YAN Mingwei (1989-), male, Postdoctor. E-mail: mwyan@ipe.ac.cn
The phase composition and reaction mechanism of aluminum-spinel (Al-MgAl2O4) composite were investigated after being treated at 580℃ for 8 h and 1 700℃ for 3 h in flowing high purity nitrogen. The results show that after being treated at 580℃ for 8 h, the Al-MgAl2O4 composite forms an area phenomenon with the aluminum-aluminum nitride (Al-AlN) core-shell structure in the outside area. When the temperature increases up to a critical value, the Al-AlN core-shell structure in the outside area breaks, Al(l/g) reacts with N2 to form AlN and with O2 to form Al2O(g). This process prompts formation of an MgAl2O4 spinel with stoichiometric ratio that allows decomposition into Al2O3-rich spinel and Mg(g). On the one hand, AlN reacts with Al2O3-rich spinel to form MgAlON spinel, and on the other hand, AlN is transformed into (Mg,Al)(N,O) through the solid solution reaction of Mg(g) and O2(g) into AlN. Phase composition of the inside area is different from the outside area in which MgAlON with flake crystal morphology forms via a gas-gas phase reaction: Al2O(g)+O2(g)+N2(g)+Mg(g)→MgAlON(s) or Al(g)+O2(g)+N2(g)+Mg(g)→MgAlON(s) in which Al2O3-rich spinel doesn't further form MgAlON spinel.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |