Resonant and off-resonant transients in electromagnetically induced transparency: Turn-on and turn-off dynamics

Published versio

Solvothermal synthesis of copper-doped BiOBr microflowers with enhanced adsorption and visible-light driven photocatalytic degradation of norfloxacin

© 2020 Elsevier B.V. Photocatalysts based on copper-doped bismuth oxybromide (Cu-doped BiOBr) were synthesised using a solvothermal method and assessed for their ability to degrade norfloxacin under visible light. The Cu atoms were successfully doped into the crystal lattice of BiOBr, yielding Cu-doped BiOBr microflowers with a morphology and crystal structure identical to that of pristine BiOBr. The as-prepared Cu-doped BiOBr showed activity superior to BiOBr in the photocatalytic degradation of norfloxacin under visible-light irradiation, which was attributed to its improved light-harvesting properties, enhanced charge separation and interfacial charge transfer. Furthermore, we found for the first time that the introduction of Cu into BiOBr enhanced the adsorption capacity between the photocatalyst and norfloxacin, which we considered to be the main contribution to its improved performance. Cu-doped BiOBr containing the optimal proportion of Cu and Bi (Cu:Bi = 0.03) had a photocatalytic degradation constant of 0.64 ×10−2 min−1, which is 2.28 times higher than that of undoped BiOBr. The primary oxidation pathway was determined to involve the transfer of photogenerated holes to norfloxacin. Finally, we demonstrated that the Cu-doped BiOBr photocatalyst retained 95% of its initial activity even after five successive catalytic cycles, confirming its recyclability

Can Hong Kong price-manage its cross-harbor-tunnel congestion?

Hong Kong drivers face daily congestion, especially at the Cross Harbor Tunnel (CHT) whose tolls are substantially lower than those of the drivers' other two tunnel options: the Eastern Harbor Crossing (EHC) and the Western Harbor Crossing (WHC). In 2013, the Hong Kong Special Administrative Region (HKSAR) Government issued a consultation paper, seeking public comments on three toll-change proposals that would raise the CHT's tolls and lower the EHC's tolls. The WHC's tolls would remain unchanged due to its congested connecting roads. Using monthly crossing data available from the HKSAR's Transport Department for 2000-2012, this paper uses a Generalized Leontief demand system to document that the usage patterns of the three tunnels is price-responsive. Hence, we conclude that the proposed toll changes are likely to be effective in transportation demand management, by shifting a portion of the CHT's usage to the EHC and WHC, thereby relieving the CHT's congestion.School of Accounting and Financ

Measurement of the isolated diphoton cross-section in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The ATLAS experiment has measured the production cross-section of events with two isolated photons in the final state, in proton-proton collisions at sqrt(s) = 7 TeV. The full data set acquired in 2010 is used, corresponding to an integrated luminosity of 37 pb^-1. The background, consisting of hadronic jets and isolated electrons, is estimated with fully data-driven techniques and subtracted. The differential cross-sections, as functions of the di-photon mass, total transverse momentum and azimuthal separation, are presented and compared to the predictions of next-to-leading-order QCD.Comment: 15 pages plus author list (27 pages total), 9 figures, 2 tables, final version to appear in Physical Review