福建热带气旋年频数异常与大气环流及海温的特征

本文通过对1951－1996年北半球500、100hPa月平均高度场及太平洋月平均海温场的合成分析和相关分析,给出影响福建热带气旋年频数异常的大气环流及海温场特征,并分析可能存在的机理,为TC频数的短期气候预测奠定基础。     

延长陆相页岩气水平井提速技术研究

“延安国家级陆相页岩气示范区”已钻水平井存在机械钻速低、钻井周期较长等问题,直接影响陆相页岩气的低成本、高效勘探开发。提高机械钻速是缩短钻井周期、降低钻井成本的重要手段,也是优快钻井的直接体现。在分析了延安陆相页岩地层岩石力学特性的基础上,开展了优选钻头、优化钻井机械参数和水力参数等3个方面的研究,以增强钻头对地层的适应性、提升井眼清洁能力和提高机械钻速。最终形成了适合陆相页岩气水平井的钻井关键技术,并在示范区3口水平井进行了成功应用,钻井周期缩短11 d,水平段机械钻速提高120.08%,实现了陆相页岩气水平井的优快钻井,具有较好的推广价值。     

A comprehensive methodology for discovering semantic relationships among geospatial vocabularies using oceanographic data discovery as an example

It is challenging to find relevant data for research and development purposes in the geospatial big data era. One long-standing problem in data discovery is locating, assimilating and utilizing the semantic context for a given query. Most research in the geospatial domain has approached this problem in one of two ways: building a domain-specific ontology manually or discovering automatically, semantic relationships using metadata and machine learning techniques. The former relies on rich expert knowledge but is static, costly and labor intensive, whereas the second is automatic and prone to noise. An emerging trend in information science takes advantage of large-scale user search histories, which are dynamic but subject to user- and crawler-generated noise. Leveraging the benefits of these three approaches and avoiding their weaknesses, a novel methodology is proposed to (1) discover vocabulary-based semantic relationships from user search histories and clickstreams, (2) refine the similarity calculation methods from existing ontologies and (3) integrate the results of ontology, metadata, user search history and clickstream analysis to better determine their semantic relationships. An accuracy assessment by domain experts for the similarity values indicates an 83% overall accuracy for the top 10 related terms over randomly selected sample queries. This research functions as an example for building vocabulary-based semantic relationships for different geographical domains to improve various aspects of data discovery, including the accuracy of the vocabulary relationships of commonly used search terms.     

西非被动大陆边缘盐构造样式与成因机制

基于三维地震资料,对西非陆缘盐构造样式及分布特征进行了刻画,剖析了其形成演化机制与控制因素。西非陆缘盐上地层滑脱形成典型的薄皮构造,前缘发育挤压变形,后缘发育拉张变形,两者之间为过渡变形。拉张区发育白垩系盐筏、前盐筏、新近系盐筏等盐构造;过渡变形区以发育各种底辟构造为特征;挤压变形区主要发育侵位盐席构造。重力滑脱作用是被动陆缘盐构造发育过程中始终存在的驱动机制,重力扩展作用在大陆边缘成熟阶段作用明显,在陆缘演化早期并不突出。陆缘构造活动控制盐构造的形成,差异沉积负载作用影响着盐上地层滑移特征,而盐下底形对盐岩流动、盐上地层滑移速率及相关断裂体系的产生与沉积响应具有重要影响。