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Random pinhole attenuator for high-power laser beams

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High Power Laser science and Engineering 2024年第3期12卷 116-121页

作者： Seong Cheol Park Hyeok Yun Jin Woo Yoon Seong Ku Lee Jae Hee Sung Il Woo Choi Chang Hee Nam Kyung Taec Kim Department of Physics and Photon science Gwangju Institute of Science and TechnologyGwangjuRepublic of Korea Center for Relativistic Laser science Institute for Basic ScienceGwangjuRepublic of Korea Advanced Photonics Research institute Gwangju Institute of Science and TechnologyGwangjuRepublic of Korea

The intensity attenuation of a high-power laser is a frequent task in the measurements of optical *** intensity can be attenuated by inserting an optical element,such as a partial reflector,polarizer or absorption *** devices are,however,not always easily applicable,especially in the case of ultra-high-power lasers,because they can alter the characteristics of a laser beam or become easily *** this study,we demonstrated that the intensity of a laser beam could be effectively attenuated using a random pinhole attenuator(RPA),a device with randomly distributed pinholes,without changing the beam *** this device,a multi-PW laser beam was successfully attenuated and the focused beam profile was measured without any alterations of its *** addition,it was confirmed that the temporal profile of a laser pulse,including the spectral phase,was ***,the RPA possesses significant potential for a wide range of applications.

关键词： high-power laser intensity attenuation laser diagnostics

Fiber Bundle Topology Optimization for Surface Flows

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 236-264页

作者： Yongbo Deng Weihong Zhang Jihong Zhu Yingjie Xu Jan G Korvink State Key Laboratory of Applied Optics Changchun Institute of OpticsFine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China State IJR Center of Aerospace Design and Additive Manufacturing Northwestern Polytechnical UniversityXi’an 710072China institute of Microstructure Technology(IMT) Karlsruhe Institute of Technology(KIT)Hermann-von-Helmholtzplatz 176344 Eggenstein-LeopoldshafenGermany

This paper presents a topology optimization approach for the surface flows on variable design *** this approach,the matching between the pattern of a surface flow and the 2-manifold used to define the pattern can be optimized,where the 2-manifold is implicitly defined on another fixed 2-manifold named as the base *** fiber bundle topology optimization approach is developed based on the description of the topological structure of the surface flow by using the differential geometry concept of the fiber *** material distribution method is used to achieve the evolution of the pattern of the surface *** evolution of the implicit 2-manifold is realized via a homeomorphous *** design variable of the pattern of the surface flow and that of the implicit 2-manifold are regularized by two sequentially implemented surface-PDE *** two surface-PDE filters are coupled,because they are defined on the implicit 2-manifold and base manifold,*** surface Navier-Stokes equations,defined on the implicit 2-manifold,are used to describe the surface *** fiber bundle topology optimization problem is analyzed using the continuous adjoint method implemented on the first-order Sobolev *** numerical examples have been provided to demonstrate this approach,where the combination of the viscous dissipation and pressure drop is used as the design objective.

关键词： Fiber bundle Topology optimization 2-manifold Surface flow Material distribution method Porous medium model

Non-destructive buffer enabling near-infrared-transparent inverted inorganic perovskite solar cells toward 1400 h light-soaking stable perovskite/Cu（In,Ga）Se2 tandem solar cells

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Journal of Energy Chemistry 2024年第10期97卷 622-629页

作者： Yu Zhang Zhaoheng Tang Zhongyang Zhang Jiahong Tang Minghua Li Siyuan Zhu Wenyan Tan Xi Jin Tongsheng Chen Jinsong Hu Chao Zhou Chunlei Yang Qijie Liang Xugang Guo Weimin Li Weiqiang Chen Yan Jiang MOE Key Laboratory of Laser Life science & Guangdong Provincial Key Laboratory of Laser Life science Guangzhou Key Laboratory of Spectral Analysis and Functional Probes College of Biophotonics South China Normal University School of Materials science and Engineering Beijing Institute of Technology Songshan Lake Materials Laboratory Department of Materials science and Engineering Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices Southern University of Science and Technology Beijing Advanced Innovation Center for Soft Matter science and Engineering College of Chemical Engineering College of Materials Science and Engineering Beijing University of Chemical Technology Department of Physics Liaoning University Beijing National Laboratory for Molecular sciences (BNLMS) Institute of Chemistry Chinese Academy of Sciences School of Physics and Materials science Guangzhou University Shenzhen institute of Advanced Technology Chinese Academy of Sciences

Near-infrared（NIR） transparent inverted all-inorganic perovskite solar cells（PSCs） are excellent top cell candidates in tandem *** essential challenge is the replacement of metal contacts with transparent conductive oxide（TCO） electrodes,which requires the introduction of a buffer layer to prevent sputtering *** this study,we show that the conventional buffers（i.e.,small organic molecules and atomic layer deposited metal oxides） used for organic-inorganic hybrid perovskites are not applicable to all-inorganic perovskites,due to non-uniform coverage of the vulnerable layers underneath,deterioration upon ion bombardment and moisture induced perovskite phase transition,A thin film of metal oxide nanoparticles by the spin-coating method serves as a non-destructive buffer layer for inorganic ***-inorganic inverted near-infrared-transparent PSCs deliver a PCE of 17.46% and an average transmittance of 73.7% between 780 and 1200 *** combination with an 18.56% Cu（In,Ga）Se2bottom cell,we further demonstrate the first all-inorganic perovskite/CIGS 4-T tandem solar cell with a PCE of 24.75%,which exhibits excellent illumination stability by maintaining 86.7% of its initial efficiency after 1400 *** non-destructive buffer lays the foundation for efficient and stable NIR-transparent inverted inorganic perovskite solar cells and perovskite-based tandems.

关键词： Buffer layer CsPbI3 perovskite Inverted perovskite solar cells Stability Tandem solar cells

Postmortem ^(7)Li NMR analysis for assessing the reversibility of lithium metal electrodes in lithium metal batteries

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Journal of Energy Chemistry 2024年第7期94卷 430-440页

作者： Jaewon Baek Sunha Kim Hee-Tak Kim Oc Hee Han Department of Chemical&Biomolecular Engineering KAISTDaejeon 34141Republic of Korea Metropolitan Seoul Center Korea Basic Science InstituteSeoul 03759Republic of Korea Graduate School of Analytical science&Technology Chungnam National UniversityDaejeon 34134Republic of Korea

Despite the proficiency of lithium(Li)-7 NMR spectroscopy in delineating the physical and chemical states of Li metal electrodes,challenges in specimen preparation and interpretation impede its *** this study,we conducted a comprehensive postmortem analysis utilizing ^(7)Li NMR,employing a stan-dard magic angle spinning probe to examine protective-layer coated Li metal electrodes and LiAg alloy electrodes against bare Li metal electrodes within Li metal batteries(LMBs).Our investigation explores the effects of sample burrs,alignment with the magnetic field,the existence of liquid electrolytes,and precycling on the ^(7)Li NMR *** contrasting NMR spectra before and after cycling,we identi-fied alterations in Li^(0) and Li^(+) signals attributable to the degradation of the Li metal *** NMR analyses decisively demonstrate the efficacy of the protective layer in mitigating dendrite and solid elec-trolyte interphase ***,we noted that Li*ions near the Li metal surface exhibit magnetic susceptibility anisotropy,revealing a novel approach to studying diamagnetic species on Li metal elec-trodes in *** study provides valuable insights and practical guidelines for characterizing distinct lithium states within LMBs.

关键词： NMR spectroscopy Lithium-7 Lithium metal battery Electrolyte Electrode-protective layer Solid electrolyte interface Magnetic susceptibility anisotropy Lithium-metal NMR signal Diamagnetic^(7)Li NMR signal

Facile synthesis of accordion-like porous carbon from waste PET bottles-based MIL-53(Al) and its application for high-performance Zn-ion capacitor

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Green Energy & Environment 2024年第7期9卷 1138-1150页

作者： Jiaxin Li Shuai Zhang Yumeng Hua Yichao Lin Xin Wen Ewa Mijowska Tao Tang Xuecheng Chen Rodney S.Ruoff Faculty of Chemical Technology and Engineering West Pomeranian University of Technology Key State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied Chemistry Chinese Academy of Sciences School of Safety Engineering China University of Mining and Technology institute of Advanced Electrical Materials Qingdao University of Science and Technology institute for basic science Center for Multiple Dimensional Carbon Materials Department of Chemistry Ulsan National Institute of Science and Technology (UNIST) Department of Materials science and Engineering Ulsan National Institute of Science and Technology (UNIST) School of Energy and Chemical Engineering Ulsan National Institute of Science and Technology (UNIST)

It is of great scientific and economic value to recycle waste poly（ethylene terephthalate）(PET) into high-value PET-based metal organic frameworks（MOFs） and further convert it into porous carbon for green energy storage applications. In the present study, a facile and costeffective hydrothermal process was developed to direct recycle waste PET bottles into MIL-53（Al） with a 100% conversation, then the MOFderived porous carbon was assembled into electrodes for high-performance supercapacitors. The results indicated that the as-synthesized carbon exhibited high SSA of 1712 m2g-1and unique accordion-like structure with hierarchical porosity. Benefit to these advantageous characters, the assembled three-electrode supercapacitor displayed high specific capacitances of 391 F g-1at the current density of 0.5 A g-1and good rate capability of 73.6% capacitance retention at 20 A g-1in 6 mol L-1KOH electrolyte. Furthermore, the assembled zinc ion capacitor still revealed outstanding capacitance of 335 F g-1at 0.1 A g-1, excellent cycling stability of 92.2% capacitance retention after 10 000 cycles and ultra-high energy density of 150.3 Wh kg-1at power density of 90 W kg-1in 3 mol L-1ZnSO4electrolyte. It is believed that the current work provides a facile and effective strategy to recycle PET waste into high-valuable MOF, and further expands the applications of MOF-derived carbons for high-performance energy storage devices, so it is conducive to both pollution alleviation and sustainable economic development.

关键词： PET Recycling Porous carbon Supercapacitor Energy storage

The weakening effect of urbanization on tropical cyclone surface winds : An observational study for Shanghai

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TROPICAL CYCLONE RESEARCH AND REVIEW 2024年第1期13卷 15-23页

作者： Zhang, Lechuan Yu, Hui Ao, Xiangyu Tang, Shengming Chinese Acad Meteorol Sci Beijing Peoples R China China Meteorol Adm Shanghai Typhoon Inst Shanghai Peoples R China

The observation -reanalysis difference method (OMR) and wind pro fi le fi tting method were used to analyze the in fl uence urbanization has on the near -surface wind speed in Shanghai during tropical cyclone events. The data used include daily wind speed data from the Shanghai Meteorological Observatory Station collected from 1991 to 2020, hourly wind speed data from 100 m high wind towers from 2017 to 2019, and reanalysis data that covered the same period. The results indicated that during tropical cyclone occurrence, the wind speed of the OMR in the central urban region was signi fi cantly lower than that in the suburban area, and the OMR declined more obviously over the year, down to - 8 m/s in 2020. Urbanization leads to the increase of average wind weakening rate to be higher than the maximum wind weakening rate, causing the maximum weakening rate of the central urban region to the average wind over 80%, while maximum wind speed was less than 80%. The weakening rate of both the average and maximum wind speeds during tropical cyclone impacts is greater than the rate that the annual average wind speed was reduced. A logarithmic variation was visible in the wind pro fi le of the island station during tropical cyclone occurrence, with an average friction velocity U * of 0.9389 m/s and an average rough length Z 0 of 0.4915 m. The wind speed during tropical cyclone events was higher than the three-year average wind speed within each layer. The suburban stations show a linear variation, and every hundred meters of height results in an increase of 5 - 6 m/s in the wind speed change rate. At 100 m of altitude, the wind speed in the suburban region is reduced by approximately 40%. (c) 2024 The Shanghai Typhoon institute of China Meteorological Administration. Publishing services by Elsevier B.V. on behalf of KeAi Communication Co. Ltd. This is an open access article under the CC BY -NC -ND license (http://***/licenses/by-nc-nd/4.0/).

关键词： Urbanization Tropical cyclone Shanghai Wind speed SPEED

Influence of Various Earth-Retaining Walls on the Dynamic Response Comparison Based on 3D Modeling

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Computer Modeling in Engineering & sciences 2024年第6期139卷 2835-2863页

作者： Muhammad Akbar Huali Pan Jiangcheng Huang Bilal Ahmed Guoqiang Ou institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu610000China institute of International Rivers and Eco-Security Yunnan UniversityKunming650500China Department of Structural Engineering Faculty of Civil EngineeringDoctoral SchoolAkademicka 2Silesian University of TechnologyGliwice44-100Poland

The present work aims to assess earthquake-induced earth-retaining(ER)wall *** study is on the dynamics analysis of various earth-retaining wall designs in hollow precast concrete panels,reinforcement concrete facing panels,and gravity-type earth-retaining *** finite element(FE)simulations utilized a 3D plane strain condition to model full-scale ER walls and numerous nonlinear dynamics *** seismic performance of differentmodels,which includes reinforcement concrete panels and gravity-type and hollowprecast concrete ER walls,was simulated and examined using the FE *** also displays comparative studies such as stress distribution,deflection of the wall,acceleration across the wall height,lateral wall displacement,lateral wall pressure,and backfill plastic *** components of the created ER walls were found throughout this research *** is a granular reinforcement backfill,while the other is a wall-facing panel and base *** dynamic response effects of varied earth-retaining walls have also been *** was discovered that the facing panel of the model significantly impacts the earthquake-induced displacement of ER *** proposed analytical model’s validity has been evaluated and compared with the reinforcement concrete facing panels,gravity-type ER wall,scientifically available data,and American Association of State Highway and Transportation Officials(AASHTO)guidelines results based on FE *** results of the observations indicate that the hollow prefabricated concrete ER wall is the most feasible option due to its lower displacement and high-stress distribution compared to the two *** methodology and results of this study establish standards for future analogous investigations and professionals,particularly in light of the increasing computational capabilities of desktop computers.

关键词： Seismic analysis finite element modeling earth-retaining ER walls dynamic response structural resilience

The use of electrokinetics promises a sustainable mining future

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The Innovation 2024年第3期5卷 17-18页

作者： Gaofeng Wang Xiaoliang Liang Jianxi Zhu Hongping He CAS Key Laboratory of Mineralogy and Metallogeny/Guangdong Provincial Key Laboratory of Mineral Physics and Material Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China CAS Center for Excellence in Deep Earth science Guangzhou 510640China University of the Chinese Academy of sciences Beijing 100049China

Moving toward a zero-carbon economy is an ambitious goal of all human *** of various metal resources plays a central role in such a *** earth elements(REEs),especially heavy REEs(HREEs),are crucial for the development of future green and zero-carbon economies due to their irreplaceable roles in many applications of renewable energy technologies;e.g.,solar panels,wind turbines,and hybrid vehicle ***-adsorption rare earth deposits(IADs)are the primary repositories for HREEs and supply more than 95%of the global HREE demand.1 However,current mining technologies using excessive ammonium salts have caused devastating harm to the local environment while exhibiting a low recovery rate of REEs,a long mining period,and landslide *** 2018,the adoption of ammonium salt-based techniques in REE mining has been prohibited,exacerbating the scarcity of REEs that could lead to disruptions of the supply ***,metals are currently almost exclusively extracted from their ores via physical excavation or chemical *** energy-intensive and environmentally damaging techniques remain among the foremost CO_(2) *** mining industry is in desperate need of a new generation of mining technology.

关键词： mining replace earth

Enhanced prediction of anisotropic deformation behavior using machine learning with data augmentation

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Journal of Magnesium and Alloys 2024年第1期12卷 186-196页

作者： Sujeong Byun Jinyeong Yu Seho Cheon Seong Ho Lee Sung Hyuk Park Taekyung Lee School of Mechanical Engineering Pusan National UniversityBusan 46241South Korea School of Materials science and Engineering Kyungpook National UniversityDaegu 41566South Korea

Mg alloys possess an inherent plastic anisotropy owing to the selective activation of deformation mechanisms depending on the loading *** characteristic results in a diverse range of flow curves that vary with a deformation *** study proposes a novel approach for accurately predicting an anisotropic deformation behavior of wrought Mg alloys using machine learning(ML)with data *** developed model combines four key strategies from data science:learning the entire flow curves,generative adversarial networks(GAN),algorithm-driven hyperparameter tuning,and gated recurrent unit(GRU)*** proposed model,namely GAN-aided GRU,was extensively evaluated for various predictive scenarios,such as interpolation,extrapolation,and a limited dataset *** model exhibited significant predictability and improved generalizability for estimating the anisotropic compressive behavior of ZK60 Mg alloys under 11 annealing conditions and for three loading *** GAN-aided GRU results were superior to those of previous ML models and constitutive *** superior performance was attributed to hyperparameter optimization,GAN-based data augmentation,and the inherent predictivity of the GRU for *** a first attempt to employ ML techniques other than artificial neural networks,this study proposes a novel perspective on predicting the anisotropic deformation behaviors of wrought Mg alloys.

关键词： Plastic anisotropy Compression Annealing Machine learning Data augmentation