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An ultra-thin bolt tension sensor and online monitoring system: For application in hydropower plant unit

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FRONTIERS OF STRUCTURAL AND CIVIL ENGINEERING 2024年第9期18卷 1388-1400页

作者： zhang, Shaoquan Tan, Yanke Ge, Hanbin zhang, Qilin Meijo Univ Dept Civil Engn Nagoya 4688502 Japan Tongji Univ Coll Civil Engn Shanghai 200092 Peoples R China

The condition of bolted connections significantly affects the structural safety. However, conventional bolt tension sensors fail to provide precise measurements due to their bulky size or inadequate stability. This study employs the piezoresistive effect of crystalline silicon material to fabricate an ultrathin sensor. The sensor exhibits a linear relationship between pressure and voltage, an exceptional stability at varying temperatures, and a superior resistance to corrosion, making it adaptable and user-friendly for applications of high-strength bolt tension monitoring. A monitoring system, incorporating the proposed sensor, has also been developed. This system provides real-time display of bolt tension and enables the assessment of sensor and structural conditions, including bolt loosening or component failure. The efficacy of the proposed sensor and monitoring system was validated through a project carried out at the Xiluodu Hydropower Plant. According to the results, the sensor and online monitoring system effectively gauged and proficiently conveyed and stored bolt tension data. In addition, correlations were created between bolt tensions and essential unit parameters, such as water head, active power, and pressures at vital points, facilitating anomaly detection and early warning.

关键词： ultra-thin sensor high-strength bolt tension online monitoring system anomaly alarm hydro-generator units

Integrated strategy for real-time wind power fluctuation mitigation and energy storage system control

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Global Energy Interconnection 2024年第1期7卷 71-81页

作者： Yu zhang Yongkang zhang Tiezhou wu Hubei University of Technology Hubei Key Laboratory of Solar Energy Efficient Utilization and Energy Storage Operation ControlHubeiWuhan 430068P.R.China

To address the impact of wind-power fluctuations on the stability of power systems,we propose a comprehensive approach that integrates multiple strategies and methods to enhance the efficiency and reliability of a ***,we employ a strategy that restricts long-and short-term power output deviations to smoothen wind power fluctuations in real ***,we adopt the sliding window instantaneous complete ensemble empirical mode decomposition with adaptive noise(Sw-ICEEMDAN)strategy to achieve real-time decomposition of the energy storage power,facilitating internal power distribution within the hybrid energy storage ***,we introduce a rule-based multi-fuzzy control strategy for the secondary adjustment of the initial power allocation commands for different energy storage *** simulation validation,we demonstrate that the proposed comprehensive control strategy can smoothen wind power fluctuations in real time and decompose energy storage *** with traditional empirical mode decomposition(EMD),ensemble empirical mode decomposition(EEMD),and complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN)decomposition strategies,the configuration of the energy storage system under the Sw-ICEEMDAN control strategy is more ***,the state-of-charge of energy storage components fluctuates within a reasonable range,enhancing the stability of the power system and ensuring the secure operation of the energy storage system.

关键词： Sw-ICEEMDAN HESS Real-time smoothing Rule-based multi-fuzzy control SoC

Bifunctional passivation by lewis-base molecules for efficient printable mesoscopic perovskite solar cells

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Journal of Energy Chemistry 2024年第9期96卷 177-184页

作者： Hang Yang Jianhong Zhao Xiaodong Ren Tong Zhou Henbing zhang.w.ilong zhang Jin zhang Guangzhi Hu Yuming zhang.w.n-Hua zhang Qingju Liu Yunnan Key Laboratory for Micro/Nano Materials & Technology National Center for International Research on Photoelectric and Energy Materials School of Materials and Energy Yunnan UniversityKunming 650091YunnanChina Institute for Ecological Research and Pollution Control of Plateau Lakes School of Ecology and Environmental Science Yunnan UniversityKunming 650091YunnanChina

Printable mesoscopic perovskite solar cells(PM-PSCs)possess notable merits in terms of cost-effectiveness,easy manufacturing,and large scale ***,the absence of a hole transport layer contributes to the exacerbation of carrier recombination,and the defects between the perovskite and electron transport layer(ETL)interfaces significantly decrease the efficiency of the *** this study,a bifunctional surface passivation approach is proposed by applying a thioacetamide(TAA)surfactant on the mesoporous TiO_(2)*** results demonstrate that TAA molecules could interact with TiO_(2),thereby diminishing the oxygen vacancy ***,the amino group and sulfur atoms in TAA molecules act as Lewis base to effectively passivate the uncoordinated Pb^(2+)in perovskite and improve the morphology of perovskite,and decrease the trap-state density of *** TAA passivation mechanism improves the alignment of energy levels between TiO_(2)and perovskite,facilitating electron transport and reducing carrier ***,the TAA-passivated device achieved a champion power conversion efficiency(PCE)of 17.86%with a high fill factor(FF)of 79.16%and an open-circuit voltage(V_(OC))of 0.971 *** investigation presents a feasible strategy for interfacial passivation of the ETL to further improve the efficiency of PM-PSCs.

关键词： Perovskite solarcells Carbon electrode Thioacetamide Interfacial passivation

A Possible γ-Ray Pulsation from PSR J1740-5340B in the Globular Cluster NGC 6397

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Research in Astronomy and Astrophysics 2024年第1期24卷 285-291页

作者： Jiao Zheng Pengfei zhang Li zhang Department of Astronomy School of Physics and AstronomyKey Laboratory of Astroparticle Physics of Yunnan ProvinceYunnan UniversityKunming 650091China

Recently, a new radio millisecond pulsar(MSP) J1740-5340B, hosted in the globular cluster(GC) NGC 6397,was reported with a 5.78 ms spin period in an eclipsing binary system with a 1.97 days orbital period. Based on a modified radio ephemeris updated by tool tempo2, we analyze the ~15 yr γ-ray data obtained from the Large Area Telescope on board the Fermi Gamma-ray Space Telescope and detect PSR J1740-5340B's γ-ray pulsation at a confidence level of ~4σ with a weighted H-test value of ~26. By performing a phase-resolved analysis, the γ-ray luminosity in on-pulse interval of PSR J1740-5340B is L_(γ)~ 3.8 × 10^(33) erg s^(-1) using NGC 6397's distance of 2.48 kpc. And γ-rays from the on-pulse part of PSR J1740-5340B contribute ~90% of the total observed γ-ray emissions from NGC 6397. No significant γ-ray pulsation of another MSP J1740-5340A in the GC is *** that the previous four cases of MSPs in GCs, more data in γ-ray, X-ray, and radio are encouraged to finally confirm the γ-ray emissions from MSP J1740-5340B, especially starving for a precise ephemeris.

关键词： gamma-rays:galaxies (stars:)pulsars:individual(PSR J1740-5340B) (Galaxy:)globular clusters:individual(NGC 6397)

Integration of Multiple Spectral Data via a Logistic Regression Algorithm for Detection of Crop Residue Burned Areas:A Case Study of Songnen Plain,Northeast China

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Chinese Geographical Science 2024年第3期34卷 548-563页

作者： zhang Sumei zhang Yuan ZHAO Hongmei College of Mining and Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China

The burning of crop residues in fields is a significant global biomass burning activity which is a key element of the terrestrial carbon cycle,and an important source of atmospheric trace gasses and *** estimation of cropland burned area is both crucial and challenging,especially for the small and fragmented burned scars in *** we developed an automated burned area mapping algorithm that was implemented using Sentinel-2 Multi Spectral Instrument(MSI)data and its effectiveness was tested taking Songnen Plain,Northeast China as a case using satellite image of *** employed a logistic regression method for integrating multiple spectral data into a synthetic indicator,and compared the results with manually interpreted burned area reference maps and the Moderate-Resolution Imaging Spectroradiometer(MODIS)MCD64A1 burned area *** overall accuracy of the single variable logistic regression was 77.38%to 86.90%and 73.47%to 97.14%for the 52TCQ and 51TYM cases,*** comparison,the accuracy of the burned area map was improved to 87.14%and 98.33%for the 52TCQ and 51TYM cases,respectively by multiple variable logistic regression of Sentind-2 *** balance of omission error and commission error was also *** integration of multiple spectral data combined with a logistic regression method proves to be effective for burned area detection,offering a highly automated process with an automatic threshold determination *** method exhibits excellent extensibility and flexibility taking the image tile as the operating *** is suitable for burned area detection at a regional scale and can also be implemented with other satellite data.

关键词： crop residue burning burned area Sentinel-2 Multi Spectral Instrument(MSI) logistic regression Songnen Plain,China

Fully distributed dynamic event-triggered formation-containment tracking for multiagent systems with multiple types of disturbances

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Science China(Information Sciences) 2024年第1期67卷 168-186页

作者： weihua LI Huaguang zhang Juan zhang Rui wANG College of Information Science and Engineering Northeastern University State Key Laboratory of Synthetical Automation for Process Industries Northeastern University

This paper is dedicated to addressing the time-varying output formation-containment tracking(TVOFCT) problem for heterogeneous linear multiagent systems(MASs) with multiple types of disturbances under directed communication *** agents are divided into tracking leaders,formation leaders,and *** the output space,the formation leaders are required to form an expected geometric formation while tracking the tracking leader,and the followers are required to enter the convex hull spanned by formation ***,a disturbance observer is designed to observe the disturbance with deterministic ***,by combining adaptive technology with event-triggered technology,an independent fully distributed dynamic event-triggered(FDDET) compensator is designed to estimate the state of the tracking *** main advantages of this compensator lie in the following three aspects:(1) the adaptive weight does not increase unboundedly;(2) the interval time between events is expanded;(3) the design does not rely on any global *** to the design of this compensator,an independent FDDET convex hull observer is further designed to observe the convex hull spanned by formation ***,based on the designed disturbance observer,compensator,and convex hull observer,the adaptive disturbance rejection control input which can make the MASs achieve TVOFCT is ***,a numerical simulation is provided to clearly verify the validity of the theoretical results.

关键词： formation-containment tracking disturbance rejection multiagent systems fully distributed control dynamic event-triggered control

A hierarchical enhanced data-driven battery pack capacity estimation framework for real-world operating conditions with fewer labeled data

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Journal of Energy Chemistry 2024年第4期91卷 417-432页

作者： Sijia Yang Caiping zhang Haoze Chen Jinyu wang Dinghong Chen Linjing zhang.w.ige zhang National Active Distribution Network Technology Research Center(NANTEC) Beijing Jiaotong UniversityBeijing 100044China

Battery pack capacity estimation under real-world operating conditions is important for battery performance optimization and health management,contributing to the reliability and longevity of batterypowered ***,complex operating conditions,coupling cell-to-cell inconsistency,and limited labeled data pose great challenges to accurate and robust battery pack capacity *** address these issues,this paper proposes a hierarchical data-driven framework aimed at enhancing the training of machine learning models with fewer labeled *** traditional data-driven methods that lack interpretability,the hierarchical data-driven framework unveils the“mechanism”of the black box inside the data-driven framework by splitting the final estimation target into cell-level and pack-level intermediate targets.A generalized feature matrix is devised without requiring all cell voltages,significantly reducing the computational cost and memory *** generated intermediate target labels and the corresponding features are hierarchically employed to enhance the training of two machine learning models,effectively alleviating the difficulty of learning the relationship from all features due to fewer labeled data and addressing the dilemma of requiring extensive labeled data for accurate *** only 10%of degradation data,the proposed framework outperforms the state-of-the-art battery pack capacity estimation methods,achieving mean absolute percentage errors of 0.608%,0.601%,and 1.128%for three battery packs whose degradation load profiles represent real-world operating *** high accuracy,adaptability,and robustness indicate the potential in different application scenarios,which is promising for reducing laborious and expensive aging experiments at the pack level and facilitating the development of battery technology.

关键词： Lithium-ion battery pack Capacity estimation Label generation Multi-machine learning model Real-world operating

CF-DAN: Facial-expression recognition based on cross-fusion dual-attention network

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Computational Visual Media 2024年第3期10卷 593-608页

作者： Fan zhang Gongguan Chen Hua wang Caiming zhang Shandong Technology and Business University Shandong 264005China School of Information and Electrical Engineering Ludong UniversityYantai 264025China Shangdong University Shandong 250100China

Recently, facial-expression recognition (FER)has primarily focused on images in the wild, includingfactors such as face occlusion and image blurring, ratherthan laboratory images. Complex field environmentshave introduced new challenges to FER. To addressthese challenges, this study proposes a cross-fusion dualattention network. The network comprises three parts:(1) a cross-fusion grouped dual-attention mechanism torefine local features and obtain global information;(2) aproposed C2 activation function construction method,which is a piecewise cubic polynomial with threedegrees of freedom, requiring less computation withimproved ﬂexibility and recognition abilities, whichcan better address slow running speeds and neuroninactivation problems;and (3) a closed-loop operationbetween the self-attention distillation process andresidual connections to suppress redundant informationand improve the generalization ability of the *** recognition accuracies on the RAF-DB, FERPlus,and AffectNet datasets were 92.78%, 92.02%, and63.58%, respectively. Experiments show that this modelcan provide more effective solutions for FER tasks.

关键词： facial-expression recognition(FER) cubic polynomial activation function dualattention mechanism interactive learning self-attention distillation

The multiple roles of crop structural change in productivity,nutrition and environment in China:A decomposition analysis

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Journal of Integrative Agriculture 2024年第5期23卷 1763-1773页

作者： Xiangyang zhang Yumei zhang Shenggen Fan College of Economics and Management China Agricultural UniversityBejing 100083China Academy of Global Food Economics and Policy China Agricultural UniversityBejing 100083China

China's crop structure has undergone significant changes in the last two decades since 2000,with an increase in the share of cereals,vegetables,and fruit,squeezing out other *** a result,land productivity,nutrient supply,and carbon emissions have *** to reallocate limited farmland among crops to achieve the multiple goals of agrifood systems becomes an important *** study explores the sources of land productivity and nutrition supply growth and carbon emissions reduction,and identifies the multiple roles of crop structural change from 2003 to 2020 based on a decomposition *** results reveal that the growth within crops is still the primary driver in land productivity and nutrition supply and the reduction in carbon ***,structural change also plays various roles at different *** 2003 to 2010,crop structural change increased the total calorie supply but lowered land productivity and contributed at least 70%of the total growth of carbon *** crop structure was relatively stable,and their effects were modest from 2010 to *** 2015 to 2020,the crop structural change began to play a greater role and generate synergistic effects in improving land productivity,micronutrient supply,and reducing carbon emissions,contributing to approximately a quarter of the growth of land productivity and 30%of total carbon emissions *** results suggest that strategies for crop structural change should comprehensively consider its multiple impacts,aiming to achieve co-benefits while minimizing trade-offs.

关键词： crop structural change land productivity nutrition carbon emissions