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ON PROPERTIES OF q-DIFFERENCE EQUATIONS 被引量:1
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作者 郑秀敏 陈宗煊 《Acta Mathematica Scientia》 SCIE CSCD 2012年第2期724-734,共11页
In this article, we consider some type of q-difference equations, which have meromorphic solutions with Borel exceptional zeros and poles. We also give a precise result in the finite order case and some further result... In this article, we consider some type of q-difference equations, which have meromorphic solutions with Borel exceptional zeros and poles. We also give a precise result in the finite order case and some further results in a particular case where qi = qi. 展开更多
关键词 q-difference equation meromorphic solution Borel exceptional zeros andpoles
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On Properties of Meromorphic Solutions for Certain q-Difference Equation
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作者 Lei TAO Jianren LONG 《Journal of Mathematical Research with Applications》 CSCD 2023年第1期83-90,共8页
Let q be a finite nonzero complex number,let the q-difference equation f(qz)f(z/p)=R(z,f(z))=P(z,f(z))/Q(z,f(z))=Σ_(j=0)^(p)=0aj(z)f^(j)(z)/Σ_(k=0)b_(k)(z)f^(k)(z)(+)admit a nonconstant meromorphic solution f,where ... Let q be a finite nonzero complex number,let the q-difference equation f(qz)f(z/p)=R(z,f(z))=P(z,f(z))/Q(z,f(z))=Σ_(j=0)^(p)=0aj(z)f^(j)(z)/Σ_(k=0)b_(k)(z)f^(k)(z)(+)admit a nonconstant meromorphic solution f,where p and q are nonnegative integers,a_(j)with 0≤j≤p and b_(k)with 0≤k≤q polynomials in zwith a_(p)≠0 and b_(q)≠0 such that P(z,f(z))and Q(z,f(z))are relatively prime polynomials in f(z)and let m=p-q≥3.Then,(+)has no transcendental meromorphic solution when|q|=1,and the lower bound of the lower order of f is obtained when m≥3 and |q|≠1. 展开更多
关键词 complex q-difference equation transcendental meromorphic function order of growth EXISTENCE
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Some Properties of Solutions for Some Types of Q-Difference Equations Originated from Q-Difference Painlevé Equation
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作者 Hongyan XU Xiumin ZHENG 《Journal of Mathematical Research with Applications》 CSCD 2020年第5期507-518,共12页
In this paper,we mainly investigate some properties of meromorphic solutions for several q-difference equations,which can be seen as the q-difference analogues of Painlevéequations.Some results about the existenc... In this paper,we mainly investigate some properties of meromorphic solutions for several q-difference equations,which can be seen as the q-difference analogues of Painlevéequations.Some results about the existence and the estimates of growth of meromorphic solution f for q-difference equations are obtained,especially for some estimates for the exponent of convergence of poles of△qf(z):=f(qz)-f(z),which extends some previous results by Qi and Yang. 展开更多
关键词 meromorphic function q-difference equation zero order
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A Cauchy Problem for Some Fractional q-Difference Equations with Nonlocal Conditions
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作者 Maryam Al-Yami 《American Journal of Computational Mathematics》 2016年第2期159-165,共7页
In this paper, we discussed the problem of nonlocal value for nonlinear fractional q-difference equation. The classical tools of fixed point theorems such as Krasnoselskii’s theorem and Banach’s contraction principl... In this paper, we discussed the problem of nonlocal value for nonlinear fractional q-difference equation. The classical tools of fixed point theorems such as Krasnoselskii’s theorem and Banach’s contraction principle are used. At the end of the manuscript, we have an example that illustrates the key findings. 展开更多
关键词 Cauchy Problem Fractional q-difference equation Nonlocal Conditions Fixed Point Krasnoselskii’s Theorem
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Properties on Solutions of Some q-Difference Equations 被引量:3
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作者 Bao Qin CHEN Zong Xuan CHEN Sheng LI 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2010年第10期1877-1886,共10页
We consider the properties on solutions of some q-difference equations of the form ∑ n j=0 aj(z)f(qj z)=an+1(z), where a0(z),..., an+1(z) are meromorphic functions, a0(z)an(z) ≠ 0 and q ∈ C such th... We consider the properties on solutions of some q-difference equations of the form ∑ n j=0 aj(z)f(qj z)=an+1(z), where a0(z),..., an+1(z) are meromorphic functions, a0(z)an(z) ≠ 0 and q ∈ C such that 0 〈 |q| ≤ 1. We give estimates on the upper bound for the length of the gap in the power series of entire solutions of (*) when the coefficients a0(z),..., an+1(z) are polynomials and 0 〈 |q| 〈 1. For some special cases, we give estimates of growth of f(z). And we also show that the case 0 〈 |q| 〈 1 is different from the case |q|=1. 展开更多
关键词 q-difference equation entire coefficient Fabry gap GROWTH
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Value Distribution of Meromorphic Solutions of Some q-Difference Equations 被引量:3
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作者 Xiu Min ZHENG Zong Xuan CHEN 《Journal of Mathematical Research and Exposition》 CSCD 2011年第4期698-704,共7页
In this paper, we consider the value distribution of meromorphic solutions of order zero of some kind of q-difference equations and examples are also given to elaborate our results.
关键词 q-difference equation meromorphic solution zero-order.
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BIOLOGICAL INVASION PROBLEM WITH FREE BOUNDARY NONLOCAL DIFFUSION EQUATION 被引量:2
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作者 HE Yu-rong ZHANG Ya-rong 《数学杂志》 2025年第1期48-56,共9页
In order to better describe the phenomenon of biological invasion,this paper introduces a free boundary model of biological invasion.Firstly,the right free boundary is added to the equation with logistic terms.Secondl... In order to better describe the phenomenon of biological invasion,this paper introduces a free boundary model of biological invasion.Firstly,the right free boundary is added to the equation with logistic terms.Secondly,the existence and uniqueness of local solutions are proved by the Sobolev embedding theorem and the comparison principle.Finally,according to the relevant research data and contents of red fire ants,the diffusion area and nest number of red fire ants were simulated without external disturbance.This paper mainly simulates the early diffusion process of red fire ants.In the early diffusion stage,red fire ants grow slowly and then spread over a large area after reaching a certain number. 展开更多
关键词 Free boundary biological invasion differential equation
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DEEP NEURAL NETWORKS COMBINING MULTI-TASK LEARNING FOR SOLVING DELAY INTEGRO-DIFFERENTIAL EQUATIONS 被引量:1
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作者 WANG Chen-yao SHI Feng 《数学杂志》 2025年第1期13-38,共26页
Deep neural networks(DNNs)are effective in solving both forward and inverse problems for nonlinear partial differential equations(PDEs).However,conventional DNNs are not effective in handling problems such as delay di... Deep neural networks(DNNs)are effective in solving both forward and inverse problems for nonlinear partial differential equations(PDEs).However,conventional DNNs are not effective in handling problems such as delay differential equations(DDEs)and delay integrodifferential equations(DIDEs)with constant delays,primarily due to their low regularity at delayinduced breaking points.In this paper,a DNN method that combines multi-task learning(MTL)which is proposed to solve both the forward and inverse problems of DIDEs.The core idea of this approach is to divide the original equation into multiple tasks based on the delay,using auxiliary outputs to represent the integral terms,followed by the use of MTL to seamlessly incorporate the properties at the breaking points into the loss function.Furthermore,given the increased training dificulty associated with multiple tasks and outputs,we employ a sequential training scheme to reduce training complexity and provide reference solutions for subsequent tasks.This approach significantly enhances the approximation accuracy of solving DIDEs with DNNs,as demonstrated by comparisons with traditional DNN methods.We validate the effectiveness of this method through several numerical experiments,test various parameter sharing structures in MTL and compare the testing results of these structures.Finally,this method is implemented to solve the inverse problem of nonlinear DIDE and the results show that the unknown parameters of DIDE can be discovered with sparse or noisy data. 展开更多
关键词 Delay integro-differential equation Multi-task learning parameter sharing structure deep neural network sequential training scheme
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Quantum K-theory and q-difference Equations
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作者 Yong Bin RUAN Yao Xiong WEN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2022年第10期1677-1704,共28页
This is a set of lecture notes for the first author’s lectures on the difference equations in2019 at the Institute of Advanced Study for Mathematics at Zhejiang University.We focus on explicit computations and exampl... This is a set of lecture notes for the first author’s lectures on the difference equations in2019 at the Institute of Advanced Study for Mathematics at Zhejiang University.We focus on explicit computations and examples.The convergence of local solutions is discussed. 展开更多
关键词 Quantum K-theory q-difference equation
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A class of quasilinear equations with-1 powers
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作者 ZHANG Heng SUN Yijing 《中国科学院大学学报(中英文)》 北大核心 2025年第1期13-19,共7页
This paper deals with quasilinear elliptic equations of singular growth like-Δu-uΔ(u^(2))=a(x)u^(-1).We establish the existence of positive solutions for general a(x)∈L^(p)(Ω),p>2,whereΩis a bounded domain inℝ... This paper deals with quasilinear elliptic equations of singular growth like-Δu-uΔ(u^(2))=a(x)u^(-1).We establish the existence of positive solutions for general a(x)∈L^(p)(Ω),p>2,whereΩis a bounded domain inℝ^(N)with N≥1. 展开更多
关键词 quasilinear singular equation -1 power elliptic equation
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Normalized Solutions of Nonlinear Choquard Equations with Nonconstant Potential
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作者 LI Nan XU Liping 《应用数学》 北大核心 2025年第1期14-29,共16页
In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with ... In this paper,we mainly focus on a type of nonlinear Choquard equations with nonconstant potential.Under appropriate hypotheses on potential function and nonlinear terms,we prove that the above Choquard equation with prescribed 2-norm has some normalized solutions by introducing variational methods. 展开更多
关键词 Nonlinear Choquard equation Potential function Variational method Normalized solution
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Two Second-Order Ecient Numerical Schemes for the Boussinesq Equations
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作者 LIU Fang WANG Danxia ZHANG Jianwen 《应用数学》 北大核心 2025年第1期114-129,共16页
In this paper,we construct two fully decoupled,second-order semi-discrete numerical schemes for the Boussinesq equations based on the scalar auxiliary variable(SAV)approach.By introducing a scalar auxiliary variable,t... In this paper,we construct two fully decoupled,second-order semi-discrete numerical schemes for the Boussinesq equations based on the scalar auxiliary variable(SAV)approach.By introducing a scalar auxiliary variable,the original Boussinesq system is transformed into an equivalent one.Then we discretize it using the second-order backward di erentiation formula(BDF2)and Crank-Nicolson(CN)to obtain two second-order time-advanced schemes.In both numerical schemes,a pressure-correction method is employed to decouple the velocity and pressure.These two schemes possess the desired property that they can be fully decoupled with satisfying unconditional stability.We rigorously prove both the unconditional stability and unique solvability of the discrete schemes.Furthermore,we provide detailed implementations of the decoupling procedures.Finally,various 2D numerical simulations are performed to verify the accuracy and energy stability of the proposed schemes. 展开更多
关键词 Scalar auxiliary variable approach Pressure-correction method Fully decoupled Unconditional stability Boussinesq equations
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WELL-POSEDNESS AND PEAKON SOLUTIONS FOR A HIGHER ORDER CAMASSA-HOLM TYPE EQUATION
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作者 CHEN shuang 《数学杂志》 2025年第1期57-71,共15页
In this paper,we delve into a generalized higher order Camassa-Holm type equation,(or,an ghmCH equation for short).We establish local well-posedness for this equation under the condition that the initial data uo belon... In this paper,we delve into a generalized higher order Camassa-Holm type equation,(or,an ghmCH equation for short).We establish local well-posedness for this equation under the condition that the initial data uo belongs to the Sobolev space H'(R)for some s>2.In addition,we obtain the weak formulation of this equation and prove the existence of both single peakon solution and a multi-peakon dynamic system. 展开更多
关键词 Generalized higher order Camassa-Holm type equation Local well-posedness PEAKON
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Analytic Smoothing Effect of Cauchy Problem for a Class of Kolmogorov-Fokker-Planck Equations
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作者 CAO Xiaodong XU Chaojiang XU Yan 《数学进展》 北大核心 2025年第5期1015-1030,共16页
We study the Cauchy problem of the Kolmogorov-Fokker-Planck equations and show that the solution enjoys an analytic smoothing effect with L?initial datum for positive time.
关键词 Kolmogorov-Fokker-Planck equation analytic smoothing effect
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Investigating Solutions in Nonlinear Evolution Equations:A Focus on Local Existence in Mixed Types
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作者 NAFFISA Toureche Trouba FAN Long ABDELGHANI Dahou 《应用数学》 北大核心 2025年第3期691-702,共12页
With the urgent need to resolve complex behaviors in nonlinear evolution equations,this study makes a contribution by establishing the local existence of solutions for Cauchy problems associated with equations of mixe... With the urgent need to resolve complex behaviors in nonlinear evolution equations,this study makes a contribution by establishing the local existence of solutions for Cauchy problems associated with equations of mixed types.Our primary contribution is the establishment of solution existence,illuminating the dynamics of these complex equations.To tackle this challenging problem,we construct an approximate solution sequence and apply the contraction mapping principle to rigorously prove local solution existence.Our results significantly advance the understanding of nonlinear evolution equations of mixed types.Furthermore,they provide a versatile,powerful approach for tackling analogous challenges across physics,engineering,and applied mathematics,making this work a valuable reference for researchers in these fields. 展开更多
关键词 Nonlinear evolution equation Contraction mapping principle Sobolev space Dissipative system
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Methods for Exact Solutions of Nonlinear Ordinary Differential Equations
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作者 Robert CONTE Micheline MUSETTE +1 位作者 Tuen Wai NG WU Chengfa 《数学进展》 北大核心 2025年第2期379-389,共11页
In order to find closed form solutions of nonintegrable nonlinear ordinary differential equations,numerous tricks have been proposed.The goal of this short review is to explain how a theorem of Eremenko on meromorphic... In order to find closed form solutions of nonintegrable nonlinear ordinary differential equations,numerous tricks have been proposed.The goal of this short review is to explain how a theorem of Eremenko on meromorphic solutions of some nonlinear ODEs together with some classical,19th-century results,can be turned into algorithms(thus avoiding ad hoc assumptions)which provide all(as opposed to some)solutions in a precise class.To illustrate these methods,we present some new such exact solutions,physically relevant. 展开更多
关键词 elliptic solution complex Ginzburg-Landau equation Closed-form solution Nevanlinna theory
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A New Class of Efficient Schemes for the Cahn-Hilliard-Navier-Stokes Equations
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作者 WANG Lijing WANG Danxia ZHANG Jianwen 《应用数学》 北大核心 2025年第3期607-624,共18页
In this paper,we construct a new class of efficient and high-order schemes for the Cahn-Hilliard-Navier-Stokes equations with periodic boundary conditions.These schemes are based on two types of scalar auxiliary varia... In this paper,we construct a new class of efficient and high-order schemes for the Cahn-Hilliard-Navier-Stokes equations with periodic boundary conditions.These schemes are based on two types of scalar auxiliary variable approaches.By using a new pressure correction method,the accuracy of the pressure has been greatly improved.Furthermore,one only needs to solve a series of fully decoupled linear equations with constant coefficients at each time step.In addition,we prove the unconditional energy stability of the schemes,rigorously.Finally,plenty of numerical simulations are carried out to verify the convergence rates,stability,and effectiveness of the proposed schemes numerically. 展开更多
关键词 Cahn-Hilliard-Navier-Stokes equation Scalar auxiliary variable Pressurecorrection Unconditional energy stability
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Transportation Cost-information Inequalities for Stochastic Heat Equations Driven by Fractional Noise
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作者 ZHANG Bin YAO Zhigang LIU Junfeng 《数学进展》 北大核心 2025年第1期212-224,共13页
In this paper,we prove the transportation cost-information inequalities on the space of continuous paths with respect to the L~2-metric and the uniform metric for the law of the mild solution to the stochastic heat eq... In this paper,we prove the transportation cost-information inequalities on the space of continuous paths with respect to the L~2-metric and the uniform metric for the law of the mild solution to the stochastic heat equation defined on[0,T]×[0,1]driven by double-parameter fractional noise. 展开更多
关键词 transportation cost-information inequality stochastic heat equation fractional noise
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Limit Behavior of Pseudo-relativistic Hartree Equation with Respect to Particle Mass
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作者 XU Zefeng CHEN Yuanhui WANG Qingxuan 《数学进展》 北大核心 2025年第6期1300-1306,共7页
In this paper,we study the following pseudo-relativistic Hartree equation i∂_(t)Ψ-(|x|^(-1)*|Ψ|^(2))Ψwith(t,x)∈R×R^(3)We mainly focus on the normalized ground state solitary waves of the formΨ(t,x)=e^(itμ)... In this paper,we study the following pseudo-relativistic Hartree equation i∂_(t)Ψ-(|x|^(-1)*|Ψ|^(2))Ψwith(t,x)∈R×R^(3)We mainly focus on the normalized ground state solitary waves of the formΨ(t,x)=e^(itμ)φm(x)with||φm||_(2)^(2)=N.We investigate limit behaviors of energy and minimizer of the corresponding frinetional of this equationas m→+∞.We prove that m_(k)^(-3/2)φm_(k)→φ∞(x)in H^(-1/2(R^(3)))by energy method and lim_(m→+∞)+m^(-1)e(N)=e(N),whereφ_(m)(β∞)is a minimizer of e(N)(e(N). 展开更多
关键词 limit behavior pseudo-relativistic Hartree equation ground state solution
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On Linear Equations with Three Prime Variables in Arithmetic Progressions
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作者 KONG Yafang 《数学进展》 北大核心 2025年第6期1233-1242,共10页
Let a_(1),a_(2),a_(3)be nonzero integers with gcd(a_(1),a_(2),a_(3))=1,and let k be any positive integer,K=max[3,|a_(1)|,|a_(2)|,|a_(3)|,k].Suppose that l_(1),l_(2),l_(3)are integers each coprime to k.Suppose further ... Let a_(1),a_(2),a_(3)be nonzero integers with gcd(a_(1),a_(2),a_(3))=1,and let k be any positive integer,K=max[3,|a_(1)|,|a_(2)|,|a_(3)|,k].Suppose that l_(1),l_(2),l_(3)are integers each coprime to k.Suppose further that b is any integer satisfying some necessary congruent conditions.The solvability of linear equation a_(1)p_(1)+a_(2)p_(2)+a_(3)p_(3)=b(p_(j)=l_(j)(mod k),1≤j≤3)with prime variables pi,p_(2),ps is investigated.It is proved that if ai,a_(2),a_(3)are all positive,then the above equation is solvable whenever b≥K^(25);if a,a_(2),a_(3)are not all of the same sign,then the above equation has a solution p_(1),p_(2),p_(3)satisfying max(p_(1),p_(2),p_(3))≤3|b|+K^(25). 展开更多
关键词 ternary linear equation small prime solution arithmetic progression
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