Computation of response spectra from mining tremors using neural networks

Underground coal and copper ore exploitation in two Polish mining regions causes mining tremors and a series of other negative phenomena in the environment. Although these tremors are strictly connected with human activity, they differ considerably from other paraseismic vibrations. The moment of their occurrence is not to be foreseen likewise for earthquakes. The main problem discussed in the paper was formulated as the neural network evaluation of a relation between mining tremor energies, epicentral distances and acceleration response spectra. Back-propagation neural networks with Resilient back-propagation learning method were used. Each input vector included information about the mining tremor energy and the epicentral distance. Values of acceleration response spectrum were expected as the outputs of neural networks. Neurally evaluated spectra were compared with spectra computed on the basis of experimental data. After the network is trained and tested, it can be used for mapping of new data of mining tremor energies and epicentral distances into the spectra. Then, what is the substantial advantage of neural approach, the prediction of acceleration response spectra can be performed without recording of surface vibrations. In the light of the results, it is visible that the presented way of computation of acceleration response spectra can be peculiarly applied to prognosis of mining tremors influences on structures.     

区域创新政策评价的框架、测度与检验

构建区域创新政策评价的理论框架,在宏观知识生产函数中引入信息化作为创新技术进步的替代变量,基于DEA与Malmquist指数,用全要素生产率指数存量来衡量区域创新政策。并以省际高技术产业为例进行了实证,研究结果表明:区域创新政策的特征和评价维度决定评价的多样性,基于政策效果与政策交互作用的区域创新政策评价具有重要意义;区域创新政策总体上处于稳步提高阶段,较低地区以西部中部地区为主;区域创新政策测度模型系统性较好,其检验方法有待进一步深化;采用政府研发经费投入作为区域创新政策的替代变量值得商榷。     

长江经济带开发区空间分布与产业集聚特征研究

采用最近邻指数、Ripley’s L函数、核密度估计等方法分析长江经济带开发区的空间分布与产业集聚特征,结果表明:①长江经济带开发区总体上呈东密西疏、东强西弱、东中西段分异的显著集聚分布特征;②基于主导产业划分的各类开发区在空间上均为集聚分布,集聚强度和规模随距离的增加基本都呈"先增加后减小"的规律,集聚形态各异,主要有"单核心""双核心""多核心"3种;③长江经济带东段地区主要以装备制造、通信电子、汽车制造、新材料、生物医药等资本技术密集型产业集聚为主,中、西段地区则集聚了化学工业、金属加工、食品制造、纺织服装等资本与劳动密集型产业。要加强经济带上中下游开发区之间的多维良性互动,注重绿色发展、创新发展与结构优化,进一步提升其对长江经济带高质量发展的引领与支撑作用。     

冷水江煤矿塘冲矿井的地质采勘对比分析

塘冲矿井的大量井巷地质资料与原勘探精查报告对比分析表明,原精查报告内容与实际情况有较大出入,特别是控煤褶皱、断裂,煤层厚度与储量等方面,都存在较大差异,对矿山采矿影响颇大。究其原因,可能是勘查阶段受规范和技术手段等的限制,使原报告精度不够。因此,本文提出改进勘探方法,完善规范,提高勘查精度和加强煤矿生产补充勘探,都显得十分重要。     

建立乌鲁木齐国际机场临空经济区的战略思考

随着机场规模的扩大,客货运量的大幅增加,航线网络在全球的扩展,机场对周边地区的土地利用模式产生了一定的影响,这种影响将引起机场周边地区的经济结构、产业结构随之改变,最终逐渐形成一个对区域经济发展起到重要推动作用的临空经济区域。乌鲁木齐国际机场是全国第5大门户机场,但长期以来仅作为航空运输的节点,功能单一,机场周边地区的经济并未得到长足的发展。首先介绍了临空经济区的概念和发展背景,总结分析国内外大机场周边发展临空经济的经验,然后结合乌鲁木齐机场和腹地经济的现实情况,提出建立乌鲁木齐机场临空经济区的构想,并就临空经济区的产业发展方向和布局进行了探讨。     

开采沉陷土体变形与孔隙水压相互作用研究进展

本文通过实验、实测和理论分析研究了开采沉陷土体变形与孔隙水压力之间的相互作用,结果表明,随着开采的进行,土体的应力变形发生变化造成了超静孔隙水压力的产生和消散,反映在土体变形上出现随开采时间延续而发展的附加压缩和膨胀变形,这种压缩或膨胀在土体的不同部位相互叠加,有时还叠加了底部含水层水位下降引起的地面下沉。这些结果揭示了厚松散含水层地区开采沉陷特殊性的机理,对开采沉陷预测及水体下采煤具有重要意义。     

Geology and geochemistry of Iberian roofing slates

This article analyzes the geochemical and mineralogical composition of the roofing slate deposits of the Iberian Peninsula. Most roofing slate deposits are found on Middle and Upper Ordovician terrains, although there are also deposits in the Ediacaran, Cambrian and Devonian terrains. Samples of slate were taken in most of the active quarries of the Iberian Peninsula, and being analyzed by X-ray Diffraction and Fluorescence. Each lithotect or slate productive formation has its own specific proportions of major and trace elements, being able to differentiate between them by using these relationships. This fact is particularly interesting in geological exploration and prospecting, as it allows knowing exactly the slate lithotect, and also for restoration work in the architectural heritage, due to the ability of identifying the source of the original slate tiles.     

我国地质勘查行业诚信体系建设的路径探讨

从我国地勘行业诚信现状和面临的新形势来看,地勘行业诚信体系被视为行业健康发展的命脉和基础。通过分析地勘行业诚信体系建设的现状和面临的问题,借鉴国外发达国家社会信用体系建设的模式,提出政府主导构建地勘行业诚信体系的模式。在此基础上,运用斜坡球体理论提出了地勘行业诚信体系建设的支撑力、下滑力和拉动力以及相互之间的驱动机制,并从抑制及减少下滑力、增强拉动力和构筑牢固的支撑力三方面提出了政府主导模式下各参与方建设地勘行业诚信体系的实现路径和具体措施。     

Reservoir sediments – a witness of mining and industrial development (Malter Reservoir, eastern Erzgebirge, Germany)

The Malter Reservoir is situated about 30 km south of Dresden (eastern Germany) in a historical mining area of the eastern Erzgebirge. It was built in 1913 for the protection from floodwaters, droughts and for generating electricity. The river Rote Wei?eritz is the main source of clastic input into the lake. Geochemical and sedimentological data of gravity-and piston-cores, recovered from the deepest point of the lake, document the environmental history of the drainage area since 1963. ¹³⁷Cs dating gives an average sedimentation rate of ∼2.9 cm/year. Within the whole core, heavy metals are strongly enriched (parentheses refer to enrichment factors as compared with average shale): cadmium (290), silver (140), bismuth (90), antimony (25), lead (21), zinc (14), tin (13), uranium (9), tungsten (9), molybdenum (5), copper (4), thallium (3) and chromium (2). Enrichments are detectable for the whole registered time-period of 81 years. Peaks of up to 27 mg/kg silver, 37 mg/kg bismuth, 91 mg/kg cadmium, 410 mg/kg chromium, 240 mg/kg copper, 20 mg/kg molybdenum, 14000 mg/kg phosphorus, 740 mg/kg lead, 6,5 mg/kg antimony, 74 mg/kg tin, 52 mg/kg tungsten and 1900 mg/kg zinc reflect local events caused by human impact. Inputs from different pollution sources at different times are represented by highly variable elemental concentrations and ratios within the core. High pH values within the water and the sediment column, the large adsorption capacity of the fine-grained C_org.-rich sediment, and the presence of low Eh-values and sulphide ions in the sediment prevent the remobilisation of the toxic elements. Erosion of these contaminated sediments during floods, channel flows or resuspension during removal of the sediments may lead to a downstream transfer of pollutants. Contents of P and C_org., as well as diatom abundance, indicate a change from oligotrophic to eutrophic conditions in the lake during ∼1940–1950. This was mainly caused by high agricultural activity in the drainage area. Reduced contents of Cu, Zn, Cd and Cr since the reunification of East and West Germany are obviously caused by increasing environmental protection measures, such as wastewater purification and especially the closing of contaminating industries. Revision received: 23 September 1999 · Accepted: 17 December 1999     

唐山市钢铁工业发展特征及动力机制分析

唐山市钢铁工业自20世纪80年代以来一直为唐山市的支柱产业,90年代以来,省属特大型企业唐钢和地方钢铁企业都得到了迅速发展,在唐山市经济总量中占据着举足轻重的地位。本文详细分析唐山市钢铁产业的发展过程,探讨改革开放以来影响城市最具代表性产业的驱动因素。研究表明,基于本地化的区域产业基础和国家引导下的制度因素是唐山市钢铁工业迅速发展的主要驱动力,企业在动态的环境中适应和创新的能力则是内在因素。产品结构雷同、彼此利益独立使企业之间面临着激烈竞争,因此建议发挥政府的协调作用,引导地方企业调整工艺流程和产品结构,扶植相关产业,促进区域经济整体发展。