Physics of ion acceleration in the solar flare on 2005 September 7 determines γ-ray and neutron production

Relativistic neutrons were observed by the neutron monitors at Mt. Chacaltaya and Mexico City and by the solar neutron telescopes at Chacaltaya and Mt. Sierra Negra in association with an X17.0 flare on 2005 September 7. The neutron signal continued for more than 20 min with high statistical significance. Intense emissions of γ-rays were also registered by INTEGRAL, and during the decay phase by RHESSI. We analyzed these data using the solar-flare magnetic-loop transport and interaction model of Hua et al. [Hua, X.-M., Kozlovsky, B., Lingenfelter, R.E. et al. Angular and energy-dependent neutron emission from solar flare magnetic loops, Astrophys. J. Suppl. Ser. 140, 563–579, 2002], and found that the model could successfully fit the data with intermediate values of loop magnetic convergence and pitch-angle scattering parameters. These results indicate that solar neutrons were produced at the same time as the γ-ray line emission and that ions were continuously accelerated at the emission site.     

Sb对AE41镁合金组织和性能的影响

研究了Sb元素对AE41(Mg-4A l-1RE)镁合金组织和性能的影响。结果表明,加入Sb后基体中出现了弥散颗粒质点。该颗粒质点相主要为RE2Sb相,但当含Sb量较高时,该颗粒质点主要为RE2Sb相和RESb相的复合物。随着Sb加入量的增加,枝条状A l11RE3相在数量降低的同时在形态上逐渐变短变细,弥散RE-Sb颗粒质点数量和尺寸增大,晶界处零星散布离异共晶β相的数量也提高。加入Sb改善了合金的流动性。合金的拉伸强度、塑性、硬度和冲击韧性随着含Sb量的增加而提高,但Sb含量过大时合金的综合力学性能下降。