SCS2D程序反演参数的应用效果分析

SCS2D程序中反演参数应用不当将使反演的地电模型与实际的地电模型产生较大的差别。通过对该软件反演参数圆滑系数、模型顶层厚度、初始背景模型的应用效果分析,为正确选择应用各参数、提高资料的反演精度打下基础。     

带权重的相关函数在半解析模型和SDSS数据中的应用

基于半解析模型和SDSS DR4(Sloan Digital Sky Survey Data Release 4),研究了环境对星系性质的影响.通过对以颜色、恒星形成率和恒星质量的带权重的相关函数的测量,发现半解析模型在颜色和恒星质量上与SDSS数据符合得比较好,而恒星形成率则在SDSS数据中表现为与环境无关.此结论证实了半解析模型对星系中部分性质与环境关系的预测,但对于恒星形成率为何与环境无关仍有待研究.     

Measuring ΩM and ΩΛ with long‐duration gamma‐ray bursts

Gamma‐ray bursts (GRBs) are one of the most luminous events in the Universe. In addition, the Universe itself is almost transparent to γ ‐rays, making GRBs detectable up to very high redshifts. As a result, GRBs are very suitable to probe the cosmological parameters. This work shows the potential of long‐duration GRBs for measuring the cosmological parameters Ω_M and Ω_Λ by comparing the observed log N ‐log P distribution with the theoretical one. Provided that the GRBs rate and luminosity function are well determined, the best values and 1σ confidence intervals obtained are Ω_M = 0.22^+0.05_–0.03 and Ω_Λ = 1.06^+0.05_–0.10. Finally, a set of simulations show the ability of the method to measure Ω_M and Ω_Λ (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

水文地质参数计算方法探讨

阐述了水文地质参数的重要性,及其发展和尚需完善的方面。推出可以解决基岩裂隙、溶隙含水层坐标距离与水力距离不一致问题的导水系数计算方法。该方法的特点是简捷,能较直观地判别含水层主要水文地质参数的大小,具有很高的可靠性。     

内蒙大井铜多金属矿床岩矿石磁参数研究

通过对大井矿区岩矿石标本进行磁参数测试、岩矿鉴定和主要成矿元素的化学分析,运用数理统计和相关分析的方法,分析了大井矿区岩矿石磁性的分布规律及产生磁性的主要矿物,并指出了该区进行高精度磁测的可行性,对引起磁异常零乱特征作了剖析,最后以南矿区实例说明磁测工作的应用效果。     

武所屯煤矿12煤老空积水区水文地质参数研究

通过该矿12煤老空积水的疏放试验,选取相应的数学模型,计算了太原组12煤老空积水区的水文地质参数——渗透系数、充水系数;为滕北矿区类似条件下的老空积水疏放提供了理论依据。根据试验提出了利用集水廊道原理,扩大钻孔涌水量,节约工程费用,提高疏放效率的工程设计方法。     

西南喀斯特地区不同石漠化阶段土壤物理参数的变异研究

为了探索中国西南喀斯特地区石漠化过程中土壤物理性质的变异规律,采用野外采样与实验室分析相结合的方法,对贵州省荔波县及普定县不同石漠化阶段典型土壤的物理参数进行了研究。结果表明：土壤有机质质量分数随石漠化程度的加深逐渐减小;非石漠化土壤重度仅为6.15 N/m^3,随着石漠化的发展,土壤重度逐渐增大,总孔隙度随之减小;石漠化的发展导致土壤黏粒含量升高;土壤水稳性团聚体质量分数及微团聚体的结构系数均随石漠化程度加深而减小;土壤有机质质量分数与重度、砂粒含量、大于5 mm团聚体含量及结构系数的相关系数分别为-0.921 2、0.827 7、0.907 2、0.899 3,均达到极显著水平。通过封山育林等措施增加喀斯特地区有机质积累可改善土壤物理性质,对防治石漠化具有重要意义。     

Textural and geochemical characteristics of the Ajali Sandstone,Anambra Basin,SE Nigeria: Implication for its provenance

This study presents the mineralogical, textural and geochemical characteristics of the regional Maastrichtian Ajali Sandstone in Anambra Basin, SE Nigeria. The intent is to highlight possible constraints on the chemical weathering conditions of the source materials on one hand, and to infer the provenance on the other hand. The investigation approach involved field studies and collection of samples from 12 different outcrop locations, followed by laboratory studies involving grain-size analysis (GSA), major and trace elements analyses using the X-ray fluorescence (XRF) method as well as thin section petrography. Field studies show that the sandstones are friable at all locations and range in color from white in freshly cut stone, to reddish brown on weathering. In addition, the sandstone units are cross-bedded and show graded bedding exemplified by fining upward sequence. Textural examination indicates that the sandstones range from fine to medium sands, constituting about 76 to 99% sand fraction, with graphic mean grain size of 0.23 to 0.53 mm. Standard deviation (sorting) ranges from 0.56 to 1.24 Ø and implies moderately well sorted sediments. Inferred from the textural indices, the depo-environmental discrimination of the Ajali Sandstone revealed a fluvial/river system-dominated sedimentary process. The sandstones are quartz arenite with quartz greater than 90% and less than 5% K-feldspar which indicate a predominant basement source as also revealed by the heavy mineral assemblages. In addition, major elemental oxides shows SiO₂ content greater than 96% for the fresh Ajali Sandstone samples with extreme depletion of mobile oxides such as Na₂O, CaO and the ferromagnesian minerals through weathering and sedimentary processes. Provenance and tectonic setting discrimination using geochemical data and compositional maturity revealed typical felsic igneous-dominated cratonic environment while inter-elemental ratios (such as Zr/Cr, Y/Ni, Th/Sc, La/Sc and La/Co) and ternary plots (e.g. Th–Sc–Zr; La-Th–Sc and Th-Co-Zr) reflect passive continental margin setting for the Ajali Sandstone. Consequently, the source area is constrained to the Precambrian basement rock units of Adamawa-Oban massif areas to the east of the Anambra Basin and the adjacent Abakaliki Anticlinorium.