有理函数的高阶导数公式

导数是微积分学的重要研究对象,寻求函数的高阶导数公式是困难的,只有极少数类型的函数可以得到高阶导数公式.本文给出了有理函数的高阶导数的公式,我们从分解真分式入手,由于任意一个真分式都可以分解成最高分式之和,再利用导数的运算法则及公式,把复数部分转换为三角式进行化简,进而推算出有理函数的高阶导数的公式.最后本文结合实例对有理函数的高阶求导做出了讨论.     

一阶导数形式不变性

针对数学教材中由导数基本公式到复合函数求导法则过渡形式不一致现象,提出一阶导数的一致形式、修订复合函数求导法则、给出导数基本公式的一般形式.     

一组三个函数乘积的高阶导数公式及其行列式表示

研究了三个函数乘积的高阶导数,得到了一组相应的导数公式.利用这些公式求该类函数的高阶导数以及进行近似计算,或做函数的近似表示,将起到较好的简化作用.     

一类log-cosine和log-sine积分的闭形式

考虑了Beta函数偏导数的递推公式的表示问题.利用Beta函数偏导数的递推公式,给出一类log--cosine和log-sine积分的闭形式.     

例谈构造法解导数与不等式问题

<正>导数的思想最初是由法国数学家费马提出的,在中学数学中,导数的思想为研究函数的图像和性质起到了重要的作用,是高考数学的重要考点之一,本文从构造法的角度来谈一谈解导数与不等式的问题.一、基本求导法则与公式要想通过题目中的导数构造辅助函数,就必须对基本求导法则与公式非常熟悉,现在把基本求导法则与基本初等函数的导数公式列     

在新的Schwarz定义下的调和函数的Ahlfors-Weill延拓

近年来,很多学者将解析函数的结果推广到调和函数,利用调和函数的Schwarz导数的范数的范围以及调和函数的延拓公式的Beltrami系数,证明该延拓公式能够拟共形延拓到■.本文将根据聂丽萍和杨宗信给出的Schwarz导数的新定义,利用Efraimidis等人的方法,估计出Schwarz导数的范数的范围.进一步借助此范数的上界估计证明在Schwarz导数的新定义下,Efraimidis等人给出的调和函数的Alhfors-Weill延拓公式仍成立.     

反函数导数教学中的两点建议

提出了反函数导数教学中的两点建议:其一是用复合函数的极限运算法则合理解释求导公式的推导中求极限时用到的换元法;其二是在计算反函数的高阶导数时正确分析低阶导数的复合结构.同时为加深学生对求导公式的理解,教学中可引入具体例题验证公式.     

Stein流形上Bochner-Martinelli型积分的导数的Plemelj公式

运用局部化方法和双全纯映射,通过Stein流形和C~n空间中Bochner-Martinelli核的联系,借助已获得的C~n空间中导数的Plemelj公式,得到Stein流形上导数的Plemelj公式.     

莱布尼茨公式的图示方法及推广

为解释高阶导数莱布尼茨公式和二项式定理形式上的相似性,提出了一种图形化的分析和证明思路.通过引入指数升幂算符和导数升阶算符将公式中的不同数学概念分离出来,进而在"树图"框架内对不同公式进行统一分析.相比于传统的"猜想-证明"方法,这里采用的方法具有简便、直观的优点,有利于加深学生对莱布尼茨公式的理解,并可直接导出多个函数乘积的高阶导数公式.     

活用导数定义巧解一类考题

在学习过导数这一概念后,一般都是利用导数基本公式及运算法则等进行运算,而对导数的定义不够重视.实际上,导数的定义在求导数以及实际运用中有重要的作用.解题时,若能巧妙运用导数的定义,有时候能达到事半功倍的效果.     

RECENT PROGRESS ON SPHERICAL HARMONIC APPROXIMATION MADE BY BNU RESEARCH GROUP ——In memory of Professor Sun Yongsheng

As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years （2001-2005）. The main topics are： convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.     

On a class of self-similar processes with stationary increments in higher order Wiener chaoses

We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.     

A REPRESENTATION FORMULA RELATED TO SCHR(O)DINGER OPERATORS

Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.     

On a class of Riemann surfaces

It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.     

Boundedness for commutators of multipliers on Hardy type spaces

In this paper, we study the commutators generalized by multipliers and a BMO function. Under some assumptions, we establish its boundedness properties from certain atomic Hardy space Hb^p（R^n） into the Lebesgue space L^p with p 〈 1.     

A unified approach to certain problems of best local approximation

In this paper we study best local quasi-rational approximation and best local approximation from finite dimensional subspaces of vectorial functions of several variables. Our approach extends and unifies several problems concerning best local multi-point approximation in different norms.     

THE 8~(th) INTERNATIONAL CONGRESS ON INDUSTRIAL AND APPLIED MATHEMATICS

<正>August 10-14,2015Beijing,ChinaThe International Congress on Industrial and Applied Mathematics(ICIAM)is the premier international congress in the field of applied mathematics held every four years under the auspices of the International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists     

Towards Excellence in Science Chinese Academy of Sciences

<正>May 26,2014,Beijing Science is a human enterprise in the pursuit of knowledge.The scientific revolution that occurred in the 17th Century initiated the advances of modern science.The scientific knowledge system created by