by Chuen Ka Yee. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 134-166). / Abstracts in English and Chinese. / ACKNOWLDEGEMENT --- p.ii / PUBLICATIONS --- p.iii-iv / ABBREVIATIONS --- p.v-viii / INDEX FOR FIGURES --- p.ix xii / INDEX FOR TABLES --- p.xiii / ABSTRACT (Chinese and English) --- p.xiv-xvi / TABLE OF CONTENT --- p.xvii / Chapter 1. --- INTRODUCTION --- p.1-37 / Chapter 2. --- OBJECTIVES --- p.38-40 / Chapter 3. --- METHODS AND MATERIALS --- p.41 -70 / Chapter 4. --- RESULTS AND DISCUSSION --- p.71-130 / Chapter 5. --- GENERAL DISCUSSION AND CONCLUSION --- p.131-133 / BIBLIOGRAPHY --- p.134-166