【正文】 和永磁體剩余磁場強度（圖14）之間的關系，以及磁懸浮力曲線與超導樣品厚度和縱橫比的關系（圖15） 圖14 磁懸浮力曲線隨不同等效電流和永磁體不同的剩余磁場的變化 圖15 磁懸浮力曲線與超導樣品厚度和縱橫比的關系 [1] F. Hellman, E. M. Gyorgy, D. W. Johnson, Jr.,H. M. O’Bryan, and R. C. Sherwood, ”Levitation of a magnet over a ?at typeII superconductor”, J. Appl. Phys 63, 447450(1988).[2]W. G. Harter, A. M. Hermann, and Z. Z. Sheng, ”Levitation e?ects involving high Tc thallium based superconductors”, Appl. Phys. Lett. 53, 11191121(1988). [3] F. Hellman, E. M. Gyorgy, D. W. Johnson, Jr.,H. M. O’Bryan, and R. C. Sherwood, ”Levitation of a magnet over a ?at typeII superconductor”, J. Appl. Phys 63, 447450(1988). [4] A. R. Conn, N. I. M. Gould, Ph. L. Toint, LANCELOT: A Fortran Package for LargeScale Nonlinear Optimization, Springer Series in Computational Mathematics(Springer Verlag, Berlin 1992).[5] J. R. Hull 2000 Supercond. Sci. Techno. 13 R1。 Appl. Phys. Lett. 90 042503.[17] D. L. Shi, D. Qu. Sagar, and K. Lahir 1997Appl. Phys. Lett. 70 3606.[18] Y. S. Cha, J. R. Hull, T. M. Mulcahy, and T. D. Rossing, J. Appl. Phys. 70, 6504 (1991).[19] B. Lehndorff, H. G. K252。 Phys. Rev. Lett. 8, 250 (1962).[25] For example, K. V. Bhagwat and P. Chaddah, Pramana 33, 521 (1989)。 P. N. Mikheenko and Y. E. Kuzovlev, Physica C 204, 229 (1993)。 M. W. Coffey Phys. Rev. B 52 R9851(1995)。李老師將總結的研究方法和積累的科研經(jīng)驗都毫無保留地向我傳授，所有這一切將使我終生受益。其實，我從大一下學期就結識了李老師，在以后的學習和生活中，李老師給了我很多幫助和關懷。2009年下學期，李老師每周都抽出二個小時間給我我講解他在超導理論方面的科學探索，李老師知識淵博，思維敏捷，思路開闊，考慮問題細致而周全，從他身上我了解了開展科研工作的方法和步驟，知道了從事科研所必備的素質和精神。畢業(yè)設計期間，與他們共同合作，相互學習，一起談論，使我受益匪淺。27。這段珍貴的學習經(jīng)歷使我受益匪淺，無論是學術上還是人生閱歷上，對我以后的發(fā)展有很大的幫助。在平時的學習和生活當中，我得到了許多同學的幫助和真誠的鼓勵，在此表示衷心的感謝。李老師經(jīng)常鼓勵我勤于思考，敢于質疑，勇于創(chuàng)新。感謝賈瑜教授、孫強教授、胡行教授、曹義剛教授等，他們給我提供了一個良好的科研環(huán)境，在學習和科研中給予了巨大的關心和支持。 E. Rodr?guez, J. Luzuriaga, C. D’Ovidio, and C. Esparza, ‘‘Softening of the fluxline structure in La2xSrxCuO4 measured by a vibrating reed,’’ Phys. Rev. B 42, 10796–10800 (1990).[40] Y. B. Kim, C. F. Hempstead and A. R. Strand, ‘‘Critical persistent currents in hard superconductors,’’ Phys. Rev. Lett. 9, 306–309 (1962).[41]. Brandt E H, 1996 Phys. Rev. B 54 (6) 4246. [42]. Brandt E H, 1998 Phys. Rev. B 58 (10) 6506. [43]. Qin M J, Li G, Liu H K, and Dou S X, Brandt E H, 2002 Phys. Rev B 66 (10) 024516.[44] Raphael B. Kasal, Rubens de Andrade Simulation of Dynamic Levitation Force Taking Flux Creep Into Account , JUNE 2007，21582161[45] . Herrmann, C. Cottevielle,G. Duperray, , T. Verhaege,C. Albrecht, ,“Cryogenic load calculation on high current lead,” Cryogenics, vol. 33, pp. 555–562, 1993.[46] T. Rettelbach and G. J. Schimitz, “3D simulation of temperature, electric field and current density evolution in superconducting ponents,” Superconductor Science and Technology,–653,2003.[47] J. Grundmann, M. Lindmayer, R. Rockelein, and W. Schmidt, “Simulation of HTS switching with the finite element analysis program ANSYS,” Superconductor Science and Technology, vol. 16, –565, 2003.[48] 楊萬民，周廉，馮勇等，Effect of grainalignment on the levitation force of meltprocessed YBCO bulk Vol 8 No 7 1999 533538.V. 致謝首先感謝我的導師李平林教授，李老師淵博的學識、嚴謹?shù)膶W風、認真的工作態(tài)度和開闊的事業(yè)令我敬佩。 E. H. Brandt, ibid. 54, 4246 (1996).[26] E. H. Brandt, Am. J. Phys. 58, 43 (1990).[27] M. J. Qin, G. Li, H. K. Liu, S. X. Dou, E. H. Brant, Phys. Rew. B 66 024516(2002).[28] Hellman F., Gyorgy E M, Johnson D W, . 1988 Appl. Phys. 63 447。s, and J. S. Mu241。cke, and H. Piel, Physica C 247, 280 (1995).[20] P. Z. Chang, F. C. Moon, J. R. Hull, and T. M. Mulcahy, J. Appl. Phys. 67, 4358 (1990).[21] B. A. Tent et al, 1998 Phys. Rev. B 58, 11761。 N. Koshizuka, F. Ishikawa, H. Nasu, M. Murakami, et al., Phys. C 378 (2001) 11.[7] Wang J J, He C Y, Meng L F, . 2003 . 16 527 533[8] J. R. Hull, E. F. Hilton, T. M. Mulcahy, Z. J. Yang, and A. Lockwood, “Low friction in mixedmu superconducting bearings,’’ J. Appl. Phys. 78(11), 6833–6838 (1995).[9] J. R. Wang, P. X. Zhang, L. Zhou, M. Z. Wu, W. Gawalek, P. Gornert, H. Weh, in: 15th Inter. Conf. on Magnet Technol., Beijing, October 20 24, 1997.[10] F. C. Moon, M. M. Yanoviak, R. Ware. Hysteretic levitation forces in superconducting ceramics [J]. Appl. Phys. Lett., 1988, 52 (18): 15341536. [11] K. Hiroaki, O. Assushi. Measurement and analysis of lateral forces between magnets and highTc superconductors [J]. J. Appl. Phys., 1995, 77 (2): 770778]. [12] M. Masato, O. Terutugu, F. Hiroyuki, et al. Large levitation force due to flux pinning in YBaCuO superconduc