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Cyclic Gradient Methods for Unconstrained Optimization

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Journal of the Operations Research Society of China 2024年第3期12卷 809-828页

作者： ya Zhang Cong sun School of Science Beijing University of Posts and TelecommunicationsBeijing100876China

Gradient method is popular for solving large-scale *** this work,the cyclic gradient methods for quadratic function minimization are extended to general smooth unconstrained optimization *** with nonmonotonic line search,we prove its global ***,the proposed algorithms have sublinear convergence rate for general convex functions,and R-linear convergence rate for strongly convex *** experiments show that the proposed methods are effective compared to the state of the arts.

关键词： Gradient method Unconstrained optimization Nonmonotonic line search Global convergence

High-precision analytical solutions for Earth coverage of constellation equipped with reentry glide vehicles

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Chinese Journal of Aeronautics 2024年第9期37卷 385-398页

作者： Ping MA Weibo sun Jie GAO Tao chao Control and Simulation Center Harbin Institute of TechnologyHarbin 150001China Beijing Institute of Spacecraft System Engineering Beijing 100094China

To efficiently and accurately design satellite constellations equipped with Reentry Glide Vehicles(RGVs),new analytical solutions are developed for calculating their coverage ***,a new coverage model is established by approximating the Reentry Reachable Domain(RRD).However,the computation of real-time relative distances between satellites and targets,which is essential for coverage analysis based on this model,imposes a significant compu-tational *** address this challenge,a coverage analysis method based on two-dimensional map theory is *** method represents the coverage conditions of a target as a fixed area on a two-dimensional map and transforms the satellite trajectory into a series of parallel *** determining the intersection points between these lines and the area boundaries,the coverage ana-lytical solutions for a target point are *** this basis,coverage theorems are presented for rapid calculation of the constellation coverage performance for an *** results demon-strate the effectiveness and high precision of the proposed analytical solutions.

关键词： Constellation Analytical solutions Reentry glide vehicle Reentry reachable domain Two-dimensional map

Cascade electrolysis and thermocatalysis: a reliable system for upgrading C1 to C4 hydrocarbons

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Rare Metals 2024年第1期43卷 410-412页

作者： chao-Yue sun Wen Li Hai-Qing Wang Institute for Advanced Interdisciplinary Research(iAIR) College of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022China

The carbon cycle is important for maintaining a stable climate and carbon balance on Earth. Renewable-electricitydriven upcycling of carbon dioxide (CO_(2)) into value-added multi-carbon molecules is a potentially sus... 详细信息

关键词： cycling hydrocarbons enable

OsPDR20 is an ABCG metal transporter regulating cadmium accumulation in rice

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Journal of Environmental Sciences 2024年第2期136卷 21-34页

作者： He Li chao Li Di sun Zhi Min yang Department of Biochemistry and Molecular Biology College of Life SciencesNanjing Agricultural UniversityNanjing 210095China

Cadmium(Cd)is a non-essential toxic heavy metal,seriously posing high environmental risks to human *** genetic resources relevant to functional genes is important for understanding the metal absorption and accumulation in crops and bioremediation of Cd-polluted *** study investigated a functionally uncharacterized ATP binding cassette transporter G family(ABCG)gene encoding a Pleiotropic Drug Resistance 20(PDR20)type metal transporter which is localized to the plasma membrane of ***20 was transcriptionally expressed in almost all tissues and organs in lifespan and was strongly induced in roots and shoots of young rice under Cd *** expression of OsPDR20 in a yeast mutant ycf1 sensitive to Cd conferred cellular tolerance with less Cd *** of OsPDR20 by RNA interference(RNAi)moderately attenuated root/shoot elongation and biomass,with reduced chlorophylls in rice grown under hydroponic medium with 2 and 10μmol/L Cd,but led to more Cd accumulation.A field trial of rice grown in a realistic Cd-contaminated soil(0.40 mg/kg)showed that RNAi plants growth and development were also compromised compared to wild-type(WT),with smaller panicles and lower spikelet fertility but little effect on yield of ***,OsPDR20 suppression resulted in unexpectedly higher levels of Cd accumulation in rice straw including lower leaves and culm and *** results suggest that OsPDR20 is actively involved in Cd accumulation and homeostasis in rice *** increased Cd accumulation in the RNAi plants has the potential application in phytoremediation of Cd-polluted wetland soils.

关键词： Rice ABCG transporter Cadmium accumulation Phytoremediation

Regional Multi-Agent Cooperative Reinforcement Learning for City-Level Traffic Grid Signal Control

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IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 1987-1998页

作者： Yisha Li ya Zhang Xinde Li Changyin sun School of Automation Southeast UniversityNanjing 210096 Key Laboratory of Measurement and Control of Complex Systems of Engineering Ministry of EducationSoutheast UniversityNanjing 210096China

This article studies the effective traffic signal control problem of multiple intersections in a city-level traffic system.A novel regional multi-agent cooperative reinforcement learning algorithm called RegionSTLight is proposed to improve the traffic *** a regional multi-agent Q-learning framework is proposed,which can equivalently decompose the global Q value of the traffic system into the local values of several regions Based on the framework and the idea of human-machine cooperation,a dynamic zoning method is designed to divide the traffic network into several strong-coupled regions according to realtime traffic flow *** order to achieve better cooperation inside each region,a lightweight spatio-temporal fusion feature extraction network is *** experiments in synthetic real-world and city-level scenarios show that the proposed RegionS TLight converges more quickly,is more stable,and obtains better asymptotic performance compared to state-of-theart models.

关键词： Human-machine cooperation mixed domain attention mechanism multi-agent reinforcement learning spatio-temporal feature traffic signal control

Mechanics and physics under supergravity conditions

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Acta Mechanica Sinica 2024年第6期40卷 1-2页

作者： chaofeng Lü chao sun Shengqiang Cai Faculty of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315211China New Cornerstone Science Laboratory Center for Combustion EnergyDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China Department of Mechanical and Aerospace Engineering University of CaliforniaSan DiegoLa Jolla CA 92093USA

"Supergravity"refers to the conditions where the effective gravity is greater than that of *** conditions are generally relevant to stellar evolution,geophysical movement,astrophysical flows,and *** also frequently occur in various engineering scenarios involving acceleration,such as the launch of space shuttles,operation of rotor engines,impacts and explosions,chemical separation processes,and overloaded testing *** is already demonstrated in physiological experiments that living organisms of animals or plants could be damaged,either temporarily or permanently,when subjected to *** create supergravity conditions for scientific research on the Earth,centrifugal equipment or rapidly rotating devices are omnipresent in various fields,such as aerospace engineering,geophysical science,chemical and biomedical engineering,nuclear engineering,rotating flows,and physical modeling tests.

关键词： geophysical Earth stellar

Review on recent advances of inorganic electrode materials for potassium-ion batteries

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Tungsten 2024年第1期6卷 174-195页

作者： Jian-Zhen Xiong Ze-Cheng yang Xin-Liang Guo Xi-Ying Wang chao Geng Zong-Fu sun An-Yong Xiao Quan-chao Zhuang ya-Xin Chen Zhi-Cheng Ju School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China

Rechargeable potassium-ion batteries(PIBs)have great potential in the application of electrochemical energy storage devices due to the low cost,the abundant resources and the low standard reduction potential of *** electrode materials are the key factors to determine the electrochemical performance of devices,relevant research is being carried out to build high-performance *** recent years,significant progress has been made in the study of the design of inorganic electrode ***,we review the cathode materials(Prussian blue and its analogues,layered oxides and poly anionic compounds)and the anode materials(antimony-based,selenium-based and bismuth-based compounds).On the basis of previous work,the structural design principles for improving the performance of electrode materials are reasonably *** the same time,the problems that need to be solved in the preparation of electrode materials and the direction of future research and improvement are pointed out.

关键词： Inorganic electrode materials Potassium-ion batteries Cathode materials Anode materials

Real-Time Energy Management for Net-Zero Power Systems Based on Shared Energy Storage

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 371-380页

作者： Pengbo Du Bonan Huang Ziming Liu chao yang Qiuye sun School of Information Science and Engineering Northeastern UniversityShenyang 110004China Information and Communication Branch State Grid Liaoning Electric Power Company Ltd.Shenyang 110004China IEEE

Battery energy storage systems(BESSs)serve a crucial role in balancing energy fluctuations and reducing carbon emissions in net-zero power ***,the efficiency and cost performance have remained significant challenges,which hinders the widespread adoption and development of *** address these challenges,this paper proposes a real-time energy management scheme that considers the involvement of prosumers to support net-zero power *** scheme is based on two shared energy storage models,referred to as energy storage sale model and power line lease *** energy storage sale model balances real-time power deviations by energy interaction with the goal of minimizing system costs while generating revenue for shared energy storage providers(ESPs).Additionally,power line lease model supports peer-to-peer(P2P)power trading among prosumers through the power lines laid by ESPs to connect each *** model allows ESP to earn profits from the use of power lines while balancing power deviations and better consuming renewable *** results validate the effectiveness of the proposed scheme,ensuring stable power supply for net-zero power systems and providing benefits for both the ESP and prosumers.

关键词： Shared energy storage energy storage provider(ESP) energy management peer-to-peer(P2P)trading net-zero power system

Characteristics of Bi-2223 HTS Tapes Under Short-Circuit Current Impacts in Hybrid Energy Transmission Pipelines

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 736-745页

作者： Yuguang sun chao Yin Weizhen Li Xinyang Li Xiaohua Jiang Department of Electric Engineering Tsinghua UniversityBeijing 100084China

A hybrid energy transmission pipeline is proposed with the aim of long-distance cooperative transmission of electricity and chemical fuels, which is composed of an inner high-temperature superconducting (HTS) power cable and outer liquefied natural gas (LNG) pipeline. The flowing LNG could maintain the operating temperature of the inner HTS power cable within the range of 85 K-90 K, thus the Bi-2223 superconductors in the HTS power cable produce little Joule loss with the transmission current below the critical current. Owing to the advantages of high power density, low transmission losses and economical manufacturing costs, the hybrid energy transmission pipeline is expected to be widely utilized in the near future. In order to ensure the safety of the HTS power cable and explosive LNG in case of short-circuit faults, this paper tests and analyzes the characteristics of Bi-2223 HTS tapes of the Type HT-CA, Type HT-SS and Type H models under short-circuit current impacts at the LNG cooling temperature (85 K-90 K). An experimental platform is designed and established for the ampacity tests of HTS tapes above LN2 cooling temperature (77 K). The AC over-current impact tests at 85 K-90 K are carried out on each sample of Bi-2223 tapes respectively, and the experimental results are analyzed and compared to evaluate their performances under different operating conditions. The results indicate that the Type HT-CA tape can withstand 50 Hz short-circuit current impact with the amplitude of 1108 A (10 times of critical current Ic ) for 100 ms at 90 K, and its resistance is the smallest of the three tested samples under similar current impacts. Therefore, the Type HT-CA Bi-2223 tape is the optimal superconductor of the HTS power cable in the hybrid energy transmission pipeline.

关键词： Bi-2223 high-temperature superconducting(HTS)tape critical current hybrid energy transmission pipeline liquefied natural gas(LNG)cooling temperature short-circuit current impact characteristics