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阴离子交换纤维的制备及吸附Cr(VI)性能研究 总被引:2,自引:0,他引:2
采用共辐射引发接枝共聚法在聚丙烯纤维上接枝苯乙烯-二乙烯苯,通过氯甲基化反应和胺化反 应制备强碱性阴离子交换纤维。当单体体积分数为20%-25%,辐射剂量率为1.2~1.8 kGy/h时,接枝率 可以控制在150%~250%。当氯甲基化反应温度(38±2)℃,反应时间15~25 h,胺化反应温度(30±2)℃, 反应时间15-20 h时,制备的强碱性阴离子交换纤维交换容量达到3.00 mmol/g以上。将该纤维对Cr(Ⅵ) 进行吸附试验,结果纤维对Cr(Ⅵ)的吸附以液膜扩散为主,吸附速度很快,8 min可达到吸附饱和,吸附反应 速率常数为0.015 s-1,静态吸附饱和容量为257.6 mg/g,吸附行为符合Freundlish等温吸附模型。 相似文献
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To increase the detectability of split Hopkinson pressure bar (SHPB) of low-impedance materials, modifications were conducted on traditional SHPB apparatus with a PMMA tube to output transmitted signal, and weak signals were further amplified by semiconductor strain gauges. Experiments on soft rubbers and cushioning foam materials were carried out. In order to analyze the accuracy of the experimental results, the stress equilibrium issues involved in the assumptions of SHPB were investigated. First, by way of re-constructing loading process of incident wave, the stress-strain curve was obtained, along with the stress equilibrium ratio of specimen. Secondly, the influences on the accuracy of stress-strain curves were investigated through the elastic modulus comparisons. And the results illustrate that the bilinear incident wave from experiments can ensure the stress equilibrium deformation of specimen after 2 normalized times, much sooner than ramp incident waves. Moreover, it even facilitates specimen deformation with a constant strain rate. The results confirm that the detectability of the modified SHPB can be down to tens kPa with enough accuracy level. 相似文献
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云南建工第五建设有限公司(以下简称云南建工五建公司)是原云南省第五建筑工程公司经云南省国资委批复改制成的国有控股有限公司,具有国家房屋建筑施工总承包一级、市政公用工程总承包一级、消防设施工程专业承包一级、机电设备安装工程专业承包一级、体育场地设施工程专业承包一级、钢结构工程专业承包二级、混凝土预制构件专业承包二级、起重设备专业承包三级资质,主要从事工业与民用建筑施工,是集建筑施工、房地产开发、建筑材料生产等为一体的综合性建筑施工企业。云南建工五建公司几经演变,每一时期都审势度时,调整战略,在改革中不断发展壮大,始终处于云南省建筑行业的领先地位。 相似文献
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针对交通标志识别算法识别精度低、计算复杂度高等问题,提出一种采用组合矩特征分类交通标志的方法。首先对图像进行预处理,并基于颜色特征分割,再采用形态学的方法处理粗分割图像,从而提取目标区域。然后分别提取标志图像的Legendre矩及小波矩特征,利用串行特征融合技术获取组合优化特征,将特征值输入渐进直推式支持向量机,并采用模拟退火算法对其进行参数优化,最后使用优化后的识别算法实现目标图像的识别。仿真结果表明,与现有的其他交通标志识别算法相比,采用组合矩与优化后渐进直推式支持向量机的识别方法有更好的识别效果。 相似文献
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