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利用密度泛函理论在B3LYP方法6-31G水平上对α-直链烯烃在TiCl3/AlEt2Cl催化体系的链增长规律进行了相应的计算.对反应物、产物以及各种可能的中间体和过渡态进行了全参数优化,在同一理论水平上对势能面上的全部驻点进行了振动频率分析,并从过渡态分别向反应物和产物方向进行了内禀反应坐标计算.计算结果表明,在TiCl3/AlEt2Cl催化剂优化的构型上首先形成配位化合物,进而形成过渡态,过渡态与配位化合物的能量差为40.687 kJ/mol,最后是双键打开和Ti-C(4)断裂,从而完成整个聚合反应历程.计算结果也初步表明随着α-直链烯烃碳原子数的增加,链增长机理未发生本质变化.由聚合反应活化能与α-直链烯烃碳原子数的关系可以看出,碳原子数为6~10时反应活化能较低,是聚合反应合成减阻剂的最佳选择.  相似文献
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<正>This paper reports that GaSb thin films have been co-deposited on soda-lime glass substrates.The GaSb thin film structural properties are characterized by Raman spectroscopy.The Sb-A1g/GaSb-TO ratio decreases rapidly with the increase of substrate temperature,which suggests a small amount of crystalline Sb in the GaSb thin film and suggests that Sb atoms in the thin film decrease.In Raman spectra,the transverse optical(TO) mode intensity is stronger than that of the longitudinal optical(LO) mode,which indicates that all the samples are disordered.The LO/TO intensity ratio increases with increasing substrate temperature which suggests the improved polycrystalline quality of the GaSb thin film.A downshift of the TO and LO frequencies of the polycrystalline GaSb thin film to single crystalline bulk GaSb Raman spectra is also observed.The uniaxial stress in GaSb thin film is calculated and the value is around 1.0 GPa.The uniaxial stress decreases with increasing substrate temperature.These results suggest that a higher substrate temperature is beneficial in relaxing the stress in GaSb thin film.  相似文献
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