国家自然科学基金资助体系下的地下水科学领域发展总结和分析     

夏露 《地质论评》2023,69(5):2023050022-2023050022

地下水属于基础性、战略性水资源,其科学开发利用和保护关系到人类社会与生态系统的协同健康发展。因此,地下水一直是自然科学关注的热点和焦点之一。笔者统计分析了1986~2022年期间国家自然科学基金委对地下水科学领域的资助情况,从受资助项目的学部学科分布、项目类型和主要研究方向入手,总结了地下水科学研究现状,揭示了目前存在的短板和瓶颈问题,并分析了地下水科学发展趋势。研究结果表明：①地下水科学领域资助项目的数量和类型均呈快速增长态势;②地下水科学领域与其他学科领域的交叉融合越来越频繁、紧密,涉及多个学部和学科,申报与资助均呈现“多点开花”态势;③地下水科学作为地球科学的分支学科,面临新的机遇和挑战,许多重大科学问题亟待解决,需进一步提高重大项目支持力度;④地下水科学研究具备与更多相关领域交叉渗透的潜力,如海洋学、化学、气象学和大气科学等,国家自然科学基金委可为地下水科学与其他学科交叉提供培育平台。  相似文献   

Origin,discovery, exploration and development status and prospect of global natural hydrogen under the background of “carbon neutrality”     

《China Geology》2022,5(4):722-733

Global energy structure is experiencing the third transition from fossil energy to non-fossil energy, to solve future energy problems, cope with climate change, and achieve net-zero emissions targets by 2050. Hydrogen is considered to be the most potential clean energy in this century under the background of carbon neutrality. At present, the industrial methods for producing hydrogen are mainly by steam-hydrocarbon (such as coal and natural gas) reforming and by electrolysis of water, while the exploration and development of natural hydrogen had just started. According to this literature review: (1) Natural hydrogen can be divided into three categories, including free hydrogen, hydrogen in inclusions and dissolved hydrogen; (2) natural hydrogen could be mainly from abiotic origins such as by deep-seated hydrogen generation, water-rock reaction or water radiolysis; (3) natural hydrogen is widely distributed and presents great potential, and the potential natural hydrogen sources excluding deep source of hydrogen is about (254±91)×10⁹ m³/a according to a latest estimate; (4) at present, natural hydrogen has been mined in Mali, and the exploration and development of natural hydrogen has also been carried out in Australia, Brazil, the United States and some European countries, to find many favorable areas and test some technical methods for natural hydrogen exploration. Natural hydrogen is expected to be an important part of hydrogen energy production in the future energy pattern. Based on a thorough literature review, this study introduced the origin, classification, and global discovery of natural hydrogen, as well as summarized the current global status and discussed the possibility of natural hydrogen exploration and development, aiming to provide reference for the future natural hydrogen exploration and development.©2022 China Geology Editorial Office.  相似文献   

Stability analysis of seabed strata and casing structure during the natural gas hydrates exploitation by depressurization in horizontal wells in South China Sea     

Peng-fei Xie  Lin Yang  Qian-yong Liang  Xu-hui Zhang  Liang-hua Zhang  Bin Zhang  Xiao-bing Lu  Hui-ce He  Xue-min Wu  Yi-fei Dong 《China Geology》2022,5(2):300-309

Natural gas hydrates (NGHs) are a new type of clean energy with great development potential. However, it is urgent to achieve safe and economical NGHs development and utilization. This study established a physical model of the study area using the FLAC^3D software based on the key parameters of the NGHs production test area in the South China Sea, including the depressurization method, and mechanical parameters of strata, NGHs occurrence characteristics, and the technological characteristics of horizontal wells. Moreover, this study explored the law of influences of the NGHs dissociation range on the stability of the overburden strata and the casing structure of a horizontal well. The results are as follows. With the dissociation of NGHs, the overburden strata of the NGHs dissociation zone subsided and formed funnel-shaped zones and then gradually stabilized. However, the upper interface of the NGHs dissociation zone showed significant redistribution and discontinuity of stress. Specifically, distinct stress concentration and corresponding large deformation occurred in the build-up section of the horizontal well, which was thus prone to suffering shear failure. Moreover, apparent end effects occurred at the end of the horizontal well section and might cause the deformation and failure of the casing structure. Therefore, it is necessary to take measures in the build-up section and at the end of the horizontal section of the horizontal well to prevent damage and ensure the wellbore safety in the long-term NGHs exploitation.©2022 China Geology Editorial Office.  相似文献   

Identification of functionally active aerobic methanotrophs and their methane oxidation potential in sediments from the Shenhu Area,South China Sea     

Jing Li  Chang-ling Liu  Neng-you Wu  Xiao-qing Xu  Gao-wei Hu  Yan-long Li  Qing-guo Meng 《China Geology》2022,5(2):285-292

Large amounts of gas hydrate are distributed in the northern slope of the South China Sea, which is a potential threat of methane leakage. Aerobic methane oxidation by methanotrophs, significant methane biotransformation that occurs in sediment surface and water column, can effectively reduce atmospheric emission of hydrate-decomposed methane. To identify active aerobic methanotrophs and their methane oxidation potential in sediments from the Shenhu Area in the South China Sea, multi-day enrichment incubations were conducted in this study. The results show that the methane oxidation rates in the studied sediments were 2.03–2.36 μmol/gdw/d, which were higher than those obtained by sediment incubations from other areas in marine ecosystems. Thus the authors suspect that the methane oxidation potential of methanotrophs was relatively higher in sediments from the Shenhu Area. After the incubations family Methylococcaea (type I methanotrophs) mainly consisted of genus Methylobacter and Methylococcaea_Other were predominant with an increased proportion of 70.3%, whereas Methylocaldum decreased simultaneously in the incubated sediments. Collectively, this study may help to gain a better understanding of the methane biotransformation in the Shenhu Area.©2022 China Geology Editorial Office.  相似文献   

鄂尔多斯盆地南部延长组长7油组页岩层系天然裂缝发育特征及主控因素     

李彦录  陆诗磊  夏东领  吕文雅  梁丰  唐磊  李睿琦  王磊飞 《地质科学》2022,57(1):73-87

利用地表露头、岩心、薄片和测井资料,对鄂尔多斯盆地南部长7油层组陆相页岩层系天然裂缝的成因类型、发育特征和主控因素进行研究。按地质成因,鄂尔多斯盆地南部长7油层组页岩层系的天然裂缝可以分为构造裂缝和成岩裂缝两大类,其中构造裂缝主要包括剪切裂缝和张性裂缝;成岩裂缝主要包括层理缝、页理缝和收缩裂缝。不同岩性中的天然裂缝发育情况明显不同,致密砂岩中以构造裂缝为主,层理缝仅在粉砂岩和局部细砂岩中发育;页岩和凝灰岩中页理缝、层理缝和构造裂缝均比较发育。不同类型的天然裂缝主控因素明显不同,构造裂缝的发育主要受岩性和岩石力学层层厚控制;砂岩中层理缝的发育主要受碳质纹层、粘土矿物转化程度等因素控制;凝灰岩中层理缝的发育主要受刚性玻屑脱玻化作用的控制;页岩中页理缝的发育主要受纹层、TOC含量和黄铁矿含量的控制。  相似文献   

岩心中的天然缝与诱导缝的识别与分析——以鄂尔多斯盆地延长组岩心裂缝为例          下载免费PDF全文

姜琳  王清晨  戈金明  胡中杰 《地质科学》2015,(3):926-942

由于取心成本昂贵, 从岩心中获得天然缝、诱导缝和其他构造特征的准确信息显得尤为重要。岩心裂缝识别中的一项重要任务是判识天然缝和诱导缝。文中综合论述了天然缝和诱导缝的物理特征, 重点分析了天然缝形态及发育过程和诱导缝的多种成因模式, 并以鄂尔多斯盆地延长组岩心中裂缝为例进行分析。文中引用了国外对裂缝研究常用的专业术语, 指出裂缝面形态结构是追踪模式Ⅰ裂缝(节理)从扩展初始点到终止处的运动学的关键, 这在岩心裂缝和露头裂缝分析中是非常有用的。  相似文献   

一种亮星识别算法及其在天文定向中的应用     

詹银虎  郑勇  张超  李铸洋  张中凯 《测绘学报》2015,44(3):257-263

基于全站仪对任意亮星的观测采样,提出了一种利用高度角序列和水平角速率进行联合匹配的任意亮星识别算法。通过引入天体地平坐标计算程序,算法可正确辨别行星和恒星。本文分析了任意亮星高度角和水平角速率的观测误差和计算误差,以此给出了匹配阈值条件的设定依据,并在此基础上制定了有效的匹配策略。仿真计算及实际观测试验均表明,该算法具有100%的识别成功率,远优于现有算法。将此算法应用于任意亮星天文定向,定向结果的内符合精度达到2″,外部检核精度达到1.6″。采用多颗任意亮星进行定向,可有效减弱由测站位置误差引入的定向系统误差,提高绝对定向精度。本文提出的天文定向适用于多云及雾霾天气。  相似文献   

Linking pesticides and human health: A geographic information system (GIS) and Landsat remote sensing method to estimate agricultural pesticide exposure     

《Applied geography (Sevenoaks, England)》2015

Accurate pesticide exposure estimation is integral to epidemiologic studies elucidating the role of pesticides in human health. Humans can be exposed to pesticides via residential proximity to agricultural pesticide applications (drift). We present an improved geographic information system (GIS) and remote sensing method, the Landsat method, to estimate agricultural pesticide exposure through matching pesticide applications to crops classified from temporally concurrent Landsat satellite remote sensing images in California. The image classification method utilizes Normalized Difference Vegetation Index (NDVI) values in a combined maximum likelihood classification and per-field (using segments) approach. Pesticide exposure is estimated according to pesticide-treated crop fields intersecting 500 m buffers around geocoded locations (e.g., residences) in a GIS. Study results demonstrate that the Landsat method can improve GIS-based pesticide exposure estimation by matching more pesticide applications to crops (especially temporary crops) classified using temporally concurrent Landsat images compared to the standard method that relies on infrequently updated land use survey (LUS) crop data. The Landsat method can be used in epidemiologic studies to reconstruct past individual-level exposure to specific pesticides according to where individuals are located.  相似文献   

The fisherly imagination: The promise of geographical approaches to marine management     

《Geoforum》2015

The management of the sea has increased exponentially in the last half-century, and different academic disciplines have been vital in shaping this management. Human geography, despite its explicit focus on the human–environment nexus, has so far had little impact on human relations with the sea. Based on empirical research conducted in England and Scotland, we argue that human geography is uniquely placed to offer effective solutions to marine resource management problems, and that geographers have the potential to offer key insights into how human populations can best interact with the living seas. Three of the most important current scholarly ‘imaginations’ of the sea, and the policies they inform (economics and market-based management, conservation biology and area based protection, and anthropology and community management), are outlined. A potential ‘geographical imagination’ of the sea, drawing on key themes in contemporary scholarship is then presented, and grounded in empirical research. It is argued that human–ocean relations should be a key feature of geographical research agendas.  相似文献   

天文学英语新词自动提取系统     

余恒  崔辰州  张晖 《天文研究与技术》2015,(3)

科技名词中文译名标准化和规范化工作是推动我国科技进步和科学知识传播的重要基础。新的科学概念和技术名词层出不穷,如何及时发现并确定新生术语的中文译名是一项普遍的社会需求。介绍了一套全新的天文学英语新词自动提取系统。该系统综合使用脚本过滤、术语识别、正则表达匹配等多种方法,能够自动追踪Ar Xiv论文数据库的更新,分析天文学论文的内容,生成推荐术语列表,从而将学科专家从繁重的科技新词收集整理工作中解放出来,把有限的精力集中到更能体现专业素养的新词审定工作当中。这个系统将为推动天文学等基础学科的新词收集,乃至学科标准化等工作发挥积极作用。  相似文献