中国科学院数学与系统科学研究院期刊网

28 November 2025, Volume 48 Issue 6
    

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  • XU YUTING, TAO CHANGQI
    Acta Mathematicae Applicatae Sinica. 2025, 48(6): 829-856. https://doi.org/10.20142/j.cnki.amas.202501043
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    At present, research on functional regression models is mainly based on the estimation of mean regression. However, mean regression only studies the influence of covariates on the mean position of response variables in the conditional distribution, and cannot reflect the relationship between the two at the tail of the conditional distribution, which can lead to information leakage and be easily affected by outliers. At the same time, there is currently no relevant research on partially functional linear additive models in the spatial dimension. In fact, economic relationships between variables exhibit more nonlinear characteristics in space, and ignoring this nonlinear relationship in spatial lag models can easily lead to model setting errors. To overcome the above shortcomings, this paper combines parametric models and semi parametric models with functional data to propose a new partially functional linear additive spatial lag quantile. Regression model. Furthermore, A tool variable estimation method for the model was constructed based on functional principal component analysis and B-spline approximation. Under some regular conditions, the consistency and asymptotic normality of the model parameter estimates were given, and the optimal convergence speed of the function estimates was obtained. The large sample nature of these estimates was also proved. The model can reflect spatial dependence and the influence of functional data, as well as capture multiple nonlinear effects caused by covariates, reducing the risk of model error, solving the curse of dimensionality, and having high robustness. Finally, numerical simulations and practical applications show that the proposed model and method are effective.
  • Guo PING, WANG YE, YU QING, LI CHENLONG, HUA ZHIQIANG
    Acta Mathematicae Applicatae Sinica. 2025, 48(6): 857-871. https://doi.org/10.20142/j.cnki.amas.202501044
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    The convergence and the order of the convergence for the truncated EM numerical solution of the stochastic delay differential equations are researched by using the result that numerical scheme which satisfies stochastic C stability and stochastic B consistency is strongly convergent. Under the local Lipschitz condition and Khasminskii condition and monotonicity condition, the truncated EM scheme for the stochastic delay differential equations is strongly convergent with the order 1/2.
  • JI HAOYU, ZHANG YUPING, WEI GUANGMEI
    Acta Mathematicae Applicatae Sinica. 2025, 48(6): 872-886. https://doi.org/10.20142/j.cnki.amas.202501016
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    In this paper, a (2+1)-dimensional Yu-Toda-Sasa-Fukuyama (YTSF) equation is investigated, which can model the interfacial wave in a two-layer liquid or elastic quasiplane wave in a lattice. Lie group method is a powerful and fundamental tool in studying the properties of differential equations and obtaining the invariant solutions. Using Lie symmetry approach, infinitesimal generators, symmetry groups and invariant solutions of this equation are presented, and the optimal system is given with adjoint representation. By means of the optimal system, some symmetry reductions to partial differential equations (PDEs) are obtained and some similarity solutions are provided. With Lagrangian, it is shown that the YTSF equation is nonlinearly self-adjoint. Furthermore, based on Lie point symmetries and nonlinear self-adjointness, the conservation laws for YTSF equation are derived, then an infinite number of conservation laws can be constructed through choosing different parameter functions.
  • ZHANG YE, LIU GUAN-TING
    Acta Mathematicae Applicatae Sinica. 2025, 48(6): 887-898. https://doi.org/10.20142/j.cnki.amas.202401071
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    The fracture problem of multi-branch fast propagation crack in one -dimensional hexagonal piezoelectric quasicrystals is studied, the analytical expressions of stress, field intensity factor and energy release rate of fast propagation crack with multi-branch under electric non-permeability are given by using the complex function method, the influence of the deflection angle and the relative size of the crack on the field intensity factor of the fast propagation crack and the energy release rate on the propagation velocity are analyzed. The results show that the field intensity factor at the crack tip decreases with the increase of the deflection angle, and the field intensity factor at the crack tip decreases with the increase of the relative size of the crack The energy release rate increases with the increase of the propagation velocity of the crack, the field intensity factor at the crack tip decreases with the increase of the propagation velocity of the crack, and the energy release rate increases with the increase of the propagation length of the main crack, the field intensity factor at the crack tip decreases and the energy release rate increases with the crack propagation velocity.
  • ZHANG PENG, LI MINGJIN, TAI ZHUYING
    Acta Mathematicae Applicatae Sinica. 2025, 48(6): 899-909. https://doi.org/10.20142/j.cnki.amas.202401075
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    In this paper, the properties of the analytic solution of the nonhomogeneous linear complex differential equation
    f(k)+Bk-1(z) f(k-1)+…+B1(z) f'+B0(z) f=Bk(z)
    is discussed by combining the theory of analytic function space and complex differential equation. Firstly, the condition of coefficients belonging to the weighted Bergman space$(A_\omega^p)$ is obtained. Secondly, the inverse problem is discussed, that is, the coefficients belong to the weighted Bergman space $\left(A_{\omega_{[k p]}}^p\right)$ when all the solutions belong to the weighted Bergman space $(A_\omega^p)$. Finally, the properties of weighted Bergman space $(A_{2(\rho+2)}^p)$ for solutions of second-order homogeneous differential equations are discussed.
  • QIAN JINHUA, ZHANG Bo, WANG YIMENG
    Acta Mathematicae Applicatae Sinica. 2025, 48(6): 910-921. https://doi.org/10.20142/j.cnki.amas.202401085
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    The involute-evolute counterparts in 3-space are defined in this paper. Based on this definition, the existence and relationship of null involute-evolutes derived from pseudo null curves in Minkowski 3-space are studied. Meanwhile, the null evolutes are expressed by the structure function of pseudo null curves and the detailed structure of the null evolutes derived from pseudo null helices is explored. Last but not least, several practical examples and corresponding graphs are given.
  • LI GAOYU, TAN ZHONGQUAN
    Acta Mathematicae Applicatae Sinica. 2025, 48(6): 922-940. https://doi.org/10.20142/j.cnki.amas.202501024
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    Let $\left \{ X_{n},n\ge 1 \right \}$ be a sequence of independent and identically distributed random variables. Let $N\left (n\right)$ be a sequence of positive integer random variables. In this paper, we obtain the joint limit distribution of the extremes $M_{N\left(n \right)}=\{X_{1}, X_{2},\cdots,X_{N(n)}\}$ and the partial sums $S_{N\left (n \right)}=\sum\limits_{i=1}^{N(n)}X_{i}$. The results are also extended to the case of the extreme order statistics and the partial sums. In the end, the strongly mixing cases are also considered.
  • PENG KUIAN, CHEN WANGXUE, ZHAO HONGLUE
    Acta Mathematicae Applicatae Sinica. 2025, 48(6): 941-952. https://doi.org/10.20142/j.cnki.amas.202401086
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    In statistical parameter estimation problems, how well the parameters are estimated largely depends on the sampling design used. In this paper, a maximum likelihood estimator (MLE) of the parameter of the SBB distribution and its properties are respectively studied under simple random sampling (SRS) and ranked set sampling(RSS). Both theoretical and numerical results demonstrate that the MLE under RSS is asymptotically more effective than the MLE under SRS. Additionally, we investigate the asymptotic efficiency of the MLE under imperfect ranked set sampling (IRSS), taking into account the potential presence of ranked errors. Numerical results show that the asymptotic efficiency is influenced by the ranked judgement, but the MLE under IRSS is at least as effective as the MLE under SRS.
  • YANG Xu, LI XIN
    Acta Mathematicae Applicatae Sinica. 2025, 48(6): 953-977. https://doi.org/10.20142/j.cnki.amas.202501045
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    In non-cylindrically symmetric media, by investigating the Maxwell equations with Kerr-like nonlinear terms, a new semilinear elliptic equation is derived. Then, using the Hilbert-Schmidt theory, the spectrum of the operator $L$ is given, where the eigenvalue $0$ has infinite multiplicity. Since the kernel space of the operator $L$ is infinite-dimensional, the energy functional of this semilinear elliptic equation is strongly indefinite. Therefore, we construct an appropriate Sobolev space and prove the existence of a ground state solution for the equation by means of the variational method. In addition, if the nonlinear term is even, the energy functional has an unbounded sequence of critical values.
  • WANG NA, HU YUXI
    Acta Mathematicae Applicatae Sinica. 2025, 48(6): 978-998. https://doi.org/10.20142/j.cnki.amas.202501014
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    We consider an initial boundary value problem for hyperbolic compressible Navier-Stokes equations on a half line. After transforming the system into Lagrangian coordinate, the resulting system possesses a structure with uniform characteristic boundary. We first construct an approximate system with non-characteristic boundary, and get a uniform global smooth solutions by basic energy methods. Then, by passing to a limit and using compactness argument, we obtain a global solution of the original problem. Moreover, as the relaxation parameter goes to zero, we show that the solutions of relaxed system converge globally to that of classical compressible Navier-Stokes system.