共查询到14条相似文献，搜索用时 125 毫秒
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利用土工合成材料综合测定仪测定了江苏盐城产糙米与不锈钢板、混凝土板、木板三种不同固体界面的摩擦系数。实验结果表明:随着剪切速率(1.33mm/min、2.67mm/min、4.33mm/min、5.20mm/min)的增大,糙米与固体界面的摩擦系数逐渐减小;随着法向压应力(25kPa、50kPa、75kPa、100kPa)的增加,糙米与固体界面的摩擦系数逐渐减小;随着糙米含水率(15.32%w.b、16.24%w.b、17.54%w.b、18.46%w.b)的增大,糙米与固体界面的摩擦系数逐渐增大。根据实验结果,分别拟合出糙米和不锈钢板、混凝土板、木板三种不同固体界面摩擦系数与剪切速率、法向压应力、含水率的关系方程。 相似文献
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稻谷仓壁材料摩擦系数的实验研究 总被引：1，自引：0，他引：1
利用土工合成材料综合测定仪测定了不同法向压应力（25 kPa、50 kPa、100kPa、150 kPa、200 kPa）下稻谷（水分含量为13.55%、15.14%、17.00%、19.19%w.b）与不同仓壁材料（不锈钢板、混凝土板、木板）的摩擦系数。结果表明：稻谷与不锈钢板摩擦系数较小,与混凝土板和木板的摩擦系数较大;随着法向压应力的增大,稻谷与各仓壁材料的摩擦系数均呈不同幅度的减小;随着水分的增大,稻谷与各仓壁材料的摩擦系数增大。根据实验结果,可拟合出摩擦系数与法向压应力、水分含量的关系方程。 相似文献
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小麦堆压缩特性的实验研究 总被引：2，自引：0，他引：2
利用回弹模量仪对小麦堆（河南产）（水分为11.7%,13.33%,15.18%,16.55%,18.18%w.b）的密度和无侧向膨胀压缩体变模量进行了实验测定,实验选定加在样品顶部的压应力为：50 kPa、100 kPa、150 kPa、200 kPa、250 kPa、300 kPa,通过计算得出对应的样品平均竖直压应力为：36.8 kPa、74.8 kPa、110.9 kPa、153.4 kPa、184.7 kPa、221.0 kPa。进而得到样品所受的平均压应力为：18.3 kPa、41.9 kPa、66.7kPa、91.0 kPa、110.9 kPa、133.248 kPa。实验结果表明：在同一水分下,随着平均压应力的增大,小麦堆的密度也增大。在同一水分下,随着平均压应力的增大,小麦堆的体变模量也增大。拟合方程为y=axb,其中参数a、b随水分的不同而变化。 相似文献
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小麦堆体变模量的测定与实验研究 总被引：2，自引：0，他引：2
利用应变控制式三轴仪对小麦的体积压缩和体变模量进行了实验测定,并探讨了围压和水分对体变模量的影响。结果表明:小麦堆的体积随着围压的增大而减小;小麦堆(水分为13.7%、16.4%、18%)的体变模量随着围压(5 kPa～30 kPa)的增大而增大,它们的体变模量的范围分别为173.5 kPa～259.3 kPa、164 kPa～240 kPa、151 kPa～229.4kPa;小麦堆体变模量随着水分的增大而减小,当小麦堆围压为30 kPa,水分为13.7%～18%时,它的体变模量变化范围为223.5 kPa～270 kPa。 相似文献
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The mechanical behavior and mechanism of the interface between structure and coarse grained soil are investigated through simple shear tests on the conditions of bentonite slurry, clay slurry and without slurry, respectively. The results indicate that different kinds of slurry have important influence on shear strength. Compared with the interface without slurry, the shear strength with bentonite slurry reduces by 45% approximately, significantly more than clay slurry which reduces by 10%. The value of the friction angle with bentonite slurry is about 60% of that with clay slurry. Shear displacement increases as upright stress increases when reaches its failure states at the same height, and shear displacement with bentonite slurry is smaller than that with clay slurry when with the same upright stress and height. The upright displacement with bentonite slurry is greater than that with clay slurry under the same upright stress. In addition, shear dilatation is apparent under the low normal stress when without slurry. Otherwise, it appears as shear contraction. 相似文献
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It is vital to get the accurate data of the shear strength parameters of gravel soil with different water content and compactedness before they conduct the stability analysis for gravel soil roadbed. Under several test conditions, a series of direct shear tests were performed by using some gravel soil samples obtained from a selected roadbed which is under the influence of water level fluctuation. The corresponding results show that the gravel soil cohesion increased as the water content of fine soil increases till it meets its peak value, then it will decrease as the water content keeps increase. However, the internal friction angle will decrease slowly with the increase of water content of fine soil in the initial phase, and then it will decrease rapidly as the water content keeps increase. And on the other hand, the fitted shear strength parameters calculated from the test data has been influenced by the pre-load values that used to prepare soil samples, especially for the condition that the pre-load value less than the normal stress value applied in the direct shear test. All in all, the fitted shear parameters will be controlled by the relationship among water content, pre-load value and normal stress. 相似文献
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镉胁迫下硅对水稻生物量及生理特性的影响 总被引：8，自引：0，他引：8
摘 要：通过水培试验,研究了镉胁迫(3 mg/L,以Cd计)下不同加硅量(0、30、60、90 、120mg/L,以SiO2计)对水稻生物量、植株含镉量、过氧化氢酶(CAT)的活性、丙二醛(MDA)和游离脯氨酸(Pro)含量的影响,结果表明：与无硅处理相比,加硅使水稻茎叶鲜重增加11.1%～14.39%,根重增加15.7%～25.7%,株高增加8.0%～13.6%;植株含镉量23.9%～26.5%;叶片CAT活性增加12.3%～16.6%,MDA含量降低18.0%～24.6%,Pro含量降低31.5%～33.7%。加硅处理与对照间的差异均达到5%显著水平。水稻叶片CAT活性与植株镉含量间呈线性负相关关系(r=0.980＊＊,n=5), MDA含量与植株镉含量间呈线性正相关关系(r=0.956＊,n=5),Pro含量与植株镉含量间呈线性正相关关系(r=0.990＊＊,n=5)。上述结果说明,加硅抑制水稻吸收镉,改善水稻逆境生理状况,缓解了镉对水稻的毒害作用,促进了水稻的生长发育。 相似文献