Dimension-controllable supramolecular organic frameworks(SOFs)with aggregation-enhanced fluorescence are hierarchically fabricated through the host-guest interactions of cucurbit[8]uril(CB[8])and coumarin-modified tet...Dimension-controllable supramolecular organic frameworks(SOFs)with aggregation-enhanced fluorescence are hierarchically fabricated through the host-guest interactions of cucurbit[8]uril(CB[8])and coumarin-modified tetraphenylethylene derivatives(TPEC).The three-dimensional layered SOFs could be constructed from the further stacking of two-dimensional mono-layered structures via simply regulating the self-assembly conditions including the culturing time and concentration.Upon light irradiation under the wavelength of 365 nm,the photodimerization of coumarin moieties occurred,which resulted in the transformation of the resultant TPECn/CB[8]4n two-dimensional SOFs into robust covalently-connected 2D polymers with molecular thickness.Interestingly,the supramolecular system of TPEC/CB[8]exhibited intriguing multicolor fluorescence emission from yellow to blue in the time range of 0-24 h at 365 nm irradiation,possessing potential applicability for photochromic fluorescence ink.展开更多
The concept of global governance first appeared in research on international political governance in the early 1990s. At the time much of the theoretical research on global governance was to some extent isolated from ...The concept of global governance first appeared in research on international political governance in the early 1990s. At the time much of the theoretical research on global governance was to some extent isolated from the realities of world development, but since the beginning of the 21th century, global governance research has been turning to real world issues, We propose the construction, from a public management perspective, of a governance ＂issue-actor-mechanism＂ framework. This sees postwar global governance practice as the old paradigm. The paper points out that the rapid global development after the end of the Cold War has had a crucial impact on the traditional governance paradigm, followed by the emergence of new global governance issues and changes in new governance actors resulting from the changing world of the last twenty or thirty years which have led to the failure of traditional governance mechanisms. These ＂issue-actor-mechanism＂ changes are closely interlocked, and hence require a new global governance paradigm that can reflect the complex interconnections of governance issues, actors and mechanisms. We thus need to reexamine and refresh our perceptions of the world and open up a new research agenda.展开更多
基金supported by Anhui Province Natural Science Funds(2008085QE209)K2020-03 from the State Key Laboratory of Molecular Engineering of Polymers(Fudan University)。
文摘Dimension-controllable supramolecular organic frameworks(SOFs)with aggregation-enhanced fluorescence are hierarchically fabricated through the host-guest interactions of cucurbit[8]uril(CB[8])and coumarin-modified tetraphenylethylene derivatives(TPEC).The three-dimensional layered SOFs could be constructed from the further stacking of two-dimensional mono-layered structures via simply regulating the self-assembly conditions including the culturing time and concentration.Upon light irradiation under the wavelength of 365 nm,the photodimerization of coumarin moieties occurred,which resulted in the transformation of the resultant TPECn/CB[8]4n two-dimensional SOFs into robust covalently-connected 2D polymers with molecular thickness.Interestingly,the supramolecular system of TPEC/CB[8]exhibited intriguing multicolor fluorescence emission from yellow to blue in the time range of 0-24 h at 365 nm irradiation,possessing potential applicability for photochromic fluorescence ink.
文摘The concept of global governance first appeared in research on international political governance in the early 1990s. At the time much of the theoretical research on global governance was to some extent isolated from the realities of world development, but since the beginning of the 21th century, global governance research has been turning to real world issues, We propose the construction, from a public management perspective, of a governance ＂issue-actor-mechanism＂ framework. This sees postwar global governance practice as the old paradigm. The paper points out that the rapid global development after the end of the Cold War has had a crucial impact on the traditional governance paradigm, followed by the emergence of new global governance issues and changes in new governance actors resulting from the changing world of the last twenty or thirty years which have led to the failure of traditional governance mechanisms. These ＂issue-actor-mechanism＂ changes are closely interlocked, and hence require a new global governance paradigm that can reflect the complex interconnections of governance issues, actors and mechanisms. We thus need to reexamine and refresh our perceptions of the world and open up a new research agenda.
