结合储层CO_(2)埋存技术,自主搭建了地层温度压力条件下CO_(2)埋存实验装置,开展了多介质辅助CO_(2)埋存实验研究。研究结果表明,乙醇-KOH体系能够有效进行CO_(2)矿化埋存,其中96%乙醇+3 g KOH 500 mL溶液捕集CO_(2)能力最强,是最佳的CO...结合储层CO_(2)埋存技术,自主搭建了地层温度压力条件下CO_(2)埋存实验装置,开展了多介质辅助CO_(2)埋存实验研究。研究结果表明,乙醇-KOH体系能够有效进行CO_(2)矿化埋存,其中96%乙醇+3 g KOH 500 mL溶液捕集CO_(2)能力最强,是最佳的CO_(2)矿化埋存溶液配比。经CO_(2)矿化埋存后,低渗透岩心孔隙度平均降低7.07%,孔隙度变化率与孔隙度呈正相关关系,渗透率平均降低16.01%。因此,96%乙醇+3 g KOH能够加速CO_(2)在储层中的CO_(2)沉淀过程,缩短CO_(2)在储层中的矿化埋存时间。该研究可重复性、准确性和可扩展性较强,能够激发学生自主设计实验的积极性及创新意识,培养学生的独立思考能力,有利于学生将理论知识与实际工程问题相结合,实现科研能力与创新能力的相互促进。展开更多
Monitoring alpine wetland degradation on the Qinghai-Tibet Plateau is crucial for understanding the responses to and resilience against climate change but has been challenging due to limited images in cloudy high-moun...Monitoring alpine wetland degradation on the Qinghai-Tibet Plateau is crucial for understanding the responses to and resilience against climate change but has been challenging due to limited images in cloudy high-mountain areas.Based on 3 elements,spectral-temporal characterization,classification,and degradation detection for wetland covers,this study proposes a continuous classification and degradation detection algorithm for alpine wetlands(AW-CCD).This algorithm relates to water-related landscape change processes,including multiscenario detection of snowmelt,lake,and river shrinkage and the transition of a swampy meadow to an alpine meadow with decreased soil wetness.AW-CCD uses the spectral-temporal index features to classify wetlands on an annual basis and then capture wetland degradation processes to combine long-time-series inter-annual parameters and seasonal soil wetness.This study detected snow cover from clouds based on the Landsat Quality Assessment band and spectral changes during snow-bare rock transition.Through the meadow spectral ratio vegetation index and seasonal soil wetness frequency across years,swampy and alpine meadow dynamics are tracked by wetness loss and increasing grass signal.By effectively characterizing multiple surface changes through spectral-temporal analysis,AW-CCD provides annual wetland mapping and monitoring metrics for multiscenario degradation.Results show an improvement in snow and meadow mapping accuracy by 5%and 3%,respectively,with a mapping accuracy of 94.9%in the Maidika Wetland in 2022.Spatial-temporal patterns demonstrated multiscenario degradation during 2 decades,with snow and river areas decreasing by 5.04%and 16.74%,respectively,and 3.23%of swampy meadows transitioning to alpine meadows.Degradation was most pronounced before 2009,followed by stability until 2015 and renewed degradation thereafter.This study highlights the effectiveness of AW-CCD in capturing the multiscenario responses of alpine wetlands to climatic changes on the Qinghai-Tibet Plateau.展开更多
New immigrant groups have become a focus of American academia since the 1960s,and have attracted attention from economics,sociology,history and other disciplines.In China,under the impact of the new social history and...New immigrant groups have become a focus of American academia since the 1960s,and have attracted attention from economics,sociology,history and other disciplines.In China,under the impact of the new social history and history cultural turn,those research studies of the new immigrant groups usually focus on the cultural and psychological perspective of immigrants,however,the studies on the impact of immigration on the U.S.economy are still rare.The Impact of Immigration on American Labor Market and Economy,1965-2005 is a significant interdisciplinary historical work and addresses notable gaps in the study of immigration in China.展开更多
文摘结合储层CO_(2)埋存技术,自主搭建了地层温度压力条件下CO_(2)埋存实验装置,开展了多介质辅助CO_(2)埋存实验研究。研究结果表明,乙醇-KOH体系能够有效进行CO_(2)矿化埋存,其中96%乙醇+3 g KOH 500 mL溶液捕集CO_(2)能力最强,是最佳的CO_(2)矿化埋存溶液配比。经CO_(2)矿化埋存后,低渗透岩心孔隙度平均降低7.07%,孔隙度变化率与孔隙度呈正相关关系,渗透率平均降低16.01%。因此,96%乙醇+3 g KOH能够加速CO_(2)在储层中的CO_(2)沉淀过程,缩短CO_(2)在储层中的矿化埋存时间。该研究可重复性、准确性和可扩展性较强,能够激发学生自主设计实验的积极性及创新意识,培养学生的独立思考能力,有利于学生将理论知识与实际工程问题相结合,实现科研能力与创新能力的相互促进。
基金supported by the National Natural Science Foundation of China(grant number 42071399)the Second Tibetan Plateau Scientific Expedition and Research,(grant number 2019QZKK060)+1 种基金the Humanities and Social Science Fund of Ministry of Education of China(grant number 23YJAZH019)the Science and Technology Plan Projects of Tibet Autonomous Region(grant number XZ202301ZY0021G).
文摘Monitoring alpine wetland degradation on the Qinghai-Tibet Plateau is crucial for understanding the responses to and resilience against climate change but has been challenging due to limited images in cloudy high-mountain areas.Based on 3 elements,spectral-temporal characterization,classification,and degradation detection for wetland covers,this study proposes a continuous classification and degradation detection algorithm for alpine wetlands(AW-CCD).This algorithm relates to water-related landscape change processes,including multiscenario detection of snowmelt,lake,and river shrinkage and the transition of a swampy meadow to an alpine meadow with decreased soil wetness.AW-CCD uses the spectral-temporal index features to classify wetlands on an annual basis and then capture wetland degradation processes to combine long-time-series inter-annual parameters and seasonal soil wetness.This study detected snow cover from clouds based on the Landsat Quality Assessment band and spectral changes during snow-bare rock transition.Through the meadow spectral ratio vegetation index and seasonal soil wetness frequency across years,swampy and alpine meadow dynamics are tracked by wetness loss and increasing grass signal.By effectively characterizing multiple surface changes through spectral-temporal analysis,AW-CCD provides annual wetland mapping and monitoring metrics for multiscenario degradation.Results show an improvement in snow and meadow mapping accuracy by 5%and 3%,respectively,with a mapping accuracy of 94.9%in the Maidika Wetland in 2022.Spatial-temporal patterns demonstrated multiscenario degradation during 2 decades,with snow and river areas decreasing by 5.04%and 16.74%,respectively,and 3.23%of swampy meadows transitioning to alpine meadows.Degradation was most pronounced before 2009,followed by stability until 2015 and renewed degradation thereafter.This study highlights the effectiveness of AW-CCD in capturing the multiscenario responses of alpine wetlands to climatic changes on the Qinghai-Tibet Plateau.
文摘New immigrant groups have become a focus of American academia since the 1960s,and have attracted attention from economics,sociology,history and other disciplines.In China,under the impact of the new social history and history cultural turn,those research studies of the new immigrant groups usually focus on the cultural and psychological perspective of immigrants,however,the studies on the impact of immigration on the U.S.economy are still rare.The Impact of Immigration on American Labor Market and Economy,1965-2005 is a significant interdisciplinary historical work and addresses notable gaps in the study of immigration in China.
