993 resultados para 207-1257B
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Seguem-se observações preliminares sobre o contingenciamento de 2013, baseadas na 1ª Avaliação de receitas e despesas, anunciada somente em 22 de maio por conta da sanção tardia do orçamento; nos limites de pagamento e de movimentação e empenho das dotações do Executivo do Decreto 8.021/13, de 29 de maio, e da Portaria Ministério do Planejamento 207, de 31 de maio, assim como nas previsões constantes da proposta e da Lei aprovada.
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We report the generation of 207-fs pulses with 1.2mW average power at 1036 nm directly from a passively mode-locked Yb-doped fibre laser with a nonlinear optical loop mirror for mode-locking and pairs of diffraction gratings for intracavity dispersion compensation. These results imply a 4-fold reduction in pulse duration over previously reported figure-of-eight cavity passively mode-locked Yb-doped fibre lasers. Stable pulse trains are produced at the fundamental repetition rate of the resonator, 24.0MHz. On the other hand, this laser offers a cleaner spectrum and greater stability and is completely self-starting.
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本文报道了利用兰州重离子加速器国家实验室的ECR离子源引出的高电荷态离子207Pb36+入射到金属Nb表面产生的二次离子的实验测量结果.实验发现,二次离子产额Y随入射初动能Ek的增加有先增加后减小的关系,在初动能为576 keV时二次离子产额达到最大.通过对实验点做高斯拟合发现,曲线峰值对应的入射初动能为602 keV.分析表明,这是势能沉积作用与线性级联碰撞过程协同作用的结果.高电荷态离子本身携带的高势能沉积在靶表面引起势能溅射,促进了二次离子的发射;而主导二次离子溅射的过程是动能溅射,它与靶表面的动量沉积(核能损)过程密切相关.
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报道了利用兰州重离子加速器国家实验室ECR源引出的高电荷态离子207Pbq+(24≤q≤36)入射到Si(110)表面产生的电子发射的实验测量结果.结果表明,高电荷态离子与固体表面相互作用产生的电子发射产额Y与入射离子的电荷态q、入射角度ψ和入射能量E都有很强的关联.首次发现,电子发射产额Y与入射角度ψ间有接近1/tanψ的关系.理论分析认为,这些过程与基于经典过垒模型的势能电子发射过程密切相关.
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利用能量为 85— 95MeV的1 6O束流 ,通过1 96Pt(1 6O ,5n) 2 0 7Rn反应布居了2 0 7Rn的高自旋态 .实验进行了γ射线的激发函数、γ射线的单谱、衰变谱和γ γ t符合测量 .建立了由 1 7条γ射线组成的2 0 7Rn能级纲图 ,并且基于实验测量的DCO系数建议了各能级的自旋值 .用一个f5 2 价中子空穴与2 0 8Rn核芯耦合定性地解释了2 0 7Rn的低位激发态
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The electron emission induced by highly charged ions Pb-207(q+) (24 <= q <= 36) interacting with Si(110) surface is reported. The result shows that the electron emission yield Y has a strong dependence on the projectile charge state q, incidence angle psi and impact energy E. In fitting the experimental data we found a nearly 1/tan psi dependence of Y. Theoretical analysis shows that these processes are closely related to the process of potential electron emission based on the classical over-the-barrier model.
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116 hojas : ilustraciones, fotográficas a color.
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Anthropogenically deposited lead (Pb) binds efficiently to soil organic matter, which can be mobilized through hydrologically mediated mechanisms, with implications for ecological and potable quality of receiving waters. Lead isotopic ((206)Pb/(207)Pb) ratios change down peat profiles as a consequence of long-term temporal variation in depositional sources, each with distinctive isotopic signatures. This study characterizes differential Pb transport mechanisms from deposition to streams at two small catchments with contrasting soil types in upland Wales, U.K., by determining Pb concentrations and (206)Pb/(207)Pb ratios from soil core profiles, interstitial pore waters, and stream water. Hydrological characteristics of soils are instrumental in determining the location in soil profiles of exported Pb and hence concentration and (206)Pb/(207)Pb ratios in surface waters. The highest Pb concentrations from near-surface soils are mobilized, concomitant with high dissolved organic carbon (DOC) exports, from hydrologically responsive peat soils with preferential shallow subsurface flows, leading to increased Pb concentrations in stream water and isotopic signatures more closely resembling recently deposited Pb. In more minerogenic soils, percolation of water allows Pb, bound to DOC, to be retained in mineral horizons and combined with other groundwater sources, resulting in Pb being transported from throughout the profile with a more geogenic isotopic signature. This study shows that (206)Pb/(207)Pb ratios can enhance our understanding of the provenances and transport mechanisms of Pb and potentially organic matter within upland soils.
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Abbaye Saint-Maur-des-Fossés ; cf. B. de Montfaucon, Bibliotheca bibliothecarum, II, 1739, p. 1141-1143 : "50. 1073. Nicolai de Gorham O. P. sermonum * Hiemata". Ex-libris : F. 1 : "Sti Germani a Pratis". Paris (Saint-Maur-des-Fossés ?).
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