从滇黔桂“金三角”区域地层地球化学演化特征探讨卡林型金矿的物质来源   总被引：3，自引：0，他引：3       下载免费PDF全文

周余国  刘继顺  王作华  欧阳玉飞  高启芝  刘德利  黄元有 《地学前缘》2009,16(2):199

选用滇黔桂地区东经103°～110°,北纬22°～26°,面积约20万km2,34幅1∶20万水系沉积物统计结果资料,全面系统地探讨本区及其邻近区域地层地球化学特征及其与成矿的关系。结果表明:(1)与华南地区相比,本区存在Sb、As、Au、Hg等低温元素矿集区的地球化学块体,金具有深源性,而砷、锑、汞则是区域性的高背景,本区金与砷、锑、汞的相伴,既有必然性,又有偶然性;(2)与基性岩浆活动有关的亲基性场元素、氧化物、矿化剂高背景的形成,是本区右江裂谷带、富宁—关岭南北向断裂带、文山—富宁逆冲推覆构造带,特别是峨眉地幔柱所产生的基性岩浆喷溢及火山碎屑浊流沉积的客观地球化学反映;(3)黔西南地区二叠纪峨眉山玄武岩喷发导致二叠系和三叠系金及大量亲基性场元素的突变,右江裂谷活动至少始于寒武纪,随着时间的推移,由桂西往黔西南逐渐裂开;(4)滇黔桂"金三角"地区卡林型金矿的物源与裂谷、特提斯和区域性深大断裂和峨眉地幔柱长期活动相伴的基性火成岩及火山碎屑浊流沉积有关。  相似文献   

Zn_3(PhCH=CHCOO)_6(phen)_2·H_2O的纳米晶结构计算及环境属性     

陈洪  胡波  宫斯宁  陈敬中  王长娟  潘会  吴秀玲 《地球科学》2009,(4)

Zn3(PhCH=CHCOO)6(phen)2.H2O晶体具有与锰氧化物及锰氢氧化物类似的微结构,在生成环境与晶体化学微结构方面有明显的环境属性,是一种新生环境矿物.为研究其纳米晶结构、最佳纳米尺度和环境矿物属性,在溶液法合成该配合物晶体的基础上,采用纳米晶参数计算方法,对该配合物纳米级微粒的晶胞数、原子数、表面原子数和表面活性随微粒在纳米尺度范围内的变化进行了计算,对比锰氢氧化物结构,发现该配合物晶体活性、表面效应与颗粒尺度有密切关系,内部结构具有鲜明的环境属性.结合晶体颗粒的比表面积与总原子数相对颗粒尺度的变化关系,理论上确定了该颗粒最佳纳米化尺度为138nm,为此类物质纳米晶在环境方面的研究应用奠定了基础.  相似文献   

Aerodynamic Characteristics of the Crest with Membrane Attachment on Cretaceous Pterodactyloid Nyctosaurus     

XING Lida WU Jianghao LU Yi L Junchang JI Qiang Institute of Geology  Chinese Academy of Geological Sciences  Beijing  China School of Transportation Science  Engineering  Beijing University of Aeronautics  Astronautics  Beijing  China 《《地质学报》英文版》2009,83(1)

The Nyctosaurus specimen KJ1 was reconstructed under the hypothesis that there is a membrane attached to the crest;the so-called headsail crest.The aerodynamic forces and moment acting on the headsail crest were analyzed.It was shown that KJ1 might adjust the angle of the headsail crest relative to the air current as one way to generate thrust (one of the aerodynamic forces,used to overcome body drag in forward flight) and that the magnitude of the thrust and moment could vary with the gesture angle and ...  相似文献   

Permeability Heterogeneity in a Fractured Sandstone–Mudstone Rock Mass in Xiaolangdi Dam Site, Central China   总被引：1，自引：0，他引：1  

JIANG Xiaowei  WAN Li  WANG Xusheng  KANG Aibin  HUANG Jun  and HUANG Guoxing 《《地质学报》英文版》2009,83(5):962-970

Abstract: Heterogeneity of permeability in fractured media is a hot research topic in hydrogeology. Numerous approaches have been proposed to characterize heterogeneity in the last several decades. However, little attention has been paid to correlate permeability heterogeneity with geological information. In the present study, several causes of permeability heterogeneity, that is, lithology, tectonism, and depth, are identified. The unit absorption values (denoted as ω), which are results obtained from the packer test, are employed to represent permeability. The variability of permeability in sandstone–mudstone is so significant that the value of unit absorptions span 3–4 orders of magnitude at any depth with several test sections. By declustering, it has been found that under a similar tectonic history, the means of permeability differ greatly at different formations as a result of different mudrock contents. It has also been found that in the same formation, permeability can be significantly increased as a result of faulting. The well-known phenomenon, the decrease in permeability with depth, is found to be caused by the fractures in the rock mass, and the relationship between permeability and depth can be established in the form of logω–logd. After subtracting the trend of ω with absolute depth, the mean of the residual value at each relative depth can be well correlated with the distribution of mudstone. The methods proposed in this paper can be utilized to research in similar study areas.  相似文献   

A Lightning Activity Forecast Scheme Developed for Summer Thunderstorms in South China   总被引：1，自引：0，他引：1       下载免费PDF全文

WANG Fei  ZHANG Yijun  DONG Wansheng 《Acta Meteorologica Sinica》2010,24(5):631-640

Based on the relationship between lightning flash density and radar echoes and a statistical analysis using satellite and radar observations,a scheme was introduced into the mesoscale model GRAPES (Global and Regional Assimilation and PrEdiction System) to forecast the cloud to ground (CG) flash activities.Because the relationship is a necessary but not sufficient condition for lightning,an additional constraint condition related to temperature of cloud top is added into the scheme to determine whether the ...  相似文献   

利用数字强震仪记录实时仿真地动位移   总被引：14，自引：2，他引：12       下载免费PDF全文

金星  马强  李山有 《地震学报》2005,27(1):79-85

随着现代强震仪及通讯技术的发展, 强震动观测资料的应用范围愈来愈广, 强震观测可以拓展到地震观测领域, 强震数据的实时仿真是这一拓展的基础. 为适应这一发展趋势, 在笔者曾经提出的单自由度系统地震反应递归公式的基础上, 本文提出了一套基于地震仪原理, 及长周期单自由度系统地震动力反应原理的由宽频带强震动记录仿真位移记录的新方法. 研究表明此方法是有效的, 可广泛应用于地震监测.   相似文献   

Study on mine earthquake activity rules for Laohutai coal mine in Fushun of Liaoning     

HAN Xiaomin  CHEN Li  SUN Wenda . College of Construction Engineering  Jilin University  Changchun  China  . A. Alfred Taubman College of Architecture  Urban Planning  University of Michigan  Ann Arbor  USA 《东北亚地学研究》2011,(2)

According to earthquake data of Fushun earthquake administration,the seismic analysis and statistical methods are utilized in order to analyze earthquake frequency,b-value timing and energy creep trends in Laohutai coal mine. By using least squares linear regression method,the relational expression between frequency and magnitude of mine earthquake in Laohutai coal mine is given. And the possible largest magnitude mine earthquake inferred has also been calculated. And this paper also provides a theoretical ...  相似文献   

Application of principal component analysis to evaluation of black soil degradation in Jilin     

NIU Cencen  WANG Qing  WEN Xiuyu  GUO Yuan  ZHAGN Penglei  ZHU Rongyue  HE Xianhui College of Construction Engineering  Jilin University  Changchun  China 《东北亚地学研究》2011,(1)

Principal Component Analysis(PCA) can simplify the structure of database by replacing multi-dimensional parameters with relatively less comprehensive variables in order to ensure the minimum lost in initial data.In this paper,eighteen black soil samples from different sites were tested and thirteen distinctive indexes were chosen to evaluate the degeneration of black soil.By using principal component analysis,variables of thirteen dimensions can be diminished to six unrelated principal indexes.Analysis show...  相似文献   

基于最小人均耕地面积和耕地压力指数的普安县粮食安全研究   总被引：1，自引：0，他引：1  

王金凤  周德全 《西部资源》2011,(5):46-48

地方粮食安全是国家粮食安全的重要组成部分,耕地是粮食生产的物质基础,耕地变化必将对粮食安全产生深远的影响。文章以贵州省普安县为例,运用最小人均耕地面积耕地压力指数模型测度粮食安全状况,分析了普安县1997-2010年间粮食安全和变化特点,并运用回归分析法、指数平滑模型,对其未来10年最小人均耕地面积以及耕地压力指数进行了粮食安全预测,同时提出了保障粮食安全的建议。  相似文献   

一种基于高分辨率雷达影像以及外部DEM辅助的复杂地形制图方法     

卢丽君  张继贤  王腾 《测绘学报》2011,40(4):459-463

为满足在坡度陡、高差大的复杂地形地区高精度DEM制图的需要,在传统的雷达干涉测量技术的基础上,通过引入外部DEM,建立外部DEM模拟相位和干涉解缠相位的对应关系,构建多维线性模型,进行线性回归分析,去除误差相位趋势;同时根据引入的外部DEM估计高程的误差范围,进行高程点的滤波,达到精化DEM的目的,形成最终的DEM产品。该方法已经应用于高分辨雷达影像（COSMO数据）在云南德钦地区DEM地形图的制作,通过GPS数据的验证,其精度达到了国家1∶50 000 DEM制图要求。  相似文献