Graphene oxide（GO） has a wide fluorescence bandwidth,which makes it a prospective candidate for numerous applications.For many of these applications,the fluorescence yield of GO should be further increased.The sp2-h...Graphene oxide（GO） has a wide fluorescence bandwidth,which makes it a prospective candidate for numerous applications.For many of these applications,the fluorescence yield of GO should be further increased.The sp2-hybridized carbons in GO confine the π-electrons.Radiative recombination of electron-hole pairs in such sp2 clusters is the source of fluorescence in this material.Palladium nanoparticles are good catalysts for sp2 bond formations.We report on the preparation of GO,palladium nanoparticles and their nanocomposites in two different solvents.It is shown that palladium nanoparticles can considerably enhance the intrinsic fluorescence of GO in the blue-green part of the visible light spectrum.Fluorescence enhancement has been attributed to the catalytic role of palladium nanoparticles in increasing the number of sp2 bonds of GO with the molecules of the surrounding media.It is shown that palladium nanoparticles could be the nanoparticle of choice for fluorescence enhancement of GO because of their catalytic role in sp2 bond formation.展开更多
A cross-shaped photonic crystal waveguide formed by a square lattice Al_2O_3 rods array is numerically and experimentally investigated. The band gap of the TE mode for the photonic crystals and transmission characteri...A cross-shaped photonic crystal waveguide formed by a square lattice Al_2O_3 rods array is numerically and experimentally investigated. The band gap of the TE mode for the photonic crystals and transmission characteristics of waveguides are calculated by the plane wave expansion method and the finite element method.We perform the experiments in the microwave regime to validate the numerical results. The measured reflection and transmission characteristics of the photonic crystals show a large band gap between 8.62 and 11.554 GHz（relative bandwidth is 29.34%）. The electromagnetic waves are transmitted stably in the waveguides, and the transmission characteristics maintain a high level in the band gap.展开更多
文摘Graphene oxide（GO） has a wide fluorescence bandwidth,which makes it a prospective candidate for numerous applications.For many of these applications,the fluorescence yield of GO should be further increased.The sp2-hybridized carbons in GO confine the π-electrons.Radiative recombination of electron-hole pairs in such sp2 clusters is the source of fluorescence in this material.Palladium nanoparticles are good catalysts for sp2 bond formations.We report on the preparation of GO,palladium nanoparticles and their nanocomposites in two different solvents.It is shown that palladium nanoparticles can considerably enhance the intrinsic fluorescence of GO in the blue-green part of the visible light spectrum.Fluorescence enhancement has been attributed to the catalytic role of palladium nanoparticles in increasing the number of sp2 bonds of GO with the molecules of the surrounding media.It is shown that palladium nanoparticles could be the nanoparticle of choice for fluorescence enhancement of GO because of their catalytic role in sp2 bond formation.
基金supported by the National Natural Science Foundation of China under Grant No.61171006
文摘A cross-shaped photonic crystal waveguide formed by a square lattice Al_2O_3 rods array is numerically and experimentally investigated. The band gap of the TE mode for the photonic crystals and transmission characteristics of waveguides are calculated by the plane wave expansion method and the finite element method.We perform the experiments in the microwave regime to validate the numerical results. The measured reflection and transmission characteristics of the photonic crystals show a large band gap between 8.62 and 11.554 GHz（relative bandwidth is 29.34%）. The electromagnetic waves are transmitted stably in the waveguides, and the transmission characteristics maintain a high level in the band gap.
