The microstructural modification for NdFeB magnetic powders (MQP-B) after Zn vapor sorption has been investigated by transmission electron microscopy (TEM). It is found that a coating layer about 100 nm thick was formed on the surface of powder. Selected area electron diffraction (SAED) pattern and high resolution transmission electron microscopy (HRTEM) analyses show that the coating layer consists of condensed nano-scale crystallites of Fe 11 Zn 40 , NdZn 5 and Zn. After the temperature for Zn vapor sorption is raised to 648 K, a thin layer has been formed on boundaries of Nd 2 Fe 14 B grains locally in the rim region of the powders. The morphology of the grain-boundary thin-layers is very similar to that in HDDR-NdFeB magnet powder after Zn vapor sorption treatment. Since the latter has a good thermal stability of magnetic property, the Zn vapor sorption treatment is expected to improve also the thermal stability of MQP-B magnet.

Context: Limited documentation exists on the effectiveness of education-based (EG) versus peer discussionbased (PDG) group interventions on perceived competence of adolescents suffering from medulloblastoma. Aims: This study was conducted to investigate which of these approaches offers the more beneficial outcomes to participants. Settings and Design: In a hospital in Zhenjiang, China, a total of 45 pediatric patients with standard risk or high risk medulloblastoma were randomly assigned to the EG or PDG interventions. Methods and Material: The Self-Perception Profile for Children (SPPC) and the Life Orientation Test-Revised (LOT-R) questionnaires were used to measure perceived competence and dispositional optimism or pessimism. Statistical analysis used: Adjustment was measured before the intervention, immediately after the intervention, at two weeks after, and six months after the intervention. Results: Participants in both groups showed improvement over time. The EG participants scored themselves higher on subscales including social acceptance, global self-worth and behavioral conduct at 2 weeks compared with those in the PDG (P<0.05). However, no significant differences were found between the groups at 6 months. Moreover, pessimists did not benefit more by attending an EG intervention than they did by attending a PDG intervention. Conclusion: The results show EG intervention seeming to enhance shortterm, rather than long-term, perceived competence. Longitudinal studies are warranted to further identify targeted interventions to maximize healthy survivorship.

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Matthiessen’s rule has been applied to analyze the simultaneously measured electrical and thermal conductivities of polycrystalline platinum nanofilms. The results show that the greatly reduced conductivities are mainly attributed to the grain boundary scatterings. By taking into account the background scattering and the grain boundary scattering, Mathienssen’s rule slightly underestimates the thermal conductivity, but obviously overestimates the electrical conductivity. By introducing an additional parameter characterizing electron scattering on the grain boundary in Matthiessen’s rule, the agreement between the theoretical predictions and the observed results are greatly improved. Further studies show that when the mean grain size is much smaller than the corresponding mean free path, the electrons’ behavior inside the grains becomes affected by the grain boundaries and the underlying assumption of independent scattering processes for Mathiessen’s rule will become invalid.

The joint property of aldary (T3 copper, B5 cupronickel and H96 brassiness) with 35CrMnSi by the use of inertial radial friction welding techniques is studied to meet the requirements of product operation . The microstructure of the welding joint, shear testing, vickers hardness and electron probe tests are carried out to verify the material weldability. The results show good performance of T3 copper, B5 cupronickel and H96 brassiness welded well with steel. The joints shear strength is more than 200Mpa, and no air hole flaw in weld seam that often occur in general fusion welding with dissimilar material. The welding properties can satisfy the requirements of the products. The results also indicate that under the same welding specification, the region of HAZ is related to thermal conductivity and melting point of copper-alloy, the microstructures of HAZ on B5＋35CrMnSi steel side is wider than others .