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presented in Ref. [52] consists of a wrapped screen mesh, made of single-plaited stainless steel. Stainless steel is a steel alloy composed of iron and different proportions of chromium, which is responsible......
and Zr-based coating systems. 3.1.1 SiC coating Due to its outstanding oxidation resistance, low neutron absorption cross section, high thermal stability and good compatibility with C/C composites, SiC... to the excessive consumption of the outer Cr-Al-Si alloy coating and there are also some defects appearing in the SiO2 glass layer. SHI et al [67] prepared a La-Mo-Si-O-C coating on the surface of porous SiC pre......
testing procedure. In addition, it is environmentally significant to carry out this research as the silica fume is the waste from the metal and alloy production industry, while nano- silica can......
100%的Cu和95%的Li被浸出,Mn的浸出率也超过了70%,而Al,Ni以及Co的浸出率只有40%左右.经分析发现,黑曲霉代谢活动中产生的有机酸主要包括柠檬酸,苹果酸,草酸和葡萄糖酸等,其中柠檬酸对金属的浸出率贡献最大. 尽管通过一些离子的催化作用或者改变菌种体系可以使一些金属的浸出率显著提高,但生物浸出方法仍然难以在工业中大规模应用,其原因是:一方面,菌种难培养不易存活,对生长环境要求高;另...现Co,Ni以及Cu的高效浸出,而Mn和Al基本不被浸出. 2.5 辅助强化浸出 一般地,酸浸出和氨浸出都需要较长的浸出时间和较高的浸出温度.为了提高金属的浸出效率,可采用一些辅助方法来增强浸出.常见的辅助浸出手段有超声辅助以及机械化学辅助[71-72]. JIANG等[71]以H2SO4作为浸出剂,H2O2作为还原剂从废旧LiCoO2中浸出Li和Co.在浸出温度为30 ℃和浸出时间为30 min......
算 常用的载氧体为Fe,Co,Ni,Cu和Mn的氧化物,在600~1 200 ℃下CH4与常见氧化物的反应热力学数据如图3所示,lg K越大说明金属氧化物与CH4反应越容易,MnO2/Mn2O3,Mn2O3/Mn3O4,Co3O4/CoO,CuO/Cu2O比Fe2O3/Fe3O4和NiO/Ni更容易氧化CH4,并且Fe2O3/Fe3O4,Mn2O3/Mn3O4,CuO/Cu2O和NiO/Ni都可以...可以提高载氧体的反应活性[68].IMTIAZ等[69-70]使用Cu改性的铁基载氧体,Cu0可以促进FeO还原到Fe0,并且Cu覆盖在表面有利于提高载氧体的抗积碳性能,QIN等[71]使用1%的Cu改性铁基载氧体,在700 ℃时CH4转化率是未改性载氧体的470%.稀土金属如La,Ce和Y等也被用于改性铁基载氧体,KANG等[72]发现Y改性的Fe2O3/Al2O3载氧体CH4转化率达98%的同......
alloy surface is more conducive to the proliferation of osteoblasts [22]. Table 3 Effects of sintering temperature on porosity, density, and flexural properties of 3DP HAAW composites Table 4......
度要求较高[40]. 而后,Hylsa公司又基于HYL-Ⅲ工艺开发了HYL-ZR工艺,该工艺可以直接使用焦炉煤气,煤制气等富氢气体,为富煤缺气的地区发展气基直接还原工艺开辟了新路径. 与Midrex工艺相比,采用V(H2)/V(CO)=1的煤制气生产1 t海绵铁产品,还原气消耗量增加约100 m3,而能量利用率提高约3.3%[35].周渝生等[44]认为,中国的能源结构适合发展以煤气为气源的气基直... ℃条件下还原钛铁矿,反应初始的1 h时间内,低H2压力下还原反应速率更高,随着反应的进行,则需要提高H2压力才能保持与初始相当的还原反应速率. ZHAGN等[66]采用H2辅助镁热还原TiO2制备了钛金属粉末.由于钛对氧具有极强的亲和力,Mg难以直接还原TiO2,而高温条件下Ti-H-O固溶体稳定性低于Ti-O固溶体,因此,可采用H2气氛增强Mg与Ti-O反应的热力学驱动力,通过镁的进一步脱氧作用......
forces from rock blocks. Cutters today can either incorporate hard, fine grained carbides into the matrix of the disc material or apply a hardened coating of alloy powder on the steel substrate......