共搜索到8572条信息,每页显示10条信息,共858页。用时:0小时0分1秒75毫秒
supersaturated solid solution, since most of the particles remained in the solid phase during sintering. As the laser beam left, the molten pool subsequently underwent an extremely rapid solidification......
in the cooling rate and a decrease in the solidification time of the molten metal slow down diffusion. This causes an increase in the number, restriction of grain growth, refining and more homogeneous......
改善措施 In基钎料以其优异的低温性能具有良好的应用前景[65].目前,已经有一些针对低温环境的In基钎料投入使用[66],但铟基钎料不仅成本过高,而且其低熔点无法适应太空的大温变环境,具有很大的使用局限性.Sb能够抑制SnCuNi钎料发生灰锡转变,避免组织应力的产生[67].目前,关于改善极低温下无铅钎料可靠性的研究还比较少,需要研究人员加以关注. 图8 -196 ℃存储后......
]主要集中于有关分散元素成矿,超大型矿床成矿,热水沉积盆地成岩成矿,幔汁成矿与地幔柱-热点成矿,后碰撞(伸展)成矿系统,多岛弧盆成矿与陆内转换成矿和成矿系统论等方面. 1) 稀有分散成矿元素成矿理论 分散稀散元素成矿机制奠定了稀有分散元素成矿学的地球化学基础,丰富了矿床学与矿床地球化学理论[3, 20-24].分散稀散元素主要包括镉,锗,硒,铼,碲,铊,铟,硒,镓等,过去一直认为它们不能形成独立矿床......
岩型铜钼金矿床是目前世界铼产量的主要来源.据估计,智利是世界上铼储量最丰富的国家,探明储量为1300 t,占全球储量近50%[4].其次是美国,俄罗斯等国.在我国,相比较镓,锗,铟,镉,铊等稀散金属,铼资源严重不足,保有存量仅有 237t[5],主要分布在黑龙江多宝山,吉林大黑山,陕西金堆城,河南栾川等地[6].几乎所有得铼矿藏均与辉钼矿或硫铜矿伴生存在,且在伴生矿中铼含量仅有1×10-9~1......
, 2000, 26(1): 67?71. [19] XIE Zhi-peng, HUANG Yong, CHEN Ya-li, JIA Yu. A new gel casting of ceramic by reaction of sodium alginate and calcium iodate at increased temperatures[J]. Journal......
mechanics of laser shock peening of novel biodegradable magnesium- calcium alloy[J]. Journal of the Mechanical Behavior of Biomedical Materials, 2010, 3(7): 488-496. [57] OCANA J L, MORALES M, PORRO J......
of Materials Science, 2013, 48(17): 5810-5817. [63] COUILLAOUD S, LU Y F, SILVAIN J F. Thermal conductivity improvement of copper–carbon fiber composite by addition of an insulator: calcium hydroxide[J......
ultra-thick gypsum-salt layer in the Paleogene Kumugeliemu Formation [7, 34, 54]. Calcium sulfate and magnesium sulfate are the major components of this gypsum-salt layer, and potassium and sodium salts......
are as follows [34]: (2) (3) where κ is the amount of bound water; v is the ratio of calcium to silicon (C/S), which is related to temperature, water-cement ratio, and other......