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Magnetic coupling engineered porous dielectric carbon within ultralow filler loading toward tunable and high-performance microwave absorption 被引量:6
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作者 Wang Yang Bo Jiang +7 位作者 Zhihui liu Rui li liqiang Hou Zhengxuan li Yongli Duan Xingru Yan Fan Yang yongfeng li 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2021年第11期214-223,共10页
Developing microwave absorption(MA)materials with satisfied comprehensive performance is a great challenge for tackling severe electromagnetic pollution.In particular,the magnetic component/carbon hybrids absorbers al... Developing microwave absorption(MA)materials with satisfied comprehensive performance is a great challenge for tackling severe electromagnetic pollution.In particular,the magnetic component/carbon hybrids absorbers always suffer from high filler loading.Herein,we propose a feasible strategy to construct hierarchical porous carbon with tightly embedded Ni nanoparticles(Ni@NPC).These highly dispersed Ni nanoparticles produce strong magnetic coupling networks to enhance magnetic loss abilities.Moreover,the interconnected hierarchical dielectric carbon network affords favorable dipolar/interfacial polarization,conduction loss,multiple reflection and scattering.Impressively,with an ultralow filler loading of 5 wt.%,the resultant Ni@NPC/paraffin composite achieves an excellent MA performance with a minimum reflection loss of as high as-72.4 dB and a broad absorption bandwidth of 5.0 GHz.This capability outperforms most current magnetic-dielectric hybrids counterparts.Furthermore,the MA capacity can be easily tuned with adjustments in thickness,content and type of magnetic material.Thus,this work opens up new avenues for the development of high-performance and lightweight MA materials. 展开更多
关键词 Hierarchical porous carbon Magnetic nanoparticles Magnetic coupling Ultralow filler loading High-performance microwave absorption
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Reduced graphene oxide supported Pd-Cu-Co trimetallic catalyst:synthesis,characterization and methanol electrooxidation properties 被引量:2
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作者 Fan Yang Bing Zhang +4 位作者 Sen Dong Chunxia Wang Andong Feng Xiaoxu Fan yongfeng li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第2期72-78,共7页
Trimetallic palladium-copper-cobalt nanoparticles supported on reduced graphene oxide(PdCuCo/RGO)with different molar ratios of Pd,Cu and Co can be synthesized by facile chemical reduction with NaBH_4 as reductant and... Trimetallic palladium-copper-cobalt nanoparticles supported on reduced graphene oxide(PdCuCo/RGO)with different molar ratios of Pd,Cu and Co can be synthesized by facile chemical reduction with NaBH_4 as reductant and cetrimonium bromide as stabilizer.The morphology,structure and composition of the as-synthesized catalysts are characterized by transmission electron microscopy,X-ray diffraction and Xray photoelectron spectroscopy.The cyclic voltammetry and chronoamperometry are utilized to investigate the electrochemical activities and stabilities of the as-obtained catalysts.The results demonstrate that the PdCuCo/RGO catalyst shows superior catalytic activity and stability for methanol electrooxidation in alkaline media compared with PdCu/RGO,PdCo/RGO,and Pd/RGO catalysts.These findings suggest that the PdCuCo/RGO catalyst possesses a great potential as a promising anode catalyst for direct methanol fuel cells. 展开更多
关键词 Trimetallic nanoparticles REDUCED graphene OXIDE METHANOL OXIDATION
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Mo-doped CoP nanoparticles anchored on porous Co-N-C framework as an efficient bifunctional electrocatalyst for pH-universal water splitting 被引量:1
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作者 Guohua li Fan Yang +7 位作者 Sai Che Hongchen liu Neng Chen Jinxiu Qian Chunhui Yu Bo Jiang Mengxi liu yongfeng li 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第35期58-66,共9页
Designing highly active and stable noble-metal-free electrocatalysts for water splitting over a wide pH range is critical yet remains significantly challenging.In this work,Mo-doped CoP nanoparticles(Mo-CoP)supported ... Designing highly active and stable noble-metal-free electrocatalysts for water splitting over a wide pH range is critical yet remains significantly challenging.In this work,Mo-doped CoP nanoparticles(Mo-CoP)supported and enwrapped by porous single-atomic-Co doped carbon framework(Co-N-C)were designed and prepared by a simple one-pot pyrolysis method.The Mo-CoP/Co-N-C electrocatalyst exhibits superior performance with low overpotentials of only 45 mV for hydrogen evolution reaction(HER)and 201 mV for oxygen evolution reaction(OER)in 1 M KOH at 10 mA cm^(-2)current density.Such excellent catalytic activity can be ascribed to enhanced intrinsic activity,large surface area,and highly exposed active sites.Meanwhile,an extremely small overpotential of only 250 mV is required for a large current density of 500 mA cm^(-2)in HER,which exceeds the performance of benchmark 10%Pt/C.Besides,Mo-CoP/Co-N-C also exhibits superior HER performance in acidic and neutral mediums,with overpotentials of only 41 and 98 mV in 0.5 M H_(2)SO_(4),and 1 M PBS,respectively,thus achieving efficient water splitting at a wide pH range.The long-term stabilities are guaranteed with no significant decline of catalytic activities for more than 24 h in all electrolytes,which can be ascribed to the carbon layer encapsulation structure.Addition-ally,in overall water splitting,the electrocatalytic cell consisting of the as-synthesized Mo-CoP/Co-N-C only requires a cell voltage of 1.611 V at 100 mA cm^(-2)with excellent stability,exceeding that of the benchmark Pt/C||RuO(2) couple(1.645 V at 100 mA cm^(-2)).This work not only presents a highly efficient electrocatalyst for pH-universal water splitting but also provides a new perspective for the design and construction of transition metal catalysts with excellent stability. 展开更多
关键词 Cobalt phosphide Mo doping Single atomic catalyst Water splitting pH-universal
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Laser ablation mechanism and performance of glass fiber-reinforced phenolic composites:An experimental study and dual-scale modelling 被引量:1
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作者 Ran BI Pengfei SHEN +4 位作者 Longyu ZHU Zhengzheng MA Chuyang LUO yongfeng li lijian PAN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2024年第8期470-485,共16页
Both experimental and simulation approaches were employed to investigate the laser ablation mechanism and performances of Glass Fiber Reinforced Phenolic Composites(GFRP).During the ablation process,the difference in ... Both experimental and simulation approaches were employed to investigate the laser ablation mechanism and performances of Glass Fiber Reinforced Phenolic Composites(GFRP).During the ablation process,the difference in thermal conductivities of the glass fibers and the resin matrix as well as their discrepant physical and chemical reactions form a conical ablation morphology.The formation of a residual carbon layer effectively mitigates the ablation rate in the thickness direction.A higher power density results in a faster ablation rate,while a longer irradiation time leads to a larger ablation pit diameter.To account for the variation in thermal conductivity between the fiber and resin,a macro-mesoscale model was developed to differentiate the matrix from the fiber components.Finite element analysis revealed that laser irradiation leads to phenolic decomposition,glass fiber melting vaporization,and residual carbon skeleton evaporation.The dual-scale model exhibits precise prediction capabilities concerning the laser ablation process of GFRP,and its accuracy is confirmed through the comparison of simulation and experimental results for the GFRP laser ablation process.This model provides a feasible method for performance evaluation and lifetime prediction of GFRP subjected to continuous wave laser irradiation. 展开更多
关键词 Polymer-matrix composites Continuous-wave laser Microstructural analysis Ablation mechanism Finite element method
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Evaluation of Holstein cows with different tongue‑rolling frequencies:stress immunity,rumen environment and general behavioural activity
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作者 Fuyu Sun Xiaoyang Chen +2 位作者 yongfeng li Guangyong Zhao Xianhong Gu 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第6期2686-2700,共15页
Background The tongue-rolling behaviour of cows is regarded as an outward sign of stressed animals in a low welfare status.The primary aim of this observational study was to evaluate the association between the freque... Background The tongue-rolling behaviour of cows is regarded as an outward sign of stressed animals in a low welfare status.The primary aim of this observational study was to evaluate the association between the frequency of tongue-rolling behaviour and its physiological function.The secondary aim was to explore the relationship between general activities and the frequency of tongue-rolling behaviour of cows.A total of 126 scan sampling behavioural observations were collected over 7 d on 348 Holstein cows with the same lactation stage in the same barn.The tongue-rolling frequency was defined as the number of tongue-rolling observations as a percentage to the total observations per individual cow.According to their tongue-rolling frequency,the cows were grouped into the CON(no tongue-rolling),LT(frequency 1%),MT(frequency 5%),and HT(frequency 10%)groups.Six cows from each group were randomly selected for sampling.Serum samples,rumen fluid,milk yield,and background infor-mation were collected.The general behaviour data during 72 continuous hours of dairy cows,including eating time,rumination time,food time(eating time+rumination time),and lying time,were recorded by the collar sensor.Results Cortisol(P=0.012),γ-hydroxybutyric acid(P=0.008),epinephrine(P=0.030),and dopamine(P=0.047)levels were significantly higher in tongue-rolling groups than in the CON group.Cortisol levels and tongue-rolling frequency had a moderate positive correlation(linearly r=0.363).With the increase in tongue-rolling frequency,the rumen pH decreased first and then increased(P=0.013),comparing to the CON group.HT cows had significantly less food time than CON cows(P=0.035).The frequency of tongue-rolling had a moderate negative relationship with rumination time(r=-0.384)and food time(r=-0.492).Conclusions The tongue-rolling behaviour is considered as a passive coping mechanism,as the stress response in cows with high tongue-rolling frequency increased.Food intake and rumination activities were all closely related to the occurrence of tongue-rolling behaviour. 展开更多
关键词 General activity Holstein cow Rumen fermentation Stress immunity Tongue rolling
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Exfoliated multi-layered graphene anode with the broadened delithiation voltage plateau below 0.5 V
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作者 Xinlong Ma Xinyu Song +6 位作者 Yushu Tang Enzuo liu Chenggen Xu Chuanlei Qi Yun li Jinsen Gao yongfeng li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第10期233-242,共10页
The commercial graphite(CG)is the conventional anode material for lithium ion batteries(LIBs)due to its low delithiation voltage plateau(below 0.5 V)and extraordinary durability.Nevertheless,the further promotion of e... The commercial graphite(CG)is the conventional anode material for lithium ion batteries(LIBs)due to its low delithiation voltage plateau(below 0.5 V)and extraordinary durability.Nevertheless,the further promotion of energy density of LIBs is restricted by the limited capacity below 0.5 V of CG.Here,based on the supercritical CO2 exfoliation technique,the production of multi-layered graphene(MLG)is achieved from the pilot scale production line.The great merit of the exfoliated MLG anode is that the voltage plateau below 0.5 V is broadened obviously as compared to those of natural graphite and CG.Additionally,no obvious lithium dendrites are observed for MLG during the lithiation process.The large delithiation capacity under the low voltage plateau of MLG is mainly benefited from the combination of Li intercalation and boundary storage mechanism,which is further confirmed by the density functional theory calculations.The LiFePO4/MLG full cell can afford the satisfactory electrochemical property with respect to the capacity,energy density and ultralong cycling stability(90%capacity retention after 500 cycles at 2 C),significantly better than that of LiFePO4/CG.Besides,this developed technique not only dedicates to producing the high-performance anode for LIBs but also opens a door for the mass production of MLG in the industrial scale. 展开更多
关键词 Multi-layered graphene Supercritical CO2 exfoliation ANODE Broadened delithiation voltage plateau Intercalation and boundary storage
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High mass loading NiCo_(2)O_(4) with shell-nanosheet/core-nanocage hierarchical structure for high-rate solid-state hybrid supercapacitors
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作者 Wang Yang liqiang Hou +5 位作者 Peng Wang Yun li Rui li Bo Jiang Fan Yang yongfeng li 《Green Energy & Environment》 SCIE EI CSCD 2022年第4期723-733,共11页
Rational design of advanced structure for transition metal oxides(TMOs) is attractive for achieving high-performance supercapacitors.However, it is hampered by sluggish reaction kinetics, low mass loading, and volume ... Rational design of advanced structure for transition metal oxides(TMOs) is attractive for achieving high-performance supercapacitors.However, it is hampered by sluggish reaction kinetics, low mass loading, and volume change upon cycling. Herein, hierarchical Ni Co_(2)O_(4) architectures with 2D-nanosheets-shell and 3D-nanocages-core(2D/3D h-NCO) are directly assembled on nickel foam via a facile one-step way.The 2D nanosheets are in-situ generated from the self-evolution of initial NCO nanospheres. This 2D/3D hierarchical structures ensure fast ion/electron transport and maintain the structural integrity to buffer the volume expansion. The 2D/3D h-NCO electrode with an ultrahigh mass loading(30 mg cm^(-2)) achieves a high areal capacity of 4.65 C cm^(-2)(equivalent to 1.29 mAh cm^(-2)) at a current density of 4 mA cm^(-2), and retains 3.7 C cm^(-2) even at 50 mA cm^(-2). Furthermore, the assembled solid-state hybrid supercapacitor yields a high volumetric energy density of 4.25 mWh cm^(-3) at a power density of 39.3 mW cm^(-3), with a high capacity retention of 92.4% after 5000 cycles. Therefore, this work provides a new insight to constuct hierarchical electrodes for energy storage application. 展开更多
关键词 Transition-metal oxides Hierarchical structure High mass loading FREE-STANDING SUPERCAPACITORS
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The Distribution and Morphology Alterations of Microfilaments and Microtubules in Mesophyll Cells and Root-Tip Cells of Wheat Seedlings under Enhanced Ultraviolet-B Radiation
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作者 limei Gao yongfeng li +2 位作者 Aihua Guo Jingru Zhai Rong Han 《American Journal of Plant Sciences》 2014年第22期3423-3431,共9页
The distribution and morphology alterations of microfilaments and microtubules in the mesophyll cells and root-tip cells of wheat seedlings, which had been radiated by enhanced ultraviolet-B (10.08 KJ·m-2·d-... The distribution and morphology alterations of microfilaments and microtubules in the mesophyll cells and root-tip cells of wheat seedlings, which had been radiated by enhanced ultraviolet-B (10.08 KJ·m-2·d-1), were examined through the confocal laser scanning microscope (Model FV1000, Olympus, Japan). Microtubule was labeled with an indirect immunofluorescence staining method, and microfilament was labeled with fluorescein isothiocyanate-phalloidin (FITC-Ph) as probes. The results indicated that microtubules in mesophyll cells, compared with the controls, would be depolymerized significantly, and dispersed randomly showing some spots or short rods in the cytoplasm, under the enhanced UV-B radiation condition. The microtubule bundles tended to be diffused, and the fluorescence intensity of that significantly decreased. The distribution pattern of microfilaments, which usually arranged parallelly in control cells, was broken up by enhanced UV-B radiation. We further investigated the distribution and morphology of microtubules in root-tip cells during every stage of cell division, and found that these aberrant phenomena of microtubules were often associated with abnormal cell division. Our findings suggested that the distribution, morphology and structure of cytoskeleton in mesophyll cells and root-tip cells of wheat seedlings would be affected by enhanced UV-B radiation, which might be related to abnormal cell division caused by enhanced UV-B radiation as an extracellular signal. 展开更多
关键词 Wheat MICROFILAMENT MICROTUBULE ENHANCED UV-B Radiation Confocal Laser Scanning Microscope
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Electron-deficient borate anions tailoring the electronic structure of defect-rich amorphous nickel-cobalt cathode for superior capacitive energy storage
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作者 Shaoxiong Du Wang Yang +7 位作者 Ziyang Cao lingyu Kong Yao Yao Xi Wu Tianyu Bai Chen Zhang Zhengxuan li yongfeng li 《Journal of Energy Chemistry》 2025年第10期786-797,共12页
Designing transition metal nickel-cobalt-based battery-type electrode materials driven by anions is crucial for achieving rapid OH-ion transport under electrochemical activation conditions,thereby improving capacitanc... Designing transition metal nickel-cobalt-based battery-type electrode materials driven by anions is crucial for achieving rapid OH-ion transport under electrochemical activation conditions,thereby improving capacitance performance.Herein,borate anions are selected through theoretical calculations,and twodimensional(2D)defect-rich amorphous nickel-cobalt-based borate is synthesized via a facile chemical reduction method.Under potentiostatic modification,activated products(NCB-G-E)are obtained.In situ Raman spectra reveal that electron-deficient borate extracts electrons from metal centers,facilitating the oxidation state transition of Ni and Co.Theoretical calculations show that in situ adsorbed borate regulates the d-band centers of metal sites,enhancing OH^(-)intermediate adsorption.Meanwhile,borate anion adsorption accelerates the deprotonation and activation processes.Electrochemical tests demonstrate that NCB-G-E displays superior capacitance performance,with a high quality specific capacity of383.3 mA h g^(-1)and 65% retention rate at 30 A g^(-1),surpassing most nickel-cobalt-based electrodes.The assembled asymmetric supercapacitor presents an impressive energy density of 68.2 Wh kg^(-1)and good cycling stability.This work highlights the role of electron-deficient borate in tuning metal band structure and promoting oxidation state transition through synergistic defect advantages,offering new prospects for advanced battery-type energy storage materials. 展开更多
关键词 Nickel-cobalt borate Anion driven Potentiostatic strengthening Oxygen vacancies Supercapacitors
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Enhanced oxygen reduction reaction on La-Fe bimetal in porous N-doped carbon dodecahedra with CNTs wrapping
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作者 Yi Zhou Yanzhen liu +3 位作者 Yani Yan Zonglin Yi yongfeng li Cheng-Meng Chen 《Chinese Chemical Letters》 2025年第1期618-622,共5页
The oxygen reduction reaction(ORR)is a crucial process in Zn-air systems,and the catalyst plays a significant role in this reaction.However,reported catalysts often suffer from poor durability and stability during the... The oxygen reduction reaction(ORR)is a crucial process in Zn-air systems,and the catalyst plays a significant role in this reaction.However,reported catalysts often suffer from poor durability and stability during the ORR process.Herein,we synthesized La-Fe bimetallic nanoparticles encapsulated in a N-doped porous carbon dodecahedron(La-Fe/NC)originated from ZIF-8 by a simple direct carbonization.The La-Fe/NC catalyst had a numerous mesopores and dendritic outer layer generated by carbon nanotubes(CNTs),forming a high conductivity network that helped to optimize electron transfer and mass transport in the ORR process.The effect of different doping transition metals and metal ratios on the ORR activity of Zn-air batteries was investigated.In alkaline media,the La-Fe/NC showed the highest ORR catalytic activity,with a half-wave potential(E_(1/2))of 0.879 V(vs.RHE,Pt/C 0.845 V).After 5000 cycles,the E_(1/2)of the La-Fe/NC catalyst only decreased by 7 m V,and its performance in stability tests and methanol tolerance tests was superior to Pt/C.When used as the air electrode in a Zn-air battery,the La-Fe/NC catalyst demonstrated an excellent specific capacity of 755 m Ah/g and a peak power density of179.8 m W/cm~2.The results provide important insights for the development of high-performance Zn-air batteries and new directions for the design of ORR catalysts. 展开更多
关键词 ELECTROCATALYST ORR Bimetallic nanoparticle Dendritic CNTs Zn-air battery
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Reconfigurable origami chiral response for holographic imaging and information encryption
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作者 Zhibiao Zhu yongfeng li +4 位作者 Jiafu Wang Ze Qin lixin Jiang Yang Chen Shaobo Qu 《Opto-Electronic Science》 2025年第4期1-11,共11页
With the rapid development of holographic technology,metasurface-based holographic communication schemes have demonstrated immense potential for electromagnetic(EM)multifunctionality.However,traditional passive metasu... With the rapid development of holographic technology,metasurface-based holographic communication schemes have demonstrated immense potential for electromagnetic(EM)multifunctionality.However,traditional passive metasurfaces are severely limited by their lack of reconfigurability,hindering the realization of versatile holographic applications.Origami,an art form that mechanically induces spatial deformations,serves as a platform for multifunctional devices and has garnered significant attention in optics,physics,and materials science.The Miura-ori folding paradigm,characterized by its continuous reconfigurability in folded states,remains unexplored in the context of holographic imaging.Herein,we integrate the principles of Rosenfeld with L-and D-metal chiral enantiomers on a Miura-ori surface to tailor the aperture distribution.Leveraging the continuously tunable nature of the Miura-ori's folded states,the chiral response of the metallic structures varies across different folding configurations,enabling distinct EM holographic imaging functionalities.In the planar state,holographic encryption is achieved.Under specific folding conditions and driven by spin circularly polarized(CP)waves at a particular frequency,multiplexed holographic images can be reconstructed on designated focal planes with CP selectivity.Notably,the fabricated origami metasurface exhibits a large negative Poisson ratio,facilitating portability and deployment and offering novel avenues for spin-selective systems,camouflage,and information encryption. 展开更多
关键词 ORIGAMI RECONFIGURABLE chiral response holographic imaging information encryption
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Corrosion Behaviors of Nitride Coatings on Titanium Alloy in NaCl-Induced Hot Corrosion 被引量:7
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作者 Mingming Zhang Yipeng Feng +6 位作者 Yahui Wang Yunsong Niu li Xin yongfeng li Jianxiu Su Shenglong Zhu Fuhui Wang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2021年第10期1434-1446,共13页
TiN and TiAlN coatings were deposited by arc ion plating on titanium alloys to study their hot corrosion resistance when they were exposed to NaCl at 600℃.The microstructure and corrosion behaviors of nitride coating... TiN and TiAlN coatings were deposited by arc ion plating on titanium alloys to study their hot corrosion resistance when they were exposed to NaCl at 600℃.The microstructure and corrosion behaviors of nitride coatings were studied using scanning electron microscope,X-ray diffraction,electro-probe microanalyzer and X-ray photoelectron spectroscopy.The results showed that nitride coatings with the different compositions and the ones with the same composition but different thicknesses presented different hot corrosion resistance.TiN and thin TiAlN coatings showed poor corrosion resistance.Serious internal oxidation attacked the alloy substrate.Their corrosion products were mainly consisted of non-protective TiO2 and sodium salt.By contrast,the thick TiAlN coating presented outstanding corrosion resistance.Besides sodium salt,the corrosion products were composed of protective Al_(2)O_(3).The increasing thickness of TiAlN significantly enhanced the hot corrosion resistance.The corrosion mechanisms of alloy,TiN and TiAlN coatings were discussed in detail. 展开更多
关键词 Titanium alloy NITRIDE COATING Hot corrosion resistance
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Multiscale structure and interface engineering of Fe/Fe_(3)C in situ encapsulated in nitrogen-doped carbon for stable and efficient multi-band electromagnetic wave absorption 被引量:5
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作者 Bo Jiang Wang Yang +7 位作者 Hengxuan Bai Chen Zhang Siyuan li Shaoxiong Du Ye Wang li Sun Xiaobai Wang yongfeng li 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第27期9-20,共12页
Most reported electromagnetic wave absorption(EWA)materials show significant effective absorption in a certain frequency range,but their performances deteriorate dramatically as the frequency changes.As the range of w... Most reported electromagnetic wave absorption(EWA)materials show significant effective absorption in a certain frequency range,but their performances deteriorate dramatically as the frequency changes.As the range of working frequencies for electronic devices is gradually widening,it is of great interest to explore frequency-insensitive EWA materials that can achieve efficient absorption in every waveband by simply changing the absorption thickness.To this end,a multi-scale absorber(Fe/Fe_(3) C@NC)is rationally synthesized by chemical foaming and in-situ growth strategy.By controlling the growth of carbon nan-otubes,the Fe/Fe_(3) C@NC-2 exhibits a well-constructed 3D multi-scale architecture.Thanks to dipole po-larization,interface polarization and magnetic-dielectric energy conversion,the Fe/Fe_(3) C@NC-2 overcomes the frequency dispersion behavior and keeps a stable dielectric attenuation capability across the entire frequency range.Consequently,it delivers a superb full-band absorption of-50.1,-59.83,-55.87 and-51.91 dB in the S,C,X and Ku bands,respectively.The maximum radar cross-sectional reduction reaches 35.44 dB m^(-2) when the incidentθis 20°,testifying its impressive performance.Surprisingly,this EWA material also shows a remarkable resistance to oxidation and corrosion derived from the tightly coated carbon layers.This work provides new insight into the design of multi-band and stable EWA materials for practical application. 展开更多
关键词 Multi-scale structure Heterogeneous interface Multiple bands Magnetic-dielectric composites Electromagnetic waves absorption
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Kinetics of methanol steam reforming over COPZr-2 catalyst 被引量:4
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作者 yongfeng li Weiming lin +2 位作者 lin Yu Zhifeng Hao Rongjian Mai 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2008年第2期171-174,共4页
The COPZr-2 catalyst, which was prepared in our prophase research, showed good catalytic performance in methanol steam reforming reaction. In this article, the best one was chosen as an example to study the reaction k... The COPZr-2 catalyst, which was prepared in our prophase research, showed good catalytic performance in methanol steam reforming reaction. In this article, the best one was chosen as an example to study the reaction kinetics of methanol steam reforming over this type of catalyst. First, the effects of methanol conversion to outlet CO2 and methanol conversion to outlet CO on methanol pseudo contact time W/FMeOH were investigated. Then by applying the reaction route that methanol direct reforming (DR) and methanol decomposition (DE) were carried out in parallel, the reaction kinetic model with power function type was established. And the parameters for the model were estimated using a non-linear regression program which computed weighted least squares of the defined objects function. Finally, the kinetic model passed the correlation test and the F-test. 展开更多
关键词 METHANOL REFORMING KINETICS COPZr-2
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Electrochemical synthesis of FeN_(x) doped carbon quantum dots for sensitive detection of Cu^(2+) ion 被引量:3
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作者 Siyuan Sun Weijie Bao +5 位作者 Fan Yang Xingru Yan Yang Sun Ge Zhang Wang Yang yongfeng li 《Green Energy & Environment》 SCIE EI CSCD 2023年第1期141-150,共10页
A novel strategy was developed to fabricate FeNx-doped carbon quantum dots(Fe-N-CQDs)to detect Cu^(2+) ions selectively as a fluorescence probe.The Fe-N-CQDs were synthesized by an efficient electrolysis of a carbon c... A novel strategy was developed to fabricate FeNx-doped carbon quantum dots(Fe-N-CQDs)to detect Cu^(2+) ions selectively as a fluorescence probe.The Fe-N-CQDs were synthesized by an efficient electrolysis of a carbon cloth electrode,which was coated with monoatomic ironanchored nitrogen-doped carbon(Fe-N-C).The obtained Fe-N-CQDs emitted blue fluorescence and possessed a quantum yield(QY)of 7.5%.An extremely wide linear relationship between the Cu^(2+) concentration and the fluorescence intensity was obtained in the range from 100 nmol L^(-1) to 1000 nmol L^(-1)(R^(2)=0.997),and the detection limit was calculated as 59 nmol L^(-1).Moreover,the Fe-N-CQDs demonstrated wide range pH compatibility between 2 and 13 due to the coordination between pyridine nitrogen and Fe^(3+),which dramatically reduced the affection of the protonation and deprotonation process between H^(+) and Fe-N-CQDs.It is notable that the Fe-N-CQDs exhibited a rapid response in Cu^(2+) detection,where stable quenching can be completed in 7 s.The mechanism of excellent selective detection of Cu^(2+) was revealed by energy level simulation that the LUMO level of Fe-N-CQDs(-4.37 eV)was close to the redox potential of Cu^(2+),thus facilitating the electron transport from Fe-N-CQDs to Cu^(2+). 展开更多
关键词 ELECTROLYSIS FeNx-doped CQDs Cu2t detection pH compatibility Quick response
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A facile preparation of hausmannite as a high-performance catalyst for toluene combustion 被引量:1
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作者 Qi liu Gao Cheng +6 位作者 Ming Sun Weixiong Yu Xiaohong Zeng Shichang Tang yongfeng li lin Yu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2022年第4期392-401,共10页
Mesoporous transition metal oxide catalysts are well-used in the elimination of volatile organic compounds.In this study,we developed an efficient method for the preparation of mesoporous-Mn_(3)O_(4)(mMn_(3)O_(4))with... Mesoporous transition metal oxide catalysts are well-used in the elimination of volatile organic compounds.In this study,we developed an efficient method for the preparation of mesoporous-Mn_(3)O_(4)(mMn_(3)O_(4))without the use of templates or surfactants.In this method,KCl protects oxygen defects on the surface of fresh Mn_(3)O_(4) crystallites.m-Mn_(3)O_(4) shows higher ameliorative catalytic activity than bulk-Mn_(3)O_(4)(b-Mn_(3)O_(4)) and calcined-Mn_(3)O_(4)(c-Mn_(3)O_(4)),achieving toluene catalytic oxidation of T_(10) and T_(90)(the temperature at a conversion rate of about 10%and 90%)at 191℃and 230℃,respectively(WHSV=40,000 ml·g^(-1)·h^(-1)).Based on various characterizations,the prepared m-Mn_(3)O_(4)has large specific surface area and abundant oxygen defects,and thus can provide more surface active sites,which give it superior toluene combustion activity. 展开更多
关键词 CATALYSIS NANOMATERIALS Environment TOLUENE Solvents Mn_(3)O_(4)
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Single Exposure to Cocaine Impairs Reinforcement Learning by Potentiating the Activity of Neurons in the Direct Striatal Pathway in Mice 被引量:1
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作者 Zhijun Diao Yuanyuan Di +10 位作者 Meilin Wu Chenyang Zhai Mengsi Kang yongfeng li Yingxun liu Chunling Wei Qiaohua Zheng Jing Han Zhiqiang liu Yingfang Tian Wei Ren 《Neuroscience Bulletin》 SCIE CAS CSCD 2021年第8期1119-1134,共16页
Plasticity in the glutamatergic synapses on striatal medium spiny neurons(MSNs)is not only essential for behavioral adaptation but also extremely vulnerable to drugs of abuse.Modulation on these synapses by even a sin... Plasticity in the glutamatergic synapses on striatal medium spiny neurons(MSNs)is not only essential for behavioral adaptation but also extremely vulnerable to drugs of abuse.Modulation on these synapses by even a single exposure to an addictive drug may interfere with the plasticity required by behavioral learning and thus produce impairment.In the present work,we found that the negative reinforcement learning,escaping mild foot-shocks by correct nose-poking,was impaired by a single in vivo exposure to 20 mg/kg cocaine 24 h before the learning in mice.Either a single exposure to cocaine or reinforcement learning potentiates the glutamatergic synapses on MSNs expressing the striatal dopamine 1(D1)receptor(D1-MSNs).However,24 h after the cocaine exposure,the potentiation required for reinforcement learning was disrupted.Specific manipulation of the activity of striatal D1-MSNs in D1-cre mice demonstrated that activation of these MSNs impaired reinforcement learning in normal D1-cre mice,but inhibition of these neurons reversed the reinforcement learning impairment induced by cocaine.The results suggest that cocaine potentiates the activity of direct pathway neurons in the dorsomedial striatum and this potentiation might disrupt the potentiation produced during and required for reinforcement learning. 展开更多
关键词 COCAINE Reinforcement learning STRIATUM Medium spiny neurons Long-term potentiation
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Biodegradable interference distraction implant:a promising replacement for conventional implant in patients with insufficient alveolar bone height
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作者 yongfeng li Tao li +8 位作者 Bo Shao Yingying Sun Yuan Gao Yongqiang Zhang Qi Gao Shuning Shen Qiang Niu Mingming Shen liang Kong 《医用生物力学》 EI CAS CSCD 北大核心 2013年第S1期113-114,共2页
Background Dental implants have been widely used in the last few decades.However,patients with insufficient bone height need reconstructive surgeries before implant insertion.Distraction implant(Dl)has been invented t... Background Dental implants have been widely used in the last few decades.However,patients with insufficient bone height need reconstructive surgeries before implant insertion.Distraction implant(Dl)has been invented to simplify the treatment procedure,but the shortcomings of Dl have limited its clinical use.We introduced biodegradable polyester to a novel Dl,called biodegradable interference distraction implant(BIDI).The purpose of this study was to assess the radiological,histological,and biomechanical properties of BIDI in animal models.Methods BIDIs were manufactured and inserted into the atrophied mandibles of 6 dogs. 展开更多
关键词 IMPLANT DISTRACTION ALVEOLAR BIODEGRADABLE radiological insufficient REPLACEMENT polyester SHORTCOMINGS simplify
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Co-planted barnyardgrass reduces rice yield by inhibiting plant above-and belowground-growth during post-heading stages
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作者 Zichang Zhang Jingjing Cao +4 位作者 Tao Gu Xia Yang Qiong Peng lianyang Bai yongfeng li 《The Crop Journal》 SCIE CSCD 2021年第5期1198-1207,共10页
Barnyardgrass (Echinochloa spp.) is the most common noxious weed in rice paddies as it inhibits rice growth and reduces grain yield.To date,little information is available on above-and belowgroundgrowth changes in ric... Barnyardgrass (Echinochloa spp.) is the most common noxious weed in rice paddies as it inhibits rice growth and reduces grain yield.To date,little information is available on above-and belowgroundgrowth changes in rice due to neighboring barnyardgrass.This study aimed to investigate the changes in root traits and shoot growth of rice when it is grown with different kinds of barnyardgrass.Japonica rice plants (var.Nanjing 9108) were co-cultured with two varieties of Echinochloa crusgalli (L.) Beauv.(EP,var.mitis (pursh) Petern;EH,var.zelayensis (H.B.K.) Hitchc),and E.colonum (L.) Link (EL) in the field in 2017 and 2018.Four treatments included control (i.e.,weed free rice plants) and co-cultures with each of three barnyardgrasses (EP,EH,and EL).The results revealed that EP,EH,and EL treatments significantly reduced rice grain yields by 30.6%–36.2%,42.5%–46.5%,and 10.6%–14.3%,respectively.Shoot growth including shoot dry weight,leaf photosynthetic rate,zeatin (Z) and zeatin riboside (ZR) in grains,and activities of key enzymes involved in sucrose-to-starch conversion in grains and root traits,such as length density,root dry weight,total absorbing surface area,active absorption surface area,oxidation activity,and Z+ZR contents in roots were dramatically reduced during post-heading stages of rice when grown with the three kinds of barnyardgrass.Moreover,above-mentioned rice shoot growth indices were strongly and positively correlated with root traits.These results suggested the decrease in rice shoot growth and root traits during post-heading stages contributes to the reduction in the rice yield when it grows with barnyardgrass neighbors. 展开更多
关键词 Rice BARNYARDGRASS Grain yield Root traits Shoot traits
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Transcriptomic and proteomic studies of condylar ossification of the temporomandibular joint in porcine embryos
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作者 Lei Xiang yongfeng li +5 位作者 Xuewen Wang HuaWei liu Ping Chang Xiaodan Mu Tengyue Tianteng Min Hu 《Animal Models and Experimental Medicine》 CAS CSCD 2023年第4期294-305,共12页
Background:The ossification mechanism of the temporomandibular joint(TMJ)condyle remains unclear in human embryo.The size and structure of TMJ,shape of articular disc and the characteristics of omnivorous chewing in t... Background:The ossification mechanism of the temporomandibular joint(TMJ)condyle remains unclear in human embryo.The size and structure of TMJ,shape of articular disc and the characteristics of omnivorous chewing in the pig are similar to those of humans.The pig is an ideal animal for studying the mechanism of ossification of the TMJ condyle during the embryonic period.Method:In a previous study by our group,it was found that there was no condylar ossification on embryonic day(E)45,but the ossification of condyle occurred between E75 and E90.In this study,a total of 12 miniature pig embryos on E45 and E85 were used.Six embryos were used for tissue sections(3 in each group).The remaining six embryos were used for transcriptomic and proteomic studies to find differential genes and proteins.The differentially expressed genes in transcriptome and proteomic analysis were verified by QPCR.Results:In total,1592 differential genes comprising 1086 up-regulated genes and 506 down-regulated genes were screened for fold changes of≥2 to≤0.5 between E45 and E85.In the total of 4613 proteins detected by proteomic analysis,there were 419 differential proteins including 313 up-regulated proteins and 106 down-regulated proteins screened for fold changes of≥2 to≤0.5 between E45 and E85.A total of 36 differential genes differing in both transcriptome and proteome analysis were found.QPCR analysis showed that 14 of 15 selected genes were consistent with transcriptome analysis.Conclusion:Condylar transcriptome and proteomic analysis during the development of TMJ in miniature pigs revealed the regulatory genes/proteins of condylar ossification. 展开更多
关键词 CONDYLE EMBRYO miniature pig OSSIFICATION proteomics transcriptome
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