Non-Linear Theory and Power-Law Models for Information Integration and Mineral Resources Quantitative Assessments

Singular physical or chemical processes may result in anomalous amounts of energy release or mass accumulation that, generally, are confined to narrow intervals in space or time. Singularity is a property of different types of non-linear natural processes including cloud formation, rainfall, hurricanes, flooding, landslides, earthquakes, wildfires, and mineralization. The end products of these non-linear processes can be modeled as fractals or multifractals. Hydrothermal processes in the Earth’s crust can result in ore deposits characterized by high concentrations of metals with fractal or multifractal properties. Here we show that the non-linear properties of the end products of singular mineralization processes can be applied for prediction of undiscovered mineral deposits and for quantitative mineral resource assessment, whether for mineral exploration or for regional, national and global planning for mineral resource utilization. In addition to the general theory and framework for the non-linear mineral resources assessment, this paper focuses on several power-law models proposed for characterizing non-linear properties of mineralization and for geoinformation extraction and integration. The theories, methods, and computer system discussed in this paper were validated using a case study dealing with hydrothermal Au mineral potential in southern Nova Scotia, Canada.     

Inversely-Mapped Analytical Solutions for Flow Patterns around and within Inclined Elliptic Inclusions in Fluid-Saturated Rocks

In this paper, an inverse mapping is used to transform the previously-derived analytical solutions from a local elliptical coordinate system into a conventional Cartesian coordinate system. This enables a complete set of exact analytical solutions to be derived rigorously for the pore-fluid velocity, stream function, and excess pore-fluid pressure around and within buried inclined elliptic inclusions in pore-fluid-saturated porous rocks. To maximize the application range of the derived analytical solutions, the focal distance of an ellipse is used to represent the size of the ellipse, while the length ratio of the long axis to the short one is used to represent the geometrical shape of the ellipse. Since the present analytical solutions are expressed in a conventional Cartesian coordinate system, it is convenient to investigate, both qualitatively and quantitatively, the distribution patterns of the pore-fluid flow and excess pressure around and within many different families of buried inclined elliptic inclusions. The major advantage in using the present analytical solution is that they can be conveniently computed in a global Cartesian coordinate system, which is widely used in many scientific and engineering computations. As an application example, the present analytical solutions have been used to investigate how the dip angle of an inclined elliptic inclusion affects the distribution patterns of the pore-fluid flow and excess pore-fluid pressure when the permeability ratio of the elliptic inclusion is of finite but nonzero values.     

靖远矿区采煤沉陷区复垦综合评价方法研究

以靖远矿区为例,从土地复垦和恢复生态学的角度出发,建立了靖远矿区采煤沉陷区复垦综合评价系统,选择土壤条件（土层厚度、土壤质地、有机质含量、土壤水分）、地形改造条件（地面坡度、地表破坏程度、改造难易程度）、气候及水文条件（年降雨量、灌溉条件）作为分类及评价因子对复垦潜力进行评价。将采煤沉陷地分为四种潜力区,对每种潜力类型区的复垦开发利用方向进行了优化设计,从理论上和实践上对靖远矿区采煤沉陷地的复垦能力以及复垦过程中用地结构的优化作了探讨,以期对当地沉陷地的复垦提供一定的科学依据。     

Calorimetric study of the coesite-stishovite transformation and calculation of the phase boundary

High temperature drop-solution calorimetry in molten 2 PbO · B₂O₃ at 1044 K for coesite and stishovite polymorphs of silica was carried out to determine the enthalpy of the coesite-stishovite transition. These experiments were performed on high-purity, single-phase samples of coesite and stishovite. Our new value for the enthalpy of the coesitestishovite transition (ΔH ₂₉₈ ⁰ ) is 29.85 ± 0.78 kJ/mol, which is about 35% lower than previously reported by Akaogi and Navrotsky (1984) and Holm et al. (1967), but which compares well with new measurements by Akaogi et al. (1994b). Using these new data, we have calculated the equilibrium phase boundary between coesite and stishovite and obtained a slope, dP/dT=0.0031 (2) GPa/K. This calculated slope is in good agreement with that determined [0.0026 (2) GPa/K] from the in-situ X-ray diffraction study of Zhang et al. (1996).     

SOMATOM AR.C型CT机复位故障检修

本文介绍了由电源故障引起的不可逆转故障,并讨论了维修和故障的排除。     

青藏高原研究进入最佳期和青年肩负的责任

这是中国青藏高原研究会理事长刘东生院士在该会青藏高原青年科技奖第一次颁奖大会(1996年3月6日)上的演讲。本文指出了当前青藏高原研究的方向,表达了对青年一代的殷切期望。征得作者同意,以飨读者。青藏高原青年科技奖获奖者是:丁林、王保海、方小敏、刘晓东、刘燕华、张春光、高锐、姚檀栋、彭敏、廖俊国。     

Quartz-grain surfaces of debris flow material in the marginal mountains of Tibet

Debris flow is a natural phenomenon which occurs on steep slopes of mountain regions. Very often morainic material and nonmorainic sediments, such as debris flow material, fluvial and other sediments, are mixed in the marginal mountain systems of the Tibetan Plateau. The study of quartz-grain surface features of debris flow has an important significance for differentiating between different origins of Quaternary sediments. Features of quartz-grain in debris flow will be described as below:

1. The predominant shapes of quartz grains are irregular.
2. The degree of roundness of grains is in general are angular to subangular in shape.
3. The textures of quartz-grains in debris flows are conchoidal fractures, parallel steps and mechanical V-marks. Parallel steps are especially abundant. Their presence is the most characteristic indicator of debris flow sand, aiding in the differentiation between debris flow and glacial sand.
4. Fresh cleavage planes are extremely flat.

     

珠江口盆地西江主洼油气差异分布机制

西江主洼是珠江口盆地一个低勘探程度洼陷，油气差异聚集特征明显，但其机理不清。本文在断陷盆地油气成藏理论指导下，利用研究区地质、地球物理和地球化学等资料，开展了烃源岩、断盖组合、储集体系和运聚模式等方面的研究。结果表明，裂陷期沉降、沉积中心有序迁移，造成主力烃源岩自东向西由文四段迁移至文三段、文一+二段，控制东、西部油气差异分布。恩平组区域性泥岩发育且晚期断裂缺乏，导致油气纵向上更易聚集于下构造层；区域泥岩减薄尖灭或晚期断裂切开盖层的区域，上构造层有一定油气分布。"源-汇"类型从宏观上控制储层优劣，影响下构造层油气富集程度；"仓储"运移是控制上构造层油气规模聚集的主要模式。下构造层古近系应作为重点部署方向，东部围绕文四段、西部围绕文三段、文一+二段烃源岩构成的含油气系统展开；上构造层勘探需关注珠海组，在隆起周边寻找具备"仓储"运移模式的有利区带。     

Refugee flow or brain-drain? The humanitarian policy and post-Tiananmen mainland Chinese immigration to Canada

"The humanitarian policy that the Canadian government implemented in response to the 1989 Tiananmen Square crackdown changed a migration system primarily based on personal networks into a brain drain. Post-Tiananmen mainland Chinese immigrants (MCIs) were better educated than those arriving in Canada previously. Among the post-Tiananmen MCIs, those who landed under the policy were better educated than those landing in other categories. The analysis suggests that post-Tiananmen MCIs represented a brain-drain rather than a refugee flow, that the humanitarian policy implicitly contained ideological and human capital concerns in addition to humanitarian concerns, and that Canada benefited from the policy by obtaining human capital as well as satisfying its humanitarian obligations and ideological aspirations."     

人工触发闪电电流测量及特征性分析

通过对１９９３年７月２７日的人工触发闪电电流、跨步电压的直接测量结果的分析发现,在正电场下触发的慢型放电过程由连续电流和双极性的电流脉冲过程组成,其放电特性与雷暴的电特性有关。闪电电流最大值为１．２ｋＡ,持续时间为２５ｍｓ,中和电荷量为８．９Ｃ。跨步电压与电流的测量结果相一致,是一种间接测量电流的方法。