Where Are Porphyry Copper Deposits Spatially Localized? A Case Study in Benguet Province,Philippines

To provide guides for exploration of porphyry copper mineralization at a district scale, we examine the spatial association between known porphyry copper deposits and geologic features in Benguet, Philippines. The spatial associations between the porphyry copper deposits and strike-slip fault discontinuities, batholithic pluton margins and porphyry plutons are quantified using weights of evidence modeling. In the training and testing district, the porphyry copper occurrences are associated spatially with strike-slip fault discontinuities, batholithic pluton margins and contacts of porphyry plutons within distances of 3 km, 2.25 km, and 1 km, respectively. In addition, the porphyry plutons are associated spatially with strike-slip fault discontinuities and contacts of batholithic plutons within a distance of 2.25 km and 3 km, respectively. Based on these significant spatial associations, predictive maps are generated to delineate zones favorable for porphyry copper mineralization and zones favorable for emplacement of porphyry plutons in Benguet province, Philippines. Validations of the predictive models demonstrate their efficacy in pointing to zones for subsequent follow-up exploration work.     

基于支持度矩阵的Apriori改进算法

提出了一种利用支持度矩阵生成频繁项集的Apriori改进算法。通过上三角分块稀疏矩阵的行列性质和非频繁列之间的约束关系,改进的算法避免了Apriori连接步中大量非频繁候选k-项集的产生及其在剪枝步中(k-1)-子集的分解和判断。该算法能够有效地压缩搜索空间,降低Apriori连接和剪枝步骤的开销。     

一类新型疏水缔合聚合物的合成及成胶性能

以甲氧基聚乙二醇丙烯酸酯(MPEGA)和甲基丙烯酸二甲氨基乙酯(DMAEMA)为均聚单体,通过乳液聚合制备一类新型疏水缔合型聚合物P(MPEGA-DMAEMA),采用FT-IR和1HNMR表征新型聚合物的化学结构;利用主剂P(MPEGA-DMAEMA)和交联剂醋酸铬形成凝胶体系,考察主剂P(MPEGA-DMAEMA)和交联剂醋酸铬的质量分数、pH值、温度、矿化度对新型聚合物凝胶体系成胶性能的影响.结果表明:当主剂P(MPEGA-DMAEMA)质量分数为1.2%、交联剂醋酸铬质量分数为0.2%、pH值为7、温度为45e时,该新型聚合物凝胶体系具有最佳的成胶强度.将新型聚合物凝胶体系应用于岩心封堵,在最佳成胶条件下,堵水率高于90%,堵油率低于40%,具有较好的选择封堵性.     

准噶尔沙蒿群落主要物种间的关联性分析

采用方差比率法(VR),基于2×2列联表的χ2统计量、Ochiai联结指数(OI)以及去势对应分析(DCA),对准噶尔荒漠地区15个准噶尔沙蒿(Artemisia songarica)群落21个主要物种间的关联性进行了分析。结果表明:准噶尔沙蒿群落物种间总体为显著正关联(VR=2.726>1)。210个种对中,正关联种对数(125对)多于负关联种对(85),且前者达到显著关联的种对数(53)也多于后者(4)。准噶尔沙蒿与伴生种间虽为显著正关联,但OI联结指数稍小。群落内多数伴生种间的关联性较弱(OI<0.4),表明物种多趋于独立和随机分布。群落优势种琉苞菊、角果藜、囊果苔草、尖喙牻牛儿苗、齿稃草和条叶庭荠之间为显著正关联,且OI指数最大,表明这些物种具有相似的生态需求。DCA排序图中的种间距离和分布位置较好地表征了物种之间的相互关系,印证了上述结论。总之,准噶尔沙蒿群落虽生境不同,但群落内种间关系总体上较稳定,这对准噶尔沙蒿种群分布和群落发展较有利。     

从植物种间联结性探讨白梭梭种群生态种组分类——以古尔班通古特沙漠为例

在2×2联列表的基础上,应用χ2检验、联结系数、spearman秩相关,检测古尔班通古特沙漠植物种间关系,以期分析各物种在沙垄不同地貌部位的变化异同及种群稳定性。结果表明:①灌草两层共435个种对中,联结程度达到显著的种对较少;极显著的有15种对,显著的有22种对,其余398种对联结程度不显著。②按组间联系及种间的正负关联性,将30个主要优势种划分为5个生态种组。灌木层植物可分为3个种组:Ⅰ.白梭梭、沙拐枣;Ⅱ.蛇麻黄;Ⅲ.绢蒿;草本层分为两个种组:Ⅰ.苔草、尖喙牻牛儿苗、条叶庭芥、角果藜;Ⅱ.对节刺、沙生千里光、东方旱麦草;并提出各生态种组物种的分布特征。     

电子海图最优航线自动生成算法的改进

从航路二叉树的构建、可操作性质量评价指标的构建以及最短距离航线算法与最短时间航线算法相结合三方面,初步探讨了航线自动生成的改进算法,以得到更合理和实用的航线。     

基于空间位置的矿产资源关联分析和预测方法:以我国西部地区为例

基于矿产资源空间位置的研究方法对勘探找矿具有重要意义。设计开发了基于空间位置关联分析和预测方法,该方法根据隐伏矿体预测的相似-类比理论,通过分析已公开的矿产资源空间分布数据,获取已知矿种的相关性,进一步对隐伏矿体进行分析和预测。以我国西部部分地区的矿产资源空间分布数据为样本,采用Apriori算法分析已知矿种空间位置上的关联关系,通过分析得出该区域矿种的共生和伴生等关联关系,获得隐伏矿体的预测结果。通过与现有成果对比证明该方法的有效性和可行性,利用GoogleEarth等可视化的工具进行预测结果展现,以便更好地进行对比研究。研究的创新点在于设计开发了基于空间位置关联分析和预测方法,利用该方法对已知矿种空间位置进行关联分析,推导出所在区域矿种的共生和伴生等关系,对隐伏矿体进行了分析预测。     

关中地区土地利用综合分区及对策研究

基于社会经济和自然生态的现状,结合关中地区的土地利用特征,建立了关中地区的土地利用综合分区评价指标体系,并运用空间关联指数的探索性空间数据分析方法对关中地区的社会经济综合指数和自然生态综合指数空间分布进行了研究。结果表明,关中地区的自然生态综合指数高值集聚区主要位于秦岭北麓,以城区为中心的渭河平原是社会经济最为聚集的地区。结合社会经济综合指数和自然生态综合指数的空间分布,以县区为基本单元把关中地区的土地利用分为5种类型区。最后根据定量评价结果和三大地貌单元,对关中地区土地利用提出了对策建议。     

公安业务地理信息关联采集方式的研究

地理信息采集是各类业务GIS的基础工作,公安业务地理信息采集常常采用人工地图标注模式进行。公安业务地理信息分为独立业务地理信息和带关联信息的业务地理信息,通过分析带关联信息的业务地理信息的特点,提出主图层、子图层等概念。人工地图采集方式分为:常规独立采集方式和关联采集方式。常规的独立采集方式缺乏关联性,容易重复采集,而关联采集方式既可以保证同一空间位置的多类信息在坐标描述上的绝对一致性,以及其属性之间的传承关系,又可以实现多类信息之间的精确指定关联采集。最后,进行了业务地理信息关联采集方式的流程研究、数据模型研究与功能实现。结果表明,通过这种关联采集方式,极大地减轻了公安行业人工地图采集的工作量,并能使公安业务地理信息之间的关联性清晰化、精确化,满足了公安业务中大量存在的地理信息采集、管理需求。     

Climatic Characteristics of Binary Tropical Cyclones in the Northwest Pacific Ocean

Based on typhoon best track data of China Meteorological Administration and NCEP global reanalysis data, this study analyzed the characteristics of binary tropical cyclones (TC) in the Northwest Pacific Ocean during 1951 to 2014 by using the objective determine standard. When the distance between the two TCs d≤ 1 800 km, they are defined as binary tropical cyclones or binary typhoons. And binary typhoons are divided into two different types which are typical binary typhoons and atypical binary typhoons. The climatic characteristics of binary tropical cyclones are as follows: There were 699 pairs of binary typhoons in Northwest Pacific Ocean during 1951 to 2014. In these cases, there were 446 pairs of typical binary typhoons and 253 pairs of atypical cases, occupying 63.8% and 36.2%, respectively. The proportion of typical cases increased with the shortest distance decreasing, while the proportion of atypical cases decreased with the shortest distance decreasing. When the speed of typical binary typhoons moving towards each other reached the peak, binary typhoons mainly showed the east to west direction. At this time, typhoons were controlled by easterly stream of the southern edge of the subtropical high. In this situation, the east typhoon moved toward the west typhoon quickly. When the anticlockwise angular velocity of typical binary typhoons reached the peak, binary cases distributed northeast to southwest or east-northeast to west-southwest, appearing in west and southwest edge of the subtropical high and mainly being controlled by southeasterly stream, thus benefiting the anticlockwise rotation between the typical binary typhoons.