检索结果-南通市图书馆

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

建造中金属油罐在风荷载作用下的屈曲

钢结构(中英文) 2010年第7期 82-83页

作者： Rossana C.Jaca luis a.godoy

通常按考虑最终形状方法设计壳体结构,因此,需假定结构满足稳定性要求。但是,中等风力作用下金属油罐频繁倒塌,这引起了高度重视。介绍了发生在阿根廷巴塔哥尼亚的中等风力作用下在建油罐倒塌的分析研究。虽以点焊方式固定油罐的圆筒部... 详细信息

通常按考虑最终形状方法设计壳体结构,因此,需假定结构满足稳定性要求。但是,中等风力作用下金属油罐频繁倒塌,这引起了高度重视。介绍了发生在阿根廷巴塔哥尼亚的中等风力作用下在建油罐倒塌的分析研究。虽以点焊方式固定油罐的圆筒部分,但倒塌时顶部移位。为了解倒塌机理,建立倒塌尽可能符合实际的壳体结构模型,进行了几何非线性有限元静力分析。结果表明,因为倒塌时存在风速,只能通过结构的一些特性即焊接的局部性、与底板连接的不充分性解释倒塌机理。

关键词：屈曲有限元倒塌油罐风

Relationship between Physical and Chemical Soil Attributes and Plant Species Diversity in Tropical Mountain Ecosystems from Brazil

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2014年第4期11卷 875-883页

作者： Ferna de CARVALHO Edward luis godoy Francy J. G. LISBOA Fatima Maria de Souza MOREIRA Francisco Adriano de SOUZA Ricardo luis Louro BERBARA G Wilson FERNES Laboratory of Evolutionary Ecology and Biodiversity Department of Geral Biology Institute of Biology Sciences Federal University of Minas Gerais Belo Horizonte MG 30161-901 P.O. Box 486 Brazil Department of Biology Microbiology and Biological Processes Department of Soil Science Federal University of LavrasLavras Minas Gerais 37200-000 P.O.Box 3037 Brazil Department of Biological Sciences Ferderal University of S?o Jo?o Del Rei S?o Jo?o del-Rei Minas Gerais 36307-352Brazil Laboratory of Soil Biology Department of Soil Science Federal Rural University of Rio de Janeiro Seropédica Rio de Janeiro 23890-000 Brazil Embrapa Maize and Sorghum Center for Applied Biology Rod. MG 424 KM 45 Caixa Postal Sete Lagoas Minas Gerais 35701-970 P.O. Box 285 Brazil

Although the high diversity of plant species in the rupestrian fields has been primarily attributed to the existence of a set of distinct habitats, few studies support this assertion. The present study aimed to further investigate the relationship between physical and chemical attributes of soils with the diversity of plant species in this unique ecosystem. The rupestrian field is a unique vegetation formation that covers some of the southeastern Brazilian mountains in the transition of the Atlantic rain forest and the Cerrado(savanna). Different habitats occur according to soil characteristics(e.g., presence of rocks, sand, fertility, hydrology, etc.). These attributes ultimately influence the vegetation that is highly adapted to the harsh edaphic and climatic mountain conditions. Five distinct habitats were studied by us: rocky outcrops, peat bogs, sandy bogs, quartz gravel fields, and "cerrado"(savanna). A floristic survey indicated that four families are found at greater frequency: Poaceae, Asteraceae, Cyperaceae, and Leguminosae. The greatest diversity of plant species was found in the rocky outcrops habitat, followed by cerrado, peat bog, quartz gravel grassland, and sandy bogs, respectively. The main difference in the floristic composition among these habitats was related to the dominant species. Trachypogon spicatus(Poaceae) was the most dominant species in the rocky outcrops, Axonopus siccus(Poaceae) in the peat bogs, Lagenocarpus rigidus(Cyperaceae) in the sandy bogs, Schizachyrium tenerum(Poaceae) in the cerrado, while Vellozia sp. 8(Velloziaceae) dominated the vegetation in the quartz gravel grassland. This study demonstrated that physical and chemical soil properties strongly related the diversity of plant species occurring in the different habitats of rupestrian fields.

关键词：植物物种多样性山地生态系统土壤特性热带雨林属性化学物理巴西

维普期刊数据库

Antibacterial approaches in tissue engineering using metal ions and nanoparticles:From mechanisms to applications

在线全文

学校读者我要写书评

暂无评论

Bioactive Materials 2021年第12期6卷 4470-4490页

作者： Maria.godoy-Gallardo Ulrich Eckhard luis M.Delgado Yolanda J.D.de Roo Puente Mireia Hoyos-Nogués F.Javier Gil Roman A.Perez Bioengineering Institute of Technology Universitat Internacional de CatalunyaCarrer de Josep Trueta08195del VallèsSant CugatBarcelonaSpain Proteolysis Lab Department of Structural BiologyMolecular Biology Institute of BarcelonaCSICBarcelona Science ParkBaldiri Reixac 15-2108028BarcelonaSpain

Bacterial infection of implanted scaffolds may have fatal consequences and,in combination with the emergence of multidrug bacterial resistance,the development of advanced antibacterial biomaterials and constructs is of great *** decades ago,metals and their ions had been used to minimize bacterial infection risk and,more recently,metal-based nanomaterials,with improved antimicrobial properties,have been advocated as a novel and tunable alternative.A comprehensive review is provided on how metal ions and ion nanoparticles have the potential to decrease or eliminate unwanted *** mechanisms such as oxidative stress induction,ion release and disruption of biomolecules are currently well ***,the exact antimicrobial mechanisms of the discussed metal compounds remain poorly *** combination of different metal ions and surface decorations of nanoparticles will lead to synergistic effects and improved microbial killing,and allow to mitigate potential side effects to the *** with a general overview of antibacterial mechanisms,we subsequently focus on specific metal ions such as silver,zinc,copper,iron and gold,and outline their distinct modes of ***,we discuss the use of these metal ions and nanoparticles in tissue engineering to prevent implant failure.

关键词： Metal ions Metal nanoparticles Mechanism of action Antibacterial activity Tissue engineering Biomaterials applications

Agrobacterium-mediated transient transformation of Pentalinon andrieuxii Mü***.

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Bioscience and Biotechnology 2012年第3期3卷 256-258页

作者： Alejandro Yam-Puc Elide Aviles-Berzunza Manuel J.Chan-Bacab luis Manuel Pena-Rodriguez Gregorio godoy-Hernandez Centro de Investigacion Cientifica de Yucatan A.C.Laboratorio de Quimica OrganicaUnidad de BiotecnologiaMeridaMexico Unidad de Bioquimica y Biologia Molecular MeridaMexico Departamento de Microbiologia Ambiental y Biotecnologia Universidad Autonoma de CampecheCampecheMexico

Sections of hypocotyls, roots and leaves from Pentalinon andrieuxii plantlets were transiently transformed with Agrobacterium tumefaciens LBA4404 bearing the binary plasmid pCAMBIA2301 with an interrupted β-Glucuronidase (GUS) gene. Histochemical GUS assays showed transient gene expression in all infected tissues, being older roots those which displayed the most intense GUS staining. To our knowledge, this is the first report of Pentalinon andrieuxii susceptibility to Agrobacterium tumefaciens-mediated genetic transformation.

关键词： β-Glucuronidase Agrobacterium tumefaciens Kanamycin Apocynaceae

Geomechanical model for a seismically active geothermal field:Insights from the Tinguiririca volcanic-hydrothermal system

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geoscience Frontiers 2019年第6期10卷 2117-2133页

作者： L.Giambiagi P.Alvarez S.Spagnotto E.godoy A.Lossada J.Mescua M.Barrionuevo J.Suriano IANIGLA CCT MendozaCONICETParque San Martín s/n5500MendozaArgentina TEHEMA S.A. Subercaseaux 4100PirqueChile Universidad Nacional de San luis Consejo Nacional de Investigaciones Científicas y TécnicasArgentina Universidad de Buenos Aires Consejo Nacional de Investigaciones Científicas y TécnicasInstituto de Estudios Andinos(IDEAN)Facultad de Ciencias Exactas y NaturalesBuenos AiresArgentina Facultad de Ciencias Exactas y Naturales Universidad Nacional de CuyoArgentina

In this work,we develop a multidisciplinary approach to investigate a geothermal system located at the volcanic arc of a subduction-related orogen and highlight the interplay between active *** field and fluid *** using results of field investigations from the Tinguiririca geothermal field in the High Andes of Chile(35°S),empirical analysis,and numerical models of static stress variations,we proposed a geomechanical model for evaluating the distribution of hydrothermal manifestations in a seismically-active *** present geomechanical model follows four major steps:(1)development of the 3 D structural model of fault pattern;(2)estimation of the in-situ stress field;(3)calculation of the resolved-shear-to-normal-stress ratio(slip tendency)on each fault with varying geomechanical parameters(coefficient of friction,pore pressure and cohesion)as inputs;and(4)estimation of Coulomb static stress changes as a consequence of failure in a nearby *** combination of all these analyses,we characterize in detail both the active deformation in the geothermal field and its relationship with hot fluid migration.

关键词： Southern central Andes Paleostress analysis Fluid migration Coulomb staric stress change

维普期刊数据库

The role of green manure nitrogen use by corn and sugarcane crops in Brazil

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences 2013年第12期4卷 89-108页

作者： Edmilson José Ambrosano Heitor Cantarella Gláucia Maria Bovi Ambrosano Fábio luis Ferreira Dias Fabrício Rossi Paulo Cesar Ocheuze Trivelin Takashi Muraoka APTA Regional Center South PolePiracicabaBrazil APTA Agronomic Institute of Campinas(IAC)CampinasBrazil Department of Social Dentistry State University of Campinas(UNICAMP)PiracicabaBrazil College of Animal Science and Food Engineering University of São Paulo(USP)PirassunungaBrazil Center for Nuclear Energy in Agriculture(CENA/USP) PiracicabaBrazil

Three assays were developed from April 3, 1995 to October 10, 2005. The work with corn was conducted in a greenhouse, using velvet bean (Mucuna aterrima) and sunn hemp (Crotalaria juncea) as green manure with 15N labeling of either shoots or roots, in two soils with contrasting textural classes. The mineralization of N from legume plants incorporated into the two soils was investigated too. This work included two green manures: velvet bean and sunn hemp, and the common bean (Phaseolus vulgaris) residues. Nitrogen from the velvet bean accounted for a greater proportion of the soil inorganic N;shoots were responsible for most of N accumulated. Common bean residues caused immobilization of inorganic N. The leguminous species added were intensively and promptly mineralized, preserving the soil native nitrogen. One hundred days after emergence of the corn, velvet bean provided higher accumulation of nitrogen in the soil, higher absorption by corn plants and accumulation in the aerial part. The green manure decomposition was more intense in the medium textured soil. In this soil, highest nitrogen losses were also observed. The sugarcane (Saccharum spp.) was cultivated for five years in the field and was harvested three times;15N recovery was evaluated in the first two harvests. The combination of inorganic fertilizer and green manure resulted in higher sugarcane yields than either N source applied separately;however, in the second cutting the yields were higher where sunn hemp was used than in plots with ammonium sulfate. The recovery of N by the first two consecutive harvests accounted for 19% to 21% of the N applied as sunn hemp and 46% to 49% of the N applied as ammonium sulfate. Very little inorganic N was present in the 0-40 cm soil layer with both N sources.

关键词： Saccharum spp. Biological Nitrogen Fixation 15N Isotope Technique N-Mineralization Mineral Nitrogen