The interpretation of reaction textures in Fe‐rich metapelitic granulites of the Musgrave Block,central Australia: constraints from mineral equilibria calculations in the system K2O–FeO–MgO–Al2O3–SiO2–H2O–TiO2–Fe2O3

Fe‐rich metapelitic granulites of the Musgrave Block, central Australia, contain several symplectic and coronal reaction textures that post‐date a peak S2 metamorphic assemblage involving garnet, sillimanite, spinel, ilmenite, K‐feldspar and quartz. The earliest reaction textures involve spinel‐ and quartz‐bearing symplectites that enclose garnet and to a lesser extent sillimanite. The symplectic spinel and quartz are in places separated by later garnet and/or sillimanite coronas. The metamorphic effects of a later, D3, event are restricted to zones of moderate to high strain where a metamorphic assemblage of garnet, sillimanite, K‐feldspar, magnetite, ilmenite, quartz and biotite is preserved. Quantitative mineral equilibria calculations in the system K₂O–FeO–MgO–Al₂O₃–SiO₂–H₂O–TiO₂–Fe₂O₃ (KFMASHTO) using Thermocalc 3.0 and the accompanying internally consistent dataset provide important constraints on the influence of TiO₂ and Fe₂O₃ on biotite‐bearing and spinel‐bearing equilibria, respectively. Biotite‐bearing equilibria are shifted to higher temperatures and spinel‐bearing equilibria to higher pressures and lower temperatures in comparison to the equivalent equilibria in K₂O–FeO–MgO–Al₂O₃–SiO₂–H₂O (KFMASH). The sequence of reaction textures involving spinel is consistent with a D2 P–T path that involved a small amount of decompression followed predominantly by cooling within a single mineral assemblage stability field. Thus, the reaction textures reflect changes in modal proportions within an equilibrium assemblage rather than the crossing of a univariant reaction. The D3 metamorphic assemblage is consistent with lower temperatures than those inferred for D2.     

An oases dynamics model and its application in the Manas oasis

This study applies theories of systems and system dynamics to ecological economic systems in the oasis environment, with the intention of finding the basic characteristics of the oasis environment and its feedback structures. This study explores the inner mechanisms of economic development in the oasis environment and its relationship to policy variables. This model is applied to economic development in the Manas oasis of the Xinjiang Uygur Autonomous Region of China. System dynamics method starts from studying feedback structure within the system study and then searches for the best solution through identifying the right "policy point" and through model simulation in the computer. It embodies the cream of "systems cybernetics theory". This study is justified because the nature of the oasis system and the simulation results are scientifically sound and practically feasible.     

月壤中的氦-3

除了极少数非常陡峭的山脉与撞击坑和火山通道的峭壁外，整个月球表面几乎都被一层厚度不等的月尘、岩屑和岩块的混合堆积物即月壤所覆盖。由于月球无大气层等特殊环境，太阳光长驱直入，太阳风粒子直接注入到月壤细小颗粒上使月壤中富含稀有气体等太阳风粒子组分。本文在系统阐述月壤的形成过程与形成机制的基础上，分析了月壤中稀有气体的来源及其浓度与月壤的成熟度、月壤颗粒大小、月壤矿物组成和化学成分的相关关系，进而利用已有的探测数据和分析结果，对月壤中氦-3资源的开发利用前景进行了初步评估。     

甘肃北山公婆泉盆地中生代地层特征与砂岩型铀成矿条件分析

根据野外实地考察，综合前人的工作资料，从地层结构、层位、沉积体系、岩性及形成砂岩型铀矿的条件出发，概括了公婆泉盆地中生代地层的主要特征；确定了目的层并浅要分析了砂岩型铀成矿条件，对下一步铀矿找矿工作具有一定的现实意义。     

真空-堆载预压处理高速公路软基的有限元计算

根据高速公路路基的变形特点，提出了真空-堆载联合预压法处理软基的三维Biot固结有限元计算模型，将砂井按照实际尺寸划分单元，避免了平面计算方法中的砂井处理的问题，较以往的平面数值方法更接近实际情况。结合修正剑桥模型，对某真空-堆载联合预压试验段进行了计算、分析，结果令人满意。     

差异性风化岩石作为桩基持力层设计应注意的若干问题

基岩中存在软弱夹层为岩石的差异性风化的主要特征。在不均匀性地基土上选用该类地层作为钻孔灌注桩持力层时，它的存在将对桩长、单桩承载力、桩体沉降等带来不同程度的影响。以黄石电厂为例，指出在选用差异性风化岩石作为桩基持力层时应注意的若干问题。     

陕西彬县大佛寺D4钻孔勘察地球化学研究

运用烃类勘察地球化学方法，对鄂尔多斯盆地南部彬县大佛寺井田钻遇中休罗统煤层的耽钻孔，进行了垂向剖面多指标的综合地球化学研究。结果表明：剖面中所有岩样中的烃类物质均为热解烃生成初期演化阶段的煤成烃产物，具明显的同一性；由煤层至地表黄土，所有岩样中的烃类呈明显的、规律性垂直向上运移。这证实地下煤层烃类在近地表具有很好的地球化学信息显示，利用勘察地球化学方法找煤／煤层气是可行的。