濒危植物延龄草种群空间分布格局的研究

延龄草（Trillium tschonoshii Maxim.）属百合科植物;是珍贵中药材,属于国家医药管理局管理的二类药材;是珍稀濒危物种,属国家Ⅲ级重点保护野生植物.本研究采用计盒维数刻画了延龄草不同生境下的种群空间分布格局.在西天目山、清凉峰延龄草主要分布海拔120～1300m之间的山坡、水沟边的华东野胡桃、灯台树、短柄栎等林下;土壤pH值为6.55～6.91;土壤的有机物占11.36%～11.83%.种群中个体数量在2～17个;计盒维数在0.33～0.79之间.由于人为过度挖掘,加上生境的破碎化,延龄草种群在西天目山、清凉峰高度集群化、占据生态空间的能力很小,延龄草处于濒危状态,应加以重点保护.     

利用Excel的统计函数进行概率运算

利用EXCEL的统计函数可以使复杂的二项分布概率计算和正态分布概率计算变得简单,同时,可以利用计算符号把多个统计函数连接起来,制成统计分析程序,用于比较大的复杂的统计计算和分析.     

单步/连续计数脉冲产生电路的设计

介绍一个能产生单步和连续计数脉冲的电路,该电路具有结构简单、使用元件少、工作稳定等特点。该电路与计数电路和其他数控模拟电路组合,可实现对各种不同模拟信号的数字控制。     

距离变换和分水岭分割的粘连人群分割算法

基于视频图像的人数统计系统存在的一大难题是,无法有效地分割粘连人群,严重影响人数统计的精度．一种基于距离变换和分水岭相结合的算法,用以提取行人头部的位置信息．实验证明,该算法可以准确地分割出粘连人群的个体,从而实现精确的人数统计．     

Teachers’ Journeys: A Case of Teachers of Learners Aged Five to Six

South Africa’s esteem is low with regard to current learner achievement in mathematics. Results from international studies, such as TIMMS and SACMEQ, continuously indicate that South African learners perform below international benchmarks in mathematics. Research and evaluation studies assert that teacher practices and poor early mathematics stimulation influence this state of affairs. Hence, this article reports on a study that explored the developmental progression of Grade R teachers’ mathematics knowledge and general knowledge of teaching participating in a professional development intervention. In this article I report on data collected after a two-day workshop conducted with the teachers. The video recordings of 14 teachers’ self-selected lessons were collected and transcribed, using a lesson observation tool, and analysed by means of thematic analysis. The findings indicated that teachers’ knowledge of number sense forms a strong foundation for improving the quality instruction of number knowledge. The first step seen to be taken by these teachers to engage the learners was the question and answer approach. The lessons of those who tried to let learners engage lacked structure and resulted in chaos. Demonstration and drill were used to develop the learners’ content knowledge. The teachers’ practices were inadequate as far as developing conceptual understanding is concerned; and their classroom management skills were not sufficiently developed to include all learners in their mediation. In instances where all the learners participated, the teacher directed the participation and did not allow for learner-to-learner engagement. It is crucial to note that they showed potential for growth and willingness to learn despite the limited or minimal the training they received.     

电压数字化测量的量化误差

模数转换有反馈比较式和积分式．但是,Ａ／Ｄ转换的量化误差不都是±ＬＳＢ／２．双积分转换的量化误差ΔＵＮ来源于对时钟脉冲的计数,且为－１≤ΔＵＮ≤１,已为实验所证实     

场地竞走和长距离跑几种记圈方法的比较研究

综合运用各类调查法、文献资料法、观察统计法和分析比较法对场地竞走和长距离跑几种记圈方法从科学性和实用性方面进行研究。研究结果认为,单一的记圈方法有缺点和优点,综合法集中了各种单一方法的优点,又对各种单一方法的缺点起到了互辅作用。建议在比赛中采用综合法比较好。     

Effectiveness of the Additional Early Mathematics program for teaching children early mathematics

This paper presents the results of a study of the development of early mathematical competence among young poor arithmetic achievers in the 4–7 year age group. Research has shown that arithmetic difficulties later in life can be explained by an insufficient development of early mathematical competence: i.e. different aspects of early mathematical competence. The different aspects of early mathematical competence are derived from cognitive psychology and from a didactical point of view with an emphasis on (the various phases of) counting. The Piagetian operations (seriation, correspondence and classification) are used, however, as much as possible embedded in a counting context.After selection by way of an early mathematical competence test, children with a score below a criterium are presented with an additional program. This program consists of activities, embedded in real (daily) life themes, in which attention is paid to the different aspects of early mathematical competence. The program is given to the children with a guiding or a structuring instruction form. The results of the study show that it is possible to stimulate the development of early mathematical competence among young poor arithmetic achievers. The way in which instruction is offered has no influence on achievement.     

对一道化学平衡计算题的讨论

通过对《无机及分析化学》教材中一道化学平衡计算题所给出数据进行的分析讨论。总结出化学平衡常数与温度之间的定量关系，计算出在不同温度下CO转化为CO2时反应平衡常数值，并与其他一些教材上不同温度时的平衡常数值加以比较对照，可作为今后计算化学平衡常数的修正参考。     

一类概率问题的逻辑思考

采用“分组分类取元法”研究了抽取类“古典概率模型”中的重复计算问题的解决办法。