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Multiple Tin Compounds Modified Carbon Fibers to Construct Heterogeneous Interfaces for Corrosion Prevention and Electromagnetic Wave Absorption 被引量:1
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作者 Zhiqiang Guo Di Lan +6 位作者 Zirui Jia Zhenguo Gao Xuetao Shi Mukun He Hua Guo Guanglei Wu pengfei yin 《Nano-Micro Letters》 SCIE EI CAS 2025年第1期507-527,共21页
Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly urgent.Multi-component interface engineering is con... Currently,the demand for electromagnetic wave(EMW)absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly urgent.Multi-component interface engineering is considered an effective means to achieve high-efficiency EMW absorption.However,interface modulation engineering has not been fully discussed and has great potential in the field of EMW absorption.In this study,multi-component tin compound fiber composites based on carbon fiber(CF)substrate were prepared by electrospinning,hydrothermal synthesis,and high-temperature thermal reduction.By utilizing the different properties of different substances,rich heterogeneous interfaces are constructed.This effectively promotes charge transfer and enhances interfacial polarization and conduction loss.The prepared SnS/SnS_(2)/SnO_(2)/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt%in epoxy resin.The minimum reflection loss(RL)is−46.74 dB and the maximum effective absorption bandwidth is 5.28 GHz.Moreover,SnS/SnS_(2)/SnO_(2)/CF epoxy composite coatings exhibited long-term corrosion resistance on Q235 steel surfaces.Therefore,this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments. 展开更多
关键词 Electrostatic spinning Component regulation Heterogeneous interfaces Electromagnetic wave absorption Corrosion protection
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Multiphase Interfacial Regulation Based on Hierarchical Porous Molybdenum Selenide to Build Anticorrosive and Multiband Tailorable Absorbers 被引量:10
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作者 Tianbao Zhao Zirui Jia +3 位作者 Jinkun Liu Yan Zhang Guanglei Wu pengfei yin 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第1期85-105,共21页
Electromagnetic wave(EMW)absorbing materials have an irreplaceable position in the field of military stealth as well as in the field of electromagnetic pollution control.And in order to cope with the complex electroma... Electromagnetic wave(EMW)absorbing materials have an irreplaceable position in the field of military stealth as well as in the field of electromagnetic pollution control.And in order to cope with the complex electromagnetic environment,the design of multifunctional and multiband high efficiency EMW absorbers remains a tremendous challenge.In this work,we designed a three-dimensional porous structure via the salt melt synthesis strategy to optimize the impedance matching of the absorber.Also,through interfacial engineering,a molybdenum carbide transition layer was introduced between the molybdenum selenide nanoparticles and the three-dimensional porous carbon matrix to improve the absorption behavior of the absorber.The analysis indicates that the number and components of the heterogeneous interfaces have a significant impact on the EMW absorption performance of the absorber due to mechanisms such as interfacial polarization and conduction loss introduced by interfacial engineering.Wherein,the prepared MoSe_(2)/MoC/PNC composites showed excellent EMW absorption performance in C,X,and Ku bands,especially exhibiting a reflection loss of−59.09 dB and an effective absorption bandwidth of 6.96 GHz at 1.9 mm.The coordination between structure and components endows the absorber with strong absorption,broad bandwidth,thin thickness,and multi-frequency absorption characteristics.Remarkably,it can effectively reinforce the marine anticorrosion property of the epoxy resin coating on Q235 steel substrate.This study contributes to a deeper understanding of the relationship between interfacial engineering and the performance of EMW absorbers,and provides a reference for the design of multifunctional,multiband EMW absorption materials. 展开更多
关键词 Interfacial engineering ANTICORROSION MULTIBAND Electromagnetic wave absorber
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Mechanically mixing copper and silver into self-supporting electrocatalyst for hydrogen evolution 被引量:3
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作者 Xinzhuo Hu Zhe Liu +9 位作者 Yi Feng Yongfeng Zhang Zhe Li Zhennan Chen Jing Mao Jing Yang Hui Liu pengfei yin Lei Cui Xiwen Du 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第10期1906-1913,共8页
Commercial hydrogen production involves the development of efficient hydrogen evolution reaction catalysts.Herein,we adopted a friction stir processing(FSP)technique to mix immiscible metals homogenously and obtain a ... Commercial hydrogen production involves the development of efficient hydrogen evolution reaction catalysts.Herein,we adopted a friction stir processing(FSP)technique to mix immiscible metals homogenously and obtain a self-supporting copper-silver(CuAg)catalyst.The gust of Ag atoms with larger atomic sizes caused a tensile strain in the Cu matrix.Meanwhile,the chemical-potential difference induced electron transfer from Cu to Ag,and the two factors jointly led to the upshift of Cu d-band and improved the catalytic activity.Consequently,the CuAg electrode exhibited a high turnover frequency(12 times that of pure Cu),a low overpotential at high current density(superior to platinum foil),and high durability(1.57%decay over 180 h).Our work demonstrates that FSP is a powerful method for preparing self-supporting catalysts of immiscible alloys with high catalytic performance. 展开更多
关键词 hydrogen evolution reaction CATALYST friction stir processing strain electron transfer
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Innovative preparation of Co@Cu Fe_(2)O_(4) composite via ball-milling assisted chemical precipitation and annealing for glorious electromagnetic wave absorption 被引量:2
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作者 Xing Feng pengfei yin +6 位作者 Limin Zhang Xiyuan Sun Jian Wang Liang Zhao Changfang Lu Zhihua Gao Yongxin Zhan 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第3期559-569,共11页
To deal with the growing electromagnetic hazards,herein a Co@CuFe_(2)O_(4)absorbing agent with excellent impedance matching at thin thickness was obtained via an innovative route of ball-milling assisted chemical prec... To deal with the growing electromagnetic hazards,herein a Co@CuFe_(2)O_(4)absorbing agent with excellent impedance matching at thin thickness was obtained via an innovative route of ball-milling assisted chemical precipitation and annealing.The as-prepared composite possesses excellent interface polarization ability due to sufficient contact between CuFe_(2)O_(4)NPs and flat Co,and this compressed Co lamella can also provide sufficient eddy current loss.Moreover,the dipole polarization,electron hopping/conduction,and structural scattering also contribute to the broadband microwave absorption of the composite.Thus,the minimum microwave reflection loss achieves-35.56 d B at12.93 GHz for 1.8 mm thickness,and the broadest efficient absorption bandwidth can reach 6.74 GHz for a thinner thickness of 1.72 mm.The preparation method reported here can be referenced as a new-type route to manufacture electromagnetic absorbers with outstanding performance. 展开更多
关键词 electromagnetic wave ABSORPTION ball-milling COBALT copper ferrite
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Multiscale structural engineering of atomically dispersed FeN4 electrocatalyst for proton exchange membrane fuel cells 被引量:1
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作者 Ruguang Wang Yuanyuan Yang +4 位作者 Yang Zhao Liujing Yang pengfei yin Jing Mao Tao Ling 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第7期629-635,共7页
Atomically dispersed iron-nitrogen-carbon(Fe-N-C) catalysts have emerged as the most promising alternative to the expensive Pt-based catalysts for the oxygen reduction reaction(ORR) in proton exchange membrane fuel ce... Atomically dispersed iron-nitrogen-carbon(Fe-N-C) catalysts have emerged as the most promising alternative to the expensive Pt-based catalysts for the oxygen reduction reaction(ORR) in proton exchange membrane fuel cells(PEMFCs),however suffer from low site density of active Fe-N4 moiety and limited mass transport during the catalytic reaction.To address these challenges,we report a three-dimensional(3D) metal-organic frameworks(MOF)-derived Fe-N-C single-atom catalyst.In this well-designed Fe-N-C catalyst,the micro-scale interconnected skeleton,the nano-scale ordered pores and the atomic-scale abundant carbon edge defects inside the skeleton significantly enhance the site density of active Fe-N4 moiety,thus improving the Fe utilization in the final catalyst.Moreover,the combination of the above mentioned micro-and nano-scale structures greatly facilitates the mass transport in the 3D Fe-N-C catalyst.Therefore,the multiscale engineered Fe-N-C single-atom catalyst achieves excellent ORR performance under acidic condition and affords a significantly enhanced current density and power density in PEMFC.Our findings may open new opportunities for the rational design of FeN-C catalysts through multiscale structural engineering. 展开更多
关键词 Fe–N–C catalyst Fe-N4 Proton exchange membrane fuel cells Oxygen reduction reaction Single-atom catalyst
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Technical factors affecting the performance of anion exchange membrane water electrolyzer 被引量:1
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作者 Xun Zhang Yakang Li +3 位作者 Wei Zhao Jiaxin Guo pengfei yin Tao Ling 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第11期2259-2269,共11页
Anion exchange membrane(AEM)electrolysis is a promising membrane-based green hydrogen production technology.However,AEM electrolysis still remains in its infancy,and the performance of AEM electrolyzers is far behind ... Anion exchange membrane(AEM)electrolysis is a promising membrane-based green hydrogen production technology.However,AEM electrolysis still remains in its infancy,and the performance of AEM electrolyzers is far behind that of well-developed alkaline and proton exchange membrane electrolyzers.Therefore,breaking through the technical barriers of AEM electrolyzers is critical.On the basis of the analysis of the electrochemical performance tested in a single cell,electrochemical impedance spectroscopy,and the number of active sites,we evaluated the main technical factors that affect AEM electrolyzers.These factors included catalyst layer manufacturing(e.g.,catalyst,carbon black,and anionic ionomer)loadings,membrane electrode assembly,and testing conditions(e.g.,the KOH concentration in the electrolyte,electrolyte feeding mode,and operating temperature).The underlying mechanisms of the effects of these factors on AEM electrolyzer performance were also revealed.The irreversible voltage loss in the AEM electrolyzer was concluded to be mainly associated with the kinetics of the electrode reaction and the transport of electrons,ions,and gas-phase products involved in electrolysis.Based on the study results,the performance and stability of AEM electrolyzers were significantly improved. 展开更多
关键词 hydrogen production anion exchange membrane water electrolyzer CATALYST membrane electrode assembly
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一种双频段双模大功率旋转关节设计
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作者 尹鹏飞 张宏刚 《电子科学技术》 2017年第3期5-9,16,共6页
本论文所讨论的一种双频段大功率旋转关节的主要特点是可以同时工作在S与X频段,具有功率容量大,旋转性能稳定的特点。本论文所讨论的旋转关节主要创新点在于将X频段TM_(01)(Transverse Magnetic)模式的旋转关节与S频段工作在TEM模式的... 本论文所讨论的一种双频段大功率旋转关节的主要特点是可以同时工作在S与X频段,具有功率容量大,旋转性能稳定的特点。本论文所讨论的旋转关节主要创新点在于将X频段TM_(01)(Transverse Magnetic)模式的旋转关节与S频段工作在TEM模式的旋转关节进行结合,X频段旋转关节的主体采用圆波导;S频段通道采用对称激励的形式以得到所需的工作模式,使关节具有双通道、双频段以及大功率容量的特点。该旋转关节两个通道的VSWR指标设计值低于1.085,X频段通道功率容量大于200kW,S频段通道功率容量大于100kW。 展开更多
关键词 微波 旋转关节 波导 反射损耗 带宽 电磁场
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CCSD(T) study on the structures and chemical bonds of AnO molecules (An = Bk–Lr)
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作者 Xiyuan Sun pengfei yin +1 位作者 Kaiming Wang Gang Jiang 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第3期220-224,共5页
The molecular geometries and dissociation energies of AnO (An = Bk–Lr) molecules were first obtained at thecoupled-cluster single-, double-, and perturbative triple-excitations [CCSD(T)] level of theory. Four hybrid ... The molecular geometries and dissociation energies of AnO (An = Bk–Lr) molecules were first obtained at thecoupled-cluster single-, double-, and perturbative triple-excitations [CCSD(T)] level of theory. Four hybrid functionals,B3LYP, M06-2X, TPSSh, and PBE0, were also employed in the calculations for the sake of comparison. In comparison ofthe CCSD(T) results, B3LYP, TPSSh, and PBE0 functionals can obtain more appropriate results than M06-2X and MP2.The analyses on molecular orbitals show that the 7s, 6d, and 5f atomic orbitals of actinide (An) atoms participate in thebonding of An–O bonds. The partial covalent nature between An and O atoms is revealed by QTAIM analyses. 展开更多
关键词 ab initio calculation AnO(Bk-Lr)molecules density functional theory(DFT) chemical bond
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Controllable heterogeneous interfaces and dielectric modulation of biomass-derived nanosheet metal-sulfide complexes for high-performance electromagnetic wave absorption 被引量:4
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作者 Zehua Zhou Di Lan +4 位作者 Junwen Ren Yuhang Cheng Zirui Jia Guanglei Wu pengfei yin 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第18期165-173,共9页
Constructing new environmentally friendly dielectric coupling models is an effective strategy for design-ing high-performance wave absorbers.However,biomass carbon materials with high potential energy and a lack of ma... Constructing new environmentally friendly dielectric coupling models is an effective strategy for design-ing high-performance wave absorbers.However,biomass carbon materials with high potential energy and a lack of magnetic response mechanism do not fulfill the requirements.In this work,the effects of different pyrolysis temperatures and the introduction of different metal sulfides on the microscopic morphology and dielectric-magnetic properties of the composites were investigated.Among them,K el-ement detected in the biomass effectively modulates the conduction loss.The minimum reflection loss(RL_(min))of-62.42 dB at 1.8 mm and the maximum effective absorption bandwidth(EAB_(max))of-62.42 dB at 1.9 mm were obtained due to the non-uniform interfacial-induced polarization of the metal-sulfide nanosheets and the scattering of the electromagnetic waves(EW)by the“island”microstructures.This study provides a powerful reference for the modification and application of biomass materials. 展开更多
关键词 Biomass materials Metal sulfide Electromagnetic wave absorption Oxygen vacancy Interfacial polarization
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Multi-level hollow sphere rich in heterojunctions with dual function:Efficient microwave absorption and antiseptic 被引量:3
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作者 Liyuan Yu Di Lan +5 位作者 Zhiqiang Guo Ailing Feng Guanglei Wu Zirui Jia Xing Feng pengfei yin 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第22期155-165,共11页
Effective electromagnetic wave absorption is now possible thanks to the design of the dielectric-magnetic double loss mechanism and the rich heterogeneous structure.In this study,hollow carbon spheres with rich hetero... Effective electromagnetic wave absorption is now possible thanks to the design of the dielectric-magnetic double loss mechanism and the rich heterogeneous structure.In this study,hollow carbon spheres with rich heterostructures were synthesized using an easy and effective in situ growing approach.In addition to improving impedance matching,the hollow structure also reduces material density and weight.By modifying the load,this system can alter the dielectric characteristics of MXene,which in turn affects the sample’s ability to absorb electromagnetic waves.MXene and the carbon material create a thick conductive network during the whole electromagnetic wave absorption process,creating the ideal environment for conduction loss.The sample’s ability to attenuate electromagnetic waves is further improved by the interfacial polarization that the rich heterogeneous structure can produce.Co-magnetic nanoparticle nanoparticles are the main source of magnetic loss.The MXene@Co/C-100–800(MCC-100–800)exhibits excellent electromagnetic wave absorption performance under the synergy of multiple loss mechanisms,with the maximum effective absorption bandwidth(EAB_(max))reaching 7.20 GHz and the minimum reflection loss(RL_(min))being–53.99 dB at 2.10 mm.Finally,this work is guided by the coating engineering of MXene and provides new ideas for the rational design of heterostructures of nanomaterials. 展开更多
关键词 HETEROSTRUCTURE Dielectric-magnetic double loss MXene Hollow carbon sphere Electromagnetic wave absorption
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Structural engineering of porous biochar loaded with ferromagnetic/anti-ferromagnetic NiCo_(2)O_(4)/CoO for excellent electromagnetic dissipation with flexible and self-cleaning properties 被引量:3
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作者 pengfei yin Yumei Luo +5 位作者 Di Lan Jian Wang Xing Feng Zirui Jia Guanglei Wu Yi Zhang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第13期12-22,共11页
Design of multi-functional microwave absorption materials with strong dissipation ability is a practical approach to address the current issue of electromagnetic radiation pollution.Herein,based on the ex-change bias ... Design of multi-functional microwave absorption materials with strong dissipation ability is a practical approach to address the current issue of electromagnetic radiation pollution.Herein,based on the ex-change bias interaction between ferromagnetic and anti-ferromagnetic interfaces,a series of absorbers composed of the porous biochar loaded with ferromagnetic/anti-ferromagnetic NiCO_(2)O_(4)/CoO were suc-cessfully prepared via a fairly simple process of one-step calcination.By regulating the calcination tem-perature,the pore size and porosity of porous carbon,morphology of loaded NPs as well as the elec-tromagnetic response property and impedance matching characteristic in such composites can be mod-ulated.The porous biochar/NiCO_(2)O_(4)/CoO composite prepared under 350 ℃ possesses a remarkable elec-tromagnetic absorption reflection loss(RL)of-48.41 dB at 9.12 GHz with 2.5 mm thickness,and the effective absorption bandwidth(EAB)of 4.32 GHz with 2.2 mm thickness is located at X band,this is owing to the strong coupling effect of multiple dielectric polarizations,magnetic resonances,and eddy current consumption under matched impedance.In addition,the microwave absorbing patch prepared with this composite exhibits a well-hydrophobic property for self-cleaning function,and the large exten-sibility with substantial breaking strength endows its practical usage as a flexible absorber. 展开更多
关键词 Microwave dissipation Porous biochar Nickel-cobalt ferrite Cobaltous oxide Hydrophobic flexibility
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Optimization of multiple attenuation mechanisms by cation substitution in imidazolic MOFs-derived porous composites for superior broadband electromagnetic wave absorption 被引量:2
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作者 Hao Yu Xin Kou +5 位作者 Xueqing Zuo Ding Xi Haijun Guan pengfei yin Lijia Xu Yongpeng Zhao 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2024年第9期176-187,共12页
Metal-organic frameworks(MOFs)derived composites are extremely potential electromagnetic wave(EMW)absorbers.However,the permittivity of absorbers directly derived from MOFs with solid structure is usually relatively l... Metal-organic frameworks(MOFs)derived composites are extremely potential electromagnetic wave(EMW)absorbers.However,the permittivity of absorbers directly derived from MOFs with solid structure is usually relatively low,inevitably limiting their further applications.Cation substitution can primely overcome the problem by regulating the morphology and atomic space occupation to enhance multiple loss mechanisms and impedance matching characteristics.However,universal mechanisms of the effect on EMW absorption performance influenced by cation substitution are still comparatively inadequate,which prospectively requires further exploration.Herein,a series of imidazolic MOFs were fabricated by ultrasonic symbiosis method and tailored by subsequent cation substitution strategy to prepare target porous composites.At a low filling rate and thin thickness,the as-obtained samples reach the optimal reflection loss and effective absorption bandwidth values of–49.81 dB and 7.63 GHz,respectively.The intercoupling between multiple atoms lays a significant foundation for abundant heterogeneous interfaces and defect vacancies,which effectively ameliorate the attenuation mechanisms.Meanwhile,the porous structure introduced by cation substitution reduces the bulk density to enhance the impedance matching and multiple reflections simultaneously.This study provides a helpful idea to exceedingly improve the EMW absorbing performance of imidazolic MOFs-derived composites by cation substitution. 展开更多
关键词 Multiple attenuation mechanisms Cation substitution Porous composites Electromagnetic wave absorption
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Edge dislocation-induced strains break the limit of PtNi alloys in boosting Pt mass activity for efficient alkaline hydrogen evolution
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作者 Miao Zhou Yao Zhao +8 位作者 Zhanwei Liu Xueru Zhao Enzuo Liu Liyang Xiao pengfei yin Cunku Dong Hui Liu Xiwen Du Jing Yang 《Nano Research》 SCIE EI CSCD 2024年第6期4711-4719,共9页
Creating lattice defects and alloying to produce strain effect in Pt-based bimetallic alloys are both effective methods to optimize the crystal and electronic structure and improve the electrocatalytic performance.Unf... Creating lattice defects and alloying to produce strain effect in Pt-based bimetallic alloys are both effective methods to optimize the crystal and electronic structure and improve the electrocatalytic performance.Unfortunately,the principles that govern the alkaline hydrogen evolution reaction(HER)performance remain unclear,which is detrimental to the rational design of efficient Pt-based electrocatalysts.Herein,PtNi alloys with different Pt/Ni ratios and edge dislocations were synthesized,and the effects of Pt/Ni composition and edge dislocations on the alkaline HER electrocatalytic activity of PtNi alloys were systematically studied.Combined experimental and theoretical investigations reveal that tuning Pt/Ni ratio results in only 1.1 times enhancements in Pt mass activity,whereas edge dislocations-induced extra tensile strain on Ni site and compressive strain on Pt site further boost the alkaline HER intrinsic activity at all Pt/Ni ratios.Impressively,the introduction of edge dislocations in PtNi alloys could break the limit of alloying in boosting Pt mass activity and result in up to 13.7-fold enhancement,in the case that Pt and Ni contents are nearly identical and thus edge dislocation density reaches the maximum.Fundamental mechanism studies demonstrate that the edge dislocation strategy could make a breakthrough in facilitating water dissociation kinetics of PtNi alloys. 展开更多
关键词 edge dislocations PtNi composition strain effects water dissociation hydrogen evolution reaction
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A Classifier Using Online Bagging Ensemble Method for Big Data Stream Learning 被引量:6
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作者 Yanxia Lv Sancheng Peng +4 位作者 ying Yuan Cong Wang pengfei yin Jiemin Liu Cuirong Wang 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2019年第4期379-388,共10页
By combining multiple weak learners with concept drift in the classification of big data stream learning, the ensemble learning can achieve better generalization performance than the single learning approach. In this ... By combining multiple weak learners with concept drift in the classification of big data stream learning, the ensemble learning can achieve better generalization performance than the single learning approach. In this paper,we present an efficient classifier using the online bagging ensemble method for big data stream learning. In this classifier, we introduce an efficient online resampling mechanism on the training instances, and use a robust coding method based on error-correcting output codes. This is done in order to reduce the effects of correlations between the classifiers and increase the diversity of the ensemble. A dynamic updating model based on classification performance is adopted to reduce the unnecessary updating operations and improve the efficiency of learning.We implement a parallel version of EoBag, which runs faster than the serial version, and results indicate that the classification performance is almost the same as the serial one. Finally, we compare the performance of classification and the usage of resources with other state-of-the-art algorithms using the artificial and the actual data sets, respectively. Results show that the proposed algorithm can obtain better accuracy and more feasible usage of resources for the classification of big data stream. 展开更多
关键词 big data STREAM classification ONLINE BAGGING ensemble LEARNING concept DRIFT
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Synthesis of MoX2 (X =Se or S) monolayers with high-concentration 1T'phase on 4H/fcc-Au nanorods for hydrogen evolution 被引量:4
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作者 Zhengqing Liu Xiao Zhang +13 位作者 Yue Gong Qipeng Lu Zhicheng Zhang Hongfei Cheng Qinglang Ma Junze Chen Meiting Zhao Bo Chen Ye Chen Xue-Jun Wu pengfei yin Lin Gu Yaping Du Hua Zhang 《Nano Research》 SCIE EI CAS CSCD 2019年第6期1301-1305,共5页
Controlled synthesis of transition metal dichalcogenide (TMD) monolayers with unusual crystal phases has attracted increasing attention due to their promising applications in electrocatalysis.However,the facile and la... Controlled synthesis of transition metal dichalcogenide (TMD) monolayers with unusual crystal phases has attracted increasing attention due to their promising applications in electrocatalysis.However,the facile and large-scale preparation of TMD monolayers with high-concentration unusual crystal phase still remains a challenge.Herein,we report the synthesis of MoX2 (X =Se or S) monolayers with high-concentration semimetallic 1T'phase by using the 4H/face-centered cubic (fcc)-Au nanorod as template to form the 4H/fcc-Au@MoX2 nanocomposite.The concentrations of 1T'phase in the prepared MoSe2 and MoS2 monolayers are up to 86% and 81%,respectively.As a proof-of-concept application,the obtained Au@MoS2 nanocomposite is used for the electrocatalytic hydrogen evolution reaction (HER) in acid medium,exhibiting excellent performance with a low overpotential of 178 mV at the current density of 10 mNcm^2,a small Tafel slope of 43.3 mV/dec,and excellent HER stability.This work paves a way for direct synthesis of TMD monolayers with high-concentration of unusual crystal phase for the electrocatalytic application. 展开更多
关键词 MOS2 monolayers semimetallic 1T'phase 4H/face-centered CUBIC (fcc)-Au NANORODS hydrogen evolution
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Simultaneous optimization of conduction and polarization losses in CNT@NiCo compounds for superior electromagnetic wave absorption 被引量:1
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作者 Yongpeng Zhao Zhicheng Lin +14 位作者 Li Huang Zitong Meng Hao Yu Xin Kou Zhiyong Zou Peng Huang Yuchao Wang Ding Xi pengfei yin Gehong Su Zhiqiang Fan Zhiping Su Dongbei Xu Lujun Pan Lijia Xu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第35期34-46,共13页
Polarization and conduction losses are the two most crucial dielectric loss mechanisms for carbon-based composites,but their synergistic effects in different frequency bands need to be further revealed.More importantl... Polarization and conduction losses are the two most crucial dielectric loss mechanisms for carbon-based composites,but their synergistic effects in different frequency bands need to be further revealed.More importantly,for polarization and conduction losses,the strengthening of one party always comes at the expense of the other,which inevitably limits the overall performance of the absorbers.Herein,we have developed a composite of CNT and NiCo hybrid particles via a scalable wet chemical process and an-nealing method.Through the adjustment of the precursor and the annealing temperature,the conduction and polarization losses of the composite are optimized simultaneously.The optimized samples achieved the full absorption of the X and Ku bands under conditions of low filling rate and thin thickness.Further theoretical and experimental studies have revealed conduction loss and polarization loss laws at different frequency ranges.The synergistic effect of conductive loss and magnetic loss in the low-frequency region ensures that the sample exhibits high microwave dissipation performance.However,in the medium and high-frequency part,the magnetic loss can be almost ignored and the timely replenishment of polar-ization loss keeps the wave-absorbing performance at a high level.The excellent multi-band absorption characteristics make the as-obtained absorbers meet the needs of future applications. 展开更多
关键词 CNT@NiCo compounds Conduction loss Polarization loss Electromagnetic wave absorption
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The Application of UAV-Based Hyperspectral Imaging to Estimate Crop Traits in Maize Inbred Lines 被引量:1
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作者 Meiyan Shu Mengyuan Shen +8 位作者 Jinyu Zuo pengfei yin Min Wang Ziwen Xie Jihua Tang Ruili Wang Baoguo Li Xiaohong Yang Yuntao Ma 《Plant Phenomics》 SCIE 2021年第1期351-364,共14页
Crop traits such as aboveground biomass(AGB),total leaf area(TLA),leaf chlorophyll content(LCC),and thousand kernel weight(TWK)are important indices in maize breeding.How to extract multiple crop traits at the same ti... Crop traits such as aboveground biomass(AGB),total leaf area(TLA),leaf chlorophyll content(LCC),and thousand kernel weight(TWK)are important indices in maize breeding.How to extract multiple crop traits at the same time is helpful to improve the efficiency of breeding.Compared with digital and multispectral images,the advantages of high spatial and spectral resolution of hyperspectral images derived from unmanned aerial vehicle(UAV)are expected to accurately estimate the similar traits among breeding materials.This study is aimed at exploring the feasibility of estimating AGB,TLA,SPAD value,and TWK using UAV hyperspectral images and at determining the optimal models for facilitating the process of selecting advanced varieties.The successive projection algorithm(SPA)and competitive adaptive reweighted sampling(CARS)were used to screen sensitive bands for the maize traits.Partial least squares(PLS)and random forest(RF)algorithms were used to estimate the maize traits.The results can be summarized as follows:The sensitive bands for various traits were mainly concentrated in the near-red and red-edge regions.The sensitive bands screened by CARS were more abundant than those screened by SPA.For AGB,TLA,and SPAD value,the optimal combination was the CARS-PLS method.Regarding the TWK,the optimal combination was the CARS-RF method.Compared with the model built by RF,the model built by PLS was more stable.This study provides guiding significance and practical value for main trait estimation of maize inbred lines by UAV hyperspectral images at the plot level. 展开更多
关键词 CROP BREEDING forest
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Explanations of the DAMPE high energy electron/positron spectrum in the dark matter annihilation and pulsar scenarios
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作者 BingBing Wang XiaoJun Bi +1 位作者 SuJie Lin pengfei yin 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2018年第10期19-29,共11页
Many studies have shown that either the nearby astrophysical source or dark matter (DM) annihilation/decay can be used to explain the excess of high energy cosmic ray (CR) e^±which is detected by many experim... Many studies have shown that either the nearby astrophysical source or dark matter (DM) annihilation/decay can be used to explain the excess of high energy cosmic ray (CR) e^±which is detected by many experiments, such as PAMELA and AMS-02. Recently, the dark matter particle explorer (DAMPE) collaboration has reported its first result of the total CR e^± spectrum from 25 GeV to 4.6TeV with high precision. In this work, we study the DM annihilation and pulsar interpretations of this result. We show that the leptonic DM annihilation channels to r+'/"-, 4p, 4"/', and mixed charged lepton final states can well explain the DAMPE e^± spectrum. We also find that the mixed charged leptons channel would lead to a sharp drop structure at - TeV. However, the ordinary DM explanations have been almost excluded by the constraints from the observations of gamma-ray and CMB, unless some exotic DM models are introduced. In the pulsar scenario, we analyze 21 nearby known pulsars and assume that one of them dominantly contributes to the high energy CR e^± spectrum. Involving the constraint from the Fermi-LAT observation of the e^± anisotropy, we find that two pulsars could explain the DAMPE e^± spectrum. Our results show that it is difficult to discriminate between the DM annihilation and single pulsar explanations of high energy e^± with the current DAMPE result. 展开更多
关键词 cosmic rays dark matter PULSARS
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