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Feature Selection Using Tree Model and Classification Through Convolutional Neural Network for Structural Damage Detection

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Acta Mechanica Solida Sinica 2024年第3期37卷 498-518页

作者： Zihan jin Jiqiao Zhang Qianpeng He Silang zhu Tianlong Ouyang Gongfa Chen School of Civil and Transportation Engineering Guangdong University of TechnologyGuangzhou510006China Guangdong Tianxin Electric Power Engineering Testing Co. LtdGuangzhou510663China

Structural damage detection(SDD)remains highly challenging,due to the difficulty in selecting the optimal damage features from a vast amount of *** this study,a tree model-based method using decision tree and random forest was employed for feature selection of vibration response signals in *** datasets were obtained by numerical experiments and vibration experiments,*** features extracted using this method were input into a convolutional neural network to determine the location of structural *** indicated a 5%to 10%improvement in detection accuracy compared to using original datasets without feature selection,demonstrating the feasibility of this *** proposed method,based on tree model and classification,addresses the issue of extracting effective information from numerous vibration response signals in structural health monitoring.

关键词： Feature selection Structural damage detection Decision tree Random forest Convolutional neural network

Effect of Low-Temperature Thermal Oxidation on the Capillary Performance of Sintered Copper Powder Wicks

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Journal of Thermal Science 2024年第1期33卷 29-40页

作者： zhu Minghan FANG Runquan HU Yanxin ZHANG Jiangyun SHAO Dan HUANG jin School of Material and Energy Guangdong University of TechnologyGuangzhou 510006China School of Electric Power Engineering Guangdong Polytechnic of Water Resources and Electric EngineeringGuangzhou 510006China Research into Artifacts Guangdong Key Laboratory of Battery SafetyGuangzhou Institute of Energy testingGuangzhou 511447China

In this study,a composite powder capillary wick is prepared,manufactured by sintering copper powder and surface treated by low-temperature thermal *** is used to improve the performance of the capillary *** forced flow method and infrared imaging method are used to test the permeability and capillary performance of the *** effects of different oxidation temperatures on the performance of capillary wick are *** experimental results show that the wetting performance of the oxidized samples is significantly *** the increase of oxidation temperature,the permeability *** capillary height and velocity of the thermally oxidized samples are significantly higher than those of the untreated capillary ***,the oxidation temperature needs to be adjusted to obtain the best capillary *** highest capillary performance is found at oxidation temperature of 300℃,with an increase of 46% compared to the untreated *** with other composite wicks show that the sample with an oxidation temperature of 300℃ has competitive capillary performance,making it a favorable alternative to two-phase heat transfer *** study shows that combining low-temperature thermal oxidation technology with powder sintering is a convenient and effective method to improve the capillary performance of powder wicks.

关键词： low-temperature thermal oxidation capillary performance copper powder permeability

Low-Carbon Dispatching for Virtual Power Plant with Aggregated Distributed Energy Storage Considering Spatiotemporal Distribution of Cleanness Value

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 346-358页

作者： Hongchao Gao Tai jin Guanxiong Wang Qixin Chen Chongqing Kang jingkai zhu State Key Laboratory of Power System Operation and Control Department of Electrical EngineeringTsinghua UniversityBeijing 100084China Sichuan Energy Internet Research Institute Tsinghua University Chengdu 200016China Power Dispatching and Control Center of Shanghai Municipal Electric Power Company Shanghai 200122China IEEE

The scale of distributed energy resources is increasing,but imperfect business models and value transmission mechanisms lead to low utilization ratio and poor *** address this issue,the concept of cleanness value of distributed energy storage(DES)is proposed,and the spatiotemporal distribution mechanism is discussed from the perspectives of electrical energy and *** on this,an evaluation system for the environmental benefits of DES is constructed to balance the interests between the aggregator and the power system ***,an optimal low-carbon dispatching for a virtual power plant(VPP)with aggregated DES is constructed,where-in energy value and cleanness value are both *** achieve the goal,a green attribute labeling method is used to establish a correlation constraint between the nodal carbon potential of the distribution network(DN)and DES behavior,but as a cost,it brings multiple nonlinear ***,a solution method based on the convex envelope(CE)linear re-construction method is proposed for the multivariate nonlinear programming problem,thereby improving solution efficiency and ***,the simulation verification based on the IEEE 33-bus DN is *** simulation results show that the multidimensional value recognition of DES motivates the willingness of resource users to ***,resolving the impact of DES on the nodal carbon potential can effectively alleviate overcompensation of the cleanness value.

关键词： Distributed energy storage virtual power plant(VPP) spatiotemporal distribution low-carbon dispatching

Vulnerability assessment of UAV engine to laser based on improved shotline method

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Defence Technology（防务技术） 2024年第3期33卷 588-600页

作者： Le Liu Chengyang Xu Changbin Zheng Sheng Cai Chunrui Wang jin guo Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China University of Chinese Academy of Sciences Beijing 100049China

Laser anti-drone technology is entering the sequence of actual combat,and it is necessary to consider the vulnerability of typical functional parts of *** the concept of"vulnerability"was proposed,a variety of analysis programs for battlefield targets to traditional weapons have been developed,but a comprehensive assessment methodology for targets'vulnerability to laser is still *** on the shotline method,this paper proposes a method that equates laser beam to shotline array,an efficient vulnerability analysis program of target to laser is established by this method,and the program includes the circuit board and the wire into the vulnerability analysis category,which improves the precision of the vulnerability *** the UAV engine part as the target of vulnerability analysis,combine with the"life-death unit method"to calculate the laser penetration rate of various materials of the UAV,and the influence of laser weapon system parameters and striking orientation on the killing probability is quantified after introducing the penetration rate into the vulnerability analysis *** quantitative analysis method proposed in this paper has certain general expansibility,which can provide a fresh idea for the vulnerability analysis of other targets to laser.

关键词： Laser weapon Laser damage Vulnerability UAV Engine Killing probability

An integrated portable bio-monitoring system based on tough hydrogels for comprehensive detection of physiological activities

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Nano Research 2024年第1期17卷 321-332页

作者： Congcong Yang Chenchen Ji Fengjiao guo Chunjiang jin Hongyu Mi Zhongchang Wang State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources School of Chemical Engineering and TechnologyXinjiang UniversityUrumqi 830017China International Iberian Nanotechnology Laboratory(INL) Avenide Mestre Jose VeigaBraga 4715-330Portugal

Advanced soft ion-conducting hydrogels have been developed rapidly in the integrated portable health monitoring equipment due to their higher sensitivity,sensory traits,tunable conductivity,and stretchability for physiological activities and personal healthcare ***,traditional hydrogel conductors are normally susceptible to large deformation and strong mechanical stress,which leads to inferior electro-mechanical stability for real application ***,a strong ionically conductive hydrogel(poly(vinyl alcohol)-boric acid-glycerol/sodium alginate-calcium chloride/electrolyte ions(PBG/SC/EI))was designed by engineering the covalently and ionically crosslinked networks followed by the salting-out effect to further enhance the mechanical strength and ionic conductivity of the *** to the collective effects of the energy-dissipation mechanism and salting-out effect,the designed PBG/SC/EI with excellent structural integrity and robustness exhibits exceptional mechanical properties(elongation at break for 559.1%and tensile strength of 869.4 kPa)and high ionic conductivity(1.618 S·m^(-1)).As such,the PBG/SC/EI strain sensor features high sensitivity(gauge factor=2.29),which can effectively monitor various kinds of human motions(joint motions,facial micro-expression,faint respiration,and voice recognition).Meanwhile,the hydrogel-based Zn||MnO_(2)battery delivers a high capacity of 267.2 mAh·g^(-1)and a maximal energy density of 356.8 Wh·kg^(-1)associated with good cycle performance of 71.8%capacity retention after 8000 ***,an integrated bio-monitoring system with the sensor and Zn||MnO_(2)battery can accurately identify diverse physiological activities in a real-time and non-invasive *** work presents a feasible strategy for designing high-performance conductive hydrogels for highly-reliable integrated bio-monitoring systems with excellent practicability.

关键词： Ionically conductive hydrogel strain sensor Zn-based battery integrated bio-monitoring system human motion monitoring

Magnetic phase transition and continuous spin switching in a high-entropy orthoferrite single crystal

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Frontiers of physics 2024年第2期19卷 157-167页

作者： Wanting Yang Shuang zhu Xiong Luo Xiaoxuan Ma Chenfei Shi Huan Song Zhiqiang Sun Yefei guo Yuriy Dedkov Baojuan Kang jin-Ke Bao Shixun Cao Department of Physics Shanghai UniversityShanghai 200444China Materials Genome Institute and International Center for Quantum and Molecular Structures Shanghai UniversityShanghai 200444China School of Physics Southeast UniversityNanjing 211189China Shanghai Key Laboratory of High Temperature Superconductors Shanghai UniversityShanghai 200444China

Rare-earth orthoferrite REFeO_(3)(where RE is a rare-earth ion)is gaining *** created a high-entropy orthoferrite(Tm_(0.2)Nd_(0.2)Dy_(0.2)Y_(0.2)Yb_(0.2))FeO_(3)(HEOR)by doping five RE ions in equimolar ratios and grew the single crystal by optical floating zone *** strongly tends to form a single-phase structure stabilized by high configurational *** the low-temperature region(11.6‒14.4 K),the spin reorientation transition(SRT)ofΓ_(2)(F_(x),C_(y),G_(z))‒Γ_(24)‒Γ_(4)(G_(x),A_(y),F_(z))*** weak ferromagnetic(FM)moment,which comes from the Fe sublattices distortion,rotates from the a-to *** two-step dynamic processes(Γ_(2)‒Γ_(24)‒Γ_(4))are identified by AC susceptibility *** in HEOR can be tuned in the range of 50‒60000 Oe,which is an order of magnitude larger than that of orthoferrites in the peer system,making it a candidate for high-field spin *** spin-switching(SSW)and continuous spin-switching(CSSW)effects occur under low magnetic fields due to the strong interactions between RE‒Fe *** CSSW effect is tunable between 20‒50 Oe,and hence,HEOR potentially can be applied to spin modulation ***,because of the strong anisotropy of magnetic entropy change()and refrigeration capacity(RC)based on its high configurational entropy,HEOR is expected to provide a novel approach for refrigeration by altering the orientations of the crystallographic axes(anisotropic configurational entropy).

关键词： high-entropy oxide rare-earth orthoferrite spin reorientation transition spin switching magnetocaloric effect

Interdecadal changes in the western Siberian summer mean and extreme rainfall during 1982-2021

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Atmospheric and Oceanic Science Letters 2024年第3期17卷 37-41页

作者： Yali zhu Fangwu Song Dong guo Nansen-zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjingChina Carbon Neutrality Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijingChina

本文研究发现,西西伯利亚夏季降水在1995年后显著增加,2012年后又有所减少,极端降水日数和强度呈现一致的变化特征.伴随这两次降水的年代际增加/减少,西西伯利亚上空出现异常气旋/反气旋和水汽幅合/幅散.极端降水发生时的区域环流特征... 详细信息

本文研究发现,西西伯利亚夏季降水在1995年后显著增加,2012年后又有所减少,极端降水日数和强度呈现一致的变化特征.伴随这两次降水的年代际增加/减少,西西伯利亚上空出现异常气旋/反气旋和水汽幅合/幅散.极端降水发生时的区域环流特征在三个时段基本一致:西西伯利亚低空出现气旋性异常,高空为西北-东南向的异常气旋-反气旋偶极子型.1995-2011年期间,极端降水日数更多,强度更强,上述异常环流型也更强.

关键词：西伯利亚夏季降水年代际变化乌拉尔高压北大西洋波流相互作用

Emerging high-entropy strategy: A booster to the development of cathode materials for power batteries

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Journal of Advanced Ceramics 2024年第8期13卷 1093-1118页

作者： Liping Huang jinging zhu J-Xuan Liu Houzheng Wu guo-Jun Zhang State Key Laboratory for Modification of Chemical Fibers and Polymer Materials Institute of Functional MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai 201620China SIAMC Advanced Materials Cooperation Huzhou 313100China

The coordinated development of new energy vehicles and the energy storage industry has become essential for reducing carbon *** cathode material is the key material that determines the energy density and cost of a power battery,but currently developed and applied cathode materials cannot meet the requirements for high specific capacity,low cost,safety,and good ***-entropy materials(HEMs)are a new type of single-phase material composed of multiple principal elements in equimolar or near-equimolar *** interaction between multiple elements can play an important role in improving the comprehensive properties of the material,which is expected to solve the limitations of battery materials in practical ***,this review provides a comprehensive overview of the current development status and modification strategies of power batteries(lithium-ion batteries(LiBs)and sodium-ion batteries(SIBs)),proposes a high-entropy design strategy,and analyses the structure-activity relationship between the high-entropy effects and battery ***,future research topics related to high-entropy cathode materials,including computational guide design,specific synthesis methods,high-entropy electrochemistry,and high-throughput databases,are *** review aims to provide practical guidance for the development of high-entropy cathode materials for next-generation power batteries.

关键词： cathode materials lithium-ion battery(LIB) sodium-ion battery(SIB) high-entropy strategy

Metal/covalent organic frameworks for aqueous rechargeable zinc-ion batteries

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Science China Chemistry 2024年第1期67卷 247-259页

作者： Hu Hong Xun guo Jiaxiong zhu zhuoxi Wu Qing Li Chunyi Zhi Department of Materials Science and Engineering City University of Hong KongHong Kong 999077China

Lithium-ion batteries(LIBs)have become one of the most successful energy storage systems due to their high operating voltage,high energy density,and long cycle ***,with the widespread use of LIBs in recent decades,lithium resources are at risk of being ***,it is necessary to find a substitute for LIBs to meet the needs of future large-scale energy storage *** of their competitiveness,low cost,and high safety,aqueous rechargeable zinc-ion batteries(ARZIBs)are regarded as promising components in the post-lithium-ion-battery *** the tunable composition,ordered porous channels,and controllable structure of metal-organic frameworks(MOFs)and covalent organic frameworks(COFs),these frameworks are viewed as potential materials for developing high-performance *** this review,we focus on the recent developments in the applications of MOF-/COF-based materials in ARZIBs,including in electrode materials,anode modifications,separators,and solid *** then focus on the critical factors and optimization techniques of MOF-/COF-based materials that affect the performance of ***,we conclude with some projections for the expansion of ARZIBs containing MOF-/COF-based materials.

关键词： metal/covalent organic frameworks aqueous zinc-ion batteries electrode materials anode modifications separators electrolytes