Aerogels are ultra-lightweight,porous materials defined by a complex network of interconnected pores and nanostructures,which effectively suppress heat transfer,making them exceptional for thermal insulation.Furthermo...Aerogels are ultra-lightweight,porous materials defined by a complex network of interconnected pores and nanostructures,which effectively suppress heat transfer,making them exceptional for thermal insulation.Furthermore,their porous architecture can trap and scatter light via multiple internal reflections,extending the optical path within the material.When combined with suitable light-absorbing materials,this feature significantly enhances light absorption(darkness).To validate this concept,mesoporous silica aerogel particles were incorporated into a resorcinol-formaldehyde(RF)sol,and the silica-to-RF ratio was optimized to achieve uniform carbon compound coatings on the silica pore walls.Notably,increasing silica loading raised the sol viscosity,enabling formulations ideal for direct ink writing processes with excellent shape fidelity for super-black topographical designs.The printed silica-RF green bodies exhibited remarkable mechanical strength and ultra-low thermal conductivity(15.8 m W m^(-1) K^(-1))prior to pyrolysis.Following pyrolysis,the composites maintained structural integrity and printed microcellular geometries while achieving super-black coloration(abs.99.56%in the 280-2500 nm range)and high photothermal conversion efficiency(94.2%).Additionally,these silica-carbon aerogel microcellulars demonstrated stable electrical conductivity and low electrochemical impedance.The synergistic combination of 3D printability and super-black photothermal features makes these composites highly versatile for multifunctional applications,including on-demand thermal management,and efficient solar-driven water production.展开更多
By analyzing and comparing the existing methods for the division of urban economic region, this paper supplemented and developed the breaking point theory. In this model, put forward for the first time using ＂the spa...By analyzing and comparing the existing methods for the division of urban economic region, this paper supplemented and developed the breaking point theory. In this model, put forward for the first time using ＂the space-time distance＂ to replace ＂the space- linear distance＂ and ＂the city comprehensiveness quality- fuzzy comprehensive assessment Index＂ to ＂the urban population or GDP＇. Set up the algorithm of including ＂the space- time distance＂ and the city radiation scope changed with the changes of traffic conditions. Thus has realized ＂dynamically＂ tracing of the city radiation scope influenced by the traffic conditions. Taking Yichang city as an example, the paper analyzed the city function localization in the times of new traffic environments. Because China＇s cities are at the times of the traffic great changes, therefore, the method and the main conclusions of this paper have some methodology guiding sense to the majority cities of deffernt country to re-position.展开更多
基金financially supported by the Swiss National Science Foundation(grant number IZLRZ2_164058)the China Scholarship Council Ph.D.student exchange programthe Priority Academic Program Development of Jiangsu Higher Education Institution(PAPD)。
文摘Aerogels are ultra-lightweight,porous materials defined by a complex network of interconnected pores and nanostructures,which effectively suppress heat transfer,making them exceptional for thermal insulation.Furthermore,their porous architecture can trap and scatter light via multiple internal reflections,extending the optical path within the material.When combined with suitable light-absorbing materials,this feature significantly enhances light absorption(darkness).To validate this concept,mesoporous silica aerogel particles were incorporated into a resorcinol-formaldehyde(RF)sol,and the silica-to-RF ratio was optimized to achieve uniform carbon compound coatings on the silica pore walls.Notably,increasing silica loading raised the sol viscosity,enabling formulations ideal for direct ink writing processes with excellent shape fidelity for super-black topographical designs.The printed silica-RF green bodies exhibited remarkable mechanical strength and ultra-low thermal conductivity(15.8 m W m^(-1) K^(-1))prior to pyrolysis.Following pyrolysis,the composites maintained structural integrity and printed microcellular geometries while achieving super-black coloration(abs.99.56%in the 280-2500 nm range)and high photothermal conversion efficiency(94.2%).Additionally,these silica-carbon aerogel microcellulars demonstrated stable electrical conductivity and low electrochemical impedance.The synergistic combination of 3D printability and super-black photothermal features makes these composites highly versatile for multifunctional applications,including on-demand thermal management,and efficient solar-driven water production.
文摘By analyzing and comparing the existing methods for the division of urban economic region, this paper supplemented and developed the breaking point theory. In this model, put forward for the first time using ＂the space-time distance＂ to replace ＂the space- linear distance＂ and ＂the city comprehensiveness quality- fuzzy comprehensive assessment Index＂ to ＂the urban population or GDP＇. Set up the algorithm of including ＂the space- time distance＂ and the city radiation scope changed with the changes of traffic conditions. Thus has realized ＂dynamically＂ tracing of the city radiation scope influenced by the traffic conditions. Taking Yichang city as an example, the paper analyzed the city function localization in the times of new traffic environments. Because China＇s cities are at the times of the traffic great changes, therefore, the method and the main conclusions of this paper have some methodology guiding sense to the majority cities of deffernt country to re-position.
