排序方式: 共有75条查询结果,搜索用时 15 毫秒
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通过黄河泥沙的活性指数(PAI)和活性率(K)以及黄河泥沙基生土砌块的抗压强度和软化系数,来评价CaCl_2,CaCl_2与水玻璃复合激发剂对黄河泥沙的活化效果,并通过FTIR和XRD分析了CaCl_2的活化机理.结果表明:CaCl_2与水玻璃质量比为1∶1的复合激发剂能够明显改善黄河泥沙的反应活性,其用量为6%(质量分数)时,胶砂试件的活性指数达到0.63;CaCl_2通过Ca~(2+)与黏粒中Na~+的离子交换作用,加速黏土矿物的水解并释放出硅铝离子,从而提高黄河泥沙的反应活性,改善黄河泥沙基生土砌块的力学性能. 相似文献
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The complex nature of laser-material interaction causes non-stoichiometric ablation of alloy samples.This is attributed to matrix effect, which reduces analyzing capability. To address this issue, the analytical performance of three different normalization methods, namely normalization with background, internal normalization and three point smoothing techniques at different parameter settings is studied for quantification of Ag and Zn by Laser induced breakdown spectroscopy(LIBS).The LIBS spectra of five known concentration of silver zinc binary composites have been investigated at various laser irradiances(LIs). Calibration curves for both Ag(I) line(4d~(10)5s~2S_(1/2)→4d~(10)5p~2P_(1/2) at 338.28 nm) and Zn(I) line(4s5s~3S_1→4s4p~3P_2 at 481.053 nm) have been determined at LI of 5.86?×?10~(10)W cm~(-2). Slopes of these calibration curves provide the valuation of matrix effect in the Ag–Zn composites. With careful sample preparation and normalization after smoothing at optimum parameter setting(OPS), the minimization of sample matrix effect has been successfully achieved. A good linearity has been obtained in Ag and Zn calibration curve at OPS when normalized the whole area of spectrum after smoothing and the obtained coefficients of determination values were R~2?=?0.995 and 0.998 closer to 1. The results of matrix effect have been further verified by analysis of plasma parameters. Both plasma parameters showed no change with varying concentration at OPS. However, at high concentration of Ag, the observed significant changes in both plasma parameters at common parameter setting PS-1 and PS-2 were the gesture of matrix effect. In our case, the better analytical results were obtained at smoothing function with optimized parameter setting that indicates it is more efficient than normalization with background and internal normalization method. 相似文献
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以热活化氧化铝赤泥为主要原料制备赤泥地聚物砂浆,对比研究了激发剂种类和掺量对赤泥地聚物力学性能的影响及其合成机理。结果表明,水玻璃、石灰-碱(质量比为2∶1)、石膏-碱(质量比为2∶1)均能改善氧化铝赤泥的反应活性,促进赤泥地聚物的合成,其中水玻璃(氧化硅与氧化钠物质的量比为1.5)的改性效果最为显著。水玻璃、石灰-碱、石膏-碱的最佳掺量分别为20%、7%、10%。水玻璃掺量为20%时,赤泥地聚物砂浆28 d抗压强度和28 d抗折强度分别为32.1 MPa和6.0 MPa。改变激发剂的种类和掺量,可以调整赤泥地聚物砂浆体系的碱度,改变铝硅酸结构的解聚和地聚物的缩聚过程,从而影响其力学性能。 相似文献
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通过超高性能纤维混凝土坍落度和力学性能试验,研究了纤维种类和掺量对其工作性和弯拉性能的影响,并探讨了钢纤维与聚乙烯醇纤维的混杂效应对其抗压强度、折压比和拉压比的影响。结果表明:纤维明显降低超高性能混凝土的工作性;超高性能纤维混凝土的抗压强度随钢纤维的掺量提高变化不大,随聚乙烯醇纤维的掺量增大而显著降低;钢纤维和聚乙烯醇纤维均能改善超高性能混凝土的弯拉性能;超高性能钢-聚乙烯醇混杂纤维混凝土对超高性能钢纤维混凝土的折压比和拉压比的增益比随着钢纤维掺量的提高而增加,钢纤维与聚乙烯醇纤维在改善超高性能混凝土弯拉性能上具有良好的协同效应。 相似文献
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通过未改性生土材料、水泥改性生土材料、黄麻改性生土材料和水泥/黄麻复合改性生土材料的毛细吸水试验,研究了改性方法对生土材料毛细吸水速率、毛细吸收系数和表面渗入深度等水分传输参数的影响及其作用机理.结果表明:生土材料的毛细吸水量与时间平方根呈线性关系;水泥改性生土材料的毛细吸收系数和初始吸水速率较未改性生土材料的毛细吸收系数和初始吸水速率分别降低19.8%和25.3%,而黄麻改性生土材料的毛细吸收系数和初始吸水速率分别提高了43.4%和26.2%;黄麻纤维明显提高了生土材料水分的表面渗入深度;水泥改变了黄土颗粒表面状态和生土材料的孔结构,从而影响了生土材料的水分传输特性. 相似文献