全文获取类型
收费全文 | 57篇 |
免费 | 3篇 |
专业分类
电工技术 | 15篇 |
综合类 | 2篇 |
化学工业 | 6篇 |
金属工艺 | 3篇 |
机械仪表 | 3篇 |
建筑科学 | 6篇 |
轻工业 | 6篇 |
石油天然气 | 3篇 |
无线电 | 2篇 |
冶金工业 | 9篇 |
自动化技术 | 5篇 |
出版年
2021年 | 1篇 |
2020年 | 3篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 1篇 |
2012年 | 3篇 |
2011年 | 11篇 |
2010年 | 5篇 |
2009年 | 1篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 1篇 |
2004年 | 3篇 |
2002年 | 6篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有60条查询结果,搜索用时 187 毫秒
41.
The electrodes for hardfacing medium carbon steel with six additions of rare earth oxide were developed in this work. By means of optical microscopy and scanning electron microscopy, the microstructure, inclusion and the fractograph of the hardfacing metal were observed. Then, the effects of rare earth oxide on microstructure and inclusions in hardfacing metal were analyzed. The effectiveness of rare earth oxide as heterogeneous nuclei of δ-Fe was calculated with the misfit theory. The results showed that, the microstructure of hardfacing metal was composed of ferrite and small amount of pearlite. The microstructure was refined at first and then coarsened with the increase of rare earth oxide addition. The fractograph was changed from brittle to equiaxed dimples, then became quasi-cleavage and cleavage gradually. The calculated results showed that, the ferrite grain size could be refined because that LaAlO3 as heterogeneous nuclei of δ-Fe was moderately effective, and the ferrite grain size was coarsened because the misfits between Ce2O3 and δ-Fe, Ce2O2S and δ-Fe were increased with futher increase of rare earth oxide addition. 相似文献
42.
简述了PVC管材配方设计的关键因素润滑剂的特性及其对混料、生产工艺、产品质量的影响,并通过生产实践证实了润滑体系在生产中的重要性. 相似文献
43.
44.
The flux cored wires with different rare earth oxide additions for hardfacing the workpieces of medium-high carbon steel were developed. The microstructure of the hardfacing layer was observed using the optical microscopy. The average dimension of primary austenite grains in hardfacing layer was measured by image analyzer. The primary austenite grain growth activation energy and index were calculated according to Sellars’s mode and Beck formula, respectively. Moreover, the effect of rare earth oxide on the growth dynamics of primary austenite grain was analyzed, and then discussed with the misfit theory. The experimental results showed that, by adding rare earth oxide, the average dimension of primary austenite grains in hardfacing layer of medium-high carbon steel decreased, and it was the smallest when the addition of rare earth oxide was 5.17 wt.%. Meanwhile, at this rare earth oxide addition, the primary austenite grain growth activating energy in hardfacing layer was the largest, while its index was the smallest. The calculated results indicated that the primary austenite grain could be refined because LaAlO3 as heterogeneous nuclei of γ-Fe was the most effective. 相似文献
45.
46.
纳米金刚石无助剂烧结的可行性分析 总被引:2,自引:0,他引:2
本文主要阐述了金刚石烧结的目前国内外研究现状,比较了国内外烧结的异同点及其优缺点。参阅大量中外文献,分析了纳米金刚石的一些特性,及用纳米金刚石无助剂烧结需要解决的问题,分析了纳米金刚石无助剂烧结的可行性。分析表明,消除吸附物,利用纳米金刚石众多的悬键、合理的工艺条件相结合,是可以实现无助剂烧结的。 相似文献
47.
48.
49.
50.