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High Voltage 2024年第1期9卷 163-171页

作者： Li Cai Yifeng Ke Wenchao Fan Ruisheng Yan Mi Zhou Jianguo Wang Yadong Fan engineering Research Center of Ministry of Education for lightning protection and Grounding Technology School of Electrical Engineering and AutomationWuhan UniversityWuhanChina

As the wind turbine height increases,the probability of multiple upward leaders flashes within the wind farm increases.In this study,an upward lightning flash containing 21 upward positive leaders(UPLs)initiated from different wind turbines in Zhangbei Wind Farm was analysed.The average speed of the UPLs was 1.2×10^(5) m/s,which mostly decreased to zero before reaching the cloud height.Only four UPLs developed to cloud height,with prolonged periods of bright light on three of them and with a minimum duration of 126 ms.A total of nine return strokes occurred on the other two dissipated leader channels,and the numbers of strokes on the two channels was six and three,respectively.The average interstroke interval for the return strokes was 10.5 ms.Most of these nine return strokes had peak currents smaller than 10 kA.The high-speed video frames confirmed that competition does exist between the UPLs,and the range of shielding effects increases as the height of the ULs increases.The effect of fan rotation on the initiation of upward leaders and the shielding effect between the wind turbines and upward leaders are discussed.

关键词： flash return initiated

Assessing target optical camouflage effects using brain functional networks:A feasibility study

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Defence Technology（防务技术） 2024年第4期34卷 69-77页

作者： Zhou Yu Li Xue Weidong Xu Jun Liu Qi Jia Jianghua Hu Jidong Wu National Key laboratory of lightning protection and Electromagnetic Camouflage Army engineering University Nanjing 210007JiangsuChina Unit 31608 of PLA Xiamen 361000FujianChina School of Biological Sciences&Medical engineering Southeast UniversityNanjing 210096JiangsuChina

Brain functional networks model the brain's ability to exchange information across different regions,aiding in the understanding of the cognitive process of human visual attention during target searching,thereby contributing to the advancement of camouflage evaluation.In this study,images with various camouflage effects were presented to observers to generate electroencephalography(EEG)signals,which were then used to construct a brain functional network.The topological parameters of the network were subsequently extracted and input into a machine learning model for training.The results indicate that most of the classifiers achieved accuracy rates exceeding 70%.Specifically,the Logistic algorithm achieved an accuracy of 81.67%.Therefore,it is possible to predict target camouflage effectiveness with high accuracy without the need to calculate discovery probability.The proposed method fully considers the aspects of human visual and cognitive processes,overcomes the subjectivity of human interpretation,and achieves stable and reliable accuracy.

关键词： Camouflage effect evaluation Electroencephalography(EEG) Brain functional networks Machine learning

Molecular design of recyclable thermosetting polyimide and its composite with excellent mechanical and tribological properties

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Friction 2024年第3期12卷 452-461页

作者： Xiaoyue WANG Zenghui YANG Tingmei WANG Qihua WANG Xinrui ZHANG Song LI Key laboratory of Science and Technology on Wear and protection of Materials Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics engineering University of Chinese Academy of SciencesBeijing 100049China State Key laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

Recyclability of thermosetting polymers and their composites is a challenge for alleviating environmental pollution and resource waste.In this study,solvent-recyclable thermosetting polyimide(PI)and its composite were successfully synthesized.The tensile strength,elongation at break,and Young’s modulus of PI are 108.70±7.29 MPa,19.35%±3.89%,and 2336.42±128.00 MPa,respectively.The addition of reduced graphene oxide(RGO)not only enhances the mechanical properties of PI but also endows it with excellent tribological properties.The PI illustrates a high recycling efficiency of 94.15%,but the recycled composite exhibits inferior mechanical properties.The recycling and utilization of PI and its composite are realized through imine bonds(-C=N),which provides new guidance for solving the problem of environmental pollution and resource waste and is potential application in the field of sustainable tribology.

关键词： thermosetting polyimide(PI) recyclability dynamic covalent bonds friction and wear polymer composites

Tribological properties of PTFE-based fabric composites at cryogenic temperature

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Friction 2024年第2期12卷 245-257页

作者： Mingkun XU Zidan WANG Lihe GUO Liming TAO Tianbao MA Tingmei WANG Qihua WANG Key laboratory of Science and Technology on Wear and protection of Materials Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China State Key laboratory of Tribology Tsinghua UniversityBeijing 100084China Center of Materials Science and Optoelectronics engineering University of Chinese Academy of SciencesBeijing 100049China

Fabric composites are widely employed in self-lubricating bearing liners as solid lubrication materials.Although the tribological behaviors of fabric composites have been extensively studied,the cryogenic tribological properties and mechanisms have been scarcely reported and are largely unclear to instruct material design for aerospace and other high-tech applications.Herein,the tribological properties of polytetrafluoroethylene(PTFE)-based hybrid-fabric composites were investigated at cryogenic and ambient temperatures in the form of pin-on-disk friction under heavy loads.The results suggest that the friction coefficients of the hybrid-fabric composites obviously increase with a decrease in wear when the temperature drops from 25 to−150°C.Moreover,thermoplastic polyetherimide(PEI),as an adhesive for fabric composites,has better cryogenic lubrication performance than thermosetting phenol formaldehyde(PF)resin,which can be attributed to the flexible chemical structure of PEI.The excellent lubrication performance of hybrid-fabric composites is attributed to the transfer film formed by PTFE fibers on the surface of fabrics.

关键词： cryogenic temperatures fabric composites friction and wear transfer film

Unveiling non-radiative center control in CsPbBr_(3) nanocrystals:A comprehensive comparative analysis of hot injection and ligandassisted reprecipitation approaches

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Nano Research 2024年第5期17卷 4525-4534页

作者： Daocheng Hong Yuchen Zhang Shuhan Pan Hanyu Liu Wei Mao Wanli Zhang Yuhui Ye Zhihong Wei Xuxing Lu Xiaoyong Wang Zhenda Lu Yuxi Tian Key laboratory for Advanced Technology in Environmental protection of Jiangsu Province Yancheng Institute of TechnologyYancheng 224051China laboratory of Mesoscopic Chemistry of MOE School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China College of engineering and Applied Sciences Nanjing UniversityNanjing 210023China National laboratory of Solid State Microstructures School of PhysicsCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China School of Electronic Electrical Engineering and PhysicsFujian University of TechnologyFuzhou 350118China

Metal-halide perovskite nanocrystals(NCs)have gained significant attention in the field of optoelectronic and photonic devices due to their promising applications.Despite their exceptional optical properties,the impact of different synthetic strategies on the fundamental nature of NCs,such as nonradiative recombination centers,remains poorly understood.In this study,we investigated the photophysical properties of CsPbBr_(3) NCs synthesized using two distinct methods,hot injection and ligand-assisted reprecipitation,at the individual particle level.We observed different blinking behaviors under specific photoexcitation power densities and proposed,through intensity-lifetime analysis and Monte-Carlo simulations,that these different synthetic strategies can fabricate NCs with similar crystal structures but distinct surface quenchers with varying energy levels,which significantly affected the photo-induced blinking-down and blinking-up behaviors in individual NCs.Our findings indicate a practical and feasible approach for controlling defect engineering in perovskite NCs,with significant implications for their use in optoelectronic and other technological applications.

关键词： metal-halide perovskite nanocrystals photophysical properties nonradiative recombination centers hot injection method ligand-assisted reprecipitation

Facile low-temperature supercritical carbonization method to prepare high-loading nickel single atom catalysts for efficient photodegradation of tetracycline

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Journal of Environmental Sciences 2024年第4期138卷 373-384页

作者： Han Qiao Lirong Zheng Shiwen Hu Gang Tang Hongri Suo Chongxuan Liu School of Environment Harbin Institute of TechnologyHarbin 150090China State Environmental protection Key laboratory of Integrated Surface Water-Groundwater Pollution Control School of Environmental Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China Beijing Synchrotron Radiation Facility(BSRF) Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China

Environmental photocatalysis is a promising technology for treating antibiotics in wastewater.In this study,a supercritical carbonization method was developed to synthesize a single-atom photocatalyst with a high loading of Ni(above 5 wt.%)anchored on a carbonnitrogen-silicate substrate for the efficient photodegradation of a ubiquitous environmental contaminant of tetracycline(TC).The photocatalyst was prepared from an easily obtained metal-biopolymer-inorganic supramolecular hydrogel,followed by supercritical drying and carbonization treatment.The low-temperature(300℃)supercritical ethanol treatment prevents the excessive structural degradation of hydrogel and greatly reduces the metal clustering and aggregation,which contributed to the high Ni loading.Atomic characterizations confirmed that Ni was present at isolated sites and stabilized by Ni-N and Ni-O bonds in a Ni-(N/O)_(6)-C/SiC configuration.A 5%Ni-C-Si catalyst,which performed the best among the studied catalysts,exhibited a wide visible light response with a narrow bandgap of 1.45 eV that could efficiently and repeatedly catalyze the oxidation of TC with a conversion rate of almost 100% within 40 min.The reactive species trapping experiments and electron spin resonance(ESR)tests demonstrated that the h+,and·O_(2)-were mainly responsible for TC degradation.The TC degradation mechanism and possible reaction pathways were provided also.Overall,this study proposed a novel strategy to synthesize a high metal loading singleatom photocatalyst that can efficiently remove TC with high concentrations,and this strategy might be extended for synthesis of other carbon-based single-atom catalysts with valuable properties.

关键词： Carbon-based single-atom catalyst Nickel Photocatalytic degradation Tetracycline Visible light

Topological laser on square lattice with gain–loss-induced higher-order corner modes

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Chinese physics B 2024年第6期33卷 189-195页

作者：廖明杰韦梅松王帅领许静平羊亚平 MOE Key laboratory of Advanced Micro-Structured Materials School of Physics Science and EngineeringTongji UniversityShanghai 200092China

We investigate the higher-order topological laser in the two-dimensional(2D) coupled-cavity array. By adding staggered on-site gain and loss to the 2D Hermitian array with a trivial phase, the system will emerge degenerate topological corner modes, which are protected by bulk band gap. For such a non-Hermitian model, by adjusting the parameters of the system and introducing the pumping into the cavity at the corner, a single-mode lasing with topological protection emerges.Furthermore, single-mode lasing exists over a wide range of pumping strengths. No matter where the cavity is initially stimulated, after enough time evolution, all the cavities belonging to the topological corner mode can emit a stable laser.

关键词： topological corner modes nonlinear saturated gain single-mode lasing

Towards hydrometeorological thresholds of reservoir-induced landslide from subsurface strain observations

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Science China Technological Sciences 2024年第6期67卷 1907-1922页

作者： YE Xiao ZHU HongHu WANG Jia ZHENG WanJi ZHANG Wei SCHENATO Luca PASUTO Alessandro CATANI Filippo School of Earth Sciences and engineering Nanjing University Department of Geosciences University of Padova School of Geosciences and Info-physics Central South University Department of Information engineering University of Padova National Research Council-Research Institute for Geo-Hydrological protection(CNR-IRPI)

Synergistic multi-factor early warning of large-scale landslides is a crucial component of geohazard prevention and mitigation efforts in reservoir areas. Landslide forecasting and early warning based on surface displacements have been widely investigated.However, the lack of direct subsurface real-time observations limits our ability to predict critical hydrometeorological conditions that trigger landslide acceleration. In this paper, we leverage subsurface strain data measured by high-resolution fiber optic sensing nerves that were installed in a giant reservoir landslide in the Three Gorges Reservoir(TGR) region, China, spanning a whole hydrologic year since February 2021. The spatiotemporal strain profile has preliminarily identified the slip zones and potential drivers, indicating that high-intensity short-duration rainstorms controlled the landslide kinematics from an observation perspective. Considering the time lag effect, we reexamined and quantified potential controls of accelerated movements using a data-driven approach, which reveals immediate response of landslide deformation to extreme rainfall with a zero-day shift. To identify critical hydrometeorological rules in accelerated movements, accounting for the dual effect of rainfall and reservoir water level variations, we thus construct a landslide prediction model that relies upon the boosting decision tree(BDT) algorithm using a dataset comprising daily rainfall, rainfall intensity, reservoir water level, water level fluctuations, and slip zone strain time series. The results indicate that landslide acceleration is most likely to occur under the conditions of mid-low water levels(i.e., 57.9 mm and rainfall intensity> 24.4 mm/h). Moreover, this prediction model allows us to update hydrometeorological thresholds by incorporating the latest monitoring dataset. Standing on the shoulder of this landslide case, our study informs a practical and reliable pathway for georisk

关键词： slow-moving landslide fiber-optic monitoring subsurface strain hydrometeorological threshold extreme weather

Transfer learning and neural networks in predicting quadrupole deformation

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Chinese physics C 2024年第6期48卷 162-168页

作者：原林李佳星张鸿飞 School of Science Xi'an Polytechnic UniversityXi'an 710048China engineering Research Center of Flexible Radiation protection Technology Universities of Shaanxi ProvinceXi'an 710048China Xi'an Key laboratory of Nuclear protection Textile Equipment Technology Xi'an 710048China School of physics Xi'an Jiaotong UniversityXi'an 710049China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

Accurately determining the quadrupole deformation parameters of atomic nuclei is crucial for understanding their structural and dynamic properties.This study introduces an innovative approach that combines transfer learning techniques with neural networks to predict the quadrupole deformation parameters of even-even nuclei.With the application of this innovative technique,the quadrupole deformation parameters of 2331 even-even nuclei are successfully predicted within the nuclear region defined by proton numbers 8≤Z≤134 and neutron numbers N≥8.Additionally,we discuss the impact of nuclear quadrupole deformation parameters on the capture cross-sections in heavy-ion fusion reactions,reconstructing the capture cross-sections for the reactions48Ca+244Pu and48Ca+248Cm.This research offers new insights into the application of neural networks in nuclear physics and highlights the potential of merging advanced machine learning techniques with both theoretical and experimental data,particularly in fields where experimental data are limited.

关键词： nuclear deformation neural networks transfer learning heavy-ion fusion reactions

Zincophilic Ti_(3)C_(2)Cl_(2)MXene and anti-corrosive Cu NPs for synergistically regulated deposition of dendrite-free Zn metal anode

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Journal of Materials Science & Technology 2024年第2期169卷 137-147页

作者： Yunfei Shen Yi Liu Kaisheng Sun Tiantian Gu Gang Wang Yue Yang Jianxiang Pang Yang Zheng Xiaodong Yang Long Chen Key laboratory for Green Process of Chemical engineering of Xinjiang Bingtuan School of Chemistry and Chemical EngineeringShihezi UniversityShihezi 832003China Institute for Chemistry Chemnitz University of TechnologyChemnitz 09107Germany CAS Key laboratory of Functional Materials and Devices for Special Environments Xinjiang Key Laboratory of Electronic Information Materials and DevicesCenter of Materials Science and Optoelectronics EngineeringXinjiang Technical Institute of Physics and Chemistry of CASUrumqi 830011China Key laboratory of Ecophysics and Department of physics College of ScienceShihezi UniversityShihezi 832003China

Dendrites growth,chemical corrosion,and hydrogen evolution reaction(HER)on zinc anodes are the main barriers for the development of aqueous zinc-ion batteries(AZIBs).Constructing interfacial protec-tive layer is an effective way to alleviate the side reactions on the anodes.Herein,Cu/Ti_(3)C_(2)Cl_(2)MXene(CMX)with high zincophilic and hydrophobic property is prepared by the lewis molten salts etching method,and the CMX interface protection layer is constructed by a simple spin coating.The CMX coat-ing layer can provide abundant nucleation sites and uniformize the charge distribution through the zin-cophilic Ti_(3)C_(2)Cl_(2)MXene matrix,leading to homogenous Zn deposition.In addition,the hydrophobic coat-ing contained anti-corrosive Cu nanoparticles can prevent the Zn anode from the electrolyte,beneficial for suppressing the chemical corrosion and HER.Therefore,the stable and reversible Zn plating/stripping is achieved for the Zn anode coated by the CMX,which exhibits the lifespan of over 1400 h at 0.5 mA cm^(−2),and even can steadily run for 700 h with 65 mV at 10 mA cm^(−2).Furthermore,CMX@Zn shows a high coulombic efficiency of over 100%for 3800 cycles,which indicates that the CMX@Zn electrode has excellent stability and reversibility of Zn stripping/plating.The full batteries assembled with ZnCoMnO/C(ZCM)cathodes also exhibits higher capacity(450.6 mAh g^(−1)at 0.1 A g^(−1))and cycle stability(capacity retention of 70%after 1500 cycles).This work enhanced the lifespan of AZIBs and broaden the research of multifunctional coating layer to other secondary batteries based on metal anodes.

关键词： Zinc anode Spin coating Zincophilic MXene Anti-corrosive Cu NPs Multifunctional coating