排序方式: 共有63条查询结果,搜索用时 15 毫秒
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用自制的带甲基侧基的环氧树脂(TMBP)作为界面增容剂, 从拉伸性能、键合胶含量、动态性能、扫描电镜和流变性能等方面, 研究了TMBP对炭黑在丁苯橡胶中分散度的影响, 并与市售通用双酚A型环氧树脂(E-51)和橡胶工业常用软化剂邻苯二甲酸二辛酯(DOP)进行了比较. 结果表明, 带甲基侧基的环氧树脂TMBP在提高炭黑分散性方面的效果远比E-51好, 其作用模式具有典型的增容特性. 相似文献
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采用硅氢加成反应制备了2-(3,4-环氧环己基)乙基三乙氧基硅烷(ETEO),用ETEO对纳米SiO_2进行表面接枝得到新型硅基纳米SiO_2(ETEO-SiO_2),并制备环氧树脂/ETEO-SiO_2复合涂层.利用傅里叶变换红外光谱(FTIR)、氢核磁共振谱(~1H NMR)与X射线光电子能谱分析(XPS)对ETEO和ETEO-SiO_2进行了表征.场发射扫描电子显微镜(FESEM)观察到ETEO-SiO_2涂层横截面粗糙,ETEO-SiO_2具有良好分散性.接触角分析表明ETEO-SiO_2涂层疏水性提高.利用电化学阻抗实验与盐雾实验研究了复合涂层的防腐蚀性能,结果表明,添加ETEO-SiO_2纳米粒子后涂层的防腐蚀性能远优于纯环氧树脂和纳米SiO_2复合环氧树脂涂层,当ETEO-SiO_2纳米粒子添加量达到4%(质量分数)时,防腐蚀性能最佳.纳米SiO_2表面接枝ETEO后,ETEOSiO_2纳米粒子与环氧树脂基体之间的相容性增加,分散稳定性提高,涂层更加致密,减少了腐蚀介质所需的扩散通道并抑制腐蚀反应过程的进行,提高了复合涂层的防腐蚀性能. 相似文献
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佝偻病患者的全血微量元素分析 总被引:5,自引:2,他引:5
为探讨佝偻病与血微量元素的关系,检测了326例佝偻病患儿全血微量元素水平。结果显示,本组佝偻病40.1%的病例血锌低于第25百分位数值,病情严重组的血锌值明显低于病情较轻组,且有统计学意义,按全血锌百分位数值分布及结合资料,显示病情愈重低血锌病例愈多;病情较轻组的铁水平较病情严重组低,且有统计学意义,按全血铁百分位数值分布及结合资料亦显示,病情严重的佝偻病组铁在中位数以上的病例数较病情较轻的佝偻病组多,有统计学意义;本组佝偻病69.6%的病例血铅含量超过100μg/L,病情严重组的血铅值明显高于病情较轻组,且有统计学意义,按全血铅百分位数值分布结合资料,显示病情愈重高血铅的病例愈多。提示佝偻病的治疗需提高血锌水平及防治铅中毒。 相似文献
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Cao Li-Ping 《Frontiers of Physics》2015,10(4):107801
The optical absorption properties of femtosecond-laser-made “black silicon” as a function of the annealing conditions were investigated. We found that the annealing process changes the surface morphology and absorption spectroscopy of the “black silicon” samples, and obtained a maximum sub-band-gap absorptance value of approximately 30% by annealing at 1000 °C for 30 min. The thermal relaxation and atomic structural transformation mechanisms are used to describe the lattice recovery and the increase and decrease of the substitutional dopant atom concentration in the microstructured surface during the annealing. Our results confirm that: i) owing to the thermal relaxation, the lattice defects decrease with the increase of the annealing temperature; ii) the quasi-substitutional and interstitial configurations of the doped atoms transform into substitutional arrangements when the annealing temperature increases; iii) the quasi-substitutional and interstitial configurations with higher energies of the doped atoms transform into interstitial configurations with the lowest energy after high-temperature annealing for a long period of time, causing the deactivation or reactivation of the sub-band-gap absorptance by diffusion. The results demonstrate that the annealing can improve the properties of “black silicon”, including defects repairing, carrier lifetime lengthening, and retention of a high absorptive performance. 相似文献
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