There is growing evidence to suggest that the black hole mass has been previously underestimated with the Hb line width for certain Active Galactic Nuclei (AGN). With the assumption of the flatter rather than isotropi...There is growing evidence to suggest that the black hole mass has been previously underestimated with the Hb line width for certain Active Galactic Nuclei (AGN). With the assumption of the flatter rather than isotropic velocity distribution of gases in the broad-line region of AGN, we investigated the properties of Narrow Line Seyfert 1 (NLS1) galaxies, like the black hole mass and the Eddington ratio, and compared with Broad Line Seyfert 1 (BLS1) galaxies. Since gamma-rays detected in a few NLS1s which favored a smaller viewing angle in NLS1s than BLS1s, with the projection effect, we estimated the relative black hole mass and Eddington ratio for NLS1s and BLS1s. The result implies that the NLS1s and BLS1s have similar black hole masses and Eddington ratios, peaked at a larger black hole mass and lower Eddington ratio for the NLS1s than thought before. Furthermore, with applying the correction factor 6 of average black hole mass as derived from the modeling of both optical and UV data in radio-loud NLS1s by Calderone et al., to the Xu et al. sample, we find that the NLS1s and BLS1s also show similar black hole masses and Eddington ratios, peaked at 2.0 × 107 solar masses and 0.12 (Eddington ratio) for the NLS1s. The relation due to the enhanced black hole masses of NLS1s is discussed. In addition, there seems to show a linear correlation between jet power and disk luminosity for the flat spectrum radio-loud NLS1 sample, which implies an accretion dominated rather than black hole spin dominated jet.展开更多
ZnO doped Pt/CeO2 nanocomposites were prepared by electrospinning and reduction impregnation.Xray diffraction（XRD）,transmission electron microscopy（TEM）,energy disperse spectroscopy（EDS） and X-ray photoelectron ...ZnO doped Pt/CeO2 nanocomposites were prepared by electrospinning and reduction impregnation.Xray diffraction（XRD）,transmission electron microscopy（TEM）,energy disperse spectroscopy（EDS） and X-ray photoelectron spectroscopy（XPS） were employed to characterize the nanocomposites.It is observed that ZnO and CeO2 form the hexagonal wurtzite phase and cubic fluorite phase in the nanocomposite,respectively,whilst Pt nanoparticles（NPs） with the number-averaged size of ca.3.1 nm are uniformly distributed on the surface of nanofibers.The mass fraction of Pt NPs in the nanocomposites is about 10 wt%.The doping of ZnO is effective to promote reactive oxygen species,surface reaction sites and the interaction between Pt and oxides.The catalytic performance of nanocomposites was evaluated by the methanol electro-oxidation.indexed with the catalytic activity,stability of catalyst.As a result,it is found that the nanocomposite exhibits much higher activity and stability for methanol oxidation than the undoped Pt/CeO2 catalyst.展开更多
文摘There is growing evidence to suggest that the black hole mass has been previously underestimated with the Hb line width for certain Active Galactic Nuclei (AGN). With the assumption of the flatter rather than isotropic velocity distribution of gases in the broad-line region of AGN, we investigated the properties of Narrow Line Seyfert 1 (NLS1) galaxies, like the black hole mass and the Eddington ratio, and compared with Broad Line Seyfert 1 (BLS1) galaxies. Since gamma-rays detected in a few NLS1s which favored a smaller viewing angle in NLS1s than BLS1s, with the projection effect, we estimated the relative black hole mass and Eddington ratio for NLS1s and BLS1s. The result implies that the NLS1s and BLS1s have similar black hole masses and Eddington ratios, peaked at a larger black hole mass and lower Eddington ratio for the NLS1s than thought before. Furthermore, with applying the correction factor 6 of average black hole mass as derived from the modeling of both optical and UV data in radio-loud NLS1s by Calderone et al., to the Xu et al. sample, we find that the NLS1s and BLS1s also show similar black hole masses and Eddington ratios, peaked at 2.0 × 107 solar masses and 0.12 (Eddington ratio) for the NLS1s. The relation due to the enhanced black hole masses of NLS1s is discussed. In addition, there seems to show a linear correlation between jet power and disk luminosity for the flat spectrum radio-loud NLS1 sample, which implies an accretion dominated rather than black hole spin dominated jet.
基金Project supported by the National Natural Science Foundation of China(21475021,21427807)the Natural Science Foundation of Jiangsu Province(BK20141331)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘ZnO doped Pt/CeO2 nanocomposites were prepared by electrospinning and reduction impregnation.Xray diffraction（XRD）,transmission electron microscopy（TEM）,energy disperse spectroscopy（EDS） and X-ray photoelectron spectroscopy（XPS） were employed to characterize the nanocomposites.It is observed that ZnO and CeO2 form the hexagonal wurtzite phase and cubic fluorite phase in the nanocomposite,respectively,whilst Pt nanoparticles（NPs） with the number-averaged size of ca.3.1 nm are uniformly distributed on the surface of nanofibers.The mass fraction of Pt NPs in the nanocomposites is about 10 wt%.The doping of ZnO is effective to promote reactive oxygen species,surface reaction sites and the interaction between Pt and oxides.The catalytic performance of nanocomposites was evaluated by the methanol electro-oxidation.indexed with the catalytic activity,stability of catalyst.As a result,it is found that the nanocomposite exhibits much higher activity and stability for methanol oxidation than the undoped Pt/CeO2 catalyst.
