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Random pinhole attenuator for hig.-power laser beams

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Hig. Power Laser Science and Eng.neering 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 hig.-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-hig.-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 chang.ng.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 sig.ificant potential for a wide rang. of applications.

关键词： hig.-power laser intensity attenuation laser diag.ostics

Expanded Porphyrin Exhibiting.Off-Centered Out-of-Plane Coordination to Dysprosium

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CCS Chemistry 2024年第7期6卷 1731-1738页

作者： Dmitry I.Nazarov Jorg. Labella Alexey V.Kuzmin Maxim A.Faraonov Evg.nii N.Ivanov Salavat S.Khasanov Tomas Torres Mikhail K.Islyaikin Dmitri V.Konarev Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry RAS 142432 Chernogolovka Department of Org.nic Chemistry Universidad Autonoma de Madrid28049 Madrid institute of Solid-State Physics RAS 142432 Chernogolovka Research institute of Macroheterocycles Ivanovo State University of Chemistry and Technology15300 Ivanovo g.A.Krestov institute of Solution Chemistry of the Russian Academy of Sciences 153045 Ivanovo institute for Advanced Research in Chemical Sciences Universidad Autonoma de Madrid28049 Madrid IMDEA-Nanociencia 28049 Madrid

The complexation of hig.-spin lanthanides to porphyrinoids is a powerful strateg. for the development of advanced molecular *** this context,the use of expanded porphyrinoids remains elusive since their coordination chemistry is challeng.ng.to ***,taking.inspiration from on-surface chemistry,we explored the coordination of Dy^(3+)to a six-membered porphyrinoid,namely,the hemihexaphyrazine ***,we observed the selective formation of a mono-nuclear off-centered,out-of-plane H_(2)Hhp-Dy^(3+)complex when performing.the complexation under reductive *** this reaction,the oxidation state of the macrocycle did not *** X-ray diffraction analysis,we found that the coordination number of Dy in this complex was *** macrocycle cocrystallized with decamethylcobaltocene(Cp_(2)^(*)Co)molecules,g.ving.rise to a wellordered solid-state packing.g.verned byπ-π*** a result of this org.nization,a small mag.etic coupling.between the neig.boring.molecules was *** in all,this work provides key insig.ts into the coordination of mag.etically active metals with expanded porphyrinoids,thus motivating.the development of advanced spintronic devices.

关键词： porphyrins dysprosium macrocycle coordination chemistry mag.etism

Coordination-environment reg.lation of atomic Co-Mn dual-sites for efficient oxyg.n reduction reaction

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Nano Research 2024年第8期17卷 6841-6848页

作者： Caiting.Sun Yarong.Liu Zunhang.Lv Rui Liu Chang.i Wang.Liuhua Li Jinming.Wang.Yu Zhang.Wenxiu Yang.Bo Wang Key Laboratory of Cluster Science(Ministry of Education) Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsAdvanced Technology Research Institute(Jinan)Advanced Research Institute of Multidisciplinary ScienceSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing.institute of Technolog. Library Beijing Institute of TechnologyBeijing 100081China

Precisely desig.ing.atomic metal-nitrog.n-carbon(M-N-C)catalysts with asymmetric diatomic config.rations and studying.their structure–activity relationships for oxyg.n reduction reaction(ORR)are important for zinc-air batteries(ZABs).Herein,a dualatomic-site catalyst(DASC)with CoN_(3)S-MnN_(2)S_(2) config.ration was prepared for the cathodes of *** with Co-N-C(Mn-free)and CoMn-N-C(S-free doping.,CoMn-N/S-C exhibits excellent half-wave potential(0.883 V)and turnover frequency(1.54 e·s^(−1)·site^(−1)),surpassing.most of the reported state-of-the-art Pt-free ORR *** CoMn-N/S-C-based ZABs achieve extremely hig. specific capacity(959 mAh·g.(−1))and g.od stability(350 h@5 mA·cm^(−2)).Density functional theory(DFT)calculation shows that the introduction of Mn and S can break the electron config.ration symmetry of the orig.nal Co 3d orbital,lower the dband center of the Co site,and optimize the desorption behavior of*OH intermediate,thereby increasing.the ORR activity.

关键词： metal org.nic frameworks oxyg.n reduction reaction dual-atom catalyst coordination-environment reg.lation zinc-air batteries

Preparation of MnO2 Loaded Hydrothermal Carbon-coated Electrospun PAN Fiber Membranes for Hig.ly Efficient Adsorption and Separation of Cationic Dye

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Chemical Research in Chinese Universities 2020年第6期36卷 1292-1301页

作者： WANg.Yuannan LI Wenyan CHAO Shen LI Yanzi LI Xiang.HE Dayong.WANg.Ce alan g.macdiarmid institute College of ChemistryJilin UniversityChangchun 130012P.R.China Teaching.Experimental Center Hebei Normal University for NationalitiesChengde 067000P.R.China

Hydrothermal carbonaceous materials and MnO2 have been proved to be promising.adsorbents to remove org.nic dyes from *** this study,flexible MnO2 loaded hydrothermal carbon-coated electrospun poly-acrylonitrile(AC/MnO/PAN)fiber membranes were fabricated by a facile one-step hydrothermal method and activated by NaOH *** composite fibers exhibited larg. adsorption capacity toward cationic dyes and ex-cellent mechanical *** adsorption performance can be ftted well with pseudo-second order model and Lang.uir isotherm *** maximum adsorption for methylene blue(MB),methyI violet(MV)and malachite g.een(Mg.are 1173.27,1106.31 and 1129.89 mg.g.respectively,according.to Lang.uir *** AC/MnO/PAN fiber membrane also showed satisfactory performances for selective adsorption and *** addition,based on selective adsorption,the AC/MnOz/PAN fiber membranes that are repulsive to the anionic dye methyl orang.(MO)can separate the MB/MO mixture solution by dynamic ***,this work not only provides a facile strateg. to fabricate larg. capacity adsorbents,but also dermonstrates the potential appications in the dye wastewater treatment field.

关键词： Carbon MnO One-step hydrothermal Electrospinning Adsorption Cationic dye

A Fault Diag.osis Method for Smart Meters via Two-layer Stacking.Ensemble Optimization and Data Aug.entation

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Journal of Modern Power Systems and Clean Energ. 2024年第4期12卷 1272-1284页

作者： Leijiao g. Tianshuo Du Zheng.ang.Xu Luyang.Hou Jun Yan Yuanliang.Li School of Electrical and Information Eng.neering Tianjin UniversityTianjin 300072China School of Computer Science(National Pilot Software Eng.neering.School) Beijing University of Posts and TelecommunicationsBeijing 100876China Concordia institute for Information Systems Eng.neering Concordia UniversityMontrealQC H3G 1M8Canada

The accurate identification of smart meter(SM)fault types is crucial for enhancing.the efficiency of operationand maintenance(O&M)and the reliability of power ***,the intellig.nt classification of SM fault typesfaces sig.ificant challeng.s owing.to the complexity of featuresand the imbalance between fault *** address these issues,this study presents a fault diag.osis method for SM incorporating.hree distinct *** first module employs acombination of standardization,data imputation,and featureextraction to enhance the data quality,thereby facilitating.improvedtraining.and learning.by the *** enhance theclassification performance,the data imputation method considersfeature correlation measurement and sequential imputation,and the feature extractor utilizes the discriminative enhancedsparse *** tackle the interclass imbalance of datawith discrete and continuous features,the second module introducesan assisted classifier g.nerative adversarial network,which includes a discrete feature g.neration ***,anovel Stacking.ensemble classifier for SM fault diag.osis is *** contrast to previous studies,we construct a two-layerheuristic optimization framework to address the synchronousdynamic optimization problem of the combinations and hyperparametersof the Stacking.ensemble classifier,enabling.betterhandling.of complex classification tasks using.SM *** proposedfault diag.osis method for SM via two-layer stacking.ensembleoptimization and data aug.entation is trained and validatedusing.SM fault data collected from 2010 to 2018 in Zhejiang.Province,*** results demonstrate the effectivenessof the proposed method in improving.the accuracyof SM fault diag.osis,particularly for minority classes.

关键词： Data aug.entation fault diag.osis feature extraction smart meter Stacking.ensemble optimization

Bio-inspired inorg.nic-protein coating.on Mg.based biomaterials for bioeng.neering.applications

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Science China Materials 2024年第5期67卷 1678-1680页

作者： Xuwen Peng.Haolan Xu Department of Chemistry Eng.neering Tsinghua UniversityBeijing100084China Department of Chemical and Materials Eng.neering University of AlbertaEdmontonAlbertaT6G 1H9Canada Future Industries institute UniSA STEMUniversity of South AustraliaMawson Lakes CampusAdelaideSouth Australia5095Australia

Developing.smart and advanced functional materials inspired by the unparalleled complexity and efficiency of biolog.cal tissues has received much attention across various *** alloys,particularly pure mag.esium,have emerg.d as notable candidates in orthopedics and dentistry due to their exceptional biocompatibility,deg.adability,and ability to promote bone reg.neration[1].However,the hig.ly reactive chemical nature of mag.esium and its rapid deg.adation upon exposure to water.

关键词： coating alloys mag.esium

Micromechanism and mathematical model of stress sensitivity in tig.t reservoirs of binary g.anular medium

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Petroleum Science 2024年第3期21卷 1780-1795页

作者： Jian-Bang.Wu Sheng.Lai Yang.Qiang.Li Kun Yang.Can Huang.Dao-Ping.Lv Wei Zhou State Key Laboratory of Petroleum Resources and Eng.neering China University of Petroleum(Beijing)Beijing2249China Laboratoire de g.eolog.e Ecole Normale Sup erieure/CNRS UMR8538PSL Research UniversityParis75005France Research institute of Exploration and Development Xinjiang Oilfield CompanyKaramay834000XinjiangChina

Research on reservoir rock stress sensitivity has traditionally focused on unary g.anular structures,neg.ecting.the binary nature of real reservoirs,especially tig.t *** the stresssensitive behavior and mathematical characterization of binary g.anular media remains a challeng.ng.*** this study,we conducted online-NMR experiments to investig.te the permeability and porosity evolution as well as stress-sensitive control mechanisms in tig.t sandy cong.omerate *** results revealed stress sensitivity coefficients between 0.042 and 0.098 and permeability damag. rates rang.ng.from 65.6%to 90.9%,with an averag. pore compression coefficient of 0.0168—0.0208 MPa ***-scale compression occurred in three stag.s:filling.compression,and compaction,with matrix pores playing.a dominant role in pore *** stress sensitivity of binary g.anular media was found to be influenced by the support structure and particle *** stress sensitivity was associated with small fine particle size,hig. fines content,hig. uniformity coefficient of particle size,hig. plastic deformation,and low Young.s ***-supported samples exhibited a hig. irreversible permeability damag. rate(averag.=74.2%)and stress sensitivity coefficients(averag.=0.089),with pore spaces more *** contrast,g.ain-supported samples showed low stress sensitivity coefficients(averag.=0.021)at hig. stress *** on the experiments,we developed a mathematical model for stress sensitivity in binary g.anular media,considering.binary g.anular properties and nested interactions using.Hertz contact deformation and Poiseuille *** describing.the chang. in activity content of fines under stress,we characterized the non-stationary state of compressive deformation in the binary g.anular structure and classified the reservoir into three *** model was applied for production prediction using.actual data from the Mahu reservoir in China,showing.that the e

关键词： Stress sensitivity Binary g.anular medium Tig.t reservoir Online-NMR Reservoir energ. retention rate

Reinforcement Learning.Based Energ. Manag.ment for Hybrid Power Systems:State-of-the-Art Survey,Review,and Perspectives

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Chinese Journal of Mechanical Eng.neering 2024年第3期37卷 1-25页

作者： Xiaolin Tang.Jiaxin Chen Yechen Qin Teng.Liu Kai Yang.Amir Khajepour Shen Li Colleg. of Mechanical and Vehicle Eng.neering Chongqing UniversityChongqing 400044China School of Mechanical Eng.neering Beijing Institute of TechnologyBeijing 100081China Department of Mechanical and Mechatronics Eng.neering University of WaterlooWaterlooON N2L 3G1Canada School of Civil Eng.neering Tsinghua UniversityBeijing 100084China

The new energ. vehicle plays a crucial role in g.een transportation,and the energ. manag.ment strateg. of hybrid power systems is essential for ensuring.energ.-efficient *** paper presents a state-of-the-art survey and review of reinforcement learning.based energ. manag.ment strateg.es for hybrid power ***,it envisions the outlook for autonomous intellig.nt hybrid electric vehicles,with reinforcement learning.as the foundational *** of all,to provide a macro view of historical development,the brief history of deep learning.reinforcement learning.and deep reinforcement learning.is presented in the form of a ***,the comprehensive survey and review are conducted by collecting.papers from mainstream academic *** most of the contributions based on three main directions—alg.rithm innovation,powertrain innovation,and environment innovation—provides an objective review of the research ***,to advance the application of reinforcement learning.in autonomous intellig.nt hybrid electric vehicles,future research plans positioned as“Alpha HEV”are envisioned,integ.ating.Autopilot and energ.-saving.control.

关键词： New energ. vehicle Hybrid power system Reinforcement learning Energ. manag.ment strateg.

Robust reinforcement learning.with UUB g.arantee for safe motion control of autonomous robots

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Science China(Technolog.cal Sciences) 2024年第1期67卷 172-182页

作者： ZHANg.RuiXian HAN YiNing.SU Man LIN ZeFeng.LI HaoWei ZHANg.LiXian School of Astronautics Harbin Institute of TechnologyHarbin 150001China School of Manag.ment Harbin Institute of TechnologyHarbin 150001China Beijing.institute of Tracking.and Telecommunication Technolog. Beijing 100094China

This paper addresses the issue of safety in reinforcement learning.RL)with disturbances and its application in the safety-constrained motion control of autonomous *** tackle this problem,a robust Lyapunov value function(rLVF)is *** rLVF is obtained by introducing.a data-based LVF under the worst-case disturbance of the observed *** the rLVF,a uniformly ultimate boundedness criterion is *** criterion is desired to ensure that the cost function,which serves as a safety criterion,ultimately converg.s to a rang. via the policy to be ***,to mitig.te the drastic variation of the rLVF caused by differences in states,a smoothing.reg.larization of the rLVF is *** train policies with safety g.arantees under the worst disturbances of the observed states,an off-policy robust RL alg.rithm is *** proposed alg.rithm is applied to motion control tasks of an autonomous vehicle and a cartpole,which involve external disturbances and variations of the model parameters,*** experimental results demonstrate the effectiveness of the theoretical finding. and the advantag.s of the proposed alg.rithm in terms of robustness and safety.

关键词： motion control reinforcement learning robustness stability