甘肃花草滩煤矿区沉积相演化与内部构造的地质意义探讨

花草滩煤矿区地处北祁连褶皱带中段北侧,酒东盆地东端。古生界和中生界地层在区内发育较完整,其中石炭系太原组为含煤地层。经二、三维地震勘探、钻探等工作证实矿床总体上受单斜构造控制。石炭纪中期盆地呈逐渐上升趋势,沉积相演化经历了由海相逐渐过渡到海陆交汇相,再到陆相沉积的阶段。F5和F8断层具顺层断裂特征,破坏煤层的连续性,在一定程度上控制了瓦斯突出区的分带,可作为煤矿瓦斯含量高低的分界标志。     

松软地层防渗灌浆帷幕结构性状实验研究

松软地层透水率较大,防渗灌浆工程吃浆量相对较大,浆液扩散极不规则,形成的防渗帷幕,包括防渗幕体厚度、力学性能、防渗效果等结构性状难以准确把握,现有的方法和技术主要采用压水试验、标贯、钻孔取心、物探等方法获取相关信息,但带有极大的不确定性,直接影响到防渗质量的评价。在现场进行多工况灌浆原型试验研究,通过注水试验、孔斜测定、取心测试、全断面开挖等多种方法,真实呈现防渗幕体的性状,包括幕体有效厚度及其影响范围、幕体强度性能和渗透性能。结果表明,在松软地层采用浆体封闭、脉动灌浆控制灌浆工艺,孔距1.5m,两排排距0.8m,并采用适宜的灌浆控制参数灌注可控性黏土水泥浆材,简便高效,孔周挤密区、结石体及胶结体形成的有效幕体均一性好,防渗效果达到5lu以下,灌后28d结石体强度达到3MPa以上。灌浆工艺和参数可直接供类似地层应用。对于不同类型地层在不同灌浆材料、灌浆工艺、灌浆参数情形下的灌浆结构性状,有必要研发物理模型进行大样本室内试验研究。     

Optimum design of nailed soil slopes

In this paper, a generalized method of computer based optimum design of soil-nailed slopes is reported. A limit equilibrium formulation satisfying overall and internal equilibrium and considering the effect of tensile resistance of the reinforcement has been used in computing the stability of nailed slopes. The quantity of steel requirement for raising the factor of safety to a desired value is estimated. The location, size (length and diameter) and orientation of the nails and the location and shape of the critical shear surface have been treated as variables. The solutions have been isolated by formulating the problem as one of non-linear programming. The applicability of the developed method has been verified by comparing the predicted failure surfaces with those observed in model tests as well as in the field and also reported theoretical results.     

Adjoint method for the optimum planning of industrial pollutant sources

The deterioration of air quality is threatening the life and health of people. Scientists in China and other countries have done a great deal of research work on the details of air pollution and the methods of preven-tion and control during the past decades. Up to now, most of the achievements are concentrated on the techniques of controlling pollutant sources and the programs of reduction, which focus on the improve-ment of air quality and the restoration of environment. The techniques of con…     

Constraints from Moho geometry and crustal thickness on the geodynamic origin of the Vrancea Seismogenic Zone (Romania)

Reprocessing of industry deep seismic reflection data (Ramnicu Sarat and Braila profiles) from the SE Carpathian foreland of Romania provides important new constraints on geodynamic models for the origin of the intermediate depth Vrancea Seismogenic Zone (VSZ). Mantle (70–200 km) earthquakes of the VSZ are characterized by high magnitudes (greater than 6.5), frequent occurrence rates (approximately 25 years), and confinement in a very narrow (30 × 70 × 200 km³) near vertical zone atypical for a Wadati–Benioff plane, located in front of the orogen. These two deep (20 s) seismic reflection profiles (70 km length across the foreland) reveal (1) a high-amplitude, gently east-dipping reflection across most of the section from what we interpret to be the Moho at  15 s (40–42 km) on the Ramnicu Sarat line to  16 s (47–48 km) on the Braila line, (2) a thick sedimentary cover increasing in thickness from east (1 s;  800 m) to west (7.5 s; 14 km), (3) an eastward increase in crustal thickness from 38 km (near VSZ) to  45 km, (4) seismic and topographic evidence for a newly imaged, possibly seismically active basement fault with a surface offset of 30 m observed on the Ramnicu Sarat line, (5) a lack of notable west-dipping structures in the crust and across the Moho, and (6) variable displacements on Peceneaga–Camena Fault of  5 km at Moho and  200 m at the basement–sedimentary cover contact.These observations appear to argue against recent models for west-dipping subduction of oceanic lithosphere at or in the vicinity of the Vrancea Seismogenic Zone given the lack of west-dipping fabrics in the lower crust and across the crust–mantle boundary. Consequently, one possible explanation for the geodynamic origin of VSZ could be partial delamination of the continental lithosphere in an intra-plate setting along a sub-horizontal lithospheric interface in the Carpathian hinterland that likely involves remnant lithospheric coupling between the crust and uppermost mantle in the foreland.     

基于路径的聚类分析

聚类分析的很多算法中都采用连接两点直线的欧氏距离来判断空间亲疏性,然而当有障碍物层存在时,连接两点的直线已不能完全表达它们之间的关系,特别是当有指定的交通路线时,两点之间的连通路径和距离必须遵从特定的路径.文中讨论在了障碍物或指定的交通路线存在的情况下点集的聚类分析,给出了解决有障碍物或指定交通路线时进行聚类分析的算法PathClust.     

月球Airy均衡状态与月壳厚度估计

月球水准面异常和表面地形变化是其内部密度不均匀和各个界面的起伏变化的体现,因此利用水准面和地形之比(geoid to topography ratio,GTR)可估计月球均衡和月壳厚度。本文基于月球重力场模型SGM100h和地形模型STM359_grid-02,经过去除表面玄武岩填充和深层异常质量影响,并结合理论Airy均衡模型中GTR与参考月壳厚度的关系,计算得到了新的月壳厚度模型。该模型的月壳平均厚度为36.9 km,背面比正面平均厚约13.5 km,Apollo12/14登陆点的月壳厚度分别是28.3 km和29.1 km。在各月海盆地存在着中央较薄、四周逐渐增厚的趋势。     

平流层爆发性增温过程中臭氧的垂直分布特征

利用ECMWF资料分析了平流层爆发性增温 (SSW) 过程中臭氧体积混合比的垂直分布的变化, 结果表明: 平流层爆发性增温过程中臭氧体积混合比增大, 而其极大值大多数形成在增温盛期。同时臭氧体积混合比的高值区在爆发性增温过程中随高度发生一定的变化, 据此对其变化分为两类: (1) 下传型: 在增温初期臭氧体积混合的高值区随高度下传至一定高度, 在增温盛期形成极大值然后随高度抬升到大致增温前的高度。 (2) 增厚型: 在增温过程中臭氧体积混合比的高值区厚度增加, 同时附近区域的臭氧体积混合比也增大, 而且在增温前臭氧体积混合比高值区在高度上没有多大变化, 增温开始后有所抬升。平流层爆发性增温过程中臭氧高值区随高度变化的这两种类型, 是由于平流层爆发性增温期间剩余环流对臭氧输送的结果。臭氧变化的下传型是由于在爆发性增温前剩余环流存在着中纬度向极地的明显输送, 并且伴随着极地强烈的下沉运动, 这就使得中纬度输送来的臭氧向下输送, 因此出现了臭氧高值区的下传; 而臭氧变化的增厚型是由于在爆发性增温期间剩余环流不但有中纬度向极地的输送, 而且在极地附近5 hPa高度处出现了上下两支输送气流, 向上的输送气流使中纬度输送来的臭氧向上输送, 而向下的输送气流使中纬度输送来的臭氧向下输送, 进而使增温期间极地附近的臭氧的高值区增厚。同时分析还表明: 平流层爆发性增温过程中中纬度臭氧体积混合比减少。