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Safe Q-Learning for Data-Driven Nonlinear Optimal Control With Asymmetric State Constraints

IEEE/CAA Journal of Automatica Sinica 2024年第12期11卷 2408-2422页

作者： Mingming Zhao Ding Wang Shijie Song Junfei Qiao the School of Information Science and Technology the Beijing Key Laboratory of Computational Intelligence and Intelligent Systemthe Beijing Laboratory of Smart Environmental Protectionand the Beijing Institute of Artificial IntelligenceBeijing University of Technology.Beijing 100124China IEEE the School of Mechanical and Electrical Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

This article develops a novel data-driven safe Q-learning method to design the safe optimal controller which can guarantee constrained states of nonlinear systems always stay in the safe region while providing an optimal ***,we design an augmented utility function consisting of an adjustable positive definite control obstacle function and a quadratic form of the next state to ensure the safety and ***,by exploiting a pre-designed admissible policy for initialization,an off-policy stabilizing value iteration Q-learning(SVIQL)algorithm is presented to seek the safe optimal policy by using offline data within the safe region rather than the mathematical ***,the monotonicity,safety,and optimality of the SVIQL algorithm are theoretically *** obtain the initial admissible policy for SVIQL,an offline VIQL algorithm with zero initialization is constructed and a new admissibility criterion is established for immature iterative ***,the critic and action networks with precise approximation ability are established to promote the operation of VIQL and SVIQL ***,three simulation experiments are conducted to demonstrate the virtue and superiority of the developed safe Q-learning method.

关键词： Adaptive critic control adaptive dynamic programming(ADP) control barrier functions(CBF) stabilizing value iteration Q-learning(SVIQL) state constraints

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Deliberate design of MOF-based pre-catalyst rationalizing the structural reconstruction toward efficient oxygen evolution reaction

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science China Chemistry 2025年第6期68卷 2388-2398页

作者： Yunhui Chen Meng Tian Zhongqi Zhang Guangzhao Wang Yan Guo Jing Wu Dawei Qi Zhenhua Yan Xiangyu Liu Xi Liu State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering College of Chemistry and Chemical EngineeringNingxia University Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of Chongqing School of Electronic Information Engineering Yangtze Normal University Frontiers Science Center for New Organic Matter Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) State Key Laboratory of Advanced Chemical Power Sources College of Chemistry Nankai University School of Chemistry and Chemical Engineering In-situ Center for Physical Sciences Frontiers Science Center for Transformative MoleculesShanghai Jiao Tong University

Metal-organic frameworks（MOFs）, that have emerged as promising electrocatalysts in oxygen evolution reaction（OER）,usually undergo structural reconstruction to form metal hydroxides as active sites. However, it remains a great challenge to design and synthesize ideal MOF-based pre-catalysts for properly cognizing and utilizing the reconstruction process toward efficient OER activity. Herein, the well-defined MOF-808 is post-modified by 2-hydroxyphosphonoacetic acid（HPAA） to form a micro-adsorber that enables to capture of metal ions effectively. Fe3+and Ni2+ions are synergistically anchored into the microadsorber, developing a Fe/Ni-containing pre-catalyst that can be dynamically electrooxidized to be an active and stable dual-site electrocatalyst denoted by R-MOF-HPAA@Fe Ni with abundant metal sites. As a result, R-MOF-HPAA@Fe Ni exhibits an excellent OER performance with a low overpotential of 272 m V and Tafel slope of 35.9 m V dec-1, as well as long-term stability over 300 h at 10 m A cm-2. Experiments and theoretical calculations suggest the resulting catalyst mainly follows a lattice oxygen mechanism（LOM） of dual-metal-site mechanism（DMSM）. Owing to the chelating role of HPAA, the post-synthesized MOFHPAA behaves as a trap to uniformly and firmly adhere Fe3+and Ni2+ions, leading to a functionalized MOF-based pre-catalyst which can be structurally evolved into atomic level-distributed OER electrocatalysts.

关键词： metal-organic frameworks functionalization electrochemical reconstruction electrocatalyst oxygen evolution reaction

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A merged machine learning model for seasonal climate prediction in China

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science China Earth sciences 2025年第5期68卷 1469-1484页

作者： Danwei QIAN Yanyan HUANG Huijun WANG State Key Laboratory of Climate System Prediction and Risk Management/Key Laboratory of Meteorological Disaster Ministry of Education/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and Technology Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) Nansen-Zhu International Research Centre Institute of Atmospheric Physics Chinese Academy of Sciences

Improving the current level of skill in seasonal climate prediction is urgent for achieving sustainable socioeconomic development, and this is especially true in China where meteorological disasters are experienced frequently. In this study, based upon big climate data and traditional statistical prediction experiences, a merged machine learning model(Y-model) was developed to address this, as well as to further explore unknown potential predictors. In Y-model, empirical orthogonal function analysis was firstly applied to reduce the data dimensionality of the target predictand(temperature and precipitation in the four seasons over China). Image recognition techniques were used to automatically identify possible predictors from the big climate data. These predictors, associated with significant circulation anomalies, were recombined into a large ensemble according to different threshold settings for five factors determining the statistical forecast skill. Facebook Prophet was chosen to conduct the independent hindcasts for each season's climate at a lead time of two months. During 2011–2022, the seasonal climate in China was skillfully predicted by Y-model, with an averaged pattern correlation coefficient skill of 0.60 for temperature and 0.24 for precipitation, outperforming CFSv2. Potential predictor analysis for recent extreme events suggested that prior signals from the Indian Ocean and the stratosphere were important for determining the super Mei-yu in 2020, while the prior sea surface temperature over the western Pacific and the soil temperature over West Asia may have contributed to the extreme high temperatures in 2022. Our study provides new insights for seasonal climate prediction in China.

关键词： Machine learning Seasonal climate prediction China’s climate Image recognition techniques Large ensemble

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Meter-Scale Thin-Walled Structure with Lattice Infill for Fuel Tank Supporting Component of Satellite:Multiscale Design and Experimental Verification

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Computer Modeling in engineering & sciences 2024年第1期138卷 201-220页

作者： Xiaoyu Zhang Huizhong Zeng Shaohui Zhang Yan Zhang Mi Xiao Liping Liu Hao Zhou Hongyou Chai Liang Gao Beijing Key Laboratory of Lightweight Multi-Functional Composite Materials and Structures Beijing Institute of TechnologyBeijing100081China Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System EngineeringChina Academy of Space TechnologyBeijing100094China Key Laboratory of Metallurgical Equipment and Control Technology Ministry of EducationWuhan University of Science and TechnologyWuhan430081China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan430074China

Lightweight thin-walled structures with lattice infill are widely desired in satellite for their high stiffness-to-weight ratio and superior buckling strength resulting fromthe sandwich *** structures can be fabricated bymetallic additive manufacturing technique,such as selective laser melting(SLM).However,the maximum dimensions of actual structures are usually in a sub-meter scale,which results in restrictions on their appliance in aerospace and other *** this work,a meter-scale thin-walled structure with lattice infill is designed for the fuel tank supporting component of the satellite by integrating a self-supporting lattice into the thickness optimization of the *** designed structure is fabricated by SLM of AlSi10Mg and cold metal transfer welding ***-static mechanical tests and vibration tests are both conducted to verify the mechanical strength of the designed large-scale lattice thin-walled *** experimental results indicate that themeter-scale thin-walled structure with lattice infill could meet the dimension and lightweight requirements of most spacecrafts.

关键词： Thin-walled structure lattice infill supporting component selective laser melting satellite

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Computational temporal ghost imaging based on complementary modulation

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Chinese Physics B 2024年第11期33卷 278-283页

作者： Jia-Wei Li Wei Zhang Xue-Feng Liu Xu-Ri Yao Center for Quantum Technology Research and Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurements (MOE) School of Physics Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Electronics and Information Technology for Space Systems National Space Science CenterChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

We report an experimental demonstration of temporal ghost imaging in which a digital micromirror device(DMD)and+1/-1 binary modulation have been combined to give an accurate reconstruction of a nonperiodic time *** to the 0/1 modulation,the reconstruction signal can be improved greatly by+1/-1 binary modulation even with half of the *** results show that 0/1 binary temporal objects up to 4 kHz and sinusoidal time objects up to 1 kHz can be reconstructed by this *** influences of modulation speed and array detector gray levels are also discussed.

关键词： temporal ghost imaging complementary modulation

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Cluster-Based Redundancy Configuration Model for System-Of-systems 1

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12th China Conference on Command and Control, C2 2024

作者： Wu, Saisai Zhu, Baisong Xu, Chengtao Liu, Junxian National Key Laboratory of Information Systems Engineering National University of Defense Technology Changsha410073 China

ISBN: (数字)9789819777747

ISBN: (纸本)9789819777730

In the context of high-intensity warfare, our combat System-of –systems (SOS) consistently grapples with interference and attacks from the enemy. The implementation of redundancy within the combat SOS stands out as a pivotal approach to bolster its resilience. This paper introduces a method grounded in network modeling for combat SOS. It puts forth a redundant configuration strategy for SOS members, employing a cluster-based approach. This entails the segmentation of SOS members into multiple clusters, the establishment of Cluster-Based Redundancy Configuration Model for System-of-systems (CBRCM), and the formulation of a scheduling strategy for cluster redundancy based on the criticality assessment of SOS members. Through simulation analyses encompassing scenarios of both random and intentional attacks on combat SOS, this paper substantiates the efficacy of the proposed redundant configuration model in evaluating alterations in SOS capabilities. © Chinese Institute of Command and Control 2024.

关键词： cluster combat SOS criticality redundancy configuration

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Hydrogel bioadhesives harnessing nanoscale phase separation for Achilles tendon repairing

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Nano Research 2024年第2期17卷 778-787页

作者： Jun Zhang Xingmei Chen Jingseng Lin Pei Zhang Iek Man Lei Yue Tao Jiajun Zhang Tian Luo Ji Liu Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen 518055China Research and Innovation Center SKG Health TechnologyShenzhen 518000China SAFE(Shenzhen)Medical Technology Company Limited Shenzhen 518000China Shenzhen Key Laboratory of Biomimetic Robotics and Intelligent Systems Department of Mechanical and Energy EngineeringSouthern University of Science and TechnologyShenzhen 518055China Guangdong Provincial Key Laboratory of Human-Augmentation and Rehabilitation Robotics in Universities Southern University of Science and TechnologyShenzhen 518055China

Repairing Achilles tendon has emerged as a long-standing challenge in the orthopaedic *** suture is the gold standard for re-attaching and repairing the fractured Achilles tendons in clinical surgeries,it is still subjected to numerous adverse side-effects,including chronic inflammatory,tendon tissue re-rupture,scar formation,and post-surgical peritendinous *** this work,we develop a class of hydrogel bioadhesives with tailored nanoscale phase separation for Achilles tendon *** address the existing limitations of sutures,our hydrogel bioadhesives encompass three core functionalities:(i)instant and tough adhesion to Achilles tendon tissues,(ii)extraordinary long-term adhesion robustness under wet and dynamic in vivo conditions,and(iii)anti-postsurgical peritendinous *** our hydrogel bioadhesives with sutures,such kind of integrated approach enables a conformable yet robust biointerface with the tendon tissues,and prevents the fibroblast migration and formation of connective tissues,thus facilitating the tendon *** hydrogel bioadhesives reported here open up new opportunities for the repairing of fractured Achilles tendons in diverse and complicated clinical scenarios.

关键词： hydrogels phase separation bioadhesion robustness tendon repairing

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Epitaxial growth of 2D gallium selenide flakes for strong nonlinear optical response and visible-light photodetection

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Frontiers of physics 2023年第5期18卷 237-244页

作者： Mengting Song Nan An Yuke Zou Yue Zhang Wenjuan Huang Huayi Hou Xiangbai Chen Hubei Key Laboratory of Optical Information and Pattern Recognition Wuhan Institute of TechnologyWuhan 430205China State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

As an emerging groupⅢ–Ⅵsemiconductor two-dimensional(2D)material,gallium selenide(GaSe)has attracted much attention due to its excellent optical and electrical *** this work,high-quality epitaxial growth of few-layer GaSe nanoflakes with different thickness is achieved via chemical vapor deposition(CVD)*** to the non-centrosymmetric structure,the grown GaSe nanoflakes exhibits excellent second harmonic generation(SHG).In addition,the constructed GaSe nanoflake-based photodetector exhibits stable and fast response under visible light excitation,with a rise time of 6 ms and decay time of 10 *** achievements clearly demonstrate the possibility of using GaSe nanoflake in the applications of nonlinear optics and(opto)-electronics.

关键词： 2D materials gallium selenide second harmonic generation chemical vapor deposition photodetector

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Ce-UiO-66 nanozymes with charge-regulated uricase-like activity for enzyme/reagent-free detection of uric acid

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Nano Research 2025年第2期18卷 675-686页

作者： Zhixiong Guo Da Chen Wei Gao Yongquan Qu Zhimin Tian Key Laboratory of Special Functional and Smart Polymer Materials of Ministry of Industry and Information Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710054China State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China

Designing highly performed uricase-like nanozymes through enzymatic-like colorimetric analysis system is of vital significance for the quantitative detection of uric acid(UA).Herein,series of Ce-UiO-66 nanozymes with different surface charges through the ligand engineering strategy were rationally designed and synthesized as efficient uricase mimics with tailorable uricase-like activities to catalytically convert UA into allantoin and ***,by tuning the functional groups of 1,4-benzoic acid ligands,we explored the relationships between the surface charges of Ce-UiO-66-X(X=H,NO_(2),Br,CH_(3),and OH)nanozymes and their uricase-like *** them,Ce UiO-66-CH_(3) with the moderate surface charge exhibited optimal substrate adsorption and product desorption,displaying the highest uricase-like ***,H2O2,as the product of UA oxidation,enabled Ce-UiO-66-CH_(3) itself as a dose-dependent chromogenic substrate of H_(2)O_(2),giving a white-to-orange color evolution due to the Ce-UiO-66-CH_(3)-to-CeO_(2) phase ***,a smartphone-assisted all-in-one enzyme/reagent-free biosensor based on Ce-UiO-66-CH_(3) was established for the precise visual detection of UA analysis,which was featured by a wide detection range(31–4000µM),a high sensitivity(limit of detection:8.9µM),a rapid response(-3 min),a high structural stability,and a high anti-interference ability.

关键词： Ce-UiO-66 uricase-like nanozyme colorimetric uric acid analysis enzyme/reagent-free detection smartphone

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Long-wave infrared emission properties of strain-balanced InAs/In_(x)Ga_(1-x)As_(y)Sb_(1-y)type-Ⅱsuperlattice on different substrates

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Rare Metals 2024年第7期43卷 3194-3204页

作者： Chao Shi Xuan Fang Hong-Bin Zhao Deng-Kui Wang Xi Chen Dan Fang Dong-Bo Wang Xiao-Hua Wang Jin-Hua Li State Key Laboratory of High Power Semiconductor Lasers School of PhysicsChangchun University of Science and TechnologyChangchun 130022China State Key Laboratory of Advanced Materials for Smart Sensing China General Research Institute for Nonferrous MetalsBeijing 100088China Department of Opto-Electronic Information Science School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China

High-performance type-Ⅱsuperlattices ofⅢ-Ⅴsemiconductor materials play an important role in the development and application of infrared optoelectronic *** the quality of epitaxial materials and clarifying the luminescent mechanism are of great significance for practic al applic *** this work,strain-balanced and high-quality In As/In_(x)Ga_(1-x)As_(y)Sb_(1-y)superlattices without lattice mismatch were achieved on InAs and GaSb substrates *** grown on In As substrate could exhibit higher crystal quality and surface flatness based on high-resolution X-ray diffraction(HRXRD)and atomic force microscopy(AFM)measurements'***,the strain distribution phenomenon from geometric phase analysis indicates that fluctuations of alloy compositions in superlattices on GaSb substrate are more *** addition,the optical properties of superlattices grown on different substrates are discussed *** of the difference in fluctuations of element composition and interface roughness of superlattices on different substrates,the superlattices grown on In As substrate would have higher integral intensity and narrower full-width at half maximum of long-wave infrared ***,the thermal quenching of emission intensity indicates that the superlattices grown on the In As substrate have better recombination ability,which is beneficial for increasing the operating temperature of infrared optoelectronic devices based on this type of superlattices.

关键词： Photoluminescence Alloy compositions fluctuations InAs(Sb)/In_(x)Ga_(1-x)As_(y)Sb_(1-y) Type-Ⅱsuperlattice Substrate

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