Dynamic Characteristics of Selemion CMV-Based IPMC Actuators in High Humidity Environment

Electrically-induced bending of Selemion IPMC is caused by the charge induced into the IPMC. This induced charge quantity is susceptible to the absolute humidity of environment. There are two types of charges, the charge causing bending and the rest of charge that causes no bending. In the high humidity environments, where absolute humidity is above 10 gm-3, the quantity of charge causing no bending accounts for the large part of whole charge induced into the Selemion IPMC, while quantity of such charge is negligibly small at the absolute humidity of less than 10 gm-3. Estimating the quantity of those two types of charges individually, we successively analyzed the bending stability of Selemion IPMC at the absolute humidity above 10 gm-3. Consequently, we deduced the following conclusions. 1) There exists a large time delay in the current in response to the voltage input, 2) Current is highly dumping, and 3) Bending behavior is marginally stable under the input of any frequency.

不同平台的绝对表观扩散系数值可能存在实质性差异:一项多厂家、多机构的比较研究

目的 评价在不同成像设备、生产厂家、磁场强度及不同设备条件下取得的绝对表观扩散系数（ADC）值是否改变或呈何种程度的改变。材料和方法 本研究获得志愿者知情同意并经研究机构审查委员会同意。12名健康志愿者在7个研究机构使用4家生产厂家的10台不同的1．5T与3．0T场强的MR设备，采用基本相同的参数进行扩散加权成像。