Proline is a natural amino acid that can be considered as an excellent,efficient,and versatile organocatalyst for various asymmetric reactions.The encapsulation of organocatalysts,such as proline and related derivativ...Proline is a natural amino acid that can be considered as an excellent,efficient,and versatile organocatalyst for various asymmetric reactions.The encapsulation of organocatalysts,such as proline and related derivatives,into a porous material,can not only construct a novel heterogeneous catalyst but also provide a platform to mimic and explore the catalytic processes in a biological system.In this regard,metal–organic frameworks(MOFs)and covalent-organic frameworks(COFs)show superiority because of their crystalline structure,rational designable and tunable framework.In this review,we mainly focus on chiral pyrrolidine functionalized MOFs and COFs;the synthetic strategies and related applications of these materials have been summarized systematically.展开更多
Nanoelectromechanical systems(NEMS)based on atomically-thin tungsten diselenide(WSe_(2)),benefiting from the excellent material properties and the mechanical degree of freedom,offer an ideal platform for studying and ...Nanoelectromechanical systems(NEMS)based on atomically-thin tungsten diselenide(WSe_(2)),benefiting from the excellent material properties and the mechanical degree of freedom,offer an ideal platform for studying and exploiting dynamic strain engineering and cross-scale vibration coupling in two-dimensional(2D)crystals.However,such opportunity has remained largely unexplored for WSe_(2)NEMS,impeding exploration of exquisite physical processes and realization of novel device functions.Here,we demonstrate dynamic coupling between atomic lattice vibration and nanomechanical resonances in few-layer WSe_(2)NEMS.Using a custom-built setup capable of simultaneously detecting Raman and motional signals,we accomplish cross-scale mode coupling between the THz crystal phonon and MHz structural vibration,achieving GHz frequency tuning in the atomic lattice modes with a dynamic gauge factor of 61.9,the best among all 2D crystals reported to date.Our findings show that such 2D NEMS offer great promises for exploring cross-scale physics in atomically-thin semiconductors.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000)the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(QYZDB-SSW-SLH019)the National Natural Science Foundation of China(21905281 and 21771177).
文摘Proline is a natural amino acid that can be considered as an excellent,efficient,and versatile organocatalyst for various asymmetric reactions.The encapsulation of organocatalysts,such as proline and related derivatives,into a porous material,can not only construct a novel heterogeneous catalyst but also provide a platform to mimic and explore the catalytic processes in a biological system.In this regard,metal–organic frameworks(MOFs)and covalent-organic frameworks(COFs)show superiority because of their crystalline structure,rational designable and tunable framework.In this review,we mainly focus on chiral pyrrolidine functionalized MOFs and COFs;the synthetic strategies and related applications of these materials have been summarized systematically.
基金support from the National Science Fund for Distinguished Young Scholars(Grant No.T2325007)Opening Foundation of Hubei Key Laboratory of MicroNanoelectronic Materials and Devices(Grant No.K202307)+3 种基金National Natural Science Foundation of China(Grant Nos.62450003,62404029,62401104,U21A20459,62250073,61774029)Opening Foundation of State key laboratory of precision measuring technology and instruments(Tianjin University)(Grant No.Pilab2411)China Postdoctoral Science Foundation(Grant Nos.GZB20230107,GZB20240109)Natural Science Foundation of Sichuan Province(Grant Nos.2024NSFSC1408,2024NSFSC1430).
文摘Nanoelectromechanical systems(NEMS)based on atomically-thin tungsten diselenide(WSe_(2)),benefiting from the excellent material properties and the mechanical degree of freedom,offer an ideal platform for studying and exploiting dynamic strain engineering and cross-scale vibration coupling in two-dimensional(2D)crystals.However,such opportunity has remained largely unexplored for WSe_(2)NEMS,impeding exploration of exquisite physical processes and realization of novel device functions.Here,we demonstrate dynamic coupling between atomic lattice vibration and nanomechanical resonances in few-layer WSe_(2)NEMS.Using a custom-built setup capable of simultaneously detecting Raman and motional signals,we accomplish cross-scale mode coupling between the THz crystal phonon and MHz structural vibration,achieving GHz frequency tuning in the atomic lattice modes with a dynamic gauge factor of 61.9,the best among all 2D crystals reported to date.Our findings show that such 2D NEMS offer great promises for exploring cross-scale physics in atomically-thin semiconductors.
