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Dynamic analysis of spatial parallel manipulator with rigid and flexible couplings

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Journal of Central South University 2017年第4期24卷 840-853页

作者：刘善增戴建生沈刚李艾民曹国华冯世哲孟德远 School of Mechatronic Engineering China University of Mining and Technology King's College University of London

The dynamics of spatial parallel manipulator with rigid and flexible links is explored. Firstly, a spatial beam element model for finite element analysis is established. Then, the differential equation of motion of beam element is derived based on finite element method. The kinematic constraints of parallel manipulator with rigid and flexible links are obtained by analyzing the motive parameters of moving platform and the relationships of movements of kinematic chains, and the overall kinetic equation of the parallel mechanism with rigid and flexible links is derived by assembling the differential equations of motion of components. On the basis of abovementioned analyses, the dynamic mechanical analysis of the spatial parallel manipulator with rigid and flexible links is conducted. After obtaining the method for force analysis and expressions for the calculation of dynamic stress of flexible components, the dynamic analysis and simulation of spatial parallel manipulator with rigid and flexible links is performed. The result shows that because of the elastic deformation of flexible components in the parallel mechanism with rigid and flexible links, the force on each component in the mechanism fluctuates sharply, and the change of normal stress at the root of drive components is also remarkable. This study provides references for further studies on the dynamic characteristics of parallel mechanisms with rigid and flexible links and for the optimization of the design of the mechanism.

关键词： rigid and flexible couplings parallel mechanism finite element force analysis dynamic stress

Nonlinear Super Integrable couplings of Super Yang Hierarchy and Its Super Hamiltonian Structures

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Journal of Applied Mathematics and Physics 2017年第4期5卷 792-800页

作者： Sixing Tao Yunling Ma School of Mathematics and Statics Shangqiu Normal University Shangqiu China

Nonlinear super integrable couplings of the super Yang hierarchy based upon an enlarged matrix Lie super algebra were constructed. Then its super Hamiltonian structures were established by using super trace identity. ... 详细信息

关键词： Lie Super Algebra Nonlinear Super Integrable couplings Super Yang Hierarchy Super Hamiltonian Structures

The algebraic structure of discrete zero curvature equations associated with integrable couplings and application to enlarged Volterra systems

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Science China Mathematics 2009年第1期52卷 147-159页

作者： LUO Lin FAN EnGui Department of Mathematics Shanghai Second Polytechnic UniversityShanghai 201209China School of Mathematical Sciences Fudan UniversityShanghai 200433China Department of Mathematics Xiaogan UniversityXiaogan 432100China

An algebraic structure of discrete zero curvature equations is established for integrable coupling systems associated with semi-direct sums of Lie algebras. As an application example of this algebraic structure, a τ-... 详细信息

关键词： discrete zero curvature equation integrable couplings τ-symmetry algebra

An Analytical Method for Delineating Feasible Region for PV Integration Capacities in Net-zero Distribution Systems Considering Battery Energy Storage System Flexibility

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JOURNAL OF MODERN POWER SYSTEMS AND CLEAN ENERGY 2024年第2期12卷 475-487页

作者： Zhang, Shida Ge, Shaoyun Liu, Hong Hou, Guocheng Wang, Chengshan Tianjin Univ Sch Elect & Informat Engn Tianjin 300072 Peoples R China

To provide guidance for photovoltaic (PV) system integration in net-zero distribution systems (DSs), this paper proposes an analytical method for delineating the feasible region for PV integration capacities (PVICs), where the impact of battery energy storage system (BESS) flexibility is considered. First, we introduce distributionally robust chance constraints on network security and energy/carbon net-zero requirements, which form the upper and lower bounds of the feasible region. Then, the formulation and solution of the feasible region is proposed. The resulting analytical expression is a set of linear inequalities, illustrating that the feasible region is a polyhedron in a high-dimensional space. A procedure is designed to verify and adjust the feasible region, ensuring that it satisfies network loss constraints under alternating current (AC) power flow. Case studies on the 4-bus system, the IEEE 33-bus system, and the IEEE 123-bus system verify the effectiveness of the proposed method. It is demonstrated that the proposed method fully captures the spatio-temporal coupling relationship among PVs, loads, and BESSs, while also quantifying the impact of this relationship on the boundaries of the feasible region.

关键词： Net zero couplings Uncertainty Photovoltaic systems Network security Carbon Measurement Net-zero distribution system photovoltaic (PV) integration capacity feasible region battery energy storage system (BESS) ACTIVE DISTRIBUTION NETWORKS POWER FLEXIBILITY OPERATION DISPATCH

High-frequency Resonance Analysis and Impedance Reshaping Control of MMC-HVDC System Based on Frequency Coupling Impedance Model

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JOURNAL OF MODERN POWER SYSTEMS AND CLEAN ENERGY 2024年第2期12卷 646-657页

作者： Wang, Juanjuan Chen, Wei Liu, Yuekun Fu, Chuang Ye, Yunming Feng, Junjie South China Univ Technol Sch Elect Power Guangzhou Peoples R China Guangdong Power Grid Co Ltd Guangzhou Peoples R China Elect Power Res Inst China Southern Power Grid Guangzhou Peoples R China

In recent years, high-frequency resonance (HFR) events occurred in several modular multilevel converter based high-voltage direct current (MMC-HVDC) projects. The time delay of an MMC-HVDC system is the critical factor that induces HFR. The frequency coupling affects the impedance characteristics of an MMC and further deteriorates system stability. Therefore, in this paper, a multi-input multi-output admittance model of an MMC-HVDC system is developed to analyze its frequency characteristics. The effects of current loop, power loop, phase-locked loop, and operating point on the MMC frequency coupling degree are analyzed in detail. Meanwhile, to further suppress HFR in the MMC-HVDC system, an enhanced impedance reshaping control strategy based on the equivalent single-input single-output impedance model is proposed. Finally, the accuracy of the enhanced impedance model and the effectiveness of the impedance reshaping control are verified by electromagnetic transient simulations in PSCAD.

关键词： Impedance couplings Power system stability Phase locked loops Frequency control Resonant frequency Damping Modular multilevel converter based high-voltage direct current (MMC-HVDC) high-frequency resonance frequency coupling impedance model impedance reshaping control GRID-CONNECTED INVERTER STABILITY ANALYSIS

Design,synthesis,and applications of stereospecific 1,3-diene carbonyls

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Science China Chemistry 2022年第5期65卷 912-917页

作者： Qiang Feng Shihui Wang Xingxing Ma Changqing Rao Qiuling Song Institute of Next Generation Matter Transformation College of Material Sciences&EngineeringHuaqiao UniversityXiamen 361021China Key Laboratory of Molecule Synthesis and Function Discovery Fujian Province UniversityCollege of ChemistryFuzhou UniversityFuzhou 350108China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang 453007China

The strategy toward the synthesis of various 1,3-dienals or 1,3-dienones is disclosed between diazo compounds and furans,which features metal-free,additive-free,broad functional group tolerance,and readily accessible starting materials.Notably,this strategy is applicable in both intramolecular and intermolecular protocols.Mechanistic studies suggested that the reactions undergo a cyclopropanation/rearrangement sequence.With an E/E-1,3-dienal,corresponding N-tosylhydrazones were readily prepared and subjected to phenylboronic acid to form a double bond migration product and indoles to construct a five-member ring via [3 + 2] annulation reaction.

关键词： 1,3-dienes aldehydes ketones [3+2]annulation couplings

Generation of cluster states in thermal cavity

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Chinese Optics Letters 2007年第6期5卷 364-366页

作者：陈美锋马宋设张晓岚 Department of Electronic Science and Applied Physics Fuzhou University

A scheme is reported for generating a multi-atom the simultaneous interaction of two two-level atoms cluster state in thermal cavities, which is based on with a single-mode cavity field driven by a classical field. The photon-number-dependent parts in the evolution operator are cancelled with the assistant of a strong classical field, so the scheme is insensitive to the thermal field. In the present scheme, the detuning between the atoms and the cavity is equal to the atom-cavity coupling strength, thus the operation speed is greatly improved, which is important in view of decoherence.

关键词： couplings Mathematical operators Photons

Discrete modulational instability and bright localized spin wave modes in easy-axis weak ferromagnetic spin chains involving the next-nearest-neighbor coupling

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Chinese Physics B 2019年第7期28卷 449-458页

作者：谢家玉邓志豪昌霞唐炳 College of Physics Mechanical and Electrical Engineering Jishou University Jishou 416000 China The Collaborative Innovation Center of Manganese-Zinc-Vanadium Industrial Technology Jishou University Jishou 416000 China

We report a theoretical work on the properties of modulational instability and bright type nonlinear localized modes in one-dimensional easy-axis weak ferromagnetic spin lattices involving next-nearest-neighbor couplings.With a linear stability analysis, we calculate the growth rates of the modulational instability, and plot the instability regions.When the strength of the next-nearest-neighbor coupling is large enough, two new asymmetric modulational instability regions appear near the boundary of the first Brillouin zone.Furthermore, analytical forms of the bright nonlinear localized modes are constructed by means of a quasi-discreteness approach.The influence of the next-nearest-neighbor coupling on the Brillouin zone center mode and boundary mode are discussed.In particular, we discover a reversal phenomenon of the propagation direction of the Brillouin zone boundary mode.

关键词： modulational instability analysis intrinsic localized spin-wave modes weak ferromagnets next-nearest-neighbor couplings

Ab Initio Calculations of Differential Cross Sections for Single Charge Transfer in ^3He^2＋＋ ^4He Collisions

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Chinese Physics Letters 2007年第7期24卷 1999-2002页

作者：吴勇闫冰刘玲王建国 Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics PO Box 8009-57 Beijing 100088 lnstitute of Atomic and Molecular Physics Jilin University Changchun 130012 Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000

The single charge transfer process in ^3He^2＋＋ ^4He collisions is investigated using the quantum-mechanical molecular- orbital close-coupling method, in which the adiabatic potentials and radial couplings are calculated by using the ab initio multireference single- and double-excitation configuration interaction methods. The differential cross sections for the single charge transfer are presented at the laboratorial energies E = 6 keV and lOkeV for the projectile ^3He^2＋. Comparison with the existing data shows that the present results are better in agreement with the experimental measurements than other calculations in the dominant small angle scattering, which is attributed to the accurate calculations of the adiabatic potentials and the radial couplings.

关键词： ELECTRON-CAPTURE INELASTIC PROCESSES DIVERTOR PLASMA CI CALCULATIONS EXCITED-STATES ENERGIES WAVEFUNCTIONS REGIME IONS HE Collisions Adiabatic potential ab initio calculations Differential cross sections charge transfer WAVE FUNCTIONS Energy sources configuration interactions Electron capture Ions couplings helium excited states Adiabatic