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1.
Shear-box test with strain measurement was used to study time-dependent stress and strain of in-plane shear(Mode Ⅱ) fracture process of rock and to reveal the mechanism of Mode Ⅱ fracture.Numerical results show that the maximum shear stress τmax at the crack tip is much larger than the maximum tensile stress σ1 and the ratio of τmax/σ1 is about 5,which favors Mode Ⅱ fracture of rock.Test results indicate that the strain—time curve comprises three stages:the linear deformation stage,the micro-cracking stage ... 相似文献
2.
In order to study the effect of PVA fiber on the dynamic and static mechanical properties of low-temperature freeze-thaw concrete under the saturated surface dry state, different contents of PVA fiber were added to prepare concrete in this experiment. The concrete was subjected to compression, flexural and SHPB impact tests combined with scanning electron microscopy for microstructure analysis, after different times of freeze-thaw cycles in the temperature range of 20--70℃. The experimental resu... 相似文献
3.
Ｉｎｂｉｏｈｙｄｒｏｍｅｔａｌｌｕｒｇｙ ,Ｔ .ｆｅｒｒｏｏｘｉｄａｎｓｉｓｏｎｅｏｆｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｍｉｃｒｏｏｒｇａｎｉｓｍｓ[1]ｆｏｒｔｈｅｅｘｔｒａｃｔｉｏｎｏｆｂａｓｅｍｅｔａｌｓｉｎｃｌｕｄｉｎｇｃｏｐｐｅｒ[2～ 4 ],ｎｉｃｋｅｌ[5,6 ],ｚｉｎｃ[7],ｌｅａｄ[8]ｅｔｃ ,ａｎｄｔｈｅｐｒｅｔｒｅａｔｍｅｎｔｏｆａｒｓｅｎｉｃｒｅｆｒａｃｔｏｒｙｇｏｌｄｏｒｅｓ[9～ 12 ].ＴｈｅｓｔｕｄｉｅｓｏｎｔｈｅｇｒｏｗｔｈｏｆＴ .ｆｅｒｒｏｏｘｉｄａｎｓｈａｖｅｂｅｅｎｃｏｎｄｕｃｔｅｄ… 相似文献