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Multi-blade rubbing characteristics of the shaft-disk-blade-casing system with large rotation

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Applied Mathematics and Mechanics(English Edition) 2024年第1期45卷 111-136页

作者： Zhiyuan WU Linchuan ZHao Han YAN Ge YAN ao chen Wenming ZHANG State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Institute of Aerospace Systems Engineering Shanghai 201108China

Blade rubbing faults cause detrimental impact on the operation of aeroengines. Most of the existing studies on blade rubbing in the shaft-disk-blade-casing(SDBC) system have overlooked the elastic deformation of the blade, while some only consider the whirl of the rotor, neglecting its spin. To address these limitations, this paper proposes a dynamic model with large rotation for the SDBC system. The model incorporates the spin and whirl of the rotor, enabling the realistic reproduction of multiblade rubbing faults. To verify the accuracy of the SDBC model with large rotation and demonstrate its capability to effectively consider the rotational effects such as the centrifugal stiffening and gyroscopic effects, the natural characteristics and dynamic responses of the proposed model are compared with those obtained from reported research and experimental results. Furthermore, the effects of the rotating speed, contact stiffness,and blade number on the dynamic characteristics of the SDBC system with multi-blade rubbing are investigated. The results indicate that the phase angle between the rotor deflection and the unbalance excitation force increases with the increasing rotating speed,which significantly influences the rubbing penetration of each blade. The natural frequency of the SDBC system with rubbing constrain can be observed in the acceleration response of the casing and the torsional response of the shaft, and the frequency is related to the contact stiffness. Moreover, the vibration amplitude increases significantly with the product of the blade number under rubbing, and the rotating frequency approaches the natural frequency of the SDBC system. The proposed model can provide valuable insight for the fault diagnosis of rubbing in bladed rotating machinery.

关键词： shaft-disk-blade-casing(SDBC) large rotation spin and whirl multi-blade rubbing rotational effect

Advances in sodium-ion batteries at low-temperature: Challenges and strategies

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Journal of Energy Chemistry 2024年第3期90卷 518-539,I0012页

作者： Haoran Bai Xiaohui Zhu Huaisheng ao Guangyu He Hai Xiao Yinjuan chen Key Laboratory of Advanced Catalytic Materials and Technology Advanced Catalysis and Green Manufacturing Collaborative Innovation CenterChangzhou UniversityChangzhou 213164JiangsuChina Department of Chemistry Tsinghua UniversityBeijing 100084China

With the continuing boost in the demand for energy storage,there is an increasing requirement for batteries to be capable of operation in extreme environmental conditions.Sodium-ion batteries(SIBs) have emerged as a highly promising energy storage solution due to their promising performance over a wide range of temperatures and the abundance of sodium resources in the earth's crust.Compared to lithiumion batteries(LIBs),although sodium ions possess a larger ionic radius,they are more easily desolvated than lithium ions.Fu rthermore,SIBs have a smaller Stokes radius than lithium ions,resulting in improved sodium-ion mobility in the electrolyte.Nevertheless,SIBs demonstrate a significant decrease in performance at low temperatures(LT),which constrains their operation in harsh weather conditions.Despite the increasing interest in SIBs,there is a notable scarcity of research focusing specifically on their mechanism under LT conditions.This review explores recent research that considers the thermal tolerance of SIBs from an inner chemistry process perspective,spanning a wide temperature spectrum(-70 to100℃),particularly at LT conditions.In addition,the enhancement of electrochemical performance in LT SIBs is based on improvements in reaction kinetics and cycling stability achieved through the utilization of effective electrode materials and electrolyte components.Furthermore,the safety concerns associated with SIBs are addressed and effective strategies are proposed for mitigating these issues.Finally,prospects conducted to extend the environmental frontiers of commercial SIBs are discussed mainly from three viewpoints including innovations in materials,development and research of relevant theoretical mechanisms,and intelligent safety management system establishment for larger-scale energy storage SIBs.

关键词： Low-temperature Sodium-ion batteries Reaction kinetics Cycle stability Safety concerns of Sodium-ion batteries

Europium-bearing organic framework with excellent X-ray scintillating luminescence

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Journal of Rare Earths 2024年第2期42卷 251-255,I0001页

作者： Yugang Zhang Lanhua chen Xia Wang Wei Liu Shu'ao Wang State Key Laboratory of Radiation Medicine and Protection School for Radiological and Interdisciplinary Sciences(RAD-X)and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education InstitutionsSoochow UniversitySuzhou215123China School of Environmental and Materials Engineering Yantai UniversityYantai264005China

Two europium-bearing organic frameworks,termed as EuTPO-1 and EuTPO-2(H_(3)TPO=tris(4-carboxylphenyI)-phosphineoxide),are reported in this work.A series of characterizations of EuTPO-1and EuTPO-2,such as X-ray crystallography and photoluminescence spectroscopy,was performed to expatiate their structure and physicochemical properties.Both of them are constructed by dimers of the europium-oxygen subunit of [Eu_(2)O_(16)] and TPO molecule.Benefiting from high X-ray stopping attenuation and excellent luminescence efficiency,they emit sufficient luminescence when irradiated with Xrays.Meanwhile,they possess stable light outputs when exposed to high humidities and strong radiation dose,outperforming the commercial scintillator CsI:Tl.This result paves the way for developing new scintillator and enriches the compound of europium-bearing organic framework with X-ray scintillating luminescence.

关键词： Metal-organic frameworks Scintillating material Luminescence efficiency Rare earths

Di-and tri-methylation of histone H3K36 play distinct roles in DNA double-strand break repair

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Science China(Life Sciences) 2024年第6期67卷 1089-1105页

作者： Runfa chen Meng-Jie Zhao Yu-Min Li ao-Hui Liu Ru-Xin Wang Yu-Chao Mei Xuefeng chen Hai-Ning Du Hubei Key Laboratory of Cell Homeostasis College of Life SciencesTaiKang Center for Life and Medical SciencesFrontier Science Center for Immunology and MetabolismHubei Clinical Research Center of Emergency and ResuscitationEmergency Center of Zhongnan HospitalWuhan UniversityWuhan 430072China Hubei Key Laboratory of Cell Homeostasis College of Life SciencesTaiKang Center for Life and Medical SciencesFrontier Science Center for Immunology and MetabolismWuhan UniversityWuhan 430072China

Histone H3 Lys36(H3K36)methylation and its associated modifiers are crucial for DNA double-strand break(DSB)repair,but the mechanism governing whether and how different H3K36 methylation forms impact repair pathways is unclear.Here,we unveil the distinct roles of H3K36 dimethylation(H3K36me2)and H3K36 trimethylation(H3K36me3)in DSB repair via non-homologous end joining(NHEJ)or homologous recombination(HR).Yeast cells lacking H3K36me2 or H3K36me3 exhibit reduced NHEJ or HR efficiency.y Ku70 and Rfa1 bind H3K36me2-or H3K36me3-modified peptides and chromatin,respectively.Disrupting these interactions impairs y Ku70 and Rfa1 recruitment to damaged H3K36me2-or H3K36me3-rich loci,increasing DNA damage sensitivity and decreasing repair efficiency.Conversely,H3K36me2-enriched intergenic regions and H3K36me3-enriched gene bodies independently recruit y Ku70 or Rfa1 under DSB stress.Importantly,human KU70 and RPA1,the homologs of y Ku70 and Rfa1,exclusively associate with H3K36me2 and H3K36me3 in a conserved manner.These findings provide valuable insights into how H3K36me2 and H3K36me3 regulate distinct DSB repair pathways,highlighting H3K36 methylation as a critical element in the choice of DSB repair pathway.

关键词： histone H3K36 methylation Ku70 RPA non-homologous end joining homologous recombination

Performance Characterization of CR/PU Asphalt for Potential Application in Assembled Fast-Repairing Engineering

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Fluid Dynamics & Materials Processing 2024年第5期20卷 1063-1074页

作者： Hong Pang ao Lu Ming Xiong chen chen Xian Cao Xiong Xu Jing Wang Hubei Regional Management Headquarters CCCC Asset Management Co.Ltd.Beijing101399China School of Civil Engineering and Architecture Wuhan Institute of TechnologyWuhan430073China Hubei Provincial Engineering Research Center for Green Civil Engineering Materials and Structures Wuhan Institute of TechnologyWuhan430073China

Conventional repairing methods for asphalt pavement have some inconveniences,such as insufficient strength,and are typically time-consuming.To address these issues,this study proposes a new technological method to design and prepare a high-performance assembled asphalt concrete block for fast repair of the potholes.A series of composite modified asphalt binders with 10%crumb rubber(CR)and different dosages(0%,1%,3%,5%)of polyurethane(PU)are examined to determine the optimized binder.Subsequently,the corresponding asphalt mixtures are prepared for further comparison and assessment of engineering properties,such as moistureinduced damage,high-temperature deformation,and low-temperature cracking characteristics.The test results show that PU can significantly improve the high-temperature performance and hardness of(crumb rubber modified asphalt)CRMA binder;3%PU contributes allowing the resistance of CRMA mixture to moisture-induced damage at higher levels,particularly under water whole immersion;as 3%PU is added,the high-temperature rutting deformation resistance of the CRMA mixture increases significantly,and the low-temperature anti-cracking properties are also improved slightly.Therefore,the innovatively designed high-quality assembled fast-repairing asphalt concrete block is recommended as an appropriate option for highway maintenance.

关键词： Composite modified asphalt crumb rubber polyurethane assembled fast-repairing asphalt concrete maintenance engineering

Molecular understanding of cation effects on double layers and their significance to CO-CO dimerization

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National Science Review 2023年第9期10卷 125-135页

作者： Jia-Bo Le ao chen Yongbo Kuang Jun cheng Key Laboratory of Advanced Fuel Cells and Electrolyzers Technology of Zhejiang Province Ningbo Institute of Materials Technology and EngineeringChinese Academy of Sciences State Key Laboratory of Physical Chemistry of Solid Surfaces iChEM College of Chemistry and Chemical EngineeringXiamen University Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM)

Cation effects have been shown in numerous experiments to play a significant role in electro catalysis.To understand these effects at the molecular level,we systematically investigate the structures and capacitances of electric double layers with a variety of cations as counter charges at Pt(111)-COad/water interfaces with ab initio molecular dynamics.It is encouraging to find that the computed Helmholtz capacitances for different cations are in quantitative agreement with experiments,and that the trend of cation effects on capacitances shows clear correlation with the structures of interface cations of differing sizes and hydration energies.More importantly,we demonstrate the Helmholtz capacitance as the key descriptor for measuring the activity of CO-CO dimerization,the rate-determining step for C2+formation in electroreduction of CO and CO2.Our work provides atomistic insights into cation effects on electric double layers and electrocatalysis that are crucial for optimizing electrode and electrolyte materials.

关键词： cation effect electrocatalysis electric double layer CO-CO dimerization ab initio molecular dynamics

Promoting Ethylene (co)Polymerization in Aliphatic Hydrocarbon Solvents Using tert-Butyl Substituted Nickel Catalysts

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Chinese Journal of Chemistry 2022年第2期40卷 215-222页

作者： ao chen Daohong Liao Changle chen Hefei National Laboratory for Physical Sciences at the Microscale CAS Key Laboratory of Soft Matter ChemistryDepartment of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefeiAnhui 230026China

In the past few decades,the development of high-performance catalysts has been a key driving force and a center of research efforts in the field of olefin polymerization.However,a major discrepa ncy exists between in dustrial researches which utilize aliphatic hydrocarb on solventsz and academic researches which predominantly focus the catalytic properties in aromatic solvents.In this con-tribution,a novel diaryl-methyl aniline bearing eight tert-butyl groups was prepared and subsequently transformed to four different kinds of imine-type ligands.The corresponding nickel complexes as well as their counterparts derived from diphenyl-methyl aniline without the tert-butyl groups were prepared and investigated in ethylene polymerization.

关键词： Ethylene polymerization Polyethylene Nickel Solvent effects Steric hindranee

Comprehensive insight into the occurrence characteristics,influencing factors and risk assessments of antibiotics in the Chaohu Basin

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 57-71页

作者： Shuanggang Hu Hongzhi Zhang Yongjie Yang Kangping Cui Junjie ao Xuneng Tong Mengchen Shi Yi Wang Xing chen chenxuan Li Yihan chen School of Resources and Environmental Engineering Hefei University of TechnologyHefei230009China Ministry of Education-Shanghai Key Laboratory of Children’s Environmental Health Xinhua HospitalShanghai Jiao Tong University School of MedicineShanghai200092China Department of Civil & Environmental Engineering National University of SingaporeSingapore117576Singapore College of Resources and Environment Anhui Agricultural UniversityHefei230036China

The pollution of antibiotics in aquatic environments has received extensive attention.Yet,research on antibiotic contamination in river-lake systems,a significant form of modern aquatic environments,still needs to be explored.This study focuses on the Chaohu Basin(China)investigating the occurrence characteristics,influencing factors,and risk assessments of antibiotics in the river-lake system.The total antibiotic concentrations in the water phase and sediment phase were 3.14–1887.49 ng/L and 0.92–1553.75 ng/g,respectively.Clindamycin was the predominant antibiotic in the water phase,whereas tetracycline prevailed in the sediment phase.Notable differences in concentration and structural composition of antibiotics between the tributaries(river system)and Chaohu Lake were observed,indicating the involvement of various geochemical processes in the attenuation of antibiotics during transport to the receiving lake.Spatial analysis suggested that the western river is the primary source of antibiotics in Chaohu Lake.Controlling nutrient influx in heavily polluted areas is crucial to addressing the escalating issue of antibiotic pollution in the river-lake system.The widespread occurrence of clindamycin in the waters is likely due to wastewater treatment plant discharges,and high-intensity human activities continue to exacerbate antibiotic contamination.Risk assessment indicated that sulfamethoxazole,tetracycline,lincomycin,and clindamycin ranked in the top four with the highest risks to the most sensitive aquatic organisms.Nonetheless,the antibiotics presented no risk to consumer health.This study provides valuable insights for controlling antibiotic pollution in riverlake systems.

关键词： Antibiotics Occurrence characteristics Influencing factors Risk assessments River-lake system

Texture and Se vacancy optimization induces high thermoelectric performance in Bi2Se3 flexible thin films

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Rare Metals 2024年第6期43卷 2796-2804页

作者： Dong-Wei ao Wei-Di Liu Yue-Xing chen Fan Ma Yi-Jie Gu Zhuang-Hao Zheng School of Machinery and Automation Weifang University Australian Institute for Bioengineering and Nanotechnology The University of Queensland Shenzhen Key Laboratory of Advanced Thin Films and Applications Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong ProvinceCollege of Physics and Optoelectronic EngineeringShenzhen University School of Materials Science and Engineering Inner Mongolia University of Technology

Bi2Se3-based flexible thin film with high thermoelectric performance is promising for the waste heat recovery technology.In this work,a novel post-selenization method is employed to prepare n-type Bi2Se3flexible thin films with highly textured structure.The strengthened texture and Se vacancy optimization can be simultaneously achieved by optimizing the selenization temperature.The highly oriented texture leads to the increased carrier mobility and results in a high electric conductivity of ～290.47 S·cm-1at 623 K.Correspondingly,a high Seebeck coefficient(> 110 μW·K-1) is obtained due to the reduced carrier concentration,induced by optimizing vacancy engineering.Consequently,a high power factor of 3.49 μW·cm-1·K-2at 623 K has been achieved in asprepared highly-bendable Bi2Se3flexible thin films selenized at 783 K.This study introduces an effective post-selenization method to tune the texture structure and vacancies of Bi2Se3flexible thin films,and correspondingly achieves high thermoelectric performance.

关键词： Thermoelectric Bi 2 Se 3 Flexible thin film Post-selenization