Controversies and arguments about the origin of plan-etary water have aroused enthusiasm to search for possible chemical sources.Considering the CO_(2)-rich atmospheres of Mars,Venus,and the prebiotic Earth,we propose...Controversies and arguments about the origin of plan-etary water have aroused enthusiasm to search for possible chemical sources.Considering the CO_(2)-rich atmospheres of Mars,Venus,and the prebiotic Earth,we propose that chemical reactions between HOCO^(+)and H_(2)can contribute to the production of H_(2)O on the basis of high-level calculations.As for the reagents,HOCO^(+)can form via the protonation of CO_(2),while H+and H_(2)are from the solar wind or in-terstellar space.Note that one of the reaction path-ways undergoes multiple transition-state complexes and exhibits the roaming-like dynamics feature.More-over,intermolecular proton or hydrogen transfer is a key step in the production of H_(2)O,there-by H-tunneling effect profoundly enhances the reaction rate in a wide range of temperatures or collision energies.展开更多
A new kind of quantum interference between Raman scattering and single-photon absorption is predicted theoretically, which gives an expanded view of quantum interference. Its potential application is also proposed.
在有机相中合成了不同尺寸的CdS和CdSe量子点,并利用Langmuir-Blodgett(LB)技术将相同尺寸的CdS和CdSe量子点组装成多层复合纳米有序结构.采用荧光光谱研究了CdS和CdSe量子点在混合体系和多层复合纳米有序结构状态下的荧光共振能量转移(...在有机相中合成了不同尺寸的CdS和CdSe量子点,并利用Langmuir-Blodgett(LB)技术将相同尺寸的CdS和CdSe量子点组装成多层复合纳米有序结构.采用荧光光谱研究了CdS和CdSe量子点在混合体系和多层复合纳米有序结构状态下的荧光共振能量转移(Fluorescence resonance energy transfer,FRET).我们观察到CdS和CdSe量子点混合溶液与当溶剂挥发形成固态膜中,CdS量子点的荧光强度较溶液状态下强烈猝灭,表明当颗粒间距离减小时CdS和CdSe量子点间产生较高效率的荧光共振能量转移.在多层复合纳米有序结构中,随着给体CdS量子点层数的增加,单层受体CdSe量子点的荧光逐步增强,这表明层间纵向能量转移率随给体层数的增加而提高.展开更多
基金supported by the National Natural Sci-ence Foundation of China(Nos.22233004,22003062)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0970000).
文摘Controversies and arguments about the origin of plan-etary water have aroused enthusiasm to search for possible chemical sources.Considering the CO_(2)-rich atmospheres of Mars,Venus,and the prebiotic Earth,we propose that chemical reactions between HOCO^(+)and H_(2)can contribute to the production of H_(2)O on the basis of high-level calculations.As for the reagents,HOCO^(+)can form via the protonation of CO_(2),while H+and H_(2)are from the solar wind or in-terstellar space.Note that one of the reaction path-ways undergoes multiple transition-state complexes and exhibits the roaming-like dynamics feature.More-over,intermolecular proton or hydrogen transfer is a key step in the production of H_(2)O,there-by H-tunneling effect profoundly enhances the reaction rate in a wide range of temperatures or collision energies.
基金supported by the State Key Development Project for Basic Research of China (Grant No 2006CB921304)
文摘A new kind of quantum interference between Raman scattering and single-photon absorption is predicted theoretically, which gives an expanded view of quantum interference. Its potential application is also proposed.
文摘在有机相中合成了不同尺寸的CdS和CdSe量子点,并利用Langmuir-Blodgett(LB)技术将相同尺寸的CdS和CdSe量子点组装成多层复合纳米有序结构.采用荧光光谱研究了CdS和CdSe量子点在混合体系和多层复合纳米有序结构状态下的荧光共振能量转移(Fluorescence resonance energy transfer,FRET).我们观察到CdS和CdSe量子点混合溶液与当溶剂挥发形成固态膜中,CdS量子点的荧光强度较溶液状态下强烈猝灭,表明当颗粒间距离减小时CdS和CdSe量子点间产生较高效率的荧光共振能量转移.在多层复合纳米有序结构中,随着给体CdS量子点层数的增加,单层受体CdSe量子点的荧光逐步增强,这表明层间纵向能量转移率随给体层数的增加而提高.
基金Research supported by the National Natural Science Foundation of China(10947143)the Natural Science Foundation for Colleges and Universities of Jiangsu Province(09KJB140010)the Doctorial Start-up Fund of Xuzhou Normal University(08XLR02)
