检索结果-南通市图书馆

Prescribed time control based on the periodic delayed sliding mode surface without singularities

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第7期67卷 256-270页

作者： Bin ZHOU Yi DING Kang-Kang ZHANG Guang-Ren DUAN center for Control theory and Guidance Technology Harbin Institute of Technology

In this paper, nonsingular prescribed-time control is studied based on periodic delayed sliding mode surfaces. Different from the existing sliding mode control, where either singularity problems may appear or the convergence time depends on the initial state, the proposed sliding mode control approaches can achieve prescribed-time convergence without singularity. The proposed nonsingular sliding mode control approaches can be applied to both second-order and high-order nonlinear systems with prescribed-time convergence. As applications of the proposed sliding mode control approaches, the control of hypersonic vehicle systems is revisited. Numerical simulations on the nonlinear model of the hypersonic vehicle system show the effectiveness of the proposed methods.

关键词： prescribed-time control smooth periodic delayed feedback sliding mode control high-order nonlinear systems hypersonic vehicle systems

Implications of neutron skin measurements on Skyrme equations of state

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第6期48卷 155-161页

作者：管大为裴俊琛蒋崇基 State Key Laboratory of nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China Southern center for nuclear-Science {2.(SCNT) Institute of Modern PhysicsChinese Academy of SciencesHuizhou 516000China

The recent measurements of neutron skins via parity violation in electron scattering have extracted an abnormally thick neutron skin for 2.8 Pb,which has significant consequences in nuclear equation of state(EoS)and neutron star *** this study,we perform optimizations of extended Skyrme forces in a consistent manner by including neutron skin thicknesses from PREX-Ⅱand CREX experiments and investigate nuclear EoSs and neutron stars in the GW170817 event By varying the fitting weights of neutron skins,several new Skyrme parameterizations are *** results show the competition in the fitting procedure to simultaneously describe neutron skins,other properties of finite nuclei,and neutron star *** prospects of resolving neutron skin issues are also discussed.

关键词： neutron skin equation of state neutron star Skyrme force

Electromagnetic fields in ultra-peripheral relativistic heavy-ion collisions

在线全文

学校读者我要写书评

暂无评论

nuclear Science and Techniques 2024年第2期35卷 103-109页

作者： Jie Zhao Jin-Hui Chen Xu-Guang Huang Yu-Gang Ma Key Laboratory of nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research center for Theoretical nuclear Physics NSFC and Fudan UniversityShanghai 200438China Physics Department and center for Particle Physics and Field theory Fudan UniversityShanghai 200438China

Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic *** these collisions,highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon *** exchange of photons can induce photonuclear and two-photon interactions and excite *** excitation of the ions results in Coulomb dissociation with the emission of photons,neutrons,and other ***,the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ***,the two colliding ions experience an electromagnetic force that pushes them in opposite directions,causing a back-to-back correlation in the emitted *** a Monte Carlo simulation,we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs,which would provide a clear means to study strong electromagnetic fields and their effects.

关键词： Electromagnetic fields Neutrons Ultra-peripheral relativistic heavy-ion collisions(UPC)

A FAS approach for stabilization of generalized chained forms: part 2. Continuous control laws

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第3期67卷 114-135页

作者： Guang-Ren DUAN center for Control theory and Guidance Technology Harbin Institute of Technology Shenzhen Key Laboratory of Control theory and Intelligent Systems Southern University of Science and Technology

In this paper, continuous time-varying stabilizing controllers for the type of general nonholonomic systems proposed and treated in part 1 are designed using the fully actuated system(FAS) approach. The key step is to differentiate the first scalar equation, and by control of the obtained second-order scalar system, a proportional plus integral feedback form for the first control variable is obtained. With the solution to this designed second-order scalar system, the rest equations in the nonholonomic system form an independent time-varying subsystem which is then handled by the FAS approach. The overall designed controller contains an almost arbitrarily chosen design parameter, and is proven to guarantee the uniformly and globally exponential stability of the closed-loop system. The proposed approach is simple and effective,and is demonstrated with a practical example of ship control.

关键词： nonholonomic systems feedback stabilization fully actuated systems Lyapunov stability continuous controllers

Applying deep learning technique to chiral magnetic wave search

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第8期48卷 170-176页

作者： Yuan-Sheng Zhao Xu-Guang Huang Physics Department and center for Particle Physics and Field theory Fudan UniversityShanghai 200433China Key Laboratory of nuclear Physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200433China Shanghai Research center for Theoretical nuclear Physics National Natural Science Foundation of China and Fudan UniversityShanghai 200438China

The chiral magnetic wave(CMW)is a collective mode in quark-gluon plasma originated from the chiral magnetic effect(CME)and chiral separation *** detection in heavy-ion collisions is challenging owing to significant background ***[*** et al.,***.C 106,L051901(2.2.)],we constructed a neural network that accurately identifies the CME-related signal from the final-state pion *** this study,we have generalized this neural network to the case of CMW *** show that,after an updated training,the neural network effectively recognizes the CMW-related ***,we have assessed the performance of the neural network in comparison with other known methods for CMW search.

关键词： deep learning chiral magnetic wave relativistic heavy-ion collisions

Estimating the production of dark photons withηdecay in high-energy collisions

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第10期48卷 150-156页

作者： Wei Kou Xurong Chen Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Southern center for nuclear Science {2. Institute of Modern PhysicsChinese Academy of SciencesHuizhou 516000China

We propose searching for dark photon signals in the decay channel of η mesons,specifically through the leptonic decay(A'→e^(+)e^(-)(μ^(+)μ^(-)))observable in photon-photon interactions during ultra-peripheral heavy-ion *** estimate the total cross-section for dark photon production in ultra-peripheral PbPb collisions at current and future hadron *** findings support the potential for detecting dark photon signals at the LHC,HighLuminosity LHC,High-Energy LHC,and Future Circular Collider.

关键词： dark photon ηdecay ultra-peripheral collision lead-lead collision

Effect of toroidal mode coupling on explosive dynamics of m/n=3/1 double tearing mode

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasma Science and Technology 2024年第10期26卷 8-16页

作者： Xingqiang LU Ge GAO Zhiwei MA Wei GUO Xin LI College of nuclear Equipment and nuclear Engineering Yantai UniversityYantai 264005People’s Republic of China Institute for Fusion theory and Simulation Department of PhysicsZhejiang UniversityHangzhou 310027People’s Republic of China

The CLT code was used to quantitatively study the impact of toroidal mode coupling on the explosive dynamics of the m/n=3/1 double tearing *** focus of this study was on explosive reconnection processes,in which the energy bursts and the main mode no longer dominates when the separation between two rational surfaces is relatively large in the medium *** development of higher m and n modes is facilitated by a relatively large separation between two rational surfaces,a small q_(min)(the minimum value of the safety factor),or low *** relationships between the higher m and n mode development,explosive reconnection rate,and position exchange of 3/1 islands are summarized for the first *** plays a more important role than q_(min)in enhancing the development of higher m and n *** a relatively large separation,the good development of higher m and n modes greatly reduces the reconnection rate and suppresses the development of the main mode,resulting in the main mode not being able to develop sufficiently large to generate the position changes of 3/1 islands.

关键词： toroidal mode coupling higher m and n modes explosive growth reconnection rate position change

A FAS approach for stabilization of generalized chained forms: part 1. Discontinuous control laws

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第2期67卷 118-143页

作者： Guang-Ren DUAN center for Control theory and Guidance Technology Harbin Institute of Technology center for Control Science and Technology Southern University of Science and Technology

In this paper, a type of general nonholonomic systems is proposed, which contains both the Brockett’s two example systems, and their extended n-dimensional chained forms, as special cases. For the stabilization of such systems, a stabilizing controller is proposed based on the fully actuated system(FAS)approach, which is discontinuous at the origin but time-invariant when the open-loop system is time-invariant,and drives the feasible trajectories of the system to the origin exponentially. Furthermore, the proposed FAS approach is also extended to the sub-normal system case and the time-delay system case.

关键词： nonholonomic systems feedback stabilization exponential convergence sub-fully actuated systems time-delay systems

Unbound^(2.)O,the heaviest oxygen isotope observed:a cutting-edge probe for testing nuclear models

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

nuclear Science and Techniques 2024年第2期35卷 1-2页

作者： Jian-Guo Li Bai-Shan Hu Shuang Zhang Fu-Rong Xu School of Physics and State Key Laboratory of Nuclear Physics and TechnologyPeking UniversityBeijing 100871China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Southern center for nuclear-Science {2.(SCNT) Institute of Modern PhysicsChinese Academy of SciencesHuizhou 516000China

The beyond-dripline oxygen isotopes^(2.,2.)O were recently observed at RIKEN,and were found to be unbound decaying into^(2.)O by emitting *** unbound feature of the heaviest oxygen isotope,^(2.)O,provides an excellent test for stateof-the-art nuclear *** atomic nucleus is a self-organized quantum manybody system comprising specific numbers of protons Z and neutrons N.

关键词： testing quantum system