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Influence of structure coupling effect on damping coefficient of offshore wind turbine blades
Jianping Zhang,Zhen Gong,Haolin Li,Mingqiang Wang,Zhiwei Zhang,Fengfeng Shi 한국풍공학회 2019 Wind and Structures, An International Journal (WAS Vol.29 No.6
The aim of this study was to explore the influence of structure coupling effect on structural damping of blade based on the blade vibration characteristic. For this purpose, the scaled blade model of NREL 5 MW offshore wind turbine was processed and employed in the wind tunnel test to validate the reliability of theoretical and numerical models. The attenuation curves of maximum displacement and the varying curves of equivalent damping coefficient of the blade under the rated condition were respectively compared and analyzed by constructing single blade model and whole machine model. The attenuation law of blade dynamic response was obtained and the structure coupling effect was proved to exert a significant influence on the equivalent damping coefficient. The results indicate that the attenuation trend of the maximum displacement response curve of the single blade varies more obviously with the increase of elastic modulus as compared to that under the structure coupling effect. In contrast to the single blade model, the varying curve of equivalent damping coefficient with the period is relatively steep for the whole machine model. The findings are of great significance to guide the structure design and material selection for wind turbine blades.
ox-LDL regulates proliferation and apoptosis in VSMCs by controlling the miR-183-5p/FOXO1
Fan Mingqiang,Huang Yinglong,Li Kunsheng,Yang Xiangxiang,Bai Jing,Si Qiaoke,Peng Zhengfei,Jia Chunwen,Zhang Qiangnu,Tao Ding 한국유전학회 2022 Genes & Genomics Vol.44 No.6
Background: microRNA-mRNA axes that are involved in oxidized low-density lipoprotein (ox-LDL)-induced vascular smooth muscle cells (VSMCs) proliferation/apoptosis imbalance need to be further investigated. Objective: To investigate the functional role of miR-183-5p/FOXO1 in VSMCs and its interaction with ox-LDL. Methods: RNA sequencing was used to detect transcriptome changes of VSMCs treated with ox-LDL. miR-183-5p and FOXO1 expression levels in VSMCs after ox-LDL treatment were assessed using qRT-PCR and western blotting. The regulatory effect of miR-183-5p on FOXO1 has been tried to prove using a dual-luciferase reporter assay. The functions of miR-183-5p, and FOXO1 were analyzed by CCK-8 assay and flow cytometry assay. The tissue samples or serum samples of high fat-feeding mice and carotid atherosclerosis patients were collected, and the levels of miR-183-5p/FOXO1 were analyzed. Results: RNA sequencing data showed 81 miRNAs including miR-183-5p was significantly changed after ox-LDL treatment in VSMCs. FOXO1, a miR-183-5p's potential target, was also down-regulated in ox-LDL treated cells. qRT-PCR and western blot found that expression of FOXO1 mRNA and protein significantly reduced in VSMCs treated with ox-LDL, accompanied by overexpression of miR-183-5p. miR-183-5p inhibited FOXO1 mRNA by binding to its 3' UTR. Interference miR-183-5p/FOXO1 could change proliferation/apoptosis imbalance in VSMCs under ox-LDL stimulation. Higher levels of miR-183-5p but reduced FOXO1 can be found in the thoracic aorta tissues of high fat-feeding mice. In serum samples from individuals with carotid atherosclerosis, Higher levels of miR-183-5p were observed. the miR-183-5p level was positively related to the level of serum ox-LDL in patients. Conclusions: Aberrant expression of miR-183-5p/FOXO1 pathway mediated ox-LDL-induced proliferation/apoptosis imbalance in VSMCs. The miR-183-5p/FOXO1 axis can potentially be utilized as the target in the treatment of patients with atherosclerosis.
Reciprocal degree distance and graph properties
An, Mingqiang,Zhang, Yinan,Das, Kinkar Ch.,Xiong, Liming Elsevier 2019 Discrete Applied Mathematics Vol.258 No.-
<P><B>Abstract</B></P> <P>The reciprocal degree distance (RDD), defined for a connected graph G as vertex-degree- weighted sum of the reciprocal distances, that is, R D D ( G ) = <SUB> ∑ u ≠ v </SUB> <SUB> d G </SUB> ( u ) + <SUB> d G </SUB> ( v ) <SUB> d G </SUB> ( u , v ) , where <SUB> d G </SUB> ( u ) is the degree of the vertex u in the graph G and <SUB> d G </SUB> ( u , v ) denotes the distance between two vertices u and v in the graph G . The reciprocal degree distance is a weight version of the Harary index, just as the degree distance is a weight version of the Wiener index. Finding sufficient conditions for graphs possessing certain properties is an important and meaningful problem. In this paper, we give sufficient conditions for a graph to be k -connected or β -deficient in terms of the reciprocal degree distance.</P>
Dynamic analysis of offshore wind turbines
Jianping Zhang,Mingqiang Wang,Zhen Gong,Fengfeng Shi 한국풍공학회 2020 Wind and Structures, An International Journal (WAS Vol.31 No.4
For large-scale 5MW offshore wind turbines, the discrete equation of fluid domain and the motion equation of structural domain with geometric nonlinearity were built, the three-dimensional modeling of the blade considering fluid-structure interaction (FSI) was achieved by using Unigraphics (UG) and Geometry modules, and the numerical simulation and the analysis of the vibration characteristics for wind turbine structure under rotating effect were carried out based on ANSYS software. The results indicate that the rotating effect has an apparent effect on displacement and Von Mises stress, and the response and the distribution of displacement and Von Mises stress for the blade in direction of wingspan increase nonlinearly with the equal increase of rotational speeds. Compared with the single blade model, the blade vibration period of the whole machine model is much longer. The structural coupling effect reduces the response peak value of the blade displacement and Von Mises stress, and the increase of rotational speed enhances this coupling effect. The maximum displacement difference between two models decreases first and then increases along wingspan direction, the trend is more visible with the equal increase of rotational speed, and the boundary point with zero displacement difference moves towards the blade root. Furthermore, the Von Mises stress difference increases gradually with the increase of rotational speed and decreases nonlinearly from the blade middle to both sides. The results can provide technical reference for the safe operation and optimal design of offshore wind turbines.
Ultrafast epitaxial growth of metre-sized single-crystal graphene on industrial Cu foil
Xu, Xiaozhi,Zhang, Zhihong,Dong, Jichen,Yi, Ding,Niu, Jingjing,Wu, Muhong,Lin, Li,Yin, Rongkang,Li, Mingqiang,Zhou, Jingyuan,Wang, Shaoxin,Sun, Junliang,Duan, Xiaojie,Gao, Peng,Jiang, Ying,Wu, Xiaoson Elsevier 2017 Science bulletin Vol.62 No.15
Flexural Performance of Prestressed Composite Recycled Aggregate Slabs with Steel Tube Trusses
Enming Liu,Mingqiang Lin,Qun Xie,Yue Zhang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.12
A new type of prestressed composite recycled aggregate floor slab was developed and its flexural performance was studied. The composite floor comprises a top cast-in-place slab made of recycled coarse aggregate concrete and a bottom precast concrete slab with grouted steel tube trusses. The cracking load, ultimate load, deflection, steel tube strain, concrete strain and failure process are studied for different contents of recycled coarse aggregates. Results show that the mechanical performance of the prestressed composite recycled aggregate slab has two distinctive stages. And the load bearing capacity decreases with the increase in the amount of recycled coarse aggregates. When the composite slab fails, the prestressed steel wires in the tension zone yield and concrete in the compression zone is crushed. This failure characteristic reflects that the reinforcement ratio of the component is appropriate. The cracking moment and ultimate moment calculation formulas of the composite slab are established and could predict the cracking and failure points. In the formulas, the influence of the amount of recycled coarse aggregates on the flexural capacity is considered. By controlling the content of recycled aggregates, the composite slabs with steel tube trusses can be sued in practical applications.
Xuehan Wang,Mingxuan Li,Liwei Liu,Rui Mou,Xiuming Zhang,Yanling Bai,Haijin Xu,Mingqiang Qiao 한국미생물학회 2012 The journal of microbiology Vol.50 No.6
A Pseudomonas aeruginosa mutant strain M122 was isolated from a Mu transposon insertion mutant library. In our prophase research, we have found that PA0058, a novel gene encodes a 234-residue conserved protein, was disrupted in the M122 mutant. In this study, the bacteriostatic experiment in vitro indicates that M122 has abnormally high aminoglycoside resistance. We expressed PA0058 in E. coli and found that PA0058 oxidizes and reduces disulfide. This biochemical characterization suggests that PA0058 is a novel disulfide oxidoreductase. Hence, the protein was designated as DsbM. Microarray analysis of the M122 mutant showed its unusual phenotype might be related to the bacterial antioxidant defense system mediated by the oxyR regulon. Meanwhile, we detected –SH content in the periplasm of M122 and wild strain and found a lower –SH/S–S ratio in M122. Therefore, we consider that the loss of dsbM function decreased the –SH/S–S ratio, which then prolongs the OxyR-regulated response, thereby conferring high aminoglycoside resistance to the M122 mutant strain. Our findings have important implications for understanding the mechanisms underlying aminoglycoside resistance in P. aeruginosa.
Shin, Dong Won,Lee, So Young,Lee, Chang Hyun,Lee, Kwan-Soo,Park, Chi Hoon,McGrath, James E.,Zhang, Mingqiang,Moore, Robert B.,Lingwood, Mark D.,Madsen, Louis A.,Kim, Young Taek,Hwang, Inchul,Lee, Youn American Chemical Society 2013 Macromolecules Vol.46 No.19
<P>Ordered morphologies in disulfonated poly(arylene sulfide sulfone nitrile) (SPSN) copolymers were generated via thermal annealing followed by multiblock copolymer synthesis. While SPSN random copolymers (R-SPSN) showed featureless morphologies, the SPSN multiblock copolymers (B-SPSN) exhibited cocontinuous lamellar morphologies with a center-to-center interdomain size of up to 40 nm. In spite of the well-ordered, interconnected hydrophilic domains, the water self-diffusion coefficient (e.g., <I>D</I> = (0.7–2.0) × 10<SUP>–10</SUP> m<SUP>2</SUP> s<SUP>–1</SUP>) and proton conductivity (e.g., σ = 0.16–0.20 S cm<SUP>–1</SUP> in deionized water at 30 °C) through B-SPSN were lower than those of the corresponding R-SPSN (e.g., <I>D</I> = (3.5–3.9) × 10<SUP>–10</SUP> m<SUP>2</SUP> s<SUP>–1</SUP> and σ = 0.21 S cm<SUP>–1</SUP>) due to the relatively lower water uptake of the B-SPSN after thermal annealing. The reduced water uptake of B-SPSN was beneficial to reduction of peroxide degradation rate. Thermal annealing produced significant gains in morphological ordering and finer control over desired membrane properties for proton conduction applications.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/mamobx/2013/mamobx.2013.46.issue-19/ma400889t/production/images/medium/ma-2013-00889t_0010.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ma400889t'>ACS Electronic Supporting Info</A></P>