浅析宁芜北段铜矿地质特征、找矿前景与方向   总被引：4，自引：0，他引：4       下载免费PDF全文

侯龙海 《江苏地质》2008,32(4):263-270

在综合分析区域地质背景、铜矿床基本特征、主要控矿因素、找矿标志的前提下,对该区寻找铜矿的前景提出了看法,指出宁芜北段今后寻找铜矿应侧重斑岩型铜矿,提出了皇姑山等地区可作为今后寻找铜矿的重点地段及今后找矿的工作建议。  相似文献   

GPS网中已知点粗差探测时限差的研究     

伊晓东  杨耀宇  郭英起 《测绘与空间地理信息》2008,31(1):4-5

在利用附合导线法对GPS网中已知点的可靠性进行检核时,本文对如何合理地、客观地确定限差,以达到有效检核的目的进行了探讨,提出了检核限差标准。并结合实例进行计算和分析,成功地剔除了含有粗差的已知点。  相似文献   

谈基础地理信息数据成果的容灾与备份     

崔永利  刘春伟  王宝山 《测绘与空间地理信息》2008,31(6)

成果容灾及备份是数据管理的主要内容之一,建立完善、高效、安全的管理体制是一个循序渐进的过程.本文从基础地理信息数据成果管理的角度,简单描述容灾备份的管理内容、方法及存在的问题.  相似文献   

GIS中最佳遍历分析算法与实现     

刘小生  余豪峰 《地理空间信息》2008,6(1):10-12

首先介绍了地理信息系统（GIS）网络分析的发展概况;其次在已有GIS最佳遍历分析存在问题的基础上,提出了一种最佳多路遍历分析算法。并在ArcEngine环境下,以某县交通网为例,利用C#.net及ArcEngine二次开发类库实现了其最佳多路灾情巡视路线分析。算法适用范围广,可以推广到很多同类的地理网络问题。  相似文献   

临港新城地质特征及其对新城规划与建设的影响分析   总被引：2，自引：1，他引：1  

沈闪亮 《上海国土资源》2008,(1):24-28

结合临港新城三维地质调查所取得的成果,分析了该城区地质特征及对新城建设的影响,为新城规划建设提供科学依据和服务。  相似文献   

Dynamics of the mid-ocean ridge plate boundary: Recent observations and theory     

Yongshun John Chen 《Pure and Applied Geophysics》1996,146(3-4):621-648

The global mid-ocean ridge system is one of the most active plate boundaries on the earth and understanding the dynamic processes at this plate boundary is one of the most important problems in geodynamics. In this paper I present recent results of several aspects of mid-ocean ridge studies concerning the dynamics of oceanic lithosphere at these diverging plate boundaries. I show that the observed rift valley to no-rift valley transition (globally due to the increase of spreading rate or locally due to the crustal thickness variations and/or thermal anomalies) can be explained by the strong temperature dependence of the power law rheology of the oceanic lithosphere, and most importantly, by the difference in the rheological behavior of the oceanic crust from the underlying mantle. The effect of this weaker lower crust on ridge dynamics is mainly influenced by spreading rate and crustal thickness variations. The accumulated strain pattern from a recently developed lens model, based on recent seismic observations, was proposed as an appealing mechanism for the observed gabbro layering sequence in the Oman Ophiolite. It is now known that the mid-ocean ridges at all spreading rates are offset into individual spreading segments by both transform and nontransform discontinuities. The tectonics of ridge segmentation are also spreading-rate dependent: the slow-spreading Mid-Atlantic Ridge is characterized by distinct bulls-eye shaped gravity lows, suggesting large along-axis variations in melt production and crustal thickness, whereas the fast-spreading East-Pacific Rise is associated with much smaller along-axis variations. These spreading-rate dependent changes have been attributed to a fundamental differences in ridge segmentation mechanisms and mantle upwelling at mid-ocean ridges: the mantle upwelling may be intrinsically plume-like (3-D) beneath a slow-spreading ridge but more sheet-like (2-D) beneath a fast-spreading ridge.  相似文献   

SOME NEW UNDERSTANDINGS OF LAND-SURFACE PROCESSES IN ARID AREA FROM THE HEIFE^*          下载免费PDF全文

Hu Yinqiao  Gao Youxi 《Acta Meteorologica Sinica》1996,10(2):233-246

The survey for the HEIFE(Atmosphere-Land Surface Processes Experiment at Heihe River Basin,Western China) is given in the paper.The following basic subjects for land-surface processes in arid areas are studied:(1) the general characteristics of the energy budget on ground surface in arid areas;(2) the parameterization of the land surface processes;(3) the interaction between oasis and its desert circumstances,a special phenomenon in arid areas.The analysis shows that the sensible heat flux in the surface energy budget is in the majority,and the latent heat flux may be neglected.The influence of atmospheric stratification stability on the turbulent transfer of energy and substance must be considered in parameterization of land surface processes in arid areas.The "cold island effect" phenomenon in oasis and the "humidity inversion" phenomenon in desert near oasis are the result of the interaction between them.The results would improve the understanding of land surface processes in arid areas.  相似文献   

An integrable case of a rotational motion analogous to that of Lagrange and Poisson for a gyrostat in a Newtonian force field     

J. A. Cavas  A. Vigueras 《Celestial Mechanics and Dynamical Astronomy》1994,60(3):317-330

The scope of the present paper is to provide analytic solutions to the problem of the attitude evolution of a symmetric gyrostat about a fixed point in a central Newtonian force field when the potential function isV ⁽²⁾.We assume that the center of mass and the gyrostatic moment are on the axis of symmetry and that the initial conditions are the following: (t ₀)=₀, (t ₀)=₀, (t ₀)=(t ₀)=₀, ₁(t ₀)=0, ₂(t ₀)=0 and ₃(t ₀)= ₃ ⁰ .The problem is integrated when the third component of the total angular momentum is different from zero (B ₁ 0). There now appear equilibrium solutions that did not exist in the caseB ₁=0, which can be determined in function of the value ofl ₃ ^r (the third component of the gyrostatic momentum).The possible types of solutions (elliptic, trigonometric, stationary) depend upon the nature of the roots of the functiong(u). The solutions for Euler angles are given in terms of functions of the timet. If we cancel the third component of the gyrostatic momentum (l ₃ ^r =0), the obtained solutions are valid for rigid bodies.  相似文献   

林草复合经营模式养分动态关系   总被引：2，自引：0，他引：2  

王海明  李贤伟  陈治谏  王海娥 《山地学报》2006,24(2):156-160

林草复合经营模式在目前的退耕还林工程中起着重要的作用，研究林草复合模式的林与草之间的营养元素关系，通过对不同林草养分的研究得出林木、草、土壤之间的养分动态关系，对矿质养分相互关系的研究为合理搭配林草提供重要依据，为退化山地生态系统的恢复和重建提供重要的模式。模式Ⅰ在退耕还林初期，土壤养分供给氮素虽未亏缺，但从三者问的消长关系看出：氮磷素供应并不富足，特别是水解性氮。土壤交换性钙供应不足，引起杉木与黑麦草对钙质竞争。而土壤全钙含量很高，钙质向交换性钙转化的速度缓慢。模式Ⅱ与模式Ⅰ得到相似结果，所以在这两种模式中应加强人为管理，在退耕初期应适当增施氮磷钙肥，辅以土壤结构改良，加速土壤养分向植物可利用态转化。模式Ⅲ牛鞭草的生物量极高，磷、钙索相对缺乏。由于牛鞭草被不断的采割用于牲畜的饲料，对该模式中必须进行一定养分的输入，以保持杂交竹与牛鞭草这一林草生态系统的养分平衡。  相似文献   

区域大气环境质量灰关联评价方法探讨   总被引：7，自引：0，他引：7  

姚焕玫  黄仁涛  蒋文凯 《武汉大学学报(信息科学版)》2005,30(4):326-328

针对区域中大气环境质量的特点，采用对数主成分分析方法获得各环境指标的权重及各监测点的横向排名，再用适宜的灰度关联方法进行了评价。整个过程在MATLAB6．5中实现，计算简便易行，与传统的综合指数法相比较，其评价结果更符合客观实际。  相似文献