Simple encapsulation of 3 nm gold nanoparticles in ordered mesoporous carbon with large pores of 17 nm and thick pore walls of 16 nm was achieved by a metal–ligand coordination assisted-selfassembly approach.Polystyr...Simple encapsulation of 3 nm gold nanoparticles in ordered mesoporous carbon with large pores of 17 nm and thick pore walls of 16 nm was achieved by a metal–ligand coordination assisted-selfassembly approach.Polystyrene-block-polyethylene-oxide(PS-b-PEO)diblock copolymer with a large molecular weight of the PS chain and mercaptopropyltrimethoxysilane were used as the template and the metal ligand,respectively.Small-angle X-ray scattering,X-ray diffraction,transmission electron microscopy,and X-ray photoelectron spectroscopy showed that monodispersed aggregation-free gold nanoparticles approximately 3 nm in size were partially embedded in the large open pore structure of the ordered mesoporous carbon.The strong coordination between the gold species and the mercapto groups and the thick porous walls increased the dispersion of the gold nanoparticles and essentially inhibited particle aggregation at 600℃.The gold nanoparticles in the ordered mesoporous carbon are active and stable in the reduction of nitroarenes involving bulky molecules using sodium borohydride as a reducing agent under ambient conditions(30℃)in water.The large interconnected pore structure facilitates the mass transfer of bulky molecules.展开更多
The genus Roegneria was firstly established with Roegneria caucasica C.Koch as the model species.Being the largest genera in the tribe Triticeae(Poaceae),Roegneria includes 130 species mainly distributed in the north ...The genus Roegneria was firstly established with Roegneria caucasica C.Koch as the model species.Being the largest genera in the tribe Triticeae(Poaceae),Roegneria includes 130 species mainly distributed in the north temperate zone.There are 70 Roegneria species and 22 variants,which are widely distributed in different regions of China(Lei,2018).The diversified morphology of Roegneria species has caused controversy in their taxonomy.It has been argued whether Roegneria species should be included in the genus Elymus or considered as an independent genus(Lei et al.,2018).The investigation of the cytological and genomic feature would help to clarify the taxonomic placement of Roegneria.展开更多
基金supported by the National Natural Science Foun-dation of China(22025204,92034301,21773156,and 51932005)the Shanghai Sci.&Tech.and Edu.Committee(19070502700)the Innovation Program of the Shanghai Municipal Education Com-mission(2021-01-07-00-02-E00119).
文摘Simple encapsulation of 3 nm gold nanoparticles in ordered mesoporous carbon with large pores of 17 nm and thick pore walls of 16 nm was achieved by a metal–ligand coordination assisted-selfassembly approach.Polystyrene-block-polyethylene-oxide(PS-b-PEO)diblock copolymer with a large molecular weight of the PS chain and mercaptopropyltrimethoxysilane were used as the template and the metal ligand,respectively.Small-angle X-ray scattering,X-ray diffraction,transmission electron microscopy,and X-ray photoelectron spectroscopy showed that monodispersed aggregation-free gold nanoparticles approximately 3 nm in size were partially embedded in the large open pore structure of the ordered mesoporous carbon.The strong coordination between the gold species and the mercapto groups and the thick porous walls increased the dispersion of the gold nanoparticles and essentially inhibited particle aggregation at 600℃.The gold nanoparticles in the ordered mesoporous carbon are active and stable in the reduction of nitroarenes involving bulky molecules using sodium borohydride as a reducing agent under ambient conditions(30℃)in water.The large interconnected pore structure facilitates the mass transfer of bulky molecules.
基金financially supported by the National Key Research and Development Program of China(No.2020YF E0202900)the National Natural Science Foundation of China(No.32011530167)+4 种基金the National Natural Science Foundation of China International(Regional)Cooperation and Exchange Program(No.31661143005)the National Key Research and Development Program(No.2016YFD0102001-004)Jiangsu Province Modern Agricultural Industry Technology System[No.JATS(2020)411JATS(2021)463]Seed Industry Revitalization Project of Jiangsu Province(JBGS2021006,2021013,2021047).
文摘The genus Roegneria was firstly established with Roegneria caucasica C.Koch as the model species.Being the largest genera in the tribe Triticeae(Poaceae),Roegneria includes 130 species mainly distributed in the north temperate zone.There are 70 Roegneria species and 22 variants,which are widely distributed in different regions of China(Lei,2018).The diversified morphology of Roegneria species has caused controversy in their taxonomy.It has been argued whether Roegneria species should be included in the genus Elymus or considered as an independent genus(Lei et al.,2018).The investigation of the cytological and genomic feature would help to clarify the taxonomic placement of Roegneria.
