3,118 research outputs found
Radiative penguin Bs decays at Belle
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 SS at the Oxygen Evolving Complex with the Spin Marker under the Photoelectric Polarization
Water oxidation in the oxygen evolving complex (OEC) of the photosystem II is
catalyzed by the core cluster CaMnO which was projected to experience
five intermediate states S() 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 SS
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 S 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 S 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
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
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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