Competition of coagulation sink and source rate: New particle formation in the Pearl River Delta of China

The coagulation sink and its role in new particle formation are investigated based on data obtained during the PRIDE-PRD2004 campaign at Xinken of Pearl River Delta, China. Analysis of size distributions and mode contributions of the coagulation sink show that the observed higher load of accumulation mode particles impose a significant effect on the coagulation sink and result in higher coagulation sinks at Xinken despite of the lower total particle number compared with other areas. Hence it is concluded that the higher coagulation sink may depress the occurrence frequency of new particle formation events. The strategies targeting at controlling accumulation mode particles may have influenc…

Inside Front Cover: Redox-Tunable Defects in Colloidal Photonic Crystals (Adv. Mater. 20/2005)

The inside front cover illustrates reversible tuning of an intragap transmitting state induced by redox cycling, accomplished using a redox-active polyferrocenylsilane polyelectrolyte multilayer planar defect embedded in a colloidal photonic crystal (CPC) synthesized by a bottom–up method combining colloidal self-assembly and microcontact printing. In work reported on p. 2455 by Manners, Ozin, and co-workers, the wavelength position of the defect state can be changed by changing the oxidation state of the ferrocene moieties in the polymer backbone. This could find applications in electrochemically tunable microcavities, and—if light emitters are incorporated—electrochemically tunable CPC-ba…

Physicochemical uptake and release of volatile organic compounds by soil in coated-wall flow tube experiments with ambient air

Volatile organic compounds (VOCs) play a key role in atmospheric chemistry. Emission and deposition on soil have been suggested as important sources and sinks of atmospheric trace gases. The exchange characteristics and heterogeneous chemistry of VOCs on soil, however, are not well understood. We used a newly designed differential coated-wall flow tube system to investigate the long-term variability of bidirectional air–soil exchange of 13 VOCs under ambient air conditions of an urban background site in Beijing. Sterilized soil was investigated to address physicochemical processes and heterogeneous/multiphase reactions independently from biological activity. Most VOCs revealed net depositio…

Redox-Tunable Defects in Colloidal Photonic Crystals