【作者】 黄霞；

【导师】 叶瑛；

【作者基本信息】 浙江大学 ， 地质学， 2008， 博士

【摘要】 国际海底区域蕴藏着丰富的战略金属、能源和生物资源,是人类生命维系和社会持续发展的重要支持系统。海底热液体系不仅具有潜在的巨大经济价值而且对研究地球深部物质运动过程、构造活动、板块运动及生命起源也有积极意义,因此对它的勘查研究是当代海洋科学、地质学及生物学等众多学科共同面临的使命。在国家“863”项目的大力支持下,本论文研制一套具有自主知识产权、适用于海底原位探测的多参数地球化学传感器,它集成了参比电极、pH电极、硫化氢电极以及溶解氧电极,能直接获取热液体系的原位探测数据,它不仅对从地学、化学、生物学、深部地球物质等方面广泛研究热液体系具有重要意义,此外还将极大地促进海洋资源的探测、海洋环境的监测和保护、海洋科学的研究。通过分析国内外现有的原位地球化学传感器技术及各电极的制作方法,本文采用贵金属丝作为电极的基材,实现探测电极的固体化和微型化;采用熔融法制作Ag/AgCl参比电极,提高其使用寿命;采用以含超细银粉环氧树脂为中间层的方法制作Ag/Ag₂S电极,提高其检测下限;采用熔融过氧化钠法以及外覆质子半透膜技术制作Ir/IrO₂电极,提高其抗干扰能力;以及采用在金丝表面镀DePeX膜提高溶解氧电极的使用寿命及探测能力。在实验过程中,通过不断的标定及反复测试,根据反馈结果进一步完善电极性能。浙江大学有关课题组和美国明尼苏达大学合作研制的原位地球化学传感器成功应用于对东太平洋海隆Tica热液区生物栖息地为期12天的连续测试,在该地区首次实现了化学量原位长期观测。探测数据显示Tica热液区海水温度变化范围介于10℃至20.5℃,总溶解H₂S的浓度介于7.4～27.3μmol/L。原位探测数据分析结果表明,潮汐作用引起扩散流温度和化学成分的周期变化。海底原位地球化学传感器是一个可扩展的、通用性较强的技术平台,具有广泛的应用前途,尤其在天然气水合物探测以及海底长期观测系统等方面都具有巨大的潜在应用前景。本文研究成果可缩短我国与世界发达国家在深海海底资源调查技术上的差距。为今后我国深海矿产资源调查、勘探和开采打下良好基础。更多还原

【Abstract】 There are abundant strategic metal resources, energy sources and biological resources in International seabed area. It is an important supporting system for human life maintaining and sustainable social development. Seafloor hydrothermal system no only have potential tremendous economic value but also have the active significance for research in physical movement in deep earth, tectonic activities, plate movement and origin of life. Nowadays, subjects of marine science, geology and biology face the same mission of investigation of seafloor hydrothermal system. Upon the support of State 863 Program, a set of geochemical sensor with independent intellectual property containing reference electrode, pH electrode, H₂S electrode and dissoloved oxygen electrode is prepared for in-situ detecting on seafloor. It is useful to help people study hydrothermal system from geological, chemical, biological and other aspects, and thus greatly promote research in the field of sea resources detecting, sea environment observation and protection, and marine science.After studying in existing geochemical sensor and comparing previous preparation methods of these electrodes at home and aboard, the methods are taken as following: using noble metal as basic material, realizing the solidification and micromation of detecting electrodes; using AgCl melt to make reference electrode, enhancing its lifetime; using epoxy resin with ultra thin silver power as the middle layer to prepare Ag/Ag₂S electrode, enhancing its detecting limit; using Na₂O₂ melt to prepare Ir/IrO₂ electrode coated with Nafion, a kind of proton selective substance produced by DuPon, enhancing its resistance ability; using Au coated with DePeX membrane as DO electrode, enhancing its liftime and detecting ability. Constantly improve the electrodes performance by experimental calibrations according to the feedback.As a collaboration project between Zhejiang University and the University of Minnesota, a joint team has been working together on in-situ geochemical sensors for seafloor hydrothermal system. The device had been working continuously in a microbial cluster near TICA-vent for about 12 days and realized long-term chemical compositon monitoring for the first time in this area. Time-series records show that temperature fluctuates between 10°C and 20.5°C, and total dissolved varies from 7.4 to 27.3μmol/L. Through the analysing results of detecting data, it is found that temperature and chemical component concentration change periodically could be refered to tide influence.As a universal technical platform, in-situ geochemical sensor can be used widely. It has great potential applications in natural gas hydrate detecting, seabed observation system and other fields. Research results in this paper can reduce the gap in deep seafloor resources investigation technology between China and western countries and lay a sound foundation for deep-sea mineral resources investigation, exploration and exploitation.更多还原