29,437 research outputs found
TBAB Semi-Clathrate Hydrate Formation and its Application in CO2Separation from CO2/CH4Mixture Gases
水合物法气体分离技术是一种新型的CO2分离方法,不同的分离条件对CO2气体分离的效果影响显著。四丁基溴化铵(TBAB)的添加能显著改善CO2/CH4混合气水合物的相平衡条件,促进CO2水合物的生成。作者主要研究在质量浓度为40%的TBAB水溶液体系中,压力为3.2MPa下,不同过冷度及气水比例的条件对CO2/CH4混合气水合物的生成过程及CO2的分离效果的影响规律。实验结果表明,当压力为3.2MPa时,气水比越小,CO2分离效果越好。同时,存在最佳的过冷度使得反应过程中气体消耗量最大以及CO2分离效果最好,而且CO2分离效果并非与过冷度完全成正比。当气水比为0.54,过冷度为6K时,反应结束后气相中CH4的摩尔比例为81.59%,CO2的摩尔比例为18.41%,CO2气体分离系数为4.43,CO2分离效果最好
Greenhouse gas emissions from croplands of China
China possesses cropland of 1.33 million km 2. Cultivation of the cropland not only altered the biogeochemical cycles of carbon (C) and nitrogen (N) in the agroecosystems but also affected global climate. The impacts of agroecosystems on global climate attribute to emissions of three greenhouse gases, namely carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)
Sedimentary organic geochemistry research of source rocks of the potential gas hydrate-bearing areas in the northern South China Sea
天然气水合物是二十一世纪新能源,我国南海北部陆坡是天然气水合物发育的理想场所,深入研究南海北部陆坡天然气水合物成藏机制和富集规律,为我国海洋天然气水合物资源勘探和开发提供重要的理论依据和指导,具有重要的经济和科学意义。其中气源条件既是天然气水合物形成发育的物质基础,又是天然气水合物成藏的关键。本论文依托国家“973”计划子课题《南海北部天然气水合物成藏的气源条件研究》(项目编号:2009CB21951)、国家自然科学基金项目《南海北部海底沉积层硫酸盐-甲烷体系产消机制及其界面(SMI)特征研究》(项目编号:40976035)和《天然气水合物成藏体系中产甲烷与甲烷厌氧氧化作用生物标志物和分子生物...Gas hydrate, as resource of the twenty-first century, is widely developed in the northern slope of the South China Sea. Further study on gas hydrate accumulation mechanism and enrichment patterns is required, to provide an important theoretical basis and guidance for marine gas hydrate resource exploration and development. Among them, gas source condition is not only the material basis of gas hydr...学位:理学博士院系专业:海洋与环境学院_海洋地质学号:2242010015358
室内植物表型平台及性状鉴定研究进展和展望
Plant phenomics is under rapid development in recent years, a research field that is progressing towards integration, scalability, multi-perceptivity and high-throughput analysis. Through combining remote sensing, Internet of Things (IoT), robotics, computer vision, and artificial intelligence techniques such as machine learning and deep learning, relevant research methodologies, biological applications and theoretical foundation of this research domain have been advancing speedily in recent years. This article first introduces the current trends of plant phenomics and its related progress in China and worldwide. Then, it focuses on discussing the characteristics of indoor phenotyping and phenotypic traits that are suitable for indoor experiments, including yield, quality, and stress related traits such as drought, cold and heat resistance, salt stress, heavy metals, and pests. By connecting key phenotypic traits with important biological questions in yield production, crop quality and Stress-related tolerance, we associated indoor phenotyping hardware with relevant biological applications and their plant model systems, for which a range of indoor phenotyping devices and platforms are listed and categorised according to their throughput, sensor integration, platform size, and applications. Additionally, this article introduces existing data management solutions and analysis software packages that are representative for phenotypic analysis. For example, ISA-Tab and MIAPPE ontology standards for capturing metadata in plant phenotyping experiments, PHIS and CropSight for managing complicated datasets, and Python or MATLAB programming languages for automated image analysis based on libraries such as OpenCV, Scikit-Image, MATLAB Image Processing Toolbox. Finally, due to the importance of extracting meaningful information from big phenotyping datasets, this article pays extra attention to the future development of plant phenomics in China, with suggestions and recommendations for the integration of multi-scale phenotyping data to increase confidence in research outcomes, the cultivation of cross-disciplinary researchers to lead the next-generation plant research, as well as the collaboration between academia and industry to enable world-leading research activities in the near future
Response of carbon and nitrogen geochemical characteristics on the formation and decomposition of gas hydrate in sediments from the northern South China Sea
全球90%的海域分布有天然气水合物,其储量丰富,被认为是21世纪的重要清洁能源;天然气水合物的主要成分为甲烷,其增温潜力是CO2的23倍之多。因此,海底天然气水合物具有重要的能源、经济、环境效应。我国南海具有天然气水合物成藏的有利温度、压力、地质构造等条件,尤其是在南海北部神狐海域和珠江口盆地,广州海洋地质调查局先后于2007年、2013年、2016年钻获水合物实物样品。因而,研究南海北部不同海域天然气水合物潜在区沉积物碳氮地化特征对水合物生成/分解的响应,对我国天然气水合物勘探开发具有重要的现实意义。 本论文依托国家自然科学基金项目《天然气水合物成藏体系中产甲烷与甲烷厌氧氧化作用生物标志物...Marine gas hydrate, as one of the largest methane reservoirs on Earth, is an important subject about the effects of energy, economy and environment. China drilled and obtained gas hydrate samples from the northern South China Sea (SCS) in 2007, 2013 and 2016, suggesting the best prospect area of marine gas hydrate for the northern SCS. Thus, studying carbon and nitrogen geochemical characteristics...学位:理学博士院系专业:海洋与地球学院_海洋地质学号:2232013015379
2010_2016年国际极地研究综合评价分析
极地在气候系统、全球资源和战略中具有重要意义,并且随着人类对它的开发,极地研究也日益成为地球与环境科学领域的核心和热点议题。基于Web of Science 数据库收录的2010 - 2016 年SCI文章,利用文献计量方法,结合国际政策和战略,分析了2010 - 2016 年极地研究的发展格局和变化趋势。结果表明: ( 1) 近年来国际极地研究论文年发文量总体呈持续增长态势,年均增幅为3. 6%。( 2)发达国家及高纬度国家是极地领域的主要研究力量,美国占据绝对优势。( 3) 在SCI 发表的国际极地研究论文来源期刊共计915 种,来自57 个国家,美国期刊占1 /3。( 4) 结合欧盟极地研究优先领域和文献计量方法得出,极地研究未来新的发展方向侧重于人文及社会因素,重点提倡人类对极地的影响以及新技术应用。建议我国科研人员密切关注国际极地研究的发展态势和进展,鼓励海洋学、气象学、地质学、环境生态学、生物学、社会学和政治学等领域专家有计划地开展极地研究,为我国赢取极地研究国际发言权和参与度。</p
A Numerical Simulation Study on Natural Gas Hydrate Reservoir Exploitation
The TOUGH2 is a set of seepage simulation software developed by the Lawrence Berkeley National Laboratory; its function has many common grounds with aspects of gas hydrate reservoir exploitation including gas and fluid seepage, mass and heat transferenc
Study on sedimentary characteristics and its effects on the formation and decomposition of gas hydrate on continental slope of the northern South China Sea
南海是中国最大的边缘海,覆盖着巨厚的富含有机质的沉积地层,沉积速率高,具备良好的生油生烃能力,具有巨大的资源潜力,是我国的海洋油气资源宝库。天然气水合物作为分布广储量大且对环境友好的资源,具有极高的科学意义和社会意义,南海北部陆坡是我国天然气水合物赋存的最有利海域。近年来南海北部多处天然气水合物钻探采样为我国天然气水合物资源的研究提供了强有力的支撑。本文通过对南海北部陆坡台西南盆地邻近海域地质调查所获沉积物柱状样进行粒度、有机碳、孔隙水、元素矿物等地球化学分析,以研究南海北部陆坡沉积物的分布特征及变化规律,并对比天然气水合物赋存区的沉积环境特征,探讨研究区域沉积物特征对天然气水合物形成、分解的...The South China Sea is the largest marginal sea of China, covered with thick sedimentary strata rich in organic matter, with high deposition rate, it is a good source of hydrocarbon generation ability, which has a great resource potential, it is a precious ocean oil and gas resource of China. As a widely distributed,large reserved and friendly to the environment resources, gas hydrate has importa...学位:理学硕士院系专业:海洋与环境学院_海洋地质学号:2242010115131
Study of preparations of porous polymer coating films and separation membranes via vapor induced phase separation and their properties
近年来,多孔聚合物膜材料在水处理、气体分离、能源和医药生物等领域得到了广泛的应用。在多种制备聚合物多孔膜的方法中,蒸气诱导相分离法(VIPS)因其工艺简便以及良好的可控性而被应用于制备具有特定结构的聚合物多孔膜材料。本文使用苯乙烯-丁二烯-苯乙烯四臂星型嵌段共聚物[(SB)4]作为原料,并通过蒸气诱导相分离法和喷涂法结合的方式制备出超疏水涂层膜和油水分离膜材料。同时将聚醚砜(PES)溶液暴露在水蒸气气氛下来制备蜂窝状多孔膜材料。此外本文探讨了聚合物溶液的组成、非溶剂气氛的选择、非溶剂气氛暴露时间等因素对所制得的多孔膜材料形貌和结构的影响,并研究了所得材料在涂层和分离膜领域的应用。具体的研究工作...In recent years, porous polymer membrane materials have been widely applied in many fields, such as water treatment, gas separation, energy, medicine and biology. Among the many methods for preparing porous polymer membranes, vapor induced phase separation (VIPS) has been used in the preparation of porous polymer membrane materials with specific structures based on its simplicity and good controll...学位:理学硕士院系专业:材料学院_高分子化学与物理学号:2072014115006
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