采用广角X射线衍射仪、差示扫描量热仪等测定了β成核剂改性聚丙烯(PP)(β-PP)中β晶含量,研究了β晶含量与PP悬臂梁缺口冲击强度的关系、β成核剂的成核热稳定性及β成核剂对PP结晶速率的影响。结果表明:随着β成核剂用量的增加,PP的...采用广角X射线衍射仪、差示扫描量热仪等测定了β成核剂改性聚丙烯(PP)(β-PP)中β晶含量,研究了β晶含量与PP悬臂梁缺口冲击强度的关系、β成核剂的成核热稳定性及β成核剂对PP结晶速率的影响。结果表明:随着β成核剂用量的增加,PP的抗冲击性能提高,但其冲击强度与β晶含量不成正比;β晶含量与β-PP的结晶度达到平衡时,PP冲击强度最佳,当β成核剂质量分数为0.05%时,β-PP的冲击强度最高,达82.4 k J/m2,此时β晶含量为75.78%,β-PP结晶度为77.3%;加入β成核剂使PP的结晶速率降低,较快的降温速率会减少β晶的形成。展开更多
In the crystalline rock region of the Huangling anticline center located in the eastern part of the Three Gorges of the Yangtze River, 6 typical geological topographical section lines were selected and their paleotopo...In the crystalline rock region of the Huangling anticline center located in the eastern part of the Three Gorges of the Yangtze River, 6 typical geological topographical section lines were selected and their paleotopographies were reconstructed. Based on the difference between the present topography and the paleotopography, the denudation thicknesses of different topographical positions could be calculated. According to the principle of denudation correlated with deposition, the initial denudation age of the crystalline rock was inferred from the sedimentary strata deposited in the Jianghan basin near the Huangling anticline, including crystalline rock gravel from the Huangling anticline, which was about 56.5 MaBP. The widespread and intensive denudation took place at about 2.4 MaBP. On the basis of the above-mentioned initial denudation age (56.5 MaBP) and the denudation thicknesses, the denudation rates of different topographical summit levels, different topographical terrace levels and various watershed systems were calculated. The greatest denudation rate is 49.56 mm/ka. The average denudation rate is 16.97 mm/ka in the crystalline rock region of the Huangling anticline.展开更多
文摘采用广角X射线衍射仪、差示扫描量热仪等测定了β成核剂改性聚丙烯(PP)(β-PP)中β晶含量,研究了β晶含量与PP悬臂梁缺口冲击强度的关系、β成核剂的成核热稳定性及β成核剂对PP结晶速率的影响。结果表明:随着β成核剂用量的增加,PP的抗冲击性能提高,但其冲击强度与β晶含量不成正比;β晶含量与β-PP的结晶度达到平衡时,PP冲击强度最佳,当β成核剂质量分数为0.05%时,β-PP的冲击强度最高,达82.4 k J/m2,此时β晶含量为75.78%,β-PP结晶度为77.3%;加入β成核剂使PP的结晶速率降低,较快的降温速率会减少β晶的形成。
文摘In the crystalline rock region of the Huangling anticline center located in the eastern part of the Three Gorges of the Yangtze River, 6 typical geological topographical section lines were selected and their paleotopographies were reconstructed. Based on the difference between the present topography and the paleotopography, the denudation thicknesses of different topographical positions could be calculated. According to the principle of denudation correlated with deposition, the initial denudation age of the crystalline rock was inferred from the sedimentary strata deposited in the Jianghan basin near the Huangling anticline, including crystalline rock gravel from the Huangling anticline, which was about 56.5 MaBP. The widespread and intensive denudation took place at about 2.4 MaBP. On the basis of the above-mentioned initial denudation age (56.5 MaBP) and the denudation thicknesses, the denudation rates of different topographical summit levels, different topographical terrace levels and various watershed systems were calculated. The greatest denudation rate is 49.56 mm/ka. The average denudation rate is 16.97 mm/ka in the crystalline rock region of the Huangling anticline.
