Ozone data from 13 rural and 11 urban sites for the growth season (April through September) during 1990-2006 have been analysed on the basis of recently introduced photochemical pollution indicators. The indicators predict that urban sites are prone to photochemical pollution, although compared to some rural sites, the urban sites have lower average ozone concentrations and showed lower values ...

Holographic experiments are performed on a series of dual-use chromophore molecules wherein both irreversible photochromic and erasable photorefractive holographic gratings can be written in the same storage volume. At 675 nm, the chromophore undergoes a photochemical reaction leading to the creation of irreversible holographic gratings. Alternatively, at longer wavelengths, application of an e...

We conducted irradiation experiments with riverine, estuarine, and marine water samples to investigate the possibility of photochemical methane (CH4) formation. CH4 photoproduction was undetectable under oxic conditions or in the absence of methyl radical precursors indicating that its photochemical formation is negligible in the present ocean. Significant photochemical CH4 production was obser...

Research into the photochcmistry of biopolymcrs has increased in scope and scale to such an extent in recent years that it has become necessary to limit this review to a consideration of photochemical approaches to the structure of polynucleotides. Treatment proceeds from the constituent monomers to the polymer to emphasize the changes in photophysical and photochemical properties of the monome...

Photochemical reactions contribute in a significant way to the existing repertoire of carbon-carbon bond-forming reactions by allowing access to exceptional molecular structures that cannot be obtained by conventional means. In this Review, the most important photochemical transformations that have been employed in natural product synthesis are presented. Selected total syntheses are discussed ...

Seoul is one of the most severe smoggy cities in the world. During summer afternoons, the fine particles formed by photochemical reactions could contribute visibility reduction. The formation and growth of secondary ambient aerosols might be affected by primary air pollutants and by meteorological factors. In this work, the photochemical reaction of Seoul ambient air was investigated in indoor ...