| 摘要 | 第1-11页 |
| Abstract | 第11-18页 |
| 1 Introduction | 第18-35页 |
| ·Nitrogen cycle in marine environment | 第18-29页 |
| ·Nitrogen composition | 第18-19页 |
| ·Nitrogen budget in marine environments | 第19-22页 |
| ·Marine nitrogen transformation processes | 第22-27页 |
| ·Methods in determining nitrogen transformations | 第27-29页 |
| ·N-loss in continental shelf sediments | 第29-31页 |
| ·Introduction to the East China Sea | 第31-34页 |
| ·General description | 第31-33页 |
| ·Nitrogen budget in the East China Sea | 第33-34页 |
| ·Aims of this thesis | 第34-35页 |
| 2 Application of the isotope pairing technique in sediments where anammox, denitrification and DNRA coexist | 第35-60页 |
| Abstract | 第36-37页 |
| ·Introduction | 第37-40页 |
| ·Materials and procedures | 第40-55页 |
| ·Assumptions | 第40-41页 |
| ·Revised equations for calculations of anammox and denitrification rates after DNRA intrusion | 第41-45页 |
| ·Quantification effects of DNRA on anammox, denitrification and total benthic N2production | 第45-51页 |
| ·Revised procedure for estimating actual anammox, denitrification and DNRA rates in slurry incubation | 第51-55页 |
| ·Assessment | 第55-57页 |
| ·Discussion | 第57-58页 |
| ·Comments and recommendations | 第58-60页 |
| 3 Anaerobic ammonium oxidation, denitrification and dissimilatory nitrate reduction to ammonium in the East China Sea sediment | 第60-87页 |
| Abstract | 第61-62页 |
| ·Introduction | 第62-66页 |
| ·Materials and methods | 第66-72页 |
| ·Sample collection and preparation | 第66页 |
| ·15N slurry incubations | 第66-67页 |
| ·Chemical analysis | 第67-68页 |
| ·Rate calculations | 第68-72页 |
| ·Results | 第72-78页 |
| ·Water column and sediment characteristics | 第72-73页 |
| ·15N slurry incubations | 第73-74页 |
| ·Nitrate storage and release in the sediment | 第74-75页 |
| ·N-loss and nitrate reduction in slurry incubation | 第75-78页 |
| ·Discussion | 第78-85页 |
| ·The influence of nitrate release and DNRA on anammox and denitrification rates calculation with isotope pairing method | 第78-81页 |
| ·Distribution and regulation of anammox, denitrification and DNRA in ECS sediments | 第81-83页 |
| ·Biogeochemical significance of anammox, denitrification and DNRA in the ECS sediments | 第83-85页 |
| ·Conclusions | 第85-87页 |
| 4 Direct measurements of benthic N-loss and DNRA in the East China Sea | 第87-115页 |
| Abstract | 第88-89页 |
| ·Introduction | 第89-91页 |
| ·Methods | 第91-97页 |
| ·Sample collection and preparation | 第91-92页 |
| ·General sediment characteristics | 第92-94页 |
| ·Net fluxes of O_2and dissolved inorganic nitrogen | 第94-95页 |
| ·Core incubation for benthic N-loss | 第95-96页 |
| ·Slurry incubation for tracking anammox, denitrification and DNRA | 第96页 |
| ·Chemical analysis | 第96-97页 |
| ·Results | 第97-102页 |
| ·General characteristics of the investigation sites | 第97-98页 |
| ·Pore water nitrogen species profiles | 第98-99页 |
| ·Oxygen and nutrients net fluxes | 第99-100页 |
| ·Slurry incubation | 第100-101页 |
| ·Concentration series test for core incubation | 第101页 |
| ·N-loss from core incubation | 第101-102页 |
| ·DNRA from core incubation | 第102页 |
| ·Discussion | 第102-115页 |
| ·Isotope pairing technique testing with~(15)NO_3~- concentration and time series when anammox and denitrification co-exist | 第102-105页 |
| ·Underestimation of N-loss by~(15)NO_3~- diffusion limitation | 第105-108页 |
| ·Other evidence for supporting underestimation of benthic N-loss by IPT | 第108-110页 |
| ·A revised procedure for estimating benthic N-loss | 第110-111页 |
| ·DNRA and its effect on benthic nitrogen cycle | 第111-114页 |
| ·Global significance of the additional N-loss | 第114-115页 |
| 5 Response of benthic nitrogen cycle to hypoxia of the Changjiang estuary | 第115-145页 |
| Abstract | 第116-117页 |
| ·Introduction | 第117-119页 |
| ·Materials and Methods | 第119-126页 |
| ·Sites description | 第119页 |
| ·Sediment and water sampling | 第119-120页 |
| ·Sediment characteristics | 第120-121页 |
| ·Sediment oxygen profiles | 第121-123页 |
| ·Track anammox, denitrification and DNRA with slurry incubations | 第123页 |
| ·Measuring oxygen uptake and nutrient fluxes with intact core incubations | 第123-124页 |
| ·Measuring anammox, denitrification and DNRA with intact core incubation | 第124-125页 |
| ·Rates calculations | 第125-126页 |
| ·Results | 第126-135页 |
| ·General characteristics | 第126-127页 |
| ·Pore water profiles of oxygen and nitrate | 第127-128页 |
| ·Sediment oxygen uptake (SOU) | 第128-129页 |
| ·Partitioning of anammox, denitrification and DNRA | 第129-130页 |
| ·Benthic N-loss and DNRA from core incubation | 第130-132页 |
| ·Nutrients net fluxes, nitrification and mineralization | 第132-133页 |
| ·Correlation of measured benthic nitrogen transformation rates with bottom water oxygen | 第133-135页 |
| ·Discussion | 第135-145页 |
| ·Response of SOU to reduced oxygen | 第135-136页 |
| ·Response of nutrient fluxes to reduced oxygen | 第136-137页 |
| ·Response of anammox, denitrification and DNRA to reduced oxygen | 第137-141页 |
| ·Integrated response of benthic nitrogen cycle to reduced oxygen | 第141-143页 |
| ·The fate of organic nitrogen | 第143-145页 |
| 6 Conclusions and Prospect | 第145-147页 |
| Reference | 第147-161页 |
| Acknowledgements | 第161-163页 |
| Supplementary Material 1 for Chapter 3 | 第163-168页 |
| Supplementary Material 2 for Chapter 3 | 第168-170页 |
| 个人简历 | 第170页 |
| 发表的学术论文 | 第170-171页 |
