关于解析几何课程教学反思

本文就高等师范院校数学教育各专业解析几何教学的措施、内容、方法和手段等将如何改革进行了思考,提出了自己的看法。     

仰韶文化半坡类型彩陶器的艺术特点

半坡型彩陶文化是仰韶文化中历史较早,特点突出,影响较大的一个类型。器形丰富,多见圆底或平底钵、平底盆、鼓腹罐、细颈瓶。彩陶器的装饰纹样采用散点式构图,＂鱼纹＂和＂人面鱼纹＂以及由鱼头、鱼身演化而来的几何纹是半坡类型中最具特色的彩陶纹样。半坡型彩陶器造型规正,纹饰简洁生动,富有浓郁的原始气息,是当时经济、社会生活的艺术记录;同时反映了原始先民质朴的审美意识。     

超几何分布的期望和方差的一种新求法

本文介绍如何运用概率母函数来求超几何分布的期望和方差     

Neck-controlled sensitivity study on nano-grain SnO_2 gas sensors

1. Introduction SnO2 is an n-type semiconductor with rutile crystal structure and with a wide band gap of about 3.6 eV. SnO2 has a wide range of applications as photo-detectors, heat mirrors, transparent electrodes for solar cells, conductive filler, thick resistors, catalysts and gas sensors. One of the most important applications of SnO2 lies in gas sensors [1]. SnO2 gas sensors have been attracting much attention [2-5] because of their many advantages over current technologies for detect…     

LED照明与弱光聚集单体双向灯具二次配光设计

提出利用灯具空间结构双向调控光能、单个体多功能的光学设计新理念,构造矩形复合抛物面作为灯具灯罩、LED反光杯、太阳能聚光杯。在照明方面很好地满足了关于A、AA级的照度和照度均匀度要求;在弱光聚集方面,其太阳能芯片位置的照度是不经聚光情况的1.25倍;在聚光模式下,太阳能芯片的光伏转化效率是非聚光模式下的1.62倍。该矩形复合抛物面的设计双向提升了以往被忽略的灯罩结构的空间利用率,是对当前市面上非聚光模式收集太阳能产品设计的有效补充。     

复数法在平面几何中的应用

对于正多边形、圆、旋转变换、等腰直角三角形等有关平面几何问题,用复数法来求解或求证显得较为简捷方便。     

计算螺旋锥齿轮近似齿廓方程等距变换法

以机械工程中的近似取代为基点,运用微分几何中的等距变换理论为工具,建立起以渐开线为齿廓曲线的螺旋锥齿轮近似齿廓方程。     

Teachers’ Critical Evaluations of Dynamic Geometry Software Implementation in 1:1 Classrooms

Although the use of dynamic software in high school mathematics in the United States has emerged as a research topic, little research has been conducted on how teachers integrate new software in relation to at-home technology networks. Interviews with eight mathematics teachers from four North Carolina counties participating in 1:1 laptop initiatives are analyzed to trace similar decision-making themes, including Internet access, laptop availability, software use, and teacher training. This article outlines how current technologies in classrooms were critically examined by the teachers and how network connectivity impressions affected hardware and software use.     

Stochastic optimal control of first-passage failure for rectangular thin plate vibration model under gaussian white-noise excitations

A rectangular thin plate vibration model subjected to inplane stochastic excitation is simplified to a quasinonintegrable Hamiltonian system with two degrees of freedom. Subsequently a one-dimensional Ito? stochastic differential equation for the system is obtained by applying the stochastic averaging method for quasi-nonintegrable Hamiltonian systems. The conditional reliability function and conditional probability density are both gained by solving the backward Kolmogorov equation numerically. Finally, a stochastic optimal control model is proposed and solved. The numerical results show the effectiveness of this method.     

努力开发学生智能的实验研究--在画法几何教学中进行模块式教学的尝试

画法几何是一门基础理论课，有严格的系统性和逻辑性，整个理论系统由许多概念构成，而若干个概念能够完成某种功能，多种功能组成了整个理论系统。为此，结合教学作一些联想：画法几何的理论系统也可以采用计算机系统的结构模式，用模块式结构安排教学，以提高其理论的系统性和完整性，为组织CAI教学，为学生学好画法几何理论课作一次新的探索。