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中国通信:英文版 2023年第9期20卷 1-19页

作者： Shanshan ma Bingpeng zhou The School of Electronics and Communication Engineering Sun Yat-sen UniversityShenzhen 518107China

In this paper,joint location and velocity estimation(JLVE)of vehicular terminals for 6G integrated communication and sensing(ICAS)is studied.We aim to provide a unified performance analysis framework for ICAS-based JLVE,which is challenging due to random fading,multipath interference,and complexly coupled system models,and thus the impact of channel fading and multipath interference on JLVE performance is not fully understood.To address this challenge,we exploit structured information models of the JLVE problem to render tractable performance quantification.Firstly,an individual closedform Cramer-Rao lower bound for vehicular localization,velocity detection and channel estimation,respectively,is established for gaining insights into performance limits of ICAS-based JLVE.Secondly,the impact of system resource factors and fading environments,e.g.,system bandwidth,the number of subcarriers,carrier frequency,antenna array size,transmission distance,spatial channel correlation,channel covariance,the number of interference paths and noise power,on the JLVE performance is theoretically analyzed.The associated closed-form JLVE performance analysis can not only provide theoretical foundations for ICAS receiver design but also provide a perfor mance benchmark for various JLVE methods。

关键词： integrated sensing and communication vehicular state sensing Cramer-Rao lower bound

Group-Consensus of Hierarchical Containment Control for Linear Multi-Agent Systems

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IEEE/CAA Journal of Automatica Sinica 2023年第6期10卷 1462-1474页

作者： Jingshu Sang Dazhong ma Yu zhou the College of Information Science and Engineering Northeastern UniversityShenyang 110004China

The existing containment control has been widely developed for several years, but ignores the case for large-scale cooperation. The strong coupling of large-scale networks will increase the costs of system detection and maintenance. Therefore, this paper is concerned with an extensional containment control issue, hierarchical containment control. It aims to enable a multitude of followers achieving a novel cooperation in the convex hull shaped by multiple leaders. Firstly, by constructing the three-layer topology, large-scale networks are decoupled. Then,under the condition of directed spanning group-tree, a class of dynamic hierarchical containment control protocol is designed such that the novel group-consensus behavior in the convex hull can be realized. Moreover, the definitions of coupling strength coefficients and the group-consensus parameter in the proposed dynamic hierarchical control protocol enhance the adjustability of systems. Compared with the existing containment control strategy, the proposed hierarchical containment control strategy improves dynamic control performance. Finally, numerical simulations are presented to demonstrate the effectiveness of the proposed hierarchical control protocol.

关键词： Group-consensus behavior hierarchical containment control linear multi-agent systems three-layer topology

Catalytic enantioselective domino alkenylation-alkynylation of alkenes: stereoselective synthesis of 5–7 membered azacycles and carbocycles

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Science China Chemistry 2023年第6期66卷 1701-1706页

作者： Zhaoming ma Lantian Sun Jianrong Steve zhou State Key Laboratory of Chemical Oncogenomics Guangdong Provincial Key Laboratory of Chemical GenomicsSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhen 518055China Department of Chemistry Hong Kong Baptist UniversityHong KongChina

Enantioselective domino alkenylation-alkynylation of olefins is achieved for the first time,using terminal alkynes directly as pronucleophiles.The new reaction enables facile construction of azacycles carrying quaternary stereocenters,including 5–7 membered pyrrolidines,piperidines and tetrahydroazepines.Moreover,alkynyl groups in azacyclic products provide a useful handle for derivatization that formed both fused and bridged azabicycles.

关键词： membered cycles synthesis

Sound Insulation Performance of Pyramidal Truss Core Cylindrical Sandwich Structure

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Acta Mechanica Solida Sinica 2022年第3期35卷 504-517页

作者： Yu-zhou Wang Li ma Center for Composite materials Harbin Institute of TechnologyHarbin 150080China

Recently,cylindrical structures have been exploited in various fields due to their excellent mechanical properties.With the increase in the application of cylindrical shell structures,researchers are paying more and more attention to its acoustic performance and sound insulation applications.By inserting the pyramidal truss lattice into the cylindrical shell structure,a cylindrical sandwich structure is obtained and the sound insulation performance of the structure is investigated.The space-harmonic expansion method and the principle of virtual work are employed to establish a theoretical model for the acoustic analysis of cylindrical sandwich structures.The vibro-acoustic coupling is taken into account by imposing the velocity continuity condition at the fluid-solid interface.The sound transmission loss(STL)performance of the structure is examined by establishing both theoretical and finite element models.Subsequently,the influence of various parameters on sound transmission loss is researched and analyzed.

关键词： Cylindrical sandwich structure Pyramidal truss core Sound transmission loss(STL) Vibro-acoustic coupling

Multiple Change Points Detection in High-Dimensional Multivariate Regression

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Journal of Systems Science & Complexity 2022年第6期35卷 2278-2301页

作者： ma Xiaoyan zhou Qin ZI Xuemin School of Statistics and Data Science LPMC and KLMDASRNankai UniversityTianjin 300071China School of mathematics and Statistics Jiangsu Normal UniversityXuzhou 221116China School of Science Tianjin University of Technology and EducationTianjin 300222China

This paper considers the problem of detecting structural changes in a high-dimensional regression setting. The structural parameters are subject to abrupt changes of unknown magnitudes at unknown locations. The authors propose a new procedure that minimizes a penalized least-squares loss function via a dynamic programming algorithm for estimating the locations of change points. To alleviate the computational burden, the authors adopt a prescreening procedure by eliminating a large number of irrelevant points before implementing estimation procedure. The number of change points is determined via Schwarz’s information criterion. Under mild assumptions, the authors establish the consistency of the proposed estimators, and further provide error bounds for estimated parameters which achieve almost-optimal rate. Simulation studies show that the proposed method performs reasonably well in terms of estimation accuracy, and a real data example is used for illustration.

关键词： Consistency dynamic programming low-rank structure multi-task learning nuclear norm

Shortened processing duration of high-performance Sm-Co-Fe-Cu-Zr magnets by stress-aging

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Journal of materials Science & Technology 2022年第11期106卷 70-76页

作者： Xianglong zhou Tao Yuan Tianyu ma Frontier Institute of Science and Technology State Key Laboratory for Mechanical Behavior of Materialsand MOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterXi’an Jiaotong UniversityXi’an 710049China The Southwest Applied magnetism Research Institute Mianyang 621000China

Simultaneously achieving high energy product and high coercivity in the 2:17-type Sm-Co-Fe-Cu-Zr high temperature magnets has been closely relied on long-term isothermal aging to develop complete cellu-lar nanostructure.In this work,we report a novel stress-aging approach that can substantially shorten the aging time to fabricate high-performance Sm-Co-Fe-Cu-Zr magnets.As exhibited by a model magnet Sm_(25) Co_(50.2) Fe_(16.2) Cu_(5.6) Zr_(3.0)(wt.%),applying 90 MPa compressive stress can shorten the aging time from 20 h for conventional isothermal aging to 10 h at the same aging temperature for achieving nearly equiv-alent magnetic performance.Further comparative study between the 10 h-aged samples under stress-containing and stress-free conditions revealed that the stress not only promotes the precipitation of the cell boundary phase that are essential for enhancing the coercivity but also accelerates the dissociation of the cell edge defects that are detrimental to squareness factor,without destroying the[001]crystal-lographic texture.Such microstructural improvements enable the achievement of high-performance with maximum energy product of∼30 MGOe and coercivity above 35 kOe at reduced aging time.

关键词： Permanent magnets Sm-Co magnets Precipitation Stress-aging

Phase regimes of parity-time-symmetric coupled-ring systems at exceptional points

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Photonics Research 2022年第10期10卷 2374-2379页

作者： ZHUANG ma XIAOYAN zhou LIN ZHANG Tianjin Key Laboratory of Integrated Opto-electronics Technologies and Devices School of Precision Instruments and Opto-electronics EngineeringTianjin UniversityTianjin 300072China Peng Cheng Laboratory Shenzhen 518038China

The optical coupled resonant system consisting of an integrated resonator with gain and a resonator with loss provides an excellent platform to create exceptional points(EPs)in non-Hermitian systems.Most previous studies have focused on the striking intensity feature of EPs,but its phase response is seldom investigated.In this work,we present a thorough study on the phase response of an EP system.Intriguingly,the phase response exhibits distinct behavior depending on the ordering of the ring resonators:when the input light in a bus waveguide is coupled directly or indirectly to the ring with a gain,the phase response is featured by nonmonotonic transition and 2π monotonic transition,respectively.We also prove that the newly identified phase features are theoretically guaranteed.These phase responses produce unique group delays that have never been found in other coupled resonant systems.The results deepen our understanding on EPs in non-Hermitian systems and are potentially useful for practical applications exploiting phase features.

关键词： resonator waveguide coupled

Investigation on C_(2)H_(4)-Air combustion mode in a non-premixed rotating detonation combustor

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Propulsion and Power Research 2022年第1期11卷 85-96页

作者： Shengbing zhou Hu ma Yuan ma Changsheng zhou Ning Hu College of Aerospace Engineering Chongqing UniversityChongqing400044China School of Mechanical Engineering Nanjing University of Science and TechnologyNanjingJiangsu210094China Qingdao Campus of Naval Aeronautical University QingdaoShandong266100China School of Mechanical Engineering Hebei University of TechnologyTianjin300401China

Based on the working characteristics of the rotating detonation combustor,the combustion mode of C_(2)H_(4)-Air under non-premixed injection conditions is experimentally studied in this paper.By changing the equivalence ratio,we observed the acoustic deflagration mode,fast deflagration mode,stable detonation mode,and weak detonation mode in the combustor.The velocity and pressure of the shock wave increase gradually as the equivalence ratio increases from 0.6 to 1.8.The stable detonation region appears near the stoichiometric ratio and the velocity of the detonation wave is relatively stable.When the equivalence ratio of the mixture is larger than 1.32,the stable detonation wave will suddenly extinguish,forming a weak detonation mode until the end of the combustor operation.The combustion mode of weak detonation is greatly affected by the fuel injection pressure ratio,and the release rate of energy is the main reason for the formation of deflagration mode or detonation mode.

关键词： Rotating detonation combustor Detonation wave Deflagration Non-premixed injection C2H4

Dislocation behavior in Cu single crystal joints under the ultrasonically excited high-strain-rate deformation

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Journal of materials Science & Technology 2023年第10期141卷 66-77页

作者： Qiuchen ma Jingyuan ma Jianli zhou Xiaoxiong Zheng Hongjun Ji The State Key Laboratory of Advanced Welding and Joining School of Materials Science and EngineeringHarbin Institute of Technology at ShenzhenShenzhen 518055China Sauvage Laboratory for Smart materials Shenzhen Key Laboratory of Flexible Printed Electronics TechnologySchool of Materials Science and EngineeringHarbin Institute of Technology(Shenzhen)Shenzhen 518055China School of Science Harbin Institute of Technology at ShenzhenShenzhen 518055China

The coupling effects of ultrasonic excitation and high-strain-rate deformation are the core factors for weld formation during ultrasonic welding.However,interfacial deformation behavior still shrouds in uncer-tainty because of the contradictory features between mutual dislocation retardation caused by severely frictional deformation and ultrasonic-accelerated dislocation motion.[101]and[111]-oriented Cu single crystals which tended to form geometrically necessary boundaries(GNBs)were selected as the welding substrates to trace the uniquely acoustoplastic effects in the interfacial region under the ultrasonically excited high-strain-rate deformation.It was indicated that for a low energy input,micro-welds localized at the specific interface region,and equiaxed dislocation cells substituting for GNBs dominated in the ini-tial single crystal rotation region.As the welding energy increased,continuous shear deformation drove the dynamic recrystallization region covered by equiaxed grains to spread progressively.Limited discrete dislocations inside the recrystallized grains and nascent dislocation cells at the grain boundaries were ob-served in[101]and[111]joints simultaneously,suggesting that the ultrasonic excitation promoted motion of intragranular dislocation and pile-up along the sub-grain boundaries.The interfacial morphology be-fore and after expansion of recrystallization region all exhibited the weakening of orientation constraint on dislocation motion,which was also confirmed by the similar micro-hardness in joint interface.The first-principle calculation and applied strain-rate analysis further revealed that ultrasonic excitation en-hanced dislocation slipping,and enabled dislocation motion to accommodate severe plastic deformation at a high-strain-rate.

关键词： Acoustoplasticity Ultrasonic welding Cu single crystal Dynamic recrystallization Dislocation cell High-strain-rate deformation

An overview of functional biolubricants

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Friction 2023年第1期11卷 23-47页

作者： Lumin YANG Xiaoduo ZHAO Zhengfeng ma Shuanhong ma Feng zhou State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of materials Science and Optoelectronics Enginering University of Chinese Academy of SciencesBeijing 100049China Yantai Zhongke Research Institute of Advanced materials and Green Chemical Engineering Yantai 264006China Shandong Laboratory of Yantai Advanced materials and Green manufacture Yantai 264006China

At present,more and more diseases are associated with the lubrication dysfunction,which requires a systematic study of the complex lubrication behavior of tissues and organs in human body.Natural biomacromolecular lubricants are essential for maintaining ultra-low coefficients of friction between sliding biological interfaces.However,when the surface lubrication performance of tissues or organs destroys heavily,it will bring friction/shear damage for sliding contact interfaces.Therefore,the application of exogenous biological lubricating materials to improve the lubrication situation of damaged tissue or organ interfaces has attracted extensive attention of researchers.In this review,based on a simple summary of lubrication mechanism at sliding biological interface,we systematically introduce the research progress of several kinds of representatively biolubrication materials,including eye drops,tissue anti-adhesion agents,joint lubricants,and medical device lubricants.Meanwhile,the lubrication mechanism and individual advantage and shortcoming for each of these synthetic exogenous lubricated materials are clarified.Correspondingly,the important lubrication application functionality of these biolubricant materials in typically medical surgery scenes,such as dry eye syndrome,tissue adhesion,arthritis,and interventional medical devices,is discussed.Finally,we look forward to the future development direction of artificial biolubricant materials.

关键词： biolubricants eye drops tissue anti-adhesion arthritis treatment medical devices