Bilinear and quadratic Hamiltonians in two-mode cavity quantum electrodynamics

In this work we show how to engineer bilinear and quadratic Hamiltonians in cavity quantum electrodynamics (QED) through the interaction of a single driven two-level atom with cavity modes. The validity of the engineered Hamiltonians is numerically analyzed even considering the effects of both dissipative mechanisms, the cavity field and the atom. The present scheme can be used, in both optical and microwave regimes, for quantum state preparation, the implementation of quantum logical operations, and fundamental tests of quantum theory.Comment: 11 pages, 3 figure

Estabelecimento de vochysia tucanorum (C.K. spreng.) mart. (vochysiaceae) em área sombreada e aberta.

Respostas de longo prazo tais como o desenvolvimento inicial, a taxa de sobrevivência, a concentração de nutrientes foliares e o conteúdo de clorofila foram determinados para avaliar a performance de indivíduos jovens de Vochysia tucanorum (C.K.Spreng.) Mart. crescendo sob sombra ou em área aberta. As trocas gasosas foliares e a fluorescência da clorofila foram determinadas durante os cursos diários nas estações seca e chuvosa para se obter respostas imediatas do balanço hídrico e de carbono. Sob sombra ocorreu um efeito negativo e significativo na taxa de sobrevivência e crescimento..

Una aproximación a la figura de Johann Wolfgang von Goethe como educador: el caso de Peter im Baumgarten

Acabamos de celebrar el 260 aniversario del nacimiento de Goethe. La mayoría de los entendidos ubica a este polifacético y extraordinario autor en el mundo de la literatura, principalmente por su obra “Fausto” y las implicaciones de esta enorme creación literaria. Sin embargo, las ciencias naturales ejercieron siempre en la vida de Goethe una profunda atracción, aunque esa parte de su pensamiento sea menos conocida. La vida de Goethe fue de una riqueza e intensidad admirables. Su amplia y extensa actividad queda muy bien reflejada en sus obras que en ocasiones tienen parte de autobiográfico, así como en su diario y su abundante correspondencia. En este artículo abordaremos colateralmente un aspecto apenas conocido dentro de los intereses científicos de Goethe, a saber, la ingeniería forestal. Para ello nos centraremos principalmente en la vida de un adolescente suizo, Peter im Baumgarten, al que Goethe acogió como tutor proporcionándole una buena formación como forestal. Podremos comprobar así un aspecto muy humano de la personalidad de Goethe y su compromiso por la educación y la formación, en especial de los más jóvenes.We have just celebrated the 260th anniversary of Goethe’s birth. The majority of experts associate this multifaceted, extraordinary author with literature, primarily for his work “Faust” and the implications of this great literary creation. However, natural sciences always attracted Goethe’s attention, but this part of his work is less well-known. Goethe had a very intense life. His extensive activity is present in his works and at times reflects an autobiographical character. In this article we will collaterally discuss a barely known aspect of Goethe’s scientific interests, namely, forest engineering. In order to discuss this aspect we will focus primarily on the life of a Swiss teenager, Peter im Baumgarten, whom Goethe personally tutored and taught much forest engineering. Thus, we shall confirm a private aspect of Goethe’s personality and his commitment to education, especially with respect to young people.peerReviewe

Acrocarpus fraxinifolius Wight & Arn.

Seminário realizado em Curitiba, de 6 a 8 de outubro de 1998

Effects of contrasting irradiances on carbon balance, biomass partition, and leaf nutrient contents in brazilian cerrado woody species.

It was evaluated growth and photosynthetic peformance of two leguminosae woody species under contrasting irradiances environments, Anadenanthera falcata (Benth.) Speg. and Stryphnodendron adstringens (Mart.) Coville. Under total irradiance in open area both species presented greater biomass accumulation, height, stem diameter, total leaf area and higher photosynthetic capacity on area bases (Amaxa). Shaded individuals under canopy modified the biomass partition, presenting greater mean values of leaf area rate (LAR), and smaller values of the specific leaf mass (SLM), repiration in dark (Rd), and apparent photorespiration (Pr) , apparent carboxylation efficiency (eletron transport rate (J). High transitory concentrations of CO2 increased the photosynthetic capacity under total irradiance (83%) and under canopy (71%)

Nonadiabatic coherent evolution of two-level systems under spontaneous decay

In this paper we extend current perspectives in engineering reservoirs by producing a time-dependent master equation leading to a nonstationary superposition equilibrium state that can be nonadiabatically controlled by the system-reservoir parameters. Working with an ion trapped inside a nonindeal cavity we first engineer effective Hamiltonians that couple the electronic states of the ion with the cavity mode. Subsequently, two classes of decoherence-free evolution of the superposition of the ground and decaying excited levels are achieved: those with time-dependent azimuthal or polar angle. As an application, we generalise the purpose of an earlier study [Phys. Rev. Lett. 96, 150403 (2006)], showing how to observe the geometric phases acquired by the protected nonstationary states even under a nonadiabatic evolution.Comment: 5 pages, no figure

Hacia una cultura de la sostenibilidad a través de los textos de Goethe

Se celebra este año el 260 aniversario del nacimiento de Goethe inmersos en pleno Decenio de las Naciones Unidas de la Educación para el Desarrollo Sostenible y el Cambio Climático. Nos gustaría con este artículo rescatar la aportación personal y profesional de Goethe al desarrollo sostenible, tras haber detectado una tendencia generalizada a ubicar a este polifacético autor en el mundo de la literatura. La participación de Goethe en actividades oficiales dirigidas a promover la sostenibilidad, tales como su presencia en el Geheimrat, el impulso al sector de la minería, su preocupación por encontrar energías alternativas, la supervisión de las plantaciones en el Ducado de Sajonia-Weimar-Eisenach, la lucha contra las plagas de parásitos forestales, su interés por la formación forestal etc., dan muestra del compromiso de Goethe con el medioambiente.This year we celebrate the 260th anniversary of Goethe’s birth, which also coincides with the UNESCO’s decade long project for the education of sustainable development and climate change. With this article, we would like to discover both Goethe’s personal and professional contribution to the sustainable development, because we have detected a general tendency to place this multi-faceted author in the world of literature. Goethe’s participation in public activities, which are directed to promote the sustainability include examples such as: his presence in Geheimrat, the push towards the mining sector, his concern to find alternative energies, the supervision of the Duchy of Saxe-Weimar-Eisenach plantations, the fight against the plague of forest parasites, his interest in forestry education, etc. The previously mentioned examples show Goethe’s intense concern for the environment

A Study of Single- and Double-Averaged Second-Order Models to Evaluate Third-Body Perturbation Considering Elliptic Orbits for the Perturbing Body

The equations for the variations of the Keplerian elements of the orbit of a spacecraft perturbed by a third body are developed using a single average over the motion of the spacecraft, considering an elliptic orbit for the disturbing body. A comparison is made between this approach and the more used double averaged technique, as well as with the full elliptic restricted three-body problem. the disturbing function is expanded in Legendre polynomials up to the second order in both cases. the equations of motion are obtained from the planetary equations, and several numerical simulations are made to show the evolution of the orbit of the spacecraft. Some characteristics known from the circular perturbing body are studied: circular, elliptic equatorial, and frozen orbits. Different initial eccentricities for the perturbed body are considered, since the effect of this variable is one of the goals of the present study. the results show the impact of this parameter as well as the differences between both models compared to the full elliptic restricted three-body problem. Regions below, near, and above the critical angle of the third-body perturbation are considered, as well as different altitudes for the orbit of the spacecraft.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Inst Nacl Pesquisas Espaciais, BR-12227010 Sao Jose Dos Campos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, BR-12231280 Sao Jose Dos Campos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, BR-12231280 Sao Jose Dos Campos, SP, BrazilCNPq: 150195/2012-5CNPq: 304700/2009-6FAPESP: 2011/09310-7FAPESP: 2011/08171-3Web of Scienc