Tunable three-dimensional intensity distribution by a pure phase-shifting apodizer

The three-dimensional distribution of light intensity that is modulated by a pure phase-shifting apodizer is studied. Results show that the Strehl ratio can be altered by the proposed apodizer and by the waist width of incident Gaussian beams. By changing geometrical parameters of the proposed apodizer, we can increase the focal depth to several times that of the original system. The proposed apodizer can also be used to realize focal splitting and local minimum of intensity, which may be advantageous for constructing an optical trap. Furthermore, the local minimum of intensity number is tunable by changing the parameters of the apodizer. (c) 2005 Optical Society of America

Superresolution by three-zone pure phase plate with 0, pi, 0 phase variation

Superresolution is very important in imaging and optical storage systems, and has attracted much attention. In this article, concentric three-zone phase plate with 0, pi, 0 phase variation has been investigated numerically to show that this kind of phase plate can be used to obtain three-dimensional superresolution. In addition, the number of intensity maximum, focal depth, focal shift, full-width half-maximum, and relative intensity of side lobe are listed for different radii of the phase zones, which paves the way for design of the phase plate. Therefore, one can choose values of radii for desired intensity distribution in focal region, such as for the purpose of radial superresolution with high focal depth in optical storage. (c) 2006 Elsevier Ltd. All rights reserved.

Raman spectroscopic investigation of pure and ytterbium-doped rare earth silicate crystals

Raman spectroscopy was used to study the molecular structure of a series of selected rare earth (RE) silicate crystals including Y2SiO5 (YSO), LU2SiO5 (LSO), (Lu0.5Y0.5)(2)SiO5 (LYSO) and their ytterbium-doped samples. Raman spectra show resolved bands below 500 cm(-1) region assigned to the modes of SiO4 and oxygen vibrations. Multiple bands indicate the nonequivalence of the RE-O bonds and the lifting of the degeneracy of the RE ion vibration. Low intensity bands below 500 cm(-1) are an indication of impurities. The (SiO4)(4-) tetrahedra are characterized by bands near 200 cm(-1) which show a separation of the components of nu(4) and nu(2), in the 500-700 cm(-1) region which are attributed to the distorting bending vibration and in the 880-1000 cm(-1) region which are attributed to the symmetric and antisymmetric stretching vibrational modes. The majority of the bands in the 300-610 cm(-1) region of Re2SiO5 were found to arise from vibrations involving both Si and RE ions, indicating that there is considerable mixing of Si displacements with Si-O bending modes and RE-0 stretching modes. The Raman spectra of RE silicate crystals were analyzed in terms of the molecular structure of the crystals, which enabled separation of the bands attributed to distinct vibrational units. Copyright (C) 2007 John Wiley & Sons, Ltd.

A voz e a vez de Eva: a nova heroína contemporânea em obras de José Saramago

A proposta deste trabalho é realizar uma análise da figura feminina nos romances Jangada de pedra, História do cerco de Lisboa e Ensaio sobre a cegueira, de José Saramago. Iniciando por uma breve pesquisa da história da mulher como forma de traçar a longa trajetória por que passou até a sua emancipação, o estudo revela, através da análise de diferentes identidades femininas, a abertura de uma nova concepção de mulher na literatura portuguesa.O escritor propõe em sua obra uma reflexão sobre a situação do mundo através do indivíduo e suas atitudes, responsabilidades e anseios. Os ensinamentos que seus romances costumam transmitir aos leitores, na maioria das vezes, partem de personagens femininas. A mulher se completa realizando o papel de mãe, protetora e companheira e, ao mesmo tempo, de amante e guerreira. Considerada pelo presente trabalho uma heroína contemporânea, ela engloba estas duas vertentes que a sociedade por muito tempo insistiu em separar, cuidando da casa e da família ao mesmo tempo em que trabalha e busca seu sustento fora de casa Também é a mulher que, nesta obra, tem o poder da sensibilidade e da compaixão ajudando àqueles que precisam, mesmo quando mal os conhece. E também é ela quem consegue, encantadoramente, metamorfosear-se de menina a mulher, intercalando as imagens de santa e prostituta, sedutora externamente e pura em sua essência.Entretanto, a escrita saramagueana não trata apenas de inibir a matriz patriarcal, ignorando com isso o papel do homem. O que há é o resgate das culturas primitivas matriarcais, com a mulher e o homem governando em igualdade e harmonia. Por este motivo, o homem também é muito importante em seus romances já que, em união com a mulher, incentivado e guiado por ela, partem juntos, através do amor, para uma travessia (humana) existencial, na busca do conhecimento

Etymological notes on Aleut (III). With methodological notes on (Eskimo-Aleut) historical linguistics

[EN] The goal of this contribution is twofold: on the one hand, to review two relatively recent contributions in the field of Eskimo-Aleut historical linguistics in which it is proposed that Eskimo-Aleut languages are related genealogically to Wakashan (Holst 2004) and?/or Nostratic (Krougly-Enke 2008). These contributions can be characterized by saying that their authors have taken little care to be diligent and responsible in the application of the comparative method, and that their familiarity with the languages involved is insufficient. Eskimo-Aleut languages belong to a very exclusive group of language families that have been (and still are) used, sometimes compulsively, in the business of so-called “long-range comparisons”. Those carrying out such studies are very often unaware of the most basic facts regarding the philological and linguistic traditions of those languages, as a result of what mountains of very low quality works with almost no-relevancy for the specialist grow every year to the desperation of the scientific community, whose attitude toward them ranges from the most profound indifference to the toughest (and most explicit) critical tone. Since Basque also belongs to this group of “compare-with-everything-you-come- across” languages, it is my intention to provide the Basque readership with a sort of “pedagogical case” to show that little known languages, far from underrepresented in the field, already have a very long tradition in historical and comparative linguistics, i.e. nobody can approach them without previous acquaintance with the materials. Studies dealing with the methodological inappropriateness of the Moscow School’s Nostratic hypothesis or the incorrectness of many of the proposed new taxonomic Amerindian subfamilies (several of them involving the aforementioned Wakashan languages), that is to say, the frameworks on which Krougly-Enke and Holst work, respectively, are plenty (i.a. Campbell 1997: 260-329, Campbell & Poser 2008: 234-96), therefore there is no reason to insist once more on the very same point. This is the reason why I will not discuss per se Eskimo-Aleut–Wakashan or Eskimo-Aleut–Nostratic. On the contrary, I will focus attention upon very concrete aspects of Krougly-Enke and Holst´s proposals, i.e. when they work on “less ambitious” problems, for example, dealing with the minutiae of internal facts or analyzing certain words from the sole perspective of Eskimo-Aleut materials (in other words, those cases in which even they do not invoke the ad hoc help of Nostratic stuff). I will try to explain why some of their proposals are wrong, demonstrate where the problem lies, and fix it if possible. In doing so, I will propose new etymologies in an attempt at showing how we may proceed. The main difference between this and handbook examples lies in the reality of what we are doing: this is a pure etymological exercise from beginning to end. I will try to throw a bit of light on a couple of problematic questions regarding Aleut historical phonology, demonstrating how much work should be done at the lowest level of the Eskimo-Aleut pyramid; it is technically impossible to reach the peak of the pyramid without having completed the base. As far as Aleut is regarded, I will mainly profit not only from the use of the traditional philological analysis of Aleut (and, eventually, of Eskimo) materials, but also of diachronic typology, bringing into discussion what in my opinion seems useful, and in some cases I think decisive, parallels. It is worth noting that this paper makes up yet another part of a series of exploratory works dealing with etymological aspects of the reconstruction of Proto-Eskimo-Aleut, with special emphasis on Aleut (vid. i.a. Alonso de la Fuente 2006/2007, 2008a, 2008b, 2010a), whose main goal is to become the solid basis for an etymological dictionary of the Aleut language, currently in progress.

Autonomia legislativa e participação igualitária: o Direito Político de Jean-Jacques Rousseau no desenvolvimento do problema teológico-político da modernidade

O presente trabalho tem por objetivo apresentar os conceitos de lei e soberania no Contrato Social de Rousseau sob uma perspectiva histórico-filosófica, retratando o surgimento do modelo filosófico-jurídico da legitimação do poder a o nascimento (ou renascimento, a depender de como se considere o período imperial romano) do conceito de soberania como completa liberdade em relação às leis existentes, ou sujeição apenas à própria razão. A partir desse fato histórico, como de outros relativos à filosofia tardoescolástica de Escoto, com sua distinctio formalis ex natura rei que permitiu a emergência de uma antropologia como a de Rousseau, que divide os seres humanos em camadas sobrepostas e o voluntarismo nominalista de Ockham, que permitiu a elaboração de um conceito como vontade geral. Procura-se demonstrar também como a concepção nominalista de um Deus absconditus tornou a justificação de um poder que é pura vontade separada daqueles que ordena ininteligível. Neste sentido, a crise de heteronomia em relação à transcendência que não é pura heteronomia, mas participação na ordem criada acaba gerando uma crise da heteronomia em razão ao poder secular, dando origem à autonomia soberana do povo pela vontade geral.