Results 21 to 30 of about 9,906 (122)
Synthesizing Empirical Research on Learner Metacognition in Second Language Writing
ABSTRACT Despite considerable research interest in learner metacognition in second language (L2) writing, there is not yet a review that synthesizes the existing empirical findings and discusses their implications. To fill the void, this systematic review synthesized 39 empirical studies on learner metacognition in L2 writing and examined their salient
Chen Li, Icy Lee, Zhicheng Mao
wiley +1 more source
探索三生空间演变的生态环境效应及驱动因素, 可为国土空间优化及生态环境保护的实施提供科学依据。以松花江流域哈尔滨段为例, 运用网格单元法, 结合生态环境质量指数、全局自相关模型、核密度函数等方法分析1986—2016年三生空间演变的生态环境效应时空分异特征, 并借助地理探测器模型揭示生态环境质量空间分异的驱动因素。结果表明: (1)1986—2016年研究区三生空间以生产空间为主, 其中农业生产空间和林业生态空间所占比重最大, 呈现生产空间和生态空间减少、生活空间增加的变化趋势; (2 ...
盖兆雪 +3 more
doaj
Spatially Downscaling of Future Food Demand for Policy Planning
ABSTRACT Understanding the subnational dynamics of food demand, while accounting for the evolution of the agrifood system at the global level, remains a challenge for designing food policy to ensure food security. To link global agrifood systems with subnational food policy planning, we downscale per capita food demand for 62 food commodities at the ...
Chun Song +3 more
wiley +1 more source
以太湖典型地区宜兴市大浦镇湖滨公路以东50hm2蔬菜地为研究对象,网格法(50m×50m)采集表层(0~20cm)土壤156个,采用传统统计和地统计学相结合的方法,研究了土壤氮素及pH的空间变异特征。结果表明:土壤全N和NH4 -N有明显的空间变异结构。全N符合指数模型,NH4 -N变异函数符合线性模型,全N有强烈的空间相关性,NH4 -N有中等的空间相关性。土壤pH普遍偏低,pH变异函数符合指数模型,在小范围内具有强烈的空间相关性。土壤碱解N与pH呈显著负相关,表明施用氮肥是导致土壤pH下降的主要原因。
王彩绒 吕家珑 胡正义 杨林章 高义明
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ABSTRACT Water governance has emerged as a critical analytical framework for addressing the complexity of socioecological water systems in contexts of increasing climate vulnerability and anthropogenic pressure. This study presents a systematic review and bibliometric analysis of 50 scientific articles indexed on water governance published between 2018
Roger Pichis‐García +1 more
wiley +1 more source
为研究小流域尺度下土壤有机碳的变异规律,运用地统计学方法对研究区0—10,10—20,20—40 cm土壤有机碳含量的空间变异性进行了研究。结果表明:流域内不同土层有机碳含量属于中等强度变异,具有强烈的空间自相关性;土壤有机碳含量在0,135°方向上空间变异程度明显,空间分布的各向异性显著;克里格插值结果显示流域内阴坡土壤有机碳含量明显高于阳坡,高海拔区域土壤有机碳含量高于低海拔区域;不同土层间,土壤有机碳含量均表现为青海云杉 > 灌丛 > 草地,表明不同植被类型对土壤有机碳含量和分布有着重要影响 ...
芦倩, 李毅, 刘贤德, 赵维俊
doaj
ABSTRACT In conventional piezoceramics, the coordinated change between the dielectric constant (εr) and the piezoelectric charge constant (d33) usually limits the piezoelectric voltage constant g33 (g33 = d33/εr), a critical figure of merit for piezoelectric sensors.
Xiaoying Feng +7 more
wiley +1 more source
In this study we analyze the role of phylogeny, environment, and community structure on sociality. Using structural equation modeling (SEM) we aim to quantify the direct and indirect impacts of variables on behaviors including social grouping, reproduction, and space use among Carnivora species.
Jessica Ward +3 more
wiley +1 more source
探讨了研究土壤空间变异所必须考虑的相关尺度问题,立足国内,兼顾国外,介绍了近年来土壤特性空间变异性几种研究方法及应用的研究动态,讨论了空间变异研究方法的各自特点及今后研究和应用的发展趋势,展望了空间变异性研究在土壤科学、水土保持与水资源系统中的应用前景。
李毅 王文焰 王全九
doaj
喀斯特坡面伴随有大量直径>25 cm的块石出露,为探明块石出露对土壤理化性质的影响,以坡面4个块石出露的农地和1个对照组为研究对象,分析土壤理化性质空间变异特征。结果表明:(1)在块石出露的农地中,土壤容重、黏粒、粉粒和砂粒的变化分别为0.87~1.42 g/cm3,25.70%~41.80%,38.11%~51.60%,13.76%~27.54%,土壤容重、黏粒和粉粒空间变异性均为弱且高于对照组,砂粒空间变异性为中等且低于对照组。(2)土壤全碳、全氮、全磷、全钾变化分别为9.82~23.13,0.94~
陈磊, 张卓栋, 李业桐
doaj

