小学数学实践活动的特点

实践活动课程以综合、开放、灵活多变的教学内容与形式,改变了传统教学中重学科知识而轻综合应用、重抽象思维而轻实践技能等不良倾向,有利于学生主体性的发挥。《数学课程标准》(实验稿)明确地将“实践与综合应用”作为与“数与代数”、“空间与图形”、“统计与概率”相并列的学习领域,其目的是增强学生应用数学的意识,提高学生的实践能力,为今后更有效地进行高水平的实践活动打好基础。本文着重谈谈小学数学实践活动的特点。数学实践活动是学生在教师引导下,在已有知识体验的基础上,从所熟悉的现实生活中发现、选择和确定问题,主动应用知…     

Large‐scale diagnostic assessment: comparison of eighth graders’ mathematics performance in the United States,Singapore and Israel

A diagnostic model for large‐scale assessment was applied to TIMSS data to compare mathematics performance of eighth graders from three countries—the US, Singapore, and Israel. Compared were attribute mastery probabilities for content, skills and cognitive processes underlying students’ performance on the 1999 TIMSS‐R mathematics test. Also compared were the proportions of students from the three samples in each of eight hierarchically ordered clusters of knowledge states. The results indicated significant differences in favour of the Singaporean sample on most attributes underlying the test. The results were discussed in light of the cultural context of education in the respective countries.     

两种方式下经营风险的对比分析

在假定：1)销售量为随机变量；2)销售增长率为随机变量这两种方式下，研究经营风险的变化．结果表明：降低保本销售量、提高销售量和销售稳定性可以有效地降低经营风险．     

标杆管理:提高行政效率的过程

在当代中国各级行政机关中,行政效率低下这个问题在不同程度上普遍存在.本文试图通过分析效率低下的原因,相应提出在行政部门引进标杆管理的对策,分析标杆管理的涵义及其实践意义,并就在实行标杆管理时应该注意的一系列问题提出了一些看法,以期使行政效率得以提高.     

Imaging Analysis by Means of Fractional Fourier Transform

Starting from the diffraction imaging process,we have discussed the relationship between optical imaging system and tional Fourier transform,and proposed a specific system which can form an inverse amplified image of input function.     

NFOA-BP融合算法及其在焚烧炉温度控制中的应用

污泥焚烧炉温度控制过程中,由于投入污泥块热值不均以及外界环境干扰,传统的PID控制不能快速稳定地将炉温控制在所需范围内。为适应环境变化,实现更高效的炉温控制,提出一种基于NFOA-BP算法的污泥焚烧温度控制方法。该方法将改进型果蝇算法与BP神经网络结合,通过NFOA算法优化神经网络的初始权重和阈值,进而提高神经网络的全局搜索能力。将NFOA-BP算法应用于污泥焚烧炉温度控制系统,与传统PID温度控制系统进行仿真对比实验。结果表明该系统响应平稳、迅速,超调减小,正确率达到95%以上,比传统PID调节方法提高5%左右。     

Effects of glucose and gibberellic acid on glucosinolate content and antioxidant properties of Chinese kale sprouts

Glucosinolates, anthocyanins, total phenols, and vitamin C, as well as antioxidant capacity, were investigated in Chinese kale sprouts treated with both glucose and gibberellic acid (GA₃). The combination of 3% (0.03 g/ml) glucose and 5 μol/L GA₃ treatment was effective in increasing glucosinolate content while glucose or GA3 treatment alone did not influence significantly almost all individual glucosinolates or total glucosinolates. The total phenolic content and antioxidant activity of Chinese kale sprouts were enhanced by combined treatment with glucose and GA₃, which could be useful in improving the main health-promoting compounds and antioxidant activity in Chinese kale sprouts.     

实施文档一体化管理推进高校档案信息化建设

高校档案的信息化管理是技术发展的要求,文档一体化管理可以提高高校档案建设的信息化水平。应当采取建立健全档案管理规范、系统规划档案管理软件、提高办公自动化水平、明确文档一体化管理流程、合理选择文档一体化管理系统等措施,来实施文档一体化管理以推进高校档案信息化建设。     

市地科技信息机构网络建设之浅见

针对国内外信息网络建设的发展趋势和临沂市科技信息网络建设的现状，以及市地科技信息机构网络建设中存在的问题，认为市地科技信总机构的网络建设应加大经费投入，加强科技网络信息资源建设、宣传力度和人才队伍建设，采取低价策略，实施信息服务。     

西部大开发中的四川省农业结构调整

四川作为一个传统的农业大省，其农业结构不合理。本简要阐述了四川省的农生结构的调整思路、方法以及在结构调整中应注意的问题。