镍超微颗粒的表面磁性

本文报道了镍超微颗粒宏观磁性的测量结果,分析了表面包覆的氧化层对表面和/或界面磁性的影响。结果表明,表面和/或界面有较强的有效各向异性,在低温,强场下对磁性另有些贡献。 关键词：     

Scale-Free Statistics of Bulletin-Board-System Server Visiting

The scale-free power-lave-like signature of statistics of electronic-bulletin-board-system (BBS) server visiting is reported.The Tsallis entropy approach was employed to fit data sets acquired from servers sited at three Chinese universities.It was found that the exponent of power-law-like probability distribution function, as well as the factor similar to the Lagrange multiplier introduced by the maximum entropy principle,probably depends on the number of discussion forums in BBS servers,while the mathematic expectation does not.It was concluded that statistics of BBS visiting is a good realistic candidate for complex network studies.     

Ni/NiO界面的高场磁化研究

报道在表面包覆ＮｉＯ的Ｎｉ超微颗粒和Ｎｉ／ＮｉＯ多层膜中Ｎｉ／ＮｉＯ界面的磁性实验结果．在Ｔ＜８０Ｋ下Ｎｉ／ＮｉＯ界面存在较大的磁化强度（Ｈ＝４０kＯｅ），并随温度上升而快速下降．对高场磁化（５－６５kＯｅ）实验数据进行拟合，结果表明Ｎｉ／ＮｉＯ界面存在类似磁矩排列不一致的结构． 关键词：