作者机构:
[Liu, Hongliang] School of Mathematics and Physics, University of South China, Hengyang, 421001, PR China;[Cheng, Jun] School of Mathematics and Statistics, Guangxi Normal University, Guilin, 541004, PR China. Electronic address: jcheng@gxnu.edu.cn;[Cao, Jinde] School of Mathematics, Southeast University, Nanjing 210096, PR China;[Katib, Iyad] Department of Computer Science, Faculty of Computing and Information Technology, King Abdulaziz University, Jeddah 21589, Saudi Arabia
通讯机构:
[Cheng, Jun] S;School of Mathematics and Statistics, Guangxi Normal University, Guilin, 541004, PR China. Electronic address:
摘要:
This study addresses the preassigned-time synchronization for complex-valued memristive neural networks with reaction-diffusion terms and Markov parameters. Employing a preassigned-time stable control strategy, two distinct controllers with varying power exponent parameters are designed to ensure that synchronization can be achieved within a predefined time frame. Unlike existing finite/fixed-time results, a priori specification of the settling time is addressed. Furthermore, Green's formula and boundary conditions are efficiently applied to overcome potential symmetry loss. Additionally, the activation function's constraint range is more lenient compared to existing constraints. Finally, the effectiveness of the presented methods are demonstrated through two examples.
作者机构:
[Ni, Shunli; Ni, SL; Xu, Zhenghua; Zou, Zhiwei; Li, Zhifeng] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Lin, Zefeng; Ren, Zhi-an; Zhou, Menghu; Ruan, Binbin] Chinese Acad Sci, Inst Phys, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, Peoples R China.
通讯机构:
[Ni, SL ] U;Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.
摘要:
Here, pristine and Pd-intercalated 2H-TaS2 single crystals with (00l) orientation were grown by the chemical vapor transport technique. The superconductivity (SC) and charge density wave (CDW) were characterized by magnetic and electrical transport measurements. We find that SC and CDW in the pristine 2H-TaS2 condense respectively at transition temperatures Tc - 0.8 K and TCDW -78 K. The CDW order is completely suppressed, and Tc is greatly enhanced to 4.5 K in 2H-Pd0.04TaS2, which concludes a competing relation between the two collective electronic states. The positive Hall coefficient RH for both samples above 78 K indicates that hole-type carriers dominate the transport properties, and almost the same RH reveals tiny charge transfer between the intercalant Pd and the host TaS2. The difference of RH below 78 K between TaS2 and Pd0.04TaS2 is attributed to the reconstruction of the Fermi surface by Pd-intercalation-induced collapse of the CDW order. Therefore, the prominently improved Tc in 2H-Pd0.04TaS2 is mainly caused by the change of electronic structure due to the suppression of the CDW state rather than charge injection by Pd intercalation.
作者机构:
[Lin, Wenbin; Yang, Bo] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Lin, Wenbin] Southwest Jiaotong Univ, Sch Phys Sci & Technol, Chengdu 610031, Peoples R China.;[Li, Jie] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
通讯机构:
[Wenbin Lin] S;School of Mathematics and Physics, University of South China, Hengyang, China<&wdkj&>School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, China
摘要:
In the present work, based on Wentzel-Kramers-Brillouin theory, we systematically study the cluster
radioactivity half-lives of 22 nuclei ranging from 221Fr to 242Cm by using a phenomenological model, which considers
the screened electrostatic effect of Coulomb potential. In this model, there are two adjustable parameters i.e. the
parameter t and g, which are related to the screened electrostatic barrier and the strength of spectroscopic factor,
respectively. The calculated results indicate this model can well reproduce the experimental data while the corre sponding root-mean-square (rms) deviation is 0.660. In addition, we extend this model to predict the half-lives of
possible cluster radioactive candidates whose cluster radioactivity are energetically allowed or observed but not
yet quantified in the evaluated nuclear properties table NUBASE2020. The predicted results are consistent with
the ones obtained by using other theoretical models and/or empirical formulae including the universal decay law
(UDL) proposed by Qi et al. [Phys. Rev. C 80, 044326 (2009)], a semi-empirical model for both α decay and cluster
radioactivity proposed by Santhosh et al. [J. Phys. G 35, 085102 (2008)] and a unified formula of half-lives for α
decay and cluster radioactivity proposed by Ni et al. [Phys. Rev. C 78, 044310 (2008)].
摘要:
In 5G frequency division duplex (FDD) systems, the user equipment needs to feedback the measured downlink channel state information (CSI) to the base station to improve the throughput. For massive multiple-input-multiple-output (MIMO) systems, each antenna in base station needs its CSI feedback, which results in significant transmission overhead and latency. We propose an attention-based deep learning network to directly predict the downlink CSI from the corresponding uplink one, eliminating the feedback overhead completely. Specifically, the uplink CSI is first compressed based on the 3D inverse discrete Fourier transform, then is fed into an attention-based deep learning network which can focus on key CSI characteristics. The simulation results show that the proposed method achieves high prediction accuracy and low complexity, indicating prospective applications in FDD massive MIMO systems.
摘要:
通用视频编码(versatile video coding,VVC)标准由联合视频专家组共同制定,它遵循基于混合块的编解码器及其前身高效视频编码(high efficient video coding,HEVC)的传统架...展开更多 通用视频编码(versatile video coding,VVC)标准由联合视频专家组共同制定,它遵循基于混合块的编解码器及其前身高效视频编码(high efficient video coding,HEVC)的传统架构。与HEVC相比,VVC的帧内预测功能包含大量修改,编码效率大大提高。在VVC的基础上,提出了一种改进的基于亮度残差的帧内编码算法,通过减少率失真代价的检查次数,在保证编码质量不受较大影响的前提下,降低了计算复杂性,并提高了VVC的帧内编码效率。实验结果表明,在VTM16.0的VVC软件版本下,在相同配置下,改进算法的编码时间可以减少27.03%,而Bj?ntegaard-Delta rate只增加了0.9%。收起
摘要:
In the present work, the cluster radioactivity preformation probability Pc in the scheme of NpNn for the effective number of the valence particles (holes) in trans-lead nuclei has been systematically investigated. This quantity has been explored in the simplified parametrization of NpNn as well as the multiplication NpNnI of this product with the isospin asymmetry I. The calculations for Pc are both performed in microscopic and model-dependent way. Within the microscopic approach, based on our previous work [Chin. Phys. C 47, 014101 (2023)], Pc is calculated in cluster formation model combined with the exponential relationship of Pc to the & alpha; decay preformation probability P & alpha; when the mass number of the emitted cluster Ac 28. While Ac 28, Pc is obtained through the charge-number dependence of Pc on the decay products proposed by Ren et al. [Phys. Rev. C 70, 034304 (2004)]. In the model-dependent approach, Pc is extracted through the ratios from calculated cluster radioactivity half-lives in the framework of unified fission model proposed by Dong et al. [Eur. Phys. J. A 41, 197 (2009)] to experimental ones. Both of the results show Pc in logarithmic form are linear to NpNn as well as NpNnI. For comparison, the parent-mass-number dependence analytical formula as well as the model proposed by Wei and Zhang [Phys. Rev. C 96, 021601(R) (2017)] are also used. Furthermore, the preformation mechanic for cluster radioactivity has also been discussed.
期刊:
Journal of Scientific Computing,2023年95(1):1-23 ISSN:0885-7474
通讯作者:
Li-Lian Wang
作者机构:
[Li, Lin] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Li, Lin] Univ South China, Hunan Key Lab Math Modeling & Sci Comp, Hengyang 421001, Peoples R China.;[Wang, Li-Lian] Nanyang Technol Univ, Sch Phys & Math Sci, Div Math Sci, Singapore 637371, Singapore.;[Li, Huiyuan] Chinese Acad Sci, Lab Parallel Comp Inst Software, State Key Lab Comp Sci, Beijing 100190, Peoples R China.
通讯机构:
[Li-Lian Wang] D;Division of Mathematical Sciences, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore
摘要:
It is quite common that a nonlinear partial differential equation (PDE) admits multiple distinct solutions and each solution may carry a unique physical meaning. One typical approach for finding multiple solutions is to use the Newton method with different initial guesses that ideally fall into the basins of attraction confining the solutions. In this paper, we propose a fast and accurate numerical method for multiple solutions comprised of three ingredients: (i) a well-designed spectral-Galerkin discretization of the underlying PDE leading to a nonlinear algebraic system (NLAS) with multiple solutions; (ii) an effective deflation technique to eliminate a known (founded) solution from the other unknown solutions leading to deflated NLAS; and (iii) a viable nonlinear least-squares and trust-region (LSTR) method for solving the NLAS and the deflated NLAS to find the multiple solutions sequentially one by one. We demonstrate through ample examples of differential equations and comparison with relevant existing approaches that the spectral LSTR-Deflation method has the merits: (i) it is quite flexible in choosing initial values, even starting from the same initial guess for finding all multiple solutions; (ii) it guarantees high-order accuracy; and (iii) it is quite fast to locate multiple distinct solutions and explore new solutions which are not reported in literature.
摘要:
The commercial exploitation of the deep-sea massive deep-sea polymetallic nodules depends on the excellent tractive performance of the deep-sea tracked miner. The walking safety and trafficability of the deep-sea tracked miner are greatly influenced by the traction of the crawler with multi track shoes. The total tractions generated from the two cases of failure surface under the uniformed pressure are deduced and analyzed based on the principle of virtual power. By substituting specified parameters, the traction weakening effect of multi track shoes is discovered, and then corresponding expression is put forward and verified by comparing the tested and theoretical traction relationships based on the traction test of multi track shoes. The research results show that the height and the distance should be considered into the design in a comprehensive way because of the existence of the weakening effect. The mechanism revealing of the source of the multi track shoe tractions could help to achieve the appropriate size of the track shoe and more traction according to the different track shoe distance.
摘要:
In this paper, the speed selection for the time periodic traveling wave solutions of a two-species competition lattice model of diffusive Lotka-Volterra type is investigated. By using the upper-lower solution method, an abstract result and several explicit sufficient conditions for linear selection are established. Moreover, a general condition for nonlinear selection is also obtained, which indicates that the minimal speed is nonlinearly selected if the system admits a lower solution with faster decay at the far end. Based on this result, some explicit conditions for nonlinear selection are found by constructing novel lower solutions.(c) 2022 Elsevier Inc. All rights reserved.
期刊:
Journal of Radioanalytical and Nuclear Chemistry,2023年332(2):251-259 ISSN:0236-5731
通讯作者:
Zhenghua Xu<&wdkj&>Yong Liu
作者机构:
[Yifan Chen; Xianwei Wu; Xingwang Dai] School of Resources Environmental and Safety Engineering, University of South China, Hengyang, China;[Tiejun Zhang] China Nuclear Industry 23 Construction Co., LTD., Beijing, China;[Min Zhang] China Nuclear Huachen Construction Engineering Co., LTD., Xi’an, China;[Zhenghua Xu] School of Mathematics and Physics, University of South China, Hengyang, China;[Yong Liu] College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
通讯机构:
[Zhenghua Xu] S;[Yong Liu] C;School of Mathematics and Physics, University of South China, Hengyang, China<&wdkj&>College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
关键词:
Radon;Stable zone;WOA-BP;Early warning
摘要:
Radon is a radioactive gas produced by the decay of radium in uranium tailings, which can migrate to the atmosphere through tiny pores in the soil and can be used to characterize the internal stability of tailings dam. A method for determining the stable zone of radon is proposed, in which the radon concentration of uranium tailings pond is divided into stable zone, asymptotically stable zone, and unstable zone, and through the WOA-BP neural network algorithm for intelligent early warning of stability zone. The results show that the MAPE (Mean Absolute Percentage Error) is reduced by 20.16% by dividing the stable region, And MAPE of WOA-BP neural network algorithm is 8.22% lower than that of BP neural network algorithm. It shows that this method can provide guidance for the safe and stable operation of uranium tailings pond.
期刊:
Physics of the Dark Universe,2023年42:101308 ISSN:2212-6864
通讯作者:
Lin, WB
作者机构:
[Li, Jie] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Lin, Wenbin; Yang, Bo; Lin, WB] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Wang, Yu] Univ Rome, Dip Fis, ICRA, Ple Aldo Moro 5, I-00185 Rome, Italy.;[Lin, Wenbin] Southwest Jiaotong Univ, Sch Phys Sci & Technol, Chengdu 610031, Peoples R China.
通讯机构:
[Lin, WB ] U;Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.
关键词:
Quark stars;Massive gravity;MIT bag model;Tolman-Oppenheimer-Volkoff equation
摘要:
We investigate the structure of quark stars in de Rham-Gabadadze-Tolley like massive gravity with an anisotropic matter source. The MIT bag model as the equation of state for compact stars is used to numerically solve the modified Tolman-Oppenheimer-Volkoff equation. We analyze the effects of bag constant, anisotropy parameter and massive gravity parameters on the structure of quark stars. The results show that the mass and radius of the quark star depend on these parameters significantly, and the maximum mass can satisfy the observational data for the massive pulsar PSR J0348+0432. Furthermore, we also discuss other properties of quark stars, including dynamical stability, Schwarzschild radius and compactness.& COPY; 2023 Elsevier B.V. All rights reserved.