Observation of Cu nanometre scale clusters formed in Fe85Si2B8P4Cu1 nanocrystalline soft magnetic alloy by a spherical aberration-corrected TEM/STEM

Microstructure of a nanocrystalline soft magnetic Fe₈₅Si₂B₈P₄Cu₁ alloy (NANOMET^®) was investigated by the state of the art spherical aberration-corrected TEM/STEM. Observation by TEM shows that the microstructure of NANOMET^® heat treated at 738 K for 600 s which exhibits the optimum soft magnetic properties has homogeneously distributed bcc-Fe nanocrystallites with the average grain size of 30 nm embedded in an amorphous matrix. Elemental mappings indicate that P is excluded from bcc-Fe grains and enriched outside the grains, which causes to retard the grain growth of bcc-Fe crystallites. The aberration-corrected STEM-EDS analysis with the ultrafine electron probe successfully proved that Cu atoms form nanometre scale clusters inside and/or outside the bcc-Fe nanocrystallites.     

3-6年级小学生师生关系:结构、类型及其发展

本研究采用师生关系教师评定量表,由14名班主任教师对498名3-6年级学生与教师的关系进行评价.结果表明:(1)师生关系量表具有较好的信度和效度,师生关系特点主要表现在冲突性、亲密性和反应性三个维度上.(2)快速聚类分析的结果表明,3-6年级学生的师生关系可划分为3种类型:冷漠型、冲突型、亲密型,其分布比例分别为23.0%、33.7%、43.3%.(3)师生关系随学生年级增长而变化.在师生关系各维度及总分上,存在显著的年级差异.随年级的上升,积极师生关系类型的比例逐渐下降,而消极师生关系类型的比例逐步上升.