有序熔楔和转捩

本文研究烧蚀表面上的一种尖楔状沟槽,简称熔楔。实验表明,熔楔是边界层转捩区的一种烧蚀现象;在蜂蜡和一些高温材料的球头上,熔楔排列有序,形成规则图象。在所实验的参数范围内,熔楔的条数保持在20条左右,不随来流马赫数、球头半径和烧蚀材料类型不同而改变。在分析研究熔楔内部结构和外流条件的基础上,本文提出熔楔形成机理和内外流动模型的设想,并对熔楔的形态、分布以及由它引导出菱形花纹等现象作了解释。

Free surface vibration in oscillatory convection of half floating zone

Projecting an orthographical grating mask (20pl/mm) on the surface of a small liquid bridge and receiving the reflected distortion image, one can calculate out reversely the shape of free surface of a liquid bridge. In this way we measured the surface shape of a small floating zone and the two-dimensional deformation of its vibration. The mechanism of thermocapillary oscillatory convection and the three-dimensional variation of the free surface are revealed experimentally. The principle for space experiment has been studied in our laboratory.

A factor model of seasonality in stock returns

Published as an article in: The Quarterly Review of Economics and Finance, 2004, vol. 44, issue 2, pages 224-236.

Gestão de documentos no Poder Legislativo: análise do funcionamento de uma Comissão Parlamentar de Inquérito

Estudo de caráter exploratório que visa analisar o funcionamento de uma Comissão Parlamentar de Inquérito da Câmara dos Deputados a partir do ferramental metodológico da gestão de documentos e da arquivologia. A pesquisa foi realizada a partir das fontes primárias do acervo da Comissão Parlamentar de Inquérito da Pirataria de Produtos Industrializados. As unidades da Câmara dos Deputados objeto de análise foram a Coordenação de Arquivo e o Departamento de Comissões. A interpretação dos dados e a discussão teórica apoiaram-se na literatura especializada nas áreas de gestão de documentos, arquivologia, ciência da informação. A implantação da gestão de documentos foi analisada tendo em conta a sua relevância para o alcance da transparência administrativa. Foram analisados os tipos de controle realizados pelos parlamentos e abordadas as principais características das Comissões Parlamentares de Inquérito. Os resultados indicaram que: i) a gestão de documentos é uma importante ferramenta de gerenciamento para as modernas administrações; ii) a aplicação da gestão de documentos nas Comissões Parlamentares de Inquérito pode contribuir para maior eficácia desses instrumentos legislativos de investigação; iii) a implantação de um programa de gestão de documentos possibilita maior acesso do público aos documentos e às informações da instituição.

Desarrollo y optimización de herramientas biotecnológicas para la obtención de material clonal de "Pinus radiata" D. Don

224 p. : il. col.

一个基于非均匀网格上的二阶基本无振荡差分格式

在基本无振荡格式的构造中,将通常的对流通量f的逼近方式推广到对通量导数的逼近,这一构造方法可以有效地应用到非均匀或非结构网格.直接基于非均匀网格上,构造了一个二阶的基本无振荡(ENO)差分格式.该格式具有形式简单,对网格的划分灵活,与传统格式相比不增加计算量等优点.几个数值算例证明了格式的有效性.

Carfentrazone-ethyl Pond Dissipation and Efficacy on Floating Plants

Carfentrazone-ethyl (CE) is a reduced risk herbicide that is currently being evaluated for the control of aquatic weeds. Greenhouse trials were conducted to determine efficacy of CE on water hyacinth ( Eichhornia crassipes (Mart.) Solms- Laub.), water lettuce ( Pistia stratiotes L.), salvinia ( Salvinia minima Baker) and landoltia (Landoltia punctata (G. Mey.) Les & D. J. Crawford ) . CE controlled water lettuce, water hyacinth and salvinia at rates less than the maximum proposed use rate of 224 g ha -1 . Water lettuce was the most susceptible to CE with an EC 90 of 26.9 and 33.0 g ha -1 in two separate trials. Water hyacinth EC 90 values were calculated to be 86.2 to 116.3 g ha -1 , and salvinia had a similar susceptibility to water hyacinth with an EC 90 of 79.1 g ha -1 . Landoltia was not adequately controlled at the rates evaluated. In addition, CE was applied to one-half of a 0.08 ha pond located in North Central, Florida to determine dissipation rates in water and hydrosoil when applied at an equivalent rate of 224 g ha -1 . The half-life of CE plus the primary metabolite, CE-chloropropionic acid, was calculated to be 83.0 h from the whole pond, and no residues were detected in water above the limit of quantification (5 μg L -1 ) 168 h after treatment. CE dissipated rapidly from the water column, did not occur in the sediment above the levels of quantification, and in greenhouse studies effectively controlled three species of aquatic weeds at relatively low rates.(PDF contains 6 pages.)

Superstición y brujería en el Duranguesado a fines de la Edad Media: ¿Amboto 1507?

[ES] En este investigación se analiza el rico mundo de las supersticiones, de la magia, de la hechicería y de la brujería vasca medieval, centrándose especialmente en el foco de brujería que afectó a la comarca del Duranguesado y que ha pasado a la historiografía y a la tradición popular bajo el sobre nombre de brujas del Amboto.

Collecção das Leis do Imperio do Brasil de 1848

Parte 1 - Leis

Collecção das Leis do Imperio do Brasil de 1849

Parte 1 - Decisões

EQUIVALENT MODEL OF EXPANSION OF CEMENT MORTAR UNDER SULPHATE EROSION

The expansion property of cement mortar under the attack of sulfate ions is studied by experimental and theoretical methods. First, cement mortars are fabricated with the ratio of water to cement of 0.4, 0.6, and 0.8. Secondly, the expansion of specimen immerged in sulphate solution is measured at different times. Thirdly, a theoretical model of expansion of cement mortar under sulphate erosion is suggested by virtue of represent volume element method. In this model, the damage evolution due to the interaction between delayed ettringite and cement mortar is taken into account. Finally, the numerical calculation is performed. The numerical and experimental results indicate that the model perfectly describes the expansion of the cement mortar.