花岗岩研究进展 ———ISMA花岗岩类分类综述   总被引：4，自引：0，他引：4       下载免费PDF全文

陈建林  郭原生  付善明 《甘肃地质》2004,13(1):67-72

本文在论述花岗岩主要分类的基础上论述了ISMA花岗岩类的基本含义,讨论了人们在以后应用和推广ISMA这类花岗岩分类方案时存在的一些问题,指出了ISMA花岗岩类本身在分类过程中存在的一些基本问题。  相似文献   

巧用CASIO fx-4800P计算器测设线路复合曲线     

李铭石  周照群  张进民 《现代测绘》2004,27(3):38-40

应用地面点与线路中线相对关系的统一数学模型，使用CASIO fx-4800P程序型计算器编制的适合野外测设线路各种复合曲线(包括直线、缓和曲线、圆曲线的任意组合)的实用程序。  相似文献   

矢量地形图拓扑等问题的研究与实践     

赵明  王庆  陈昕  鞠建荣  张凤梅 《现代测绘》2004,27(5):44-45,48

对矢量地图生产过程中常见的图形拓扑、数据冗余问题进行分析和研究；在此基础上结合生产实践，提出了相应的解决办法。研制了基于AutoCAD2000平台的相关程序。  相似文献   

A Comparison of Public Lands and Farmlands for Grassland Bird Conservation     

Mary Ann Cunningham 《The Professional geographer》2005,57(1):51-65

Midwestern states have invested extensively in grasslands for wildlife conservation, yet these public lands make up a minority of grassland habitat. How effective are public grasslands, relative to private lands, for conserving native songbird populations? I compare private and public lands in southern Minnesota using bird survey data from Conservation Reserve Program (CRP) fields and public lands and assessing fragmentation in a GIS. Bird abundance and diversity were greater on CRP lands. Vegetation composition, field isolation, and field size appear to explain differences in bird counts. Land cover data show that grassland habitat on public lands is scarce and widely scattered. The CRP provides more, and here better, habitat for grassland birds. Funding partly explains this disparity. Trends in farm set‐aside program rules and distribution, which can be vary greatly over time, will strongly influence the success or failure of biodiversity conservation in this region.  相似文献   

Research relevance, 'knowledge transfer' and the geographies of CASE studentship collaboration   总被引：1，自引：0，他引：1  

David Demeritt  Loretta Lees 《Area》2005,37(2):127-137

The Co-operative Awards in Science and Engineering (CASE) studentship programme of the UK Research Councils provide one example of wider efforts internationally to encourage so-called 'knowledge transfer' and thereby harness publicly supported university research more closely to the goals of national competitiveness, regional economic development and local regeneration. In this paper we describe the implications of how the various UK research councils have interpreted the objectives and beneficiaries of 'knowledge transfer', both for the relative opportunities available to human and physical geographers for collaboration through CASE and for the sorts of values that their research must serve. Then, we draw on unpublished data from the Economic and Social Research Council (ESRC) to explore the geographies of CASE studentship allocation and participation. The broad regional and institutional patterns of participation we describe have important implications for ongoing debates in the UK about research selectivity and the role of the university as an engine of local development, while the striking disciplinary patterns of CASE participation, and in particular the overwhelming success of geographers in this competitive programme, provide an opportunity to reassess claims about whether and for whom geographical research is relevant.  相似文献   

Cenozoic bottom current sedimentation in the Cape basin, South Atlantic   总被引：1，自引：0，他引：1  

Etienne Wildeboer Schut  Gabriele Uenzelmann-Neben 《Geophysical Journal International》2005,161(2):325-333

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Microcrack networks in granite affected by a fault zone: Visualization by confocal laser scanning microscopy     

Celia T. Onishi  Ichiko Shimizu   《Journal of Structural Geology》2005,27(12):170

Microcracks in the Cretaceous Ryoke-type granite in Japan were investigated by using deep drilling core samples collected in the Mizunami Underground Research Project of the Japan Nuclear Cycle Development Institute (JNC). The granite body suffered brittle deformation associated with Tertiary thrust movement. Based on core-scale and microscopic deformation features, the drill core from a depth of 300 to 700 m is divided into four domains, i.e. (A) undeformed granite, (B) granite intruded by cataclastic seams, (C) fractured granite in the fault damage zone, and (D) foliated cataclasite at the fault center. To characterize microcrack geometries in each domain, we employed the impregnation method using a low-viscous acrylic resin doped with fluorescent agents and captured the microcrack images by confocal laser scanning microscopy (CLSM). The CLSM image in the fault damage zone revealed anisotropic development of microcrack networks related to the fault movement. Both CLSM observation and porosity measurements reveal a drastic increase of micro-pores in the foliated cataclasite, possibly caused by fragmentation, and granulation and crack sealing in the fault zone.  相似文献   

The evolution of the electronics industry in Johor (Malaysia): Strategic coupling,adaptiveness, adaptation,and the role of agency     

《Geoforum》2016

Bringing together concepts from the global production networks and evolutionary economic geography literature, this article empirically examines the trajectory of the electrical and electronics industry in Johor (Malaysia). Based on trends in firm entries and exit as well as interviews with companies, we find limited robustness in the industry’s trajectory. While there is evidence of the role of ‘structure’ in this outcome, we argue that human agency – particularly the actions of subnational policy-makers – is key. This is manifest in a preference for fostering regional ‘adaptiveness’ through the often uncritical promotion of a diversity of economic sectors. This compromises the meaningful pursuit of regional ‘adaptation’ in the form of new and more complex branches emerging from existing industries. This arrested development, in turn, hinders an effective strategic coupling between the regional economy and multinational corporations, thus undermining regional resilience.  相似文献   

Simulation of quasi-linear mesoscale convective systems in northern China: Lightning activities and storm structure   总被引：1，自引：0，他引：1  

Wanli Li  Xiushu Qie  Shenming Fu  Debin Su  Yonghai Shen 《大气科学进展》2016,33(1):85-100

Two intense quasi-linear mesoscale convective systems(QLMCSs) in northern China were simulated using the WRF(Weather Research and Forecasting) model and the 3D-Var(three-dimensional variational) analysis system of the ARPS(Advanced Regional Prediction System) model.A new method in which the lightning density is calculated using both the precipitation and non-precipitation ice mass was developed to reveal the relationship between the lightning activities and QLMCS structures.Results indicate that,compared with calculating the results using two previous methods,the lightning density calculated using the new method presented in this study is in better accordance with observations.Based on the calculated lightning densities using the new method,it was found that most lightning activity was initiated on the right side and at the front of the QLMCSs,where the surface wind field converged intensely.The CAPE was much stronger ahead of the southeastward progressing QLMCS than to the back it,and their lightning events mainly occurred in regions with a large gradient of CAPE.Comparisons between lightning and non-lightning regions indicated that lightning regions featured more intense ascending motion than non-lightning regions;the vertical ranges of maximum reflectivity between lightning and non-lightning regions were very different;and the ice mixing ratio featured no significant differences between the lightning and non-lightning regions.  相似文献   

苏鲁超高压变质带超镁铁岩深部碳酸盐交代作用的证据     

陈世忠  杨经绥  许志琴  朱筱婷 《地质学报》2016,90(10):2721-2732

中国大陆科学钻探工程第三先导孔(PP3钻孔),位于秦岭-大别-苏鲁超高压造山带的东部,赣榆岗上超镁铁岩体中。钻孔中超镁铁岩的岩性包括纯橄岩和石榴超镁铁岩等,该超镁铁岩的SiO_2含量均值在43.68%,变化范围为41.9%~47.11%;MgO均值在44.71%,变化范围为47.12%~48.62%;Cr_2O_3均值在0.39%,变化范围为0.30%~0.47%;CaO均值0.12%(变化范围为0.006%~0.34%);Na2O均值在0.05%(变化范围为0.005%~0.32%)。超镁铁质岩的Mg#(Mg/(Mg+Fe)×100)稳定在91.9~93.0之间,Cr#(Cr/(Cr+Fe)×100)均值在38,较高;变化在30~45之间,变化小。其中闪石化金云母超镁铁岩具有最低的值(Cr#=19)。Ni含量在2100×10~(-6)~2500×10~(-6),CaO含量均值为0.13%,Al_2O_3含量均值为0.41%。岩体成分均一,表现为高镁,低钙和低铝的特征。超镁铁岩的不相容元素和稀土元素总量很低,稀土元素总量均值在0.60×10~(-6)。(La/Yb)N比值在6.9~51.2,均值在16.1,重稀土元素严重亏损,是中国东部最亏损的地幔岩之一。超镁铁岩中橄榄石成分(Fo在88.7~93.1之间,Fa在6.8~11.1之间),从早期到晚期,岩石Fo值从93→91~92.4→88.7~89.1。铬尖晶石Cr#值从51到89变化,TiO_2和MnO_2值分别低于0.26%和0.46%,晚期铬尖晶石Cr#值增大,Ti含量减小。单斜辉石由透辉石(Wo_(45.9)8En_(47.89)Fs_(2.73)Ac_(3.39))和顽透辉石(Wo_(27.61)En_(68.78)Fs_(2.27)Ac_(1.34))两种,透辉石(Cpx_Ⅰ)在顽透辉石(Cpx_Ⅱ)中呈被交代的残余粒状。角闪石和金云母呈明显的条带状和脉状,局部发育。岩石具有弱的Na和K交代作用,较高的Sr和Ba等元素,亏损高场强元素(HSFE),以及特征的稀土元素和微量元素配分曲线;岩石中主要组成矿物橄榄石从早期到晚期,矿物Mg#指数下降(Mg#从93→88);单斜辉石中可看到透辉石被顽透辉石交代现象;次生角闪石和金云母的形成等特征都显示超镁铁岩经历了碳酸盐交代作用。在超镁铁岩矿物橄榄石中发现细小白云石和菱镁矿等碳酸盐矿物更有力证明了苏鲁超高压变质带超镁铁岩经历了深部碳酸盐交代作用。PP3钻孔超镁铁岩属于强烈亏损地幔岩区域,单斜辉石和角闪石等含水矿物在超镁铁岩中含量低,交代作用的范围和规模有限,且交代作用在动力学上是快速的和不平衡的过程。  相似文献