高阶线性微分方程的解及其解的导数的不动点

研究了复域齐次和非齐次线性微分方程的解及其解的导数的不动点与超级问题,得到了整函数系数的齐次和非齐次线性微分方程的解及其解的导数的不动点的两个结果,所得结果推广了一些相关结果.     

亚纯函数结合导数的辐角分布

本文研究了亚纯函数结合导数的辐角分布. 利用覆盖曲面的方法, 获得了平面上一类零级亚纯函数结合其导数的奇异方向的存在性, 推广了杨乐等关于有限正级亚纯函数的相关结果.     

Bruck猜想的一类微分和差分方程

运用值分布以及Wiman-Valiron理论研究了整函数与它的k阶导数分担某些小函数问题,得到了一些涉及到Bruck猜想的唯一性结果.     

关于亚纯函数及其导数的Borel方向

亚纯函数及其导数的Borel方向之间有密切关系,本文运用Nevanlinna理论证明有穷正级亚纯函数f（z）的Borel方向也是f'（z）或（zf（z))'或（z 1）f（z))'的Borel方向.     

关于一类二阶微分方程解的增长性

本文研究一类二阶微分方程解的增长性,其中方程的系数是级为n的整函数.利用Nevanlinna值分布的基本理论和复振荡理论证明,得到当其系数满足一定条件时,这类方程的每个非零解有无穷级且超级为n,推广了Kwon[12]和陈宗煊[13,14]等人的结果.     

零级亚纯函数与多项式的复合函数的对数导数引理及其应用

研究零级亚纯函数与多项式的复合函数的对数导数引理.作为其应用,我们获得了零级亚纯函数与多项式复合函数的Nevanlinna特征和第二基本定理.     

一类二阶非齐次微分方程解的增长性与不动点[英文]

研究方程f''+A(z)f'' B(z)f=F解的增长性与解及其导数的不动点问题,其中A(z),B(z),F(z)(不恒等于0)是整函数,F的级为无穷,得到了方程解的超级、二级不同零点收敛指数,方程解及其一阶和二阶导数的二级不动点收敛指数等的精确估计.     

二阶线性微分方程解与不动点的关系

使用Nevanlinna值分布的基本理论和方法,研究了几类二阶线性微分方程解及解的导数与其不动点之间的关系,得到了方程解及其导数的不动点的不同点收敛指数为无穷和二级收敛指数等于解的超级的精确结果.     

一类二阶非齐次微分方程解的增长性与不动点(英文)

本文研究方程f′′+A(z)f′+B(z)f=F解的增长性、解及其导数的不动点问题,其中A(z),B(z)(不恒等于0),F(z)(不恒等于0)是整函数,F的级为无穷.得到方程解的超级、二级不同零点收敛指数、方程解及其一阶和二阶导数的二级不动点收敛指数等的精确估计.     

关于多复变整函数及其全导数

首先研究了与Saxer-Millioux定理相关的复微分方程,并运用多复变对数导数引理将该结果推广至关于整函数全导数的微分多项式;其次利用Clunie的结果将Hayman的定理推广至多复变整函数的全导数情形;最后作为推论得到一些多复变Picard型定理.     

二阶复域微分方程解的不动点与超级

文中首次研究了４种类型的整函数系数的二阶线性微分方程的解的不动点及超级问题,得到：复域微分方程解的不动点性质,由于受到微分方程的制约,与一般超越整函数的不动点性质相比,是十分有趣的．     

Entire functions sharing one polynomial with their derivatives

In this paper, we study the growth of solutions of ak-th order linear differential equation and that of a k + 1-th order linear differential equation. From this we affirmatively answer a uniqueness question concerning a conjecture given by Brück in 1996 under the restriction of the hyper order less than 1/2, and obtain some uniqueness theorems of a nonconstant entire function and its derivative sharing a finite nonzero complex number CM. The results in this paper also improve some known results. Some examples are provided to show that the results in this paper are best possible.     

关于高阶整函数系数微分方程解的增长性的进一步结果

本文研究一类高阶整函数系数微分方程的增长性问题，当存在某个系数对方程的解的性质起主要支配作用时，得到了齐次与非齐次方程解的超级的精确估计及方程的解与小函数的关系。     

二阶复域微分方程亚纯解的不动点与超级

研究了亚纯函数系数的二阶线性微分方程解的不动点及超级问题,得到了有关复域微分方程亚纯解的不动点性质,并且由于受到微分方程的制约,其性质与一般亚纯函数的不动点性质相比,显得十分有趣.     

Admissible meromorphic solutions of algebraic differential‐difference equations

By using Nevanlinna theory, we generalize a result given by Wittich to complex differential‐difference equations. The result obtained is that the differential‐difference equation in f which is of only one dominant term, has no admissible meromorphic solution f with hyper‐order less than 1 provided N(r,f) = S(r,f).     

一类高阶微分方程解的增长性

本文研究了微分方程f^（k）＋Ak（z）e^ακ-^12f^（κ-1）,…,＋A0（z）e^a0z=0的增长性,其中Aj（z）（j=0,1…κ-1）是整函数,其级小于1．在αj（j=0,1,…,κ-1）满足某条件下,得到该方程的任一超越解的超级等于1的结论．     

Higher order optimality conditions with an arbitrary non-differentiable function

In this paper, we introduce a higher order directional derivative and higher order subdifferential of Hadamard type of a given proper extended real function. We obtain necessary and sufficient optimality conditions of order n (n is a positive integer) for unconstrained problems in terms of them. We do not require any restrictions on the function in our results. In contrast to the most known directional derivatives, our derivative is harmonized with the classical higher order Fréchet directional derivative of the same order in the sense that both of them coincide, provided that the last one exists. A notion of a higher order critical direction is introduced. It is applied in the characterizations of the isolated local minimum of order n. Higher order invex functions are defined. They are the largest class such that the necessary conditions for a local minimum are sufficient for global one. We compare our results with some previous ones. As an application, we improve a result due to V. F. Demyanov, showing that the condition introduced by this author is a complete characterization of isolated local minimizers of order n.     

整函数分担多项式的增长性的进一步估计

运用正规族理论将整函数分担多项式增长级的结果进一步精确化估计.同时举例说明的结果是有意义的.     

复非线性代数微分方程解的增长级(英文)

本文研究了一类非线性微分方程的解的增长级的问题.利用亚纯函数的Nevanlinna值分布理论和Wiman-Valiron整函数理论的方法,获得了比以往文献更为精确,更为一般的结论,推广了Gol’dberg,Barsegian,Hayman以及Korhonen等作者的一些结果.     

Calculation of Stresses and Consistent Tangent Moduli from Automatic Differentiation of Hyerelastic Strain Energy Functions Through the Use of Hyper Dual Numbers

Many materials as e.g. engineering rubbers, polymers and soft biological tissues are often described by hyperelastic strain energy functions. For their finite element implementation the stresses and consistent tangent moduli are required and obtained mainly in terms of the first and second derivative of the strain energy function. Depending on its mathematical complexity in particular for anisotropic media the analytic derivatives may be expensive to be calculated or implemented. Then numerical approaches may be a useful alternative reducing the development time. Often-used classical finite difference schemes are however quite sensitive with respect to perturbation values and they result in a poor accuracy. The complex-step derivative approximation does never suffer from round-off errors, cf. [1], [2], but it can only provide first derivatives. A method which also provides higher order derivatives is based on hyper dual numbers [3]. This method is independent on the choice of perturbation values and does thus neither suffer from round-off errors nor from approximation errors. Therefore, here we make use of hyper dual numbers and propose a numerical scheme for the calculation of stresses and tangent moduli which are almost identical to the analytic ones. Its uncomplicated implementation and accuracy is illustrated by some representative numerical examples. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)