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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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Defects‑Rich Heterostructures Trigger Strong Polarization Coupling in Sulfides/Carbon Composites with Robust Electromagnetic Wave Absorption
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作者 Jiaolong Liu Siyu Zhang +14 位作者 Dan Qu Xuejiao Zhou Moxuan Yin Chenxuan Wang Xuelin Zhang Sichen Li Peijun Zhang Yuqi Zhou Kai Tao Mengyang Li Bing Wei Hongjing Wu Mengyang Li Bing Wei Hongjing Wu 《Nano-Micro Letters》 SCIE EI CAS 2025年第1期528-547,共20页
Defects-rich heterointerfaces integrated with adjustable crystalline phases and atom vacancies,as well as veiled dielectric-responsive character,are instrumental in electromagnetic dissipation.Conventional methods,how... Defects-rich heterointerfaces integrated with adjustable crystalline phases and atom vacancies,as well as veiled dielectric-responsive character,are instrumental in electromagnetic dissipation.Conventional methods,however,constrain their delicate constructions.Herein,an innovative alternative is proposed:carrageenan-assistant cations-regulated(CACR)strategy,which induces a series of sulfides nanoparticles rooted in situ on the surface of carbon matrix.This unique configuration originates from strategic vacancy formation energy of sulfides and strong sulfides-carbon support interaction,benefiting the delicate construction of defects-rich heterostructures in M_(x)S_(y)/carbon composites(M-CAs).Impressively,these generated sulfur vacancies are firstly found to strengthen electron accumulation/consumption ability at heterointerfaces and,simultaneously,induct local asymmetry of electronic structure to evoke large dipole moment,ultimately leading to polarization coupling,i.e.,defect-type interfacial polarization.Such“Janus effect”(Janus effect means versatility,as in the Greek two-headed Janus)of interfacial sulfur vacancies is intuitively confirmed by both theoretical and experimental investigations for the first time.Consequently,the sulfur vacancies-rich heterostructured Co/Ni-CAs displays broad absorption bandwidth of 6.76 GHz at only 1.8 mm,compared to sulfur vacancies-free CAs without any dielectric response.Harnessing defects-rich heterostructures,this one-pot CACR strategy may steer the design and development of advanced nanomaterials,boosting functionality across diverse application domains beyond electromagnetic response. 展开更多
关键词 Defects-rich heterointerfaces Sulfides Polarization coupling Electromagnetic wave absorption
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Integration of Electrical Properties and Polarization Loss Modulation on Atomic Fe–N‑RGO for Boosting Electromagnetic Wave Absorption
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作者 Kaili Zhang Yuefeng Yan +4 位作者 Zhen Wang Guansheng Ma Dechang Jia Xiaoxiao Huang Yu Zhou 《Nano-Micro Letters》 SCIE EI CAS 2025年第2期517-532,共16页
Developing effective strategies to regulate graphene’s conduction loss and polarization has become a key to expanding its application in the electromagnetic wave absorption(EMWA)field.Based on the unique energy band ... Developing effective strategies to regulate graphene’s conduction loss and polarization has become a key to expanding its application in the electromagnetic wave absorption(EMWA)field.Based on the unique energy band structure of graphene,regulating its bandgap and electrical properties by introducing heteroatoms is considered a feasible solution.Herein,metal-nitrogen doping reduced graphene oxide(M–N-RGO)was prepared by embedding a series of single metal atoms M–N_(4) sites(M=Mn,Fe,Co,Ni,Cu,Zn,Nb,Cd,and Sn)in RGO using an N-coordination atom-assisted strategy.These composites had adjustable conductivity and polarization to optimize dielectric loss and impedance matching for efficient EMWA performance.The results showed that the minimum reflection loss(RL_(min))of Fe–N-RGO reaches−74.05 dB(2.0 mm)and the maximum effective absorption bandwidth(EAB_(max))is 7.05 GHz(1.89 mm)even with a low filler loading of only 1 wt%.Combined with X-ray absorption spectra(XAFS),atomic force microscopy,and density functional theory calculation analysis,the Fe–N_(4) can be used as the polarization center to increase dipole polarization,interface polarization and defect-induced polarization due to d-p orbital hybridization and structural distortion.Moreover,electron migration within the Fe further leads to conduction loss,thereby synergistically promoting energy attenuation.This study demonstrates the effectiveness of metal-nitrogen doping in regulating the graphene′s dielectric properties,which provides an important basis for further investigation of the loss mechanism. 展开更多
关键词 Electromagnetic wave absorption Fe-N-RGO Dipole polarization Conduction loss Impedance matching
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Low‑Temperature Oxidation Induced Phase Evolution with Gradient Magnetic Heterointerfaces for Superior Electromagnetic Wave Absorption
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作者 Zizhuang He Lingzi Shi +6 位作者 Ran Sun Lianfei Ding Mukun He Jiaming Li Hua Guo Tiande Gao Panbo Liu 《Nano-Micro Letters》 SCIE EI CAS 2025年第1期191-204,共14页
Gradient magnetic heterointerfaces have injected infinite vitality in optimizing impedance matching,adjusting dielectric/magnetic resonance and promoting electromagnetic(EM)wave absorption,but still exist a significan... Gradient magnetic heterointerfaces have injected infinite vitality in optimizing impedance matching,adjusting dielectric/magnetic resonance and promoting electromagnetic(EM)wave absorption,but still exist a significant challenging in regulating local phase evolution.Herein,accordion-shaped Co/Co_(3)O_(4)@N-doped carbon nanosheets(Co/Co_(3)O_(4)@NC)with gradient magnetic heterointerfaces have been fabricated via the cooperative high-temperature carbonization and lowtemperature oxidation process.The results indicate that the surface epitaxial growth of crystal Co_(3)O_(4) domains on local Co nanoparticles realizes the adjustment of magnetic-heteroatomic components,which are beneficial for optimizing impedance matching and interfacial polarization.Moreover,gradient magnetic heterointerfaces simultaneously realize magnetic coupling,and long-range magnetic diffraction.Specifically,the synthesized Co/Co_(3)O_(4)@NC absorbents display the strong electromagnetic wave attenuation capability of−53.5 dB at a thickness of 3.0 mm with an effective absorption bandwidth of 5.36 GHz,both are superior to those of single magnetic domains embedded in carbon matrix.This design concept provides us an inspiration in optimizing interfacial polarization,regulating magnetic coupling and promoting electromagnetic wave absorption. 展开更多
关键词 Magnetic heterointerfaces Phase evolution Interfacial polarization Magnetic coupling Electromagnetic wave absorption
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Effects of mesoscale gravity waves on sporadic E simulated by a one-dimensional dynamic model
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作者 Xu Zhou ZeZhong Li +1 位作者 XinAn Yue LiBo Liu 《Earth and Planetary Physics》 EI CAS 2025年第1期1-9,共9页
In addition to being driven by tidal winds,the sporadic E(Es)layers are modulated by gravity waves(GWs),although the effects are not yet comprehensively understood.In this article,we discuss the effects of mesoscale G... In addition to being driven by tidal winds,the sporadic E(Es)layers are modulated by gravity waves(GWs),although the effects are not yet comprehensively understood.In this article,we discuss the effects of mesoscale GWs on the Es layers determined by using a newly developed model,MISE-1D(one-dimensional Model of Ionospheric Sporadic E),with low numerical dissipation and high resolution.Driven by the wind fields resolved by the high-resolution version of the Whole Atmosphere Community Climate Model with thermosphere and ionosphere extension(WACCM-X),the MISE-1D simulation revealed that GWs significantly influence the evolution of the Es layer above 100 km but have a very limited effect at lower altitudes.The effects of GWs are diverse and complex,generally including the generation of fluctuating wavelike structures on the Es layer with frequencies similar to those of the GWs.The mesoscale GWs can also cause increases in the density of Es layers,or they can disperse or diffuse the Es layers and increase their thickness.In addition,the presence of GWs is a key factor in sustaining the Es layers in some cases. 展开更多
关键词 sporadic E ion tidal layer gravity waves numerical simulation
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Statistical analysis on the validity of the cold plasma approximation for chorus waves based on Van Allen Probe observations and their effects on radiation belt electrons
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作者 AoJun Ren Jiang Yu +2 位作者 Jing Wang ZuZheng Chen XiaoMan Liu 《Earth and Planetary Physics》 EI CAS 2025年第1期159-170,共12页
Theoretical analysis has demonstrated that the dispersion relation of chorus waves plays an essential role in the resonant interaction and energy transformation between the waves and magnetospheric electrons.Previous ... Theoretical analysis has demonstrated that the dispersion relation of chorus waves plays an essential role in the resonant interaction and energy transformation between the waves and magnetospheric electrons.Previous quantitative analyses often simplified the chorus dispersion relation by using the cold plasma assumption.However,the applicability of the cold plasma assumption is doubtful,especially during geomagnetic disturbances.We here present a systematic statistical analysis on the validity of the cold plasma dispersion relation of chorus waves based on observations from the Van Allen Probes over the period from 2012 to 2018.The statistical results show that the observed magnetic field intensities deviate substantially from those calculated from the cold plasma dispersion relation and that they become more pronounced with an increase in geomagnetic activity or a decrease in background plasma density.The region with large deviations is mainly concentrated in the nightside and expands in both the radial and azimuthal directions as the geomagnetic activity increases or the background plasma density decreases.In addition,the bounce-averaged electron scattering rates are computed by using the observed and cold plasma dispersion relation of chorus waves.Compared with usage of the cold plasma dispersion relation,usage of the observed dispersion relation considerably lowers the minimum resonant energy of electrons and lowers the scattering rates of electrons above tens of kiloelectronvolts but enhances those below.Furthermore,these differences are more pronounced with the enhancement of geomagnetic activity or the decrease in background plasma density. 展开更多
关键词 chorus waves cold plasma approximation dispersion relations scattering rates
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Graphene Aerogel Composites with Self‑Organized Nanowires‑Packed Honeycomb Structure for Highly Efficient Electromagnetic Wave Absorption
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作者 Xiao You Huiying Ouyang +6 位作者 Ruixiang Deng Qiuqi Zhang Zhenzhong Xing Xiaowu Chen Qingliang Shan Jinshan Yang Shaoming Dong 《Nano-Micro Letters》 SCIE EI CAS 2025年第2期533-547,共15页
With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers.Herein,a hierarchical porous structure and composite h... With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers.Herein,a hierarchical porous structure and composite heterogeneous interface are constructed successfully to optimize the electromagnetic loss capacity.The macro–micro-synergistic graphene aerogel formed by the ice template‑assisted 3D printing strategy is cut by silicon carbide nanowires(SiC_(nws))grown in situ,while boron nitride(BN)interfacial structure is introduced on graphene nanoplates.The unique composite structure forces multiple scattering of incident EMWs,ensuring the combined effects of interfacial polarization,conduction networks,and magnetic-dielectric synergy.Therefore,the as-prepared composites present a minimum reflection loss value of−37.8 dB and a wide effective absorption bandwidth(EAB)of 9.2 GHz(from 8.8 to 18.0 GHz)at 2.5 mm.Besides,relying on the intrinsic high-temperature resistance of SiC_(nws) and BN,the EAB also remains above 5.0 GHz after annealing in air environment at 600℃ for 10 h. 展开更多
关键词 Hierarchical porous structure Interface High-temperature resistance Graphene aerogel composites Electromagnetic wave absorption
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An investigation on the wind profiles and gravity wave dynamics in MLT region based on the meteor radars from the Meridian Project
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作者 Tai Liu Zhe Wang +2 位作者 MengXi Shi Willie Soon ShiCan Qiu 《Earth and Planetary Physics》 EI CAS 2025年第1期29-38,共10页
The meteor radar can detect the zenith angle,azimuth,radial velocity,and altitude of meteor trails so that one can invert the wind profiles in the mesosphere and low thermosphere(MLT)region,based on the Interferometri... The meteor radar can detect the zenith angle,azimuth,radial velocity,and altitude of meteor trails so that one can invert the wind profiles in the mesosphere and low thermosphere(MLT)region,based on the Interferometric and Doppler techniques.In this paper,the horizontal wind field,gravity wave(GW)disturbance variance,and GW fluxes are analyzed through the meteor radar observation from 2012−2022,at Mohe(53.5°N,122.4°E)and Zuoling(30.5°N,114.6°E)stations of the(Chinese)Meridian Project.The Lomb−Scargle periodogram method has been utilized to analyze the periodic variations for time series with observational data gaps.The results show that the zonal winds at both stations are eastward dominated,while the meridional winds are southward dominated.The variance of GW disturbances in the zonal and meridional directions increases gradually with height,and there is a strong pattern of annual variation.The zonal momentum flux of GW changes little with height,showing weak annual variation.The meridional GW flux varies gradually from northward to southward with height,and the annual periodicity is stronger.For both stations,the maximum values of zonal and meridional wind occur close to the peak heights of GW flux,with opposite directions.This observational evidence is consistent with the filtering theory.The horizontal wind velocity,GW flux,and disturbance variance of the GW at Mohe are overall smaller than those at Zuoling,indicating weaker activities in the MLT at Mohe.The power spectral density(PSD)calculated by the Lomb−Scargle periodogram shows that there are 12-month period and 6-month period in horizontal wind field,GW disturbance variance and GW flux at both stations,and especially there is also a 4-month cycle in the disturbance variance.The PSD of the 12-month and 6-month cycles exhibits maximum values below 88 km and above 94 km. 展开更多
关键词 meteor radar wind field gravity wave Lomb−Scargle method
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WavewatchⅢ模拟和统计方法在最大波高预报方面的评测分析
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作者 王娟娟 侯放 +1 位作者 吴淑萍 王久珂 《海洋预报》 CSCD 北大核心 2024年第1期1-9,共9页
为了研究WavewatchⅢ(WWⅢ)海浪模型对最大波高的模拟能力及其与传统统计关系方法的差异,通过对两次台风浪过程的后报模拟和半年的业务化预报,分析了WWⅢ数值模拟的准确度及其与统计关系方法的精度差异。研究结果表明:WWⅢ数值模拟的最... 为了研究WavewatchⅢ(WWⅢ)海浪模型对最大波高的模拟能力及其与传统统计关系方法的差异,通过对两次台风浪过程的后报模拟和半年的业务化预报,分析了WWⅢ数值模拟的准确度及其与统计关系方法的精度差异。研究结果表明:WWⅢ数值模拟的最大波高(Hmax)的精度略低于有效波高(Hs),但也达到了24 h预报相对误差(H_(max)≥1 m)低于18%、相关系数高于0.94的水平,模拟精度可靠,可以用于业务化预报;与两种统计关系方法(H_(max)和H_(s)分别为1.42和1.52)计算的最大波高相比,数值模拟的精度总体与其相当,但在H_(max)和H_(s)比值大于1.65这种易出现危险的海况下,数值模拟具有更高的准确性,更适合应用于海浪预警报服务。 展开更多
关键词 最大波高 wavewatchⅢ模型 数值模拟 统计关系 预报精度
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基于D-Wave Advantage的量子退火公钥密码攻击算法研究
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作者 王潮 王启迪 +2 位作者 洪春雷 胡巧云 裴植 《计算机学报》 EI CAS CSCD 北大核心 2024年第5期1030-1044,共15页
D-Wave专用量子计算机的原理量子退火凭借独特的量子隧穿效应可跳出传统智能算法极易陷入的局部极值,可视为一类具有全局寻优能力的人工智能算法.本文研究了两类基于量子退火的RSA公钥密码攻击算法(分解大整数N=pq):一是将密码攻击数学... D-Wave专用量子计算机的原理量子退火凭借独特的量子隧穿效应可跳出传统智能算法极易陷入的局部极值,可视为一类具有全局寻优能力的人工智能算法.本文研究了两类基于量子退火的RSA公钥密码攻击算法(分解大整数N=pq):一是将密码攻击数学方法转为组合优化问题或指数级空间搜索问题,通过Ising模型或QUBO模型求解,提出了乘法表的高位优化模型,建立新的降维公式,使用D-Wave Advantage分解了 200万整数2269753.大幅度超过普渡大学、Lockheed Martin和富士通等实验指标,且Ising模型系数h范围缩小了 84%,系数J范围缩小了 80%,极大地提高了分解成功率,这是一类完全基于D-Wave量子计算机的攻击算法;二是基于量子退火算法融合密码攻击数学方法优化密码部件的攻击,采用量子退火优化CVP问题求解,通过量子隧穿效应获得比Babai算法更近的向量,提高了 CVP问题中光滑对的搜索效率,在D-Wave Advantage上实现首次50比特RSA整数分解.实验表明,在通用量子计算机器件进展缓慢情况下,D-Wave表现出更好的现实攻击能力,且量子退火不存在NISQ量子计算机VQA算法的致命缺陷贫瘠高原问题:算法会无法收敛且无法扩展到大规模攻击. 展开更多
关键词 RSA D-wave 量子退火 CVP 量子隧穿 整数分解 量子计算
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Absorption properties and mechanism of lightweight and broadband electromagnetic wave-absorbing porous carbon by the swelling treatment 被引量:6
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作者 Jianghao Wen Di Lan +4 位作者 Yiqun Wang Lianggui Ren Ailing Feng Zirui Jia Guanglei Wu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第7期1701-1712,共12页
Bioderived carbon materials have garnered considerable interest in the fields of microwave absorption and shielding due to their reproducibility and environmental friendliness.In this study,KOH was evenly distributed ... Bioderived carbon materials have garnered considerable interest in the fields of microwave absorption and shielding due to their reproducibility and environmental friendliness.In this study,KOH was evenly distributed on biomass Tremella using the swelling induction method,leading to the preparation of a three-dimensional network-structured hierarchical porous carbon(HPC)through carbonization.The achieved microwave absorption intensity is robust at-47.34 dB with a thin thickness of 2.1 mm.Notably,the widest effective absorption bandwidth,reaching 7.0 GHz(11–18 GHz),is attained at a matching thickness of 2.2 mm.The exceptional broadband and reflection loss performance are attributed to the 3D porous networks,interface effects,carbon network defects,and dipole relaxation.HPC has outstanding absorption characteristics due to its excellent impedance matching and high attenuation constant.The uniform pore structures considerably optimize the impedance-matching performance of the material,while the abundance of interfaces and defects enhances the dielectric loss,thereby improving the attenuation constant.Furthermore,the impact of carbonization temperature and swelling rate on microwave absorption performance was systematically investigated.This research presents a strategy for preparing absorbing materials using biomass-derived HPC,showcasing considerable potential in the field of electromagnetic wave absorption. 展开更多
关键词 BIOMASS hierarchical porous carbon dielectric loss electromagnetic wave absorption
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Korean Wave: Towards Regional Cultural Diffusion?
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作者 Seiko Yasumoto 《Journal of Literature and Art Studies》 2013年第2期101-112,共12页
The aim of this paper is firstly to determine if the Korean television drama Winter Sonata and its spinoffs are contributing to contemporary cross-cultural diffusion in Japan. Secondly, if cross-cultural diffusion is ... The aim of this paper is firstly to determine if the Korean television drama Winter Sonata and its spinoffs are contributing to contemporary cross-cultural diffusion in Japan. Secondly, if cross-cultural diffusion is occurring, is it contributing to a loss of local identity? Winter Sonata is a small but significant part of the Korean Wave and in the vanguard of Korean television drama content viewed in Japan. There have been macro political changes in East Asia, largely driven by Korea, resulting in an easing of restrictions on cross-border media trade. These in turn have progressively created a new dynamic in content and volume. The methodology used for the study is triangulation including document analysis, audience analysis, and commercial outcomes. The convergent validation derived from the three parameters advances the proposition that Winter Sonata has contributed to cultural diffusion from a Japanese perspective but not to a loss of local identity. Arguably, the process is an enriching one in East Asia reinforced by multi-lateral media trade. 展开更多
关键词 popular culture korean wave cross-cultural diffusion cultural hybridity TRIANGULATION
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Tracking Regulatory Mechanism of Trace Fe on Graphene Electromagnetic Wave Absorption 被引量:4
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作者 Kaili Zhang Yuhao Liu +5 位作者 Yanan Liu Yuefeng Yan Guansheng Ma Bo Zhong Renchao Che Xiaoxiao Huang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第4期79-96,共18页
Polarization and conductance losses are the fundamental dielectric attenuation mechanisms for graphene-based absorbers, but it is not fully understood in revealing the loss mechanism of affect graphene itself. For the... Polarization and conductance losses are the fundamental dielectric attenuation mechanisms for graphene-based absorbers, but it is not fully understood in revealing the loss mechanism of affect graphene itself. For the first time, the reduced graphene oxide(RGO) based absorbers are developed with regulatory absorption properties and the absorption mechanism of RGO is mainly originated from the carrier injection behavior of trace metal Fe nanosheets on graphene. Accordingly, the minimum reflection loss(RLmin) of Fe/RGO-2composite reaches-53.38 dB(2.45 mm), and the effective absorption bandwidth achieves 7.52 GHz(2.62 mm) with lower filling loading of 2 wt%. Using off-axis electron hologram testing combined with simulation calculation and carrier transport property experiments, we demonstrate here the carrier injection behavior from Fe to graphene at the interface and the induced charge accumulation and rearrangement, resulting in the increased interfacial and dipole polarization and the conductance loss. This work has confirmed that regulating the dielectric property of graphene itself by adding trace metals can not only ensure good impedance matching, but also fully exploit the dielectric loss ability of graphene at low filler content,which opens up an efficient way for designing lightweight absorbers and may be extended to other types materials. 展开更多
关键词 Reduced graphene oxide Fe nanosheets Dielectric loss Electromagnetic wave absorption
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Structural Engineering of Hierarchical Magnetic/Carbon Nanocomposites via In Situ Growth for High-Efficient Electromagnetic Wave Absorption 被引量:3
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作者 Xianyuan Liu Jinman Zhou +1 位作者 Ying Xue Xianyong Lu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第9期262-278,共17页
Materials exhibiting high-performance electromagnetic wave absorption have garnered considerable scientific and technological attention,yet encounter significant challenges.Developing new materials and innovative stru... Materials exhibiting high-performance electromagnetic wave absorption have garnered considerable scientific and technological attention,yet encounter significant challenges.Developing new materials and innovative structural design concepts is crucial for expanding the application field of electromagnetic wave absorption.Particularly,hierarchical structure engineering has emerged as a promising approach to enhance the physical and chemical properties of materials,providing immense potential for creating versatile electromagnetic wave absorption materials.Herein,an exceptional multi-dimensional hierarchical structure was meticulously devised,unleashing the full microwave attenuation capabilities through in situ growth,selfreduction,and multi-heterogeneous interface integration.The hierarchical structure features a three-dimensional carbon framework,where magnetic nanoparticles grow in situ on the carbon skeleton,creating a necklace-like structure.Furthermore,magnetic nanosheets assemble within this framework.Enhanced impedance matching was achieved by precisely adjusting component proportions,and intelligent integration of diverse interfaces bolstered dielectric polarization.The obtain Fe_(3)O_(4)-Fe nanoparticles/carbon nanofibers/Al-Fe_(3)O_(4)-Fe nanosheets composites demonstrated outstanding performance with a minimum reflection loss(RLmin)value of−59.3 dB and an effective absorption bandwidth(RL≤−10 dB)extending up to 5.6 GHz at 2.2 mm.These notable accomplishments offer fresh insights into the precision design of high-efficient electromagnetic wave absorption materials. 展开更多
关键词 Electromagnetic wave absorption Hierarchical structure In situ growth Self-reduction
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The Influence of the Korean Wave on the Language of International Fans: Case Study of Algerian Fans
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作者 Batoul Touhami Fawwaz Al-Abed Al-Haq 《Sino-US English Teaching》 2017年第10期598-626,共29页
The linguistic influence of the Korean Wave (Hallyu, which refers to the Korean pop and drama) on the language of International fans is that of a salient but not linguistically examined phenomenon. This study invest... The linguistic influence of the Korean Wave (Hallyu, which refers to the Korean pop and drama) on the language of International fans is that of a salient but not linguistically examined phenomenon. This study investigates the major aspects of this influence and the linguistic reasons behind its global prevalence. The practical part of this study is conducted on Algerian Hallyu fans from which a sample of 139 participants responded to the questionnaire used as a research instrument for achieving the goal of this study. Findings reveal that Hallyu influence is widely spread in Algeria, where by 98.5% of the participants declared the existence of this influence. This impact on participants' language starts from using Korean words in their daily discourse to using English words with an adapted Hallyu meaning and to naming phone contacts with the accurate Korean terms of kinship and endearment. Then, they start using linguistically odd inside jokes taken from Korean idols' and K-dramas' speech, employing Korean proverbs in their conversations, and gradually adopting a different pronunciation of some English sounds. Moreover, their language stands as a sample of Corpus Planning with two types: Modernization and Graphization. Some words are modernized in order to bridge the gap through Hallyu pals' communication with more precise words, while other words are graphitized for the sake of developing new terms or new meanings or to shorten long ones. This thesis contributes to the study of random language, generally, and to Hallyu language, specifically, as an aspect of Conversation Analysis (CA). 展开更多
关键词 the korean wave (Hallyu) International fans' language conversation analysis corpus planning Algerian fans linguistic influence
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Interface Engineering of Titanium Nitride Nanotube Composites for Excellent Microwave Absorption at Elevated Temperature 被引量:4
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作者 Cuiping Li Dan Li +4 位作者 Shuai Zhang Long Ma Lei Zhang Jingwei Zhang Chunhong Gong 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第9期147-160,共14页
Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction loss.Consequently... Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction loss.Consequently,the development of high-performance EMWA materials with good impedance matching and strong loss ability in wide temperature spectrum has emerged as a top priority.Herein,due to the high melting point,good electrical conductivity,excellent environmental stability,EM coupling effect,and abundant interfaces of titanium nitride(TiN)nanotubes,they were designed based on the controlling kinetic diffusion procedure and Ostwald ripening process.Benefiting from boosted heterogeneous interfaces between TiN nanotubes and polydimethylsiloxane(PDMS),enhanced polarization loss relaxations were created,which could not only improve the depletion efficiency of EMWA,but also contribute to the optimized impedance matching at elevated temperature.Therefore,the TiN nanotubes/PDMS composite showed excellent EMWA performances at varied temperature(298-573 K),while achieved an effective absorption bandwidth(EAB)value of 3.23 GHz and a minimum reflection loss(RLmin)value of−44.15 dB at 423 K.This study not only clarifies the relationship between dielectric loss capacity(conduction loss and polarization loss)and temperature,but also breaks new ground for EM absorbers in wide temperature spectrum based on interface engineering. 展开更多
关键词 TiN nanotubes Interface engineering Polarization loss Impedance matching Electromagnetic wave absorption performance
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Nitrogen‑Doped Magnetic‑Dielectric‑Carbon Aerogel for High‑Efficiency Electromagnetic Wave Absorption 被引量:2
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作者 Shijie Wang Xue Zhang +5 位作者 Shuyan Hao Jing Qiao Zhou Wang Lili Wu Jiurong Liu Fenglong Wang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第1期313-327,共15页
Carbonbased aerogels derived from biomass chitosan are encountering a flourishing moment in electromagnetic protection on account of lightweight,controllable fabrication and versatility.Nevertheless,developing a facil... Carbonbased aerogels derived from biomass chitosan are encountering a flourishing moment in electromagnetic protection on account of lightweight,controllable fabrication and versatility.Nevertheless,developing a facile construction method of component design with carbon-based aerogels for high-efficiency electromagnetic wave absorption(EWA)materials with a broad effective absorption bandwidth(EAB)and strong absorption yet hits some snags.Herein,the nitrogen-doped magnetic-dielectric-carbon aerogel was obtained via ice template method followed by carbonization treatment,homogeneous and abundant nickel(Ni)and manganese oxide(MnO)particles in situ grew on the carbon aerogels.Thanks to the optimization of impedance matching of dielectric/magnetic components to carbon aerogels,the nitrogen-doped magnetic-dielectric-carbon aerogel(Ni/MnO-CA)suggests a praiseworthy EWA performance,with an ultra-wide EAB of 7.36 GHz and a minimum reflection loss(RLmin)of−64.09 dB,while achieving a specific reflection loss of−253.32 dB mm−1.Furthermore,the aerogel reveals excellent radar stealth,infrared stealth,and thermal management capabilities.Hence,the high-performance,easy fabricated and multifunctional nickel/manganese oxide/carbon aerogels have broad application aspects for electromagnetic protection,electronic devices and aerospace. 展开更多
关键词 Electromagnetic wave absorption Wide bandwidth Dielectric-magnetic synergy MULTIFUNCTION
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Analysis of gravity wave activity during stratospheric sudden warmings in the northern hemisphere 被引量:2
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作者 XuanYun Zeng Guang Zhong 《Earth and Planetary Physics》 EI CAS CSCD 2024年第2期415-422,共8页
Due to the significant changes they bring to high latitude stratospheric temperature and wind,stratospheric sudden warmings(SSWs)can have an impact on the propagation and energy distribution of gravity waves(GWs).The ... Due to the significant changes they bring to high latitude stratospheric temperature and wind,stratospheric sudden warmings(SSWs)can have an impact on the propagation and energy distribution of gravity waves(GWs).The variation characteristics of GWs during SSWs have always been an important issue.Using temperature data from January to March in 2014−2016,provided by the Constellation Observing System for Meteorology,Ionosphere and Climate(COSMIC)mission,we have analyzed global GW activity at 15−40 km in the Northern Hemisphere during SSW events.During the SSWs that we studied,the stratospheric temperature rose in one or two longitudinal regions in the Northern Hemisphere;the areas affected extended to the east of 90°W.During these SSWs,the potential energy density(E_(p)of GWs expanded and covered a larger range of longitude and altitude,exhibiting an eastward and downward extension.The E_(p)usually increased,while partially filtered by the eastward zonal winds.When zonal winds weakened or turned westward,E_(p)began to strengthen.After SSWs,the E_(p)usually decreased.These observations can serve as a reference for analyzing the interaction mechanism between SSWs and GWs in future work. 展开更多
关键词 stratospheric sudden warming gravity wave wind filter
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From VIB‑to VB‑Group Transition Metal Disulfides:Structure Engineering Modulation for Superior Electromagnetic Wave Absorption 被引量:2
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作者 Junye Cheng Yongheng Jin +10 位作者 Jinghan Zhao Qi Jing Bailong Gu Jialiang Wei Shenghui Yi Mingming Li Wanli Nie Qinghua Qin Deqing Zhang Guangping Zheng Renchao Che 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第2期218-257,共40页
The laminated transition metal disulfides(TMDs),which are well known as typical two-dimensional(2D)semiconductive materials,possess a unique layered structure,leading to their wide-spread applications in various field... The laminated transition metal disulfides(TMDs),which are well known as typical two-dimensional(2D)semiconductive materials,possess a unique layered structure,leading to their wide-spread applications in various fields,such as catalysis,energy storage,sensing,etc.In recent years,a lot of research work on TMDs based functional materials in the fields of electromagnetic wave absorption(EMA)has been carried out.Therefore,it is of great significance to elaborate the influence of TMDs on EMA in time to speed up the application.In this review,recent advances in the development of electromagnetic wave(EMW)absorbers based on TMDs,ranging from the VIB group to the VB group are summarized.Their compositions,microstructures,electronic properties,and synthesis methods are presented in detail.Particularly,the modulation of structure engineering from the aspects of heterostructures,defects,morphologies and phases are systematically summarized,focusing on optimizing impedance matching and increasing dielectric and magnetic losses in the EMA materials with tunable EMW absorption performance.Milestones as well as the challenges are also identified to guide the design of new TMDs based dielectric EMA materials with high performance. 展开更多
关键词 Transition metal disulfides Electromagnetic wave absorption Impedance matching Structure engineering modulation
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Propagation Properties of Shock Waves in Polyurethane Foam based on Atomistic Simulations 被引量:1
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作者 Zhiqiang Hu Jianli Shao +2 位作者 Shiyu Jia Weidong Song Cheng Wang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期117-129,共13页
Porous materials are widely used in the field of protection because of their excellent energy absorption characteristics.In this work,a series of polyurethane microscopic models are established and the effect of poros... Porous materials are widely used in the field of protection because of their excellent energy absorption characteristics.In this work,a series of polyurethane microscopic models are established and the effect of porosity on the shock waves is studied with classical molecular dynamics simulations.Firstly,shock Hugoniot relations for different porosities are obtained,which compare well with the experimental data.The pores collapse and form local stress wave,which results in the complex multi-wave structure of the shock wave.The microstructure analysis shows that the local stress increases and the local velocity decreases gradually during the process of pore collapse to complete compaction.Finally,it leads to stress relaxation and velocity homogenization.The shock stress peaks can be fitted with two exponential functions,and the amplitude of attenuation coefficient decreases with the increase of density.Besides,the pore collapse under shock or non-shock are discussed by the entropy increase rate of the system.The energy is dissipated mainly through the multiple interactions of the waves under shock.The energy is dissipated mainly by the friction between atoms under non-shock. 展开更多
关键词 Polyurethane foam Shock wave ATTENUATION Atomistic simulation
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