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A quadrilateral membrane hybrid stress element with drilling degrees of freedom

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Acta Mechanica Sinica 2012年第5期28卷 1367-1373页

作者： An-ping Wang Technology and Engineering Center for Space Utilization Chinese Academy of Sciences

A new kind of quadrilateral assumed stress hy- brid membrane element with drilling degrees of freedom and a traction-free inclined side has been developed based on an extended Hellinger-Reissner principle which is established by expanding the essential terms of the assumed stress field as polynomials in the natural coordinates of the element. The homogeneous equilibrium equations are imposed in a variational sense through the internal displacements which are also expanded in the natural coordinates, while the tractionfree conditions along the inclined side are satisfied exactly. The use of such special element in the finite element solution is shown to be highly accurate when only a very coarse element mesh is used for plates with V-shaped rounded notches or inclined sides.

关键词： Hybrid stress element Drilling degrees of free-dom Stress concentration Traction-free inclined side

Review on ω Phase in Body-Centered Cubic Metals and Alloys

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Acta Metallurgica Sinica(English Letters) 2014年第1期27卷 1-11页

作者： Dehai ping National Institute for Materials Science Sengen 1-2-1Tsukuba 305-0047Japan

An ω phase with a primitive hexagonal crystal structure has been found to be a ωmmon metastable phase in body-centered cubic （bcc） metals and alloys. In general, ω phase precipitates out as a high density of nanoscale particles and can obviously strengthen the alloys; however, ωarsening of the ω particles significantly reduces the alloy ductility. The ω phase has ωherent interfacial structure with its bcc matrix phase, and its lattice parameters are aω ---- x/2 x abcc and ωbcc= v/3/2 abcc abet. The ωmmon { 112} （111）-type twinning in bcc metals and alloys can be treated as the product of the ω ~ bcc phase transition, also known as the ω-lattice mechanism. The ω phase＇s behavior in metastable 13-type Ti alloys will be briefly reviewed first since the ω phase was first found in the alloy system, and then the existence of the ω phase in carbon steels will be discussed. Carbon plays a crucial role in promoting the ω formation in steel, and the ω phase can form a solid solution with various carbon ωntents. Hence, the martensitic substructure can be treated as an ct-Fe matrix embedded with a high density of nanoscale ω-Fe particles enriched with carbon. The reωgnition of the ω phase in steel is expected to advance the understanding of the relationship between the microstructure and mechanical properties in bcc steels, as well as the behavior of martensitic transformations, twinning formation, and martensitic substructure.

关键词： ω phase Martensitic steel Microstructure Microanalysis bcc metals Alloys Twinning

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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

Coordination of Networked Nonlinear Multi-Agents Using a High-Order Fully Actuated Predictive Control Strategy

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IEEE/CAA Journal of Automatica Sinica 2022年第4期9卷 615-623页

作者： Guo-ping Liu IEEE the Department of Electronic and Electrical Engineering Southern University of Science and Technology

This paper is concerned with the coordinative control problem of networked nonlinear multi-agents(NNM)with communication delays.A high-order fully actuated(HOFA)model is introduced to describe the nonlinear *** on this model,a HOFA predictive coordination method is proposed to compensate for the communication delays actively and achieve simultaneous stability and *** method largely simplifies the design of networked nonlinear multi-agents and makes the control performance be same for networked nonlinear multi-agents with and without communication *** analysis on the closed-loop systems derives the simultaneous stability and consensus criteria of networked nonlinear multiagents using the HOFA predictive coordination *** the presented way of designing HOFA predictive coordination controllers,a simulated example demonstrates the advantages of the proposed method.

关键词： method nonlinear coordination

Pressure Effects on Spectra of Tunable Laser Crystal GSGG： Cr^3＋ IV： Pressure—Induced Shifts of R1 Line, R2 Line, and U Band at 300 K

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Communications in Theoretical Physics 2003年第4期39卷 621-630页

作者： MADong-ping ZHANGJi-ping DepartmentofAppliedPhysics SichuanuniversityChengdu610065China InterationalCentreforMaterialsPhysics theChineseAcademyofSciencesShenyang110015China DepartmentofAppliedPhysics SichuanuniversityChengdu610065China

By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R1 line, R2 line, and U band of GSGG:Cr3+ at 300 K have been calculated, respectively. The calculated results are in good agreement with all the experimental data. Their physical origins have also been explained. It is found that the mixing-degree of and base-wavefunctions in the wavefunctions of R1 level of GSGG:Cr3+ at 300 K is remarkable under normal pressure, and the mixing-degree rapidly decreases with increasing pressure. The change of the mixing-degree with pressure plays a key role not only for the 'pure electronic' PS of R1 line and R2 line but also the PS of R1 line and R2 line due to EPI. The pressure-dependent behaviors of the 'pure electronic' PS of R1 line (or R2 line) and the PS of R1 line (or R2 line) due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R1 line (or R2 line). In the range of about 15 kbar ~ 45 kbar, the mergence and/or order-reversal between levels and levels take place, which cause the fluctuation of the rate of PS for with pressure. At 300 K, both the temperature-dependent contribution to R1 line (or R2 line or U band) from EPI and the temperature-independent one are important.

关键词： high-pressure effect spin-orbit interaction electron-phonon interaction d orbital coupling between t(2)(2)(3T(1))e(4)T(2) and t(2)(32)E tunable laser crystal

Control Strategies for Digital Twin Systems

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 170-180页

作者： Guo-ping Liu IEEE the Center for Control Science and Technology Southern University of Science and TechnologyShenzhen 518055China

With the continuous breakthrough in information technology and its integration into practical applications, industrial digital twins are expected to accelerate their development in the near future. This paper studies various control strategies for digital twin systems from the viewpoint of practical *** make full use of advantages of digital twins for control systems, an architecture of digital twin control systems, adaptive model tracking scheme, performance prediction scheme, performance retention scheme, and fault tolerant control scheme are proposed. Those schemes are detailed to deal with different issues on model tracking, performance prediction, performance retention, and fault tolerant control of digital twin systems. Also, the stability of digital twin control systems is analysed. The proposed schemes for digital twin control systems are illustrated by examples.

关键词： Digital twin control systems fault tolerant control model tracking performance prediction performance retention

Efficient CHzNHzPbl3 perovskite solar cells with 2TPA- n-DP hole-transporting layers

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Nano Research 2015年第4期8卷 1116-1127页

作者： Lifeng Zhu Junyan Xiao jiangjian Shi Junjie Wang Songtao Lv Yuzhuan Xu Yanhong Luo YinXiao Shirong Wang Qingbo Meng Xianggao Li Dongmei Li Key Laboratory for Renewable Energy (CAS) Beijing Key Laboratory for New Energy Materials and Devices 8eijing National Laboratory for Condense Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

CH3NH3PbI3 perovskite solar cells with 2TPA-n-DP （TPA = 4,4＇-（（1E, I＇E,3E,3＇E）- [1,1＇-biphenyl]4,4＇-diylbis（buta-1,3-diene-4,1-diyl））; DP = bis（N,N-di-p-tolylaniline）; n = 1, 2, 3, 4） as hole-transporting materials （HTMs） have been fabricated. After optimization of the mesoporous TiO2 film thickness, devices based on 2TPA- 2-DP with power conversion efficiencies （PCEs） of up to 12.96% have been achieved, comparable to those of devices with （2,2＇,7,7＇-tetrakis（N,N-di-p- methoxyphenylamine）-9,9＇-spirobifluorene）（spiro-OMeTAD） as HTM under similar conditions. Further time-resolved photoluminescence （PL） measurements showed a fast charge transfer process at the perovskite/2TPA-2-DP interface. With the aid of electrochemical impedance spectra, a study of the electron blocking ability of 2TPA-2-DP in the device reveals that the presence of 2TPA-2-DP can greatly increase charge transfer resistance at the HTM/Au interface in the device, thus reducing the recombination. Furthermore, the perovskite solar cells based on these four HTMs exhibit ~ood stability after testin~ for one month.

关键词： perovskite solar cells organolead halide hole-transportingmaterials interfacial recombination

Predictive Control of High-Order Fully Actuated Nonlinear Systems with Time-Varying Delays

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Journal of Systems Science & Complexity 2022年第2期35卷 457-470页

作者： LIU Guo-ping Department of Electronic and Electrical Engineering Southern University of Science and TechnologyShenzhen 518055China

This paper investigates the control problem of high-order fully actuated nonlinear systems with time-varying delays in the discrete-time *** make the compensation for time-varying delays concise,active and universal,a novel nonlinear predictive control method is *** designed nonlinear predictive controller can achieve the same expected control performance as the nonlinear systems without *** the same time,the necessary and sufficient conditions for the stability of the closed-loop nonlinear predictive control systems are *** examples show that the proposed nonlinear predictive controller design method can completely compensate for the time-varying delays of nonlinear systems.

关键词： High-order fully actuated control systems nonlinear systems predictive control timevarying delays

Networked Learning Predictive Control of Nonlinear Cyber-Physical Systems

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Journal of Systems Science & Complexity 2020年第6期33卷 1719-1732页

作者： LIU Guo-ping Department of Artificial Intelligence and Automation Wuhan UniversityWuhan 430072China

Cyber-physical systems integrate computing,network and physical environments to make the systems more efficient and cooperative,and have important and extensive application prospects,such as the Internet of *** paper studies the control problem of nonlinear cyber-physical systems with unknown dynamics and communication delays.A networked learning predictive control scheme is proposed for unknown nonlinear cyber-physical *** scheme recursively learns unknown system dynamics,actively compensates for communication delays and accurately tracks a desired *** multi-step predictors are presented to predict various step ahead outputs of the unknown nonlinear cyber-physical *** optimal design of controllers minimises a performance cost function which measures the tracking error predictions and control input increment *** system analysis leads to the stability criteria of closed-loop nonlinear cyber-physical systems employing the networked learning predictive control *** example illustrates the outcomes of the proposed scheme.

关键词： Cyber-physical systems learning control networked predictive control nonlinear systems