16 research outputs found

    Role of beam polarization in the determination of WWγWW\gamma and WWZWWZ couplings from e+e−→W+W−e^+e^-\to W^+W^-

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    We evaluate the constraints on anomalous trilinear gauge-boson couplings that can be obtained from the study of electron-positron annihilation into WW pairs at a facility with either the electron beam longitudinally polarized or both electron and positron beams transversely polarized. The energy ranges considered in the analysis are the ones relevant to the next-linear collider and to LEP~200. We discuss the possibilities of a model independent analysis of the general CPCP conserving anomalous effective Lagrangian, as well as its restriction to some specific models with reduced number of independent couplings. The combination of observables with initial and final state polarizations allows to separately constrain the different couplings and to improve the corresponding numerical bounds.Comment: 24 pages, LaTeX, 9 figures (available on request from the authors

    Four new biflavonoids from Selaginella uncinata and their anti-anoxic effect

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    National Basic Research Program of China [2006CB504100]The 60% ethanolic extract of Selaginella uncinata (Desv.) Spring possessed potent anti-anoxic effect in the anoxic PC12 cell assay. A phytochemical study of its EtOAc-soluble part led to the isolation of four new and three known biflavonoids. Their structures were established on the basis of physico-chemical properties and spectroscopic analysis. The absolute configurations of the new compounds were determined with the aid of circular dichroism (CD) spectroscopy. Compounds 4 and 5 showed potent anti-anoxic effect in the anoxic PC12 cell assay

    Evidence for three Kππ resonant states below 1.4 GeV in K+p reactions at 5 GeV/c

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    The study of K+p reactions at an incident momentum of 4.97 GeV/c suggests that the wide enhancement in the (Kππ)+ mass spectrum may be split into several resonant states. In particular, examination of the K*(892)π decay mode indicates the existence of the states K*(1230), K*(1280) and K*(1320), in addition to the well known K*(1420). The K*(1230) and K*(1320) have the properties expected from 1+ states produced by 0+ exchange. © 1967.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Anticorrosion Properties of Modified Nano-TiO2 Films Prepared by Sol-Gel Method

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    National High-Tech Research and Development Program of China (863) [2009AA03Z327]; National Natural Science Foundation of China [21073151, 21173177]TiO2 and B-Fe-Ce-modified TiO2 films were synthesized on the surfaces of 316L stainless steel (316L SS) substrates using a sol-gel and dip-coating method. The properties of the films were characterized by field emission scanning electron microscopy, atomic force microscopy, Raman spectroscopy and energy dispersive spectrometry. The corrosion resistance of the films and their ability to protect stainless steel were investigated by electrochemical impedance spectroscopy and potentiodynamic polarization curves. Both TiO2 and B-Fe-Ce-modified TiO2 films were composed of anatase nanoparticles about 15 and 10 nm in diameter, respectively. Impedance spectra of the stainless steel substrates coated TiO2 films contained semicircles for capacitive reactance in 0.5 mol . L-1 NaCl solution, but the charge transfer resistance of the B-Fe-Ce-TiO2/316L SS electrode was higher than that of the TiO2/316L SS electrode. The potentiodynamic anodic polarization curve of the B-Fe-Ce-TiO2/316L SS electrode showed a larger stable passive region and a higher breakdown potential than the TiO2/316L SS electrode, indicating that the modified film had better corrosion resistance and protective properties for 316L SS

    Electroweak measurements in electron–positron collisions at w-boson-pair energies at lep

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    Contains fulltext : 121524.pdf (preprint version ) (Open Access
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