共愉的风景——品鉴春日台中心

作为“AT建筑”首次国外建筑品鉴,我们将目光聚焦日本20世纪80年代前后新一代建筑师的实践与思考。选择金野千惠所做的春日台中心,不仅仅因为它获得了2023年日本建筑学会作品奖,更是因为作品中所展现的建筑师对当代建筑与社会、空间与技术、场所与人、开放性与社会性的深刻洞见和呈现。当站在长长的廊下看广场上玩耍的孩子,当视线穿过两栋之间的走廊望向城市街道和住宅区,当阳光从两层通高的土间通洒下似乎融合又分隔了前部的“榻榻米”公共活动空间与后面半公共的老人照护中心,当在二层推开木窗户感受木结构包裹的氛围下老人欢笑游戏的场景,这种给人的愉悦感就是共愉的风景吧。

Experimental study on characteristics of pore water conversion during methane hydrates formation in unsaturated sand

Understanding the pore water conversion characteristics during hydrate formation in porous media is important to study the accumulation mechanism of marine gas hydrate.In this study,low-field NMR was used to study the pore water conversion characteristics during methane hydrate formation in unsaturated sand samples.Results show that the signal intensity of T_(2) distribution isn’t affected by sediment type and pore pressure,but is affected by temperature.The increase in the pressure of hydrogen-containing gas can cause the increase in the signal intensity of T_(2) distribution.The heterogeneity of pore structure is aggravated due to the hydrate formation in porous media.The water conversion rate fluctuates during the hydrate formation.The sand size affects the water conversion ratio and rate by affecting the specific surface of sand in unsaturated porous media.For the fine sand sample,the large specific surface causes a large gas-water contact area resulting in a higher water conversion rate,but causes a large water-sand contact area resulting in a low water conversion ratio(C_(w)=96.2%).The clay can reduce the water conversion rate and ratio,especially montmorillonite(C_(w)=95.8%).The crystal layer of montmorillonite affects the pore water conversion characteristics by hindering the conversion of interlayer water.

Engineering and dynamics of heterogeneous catalysts via metal single atoms as promoters/precursors

Metal single-atom catalysts(SACs) have emerged as a focal point of research, captivating the scientific community due to their distinctive electronic properties and unparalleled catalytic prowess in the realm of heterogeneous catalysis. However, their significance transcends their role as mere active sites. Recent investigations have illuminated the multifaceted capabilities of metal single atoms as catalyst promoters and precursors, paving the way for the engineering of highly efficient heterogeneous catalysts. Single-atom promoters not only enhance the stabilization of active metals and tailor the support material, but regulate the reactive interfacial structure, eventually tuning the catalytic performance. Furthermore, SACs were also used as catalyst precursors to design new catalyst active sites. During the pretreatment or catalytic reaction, the structure of the metal single sites is changed significantly and transformed into the new and more active state, which improve the adsorption and reactive ability of reactants or intermediates. In this critical review, we comment the recent development of metal SACs used as catalyst promoters/precursors in engineering heterogeneous catalysts, including thermal catalysis and electrocatalysis. Furthermore, the dynamic evolution of the SACs during the pretreatment or catalytic reaction is also discussed. Finally, we provide our insight to potentially guide the future development on this emerging field.