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Fault diagnosis method for blade fracture of gas turbine based on casing vibration

Mechanical systems and Signal Processing 2025年 234卷

作者： Hu, Ming-Hui Jin, Bao-teng Liu, Shao-Peng Wang, Wei-Min Jiang, Zhi-Nong Zhang, Xiao-Yang Gao, Jin-ji State Key Laboratory of High-end Compressor and System Technology Beijing University of Chemical Technology Beijing100029 China Key Lab of Engine Health Monitoring-Control and Networking of Ministry of Education Beijing University of Chemical Technology Beijing100029 China Beijing Key Laboratory of Health Monitoring and Self-Recovery for High-End Mechanical Equipment Beijing University of Chemical Technology Beijing100029 China National Key Laboratory of Internal Combustion Engines and Power Systems Weichai Power Co. Ltd. China

Blade fracture is one of the most difficult faults to diagnose in rotating machinery. Most gas turbines can only measure casing vibration rather than directly measuring blade vibration with other sensors, making monitoring and diagnosing such faults more challenging. Research on vibration characteristics and fault diagnosis methods of blade fracture is critical to ensure the safe and reliable operation of gas turbines. The current paper presents a new method to monitor the blade fracture faults from the vibration signal of the casing. Firstly, based on the function mechanism of blade wake excitation forces, the transfer path of the vibration response of gas turbine blades and the variation rule of the wake excitation force have been investigated. Then, based on the casing vibration response model, we analyzed the dynamic evolution of vibration response in the pre- and post-fracture stages of rotor blade failure. The results indicate that the response characteristics of velocity RMS, blade passing frequency (BPF), and fundamental frequency can effectively characterize blade fracture faults. Secondly, based on the vibration-sensitive characteristics of blade fracture faults, we propose an Improved Ordered Cluster Analysis (IOCA) identification method. Considering that the blade fracture can decrease the BPF amplitude and lead to the appearance of side-frequency bands. We propose a Fault Localization Estimation (FLE) method, which constructs a fracture localization factor called ΔUBF, and the highest ΔUBF value corresponds to the stage where the blade fracture has appeared. Finally, A fault diagnosis scheme for gas turbine blade fracture based on casing vibration is proposed. An engineering case of a gas turbine blade fracture fault is analyzed. The results show that the proposed method can timely and effectively diagnose the gas turbine blade fracture fault from the vibration signal of the casing. They can further localize the blade fracture fault at the 8th and 9th s

关键词： Rotating machinery

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Unintended side effect of the coal-to-gas policy in North China Plain: Migration of the sources and health risks of ambient PAHs

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Science of the Total Environment 2025年 958卷 178050页

作者： Li, Zhiyong Liu, Chen Ren, Zhuangzhuang Liu, Jinming Ma, Xiaohua Ning, Zhi Meng, Jianwei Liu, Aiqin Ma, Huichun Wang, Lei Chen, Lan Wang, Hao Kong, Shaofei Hebei Key Lab of Power Plant Flue Gas Multi-Pollutants Control Department of Environmental Science and Engineering North China Electric Power University Baoding071003 China MOE Key Laboratory of Resources and Environmental Systems Optimization College of Environmental Science and Engineering North China Electric Power University Beijing102206 China Hebei Key Lab of Mineral Resources and Ecological Environment Monitoring Hebei Research Center for Geoanalysis Baoding071051 China Department of Atmospheric Sciences School of Environmental Sciences China University of Geosciences Wuhan430074 China

Ongoing coal-to-gas (CTG) largely cut down both coal consumption and associated PM2.5. However, a knowledge gap still existed in CTG impacts on the other energy and organic pollutant emissions. Coupling on-site investigation with statistical yearbooks, we provided a more realistic energy evolutions before (BCTG), during (DCTG), and after (ACTG) the CTG for Hebei Province. Together, we examined the impacts of CTG derived energy conversion on PM2.5-bound PAHs at urban (UA)/suburban rural (SRA)/remote rural (RRA) sites in winter 2022. As expected, the consumptions of coal and natural gas (NG) far decreased and increased from BCTG to ACTG, respectively. Accidentally, biomass usage rose by 60.7%, and rural CTG acted as a main driver. Specially, SRA's NG-shortage and coal-stove demolition should be the main inducements, and RRA's coal-sale ban was another trigger in the early stage of CTG. ∑18PAHs and ∑8TPAHs stand for the sum of 18 PAHs and 8 toxic PAHs, respectively. ∑18PAHs (ng/m3) presented as SRA (81.8) > RRA (46.4) > UA (19.4). Biomass burning (BB) and NG combustion (NGC) contributed most to∑18PAHs of 31.0% and 23.1% at SRA, resulting in the highest ∑18PAHs, ∑18PAHs/PM2.5, and ∑8TPAHs/PM2.5, and incremental lifetime cancer risk values. Also, NGC has become the second largest contributor at UA. Variations in both diagnostic ratios and source-depend isomers further proved the prominence of NGC related PAHs at UA vs. SRA. Notably, RRA was least affected by the CTG, coal combustion (CC, 40.4%) and BB (32.6%) still occupied the top positions. In short, CTG gave rise to an upsurge in biomass usage, and the incremental PAHs emissions from BB vs. NGC. This study underlined that the priorities should be given to rural NG guarantee and subsidy retention, and biomass prohibition for further air quality improvement. © 2024 Elsevier B.V.

关键词： Coal

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Engineering CRISPR/Cas12-based biosensors: Recent advances and future perspectives

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TrAC - Trends in Analytical Chemistry 2025年 191卷

作者： Yin, Lijuan Zhou, Caihong Gao, Baoxue Liu, Fufeng Ma, Long Guo, Fei State Key Laboratory of Food Nutrition and Safety Key Laboratory of Industrial Microbiology Ministry of Education Tianjin Key Laboratory of Industry Microbiology National and Local United Engineering Lab of Metabolic Control Fermentation Technology China International Science and Technology Cooperation Base of Food Nutrition/Safety and Medicinal Chemistry College of Biotechnology Tianjin University of Science and Technology Tianjin300457 China NHC Key Laboratory of Systems Biology of Pathogens Institute of Pathogen Biology and Center for AIDS Research Chinese Academy of Medical Sciences & Peking Union Medical College Beijing100730 China

Rapid, sensitive, and accurate biosensing is instrumental for clinical diagnostics, food safety, and environmental monitoring. The CRISPR/Cas12 system has emerged as a robust biosensing tool, leveraging its biocompatibility, distinctive cleavage activity, and user-friendly design. In recent years, numerous CRISPR/Cas-based biosensing strategies have been developed to enhance detection sensitivity, specificity, and portability, significantly advanced the molecular diagnostics field. This review systematically discusses recent advances in various engineering strategies aimed at improving the performance of CRISPR/Cas12-based biosensors, with emphasis on their practical applications. Specifically, progresses are highlighted in optimizing Cas effector proteins, CRISPR RNAs, and reaction buffer formulations. Diverse signal output methodologies are compared including fluorescence, colorimetry, electrochemical sensing, surface-enhanced Raman spectroscopy, and deep-learning-assisted detection techniques. Finally, challenges and future prospectives of CRISPR/Cas12-based biosensing technologies are discussed to help the development of optimal biosensing tools. © 2025

关键词： Error detection

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Brain-Conditional Multimodal Synthesis: A Survey and Taxonomy

IEEE Transactions on Artificial Intelligence

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IEEE Transactions on Artificial Intelligence 2025年第5期6卷 1080-1099页

作者： Mai, Weijian Zhang, Jian Fang, Pengfei Zhang, Zhijun South China University of Technology School of Automation Science and Engineering Guangzhou510640 China Southeast University School of Computer Science and Engineering Nanjing210096 China South China University of Technology Key Library of Autonomous Systems and Network Control Ministry of Education The School of Automation Science and Engineering Guangzhou510640 China Institute for Super Robotics Huangpu Guangzhou510555 China Nanchang University Jiangxi Thousand Talents Plan Nanchang330031 China Jishou University College of Computer Science and Engineering Jishou416000 China Guangdong Artificial Intelligence and Digital Economy Laboratory Pazhou Lab Guangzhou510335 China Shaanxi University of Technology Shaanxi Provincial Key Laboratory of Industrial Automation School of Mechanical Engineering Hanzhong723001 China Changsha Normal University School of Information Science and Engineering Changsha410100 China Guangdong University of Petrochemical Technology School of Automation Science and Engineering Institute of Artificial Intelligence and Automation Maoming525000 China

In the era of artificial intelligence generated content (AIGC), conditional multimodal synthesis technologies (e.g., text-to-image) are dynamically reshaping the natural content. Brain signals, serving as potential reflections of how the brain interprets external information, exhibit a distinctive one-to-many correspondence with various external modalities. This correspondence makes brain signals emerge as a promising guiding condition for multimodal synthesis (e.g., image, text, and audio), which is crucial for developing practical brain–computer interface systems and unraveling complex mechanisms underlying human perception. This survey comprehensively examines the emerging field of brain-conditional multimodal synthesis, termed AIGC-brain, to delineate the current landscape and future directions. To begin, related neuroimaging datasets and generative models are introduced as the foundation of AIGC-brain decoding and analysis. Next, we present a comprehensive taxonomy according to AIGC-brain methodologies, followed by task-specific representative work and implementation details to facilitate in-depth comparison and analysis. Quality assessments are then introduced for both qualitative and quantitative evaluation. Finally, this survey explores insights gained, outlining current challenges and prospects of AIGC-brain. As a pioneering survey, this article paves the way for future advances in AIGC-brain research. © 2020 IEEE.

关键词： Taxonomies

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Stochastic sub-gradient algorithm for distributed optimization with random sleep scheme

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控制理论与技术（英文版） 2015年第4期13卷 333-347页

作者： Peng YI Yiguang HONG Key Lab of Systems and Control Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China

In this paper, we consider a distributed convex optimization problem of a multi-agent system with the global objective function as the sum of agents’ individual objective functions. To solve such an optimization problem, we propose a distributed stochastic sub-gradient algorithm with random sleep scheme. In the random sleep scheme, each agent independently and randomly decides whether to inquire the sub-gradient information of its local objective function at each iteration. The algorithm not only generalizes distributed algorithms with variable working nodes and multi-step consensus-based algorithms, but also extends some existing randomized convex set intersection results. We investigate the algorithm convergence properties under two types of stepsizes: the randomized diminishing stepsize that is heterogeneous and calculated by individual agent, and the fixed stepsize that is homogeneous. Then we prove that the estimates of the agents reach consensus almost surely and in mean, and the consensus point is the optimal solution with probability 1, both under randomized stepsize. Moreover, we analyze the algorithm error bound under fixed homogeneous stepsize, and also show how the errors depend on the fixed stepsize and update rates.

关键词： Distributed optimization sub-gradient algorithm random sleep multi-agent systems randomized algorithm

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Linear Precoding Design for MIMO-PLC systems

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Tsinghua Science and Technology 2015年第2期20卷 155-163页

作者： Jisheng Peng the State Key Lab of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua Uinversity

In this paper, we consider the design of linear precoding in Multiple Input Multiple Output （MIMO） Power Line Communication （PLC） systems with finite-alphabet input. First, we derive mutual information of MIMO-PLC systems with impulsive noise. Considering the non-concavity of the objective function and the low-cost requirement of PLC systems, we choose the lower bound of the mutual information as the objective function. Subsequently, we propose a novel approach to design the precoding scheme to reduce computational complexity. Specifically, our work primarily includes the following two contributions：（1） We design the right unitary matrix that is a product of two fixed unitary matrices, which only depends on the modulation mode. Hence, the results can be saved and require less computations. （2） For the power allocation matrix, we first reduce the space of power allocation using constraints of the optimal power allocation policy. Consequently, we propose a non-linear search method to obtain the optimal power allocation in small space. In regards to the computational complexity of the analysis, we conclude that the proposed precoding matrix design scheme has low complexity and is easy to implement. Moreover, the numerical results are proven to demonstrate the performance of the proposed precoding design scheme.

关键词： precoding design MIMO-PLC impulsive noise finite-alphabet input

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Removal of sodium perfluorononyloxybenzenesulfonate (OBS) as an emerging PFAS contaminant from aquatic environments by magnetic ultrafine hydrotalcite adsorption-CPAM coagulation technique: Combined performance and mechanism

引用

Water Research 2025年 283卷 123792页

作者： Yang, Yuqing Zu, Siyi Zhang, Liqiu Liu, Yongze Jin, Jie Du, Ziwen Beijing Key Lab for Source Control Technology of Water Pollution College of Environmental Science and Engineering Beijing Forestry University Beijing100083 China China Engineering Research Center for Water Pollution Source Control & Eco-remediation College of Environmental Science and Engineering Beijing Forestry University Beijing100083 China MOE Key Laboratory of Resources and Environmental Systems Optimization College of Environmental Science and Engineering North China Electric Power University Beijing102206 China

The demand for effective remediation of aqueous per- and polyfluoroalkyl substances (PFAS), especially emerging PFAS, has constantly increased over the last few years. Although adsorption and coagulation are well-established techniques for PFAS remediation, adsorption reaction requires a long equilibrium time;coagulation performance deteriorates when PFAS concentration becomes lower. To address the challenges, an integrated approach which synergistically combined adsorption and coagulation was proposed in this study, using perfluorononenoxybenzenesulfonate (OBS) as the target emerging PFAS to evaluate performance. Ultrafine magnetic hydrotalcite (Fe3O4@LDHs), synthesized via a simple ball-milling process, served as the adsorbent in this approach. Such ultrafine material not only enhanced floc formation during coagulation but also showed rapid OBS adsorption via anion exchange. Cationic Polyacrylamide (CPAM) as the optimal coagulant contributed to OBS removal through electrostatic attraction driven by [R4N+] groups and hydrophobic interactions involving its alkyl chains. Under optimal dosage of CPAM (25 mg·L–1) and Fe3O4@LDHs (50 mg·L–1), the combined magnetic coagulation process achieved 99.89 % of OBS removal within 30 mins. Such combined method still showed effective performance in the presence of hydrocarbon organic competitors, achieving above 90 % removal of OBS from firefighting training wastewater with an acceptable dosing increase. The adsorption-coagulation technique provides a promising and fast solution for treating PFAS wastewater, such as firefighting and industrial wastewater. © 2025 Elsevier Ltd

关键词： Coagulation

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A new transient stability margin based on dynamic security region and its applications

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Science China(Technological Sciences) 2008年第6期51卷 751-760页

作者： XUE AnCheng1, 2 & MEI ShengWei1 1 State key lab of Power systems, Department of Electrical Engineering, Tsinghua University, Beijing 100084, China 2 key lab of systems and control, Institute of systems Science, Chinese Academy of Sciences, Beijing 100190, China State Key Lab of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China Key Lab of Systems Control Institute of Systems Science Chinese Academy of Sciences Beijing 100190 China

A new transient stability margin is proposed based on a new expression of dynamic security region (DSR) which is developed from the existing expression of DSR. Applications of the DSR based transient stability margin to contingency ranking and screening are discussed. Simulations in the 10-machine 39-bus New England system are performed to show the effectiveness of the proposed DSR based tran-sient stability margin.

关键词： dynamic security region (DSR) transient stability margin contingency screening

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Approximating the Spectral Abscissa for Switched Linear systems via Coordinate Transformations

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Journal of systems Science & Complexity 2016年第2期29卷 350-366页

作者： LIN Meili SUN Zhendong College of Automation Science and Engineering South China University of Technology Key Lab of Systems & Control Academy of Mathematics & Systems ScienceChinese Academy of Sciences

In this paper,an approach of square coordinate transformation is proposed to approximate the spectral abscissa for continuous-time switched linear *** applying elementary transformations iteratively,a series of minimums of least μ1 matrix set measures are obtained,which are utilized to approximate the spectral abscissa of the switched *** approach is developed into tractable numerical algorithms that provide upper bound estimates of the spectral *** simulations show the effectiveness of the proposed method.

关键词： Coordinate transformations matrix set measure spectral abscissa switched linear systems.

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Unconventional topological Weyl-dipole phonon

arXiv

引用

arXiv 2025年

作者： Wang, Jianhua Wang, Yang Zhou, Feng Wang, Wenhong Cheng, Zhenxiang Qian, Shifeng Wang, Xiaotian Yu, Zhi-Ming Institute for Superconducting and Electronic Materials Faculty of Engineering and Information Sciences University of Wollongong Wollongong2500 Australia Institute of Quantum Materials and Devices Tiangong University Tianjin300387 China Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systems School of Physics Beijing Institute of Technology Beijing100081 China Anhui Province Key Laboratory for Control and Applications of Optoelectronic Information Materials Department of Physics Anhui Normal University Anhui Wuhu241000 China

A pair of Weyl points (WPs) with opposite Chern numbers C can exhibit an additional higher-order Z2 topological charge, giving rise to the formation of a Z2 Weyl dipole. Owing to the nontrivial topological charge, Z2 Weyl dipoles should also appear in pairs, and the WPs within each Z2 Weyl dipole can not be annihilated when meeting together. As a novel topological state, the topological Weyl-dipole phase (TWDP) has garnered significant attention, yet its realization in crystalline materials remains a challenge. Here, through first-principles calculations and theoretical analysis, we demonstrate the existence of the Weyl-dipole phase in the phonon spectra of the P63 type Y(OH)3. Particularly, the Weyl dipole in this system is protected by a quantized quadrupole moment, and it distinguished from conventional Weyl dipole, as it comprises an unconventional charge-3 WP with C = −3 and three conventional charge-1 WPs with C = 1. Consequently, the Weyl-dipole phase in Y(OH)3 features unique two-dimensional (2D) sextuple-helicoid Fermi-arc states on the top and bottom surfaces, protected by the Chern number, as well as one-dimensional (1D) hinge states that connect the two Weyl dipoles along the side hinges, guaranteed by the quantized quadrupole moment. Our findings not only introduce a novel higher-order topological phase, but also promote Y(OH)3 as a promising platform for exploring multi-dimensional boundaries and the interaction between first-order and second-order topologies. Copyright © 2025, The Authors. All rights reserved.

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