YANG Ning (1996-), female, Master candidate. E-mail: yn1547543703@163.com.
A flexible, lightweight and efficient electromagnetic shielding material was prepared with activated carbon fiber felt (ACF) with the density of 0.055 g/cm3. The phase compositions and micro-morphology were characterized by X-ray diffraction and scanning electron microscopy, respectively. The electromagnetic parameters of samples at 8.2-12.4 GHz were examined by a rectangular waveguide method. The results show that high-temperature treatment can improve the degree of carbon ordering in ACF. The conductivity and electromagnetic shielding efficiency of ACF are improved after high-temperature treatment. The total electromagnetic shielding effectiveness of ACF is 39 dB after high-temperature treatment at 1 400℃, which is 23 dB greater than that of the raw material of ACF (i.e., 16 dB). It is indicated that high-temperature treatment could improve the electromagnetic shielding performance of ACF.
| 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 |