5,868 research outputs found

    Taxonomic changes in the genus Diabrotica Chevrolat (Coleoptera: Chrysomelidae: Galerucinae): results of a synopsis of North and Central America Diabrotica species

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    The following new synonyms in Diabrotica Chevrolat 1836 are proposed: D. flaviventris Jacoby 1887 and D. tibialis Jacoby 1887 are synonyms of D. adelpha Harold 1875; D. peckii Bowditch 1911 is a synonym of D. bioculata Bowditch 1911; D. nummularis Harold 1877 is a synonym of D. circulata Harold 1875; D. linensis Bechyné 1956 is a synonym of D. trifurcata Jacoby 1887; D. brunneosignata Jacoby 1887 is a synonym of D. sinuata Olivier 1790; D. duplicata Jacoby 1887 is a synonym of D. viridifasciata Jacoby 1887. Diabrotica cyaneomaculata Jacoby 1887 does not share the synapo- morphies of Diabrotica and is treated as incertae sedis. Diabrotica tripunctata (Fabricius) is removed from synonymy with D. sinuata Olivier and is considered to be a valid species. The original combination is restored for Diabrotica fasciata Kirsch, the species being transferred from Paranapiacaba Bechyné back to Diabrotica. It was found that the type series of D. godmani Jacoby contains seven different taxa: one is D. godmani itself; one is D. championi Jacoby; one is D. quad- ricollis Jacoby; three are unidentified Diabrotica species, each different from the others; and one is not a Diabrotica. The type series of D. viridicollis Jacoby contains four different taxa, D. viridicollis Jacoby itself and three different unidentified Diabrotica species

    Causal signal transmission by quantum fields. IV: The causal Wick theorem

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    Wick's theorem in the Schwinger-Perel-Keldysh closed-time-loop formalism is written in a form where the place of contractions is taken by the linear response function of the field. This result demonstrates that the physical information supplied by Wick's theorem for operators is propagation of the free field in space and time.Comment: Final version, to appear in Phys Rev

    On the electric charge of quantized vortices and the dipole moment of vortex pairs and rings in a magnetic field

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    It is shown that, in the presence of a magnetic field, a quantized vortex line in a superfluid liquid acquires a linear polarization charge, which is localized near the vortex axis over a length on the order of the coherence length. It is found that the total charge of a rectilinear vortex is nonzero, while the vortex pair and vortex ring have a nonzero dipole moment. The electric fields of rectilinear vortices near the end surface of a cylindrical vessel filled with a superfluid liquid are calculated. The electric polarization of superfluid systems in the presence of thermally activated vortex pairs and vortex rings has been studied. It is shown that such a polarization arises in the presence of relative motion of the normal and superfluid components.Comment: 16 pages, 3 figure

    Simulation of the software-defined network for a high-performance computing cluster

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    The study considers the issues of using the software-defined networks, the current state of the research trends in this area and the most significant projects. The simulation of a high-performance computer network for increase in the performance of the university computing cluster due to the optimization of topology and network traffic between the computational nodes is describe
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