A hybrid model for the charging process of the amorphous SiO2 film in radio frequency microelectromechanical system capacitive switches

Charging is one of the most important reliability issues in radio frequency microelectro-mechanical systems(RF MEMS) capacitive switches since it makes the actuation voltage unstable.This paper proposes a hybrid model to describe the transient dielectric charging and discharging process in the defect-rich amorphous SiO 2 RF MEMS capacitive switches and verifies experimentally.The hybrid model contains two parts according to two different charging mechanisms of the amorphous SiO 2,which are the polarisation and charge injection.The models for polarisation and for charge injection are established,respectively.Analysis and experimental results show that polarisation is always effective,while the charge injection has a threshold electric field to the amorphous SiO 2 film.Under different control voltage conditions,the hybrid model can accurately describe the experimental data.     

大骨山滑坡病害成因分析及工程防治对策

大骨山滑坡病害位于福建泉三高速公路YK128+630m～YK129+050m路段,病害区为凹形坡地,地层上部为第四系冲洪积层,下部为残积层及基岩风化带。依据现有地形地貌特征及钻孔揭露岩芯可判断该处为一古滑坡。斜坡上部隧道洞门施工致使坡顶开裂、洞口顶部坍塌。由于斜坡中下部下伏基岩的弱透水性,在降雨及病害区地表水的作用下,在岩土层地质界面处易形成软弱带,致使古滑坡有复活的迹象,古滑坡的复活将造成斜坡上部牵引破坏,并最终危及斜坡上部隧道洞口的稳定,为确保隧道洞口及斜坡中下部在建的林畔坑大桥的稳定与安全,采用Morgenstern-Price极限平衡分析方法,对斜坡分级进行稳定性分析计算,依据计算结果对滑坡病害进行针对性治理,在古滑坡中下部布置了锚索抗滑桩,为防止桥身墩位发生变形,在桥墩山侧布置锚索护桩。同时为消除地表水及降雨入渗对滑坡病害的影响,有针对性的在坡周及坡脚进行了截水与引水工程防治。