变流器协调控制智能优化

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A lipid droplets-targetable fluorescent probe for polarity detection in cells of iron death,inflammation and fatty liver tissue

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Chinese Chemical Letters 2024年第6期35卷 365-369页

作者： Xing Tian Di Wu Wanheng Wei guifu Dai Zhanxian Li Benhua Wang Mingming Yu Green Catalysis Center and College of Chemistry Zhengzhou UniversityZhengzhou 450001China School of Life Sciences Zhengzhou UniversityZhengzhou 450001China Shenzhen Research Institute of Central South University Shenzhen 518057China

Abnormal accumulation and metabolism of lipid droplets can lead to a variety of diseases.Polarity,a key parameter of the microenvironment,is closely associated with many diseases and dysfunctions in the body.It is important to elucidate the relationship between the physiological activity of lipid droplets(LDs)and the polarity of the microenvironment.In this work,based on push-pull mechanism,a fluorescent probe(E)-3-(5-(4-(diphenylamino)phenyl)thiophen-2-yl)-1-(2-hydroxyphenyl)prop-2-en-1-one(PPTH)with aggregation-induced emission(AIE)properties for the detection of polarity changes in cells was synthesized.PPTH not only visualize intracellular polarity fluctuation of iron death and inflammation but also distinguish between normal and fatty liver tissue.

关键词： Lipid droplets AIE Polarity Ferroptosis Fatty liver

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变分模式分解方法研究与应用综述

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仪器仪表学报 2023年第1期44卷 55-73页

作者：江星星宋秋昱杜贵府黄伟国朱忠奎苏州大学轨道交通学院苏州215131

自适应信号分解领域一个十分活跃的分支——变分模式分解(VMD)已经成为信号处理与检测技术学界一个热门的研究方向。VMD对非平稳、非线性信号具有良好的处理效果。针对VMD模型及其参数选择,发展了许多拓展模型及参数优化方法。本文回顾... 详细信息

自适应信号分解领域一个十分活跃的分支——变分模式分解(VMD)已经成为信号处理与检测技术学界一个热门的研究方向。VMD对非平稳、非线性信号具有良好的处理效果。针对VMD模型及其参数选择,发展了许多拓展模型及参数优化方法。本文回顾近十年来VMD的研究进展,对相关的文献进行总结与分析。首先,分析VMD的原理性优势及其在各个领域的应用潜力;其次,根据模型对不同信号类型的匹配能力,分类总结VMD拓展模型的不同特性和适用场景;然后,归纳VMD及其拓展模型参数优化方法的研究现状,探讨与分析不同模型参数优化方法的特点和最新研究趋势;最后,对VMD的未来发展提出6点展望,为后续的研究指明方向。

关键词：检测技术变分模式分解模式分解数目带宽平衡参数中心频率

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直流牵引供电系统多站钢轨电位交互影响分布特性

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北京交通大学学报 2022年第2期46卷 138-147页

作者：张晓萍郑子璇罗春晖杜贵府张驰苏州大学应用技术学院江苏昆山215300 苏州大学轨道交通学院江苏苏州215131

为阐明城市轨道交通多个车站钢轨电位交互影响下分布特性,分析了钢轨电位限制装置(Over Voltage Protection Device,OVPD)等装置的动态接地特性,建立了直流牵引供电系统多站钢轨电位交互影响的仿真模型.基于该仿真模型,建立了牵引供电... 详细信息

为阐明城市轨道交通多个车站钢轨电位交互影响下分布特性,分析了钢轨电位限制装置(Over Voltage Protection Device,OVPD)等装置的动态接地特性,建立了直流牵引供电系统多站钢轨电位交互影响的仿真模型.基于该仿真模型,建立了牵引供电系统的节点电压方程组并通过迭代计算进行求解,从而得到线路的潮流参数以及钢轨电位、杂散电流的分布情况.基于国内某实际线路的参数仿真分析了多站钢轨电位及杂散电流的动态分布规律,从而首次阐明了系统多站钢轨电位交互影响的机理.研究结果表明:OVPD动作会造成泄漏电流增多并抬升其他位置的钢轨电位幅值,因而触发其他站点的OVPD接续动作,进一步抬升全线钢轨电位与杂散电流.此外,多站OVPD同时动作往往为泄漏电流构成回路,导致杂散电流水平激增.以上研究为OVPD动作特性的优化以及线路钢轨电位、杂散电流的控制提供了依据.

关键词：直流牵引供电系统动态接地钢轨电位杂散电流交互影响

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