3,118 research outputs found

    Radiative penguin Bs decays at Belle

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    We report searches for the radiative penguin decays Bs to phi gamma and Bs to gamma gamma based on a 23.6 fb-1 data sample collected with the Belle detector at the KEKB e+e- energy-asymmetric collider operating at the Upsilon(5S) resonance.Comment: On behalf of the Belle Collaboration. To appear in the proceedings of the International Europhysics Conference on High Energy Physics (EPS-HEP2007), Manchester, England, 19-25 July 2007. 3 pages, 2 figure

    Dynamic Evolution of S0_0\simS3_3 at the Oxygen Evolving Complex with the Spin Marker under the Photoelectric Polarization

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    Water oxidation in the oxygen evolving complex (OEC) of the photosystem II is catalyzed by the core cluster CaMn4_4O5_5 which was projected to experience five intermediate states S(i\rm_i) in the Kok's cycle since 1970's. However, the detailed dynamics of state evolutions still remains unclear, albeit with the general fact that the process is initiated by the transfer of photoelectrons with the steady electron donors of the water molecules. Based on density functional simulations, we find that the spin flips of Manganese atoms between the consecutive states in the electric polarization field can be used as a marker to uncover the intricate dynamic evolutions and the underlying dynamics. The dynamic electron and proton transfers and water insertion and dissociation are traced to reveal the evolution pathways of S0_0\simS3_3 with commensurate spin flips towards the exact spin configuration of the next state. In particular, the various water insertions and dissociations at coordination sites of the S2_2 open and closed cubane isomers are predicted with constraints on the necessary spin flips. Our study lays a solid ground for getting through the whole Kok's cycle via the pending S4_4 state that is crucial for dioxygen generation.Comment: 8 pages, 5 figure

    2-[4-tert-Butyl-5-(2-chloro­benz­yl)-1,3-thia­zol-2-yl]isoindoline-1,3-dione

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    In the title compound, C22H19ClN2O2S, the dihedral angle between the phenyl­ene ring and the phthalimide ring system is 4.4 (1)°. There is no hydrogen bonding or π–π stacking in the crystal structure

    Assessing environmental services and disservices of urban street trees. an application of the emergy accounting

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    The urban green infrastructure (UGI), with special focus on street trees, is a very complex engineered ecosystem which plays an important role in generating ecosystem services and, if improperly managed, a number of dis-services to be prevented. This study applies the Emergy Accounting method to the cost and benefit evaluation, in order to establish a non-monetary “supply-side” assessment framework capable to assign an environmental value to each kind of services provided by urban forests and other green infrastructures. Further, the study classifies urban street tree integrated valuation framework into ecosystem services, avoided cost for human health and biodiversity damage, growing/maintenance cost and ecosystem dis-services. In a like manner, the interaction among the three different component flows in street tree ecosystems (costs, benefits and associated dis-services) are compared by means of a ternary diagram. Taking the case of the street ecosystem in Beijing, China, eleven typical urban tree species, including oak, maple, Chinese ash and linden, are selected for services and dis-services evaluation. Results show that, in general, UGI provides a large number of services to urban population, but it may also generate dis-services affecting human health, well-being and biodiversity when tree selection, location and management is not accurate. Results may help improve management practices which enhance the overall ecosystem service provision by urban forests not only in Beijing as case study but also in other cities by means of appropriate management
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