Coexisting quartz, feldspar and biotite vary widely in their δ18O values and display a remarkable 18O/16O disequilibrium relation; especially, a quartz-feldspar reversal (△ 18OQUartz_feldspar< 0) exsists in the A...Coexisting quartz, feldspar and biotite vary widely in their δ18O values and display a remarkable 18O/16O disequilibrium relation; especially, a quartz-feldspar reversal (△ 18OQUartz_feldspar< 0) exsists in the Aral granite pluton of the Altay Mountains, northern Xinjiang. The 18O / 16O exchange reaction definitely occurred between granite and water. Initial δ18O values of the granite and exotic fluid are evaluated by the mass balance consideration. The conventional method of discrimination between various magma derivations simply with δ18O values of either whole rock or separate minerals is misleading and unreliable. Experiments carried out by the authors show that the 18O / 16O exchange reaction is not accompanied by what geologists describe as petrological and mineralogical alteration effect. This decoupling relation implies that exchange reaction occurs at a relatively high temperature during subsolidus-postmagmatic cooling of magmas. The exchange mechanism is mainly diffusion-controlled. It is demonstrated through quantitative modelling that the hydrothermal system associated with the Aral pluton is long-lived (0.8-6 Ma), with a relatively high fluid flow rate (3 ×10-14 mol. s-1) and high W/ R ratio (0.79-6.14). This means that an intense flow and convection may exist at the midcrustal level of erogenic magmatic arcs.展开更多
Oxygen atom exchange reaction mechanism in the reaction of OH radicals with AsO was investigated by means of the density functional theory (DFT) with 6 311++G( 3df,3pd ) and 6 311++G( d,p ) basis sets. The calcu...Oxygen atom exchange reaction mechanism in the reaction of OH radicals with AsO was investigated by means of the density functional theory (DFT) with 6 311++G( 3df,3pd ) and 6 311++G( d,p ) basis sets. The calculated results suggest that the reaction between OH and AsO should make the oxygen atoms exchange rapidly because the barrier to isomerization is significantly less than the HO-AsO bond dissociation energy.展开更多
In this study,we present the development of microtubular solid oxide fuel cells(MT-SOFC)with a two-layer cathode:a composite cathode functional layer(CFL)adjacent to the buffer layer(BL)and a cathode current-collectin...In this study,we present the development of microtubular solid oxide fuel cells(MT-SOFC)with a two-layer cathode:a composite cathode functional layer(CFL)adjacent to the buffer layer(BL)and a cathode current-collecting layer(CCCL).CFL consists of a mixture of BL material Ce_(0.9)Sm_(0.2)O_(1.95)(SDC)and perovskite Ba_(0.5)Sr_(0.5)Co_(0.75)Fe_(0.2)Mo_(0.05)O_(3-δ)(BSCFM5),which has a high exchange rate with oxygen.The widely used cathode material La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(LSCF)with high electrical conductivity was used as the CCCL.A significant increase in the peak power density of the MT-SOFC to 1.2 W/cm^(2)at 850℃ was achieved using the proposed two-layer cathode.展开更多
基金This research was supported by the National Natural Science Foundation of China (grant No. 49373164)the President's Funds of the Chinese Academy of Sciences
文摘Coexisting quartz, feldspar and biotite vary widely in their δ18O values and display a remarkable 18O/16O disequilibrium relation; especially, a quartz-feldspar reversal (△ 18OQUartz_feldspar< 0) exsists in the Aral granite pluton of the Altay Mountains, northern Xinjiang. The 18O / 16O exchange reaction definitely occurred between granite and water. Initial δ18O values of the granite and exotic fluid are evaluated by the mass balance consideration. The conventional method of discrimination between various magma derivations simply with δ18O values of either whole rock or separate minerals is misleading and unreliable. Experiments carried out by the authors show that the 18O / 16O exchange reaction is not accompanied by what geologists describe as petrological and mineralogical alteration effect. This decoupling relation implies that exchange reaction occurs at a relatively high temperature during subsolidus-postmagmatic cooling of magmas. The exchange mechanism is mainly diffusion-controlled. It is demonstrated through quantitative modelling that the hydrothermal system associated with the Aral pluton is long-lived (0.8-6 Ma), with a relatively high fluid flow rate (3 ×10-14 mol. s-1) and high W/ R ratio (0.79-6.14). This means that an intense flow and convection may exist at the midcrustal level of erogenic magmatic arcs.
基金Supported by the National Natural Science Foundation of China(No.2 0 1710 15 2 0 1710 16 ) +1 种基金the Natural SicenceFoundation of Heilongjiang Province of China(No.E0 0 - 16 ) the Science Foundation for Excellent Youth of HeilongjiangU niversity(2 0
文摘Oxygen atom exchange reaction mechanism in the reaction of OH radicals with AsO was investigated by means of the density functional theory (DFT) with 6 311++G( 3df,3pd ) and 6 311++G( d,p ) basis sets. The calculated results suggest that the reaction between OH and AsO should make the oxygen atoms exchange rapidly because the barrier to isomerization is significantly less than the HO-AsO bond dissociation energy.
基金Foundation(project N◦21-79-30051)funded this project.
文摘In this study,we present the development of microtubular solid oxide fuel cells(MT-SOFC)with a two-layer cathode:a composite cathode functional layer(CFL)adjacent to the buffer layer(BL)and a cathode current-collecting layer(CCCL).CFL consists of a mixture of BL material Ce_(0.9)Sm_(0.2)O_(1.95)(SDC)and perovskite Ba_(0.5)Sr_(0.5)Co_(0.75)Fe_(0.2)Mo_(0.05)O_(3-δ)(BSCFM5),which has a high exchange rate with oxygen.The widely used cathode material La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(LSCF)with high electrical conductivity was used as the CCCL.A significant increase in the peak power density of the MT-SOFC to 1.2 W/cm^(2)at 850℃ was achieved using the proposed two-layer cathode.
