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    Dynamic Analysis of a Predator-Prey Model with State-Dependent Impulsive Effects
    LI Yong-feng, ZHU Cheng-zhi, LIU Yan-wei
    Chinese Quarterly Journal of Mathematics    2023, 38 (1): 1-19.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.01.001
    Abstract121)      PDF(pc) (2367KB)(255)       Save
     In this paper, a pest-dependent model and integrated pest management
    strategy is proposed, that is, when pest populations reach levels that impair economic
    development, we will use a combination of strategies, such as biological, cultural and
    chemical control strategies reduce pests to a reasonable level. First, we investigated the
    system without control measures, and discussed the existence and stability of equilibria,
    we also proved the system has no limit cycle. Then, a state feedback impulsive model is
    constructed, the existence and uniqueness of the order-one periodic solution are proved
    by means of the successor function method to confirm the feasibility of the biological and
    chemical control strategy of pest management. Secondly, the stability of system is proved
    by the analogue of the Poincar ´ e criterion. Finally, we give an example and numerical
    simulations to explain the mathematical conclusions.
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    Complexity on Proximal Quasi-Newton Methods for a Class of Nonconvex Composite Optimization
    JIN Ling-Zi
    Chinese Quarterly Journal of Mathematics    2023, 38 (1): 62-84.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.01.005
    Abstract105)      PDF(pc) (404KB)(221)       Save
    This paper studies a class of nonconvex composite optimization, whose
    objective is a summation of an average of nonconvex (weakly) smooth functions and a
    convex nonsmooth function, where the gradient of the former function has the Hölder
    continuity. By exploring the structure of such kind of problems, we first propose a
    proximal (quasi-)Newton algorithm wPQN (Proximal quasi-Newton algorithm for weakly
    smooth optimization) and investigate its theoretical complexities to find an approximate
    solution. Then we propose a stochastic variant algorithm wPSQN (Proximal stochastic
    quasi-Newton algorithm for weakly smooth optimization), which allows a random subset
    of component functions to be used at each iteration. Moreover, motivated by recent
    success of variance reduction techniques, we propose two variance reduced algorithms,
    wPSQN-SVRG and wPSQN-SARAH, and investigate their computational complexity
    separately.
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    Space-Time Legendre Spectral Collocation Methods for Korteweg-de Vries Equation
    WANG Chuan, QIAO Yan
    Chinese Quarterly Journal of Mathematics   
    Accepted: 12 April 2023

    Stability and Hopf Bifurcation of an Eco-Epidemiological Model with Delay
    BAI Hong-fang
    Chinese Quarterly Journal of Mathematics    2023, 38 (2): 157-183.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.02.005
    Abstract126)      PDF(pc) (1289KB)(173)       Save
    In this paper, an eco-epidemiological model with time delay is studied. The local stability of the four equilibria, the existence of stability switches about the predation- free equilibrium and the coexistence equilibrium are discussed. It is found that Hopf bifurcations occur when the delay passes through some critical values. Formulae are obtained to determine the direction of bifurcations and the stability of bifurcating periodic solutions by using the normal form theory and center manifold theorem. Some numerical simulations are carried out to illustrate the theoretical results.
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    Differential Identities in Prime Rings with Involution
    HUANG Shu-liang
    Chinese Quarterly Journal of Mathematics    2023, 38 (2): 134-144.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.02.003
    Abstract87)      PDF(pc) (319KB)(163)       Save
    Let R be a prime ring of characteristic different from two with the sec- ond involution ∗ and α an automorphism of R . An additive mapping F of R is called a generalized ( α,α )-derivation on R if there exists an ( α,α )-derivation d of R such that F ( xy )= F ( x ) α ( y )+ α ( x ) d ( y ) holds for all x,y∈R. The paper deals with the s- tudy of some commutativity criteria for prime rings with involution. Precisely, we describe the structure of R admitting a generalized ( α,α )-derivation F satisfying any one of the following properties:
    ( i ) F ( xx) −α ( xx) ∈Z ( R ).
    ( ii ) F ( xx )+ α ( xx ) ∈Z ( R ).
    ( iii ) F ( x ) F ( xx) −α ( xx) ∈Z ( R ).
    ( iv ) F ( x ) F (x)+ α ( xx) ∈Z ( R ).
    ( v ) F ( xx) −F ( x ) F (x ) ∈Z ( R ).
    ( vi ) F ( xx) −F (x) F ( x )=0
    for all x∈R . Also, some examples are given to demonstrate that the restriction of the various results is not superfluous. In fact, our results unify and extend several well known theorems in literature.
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    On the Eigenvalues and Eigenfunctions of the Sturm-Liouville Operator with the Barrier Potential
    SARWAR Qanitah, HUANG Zhen-you, ZAHID Abdul Hannan, XU Xin-Jian
    Chinese Quarterly Journal of Mathematics    2023, 38 (1): 50-61.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.01.004
    Abstract153)      PDF(pc) (279KB)(161)       Save
    We aim to find the eigenvalues and eigenfunctions of the barrier potential
    case for Strum-Liouville operator on the finite interval [0 ,π ] when λ> 0. Generally, the
    eigenvalue problem for the Sturm-Liouville operator is often solved by using integral
    equations, which are sometimes complex to solve, and difficulties may arise in computing
    the boundary values. Considering the said complexity, we have successfully developed
    a technique to give the asymptotic formulae of the eigenvalue and the eigenfunction for
    Sturm-Liouville operator with barrier potential. The results are of significant interest in
    the field of quantum mechanics and atomic systems to observe discrete energy levels.
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    Virtual Element Method of the Allen-Cahn Equation
    WANG Pei-zhen, TIAN Xu
    Chinese Quarterly Journal of Mathematics    2023, 38 (1): 20-29.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.01.002
    Abstract113)      PDF(pc) (307KB)(153)       Save
     In this article, the virtual element method of the Allen-Cahn equation on a
    polygon grid is discussed in the fully discrete formulation. With the help of the energy
    projection operator, we give the corresponding error estimates in the L2 norm and H1
    norm.
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    Initial Boundary Value Problem for Pseudo-Parabolic p-Laplacian Type Equation with Logarithmic Nonlinearity
    PAN Jia-hui, FANG Shao-mei
    Chinese Quarterly Journal of Mathematics    2023, 38 (4): 360-369.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.04.003
    Abstract56)      PDF(pc) (358KB)(137)       Save
     In this paper, we study the initial boundary value problem of pseudo-parabolic p-Laplacian type equation, which be use to model some important physical and biological phenomena. By using the potential well method, we obtain the global existence, asymptotic behavior and blow up results of weak solution with subcritical initial energy. Then we also extend these results to the critical initial energy.
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    Weighted Analytic Torsion for Weighted Digraphs
    REN Shi-quan, WANG Chong
    Chinese Quarterly Journal of Mathematics    2023, 38 (1): 30-49.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.01.003
    Abstract142)      PDF(pc) (389KB)(131)       Save
     In 2020, Alexander Grigor’yan, Yong Lin and Shing-Tung Yau [6] introduced
    the Reidemeister torsion and the analytic torsion for digraphs by means of the path
    complex and the path homology theory. Based on the analytic torsion for digraphs
    introduced in [6], we consider the notion of weighted analytic torsion for vertex-weighted
    digraphs. For any non-vanishing real functions f and g on the vertex set, we consider the
    vertex-weighted digraphs with the weights ( f,g ). We calculate the ( f,g )-weighted analytic
    torsion by examples and prove that the ( f,g )-weighted analytic torsion only depend on
    the ratio f/g . In particular, if the weight is of the diagonal form ( f,f ), then the weighted
    analytic torsion equals to the usual (un-weighted) torsion.
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    Independent Roman {2}-Domination in Trees
    LI Bei-bei, SHANG Wei-ping
    Chinese Quarterly Journal of Mathematics    2022, 37 (4): 386-393.   DOI: 10.13371/j.cnki.chin.q.j.m.2022.04.006
    Abstract144)      PDF(pc) (336KB)(125)       Save
    For a graph G = (V,E), a Roman {2}-dominating function f :V → {0,1,2} has the property that for every vertex v ∈V with f(v) = 0, either v is adjacent to at least one vertex u for which f(u) = 2, or at least two vertices uand u2 for which f(u1) =f(u2) = 1. A Roman {2}-dominating function f = (V0,V1,V2) is called independent if V1∪V2 is an independent set. The weight of an independent Roman {2}-dominating function f is the value ω(f) =\sumv∈V f(v), and the independent Roman {2}-domination number i{R2}(G) is the minimum weight of an independent Roman {2}-dominating function on G. In this paper, we characterize all trees with i{R2}(T) =γ(T)+ 1, and give a linear time algorithm to compute the value of i{R2}(T) for any tree T. 
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    Induced Matching-Extendability of Halin Graphs
    ZHANG Qing-nan, HUI Zhi-hao, YANG Yu, WANG An,
    Chinese Quarterly Journal of Mathematics    2022, 37 (4): 380-385.   DOI: 10.13371/j.cnki.chin.q.j.m.2022.04.005
    Abstract156)      PDF(pc) (344KB)(112)       Save
     Let G be a connected graph having a perfect matching. The graph G is said to be induced matching (IM) extendable if every induced matching M of G is contained in a perfect matching of G. In this paper, we show that Halin graph G =T ∪C is IMextendable if and only if its characteristic tree T is isomorphic to K1,3, K1,5, K1,7 or S2,2.
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    Ergodicity of Bandwidth and Cutwidth on Families of Graphs and Trees
    LIN Yi-shu, CHANG Cai-bing, LIU Yan
    Chinese Quarterly Journal of Mathematics    2022, 37 (4): 355-365.   DOI: 10.13371/j.cnki.chin.q.j.m.2022.04.003
    Abstract84)      PDF(pc) (346KB)(110)       Save
    Bandwidth, cutwidth, cyclic bandwidth, bandwidth sum and cyclic bandwidth
    sum are well-known indices about optimal labeling of graphs applied in VLSI design,
    network communications, and other areas involving the graph layout. To design the
    graphs with the given indices, we need to study the ergodicity. Let F be a set of graphs
    under consideration and ϕ an integer-valued function defined on F, namely, ϕ is an index,
    such as bandwidth and cutwidth. If there exists a graph G ∈ F such that ϕ(G) =x for
    any integer x in the interval [a,b], where a and b are the minimum and maximum of ϕ
    on F, respectively, then ϕ is said to have ergodicity on F. Let Gn be the set of simple
    connected graphs with order n and Tn the set of trees with order n. In this paper, we
    investigate the ergodicity of bandwidth, cutwidth, cyclic bandwidth, the bandwidth sum
    and cyclic bandwidth sum on Tn and Gn.

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    Some Applications of Surface Curvatures in Theoretical Physics
    YANG Yi-song
    Chinese Quarterly Journal of Mathematics    2023, 38 (3): 221-253.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.03.001
    Abstract240)      PDF(pc) (496KB)(104)       Save
    In this survey article, we present two applications of surface curvatures in theoretical physics. The first application arises from biophysics in the study of the shape of cell vesicles involving the minimization of a mean curvature type energy called the Helfrich bending energy. In this formalism, the equilibrium shape of a cell vesicle may present itself in a rich variety of geometric and topological characteristics. We first show that there is an obstruction, arising from the spontaneous curvature, to the existence of a minimizer of the Helfrich energy over the set of embedded ring tori. We then propose a scale-invariant anisotropic bending energy, which extends the Canham energy, and show that it possesses a unique toroidal energy minimizer, up to rescaling, in all parameter regime. Furthermore, we establish some genus-dependent topological lower and upper bounds, which are known to be lacking with the Helfrich energy, for the proposed energy. We also present the shape equation in our context, which extends the Helfrich shape equation. The second application arises from astrophysics in the search for a mechanism for matter accretion in the early universe in the context of cosmic strings. In this formalism, gravitation may simply be stored over a two-surface so that the Einstein tensor is given in terms of the Gauss curvature of the surface which relates itself directly to the Hamiltonian energy density of the matter sector. This setting provides a lucid exhibition of the interplay of the underlying geometry, matter energy, and topological characterization of the system. In both areas of applications, we encounter highly challenging nonlinear partial differential equation problems. We demonstrate that studies on these equations help us to gain understanding of the theoretical physics problems considered.
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    The Least Squares {P,Q,k+1}-Reflexive Solution to a Matrix Equation
    DONG Chang-zhou, LI Hao-xue
    Chinese Quarterly Journal of Mathematics    2023, 38 (2): 210-220.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.02.008
    Abstract76)      PDF(pc) (383KB)(102)       Save
     Let P ∈C m×m and Q∈C n×n be Hermitian and {k +1 } -potent matrices,
    i.e., P k+1 = P = P ∗ , Q k+1 = Q = Q ∗ , where ( · ) ∗ stands for the conjugate transpose of a
    matrix. A matrix X ∈C m×n is called {P,Q,k +1 } -reflexive (anti-reflexive) if PXQ = X
    ( PXQ = −X ). In this paper, the least squares solution of the matrix equation AXB = C
    subject to {P,Q,k +1 } -reflexive and anti--reflexive constraints are studied by converting
    into two simpler cases: k=1 and k=2.
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    A Note on Preemptive Scheduling with Multiple Maintenance Activities to Minimize the Total Late Work
    HE Ru-yan, YUAN Jin-jiang, ZHANG Yuan
    Chinese Quarterly Journal of Mathematics    2022, 37 (4): 331-342.   DOI: 10.13371/j.cnki.chin.q.j.m.2022.04.001
    Abstract93)      PDF(pc) (374KB)(97)       Save
    We study the single-machine preemptive scheduling problem with multiple maintenance activities to minimize the total late work, in which the jobs must be processed in the time space not occupied by the maintenance intervals. For this problem, we present a polynomial algorithm to determine the optimal schedule and establish a formula expression to the optimal value. Moreover, our result is used to correct some minor errors in the literature related to the single-machine (preemptive or non-preemptive) scheduling with one maintenance activity to minimize the total late work. 
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    The Semi-Convergence Properties of the Generalized Shift-Splitting Methods for Singular Saddle Point Problems
    HUANG Zhuo-Hong
    Chinese Quarterly Journal of Mathematics    2023, 38 (2): 145-156.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.02.004
    Abstract74)      PDF(pc) (300KB)(93)       Save
    Recently, some authors (Shen and Shi, 2016) studied the generalized shift- splitting (GSS) iteration method for singular saddle point problem with nonsymmetric positive definite (1,1)-block and symmetric positive semidefinite (2,2)-block. In this paper, we further apply the GSS iteration method to solve singular saddle point problem with nonsymmetric positive semidefinite (1,1)-block and symmetric positive semidefinite (2,2)-block, prove the semi-convergence of the GSS iteration method and analyze the spectral properties of the corresponding preconditioned matrix. Numerical experiment is given to indicate that the GSS iteration method with appropriate iteration parameters is effective and competitive for practical use.
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    A New Existence Theorem for Global Attractors and its Application to a Non-Classical Diffusion Equation
    QIN Yu-ming, CHEN Jia-le, JIANG Hui-te
    Chinese Quarterly Journal of Mathematics    2023, 38 (3): 276-289.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.03.003
    Abstract72)      PDF(pc) (364KB)(90)       Save
    In this paper, we first survey existed theorems and propose all 46 related open problems of the existence of global attractors for autonomous dynamical systems, then establish a new existence theorem of global attractors which will be applied to a nonclassical diffusion equation for the norm-to-weak continuous, weakly compact semigroup on H01(Ω) and H2(Ω)∩H01(Ω) respectively. As an application of this new existence theorem of global attractors, we obtain the existence of the global attractors onH01(Ω) and H2(Ω)∩ H01(Ω) respectively for a nonclassical-diffusion equation.
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    Hopf-Rinow Theorem on Convex Complex Finsler Manifolds
    LI Hong-jun
    Chinese Quarterly Journal of Mathematics    2024, 39 (1): 31-45.   DOI: 10.13371/j.cnki.chin.q.j.m.2024.01.003
    Abstract87)      PDF(pc) (365KB)(90)       Save
    Suppose (M,F) is a convex complex Finsler manifold. We prove that geodesics of (M,F) are locally minimizing. Hence, F introduces a distance function d such that (M,d) is a metric space from topology. Next, we prove the classical Hopf-Rinow Theorem holds on (M,F).
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    A Note on the Girth of 3-Regular Hamiltonian Graph
    ZHAO Qiu-lan, YUAN Jin-jiang
    Chinese Quarterly Journal of Mathematics    2022, 37 (4): 430-431.   DOI: 10.13371/j.cnki.chin.q.j.m.2022.04.011
    Abstract90)      PDF(pc) (226KB)(88)       Save
    It is well-known that the Petersen graph is nonhamiltonian. A very short proof for this result was presented in [2] due to D. B. West. In this note, by extending the proof technique in [2], we briefly show that the girth of every 3-regular hamiltonian graph on n≥10 vertices is at most (n+ 4)/3.
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    On the Stokes Phenomenon and Representation Theory of Quantum Groups
    XU Xiao-meng
    Chinese Quarterly Journal of Mathematics    2023, 38 (3): 311-330.   DOI: 10.13371/j.cnki.chin.q.j.m.2023.03.005
    Abstract59)      PDF(pc) (458KB)(87)       Save
    This is a survey paper that lists our research works in the study of Stokes phenomenon of meromorphic ordinary differential equations and its relation with representation theory of quantum groups
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