Bioleaching of chalcopyrite with different crystal phases by Acidianus manzaensis

Bioleaching of chalcopyrite with different crystal structures (α-phase,β-phase and γ-phase) by Acidianus manzaensis was comparatively studied by synchrotron radiation based X-ray diffraction (SR-XRD) and S K-edge X-ray absorption near edge structure (XANES) spectroscopy. The α-phase,β-phase and γ-phase chalcopyrite was prepared by heating original chalcopyrite at 583, 773 and 848 K, respectively. Bioleaching results showed that [Cu^2+] in the leaching solution of α-phase,β-phase,γ-phase and original chalcopyrite after 10 days of bioleaching was 1.27, 1.86, 1.43 and 1.13 g/L, respectively, suggesting that β-phase had a better leaching kinetics than others. SR-XRD and XANES results indicated that jarosite and chalcopyrite were the main components in the leaching residues in all cases, and elemental sulfur formed in the early stage of bioleaching. While for β-phase and γ-phase chalcopyrite during bioleaching, bornite was produced in the initial stage of leaching, and turned into chalcocite on day 6.

问题驱动教学法在数值分析课程教学中的研究与实践

通过分析数值分析课程的特点、教学现状以及存在的问题,提出将问题驱动教学法应用到数值分析的教学实践之中,以各种实际的“问题”为导向,将抽象的数学知识具体化,用“问题”来驱动课堂教学,激发学生内在的学习动力,引导他们积极主动地参与到教学的整个过程。