Jingbao Lian
材料科学技术（英文）
Fabrication of Gd2O2S:Pr scintillation ceramics by pressureless reaction sintering was investigated. The 2Gd2O 3˙(Gd,Pr)2(SO 4)3˙mH2O precursor was made by hydrothermal reaction using commercially available Gd2O3, Pr6O11 and H2SO4 as the starting materials. Then single phase Gd2O2SO4:Pr powder was obtained by calcining the precursor at 750°C for 2 h. The Gd2O2SO4:Pr powder compacts can be sintered to single phase Gd2O2S:Pr ceramics with a relative density of 99% and mean grain size of 30 μm at 1750°C for 2 h in flowing hydrogen atmosphere. Densification and microstructural development of the Gd2O2S:Pr ceramics were examined. Luminescence spectra of the Gd2O2S:Pr ceramic under 309 nm UV excitation and X-ray excitation show a green emission at 511 nm as the most prominent peak, which corresponds to the 3P0-3H4 transition of Pr3+ ions.
关键词:
Scintillation ceramics
吴向东
,
万敏
,
周贤宾
材料科学与工艺
doi:10.3969/j.issn.1005-0299.2004.04.015
针对建立的十字形双向拉伸试验系统,利用有限元模拟优化得到的十字形试件,采用载荷控制方式对SPEN钢板和2024-O铝合金板进行了不同加载路径下的双向拉伸试验,得到了不同硬化阶段下的实验屈服轨迹,并与现有屈服准则Hill48、Hill79、Hill90、Hill93、Gotoh、Hosford、Barlat-Lian以及Mises的理论屈服轨迹进行了对比.结果表明:对于SPEN钢板,Hosford各向异性屈服准则得到的理论屈服轨迹与实验屈服轨迹符合得最好,其次是Mises屈服准则,Hill48屈服准则最差;对2024-O铝合金板,Barlat89、Hosford屈服轨迹与实验屈服轨迹符合得最好,Mises屈服准则最差.
关键词:
双向拉伸试验
,
十字形试件
,
各向异性
,
屈服准则
