藏南特提斯喜马拉雅带中段二叠纪-白垩纪的火山活动(Ⅰ):分布特点及其意义

在野外实地考察和追索的基础上，详细厘定了特提斯喜马拉雅带中段晚古生代以来火山岩的分布特点和迁移规律。结果表明，在特提斯喜马拉雅带中段晚古生代以来的地层系统中，从二叠纪→三叠纪→侏罗纪→白垩纪，共有11个层位含规模不等的火山岩，它们以透镜体、薄夹层或以块状玄武岩、玄武质安山岩等形式产出于不同地层系统中；从二叠纪→早中三叠世→晚三叠世→侏罗纪和白垩纪，具有由西向东、从南→北→南→北的迁移规律。这些火山活动的发现和厘定，对填补特提斯喜马拉雅带火山岩研究的空白，了解陆下岩石圈地幔和软流圈地幔之间的相互作用和新特提斯洋盆的形成演化都具有一定的指示意义。     

中国中央造山带内两个超高压变质带关系

中国中央造山带内至少发育两个超高压变质带,一个是南阿尔金-柴北缘-北秦岭超高压变质带,超高压峰期变质年龄为早古生代(500～400 Ma),代表扬子与中朝克拉通间的深俯冲和碰撞带;另一个是研究程度较高的大别-苏鲁超高压和高压变质带,峰期变质年龄主体是三叠纪(250～220 Ma),代表扬子克拉通内部的陆内大陆深俯冲和碰撞带。对东秦岭看丰沟及香坊沟的变质岩片详细岩石学和构造学研究以及先期造山带尺度的构造、岩石和年代学研究资料分析证明,南阿尔金-柴北缘-北秦岭超高压变质带,向东不能与大别-苏鲁超高压和高压变质带的任一部分相连,包括南大别和西北大别超高压及高压变质岩石。相反,大别-苏鲁超高压及高压变质带,向西经桐柏山,横过南襄盆地延伸到南秦岭的西峡及商南一带。仅在东秦岭-大别山范围内,两个超高压变质带分别位于南丹断裂系南北两侧,沿造山带近平行延展,之间被一系列以断裂或剪切带为边界的岩石构造岩片相隔,不能构成横贯中国中部统一的巨型超高压变质带。任何有关中国中央造山带构造格架及构造演化模型的建立,均应考虑其内部发育两个时代和功能不同的超高压变质带。     

基于拉格朗日插值法修正地形影响的分布式降水模型研究

降水量一直是进行水文分析计算的输入项，对其分布状况的模拟直接影响水文分析成果精度。降水中心位置及其中心降水量对暴雨分析尤为重要，而目前尚未见对降水中心位置方面的模型研究。在对目前国内外降水模型分析的基础上，根据天气系统降水如不受地形影响其降水量等值线在平面上的分布近似为一组同心椭圆这一原理，建立了一种能够模拟次降水过程的降水中心位置及其中心降水量的新型分布式降水数学模型，并对其进行地形影响因素修正。由于模型建立原理简单，易于实现对流域未设站研究点的实时降水量估计，同时由于模型能够指明降水中心位置及其中心降水量，因此在流域暴雨分析和洪水预报中具有实用价值。模型经实践检验具有较高精度。     

Geological investigations at a high altitude, remote coal mine on the Northwest Pakistan and Afghanistan frontier, Karakoram Himalaya

The Northwest Pakistan and Afghanistan frontier is located one of the most remote, inaccessible, and inhospitable part of the Himalayan orogenic belt. In this region, two of the world's largest and most distinct mountain belts intersect; the Karakoram Himalaya (mainly in Pakistan) and the Hindu Kush (mainly in Afghanistan). Located at high altitude, in a remote part of Northwest Pakistan, close to the border with Afghanistan, tribal villagers began excavating a series of adits into the steep mountain slopes, beneath glaciers, to extract valuable coal and carbonaceous shale resources. These were discovered in 1996, by the villagers, whilst hunting, and may represent some of the highest mine workings in the world. Small-scale mining operations subsequently developed using rudimentary mining methods and the mine became known as the Reshit or Pamir Coal Mine.The coal deposits are sedimentary, highly disturbed and tectonised, having been subjected to multiple phases of orogenic crustal deformation. The coal occurs as discrete lenses, several tens of metres in their lateral dimension, between steeply dipping, overturned and thrusted limestone beds of Jurassic age. The coal provided a vital, alternative source of fuel for the villagers since the local, traditional fuel supply was wood, which had become severely depleted, and imports of kerosene from neighbouring China and Afghanistan were too expensive.The mining operations experienced severe problems. These included several collapses of mine entrances, the failure of the adits to intersect the coal-bearing zones, the potential threat of geological hazards, mining-induced hazards and harsh high-altitude operating conditions, particularly during the winter months. International aid was provided to assist the villagers and a geological investigation was commissioned to investigate the problems at the mine.The geology of Karakoram Himalaya is relatively poorly understood. Until recently the region was restricted to foreign visitors and large areas of this mountain belt are virtually unmapped. Existing geological and topographic maps are difficult to obtain or are unavailable due to the close proximity of political frontiers, national borders and security reasons. The mineral resource potential of this region is virtually unknown. Few western geologists have visited this area due to its inaccessibility and political constraints, being situated close the frontiers with China, Afghanistan, and the disputed Pakistan and India territory of Kashmir.The Pakistan and Afghanistan border, is once again, now closed to foreign visitors. The objectives of this paper are to document the occurrence of coal and carbonaceous shale, at high altitude, in the Karakoram Himalaya and to provide details on the geology, geological hazards, reserves and labour-intensive mining operations. These observations and information may provide the basis for future mineral exploration, mining-geology, mining-engineering, feasibility studies and engineering geological investigation in the Karakoram Himalaya.     

基于全球一体化的中原城市群城市竞争力研究

全球化背景下，城市群主导世界经济的趋势不可阻挡，关于城市群的研究随之也越来越受到人们的重视。近几年，中原城市群悄悄崛起，但只是一个雏形，还存在很多问题。为了更好的促进中原城市群的发育，特别是加强城市群内部各城市发挥特长、合理分工、优势互补，进而提升中原地区区域经济的发展水平，文章选用了九大类44项城市竞争力指标，建立了城市竞争力的指标体系，从定量的角度对中原城市群的城市竞争力进行了排序、对比、分析，其城市竞争力排名依次是郑州、济源、洛阳、焦作、漯河、新乡、许昌、平顶山及开封。得到的结论如下：(1)首位城市竞争力强，但还没有发挥核心城市的作用。(2)工业型的城市经济实力竞争力强。(3)农业型城市的经济竞争力较弱。(4)产业竞争力和资金实力是影响城市综合竞争力的主要因子。(5)个别城市的单项指标存在异常点，显现出其优劣势。最后根据分析结果，笔者提出了四点优化对策，为城市群中的城市定位、产业分工、资源优化配置及相应区域互动政策的制定提供决策依据。     

Slow mass movement in the Kangchenjunga area, eastern Nepal Himalaya

Abstract   The rates of the accumulated and continuous displacement of solifluction lobes in the Kangchenjunga area, eastern Nepal Himalaya, were determined using glass fiber tubes and a strain probe. Ground temperature, precipitation and soil moisture were monitored at two sites, whose altitude differed by approximately 100 m, to understand the solifluction process. The average movement rate of the glass fiber tubes on a 31° slope at altitudes of 5412–5414 m a.s.l. was approximately 11 mm/year, being almost threefold greater than that observed on a 22° slope at 5322–5325 ma.s.l. There was no significant difference in the depth of displacement at these sites. The continuous displacement measurement near the ground surface at 5414 m showed permanent downslope movement from early July. Such movement may be attributed to additional moisture supply during the monsoon season. The amplitude of the displacement cycle was highest at the ground surface, and decreased to virtually zero at and below 20 cm in depth. Probable factors leading to the relatively slow rates of downslope displacement at the surface and depth at the studied altitudes are the lack of concurrence of the freeze–thaw cycles and the high moisture condition in the soil, and the low moisture retention capacity of the soil because of steep slopes and superficial desiccation. The rate of displacement may be more pronounced at altitudes above 5600 m because of the freeze–thaw cycles during the summer season.     

Stability and accuracy analysis of the central difference method for real‐time substructure testing

The central difference method (CDM) that is explicit for pseudo‐dynamic testing is also believed to be explicit for real‐time substructure testing (RST). However, to obtain the correct velocity dependent restoring force of the physical substructure being tested, the target velocity is required to be calculated as well as the displacement. The standard CDM provides only explicit target displacement but not explicit target velocity. This paper investigates the required modification of the standard central difference method when applied to RST and analyzes the stability and accuracy of the modified CDM for RST. Copyright © 2005 John Wiley & Sons, Ltd.     

Environmental pollution impact on water and sediments of Kumaun lakes, Lesser Himalaya, India: a comparative study

A study of the water and sediment chemistry of the Nainital, Bhimtal, Naukuchiyatal and Sattal Lakes of Kumaun, has shown that the water of these lakes are alkaline and that electrical conductivity, total dissolved solid and bicarbonate HCO ₃ ⁻ are much higher in Nainital than in the other three lakes. The weathering of limestone lithology and anthropogenic pollution, the latter due to the very high density of population in the Nainital valley, are the primary sources of enhanced parameters. The low pH of Nainital Lake water is due to low photosynthesis and enhanced respiration, increasing CO₂ in the water and the consequent enhancement of Ca²⁺ and HCO ₃ ⁻ . The dissolved oxygen in Nainital Lake is less compared to other lakes, indicating anoxic conditions developing at the mud–water interface at depth. The PO ₄ ³⁻ content in Nainital is higher (124 μg/l), showing an increasing trend over time leading to eutrophic conditions. The trace metals (Cu, Co, Zn, Ni, Mn, and Sr) are present in greater amounts in the water of Nainital Lake than in the other three lakes, though Fe and Cr are high in Bhimtal and Fe in Naukuchiyatal. The higher abundance is derived from the leaching of Fe–Mg from metavolcanic and metabasic rocks. Most of the heavy metals (Cr, Ni, Cu, Mn, Fe, Sr, and Zn) significantly enrich the suspended sediments of the lakes compared to the bed sediments which due to their adsorption on finer particles and owing to multiple hydroxide coating and organic content, except for Fe, which is enriched in the bed sediments. The high rate of sedimentation, 11.5 mm/year in Nainital, compared to Bhimtal with 4.70 mm/year, Naukuchiyatal with 3.72 mm/year, and Sattal with 2.99 mm/year, has resulted in shorter residence time, poor sorting of grains, and lesser adsorption of heavy metals, leading consequently, their depletion in the bed sediments of Nainital Lake.