YBa2Fe3O8+w的湿化学法制备以及电磁性质研究

本文成功采用湿化学法制备了高品质的YBa2Fe3O8+w(YBFO)材料,并利用XRD、M～T、R～T和SEM 等测试与分析手段研究了其结构、电导性质和磁性质.结果表明,YBFO在结构上具有与高温超导体YBa2Cu3O7(YBCO)高度的相似性,在电磁学行为上呈现出反铁磁(AFM)的半导体特征.YBFO与YBCO的相似...     

How many dimensions are required to approximate the potential energy landscape of a model protein?

A scheme to approximate the multidimensional potential energy landscape in terms of a minimal number of degrees of freedom is proposed using a linear transformation of the original atomic Cartesian coordinates. For one particular off-lattice model protein the inherent frustration can only be reproduced satisfactorily when a relatively large number of coordinates are employed. However, when this frustration is removed in a Go-type model, the number of coordinates required is significantly lower, especially around the global potential energy minimum. To aid our interpretation of the results we consider modified disconnectivity graphs where a measure of the structural diversity and a metric relation between the stationary points are incorporated.