Three-dimensional(3D)graphene monoliths are a new carbon material,that has tremendous potential in the fields of energy conversion and storage.They can solve the limitations of two-dimensional(2D)graphene sheets,inclu...Three-dimensional(3D)graphene monoliths are a new carbon material,that has tremendous potential in the fields of energy conversion and storage.They can solve the limitations of two-dimensional(2D)graphene sheets,including interlayer restacking,high contact resistance,and insufficient pore accessibility.By constructing interconnected porous networks,3D graphenes not only retain the intrinsic advantages of 2D graphene sheets,such as high specific surface area,excellent electrical and thermal conductivities,good mechanical properties,and outstanding chemical stability,but also enable efficient mass transport of external fluid species.We summarize the fabrication methods for 3D graphenes,with a particular focus on their applications in energy-related systems.Techniques including chemical reduction assembly,chemical vapor deposition,3D printing,chemical blowing,and zinc-tiered pyrolysis have been developed to change their pore structure and elemental composition,and ways in which they can be integrated with functional components.In terms of energy conversion and storage,they have found broad use in buffering mechanical impacts,suppressing noise,photothermal conversion,electromagnetic shielding and absorption.They have also been used in electrochemical energy systems such as supercapacitors,secondary batteries,and electrocatalysis.By reviewing recent progress in structural design and new applications,we also discuss the problems these materials face,including scalable fabrication and precise pore structure control,and possible new applications.展开更多
土体水分迁移过程及其规律是岩土工程、地质工程等领域的重点研究内容之一,准确掌握土体含水率时空演化是开展上述研究的重要前提。基于分布式光纤温度感测技术(fiber optic distributed temperature sensing,FO-DTS),开展了原位测试,...土体水分迁移过程及其规律是岩土工程、地质工程等领域的重点研究内容之一,准确掌握土体含水率时空演化是开展上述研究的重要前提。基于分布式光纤温度感测技术(fiber optic distributed temperature sensing,FO-DTS),开展了原位测试,记录了浅地表(0~0.5m)不同深度土体自然温度信息,基于半通滤波算法提取振幅、相位信息,结合一维瞬态热传递方程解析解提出了土体含水率估算的新方法。研究结果表明:①基于FO-DTS的高时空分辨率温度信息能够有效估算浅表土体不同深度的含水率;②该方法能够反映复杂天气变化条件下(阴、晴、雨、寒潮等)浅表土体含水率的复杂响应;③降水事件对浅表土体含水率的影响程度随着深度衰减,土体含水率的变化具有一定的滞后性。利用分布式光纤温度感测技术实现基于自然温度信息的含水率估算新方法具有高空间分辨率、易拓展、低能耗的特点,可实现0~10km内多尺度浅地表含水率快速估算,对浅地表-大气相互作用、地质和岩土工程防灾减灾具有重要意义。展开更多
基金supported by National Natural Science Foundation of China(52272039,U23B2075,51972168)Key Research and Development Program in Jiangsu Province(BE2023085)Natural Science Foundation of Jiangsu Province of China(BK20231406)。
文摘Three-dimensional(3D)graphene monoliths are a new carbon material,that has tremendous potential in the fields of energy conversion and storage.They can solve the limitations of two-dimensional(2D)graphene sheets,including interlayer restacking,high contact resistance,and insufficient pore accessibility.By constructing interconnected porous networks,3D graphenes not only retain the intrinsic advantages of 2D graphene sheets,such as high specific surface area,excellent electrical and thermal conductivities,good mechanical properties,and outstanding chemical stability,but also enable efficient mass transport of external fluid species.We summarize the fabrication methods for 3D graphenes,with a particular focus on their applications in energy-related systems.Techniques including chemical reduction assembly,chemical vapor deposition,3D printing,chemical blowing,and zinc-tiered pyrolysis have been developed to change their pore structure and elemental composition,and ways in which they can be integrated with functional components.In terms of energy conversion and storage,they have found broad use in buffering mechanical impacts,suppressing noise,photothermal conversion,electromagnetic shielding and absorption.They have also been used in electrochemical energy systems such as supercapacitors,secondary batteries,and electrocatalysis.By reviewing recent progress in structural design and new applications,we also discuss the problems these materials face,including scalable fabrication and precise pore structure control,and possible new applications.
文摘土体水分迁移过程及其规律是岩土工程、地质工程等领域的重点研究内容之一,准确掌握土体含水率时空演化是开展上述研究的重要前提。基于分布式光纤温度感测技术(fiber optic distributed temperature sensing,FO-DTS),开展了原位测试,记录了浅地表(0~0.5m)不同深度土体自然温度信息,基于半通滤波算法提取振幅、相位信息,结合一维瞬态热传递方程解析解提出了土体含水率估算的新方法。研究结果表明:①基于FO-DTS的高时空分辨率温度信息能够有效估算浅表土体不同深度的含水率;②该方法能够反映复杂天气变化条件下(阴、晴、雨、寒潮等)浅表土体含水率的复杂响应;③降水事件对浅表土体含水率的影响程度随着深度衰减,土体含水率的变化具有一定的滞后性。利用分布式光纤温度感测技术实现基于自然温度信息的含水率估算新方法具有高空间分辨率、易拓展、低能耗的特点,可实现0~10km内多尺度浅地表含水率快速估算,对浅地表-大气相互作用、地质和岩土工程防灾减灾具有重要意义。
