Results 31 to 40 of about 9,777 (155)

Hydrochemical characteristics and water quality dynamic analysis of shallow groundwater in Huaibei Plain [PDF]

open access: yes
Shallow groundwater is the most important source of agricultural water supply in Huaibei Plain, and its water quality has attracted wide attention.
Chunfang ZHU   +7 more
core   +1 more source

Synthesizing Empirical Research on Learner Metacognition in Second Language Writing

open access: yesInternational Journal of Applied Linguistics, EarlyView.
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

湿地土壤养分的空间异质性研究方法构想

open access: yesShuitu Baochi Xuebao, 2001
湿地土壤养分是时空连续的变异体,不论尺度大小均具有高度的空间异质性.湿地土壤养分变量属于区域化变量,同时具有随机性和结构性,仅运用经典的Fister统计方法已经不能满足土壤空间异质性研究的需要.地统计学是近几十年发展起来的一门新的空间分析方法,其变异函数则适合于定量研究区域化变量空间结构变异特征,能够全面反映区域化变量的结构性.作者在前人的工作基础上意欲用地统计学的区域化变量理论和变异函数对湿地土壤养分的空间异质性进行定量研究,并对其研究方法进行了构想.#
白军红 余国营 张玉霞
doaj  

海表二氧化碳分压时间序列观测研究进展 [PDF]

open access: yes, 2013
根据时间序列观测特征首次分类总结了海表CO2分压时间序列观测现状,着重介绍了CO2监测浮标的建设和布放情况 ...
董旭
core  

Research progress on the application and development of the material point method in dynamic simulation of geological hazards [PDF]

open access: yes
Numerical simulation is commonly used to address large deformation geological disasters such as collapses, landslides, and debris flows. Accurately and efficiently simulating these issues has always been a challenge.
Bin LI   +4 more
core   +1 more source

Constructing Asymmetric Cu–OV–Mn Sites on MOFs‐Derived Cu‐MnOx Microspheres With Abundant Oxygen Vacancies for Enhanced Photothermal VOC Degradation

open access: yesRare Metals, Volume 45, Issue 5, May 2026.
ABSTRACT With the growing severity of volatile organic compounds (VOCs) pollution, metal‐organic frameworks (MOFs)‐derived materials offer a promising solution through efficient photothermal catalysis. In this paper, M‐MnOx (M = Cu, Ni, Co, Fe) catalysts derived from manganese‐based MOFs were successfully prepared by the sacrificial template method and
Yizhong Liao   +10 more
wiley   +1 more source

祁连山排露沟流域土壤有机碳空间变异性研究

open access: yesShuitu Baochi Xuebao, 2020
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  

Testing AnnAGNPS for water quality modelling in the typical sub-watersheds in Jiulong River watershed [PDF]

open access: yes, 2005
在中国东南丘陵山区一中尺度流域———九龙江流域选取4个土地利用方式不一的典型小流域,借助GIS和相关资料率定模型参数,并通过对2003年4月至9月各小流域出口降雨水质水量的同步监测,检验了连续分布式参数模型(AnnualizedAGriculturalNonPointSourceModel,AnnAGNPS)的适用性.研究结果表明,模型对于地表径流量的模拟能力好于对泥沙和营养盐的模拟,对总磷和泥沙输出的模拟结果表现出了较大的不确定性.
张珞平   +3 more
core  

Characteristics and Drivers of Spatial and Temporal Soil Erosion in Anshun City, Karst Region [PDF]

open access: yes
[Objective] To explore the spatial and temporal evolution of soil erosion in Anshun City, southwest karst region, as well as the main controlling factors of soil erosion, and to master the soil erosion situation in the region, in order to help the ...
LI Yuan, LIU Ziqi, WU Wenxian
core   +1 more source

Spatially Downscaling of Future Food Demand for Policy Planning

open access: yesWorld Food Policy, Volume 12, Issue 1, May 2026.
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

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