1999年7月19～23日在阿根廷首都布宜诺斯艾利斯举行了第12届内耗与超声衰减国际学术会议(The 12th International Conference on Internal Friction and Ultrasonic At-tenuation in Solids),这是20世纪的最后一届会议,在回顾几十年来...1999年7月19～23日在阿根廷首都布宜诺斯艾利斯举行了第12届内耗与超声衰减国际学术会议(The 12th International Conference on Internal Friction and Ultrasonic At-tenuation in Solids),这是20世纪的最后一届会议,在回顾几十年来成就的同时,对21世纪学科的发展进行了展望。共有20多个国家的100多位学者参加了会议,共发表论文184篇,其中特邀报告12篇,口头报告114篇,墙报58篇。与会代表分别就非晶材料,陶瓷材料,高温超导体。展开更多
High-temperature superconductors in superconductor apparatuses are subjected to mechanical strains under operating conditions.These strains cause the degradation of the critical current densities and influence AC loss...High-temperature superconductors in superconductor apparatuses are subjected to mechanical strains under operating conditions.These strains cause the degradation of the critical current densities and influence AC losses in the superconductors.Based on the dynamic process of thermomagnetic interaction,we report the results of numerical analysis of AC losses in an infinite high-temperature superconducting slab subjected to a uniform in-plane strain in an alternating external magnetic field parallel to the sample surface.The numerical analysis shows the details of electromagnetic phenomena in the slab and the dependences of AC loss on various external parameters including the uniform strain in the slab and the amplitude and frequency of the external magnetic field.In this paper,we find that whether the magnetic field fully penetrates the superconductor is the key factor that influences the features of AC loss.When the magnetic field cannot fully penetrate the superconductor,the loss rises with increasing strain or decreasing frequency.When the magnetic field can fully penetrate the superconductor,the feature is just opposite.We also analyze the effects of periodic strain on AC loss.It is interesting to find that when the periodic strain frequency equals the external magnetic field frequency,the AC loss reaches the maximum,regardless if the magnetic field fully penetrates the superconductor or not.展开更多
文摘1999年7月19～23日在阿根廷首都布宜诺斯艾利斯举行了第12届内耗与超声衰减国际学术会议(The 12th International Conference on Internal Friction and Ultrasonic At-tenuation in Solids),这是20世纪的最后一届会议,在回顾几十年来成就的同时,对21世纪学科的发展进行了展望。共有20多个国家的100多位学者参加了会议,共发表论文184篇,其中特邀报告12篇,口头报告114篇,墙报58篇。与会代表分别就非晶材料,陶瓷材料,高温超导体。
基金supported by the National Natural Science Foundation of China(Grant Nos.11032006,11121202 and 11202087)National Key Project of Magneto-Constrained Fusion Energy Development Program(Grant No.2013GB110002)
文摘High-temperature superconductors in superconductor apparatuses are subjected to mechanical strains under operating conditions.These strains cause the degradation of the critical current densities and influence AC losses in the superconductors.Based on the dynamic process of thermomagnetic interaction,we report the results of numerical analysis of AC losses in an infinite high-temperature superconducting slab subjected to a uniform in-plane strain in an alternating external magnetic field parallel to the sample surface.The numerical analysis shows the details of electromagnetic phenomena in the slab and the dependences of AC loss on various external parameters including the uniform strain in the slab and the amplitude and frequency of the external magnetic field.In this paper,we find that whether the magnetic field fully penetrates the superconductor is the key factor that influences the features of AC loss.When the magnetic field cannot fully penetrate the superconductor,the loss rises with increasing strain or decreasing frequency.When the magnetic field can fully penetrate the superconductor,the feature is just opposite.We also analyze the effects of periodic strain on AC loss.It is interesting to find that when the periodic strain frequency equals the external magnetic field frequency,the AC loss reaches the maximum,regardless if the magnetic field fully penetrates the superconductor or not.
