998 resultados para Heron do Carmo


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本世纪以来对虎斑夜鳽分布地点的新发现,表明该种从滨海到内陆漫布于中国长江以南广大地区,并向北渗透直逼东洋界北限秦岭-淮河一线;作者据此将各地的虎斑夜鳽初划为11个亚群,提出目前该种存有3个相对健康而稳定的亚群,即黄山-天目山亚群、南岭亚群和广西亚群,且每个亚群的分布范围均至少不会小于5000km2,其中以黄山-天目山亚群的记录由历史至现今相对最为长久而完整,进而提出今后在上述诸亚群范围之外还会有新的发现.文中指出,尽管近期对虎斑夜鳽分布状况有了新认识,目前仍可视该种的受胁等级为濒危.

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2006年10月28日凌晨3点,笔者在位于云南省新平县哀牢山的金山丫口鸟类环志站进行夜间鸟类环志工作时,用灯光诱捕到一只鹭科鸟类,经鉴定为海南(Gorsachius magnificus),为云南省鸟类物种新记录。形态特征:头和颊部黑褐色;枕部具黑褐色的延长羽冠;有明显的白色眼后条纹,颊纹白色;眼球外凸,黄绿色的眼睑向外伸出;眼先裸露皮肤呈黄绿色;喉白,中央有褐色条纹;颈侧棕色,前端有黑色条纹,前颈具褐白斑驳的条纹,后颈黑褐色;背部、翅和尾羽褐色;第一枚初级飞羽外栗红色;胸、腹部、尾下覆羽及翅下覆羽白色,杂有褐色斑纹;上嘴黑色,下嘴嘴基黄色,嘴端黑色;虹膜褐色(中国鸟类野外手册上记载的虹膜为黄色,MacKinnon et al,2000);跗黄绿色。雌性标本量度(g,mm)如下:体重563,全长565,嘴峰72,翅长305,尾长111,跗76。海南是中国的特有种鸟类,属国家Ⅱ级重点保护鸟类。分布于中国南方的少数地区,国外仅在越南东京有过一次记录(MacKinnon et al,2000),种群数量稀少,过去曾记录于安徽、浙江、福建(Cheng,1987)、海南、广西及广东(Gao et al,200...

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Measurement of acceleration in dynamic tests is carried out routinely, and in most cases, piezoelectric accelerometers are used at present. However, a new class of instruments based on MEMS technology have become available and are gaining use in many applications due to their small size, low mass and low-cost. This paper describes a centrifuge lateral spreading experiment in which MEMS and piezoelectric accelerometers were placed at similar depths. Good agreement was obtained when the instruments were located in dense sands, but significant differences were observed in loose, liquefiable soils. It was found that the performance of the piezoelectric accelerometer is poor at low frequency, and that the relative phase difference between the piezoelectric and MEMS accelerometer varies significantly at low frequency. © 2010 Taylor & Francis Group, London.

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Most modern design codes do not allow for movement between a shallow foundation and the underlying soil during seismic loading. Consequently, the full magnitude of seismic energy is transmitted from the soil to the foundation during an earthquake. This energy either has to be dissipated before reaching the superstructure via engineering solutions such as base isolation systems, or the structure itself must withstand the full impact of the earthquake resulting in high material usage and expensive design. However, the inherent hysteric behaviour of soil can be used to isolate a foundation from the underlying soil. As part of a study into the soil-structure-interaction of shallow foundations, methods to optimise foundation isolation were investigated. In this paper the results from centrifuge tests investigating two of these methods are compared to results when no special foundation layout was implemented and the impact of the proposed isolation methods is discussed. © 2010 Taylor & Francis Group, London.

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Rock-fill dams are popular in developing countries due to their ease of construction and use of local materials. They are used to store water and to provide flood defences. The presence of such dams in earthquake-prone regions poses risks, particularly from ground liquefaction. In this paper, results from physical model tests on dams with different configurations are presented. Model dams with impermeable cores including sheet pile walls and clay cores were tested and the effect of reservoir water was investigated. High-speed photography was used to capture the response of the model dams allowing the movement of foundation soil below the dam to be established. It is concluded that the stiffness of the impermeable core has a significant influence on the ultimate deformation of the dam. The presence of reservoir water led to increased downstream movements of the dam and differential settlements between the upstream and downstream sides.

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Underground structures constitute crucial components of the transportation networks. Considering their significance for modern societies, their proper seismic design is of great importance. However, this design may become very tricky, accounting of the lack of knowledge regarding their seismic behavior. Several issues that are significantly affecting this behavior (i.e. earth pressures on the structure, seismic shear stresses around the structure, complex deformation modes for rectangular structures during shaking etc.) are still open. The problem is wider for the non-circular (i.e. rectangular) structures, were the soilstructure interaction effects are expected to be maximized. The paper presents representative experimental results from a test case of a series of dynamic centrifuge tests that were performed on rectangular tunnels embedded in dry sand. The tests were carried out at the centrifuge facility of the University of Cambridge, within the Transnational Task of the SERIES EU research program. The presented test case is also numerically simulated and studied. Preliminary full dynamic time history analyses of the coupled soil-tunnel system are performed, using ABAQUS. Soil non-linearity and soil-structure interaction are modeled, following relevant specifications for underground structures and tunnels. Numerical predictions are compared to experimental results and discussed. Based on this comprehensive experimental and numerical study, the seismic behavior of rectangular embedded structures is better understood and modeled, consisting an important step in the development of appropriate specifications for the seismic design of rectangular shallow tunnels.

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A anaplasmose é uma importante enfermidade de bovinos de áreas tropicais e subtropicais do mundo, causada pela riquétsia intra-eritrocítica Anaplasma marginale. A vacinação tem sido a forma mais econômica e eficiente de controlar a anaplasmose bovina. Nos últimos anos, esses estudos têm se concentrado nas proteínas de membrana da riquétsia, sobretudo MSP1a e MSP2. Este trabalho teve como objetivos avaliar o grau de proteção induzido pelas proteínas de membrana MSP1a e MSP2 recombinantes de A. marginale, associadas com adjuvante CpG ODN 2006, perante desafio heterólogo e avaliar a resposta imune gerada. Novilhos da raça Aberdeen Angus foram imunizados três vezes com 200 ?g de MSP1a e/ou MSP2 recombinantes, associadas com CpG ODN 2006 e alúmen. Posteriormente, foram desafiados com 3 x 107 eritrócitos infectados com isolado heterólogo de A. marginale. Os animais experimentais apresentaram quadro clínico de anaplasmose (redução do volume globular, febre e riquetsemias detectáveis por distensões sangüíneas coradas). Não foram detectadas diferenças significativas entre os grupos imunizados e os controles quanto ao percentual de redução do volume globular, riquetsemias máximas e temperaturas retais máximas, indicando que as imunizações não foram protetoras. A despeito da significativa produção de IgG total contra MSP1a e MSP2, detectada no dia do desafio, os animais imunizados apresentaram produção significativa de IgG2 apenas contra MSP1a. As razões para as possíveis falhas de proteção são discutidas. Neste trabalho, é relatada a imunização de bovinos com MSP1a e MSP2 recombinantes de A. marginale, associadas com alúmen e CpG ODN 2006, e posterior desafio com isolado heterólogo, bem como a avaliação da resposta imune gerada.

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Estudos sobre o balanço entre o carbono estocado na biomassa e o perdido por meio da ecomposição, visando a quantificacão do acúmulo líquido de carbono de um sistema florestal.

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Avaliação espacial de algumas propriedades químicas de um solo sob sistema de palntio direto a três profundidades, visando estimar a necessidade de calagem para a soja e a aplicação a taxa variável de fertilizante fosfatado e potássico.

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Avaliação da variabilidade espacial dos teores de nutrientes nas folhas de soja cultivada em sistema plantio direto na Região dos Campos Gerais, Paraná., por meio de técnicas de agricultura de precisão e utilização da geoestatística.

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A seringueira é uma alternativa viável para a diminuição dos problemas socioeconômicos e ambientais, por se tratar de uma cultura adequada a pequenos e médios produtores e que poderá contribuir com o seqüestro de carbono da atmosfera. Este trabalho teve o objetivo de estimar o carbono orgânico estocado na fitomassa do clone IAN 873 da seringueira em solos da Região da Zona da Mata de Minas Gerais.