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INVARIANTS-PRESERVING DU FORT-FRANKEL SCHEMES AND THEIR ANALYSES FOR NONLINEAR SCHRÖDINGER EQUATIONS WITH WAVE OPERATOR

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Journal of Computational Mathematics 2024年第3期42卷 814-850页

作者： Dingwen Deng zhijun Li College of Mathematics and Information Science Nanchang Hangkong UniversityNanchang 330063China

Du Fort-Frankel finite difference method(FDM)was firstly proposed for linear diffusion equations with periodic boundary conditions by Du Fort and Frankel in *** is an explicit and unconditionally von Neumann stable ***,there has been no research work on numerical solutions of nonlinear Schrödinger equations with wave operator by using Du Fort-Frankel-type finite difference methods(FDMs).In this study,a class of invariants-preserving Du Fort-Frankel-type FDMs are firstly proposed for one-dimensional(1D)and two-dimensional(2D)nonlinear Schrödinger equations with wave *** using the discrete energy method,it is shown that their solutions possess the discrete energy and mass conservative laws,and conditionally converge to exact solutions with an order of for ofο(T^(2)+h_(x)^(2)+(T/h_(x))^(2))1D problem and an order ofο(T^(2)+h_(x)^(2)+h_(Y)^(2)+(T/h_(X))^(2)+(T/h_(y))^(2))for 2D problem in ***,τdenotes time-step size,while,hx and hy represent spatial meshsizes in x-and y-directions,***,by introducing a stabilized term,a type of stabilized invariants-preserving Du Fort-Frankel-type FDMs are *** not only preserve the discrete energies and masses,but also own much better stability than original ***,numerical results demonstrate the theoretical analyses.

关键词： Nonlinear Schrodinger equations with wave operator Du Fort-Frankel finite difference methods Discrete energy and mass conservative laws Numerical convergence

A CELL-CENTERED GODUNOV METHOD BASED ON STAGGERED DATA DISTRIBUTION, PART I: ONE-DIMENSIONAL CASE

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Journal of Computational Mathematics 2024年第4期42卷 1172-1196页

作者： Jiayin Zhai Xiao Li zhijun Shen Institute of Applied Physics and Computational Mathematics LCPP.O.Boc 8009-26Beijing 100088China College of Big Data and Internet Shenzhen Technology UniversityShenzhen 518118China Institute of Applied Physics and Computational Mathematics LCPP.O.Boa 8009-26Beijing 100088China Center for Applied Physics and Technology HEDPSPeking UniversityChina

This paper presents a cell-centered Godunov method based on staggered data distribu-tion in Eulerian *** motivation is to reduce the intrinsic entropy dissipation of classical Godunov methods in the calculation of an isentropic or rarefaction *** the same time,the property of accurate shock capturing is also *** analyzing the factors that cause nonphysical entropy in the conventional Godunov methods,we introduce two velocities rather than a single velocity in a cell to reduce kinetic energy dissipation.A series of redistribution strategies are adopted to update subcell quantities in order to improve *** examples validate that the present method can dramatically reduce nonphysical entropy *** subject classification:35Q35,76N15,76M12.

关键词： Godunov method Riemann solver Rarefaction wave Nonphysical entropy increase.

Effects of cement-enhanced soil on the ultimate lateral resistance of composite pile in clayey soil

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 183-191页

作者： zhijun Yang Kexin Chen Xudong Fu Zhiyan Zou School of Civil Engineering Wuhan UniversityWuhan430000China Changjiang Design Group Co. Ltd.Wuhan430000China Institute of Geotechnical Engineering College of Civil Engineering and ArchitectureMOE Key Laboratory of Soft Soils and Geoenvironmental EngineeringZhejiang UniversityHangzhou310000China

The composite pile consisting of core-pile and surrounding cement-enhanced soil is a promising pile foundation in recent ***,how and to what extent the cement-enhanced soil influences the ultimate lateral resistance has not been fully *** this paper,the ultimate lateral resistance of the composite pile was studied by finite element limit analysis(FELA)and theoretical upper-bound *** results of FELA and theoretical analysis revealed three failure modes of laterally loaded composite *** effects of the enhanced soil thickness,strength,and pile-enhanced soil interface characteristics on the ultimate lateral resistance were *** results show that increasing the enhanced soil thickness leads to a significant improvement on ultimate lateral resistance factor(N P),and there is a critical thickness beyond which the thickness no longer affects the N *** the enhanced soil strength induced 6.2%-232.6%increase of N ***,no noticeable impact was detected when the enhanced soil strength was eight times higher than that of the natural *** maximum increment of N P is only 30.5%caused by the increase of interface adhesion factor(a).An empirical model was developed to calculate the N P of the composite pile,and the results show excellent agreement with the analytical results.

关键词： Composite pile Ultimate soil resistance Finite element limit analysis(FELA) Plasticity theory Failure mode

CFD-DEM study on the synergistic effect of coke consumption and particle dynamics in the blast furnace raceway

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Particuology 2024年第6期89卷 270-278页

作者： Peng Xu Peng Han zhijun He Xizhong An Kang Sun Lihua Gao Key Laboratory of Green Low-Carbon and Intelligent Metallurgy School of Materials and MetallurgyUniversity of Science and Technology LiaoningAnshan 114000China Key Laboratory for Ecological Metallurgy of Multimetallic Mineral of Ministry of Education School of MetallurgyNortheastern UniversityShenyang110819China

In this study,the gas-solid flow process in the blast furnace raceway is numerically simulated using coupled computational fluid dynamics and the discrete element method(CFD-DEM).The coke reaction kinetics data are imported into the DEM model to reproduce the consumption process of each coke *** effects of inlet gas velocity and angle on the morphology of the raceway,coke consumption rate,coke bed temperature,and particle size distribution in the blast process are systematically investigated and *** results show that the consumption of coke particles promotes the formation of raceways during the blast *** the same time,a coke mixture layer is produced at the edge of the *** higher the inlet gas velocity,the thicker the coke mixture layer in the middle and upper parts of the raceway region,and the larger the proportion of small particles in the coke mixture *** effect of the inlet gas angle on the raceway region is less than the inlet gas ***,with the increase in the inlet gas angle,the high-temperature region of the coke bed extends downward gradually,which is conducive to activating the hearth.

关键词： Blast furnace Raceway Multiphase flow CFD-DEM Modeling

An Intelligent Framework for Resilience Recovery of FANETs with Spatio-Temporal Aggregation and Multi-Head Attention Mechanism

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Computers, Materials & Continua 2024年第5期79卷 2375-2398页

作者： zhijun Guo Yun Sun YingWang Chaoqi Fu Jilong Zhong Air Traffic Control and Navigation College Air Force Engineering UniversityXi’an710000China Institute of Systems Engineering Academy of Military ScienceBeijing100101China Equipment Management and UAV Engineering College Air Force Engineering UniversityXi’an710038China Defense Innovation Institute Academy of Military ScienceBeijing100071China

Due to the time-varying topology and possible disturbances in a conflict environment,it is still challenging to maintain the mission performance of flying Ad hoc networks(FANET),which limits the application of Unmanned Aerial Vehicle(UAV)swarms in harsh *** paper proposes an intelligent framework to quickly recover the cooperative coveragemission by aggregating the historical spatio-temporal network with the attention *** mission resilience metric is introduced in conjunction with connectivity and coverage status information to simplify the optimization model.A spatio-temporal node pooling method is proposed to ensure all node location features can be updated after destruction by capturing the temporal network *** with the corresponding Laplacian matrix as the hyperparameter,a recovery algorithm based on the multi-head attention graph network is designed to achieve rapid *** results showed that the proposed framework can facilitate rapid recovery of the connectivity and coverage more effectively compared to the existing *** results demonstrate that the average connectivity and coverage results is improved by 17.92%and 16.96%,respectively compared with the state-of-the-art ***,by the ablation study,the contributions of each different improvement are *** proposed model can be used to support resilient network design for real-time mission execution.

关键词： Resilience cooperative mission FANET spatio-temporal node pooling multi-head attention graph network

BDSec:Security Authentication Protocol for BeiDou-Ⅱ Civil Navigation Message

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China Communications 2024年第6期21卷 206-218页

作者： Wu zhijun Zhang Yuan Yang Yiming Wang Peng Yue Meng School of Safety Science and Engineering Civil Aviation University of ChinaTianjin 300300China School of Electronic Information and Automation Civil Aviation University of ChinaTianjin 300300China

Due to the lack of authentication mechanism in BeiDou navigation satellite system(BDS),BD-Ⅱ civil navigation message(BDⅡ-CNAV) are vulnerable to spoofing attack and replay *** solve this problem,we present a security authentication protocol,called as BDSec,which is designed by using China’s cryptography Shangyong Mima(SM) series algorithms,such as SM2/4/9 and Zu Chongzhi(ZUC)*** BDSec protocol,both of BDⅡ-CNAV and signature information are encrypted using the SM4 algorithm(Symmetric encryption mechanism).The encrypted result is used as the subject authentication *** protocol applies SM9 algorithm(Identity-based cryptography mechanism) to protect the integrity of the BDⅡ-CNAV,adopts the SM2 algorithm(Public key cryptosystem) to guarantee the confidentiality of the important session information,and uses the ZUC algorithm(Encryption and integrity algorithm) to verify the integrity of the message authentication serial number and initial information and the information in authentication initialization sub-protocol *** results of the SVO logic reasoning and performance analysis show that BDSec protocol meets security requirements for the dual user identity authentication in BDS and can realize the security authentication of BDⅡ-CNAV.

关键词： BDII civil navigation messages(BDIICNAV) BeiDou navigation satellite system(BDS) identity-based cryptography mechanism navigation message authentication protocol(BDSec)

Global dynamics analysis for a nonlinear HTLV-I model with logistic proliferation and CTL response

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International Journal of Biomathematics 2024年第3期17卷 35-55页

作者： Siyu Chen zhijun Liu Lianwen Wang Xingan Zhang School of Mathematics and Statistics Central China Normal University Wuhan Hubei 430079P.R.China School of Mathematics and Statistics Hubei Minzu University Enshi Hubei 445000P.R.China

It is beyond dispute that cytotoxic T-lymphocytes(CTLs)exert a vital function in the host's antiviral defense *** the idea of the above factor and the logistic proliferation of CD4+T-cells,we establish a HTLV-I(human T-cell leukemia virus type-I)mathematical ***,two threshold parameters Ro and Re(the basic reproduction numbers for viral infection and CTL immune response,respectively)are ***,sufficient criteria for local and global asymptotic stabilities of the feasible equilibria of the model are deduced,***,the sensitivity analyses of Ro and Rc are performed to better understand the effective strategies for HTLV-I ***,not only numerical simulations are given to illustrate the stability conclusions,but also the biological significance is stated.

关键词： HTLV-I infection logistic proliferation CTL response stability sensitivity analysis

The trajectory of rice from wild to domesticated: A new chapter in the study of origins of agriculture

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Science China Earth Sciences 2024年第09期67卷 3011-3012页

作者： zhijun ZHAO Institute of Cultural Heritage Shandong University

Rice (Oryza sativa) is one of the most important food crops in the world today, feeding more than one-third of the global population. Therefore. the domestication of rice has always been an international research topic (Gross and Zhao, 2014).When, where, and how rice was cultivated and eventually domesticated has been a hot issue in many research fields such as archaeology, biology, and agronomy (Fuller et al.,2009).

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Finite Difference-Peridynamic Differential Operator for Solving Transient Heat Conduction Problems

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2707-2728页

作者： Chunlei Ruan Cengceng Dong Zeyue Zhang Boyu Chen zhijun Liu School of Mathematics&Statistics Henan University of Science&TechnologyLuoyang471023China Longmen Laboratory Luoyang471023China

Transient heat conduction problems widely exist in *** previous work on the peridynamic differential operator(PDDO)method for solving such problems,both time and spatial derivatives were discretized using the PDDO method,resulting in increased complexity and programming *** this work,the forward difference formula,the backward difference formula,and the centered difference formula are used to discretize the time derivative,while the PDDO method is used to discretize the spatial *** new schemes for solving transient heat conduction equations have been developed,namely,the forward-in-time and PDDO in space(FT-PDDO)scheme,the backward-in-time and PDDO in space(BT-PDDO)scheme,and the central-in-time and PDDO in space(CT-PDDO)*** stability and convergence of these schemes are analyzed using the Fourier method and Taylor’s *** show that the FT-PDDO scheme is conditionally stable,whereas the BT-PDDO and CT-PDDO schemes are unconditionally *** stability conditions for the FT-PDDO scheme are less stringent than those of the explicit finite element method and explicit finite difference *** convergence rate in space for these three methods is *** constructed schemes are applied to solve one-dimensional and two-dimensional transient heat conduction *** accuracy and validity of the schemes are verified by comparison with analytical solutions.

关键词： Peridynamic differential operator finite difference method stability transient heat conduction problem