An analog of double electromagnetically induced transparency with extremely high group indexes

An asymmetric metamaterial exhibiting an analog of double electromagnetically induced transparency(EIT) in the middle-infrared region is reported.The metamaterial consists of two-layered arrays of Ushaped rings embedded in a medium,with the lower layer rotated by 90°.Our simulations demonstrate that both maximum group indexes are extremely high at the two EIT-like positions.The group index reaches about thrice the currently reported maximum value at the high-frequency EIT-like position.The transmittance at the two transparency positions also possesses extremely high Q factors,which is conducive to controlling the propagation of electromagnetic waves.     

HT-7超导托卡马克总控系统的设计与实现

为了适应当前HT-7及今后EAST装置运行的需要,对原有总控系统进行改造,扩展了系统的功能。新的总控系统主要包括放电监控子系统、分布式定时及触发子系统、控制参数设置子系统、事件触发子系统、手动微调子系统。文章详细介绍了各个子系统的硬件组成结构、软件设计和实现过程。