Acknowledgements

On the completion of the dissertation，I would like to express my sincere thanks to all those who have assisted me and conduced to this doctoral thesis. Without their help，this thesis would be an impossible mission.

First of all，I would like to express my deepest gratitude to my respected supervisors-Professor Ian Barnes，Professor David Floyd and Professor Andrew Atherton. I cannot thank them enough for their guidance and encouragement in my research for and writing of this thesis. Without their scholarly inspirations and generous help，I would not have been able to accomplish such a big research project. Moreover，their serious attitude towards academic activities will benefit me in my entire life.

Moreover，my sincere thanks also go to Ms. Sharon Richie，Ms. Jane Graves，Mr. Mark Forster and other professors and friends for their kind support and help in the accomplishment of this thesis.

I would also like to express my love and gratitude to my parents for their continual spiritual and financial support.

Finally，acknowledgements are also given to the authors listed in the references and bibliography for the quotations in the thesis.