分类: 核科学技术 >> 粒子加速器 提交时间: 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要: A biaxial rotational technique is proposed to improve the neutron irradiation uniformity for a large sample, and the theoretical method is established to predict and design the main parameters. The technique used a device to rotate the target sample around two perpendicular axes simultaneously. Numerical calculations found that the lowest common multiple of the two angular speeds should be large enough to improve the uniformity, and the minimal experimental time should be no less than 600 s. For a three-dimensional sample with a size of 20 cm�12 cm�14 cm, the maximal non-uniform neutron irradiation factor of the sample is mainly determined by the distance between the center of the sample and of the point neutron source. It was computed to be less than 10% when the distance was no less than 34 cm. Experiments were carried out on the CFBR-II reactor and the experimental results were in good accordance with the theoretical analysis. As a result, the theoretical conclusions given above are reasonable and of reference value for the design of future irradiation experiments.
提交时间: 2017-05-02
摘要: Heterovalent Sn2O3 nanosheets were fabricated via an oxidation annealing process and the formation mechanism was investigated. The temperature required to complete the phase transformation from Sn3O4 to Sn2O3 was considered. Two contrasting experiments sh
提交时间: 2017-05-02
摘要: Nanostructures of stereocomplex polylactide [sc-PLA] are obtained and studied in poly[l-lactide] [PLLA] doped with a low amount of poly[d-lactide] [PDLA] during successive melt-quenching, extrusion, spinning, and drawing processes corresponding to quiesce