997 resultados para 94-606


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A novel organic-inorganic hybrid vanadium oxide [V4O10(o-phen)(2)], involving all vanadium atoms present in +5 oxidation, has been hydrothermally synthesized and characterized by elemental analysis, IR, UV-vis, ESR, XPS spectra and TG-DTA thermal analysis. The single-crystal X-ray diffraction shows that the red-brown crystal is formed in the triclinic system, space group P (1) over bar, a = 9.782(2), b = 6.5124(14), c = 19.765(4) Angstrom, alpha = 89.94(2)degrees, beta = 100.66(2)degrees, gamma = 89.86(2)degrees. The title compound exhibits an infinite one-dimensional ladder-type tetravanadate skeleton with organonitrogen donors of o-phenanthroline ligands coordinated directly to the vanadium oxide framework.

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本文采用真空下气体输运技术制备RE_(0.06)La_(0.94)Nb_2O_6Cl(RE=Pr、Eu、Tb、Dy)小单晶和多晶粉末样品。测定其晶体结构与LaNb_2O_6Cl的晶体结构相同,为正交晶系;Eu_(0.06)La_(0.94)Nb_2O_6Cl小单晶的晶胞参数为:a=9.751,b=7.321,c=8.364。观察RE_(0.06)La_(0.94)Nb_2O_6Cl(RE=Pr、Eu、Tb、Dy)的特征激发光谱和发射光谱及其能量传递现象。

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本论文在前人数据资料和研究成果的基础上,以北衙金矿床及其相关的富碱侵入岩作为主要研究对象,以探讨滇西新生代富碱火成岩成岩过程及富碱岩浆上升演化过程中的流体分异,北衙金矿床的成因,最终揭示北衙金矿床与相关的富碱侵入岩之间的关系为主要研究目的,通过主、微量(包括稀土)元素地球化学,Pb、Sr、Nd、C、O、S及He-Ar等同位素地球化学,以及流体包裹体地球化学等方面的研究获得以下主要认识:-1.滇西新生代富碱火成岩来源于EM-II型富集地慢,源区的交代富集过程与古特提斯洋壳的俯冲有关,俯冲板片的含水流体对上覆上慢楔的交代是滇西富碱侵入岩(相当于A型花岗岩)含水的原因,这次富碱岩浆活动是一次滞后的弧岩浆活动;富碱中、酸性岩浆由碱性玄武质岩浆混染约20%的主要来自变质基底的地壳物质演化而来;滇西新生代富碱岩浆具备岛弧岩浆的氧化条件(即fogfo2>FMQ+2,FMQ代表铁橄榄石一磁铁矿一石英氧缓冲),并在其上升演化过程中分异出大量的流体相,具有较大的An、Cu成矿潜力。2.北衙金矿的矿化时代33.0±1.5Ma与相关的富碱侵入岩的成岩时代(32-34Ma)一致。3,成矿早期流体或初始流体具有富碱岩浆在变质基底内分异的流体的Nd和sr同位素组成(Isr≈0.722390,ε Nd(t)≈-2.8)、矿区及外围富碱斑岩的平均Pb同位素组成(206Pb/204Pb=18.590,207Pb/204Pb=15.606,208Pb/204Pb=38.770)、与相关富碱斑岩一致的稀土配分模式、岩浆热液的C、O同位素组成(δ13C≈-5%0,61、尧11%0)、以及壳一慢混合He-Ar同位素组成(3He尸He;1 .80-1.94 Ra,3He/3 6Ar=1 .19 * 10-3-3.93火10·3)并显示明显的He-Ar分异(4oAr*/He=0.34-0.75),且以高温、高压、高盐度、富c02为特征,说明初始流体主要在变质基底内由富碱岩浆分异而来;初始流体在上升过程中由于温度、压力降低发生富co2相和盐水相的分离,成矿元素优先分配进入富COZ相,逐步演化为成矿阶段流体;成矿阶段流体在去气或与大气降水混合过程中释放出其中的成矿元素。4.约80%的成矿金属来自富碱岩浆,其余部分主要通过岩浆流体从变质基底摄取。结论:北衙金矿与相关的富碱侵入岩具有密切的成因关系。

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Cooperatives have a long historical experience in the Spanish economy and have demonstrated their ability to compete against traditional firms in the market. To maintain this capability, while taking advantage of the competitive advantages associated with their idiosyncrasies as social economy enterprises, they should take into consideration that the economy is increasingly globalized and increasingly knowledge-based, especially with regards to technological content. As a consequence, the innovative capacity appears to be a key aspect in order to be able to challenge competitors. This article characterizes the innovative behavior of cooperatives in the region of Castile and Leon and analyses the internal and external factors affecting their innovative performance, based on data from a survey of 581 cooperatives. The results of the empirical analysis, which is performed by multivariate binary logistic regression on various types of innovation, lead us to identify the size of the organizations, the existence of planning, the R & D activities and the human capital as the main determining factors.

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The design, construction and measured performance is described of an offset parabolic reflector antenna which employs a reflectarray subreflector to tilt the focused beam from the boresight direction at 94 GHz. An analysis technique based on the method of moments (MoM) is used to design the dual-reflector antenna. Numerical simulations were employed to demonstrate that the high gain pattern of the antenna can be tilted to a predetermined angle by introducing a progressive phase shift across the aperture of the reflectarray. Experimental validation of the approach was made by constructing a 28 × 28 element patch reflectarray which was designed to deflect the beam 5° from the boresight direction in the azimuth plane. The array was printed on a 115 µm thick metal backed quartz wafer and the radiation patterns of the dual reflector antenna were measured from 92.6-95.5 GHz. The experimental results are used to validate the analysis technique by comparing the radiation patterns and the reduction in the peak gain due to beam deflection from the boresight direction. Moreover the results demonstrate that this design concept can be developed further to create an electronically scanned dual reflector antenna by using a tunable reflectarray subreflector.

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Employer's contributions - Loyalty stamps - Bad-weather stamps - Freedom to provide services - Posted Workers

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Malone, C. and Stoddart, S. Malta Archaeological Review, 1996, 1, 1-5.

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Commençant par : « Estant couché soubz ung myrthe plaisant, Et maintz chasteaulx en Espaigne faisant... » et finissant par : « Sans parage ou riens n'est nect, Moulu d'un groz Moulinet. Fin de la complaincte de Grece, composée par le dict Molinet » .