共搜索到16428条信息，每页显示10条信息，共1643页。用时：0小时0分0秒443毫秒
Heavy metals contamination characteristics in soil of different mining activity zones LIAO Guo-li(廖国礼)1, LIAO Da-xue(廖大学)2, LI Quan-ming(李全明)1 1. Mine Safety Technology Institute, China Academy... and other relevant methods. The results indicate that the average contents of Zn, Pb, Cd, Cu and As in soils are 508.6, 384.8, 7.53, 356 and 44.6 mg/kg, respectively. But the contents of heavy metals......
......
Influence of confining stress on fracture characteristics and cutting efficiency of TBM cutters conducted on soft and hard rockLIU Jing-shuo(刘京铄), CAO Ping(曹平), LIU Jie(刘杰), JIANG Zhe(蒋喆) (School... conditions and cutting efficiencies of soft and hard rock has been conducted on the triaxial testing machine (TRW-3000) designed and manufactured in Central South University (China). Results are obtained......
Co更有利于提高金属陶瓷的硬度,而Ni则能提供更好的抗弯强度和断裂韧性. REFERENCES [1] ETTMAYER P, KOLASKA H, LENGAUER W, DREYER K. Ti(C, N) cermets-metallurgy and properties[J]. International Journal of Refractory Metals Hard..., ROLANDER U, STALS L, ANDR?N H O. Microstructure of model cermets with high Mo or W content[J]. International Journal of Refractory Metals & Hard Materials, 1999, 17(6): 411?421. [15] 刘 宁. Ti(C, N......
of hard rock pillars brittle failure[2-3] 以MARTIN[8],KAISER等[16],DIEDERICHS[19]为代表的加拿大学者通过对Mine-by(AECL’s URL)实验隧洞系统研究之后得出:低围压下高应力硬岩的原位强度就是室内岩样的裂纹起裂强度,即UCSfield为0.3σc~0.5σc=σci.上述结论是目前硬岩脆性破坏的主要观点,具体含义:张拉裂...破坏单元的应力路径发生明显偏转直至最终破坏.这可能是剪切带形成后V形破裂区最大主应力逐渐释放所引起. 图12 不同卸荷速率下矿柱的破坏模式 Fig. 12 Failure modes of hard rock pillars under different unloading rates 图13 不同均质度下矿柱的破坏过程 Fig. 13 ......
Fusion Equation of Metals洪永炎摘 要:<正> An expression of initial slope of meltingcurve of pure metals was obtained as follows:(dTm/dP)o=Tmo/c, where c... forthirty-one metals agree well with experiments.It has also been proved that by using the freeelectron model of melting, the fusion equationof metals is Simon equation (Tm/Tmo)q=1+(p/d).Two parameters q......
and prospect of mining technology in hard rock mines[J]. The Chinese Journal of Nonferrous Metals, 2019, 29(9): 1828-1847. [4] 李毅中. 谈谈我国的安全生产问题[EB/OL]. http:// www.gov.cn/gzdt/2006-07/01/content... mining design for high stress hard-rock deposit based on inducing fracturing mechanism[J]. Transactions of Nonferrous Metals Society of China, 2012, 22(9): 2241-2247. [42] 刘 学, 郑军卫, 赵纪东, 王立伟. 国际矿产资源科技政策发展历......
; microstructural characteristics; dissimilar metals welding 1 Introduction Magnesium alloys are the lightest metallic materials, have the lowest density and exhibit high specific strength, good.... This process eliminates the adverse influence of single joining technique on both materials and thus could offer an alternative method for joining these dissimilar metals. In this study, joining of a magnesium......
......
3-D numerical modelling of domino failure of hard rock pillars in Fetr6 Chromite Mine, Iran, and comparison with empirical methodsS. Dehghan1, K. Shahriar2, P. Maarefvand2, K. Goshtasbi3(1... to be the most important causes of the Domino failure in this mine.Key words:hard rock; domino failure; numerical modelling; empirical method; stope; pillar; extraction ratio; W/H ratio......
