Mixed rare earth elements were incorporated into alumina ceramic materials. Hot-pressing was used to fabricate alumina matrix composites in nitrogen atmosphere protection. Microstructures and mechanical properties of ...Mixed rare earth elements were incorporated into alumina ceramic materials. Hot-pressing was used to fabricate alumina matrix composites in nitrogen atmosphere protection. Microstructures and mechanical properties of the composites were tested. It was indicated that the bending strength and fracture toughness of alumina matrix ceramic composites sintered at 1550 ℃ and 28 MPa for 30 min were improved evidently. Besides mixed rare earth elements acting as a toughening phase, AlTiC master alloys were also added in as sintering assistants, which could prompt the formation of transient liquid phase, and thus nitrides of rare earth elements were produced. All of the above were beneficial for improving the mechanical properties of alumina matrix ceramic composites.展开更多
Mixed rare earth elements were incorporated into alumina ceramic materials. Hot-pressing was used to fabricate alumina matrix composites with nitrogen atmosphere protection. Microstructures and mechanical properties o...Mixed rare earth elements were incorporated into alumina ceramic materials. Hot-pressing was used to fabricate alumina matrix composites with nitrogen atmosphere protection. Microstructures and mechanical properties of the composites were tested. It is indicates that the bending strength and fracture toughness of alumina matrix ceramic composites sintered at 1550℃ and 28 MPa for 30 min are improved evidently. Based on mixed rare earth elements acting as a toughening phase, AlTiC master alloys were also added in as sintering assistant, which could prompt the formation of transient liquid phase, and thus nitrides of rare earth elements were produced. All the above are beneficial to the improvement of mechanical properties of alumina matrix ceramic composites.展开更多
目的系统评价培土生金法联合西药治疗支气管扩张症临床疗效。方法通过检索中国知网、万方数据库、维普、中国生物医学文献数据库、Web of Science、PubMed、Embase和Cochrane Library等中外数据库,依据纳入排除标准,检索相关培土生金法...目的系统评价培土生金法联合西药治疗支气管扩张症临床疗效。方法通过检索中国知网、万方数据库、维普、中国生物医学文献数据库、Web of Science、PubMed、Embase和Cochrane Library等中外数据库,依据纳入排除标准,检索相关培土生金法联合西药治疗支气管扩张症患者随机对照试验,检索时间自建库至2022年10月15日。通过Review Manager 5.3软件对文献数据进行Meta分析。结果共纳入15篇文献,包括1381例患者。Meta分析结果显示,培土生金法联合西药治疗组患者总有效率高于单纯用西药对照组(RR=1.19,P<0.00001);用力肺活量(FVC)(MD=0.43,95%CI=0.33~0.52,P<0.00001)及第1秒用力呼气容积(FEV1)(MD=0.49,95%CI=0.16~0.82,P=0.003)结局指标改善程度优于对照组;咳嗽(MD=-0.48,95%CI=-0.67~-0.29,P<0.00001)、咳痰(MD=-0.54,95%CI=-0.77~-0.31,P<0.00001)和乏力(MD=-0.31,95%CI=-0.47~-0.15,P=0.0002)症状缓解情况优于对照组,描述性分析治疗组不良反应发生率低于对照组(P<0.05),差异均具有统计学意义。但在改善一氧化碳弥散量占预计值百分比(DLCO%)程度方面较对照组,差异无统计学意义(P>0.05)。结论培土生金法联合西药治疗可明显提高支气管扩张症患者的疗效,改善肺功能及缓解临床症状。但本研究纳入文献量少,部分文献质量偏低,仍需高质量临床研究予以证实。展开更多
基金the Outstanding Young Scientist Rewards of Shandong Province (05BS04008)the Natural Science Fund of Shandong Province (Y2007F29)
文摘Mixed rare earth elements were incorporated into alumina ceramic materials. Hot-pressing was used to fabricate alumina matrix composites in nitrogen atmosphere protection. Microstructures and mechanical properties of the composites were tested. It was indicated that the bending strength and fracture toughness of alumina matrix ceramic composites sintered at 1550 ℃ and 28 MPa for 30 min were improved evidently. Besides mixed rare earth elements acting as a toughening phase, AlTiC master alloys were also added in as sintering assistants, which could prompt the formation of transient liquid phase, and thus nitrides of rare earth elements were produced. All of the above were beneficial for improving the mechanical properties of alumina matrix ceramic composites.
文摘Mixed rare earth elements were incorporated into alumina ceramic materials. Hot-pressing was used to fabricate alumina matrix composites with nitrogen atmosphere protection. Microstructures and mechanical properties of the composites were tested. It is indicates that the bending strength and fracture toughness of alumina matrix ceramic composites sintered at 1550℃ and 28 MPa for 30 min are improved evidently. Based on mixed rare earth elements acting as a toughening phase, AlTiC master alloys were also added in as sintering assistant, which could prompt the formation of transient liquid phase, and thus nitrides of rare earth elements were produced. All the above are beneficial to the improvement of mechanical properties of alumina matrix ceramic composites.
