I would like to express my gratitude to all those who helped me during the
processof writing of this thesis and during my study years at this school.
My deepest gratitude goes first and foremost to Professor Xu, my
supervisor, forhis constant encouragement and guidance. He has offered me
valuable suggestions inthe academic studies. In the preparation of this thesis,
he has spent much time readingthrough each draft and provided me with inspiring
advice. Without his consistent andilluminating instruction, this thesis could
not have reached its present form.
Special thanks should go to express my heartfelt gratitude to the
professors andteachers at our school as well, who have instructed and helped me
a lot during the pastthree years.
At last, my thanks would go to my beloved family for their loving
considerationsand great confidence in me all through these years and their
supporting without a wordof complaint. I also owe my sincere gratitude to my
friends and my fellow classmateswho have given me their help and their time in
listening to me and helping me work outmy problems during the difficult course
of the thesis.
The completion of the thesis is attributed to many people's support
First and foremost, I want to extend my heartfelt gratitude to my
supervisor,Professor Cao Daogen, whose patient guidance, valuable suggestions
and constantencouragement make me successfully complete this thesis. His
conscientious academicspirit and modest, open-minded personality inspire me both
in academic study and dailylife. He gives me much help and advice during the
whole process of my writing, whichhas made my accomplishments possible.
Also, I would like to express my sincere gratitude to all the professors
who havetaught me in this university. Their instructions have helped broaden my
horizon andtheir enlightening teaching has provided me with a solid foundation
to accomplish thispaper and will always be of great value for my future career
and academic research.
My thanks also go to the authors whose books and articles have given
meinspiration in the writing of this paper.
Last but not least, I would like to express my special thanks to my
parents, whosecare and support motivate me to move on and make me want to be a