Carbonatation processes at the El Berrocal natural analogue granitic system (Spain): inferences from mineralogical and stable isotope studies

The El Berrocal granite/U-bearing quartz vein system has been studied as a natural analogue of a high-level radioactive waste repository. The main objective is to understand the geochemical behaviour of natural radionuclides occurring under natural conditions. In this framework, the carbonatation processes have been studied from a mineralogical and isotopic ( and ) point of view, since carbonate anions are powerful complexing agents for U(VI) under both low-temperature hydrothermal and environmental conditions. The carbonatation processes in the system are identified by the presence of secondary ankerite, with minor calcite, scattered in the hydrothermally altered granite, and Mn calcite in fracture filling materials. The isotopic signatures of these carbonates lead us to conclude that ankerite and calcite from the former were formed at the end of the same hydrothermal process that altered the granite, at a temperature range of between 72° and 61°C for ankerite, and between 52° and 35°C for calcite. The effect of edaphic CO₂ on both carbonates, greater on calcite than on ankerite, is demonstrated. Calcites from fracture fillings are, at least, binary mixtures, in different proportions, of hydrothermal calcite, formed between 25° and <100°C, and supergenic calcite, formed at ≤25°C. According to their signatures, the effect of edaphic CO₂ in both calcites is also evident. It is assumed that: (i) hydrothermal calcite from fracture fillings and ankerite from the hydrothermally altered granite are the result of the same hydrothermal process, their chemical differences being due to the intensity of the water/rock interaction which was stronger in the altered granite than in the fractures; and (ii) all of these carbonatation processes are responsible for ancient and recent migration/retention of uranium observed in the hydrothermally altered granite and fracture fillings.     

Methodological problems of intercultural comparisons of retail environments

The internationalising activities of retailers have tended to precede the theoretical contributions of academics. This is particularly the case for the cultural context within which retail internationalisation takes place. Following an examination of the growth of international retailing activity, the article reviews generic difficulties in studying inter-cultural differences before considering the specific steps which retail practitioners have taken to understand the comparative characteristics of retail and consumer markets through the growth of geodemographic and lifestyle analysis. Finally, we relate one of the most significant integrative intercultural theoretical instruments to the case of retail internationalisation within Western Europe. We find that significant insights into retailer behaviour and strategy can be gained from an understanding of the culturally-specific characteristics of the activity. This revised version was published online in July 2006 with corrections to the Cover Date.     

江苏下扬子区中—古生界的成藏条件及勘探思路

江苏下扬子区的海相中－古生界构造演化经历了前扬子板块、稳定地台和西太平洋活动陆缘等三大阶段。油气地质条件具有多套烃源岩、两类主要储层、四套区域盖层、多种成藏类型和多期成烃等特征。原始生烃量以下古生界为主,下寒武统和下志留统的生烃量约占总生烃量的６０％￣８０％。该领域的勘探应本着“整体评价、区域展开、重点突破”的原则,做到“六个结合”和“五个转变”,加快勘探节奏,重在发现,坚持以下古生界为主,大中型     

旅游地品牌特征塑造初探--以香格里拉旅游品牌为例

香格里拉是一个公共品牌，是系列旅游产品的组合，香格里拉品牌具有鲜明的特征，其特征通过品牌的个性和定位体现，品牌的个性是通过文化性和奇特性表现，信念性是品牌的定位，具体分析了香格里拉品牌的资源本体的脆弱性，旅游产品开发层次较低，品牌崇信度不确定性和品牌定位不准等问题，最后对香格里拉品牌特征的塑造，提出了建议；树立品牌意识，加强品牌管理；加强品牌定位－突出个性，构筑品牌的保护圈，实现品牌特征的接触点。     

成人英语学习动机行为调查与教学对策研究

动机是激励人们行动的心理动因.英语学习动机是推动英语学习的内部动因,成人英语学习动机是复杂的.了解他们的英语学习动机特点有利于教师改进教学手段和策略,激发与培养其学习的主动性和积极性,发挥其学习潜能,从而提高英语学习的效果.运用定量研究的方法,在年轻干部学员中进行学习动机调查,分析了其学习动机的特点,并提出成人英语教学的对策.     

Protracted oogenesis and annual reproductive periodicity in the deep‐sea pennatulacean Halipteris finmarchica (Anthozoa,Octocorallia)

Halipteris finmarchica is one of the most common species of deep‐sea pennatulacean corals in the Northwest Atlantic; it was recently determined to act as a biogenic substrate for other species and as a nursery for fish larvae. Its reproductive cycle was investigated in colonies sampled in 2006 and 2007 along the continental slope of Newfoundland and Labrador (Canada). Halipteris finmarchica exhibits large oocytes (maximum diameter of 1000 μm), which are consistent with lecithotrophic larval development. Female potential fecundity based on mature oocytes just before spawning was ~6 oocytes · polyp^?1 (500–6300 oocytes · colony^?1); male potential fecundity was 16 spermatocysts · polyp^?1 (5500–57,400 spermatocysts · colony^?1). Based on statistical analysis of size‐probability frequency distributions, males harboured one cohort of spermatocysts that matured inside 8–11 months, whereas females harboured two distinct cohorts of oocytes; a persistent pool of small ones (≤400 μm) and a small number (~20%) of larger ones that grew from ~400 to >800 μm over a year. Despite this difference in the tempo of oogenesis and spermatogenesis, a synchronic annual spawning was detected. A latitudinal shift in the spawning period occurred from south (April in the Laurentian Channel) to north (May in Grand Banks and July–August in Labrador/Lower Arctic), following the development of the phytoplankton bloom (i.e. sinking of phytodetritus). Prolonged oogenesis with the simultaneous presence of different oocyte classes in a given polyp is likely not uncommon in deep‐sea octocorals and could hamper the detection of annual/seasonal reproduction when sample sizes are low and/or time series discontinued or brief.     

顾及几何特征和拓扑连续性的道路网匹配方法

已有的道路网匹配方法需要一定的人为干预和控制,仍无法实现匹配自动化,而且对于具有一定尺度差异的数据而言,受不相关道路对象的影响,匹配结果中会存在较多的误匹配。为此,本文提出一种顾及几何特征和拓扑连续性的由粗匹配到精匹配的分层匹配策略。粗匹配阶段,利用短边中位数Hausdorff距离计算匹配对象的相似度,再以道路网弧段端点的近邻分析结果作为匹配阈值,判断匹配对象是否为同名实体;精匹配阶段,将粗匹配阶段评价结果中离散的同名实体构建为完整的道路Stroke,即以追踪的方式剔除误匹配和添加漏匹配。利用宿城区不同尺度的道路网对所提算法进行验证,结果表明,该算法具有较好的匹配效果,能够实现匹配自动化。     

多匹配策略融合的无人机影像匹配方法

针对AKAZE算法在无人机影像匹配过程中存在的匹配精度低和稳定性较差问题,本文提出一种基于多匹配策略融合的改进影像匹配方法。该方法首先对影像降采样并利用AKAZE算法检测多尺度特征。然后采用一种稳定的RootSIFT描述符进行特征描述。其次,融合最近邻距离比值、双向匹配和余弦相似度约束匹配策略进行特征匹配以降低误匹配率。最后,采用随机抽样一致性(RANSAC)算法确定最终的特征对应关系,并求得几何变换模型。实验结果表明,该方法在获得更多正确匹配点对的同时具有较高的匹配正确率和精度,能够更好适用于无人机影像匹配。     

基于图分割的可变比例尺地图分幅回溯算法

总结了地图分幅需遵循的原则,并针对地图集中可变比例尺的分幅,将其定义为基于约束条件的图分割问题,用最小生成树(minimum spanning tree,MST)将制图区域关联起来,基于回溯算法对MST裁剪实现地图集的分幅。实验结果表明,所提出的方法能较好顾及地图集分幅的相关原则,满足地图集制作的要求。同时,利用该方法设计的地图集分幅工具已成功应用于《武汉市汉阳地区地名图集》等的制作,有效提高了地图设计人员的工作效率。     

后金融危机时期我国大型勘察设计企业的发展战略研究

2007年爆发的金融危机,给我国勘察设计企业带来了深刻的影响和变革。在后金融危机时代到来之际,大型勘察设计企业作为行业的龙头力量,应该吸取经验和教训,在发展方向上进行深入研究,积极进行战略调整,通过资源整合、优化产业结构等多种方式实施企业的发展转型,增强企业的综合竞争实力和生存能力,使企业能够抵御各种经济风险,实现基业长青、可持续发展的根本目的。