38,122 research outputs found

    Kinetics and mechanism of formic acid decomposition on Ru(001)

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    The steady-state rate of decomposition of formic acid on Ru(001) has been measured as a function of surface temperature, parametric in the pressure of formic acid. The products of the decomposition reaction are C0_2, H_2, CO, and H_2)0, i.e., both dehydrogenation and dehydration occur on Ru (001). A similar product distribution has been observed on Ni(110), Ni(100), Ru(100), Fe(100), and Ni(111) surfaces; whereas only dehydrogenation to C0_2 and H_2 occurs on the Cu(100), Cu(110), and Pt(111) surfaces. Only reversible adsorption and desorption of formic acid is observed on the less reactive Ag(110) surface at low temperatures, whereas the more reactive Mo(100) surface is oxidized by formic acid at low temperatures with the products of this reaction being H_2, CO, and H_(2)O (Ref. 10). We report here the confirmation of earlier observations of the occurrence of both dehydrogenation and dehydration of formic acid on Ru(001), and more importantly, we provide a detailed mechanistic description of the steady-state decomposition reaction on this surface in terms of elementary steps

    Neural processes of proactive and reactive controls modulated by motor-skill experiences

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    This study investigated the experience of open and closed motor skills on modulating proactive and reactive control processes in task switching. Fifty-four participants who were open-skilled

    Measurement of Cosmic-ray Muons and Muon-induced Neutrons in the Aberdeen Tunnel Underground Laboratory

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    We have measured the muon flux and production rate of muon-induced neutrons at a depth of 611 m water equivalent. Our apparatus comprises three layers of crossed plastic scintillator hodoscopes for tracking the incident cosmic-ray muons and 760 L of gadolinium-doped liquid scintillator for producing and detecting neutrons. The vertical muon intensity was measured to be Iμ=(5.7±0.6)×10−6I_{\mu} = (5.7 \pm 0.6) \times 10^{-6} cm−2^{-2}s−1^{-1}sr−1^{-1}. The yield of muon-induced neutrons in the liquid scintillator was determined to be Yn=(1.19±0.08(stat)±0.21(syst))×10−4Y_{n} = (1.19 \pm 0.08 (stat) \pm 0.21 (syst)) \times 10^{-4} neutrons/(μ⋅\mu\cdotg⋅\cdotcm−2^{-2}). A fit to the recently measured neutron yields at different depths gave a mean muon energy dependence of ⟨Eμ⟩0.76±0.03\left\langle E_{\mu} \right\rangle^{0.76 \pm 0.03} for liquid-scintillator targets.Comment: 14 pages, 17 figures, 3 table
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