44 research outputs found

    Scattering of massive Dirac particles by a Kink-like potential

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    The scattering state of spin œ particles with Kink-like potential is studied under the massive Dirac equation. We obtain the scattering states in terms of the hypergeometric functions and calculate the reflection coefficient (R) and transmission coefficient (T)

    Dirac Equation under Scalar, Vector, and Tensor Cornell Interactions

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    Spin and pseudospin symmetries of Dirac equation are solved under scalar, vector, and tensor interactions for arbitrary quantum number via the analytical ansatz approach. The spectrum of the system is numerically reported for typical values of the potential parameters

    The plant traits that drive ecosystems: Evidence from three continents.

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    Question: A set of easily‐measured (‘soft’) plant traits has been identified as potentially useful predictors of ecosystem functioning in previous studies. Here we aimed to discover whether the screening techniques remain operational in widely contrasted circumstances, to test for the existence of axes of variation in the particular sets of traits, and to test for their links with ‘harder’ traits of proven importance to ecosystem functioning. Location: central‐western Argentina, central England, northern upland Iran, and north‐eastern Spain. Recurrent patterns of ecological specialization: Through ordination of a matrix of 640 vascular plant taxa by 12 standardized traits, we detected similar patterns of specialization in the four floras. The first PCA axis was identified as an axis of resource capture, usage and release. PCA axis 2 appeared to be a size‐related axis. Individual PCA for each country showed that the same traits remained valuable as predictors of resource capture and utilization in all of them, despite their major differences in climate, biogeography and land‐use. The results were not significantly driven by particular taxa: the main traits determining PCA axis 1 were very similar in eudicotyledons and monocotyledons and Asteraceae, Fabaceae and Poaceae. Links between recurrent suites of ‘soft’ traits and ‘hard’ traits: The validity of PCA axis 1 as a key predictor of resource capture and utilization was tested by comparisons between this axis and values of more rigorously established predictors (‘hard’ traits) for the floras of Argentina and England. PCA axis 1 was correlated with variation in relative growth rate, leaf nitrogen content, and litter decomposition rate. It also coincided with palatability to model generalist herbivores. Therefore, location on PCA axis 1 can be linked to major ecosystem processes in those habitats where the plants are dominant. Conclusion: We confirm the existence at the global scale of a major axis of evolutionary specialization, previously recognised in several local floras. This axis reflects a fundamental trade‐off between rapid acquisition of resources and conservation of resources within well‐protected tissues. These major trends of specialization were maintained across different environmental situations (including differences in the proximate causes of low productivity, i.e. drought or mineral nutrient deficiency). The trends were also consistent across floras and major phylogenetic groups, and were linked with traits directly relevant to ecosystem processes.Fil: DĂ­az, Sandra Myrna. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂ­a Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂ­sicas y Naturales. Instituto Multidisciplinario de BiologĂ­a Vegetal; ArgentinaFil: Hodgson, J.G.. The University. Department of Animal and Plant Sciences. Unit of Comparative Plant Ecology; Reino UnidoFil: Thompson, K.. The University. Department of Animal and Plant Sciences. Unit of Comparative Plant Ecology; Reino UnidoFil: Cabido, Marcelo Ruben. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂ­a Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂ­sicas y Naturales. Instituto Multidisciplinario de BiologĂ­a Vegetal; ArgentinaFil: Cornelissen, Johannes H. C.. Free University. Faculty Earth and Life Sciences. Department of Systems Ecology; PaĂ­ses BajosFil: Funes, Guillermo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂ­a Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂ­sicas y Naturales. Instituto Multidisciplinario de BiologĂ­a Vegetal; ArgentinaFil: PĂ©rez Harguindeguy, Natalia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂ­a Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂ­sicas y Naturales. Instituto Multidisciplinario de BiologĂ­a Vegetal; ArgentinaFil: Vendramini, Fernanda. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂ­a Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂ­sicas y Naturales. Instituto Multidisciplinario de BiologĂ­a Vegetal; ArgentinaFil: Falczuk, Valeria. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂ­a Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂ­sicas y Naturales. Instituto Multidisciplinario de BiologĂ­a Vegetal; ArgentinaFil: Zak, Marcelo RomĂĄn. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto Multidisciplinario de BiologĂ­a Vegetal. Universidad Nacional de CĂłrdoba. Facultad de Ciencias Exactas FĂ­sicas y Naturales. Instituto Multidisciplinario de BiologĂ­a Vegetal; ArgentinaFil: Khoshnevi, M.. Research Institute of Forests and Rangelands; IrĂĄnFil: PĂ©rez RontomĂ©, M. C.. Instituto Pirenaico de EcologĂ­a; EspañaFil: Shirvani, F. A.. Research Institute of Forests and Rangelands; IrĂĄnFil: Yazdani, S.. Research Institute of Forests and Rangelands; IrĂĄnFil: Abbas Azimi, R. Research Institute of Forests and Rangelands; IrĂĄnFil: Bogaard, A. The University. Department of Archaeology and Prehistory; Reino UnidoFil: Boustani, S.. Research Institute of Forests and Rangelands; IrĂĄnFil: Charles, M.. The University. Department of Archaeology and Prehistory; Reino UnidoFil: Dehghan, M.. Research Institute of Forests and Rangelands; IrĂĄnFil: de Torres Espuny, L.. Instituto Pirenaico de EcologĂ­a; EspañaFil: Guerrero Campo, J.. Instituto Pirenaico de EcologĂ­a; EspañaFil: Hynd, A.. The University. Department of Archaeology and Prehistory; Reino UnidoFil: Jones, G.. The University. Department of Archaeology and Prehistory; Reino UnidoFil: Kowsary, E.. Research Institute of Forests and Rangelands; IrĂĄn. Instituto Pirenaico de EcologĂ­a; EspañaFil: Kazemi Saeed, F.. Research Institute of Forests and Rangelands; IrĂĄnFil: Maestro MartĂ­nez, M.. Instituto Pirenaico de EcologĂ­a; EspañaFil: Romo Diez, A.. Instituto Botanico de Barcelona; EspañaFil: Shaw, S.. Research Institute of Forests and Rangelands; IrĂĄn. The University. Department of Animal and Plant Sciences; Reino UnidoFil: Siavash, B.. Research Institute of Forests and Rangelands; IrĂĄnFil: Villar Salvador, P.. Instituto Pirenaico de EcologĂ­a; Españ

    Approximate Solutions of Klein-Gordon Equation with Kratzer Potential

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    Approximate solutions of the D-dimensional Klein-Gordon equation are obtained for the scalar and vector general Kratzer potential for any l by using the ansatz method. The energy behavior is numerically discussed

    Effects of hyperfine interactions on masses of N and Δ baryons

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    Presenting a model for theoretical study of baryon masses, either in relativistic or nonrelativistic area, has always been of great importance and several suggestions have been proposed. On the other hand, taking into account the effects of hyperfine interactions leads to interesting results. In the present work, we first introduce the hyperfine interaction and the quark potential corresponding to the isospin interaction. We then obtain the wavefunctions as well as the corresponding eigenvalues. The obtained results for the spectrum of baryons show a good agreement with experimental results

    Commutative vs. Noncommutative Space Statistical Properties of Two-Dimensional Harmonic Oscillator in Magnetic Field

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    We consider the Schrödinger equation in presence of an external magnetic field in commutative and noncommutative spaces and by solving the equation in an exact analytical manner, report the statistical quantities of the system
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