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971.
972.
The elemental abundances of lunar surface are the important clues to study the formation and evolution history of the Moon. In 2010, China's Chang'E-2 (CE-2) lunar orbiter carried a set of X-ray spectrometer (XRS) to investigate the elemental abundances of the lunar surface. During CE-2's life span around the Moon, the XRS ex- perienced several events of solar flare. The X-ray solar monitor onboard recorded the spectra of solar X-rays at the same time. In this paper, we introduced the XRS instrument and data product. We analyzed the characteristics of the XRS data. Using the data obtained during an M solar flare event which had occurred on Feb. 16, 201 l, we derived the elemental abundances ofMg, A1, Si, Ca and Fe of the lunar surface in the Oceanus Procellarum. Finally, we dis- cussed the factors that influence the accuracy of the inversion. 相似文献
973.
974.
We report experimental measurements of bulk permeability changes due to a shear zone that is induced in siliceous mudstones collected from the Koetoi and Wakkanai Formations, northern Hokkaido, which are known to show different relationships between fault/fracture distribution and groundwater flow. We evaluate distributions of volumetric deformation in the induced shear zones by using micro-focus X-ray computed tomography. Measured permeability evolution while achieving the peak axial stress for specimens differed for the samples of the two formations. Permeability did not change obviously during shear for the Koetoi Fm. specimens, but in the Wakkanai Fm. specimens, the bulk permeability increased by a factor of 2.5 after reaching the peak stress. The difference in permeability change in these experiments can explain the differences in relationships between in situ groundwater flow and fracture distribution for the two formations. Analyses of the X-ray images reveal that this difference should reflect the differences of the volumetric deformation in the induced shear zones. Pore collapse occurred in the shear zone in the Koetoi Fm. specimen, which leads to porosity reduction, whereas fracture damages developed in the Wakkanai Fm. specimen, increasing porosity. These differences in the microstructure may reflect differences in yielding criteria for these host rocks. 相似文献
975.
手持式X射线荧光光谱仪在富钴结壳资源勘查中的应用 总被引:1,自引:1,他引:0
便携式X射线荧光光谱仪具有快速、无损分析的特点,本文重点研究了手持式X射线荧光光谱仪在富钴结壳碎块和浅钻岩心野外现场原位分析中的应用能力。采用压片法制样,以富钴结壳国家标准物质(GBW 07337~GBW 07339)和多金属结核国家标准物质(GBW 07249、GBW 07295和GBW 07296)作为校准样品,建立了手持式X射线荧光光谱仪测定富钴结壳样品的校准曲线。方法经国家标准物质GBW 07339验证,元素Mn、Fe、Co、Ni和Cu的精密度(RSD)在0.3%~3.0%之间,满足富钴结壳样品现场分析的要求。在海上资源勘查现场,应用手持式X射线荧光光谱仪对富钴结壳碎块和浅钻岩心原样进行了现场原位分析。富钴结壳碎块原样烘干后直接测试分析数据与实验室压片制样XRF分析数据对比表明,Mn、Fe、Co、Ni和Cu元素的测定值一致性良好;浅钻岩心的原位分析数据与实验室人工分层分析数据对比表明,各层位Mn、Fe、Co、Ni和Cu元素直接测试数据与实验室压片制样XRF分析数据分布趋势基本一致。实际应用研究表明,手持式X射线荧光光谱仪适合于现场原位分析,满足野外富钴结壳资源快速评价的要求,同时原位分析能更真实地反映原始富钴结壳岩心不同层位中各元素的变化特征,为进一步研究富钴结壳成矿机制提供更丰富的数据资料。 相似文献
976.
超细粉末压片法-X射线荧光光谱测定水系沉积物和土壤中的主量元素 总被引:4,自引:3,他引:1
X射线荧光光谱分析中,粉末压片法是一种理想的绿色环保制样技术,操作简单、制样效率高,但由于受到粒度效应和矿物效应的影响,其测定误差在5%左右,因而限制了这种技术在常量元素检测方面的应用,目前主要应用于痕量元素的测定以及对分析精度要求不高的分析领域。本文运用行星式粉碎制样机,将水系沉积物和土壤标准物质在几分钟内粉碎至平均粒径4~5μm左右,建立了超细粉末压片制样X射线荧光光谱测定SiO2、Al2O3、Fe2O3、CaO、MgO等主量元素的方法。该方法绝大多数主量元素的测量精密度(RSD)小于2%;检出限为0.003%~0.021%,优于熔融法的检出限(0.006%~0.081%),特别是原子序数小的钠元素,检出限改善4倍。本文针对水系沉积物和土壤研制的超细粉末压片法,由于样品粉碎至几微米,最大限度地减小了粒度效应的影响;X射线衍射分析表明制备样品的矿物成分以石英为主,矿物组成简单,矿物效应可以忽略不计。同时对测量数据加入烧失量进行归一化处理,各元素归一化的测量结果与标准值基本一致,方法准确度比常规压片法获得显著提高。 相似文献
977.
We present results of evolutionary computations for massive close binaries with the Brussels simultaneous evolution code for
conservative and non-conservative Roche lobe overflow (RLOF). We discuss mass transfer in massive close binaries during phases
of RLOF, common envelope, spiral-in and merging. We examine the effects of stellar wind during successive stellar evolution
phases and the final fate of primaries. We show how our library can be used to explain well-known binaries such as the WR
+ OB system V444 Cyg, HMXBs Vela X-1 and Wray 977, LMXBs like Her X-1, and binary pulsars. More details on the evolution of
massive close binaries can be found in “The Brightest Binaries” (Vanbeveren et al., 1998). 相似文献
978.
979.
We calculate the time-dependent line and recombination spectrum of nonequilibrium plasma heated by the strong radiation as
the test model of X-ray line emission of GRB afterglows. Our calculation shows that the non-equilibrium effect of plasma is
complex and important to the time evolution of the spectrum. The origin of these lines puzzles us, but is essential to understand
the nature of GRBs and their circumstellar matter. 相似文献
980.
We examined the correlation between the ROSAT Hardness Ratio 1 and Count Rates eight Narrow-line Seyfert 1 Galaxies (NLS1s) and 14 Broad-line Seyfert 1 Galaxies (BLS1s). We found that six of the NLS1s show a positive HR1-CTs correlation, and seven of the BLS1s, a negative correlation. The other two NLS1s and seven BLS1s do not show any clear HR1-CTs correlation. Thus, the spectral behavior is statistically different for the NLS1s and BLS1s. The different behaviors can possibly be interpreted in terms of a stable ‘soft excess’ that is strong in NLS1s and weak in BLS1s, plus a power law component, common to both, which softens with increasing flux. 相似文献