中文摘要：

氮的生物地球化学循环是地表环境中最复杂的物质循环之一.近年来,稳定同位素技术在氮的生物地球化学循环研究中得到了广泛应用,极大地丰富了人们对氮的来源、物理迁移及其生物地球化学循环等过程的认识,完善了氮的生物地球化学循环理论体系.本文综述了在环境水体中应用稳定同位素示踪技术及统计模型,将氮的溯源研究从定性识别拓展到定量解析;应用稳定同位素分馏理论及同位素配对技术,实现氮的生物地球化学循环转化途径的判别及其转化速率的定量解析;重点提出应进一步开展不同转化途径、不同水体环境要素对氮同位素分馏特征的影响研究,逐步完善环境水体氮循环同位素分馏理论体系,为准确认识氮循环和加强水环境保护奠定科学基础.

英文摘要：

The nitrogen cycle is one of the most complicated biogeochemical cycles in the aqueous environment.Stable isotope techniques have been widely applied in the studies of the biogeochemical cycle of nitrogen.These studies have greatly enriched our understanding of sources,migrations and biogeochemical cycles of nitrogen and established the theoretical system of the biogeochemical cycle of nitrogen.We review the present research of nitrogen sources which has been extended from the qualitative identification to the quantitative apportionment based on stable isotope tracingtechniques and statistical methods,and the existing studies of the biogeochemical cycle of nitrogen from qualitative identification to the quantitative estimation of transformation processes through the isotope fractionation in the nitrogen cycle and the isotope pairing techniques.In the end,we propose that the further study should be focused on the impacts of various nitrogen transformation processes and various environmental factors on characteristics of isotope fractionation and continually perfect the theory of aqueous nitrogen isotope fractionation.