988 resultados para Géricault, Théodore, 1791-1824.
Efficient synthesis of high-quality MCM-48 silicas through mixed surfactants and pH adjustment route
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The electrochemical reduction of yttrium ion on a molybdenum electrode in a LiCl-KCl-NaCl eutectic melt at 723 K was found to be almost reversible and to proceed by a one-step three electron reaction. The diffusion coefficient D of the Y(III) ion was measured to be (3.3 +/- 0.4) x 10(-6) cm2 s-1 by cyclic voltammetry, (5.0 +/- 0.9) x 10(-6) cm2 s-1 by the rotating disk electrode method, and (7.1 +/- 0.7) x 10(-6) cm2 s-1 by chronopotentiometry. The D values obtained by the latter two methods are in fairly good agreement with each other. The rather low D value obtained by cyclic voltammetry might be attributed to the fact that yttrium metal can dissolve slightly in the chloride melt. The standard potential of Y(III)/Y(0) couple was determined to be (-3.174 +/- 0.006) V (vs. Cl2/Cl-) by open-circuit potentiometry, (-3.15 +/- 0.02) V (vs. Cl2/Cl-) by the rotating disk electrode method and (-3.16 +/- 0.02) V (vs. Cl2/Cl) by chronopotentiometry. These three values are in good agreement with each other. Several types of Ni-Y intermetallic compounds were found to be formed on a nickel electrode.
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Resting cysts of the marine phytoplanktonic dinoflagellate Scrippsiella spp. are encountered in coastal habitats and shallow seas all over the world. Identification of Scrippsiella species requires information on cyst morphology because the plate pattern of the flagellated cell is conserved. Cysts from sediments of the East China Sea were identified based on traits from both the cysts and the thecal patterns of germinated cells. Calcareous cysts belonged predominantly to S. trochoidea (F. Stein) A. R. Loebl., S. rotunda J. Lewis, and S. precaria Montresor et Zingone. The former two species also produced smooth and noncalcified cysts in the field. A new species, S. donghaienis H. Gu sp. nov, was obtained from six noncalcified cysts with organic spines. These cysts are spherical, full of pale white and greenish granules with a mesoepicystal archeopyle. The vegetative cells consist of a conical epitheca and a round hypotheca with a plate formula of po, x, 4', 3a, 7 '', 6c (5c + t), 6 s, 5''', 2'''' and are morphologically indistinguishable from S. trochoidea. Results of internal transcribed spacer (ITS) sequence comparisons revealed that S. donghaienis was distinct from the S. trochoidea complex and appeared nested within the Calciodinellum/Calcigonellum clade. Culture experiments showed that the presence of a red body in the cyst and the shape of the archeopyle were constant within cell lines from one generation to the next, while the morphological features of the cyst wall, such as calcification and spine shape, appeared to be phenotypically plastic.
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水库建设方案的评价,涉及投入和效益两方面。投入包括资金和工期等,称为“输入”:效益包括工农业用水增加、防洪能力强增等。称为“输出”。分析这种多输入,多输出的系统,应用数据包络分析方法是非常有效的。
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The 3-D velocity images of the crest and upper mantle beneath the region of 112° -124°E, 28°-39°N including the Dabie-Sulu orogenic belt are reconstructed by using 36405 P-wave arrivals of 3437 regional and 670 distant earthquakes during the period from 1981 to 1996, and gridding the area of 0.5° * 0.5°. The results of tomography demonstrate that: 1. The results of tomographic imaging show a broad heterogeneity in P wave velocity structure for the lithosphere beneath the Dabie-Sulu orogenic belt. 2. In the Dabie orogenic belt, the velocity patterns in the crust are different among various tectonic units. The Dabie and Qinling orogenic belts are remarkable in the tomographic images, and in mm the Hongan and Dabie blocks in the Dabie orogenic belt are also imaged very distinguishably. 3. A velocity (about 5.9~6.0 km/s) layer exists in the Dabie block at depth between 15~25 km, which is coincident with the low-resistance layer at the depth of 12-23 km, being inferred to be the tectonic detachment zone and suggesting that the extension detachment structure was formed in the middle crust. Beneath the southern and northerm Dabie tectonic units, the north-dipping high-velocity (at level of 6.5 ~ 6.6 km/s) block was developed in the crust, which might be correlated with the UHP rockswith low content of the meta-ultramafic rocks. This result is in agreement with the geological observation on the surface. 4. The velocity image at 40 km depth reveals the features at the top of mantle and the configuration of the Moho discontinuity. The depth of the Moho changes slightly along the trend of the orogenic belt. It in Hongan block is less than 40 km, but it is different in the western and eastern parts of the Dabie block, the former is more than 40 km, and the latter less than or equal to 40 km. The remnant of the mountain root exists between the Shangcheng-Macheng fault and the line of Huoshan-Yuexi-Yingshan in the Dabie orogenic belt, and beneath the southern and northern Dabie tectonic units. However, the thickness of the Moho is about 40 km and there is no obvious changes, which suggest that the Dabie orogenic belt has been experienced quite in the gravity equilibration. The Moho's depth in the Sulu is less than 40 km. 5. There is a dipping slab-like high-velocity body in the uppermost mantle. It is sandwiched by slow velocities and exists beneath the Dabie-Sulu orogenic belt in the range of depths between the Moho discontinuity and 110 km at least. This high-velocity body outlines a picture of the slab interpreted as the remnant of the Triassic subducted YZ. 6. The Sulu orogenic belt displays "crocodilian" velocity structure, the upper crust of the Yangtze thrusted over the Huabei crest, and the Huabei crust indented into the Yangtze crust, where the ancient subduction zone of the Yangtze lithosphere located. Based on the previous geological data, this structure is not related with the collision between the Yangtze and Sino-Korean Blocks, but caused by the sinistral offset of the Tan-Lu Fault. Studied on the velocity structure of the eastern Huabei lithosphere indicates: 1. The 'present-day' lithosphere of the eastern Huabei is between 40-100 km thick with greatly thinned lithosphere around the Bohai Sea. Generally, thickness of the lithosphere in this region decreased eastwards. 2. The attenuation of the lithosphere is attributed to the strongly uplift of the asthenosphere. In the area between the Taihang Mountains and the Tan-Lu Fault, there is a 'lever' with red low velocity belt, it is clearly defined, transverse continuity, depth between 100-150 km, local variations visible, and an upwards trend towards the Bohai Sea. Generally, the velocity structure in the mantle beneath the lithosphere displays irregular column-shape consisting of alternating high and low velocities, and when cold high velocity ancient lithosphere connects with the hot low velocity mantle materials forming precipitous compact structure. More heat pathways from the mantle occur towards the Tan-Lu Fault. 3. The strongly irregular characteristics of the contact between the asthenosphere and the lithosphere is induced by the long-term hot, chemical erosion and alteration on the contact. 4. There are still preserved high velocity lithosphedc root beneath Huabei with 'block-shape' distribution and surrounded by hot materials. Results of our studies indicate that the evolution models of the eastern China mantle are characterized by the direct contact between the uplifted lithosphere and the Huabei Craton accompanying the upwelling of the deep mantle materials. At the contact betwen the lithosphere and the asthenosphere, the upwelled mantle materials replaced and altered the lower lithosphere forming the metasome through the hot and chemical modifications impacted on the Craton lithosphere, and changed it into the lithosphere gradually, resulting in the lithospheric thinning. Thus, the lithospheric thinning is the result of the upwelling of the asthenosphere.
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以自然土壤、沉积物样品为研究对象,研究了1,3,5-三氯苯在样品上的等温吸附过程。结果表明,线性模型和Freundlich模型能较好地拟合所有样品的等温线,而双区位反应模型(DRDM)适用范围有限。研究表明,三氯苯的吸附容量大小主要取决于样品中有机碳的含量,并且与不可提取态有机质和粘土矿物含量有一定的关系。以自然土壤、沉积物样品为研究对象,研究了1,3,5-三氯苯在样品上的等温吸附过程。结果表明,线性模型和Freundlich模型能较好地拟合所有样品的等温线,而双区位反应模型(DRDM)适用范围有限。研究表明,三氯苯的吸附容量大小主要取决于样品中有机碳的含量,并且与不可提取态有机质和粘土矿物含量有一定的关系。
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济阳坳陷CO2气藏主要发育在高青-平南深断裂中南段和阳信次级凹陷西北缘及商店火山岩穹隆构造内。气藏中CO2气体浓度为69%~97%,δ^13CCO2值为-5.67‰~-3.35‰,CH4/^3He值为(1.01~5.65)×10^8,^3He/^1He值为(2.80~4.49)×10^-6,即R/Ra为2.00~3.21,^40Ar/^36Ar值为317~1791,CO2/^3He值为(0.25~2.61)×10^9。以上地球化学数据表明,济阳坳陷气藏中CO2主要来源于地慢,且慢源CO2在成藏过程中有损失,或者有壳源CO2的加入,特别是部分碳酸盐岩变质成因CO2的加入。在对CO2气来源定性分析的基础上,还需要在各来源的定量区分和CO2气藏的成藏及其与岩浆活动的时空匹配关系等方面作进一步的研究.
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济阳坳陷是自三叠纪以来欧亚板块、印度洋板块和库拉-太平洋板块相互作用形成的一个叠置在华北板块上的中、新生代坳陷,位于华北板块东部,东临著名的郯庐大断裂。在坳陷中部的高青-平南断裂地区和西部惠民凹陷发现了大量的CO2气藏,近年来受到很多地质学家和地学工作者的注意。本文在前人资料和自己研究成果的基础上,详细分析了济阳坳陷CO2气藏的气体地球化学特征和惠民凹陷地区火成岩中方解石脉的碳氧同位素特征,为厘定区域内二氧化碳气的来源提供理论依据。通过系统的研究,获得了以下成果和结论: 济阳坳陷CO2气藏中,13CCO2值为-5.67~-3.35‰,主频率段为-4.76~-4.32‰,指示CO2气的主体为无机成因;而气藏中CH4的13C为-54.39~-35.00‰,主频率段为-54.39~-51.55‰,显示以有机成因为主。 济阳坳陷CO2气藏中3He/4He比值为2.80~4.49×10-6,主频率段为3.55~4.49×10-6;40Ar/36Ar值为317~1791,变化较大,主要分布在770~1791;13CCO2值与3He/4He成正相关关系;CO2/3Hem值介于0.769~10.2×109之间,主体为1.86~3.51×109,且CO2/3Hem值与CO2含量一定程度地正相关;CH4/3He比值介于1.01~5.65×108之间,接近于幔源流体值,而远低于壳源特征值,且CH4/3He比值随3He/4He比值减少而增加。以上种种特征都说明,济阳坳陷非烃类气藏中气体具有多来源的特征,但CO2主体是无机成因,并主要来自地幔,少量来自有机成因;在成藏过程,幔源CO2通过转变为CH4或者碳酸盐岩而丢失了部分CO2,壳源CO2和其它烃类加入到气藏中;花沟地区的气体地球化学特征与众不同,可能存在碳酸盐地层变质脱气产生的CO2的混入,但具体原因尚待进一步研究。 济阳坳陷惠民凹陷地区火成岩中方解石脉的碳同位素数据-3.30~3.14‰,氧同位素数据12.64~16.97‰,二者成正相关关系,同时也位于前人所说的沉积混染趋势线上,具有较为典型的壳幔混合特征。这些方解石脉的碳同位素又明显的位于海相碳酸盐岩范围之内,说明脉体的主要碳源不是深源的,而是来自于海相底层。
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A broca da bananeira ou moleque, Cosmopolites sordidus (Germar, 1824) (Coleoptera, Curculionidae), constitui-se na principal praga da bananeira, provocando perdas de até 80% na produção. As larvas são causadoras do dano por produzirem galerias no rizoma, enfraquecendo a planta e reduzindo o peso do cacho, que acaba tombando pela ação do vento. No entanto, por estarem protegidas dentro do rizoma, a verificação de sua presença é mais difícil e também o seu controle. Quando adulto, o besouro de coloração preta mede aproximadamente 1 cm de comprimento e é ativo no período noturno. O moleque se espalha facilmente pelo uso de mudas infestadas ou pelo caminhamento. Durante o dia, o besouro é encontrado entre as bainhas mais externas da bananeira e em restos de pseudocaule que permanecem sobre o solo após a colheita, os quais atuam como verdadeiros esconderijos para a broca.
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Poolton, Nigel; Ozanyan, K.B.; Wallinga, J.; Murray, A.S., (2002) 'Electrons in feldspar II: a consideration of the influence of conduction band-tail states on luminescence processes', Physics and Chemistry of Minerals 29(3) pp.217-225 RAE2008
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Dennis, P., Aspinall, R. J., Gordon, I. J. (2002). Spatial distribution of upland beetles in relation to landform vegetation and grazing management. Basic and Applied Ecology, 3 (2), 183?193. Sponsorship: SEERAD RAE2008
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Wydział Neofilologia: Instytut Filologii Romańskiej
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Digitized from a letter in the Drew University Methodist Collection. 1 item (4 p.); 19.5 x 32 cm.