There was a complete set of cross-polar distributive data of nitrate （NO<sub>3</sub><sup>-</sup>） content inthe surface snow of the Antarctic ice sheet along the route of the 1990 Internation...There was a complete set of cross-polar distributive data of nitrate （NO<sub>3</sub><sup>-</sup>） content inthe surface snow of the Antarctic ice sheet along the route of the 1990 International Trans-Antarctica Expedition. We have shown the profiles of nitrate concentration and flux alongthe route as the plots associated with geomagnetic latitude for further analysis on the展开更多
La1-x Cax MnO3 （x=0-0.3） perovskite-type oxides were synthesized by citrate sol-gel method. The physical and chemical properties were characterized by X-ray diffraction （XRD）, Brumauer-Emmett-Teller method （BET）...La1-x Cax MnO3 （x=0-0.3） perovskite-type oxides were synthesized by citrate sol-gel method. The physical and chemical properties were characterized by X-ray diffraction （XRD）, Brumauer-Emmett-Teller method （BET）, X-ray photoelectron spectroscopy （XPS）, NO＋O2 -TPD （temperature-programmed desorption）, activated oxygen evaluation and H2 -TPR （temperature-programmed reduction） technologies. The results showed that NO catalytic oxidation activity was significantly improved by Ca substitution, especially for lower temperature activity. The La0.9 Ca0.1 MnO 3 sample showed the maximum conversion of 82% at 300 oC. The monodentate nitrates played a crucial role for the formation of NO2 . The reducibility of Mn 4＋ ions and reactivity of activated oxygen were favorable for the catalytic performances of NO oxidation.展开更多
基金Project supported by the National Committee for Antarctic Research of China, the State Commission of Science and Technology of China, and the National Natural Science Foundation of China.
文摘There was a complete set of cross-polar distributive data of nitrate （NO<sub>3</sub><sup>-</sup>） content inthe surface snow of the Antarctic ice sheet along the route of the 1990 International Trans-Antarctica Expedition. We have shown the profiles of nitrate concentration and flux alongthe route as the plots associated with geomagnetic latitude for further analysis on the
基金Project supported by National High Technology Research and Development Program of China(863Program,2011AA03A405)
文摘La1-x Cax MnO3 （x=0-0.3） perovskite-type oxides were synthesized by citrate sol-gel method. The physical and chemical properties were characterized by X-ray diffraction （XRD）, Brumauer-Emmett-Teller method （BET）, X-ray photoelectron spectroscopy （XPS）, NO＋O2 -TPD （temperature-programmed desorption）, activated oxygen evaluation and H2 -TPR （temperature-programmed reduction） technologies. The results showed that NO catalytic oxidation activity was significantly improved by Ca substitution, especially for lower temperature activity. The La0.9 Ca0.1 MnO 3 sample showed the maximum conversion of 82% at 300 oC. The monodentate nitrates played a crucial role for the formation of NO2 . The reducibility of Mn 4＋ ions and reactivity of activated oxygen were favorable for the catalytic performances of NO oxidation.
