991 resultados para COOPER


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运用相对论平均场理论结合Wigner-Seitz近似,研究了致密物质中电子气体对56Fe和120Sr结构的影响,对关联的处理采用Bardeen-Cooper-Schrieffer方法.结果表明电子气体对单粒子能级、核子密度分布、核子分布均方根半径、原子核均方根半径等性质都有影响,并且对质子的影响大于对中子的影响.

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The proton and neutron S-1(0), pairing gaps and their isospin dependence in isospin asymmetric nuclear matter have been studied by the isospin dependent Brueckner-Hartree-Fock approach and the BCS theory. We have focused on investigating and discussing the effect of three-body force. The calculated results indicate that as the isospin asymmetry increases, the density range of the S-1(0) neutron superfluidity is narrowed slightly and the maximum value of the neutron pairing gap increases 9 while the density domain for the proton superfluidity enlarges rapidly and the peak value of the proton gap decreases remarkably. The three-body force turns out to affect only weakly the neutron S-1(0) superfluidity and its isospin dependence, i. e., it leads to a small reduction of the neutron S-1(0) paring gap. However, the three-body force not only reduces largely the strength of the proton S-1(0) gaps at high densities in highly asymmetric nuclear matter but also suppresses strongly the density domain for the proton S-1(0) superfluidity phase.

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The isospin dependence of the effective pairing interaction is discussed on the basis of the Bardeen, Cooper, and Schrieffer theory of superfluid asymmetric nuclear matter. It is shown that the energy gap, calculated within the mean field approximation in the range from symmetric nuclear matter to pure neutron matter, is not linearly dependent on the symmetry parameter owing to the nonlinear structure of the gap equation. Moreover, the construction of a zero-range effective pairing interaction compatible with the neutron and proton gaps in homogeneous matter is investigated, along with some recent proposals of isospin dependence tested on the nuclear data table.

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A new methodology is described for the one-step aqueous preparation of highly monodisperse gold nanoparticles with diameters below 5 nm using thioether- and thiol-functionalized polymer ligands. The particle size and size distribution was controlled by subtle variation of the polymer structure. It was shown that poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) were the most effective stabilizing polymers in the group studied and that relatively low molar mass ligands (similar to 2500 g/mol) gave rise to the narrowest particle size distributions. Particle uniformity and colloidal stability to changes in ionic strength and pH were strongly affected by the hydrophobicity of the ligand end group. "Multidentate" thiol-terminated ligands were produced by employing dithiols and tetrathiols as chain-transfer agents, and these ligands gave rise to particles with unprecedented control over particle size and enhanced colloidal stability. It was found throughout that dynamic light scattering (DLS) is a very useful corroboratory technique for characterization of these gold nanoparticles in addition to optical spectroscopy and TEM.

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本文给出了U原子的HFS和Cooper势外壳层光电离截面的计算方法和计算结果。因为我们所编的Cooper模型势程序给出了从特定组态的某一个光谱项光电离的截面值,所以能将壳层相同、而所处的能级位置和光谱项不同的原子光电离截面值区别开。

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The taxicab provides a significant contribution to the accessibility of a city and provides a wide range of services across many social groups. Considering the role of the taxi this books examines the impacts that the mode currently has, and how it may continue to develop in the provision of access within the city.

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Urquhart, C., Light, A., Thomas, R., Barker, A., Yeoman, A., Cooper, J., Armstrong, C., Fenton, R., Lonsdale, R. & Spink, S. (2003). Critical incident technique and explicitation interviewing in studies of information behavior. Library and Information Science Research, 25(1), 63-88. Sponsorship: JISC (for JUSTEIS element)

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Cooper, J. & Urquhart, C. (2005). Developing an effective electronic social care record for care in the home. In J. Bryant (Ed.), Current Perspectives in Healthcare Computing conference, Harrogate 21-23 March 2005 (CD-ROM). Swindon: BCS HIC Sponsorship: AHRC

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Cooper, J. & Urquhart, C. (2004). Confidentiality issues in information systems in social care. In K. Grant, D.A. Edgar & M. Jordan (Eds.), Reflections on the past, making sense of today and predicting the future of information systems, 9th annual UKAIS (UK Academy of Information Systems) conference proceedings, Annual conference, 5-7 May 2004, Glasgow Caledonian University (CD-ROM). Glasgow: Glasgow Caledonian University for UKAIS Sponsorship: AHRC

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Cooper, J. & Urquhart, C. (2005). The information needs and information-seeking behaviours of home-care workers and clients receiving home care. Health Information and Libraries Journal, 22(2), 107-116. Sponsorship: AHRC