级数加括号判敛方法的一点思考

本文介绍了两种级数加括号后收敛推得原级数收敛的方法,并给出了证明和应用实例.     

关于二重极限的某种定义的一个注记

本文考虑二重极限的某种定义的缺陷.     

关于利用中值定理求极限的一个注记

本文考虑一元微分学中利用微分中值定理求函数极限时应该注意的一些事项.     

对数求导法的一个注记

常规的对数求导法求函数的导数时往往不能直接求出函数在所有可导点处的导数,这大大限制了对数求导法的应用.本文对此进行了研究,给出了相应的改进方法.     

如何利用奇部和偶部判定级数的敛散性

本文介绍一种利用奇部和偶部判定级数敛散性的方法,利用它可以快速判定某些级数的敛散性.     

单叶双曲面直母线的一般形式

本文从几何直观角度导出了单叶双曲面单参数形式的直母线族方程,揭示了参数的几何意义,证明单叶双曲面有且仅有两族直母线,且这两族直母线可以由单叶双曲面上的椭圆确定.     

Further Result of Sideways Heat Equation and Wavelets

Sideways heat equation and wavelets" written by Teresa Regiska[1] is one of the earliestimportant literatures about solving ill-posed problem by using wavelet regularization. In thispaper a new approach of wavelet regularization for the following sideways heat equation[2] in thequarter plane (t 0, x 0) has been considered:where g L2(0, ∞). They look for such a solution u(x,·) L2(0,∞) which is bounded asx→∞. Let the definitions of g(t) and u(x, t) be exteneded to the whole real t-axis by…     

A New Proof of a TheoremAbout Wave Equation

In book [1], Professor C. D. Sogge proved the Theorem 2.2 (page 15) by the method presented by F. John. But I think we can also prove it by another method which is simpler and more direct than the original approach.