检索结果-内蒙古大学图书馆

Finite-Time Quasi-Projective Synchronization of Fractional-Order Reaction-Diffusion Delayed Neural Networks

学校读者我要写书评

暂无评论

SSRN

SSRN 2024年

作者： Wang, Zhenjie Zhang, Weiwei Zhang, Hai Chen, Dingyuan Cao, Jinde Abdel-Aty, Mahmoud School of Mathematics and Physics Anqing Normal University Anqing246133 China Department of Mathematics Nanjing University of Aeronautics and Astronautics Nanjing210093 China Key Laboratory of Modeling Simulation and Control of Complex Ecosystem in Dabie Mountains of Anhui Higher Education Institutes Anqing Normal University Anqing246133 China School of Mathematics Southeast University Nanjing210096 China Deanship of Graduate Studies and Scientific Research Ahlia University Manama10878 Bahrain

The problem of the finite-time quasi-projective synchronization (FTQPS) of fractional-order reaction-diffusion neural networks (FORDNNs) is examined by this paper. First, on the basis of the characterization of the reaction diffusion term and the concept of inequality deflation, an integral-type Lyapunov function is constructed. Subsequently, a nonlinear feedback control strategy is constructed, and sufficient conditions for FTQPS of the developed model are derived. Further, the system's synchronization speed is measured by estimating the settling time. It should be noted that the above control strategy is also applicable to conventional integer order RDNNs with time delay. Finally, a nu merical example is used to illustrate the veracity and validity of the theoretical analysis presented. © 2024, The Authors. All rights reserved.

关键词： Lyapunov functions

sQq¯q¯ (q=u, d;Q=c, b) tetraquarks in the chiral quark model

学校读者我要写书评

暂无评论

Physical Review D 2021年第7期103卷 074011-074011页

作者： Gang Yang Jialun Ping Jorge Segovia Department of Physics Zhejiang Normal University Jinhua 321004 China Department of Physics and Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 China Departamento de Sistemas Físicos Químicos y Naturales Universidad Pablo de Olavide E-41013 Sevilla Spain

The low-lying sQq¯q¯ (q=u, d, Q=c, b) tetraquark states with JP=0+, 1+, and 2+, and in the isoscalar and isovector sectors, are systematically investigated in the framework of the real- and complex-scaling range of a chiral quark model, whose parameters are fixed in advance describing hadron, hadron-hadron, and multiquark phenomenology, and thus, all results presented here are pure predictions. Each tetraquark configuration compatible with the quantum numbers studied is taken into account; this includes meson-meson, diquark-antidiquark, and K-type arrangements of quarks with all possible color wave functions in the four-body sector. Among the different numerical techniques to solve the Schrödinger-like four-body bound-state equation, we use a variational method in which the trial wave function is expanded in complex-range Gaussian basis functions because of its simplicity and flexibility. Several compact bound states and narrow resonances are found in both charm-strange csq¯q¯ and bottom-strange bsq¯q¯ tetraquark sectors, most of them as a product of the strong coupling between the different channels. In regard to the so-called X0,1(2900) structures recently discovered with good statistical significance by the LHCb Collaboration, whose properties point out to be csu¯d¯ tetraquarks, we find that they are unstable in our formalism with several candidates in the single-channel computations. We distinguish four cases with I(JP)=0(0+) quantum numbers: three K-type configurations with masses at 2.89, 2.96, and 2.97 GeV, and one hidden-color coupled-channel calculation delivering a mass 2.86 GeV. With quantum numbers I(JP)=0(1+), only one candidate can be found in the hidden-color coupled-channel calculation with mass 2.94 GeV.

关键词： Quantum chromodynamics Quark model

QQs¯s¯ tetraquarks in the chiral quark model

学校读者我要写书评

暂无评论

Physical Review D 2020年第5期102卷 054023-054023页

作者： Gang Yang Jialun Ping Jorge Segovia Department of Physics Zhejiang Normal University Jinhua 321004 China Department of Physics and Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing 210023 People’s Republic of China Departamento de Sistemas Físicos Químicos y Naturales Universidad Pablo de Olavide E-41013 Sevilla Spain

The low-lying S-wave QQs¯s¯ (Q=c, b) tetraquark states with I(JP)=0(0+), 0(1+) and 0(2+) are systematically investigated in the framework of complex scaling range of chiral quark model. Every structure including meson-meson, diquark-antidiquark and K-type configurations, and all possible color channels in four-body sector are considered by means of a commonly extended variational approach, Gaussian expansion method. Within the studied mass region, several narrow and wide resonance states are obtained for ccs¯s¯ and bbs¯s¯ tetraquarks with I(JP)=0(0+) and 0(2+). Meanwhile, narrow resonances for cbs¯s¯ tetraquarks are also found in I(JP)=0(0+), 0(1+) and 0(2+) states. The possibility of finding tetraquark structures with masses ∼0.6 GeV above the non-interacting hadron-hadron thresholds (and not close to them) is a feature related with the absence of the one-pion exchange interaction in the QQs¯s¯ sector and thus it could deserve experimental confirmation.

关键词： Particle interactions Quantum chromodynamics Quark model Strong interaction

Superexponential diffusion in nonlinear non-Hermitian systems

学校读者我要写书评

暂无评论

Physical Review A 2020年第6期102卷 062213-062213页

作者： Wen-Lei Zhao Longwen Zhou Jie Liu Peiqing Tong Kaiqian Huang School of Science Jiangxi University of Science and Technology Ganzhou 341000 China Department of Physics College of Information Science and Engineering Ocean University of China Qingdao 266100 China Graduate School of China Academy of Engineering Physics Beijing 100193 China CAPT HEDPS and IFSA Collaborative Innovation Center of the Ministry of Education Peking University Beijing 100871 China Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210023 China Jiangsu Provincial Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu 210023 China Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials SPTE South China Normal University Guangzhou 510006 China

We investigate the quantum diffusion of a periodically kicked particle subjected to both nonlinearity-induced self-interactions and PT-symmetric potentials. We find that, due to the interplay between the nonlinearity and non-Hermiticity, the expectation value of the mean square of momentum scales with time in a superexponential form 〈p2(t)〉∝exp[βexp(αt)], which is faster than any known rates of quantum diffusion. In the PT-symmetry-breaking phase, the intensity of a state increases exponentially with time, leading to the exponential growth of the interaction strength. The feedback of the intensity-dependent nonlinearity further turns the interaction energy into the kinetic energy, resulting in a superexponential growth of the mean energy. These theoretical predictions are in good agreement with numerical simulations in a PT-symmetric nonlinear kicked particle. Our discovery establishes a mechanism of diffusion in interacting and dissipative quantum systems. Important implications and possible experimental observations are discussed.

关键词： Anderson localization Atomic, optical & lattice clocks Diffusion Nonlinear optics Quantum transport Spatiotemporal chaos Wave chaos

Relaxation dynamics in the alternating XY chain following a quantum quench

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Cao, Kaiyuan Hu, Yayun Tong, Peiqing Yang, Guangwen Liu, Peng Zhejiang Lab Hangzhou311100 China Department of Physics Institute of Theoretical Physics Nanjing Normal University Nanjing210023 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing210023 China Department of Computer Science and Technology Tsinghua University Haidian District Beijing100084 China College of Information Science and Electronic Engineering Zhejiang University Hangzhou310027 China

We investigate the relaxation dynamics of the fermion two-point correlation function Cmn(t) = 〈ψ(t)|c†mcn|ψ(t)〉 in the XY chain with alternating nearest-neighbor hopping interaction after a quench. We find that the deviation δCmn(t) = Cmn(t) − Cmn(∞) decays with time following the power law behavior t−µ, where the exponent µ depends on whether the quench is to the commensurate phase (µ = 1) or incommensurate phase (µ = 1/2). This decay of δCmn(t) arises from the transient behavior of the double-excited quasiparticle occupations and the transitions between different excitation spectra. Furthermore, we find that the steady value Cmn(∞) only involves the average fermion occupation numbers (i.e. the average excited single particle) over the time-evolved state, which are different from the ground state expectation values. We also observe nonanalytic singularities in the steady value Cmn(∞) for the quench to the critical points of the quantum phase transitions (QPTs), suggesting its potential use as a signature of QPTs. Copyright © 2023, The Authors. All rights reserved.

关键词： Ground state

Mass- and energy-preserving exponential Runge-Kutta methods for the nonlinear Schrödinger equation

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Cui, Jin Xu, Zhuangzhi Wang, Yushun Jiang, Chaolong Department of Basic Sciences Nanjing Vocational College of Information Technology Nanjing210023 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Mathematical Sciences Nanjing Normal University Nanjing210023 China Department of Mathematics College of Liberal Arts and Science National University of Defense Technology Changsha410073 China School of Statistics and Mathematics Yunnan University of Finance and Economics Kunming650221 China

In this paper, a family of arbitrarily high-order structure-preserving exponential Runge-Kutta methods is developed for the nonlinear Schrödinger equation by combing the scalar auxiliary variable approach and the exponential Runge-Kutta method. By introducing an auxiliary variable, we first transform the original model into an equivalent system which admits both mass and modified energy. Then applying the Lawson method and the symplectic Runge-Kutta method in time, we derive a class of mass- and energy-conserving time-discrete schemes. Numerical experiments are addressed to demonstrate the accuracy and effectiveness of the newly proposed schemes. Copyright © 2020, The Authors. All rights reserved.

关键词： Runge Kutta methods

Arbitrary high-order linear structure-preserving schemes for the regularized long-wave equation

学校读者我要写书评

暂无评论

arXiv 2021年

作者： Jiang, Chaolong Qian, Xu Song, Songhe Cui, Jin Department of Mathematics College of Liberal Arts and Science National University of Defense Technology Changsha410073 China School of Statistics and Mathematics Yunnan University of Finance and Economics Kunming650221 China Department of Basic Sciences Nanjing Vocational College of Information Technology Nanjing210023 China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems School of Mathematical Sciences Nanjing Normal University Nanjing210023 China

In this paper, a class of arbitrarily high-order linear momentum-preserving and energy-preserving schemes are proposed, respectively, for solving the regularized long-wave equation. For the momentum-preserving scheme, the key idea is based on the extrapolation/prediction-correction technique and the symplectic Runge-Kutta method in time, together with the standard Fourier pseudo-spectral method in space. We show that the scheme is linear, high-order, unconditionally stable and preserves the discrete momentum of the system. For the energy-preserving scheme, it is mainly based on the energy quadratization approach and the analogous linearized strategy used in the construction of the linear momentum-preserving scheme. The proposed scheme is linear, high-order and can preserve a discrete quadratic energy exactly. Numerical results are addressed to demonstrate the accuracy and efficiency of the proposed scheme. Copyright © 2021, The Authors. All rights reserved.

关键词： Runge Kutta methods

Rho-pion transition form factors in the kT-factorization formalism revisited

学校读者我要写书评

暂无评论

Physical Review D 2018年第11期97卷 113002-113002页

作者： Jun Hua Shan Cheng Ya-lan Zhang Zhen-Jun Xiao Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing Jiangsu 210023 People’s Republic of China School of Physics and Microelectronics Science Hunan University Changsha Hunan 410082 People’s Republic of China Department of Faculty of Mathematics and Physics Huaiyin Institute of Technology Huaian Jiangsu 223001 People’s Republic of China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu 210023 People’s Republic of China

We revisit the evaluations for the spacelike and timelike ρπ transition form factors Fρπ(Q2) and Gρπ(Q2) with the inclusion of the next-to-leading order (NLO) QCD contributions in the framework of the kT-factorization theorem. The infrared divergence is regularized by the transversal momentum carried by external valence quarks, and ultimately absorbed into the meson wave functions. In the region of Q2≤2 GeV2, where the perturbative QCD factorization approach is applicable, the NLO contribution can bring no larger than 35% enhancement to the spacelike form factor Fρπ(Q2). For the timelike form factor derived under the kinematic exchanging symmetry, this contribution is also under control when the momentum transfer squared is large enough. We also prolong our prediction into the small Q2 region by taking the lattice QCD results into account, and subsequently obtain the coupling gρπγ=Gρπ(0)=0.596.

关键词： Form factors

Multi-task Paired Masking with Alignment modeling for Medical Vision-Language Pre-training

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Zhang, Ke Yang, Yan Yu, Jun Jiang, Hanliang Fan, Jianping Huang, Qingming Han, Weidong The Key Laboratory of Complex Systems Modeling and Simulation School of Computer Science and Technology Hangzhou Dianzi University Hangzhou310018 China Regional Medical Center for National Institute of Respiratory Diseases Sir Run Run Shaw Hospital College of Medicine Zhejiang University Hangzhou310016 China AI Lab at Lenovo Research 100094 China The School of Computer Science and Technology University of Chinese Academy of Sciences Beijing101408 China The Department of Medical Oncology at Sir Run Run Shaw Hospital College of Medicine Zhejiang University Hangzhou China The College of Mathematical Medicine Zhejiang Normal University Jinhua China

In recent years, the growing demand for medical imaging diagnosis has placed a significant burden on radiologists. As a solution, Medical Vision-Language Pre-training (Med-VLP) methods have been proposed to learn universal representations from medical images and reports, benefiting downstream tasks without requiring fine-grained annotations. However, existing methods have overlooked the importance of cross-modal alignment in joint image-text reconstruction, resulting in insufficient cross-modal interaction. To address this limitation, we propose a unified Med-VLP framework based on Multi-task Paired Masking with Alignment (MPMA) to integrate the cross-modal alignment task into the joint image-text reconstruction framework to achieve more comprehensive cross-modal interaction, while a Global and Local Alignment (GLA) module is designed to assist self-supervised paradigm in obtaining semantic representations with rich domain knowledge. Furthermore, we introduce a Memory-Augmented Cross-Modal Fusion (MA-CMF) module to fully integrate visual information to assist report reconstruction and fuse the multi-modal representations adequately. Experimental results demonstrate that the proposed unified approach outperforms previous methods in all downstream tasks, including uni-modal, cross-modal, and multimodal tasks. Copyright © 2023, The Authors. All rights reserved.

关键词： Alignment