4,754 research outputs found

    Oscillatory behavior of light in the composite Goos-Hanchen shift

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    Sem informaçãoFor incidence in the critical region, the propagation of Gaussian lasers through dielectric blocks is characterized by the joint action of angular deviations and lateral displacements. This mixed effect, known as the composite Goos-Hanchen shift, produces a lateral displacement that is dependent on the axial coordinate, recently confirmed by a weak measurement experiment. We discuss under which conditions this axial lateral displacement, which only exists for the composite Goos-Hanchen shift, presents an oscillatory behavior. This oscillation phenomenon shows a peculiar behavior of light for critical incidence and, if experimentally tested, could stimulate further theoretical studies and lead to interesting optical applications.95519Sem informaçãoSem informaçãoSem informaçã

    O papel e os desafios do fórum no enfoque do desenvolvimento territorial.

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    neste artigo apresenta a discussão, os objetivos, o resultado e o funcionamento do fórum como espaço de novas governanças nos territórios, o qual se constitui um dos eixos no projeto desenvolvido pela Embrapa, Cirad e Fao, em quatro município do Piauí e Pernambuco

    First-order transitions and triple point on a random p-spin interaction model

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    The effects of competing quadrupolar- and spin-glass orderings are investigated on a spin-1 Ising model with infinite-range random pp-spin interactions. The model is studied through the replica approach and a phase diagram is obtained in the limit pp\to\infty. The phase diagram, obtained within replica-symmetry breaking, exhibits a very unusual feature in magnetic models: three first-order transition lines meeting at a commom triple point, where all phases of the model coexist.Comment: 9 pages, 2 ps figures include

    Seasonal distribution and sex ratio of eleven noctuid species (Insecta, Lepidoptera) captured in blacklight traps on Terceira Island (Azores)

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    The adult flight periods of Agrotis segetum (DENNIS & SCHIFFERMÜLLER), Noctua pronuba (LINNAEUS), Noctua atlantica (WARREN), Peridroma saucia (HÜBNER), Xestia c-nigrum (LINNAEUS), Mythimna loreyi (DUPONCHEL), Phlogophora meticulosa (LINNAEUS), Phlogophora interrupta(WARREN), Mesapamea storai (REBEL), Autographa gamma (LINNAEUS), and Trichoplusia orichalcea (FABRICIUS) (Lepidoptera: Noctuidae) were studied between November 1992 and November 1993, at Terra Chã (110 m), Granja (310 m), Fajãs (310 m) and Santa Bárbara (525 m) on the island of Terceira, Azores archipelago, using Pennsylvania blacklight traps. While there was evidence of considerable fluctuations in abundance, A. segetum, P. saucia, X. c-nigrum, M. loreyi and P. meticulosa were present continuously at Santa Bárbara. In contrast N. pronuba, N. atlantica, M. storai, P. interrupta, A. gamma, and T. orichalcea were generally captured from Spring to beginning of Autumn. For any given species both sexes were captured simultaneously. Males of X. c-nigrum, P. meticulosa (Santa Bárbara), A. segetum and M. storai (Fajãs) were more frequent than females, while in the other species females were more abundant. However, in no case does the sex ratio deviates entirely from 1:1. Under an integrated pest management perspective, blacklight trap is an important technique for agricultural warning services, allowing to forecast the outbreaks of agricultural pests

    Relações entre a contribuição da fixação biológica de nitrogênio e a duração do ciclo de diferentes genótipos de cultivos de leguminosas de grãos.

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    Contribuição da FBN por culturas de diferentes ciclos; A senescência dos nódulos como fator limitante da FBN em genótipos de ciclo curto; Mecanismos da senescência precoce dos nódulos.bitstream/CPAMN-2010/24174/1/doc197.pd

    Produção de morango no Distrito Federal.

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    O morangueiro no Distrito Federal; Perfil dos produtores; Práticas culturais; Controle fitossanitário; Comercialização; Dificuldades e desafios.bitstream/item/109187/1/CNPH-PROD.-DE-MORAN.-DO-DF.-09.pd

    Anatomia foliar do dendezeiro, do caiaué e do híbrido interespecífico nas condições da Amazônia.

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    Apesar da importância que apresentam as espécies, estudos relacionados ao conhecimento das características anatômicas das folhas são escassos nas condições do trópico brasileiro. Foi realizada uma descrição da anatomia dos tecidos foliares, como epiderme e mesófilo, do dendezeiro, do caiaué e do HIE
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