澜沧-耿马Ms7.6级地震前兆综合加权信息量的变化

在地震综合信息量的基础上,改进了地震前兆异常的出现概率的计算方法,得到地震前兆综合加权信息量.利用"地震预报专家系统"的思想对每一异常事件进行综合评估.考虑到异常的可靠性、有效性、显著性及相互关联性,给予不同的权重,以每一异常事件的最可能发震时间来估算异常出现的概率,计算了澜沧-耿马地震的地震前兆综合加权信息量,并对这种信息量变化的特点进行了分析.     

中国大陆科学钻探主孔超高压榴辉岩中绿辉石结构水研究

本文利用傅立叶（Fourier）变换红外光谱技术对CCSD主孔100～3100米深度范围榴辉岩中的绿辉石结构水含量进行了原位分析。结果表明，所有绿辉石都舍有一定的以OH形式存在的结构水，其含量范围为45～784ppm，平均为235ppm。不同榴辉岩绿辉石之间的结构水含量差别较大，而且呈现出明显的空间分布不均一性。相关性分析显示，绿辉石的结构水含量与全岩的Mgo、TFeO、Al2O3，含量成正相关，与NaO成反相关，与绿辉石的NaO、TFeO含量成负相关，与榴辉岩的峰期变质条件无关；与其它类型榴辉岩相比，多硅白云母榴辉岩中绿辉石的结构水含量较高，平均为339ppm。由此推测，超高压榴辉岩绿辉石中所残留的结构水含量很可能与其峰期结构水含量、矿物化学成分和岩石矿物组成有关。     

基于植被-土壤二向反射模型的土壤含水量遥感

以北京地区为例，利用像元信息分解法，定量提取出区域植被盖度，由植被盖度得到区域叶面积指数，在只考虑一次散射的情况下，利用植被-土壤二向反射模型，提取出下层湿润土壤反射率。通过引入粗糙度因子建立起粗糙地表下土壤反射率与叶面积指数的函数关系，进而得出土壤含水量。     

康定温泉逸出气短期预测研究

康定温泉逸出气气体百分含量的观测始于1986年,期间先后经历了多次甘孜州及邻区5.0级以上地震。地震前康定温泉逸出气观测资料均有不同程度的短临异常。本文在系统整理和深入剖析两泉点自有观测以来的在甘孜州及邻区发生的5.0级以上地震震例资料的基础上,借助多次“攻关”成果,排除观测资料的各种干扰因素及仪器标定变更情况,总结各观测资料短临异常特征、中短期异常特征及中短期异常特征随时间变化规律,提出康定温泉逸出气短临异常指标。     

红粘土地区水泥土强度的试验研究

红粘土是亚热带气候条件下形成的一种特殊土质。含有红粘土的地基多具有上硬下软的特点,下部红粘土为天然地基软弱下卧层。采用深层搅拌法处理,可充分发挥上部硬塑红粘土的作用,形成复合地基。通过试验得到了水泥红粘土的基本力学参数。在对试验结果进行回归分析后,给出了水泥土强度的影响因素及其与强度的关系,以及不同水泥掺量、龄期水泥土之间的强度推算公式。     

云南水汞群体非均匀度异常与成组强震活动关系

阐述了一种前兆群体异常信息提取新方法前兆群体非均匀度的数学原理,并以云南水汞群体异常信息为例进行了具体计算。结果表明该方法以群体异常分布特征的变化为异常标准(ID≥1),达到异常即自动识别报警。该方法能克服个人经验的局限,易为他人进行检验,可成为本地区成组强震预测对应概率较高的新指标。     

影响黄土湿陷系数因素的分析

在工程地质勘察及土工试验资料的基础上，分析影响黄土湿陷性的主要因素，应用数理统计方法．系统研究了不同深度黄土湿陷系数随天然含水量和干密度的变化规律：黄土的湿陷系数δs随深度的增加而减小；天然含水量ω和干密度γd与黄土的湿陷系数δs均呈直线负相关关系。通过回归分析建立了黄土湿陷系数与其主要影响因素间的线性回归方程：δs=-0．00038ω-0．1022γd＋0-1839。     

空间数据库课程教学实践与思考

空间数据库课程是GIS专业的核心课程,对GIS人才培养具有非常重要的作用。但由于种种原因,空间数据库课程在课程体系、课程内容、教学模式等方面仍然存在许多问题和不足。本文首先分析了大学本科空间数据库课程在教学内容、实验与实习及教学手段等方面存在的问题,然后针对这些问题根据自己的教学体会提出了一些相应的解决办法与建议。     

Metals content in sediments of ephemeral streams with small reservoirs(the Negev Desert)

The content of 19 metals(chromium,cobalt,nickel,strontium,arsenic,magnesium,barium,cesium,gallium,rubidium,uranium,vanadium,zinc,lead,copper,cadmium,iron,manganese,and aluminum) in sediment in three ephemeral streams(Nahal Sansana,Nahal Revivim and Nahal Pura) with reservoirs in the Negev Desert is studied herein.The study was done in September 2016.The samples were collected from the surface layer of sediment(up to 10 cm) in the reservoirs and in the channels upstream and downstream of the reservoirs.Silt,which on average,accounted for 72% dominated in the sediment.In the spatial distribution of the particle size,sand and gravel fractions were deposited in the reservoirs.Aluminum,iron,and magnesium accounted for 99% of all analyzed metals.The Principal Component Analysis(PCA) and Hierarchical Cluster Analysis(HCA) showed that sediment in the Negev Desert channel upstream of the reservoirs had similar concentrations of metals.Similarities were also found between the analyzed reservoirs.The bottom sediment in reservoirs had higher concentrations of metals than sediment upstream and downstream of the reservoirs.The comparison of concentrations in upstream and downstream locations did not show any unambiguous trends because metal concentrations downstream from the reservoirs were not always lower than upstream of the reservoirs.The analysis of the sediment enrichment factor(EF) showed the highest value in the reservoirs and the lowest downstream of the reservoirs.The concentrations of most analyzed metals did not indicate the possibility of potential ecological risk(SQG).     

Early star formation and the evolution of the stellar initial mass function in galaxies

It has frequently been suggested in the literature that the stellar IMF in galaxies was top-heavy at early times. This would be plausible physically if the IMF depended on a mass-scale such as the Jeans mass that was higher at earlier times because of the generally higher temperatures that were present then. In this paper it is suggested, on the basis of current evidence and theory, that the IMF has a universal Salpeter-like form at the upper end, but flattens below a characteristic stellar mass that may vary with time. Much of the evidence that has been attributed to a top-heavy early IMF, including the ubiquitous G-dwarf problem, the high abundance of heavy elements in clusters of galaxies, and the high rate of formation of massive stars in high-redshift galaxies, can be accounted for with such an IMF if the characteristic stellar mass was several times higher during the early stages of galaxy evolution. However, significant variations in the mass-to-light ratios of galaxies and large amounts of dark matter in stellar remnants are not as easily explained in this way, because they require more extreme and less plausible assumptions about the form and variability of the IMF. Metal-free 'population III' stars are predicted to have an IMF that consists exclusively of massive stars, and they could help to account for some of the evidence that has been attributed to a top-heavy early IMF, as well as contributing importantly to the energetics and chemical enrichment of the early Universe.