排序方式: 共有35条查询结果,搜索用时 265 毫秒
1.
原位生长铝基复合材料的工艺研究 总被引:2,自引:0,他引:2
以金属氧化物粉末和铝进行置换反应原理为基础,对挤压铸造法,超声振动反应法制备原位生长的铝基复合材料的工艺进行了探索。光学金相观察和X射线衍射分析表明:挤压铸造过程中,金属氧化物与铝几乎未发生反应,挤压扣的复合材料经进一步热处理后,反应进行完全,得到Al2O3/Al复合材料;热处理后,复合材料的显微硬度值有明显的改变; 相似文献
2.
3.
4.
《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2020,65(11):2467-2474
The purpose of this study was to establish, on a first principles basis, the order of magnitude of energy requirements for a thermally processed, lunar regolith radiation shield constructed using an in-situ resource utilisation (ISRU) approach. This was done by developing a reference scenario habitat and using thermodynamic relationships and specific heat capacity expressions to determine the energy required to bring such a regolith volume up to sintering temperatures (c. 1,375 K). Once the energy requirements were developed some power system architectures were outlined conceptually and a nuclear power plant of c. 400 kW was suggested as a means to supply the necessary energy. This is well beyond current space nuclear applications. The study concludes that it is likely that the most efficient near-term solution is chemical processing of regolith, from an energy requirements perspective. The technology is also more mature and likely to be delivered on near term projects as it does not require such scaled-up power system architectures. Alternatively, bringing storm shelters up with the habitat to provide a means of weathering major solar events, and adding additional radiation protection to habitat quarters, possibly through a water blanket or similar mechanism, could provide a non-ISRU solution with current technology. However, in the longer term, the development of MW-scale power system architectures (fission, solar etc.), may permit a very large volume of material to be processed thermally for construction material, making a large, permanent human presence on the Moon more easily realisable. 相似文献
5.
J.P. Pabari Y.B. Acharya U.B. Desai S.N. Merchant 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
It is known that a wireless sensor network uses some sort of sensors to detect a physical quantity of interest, in general. The wireless sensor network is a potential tool for exploring the difficult-to-access area on the earth and the concept may be extended to space applications in future. Recently, lunar water has been detected by a few lunar missions using remote sensing techniques. The lunar water is expected to be in the form of ice at very low temperatures of permanently dark regions on the moon. To support the remote observations and also to find out potential ice bearing sites on the moon, in-situ measurement of the lunar ice is essential. However, a rover may not be able to reach the permanently shadowed regions due to terrain irregularity. One possibility to access such areas is to use a wireless sensor network on the lunar surface. 相似文献
6.
基于片状Al2O3陶瓷互锁结构强度高的特点,制备出夹杂石墨的高气孔率的Al2O3多孔陶瓷,并通过原位还原在多孔骨架中制备出Ni微粒,形成一种轻质的双损耗陶瓷基吸波材料。通过XRD、FE-SEM和EDS研究了还原温度对多孔吸波材料的组成、微观形貌、元素分布和吸波性能的影响。结果表明,还原温度升温至700 ℃可将多孔网络中Ni完全还原,形成以堆叠互锁Al2O3为基,夹杂片状石墨和孔表面覆盖Ni微粒的双损耗轻质吸波材料。当复合材料厚度为6.5 mm时,最小反射损耗为-35.01 dB,有效吸收带宽达到1.75 GHz。片状Al2O3锁定的石墨片构筑的导电网络,Ni微粒与基体之间的极化效应等共同促进复合材料良好的微波吸收性能。 相似文献
7.
8.
9.
10.