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1.
In this paper we study random orderings of the integers with a certain invariance property. We describe all such orders in a simple way. We define and represent random shuffles of a countable set of labels and then give an interpretation of these orders in terms of a class of generalized riffle shuffles. 相似文献
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Mariana Weissmann Andres Saul 《Physica C: Superconductivity and its Applications》1991,180(5-6):381-386
An alloy model is proposed for the electronic structure of high-temperature superconductors. It is based on the assumption that holes and extra electrons are localized in small copper-oxygen clusters, that would be the components of such an alloy. This model, when used together with quantum chemical calculations on small clusters, can explain the structure observed in the experimental densities of states of both hole and electron superconductors close to the Fermi energy. The main point is the strong dependence of the energy level distribution and composition on the number of electrons in a cluster. The alloy model also suggests a way to correlate Tc with the number of holes, or extra electrons, and the number of adequate clusters to locate them. 相似文献
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Arndt Meier Aaron Goldman Thomas M. Stephen Nicholas B. Jones 《Journal of Quantitative Spectroscopy & Radiative Transfer》2004,83(1):109-113
High-resolution ground-based infrared solar spectra are routinely recorded at the Network for the Detection of Stratospheric Change (NDSC) stations. These data sets play a key role in providing a long-term record of atmospheric composition and their links to climate change. The analysis of observed infrared spectra involves comparison to a computer-modeled atmosphere where knowledge of the air mass distribution is an essential component. This note summarises improvements made to an existing and widely used computer code (FSCATM) to perform refractive ray-tracing and calculation of the air mass distribution. Changes were made towards higher vertical resolution in the troposphere and increased numerical precision. The revised FSCATM improves the analysis of infrared spectra mostly through the more accurate representation of the temperature profile. Air mass differences with respect to earlier versions are documented and are typically <0.7%, exceptions being extreme cases of inversion layers. The current version provides ray tracing and air mass calculations for any terrestrial observation site. The output files are reported in a format compatible with the SFIT and SFIT2 retrieval algorithms, which are widely used for NDSC infrared atmospheric studies. The improved computer code, documentation, reference profiles, and test cases are available electronically. 相似文献
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The germ of an analytic varietyX at a pointxX is said to bequadratic if it is bi-analytically isomorphic to the germ of a cone defined by a system of homogeneous quadratic equations at the origin. Arms, Marsden and Moncrief show in [2] that under certain conditions the analytic germ of a level set of a momentum mapping is quadratic. We discuss related ideas in a more algebraic context by associating to an affine Hamiltonian action a differential graded Lie algebra, which in the presence of an invariant positive complex structure, is formal in the sence of [5].Dedicated to the memory of Bruce Reinhart 相似文献
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Saul Barshay 《Zeitschrift fur Physik C Particles and Fields》1989,45(2):235-251
The electric dipole moment of the neutron will be measured to a precision of 10?25 e-cm in the near future. We explore a new theoretical possibility that P and CP noninvariance leads to a sizable electric dipole moment. We calculate an electric dipole moment of about 10?25 e-cm. In this phenomenological theory, we calculate CP-violating observables in non-leptonic decays from theK 0 ? \(\bar K^0 \) ,Λ 0 ?Λ 0 andK +?K ? systems. In connection with CP noninvariance, the possible observable occurrence of ΔS=2 decays is discussed. We calculate possible branching ratios; in particular that forΞ 0 → π? p can be as high as about 10?6. The possible existence of a weakly interacting, neutral scalar boson, which violates P and CP in the course of its propagation as a virtual particle, is considered. 相似文献
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