地下工程中圆截面巷道应力的光粘弹性研究

利用光粘弹性实验方法模拟了地下工程中圆截面巷道围岩及冻结壁的蠕变过程，给出了巷道围岩和冻结壁的应力分布规律及随时间的变化规律，为地下工程的设计及预报提供了一种有效的实验手段。     

原油族组分成气的化学动力学模型及其标定

利用等温密封热解实验技术及恒速升温热解实验与PY—GC分析技术的结合,本文分别建立并标定了原油中各族组分,即饱和烃、芳烃、非烃和沥青质成气的化学动力学模型。结果表明,原油中不同族组分成气的过程均可用平行一级反应描述,但不同组分在平均活化能及活化能分布上有明显的差异。各族组分在地史过程中成气的过程可由各自的化学动力学模型来描述。这将使原油成气过程的定量、动态描述成为可能。     

流体短期前兆典型特征分析

长期的地震实践表明,地下流体与地震活动有密切的关系,特别是在地震短期阶段,地震前兆中流体异常表现的最为明显,并且数量最多.由于在地震孕育过程中,能够引起浅层流体异常的动力源机制比较复杂,异常变化形态也复杂多样,这对于有效分析异常产生的机理造成了很大困难.本项研究工作,通过中国大陆和华北、西北、西南等分区研究,认为可以将这些复杂的异常现象归纳为较易识别的转折型(复合型)和单一型两类异常类型,并提出了这两类前兆异常类型的综合特点.     

台风路径数值预报模式的并行化及路径预报误差分析

国家气象中心台风路径数值预报模式经过串行优化及程序并行, 成功地实现了在国产超级计算机神威上的并行运算, 并可满足业务时效要求。基于并行程序及神威机计算平台的台风路径数值预报业务系统于2002年6月30日投入实时运行, 其初估场与侧边界条件从T106L19模式产品升级为T213L31模式产品 (称为基于T213台风预报系统, 原串行系统称为基于T106台风预报系统)。通过对2002年夏秋季台风路径的检验, 总体来看, 基于T213台风预报系统48 h内的平均路径预报误差小于基于T106台风预报系统的路径预报误差。对西行及西北行登陆的台风, 基于T106台风预报系统的48 h预报好于基于T213台风预报系统的预报。对于转向台风而言, 转向后的预报, 基于T213台风预报系统的预报要好于基于T106台风预报系统的预报, 有效地减小了基于T106台风预报系统对转向台风路径预报的系统性误差:即台风转向后预报路径较实况路径偏西。     

辽宁红透山铜锌块状硫化物矿床的变质变形和成矿组分再活化

辽宁红透山铜-锌块状硫化物产在太古宙绿岩带中，矿床形成后经历了强烈的变形和变质，变质程度达高级角闪岩相。野外和显微镜研究表明，矿石在进变质过程中发生过强烈的机械再活化和重结晶，但各种进变质结构大部分已被变质峰期的全面重结晶所清除，目前保存着的结构主要是变质峰期和退变质过程的产物。退变质过程以黄铁矿变斑晶生长、矿石糜棱岩的形成、二次退火和化学再活化为特征。矿床中高度富集铜和金的矿石是韧性剪切形成的矿石糜棱岩受退变质流体叠加而成。磁黄铁矿主要是同生沉积后重结晶的产物，另有一部分由退变质热液形成，而黄铁矿变斑晶则有沉积一重结晶、磁黄铁矿退变质脱硫和热液叠加多种成因。世界各地块状硫化物矿床中的磁黄铁矿和黄铁矿各有三种成因类型。磁黄铁矿的类型有：同生沉积．变质重结晶、同生沉积黄铁矿变质和退变质热液充填或交代；黄铁矿的类型有：同生沉积-变质重结晶、磁黄铁矿退变质脱硫和退变质热液充填或交代。红透山矿区的退变质流体具有从早到晚氧逸度升高的趋势。     

从赋矿岩系岩石类型的多样性论羊拉铜矿的成因

通过野外调查和室内工作，将羊拉铜矿床按矿石的矿物成分和组构分出9种类型，包括矽卡岩型、大理岩型、砂板岩型、角岩型、凝灰质流纹岩型、玄武岩-辉绿岩型、花岗质碎裂岩-花岗斑岩型、安山岩型和绢英岩型。矽卡岩型矿石是构成矿体的最主要矿石类型，但在不同矿段可由碳酸盐岩(里农)和凝灰质火山岩(贝吾)两种原岩形成。矿体在赋矿岩系中有3种产出形态：顺层呈层状．似层状；沿花岗岩与沉积岩接触面呈透镜状；贯穿岩体和沉积岩呈大脉状。它们均与后期构造密切相关，矿体无确定的顶、底板岩石，围岩蚀变以矿体为中心呈环带状分布。研究表明，矿床相对赋矿岩系显示出明显的后成性，属于印支期花岗岩-花岗斑岩与古生代混杂岩通过强烈的接触交代作用形成的矽卡岩型铜矿床。     

基于灰关联分析的GPS高程拟合加权平均函数模型权函数优选

基于灰色系统理论的灰关联分析方法,提出了权函数的优选方法,实例分析表明其具有较好的实用价值.     

Leaf area index retrieval based on canopy reflectance and vegetation index in eastern China

The aim of this paper is to investigate the feasibility of using Landsat TM data to retrieve leaf area index (LAI). To get a LAI retrieval model based ground reflectance and vegetation index, detailed field data were collected in the study area of eastern China, dominated by bamboo, tea plant and greengage. Plant canopy reflectance of Landsat TM wavelength bands has been inversed using software of 6S. LAI is an important ecological parameter. In this paper, atmospheric corrected Landsat TM imagery was utilized to calculate different vegetation indices (VI), such as simple ratio vegetation index (SR), shortwave infrared modified simple ratio (MSR), and normalized difference vegetation index (NDVI). Data of 53 samples of LAI were measured by LAI-2000 (LI-COR) in the study area. LAI was modeled based on different reflectances of bands and different vegetation indices from Landsat TM and LAI samples data. There are certainly correlations between LAI and the reflectance of Tm3, TM4, TM5 and TM7. The best model through analyzing the results is LAI = 1.2097*MSR + 0.4741 using the method of regression analysis. The result shows that the correlation coefficient R2 is 0.5157, and average accuracy is 85.75%. However, whether the model of this paper is suitable for application in subtropics needs to be verified in the future.     

Sedimentation rates in the Wanggang salt marshes, Jiangsu

1 IntroductionLand-ocean interaction in coastalzone is one of the key m atters of the International G eosphereand Biosphere Program (IG BP). The key problem s of the second phase in the next decadeinclude the m aterial cycle, the system evolution process …     

Element mobility during pyrite weathering: implications for acid and heavy metal pollution at mining-impacted sites

Based on back scattered electron images and electron micro-probe analysis results, four alteration layers, including a transition layer, a reticulated ferric oxide layer, a nubby ferric oxide layer and a cellular ferric oxide layer, were identified in the naturally weathering products of pyrite. These layers represent a progressive alteration sequence of pyrite under weathering conditions. The cellular ferric oxide layer correlates with the strongest weathering phase and results from the dissolution of nubby ferric oxide by acidic porewater. Leaching coefficient was introduced to better express the response of element mobility to the degree of pyrite weathering. Its variation shows that the mobility of S, Co and Bi is stronger than As, Cu and Zn. Sulfur in pyrite is oxidized to sulfuric acid and sulfate that are basically released into to porewater, and heavy metals Co and Bi are evidently released by acid dissolution. As, Cu and Zn are enriched in ferric oxide by adsorption and by co-precipitation, but they would re-release to the environment via desorption or dissolution when porewater pH becomes low enough. Consequently, Co, Bi, As, Cu and Zn may pose a substantial impact on water quality. Considering that metal mobility and its concentration in mine waste are two important factors influencing heavy metal pollution at mining-impacted sites, Bi and Co are more important pollutants in this case.