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39 results on '"Yu, Chuanyong"'

24. Enhanced tribological properties of PEEK‐based composite coatings reinforced by PTFE and graphite.

Author

Liao, Yuwen, Cao, Lin, Wang, Qiwei, Li, Shuangjian, Lin, Zhidan, Li, Wei, Zhang, Peng, and Yu, Chuanyong

Subjects
COMPOSITE coating, POLYTEF, MECHANICAL wear, WEAR resistance, ARTIFICIAL joints, GRAPHITE
Abstract

The lubricating failure problems caused by friction and wear severely inhibit the regular operation and lifetime of artificial implanted joints. In order to improve their wear resistance effectively, the functional nano/micro‐composite coatings consisted of poly(ether‐ether‐ketone) (PEEK)/graphite/polytetrafluoroethylene (PTFE) were successfully prepared through electrophoretic deposition and heat treatment. Additionally, the friction and wear behaviors under different loads and lubricating mediums of the composite coatings were investigated systematically. The results show that the composite coating significantly increased the microhardness and wear resistance of PEEK coating. The introduction of graphite and PTFE fillers reduces the wear rates and coefficient of friction (COF) of the composite coating significantly. Especially under 10 N load conditions, the friction and wear tests show that the composite coatings drop by 80% of friction coefficient and an order of magnitude in wear rates compared to that of PEEK coating. The improved wear resistance can be attributed to the synergistic effect of PTFE and graphite fillers. As a result, the graphite provides good load‐bearing capacity and the PTFE lubricant endow a low friction coefficient for the composite coatings. Thus, this study provides a better approach to improve the wear resistance of PEEK‐based coatings. [ABSTRACT FROM AUTHOR]

Published
2022
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29. Clinical features and influencing prognostic factors in patients with anti-NMDAR encephalitis: a cohort follow-up study in Chinese patients

Author

Wang, Yingxin, primary, Miao, Ailiang, additional, Shi, Yongwei, additional, Ge, Jianqing, additional, Wang, Lingling, additional, Xu, Haiyan, additional, Yu, Chuanyong, additional, Yu, Yuanwen, additional, Huang, Shuyang, additional, Jiang, Wenwen, additional, Li, Yihan, additional, and Wang, Xiaoshan, additional

Published
2019
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33. POSS-Grafted PAI/MoS2Coatings for Simultaneously Improved Tribological Properties and Atomic Oxygen Resistance

Author

Yu, Chuanyong, Ju, Pengfei, Wan, Hongqi, Chen, Lei, Li, Hongxuan, Zhou, Huidi, and Chen, Jianmin

Abstract

Polyamide-imide (PAI) is extensively used in onboard spacecraft mainly as a surface-protective material owing to its inherent excellent mechanical strength, chemical inertness, irradiation resistance, high-temperature stability, and high wear resistance. Nevertheless, PAI in the low earth orbit (LEO) is severely eroded by the presence of atomic oxygen (AO). To solve this problem, in this work, the octa- and mono-amino polyhedral oligomeric silsesquioxane (OMPOSS) were incorporated into the PAI matrix by covalent grafting, and the lubricating coatings were prepared using molybdenum disulfide (MoS2) as the solid lubricant. Additionally, the effects of AO exposure on pure PAI/MoS2and POSS-reinforced PAI/MoS2coatings were investigated. More importantly, the results indicated that the coatings exhibited outstanding tribological properties and anti-AO performance owning to the addition of octa-amino POSS (OPOSS) monomers into the main chain and mono-amino POSS (MPOSS) as the end-capping reagent of the polymer. The cooperation of OPOSS and MPOSS significantly improved the AO resistance resulting from the formation of a connected and networked silicon dioxide passivating layer on the surface. As a result, the PAI-based lubricating coating modified by OMPOSS possessing excellent tribological properties and anti-AO performance would be a novel space-suitable material in LEO.

Published
2024
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34. Tribological properties of the polyacrylate/PTFE coating modified by POSS in the space environment.

Author

Yu, Chuanyong, Ju, Pengfei, Wan, Hongqi, Chen, Lei, Li, Hongxuan, Zhou, Huidi, and Chen, Jianmin

Subjects
POLYTEF, SPACE environment, BUTYL methacrylate, COMPOSITE coating, SURFACE coatings, OXYGEN
Abstract

The irradiation conditions in the low earth orbit (LEO) severely inhibit the development of polymeric materials for solid lubrication coatings used on the external surfaces of spacecraft. To solve the problem, octavinyl polyhedral oligomeric silsesquioxanes (OvPOSS) were covalently grafted onto poly(methyl/butyl methacrylate) composites (PMB). The results showed that the appropriate incorporation of OvPOSS (10 wt %) significantly reduced the friction coefficient and improved the wear resistance of the OvPOSS/PMB composite coatings. Furthermore, the impact of OvPOSS on the tribological properties of PMB/polytetrafluoroethylene (PTFE) lubrication coatings in the space environment was investigated. In particular, the degradations, mass losses, surface morphologies, and chemical compositions of POSS/PMB/PTEF composite coatings were characterized under ultraviolet (UV), electric irradiation (EI), and atomic oxygen (AO). The results indicated that OvPOSS provides numerous SiOSi bonds in the polymer matrix that improve the resistance to UV and EI. Besides, a passivating SiO2 layer was formed to prevent further erosion and degradation of the underlying PMB and PTFE components during AO irradiation. Particularly, the wear resistance of OvPOSS/PMB/PTFE coatings under AO irradiation increased significantly compared with the pristine PMB/PTFE coating. Overall, our results indicate that POSS‐containing composites are a good prospective material for space application in the LEO. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48730. [ABSTRACT FROM AUTHOR]

Published
2020
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35. Analysis of Relation Between Electroclinical Features and Cerebrospinal Fluid Antibody Titers in Patients With anti-NMDAR Encephalitis

Author

Miao, Ailiang, primary, Du, Mingyang, additional, Wang, Lingling, additional, Ge, Jianqing, additional, Lu, Hengdong, additional, Xu, Haiyan, additional, Liu, Hongxing, additional, Yu, Chuanyong, additional, Wu, Caiyun, additional, Gao, Yuan, additional, Sun, Jintao, additional, Shi, Qi, additional, and Wang, Xiaoshan, additional

Published
2018
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39. Analysis of Relation Between Electroclinical Features and Cerebrospinal Fluid Antibody Titers in Patients With anti-NMDAR Encephalitis

Author

Miao, Ailiang, Du, Mingyang, Wang, Lingling, Ge, Jianqing, Lu, Hengdong, Xu, Haiyan, Liu, Hongxing, Yu, Chuanyong, Wu, Caiyun, Gao, Yuan, Sun, Jintao, Shi, Qi, and Wang, Xiaoshan

Abstract

Purpose. This study aimed to determine the relation between electroclinical features and cerebrospinal fluid (CSF) antibody titers in patients with anti-N-methyl-d-aspartate receptor (anti-NMDAR) encephalitis. Method. Clinical symptoms and electroencephalography (EEG) at different stages were analyzed in 51 hospitalized patients with anti-NMDAR encephalitis. Results. Behavioral changes were the initial symptoms in 90.9% (20/22) of female patients with high (1:10 or 1:32) CSF antibody titers. A greater number of clinical symptoms were observed in the patients with high CSF antibody titers than in those with low (1:1 or 1:3.2) CSF antibody titers (mean 3.11 ± 1.06 vs 1.62 ± 0.65, P= .000). The number of clinical symptoms was greater in the female patients than in the male patients (mean 3.52 ± 0.98 vs 2.69 ± 1.09, P= .000). At the peak stage, worse background activity (BA) in EEG recordings was observed in patients with high CSF antibody titers than in those with low CSF antibody titers (Mann-Whitney Utest, P= .001). The peak-stage BA in EEG was worse in female patients than in male patients (Mann-Whitney Utest, P= .000). Modified Rankin scale scores were higher in patients with high CSF antibody titers than in those with low CSF antibody titers (mean 2.62 ± 1.42 vs 0.75 ± 0.97, P= .000). Brush patterns and constant chewing were observed primarily in female patients with high CSF antibody titers. Epileptic discharges were located predominately in the frontal regions and were noted to vary. Conclusion. The electroclinical features of patients with anti-NMDAR encephalitis were associated with gender and CSF antibody titers.

Published
2019
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