基于目标矩阵的大单元教学教材分析——以“三江源生态脆弱区的综合治理”为例

大单元教学需要跨单元选取教材内容并辅以主题教育资源,提取的大概念之间关系复杂,需要教师在教学前厘清概念间的逻辑关系。本文遵循学习进阶理论,以“三江源生态脆弱区的综合治理”为案例,依据地理课程标准和教材提取大概念“人地协调观是人们对人类与地理环境之间关系秉持的正确的价值观”及其次级概念,运用目标矩阵分析法梳理概念逻辑层次关系,形成可视的多阶的概念关系图,帮助教师形成清晰的教学逻辑,优化大单元课堂教学。

电网脆弱性预警指标对比分析及应用

阐述了电网的脆弱性及脆弱源等概念,定义了现有几类脆弱性预警指标,分析各指标或指标体系的特点,对所述指标进行对比分析,得出了不同指标的适用对象以及各自的优缺点。以配电网低电压脆弱性为例,进行了仿真分析。

电网脆弱性评估方法

电力系统脆弱性是近年来的热点研究问题之一,经过众多科研人员长时间的努力,取得了大量的研究成果。综述了电网脆弱性的评估现状,根据分析角度的不同和脆弱源不同,电网脆弱性评估方法也有差异。对以往典型脆弱性评估方法和脆弱性指标进行了总结和评述,所参阅的文献也力图反映出该领域的研究概貌和最新动向,并提出了完善脆弱性评估方法的建议。

Vulnerability assessment of water resources to climate change in Chinese cities

Climate change is an inevitable trend,which challenges security of water resources in China,especially in cities.Assessing vulnerability of water resource to climate change in cities has important role for policy makers. The paper constructs a vulnerability function,including exposure,sensitivity and adaptive capacity,according to the vulnerability concept proposed by IPCC,establishes an assessment indicators system of water resources to climate change in cities,and analyzes vulnerability features of Chinese cites based on 655 cities＇data in 2006.The vulnerability assessment results show that there are distinctive differences among all the cities,between east,central and west cities,between ordinary,big and mega cities,while there is no statistical significant difference between north and south cities.Based on the research,the paper suggests that strategic emphasis should focus on the central cities and ordinary cities