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Global practical stabilization of the double integrator system with an imperfect sensor and subject to a bounded disturbance

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Control Theory and Technology 2024年第3期22卷 468-478页

作者： Zhiyuan Zhu yuanlong li Zongli lin Department of Automation Shanghai Jiao Tong Universityand Key Laboratory of System Control and Information Processing of Ministry of EducationShanghai 200240China Charles L.Brown Department of Electrical and Computer Engineering University of VirginiaP.0.Box 400743CharlottesvilleVA 22904-4743USA

This paper is concerned with global practical stabilization of the double integrator system with an imperfect sensor and subject to an additive bounded output *** imperfect sensor nonlinearity possesses the nonlinear characteristics of saturation and dead *** of the presence of output dead zone and the additive disturbance,the states cannot be expected to driven into an arbitrarily small neighborhood of the *** solve the global practical stabilization problem,we proposes a low gain-based linear dynamic output feedback law,under which the first state enters and remains in a bounded set whose size is depended on the bound of disturbance and the range of dead zone and the second state enters and remains in a pre-specified arbitrarily small set,both in finite *** results illustrate the effectiveness of our proposed control method.

关键词： Output saturation Disturbance rejection Output dead zone Low gain feedback-linear output feedback Practical stabilization

New Record Ocean Temperatures and Related Climate Indicators in 2023

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Advances in Atmospheric Sciences 2024年第6期41卷 1068-1082页

作者： lijing CHENG John ABRAHAM Kevin E.TRENBERTH Tim BOYER Michael EMANN Jiang ZHU Fan WANG Fujiang YU Ricardo LOCARNINI John FASULLO Fei ZHENG yuanlong li Bin ZHANG liying WAN Xingrong CHEN Dakui WANG licheng FENG Xiangzhou SONG Yulong liU Franco RESEGHETTI Simona SIMONCELli Viktor GOURETSKI Gengxin CHEN Alexey MISHONOV Jim REAGAN Karina VON SCHUCKMANN Yuying PAN Zhetao TAN Yujing ZHU Wangxu WEI Guancheng li Qiuping REN lijuan CAO Yayang LU International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of St.Thomas School of EngineeringMinnesota 55105USA NSF National Center for Atmospheric Research BoulderColorado 80307USA University of Auckland Auckland 1010New Zealand National Oceanic and Atmospheric Administration National Centers for Environmental InformationSilver SpringMaryland 20910USA Department of Earth and Environmental Science University of PennsylvaniaPhiladelphiaPennsylvania 19104USA Institute of Oceanology Chinese Academy of SciencesQingdao 266071China National Marine Environmental Forecasting Center Ministry of Natural Resources of ChinaBeijing 100081China Oceanographic Data Center Chinese Academy of SciencesQingdao 266071China College of Oceanography Hohai UniversityNanjing 210098China National Marine Data and Information Service Tianjin 300171China Italian National Agency for New Technologies Energy and Sustainable Economic DevelopmentS.Teresa Research CenterLerici 19032Italy Istituto Nazionale di Geofisica e Vulcanologia Sede di BolognaBologna 40128Italy South China Sea Institute of Oceanology Chinese Academy of SciencesGuangzhou 510301China ESSIC/CISESS-MD University of MarylandCollege ParkMD20740USA Mercator Ocean International Toulouse 31400France Eco-Environmental Monitoring and Research Center Pearl River Valley and South China Sea Ecology and Environment AdministrationMinistry of Ecology and EnvironmentPRCGuangzhou 510611China National Meteorological Information Center China Meteorological AdministrationBeijing 100081China International Research Center of Big Data for Sustainable Development Goals Beijing 100094China

The global physical and biogeochemical environment has been substantially altered in response to increased atmospheric greenhouse gases from human *** 2023,the sea surface temperature(SST)and upper 2000 m ocean heat content(OHC)reached record *** 0–2000 m OHC in 2023 exceeded that of 2022 by 15±10 ZJ(1 Zetta Joules=1021 Joules)(updated IAP/CAS data);9±5 ZJ(NCEI/NOAA data).The Tropical Atlantic Ocean,the Mediterranean Sea,and southern oceans recorded their highest OHC observed since the *** with the onset of a strong El Niño,the global SST reached its record high in 2023 with an annual mean of~0.23℃ higher than 2022 and an astounding>0.3℃ above 2022 values for the second half of *** density stratification and spatial temperature inhomogeneity indexes reached their highest values in 2023.

关键词： ocean heat content salinity stratification global warming climate

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一种堆场使用效率计算方法

港口装卸 2024年第4期 53-54,57页

作者：李渊龙蒋强沧州黄骅港矿石港务有限公司

在港口生产作业环节,堆场智能高效地为货物缓冲储存、保管及交接提供支撑,是港口生产能力的重要保障。分析港口生产作业中堆场所面临的的问题,设计智能决策管理系统,以提高堆场的周转率及人机智能调配,助力智慧港口建设。

关键词：堆场效率计算智慧港口

结泥条件下TBM滚刀破岩能量演化机制及掘进参数优化研究

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矿业研究与开发 2024年第5期44卷 201-210页

作者：张鹏赵腾跃李元龙刘勃龙北京市政路桥股份有限公司北京100045 绍兴文理学院土木工程学院浙江绍兴市312000

岩石隧道掘进机(Tunnel Boring Machine,TBM)在泥岩地层掘进过程中,渣土易形成泥浆黏附在滚刀和刀盘表面,出现刀盘结“泥饼”现象,严重降低掘进效率。为了揭示结泥对TBM滚刀破岩效率的影响,防止滚刀结泥,使用离散元程序PFC3D模拟TBM滚... 详细信息

岩石隧道掘进机(Tunnel Boring Machine,TBM)在泥岩地层掘进过程中,渣土易形成泥浆黏附在滚刀和刀盘表面,出现刀盘结“泥饼”现象,严重降低掘进效率。为了揭示结泥对TBM滚刀破岩效率的影响,防止滚刀结泥,使用离散元程序PFC3D模拟TBM滚刀回转切割泥岩过程,计算了系统总能量E、弹性应变能Ee、摩擦能E_μ、阻尼能E_β、动能Ek和黏结能Ea,从能量演化角度研究结泥条件下TBM滚刀破岩机制。随后分析了不同刀盘推力、滚刀刀刃角和刀刃宽度下的TBM滚刀破岩过程中的能量特征,根据“累积热量和累积黏结能最低,且滚刀表面黏附的泥化物质量最小”的原则,对上述掘进参数进行优化。研究结果表明,PFC3D中的黏聚滚动阻力线性模型可实现滚刀结泥过程;在结泥情况下,泥化物的形成将显著提高机械做功,消耗大量能量,降低滚刀破岩效率;提高刀盘推力可以促进泥化物的形成,导致刀盘升温,诱发泥化物黏附在滚刀表面。选用刀刃角为40°的V形滚刀,设最优刀刃宽度为13 mm,可减小滚刀结泥情况。研究结果可为相关工程中预防刀盘结“泥饼”提供理论参考。

关键词：岩石隧道掘进机结泥能量破岩机制掘进参数

Semi-global weighted output average tracking of discrete-time heterogeneous multi-agent systems subject to input saturation and external disturbances

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Control Theory and Technology 2023年第3期21卷 315-333页

作者： Qilin Song yuanlong li Yijing Xie Zongli lin Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China Department of Electrical Engineering University of Texas at ArlingtonArlington 76019TXUSA Charles L.Brown Department of Electrical and Computer Engineering University of VirginiaCharlottesville 22904-4743VAUSA

In this paper,we revisit the semi-global weighted output average tracking problem for a discrete-time multi-agent system subject to input saturation and external *** multi-agent system consists of multiple heterogeneous linear systems as leader agents and multiple heterogeneous linear systems as follower *** design both the state feedback and output feedback control protocols for each follower *** particular,a distributed state observer is designed for each follower agent that estimates the state of each leader *** the output feedback case,state observer is also designed for each follower agent to estimate its own *** these estimates,we design low gain-based distributed control protocols,parameterized in a scalar low gain *** is shown that,for any bounded set of the initial conditions,these control protocols cause the follower agents to track the weighted average of the outputs of the leader agents as long as the value of the low gain parameter is tuned sufficiently *** results illustrate the validity of the theoretical results.

关键词： Distributed average tracking Input saturation Low gain feedback Heterogeneous multi-agent systems Output regulation

Intraseasonal variability of the surface zonal current in the equatorial Indian Ocean:Seasonal differences and causes

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Acta Oceanologica Sinica 2022年第5期41卷 12-26页

作者： Qingwen Zhong Gengxin Chen yuanlong li Qihua Peng Xiaoqing Chu State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou510301China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou511458China University of Chinese Academy of Sciences Beijing100049China Innovation Academy of South China Sea Ecology and Environmental Engineering Chinese Academy of SciencesGuangzhou510075China Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao266237China

Using observations and numerical simulations,this study examines the intraseasonal variability of the surface zonal current(u ISV)over the equatorial Indian Ocean,highlighting the seasonal and spatial differences,and the causes of the ***-amplitude u ISV occurs in the eastern basin at around 80°–90°E and near the western boundary at 45°–55°*** the eastern basin,the u ISV is mainly caused by the atmospheric intraseasonal oscillations(ISOs),which explains 91%of the standard deviation of the total u *** analysis suggests that it takes less than ten days for the intraseasonal zonal wind stress to generate the u ISV through the directly forced Kelvin and Rossby *** by the stronger zonal wind stress associated with the Indian summer monsoon ISO(MISO),the eastern u ISV in boreal summer(May to October)is about 1.5 times larger than that in boreal winter(November to April).In the western basin,both the atmospheric ISOs and the oceanic internal instabilities contribute substantially to the u ISV,and induce stronger u ISV in boreal *** budget analysis suggests that the mean flow converts energy to the intraseasonal current mainly through barotropic instabilities.

关键词： equatorial zonal current intraseasonal variability seasonal difference wind stress associated with the MISO and MJO

Design and performance investigation of modified dual reflector parabolic trough collector with double planar mirrors

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Science China(Technological Sciences) 2024年第3期67卷 902-918页

作者： li Peijing liU TaiXiu QIN yuanlong li JiChao liU QiBin School of Energy Powerand Mechanical EngineeringNorth China Electric Power University Beijing 226China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Department of Thermal Science and Energy Engineering University of Science and Technology of ChinaHefei 230027China

In a typical parabolic trough collector(PTC), sunlight is concentrated at the bottom of the absorber tube. This concentrated solar flux leads to uneven heat distribution, resulting in high local temperatures and significant thermal stress on the absorber *** limitations have restricted the application of PTCs in solar thermochemistry and other fields and have impacted their safe operation. In this study, a new PTC with dual planar mirrors(DPMS) is proposed to homogenize the circumferential solar flux distribution of the absorber tube. A design method and single-objective optimization of the new PTC with a DPMS are proposed,and an uncertainty analysis of the operational and structural parameters is performed. A coupled light-heat-structure numerical model was developed to study the heat transfer performance and structural mechanical properties. The thermodynamic properties of the PTC with DPMS under different boundary conditions were analyzed. The results show that the circumferential temperature difference of the new PTC is within 2.6 K, and the circumferential thermal deformation is within 0.9 mm under typical working conditions(the inlet velocity of the heat transfer fluid is 3 m/s, inlet temperature is 573.15 K, and the direct normal irradiance is 1000 W/m^(2)). Compared with conventional PTCs, the circumferential temperature difference is reduced by 74%–90%, and the maximum thermal deformation along the y-axis is reduced by more than 95% under all working conditions(1–5 m/s, 373.5–675.15 K, 200–1000 W/m^(2)). The new PTC maintains the uniformity of the circumferential solar flux distribution for different operating parameters(sun incident angle of 0°–3°) and installation errors(±3 mm), is suitable for solar energy applications in various fields, and has the potential for large-scale applications.

关键词： solar thermal energy parabolic trough collector secondary reflector solar flux distribution optical optimization

侏罗系油藏开发效果评价及剩余油动用潜力研究

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石油化工应用 2024年第6期43卷 55-58页

作者：张换果郑奎李元龙温进平中国石油长庆油田分公司第六采油厂陕西西安710000

本文以H区Y10油藏为例,通过地层能量、水驱状况和油藏采收率三个方面评价开发效果,利用数值模拟预测方法研究剩余油分布规律、精准部署加密调整井位并预测调整效果,开展矿场试验,分析加密调整潜力。研究表明:研究区受高采液强度开发及... 详细信息

本文以H区Y10油藏为例,通过地层能量、水驱状况和油藏采收率三个方面评价开发效果,利用数值模拟预测方法研究剩余油分布规律、精准部署加密调整井位并预测调整效果,开展矿场试验,分析加密调整潜力。研究表明:研究区受高采液强度开发及井筒套破影响,水驱效果变差,采出程度低,局部剩余油富集,数值模拟预测加密调整可有效提高油藏最终采收率,矿场试验证明加密调整效果良好、具有可实施性,建议进一步扩大加密调整范围,提高油田采收率。

关键词：侏罗系油藏开发效果剩余油加密调整采收率

Coexistence of large positive and negative magnetoresistance in Cr_(2)Si_(2)Te_(6) ferromagnetic semiconductor

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Science China Materials 2022年第3期65卷 780-787页

作者： Zhou li Wei Bai Yuliang li yuanlong li Sheng Wang Weihui Zhang Jiyin Zhao Zhe Sun Chong Xiao Yi Xie Hefei National Laboratory for Physical Sciences at the Microscale CAS Center for Excellence in NanoscienceUniversity of Science and Technology of ChinaHefei 230026China Institute of Energy Hefei Comprehensive National Science CenterHefei 230031China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China

Magnetoresistance(MR)phenomenon couples the electron transport with magnetic field,which has been at the forefront of condensed matter physics and materials ***-MR behaviors are of particularly importance for magnetic sensor and information memory applications,and their scarcity has aroused intensive ***,due to the different physical origins,combination of large positive and negative MR(pMR and nMR)in one single compound has rarely been *** present work,we achieved a coexistence of large pMR and nMR in Cr_(2)Si_(2)Te_(6) ferromagnetic semiconductor single crystal with different field ***,a large nMR of about -60% was obtained under the in-plane field,while a large pMR higher than 1000% took over in the out-of-plane *** attribute this field direction-sensitive dualistic large MR behavior to the competition and cooperation effect from the ferromagnetic interaction,orbital scattering and electronic correlation that coexist in Cr_(2)Si_(2)Te_(6),which contribute to n MR,pMR,and nMR,respectively,in dominated temperature and field ranges,and show different weights under different field *** elucidated multiple MR mechanism in this ferromagnetic semiconductor will shed light on the pursuit of coexistence of large p MR and nMR for field-sensitive device applications.

关键词： large pMR and nMR dualistic magnetoresistance Cr_(2)Si_(2)Te_(6) ferromagnetic semiconductor single crystal