http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Study on accelerated life tests for main shaft bearings in wind turbines
Sheng Jin,Hanjie Dong,Jie Chen,Xinghui Xie,Mingjun Guo 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.3
This paper focused on a 2.1 MW wind turbine main shaft bearing as the research object and analyzed its reliability under actual working conditions for three years. An accelerated life test for the main shaft bearing in a wind turbine with an amplified load was carried out depending on the reference value of the radial dynamic load rating. The test was conducted for 140 days. The bearing did not show any noticeable damage at the end of the test, which shows that the bearing could be reliable for three years. To prove the correctness of the ALT, a finite element model of the main shaft bearing was created in ABAQUS to obtain the contact stress in both the actual working conditions and the accelerated test conditions. The calculation results were transferred to FE-SAFE to calculate the fatigue life. Finally, a comparison between the theoretical and simulation acceleration factors validated the rationality of the experimental design.
The exchange bias effect and Griffiths phase in La1.5Sr0.5Co1-Ni MnO6: The impact of the divalent Ni
Zhang Hongguang,Wang Sen,Chen Wei,Wang Mingjun,Li Yongtao,Xie Liang 한국물리학회 2023 Current Applied Physics Vol.53 No.-
The effects of Co-site doping of Ni2+ ions on the crystal structure, electronic structure, and magnetic properties of La1.5Sr0.5CoMnO6 are investigated. The doping causes an increase in the anti-site disorder and a change in the content of Co2+/3+ and Mn3+/4+, as well as a change in the spin state of Co ions. Ni doping introduces Ni2+-O2-- Mn4+ ferromagnetic interactions to increase the ferromagnetic transition temperature. Samples display different dominant clusters, and field cooling promotes the presence of ferromagnetic clusters, allowing an increase in the Griffiths phase. Interestingly, Ni doping enables tuning the conventional and spontaneous exchange bias (EB) effects, increasing the EB field for intermediate concentrations. Moreover, the maxima of both EB fields do not occur in the same sample, which leads to a new understanding of the relationship between these two effects. The possible mechanisms related to the uncompensated spin and competition between ferromagnetic and antiferromagnetic clusters are discussed, respectively.
Emission properties of sequentially deposited ultrathin CH3NH3PbI3/MoS2 heterostructures
Shao Ziyi,Xiao Junting,Guo Xiao,You Siwen,Zhang Yangyang,Li Mingjun,Song Fei,Zhou Conghua,Xie Haipeng,Gao Yongli,Sun Jiatao,Huang Han 한국물리학회 2022 Current Applied Physics Vol.36 No.-
Hybrid organic-inorganic perovskite materials have obtained considerable attention due to their exotic optoelectronic properties and extraordinarily high performance in photovoltaic devices. Herein, we successively converted the ultrathin PbI2/MoS2 into the CH3NH3PbI3/MoS2 heterostructures via CH3NH3I vapor processing. Atomic force microscopy (AFM)、Scanning electron microscopy (SEM) and X-ray photoemission spectroscopy (XPS) measurements prove the high-quality of the converted CH3NH3PbI3/MoS2. Both MoS2 and CH3NH3PbI3 related photoluminescence (PL) intensity quenching in CH3NH3PbI3/MoS2 implies a Type-II energy level alignment at the interface. Temperature-dependent PL measurements show that the emission peak position shifting trend of CH3NH3PbI3 is opposite to that of MoS2 (traditional semiconductors) due to the thermal expansion and electron-phonon coupling effects. The CH3NH3PbI3/TMDC heterostructures are useful in fabricating innovative devices for wider optoelectronic applications.
Xiujuan Wu,Yujia Wang,Qiong Wu,Yi Li,Li Li,Jing Tang,Yujun Shi,Hong Bu,Ji Bao,Mingjun Xie 한국조직공학과 재생의학회 2015 조직공학과 재생의학 Vol.12 No.6
Liver disease affects millions of patients each year worldwide. Decellularized biologic matrices are plausible biomedical materials for bioengineered replacement hepatic tissue. However, one of the concerns for its safe medical application is the lack of objective assessment of the immunogen within the materials and in vivo immune responses to the matrices. The purpose of this study was to produce immunogen- reduced and biocompatible matrices from porcine liver. Whole porcine livers were perfusion decellularized and cross-linked with glutaraldehyde (GA) or genipin (GP). Proteins were extracted, and the migratory response of human leukocytes toward protein extracts was examined using an in vitro migration chamber. In addition, biopsy specimens of decellularized scaffolds were implanted subcutaneously into rodents to investigate scaffold immunogenicity. Histological staining confirmed cellular clearance from pig livers, with removal of nuclei and cytoskeletal components and widespread preservation of structural extracellular molecules. Polymerase chain reaction analysis showed that galactose-alpha-1,3-galactose-beta-1,4-N-acetylglucosamine (1,3 gal), swine leukocyte antigen, and porcine endogenous retrovirus were completely removed in the matrices. Decellularization significantly reduced the migration of monocytes compared with native porcine tissue. Although the proportion of transmigrating lymphocytes was much lower, repeating the cross-linking procedure reduced the migratory response. After implantation for 4 weeks, the decellularized and native samples were degraded, and the GA-treated group demonstrated a severe inflammatory reaction; however, minimal inflammatory cell infiltration was seen in the GPtreated group during the 8-week investigation period. In conclusion, our study provided evidence that GP crosslinking could significantly reduce the immunogenicity of decellularized liver biomaterials.