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Effect of Ellipsoidal Particle Shape on Tribological Properties of Lubricants Containing Nanoparticles

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Chinese Journal of Mechanical Engineering 2024年第4期37卷 231-242页

作者： Ling pan zhi Li Yunhui Chen Guobin Lin School of Advanced Manufacturing Fuzhou UniversityQuanzhou 362251FujianChina School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350108FujianChina

Adding nanoparticles can significantly improve the tribological properties of ***,there is a lack of understanding regarding the influence of nanoparticle shape on lubrication *** this work,the influence of diamond nanoparticles(DNPs)on the tribological properties of lubricants is investigated through friction ***,the friction characteristics of lubricants regarding ellipsoidal particle shape are investigated using molecular dynamics(MD)*** results show that DNPs can drastically lower the lubricant's friction coefficientμfrom 0.21 to *** shearing process reveals that as the aspect ratio(α)of the nanoparticles approaches 1.0,the friction performance improves,and wear on the wall *** the same time,the shape of the nanoparticles tends to be *** 0.85≤α≤1.0,rolling is ellipsoidal particles'main form of motion,and the friction force changes according to a periodic sinusoidal *** the range of 0.80≤α<0.85,ellipsoidal particles primarily exhibit sliding as the dominant movement ***αdecreases within this range,the friction force progressively *** friction coefficientμcalculated through MD simulation is 0.128,which is consistent with the experimental data.

关键词： Molecular dynamics simulation Nanoparticle additives Ellipsoidal particles Tribological properties

Downregulation of Cav3.1 T-type Calcium Channel Expression in Age-related Hearing Loss Model

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Current Medical Science 2021年第4期41卷 680-686页

作者： Chun-chen pan zhi-hui DU yi ZHAO Han-qi CHU Jin-wu SUN Department of Otorhinolaryngology-Head and Neck Surgery the First Affiliated Hospital of University of Science and Technology of ChinaDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei230001China Department of Otolaryngology-Head and Neck Surgery Tongji HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China

Objective Age-related hearing loss(AHL),characterized by degeneration of cochlea structures,is the most common sensory disorder among the elderly *** calcium channel is considered to contribute to normal ***,the role of the T-type voltage-activated calcium channel,Cav3.1,remains unclear in ***,we investigate the age-related change of Cav3.1 expression in the cochlea and D-gal-induced senescent HEI-OC1 *** Cochleae from C57BL/6 mice at 2 months and 12 months of age were *** in House Ear Institute-Organ of Corti 1(HEI-OC1)cells was induced by D-gal *** immunofluorescence technique was employed to investigate the distribution of Cav3.1 in vivo and in *** assessment was achieved by Western blotting and real-time *** In comparison with 2-month-old animals,12-month old C57BL/6 mice exhibited great loss of hair cells and elevated auditory brainstem *** Cav3.1 was located in hair cells,spiral ganglion cells,lateral walls,and the expression of Cav3.1 protein and mRNA decreased in the aged cochleae.D-gal-induced senescence assay confirmed the down-regulation of Cav3.1 expression in senescent HEI-OC1 *** Our results show that age-related down-regulated expression of Cav3.1 in the cochleae is associated with AHL and may contribute to the pathogenesis of AHL.

关键词： presbycusis HEI-OC1 cochlea C57BL/6 mouse

Rare Earth Elements(La,Ce,Pr)Modified Co/NC Catalyst for Efficient and Stable Ammonia Decomposition to Hydrogen Production

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Journal of Wuhan University of Technology(Materials Science) 2024年第6期39卷 1372-1378页

作者： ZHU yi pan Hongfei State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China National Energy Key Laboratory for New Hydrogen-ammonia Energy Technologies Foshan Xianhu LaboratoryFoshan 528200China

Co/NC catalysts modified with rare earth elements(La,Ce,Pr)were prepared by pyrolysis of rare earth elements doped *** experimental results show that the modification of rare earth elements significantly improves the ammonia decomposition activity and stability of the Co/NC *** La-Co/NC catalyst can achieve an 82.3%ammonia decomposition and 18.4 mmol hydrogen production rate at 550℃with a GHSV of 20000 cm^(3)·h^(-1).Furthermore,no obvious performance degradation is observed after 72 hours of reaction for all rare earth elements modified *** is shown that the modification of rare earth elements significantly improves the surface alkalinity and surface chemical state of the catalyst,and thus improves the ammonia decomposition activity of the catalyst.A new type of high-performance ammonia decomposition Co-based catalyst is proposed,and the promoting effect of rare earth elements on the activity of ammonia decomposition is revealed.

关键词： hydrogen carrier hydrogen production ammonia decomposition rare earth elements cobalt-based catalysts

Broadband and perfect terahertz absorber based on multilayer metamaterial with cross-ring patterned structures

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Optoelectronics Letters 2025年第1期21卷 1-6页

作者： WEN Jin LIU Zhanzhi WU Zhengwei pan Yu ZHANG ying School of Science Xi'an Shiyou University Shaanxi Key Laboratory of Measurement and Control Technology for Oil and Gas Wells

Broadband and perfect terahertz absorber based on multilayer metamaterial using cross-ring patterned structures is proposed and investigated. The structure of the absorber is double absorption layers consisting of a chromium cross ring and eight isosceles right triangles. The unique structure of the double absorbing layers excites the electric dipole multimode resonance, giving rise to high absorption performance. Meanwhile, the influence of construal parameters on absorber behavior is also discussed. The numerical results show that the absorption achieves over 90% ranging from 2.45 THz to 6.25 THz and 99% absorption in the range of 3.7—5.3 THz. The realization of broadband and perfect absorber is described using the impedance matching principle. It is obviously found that the absorber is insensitive to the high angle of incidence for both transverse electric(TE) and transverse magnetic(TM) polarizations. Compared with the former reports, this absorber has remarkable improved absorption efficiency and smaller period. The terahertz absorber may be found applications in the fields of energy capture and thermal detection.

关键词： Metamaterials

Luminescence properties of red-emitting Ca_2Al_2SiO_7:Eu^(3+) nanoparticles prepared by sol-gel method

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Rare Metals 2011年第4期30卷 374-380页

作者： CAI Jinjun pan Huanhuan WANG yi School of Chemical and Environmental Engineering Wuyi University Jiangmen 529020 China Institute of Functional Materials Wuyi University Jiangmen 529020 China School of Applied Physics and Materials Wuyi University Jiangmen 529020 China

A series of red-emitting Ca2_xA12SiOT：xEu^3＋（x = 1 mol.%-10 tool.%） phosphors were synthesized by the sol-gel method. The effects of annealing temperature and doping concentration on the crystal structure and luminescence properties of Ca2A12SiO7：Eu^3＋ phosphors were investigated. X-ray diffraction （XRD） profiles showed that all peaks could be attributed to the tetragonal Ca2A12SiO7 phase when the sample was annealed at 1000℃. Scanning electron microscopy （SEM） micrographs indicate that the phosphors have an irregularly rounded mor- phology with particles of about 200 nm. Excitation spectra showed that the strong broad band at around 258 nm and weak sharp lines in 350-490 nm were attributed to the charge transfer band of Eu^3＋-O^2- and f-f transitions within the 4f^6 configuration of Eu^3＋ ions, respectively. Emission spectra implied that the red luminescence could be attributed to the transitions from the ^5D0 excited level to the 7Fj （J = 0, 1, 2, 3, 4） levels of Eu3＋ions with the main electric dipole transition ^5D0→^7F2 （618 and 620 nm）, and Eu^3＋ ions prefer to occupy a lower symmetry site in the crystal lattice. Moreover, the photoluminescence （PL） intensity was strongly dependent on both the sintering temperature and doping concentration, and the highest PL intensity was observed at an Eu^3＋ concentration x = 7 mol.% after annealing at ll00℃. The obtained Ca2A12SiO7：Eu^＋3＋ phosphor may have potential application for the red lamp phosphor.

关键词： optical materials red phosphor sol-gel method photoluminescence silicates

Sulfur dioxide gas sensing at room temperature based on tin selenium/tin dioxide hybrid prepared via hydrothermal and surface oxidation treatment

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Rare Metals 2021年第6期40卷 1588-1596页

作者： Qian-Nan pan zhi-Min Yang Wei-Wei Wang Dong-zhi Zhang College of Control Science and Engineering China University of Petroleum(East China)Qingdao 266580China

In this paper,a novel SnSe/SnO_(2) nanoparticles(NPs) composite has been successfully fabricated through hydrothermal method and surface oxidation *** as-prepared sample was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM).A series of morphological and structural characteristics confirm that the SnSe/SnO_(2) NPs composite shows a core-shell structure with a SnO_(2) shell with thickness of 6 *** prepared SnO_(2) NPs and SnSe/SnO_(2) NPs composite were applied as gas-sensing materials,and their gas-sensing properties were investigated at room temperature *** results show that the response value of the SnSe/SnO_(2) composite sensor toward 100×10^(-6) SO_(2) is 15.15%,which is 1.32 times higher than that of pristine SnSe(11.43%).And the SnSe/SnO_(2) composite sensor also has a detection limit as low as 74×10^(-9) and an ultra-fast response *** enhanced gas-sensing performance is attributed to the formation of p-n heterojunction between SnSe and SnO_(2) and the appropriate SnO_(2) shell thickness.

关键词： SO_(2)gas sensor Room temperature detection Core-shell structure SnSe/SnO_(2)composite Debye length

Studies on the Structure of Kansuinine A from Euphorbia kansui

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Chinese Chemical Letters 2002年第12期13卷 1178-1180页

作者： Qin pan zhi Da MIN Department of Natural Medicine Chemistry China Pharmaceutical UniversityNanjing 210009

Kansuinine A is a macrocyclic jatrophane diterpene that was isolated from Euphorbia kansui. Further investigation of the structure was revealed that the benzoyl group located at C-8 and the position of C-3 was the pr... 详细信息

关键词： Euphorbia kansui kansuinine A.

Construction of 3D porous Cu_(1.81)S/nitrogen-doped carbon frameworks for ultrafast and long-cycle life sodium-ion storage

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 191-200页

作者： Chen Chen Hongyu Xue Qilin Hu Mengfan Wang pan Shang Ziyan Liu Tao Peng Deyang Zhang Yongsong Luo Key Laboratory of Microelectronics and Energy of Henan Province Henan Joint International Research Laboratory of New Energy Storage TechnologyCollege of Physics and Electronic EngineeringXinyang Normal UniversityXinyang 464000China School of Physics and Electronic Engineering Nanyang Normal UniversityNanyang 473061China

Transition metal sulfides have great potential as anode mterials for sodium-ion batteries(SIBs)due to their high theoretical specific ***,the inferior intrinsic conductivity and large volume variation during sodiation-desodiation processes seriously affect its high-rate and long-cyde performance,unbeneficial for the application as fast-charging and long-cycling SIBs ***,the three-dimensional porous Cu_(1.81)S/nitrogen-doped carbon frameworks(Cu_(1.81)S/NC)are synthesized by the simple and facile sol-gel and annealing processes,which can accommodate the volumetric expansion of Cu_(1.81)S nanoparticles and accelerate the transmission of ions and electrons during Na^(+)insertion/extraction processes,exhibiting the excellent rate capability(250.6 mA·g^(-1)at 20.0 A·g^(-1))and outstanding cycling stability(70% capacity retention for 6000 cycles at 10.0 A·g^(-1))for ***,the Na-ion full cells coupled with Na_(3)V_(2)(PO_(4))_(3)/C cathode also demonstrate the satisfactory reversible specific capacity of 330.5 mAh·g^(-1)at 5.0 A·g^(-1)and long-cycle performance with the 86.9% capacity retention at 2.0 A·g^(-1)after 750 *** work proposes a promising way for the conversionbased metal sulfides for the applications as fast-charging sodium-ion battery anode.

关键词： copper sulfide nanoparticles porous carbon framework fast charging long-cycle performance sodium-ion full batteries

Visible-light-mediated tungsten-catalyzed C-H amination of unactivated alkanes with nitroarenes

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Science China Chemistry 2022年第4期65卷 678-685页

作者： Qing Wang Shengyang Ni Xiaochen Wang yi Wang yi pan State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

Alkylamines are important motifs in pharmaceutical and material *** existing reports of C-H amination are limited to ammonia,diazo and azide nitrogen *** work describes a rapid construction of C-N bonds from accessible nitroarene and alkane feedstock under decatungstate catalysis.A variety of C-H precursors including gaseous,linear,cyclic and benzylic hydrocarbons could adopt this protocol to afford the corresponding alkylamines in high efficiency.

关键词： amination photoredox light alkane nitrobenzene