988 resultados para 530
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拉拉铜矿床位于扬子地块西缘的康滇隆起中段,赋存于经历变质的古元古代河口群海相火山-沉积岩系中,是我国重要的受变质热液叠加或改造的火山成因块状硫化物矿床(VHMS)之一,也是四川省最大的铜矿生产基地。本论文以该矿床为研究对象,在系统整理前人资料的基础上,进行了深入细致的野外地质考察和系统采样,选取代表性样品,运用电子探针分析技术、元素地球化学、同位素地球化学(Rb-Sr、Sm-Nd、S)、锆石U-Pb定年等方法手段,对矿区新元古代大规模区域变质作用的变质条件、变质原岩、广泛分布于矿区多个赋矿层位的辉长辉绿岩脉、岩石及矿石性质、硫源、成矿时代等主要岩石学及矿床学问题进行了系统研究,并结合前人研究成果,探讨了矿床的成因机制。论文主要取得以下几点认识: (1)矿区变质火山岩的成岩年龄为1695±20Ma,岩浆在上升侵位的过程中捕获了古元古代早期地壳物质,后期变质改造的时代约为700-800Ma。 (2)基于石榴石黑云母片岩中石榴石黑云母矿物对的电子探针分析数据,利用石榴石-黑云母地质温度计和多硅白云母地质压力计确定了矿区新元古代大规模区域变质作用的变质条件:变质温度为530-580℃,变质压力上限为0.66-0.76GPa,对应于高绿片岩相。 (3)矿区出露的岩石类型以云母片岩类和钠长岩类岩石为主,二者共同构成了矿区的围岩及赋矿岩石,通过对代表性样品的元素地球化学、同位素地球化学研究,采用DF函数判别法、(Al/3-K)-(Al/3-Na)图解法、La/Yb-TR图解法,并结合岩矿鉴定及结构构造特征,恢复了矿区的变质原岩。其中,矿区的云母片岩类样品的变质原岩为沉积岩,以页岩为主,主要来自大陆岛弧及上地壳物质的风化;而钠长岩类样品的变质原岩为火山岩,源自富集地幔,包括“右倾型”钠长岩和“平坦型”钠长岩,前者为分离结晶作用早期并经历一定程度地壳混染的产物,后者主要形成于分离结晶作用晚期,Nb、Ta、Zr、Hf、P、Ti等达到饱和并以副矿物晶出。 (4)综合矿区变质沉积岩及变质火山岩的构造环境判别结果,确定了二者形成于大陆岛弧的弧后盆地环境。 (5)通过对矿区变质火山岩性质、形成机制及硫同位素研究,讨论了矿床中成矿元素可能的富集机制,即地幔中大量的亲铜元素及硫元素进入母岩浆并随之上升形成区域分布的火山岩,为矿床的形成提供了必要条件。 (6)侵入河口群地层并广泛出露于矿区多个赋矿层位的辉长辉绿岩脉的化学成分与板内碱性玄武岩类似且形成于大陆裂谷环境下的类似OIB源区,是高温地幔柱部分熔融的产物,幔源岩浆在上升侵位过程中受到了地壳物质尤其是上地壳物质较小程度的混染,表明新元古代Rodinia超大陆裂解对拉拉地区的成矿作用有重要影响。 (7)拉拉铜矿床主要存在两个成矿期次,即火山喷气-沉积成矿期(1700 Ma左右)和变质热液成矿期(700-800Ma)。矿区主要存在两种类型矿石,即条纹、条带状矿石和块状、浸染状矿石,前者主要赋存于变质火山岩中,可能形成于火山喷气-沉积成矿期,后者主要赋存于变质沉积岩中,可能为变质热液成矿期的产物。
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The coadsorption of NO and O-2 on Ag(110) surface has been studied by X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS) and in situ Raman spectroscopy. The existence of oxygen enhances the adsorption of NO by forming the NOx species, that is, NO2 and NO3, and the NO in turn as a promotor facilitates the cleavage of the dioxygen bond, forming the surface atomic oxygen species having the same spectral characteristics as those produced using oxygen at high pressure. The oxygen species generated by the interaction is composed of two parts. One is produced directly by the decomposition of surface NO-O-2 complex at ca 625 K, which raised an O 1s feature at 530.5 eV and is absent at ca 800 K, while the another with an O 1s binding energy of 529.2 eV emerges at higher temperatures and shows similar properties as the reported gamma-state oxygen which bound tightly on restructured silver surface. The exposure to NO and O-2 causes noticeable changes in the morphology of the Ag(110) surface and the flat terraces superseded by small (ca 0.1 mu m) pits, and particles with typical diameters of a few micrometres were formed at elevated temperatures. (C) 1999 Elsevier Science B.V. All rights reserved.
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Os besouros coprófagos, popularmente conhecidos como "rola-bostas", ao lado de ácaros e outros insetos predadores ou competidores que atuam nas massas fecais, são grandes parceiros biológicos da pecuária (KOLLER, 1998). Por se alimentarem de fezes, esses besouros constituem a maneira mais prática e economicamente viável da qual se dispõe para remover as massas fecais de bovinos nas pastagens. Além disso, colaboram com a bovinocultura no controle de pragas e parasitos presentes nas fezes bovinas, tais como a mosca-dos-chifres (Haematobia irritans) e diversas espécies de vermes gastrintestinais (nematódeos). Os coleópteros coprófagos podem proporcionar outros benefícios ao enterrar as fezes dos animais porque aceleram a absorção de nutrientes pelo solo (adubação orgânica), o que evita perdas significativas de nitrogênio, um dos nutrientes de maior custo na conservação das pastagens cultivadas (MIRANDA et al., 2000). Outra contribuição importante é que ao cavar galerias os besouros coprófagos melhoram a aeração do solo e contribuem para a infiltração de água, melhorando as características físicas dele (FINCHER, 1981). Logo, a utilização de besouros coprófagos no controle biológico constitui uma alternativa interessante em comparação ao controle químico convencional, tendo em vista a sua abundância e diversidade relatada para diferentes regiões do Brasil (OLIVEIRA et al., 1996; RODRIGUES; MARCHINI, 1998; PEREIRA et al., 2003; MONTEIRO et al., 2006; RONQUI et al., 2006). A lógica da adoção de estratégias integradas de métodos de controle, valorizando o controle natural, reside no fato de que muitos parasitos, especialmente a mosca-dos-chifres (BARROS et al., 2002; 2007), carrapatos e vermes gastrintestinais, estão se tornando resistentes aos produtos empregados no seu controle. Além disso, o uso inadequado e sistemático de pesticidas interfere na sobrevivência de organismos benéficos presentes nas massas fecais, contribuindo para um controle biológico menos eficiente. Entre esses organismos benéficos, talvez os mais prejudicados sejam os besouros coprófagos. No presente estudo comparou-se a eficácia de captura entre armadilhas tipo alçapão segundo o modelo descrito e proposto por Lobo et al. (1988), comparando a isca tradicional de fezes bovinas com uma fonte de atração luminosa e utilizando recipiente de captura com 54 cm de diâmetro de abertura. O trabalho foi realizado na Fazenda Experimental da Embrapa Gado de Corte, localizada a 20° 27' S e 54° 37' W e a uma altitude aproximada de 530 metros, em Campo Grande, MS, situada na região central de Mato Grosso do Sul.
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Framework titanium in Ti-silicalite-1 (TS-1) zeolite was selectively identified by its resonance Raman bands using ultraviolet (W) Raman spectroscopy. Raman spectra of the TS-1 and silicalite-1 zeolites were obtained and compared using continuous wave laser lines at 244, 325, and 488 nm as the excitation sources. It was only with the excitation at 244 nm that resonance enhanced Raman bands at 490, 530, and 1125 cm(-1) appeared exclusively for the TS-1 zeolite. Furthermore, these bands increased in intensity with the crystallization time of the TS-1 zeolite. The Raman bands at 490, 530, and 1125 cm(-1) are identified as the framework titanium species because they only appeared when the laser excites the charge-transfer transition of the framework titanium species in the TS-1. No resonance Raman enhancement was detected for the bands of silicalite-1 zeolite and for the band at 960 cm(-1) of TS-1 with any of the excitation sources ranging from the visible tb UV regions. This approach can be applicable for the identification of other transition metal ions substituted in the framework of a zeolite or any other molecular sieve.
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A series of aluminosilicate zeolites are characterized by UV Raman spectroscopy for the first time, and UV Raman spectra of various zeolites give strong and clear bands with high resolution, while conventional Raman spectra of these zeolites are difficult to obtain because of a strong background fluorescence. Additionally, these zeolites show several new bands in UV Raman spectroscopy. A summary of these UV Raman spectra over various zeolites suggests that the bands at 470-530, 370-430, 290-410, and 220-280 cm(-1) can be assigned to the bending modes of 4-, 5-, 6-, and 8-membered rings of aluminosilicate zeolites, respectively. Furthermore, it is found that the band intensity of zeolites in UV Raman spectroscopy is dependent on the Si/Al ratio. Moreover, the UV Raman spectra of crystallization, for zeolite X at various times show that, in the initial stage of crystallization, the 4-membered rings (510 cm(-1)) interconnect each other to form beta -cages with 6-membered rings (390 cm(-1)), which further crystallize to zeolite X. (C) 2001 Elsevier Science B.V. All rights reserved.
Highly efficient Raman conversion in O2 pumped by a seeded narrow band second-harmonic Nd: YAG laser
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Essery, R L H, Best, M J, Betts, R A, Cox, P M & Taylor, C M, Explicit representation of subgrid heterogeneity in a GCM land-surface scheme. Journal of Hydrometeorology 4, pp 530-543 (2003).
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Grattan, J.P., Gilbertson, D.D., Hunt, C.O. (2007). The local and global dimensions of metaliferrous air pollution derived from a reconstruction of an 8 thousand year record of copper smelting and mining at a desert-mountain frontier in southern Jordan. Journal of Archaeological Science 34, 83-110
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Habbal, Shadia Rifai; Morgan, Huw; Johnson, Judd; Arndt, Martina Belz; Daw, Adrian; Jaeggli, Sarah; Kuhn, Jeff; Mickey, Don, LOCALIZED ENHANCEMENTS OF Fe+10 DENSITY IN THE CORONA AS OBSERVED IN Fe xi 789.2 nm DURING THE 2006 MARCH 29 TOTAL SOLAR ECLIPSE, The Astrophysical Journal, Volume 663, Issue 1, pp. 598-609
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R. Zwiggelaar, 'A review of spectral properties of plants and their potential use for crop/weed discrimination in row-crops', Crop Protection 17 (3), 189-206 (1998)
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Bain, William, 'Are There Any Lessons of History?: The English School and the Activity of Being an Historian', International Politics (2007) 44(5) pp.513-530 RAE2008
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Suganami, Hidemi, 'Understanding Sovereignty through Kelsen/Schmitt', Review of International Studies (2007) 33(3) pp.511-530 RAE2008
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Deb, S. K., Wilding, M. C., Somayazulu, M., McMillan, P. F. (2001). Pressure-induced amorphization and an amorphous-amorphous transition in densified porous silicon. Nature, 414, 528-530. RAE2008
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Tese apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Doutor em Ciências Sociais, especialidade em Psicologia