时序分析在危岩体监测数据处理中的应用

引入时间序列分析进行危岩体监测数据的处理,建立了危岩体变形的动态模型,取得了较好的拟会与预报精度。     

湘、黔下寒武统黑色岩系型Ni、Mo矿床中有机质与PGE成矿作用研究

湘、黔地区张家界、遵义一带分布有黑色岩系型Ni-Mo-PGE矿床,测试分析表明黑色页岩样品铂族元素含量特征参数∑PGE、Ln(Pd/Pt)、(Ru/Ir)×(Pd/Pt)、Ln[(Ru/Ir)×(Pd/Pt)]均与有机质含量特征参数有较好的相关性.趋势分析显示,铂族元素含量特征参数Ln[(Ru/Ir)×(Pd/Pt)]与总有机碳含量特征参数Ln(Corg)有很好的线性相关,线性相关公式为y=0.4762x-1.1316,相关系数R为0.7584,说明该参数为一稳定性参数,主要受有机质总量决定,集中反映了生物制约性.而与湖南张家界样品有机碳含量Ln(Corg)与铂族元素含量∑PGE同步正消长关系不一样,即贵州遵义地区铂族元素总量∑PGE与有机碳含量的相关性表现出的不一致的规律,可以解释为后生期的热事件(印支海西期,Rb-Sr等时线年龄277±37Ma)导致有机质干酪根的高成熟化、大量生过气(C>2%)和石墨化趋势,或者说是芳构化效应改变了源岩有机质而导致了有机质的损耗.     

Geodynamic setting,structure, and composition of continuous trachybasalt-trachyandesite-rhyolite series in the north of Altai-Sayan area: the role of crust-mantle interaction in continental magma formation

The geologic positions and geochemical and isotope parameters of the Ordovician-early Silurian and Early-Middle Devonian continuous volcanic series of the Minusa basin and its mountainous framing are compared. Both series are composed mostly of moderately alkaline rocks with variations in SiO₂ contents from 45 to 77 wt.%. The Ordovician-early Silurian series differs from the Early-Middle Devonian one in lower contents of TiO₂ (< 1.7 wt.%) and Fe₂O_3tot and higher contents of Al₂O₃ in all rock varieties and in the more fractionated REE patterns of trachybasalts. The compositions of both series reflect two simultaneous mechanisms of magma evolution. The main process was fractional crystallization leading to the formation of rocks from trachybasalts to trachyrhyodacites. The accessory mechanism was the contamination of fractionated melts by crustal material, anatectic melting of crust, and mixing of deep-seated magmas with crustal melts. These processes had specifics at each stage and were controlled by the composition of the sources of parental melts. Their geochemical and isotopic parameters (high alkalinity, high contents of lithophile elements, negative anomalies of Nb, Ta, and Ti, and enrichment in radiogenic Sr) point to the interaction of mantle plumes with the lithospheric mantle that was metasomatically transformed during the preceding Vendian-early Cambrian subduction processes.     

3维可视化校园信息系统的空间分析研究

数字校园是以网络为基础的系统,它利用先进的信息化手段和工具,实现从环境、资源到活动的全部数字化,拓展现实校园的时间和空间维度,提升传统校园的效率,拓展传统校园的功能,最终实现教育过程的全面信息化,从而达到提高教育管理水平和效率的目的。     

Dune-forming winds on Titan and the influence of topography

Numerous extended dunes on Saturn's moon Titan detected by the Cassini RADAR constrain the long-term pattern of surface winds. We analyse the statistics of surface wind speed and direction and their spatial and temporal variability predicted by a general circulation model (GCM) in order to constrain surface wind predictions of this GCM by dune observations. The model shows that modern winds are sufficient for saltation and dune formation at low latitudes, in agreement with the presence of dunes there. The best condition for the dune-forming wind occurs with a threshold friction speed of 0.02 m s⁻¹ or slightly less. The equatorial region is conducive to longitudinal dunes because of a combined effect of a high sand drift potential and obtuse bimodal wind pattern oblique to the equator caused by the seasonal reversal of the Hadley circulation. The cross-equatorial wind is steady, and is characterised by a high Weibull shape parameter (k∼4). The wind pattern at higher latitudes is more complex and gusty, and neither longitudinal nor transversal dunes would be able to form. Putative large-scale topography is found to have a profound influence on the near-surface wind pattern. Generally mountains cause a convergence and speeding up on the flank, while basins weaken the wind and cause a divergent flow. Longitudinal dunes can be deflected on the foot of mountains by up to 90°. If Xanadu is a hypothetical large mountain, a wind pattern converging in Xanadu that entirely disagrees with the dune observations is predicted. If instead Xanadu is a large basin, the wind arcs clockwise north of Xanadu and anti-clockwise west and southwest of Xanadu, in agreement with the dune orientations in the vicinity of Xanadu. The albedo pattern has comparatively little influence on the wind field. Isolated mountain chains cause only local-scale change in the wind pattern. However, the persistent surface easterlies in Belet, which are in conflict with the dune orientations, do not disappear by any combination of large-scale topography.     

Carbon and Noble Gas Isotopes in the Tengchong Volcanic Geothermal Area, Yunnan, Southwestern China

Carbon and noble gas isotope analyses are reported for bubbling gas samples from the Tengchong volcanic geothermal area near the Indo-Eurasian suture zone. All samples contain a resolvable component of mantle-derived 3He. Occurrence of mantle-derived 3He coincides with surface volcanism. However, 3He occurs over a larger geographic areathan do surface volcanics. δ13C values for CO2 and CH4 vary from -33.4‰ to 1.6 ‰ and from -52.8‰ to -2.8‰, respectively. He and C isotope systematics indicate that CO2 and CH4 in the CO2-rich gases originated predominantly from magmatic component mixed with crustal CO2 produced from carbonate. However, breakdown of organic matter and near-surface processes accounts for the CH4 and CO2 in N2-rich gases. 3He/4He ratio distribution pattern suggests that mantle-derived He and heat sources of high-temperature system in central Tengchong originate from a hidden magma reservoir at subsurface. CO2-rich gases with the highest 3He/4He ratio (5.2 Ra) may be representative of the     

鄂温克旗干旱、洪涝灾害期评定及预测方法

根据鄂温克旗1959—2008年气象历史资料,统一归类,并采用统计预报方法,简要评定预测出鄂温克旗50年来主要气象灾害之一的干旱、洪涝灾害期,为鄂温克旗防范旱涝灾害做参考。     

新型矿井多波多分量地震反射波观测系统的设计

针对DTC-150防爆地质超前探测仪在工程应用中存在的几个问题,提出了研制新型矿井多波多分量地震反射波观测系统的必要性.通过对大量工程预测预报资料的分析,结合煤岩有效地震波频率特性等4个关键技术的研究,得出了煤岩有效地震波频率范围和观测系统的有效布设方式,研制了高速、高精度、多通道数据采集及处理系统,给出了掌子面绕射回波形成的探测盲区和巷道声波的处理方法,提出了掌子面绕射回波与直达波不重叠的条件.新型矿井多波多分量地震反射波观测系统的研制成功为矿井提供了更为准确、更长距离的超前预测预报手段,同时也为煤矿安全生产提供了有力的保证.     

The environmental planning and management approach towards the development and management of the Osun natural spring project,Ibadan, Nigeria

There is a general shortage of potable water in Nigeria, partly through the lack of natural provision and partly because of rapid urban growth that has largely been unplanned. The paper describes the recent redevelopment of a public water facility in a run-down area of Ibadan which is part of the Sustainable Ibadan Project. Despite funding from national and international bodies, the development is strongly based at community level. The local inhabitants feel they have control over their own water supply through their representatives on the various planning and managing committees. This aims to reduce vandalism and to increase pride and involvement in the community. The project is a pilot for other projects around Ibadan, some of which have begun and others are being planned. This paper describes the administrative structures and management principles that have been employed. It forcefully advocates community-based planning and management which respects both the environment and the water-users, and involves a major “bottom-up” element. This revised version was published online in July 2006 with corrections to the Cover Date.