带齐次权的Hardy型不等式

在采用Hoffmann-Ostenhof和Laptev构造权函数的思想,进行加权推广,给出了一类带齐次权的Hardy型不等式.利用Avkhadiev和Wirths得到的一维Hardy型不等式,运用放缩法,得到一类带余项的加权Hardy型不等式.获得的结论将HoffmannOstenhof和Laptev中的相关结论推广至加权与带余项的情形.     

一类f鞅的极大值不等式(英文)

本文研究了f框架下有关f-鞅的不等式性质.利用构造停时的方法和带跳的倒向随机微分方程的比较定理,得到了一类f-鞅的极大值不等式,推广了经典鞅论中的极大值不等式.     

非线性退化抛物变分不等式问题解的存在性和唯一性

本文研究了一类基于非线性抛物算子的变分不等式问题.利用惩罚方法获得了一些关于该变分不等式解的存在性和唯一性方面的结论.该结论是对变分不等式理论的推广.     

用微微对偶不等式推广四个著名不等式

微微对偶不等式,使许多重要不等式的证明,归结为构造矩阵.本文用这种方法推广了四个著名不等式.     

加权幂平均值不等式应用功能的开拓及推广

本文通过加权幂平均值不等式的变式应用,解决了加权系数相异的一类数学问题的求解,并利用这一思想方法,得到了加权幂平均值不等式的一个推广定理,本文最后举例说明这一推广定理及其推论的应用.     

一类非线性时滞微分差分不等式

讨论了一类包含了有界和无界的非线性时滞微分差分不等式,将有界时滞不等式推广到无界时滞不等式,并得到其解的指数估计.     

一类对称函数的Schur凸性及其应用

给出一类对称函数 Schur凸性的推广 ,运用该结果并结合控制不等式理论建立若干对称函数不等式及 n维欧氏空间 En中的单形不等式 ,所得结果是以往某些结果的推广或补充 .     

一类新的Radon型不等式及其应用

给出一类新的R adon型不等式,它们在代数不等式研究中有着广泛的应用,利用它们可直接得到一大批新的分式型不等式,也可运用它们证明或推广许多不等式.     

Lq中一个不等式的推广

本文利用函数的凹凸性研究了Lq中的一类不等式,并将Hanner的不等式进行了推广得到了较好的结果.     

凸序列不等式的控制证明

利用控制不等式理论简洁地证明了一类凸序列不等式 (包括著名的 Nanson不等式的几个推广 ) ,并给出若干应用 .     

The Construction of Reducible Quadrature Rules for Volterra Integral and Integro-differential Equations

A formal relationship between quadrature rules and linear multistepmethods for ordinary differential equations is exploited forthe generation of quadrature weights. Employing the quadraturerules constructed in this way, step-by-step methods for secondkind Volterra integral equations and integro-differential equationsare defined and convergence and stability results are presented. The construction of the quadrature rules generated by the backwarddifferentiation formulae is discussed in detail. The use ofthese rules for the solution of Volterra type equations is proposedand their good performance is demonstrated by numerical experiments.     

Frobenius integrable decompositions for ninth-order partial differential equations of specific polynomial type

Frobenius integrable decompositions are presented for a kind of ninth-order partial differential equations of specific polynomial type. Two classes of such partial differential equations possessing Frobenius integrable decompositions are connected with two rational Bäcklund transformations of dependent variables. The presented partial differential equations are of constant coefficients, and the corresponding Frobenius integrable ordinary differential equations possess higher-order nonlinearity. The proposed method can be also easily extended to the study of partial differential equations with variable coefficients.     

Hopf bifurcation of a diffusive Gause‐type predator‐prey model induced by time fractional‐order derivatives

Since population behaviors possess the characteristic of history memory, we, in this paper, introduce time fractional‐order derivatives into a diffusive Gause‐type predator‐prey model, which is time fractional‐order reaction‐diffusion equations and a generalized form of its corresponding first‐derivative model. For this kind of model, we prove the existence and uniqueness of a global positive solution by using the theory of evolution equations and the comparison principle of time fractional‐order partial differential equations. Besides, we obtain the stability and Hopf bifurcation of the Gause‐type predator‐prey model in the forms of the time fractional‐order ordinary equations and of the time fractional‐order reaction‐diffusion equations, respectively. Our results show that the stable region of the parameters in these 2 models can be enlarged by the time fractional‐order derivatives. Some numerical simulations are made to verify our results.     

Approximation von operatorgleichungen mit reprokernen

In this paper we develop a method for the approximation of a broad class of operator equations by reproducing kernels. The relevant operators are defined on Hilbert spaces. Necessary and sufficient conditions for the convergence of the approximation are discussed in detail. The results can be applied-for example-to Fredholm integral operators of the first and second kind and to ordinary and partial differential operators of elliptic type. In this context we refer to [9] for methods to construct reproducing kernels.     

Numerical Solution of Arbitrary-Order Ordinary Differential and Integro-Differential Equations with Separated Boundary Conditions Using Optimal Control Technique

In this paper, a new method for solving arbitrary order ordinary differential equations and integro-differential equations of Fredholm and Volterra kind is presented. In the proposed method, these equations with separated boundary conditions are converted to a parametric optimization problem subject to algebraic constraints. Finally, control and state variables will be approximated by a Chebychev series. In this method, a new idea has been used, which offers us the ability of applying the mentioned method for almost all kinds of ordinary differential and integro-differential equations with different types of boundary conditions. The accuracy and efficiency of the proposed numerical technique have been illustrated by solving some test problems.     

一类变系数线性微分方程及其解

根据常系数线性微分方程的求解原理,通过一个适当变换,研究了一类变系数线性微分方程及其解的问题,从而可以得到这类方程在特征根都是互异单根时的解法和通解,并对三阶方程的各种情况进行了较为详尽的讨论.     

Traveling solitary wave solutions to evolution equations with nonlinear terms of any order

Many physical phenomena in one- or higher-dimensional space can be described by nonlinear evolution equations, which can be reduced to ordinary differential equations such as the Lienard equation. Thus, to study those ordinary differential equations is of significance not only in mathematics itself, but also in physics. In this paper, a kind of explicit exact solutions to the Lienard equation is obtained. The applications of the solutions to the nonlinear RR-equation and the compound KdV-type equation are presented, which extend the results obtained in the previous literature.     

Non-local symmetries of first-order equations

It is shown how one can transform scalar first-order ordinarydifferential equations which admit non-local symmetries of theexponential type to integrable equations admitting canonicalexponential non-local symmetries. As examples we invoke theAbel equation of the second kind, the Riccati equation and naturalgeneralizations of these. Moreover, our method describes howa double reduction of order for a second-order ordinary differentialequation which admits a two-dimensional Lie algebra of generatorsof point symmetries can be affected if the second-order equationis first reduced in order once by a symmetry which does notspan an ideal of the two-dimensional Lie algebra.     

非Fuchs型方程的新理论——树级数解的表现定理(Ⅰ)

在微分方程的解析理论中非Fuchs型方程的严格显式解至今并未求得(Poincaré问题),本文提出的新理论首次给出非正则积分的一般求法和显式的精确解. 本法与经典理论的根本不同在于摈弃形式解的假定,从方程本身建立对应关系,应用留数定理自动给出非正则积分的解析结构.它由无收缩部和全、半收缩部组成.前者是通常的递推级数,后者则表为树级数.树级数是类新颖的解析函数,通常的递推级数只是它的特例而已. 本文的目的是建立非正则积分的一般理论,为此需要阐明Poincaré问题(1880T.I.P.333)的实质[1]:无法求出非正则积分的显式.根据以下证明的表现定理, 非正则积分是类新颖的解析函数,其中系数D_nk是方程参数的常项树级数.     

Complex Lie symmetries for scalar second-order ordinary differential equations

A scalar complex ordinary differential equation can be considered as two coupled real partial differential equations, along with the constraint of the Cauchy–Riemann equations, which constitute a system of four equations for two unknown real functions of two real variables. It is shown that the resulting system possesses those real Lie symmetries that are obtained by splitting each complex Lie symmetry of the given complex ordinary differential equation. Further, if we restrict the complex function to be of a single real variable, then the complex ordinary differential equation yields a coupled system of two ordinary differential equations and their invariance can be obtained in a non-trivial way from the invariance of the restricted complex differential equation. Also, the use of a complex Lie symmetry reduces the order of the complex ordinary differential equation (restricted complex ordinary differential equation) by one, which in turn yields a reduction in the order by one of the system of partial differential equations (system of ordinary differential equations). In this paper, for simplicity, we investigate the case of scalar second-order ordinary differential equations. As a consequence, we obtain an extension of the Lie table for second-order equations with two symmetries.