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排序方式: 共有152条查询结果,搜索用时 31 毫秒
31.
燕辽成矿带位于华北地台东并缘,横跨两个一级构造单元,为一呈东西向展布的铀、金、多金属成矿带,目前带内已发现多个铀矿主档。通过在该带开展地质、遥感、重力、磁力、航放、水化等资料的大面积联幅解释,研究地壳演化、区域地质背景和铀成在放条件。 相似文献
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The study presents the results of U-Pb dating of zircons and whole-rock geochemical analyses of syenogranite in Angeer Yinwula area, China, with the aim of determining its formation time, petrogenesis and regional setting. Zircon U-Pb data obtained by LA-ICP-MS indicate that the syenogranite formed in the Early Cretaceous(136.1±0.9 Ma). Geochemically, the rock is characterized by high SiO_2(76.63%--77.58%) and Na_2O+K_2O(8.00%--8.32%), low MgO(0.02%--0.04%) and TFe_2O_3(0.51%--0.84%), and is enriched in LREEs and LILEs, depleted in HREEs and HFSEs. It belongs to high-K calc-alkaline, metaluminous-weakly peraluminous, exhibiting an affinity to I-type granite. All these characteristics implied that the syenogranite in this region derived from crust-mantle mixed source. Overall, the regional geology, geochronology and geochemical features suggest that the formation of the syenogranite was related to the subduction of the Paleo-Pacific Ocean. 相似文献
34.
Acta Geochimica - We studied the fluid inclusions of the Jiguanshan Mo deposit in China, which is a large porphyry deposit located in the southern Xilamulun Metallogenic Belt. The irregular Mo ore... 相似文献
35.
针对传统的人工识别浅剖图像层界方法精度不足、效率低下的问题,提出了一种基于浮泥流变特性与灰度共生矩阵的航道底质层界智能识别方法。利用航道浅剖数据计算灰度共生矩阵特征值来描述底质层界纹理,粗略提取层界边缘;通过浮泥流变特性模型智能识别、连接同一层层界矢量点,准确识别底质层界。对比智能和人工提取连云港航道浅剖数据层界实验的结果表明:结合浮泥流变特性与灰度共生矩阵算法的层界识别方法,可以准确描述底质分布情况,快速自动识别层界线,智能化提取航道底质层界。 相似文献
36.
我国的地区工业体系问题 总被引:2,自引:0,他引:2
根据我国具体情况,地区工业体系可包括大区——工业地区(基地)——工业中心——工业点四个层次.大区工业体系,华北、东北、华东已基本形成,西南、华中、华南已具雏型,西北处于初始阶段.工业地区(基地)大体可分为资源型、市场型和混合型三种,分别以辽中南、长江三角洲和京津唐三个工业基地为代表. 相似文献
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Journal of Oceanology and Limnology - Magnetotactic bacteria(MTB) display magnetotaxis ability because of biomineralization of intracellular nanometer-sized, membrane-bound organelles termed... 相似文献
38.
Bacterial diversity and community structure in the East China Sea by 454 sequencing of the 16S rRNA gene 总被引:1,自引:0,他引:1
The 454 sequencing method was used to detect bacterial diversity and community structure in the East China Sea. Overall, 149 067 optimized reads with an average length of 454 nucleotides were obtained from 17 seawater samples and five sediment samples sourced in May 2011. A total of 22 phyla, 34 classes, 74 orders, 146 families, and 333 genera were identified in this study. Some of them were detected for the first time from the East China Sea. The estimated richness and diversity indices were both higher in the sediment samples compared with in the seawater samples. All the samples were divided by their diversity indices into four regions. Similarity analysis showed that the seawater samples could be classified into six groups. The groups differed from each other and had unique community structure characteristics. It was found that different water masses in the sampling areas may have had some influence on the bacterial community structure. A canonical correspondence analysis revealed that seawater samples in different areas and at different depths were affected by different environmental parameters. This study will lay the foundation for future research on microbiology in the East China Sea. 相似文献
39.
通过对山西大同煤田石炭系口泉、吴家窑剖面砂体古流向分析,采用Gazzi-Dickinson计点法对两条实测剖面上40个砂岩样品进行显微镜观察统计,并应用Dickinson的Q-F-L和Qm-F-Lt三角图解对统计结果作了相应分析。认为上石炭统本溪组母岩源区以克拉通内陆型为主,母岩为沉积岩;上石炭统太原组母岩源区以再旋回造山带型为主,母岩区以沉积岩分布为主,并分布少量变质岩和岩浆岩岩体;山西大同煤田石炭系物源区为北侧的阴山隆起造山带,属陆内隆升构造带的构造背景。从而进一步证明了"阴山古陆"并不是自元古代以来就长期隆升的构造单元。 相似文献
40.
Qin Ye Zhongliang Yang Min Bao Weiyong Shi Hongyuan Shi Zaijin You Wenyan Zhang 《海洋学报(英文版)》2022,41(5):163-172
A 10-year(2003–2012) hindcast was conducted to study the wave field in the Zhe-Min coastal area(Key Area OE-W2) located off Zhejiang and Fujian provinces of China. Forced by the wind field from a weather research and forecasting model(WRF), high-resolution wave modelling using the SWAN was carried out in the study area. The simulated wave fields show a good agreement with observations. Using the simulation results, we conducted statistical analysis of wave power density in terms of spatial distr... 相似文献