吴卫
,
Lorenza Petrini
,
Lina Altomare
,
Silvia Farè
,
Rosaria Tremamunno
,
于振涛
,
Francesco Migliavacca
稀有金属材料与工程
可降解镁合金支架(MAS)能够改善商用裸支架和药物洗脱支架的长期治疗效果.由于镁合金支架在人体内降解速度太快,限制了其对病变血管的支撑性能.保护性聚合物涂层为镁合金支架提供了一种降低腐蚀速度的有效方法.然而,聚合物涂层在支架扩张时出现的剥离现象是阻碍其运用的一大障碍.在本研究中,分别运用有限元方法和实验方法对一种优化设计的镁合金支架进行了聚合物涂层剥离问题的研究.首先通过90°剥离实验测试,为粘聚区有限元模型提供了临界能量释放率,以此为基础的90°剥离的模拟结果和实验结果吻合良好.运用可靠的粘聚区模型参数,支架-聚合物涂层有限元模型考察了支架在扩张过程中是否会发生涂层剥离现象.本研究为考察支架聚合物涂层剥离现象提供了一种简单可靠的方法,为改善可降解镁合金支架的聚合物涂层性能提出了相应的建议.
关键词:
镁合金支架
,
涂层
,
有限元分析
,
粘聚区模型
,
剥离
Pohkok Ooi
材料科学技术（英）
Polarized far infrared (FIR) reflectance technique was applied to study the optical properties of a bulk wurtzite zinc oxide (ZnO) single crystal. Room temperature polarized FIR reflectance spectra were taken at various angles of incidence, from 20° to 70°. The theoretical polarized FIR reflectance spectra were simulated based on the anisotropic dielectric function model. Good agreement was achieved between the experimental and the theoretical FIR reflectance spectra. Through this work, a complete set of reststrahlen parameters of a bulk wurtzite ZnO at the Brillouin zone centre was obtained. Additionally, other FIR optical properties such as the real and the imaginary parts of the complex dielectric function, real and imaginary parts of the refractive index, the absorption coefficient and the reciprocal of the absorption coefficient were also obtained by using numerical calculation.
关键词:
Zinc oxide
