（毕业设计论文）《超导磁浮力的研究》.doc

摘 要 某些金属（包括合金）、有机材料、陶瓷材料在一定温度Tc以下，会出现零电阻的现象，我们称这种现象为超导现象,而这些材料则被称为超导体。超导体具有零电阻效应、完全抗磁性效应、二级相变效应、单电子隧道效应、约瑟夫森效应等几大特性。 本文研究的超导磁悬浮利用超导材料的抗磁性，将超导材料放在一块永久磁体的上方，由于磁体的磁力线不能穿过超导体，磁体和超导体之间会产生排斥力，使超导体悬浮在磁体上方Abstract When some metals(include alloys), organic materials and ceramic materials are put into below the certain temperature Tc, there would appear a phenomenon of zero resistance and we call this phenomenon as superconductivity, these material are called as superconductor. Superconductivity owns some main characters which includes: zero resistance effect, perfect diamagnetism, second-order transaction effect, single electron tunnel effect, Josephson effect and so on. The EDS Maglev which is researched in this paper is just make use of the diamagnetism of superconductors, put the superconductor above a permanent magnet, there will engender a repulsive force between the permanent magnet and superconductor which can make the superconductor float above the permanent magnet, for that the magnetic line of force of the permanent magnet cannot pass through the superconductor. There are many factors which can effect the magnetic buoyancy, for example, temperature, strength of water magnetic field, distance between superconductor and water magnet and so on. This paper aims at studding how the distance between superconductors and water magnet influents the magnetic buoyancy and the evolution of it. Key words: superconductivity，zero resistance，perfect diamagnetism，BCS theory，EDS Maglev 1 绪论 2 1.1超导体 2 1.2超导的主要特性 2 1.2.1零电阻效应 2 1.2.2完全抗磁性效应（Meissner效应） 2 1.2.3二级相变效应 2 1.2.4单电子隧道效应 2 1.2.5约瑟夫森效应（双电子隧道效应） 2 1.3超导技术的应用 2 1.3.1零电阻的应用 2 1.3.2完全抗磁性的应用 2 2 超导的微观机制 2 3超导磁浮力 2 3.1 实验装置 2 3.2 实验内容 2 3.3 实验结果 2 4 全文总结 2 致谢 2 参考文献 2 超导磁浮力的研究 1 绪论 1.1超导体 某些金属（包括合金）、有机材料、陶瓷材料在一定的温度Tc以下，会出现零电阻的现象，我们称这些材料为超导体。另外，强磁场能破坏超导状态。每一种超导材料除了有一定的临界温度Tc外，还有一个临界磁场强度Hc，当外界磁场超过Hc时，即使用低于Tc的温度也不可能获得超导态。[1] 超导现象首先是由荷兰Leiden大学学者Kamerlingh Onnes（卡末林·昂尼斯）在1911年发现的。早在1908年，Leiden实验室就掌握了He（氦）气的液化技术，He在一个大气压下液化时，温度为