期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
2012PISA数学测试与上海初中数学学业水平考试的比较研究——以“变化与关系”这一内容的试题为例 被引量:8
1
作者 徐庆惠 《外国中小学教育》 CSSCI 北大核心 2014年第4期15-20,42,共7页
2012年PISA测试的主项是数学,其目标是评估数学素养,并对数学素养作了界定。同样在上海的中小学课程标准中对数学素养也作了界定。本文结合2012PISA测试和近几年上海市初中学业水平考试在"变化与关系"这一内容主题方面的试题... 2012年PISA测试的主项是数学,其目标是评估数学素养,并对数学素养作了界定。同样在上海的中小学课程标准中对数学素养也作了界定。本文结合2012PISA测试和近几年上海市初中学业水平考试在"变化与关系"这一内容主题方面的试题情况进行分析、比较与思考。 展开更多
关键词 PISA测试 变化与关系 数学素养
下载PDF
Drought effects on the plasticity in vessel traits of two endemic Magnolia species in the tropical montane cloud forests of eastern Mexico 被引量:1
2
作者 Ernesto Chanes Rodríguez-Ramírez José Antonio Vázquez-García +2 位作者 Ignacio García-González Othón Alcántara-Ayala Isolda Luna-Vega 《Journal of Plant Ecology》 SCIE CSCD 2020年第3期331-340,共10页
Aims We aimed to evaluate how climatic fluctuations influence the plasticity of anatomical vessel traits and the width of annual tree-rings of two relict-endemic Mexican Magnolia species.Notwithstanding,few studies ha... Aims We aimed to evaluate how climatic fluctuations influence the plasticity of anatomical vessel traits and the width of annual tree-rings of two relict-endemic Mexican Magnolia species.Notwithstanding,few studies have assessed the drought effect on vessel traits in tropical montane cloud trees of eastern Mexico.Methods Through digital images of growth rings,we assessed the tree radial growth rate,age of the trees and plasticity in vessel traits regarding climatic fluctuations of the Mexican Magnolia species studied.We compared vessel density,hydraulic diameter and percentage of conductive area in drought years(DY)and non-drought years(NDY)in two Mexican Magnolia species.Important Findings For the first time,the plasticity that occurs in porous wood vessel traits to long-term climatic fluctuations was analysed for two endangered Magnolia species(Magnolia vovidesii and M.schiedeana)from two tropical montane cloud forests in Mexico.We found that temperature and precipitation were strongly associated with differences in tree-ring width when DY and NDY were compared.Our analyses revealed that a high plasticity in vessel anatomy of diffuse-porous wood was related to temperature and/or water availability for both Magnolia species studied.We concluded that anatomical adaptations to DY resulted in a substantial reduction in vessel traits when compared with NDY,and that the plastic adaptations played an essential role in water transport and safety for the survival of the studied species during stressful long periods. 展开更多
关键词 ADAPTABILITY climate variability drought–growth relationship Magnolia schiedeana Magnolia vovidesii quantitative wood anatomy
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部