729 research outputs found

    Optical Relative Calibration and Stability Monitoring for the Auger Fluorescence Detector

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    The stability of the fluorescence telescopes of the Pierre Auger Observatory is monitored with the optical relative calibration setup. Optical fibers distribute light pulses to three different diffuser groups within the optical system. The total charge per pulse is measured for each pixel and compared with reference calibration measurements. This allows monitoring the short and long term stability with respect of the relative timing between pixels and the relative gain for each pixel. The designs of the LED calibration unit (LCU) and of the Xenon flash lamp used for relative calibration, are described and their capabilities to monitor the stability of the telescope performances are studied. We report the analysis of relative calibration data recorded during 2004. Fluctuations in the relative calibration constants provide a measure of the stability of the FD.Comment: 4 pp. To appear in the proceedings of 29th International Cosmic Ray Conference (ICRC 2005), Pune, India, 3-11 Aug 200

    The Technique Research on Account Information Signing in the Commercial Bank Channel Trade System

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    摘要 在经济全球化发展的大背景下,开放和竞争已经成为世界金融发展的主流,银行业的全球竞争将日益激烈。商业银行要想在激烈的市场竞争中立于不败之地并持续发展,就需要加快金融创新、科技创新,提高核心竞争力。随着金融信息化建设的不断深入,商业银行信息系统集中化程度越来越高。正在建立的“账户信息签约系统”将不同的各个孤岛中的账户进行签约处理,使其提供客户的账户信息、银行的交易渠道链接共享,拓展多交易渠道互动及增强交易渠道个性化服务能力,实现跨交易渠道识别客户并通过签约服务应用系统为客户提供方便、快捷的账户信息。 本文分析了商业银行信息资源的特征和服役的各个系统的特点,论证了建立“账户信息签约系统”的...Abstract Under the development of economic globalization, the opening and competition has become the mainstream of financial development in twenty-one century, and the competition between international banks tends to be fiercer. If commercial banks want to succeed in this process and keep developing, they need speed up their financial and technological innovations to improve the core comp...学位:工程硕士院系专业:软件学院_工程硕士(软件工程)学号:X200523001

    Cooper pair sizes in 11Li and in superfluid nuclei: a puzzle?

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    We point out a strong influence of the pairing force on the size of the two neutron Cooper pair in 11^{11}Li, and to a lesser extent also in 6^6He. It seems that these are quite unique situations, since Cooper pair sizes of stable superfluid nuclei are very little influenced by the intensity of pairing, as recently reported. We explore the difference between 11^{11}Li and heavier superfulid nuclei, and discuss reasons for the exceptional situation in 11^{11}Li.Comment: 9 pages. To be published in J. of Phys. G special issue on Open Problems in Nuclear Structure (OPeNST

    Fragmentation in Peripheral Heavy-Ion Collisions: from Neck Emission to Spectator Decays

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    Invariant cross sections of intermediate mass fragments in peripheral collisions of Au on Au at incident energies between 40 and 150 AMeV have been measured with the 4-pi multi-detector INDRA. The maximum of the fragment production is located near mid-rapidity at the lower energies and moves gradually towards the projectile and target rapidities as the energy is increased. Schematic calculations within an extended Goldhaber model suggest that the observed cross-section distributions and their evolution with energy are predominantly the result of the clustering requirement for the emerging fragments and of their Coulomb repulsion from the projectile and target residues. The quantitative comparison with transverse energy spectra and fragment charge distributions emphasizes the role of hard scattered nucleons in the fragmentation process.Comment: 5 pages, 5 eps figures, RevTeX4, submitted to Phys. Lett.

    Directed flow in Au+Au, Xe+CsI and Ni+Ni collisions and the nuclear equation of state

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    We present new experimental data on directed flow in collisions of Au+Au, Xe+CsI and Ni+Ni at incident energies from 90 to 400A MeV. We study the centrality and system dependence of integral and differential directed flow for particles selected according to charge. All the features of the experimental data are compared with Isospin Quantum Molecular Dynamics (IQMD) model calculations in an attempt to extract information about the nuclear matter equation of state (EoS). We show that the combination of rapidity and transverse momentum analysis of directed flow allow to disentangle various parametrizations in the model. At 400A MeV, a soft EoS with momentum dependent interactions is best suited to explain the experimental data in Au+Au and Xe+CsI, but in case of Ni+Ni the model underpredicts flow for any EoS. At 90A MeV incident beam energy, none of the IQMD parametrizations studied here is able to consistently explain the experimental data.Comment: RevTeX, 20 pages, 30 eps figures, accepted for publication in Phys. Rev. C. Data files available at http://www.gsi.de/~fopiwww/pub

    Radial Flow in Au+Au Collisions at E=0.25-1.15 A GeV

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    A systematic study of energy spectra for light particles emitted at midrapidity from Au+Au collisions at E=0.25-1.15 A GeV reveals a significant non-thermal component consistent with a collective radial flow. This component is evaluated as a function of bombarding energy and event centrality. Comparisons to Quantum Molecular Dynamics (QMD) and Boltzmann-Uehling-Uhlenbeck (BUU) models are made for different equations of state.Comment: 10 pages of text and 4 figures (all ps files in a uuencoded package)

    Upper Bounds on the Neutrino-Nucleon Inelastic Cross Section

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    Extraterrestrial neutrinos can initiate deeply developing air showers, and those that traverse the atmosphere unscathed may produce cascades in the ice or water. Up to now, no such events have been observed. This can be translated into upper limits on the diffuse neutrino flux. On the other hand, the observation of cosmic rays with primary energies > 10^{10} GeV suggests that there is a guaranteed flux of cosmogenic neutrinos, arising from the decay of charged pions (and their muon daughters) produced in proton interactions with the cosmic microwave background. In this work, armed with these cosmogenic neutrinos and the increased exposure of neutrino telescopes we bring up-to-date model-independent upper bounds on the neutrino-nucleon inelastic cross section. Uncertainties in the cosmogenic neutrino flux are discussed and taken into account in our analysis. The prospects for improving these bounds with the Pierre Auger Observatory are also estimated. The unprecedented statistics to be collected by this experiment in 6 yr of operation will probe the neutrino-nucleon inelastic cross section at the level of Standard Model predictions.Comment: To be published in JCA
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