以7249高强铝合金为研究对象,通过OM、晶间腐蚀及剥落腐蚀测定等测试手段,分析探讨了稀土Ce添加量对7249铝合金晶间腐蚀及剥落腐蚀性能的影响。结果表明:当稀土的添加量为0.0
班干部是协助教师管理班级的群体,班干部权力不但对班级的正常运行有很大的影响,并且对班干部自身和其他同学的发展也有重要的影响。班干部权力的形成有多种因素,对其进行探
利用金相显微镜和微型拉伸试验机对SAC305-Bi钎料合金的润湿性、组织和力学性能进行了研究。结果表明:SAC305-Bi钎料合金的润湿性随着Bi元素含量的提高而逐渐提高;当Bi元素含
Primary production, bacterial production, par-ticulate organic carbon fluxes and organic carbon burial rates were quantified during the summer period of 1999 in
利用PCVD复合渗镀技术对W6Mo5Cr4VZ(MZ)高速钢刀具进行表面强化处理。研究了未处理及PCVD复合渗镀处理高速钢刀具的表面显微硬度,分析了PCVD前后高速钢刀具的摩擦磨损性能及
Based on the analyses of hydrocarbon inclu-sions, K-Ar dating of authigenic illites and oil/gas-watercontact retrospection as well as other methods, the marine
This paper describes the relative contents of dominant diatom species and the distributive characteristics of tropical pelagic species and diatom assemblages, a