法国几何学习空间模型(Geometric Work Space),最早由巴黎狄德罗大学的Alain Kuzniak提出,用于研究几何学习过程,之后拓展到一般数学领域,形成其他模型,如MWS(Mathematical Working Space)模型.该模型由认识论和认知两个层面,以及图形(...法国几何学习空间模型(Geometric Work Space),最早由巴黎狄德罗大学的Alain Kuzniak提出,用于研究几何学习过程,之后拓展到一般数学领域,形成其他模型,如MWS(Mathematical Working Space)模型.该模型由认识论和认知两个层面,以及图形(符号)、工具、推论三种成因组成.通过三种成因的双向转化,以及两两成因形成的垂直平面连接起两个层面,由此描述几何/数学学习的复杂动态过程.本文通过文献梳理了GWS模型的产生与发展,总结了国外对该模型的应用与实践,最后分析了该模型中国化的应用思路.展开更多
Clarifying the mechanisms through which coal mining affects groundwater storage(GWS)variations is crucial for water resource conservation and sustainable development.The Ordos Mining Region in China,a key energy base ...Clarifying the mechanisms through which coal mining affects groundwater storage(GWS)variations is crucial for water resource conservation and sustainable development.The Ordos Mining Region in China,a key energy base in China with significant strategic importance,has undergone intensive coal mining activities that have substantially disrupted regional groundwater circulation.This study integrated data from the Gravity Recovery and Climate Experiment Satellite(GRACE)and Famine Early Warning Systems Network(FEWS NET)Land Data Assimilation System(FLDAS)models,combined with weighted downscaling methodology and water balance principles,to reconstruct high-resolution(0.01°)terrestrial water storage(TWS)and GWS changes in the Ordos Mining Region,China from April 2002 to December 2021.The accuracy of GWS variations were validated through pumping test measurements.Subsequently,Geodetector analysis was implemented to quantify the contributions of natural and anthropogenic factors to groundwater storage dynamics.Key findings include:1)TWS in the study area showed a fluctuating but overall decreasing trend,with a total reduction of 8901.11 mm during study period.The most significant annual decrease occurred in 2021,reaching 1696.77 mm.2)GWS exhibited an accelerated decline,with an average annual change rate of 44.35 mm/yr,totaling a decrease of 887.05 mm.The lowest annual groundwater storage level was recorded in 2020,reaching 185.69 mm.3)Precipitation(PRE)contributed the most to GWS variation(q=0.52),followed by coal mining water consumption(MWS)(q=0.41).The interaction between PRE and MWS exhibited a nonlinear enhancement effect on GWS changes(0.54).The synergistic effect of natural hydrological factors has a great influence on the change of GWS,but coal mining water consumption will continue to reduce GWS.These findings provide critical references for the management and regulation of groundwater resource in mining regions.展开更多
Many experiments have supported the contact models,such as the GW and MB models,but the majority of previous validations have been performed under light loads,resulting in a linear relationship between normal force an...Many experiments have supported the contact models,such as the GW and MB models,but the majority of previous validations have been performed under light loads,resulting in a linear relationship between normal force and contact area.However,the real contact area fraction should never equal one;there must be a limit smaller than the apparent area,implying that the real contact area cannot increase linearly indefinitely.In this paper,the real contact area between two polymethylmethacrylate(PMMA)blocks under heavy load is measured using the total reflection method,and the contact area is analyzed using the image processing method.The results show that the real contact area increases with normal load linearly in light loads but non-linearly in heavy loads;the number of contact spots increases with load linearly in light loads but also non-linearly in heavy loads,synchronous with the change in the real contact area.The GW,MB,and Zhao,Maietta,and Chang(ZMC)models were used to predict the experiment results,but none of them predicted the non-linear stage.A revised GW model based on the bulk deformation hypothesis performs better in predicting the non-linear stage.The study’s findings can be applied to PMMA or other similar materials,and they can serve as a useful reference for future research on the contact mechanisms of other materials.展开更多
Groundwater(GW)is a vital freshwater resource extensively exploited in the Vietnamese Mekong Delta,especially during the dry seasons.This study applies the Cumulative Rainfall Departure(CRD)method to estimate GW recha...Groundwater(GW)is a vital freshwater resource extensively exploited in the Vietnamese Mekong Delta,especially during the dry seasons.This study applies the Cumulative Rainfall Departure(CRD)method to estimate GW recharge in deep aquifers of Soc Trang Province,located in the southernmost region of Vietnam under a tropical climate.Monthly rainfall records and daily GW level data of the aquifers from 2010 to 2020 were used.The Pearson correlation between observed GW levels and CDR model GW levels exceeds 0.995,indicating high model accuracy.The analysis reveals that the CRD fractions for the Upper Pleistocene(qp3),Middle Pleistocene(qp2-3),Lower Pleistocene(qp1),and Middle Pliocene(n22)aquifers are 0.085%,0.104%,0.130%,and 0.180%,respectively,totaling approximately 0.5%of the annual rainfall.This corresponds to an annual GW recharge of 25.86 million m3,or 70,850 m3/day,equivalent to 70%of the current GW abstraction rate of 101,000 m3/day.Given the critical role of GW as a freshwater source,implementing an enhanced GW recharge program using surface water and rainwater is strongly recommended.Additionally,the analysis suggests that the decline in GW levels due to abstraction corresponds to 0.85 times the mean annual precipitation,a finding that warrants further investigation.展开更多
文摘法国几何学习空间模型(Geometric Work Space),最早由巴黎狄德罗大学的Alain Kuzniak提出,用于研究几何学习过程,之后拓展到一般数学领域,形成其他模型,如MWS(Mathematical Working Space)模型.该模型由认识论和认知两个层面,以及图形(符号)、工具、推论三种成因组成.通过三种成因的双向转化,以及两两成因形成的垂直平面连接起两个层面,由此描述几何/数学学习的复杂动态过程.本文通过文献梳理了GWS模型的产生与发展,总结了国外对该模型的应用与实践,最后分析了该模型中国化的应用思路.
基金Under the National Key R&D Program Key Project(No.2021YFC3201201)National Natural Science Foundation of China(No.52360032)+2 种基金Basic Scientific Research Business Fee Project of Colleges And Universities Directly Under the Inner Mongolia Autonomous Region(No.JBYYWF2022001)Development Plan of Innovation Team of Colleges And Universities in Inner Mongolia Autonomous Region(No.NMGIRT2313)the Innovation Team of‘Grassland Talents’。
文摘Clarifying the mechanisms through which coal mining affects groundwater storage(GWS)variations is crucial for water resource conservation and sustainable development.The Ordos Mining Region in China,a key energy base in China with significant strategic importance,has undergone intensive coal mining activities that have substantially disrupted regional groundwater circulation.This study integrated data from the Gravity Recovery and Climate Experiment Satellite(GRACE)and Famine Early Warning Systems Network(FEWS NET)Land Data Assimilation System(FLDAS)models,combined with weighted downscaling methodology and water balance principles,to reconstruct high-resolution(0.01°)terrestrial water storage(TWS)and GWS changes in the Ordos Mining Region,China from April 2002 to December 2021.The accuracy of GWS variations were validated through pumping test measurements.Subsequently,Geodetector analysis was implemented to quantify the contributions of natural and anthropogenic factors to groundwater storage dynamics.Key findings include:1)TWS in the study area showed a fluctuating but overall decreasing trend,with a total reduction of 8901.11 mm during study period.The most significant annual decrease occurred in 2021,reaching 1696.77 mm.2)GWS exhibited an accelerated decline,with an average annual change rate of 44.35 mm/yr,totaling a decrease of 887.05 mm.The lowest annual groundwater storage level was recorded in 2020,reaching 185.69 mm.3)Precipitation(PRE)contributed the most to GWS variation(q=0.52),followed by coal mining water consumption(MWS)(q=0.41).The interaction between PRE and MWS exhibited a nonlinear enhancement effect on GWS changes(0.54).The synergistic effect of natural hydrological factors has a great influence on the change of GWS,but coal mining water consumption will continue to reduce GWS.These findings provide critical references for the management and regulation of groundwater resource in mining regions.
基金Supported by National Natural Science Foundation of China(Grant No.11872033)Beijing Municipal Natural Science Foundation(Grant No.3172017)。
文摘Many experiments have supported the contact models,such as the GW and MB models,but the majority of previous validations have been performed under light loads,resulting in a linear relationship between normal force and contact area.However,the real contact area fraction should never equal one;there must be a limit smaller than the apparent area,implying that the real contact area cannot increase linearly indefinitely.In this paper,the real contact area between two polymethylmethacrylate(PMMA)blocks under heavy load is measured using the total reflection method,and the contact area is analyzed using the image processing method.The results show that the real contact area increases with normal load linearly in light loads but non-linearly in heavy loads;the number of contact spots increases with load linearly in light loads but also non-linearly in heavy loads,synchronous with the change in the real contact area.The GW,MB,and Zhao,Maietta,and Chang(ZMC)models were used to predict the experiment results,but none of them predicted the non-linear stage.A revised GW model based on the bulk deformation hypothesis performs better in predicting the non-linear stage.The study’s findings can be applied to PMMA or other similar materials,and they can serve as a useful reference for future research on the contact mechanisms of other materials.
基金completed as part of the Research project(CT.2022.01.MDA.02):"Research and evaluation of the role of the hydrogeological and engineering geological factors in the change of the flows and of the coastal area of the Hau River mouth in the southwest region of Vietnam",funded by the Vietnam Ministry of Education and Training.The GW monitoring data used in this study were sourced from BIGDATA,NAWAPI.
文摘Groundwater(GW)is a vital freshwater resource extensively exploited in the Vietnamese Mekong Delta,especially during the dry seasons.This study applies the Cumulative Rainfall Departure(CRD)method to estimate GW recharge in deep aquifers of Soc Trang Province,located in the southernmost region of Vietnam under a tropical climate.Monthly rainfall records and daily GW level data of the aquifers from 2010 to 2020 were used.The Pearson correlation between observed GW levels and CDR model GW levels exceeds 0.995,indicating high model accuracy.The analysis reveals that the CRD fractions for the Upper Pleistocene(qp3),Middle Pleistocene(qp2-3),Lower Pleistocene(qp1),and Middle Pliocene(n22)aquifers are 0.085%,0.104%,0.130%,and 0.180%,respectively,totaling approximately 0.5%of the annual rainfall.This corresponds to an annual GW recharge of 25.86 million m3,or 70,850 m3/day,equivalent to 70%of the current GW abstraction rate of 101,000 m3/day.Given the critical role of GW as a freshwater source,implementing an enhanced GW recharge program using surface water and rainwater is strongly recommended.Additionally,the analysis suggests that the decline in GW levels due to abstraction corresponds to 0.85 times the mean annual precipitation,a finding that warrants further investigation.
