20,667 research outputs found
Control of spiral waves and turbulent states in a cardiac model by travelling-wave perturbations
We propose a travelling-wave perturbation method to control the
spatiotemporal dynamics in a cardiac model. It is numerically demonstrated that
the method can successfully suppress the wave instability (alternans in action
potential duration) in the one-dimensional case and convert spiral waves and
turbulent states to the normal travelling wave states in the two-dimensional
case. An experimental scheme is suggested which may provide a new design for a
cardiac defibrillator.Comment: 9 pages, 5 figure
catena-Poly[[chloridocopper(I)]-μ-η2,σ1-3-(2-allyl-2H-tetraÂzol-5-yl)pyridine]
The title compound, [CuCl(C9H9N5)]n, prepared by solvoÂthermal synthesis, is a new homometallic CuI–olefin coordination polymer in which the CuI atoms are linked by the 3-(2-allyl-2H-tetraÂzol-5-yl)pyridine ligands and are each bonded to one terminal Cl atom. The organic ligand acts as a bidentate ligand bridging two neighboring Cu centers through the bonds to the N atom of the pyridine ring and the double bond of the allyl group. Weak Cu⋯Cl [3.136 (8) Å), C—H⋯Cl and C—H⋯N interÂactions connect the coordination polymers into a three-dimensional structure
catena-Poly[[di-μ-chlorido-dicopper(I)]bisÂ[μ-η2,σ1-4-(2-allyl-2H-tetraÂzol-5-yl)pyridine]]
The title polymer, [Cu2Cl2(C9H9N5)2]n, has been prepared by the solvothermal treatment of CuCl with 4-(2-allyl-2H-tetraÂzol-5-yl)pyridine. The crystal structure shows that the title compound is a homometallic CuI–olefin coordination polymer, in which the Cu2Cl2 nodes are bridged by two olefin ligands. The asymmetric unit contains one-half of the monomer, the complete monomer having twofold rotation symmetry. The coordination environment of CuI is slightly distorted tetraÂhedral, with coordination sites being two μ2-Cl atoms, one pyridine N atom of an organic ligand and one allylic double bond of a symmetry-related ligand. Each organic molÂecule behaves as a bidentate ligand, connecting two neighboring Cu2Cl2 dimers in the polymeric chain, which runs along [010]
Weak Decays of Doubly Heavy Baryons: Multi-body Decay Channels
The newly-discovered decays into the , but the experimental data has indicated that this decay is not
saturated by any two-body intermediate state. In this work, we analyze the
multi-body weak decays of doubly heavy baryons , ,
, , and , in particular the
three-body nonleptonic decays and four-body semileptonic decays. We classify
various decay modes according to the quark-level transitions and present an
estimate of the typical branching fractions for a few golden decay channels.
Decay amplitudes are then parametrized in terms of a few SU(3) irreducible
amplitudes. With these amplitudes, we find a number of relations for decay
widths, which can be examined in future.Comment: 47pages, 1figure. arXiv admin note: substantial text overlap with
arXiv:1707.0657
Exact Single-Source SimRank Computation on Large Graphs
SimRank is a popular measurement for evaluating the node-to-node similarities
based on the graph topology. In recent years, single-source and top- SimRank
queries have received increasing attention due to their applications in web
mining, social network analysis, and spam detection. However, a fundamental
obstacle in studying SimRank has been the lack of ground truths. The only exact
algorithm, Power Method, is computationally infeasible on graphs with more than
nodes. Consequently, no existing work has evaluated the actual
trade-offs between query time and accuracy on large real-world graphs. In this
paper, we present ExactSim, the first algorithm that computes the exact
single-source and top- SimRank results on large graphs. With high
probability, this algorithm produces ground truths with a rigorous theoretical
guarantee. We conduct extensive experiments on real-world datasets to
demonstrate the efficiency of ExactSim. The results show that ExactSim provides
the ground truth for any single-source SimRank query with a precision up to 7
decimal places within a reasonable query time.Comment: ACM SIGMOD 202
catena-Poly[[bromidocopper(I)]-μ-η2,σ1-3-(2-allyl-2H-tetraÂzol-5-yl)pyridine]
The title compound, [CuBr(C9H9N5)]n, has been prepared by the solvothermal treatment of CuBr with 3-(2-allyl-2H-tetraÂzol-5-yl)pyridine. It is a new homometallic CuI olefin coordÂination polymer in which the CuI atoms are linked by the 3-(2-allyl-2H-tetraÂzol-5-yl)pyridine ligands and bonded to one terminal Br atom each. The organic ligand acts as a bidentate ligand connecting two neighboring Cu centers through the N atom of the pyridine ring and the double bond of the allyl group. A three-dimensional structure is formed through weak Cu—Br [3.1579 (8) Å], C—H⋯Br and C—H⋯N interÂactions
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