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21.
Pseudopotential ab initio calculations of several gold carbides, gold nitrides and their third-row analogues have been performed
with the goal of finding species which contain triple bonds with gold. Multiple-bond character has been observed for Cl2AuCH and Cl2AuN. Bonding in these and related compounds is analysed and the reasons why gold prefers single bonds are outlined.
Received: 8 September 1997 / Accepted: 11 December 1997 相似文献
22.
We demonstrate here that the dipole-allowed optical absorption spectrum of a parabolic quantum dot subjected to an external magnetic field reflects the interelectron interaction effects when the spin-orbit (SO) interaction is also taken into account. We have investigated the energy spectra and the dipole-allowed transition energies for up to four interacting electrons parabolically confined, and have uncovered several novel effects in those spectra that are solely due to the SO interaction. 相似文献
23.
Pekka Tukia 《Journal d'Analyse Mathématique》2004,92(1):137-189
A classical Teichmüller sequence is a sequence of quasiconformal mapsf
i with complex dilatations of the form
, where φ is a quadratic differential and 0≤k
i<1 are numbers such thatk
i→1 asi→∞. This situation occurs in the Teichmüller theory when one moves along a Teichmüller geodesic toward the boundary. The central
result is that if τ is a vertical trajectory associated to φ, then there is often, for instance if the sequence is normalized
so thatf
i fix 3 points, a subsequence such thatf
i tend either toward a constant or an injective map of τ (Theorem 4.1). If the limit is injective, it is an embedding of τ
if τ does not contain points such that τ returns infinitely often to every neighborhood of the point. The main idea is to
composef
i locally with a map ϱi so that the composed mapf
iϱi is conformal and coincides withf
i on τ. Normal family arguments are applied to the sequencef
iϱi. Various extensions are presented.
The research for this paper has been supported by the project 51749 of the Academy of Finland. 相似文献
24.
We derive sufficiently sharp local dimension-free estimates for volumes of sublevel sets of analytic functions in the unit
ball of ℂ
n
The research was partially supported by the United States-Israel Binational Science Foundation. 相似文献
25.
We solve a linear parabolic equation in d , d 1, with the third nonhomogeneous boundary condition using the finite element method for discretization in space, and the -method for discretization in time. The convergence of both, the semidiscrete approximations and the fully discretized ones, is analysed. The proofs are based on a generalization of the idea of the elliptic projection. The rate of convergence is derived also for variable time step-sizes. 相似文献
26.
Amir Averbuch Valery Zheludev Pekka Neittaanmäki Pekka Wartiainen Kari Huoman Kim Janson 《Applied Acoustics》2011,(1):22-34
We present a robust algorithm to detect the arrival of a boat of a certain type when other background noises are present. It is done via the analysis of its acoustic signature against an existing database of recorded and processed acoustic signals. We characterize the signals by the distribution of their energies among blocks of wavelet packet coefficients. To derive the acoustic signature of the boat of interest, we use the Best Discriminant Basis method. The decision is made by combining the answers from the Linear Discriminant Analysis (LDA) classifier and from the Classification and Regression Trees (CART) that is also accompanied with an additional unit, called Aisles, that reduces false alarms rate. The proposed algorithm is a generic solution for process control that is based on a learning phase (training) followed by an automatic real time detection while minimizing the false alarms rate. 相似文献
27.
Ahuja R Blomqvist A Larsson P Pyykkö P Zaleski-Ejgierd P 《Physical review letters》2011,106(1):018301
The energies of the solid reactants in the lead-acid battery are calculated ab?initio using two different basis sets at nonrelativistic, scalar-relativistic, and fully relativistic levels, and using several exchange-correlation potentials. The average calculated standard voltage is 2.13?V, compared with the experimental value of 2.11?V. All calculations agree in that 1.7-1.8?V of this standard voltage arise from relativistic effects, mainly from PbO2 but also from PbSO4. 相似文献
28.
The analytic hierarchy process with stochastic judgements 总被引:1,自引:0,他引:1
The analytic hierarchy process (AHP) is a widely-used method for multicriteria decision support based on the hierarchical decomposition of objectives, evaluation of preferences through pairwise comparisons, and a subsequent aggregation into global evaluations. The current paper integrates the AHP with stochastic multicriteria acceptability analysis (SMAA), an inverse-preference method, to allow the pairwise comparisons to be uncertain. A simulation experiment is used to assess how the consistency of judgements and the ability of the SMAA-AHP model to discern the best alternative deteriorates as uncertainty increases. Across a range of simulated problems results indicate that, according to conventional benchmarks, judgements are likely to remain consistent unless uncertainty is severe, but that the presence of uncertainty in almost any degree is sufficient to make the choice of best alternative unclear. 相似文献
29.
30.
The notion of coexistence of quantum observables was introduced to describe the possibility of measuring two or more observables
together. Here we survey the various different formalisations of this notion and their connections. We review examples illustrating
the necessary degrees of unsharpness for two noncommuting observables to be jointly measurable (in one sense of the phrase).
We demonstrate the possibility of measuring together (in another sense of the phrase) noncoexistent observables. This leads
us to a reconsideration of the connection between joint measurability and noncommutativity of observables and of the statistical
and individual aspects of quantum measurements. 相似文献