Laboratory swelling deformation tests were carried out on compacted GMZ bentonite and bentonite-sand mixtures with 30%and 50%sand contents at 20,40,60,80 and 90°C with infiltration of distilled water.Influence of...Laboratory swelling deformation tests were carried out on compacted GMZ bentonite and bentonite-sand mixtures with 30%and 50%sand contents at 20,40,60,80 and 90°C with infiltration of distilled water.Influence of temperature,initial dry density,and quartz sand content on the swelling deformation characteristic of compacted bentonite specimens was analyzed.Results indicate that the swelling deformation process is accelerated,and the maximum swelling strain increases with the increase in temperature,while the maximum swelling strain tends to be stable with increasing temperature.In the meantime,the temperature effects depend on both of the sand content and the initial dry density of the specimens,the increases of the maximum swelling strain induced by increasing temperature,are enlarged by increasing sand content or initial dry density.Adding of quartz sand to bentonite not only influences the integrality of bentonite specimen,but also increase the microfissuring in area on quartz sand,which are advantageous to the heat transfer,leading to the increase of swelling deformation capacity of the specimen.The increased dry density relatively increases the bentonite content,so the swelling property is enhanced.However,no change on mineral composition of bentonite was observed when temperature was changed from 20 to 90°C.展开更多
湿地植物是湿地生态系统的核心组成部分,为探明湿地植物研究现状与前沿趋势,利用CiteSpace软件对2002年1月~2022年10月Web of Science数据库中湿地植物相关文献进行全面梳理。结果表明:(1)相关研究经历了初步探索阶段-波动发展期-快速...湿地植物是湿地生态系统的核心组成部分,为探明湿地植物研究现状与前沿趋势,利用CiteSpace软件对2002年1月~2022年10月Web of Science数据库中湿地植物相关文献进行全面梳理。结果表明:(1)相关研究经历了初步探索阶段-波动发展期-快速发展期3个阶段。(2)大尺度湿地植物动态监测、湿地植物修复方法的创新、沿海湿地植物对气候变化的响应是当前研究的前沿热点。(3)通过文献共被引的聚类分析得到21个聚类,根据时间将其分为三个阶段,前期主要研究湿地生态环境对湿地植物生长的影响;中期主要探讨湿地植物对湿地生态环境修复的作用;当前主要研究的方向是湿地植物在全球变化背景下的贡献,以及对全球变化的响应机制及其适应策略。(4)从研究力量看,美国与中国的发文量名列前茅。展开更多
基金Project (41402260) supported by the National Natural Science Foundation of ChinaProject (20136101120006) supported by the Research Fund for the Doctoral Program of Higher Education,China
文摘Laboratory swelling deformation tests were carried out on compacted GMZ bentonite and bentonite-sand mixtures with 30%and 50%sand contents at 20,40,60,80 and 90°C with infiltration of distilled water.Influence of temperature,initial dry density,and quartz sand content on the swelling deformation characteristic of compacted bentonite specimens was analyzed.Results indicate that the swelling deformation process is accelerated,and the maximum swelling strain increases with the increase in temperature,while the maximum swelling strain tends to be stable with increasing temperature.In the meantime,the temperature effects depend on both of the sand content and the initial dry density of the specimens,the increases of the maximum swelling strain induced by increasing temperature,are enlarged by increasing sand content or initial dry density.Adding of quartz sand to bentonite not only influences the integrality of bentonite specimen,but also increase the microfissuring in area on quartz sand,which are advantageous to the heat transfer,leading to the increase of swelling deformation capacity of the specimen.The increased dry density relatively increases the bentonite content,so the swelling property is enhanced.However,no change on mineral composition of bentonite was observed when temperature was changed from 20 to 90°C.
文摘湿地植物是湿地生态系统的核心组成部分,为探明湿地植物研究现状与前沿趋势,利用CiteSpace软件对2002年1月~2022年10月Web of Science数据库中湿地植物相关文献进行全面梳理。结果表明:(1)相关研究经历了初步探索阶段-波动发展期-快速发展期3个阶段。(2)大尺度湿地植物动态监测、湿地植物修复方法的创新、沿海湿地植物对气候变化的响应是当前研究的前沿热点。(3)通过文献共被引的聚类分析得到21个聚类,根据时间将其分为三个阶段,前期主要研究湿地生态环境对湿地植物生长的影响;中期主要探讨湿地植物对湿地生态环境修复的作用;当前主要研究的方向是湿地植物在全球变化背景下的贡献,以及对全球变化的响应机制及其适应策略。(4)从研究力量看,美国与中国的发文量名列前茅。
