Based on the ABCD matrix formalism,the propagation property of an Airy beam from right-handed material（RHM） to left-handed material（LHM） is investigated.The result shows that when the Airy beam propagates in the L...Based on the ABCD matrix formalism,the propagation property of an Airy beam from right-handed material（RHM） to left-handed material（LHM） is investigated.The result shows that when the Airy beam propagates in the LHM,the intensity self-bending due to its propagation in the RHM can be compensated.In particular,if the propagation distance in the RHM is equal to that in the LHM and the refractive index of the LHM is n L =-1,the transverse intensity distribution of the Airy beam can return to its original state.展开更多
In this paper, we present the electromagnetic analysis of a rectangular cavity partially filled with a left-handed material slab. Our theoretical investigation shows that there exist novel resonant modes in the cavity...In this paper, we present the electromagnetic analysis of a rectangular cavity partially filled with a left-handed material slab. Our theoretical investigation shows that there exist novel resonant modes in the cavity, and such a cavity becomes a subwavelength cavity. The eigenvalue equation of the cavity is derived and the resonant frequencies of the novel modes are calculated by using numerical simulation. We also discuss the stability of the novel resonant modes and show the best condition under which a useful rectangular cavity of subwavelength dimensions with tolerable stability is obtained.展开更多
In this paper a comprehensive framework for treating the nonlinear propagation of ultrashort pulse in metamaterial with dispersive dielectric susceptibility and magnetic permeability is presented. Under the slowly-evo...In this paper a comprehensive framework for treating the nonlinear propagation of ultrashort pulse in metamaterial with dispersive dielectric susceptibility and magnetic permeability is presented. Under the slowly-evolving-wave approximation, a generalized （3＋1）-dimensional wave equation first order in the propagation coordinate and suitable for both right-handed material （I^HM） and left-handed material （LHM） is derived. By the commonly used Drude dispersive model for LHM, a （3＋1）-dimensional nonlinear Schrodinger equation describing ultrashort pulsed beam propagation in LHM is obtained, and its difference from that for conventional RHM is discussed. Particularly, the self-steeping effect of ultrashort pulse is found to be anomalous in LHM.展开更多
We report the coexistence of TE and TM surface modes in certain same frequency domain at the interface between one isotropic regular medium and another biaxially anistotropic left-handed medium. The conditions for the...We report the coexistence of TE and TM surface modes in certain same frequency domain at the interface between one isotropic regular medium and another biaxially anistotropic left-handed medium. The conditions for the existence of TE and TM polarized surface waves in biaxially anisotropic left-handed materials are identified, respectively. The Poynting vector and the energy density associated with surface modes are calculated. Depending on the system parameters, either TE or TM surface modes can have the time averaged Poynting vector directed to or opposite to the mode phase velocity. It is seen that the characteristics of surface waves in biaxially anisotropic left-handed media are significantly different from that in isotropic left-handed media.展开更多
The phenomena of super energy flows are studied theoretically and numerically in a parallel-plate waveguide which is filled with two layered equally-thick different media, i.e. air and specific left-handed materials ...The phenomena of super energy flows are studied theoretically and numerically in a parallel-plate waveguide which is filled with two layered equally-thick different media, i.e. air and specific left-handed materials （LHM） with εr1 = -1/（1 ＋δ） ＋iγ and μr1 = -（1 ＋ δ） ＋ iγ. In this special waveguide, two-directional super-energy flows are excited by a three-dimensional horizontal electric dipole at the same time, which has transmission patterns different from those of two-dimensional source and three-dimensional vertical electric dipole. We also show that the retardation and loss in LHM are sensitive to the amplitude of super power densities, and the dimensions of waveguide determine the propagating modes, which makes super energy flows more practical.展开更多
This paper investigates the photon tunneling and transmittance resonance through a multi-layer structure including a left-handed material（LHM）. An analytical expression for the transmittance in a five-layer structur...This paper investigates the photon tunneling and transmittance resonance through a multi-layer structure including a left-handed material（LHM）. An analytical expression for the transmittance in a five-layer structure is given by the analytical transfer matrix method. The transmittance is studied as a function of the refractive index and the width of the LHM layer. The perfect photon tunneling results from the multi-layer structure, especially from the relation between the magnitude of the refractive index and the width of the LHM layer and those of the adjoining layers. Photons may tunnel through a much greater distance in this structure. Transmittance resonance happens, the peaks and valleys appear periodically at the resonance thickness. For an LHM with inherent losses, the perfect transmittance is suppressed.展开更多
A theoretical investigation of field components for transverse electric mode in the parallel-plate waveguides has been studied. In this analysis two different types of waveguide structures have been discussed, i.e., ...A theoretical investigation of field components for transverse electric mode in the parallel-plate waveguides has been studied. In this analysis two different types of waveguide structures have been discussed, i.e., （a） normal good/perfect conducting parallel-plate waveguide filled with nonlinear left-handed material and （b） high-temperature-superconducting parallel-plate waveguide filled with nonlinear left-handed material. The dispersion relations of transverse electric mode have also been discussed for these two types of waveguide structures.展开更多
This paper derives the force of the electromagnetic radiation on left-handed materials （LHMs） by a direct application of the Lorentz law of classical electrodynamics. The expressions of radiation force are given for...This paper derives the force of the electromagnetic radiation on left-handed materials （LHMs） by a direct application of the Lorentz law of classical electrodynamics. The expressions of radiation force are given for TE-polarised and TM-polarised fields. The numerical results demonstrate that electromagnetic waves exert an inverse lateral radiation force on each edge of the beams, that is, the lateral pressure is expansive for TE-polarised beams and compressive for TM-polarised beams. The investigation of the radiation force will provide insights into the fundamental properties of LHMs and will provide to better understanding of the interaction of light with LHMs.展开更多
By applying the ABCD matrix method, we report the propagating properties of the rotating elliptical Gaussian beams（REGBs） from the right-handed material（RHM） to the left-handed material（LHM）. Based on the propag...By applying the ABCD matrix method, we report the propagating properties of the rotating elliptical Gaussian beams（REGBs） from the right-handed material（RHM） to the left-handed material（LHM）. Based on the propagation equation, we obtain the intensity distributions of the REGBs during the propagation. It is found that the rotating direction of the REGBs is opposite in the RHM and the LHM, and the rotation angles tend to be π /2 as the propagation distance is long enough.Then we analyze the relationship between the refractive index and the rotating velocity. Furthermore, the energy flow and the angular momentum（AM） of the REGBs which can rotate are also obtained.展开更多
We devise three sorts of doped left-handed materials （DLHMs） by introducing inductors and capacitors into the traditional left-handed material （LHM） as heterogeneous elements. Some new properties are presented thr...We devise three sorts of doped left-handed materials （DLHMs） by introducing inductors and capacitors into the traditional left-handed material （LHM） as heterogeneous elements. Some new properties are presented through finitedifference time-domain （FDTD） simulations. On the one hand, the resonance in the traditional LHM is weakened and the original pass band is narrowed by introducing inductors. On the other hand, the original pass band of the LHM can be shifted and a new pass band can be generated by introducing capacitors. When capacitors and inductors are introduced simultaneously, the resonance of traditional LHM is somewhat weakened and the number of original pass bands as well as its bandwidth can be changed.展开更多
Finite-difference time-domain(FDTD) method is used to simulate the propagation of electromagnetic wave in left-handed material slab(LHMs) with cold plasma model The effects of optical propagation in the left-handed ma...Finite-difference time-domain(FDTD) method is used to simulate the propagation of electromagnetic wave in left-handed material slab(LHMs) with cold plasma model The effects of optical propagation in the left-handed material compared to convex lens are discussed.The wider the LHMs is,the stronger electric field of focusing image in left-handed material slab is confirmed by the simulation with various slab length.However,the outer image point location would slightly moves to the LHMs side when the length of LHMs is reduced.展开更多
This paper reports on experimental study of the microwave properties of a composite material consisting of ferrite and copper wires. It finds that the slim ferrite rods can modify the magnetic field distribution throu...This paper reports on experimental study of the microwave properties of a composite material consisting of ferrite and copper wires. It finds that the slim ferrite rods can modify the magnetic field distribution through their anisotropy, so that the ferrite＇s negative influence on the copper wires＇ plasma will be reduced. Left-handed properties are observed even in the specimen with close stuck ferrite rods and copper wires.展开更多
High-entropy materials represent a new category of high-performance materials,first proposed in 2004 and extensively investigated by researchers over the past two decades.The definition of high-entropy materials has c...High-entropy materials represent a new category of high-performance materials,first proposed in 2004 and extensively investigated by researchers over the past two decades.The definition of high-entropy materials has continuously evolved.In the last ten years,the discovery of an increasing number of high-entropy materials has led to significant advancements in their utilization in energy storage,electrocatalysis,and related domains,accompanied by a rise in techniques for fabricating high-entropy electrode materials.Recently,the research emphasis has shifted from solely improving the performance of high-entropy materials toward exploring their reaction mechanisms and adopting cleaner preparation approaches.However,the current definition of high-entropy materials remains relatively vague,and the preparation method of high-entropy materials is based on the preparation method of single metal/low-or medium-entropy materials.It should be noted that not all methods applicable to single metal/low-or medium-entropy materials can be directly applied to high-entropy materials.In this review,the definition and development of high-entropy materials are briefly reviewed.Subsequently,the classification of high-entropy electrode materials is presented,followed by a discussion of their applications in energy storage and catalysis from the perspective of synthesis methods.Finally,an evaluation of the advantages and disadvantages of various synthesis methods in the production process of different high-entropy materials is provided,along with a proposal for potential future development directions for high-entropy materials.展开更多
Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable development.Hydroelectricity generation from ubiquitous and spontaneous phase transitions between liquid and gas...Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable development.Hydroelectricity generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy crisis.Fibrous materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first introduced.Then,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are demonstrated.Afterward,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in detail.Moreover,the potential applications including power supply,energy storage,electrical sensor,and information expression are also discussed.Finally,some existing challenges are considered and prospects for future development are sincerely proposed.展开更多
Dynamic structuralcolors can change in response todifferent environmental stimuli.This ability remains effectiveeven when the size of the speciesresponsible for the structural coloris reduced to a few micrometers,prov...Dynamic structuralcolors can change in response todifferent environmental stimuli.This ability remains effectiveeven when the size of the speciesresponsible for the structural coloris reduced to a few micrometers,providing a promising sensingmechanism for solving microenvironmentalsensing problems inmicro-robotics and microfluidics.However, the lack of dynamicstructural colors that can encoderapidly, easily integrate, and accuratelyreflect changes in physical quantities hinders their use in microscale sensing applications. Herein, we present a 2.5-dimensionaldynamic structural color based on nanogratings of heterogeneous materials, which were obtained by interweaving a pH-responsive hydrogelwith an IP-L photoresist. Transverse gratings printed with pH-responsive hydrogels elongated the period of longitudinal grating in the swollenstate, resulting in pH-tuned structural colors at a 45° incidence. Moreover, the patterned encoding and array printing of dynamic structuralcolors were achieved using grayscale stripe images to accurately encode the periods and heights of the nanogrid structures. Overall, dynamicstructural color networks exhibit promising potential for applications in information encryption and in situ sensing for microfluidic chips.展开更多
Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and...Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field.展开更多
Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,th...Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,the sluggish diffusion kinetics of bivalent Mg^(2+)in the host material,related to the strong Coulomb effect between Mg^(2+)and host anion lattices,hinders their further development toward practical applications.Defect engineering,regarded as an effective strategy to break through the slow migration puzzle,has been validated in various cathode materials for RMBs.In this review,we first thoroughly understand the intrinsic mechanism of Mg^(2+)diffusion in cathode materials,from which the key factors affecting ion diffusion are further presented.Then,the positive effects of purposely introduced defects,including vacancy and doping,and the corresponding strategies for introducing various defects are discussed.The applications of defect engineering in cathode materials for RMBs with advanced electrochemical properties are also summarized.Finally,the existing challenges and future perspectives of defect engineering in cathode materials for the overall high-performance RMBs are described.展开更多
The history of acoustic metamaterials can be traced back to the turn of the 215 century,when the local res-onances of subwavelength structures were leveraged for acoustic properties unavailable in natural materials.[1...The history of acoustic metamaterials can be traced back to the turn of the 215 century,when the local res-onances of subwavelength structures were leveraged for acoustic properties unavailable in natural materials.[1 Over a quarter of 8 century,acoustic metamaterials have continued to thrive as numerous novel acoustic effects have been investigated and realized.[2-6]However,acous-tic metamaterials were entirely passive in their early days,thus indicating that their functionalities were singular and entirely determined at the fabrication stage.Additionally,even at the effective-medium level,such passive metama-terials must obey fundamental laws,such as time reversal symmetry and causality.These limitations can be over-come by employing active components in metamaterial design.Thus,we surveyed the development,functionalities,and implications of active acoustic metamaterials.展开更多
The discovery of advanced materials is a cornerstone of human technological development and progress.The structures of materials and their corresponding properties are essentially the result of a complex interplay of ...The discovery of advanced materials is a cornerstone of human technological development and progress.The structures of materials and their corresponding properties are essentially the result of a complex interplay of multiple degrees of freedom such as lattice,charge,spin,symmetry,and topology.This poses significant challenges for the inverse design methods of materials.Humans have long explored new materials through numerous experiments and proposed corresponding theoretical systems to predict new material properties and structures.With the improvement of computational power,researchers have gradually developed various electronic-structure calculation methods,such as the density functional theory and high-throughput computational methods.Recently,the rapid development of artificial intelligence(AI)technology in computer science has enabled the effective characterization of the implicit association between material properties and structures,thus forming an efficient paradigm for the inverse design of functional materials.Significant progress has been achieved in the inverse design of materials based on generative and discriminative models,attracting widespread interest from researchers.Considering this rapid technological progress,in this survey,we examine the latest advancements in AI-driven inverse design of materials by introducing the background,key findings,and mainstream technological development routes.In addition,we summarize the remaining challenges for future directions.This survey provides the latest overview of AI-driven inverse design of materials,which can serve as a useful resource for researchers.展开更多
Na_(3)V_(2)(PO_(4))_(3)(NVP)has garnered great attentions as a prospective cathode material for sodium-ion batteries(SIBs)by virtue of its decent theoretical capacity,superior ion conductivity and high structural stab...Na_(3)V_(2)(PO_(4))_(3)(NVP)has garnered great attentions as a prospective cathode material for sodium-ion batteries(SIBs)by virtue of its decent theoretical capacity,superior ion conductivity and high structural stability.However,the inherently poor electronic conductivity and sluggish sodium-ion diffusion kinetics of NVP material give rise to inferior rate performance and unsatisfactory energy density,which strictly confine its further application in SIBs.Thus,it is of significance to boost the sodium storage performance of NVP cathode material.Up to now,many methods have been developed to optimize the electrochemical performance of NVP cathode material.In this review,the latest advances in optimization strategies for improving the electrochemical performance of NVP cathode material are well summarized and discussed,including carbon coating or modification,foreign-ion doping or substitution and nanostructure and morphology design.The foreign-ion doping or substitution is highlighted,involving Na,V,and PO_(4)^(3−)sites,which include single-site doping,multiple-site doping,single-ion doping,multiple-ion doping and so on.Furthermore,the challenges and prospects of high-performance NVP cathode material are also put forward.It is believed that this review can provide a useful reference for designing and developing high-performance NVP cathode material toward the large-scale application in SIBs.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60977068,61178015 and 11102100)the Youth Foundation of Sanming University,China (Grant No. B201008/Q)
文摘Based on the ABCD matrix formalism,the propagation property of an Airy beam from right-handed material（RHM） to left-handed material（LHM） is investigated.The result shows that when the Airy beam propagates in the LHM,the intensity self-bending due to its propagation in the RHM can be compensated.In particular,if the propagation distance in the RHM is equal to that in the LHM and the refractive index of the LHM is n L =-1,the transverse intensity distribution of the Airy beam can return to its original state.
文摘In this paper, we present the electromagnetic analysis of a rectangular cavity partially filled with a left-handed material slab. Our theoretical investigation shows that there exist novel resonant modes in the cavity, and such a cavity becomes a subwavelength cavity. The eigenvalue equation of the cavity is derived and the resonant frequencies of the novel modes are calculated by using numerical simulation. We also discuss the stability of the novel resonant modes and show the best condition under which a useful rectangular cavity of subwavelength dimensions with tolerable stability is obtained.
基金Supported by the National Natural Science Foundation of China （Grant Nos 10576012 and 60538010）, the Program for New Century Excellent Talents in University and the Specialized Research Fund for the Doctoral Program of Higher Education of China （Grant No 20040532005）.
文摘In this paper a comprehensive framework for treating the nonlinear propagation of ultrashort pulse in metamaterial with dispersive dielectric susceptibility and magnetic permeability is presented. Under the slowly-evolving-wave approximation, a generalized （3＋1）-dimensional wave equation first order in the propagation coordinate and suitable for both right-handed material （I^HM） and left-handed material （LHM） is derived. By the commonly used Drude dispersive model for LHM, a （3＋1）-dimensional nonlinear Schrodinger equation describing ultrashort pulsed beam propagation in LHM is obtained, and its difference from that for conventional RHM is discussed. Particularly, the self-steeping effect of ultrashort pulse is found to be anomalous in LHM.
基金Project supported by the National Natural Science Foundation of China （Grant No 60508005） and the Scientific Foundation for Returned 0verseas Scholars of Heilongjiang Province, China （Grant No LC05C02）.
文摘We report the coexistence of TE and TM surface modes in certain same frequency domain at the interface between one isotropic regular medium and another biaxially anistotropic left-handed medium. The conditions for the existence of TE and TM polarized surface waves in biaxially anisotropic left-handed materials are identified, respectively. The Poynting vector and the energy density associated with surface modes are calculated. Depending on the system parameters, either TE or TM surface modes can have the time averaged Poynting vector directed to or opposite to the mode phase velocity. It is seen that the characteristics of surface waves in biaxially anisotropic left-handed media are significantly different from that in isotropic left-handed media.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 60671015, 60225001 and 60621002)The State Key Development Program for Basic Research of China (Grant No 2004CB719802)the Doctorate Found of State Education Commission of China (Grant No 20040286010)
文摘The phenomena of super energy flows are studied theoretically and numerically in a parallel-plate waveguide which is filled with two layered equally-thick different media, i.e. air and specific left-handed materials （LHM） with εr1 = -1/（1 ＋δ） ＋iγ and μr1 = -（1 ＋ δ） ＋ iγ. In this special waveguide, two-directional super-energy flows are excited by a three-dimensional horizontal electric dipole at the same time, which has transmission patterns different from those of two-dimensional source and three-dimensional vertical electric dipole. We also show that the retardation and loss in LHM are sensitive to the amplitude of super power densities, and the dimensions of waveguide determine the propagating modes, which makes super energy flows more practical.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60877055 and 60806041)the Innovation Funds for Graduates of Shanghai University,China (Grant No. SHUCX102016)
文摘This paper investigates the photon tunneling and transmittance resonance through a multi-layer structure including a left-handed material（LHM）. An analytical expression for the transmittance in a five-layer structure is given by the analytical transfer matrix method. The transmittance is studied as a function of the refractive index and the width of the LHM layer. The perfect photon tunneling results from the multi-layer structure, especially from the relation between the magnitude of the refractive index and the width of the LHM layer and those of the adjoining layers. Photons may tunnel through a much greater distance in this structure. Transmittance resonance happens, the peaks and valleys appear periodically at the resonance thickness. For an LHM with inherent losses, the perfect transmittance is suppressed.
基金Project supported by Pakistan Science Foundation(Project No.PSF/Res/P-PU/Phys(131))
文摘A theoretical investigation of field components for transverse electric mode in the parallel-plate waveguides has been studied. In this analysis two different types of waveguide structures have been discussed, i.e., （a） normal good/perfect conducting parallel-plate waveguide filled with nonlinear left-handed material and （b） high-temperature-superconducting parallel-plate waveguide filled with nonlinear left-handed material. The dispersion relations of transverse electric mode have also been discussed for these two types of waveguide structures.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10974063)the Research Foundation of Wuhan National Laboratory (Grant No. P080008)the National "973" Project (Grant No. 2007CB310403)
文摘This paper derives the force of the electromagnetic radiation on left-handed materials （LHMs） by a direct application of the Lorentz law of classical electrodynamics. The expressions of radiation force are given for TE-polarised and TM-polarised fields. The numerical results demonstrate that electromagnetic waves exert an inverse lateral radiation force on each edge of the beams, that is, the lateral pressure is expansive for TE-polarised beams and compressive for TM-polarised beams. The investigation of the radiation force will provide insights into the fundamental properties of LHMs and will provide to better understanding of the interaction of light with LHMs.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11374108 and 10904041)the Foundation for the Author of Guangdong Provincial Excellent Doctoral Dissertation(Grant No.SYBZZXM201227)+4 种基金the Foundation of Cultivating Outstanding Young Scholars("ThousandHundredTen"Program)of Guangdong Province in Chinathe Fund from the CAS Key Laboratory of Geospace EnvironmentUniversity of Science and Technology of China
文摘By applying the ABCD matrix method, we report the propagating properties of the rotating elliptical Gaussian beams（REGBs） from the right-handed material（RHM） to the left-handed material（LHM）. Based on the propagation equation, we obtain the intensity distributions of the REGBs during the propagation. It is found that the rotating direction of the REGBs is opposite in the RHM and the LHM, and the rotation angles tend to be π /2 as the propagation distance is long enough.Then we analyze the relationship between the refractive index and the rotating velocity. Furthermore, the energy flow and the angular momentum（AM） of the REGBs which can rotate are also obtained.
基金supported by the National Natural Science Foundation of China (Grant Nos 60671055 and 60771060)Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant Nos 20070013002 and 20070013004)
文摘We devise three sorts of doped left-handed materials （DLHMs） by introducing inductors and capacitors into the traditional left-handed material （LHM） as heterogeneous elements. Some new properties are presented through finitedifference time-domain （FDTD） simulations. On the one hand, the resonance in the traditional LHM is weakened and the original pass band is narrowed by introducing inductors. On the other hand, the original pass band of the LHM can be shifted and a new pass band can be generated by introducing capacitors. When capacitors and inductors are introduced simultaneously, the resonance of traditional LHM is somewhat weakened and the number of original pass bands as well as its bandwidth can be changed.
基金Supported by the National Natural Science Foundation of China(60601028)
文摘Finite-difference time-domain(FDTD) method is used to simulate the propagation of electromagnetic wave in left-handed material slab(LHMs) with cold plasma model The effects of optical propagation in the left-handed material compared to convex lens are discussed.The wider the LHMs is,the stronger electric field of focusing image in left-handed material slab is confirmed by the simulation with various slab length.However,the outer image point location would slightly moves to the LHMs side when the length of LHMs is reduced.
基金Project supported by the National Natural Science Foundation of China (Grant No 50702005)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No 20070008027)the Beijing Municipal Commission of Education (Grant No SYS100080419)
文摘This paper reports on experimental study of the microwave properties of a composite material consisting of ferrite and copper wires. It finds that the slim ferrite rods can modify the magnetic field distribution through their anisotropy, so that the ferrite＇s negative influence on the copper wires＇ plasma will be reduced. Left-handed properties are observed even in the specimen with close stuck ferrite rods and copper wires.
基金supported by the National Natural Science Foundation of China(22378431,52004338,51622406,21673298)Hunan Provincial Natural Science Foundation(2023JJ40210,2022JJ20075)+3 种基金the Science and Technology Innovation Program of Hunan Province(2023RC3259)the Key R&D plan of Hunan Province(2024JK2096)Scientifc Research Fund of Hunan Provincial Education Department(23B0699)Central South University Innovation-Driven Research Programme(2023CXQD008).
文摘High-entropy materials represent a new category of high-performance materials,first proposed in 2004 and extensively investigated by researchers over the past two decades.The definition of high-entropy materials has continuously evolved.In the last ten years,the discovery of an increasing number of high-entropy materials has led to significant advancements in their utilization in energy storage,electrocatalysis,and related domains,accompanied by a rise in techniques for fabricating high-entropy electrode materials.Recently,the research emphasis has shifted from solely improving the performance of high-entropy materials toward exploring their reaction mechanisms and adopting cleaner preparation approaches.However,the current definition of high-entropy materials remains relatively vague,and the preparation method of high-entropy materials is based on the preparation method of single metal/low-or medium-entropy materials.It should be noted that not all methods applicable to single metal/low-or medium-entropy materials can be directly applied to high-entropy materials.In this review,the definition and development of high-entropy materials are briefly reviewed.Subsequently,the classification of high-entropy electrode materials is presented,followed by a discussion of their applications in energy storage and catalysis from the perspective of synthesis methods.Finally,an evaluation of the advantages and disadvantages of various synthesis methods in the production process of different high-entropy materials is provided,along with a proposal for potential future development directions for high-entropy materials.
基金funding support from the National Key Research and Development Program of China(No.2022YFB3805800)the National Natural Science Foundation of China(52173059)+1 种基金The Major Basic Research Project of the Natural Science Foundation of the Jiangsu Higher Education Institutions(21KJA540002)Jiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB555).
文摘Depleting fossil energy sources and conventional polluting power generation pose a threat to sustainable development.Hydroelectricity generation from ubiquitous and spontaneous phase transitions between liquid and gaseous water has been considered a promising strategy for mitigating the energy crisis.Fibrous materials with unique flexibility,processability,multifunctionality,and practicability have been widely applied for fibrous materials-based hydroelectricity generation(FHG).In this review,the power generation mechanisms,design principles,and electricity enhancement factors of FHG are first introduced.Then,the fabrication strategies and characteristics of varied constructions including 1D fiber,1D yarn,2D fabric,2D membrane,3D fibrous framework,and 3D fibrous gel are demonstrated.Afterward,the advanced functions of FHG during water harvesting,proton dissociation,ion separation,and charge accumulation processes are analyzed in detail.Moreover,the potential applications including power supply,energy storage,electrical sensor,and information expression are also discussed.Finally,some existing challenges are considered and prospects for future development are sincerely proposed.
基金supported by the National Natural Science Foundation of China(Grant No.61925307).
文摘Dynamic structuralcolors can change in response todifferent environmental stimuli.This ability remains effectiveeven when the size of the speciesresponsible for the structural coloris reduced to a few micrometers,providing a promising sensingmechanism for solving microenvironmentalsensing problems inmicro-robotics and microfluidics.However, the lack of dynamicstructural colors that can encoderapidly, easily integrate, and accuratelyreflect changes in physical quantities hinders their use in microscale sensing applications. Herein, we present a 2.5-dimensionaldynamic structural color based on nanogratings of heterogeneous materials, which were obtained by interweaving a pH-responsive hydrogelwith an IP-L photoresist. Transverse gratings printed with pH-responsive hydrogels elongated the period of longitudinal grating in the swollenstate, resulting in pH-tuned structural colors at a 45° incidence. Moreover, the patterned encoding and array printing of dynamic structuralcolors were achieved using grayscale stripe images to accurately encode the periods and heights of the nanogrid structures. Overall, dynamicstructural color networks exhibit promising potential for applications in information encryption and in situ sensing for microfluidic chips.
基金National Natural Science Foundation of China(32201491)Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)The authors extend their appreciation to the Deanship of Scientific Research at Northern Border University,Arar,KSA for funding this research work through the project number“NBU-FPEJ-2024-1101-02”.
文摘Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field.
基金support of the National Natural Science Foundation of China(Grant No.22225801,22178217 and 22308216)supported by the Fundamental Research Funds for the Central Universities,conducted at Tongji University.
文摘Rechargeable magnesium batteries(RMBs)have been considered a promising“post lithium-ion battery”system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market.However,the sluggish diffusion kinetics of bivalent Mg^(2+)in the host material,related to the strong Coulomb effect between Mg^(2+)and host anion lattices,hinders their further development toward practical applications.Defect engineering,regarded as an effective strategy to break through the slow migration puzzle,has been validated in various cathode materials for RMBs.In this review,we first thoroughly understand the intrinsic mechanism of Mg^(2+)diffusion in cathode materials,from which the key factors affecting ion diffusion are further presented.Then,the positive effects of purposely introduced defects,including vacancy and doping,and the corresponding strategies for introducing various defects are discussed.The applications of defect engineering in cathode materials for RMBs with advanced electrochemical properties are also summarized.Finally,the existing challenges and future perspectives of defect engineering in cathode materials for the overall high-performance RMBs are described.
文摘The history of acoustic metamaterials can be traced back to the turn of the 215 century,when the local res-onances of subwavelength structures were leveraged for acoustic properties unavailable in natural materials.[1 Over a quarter of 8 century,acoustic metamaterials have continued to thrive as numerous novel acoustic effects have been investigated and realized.[2-6]However,acous-tic metamaterials were entirely passive in their early days,thus indicating that their functionalities were singular and entirely determined at the fabrication stage.Additionally,even at the effective-medium level,such passive metama-terials must obey fundamental laws,such as time reversal symmetry and causality.These limitations can be over-come by employing active components in metamaterial design.Thus,we surveyed the development,functionalities,and implications of active acoustic metamaterials.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.62476278,12434009,and 12204533)supported by the National Key R&D Program of China(Grant No.2024YFA1408601)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302402)。
文摘The discovery of advanced materials is a cornerstone of human technological development and progress.The structures of materials and their corresponding properties are essentially the result of a complex interplay of multiple degrees of freedom such as lattice,charge,spin,symmetry,and topology.This poses significant challenges for the inverse design methods of materials.Humans have long explored new materials through numerous experiments and proposed corresponding theoretical systems to predict new material properties and structures.With the improvement of computational power,researchers have gradually developed various electronic-structure calculation methods,such as the density functional theory and high-throughput computational methods.Recently,the rapid development of artificial intelligence(AI)technology in computer science has enabled the effective characterization of the implicit association between material properties and structures,thus forming an efficient paradigm for the inverse design of functional materials.Significant progress has been achieved in the inverse design of materials based on generative and discriminative models,attracting widespread interest from researchers.Considering this rapid technological progress,in this survey,we examine the latest advancements in AI-driven inverse design of materials by introducing the background,key findings,and mainstream technological development routes.In addition,we summarize the remaining challenges for future directions.This survey provides the latest overview of AI-driven inverse design of materials,which can serve as a useful resource for researchers.
基金partly supported by the National Natural Science Foundation of China(Grant No.52272225).
文摘Na_(3)V_(2)(PO_(4))_(3)(NVP)has garnered great attentions as a prospective cathode material for sodium-ion batteries(SIBs)by virtue of its decent theoretical capacity,superior ion conductivity and high structural stability.However,the inherently poor electronic conductivity and sluggish sodium-ion diffusion kinetics of NVP material give rise to inferior rate performance and unsatisfactory energy density,which strictly confine its further application in SIBs.Thus,it is of significance to boost the sodium storage performance of NVP cathode material.Up to now,many methods have been developed to optimize the electrochemical performance of NVP cathode material.In this review,the latest advances in optimization strategies for improving the electrochemical performance of NVP cathode material are well summarized and discussed,including carbon coating or modification,foreign-ion doping or substitution and nanostructure and morphology design.The foreign-ion doping or substitution is highlighted,involving Na,V,and PO_(4)^(3−)sites,which include single-site doping,multiple-site doping,single-ion doping,multiple-ion doping and so on.Furthermore,the challenges and prospects of high-performance NVP cathode material are also put forward.It is believed that this review can provide a useful reference for designing and developing high-performance NVP cathode material toward the large-scale application in SIBs.
