长江口水下三角洲Y7柱样磁性特征及其影响因素

以长江口水下三角洲380cm长的Y7柱样为对象,在磁性测量、地球化学和粒度分析的基础上,探讨了近百年以来长江口水下三角洲沉积物磁性特征变化及其影响因素。研究结果表明,磁铁矿是主导Y7柱样磁性特征的主要矿物,相比常量元素和粒度的均一组成,磁性特征存在显著的垂向变化。     

粒组含量对钙质砂压缩变形特性影响的宏细观研究

钙质砂是一种海洋生物成因的特殊岩土介质,其颗粒形态与基本性质较一般陆源砂有很大的不同。一方面通过钙质砂及石英砂的显微镜三维成像试验,对比研究了钙质砂的三维颗粒形态特征。发现相比石英砂,钙质砂颗粒棱角更显著,轮廓趋于扁平。另一方面,对两砂进行一维压缩试验,分析了各粒组含量对钙质砂压缩特性的影响规律,并利用三维形态分析从细观上解释了钙质砂的压缩宏观特性。发现相同级配、密实度下,钙质砂的压缩性比石英砂高约60%～160%（以av1-2表征）,且粗粒组（5～1 mm）含量对钙质砂的压缩性影响最为显著;当粗粒组含量<25%,中、细粒组质量比值M一定时,存在最劣粗粒含量使钙质砂压缩性最大,且该值随着M的增大而减小,并提出了一个经验公式。     

顾及邻近点的改进PSO-SVM模型在基坑沉降预测的应用研究

针对SVM模型在基坑沉降预测领域存在参数选择困难和基于单点数据建模的缺点,建立顾及邻近点的PSO-SVM模型.采用PSO-SVM模型进行最优训练样本数量研究,结果表明短期样本的预测效果最优.将邻近点沉降变形值作为影响基坑沉降的因素引入到改进的PSO-SVM模型中,实例表明,在短期样本数据下顾及邻近点的PSO-SVM模型...     

宣汉气田的地气测量及其机理研究

地气测量在反映金矿的深部盲矿方面, 取得了很好的试验效果.为扩大应用范围, 在已知气田进行试验, 其结果能够反映4 000 m深的环状断裂构造, 异常位置在构造的垂直上方.另外, 土壤中有2组微量元素异常, 间接指示了含气范围.此外, 进行了多种扫描探针显微术观测, 发现采样器上沉积的物质是以纳米微粒及其集合体形式存在的, 为地气异常形成机理研究提供了证据.      

The use of ‘rock hard’-sodium sulphate tablets for quickly determining preferential water flow routes in soils

Subsurface water flow routes have been inferred from gypsum sphere weight loss with minimal disturbance to soil structure or flow nets (Crabtree and Trudgill, 1984). This technique is limited by the relatively slow, fixed dissolution of gypsum. A solution is to use tablets consisting of Durham's ‘Rock Hard Water Putty’ and sodium sulphate. Laboratory tests indicate that tablet dissolution is controlled by the ratio of Rock Hard to sodium sulphate and is proportional to net throughflow yet independent of throughflow pH (between 3·0 and 9·0) and throughflow rate (at rates < 0·04 1 hr^?1). The tablets are also mechanically stable, economical, and environmentally safe. Field study results using the Rock Hard-sodium sulphate tablets are consistent with both the laboratory findings and the results of previous investigators.     

Small-particle concentration fluctuations at a coastal site

Aerosol size spectra (d=10 nm–10 μm) were measured with an electrical aerosol spectrometer (EAS) at Mace Head on the west coast of Ireland. Several small aerosol particle (diameter 10–32 nm) concentration bursts were observed during the measurement period. Relationships between the events, air mass trajectories, tide height, and meteorological parameters are examined. Series of bursts were observed when a spectral transformation due to subsequent particle growth from 10 to 56–100 nm can be identified in an Eulerian experiment. Particle growth rates of between 1 and 3 nm/h were determined. These bursts appear in cold and comparatively clean arctic or polar air masses with temperature and relative humidity fluctuations, and do not correlate with low tide in some cases. These episodes, similar to those frequently found in the continental boundary layer, are thought to occur over a wide area and, for clear detection, require stable airflow for a few days. Elevated small-particle concentration events are more common during low tide or shortly after, and are typically associated with low wind speeds. Here, the increased shore exposure during low tide is thought to influence the nucleation and the subsequent growth of these aerosol particles. The occurrences of the bursts are found to depend on local wind direction. The highest d=10–32 nm particle concentrations appeared for wind sectors furthest from the tidal regions when the wind direction was 150–160°(south-easterly). Most of the events occurred during daytime when solar irradiation is most intense.     

中国乡村地域类型及分区发展途径

由于我国乡村地域差异显著,乡村振兴需分类有序推进。本研究立足于人地关系地域系统理论,从资源、环境、人文、经济等维度构建了度量乡村综合发展水平的指标体系和计量模型,划分了乡村地域类型,明确了分区发展途径。结果表明,我国乡村综合发展水平区域差异显著,呈现明显的自东向西递减规律;全国乡村地域类型可以划分为11个一级区和45个二级区,不同类型区制约因子各异;乡村发展水平差异是资源禀赋、功能定位、区位条件、政策文化等因子交互作用的综合体现。地理环境是乡村地域类型分异的决定性因素,资源禀赋状况是乡村地域分异的关键因子,人文和经济因素在乡村系统转型发展中扮演着重要作用。通过对乡村地域类型、特征及其分异机制的研究,为乡村振兴战略的顺利推进提供了理论依据。     

基于3个不等粒径颗粒接触模型的土-水特征曲线

基于热力学原理及二维液桥计算模型,以3个不等径土颗粒为研究对象,推导出基质吸力与体积含水率之间的关系,得到微观模型下的土-水特征曲线。将3个不等粒径颗粒概化为限制粒径、中值粒径和有效粒径,研究了粒径大小、颗粒级配和土颗粒接触角的大小等因素对土-水特征曲线影响的规律。计算结果表明：体积含水率相同,颗粒粒径越大,相应的基质吸力越小;在同一基质吸力下,不均匀系数 越大即土颗粒越不均匀,其体积含水率就越低;接触角对土-水特征曲线的影响是明显的,即接触角越小土颗粒亲水性越好,同一基质吸力下的体积含水率也就越大,且曲线的进气值会随着接触角的减小而减小。     

沙泉子隐伏铜镍矿地球化学勘查方法试验

在沙泉子铜镍矿上方,开展土壤微细粒全量测量、金属活动态(粘土吸附态)测量及地电化学测量的试验工作。试验结果显示,三种方法圈定的成矿元素地球化学异常分布范围与深部隐伏矿体较为吻合,表明土壤微细粒全量测量、粘土吸附态测量和地电化学测量可以有效地指示隐伏铜镍矿体,可作为该区寻找隐伏铜镍矿的有效手段。     

基于三维GIS的虚拟校园环境研究

随着虚拟现实技术的发展,三维建模与可视化技术在智慧城市中得到了广泛应用。本文采用3ds Max软件对校园建筑物、道路、树木等地物地形进行三维建模,并在SuperMap软件下进行三维可视化,结合太原师范学院,研究数据获取、数据处理、三维建模、可视化等方面关键技术,重点研究粒子特效的制作及其在雨、雪、烟花特效制作中的应用,真实再现了校园三维环境。