关于PerKai多项式

通过对相关Legendre多项式的PerKai多项式的性质的探讨 ,导出了相关Legendre多项式的正交多项式序列的一般形式     

海上甚高频数据通信系统中的多径时延

为改进传统的海上甚高频(Very High Frequency, VHF)的模拟通信方式,实现海上通信现代化,针对国际灯塔与航标协会(International Association of Lighthouse Authorities, IALA)和国际海事组织（International Maritime Organization, IMO）提出的VHF数据通信系统(VHF Data Exchange System, VDES)研究计划,建立基于正交频分复用(Orthogonal Frequency Division Multiplexing, OFDM)的数据传输模型.海上无线信道的多径时延的确定是建立OFDM系统的关键,因此通过建立海上无线信道的多径传播模型分析和计算海上无线信道的多径时延.通过实验证明,该方法能够获得较低的误码率,有效实现海上VHF数据通信.     

Examining the influence of van Hiele theory-based instructional activities on elementary preservice teachers’ geometry knowledge for teaching 2-D shapes

Teaching geometry at the elementary level is challenging. This study examines the impact of van Hiele theory-based instructional activities embedded into an elementary mathematics methods course on preservice teachers’ geometry knowledge for teaching. Pre- and post-assessment data from 111 elementary preservice teachers revealed that van Hiele theory-based instruction can be effective in improving three strands of participants’ geometry knowledge for teaching: geometry content knowledge, knowledge of students’ van Hiele levels, and knowledge of geometry instructional activities. As a result, this paper offers implications for teacher educators and policy makers to better prepare elementary preservice teachers with geometry knowledge for teaching.     

常用软件在《空间解析几何》教学上的实践

本文根据《空间解析几何》的学科特点和教学任务,介绍了常见教学软件在该学科上的应用及注意问题,积极探讨信息技术和《空间解析几何》这一学科的最佳结合形式,达到优化课堂教学,提高学生认知水平、认知能力和数学素养的目的。     

阿司匹林-β-环糊精包合物的制备工艺优选

目的寻找阿司匹林-β-环糊精包合物（ASP-β-CYD）的最佳制备工艺。方法以包合率、包合物收率为指标,采用正交实验法,初步研究饱和水溶液搅拌法、超声波法和研磨法包合阿司匹林的最佳工艺。结果饱和水溶液法制备包合物的最佳工艺为阿司匹林的质量与β-环糊精的质量的比为1：8、包合温度为50℃、包合时间为2h、干燥温度50℃。包合率可以达到79.61%,包合物收率为76.19%。超声波法的最佳包合条件为阿司匹林的质量与β-环糊精的质量的比为1：8、超声时间为40min、干燥温度为50℃。包合率可以达到73.18%,包合物收率为79.26%。研磨法的最佳包合条件为阿司匹林的质量与β-环糊精的质量的比为1：8、研磨时间为20min、干燥温度为60℃。包合率可以达到84.41%,包合物收率为74.35%。结论超声波法制备包合物得到的包合率、综合评价均比其他两种方法高。     

用几何画板解决函数最值问题教学的探讨

利用几何画板,动态演示一类含参数函数的参数运动变化过程,使学生直观理解变化,降低题目本身的内在负荷,从而减轻学生学习时的认知负荷, 促进对参数变化的深入了解.     

平面几何问题证法的探讨

本文通过对近年来全国高中数学联赛中的两道初等几何问题的多种证法(即:纯初等几何法、解析几何法和复数法)的探讨,介绍了通过建立高斯复平面,把复杂的初等几何问题转换成复数计算的思想方法.并通过三种方法的比较,展示复数法的优越性,对中学初等几何教学有一定的参考价值.     

一个重要极限的证明策略

极限理论是数学分析中研究函数的重要工具,是学好高等数学的理论基础之一,而函数极限limx→0 sinx/x=1是高等数学中常用到的一个重要极限。综合运用不同知识,给予证法比较,以期有助于复习巩固所学知识,从而提高教学质量。     

高温厌氧发酵处理牛粪的正交试验研究

在高温厌氧发酵试验中,针对影响因素多、过程复杂的特点,利用正交试验,使用自行设计反应器,在高温环境下(55℃),以产气量为指标,分析接种量、C/N、搅拌对牛粪厌氧发酵的影响.试验结果表明,三者影响程度为:C/N>接种量>搅拌,并在此基础上筛选出牛粪高温厌氧发酵的最佳方案.     

Teachers’ perspectives on “authentic mathematics” and the two-column proof form

We investigate experienced high school geometry teachers’ perspectives on “authentic mathematics” and the much-criticized two-column proof form. A videotaped episode was shown to 26 teachers gathered in five focus groups. In the episode, a teacher allows a student doing a proof to assume a statement is true without immediately justifying it, provided he return to complete the argument later. Prompted by this episode, the teachers in our focus groups revealed two apparently contradictory dispositions regarding the use of the two-column proof form in the classroom. For some, the two-column form is understood to prohibit a move like that shown in the video. But for others, the form is seen as a resource enabling such a move. These contradictory responses are warranted in competing but complementary notions, grounded on the corpus of teacher responses, that teachers hold about the nature of authentic mathematical activity when proving.