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121.
Alberto Alexandre Assis Miranda Cláudio Leonardo Lucchesi 《Discrete Applied Mathematics》2010,158(12):1275-1278
A matching covered graph is a non-trivial connected graph in which every edge is in some perfect matching. A non-bipartite matching covered graph G is near-bipartite if there are two edges e1 and e2 such that G−e1−e2 is bipartite and matching covered. In 2000, Fischer and Little characterized Pfaffian near-bipartite graphs in terms of forbidden subgraphs [I. Fischer, C.H.C. Little, A characterization of Pfaffian near bipartite graphs, J. Combin. Theory Ser. B 82 (2001) 175-222.]. However, their characterization does not imply a polynomial time algorithm to recognize near-bipartite Pfaffian graphs. In this article, we give such an algorithm.We define a more general class of matching covered graphs, which we call weakly near-bipartite graphs. This class includes the near-bipartite graphs. We give a polynomial algorithm for recognizing weakly near-bipartite Pfaffian graphs. We also show that Fischer and Little’s characterization of near-bipartite Pfaffian graphs extends to this wider class. 相似文献
122.
Leonardo Colzani 《Annali di Matematica Pura ed Applicata》1984,137(1):207-215
Summary We prove direct and converse theorems of approximation for distributions in the Hardy spaces Hp, 0
相似文献
123.
Leonardo Mora 《Bulletin of the Brazilian Mathematical Society》2011,42(1):25-43
We present a real multidimensional version of the Schwarz Lemma on a bounded convex domain D of ℝ
n
endowed with the Hilbert metric. We provide as an application an extension of a Birkhoff’s Theorem on mappings contracting
the Hilbert metric. 相似文献
124.
Guo Q Brodzeli Z Pozhidaev EP Fan F Chigrinov VG Kwok HS Silvestri L Ladouceur F 《Optics letters》2012,37(12):2343-2345
The electro-optical behavior of deformed helix ferroelectric liquid crystal in reflective mode is described in this paper. The electrically controlled reflectance has been measured at subkilohertz driving voltage frequency for different polarizations of the incident light and compared quite successfully with the simulation results. 相似文献
125.
Calcagni Gianluca Modesto Leonardo Nicolini Piero 《The European Physical Journal C - Particles and Fields》2014,74(8):1-13
Application of the effective action approach to amplitudes with loop integration is studied for collisions on two and three centers with possible gluon emission. A rule is formulated for the integration around pole singularities in the induced vertices which brings the results in agreement with the QCD. It is demonstrated that the amplitudes can be restored from the purely transverse picture by introducing the standard Feynman propagators for intermediate gluons and quarks. 相似文献
126.
The gauging of free differential algebras (FDA's) produces gauge field theories containing antisymmetric tensors. The FDA's extend the Cartan-Maurer equations of ordinary Lie algebras by incorporating p-form potentials (p>1). We study here the algebra of FDA transformations. To every p-form in the FDA, we associate an extended Lie derivative l generating a corresponding gauge transformation. The field theory based on the FDA is invariant under these new transformations. This gives geometrical meaning to the antisymmetric tensors. The algebra of Lie derivatives is shown to close and provides the dual formulation of FDA's. 相似文献
127.
We developed a constituent quark-diquark model for the nucleon and its resonances using a harmonic oscillator potential for
the interaction. The effects due to relativistic kinetic energy correction are studied. Finally, charge form factor of the
model is calculated and compared with experimental data.
相似文献
128.
129.
Lizarraga L Andrade EM Florit MI Molina FV 《The journal of physical chemistry. B》2005,109(40):18815-18821
The quasi-equilibrium electrochemomechanical behavior of relatively thick polyaniline films in sulfuric acid is investigated through experimental measurements and theoretical modeling. The leucoemeraldine (LE)-emeraldine (EM) conversion, or redox switching, is studied. The dependence of film volume and electrochemical charge is determined as a function of applied potential. It is observed that the film volume follows the charge, showing an expansion during the second half of the LE-EM oxidation. The model postulates the existence of a stable intermediate, protoemeraldine (PE), with a formal potential distribution for the PE-EM reaction. The volume change is modeled statistically considering contributions from mixing, polymer deformation, and electrostatic charge. The model shows very good agreement with the experiments, indicating that, in the conditions studied, the deformation contribution dominates the volume changes as a result of the conformational modifications undergone by the polymer in the PE-EM oxidation. 相似文献
130.
We devise a technique for defining and computing -point functions in the context of a background-independent gravitational quantum field theory. We construct a tentative implementation of this technique in a perturbatively finite model defined using spin foam techniques in the context of loop quantum gravity. 相似文献