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Mathematics of multi-agent learning systems at the interface of game theory and artificial intelligence

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Science China(Information Sciences) 2024年第6期67卷 445-447页

作者： Long WANG Feng fu Xingru CHEN Center for Systems and Control College of EngineeringPeking University Center for Multi-Agent Research Institute for Artificial IntelligencePeking University Department of Mathematics Dartmouth College Department of Biomedical Data Science Geisel School of Medicine at Dartmouth School of Science Beijing University of Posts and Telecommunications

Evolutionary game theory (EGT) and artificial intelligence(AI) are two fields that,at first glance,might seem distinct,but they have notable connections and *** former focuses on the evolution of behaviors (or strategies)in a population,where individuals interact with others and update their strategies based on imitation (or social learning).

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Ultrafast optical investigation of carrier and spin dynamics in low-dimensional perovskites

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Science China(Technological Sciences) 2024年第1期67卷 2-18页

作者： fu JinYue JIANG Ying FANG HongHua Key Laboratory for Micro-Nano Physics and Technology of Hunan Province School of Physics and ElectronicsHunan UniversityChangsha 410012China State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China

Low-dimensional perovskite(PVK)materials have attracted significant research interest,because of their quantum-confined effect,tunable band gap structures,and higher stability than that of three-dimensional(3D)*** semiconductor optoelectronic devices,high speed and small size are closely *** development of high-speed devices requires researchers to fully understand the properties of materials,especially the dynamic processes such as carrier recombination,separation,and transport,which often play a crucial role in the performance of *** an indispensable part of dynamic research,spin relaxation is also of great significance in studying the properties of materials and explore possible *** halide PVK materials have strong spin-orbit coupling(SOC),which provides a basis for information storage and processing by using spin degrees of ***,studying the carrier and spin dynamics of low-dimensional PVKs is an effective way to understand the internal properties of low-dimensional PVKs *** paper summarizes the latest research progress on the ultrafast carrier and spin dynamics in low-dimensional PVKs,to comprehensively understand their carrier and spin behaviors and present an outlook for relevant studies in this area.

关键词： low-dimensional perovskites carrier dynamics spin dynamics optoelectronic devices

Relationship between seismic structures and the diverse rupture processes of the 2023 Türkiye earthquake doublet

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Science China Earth Sciences 2024年第9期67卷 2810-2823页

作者： Zhi WANG Yi fu Shunping PEI CAS Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Recent geodetic and seismological observations of two major earthquakes in southeastern Türkiye in February 2023 have revealed complex rupture initiation,propagation,and segmentation along the East Anatolian Fault Zone(EAFZ)and surrounding ***,the role of upper crust structures along the EAFZ in determining the diverse rupture processes of this earthquake doublet remains *** further investigate this,we employed double-difference location and seismic tomography techniques to determine high-resolution seismic velocities(V_(P),V_(S))and Poisson’s ratio(σ)structures using a multiparameter joint tomographic *** dataset includes 100,833 high-quality source-receiver travel-time pairs of P-and *** find that the unique rupture processes of this earthquake doublet were primarily influenced by contrasting crustal seismic structures and localized geological *** M_(w)7.8 mainshock was initiated within a transitional edge zone characterized by a rigid part(asperity)of the seismogenic zone with sharp contrast variations in rock strength ranging from low to high along the *** comparison,the M_(w)7.6 rupture originated in a ductile belt featuring fluid saturation with low-VP,low-VS,and high-σvalues that extended parallel to the Cardak *** pronounced contrast structures observed along the former rupture can be attributed to the oblique collision system between the weakened section of the east Anatolian plateau and the brittle Arabian platform,while the latter rupture was initiated within the ductile structure associated with fluid intrusion caused by the northward subduction of the Cyprus slab and subsequent ***,the occurrence of the first earthquake(E1)serves to alleviate shear stress on the second earthquake(E2)fault,potentially impeding the initiation of an E2 *** the contrary,this event also significantly reduces the normal stress acting on the E2 fault due to a double left-lateral strike-slip system

关键词： 2023 Turkiye earthquake doublet Joint seismic tomography Tomographic transition edge Seismic rupture process Strong fault coupling

Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

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Chinese Journal of Polymer Science 2024年第4期42卷 511-520页

作者： Tian-Hao Yang Tong Wu Qiang fu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China State Key Laboratory of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu610065China

Polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

关键词： Self-limiting heating cables Positive temperature coefficient Thermal treatment Electrical treatment

Strip method to construct a two-dimensional quasilattice witheight-fold symmetry

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Chinese Physics B 2024年第9期33卷 462-465页

作者： Weishen Huang Xiujun fu School of Physics and Optoelectronics South China University of TechnologyGuangzhou 510640China

Based on the substitution rule and symmetry, we propose a method to generate an octagonal quasilattice consisting ofsquare and rhombus tiles. Local configurations and Ammann lines are used to guide the growth of the tiles in a quasiperiodicorder. The structure obtained is a perfect eight-fold symmetric quasilattice, which is confirmed by the radial distributionfunction and the diffraction pattern.

关键词： quasicrystals eight-fold symmetry Ammann–Beenker tiling

A fuzzy Trust Management Mechanism with Dynamic Behavior Monitoring for Wireless Sensor Networks

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China Communications 2024年第5期21卷 177-189页

作者： fu Shiming Zhang Ping Shi Xuehong School of Artificial Intelligence Chongqing University of EducationChongqing 400065China School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China

Traditional wireless sensor networks(WSNs)are typically deployed in remote and hostile environments for information *** wireless communication methods adopted by sensor nodes may make the network highly vulnerable to various *** encryption and authentication mechanisms cannot prevent attacks launched by internal malicious *** trust-based security mechanism is usually adopted to solve this problem in ***,the behavioral evidence used for trust estimation presents some uncertainties due to the open wireless medium and the inexpensive sensor ***,how to efficiently collect behavioral evidences are rarely *** address these issues,in this paper,we present a trust management mechanism based on fuzzy logic and a cloud ***,a type-II fuzzy logic system is used to preprocess the behavioral evidences and alleviate ***,the cloud model is introduced to estimate the trust values for sensor ***,a dynamic behavior monitoring protocol is proposed to provide a balance between energy conservation and safety *** results demonstrate that our trust management mechanism can effectively protect the network from internal malicious attacks while enhancing the energy efficiency of behavior monitoring.

关键词： behavior monitoring cloud fuzzy trust wireless sensor networks

A high-order target phase approach for the station-keeping of periodic orbits

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Astrodynamics 2024年第1期8卷 61-75页

作者： Xiaoyu fu Nicola Baresi Roberto Armellin Surrey Space Centre University of SurreyGuildfordGU27XHUK Te PūnahaĀtea-Auckland Space Institute University of AucklandAuckland1010New Zealand

A novel high-order target phase approach(TPhA)for the station-keeping of periodic orbits is proposed in this *** key elements of the TPhA method,the phase-angle Poincare map and high-order maneuver map,are constructed using differential algebra(DA)techniques to determine station-keeping epochs and calculate correction maneuvers.A stochastic optimization framework tailored for the TPhA-based station-keeping process is leveraged to search for fuel-optimal and error-robust TPhA ***-satellite orbits(QSOs)around Phobos are investigated to demonstrate the efficacy of TPhA in mutli-fidelity dynamical *** Carlo simulations demonstrated that the baseline QSO of JAXA’s Martian Moons eXploration(MMX)mission could be maintained with a monthly maneuver budget of approximately 1 m/s.

关键词： target phase approach(TPhA) station-keeping Poincarémap differential algebra(DA) quasi-satellite orbit(QSO)

Low-Complexity Reconstruction of Covariance Matrix in Hybrid Uniform Circular Array

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China Communications 2024年第3期21卷 66-74页

作者： fu Zihao Liu Yinsheng Duan Hongtao Information School Communication University of ChinaBeijing 100024China Beijing Institute of Electronic System Engineering Beijing 100854China School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China Beijing Radio Monitoring Station of State Radio Monitoring Center(SRMC) Beijing 100037China

Spatial covariance matrix(SCM) is essential in many multi-antenna systems such as massive multiple-input multiple-output(MIMO). For multi-antenna systems operating at millimeter-wave bands, hybrid analog-digital structure has been widely adopted to reduce the cost of radio frequency *** this situation, signals received at the antennas are unavailable to the digital receiver, and as a consequence, traditional sample average approach cannot be used for SCM reconstruction in hybrid multi-antenna systems. To address this issue, beam sweeping algorithm(BSA) which can reconstruct the SCM effectively for a hybrid uniform linear array, has been proposed in our previous works. However, direct extension of BSA to a hybrid uniform circular array(UCA)will result in a huge computational burden. To this end, a low-complexity approach is proposed in this paper. By exploiting the symmetry features of SCM for the UCA, the number of unknowns can be reduced significantly and thus the complexity of reconstruction can be saved accordingly. furthermore, an insightful analysis is also presented in this paper, showing that the reduction of the number of unknowns can also improve the accuracy of the reconstructed SCM. Simulation results are also shown to demonstrate the proposed approach.

关键词： hybrid array millimeter-wave spatial covariance matrix uniform circular array

Oligodendrocytes in central nervous system diseases:the effect of cytokine regulation

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Neural Regeneration Research 2024年第10期19卷 2132-2143页

作者： Chengfu Zhang Mengsheng Qiu Hui fu Center for Cognition and Brain Disorders The Affiliated Hospital of Hangzhou Normal UniversityHangzhouZhejiang ProvinceChina Department of Psychiatry National Clinical Research Center for Mental Disordersand National Center for Mental DisordersThe Second Xiangya Hospital of Central South UniversityChangshaHunan ProvinceChina Institute of Life Sciences Key Laboratory of Organ Development and Regeneration of Zhejiang ProvinceCollege of Life and Environment SciencesHangzhou Normal UniversityHangzhouZhejiang ProvinceChina Key Laboratory of Aging and Cancer Biology of Zhejiang Province School of Basic Medical SciencesHangzhou Normal UniversityHangzhouZhejiang ProvinceChina

Cytokines including tumor necrosis factor, interleukins, interferons, and chemokines are abundantly produced in various diseases. As pleiotropic factors, cytokines are involved in nearly every aspect of cellular functions such as migration, survival, proliferation, and differentiation. Oligodendrocytes are the myelin-forming cells in the central nervous system and play critical roles in the conduction of action potentials, supply of metabolic components for axons, and other functions. Emerging evidence suggests that both oligodendrocytes and oligodendrocyte precursor cells are vulnerable to cytokines released under pathological conditions. This review mainly summarizes the effects of cytokines on oligodendrocyte lineage cells in central nervous system diseases. A comprehensive understanding of the effects of cytokines on oligodendrocyte lineage cells contributes to our understanding of central nervous system diseases and offers insights into treatment strategies.

关键词： astrocyte central nervous system disease CXC chemokine cytokine interferonγ interleukin microglia oligodendrocyte oligodendrocyte precursor cell tumor necrosis factorα