Sunlight induces photochemical mineralisation of chromophoric dissolved organic matter (CDOM) to dissolved inorganic carbon (DIC) in inland waters, resulting in carbon dioxide (CO2) emissions to the atmosphere. Photochemical rate modelling is used to determine sunlightinduced CO2 emissions on large spatial and temporal scales. A sensitive model parameter is the wavelength-specific photochemical...

Mixing ratios of seven C1–C5 alkyl nitrates (RONO2) were measured during a 16-month study (August 2001–December 2002) at Tai O, a coastal site 30 km west of central Hong Kong in the Pearl River Delta, the fastest-growing industrial region in the world. The C3–C4 (rather than C1–C2) RONO2 were most abundant throughout the study, showing the importance of photochemical (rather than marine) RONO2 ...

In order to estimate vegetation photosynthesis from remote sensing observations; some critical parameters need to be quantified. From all absorbed light; the plant needs to release any excess that is not used for photosynthesis; by non-photochemical quenching; by fluorescence emission and unregulated thermal dissipation. Non-photochemical quenching (NPQ) processes are controlled photoprotective...

1. The determination of the influence of temperature on the velocity of a photochemical reaction is always of importance. This is particularly true when the mechanism of the reaction is unknown, as in the present instance of the bleaching of visual purple. The usefulness of determining the temperature coefficient lles in this. Photochemical reactions have low temperature coefficients.near unity...

We have developed a photochemical model of thrombotic middle cerebral artery (MCA) occlusion in the guinea pig for investigating factors contributing to the development of cerebral infarction. In this model, cyclic flow reductions (CFRs) after recanalization of the MCA are a common observation and might contribute to the development of cerebral infarction. Therefore, we sought to measure the ti...

Reported herein is a photochemical cascade process that combines the excited-state and ground-state reactivity of chiral organocatalytic intermediates. This strategy directly converts racemic cyclopropanols and α,β-unsaturated aldehydes into stereochemically dense cyclopentanols with exquisite stereoselectivity. Mechanistic investigations have enabled elucidating the origin of the stereoconverg...

We demonstrate a photochemical reaction between graphene and benzoyl peroxide. This reaction introduces spatially localized defects into the graphene basal plane. The reactivity of the single-layer graphene is approximately 14 times higher than that of the double-layer graphene. Our result suggests that photoexcited graphene transfers a hot electron to benzoyl peroxide and induces its decomposi...

Institute of Chemistry, Pedagogical University, Ch^ciriska 5, 25-020 Kielce, Poland Z. Naturforsch. 44b, 1589-1592 (1989); received March 29/July 21, 1989 Photochemical Reactions, Primary Aromatic Amines, Chloromethanes Major products of photochemical reactions of aniline in tetrachloromethane, chloroform and dichloromethane have been isolated and identified. The mechanisms of partial reactions...