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91.
Yi Qin Tao Xiong Ting Zhao Jianfeng Zhu Jun Yang Yi Liu Xingang Kong Xiaohan Li 《Ceramics International》2021,47(9):12641-12650
The strengthening method of multi-element M-site solid solution is a common approach to improve mechanical properties of MAX phase ceramic. However, the research on capability of multi-element A-site solid solution to improve mechanical properties has rarely been reported. Thereupon, quasi-high-entropy MAX phase ceramic bulks of Ti2(Al1?xAx)C and Ti3(Al1?xAx)C2 (A = Ga, In, Sn, x = 0.2, 0.3, 0.4) were successfully synthesized by in situ vacuum hot pressing via multi-elements solid solution. The multi-elements solid solution in single-atom thick A layer was confirmed by X-ray diffraction and X-ray photoelectron spectroscopy as well as by energy dispersive X-ray spectroscopy mappings. Effects of doped multi-elements contents on the phase, microstructure, mechanical properties, and high temperature tribological behaviors were studied. Results demonstrated that the Vickers hardness, anisotropic flexural strength, fracture toughness, and tribological properties of Ti–Al–C based MAX ceramics could be remarkably improved by constitution of quasi-high-entropy MAX phase in A layers. Moreover, the strengthening and wear mechanisms were also discussed in detail. This method of multi-element solid solution at A-site provides new way to enhance mechanical properties of other MAX phase ceramics. 相似文献
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对四川穿斗民居的田野调查发现,工匠使用的术语存在一物多名、多物同名、异物类名等现象.在梳理田野调查、已有文献大木作术语的基础上,通过设计和施工阶段术语的不同作用,分析具体营造中工匠的思维与意识.同时从术语的角度,就穿斗结构以及术语的重名、异名现象提出新的认识. 相似文献
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Mg-Zn-Nd alloy is a promising biodegradable metal material for surgical staples during the reconstruc-tion of digestive tract due to its good biocompatibility and suitable mechanical properties.However,its deformation property and corrosion resistance should be improved to make better safety and effective-ness of staples.In the present study,bi-direction drawing was adopted to maintain the initial texture characteristics,and improve mechanical property and corrosion resistance of Mg-2Zn-0.5Nd alloy.The results showed that the microstructure after bi-direction did not change too much,but the texture could maintain its initial characteristics.The ductility of the alloy with 60 % accumulative area reduction after bi-direction drawing was increased by 70 %,indicating that an outstanding deformation property of Mg-Zn-Nd alloy can be obtained by bi-direction drawing.The corrosion resistance was also improved after bi-direction drawing compared with that under single direction drawing. 相似文献
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98.
Lim SuJi Yun Choong-In Song Dahyun Kang Seok-Seong Kim Young-Jun 《Food science and biotechnology》2022,31(9):1145-1155
Food Science and Biotechnology - Oat contains a variety of phenolic compounds, including avenanthramides, which are found only in oats. This study was conducted to establish the quantitative... 相似文献
99.
Propylene molecule owns two active sites, the direct epoxidation of propylene by dioxygen is still a challenge due to the limitation of selectivity. In this work, the direct liquid-phase propylene aerobic epoxidation protocol by chloride manganese meso-tetraphenylporphyrin (MnTPPCl) was developed. The conversion of propylene was 12.7%, and the selectivity towards PO (propylene oxide) reached up to 80.5%. The formation of PO was attributed to the mechanism via high-valent Mn species, which was confirmed by means of in situ UV–vis spectrum. 相似文献
100.
Yang Mengmeng Chen Zhaofeng Liu Tianlong Wu Qiong Yang Lixia 《Journal of Porous Materials》2022,29(2):523-530
Journal of Porous Materials - In recent years, oil spills and industrial organic pollutants have caused irreparable damage to the environment and biological ecosystems. Therefore, the treatment of... 相似文献