国外离心模型试验技术在边坡工程中的应用现状与展望

首先简单介绍了国外离心模型试验技术的发展状况 ,然后探讨了其在边坡工程中的应用 ,特别是在暴雨、水库蓄水对边坡稳定性影响中的应用 ,最后提出了边坡工程中离心模型试验存在的问题以及今后发展的方向。     

Recognition of shallow karst water resources and cave potentials using thermal infrared image and terrain characteristics in semi-arid regions of Iran

Shallow karst water resources and caves may influence land surface temperatures due to cold transfer property of rocks and evaporation from buried karst. The objective of this research was to develop a method for recognition of karst areas based on evaluating the surface characteristics that manifest itself by low land surface temperature in the satellite images. Investigation of thermal ETM⁺ image of the study region in Iran showed that parts of carbonate rocks that bear karst water are relatively cooler compared to areas with similar terrain conditions. Relational modeling provided useful information on spatial distribution of areas that have the potential to hold karst water resources and/or caves. Further inspection of ASTER images, along with geotechnical, geophysical and geological field surveys verified the approach. Significant correlation was found between electrical resistivity and thermal band values. The method may be used as a primary exploratory tool for shallow karst water explorations in similar areas.     

证据权法在CC区潜在多金属结核资源预测中的应用

运用证据权法,根据东北太平洋Clarion-Clipperton地区(简称CC区)的海底断裂构造、海底沉积物类型、初级生物生产力、水深等主要控矿地质证据资料,对该地区潜在多金属结核资源进行了预测。地质证据与多金属结核矿床的空间相关性研究表明,控制多金属结核的地质证据依次为:海底沉积物类型、初级生物生产力、海底断裂构造和水深。预测结果表明,已发现的多金属结核矿床分布的后验概率区间为0.29~0.73,说明证据权法在大洋多金属结核潜在资源预测中具有良好的应用效果。多金属结核矿床形成的有利后验概率区间表明,在研究区的西南部和南部存在寻找多金属结核资源的潜力地段。     

多辐射源地空瞬变电磁响应三维数值模拟研究

地空瞬变电磁法结合地面和航空电磁法的优点,可实现探测深度和工作效率的平衡.当前地空瞬变电磁法采用单一线源激发电磁辐射场,仅能从一个侧面与地质体耦合,难以获得地质体的全息影像.采用多辐射源是解决这一问题的途径.本文采用三维矢量有限元法对两个不同地质体多个辐射源情况下的地空瞬变电磁响应开展了模拟研究,分析了多辐射源在不同辐...     

湖泊营养盐通量平衡的三维数值模拟

湖泊氮、磷通量是表征湖泊营养状态的重要指标,也是探究湖泊富营养化机制的重要途径.通过氮、磷通量的计算和质量平衡关系的分析,可以识别出在湖泊富营养化过程中起关键作用的过程.以三维水动力-水质模型为计算平台,模拟湖泊水动力、水质的动态过程,并以模拟结果为基础核算湖泊氮、磷循环通量及其在氮、磷循环整体中的贡献,识别湖泊氮、磷循环关键源汇过程的变化规律.滇池是我国富营养化湖泊的代表,同时其半封闭特性为营养物质循环提供了更为稳定的环境,以滇池为案例,基于前期校正和验证过的滇池水动力-水质模型来分析循环通量计算方法的适用性.结果发现,研究年度内滇池外海总氮的年总输入量(包括外源和内源)为7620.92 t,总输出量(包括出流、反硝化和沉降)为7637.31 t;总磷的年总输入量为(包括外源和内源)450.23 t,总输出量(包括出流和沉降)为429.57 t,其中陆域输入是最主要的氮、磷输入途径,而反硝化和沉降则是主要的输出过程.相较于传统的质量平衡方法,通过三维模型计算所得的营养盐通量平衡结果能更好地揭示湖体内所发生的氮、磷转化过程.     

基于工作流的地理处理建模技术

通过对传统地理处理建模的分析以及工作流技术的研究,提出了基于工作流的地理处理建模方法,并通过实验室选址的实现验证了该方案具有可行性.     

A Process-based Model of N2O Emission from a Rice-Winter Wheat Rotation Agro-Ecosystem： Structure, Validation and Sensitivity

In order to numerically simulate daily nitrous oxide(N2O) emission from a rice-winter wheat rotation cropping system,a process-based site model was developed(referred to as IAP-N-GAS) to track the movement and transformation of several forms of nitrogen in the agro-ecosystem,which is affected by climate,soil,crop growth and management practices.The simulation of daily N2O fluxes,along with key daily environmental variables,was validated with three-year observations conducted in East China.The validation dem...     

壁画空鼓病害的探地雷达正演模拟检测

通常西藏壁画地仗层的厚度不足10cm,有效去除直耦杂波是利用高频探地雷达识别壁画空鼓病害的关键,在此基础上计算空鼓的厚度。模拟制作西藏壁画地仗,在其内部预设深度和厚度各不相同的规则空鼓,通过正演模拟试验确定探地雷达的采集参数,积累数据处理的经验,并比较不同雷达天线的性能。结果表明,针对RAMAC探地雷达和Ground Vision数据采集、后处理软件,时窗深度宜为3ns左右,采样频率应不低于142GHz,效果最明显的两个滤波器是带通滤波和抽取均道。当雷达天线与细泥层地仗耦合较好时,中心频率1.6GHz和2.3GHz的雷达天线均能准确检测出深3cm左右、厚约2cm的空鼓,1.6GHz天线的极限垂直分辨率约0.5 cm。     

Impact of fertilizer application and urban wastes on the quality of groundwater in the Cambrai Chalk aquifer,Northern France

Since 1975, Europe sets up its policy to limit the degradation and the pollution of the aquatic environments through 30 directives and regulations. In the north of France, the nitrate concentrations measured in the groundwater exceed the water drinking limit fixed at 50 mg/L by the European framework directive in the field of water (2000/60/EC). This high concentration is due to intensive agriculture, industrialization and demographic growth. Several programs were launched in order to resolve this situation: “Ferti-better” or the use of fertilizer in moderation and installation and amelioration of wastewater collect and treatment systems. In order to estimate the influence of the anthropic activities on the quality of groundwater in the “Artois-Picardy” basin, a preliminary validation on parcel and district scale were necessary. The impact of these programs in the “Cambrai district” was evaluated using an integrated approach, which is based on the use of four numerical models: AgriFlux, VS2DT, Modflow and MT3D. The results illustrate an improvement due to the “Ferti-Better” program initiated in 1990 and punctual degradation under urbanized areas. Predictions (2015) show a spatial evolution of nitrates concentration varying with the thickness of unsaturated layer. The integrated model constitutes an efficient tool for predicting the evolution of the groundwater quality. This approach is important to control the application of the new European laws in the water field.