乌鲁木齐城市化进程对局地气候变化的影响研究

利用1976—2014年乌鲁木齐城区和郊区两个气象站的气温、降水、相对湿度和风速气象数据及1995—2014年乌鲁木齐市城市发展数据,运用线性趋势对比分析城区和郊区各气候要素的年际变化特征;采用相关分析法对城市化因子和气候要素进行了探讨。结果表明:城、郊区气温均呈明显的上升趋势,城区的年均气温高于郊区;城区降水量是郊区的3.93倍,增长速率是郊区的3.98倍;各年代城区相对湿度比郊区大,但呈下降趋势,郊区呈上升趋势;各年代郊区风速大于城区,郊区风速约为城区的2.35倍,均呈下降趋势。近20 a,乌鲁木齐城市化进程加快,对局地气候影响明显,其中对平均气温和相对湿度的影响最为显著。     

Comparison of Press-Replace Method and Material Point Method for analysis of jacked piles

In this study, installation of jacked piles in sand is simulated using Press-Replace Method (PRM) and Material Point Method (MPM) and the results are compared together. This comparison is important because a realistic and yet efficient simulation of installation of jacked piles is an appealing step towards the design and analysis of this type of displacement piles. It is shown that PRM as a method that is founded on small-strain finite element method can produce pile and soil responses that are in a promising agreement with those of MPM which is a finite-deformation analysis method.     

Compositional multivariate statistical analysis of thermal groundwater provenance: A hydrogeochemical case study from Ireland

Thermal groundwater is currently being exploited for district-scale heating in many locations world-wide. The chemical compositions of these thermal waters reflect the provenance and circulation patterns of the groundwater, which are controlled by recharge, rock type and geological structure. Exploring the provenance of these waters using multivariate statistical analysis (MSA) techniques increases our understanding of the hydrothermal circulation systems, and provides a reliable tool for assessing these resources.Hydrochemical data from thermal springs situated in the Carboniferous Dublin Basin in east-central Ireland were explored using MSA, including hierarchical cluster analysis (HCA) and principal component analysis (PCA), to investigate the source aquifers of the thermal groundwaters. To take into account the compositional nature of the hydrochemical data, compositional data analysis (CoDa) techniques were used to process the data prior to the MSA.The results of the MSA were examined alongside detailed time-lapse temperature measurements from several of the springs, and indicate the influence of three important hydrogeological processes on the hydrochemistry of the thermal waters: 1) salinity and increased water-rock interaction; 2) dissolution of carbonates; and 3) dissolution of sulfides, sulfates and oxides associated with mineral deposits. The use of MSA within the CoDa framework identified subtle temporal variations in the hydrochemistry of the thermal springs, which could not be identified with more traditional graphing methods, or with a standard statistical approach. The MSA was successful in distinguishing different geological settings and different annual behaviours within the group of springs. This study demonstrates the usefulness of the application of MSA within the CoDa framework in order to better understand the underlying controlling processes governing the hydrochemistry of a group of thermal springs in a low-enthalpy setting.     

自动气象站常见的异常问题及解决方法

对自动气象站常见的异常问题进行分析，并对这些异常问题提出解决方法。     

马海盐湖低品位固体钾矿溶解开采方法初步探讨

马海盐湖经地质勘查提交的KCl品位在8%以下的固体钾矿达486.73×104t,相当于一个中型钾镁盐矿的规模,对于这部分资源目前尚未得到利用。我国从上世纪90年代后期在盐湖矿产的开发中运用溶解采矿的方法,取得了显著的成效。文章主要通过与察尔汗盐湖的对比研究,认为对马海盐湖低品位固体钾矿完全可以进行水溶开采,并就水溶开采的必要性及其可行性进行了论述,对水溶开采的方法进行了初步的探讨。综合分析马海钾矿区的地质条件,包括固体钾矿的分布、厚度、品位以及埋藏深度等,从溶矿的效果和成本对比考虑,提出在矿区低品位固体钾矿厚度较小的东部进行沟渠式溶矿,在低品位固体钾矿厚度较大的西部进行井—渠结合式溶矿,在整个钾矿区根据固体钾矿层埋藏深度选用沟渠溶采和井—渠溶采相结合的溶矿方案,最后指出了溶解开采需要注意的几个方面的问题,这对于马海盐湖低品位固体钾矿进行工业化水溶开采具有重要的参考意义。     

瞬变电磁技术探测古墓陪葬金属器皿的应用效果

通过应用实例简要地介绍了定源大回线瞬变电磁(TEM)技术探测古墓中金属陪葬器皿的野外工作方法、数据处理及资料解释。实例表明,定源大回线TEM技术是一种探测有一定规模的陪葬金属器皿的有效方法技术。     

The influence of petrophysical properties on the salt weathering of porous building rocks

The influence of pore structure, water transport properties and rock strength on salt weathering is evaluated by means of a thorough rock characterisation and a statistical analysis. The pore structure was described in terms of its porosity, pore size distribution (quantified by mean pore radius) and specific surface area, density and water transport was characterised by means of water permeability (saturated flow) and capillary imbibition (unsaturated flow); whilst the rock strength test was carried out using uniaxial compressive strength, compressional and shear wave velocities, dynamic elastic constants and waveform energy and attenuation were obtained from the digital analysis of the transmitted signal. A principal component analysis and a stepwise multiple regression model was carried out in order to examine the direct relationships between salt weathering and petrophysical properties. From the principal component analysis, two main components were obtained and assigned a petrophysical meaning. The first component is mostly linked to mechanical properties, porosity and density whereas the second component is associated with the water transport and pore structure. Salt weathering, quantified by the percentage of weight loss after salt crystallisation, was included in both principal components, showing its dependence on their petrophysical properties. The stepwise multiple regression analysis found that rock strength has a predominant statistical weight in the prediction of salt weathering, with a minor contribution of water transport and pore structure parameters.     

滨海城市高密度电法观测精度问题探讨

在滨海软土地区的城市里,由于地下水较浅,地下水的矿化度较高,视电阻率一般都比较低,加之城市内各种工业与民用电器设施的干扰,使得开展高密度电法探测是一件颇为困难的事情,高密度电法探测的精度如何评价和取舍就成了一个不得不面对的问题,根据在天津地区开展高密度电法的实践,对这一问题进行了探讨。     

广东省及邻区活动断裂的实验研究

从实验应力分析和岩石力学的角度,综合其它学科的相关理论,给出了一种有别于传统的活动断裂的新定义及其判据。其定义为:在现代构造应力场中,存在沿原断裂面破裂和扩展的断裂。其判据为:①某断裂走向与主压应力1σ方向所夹的锐角0°≤β≤50°时,其为活动断裂;②β=25°的断裂为最活动的断裂。通过对广东省及邻区活动断裂的实验研究还得到其1σ方向分布图(广东省域从东到西,1σ方向大致为305°～360°～15°)、活动断裂或活动断裂分段的走向范围以及主要活动断裂分段内潜在的最大地震。大致为:①NW走向的断裂,除西部极少数外,全部是活动断裂。各断裂分段内潜在的最大地震在MS 5.1～7.4级之间:②研究区东部的近EW向断裂、西部NE向断裂的部分分段和SN向断裂,也是活动断裂。各分段内潜在的最大地震在MS6.8～7.5级之间。     

Spatiotemporal characteristics of the displacement field revealed with principal component analysis and the mode-rotation technique

Principal component analysis (PCA) was applied to the displacement field recorded at 147 GPS stations in the Kanto-Tokai district, Japan, for the period from January 1999 to February 2003. Some prominent geophysical events occurred during this period. Using PCA, we attempted to decompose the displacement field into some representative spatial modes and their corresponding temporal modes to quantitatively extract the primary geophysical events that have caused rapid crustal deformation in this region. The displacement field was roughly decomposed into modes corresponding to the following three major events: (1) The Miyake-Kozu volcanic event, which occurred in the region south of Tokyo in 2000. It included large-scale dyke intrusion and intensive earthquake swarm between the Miyakejima and Kozushima islands. (2) The Tokai slow-slip event, which is considered to have begun just after the Miyake-Kozu volcanic event and is ongoing as of November 2005. It occurred on the boundary between the subducting Philippine Sea Plate and the overriding Eurasian (Amurian) Plate in the Tokai district. (3) The Boso slow-slip event, which lasted for approximately 10 days in October 2002. It occurred on the boundary between the subducting Pacific Plate and the overriding North American Plate near the Boso Peninsula. In the decomposition process, we combined the mode-rotation technique with ordinary PCA. This is because PCA causes contamination between modes, i.e., a mode obtained with PCA is contaminated by other modes. For example, the first principal mode corresponding to the Miyake-Kozu volcanic event, which is by far the largest in magnitude, was clearly seen in many other modes. In order to remove such contamination, we applied the mode-rotation technique, in which the principal axes derived from PCA are rotated so as to minimize the correlation coefficients between different temporal modes for a time period in which some prominent change occurs. Combining the mode-rotation technique with PCA exhibited a better performance in separating the displacement field.