An overview of the Permian (Karoo) coal deposits of southern Africa

The coal deposits of southern Africa (Botswana, Malawi, Mozambique, Namibia, South Africa, Swaziland, Tanzania, Zambia and Zimbabwe) are reviewed. The coal seams formed during two periods, the Early Permian (Artinskian–Kungurian) and the Late Permian (Ufimian–Kazanian). The coals are associated with non-marine terrestrial clastic sedimentary sequences, most commonly mudrock and sandstones, assigned to the Karoo Supergroup. The Early Permian coals are most commonly sandstone-hosted while the younger coals typically occur interbedded with mudstones. The sediments were deposited in varying tectono-sedimentary basins such as foreland, intracratonic rifts and intercratonic grabens and half-grabens. The depositional environments that produced the coal-bearing successions were primarily deltaic and fluvial, with some minor shoreline and lacustrine settings. Coals vary in rank from high-volatile bituminous to anthracite and characteristically have a relatively high inertinite component, and medium- to high-ash content. In countries where coal is mined, it is used for power generation, coking coal, synfuel generation, gasification and for (local) domestic household consumption.     

向斜构造煤层开采地表移动规律研究

现行的地表移动预计方法，都是建立在开采工作面主断面为线性分布的基础上，因此，对于非线性分布煤层的预计将会产生较大的误差。本文以随机介质理论为基础，利用曲线积分的方法建立了地表移动与变形预计公式，并且利用数值积分法和叠加原理解算地表移动与变形值，扩大了地表移动预计理论的应用范围，同时也大大提高了预计值的精度     

依据密度测井资料评估煤层的含气量

煤层甲烷长期以来认为是对采煤工作的危害，只是近十多年来才被认为是一种潜在的能源。煤层不仅是甲烷的储层，而且是甲烷的源岩。煤的物理结构是一种双重孔隙结构，即煤层中含有由基质孔隙和裂缝孔隙组成的孔隙系统。煤层中的气（甲烷）主要吸附在基质孔隙的内表面，是吸附气，而不是存在于骨架粒间的孔隙空间内，因而传统的评价天然气储层含气量的方法虽然不能适合于评估煤层的气含量。本文利用密度测井资料和煤样煤质化验资料确定     

低沼矿区煤层气体地化特征及其灾害性

用立体地球化学的观点和方法研究了徐州煤田“低沼矿区”的瓦斯问题可以获得“低沼矿区”煤层气体是以甲烷为主,重烃含量甚低,δ~(13)C_1偏负等特征,并指出:低沼矿区具有相对性的特点,在一定条件下,煤层仍可具一定的气体灾害性。另外,用碳同位素方法还可以判别“煤层气体的活性”,以反映煤层气体和地下水的灾害倾向性。     

Estimation of the transfer function by autoregressive deconvolution techniques—An application to time series analysis

The transfer function of time-dependent models is classically inferred by the ordinary least squares (OLS) techniques. This OLS technique assumes independence of the residuals with time. However, in practical cases, this hypothesis is often not justified producing inefficient estimation of the transfer function. When the residuals constitute an autoregressive process, we propose to apply the Box-Jenkins' method to model the residuals, and to modify in a simple manner the primary convolution equation. Then, a multivariate regression technique is used to infer the transfer function of the new equation producing time-independent residuals. This three-step autoregressive deconvolution technique is particularly efficient for time series analysis. The reconstitution and the forecasting of real data are improved efficiently. Theoretically, the proposed method can be extended to the convolution equations for which the residuals follow a moving average or an autoregressive-moving average process, but the mathematical formulation is no longer direct and explicit. For this general case, we propose to approximate the moving average or the autoregressive-moving average process by an autoregressive process of sufficient order, and then the transfer function. Two case studies in hydrogeology will be used to illustrate the procedure.     

小窑采空区地质灾害综合评价研究

采用物探和钻探相结合的综合勘察方法，获取地质环境的破坏现状和采空区特征.按相关规范要求，预测小窑采空区的影响范围，剖析采空区残留空洞的稳定性，评价采空区的活化潜在威胁，分析采空引起的覆岩三带发育特征，剖析采空区引起的地表移动特征，获取相应地表变形特征参数.     

煤古植物学:历史、现状与展望

据对５０年来的文献分析，简要评述了煤古植物学这一分支学科的产生背景，研究现状和未来发展趋势；并指出，煤古植物学尽管有广泛的应用前景，但由于受研究方法和研究手段的限制，它仍处于发展的初级阶段。     

浅论砚石台煤矿滑覆构造及煤炭资源远景

对砚石台地区地层构造及滑覆构造组成要素、特征、形成机制进行了系统分析，论述了滑覆构造对煤层的影响，预测了－５００ｍ标高以下构造形态，提出－５００ｍ标高以下无须工作的建议。     

对中梁山煤矿地质构造特征的认识

根据３０多年矿井生产实测资料，对中梁山煤矿地质构造进行了分析研究，认为该矿地质构造虽然复杂，但也具有一定的规律，可分为简单、中等、复杂等不同构造区，大断层虽较多但对矿井开采影响不大，只是小型压扭性断层对采矿造成一定困难，故提出开采时应对症下药及保护资源的建议。     

Cuttability assessment of hard coal seams

Summary A number of field and laboratory tests have been carried out on more than 15 coal seams of compressive strengths ranging from 19 MPa to 44 MPa to evolve methods which would help in the selection of suitable coaling machines for hard coal seams. The effect of physico-mechanical properties on cuttability were studied in the laboratory for all these coal seams to identify the relevant parameters affecting the specific energy of coal cuttability. These data were subjected to regression analysis to find the best fit for estimation of laboratory specific energy of coal samples on the basis of simple laboratory and field tests for the strength parameters. Field studies were also conducted over a large number of active mechanized coal faces to study in situ cuttability along with the geo-mining conditions of the site. The field and the laboratory data so generated were correlated and an attempt is made to establish a relationship for estimating the field specific energy for a particular capacity of coaling machines by considering the geo-mining domain of the field in totality.