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Global Disturbance Rejection of Switched Nonlinear Systems with Switched Internal Model

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Journal of Systems Science & Complexity 2018年第1期31卷 161-172页

作者： long Lijun College of Information Science and Engineering Northeastern University State Key Laboratory of Synthetical Automation for Process Industries Northeastern University

This paper investigates the problem of global disturbance rejection for a class of switched nonlinear systems where the solvability of the disturbance rejection problem for subsystems is not assumed. The disturbances are assumed to be sinusoidal with completely unknown frequencies, phases and amplitudes. First, as an extension of the classic concept of internal model for non-switched systems, a switched internal model is proposed. Second, in order to solve the problem under study, an adaptive control method is established on the basis of the multiple Lyapunov functions method. Also,adaptive state-feedback controllers of subsystems are designed and incorporated with a switching law to asymptotically reject the unknown disturbances. Finally, an example is provided to demonstrate the effectiveness of the proposed design method.

关键词： Disturbance rejection multiple Lyapunov functions switched internal model switched nonlinear systems

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高品质学校的内涵结构、建设困境与突破路径

教学与管理 2025年第1期 19-23页

作者：邓纯臻隆平陈书忠重庆师范大学生命科学学院重庆401331 四川省攀枝花市第七高级中学校四川攀枝花617005 重庆市育才中学校重庆400050

高品质学校的创建既是区域教育高质量发展的基本组成,也是助推教育强国、人才强国建设的实践基础。综合来看,学校内部维度的高品质是一种过程取向以及主观层面的高品质,外部维度的高品质是一种结果取向以及客观层面的高品质,高品质学校... 详细信息

高品质学校的创建既是区域教育高质量发展的基本组成,也是助推教育强国、人才强国建设的实践基础。综合来看,学校内部维度的高品质是一种过程取向以及主观层面的高品质,外部维度的高品质是一种结果取向以及客观层面的高品质,高品质学校包括学生、教师、管理者以及课程、课堂、课题六个核心的动力要素。当前,高品质学校的建设依然在前沿理论、本地生源、教育资源以及师资队伍等方面存在一些阻碍,对此,建议从学校文化、优质资源、课程体系、师资队伍、管评系统等五个维度探寻突破路径,以期找到高品质学校的创新之路、高品质之路。

关键词：教育高质量发展高品质学校中小学管理学校治理

Effect of interface debonding on matrix multicracking evolution of fiber-reinfroced ceramic-matrix composites

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航空动力学报 2016年第3期31卷 527-538页

作者： LI long-biao College of Civil Aviation Nanjing University of Aeronautics and Astronautics

An analytical methodology was developed to investigate the effect of fiber/matrix interface debonding on matrix multicracking evolution of fiber-reinforced CMCs(ceramic-matrix composites).The Budiansky-Hutchinson-Evans shear-lag model was adopted to analyse the micro-stress field of the damaged *** critical matrix strain energy criterion,which presupposes the existence of an ultimate or critical matrix strain energy with matrix,was obtained to simulate the matrix multicracking evolution of *** the increase of the applied stress,the matrix multicracking and fiber/matrix interface debonding occurred to dissipate the additional energy entered into the *** fiber/matrix interface debonded length under matrix multicracking evolution was obtained by treating the interface debonding as a particular crack propagation *** conditions for no-debonding and debonding during the evolution of matrix multicracking were discussed in terms of two interfacial properties,i.e.,the interface shear stress and interface debonded *** the fiber/matrix interface was bonded,the matrix multicracking evolution was much more intense compared with the interface debonding;when the fiber/matrix interface was debonded,the matrix crack density increased with the increasing of interface shear stress and interface debonded *** theoretical results were compared with experimental data of unidirectional SiC/CAS(calcium alumina silicate),SiC/CAS-Ⅱand SiC/borosilicate composites.

关键词： ceramic-matrix composites(CMCs) matrix cracking interface debonding micromechanics critical matrix strain energy

矛盾·铺陈·距离——《木兰诗》叙事张力的三重奏

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语文教学之友 2025年第1期44卷 25-27页

作者：陈龙锁江苏省南通市如皋初级中学

花木兰这一替父从军、保家卫国的巾帼英雄形象与中国文学作品中贤良淑德、顺从奉献的传统女性形象并不完全相同。南北朝民歌《木兰诗》中,由矛盾、铺陈和距离构成的叙事张力,为深度解读文本提供了新的视角。

关键词：叙事张力木兰诗矛盾铺陈距离

均质黏土中桩靴基础贯入阻力系数Nc的解析解

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CONTROLLABILITY OF EVOLUTION INCLUSIONS WITH NONLOCAL CONDITIONS

工程力学 2025年第1期42卷 233-240页

作者：李大勇王召龙吴宇旗中国石油大学(华东)储运与建筑工程学院山东青岛266580

自升式平台的桩靴基础需逐级预压入海床一定深度，使其承载力满足承受上部平台自重荷载及所受到的海洋环境荷载的要求。随着压入深度的增加，土体将绕过桩靴基础侧面逐渐回流至基础顶部。桩靴基础在不同压入深度处，土体的回流模式不同... 详细信息

自升式平台的桩靴基础需逐级预压入海床一定深度，使其承载力满足承受上部平台自重荷载及所受到的海洋环境荷载的要求。随着压入深度的增加，土体将绕过桩靴基础侧面逐渐回流至基础顶部。桩靴基础在不同压入深度处，土体的回流模式不同，导致基础的贯入阻力发生变化。考虑完全回流和不回流两种极端情况下的土体破坏模式，利用特征线法推导了桩靴基础贯入阻力系数Nc，采用有限元极限分析法验证了计算模型的合理性。与已发表的文献中的离心机试验数据和数值模拟结果进行对比研究，验证了所提的理论方法的准确性。研究表明：光滑基底底部形成两个左右对称的弹性楔体，随着桩靴基础基底剪应力的增加，弹性楔体体积逐渐减小，当基底剪应力达到土体抗剪强度时，弹性楔体消失。贯入阻力系数Nc随着桩靴基础基底剪应力的增加呈线性增加，土体不回流情况下的贯入阻力系数比完全回流情况下的贯入阻力系数低约20%。

关键词：桩靴基础贯入阻力系数解析解均质黏土破坏模式

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Journal of Systems Science & Complexity 2005年第1期18卷 35-42页

作者： LIGuocheng SONGShiji wucheng DepartmentofAutomation TsinghuaUniversityBeijing100084China

In this paper we examine controllability problems of evolution inclusions with nonlocal conditions. Using Kakutani's fixed point theorem and Schauder's fixed point the-orem, we establish sufficient conditions for the ... 详细信息

关键词： nonlocal conditions mild solutions evolution inclusions controllability fixed point

Cooperative Target Tracking of Multiple Autonomous Surface Vehicles Under Switching Interaction Topologies

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IEEE/CAA Journal of Automatica Sinica 2023年第3期10卷 673-684页

作者： Lang Ma Yu-long Wang Qing-long Han Shanghai Key Laboratory of Power Station Automation Technology and the School of Mechatronic Engineering and AutomationShanghai UniversityShanghai 200444China School of Science Computing and Engineering TechnologiesSwinburne University of TechnologyMelbourne VIC 3122Australia IEEE

This paper is concerned with the cooperative target tracking of multiple autonomous surface vehicles(ASVs)under switching interaction *** the target to be tracked,only its position can be measured/received by some of the ASVs,and its velocity is unavailable to all the ASVs.A distributed extended state observer taking into consideration switching topologies is designed to integrally estimate unknown target dynamics and neighboring ASVs'***,a novel kinematic controller is designed,which takes full advantage of known information and avoids the approximation of some virtual control ***,a disturbance observer is presented to estimate unknown time-varying environmental ***,a distributed dynamic controller is designed to regulate the involved ASVs to cooperatively track the *** enables each ASV to adjust its forces and moments according to the received information from its *** effectiveness of the derived results is demonstrated through cooperative target tracking performance analysis for a tracking system composed of five interacting ASVs.

关键词： Autonomous surface vehicles(ASVs) cooperative target tracking distributed extended state observer switching topologies

Lowest-energy moiré band formed by Dirac zero modes in twisted bilayer graphene

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Science Bulletin 2019年第8期64卷 495-498页

作者： long Zhang Kavli Institute for Theoretical Sciences and CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences Physical Science Laboratory Huairou National Comprehensive Science Center

The recent discovery of an unconventional insulating phase and an adjacent superconducting (SC) phase in the twisted bilayer graphene (TBG)[1,2] has triggered great excitement (3–11)The two layers of graphene are rot... 详细信息

关键词： band formed by Dirac zero modes in twisted bilayer graphene Lowest-energy moir

Fuzzy Zorn’s lemma with applications

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Applied Mathematics(A Journal of Chinese Universities) 2021年第4期36卷 521-536页

作者： XIN Xiao-long FU Yu-long School of Science Xi’an Polytechnic UniversityXi’an 710048China School of Mathematics Northwest UniversityXi’an 710127China School of Cyber Engineering Xidian UniversityXi’an 710071China

We introduced the fuzzy axioms of choice,fuzzy Zorn’s lemma and fuzzy well-ordering principle,which are the fuzzy versions of the axioms of choice,Zorn’s lemma and well-ordering principle,and discussed the relations among *** an application of fuzzy Zorn’s lemma,we got the following results:(1)Every proper fuzzy ideal of a ring was contained in a maximal fuzzy ideal.(2)Every nonzero ring contained a fuzzy maximal ideal.(3)Introduced the notion of fuzzy nilpotent elements in a ring R,and proved that the intersection of all fuzzy prime ideals in a commutative ring R is the union of all fuzzy nilpotent elements in R.(4)Proposed the fuzzy version of Tychonoff Theorem and by use of fuzzy Zorn’s lemma,we proved the fuzzy Tychonoff Theorem.

关键词： fuzzy axioms of choice fuzzy Zorn’s lemma fuzzy well-ordering principle fuzzy ideal of a ring fuzzy Tychonoff Theorem