排序方式: 共有67条查询结果,搜索用时 265 毫秒
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提高煤田采掘用PCD截齿性能的研究 总被引:2,自引:0,他引:2
为了提高煤田采掘截齿的耐磨性与使用寿命,采用金刚石微粉(W40+W20+W5)与粘结剂(Co、Ni等)按一定的比例均匀混合后,与硬质合金基体装入模具,经真空处理后,装入叶蜡石块,在国产六面顶液压机高温高压条件下进行合成,然后用机械、电火花等方法进行加工,研制出金刚石强化柱齿截齿。采用90-94wt%细颗粒金刚石(400目以细)与6-10wt%粘结剂(B、Ti、Si、Co、Ni等)按一定的比例充分混合后,装入特制石墨模具,进行真空处理后,按一定方式组装成叶蜡石合成块,在国产六面顶液压机高温高压条件下进行合成,合成后对其进行球磨,研制出热稳定性金刚石聚晶截齿。切割试验结果表明,其在花岗岩中切割性能可达硬质合金截齿的150倍。预计在硬岩、中硬岩石中使用金刚石强化柱齿截齿、热稳定性金刚石聚晶截齿是最有前途的。 相似文献
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Several transport parameters (as hydraulic conductivity K, apparent diffusion coefficient Dp and diffusion accessible porosity η of HTO and iodide) have been intensively measured in the laboratory on high-quality cores taken at the Mol-1 borehole of the Mol site, in Belgium. The borehole was cored in 1997 from about 145 to 325 m depth, including the whole thickness of the Boom Formation, a Tertiary clay situated between 186 and 288 m depth (ground level), and part of the surrounding layers.The hydraulic conductivity measurements confirm the low permeability of the Boom Clay. An upper 90-m-thick clay layer within this formation can be considered as homogeneous with respect to the hydraulic conductivity. The vertical hydraulic conductivity Kv (i.e. K perpendicular to the bedding) is in the order of magnitude of 10−12 m s−1 and the average is 2.3×10−12 m s−1. This layer comprises from top to bottom the “Transition Zone”, the Putte Member, the Terhagen Member and the top of the Belsele-Waas Member of the Boom Formation. The 12 m at the base of the Formation, which corresponds to the lower part of the Belsele-Waas Member is characterised by larger Kv values (ranging between 10−11 and 9×10−11 m s−1).The same thick clay layer can also be considered as homogeneous, regarding the values of the apparent diffusion coefficient and the diffusion accessible porosity η of tritiated water (HTO) and iodide. The average value of the diffusion accessible porosity is 0.37±0.03 for HTO and 0.16±0.02 for iodide. The apparent diffusion coefficient varies from 1.1×10−10 to 5.5×10−10 m2 s−1 for HTO and from 9.1×10−11 to 5.2×10−10 m2 s−1 for iodide. 相似文献
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掘进机掘进技术的发展现状 总被引:4,自引:0,他引:4
通过对悬臂式巷道掘进机的发展历史和研制现状的分析,提出了如何确定掘进能力以及选择截割头和截齿的方法,指出了提高掘进机掘进技术需要研究的发展方向。 相似文献
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在全球高端市场中,越野轮胎起重机占移动式起重机40%的市场份额。在国内工程机械领域,越野轮胎起重机是一个极具增长潜力的产品。介绍RT550型越野轮胎起重机主要技术参数、系统构成及技术特点。 相似文献
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