利用箱式电阻炉、SEM等手段,研究了一种定向凝固Co基合金在不同介质中的热腐蚀行为及机理。研究结果表明:合金在Na2SO4中的热腐蚀最为严重,在75%Na2SO4+25%NaCl中的热腐蚀程度最轻。合金在Na2SO4中的热腐蚀过程中主要发生了酸性熔融反应,形成了Al2(SO4)3,Cr2Ni3,Cr4Ni15W和Al4CrNi15等腐蚀产物,而在NaCl中的热腐蚀主要发生了活性氧化反应,合金在75%Na2SO4+25%NaCl中热腐蚀时,部分酸性熔融反应和活性氧化反应受到抑制,主要形成了一系列的Ni-S化合物。National High Technology Research and Development Program of China (863 Program) 2007AA010601; National Natural Science Foundation of China 61070207; LOIS SYSKF1006As secure infrastructural software, secure operating systems are well known for its protection against kinds of threats and attacks. In this paper, we report the work of building EARTH operating system towards to "structurized protection" level of national security standards. EARTH has a flexible architecture supporting dynamic multiple policies, effective mandatory access control mechanism. We give formal system specification and proof of the security models and provide covert channel analysis and mitigation methods. Our experiments show that EARTH has good system performance. Furthermore, the research and development experiences and lessons learned in EARTH project is discussed
