| Table of contents | 第5-7页 |
| List of tables | 第7-8页 |
| List of ifgures | 第8-10页 |
| List of abbreviations | 第10-11页 |
| 摘要 | 第11-13页 |
| Abstract | 第13-14页 |
| CHAPTER Ⅰ INTRODUCTION | 第15-17页 |
| CHAPTER Ⅱ LITERATURE REVIEWS | 第17-29页 |
| CHAPTER Ⅲ MATERIALS AND METHODS | 第29-78页 |
| 3.1. Objective of the research | 第29页 |
| 3.2. Equipment and Instruments Used in the Experiments | 第29-33页 |
| 3.2.1. Test stand with camera system | 第29-30页 |
| 3.2.2. The 2BFQ-4 combined planter | 第30-31页 |
| 3.2.3. Physical characteristics of wheat kernels | 第31-32页 |
| 3.2.4. Determination of angle repose | 第32-33页 |
| 3.3. Modification of the Pneumatic Metering Device for Rapeseed | 第33-45页 |
| 3.3.1. The rapeseed metering device | 第33-34页 |
| 3.3.2. Operating principle of the rapeseed metering device | 第34页 |
| 3.3.3. Modifications of the rapeseed metering device to suit wheat | 第34页 |
| 3.3.4. Determination of theoretical and practical seed spacing | 第34-36页 |
| 3.3.5. Suggested seed plates for wheat | 第36-40页 |
| 2.3.6. Testing a new seed plates | 第40-42页 |
| 3.3.7. New shield and plates for the modified rapeseed metering device used for wheat | 第42-44页 |
| 3.3.8. Field experiment with modified seeder | 第44-45页 |
| 3.4. Introduction to ANSYS-CFX | 第45-46页 |
| 3.5. Simulation process | 第46-48页 |
| 3.6. The results of ANSYS simulation | 第48-55页 |
| 3.6.1. Simulation of designed pressure inlet and seed plate under different levels of negative pressure | 第48-50页 |
| 3.6.2. Comparison between cylindrical and revolved pressure inlet using a seed plate with 1.8 mm under 2.5 kPa negative pressure | 第50-52页 |
| 3.6.3. Simulation of different pressure inlets and different seed holes with 2.5 kPa negative pressure | 第52-55页 |
| 3.6.3.1. Cylindrical pressure inlet | 第52-53页 |
| 3.6.3.2. Cylindrical pressure inlet with 20 and 30 degrees | 第53-54页 |
| 3.6.3.3. Revolved pressure inlet | 第54-55页 |
| 3.7. Design of the Precision Metering Device for Wheat | 第55-58页 |
| 3.7.1. Structure of the wheat seeder | 第55-58页 |
| 3.7.2. Operating principles | 第58页 |
| 3.8. Determination of seed holding ratio | 第58-60页 |
| 3.9. Dynamic and kinematic analysis | 第60-67页 |
| 3.10. The deficiency of the seed inlet and seed tube | 第67-70页 |
| 3.11. Results of the vertical seed tube | 第70-72页 |
| 3.12. Reducing the size of the cut-off device and designing a new shield with hooked seed tube | 第72-78页 |
| 3.12.1. Laboratory testing using the new shield with hooked seed tube | 第74-76页 |
| 3.12.2. Determination of QFI, MULI, MISI and KPM | 第76页 |
| 3.12.3. Field experiment using the new shield with hooked seed tube | 第76-78页 |
| CHAPTER Ⅳ RESULTS AND DISCUSSION | 第78-87页 |
| 4.1. The results of laboratory testing using the test stand with camera system | 第78-83页 |
| 4.1.1. The effect of rotating speed (RS) and negative pressure (NP) on quality of feed index (QFI), multiple index (MULI) and miss index (MISI) | 第78-79页 |
| 4.1.2. The relationship between QFI, MULI, MISI, RS and NP | 第79-81页 |
| 4.1.3. The effect of rotating speed (RS) and negative pressure (NP) on number of kernels per meter (KPM) | 第81-82页 |
| 4.1.4. The significance and correlations between QFI, MULI, MISI, KPM RS and NP | 第82-83页 |
| 4.2. The results of field experiment | 第83-87页 |
| CHAPTER Ⅴ CONCLUSIONS AND RECOMMENDATIONS | 第87-89页 |
| 5.1. Conclusions | 第87-88页 |
| 5.2. Recommendations | 第88-89页 |
| Acknowledgements | 第89-91页 |
| REFERENCES | 第91-98页 |
| APPENDICES | 第98-134页 |
| Appendix A | 第98-99页 |
| Appendix B | 第99-100页 |
| Appendix C | 第100-101页 |
| Appendix D | 第101-102页 |
| Appendix E | 第102-103页 |
| Appendix F | 第103-104页 |
| Appendix G | 第104-105页 |
| Appendix H | 第105-119页 |
| Appendix I | 第119-134页 |
