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arXiv 2021年

作者： Yan, Weichao Nie, Zhongquan Zeng, Xunwen Dai, Guohong Cai, Mengqiang Shen, Yun Deng, Xiaohua Institute of Space Science and Technology Nanchang University Nanchang330031 China Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan030024 China Department of Physics School of Science Nanchang University Nanchang330031 China Information Engineering School Nanchang University Nanchang330031 China

Manipulation of light-induced magnetization has become a fundamentally hot topic with a potentially high impact for atom trapping, confocal and magnetic resonance microscopy, and data storage. The control of the magnetization orientation mainly relies on the direct methods composed of amplitude, phase and polarization modulations of the incident light under the tight focusing condition, leaving the achievement of arbitrary desirable three-dimensional (3D) magnetization orientation complicated, inflexible and inefficient. Here, we propose a facile approach called machine learning inverse design to achieve expected vectorial opto-magnetization orientation. This pathway is time-efficient and accurate to produce the demanded incident beam for arbitrary prescribed 3D magnetization orientation. It is highlighted that the machine learning method is not only applied for magnetization orientations, but also widely used in the control of magnetization structures. © 2021, CC BY.

关键词： Polarization

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Oxygen Vacancy-Induced Spin Polarization of Tungsten Oxide Nanowires for Efficient Photocatalytic Reduction and Immobilization of Uranium(Vi) Under Simulated Solar Light

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SSRN 2022年

作者： Yang, Xudong Li, Fan Liu, Wen Chen, Long Qi, Juanjuan Sun, Weiliang Duan, Tao Sun, Fengbin College of Environmental Sciences and Engineering The Key Laboratory of Water and Sediment Sciences Ministry of Education Peking University Beijing100871 China The Key Laboratory of Resources and Environmental System Optimization Ministry of Education College of Environmental Science and Engineering North China Electric Power University Beijing102206 China International Joint Laboratory for Regional Pollution Control Ministry of Education Peking University Beijing100871 China Department of Civil and Environmental Engineering Louisiana State University Baton RougeLA70803 United States State Key Laboratory of Environment-friendly Energy Materials Southwest University of Science and Technology Sichuan Mianyang621010 China Institute of Urban Meteorology China Meteorological Administration Beijing100089 China

Tungsten oxide nanowires (WO3-x) with rich oxygen vacancies (OVs) were fabricated through a facile hydrothermal method, which had both high adsorptive capability and photocatalytic activity. 95.1% of total U(VI) (C0 = 10 mg/L) was removed by WO3-x at pH 5, and 79.9% was transformed to U(IV) to achieve reductive immobilization after photocatalysis under simulated solar light. Band structure and optical characterizations indicated WO3-x had narrower band gap energy, but higher charger carrier separation and transfer rates compared with conventional WO3. Density functional theory (DFT) calculations further demonstrate the spin polarization state electrons of W 5d in WO3-x due to the construction of OVs, thus greatly inhibiting recombination of electron-hole pairs. In addition, the electron density increases in WO3-x and the photogenerated e– in the conduction band of WO3-x has higher reduction ability than WO3, leading to more efficient electron transfer from WO3-x to UO22+ after photo-excitation for U(VI) reduction. © 2022, The Authors. All rights reserved.

关键词： Tungsten compounds

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Typhoon-Induced Stormwater Drives Nutrient Dynamics and Triggers Phytoplankton Blooms in Laizhou Bay, China

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SSRN 2023年

作者： Li, Hongguan Li, Shanshan Zhang, Mingzheng Li, Xiuren Xu, Zehao Ma, Haoyang Liang, Shengkang Song, Dehai Li, Junlong Ma, Yuanqing Qin, Huawei Ji, Diansheng Frontiers Science Center for Deep Ocean Multispheres and Earth System Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education Ocean University of China Qingdao266100 China College of Chemistry and Chemical Engineering Ocean University of China Qingdao266100 China College of Oceanic and Atmospheric Sciences Ocean University of China Qingdao266100 China Laboratory for Marine Ecology and Environmental Science Qingdao National Laboratory for Marine Science and Technology Qingdao266237 China Key Laboratory of Physical Oceanography Ocean University of China Ministry of Education Qingdao National Laboratory for Marine Science and Technology Qingdao China State Environmental Protection Key Laboratory of Quality Control in Environmental Monitoring China National Environmental Monitoring Center Beijing100012 China Shandong Marine Resources and Environment Research Institute Yantai264000 China National Marine Environmental Monitoring Center China

The heavy rainfall brought by typhoons result in pulsed inputs of freshwater and nutrients, causing drastic changes in the offshore hydrographic and biogeochemical conditions in a short time. In this study, we evaluated the heavy rainfall impact of Typhoons Rumbia and Lekima on Laizhou Bay (LZB). We found that torrential rainfall significantly modified riverine nutrient concentrations, component ratios, and fluxes. Our results demonstrated that 9% and 16% of the annual riverine total nitrogen (TN) and total phosphorus (TP) fluxes were transported to the LZB within two weeks in Rumbia, and the proportions were 17% and 35% in Lekima, respectively. Influenced by terrestrial inputs, the sea surface temperature (SST) and sea surface salinity (SSS) decreased postRumbia, while the dissolved inorganic nitrogen (DIN) increased from 0.13 ± 0.13 mg/L to 0.47 ± 0.32 mg/L. Furthermore, the SST and SSS decreased by approximately 2.5 ℃ and 2.3 psu postLekima, and the concentration of DIN increased from 0.13 ± 0.08 mg/L to 0.58 ± 0.48 mg/L, which induced subsequent diatom blooms. However, rapid luxury uptake of dissolved inorganic phosphorus (DIP) by phytoplankton resulted in the LZB remaining under P-limited conditions. Freshwater and nutrient pulse input accelerated the growth of highly adaptable and small diatoms in coastal waters, and the dominant species transitioned to Skeletonema costatum after Lekima. We suggest that excess freshwater inputs alter the hydrodynamic structure and residence time, combined with other suitable factors, resulting in a dramatic increase in Noctiluca scintillans and the formation of harmful algal blooms (HABs) after a decline in diatom blooms. © 2023, The Authors. All rights reserved.

关键词： Nutrients

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Experimental verification of an integrated radar communication system

Experimental verification of an integrated radar communicati...

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IET International Radar Conference 2018, IRC 2018

作者： Li, Zengliang Liu, Jie Yin, Ning Wang, Youcheng Beijing Institute of Electro-Mechanical Engineering Beijing100074 China Science and Technology on Complex System Control Intelligent Agent Cooperation Laboratory Beijing100074 China

With the development of modern weapon techniques, radio frequency integrated technology has attracted widespread attention as a key technology to improve the informationalised level of missiles. Radar and communication are two typical electronic types of equipment, and their integration can support and promote the development of radio frequency integrated technology. In this study, experimental verification of an integrated radar-communication system is carried out. Firstly, the key technologies to achieve radar-communication integration are theoretically analysed. The solutions of the key issues, including signal separation, time synchronisation and frequency synchronisation, are proposed. Furthermore, a radar-communication demo is implemented and the experimental verification is carried out here to verify the feasibility of the proposed methods. © This is an open access article published by the IET under the Creative Commons Attribution License (http://***/licenses/by/3.0/)

关键词： Radar

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Model-Predictive-control-based Simultaneous Trajectory Tracking and Speed control for Intelligent Vehicles*

Model-Predictive-Control-based Simultaneous Trajectory Track...

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International Conference on Mechatronics and Machine Vision in Practice (M2VIP)

作者： Hanyang Zhuang Yikai Hu Chunxiang Wang Ming Yang University of Michigan - Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong University Shanghai China Guangxi Key Laboratory of Automobile Components and Vehicle Technology Guangxi University of Science and Technology Liuzhou China Shanghai Jiao Tong University Shanghai Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai Shanghai Engineering Research Center of Intelligent Control and Management Shanghai China

ISBN: (纸本)9781665431545

Trajectory tracking and speed control for intelligent vehicles are put forward higher requirements on accuracy by the high traffic density scenario. A standard Model Predictive control (MPC) algorithm focuses on the trajectory tracking but ignores the speed control. This paper proposes a simultaneous trajectory tracking and speed control algorithm based on MPC approach to address fine control in both space and time dimensions for intelligent vehicles. A threefold cost function including lateral and longitudinal speed as well as comfort has been proposed to improve the control algorithm. The simulations and comparisons demonstrate that the proposed method has a better tracking and speed control performance than the existing method.

关键词： Space vehicles Costs Mechatronics Trajectory tracking Intelligent vehicles Velocity control Prediction algorithms

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Mission Planning for Agile Earth Observing Satellite Based on Genetic Algorithm

Mission Planning for Agile Earth Observing Satellite Based o...

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第三十八届中国控制会议

作者： Peng Han Zhiwen He Yuanzhuo Geng Yanning Guo Chuanjiang Li Guangdong Zhao Department of Control Science and Engineering Harbin Institute of Technology Aerospace System Engineering Shanghai

A new method based on genetic algorithm and a new model are presented in this paper to solve the mission planning problem for Agile Earth Observation Satellite at multiple observation points. Firstly, a new mission planning model is established by considering various physical constraints of satellite and ground targets, and a novel performance function with multi-objective observation profits and attitude maneuvering energy consumption taken in account is designed. Then, the genetic algorithm's fitness function is determined by the performance function, a new method for calculating the fitness function is proposed based on time constraints, and the observation sequence is numerically coded. The observation sequence and the observation time are derived by genetic algorithm. Finally, simulation experiments are carried out with several Chinese cities as the observation targets. The experimental results verify the feasibility and efficiency of the proposed method.

关键词： Agile Earth Observing Satellite Mission planning Point target Genetic algorithm

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Distributed Coordinated Emergency Frequency control Strategy for Renewables-Rich Power systems Based on Multi-Agent Reinforcement Learning

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SSRN 2025年

作者： Sun, Zhenglong Han, Junpeng Chen, Weihan Zhang, Rui Liu, Yong Levron, Yoash Belikov, Juri Department of Electrical Engineering Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin China The Andrew and Erna Viterbi Faculty of Electrical & Computer Engineering Technion—Israel Institute of Technology Haifa3200003 Israel Department of Software Science Tallinn University of Technology Akadeemia Tee 15a Tallinn12618 Estonia

With the rapid growth of renewable energy in the power system and the implementation of large-capacity LCC-HVDC projects, the frequency support capability of the grid has been reduced. Simultaneously, the renewables-rich grid faces the risk of high-power shocks due to LCC-HVDC blocking. Existing centralized, single-measure approaches and the model-based emergency frequency control (EFC) methods are facing tremendous challenges. To fill this gap, this paper proposes a frequency emergency control method for renewables-rich grids that coordinates LCC-HVDC emergency power support and load shedding. The coordination of the two stabilization measures is modeled as a decentralized partially observable Markov decision process, and a multi-agent reinforcement learning (MADRL) approach is employed to optimize the power of measures for each stabilization control substation. An MADRL algorithm that integrates the system frequency response model is developed to overcome the problem of inaccurate evaluation of centralized action value in the MADRL algorithm used for EFC. This approach allows for the global optimization of the distributed coordination strategy through centralized training. The effectiveness and adaptability of the proposed method are demonstrated through simulations of the modified IEEE 39-bus system. © 2025, The Authors. All rights reserved.

关键词： Deep reinforcement learning

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Vertical profiles of biogenic volatile organic compounds as observed online at a tower in Beijing

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Journal of Environmental sciences 2020年第9期32卷 33-42页

作者： Huina Zhang Yanli Zhang Zhonghui Huang WJoe FActon Zhaoyi Wang Eiko Nemitz Ben Langford Neil Mullinger Brian Davison Zongbo Shi Di Liu Wei Song Weiqiang Yang Jianqiang Zeng Zhenfeng Wu Pingqing Fu Qiang Zhang Xinming Wang State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization Guangzhou Institute of GeochemistryChinese Academy of SciencesGuangzhou 510640China Center for Excellence in Regional Atmospheric Environment Institute of Urban Environment Chinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment and Guangdong Key Laboratory of Water and Air Pollution Control South China Institute of Environmental ScienceMinistry of Ecology and EnvironmentGuangzhou 510655China Lancaster Environment Centre Lancaster UniversityLancaster LA14YQUK Centre for Ecology and Hydrology Edinburgh EH260QBUK School of Geography Earth and Environmental Sciences University of BirminghamBirmingham B152TTUK Institute of Surface-Earth System Science Tianjin UniversityTianjin 300072China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

Vertical profiles of isoprene and monoterpenes were measured by a proton transfer reactiontime of flight-mass spectrometry(PTR-ToF-MS) at heights of 3,15,32,64,and 102 m above the ground on the institute of Atmospheric Physics(IAP) tower in central Beijing during the winter of 2016 and the summer of *** mixing ratios were larger in summer due to much stronger local emissions whereas monoterpenes were lower in summer due largely to their consumption by much higher levels of *** mixing ratios were the highest at the 32 m in summer(1.64±0.66 ppbV) and at 15 m in winter(1.41±0.64 ppbV) with decreasing concentrations to the ground and to the 102 m,indicating emission from the tree canopy of the surrounding *** mixing ratios were the highest at the 3 m height in both the winter(0.71±0.42 ppbV) and summer(0.16±0.10 ppbV) with a gradual decreasing trend to 102 m,indicting an emission from near the ground *** lowest isoprene and monoterpene mixing ratios all occurred at 102 m,which were 0.71±0.42 ppbV(winter) and 1.35±0.51 ppbV(summer) for isoprene,and 0.42±0.22 ppbV(winter) and0.07±0.06 ppbV(summer) for *** in the summer and monoterpenes in the winter,as observed at the five heights,showed significant mutual *** the winter monoterpenes were positively correlated with combustion tracers CO and acetonitrile at 3 m,suggesting possible anthropogenic sources.

关键词： winter Vertical mixing

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NiuEM: A Nested-iterative Unsupervised Learning Model for Single-particle Cryo-EM Image Processing

NiuEM: A Nested-iterative Unsupervised Learning Model for Si...

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2020 IEEE International Conference on Bioinformatics and Biomedicine, BIBM 2020

作者： Hu, Rui Cai, Jiaming Zheng, Wangjie Yang, Yang Shen, Hong-Bin Shanghai Jiao Tong University Key Lab. of Shanghai Education Commission for Intelligent Interaction and Cognitive Engineering Department of Computer Science and Engineering Shanghai200240 China Institute of Image Processing and Pattern Recognition Shanghai Jiao Tong University Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai200240 China Shanghai Jiao Tong University Department of Bioinformatics and Biostatistics Shanghai200240 China

ISBN: (纸本)9781728162157

Cryo-electron microscopy (cryo-EM) has become a mainstream technology for solving spatial structures of biomacromolecules, while the processing of cryo-EM images is a very challenging task. One of the great challenges is the high noise in the images. A common method is to cluster the images with close projecting angles to get mean images, which are used for 3D reconstruction. However, due to the extremely low signal-to-noise-ratio, common clustering methods often fail to obtain high-quality mean images, leading to poorly reconstructed structures. In this study, we present a new unsupervised learning framework, called NiuEM, to discriminate images captured from different angles and yield cluster-mean images. NiuEM first generates pseudo-labels and then exploits both contrastive loss and cross-entropy loss for training convolutional layers to learn feature representations. Moreover, the pseudo-labels are updated iteratively to enhance the reliability of labels. We assess the performance of NiuEM on four data sets via both visualized and quantitative experiments. Especially, two kinds of metrics are adopted to measure the performance, regarding the clustering quality and the resolution of reconstructed 3D models, respectively. The experimental results show that NiuEM achieves very competitive clustering accuracy in the comparison with the state-of-the-art image clustering methods. Moreover, the cluster mean images yielded by NiuEM lead to better initial 3D models compared with the mainstream reconstruction tools. © 2020 IEEE.

关键词： Image reconstruction

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Research on formation collision avoidance of aircraft cooperative penetration based on improved potential field method

Research on formation collision avoidance of aircraft cooper...

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IEEE International Conference on Unmanned systems (ICUS)

作者： Fang Wang Zhao Lu Qinghua Liu Yutong Zhu Jiandong Zhang Guoqing Shi Science and Technology on Complex System Control and Intelligent Agent Cooperation Laboratory Beijing Electro-Mechanical Engineering Institute Beijing China School of Electronics and Information Northwestern Polytechnical University Xi’an China

ISBN: (数字)9781728180250

ISBN: (纸本)9781728180267

Aiming at the problem of sudden threat avoidance in the process of aircraft formation cooperative penetration, formation collision avoidance strategies based on improved artificial potential field method are proposed. The effective range of the artificial repulsion potential field and the collision avoidance airspace of the sudden threat source are established. To improve the artificial potential field, the formation velocity correction coefficient and the threat source entry angle correction coefficient are introduced. In addition, the improved artificial repulsion potential energy function is defined. Based on the improved artificial potential filed in three-dimensional space, the formation collision avoidance controller on the horizontal and altitude channel are proposed respectively. Flight control commands such as rudder angle, aileron rudder angle, and elevator yaw angle are given. The simulation results confirm the security and efficiency of the formation collision avoidance strategy.

关键词： Collision avoidance Intelligent agents control systems Radio frequency Information systems Complex systems Aircraft

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