琼东南盆地深水区中央峡谷黄流组物源特征   总被引：3，自引：2，他引：1  

左倩媚  张道军  何卫军  王亚辉  王真真  陈杨 《海洋学报》2015,37(5):15-23

物源分析作为岩相-古地理研究的前提和基础,物源体系决定了砂体的展布和储集性能。为明确中央峡谷体系黄流组储集体展布规律及下一步勘探方向,本文应用中央峡谷最新钻井资料,采用重矿物组合、锆石U-Pb测年等分析方法,结合地震反射特征,对中央峡谷黄流组物源体系特征进行分析。地震反射特征表明来自海南隆起和昆嵩隆起物源的三角洲体系,通过二次搬运沉积了陆架斜坡区和盆底的低位海底扇,为中央峡谷的沉积充填提供了充足的粗碎屑沉积物;新钻井黄流组样品中重矿物组合以白钛矿、石榴石、磁铁矿含量较高为主要特征,与莺歌海盆地受蓝江物源影响和琼东南盆地受丽水-秋滨河物源影响的地层重矿物组合相似;锆石U-Pb测年分析表明,中央峡谷黄流组地层中样品年龄图谱具有30~2 000Ma变化范围,与莺歌海盆地受昆嵩隆起物源影响的钻井以及越南现代河流采集的沙样具有非常一致的年龄段和丰度。综上所述,中央峡谷受多物源的影响,越南昆嵩隆起为主的琼东南盆地西部物源体系,是琼东南盆地乐东凹陷晚中新世深水扇以及中央峡谷粗碎屑物质的主要沉积物供给来源区。  相似文献   

北冰洋楚科奇海浮游细菌丰度和生产力及其分布特征     

高源  何剑锋  陈敏  林凌  张芳 《海洋学报》2015,37(8):96-104

2012年夏季中国第5次北极科学考察期间,对北冰洋楚科奇海及其北部边缘海浮游细菌丰度和生产力进行了测定,并将其与环境因子进行了相关性分析。结果显示,楚科奇海浮游细菌丰度的变化范围为0.56×108~6.41×108 cells/dm3,平均为2.25×108 cells/dm3;细菌生产力介于0.042~1.92mg/(m3·d)(以碳计)之间,平均为0.54mg/(m3·d)(以碳计),与已有研究结果基本相当。陆架区细菌丰度和生产力要明显高于北部边缘区,但前者的单位细菌生产力则较低。与环境因子的相关性分析显示,细菌丰度与温度和叶绿素a浓度存在显著正相关(p0.01),表明北极变暖导致的海水升温及浮游植物生物量的增加均会促进细菌的生长,从而进一步提高细菌在海洋生态系统和碳循环中的作用。但陆架区的细菌生产力与环境参数均没有显著相关性,表明其影响因素较为复杂;生产力在北部边缘区则仅与叶绿素a存在显著正相关(p0.01),表明浮游植物生长过程产生的溶解有机碳(DOC)是细菌生长最为主要的碳源,碳源的单一可能制约细菌的生产从而导致该海域无冰状态下细菌丰度的增加不如预期,但融冰过程带来的大量DOC将促进细菌活性的增加。  相似文献   

Distribution of <Emphasis Type="Italic">Nemopilema nomurai</Emphasis> in the southwestern Sea of Japan related to meandering of the Tsushima Warm Current     

Satoshi?KitajimaEmail author  Naoki?Iguchi  Naoto?Honda  Tatsuro?Watanabe  Osamu?Katoh 《Journal of Oceanography》2015,71(3):287-296

We investigated the horizontal distribution of Nemopilema nomurai medusae using a midwater trawl in the southwestern Sea of Japan from September to October of each year from 2006 to 2012. Numerous medusae of this species found in 2006, 2007, and 2009 were mainly distributed far (>40 km) from the mainland of Japan in the western part of the survey area, but were distributed in the stations closest (<25 km) to the mainland in the eastern part, particularly in 2006 and 2009. These distribution patterns were associated with the path of the second branch of the Tsushima Warm Current (TWC) that flows offshore to the west of Oki Islands and usually approaches the mainland of Japan to the east of Oki Islands. Differences in jellyfish distribution across the survey periods were related to the distribution of the second branch being associated with types, position and intensity of eddies in the eastern part of the survey area. Hence, the formations of eddies and consequent variation in the path of the TWC would be responsible for transporting medusae from offshore to near the mainland to the east of Oki Islands. Individuals with large bells accumulated in the northwestern part of the survey area, where a cyclonic eddy was present downstream of the third branch of the TWC. This variation in bell size distribution may be ascribed to differences in the physical and/or biological factors among the three branches of the TWC.  相似文献   

综合物化探方法在深冲矿区铀多金属矿勘探中的应用     

何友宇  覃金宁  李竹溢  黄绍琼 《国土资源导刊(湖南)》2015,(1):84-89

通过研究深冲铀矿区γ能谱铀异常、氡浓度异常特征和激电异常特征,探索矿区范围岩体、断裂构造和蚀变带与物化探信息显示特征的关系。据此,结合矿区地质特征,总结物化探方法应用效果,矿致异常综合特征。  相似文献   

Impacts of the two types of El Niño on Pacific tropical cyclone activity     

XU Shibin  HUANG Fei 《中国海洋大学学报(英文版)》2015,14(2):191-198

It is well known that Tropical cyclone(TC) activities over the Pacific are affected by El Nino events. In most studies El Nino phenomena have been separated into east Pacific warming(EPW) and central Pacific warming(CPW) based on the location of maximum SST anomaly. Since these two kinds of El Nino have different impacts on Pacific tropical cyclone activities, this study investigates different features of TC activities and the genesis potential index(GPI) during EPW years and CPW years. Four contrib- uting factors, i.e., the low-level absolute vorticity, the relative humidity, the potential intensity and the vertical wind shear, are exam- ined to determine which factors are most important in causing the anomalous TC activities. Our results show that during EPW years in July–August(JA0), TC activities are more frequent with stronger intensity over the Western North Pacific(WNP) and Eastern North Pacific(ENP). The maximum anomaly center of TC activities then drifts eastward significantly in September–October(SO0). However, centers of anomalous TC activity barely change from JA0 to SO0 during CPW years. In January–February–March(JFM1) of the decaying years of warming events, TC frequency and intensity both have positive anomaly over the South Pacific. The anoma- lies in EPW years have larger amplitude and wider spatial distribution than those in CPW years. These anomalous activities of TC are associated with GPI anomaly and the key factors affecting GPI anomaly for each ocean basin are quite different.  相似文献   

建筑物立面分类与DIM点云滤波     

崔颖  黄鹤  刘祥磊  罗德安 《测绘通报》2021,(3):55-59

针对目前基于近景摄影测量方法构建建筑物立面模型过程中因密集影像匹配（DIM）点云噪声所引起的建筑物立面TIN网格模型畸变问题,本文借鉴机器学习中样本学习的思想,对建筑物立面进行了分类并对DIM点云提出了相应的滤波方法,以达到去除DIM点云噪声和改善其TIN网格模型畸变的目的。其中,针对平面结构立面,采取先对点云样本进行学习计算构建数学立面模型所需参数,再对该立面模型设定阈值并对其点云进行滤波处理的方法;针对曲面结构立面,则结合DIM点云特性先将点云样本分类标记归为立面点与非立面点,再进行样本特征值学习,使用Logistic回归算法迭代计算求解最佳回归系数,从而构建滤波分类器的方法对立面点云进行滤波处理。试验结果表明,本文滤波处理方法能将立面DIM点云噪声有效识别并去除,而且使用该方法处理后所得点云构建的建筑物立面TIN网格模型精细化程度得到有效提高,模型质量得到明显改善。  相似文献   

基于车载激光点云的高精地图矢量化成图     

赵焰  曹聿铭  黄鹤 《测绘通报》2021,(12):105-109,114

针对车载激光点云中对各特征物提取结果后矢量化成图时的自动化问题,本文基于双方向积分法实现了边缘检测及矢量化成图,旨在保证特征物基本特征的同时,也保证点云的绝对精度。将输入的特征点云进行离群点过滤,以保证外包框算法特征点云的准确度;将三维点云按照外包框算法投影至最优平面,为后续沿各方向积分提供输入;利用八邻域KD-tree算法求出样本特征点云的均值邻域半径,依据邻域半径对各方向积分提供积分域中的微分元;根据提供的微分元沿各方向进行积分,在该积分元内找到距平面最值的最优解;按照积分结果构建点云索引,并根据点云特征构建模型,最终得到高精地图的矢量化点云。试验证明了该方法在处理实际问题时的可行性。  相似文献   

塔里木克拉通北缘阔克塔格西富碱侵入岩成因及其构造意义——锆石U- Pb年代学、岩石地球化学及Sr- Nd- Hf- O同位素制约     

潘蓓蓓  黄河  张招崇  王涛  吴欢欢  秦切  李海舟 《地质学报》2023,97(7):2195-2221

富碱侵入岩具有深源浅成的属性,是示踪地幔组成的窗口。位于东天山与塔里木克拉通北缘交界处的阔克塔格以西出露一处以正长岩为主体、包含少量中—基性岩石单元的富碱侵入岩。LA- ICP- MS锆石U- Pb测年显示其侵位于227~224 Ma之间,为印支期岩浆作用产物。该岩体具有富碱（Na2O+K2O=7. 93%~ 12. 28%）、富铝（Al2O3=15. 62%~18. 67%）、贫镁（MgO=0. 12%~4. 01%）、贫钛（TiO2=0. 14%~1. 63%）的特征,属于准铝质的（A/CNK=0. 78~1. 00）高钾钙碱性—钾玄岩系列。微量元素表现出高场强元素Nb、Ta、Th、U、Zr、Hf的富集,不相容元素Sr、P、Ti的亏损特征;轻重稀土分馏明显（（La/Yb）N=15. 09~34. 90）,表现为轻稀土强烈富集的右倾型曲线,Eu异常变化较大（δEu=0. 12~1. 72）。在同位素组成上,富碱侵入岩呈现相对宽泛但总体富集的全岩Sr- Nd和锆石Hf同位素特征,(87Sr/86Sr)i=0. 70489~0. 70581,εNd(t)=14. 56~6. 74,εHf(t)=11. 48~+3. 06,锆石δ18O值（5. 49‰~6. 87‰）略高于地幔值（5. 3‰±0. 6‰）。阔克塔格西富碱侵入岩具A1型花岗岩特征,形成于板内伸展构造环境中。基于主、微量元素及Sr- Nd- Hf- O同位素特征,笔者认为该杂岩体为同源岩浆演化产物,源于富集岩石圈地幔的原始岩浆上升并经历AFC（同化混染- 分离结晶）过程。晚三叠世塔里木克拉通北缘—东天山—北山地区处于板内构造体制,A1型花岗岩和正长岩差异化的时空分布特征很可能记录了古亚洲洋自西到东 “剪刀式”的闭合过程。  相似文献   

车道线检测中自适应图像预处理算法研究     

黄鹤  梁祺策  罗德安 《测绘科学》2021,46(9):76-82

针对传统车道线检测中图像预处理算法易受光照、遮挡以及阴影等环境因素影响的问题,提出了一种自适应灰度处理算法,并与全局二值化组合用于车道线检测的图像预处理.算法结合R和G通道对车道线的敏感性自适应选取灰度处理阈值,并结合逆透视变换和全局二值化算法实现高质量预处理图像生成.为了验证本文算法实际性能,分别在Tusimple、KITTI、CULane和Caltech-lanes 4个数据集上进行了测试实验.实验结果表明:所提算法能够有效降低光照、遮挡和阴影等环境因素对预处理效果的影响,相比于传统预处理方法检测精度更高,鲁棒性与普适性更优.  相似文献   

KOSMA 12CO(2–1) and (3–2) observations toward Infrared Dark Clouds     

Dalei Li  Jarken Esimbek  Jianjun Zhou  Willem Baan  Gang Wu  Xindi Tang  Weiguang Ji  Ye Yuan  Yuxin He  Toktarkhan Komesh 《Astrophysics and Space Science》2016,361(7):220

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