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Experimental and numerical flutter analysis of a folding fin with multiple asymmetric free-plays

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Chinese Journal of Aeronautics 2024年第5期37卷 332-348页

作者： Chenyu LIU Chao AN Changchuan xie xin ZHANG Lan yang School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Beijing Institute of Electronic System Engineering Beijing 100854China Beijing Institute of Astronautical Systems Engineering Beijing 100076China

Experimental folding fin models with an adjustable free-play are tested in a wind *** fin structure is modeled using the free-interface component mode synthesis method,and its free-play is modeled as four independent nonlinear springs with asymmetric stiffness.A nonplanar unsteady vortex-lattice method considering compressibility is employed to address nonlinear deformation and high subsonic *** spline interpolation is improved through projection and *** aeroelastic characteristics of folding fins with different free-play magnitudes,initial conditions and elastic-axis positions are analyzed using an established time-marching method because of its relatively small computation scale and high *** results show good consistency among the presented method,the wind tunnel test and the harmonic balance *** is a negative correlation between the critical speed of divergent motion and the ratio of the initial condition to the free-play *** either the free-play magnitude or the initial condition is extreme(tiny or vast),the system nonlinearity degenerates to ***,the flutter prevention design of a linear model can be applied to a nonlinear model,such as moving the elastic-axis position *** presented fin configuration exhibits an unstable limit cycle oscillation because the orders of coupled flutter modes do not change with variations in equivalent linear stiffness.

关键词： Free-play Limit cycle oscillation Flutter Component mode synthesis Vortex-lattice method

Prediction of Lubricant Physicochemical Properties Based on Gaussian Copula Data Expansion

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China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 161-174页

作者： Feng xin yang Rui xie Peiyuan Xia Yanqiu School of Energy Power and Mechanical Engineering North China Electric Power UniversityBeijing 102206China

The composition of base oils affects the performance of lubricants made from *** paper proposes a hybrid model based on gradient-boosted decision tree(GBDT)to analyze the effect of different ratios of KN4010,PAO40,and PriEco3000 component in a composite base oil system on the performance of *** study was conducted under small laboratory sample conditions,and a data expansion method using the Gaussian Copula function was proposed to improve the prediction ability of the hybrid *** study also compared four optimization algorithms,sticky mushroom algorithm(SMA),genetic algorithm(GA),whale optimization algorithm(WOA),and seagull optimization algorithm(SOA),to predict the kinematic viscosity at 40℃,kinematic viscosity at 100℃,viscosity index,and oxidation induction time performance of the *** results showed that the Gaussian Copula function data expansion method improved the prediction ability of the hybrid model in the case of small *** SOA-GBDT hybrid model had the fastest convergence speed for the samples and the best prediction effect,with determination coefficients(R^(2))for the four indicators of lubricants reaching 0.98,0.99,0.96 and 0.96,***,this model can significantly reduce the model’s prediction error and has good prediction ability.

关键词： base oil data augmentation machine learning performance prediction seagull algorithm

Effects of interstitial cluster mobility on dislocation loops evolution under irradiation of austenitic steel

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Nuclear Science and Techniques 2024年第8期35卷 69-78页

作者： xin‑Hua Yan Lu Sun Du Zhou Teng xie Chang Peng Ye‑xin yang Li Chen Zhen‑Feng Tong North China Electric Power University Beijing 102206China China Nuclear Power Operations Co. LtdShenzhen 518000China

The evolution of dislocation loops in austenitic steels irradiated with Fe~+is investigated using cluster dynamics(CD)simulations by developing a CD *** CD predictions are compared with experimental results in the *** number density and average diameter of the dislocation loops obtained from the CD simulations are in good agreement with the experimental data obtained from transmission electron microscopy(TEM)observations of Fe~+-irradiated Solution Annealed 304,Cold Worked 316,and HR3 austenitic steels in the *** CD simulation results demonstrate that the diffusion of in-cascade interstitial clusters plays a major role in the dislocation loop density and dislocation loop growth;in particular,for the HR3 austenitic steel,the CD model has verified the effect of temperature on the density and size of the dislocation loops.

关键词： Cluster dynamics Dislocation loops In-cascade interstitial clusters Austenitic steels

Mesenchymal stem cell-derived exosomes: Versatile nanomaterials for skin wound treatment

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Nano Research 2024年第4期17卷 2836-2856页

作者： Yuzhen Xiao Hexi Li Junhui Zhang Songyun yang Chunsen Zhang Yizhou Huang xin Tang Huiqi xie Department of Orthopedic Surgery and Orthopedic Research Institute Laboratory of Stem Cell and Tissue EngineeringState Key Laboratory of BiotherapyWest China HospitalSichuan UniversityChengdu 610041China West China School of Basic Medical Sciences and Forensic Medicine Sichuan UniversityChengdu 610041China West China School of Public Health and West China Fourth Hospital Sichuan UniversityChengdu 610041China Sports Medicine Center West China HospitalSichuan UniversityChengdu 610041China

Accumulating studies reveal that mesenchymal stem cells(MSCs)promote skin wound healing mainly through the paracrine ***,one of the crucial paracrine mediators in wound healing,are cell-derived nanosized membranous vesicles containing diverse bioactive *** the potent ability of modulating skin cell behaviors,MSC-derived exosomes(MSC-Exos)are regarded as a promising nanomaterial for regenerative wound *** hostile conditions,MSC-Exos are efficient in protecting skin cells from severe damage and restoring their *** to recent studies,MSC-Exos possess remarkable pro-healing effects in a variety of skin wounds,typically resulting in increased wound closure,inhibited scar tissue formation,and better restoration of skin *** further enhance the therapeutic potential of MSC-Exos,the development of applicable pretreatment strategies and the optimization of exosome delivery are under intensive ***,we summarize current research progress of MSC-Exos for skin wound treatment,with an emphasis on the biological effects of these nanovesicles,the repair mechanisms,and future challenges in clinical translation.

关键词： exosomes mesenchymal stem cells diabetic wounds burn wounds scar wound healing

Heteroatom tuning in agarose derived carbon aerogel for enhanced potassium ion multiple energy storage

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Carbon Energy 2024年第3期6卷 239-254页

作者： Kaijun xie xin Liu Haolin Li Long Fang Kai Xia Dongjiang yang Yihui Zou Xiaodong Zhang State Key Laboratory of Bio-fibers and Eco-textiles Shandong Collaborative Innovation Center of Marine Biobased Fibers and Ecological TextilesInstitute of Marine Biobased MaterialsCollege of Chemistry and Chemical EngineeringCollege of Environmental Science and EngineeringQingdao UniversityQingdaoChina

The incorporation of heteroatoms into carbon aerogels(CAs)can lead to structural distortions and changes in active sites due to their smaller size and electronegativity compared to pure ***,the evolution of the electronic structure from single-atom doping to heteroatom codoping in CAs has not yet been thoroughly investigated,and the impact of codoping on potassium ion(K+)storage and diffusion pathways as electrode material remains *** this study,experimental and theoretical simulations were conducted to demonstrate that heteroatom codoping,composed of multiple heteroatoms(O/N/B)with different properties,has the potential to improve the electrical properties and stability of CAs compared to single-atom *** states near the Fermi level have revealed that doping with O/N/B generates a greater number of active centers on adjacent carbon atoms than doping with O and O/N *** a result of synergy with enhanced wetting ability(contact angle of 9.26°)derived from amino groups and hierarchical porous structure,ON-CA has the most optimized adsorption capacity(−1.62 eV)and diffusion barrier(0.12 eV)of K^(+).The optimal pathway of K^(+)in ON-CA is along the carbon ring with N or O *** K^(+)storage material for supercapacitors and ion batteries,it shows an outstanding specific capacity and capacitance,electrochemical stability,and rate ***,the assembled symmetrical K^(+)supercapacitor demonstrates an energy density of 51.8 Wh kg^(−1),an ultrahigh power density of 443Wkg^(−1),and outstanding cycling stability(maintaining 83.3%after 10,000 cycles in 1M KPF6 organic electrolyte).This research provides valuable insights into the design of highperformance potassium ion storage materials.

关键词： agarose carbon aerogels O/N/B codoping potassium-ion battery potassium-ion supercapacitor

Microstructures and mechanical properties of a commercial Mg-Al-Zn-Mn alloy with various hot-extrusion processes

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Rare Metals 2024年第3期43卷 1329-1336页

作者： He Ma Fan-Zhi Meng Qiang yang Ze-Feng xie Yuan-Ding Huang xin Qiu State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China School of Materials Science and Engineering Changchun University of Science and TechnologyChangchun130022China MagIC-Magnesium Innovation Center Helmholtz-Zentrum Geesthacht21502GeesthachtGermany Engineering Research Center of Optoelectronic Functional Materials Ministry of EducationChangchun University of Science and TechnologyChangchun130022China

Mg-Al-Zn-Mn(AZ)system alloys have become widely used due to their good castability,excellent formability and outstanding corrosion resistance[1-6].However,their strength is still much lower than that of traditional Mg... 详细信息

关键词： alloys alloy corrosion

One more step to realistic CO_(2) reduction reactions——geometric structures evolutions at gas-solid interface

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Rare Metals 2024年第2期43卷 849-852页

作者： Ya-Qiang xie xin Yu Ting Wang College of the Environment and Ecology Xiamen UniversityXiamen361102China

A rational design of copper(Cu)nanocatalyst is critical to the efficient carbon dioxide(CO_(2))conversion toward C1/C2 chemical ***,the lack of actual information on the vicinal Cu interfaces hinders the intrinsic activitystructure correlation *** with atomic-scale in situ characterizations(AP-STM and synchrotron-based AP-XPS),Park and co-workers study and identify the adsorbate-driven morphological evolution of Cu nanoclusters on the Cu(997)surface,providing real-space evidence for the critical role of vicinal structures on Cu *** observed surface roughening trends caused by dissociated atomic oxygen and CO adsorbates subsequently affect the result of successive catalytic reactions to produce critical intermediates,such as carbonate and formate,during the CO_(2)reduction reaction.

关键词： reaction critical rational

Pathogenesis of chronic enteropathy associated with the SLCO2A1 gene:Hypotheses and conundrums

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World Journal of Gastroenterology 2024年第19期30卷 2505-2511页

作者： Zhi-xin xie Yue Li Ai-Ming yang Dong Wu Qiang Wang State Key Laboratory of Complex Severe and Rare Diseases Department of GastroenterologyPeking Union Medical College HospitalChinese Academy of Medical SciencesBeijing 100730China Department of Clinical Medicine Peking Union Medical CollegeChinese Academy of Medical SciencesBeijing 100730China

Chronic enteropathy associated with the SLCO2A1 gene(CEAS)is a complex gastroenterological condition characterized by multiple ulcers in the small intestine with chronic bleeding and protein *** review explores the potential mechanisms underlying the pathogenesis of CEAS,focusing on the role of SLCO2A1-encoded prostaglandin transporter OATP2A1 and its impact on prostaglandin E2(PGE2)*** have suggested that elevated PGE2 levels contribute to mucosal damage,inflammation,and disruption of the intestinal *** effects of PGE2 on macrophage activation and Maxi-Cl channel functionality,as well as its interaction with nonsteroidal anti-inflammatory drugs play crucial roles in the progression of *** the balance between its protective and pro-inflammatory effects and the complex interactions within the gastrointestinal tract can shed light on potential therapeutic targets for CEAS and guide the development of novel,targeted therapies.

关键词： SLCO2A1 Prostaglandin E2 Chronic enteropathy associated with the SLCO2A1 gene Small intestine Macrophage

QoE oriented intelligent online learning evaluation technology in B5G scenario

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Digital Communications and Networks 2024年第1期10卷 7-15页

作者： Mingzi Chen xin Wei Peizhong xie Zhe Zhang School of Communications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing210003China Key Lab of Broadband Wireless Communication and Sensor Network Technology(Nanjing University of Posts and Telecommunications) Ministry of EducationNanjing210003China Institute of Higher Education Nanjing University of Posts and TelecommunicationsNanjing210003China

Students'demand for online learning has exploded during the post-COvID-19 pandemic ***,due to their poor learning experience,students'dropout rate and learning performance of online learning are not always *** technical advantages of Beyond Fifth Generation(B5G)can guarantee a good multimedia Quality of Experience(QoE).As a special case of multimedia services,online learning takes into account both the usability of the service and the cognitive development of the *** that affect the Quality of Online Learning Experience(OL-QoE)become more *** get over this dilemma,we propose a systematic scheme by integrating big data,Machine Learning(ML)technologies,and educational psychology ***,we first formulate a general definition of OL-QoE by data analysis and experimental *** formula considers both the subjective and objective factors(i.e.,video watching ratio and test scores)that most affect ***,we induce an extended layer to the classic Broad Learning System(BLS)to construct an Extended Broad Learning System(EBLS)for the students'OL-QoE *** the extended layer can increase the width of the BLS model and reduce the redundant nodes of BLS,the proposed EBLS can achieve a trade-off between the prediction accuracy and computation ***,we provide a series of early intervention suggestions for different types of students according to their predicted OL-QoE *** timely interventions,their OL-QoE and learning performance can be *** results verify the effectiveness oftheproposed scheme.

关键词： B5G Online learning Quality of experience