The variation of microbial community structure was investigated for the tank bioleaching process of Pb-Zn-Sn chalcopyrite concentrate in the presence of mixed moderately thermophilic bacteria. The parameters, such as ...The variation of microbial community structure was investigated for the tank bioleaching process of Pb-Zn-Sn chalcopyrite concentrate in the presence of mixed moderately thermophilic bacteria. The parameters, such as pH value, solution potential and concentrations of metal ions, were determined by the method of polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） to analyze the succession of microbial community. The results showed that a final copper extraction rate of 85.6% could be obtained after tank bioleaching for 30 d. The Acidithiobacillus caldus was the dominant population with abundance of about 73.80%in the initial stage, then Sulfobacillus thermosulfidooxidans dominated from the 18th day to the end of bioleaching, while the abundance of Leptospirillum ferriphilum changed slightly. A higher solution potential within a certain range and appropriate concentration of ferric ions were essential for this tank bioleaching of chalcopyrite.展开更多
Within the framework of the dynamical cluster decay model （DCM）, the in evaporation cross-sections （σ1n） of cold fusion reactions （Pb and Bi targets） are calculated for ZCN = 104-113 superheavy nuclei. The calc...Within the framework of the dynamical cluster decay model （DCM）, the in evaporation cross-sections （σ1n） of cold fusion reactions （Pb and Bi targets） are calculated for ZCN = 104-113 superheavy nuclei. The calculations are carried out in the fixed range of excitation energy ECN = 15 ± 1 MeV, so that the comparative analysis of reaction dynamics can be worked out. First of all, the fission barriers （Bf ） and neutron separation energies （S1n） are estimated to account the decreasing cross-sections of cold fusion reactions. In addition to this, the importance of hot optimum orientations of β24-deformed nuclei over cold one is explored at fixed angular momentum and neck-length parameters. The hot optimum orientations support all the target-projectile （t,p） combinations, which are explored experimentally in the cold fusion reactions. Some new target-projectile combinations are also predicted for future exploration. Further, the In cross-sections are addressed for ZCN = 104-113 superheavy nuclei at comparable excitation energies which show the decent agrement with experimental data upto ZCN = 109 nuclei. Finally, to understand the dynamics of higher-Z superheavy nuclei, the cross-sections are also calculated at maximum available energies around the Coulomb barrier and the effect of non-sticking moment of inertia （INS） is also investigated at these energies.展开更多
基金Project (51374248) supported by the National Natural Science Foundation of ChinaProject (NCET-13-0595) supported by the Program for New Century Excellent Talents in University,China+3 种基金Project (2012AA061501) supported by the High-tech Research and Development Program of ChinaProject (2010CB630905) supported by the National Basic Research Program of ChinaProject (20120162120010) supported by the Research Fund for the Doctoral Program of Higher Education of ChinaProject (CSUZC2012020) supported by the Open-End Fund for the Valuable in Central South University,China
文摘The variation of microbial community structure was investigated for the tank bioleaching process of Pb-Zn-Sn chalcopyrite concentrate in the presence of mixed moderately thermophilic bacteria. The parameters, such as pH value, solution potential and concentrations of metal ions, were determined by the method of polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） to analyze the succession of microbial community. The results showed that a final copper extraction rate of 85.6% could be obtained after tank bioleaching for 30 d. The Acidithiobacillus caldus was the dominant population with abundance of about 73.80%in the initial stage, then Sulfobacillus thermosulfidooxidans dominated from the 18th day to the end of bioleaching, while the abundance of Leptospirillum ferriphilum changed slightly. A higher solution potential within a certain range and appropriate concentration of ferric ions were essential for this tank bioleaching of chalcopyrite.
基金Supported by the Council of Scientific and Industrial Research(CSIR),in the Form of Research Project Grant No.03(1341)/15/EMR-Ⅱ and to DST,New DelhiINSPIRE-Fellowship Grant No.DST/INSPIRE/03/2015/000199
文摘Within the framework of the dynamical cluster decay model （DCM）, the in evaporation cross-sections （σ1n） of cold fusion reactions （Pb and Bi targets） are calculated for ZCN = 104-113 superheavy nuclei. The calculations are carried out in the fixed range of excitation energy ECN = 15 ± 1 MeV, so that the comparative analysis of reaction dynamics can be worked out. First of all, the fission barriers （Bf ） and neutron separation energies （S1n） are estimated to account the decreasing cross-sections of cold fusion reactions. In addition to this, the importance of hot optimum orientations of β24-deformed nuclei over cold one is explored at fixed angular momentum and neck-length parameters. The hot optimum orientations support all the target-projectile （t,p） combinations, which are explored experimentally in the cold fusion reactions. Some new target-projectile combinations are also predicted for future exploration. Further, the In cross-sections are addressed for ZCN = 104-113 superheavy nuclei at comparable excitation energies which show the decent agrement with experimental data upto ZCN = 109 nuclei. Finally, to understand the dynamics of higher-Z superheavy nuclei, the cross-sections are also calculated at maximum available energies around the Coulomb barrier and the effect of non-sticking moment of inertia （INS） is also investigated at these energies.
