山前带复杂构造成像方法研究

以波动理论为基础的表层波场校正与叠前深度偏移技术是提高山前带复杂构造成像精度的有效手段。本文介绍了基于广角隐式有限差分单程波传播算子的起伏地表叠前深度偏移方法,并对SEG山前带推覆构造模型进行了检验。结果表明:起伏地表波动方程叠前深度偏移照明加权成像结果与理论模型构造形态非常吻合。在此基础上,将此法用于玉门油田窟窿山模型合成数据体,分别进行了静校正与波动方程基准面延拓、叠后深度偏移与叠前深度偏移、Kirchhoff偏移与波动方程偏移的处理结果对比,得出了如下结论:①在地表起伏剧烈、表层速度横向变化大、高速地层直接出露地区,常规时移静校正误差远远大于波动方程基准面校正的误差;②在波动方程基准面校正的基础上,波动方程叠前深度偏移的精度明显高于Kirchhoff偏移法的精度;③起伏地表波动方程叠前深度一步法偏移还能合理地描述地表附近反射面的形态。     

Establishing quality management systems for European food composition databases

As part of the activities of EuroFIR (European Food Information Resource Network), the scientific validation and exploitation of food composition data will be assured by a quality framework. This paper outlines the processes and procedures implemented during the initial development of this quality framework for national food composition data compilers and for laboratories generating new data. EuroFIR’s strategic quality objectives are based upon requirements of national food composition data compilers, laboratories, and users/stakeholders. To implement thorough quality principles, a range of standard procedures and tools are being developed. Elements of a quality management system include criteria for quality control and quality assurance of the compilation process and the computerised systems in which data are hosted, as well as data quality assessment models. The results and findings obtained so far for the proposed quality framework indicate that existing guidelines and standards for laboratories should be updated to meet EuroFIR requirements. The generic compilation process has been described, including the identification of critical stages of the data compilation process and standard operating procedures are being prepared. A data quality assessment system has been developed for application to all nutrients and has been tested by national compilers within the EuroFIR network. The development of the EuroFIR quality policy through open and constructive discussions among food composition data compilers, laboratories, and users, strengthens the proposed quality standards and procedures and is fundamental to improving quality of data exchanged across Europe and beyond.     

Spatial distribution of 10m firn temperature in the Antarctic Ice Sheet

A database of Antarctic 10m firn temperature was constructed using available borehole temperature measurements with data quality control to extend knowledge of Antarctic climate.Slopes from a high-resolution digital elevation model and the main ice divide were used to delineate main drainage sectors across Antarctica.In each drainage sector,a quantitative relationship between temperature and latitude,longitude and altitude was established using available firn temperature data.Quantitative relationships inco...     

Mindful Deviation through Combining Causation and Effectuation: A Design Theory‐Based Study of Technology Entrepreneurship

Technology entrepreneurship can be seen as building upon, while also deviating from, technological paths. Such deviation has primarily been described as singular events where individuals with prior knowledge discover a new opportunity. In this article, we will instead study deviation as a process of collective decision making, seen more as something mindful than singular. The purpose is to explore mindful deviation as decision making by nascent technology entrepreneurs as they conceptualize an early platform technology. Based on case assignments undertaken by 13 teams in a venture creation programme, C‐K design theory is used to trace how nascent technology entrepreneurs in action combine causal and effectual decision‐making logics. Individually answered questionnaires also offered insights into how the entrepreneurs perceived their decision making in hindsight. The findings break with our received wisdom around how opportunities are recognized as well as how effectual and causal logics occur. As a result, mindful deviation through combinations of effectual and causal logic is suggested as a means to understand early‐stage technology entrepreneurship.     

Genomics,metagenomics,and microbial oceanography—A sea of opportunities

Microbial oceanography is an emerging discipline resulted from the interaction,cross-fertilization and integration of life science and ocean science.Microbial oceanography integrates the principles of marine microbiology,microbial ecology and oceanography to study the role of microorganisms in the biogeochemical dynamics of natural marine ecosystems.The application of genomics tools to study marine microbes is resulting in rapid advancements in microbial oceanography that has important implications in globa...     

辐射供冷与贴附射流复合空调系统防结露研究

介绍了辐射供冷与贴附射流复合空调系统的工作原理及特点;采用CFD软件分析了冷辐射板表面空气相对湿度分布以及室内空气水蒸汽质量分数分布,并对冷辐射板表面结露现象和贴附射流流场的观察实验,分别从仿真和实验两方面验证了贴附射流降低冷辐射板表面结露可能性的效果。     

噪声系数的测量方法研究

介绍了多种接收机噪声系数的测量方法,根据适用性对各种方法进行比较,并提出了一种在IQ数字中频进行噪声系数的测量方法。     

全球大油气田分布特征

通过对全球1021个大油气田的逐个解剖和统计分析,对大油气田的发现年代、油气属性及地理位置、储层地质时代、岩性、埋深、圈闭类型、储量规模、盆地类型等参数进行分析,探讨大油气田分布的主要特征,并应用含油气域的概念,阐述大油气田在全球8个含油气域中的分布特征。研究认为,全球大油田609个,主要分布于中东地区,全球大气田412个,主要分布于东欧、中亚及俄罗斯地区,大油田和大气田最富集的地区为亚洲和大洋洲及中东地区,其次为欧洲地区;全球大油气田发现高峰在1960—1990年,近20年来也陆续有重要的大油气田被发现;大油气田主要富集于中生界,其次为新生界;大油气田的储集岩性主要为砂岩,其次是碳酸盐岩,但在碳酸盐岩储层中油气储量丰度更大;大油气田主要集中在3km埋深以内;圈闭类型主要是构造圈闭。对最终可采储量分析得出,中东地区油气资源储量巨大,同时发现委内瑞拉的奥里诺科重油带的油气资源也极其丰富。大油气田所在的盆地类型主要是Bally分类模式下的Ⅱ类和Ⅰ类盆地,Klemme分类模式下的Ⅱ类盆地,Mann分类模式下的Ⅱ类和Ⅰ类盆地。在8个含油气域中,特提斯含油气域油气资源最为富集。根据大油气田的分布特征,在未来的大油气田勘探中应加强对北极含油气域、重油带、深水区及岩性圈闭的勘探,在这些领域将可能会有重大的突破。     

南大西洋被动大陆边缘盆地大油气田形成条件与分布规律——以巴西桑托斯盆地为例

南大西洋被动大陆边缘主要经历了前裂谷期、裂谷期、过渡期、漂移期4个演化阶段,发育了4套相应的沉积层序,并形成了巴西(坎普斯、桑托斯及埃斯皮里图桑托盆地等)和西非(尼日尔三角洲、下刚果、加蓬及宽扎盆地等)沿岸一系列被动大陆边缘盆地。近年来,桑托斯盆地深水区发现了Tupi和Jupiter等多个巨型油气田,作为典型的南大西洋被动大陆边缘盆地,其具有代表性的油气地质条件与分布规律可为其他盆地对比和借鉴。桑托斯盆地主力烃源岩为盐下巴雷姆阶—下阿普特阶湖相页岩和盐上赛诺曼阶—马斯特里赫特阶深海相页岩,储层包括盐下裂谷期的湖相碳酸盐岩与盐上浊积砂岩,南大西洋广泛发育的阿普特阶蒸发岩为区域盖层,同时这套蒸发岩对整个盆地的圈闭形成及油气运聚起着控制作用。结合该盆地发育的Guaratiba—Guaratiba/Guaruja/Ilhabela和Itajai-Acu-Ilhabela/Marambaia两个含油气系统与Guaratiba、Guaruja及Ilhabela等5个成藏组合特征,总结了桑托斯盆地大油气田的分布特点与控制因素,对比巴西与西非其他盆地的油气地质条件,分析认为南大西洋深水区盐下裂谷期沉积地层油气资源丰富,勘探潜力巨大,可作为今后油气勘探的重点目标。