关于函数凸(凹)性问题的讨论

根据凸（凹）函数的定义，对凸（凹）函数的性质作了进一步研究，推出了定义在区间I上的函数是凸（凹）函 数的充要条件。     

抽象Lebesgue积分在无穷级数中的一个应用

通过引入计数测度,将数学分析中的无穷级数与测度论里的抽象积分联系起来,并且在此基础上对无穷级数的一个定理给出了较为简洁的证明.     

与Dedekind函数ψ(n)倒数有关的误差项的新研究

Ψ (n)是Dedekind函数 ,以E(x)表示和式 ∑n xnΨ(n) 的渐近公式中的误差项 ,研究了E(x)的加权平方积分均值     

Unnatural Disasters: Two Calculus Projects for Instructors Teaching Mathematics for Social Justice

Abstract

We provide context and motivation for an instructor to use real-life examples in the calculus classroom. To this end we describe two specific project ideas, one related to the devastating impact of methylmercury fungicide in a grain seed supply and the other to a catastrophic methane leak. By using calculus in contexts that have social justice implications, we hope to empower students to reason for themselves, to use mathematics as a powerful tool to deepen their understanding of the world, and ultimately, to effectively confront the challenges society faces.     

形如∑anbn级数收敛判定的一个命题

比较判定形如∑anbn级数收敛的Abel．N．H判别法和Dirichlet．P．G．L判别法，套用“分而治之”的思路，给出一个新的级数收敛判别法。     

Mathematics in ancient India

In this series of articles, we intend to have a glimpse of some of the landmarks in ancient Indian mathematics with special emphasis on number theory. This issue features a brief overview of some of the high peaks of mathematics in ancient India. In the next part we shall describe Aryabhata’s general solution in integers of the equationax -by =c. In subsequent instalments we shall discuss in some detail two of the major contributions by Indians in number theory. The climax of the Indian achievements in algebra and number theory was their development of the ingeniouschakravala method for solving, in integers, the equation x² -Dy² = 1, erroneously known as the Pell equation. We shall later describe the partial solution of Brahmagupta and then the complete solution due to Jayadeva and Bhaskaracharya.     

戴煦《外切密率》对级数的认识

本文从级数除法、级数收敛速度、两级数收敛快慢之比较、级数的确定等方面探讨清代数学家戴煦在《外切密率》中对级数的认识程度,借以窥见清代数学的理论性与深度.     

Chaotic phenomenon and the maximum predictable time scale of observation series of urban hourly water consumption

The chaotic characteristics and maximum predictable time scale of the observation series of hourly water consumption in Hangzhou were investigated using the advanced algorithm presented here is based on the conventional Wolf's algorithm for the largest Lyapunov exponent. For comparison, the largest Lyapunov exponents of water consumption series with one-hour and 24-hour intervals were calculated respectively. The results indicated that chaotic characteristics obviously exist in the hourly water consumption system; and that observation series with 24-hour interval have longer maximum predictable scale than hourly series. These findings could have significant practical application for better prediction of urban hourly water consumption.     

CDMA技术在数据通信系统中的应用

人类对更高质量无线通信的需求推动了CDMA技术的出现．CDMA是按照码型结构的差别来分割信号的．在CDMA系统中，用户数的增加相当于背景噪声的增加．在保持高质量通话的同时，CDMA可以容纳更多的用户，CDMA手机的用户每次通话时，系统编码有4．4万亿种可能的排列，具有天然的保密性，其消息在空中信道上被截获的概率几乎为零．CDMA技术的标准化，推进了这项技术在世界范围内的应用．     

浅谈武术套路教学中呼吸机能的调节

呼吸机能的调节水平直接关系到武术套路演练的好坏。文章通过理论与实践的紧密结合，详细介绍了几种呼吸方法和不同拳种对呼吸机能的具体要求，并对如何加强呼吸机能的能力提出了看法和建议。