984 resultados para 118-733D


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Demonstrations of cw lasing in Cr2+:ZnSe poly-crystal are reported. The laser consists of a 1.7-mm-thick Cr2+:ZnSe poly-crystal disc pumped by a Tm-silica double-clad fibre laser at 2050nm. Using a concave high-reflection mirror with a radius of curvature of 500mm as the rear mirror, the laser delivers up to 1030mW of radiation around 2.367 mu m.

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研究了摩尔组分为70TeO2-(20-x)ZnO-xPbO-5La2O3-2.5K2O-2.5Na2O(x=0,5,10,15,20)的新型多元铅锌镧碲酸盐激光玻璃,外掺Yb2O3为玻璃摩尔组分的1%,测试了试样的物理性质及吸收光谱、荧光光谱和荧光寿命,计算了Yb^3+的吸收截面、受激发射截面、荧光有效线宽等光谱参数,结果表明:该系列玻璃都具有良好的热学稳定性((Tx-Tg)>195℃,高于TZN玻璃(118℃));当X=15时,样品具有较好的光谱性质:高的受激发射截面(1.25pm^2)、长的荧光寿命(

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[Es]Los establecimientos industriales a los que la directiva 2012/18/UE es de aplicación deben establecer las acciones necesarias para controlar y planificar los riesgos inherentes a los accidentes graves que pueden ser causados por sustancias peligrosas. Esta directiva obliga a los establecimientos afectados clasificados como nivel superior a elaborar un informe de seguridad en el que se realicen análisis de riesgos de los posibles accidentes graves con el fin de calcular los posibles daños que pudieran producirse. Para ello se siguen una serie de metodologías que incluyen desde el análisis de las posibles hipótesis de accidente grave hasta el cálculo de sus consecuencias para personas, bienes materiales y medio ambiente. El informe técnico trata de analizar las consecuencias de un accidente real provocado por una nube tóxica de dióxido de nitrógeno (NO2) y se comparan sus resultados con los datos reales del accidente. Asimismo se utilizan una serie de supuestos para analizar las consecuencias de un escenario de riesgo en la misma instalación que debiera estar incluido en el informe de seguridad.

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The encircled energy of a focusing lens is one of the parameters directly affecting the target efficiency in high-power laser facilities. The direct measurement method of the encircled energy for the focusing lens based on the scanning Hartmann test is proposed in this paper. With the scanning Hartmann test setup, the information in the whole aperture of the focusing lens can be achieved. The encircled energy can be obtained by analyzing the spot diagram on the focal plane of the focusing lens. In experiments, the encircled energy of an aspheric focusing lens is measured using this method. The measurement result is in good agreement with that derived from measurement data by an interferometer and the difference is 7.7%. (C) 2006 Elsevier GmbH. All rights reserved.

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The toxic effects of two herbicides Round up (gliphosate) and 2,4-D (herbazol) were tested on Pistia stratiotes (Linn. Araceae) samples cultivated in glass aquariums. The gliphosate appears to be more toxic on Pistia Stratiotes than 2,4-D. It was then tested on tilapia Sarotherodon melanotheron juveniles. The lethal dose for tilapia (CL50 = 13.25 mg.l -1) is about 18, 37 and 74 times higher than the glyphosate toxic dose for plants at 1, 2 and 4 meters water depth respectively.

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Morphological defects in beta-barium borate (beta-BBO) thin films grown on Sr2+ -doped alpha-BBO substrates by liquid phase epitaxy (LPE) technique were studied by scanning electron micrograph (SEM), atomic force microscopy (AFM) and optical spectroscopy. The present results indicate that the main defects exit in beta-BBO thin films are microcracks and hollow structure. The formation of microcrack is due to the lattice mismatch and the difference of thermal expansion coefficients between substrate and film. The hollow structure might be caused during the combination of islands, which formed in the initial stage. (C) 2006 Elsevier GmbH. All rights reserved.

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The hydrology of the Ebrie coastal lagoon in Abidjan area is summarized. The authors describe the oxygenation in that area during the two extreme seasons of the hydrological cycle: the low-water season (March-April) and the high-water season (Sept-Oct). The influences of the continental and oceanic waters, photosynthesis, exchanges with the atmosphere and pollution are considered. The oxigen consumption of primary organic pollution represents from 9 to 12% of the content of the waters that circulates in the area. It is geographically very heterogeneous. The central basin, swept by strong marine and fresh water currents, shows a rather high level of water oxygenation. In the peripheric bays, water circulation and mixing are less important and pollution accelerates the natural eutrophic processes. During the low-water season, a vertical stratification is responsible for a bottom anoxic layer and the deposit of reduced organic silts. On the contrary, supersaturations, up to 200%, are recorded on the surface layer. During the high-water season the break of the vertical stratification sets the loose reduced silts into suspension and partly reoxygenates the bottom waters. A classification of the different areas, based on the oxygen vertical profiles is proposed.

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Despite the clinical success of acute lymphoblastic leukemia (ALL) therapy, toxicity is frequent. Therefore, it would be useful to identify predictors of adverse effects. In the last years, several studies have investigated the relationship between genetic variation and treatment-related toxicity. However, most of these studies are focused in coding regions. Nowadays, it is known that regions that do not codify proteins, such as microRNAs (miRNAs), may have an important regulatory function. MiRNAs can regulate the expression of genes affecting drug response. In fact, the expression of some of those miRNAs has been associated with drug response. Genetic variations affecting miRNAs can modify their function, which may lead to drug sensitivity. The aim of this study was to detect new toxicity markers in pediatric B-ALL, studying miRNA-related polymorphisms, which can affect miRNA levels and function. We analyzed 118 SNPs in pre-miRNAs and miRNA processing genes in association with toxicity in 152 pediatric B-ALL patients all treated with the same protocol (LAL/SHOP). Among the results found, we detected for the first time an association between rs639174 in DROSHA and vomits that remained statistically significant after FDR correction. DROSHA had been associated with alterations in miRNAs expression, which could affect genes involved in drug transport. This suggests that miRNA-related SNPs could be a useful tool for toxicity prediction in pediatric B-ALL.

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We investigated M-2 factor and far-field distribution of beams generated by Gaussian mirror resonator. And we found usable analytical expressions of the M2 factor and the far-field distribution intensity with respect to variation of diffraction parameters. Particular attention was paid to the parameters such as mirror spot size and reflectance of the Gaussian mirror. (c) 2006 Elsevier GrnbH. All rights reserved.

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Based on the paraxial vectorial theory of beams propagating in uniaxially anisotropic media, we have derived the analytical propagation equations of beams generated by Gaussian mirror resonator (GMR) in uniaxial crystals, and given the typical numerical example to illustrate our analytical results. Due to the anisotropy crystals, the ordinary and extraordinary beams originated by incident beams generated by GMR propagate with different diffraction lengths, thus the linear polarization state and axial symmetry of the incident beams generated by GMR do not remain during propagating in crystals. (c) 2006 Elsevier GmbH. All rights reserved.