In this paper,the local fractional natural decomposition method(LFNDM)is used for solving a local fractional Poisson equation.The local fractional Poisson equation plays a significant role in the study of a potential ...In this paper,the local fractional natural decomposition method(LFNDM)is used for solving a local fractional Poisson equation.The local fractional Poisson equation plays a significant role in the study of a potential field due to a fixed electric charge or mass density distribution.Numerical examples with computer simulations are presented in this paper.The obtained results show that LFNDM is effective and convenient for application.展开更多
Any polyhedron accommodates a type of potential theoretic skeleton called a mother body. The study of such mother bodies was originally from Mathematical Physics, initiated by Zidarov [1] and developed by Bjö...Any polyhedron accommodates a type of potential theoretic skeleton called a mother body. The study of such mother bodies was originally from Mathematical Physics, initiated by Zidarov [1] and developed by Björn Gustafson and Makoto Sakai [2]. In this paper, we attempt to apply the brilliant idea of mother body to Electrostatics to compute the potentials of electric fields.展开更多
The national standardization technical committee on electrostatics,SAC/TC 597,was set up by Standardization Administration of China(SAC)recently.The Ministry of Industry and Information Technology(MIIT)is in charge of...The national standardization technical committee on electrostatics,SAC/TC 597,was set up by Standardization Administration of China(SAC)recently.The Ministry of Industry and Information Technology(MIIT)is in charge of its routine management and operational guidance,and China Electronics Standardization Institute(CESl)undertakes the secretariat.展开更多
Janus polymer nanorods with tunable compositions and microstructures possess directionally specific interactions,enabling their self-assembly into hierarchically structured materials(e.g.,biomimetic pillared nanostruc...Janus polymer nanorods with tunable compositions and microstructures possess directionally specific interactions,enabling their self-assembly into hierarchically structured materials(e.g.,biomimetic pillared nanostructures).Traditional synthesis methods usually require highly dilute conditions(<1 mg/mL)to prevent aggregation.Herein,we report the synthesis of Janus polymer nanorods by electrostatics-mediated reversible addition-fragmentation chain transfer copolymerization of cross-linkers and monomers from polymer bottlebrushes.This method achieves an unprecedentedly high solid content over 100 mg/mL,that is,two orders of magnitude higher than that attainable by conventional approaches.The composition,microstructure(e.g.,multilayered architecture),and characteristic dimension of the nanorods are broadly tunable.As a representative example,AB-type Janus nanorods are derived by orthogonal modifications of the end blocks,introducing desired functional groups to drive directional interactions.The Janus nanorods serve as building blocks to self-assemble into diverse superstructures from nanowires to continuous networks,providing a facile platform for the in-situ construction of functional materials within suitable matrices.展开更多
Non-hermiticity presents a vast newly opened territory that harbors new physics and applications such as lasing and sensing.However,only non-Hermitian systems with real eigenenergies are stable,and great efforts have ...Non-hermiticity presents a vast newly opened territory that harbors new physics and applications such as lasing and sensing.However,only non-Hermitian systems with real eigenenergies are stable,and great efforts have been devoted in designing them through enforcing parity-time(PT)symmetry.In this work,we exploit a lesser-known dynamical mechanism for enforcing real-spectra,and develop a comprehensive and versatile approach for designing new classes of parent Hamiltonians with real spectra.Our design approach is based on a new electrostatics analogy for modifed non-Hermitian bulk-boundary correspondence,where electrostatic charge corresponds to density of states and electric felds correspond to complex spectral fow.As such,Hamiltonians of any desired spectra and state localization profle can be reverse-engineered,particularly those without any guiding symmetry principles.By recasting the diagonalization of non-Hermitian Hamiltonians as a Poisson boundary value problem,our electrostatics analogy also transcends the gain/loss-induced compounding of foating-point errors in traditional numerical methods,thereby allowing access to far larger system sizes.展开更多
We present a novel method for designing transformation optical devices based on electrostatics.An arbi-trary transformation of electrostatic field can lead to a new refractive index distribution,where wave-fronts and ...We present a novel method for designing transformation optical devices based on electrostatics.An arbi-trary transformation of electrostatic field can lead to a new refractive index distribution,where wave-fronts and energy flux lines correspond to equipotential surfaces and electrostatic flux lines,respectively.Owing to scalar wave propagating exactly following an eikonal equation,wave optics and geometric optics share the same solutions in the devices.The method is utilized to design multipole lenses derived from multipoles in electrostatics.The source and drain in optics are considered as corre-sponding to positive charge and negative charge in the static field.By defining winding numbers in vir-tual and physical spaces,we explain the reason for some multipole lenses with illusion effects.Besides,we introduce an equipotential absorber to replace the drain to correspond to a negative charge with a grounded conductor.Therefore,it is a very general platform to design intriguing devices based on the combination of electrostatics and transformation optics.展开更多
A new VMD plugin that interfaces with DelPhi to provide ensemble-averaged electrostatic calculations using the Poisson-Boltzmann equation is presented.The general theory and context of this approach are discussed,and ...A new VMD plugin that interfaces with DelPhi to provide ensemble-averaged electrostatic calculations using the Poisson-Boltzmann equation is presented.The general theory and context of this approach are discussed,and examples of the plugin interface and calculations are presented.This new tool is applied to systems of current biological interest,obtaining the ensemble-averaged electrostatic properties of the two major influenza virus glycoproteins,hemagglutinin and neuraminidase,from explicitly solvated all-atom molecular dynamics trajectories.The differences between the ensemble-averaged electrostatics and those obtained from a single structure are examined in detail for these examples,revealing how the plugin can be a powerful tool in facilitating the modeling of electrostatic interactions in biological systems.展开更多
Improving the electric output and durability of triboelectric nanogenerator(TENG)remains a great challenge.In sliding-mode TENG,surface charge dissipation and charge leakage caused by the volume effect result in serio...Improving the electric output and durability of triboelectric nanogenerator(TENG)remains a great challenge.In sliding-mode TENG,surface charge dissipation and charge leakage caused by the volume effect result in serious energy waste.In this work,a durable dual output mode TENG(DDO-TENG),which includes alteranting current and direct current output modes,is designed to capture the dissipating charges in the surface of charge space accumulation area and the inner leakage charge in porous network to further improve the output performance of sliding TENGs.The output charge density of DDO-TENG reaches 0.847 mC m^(-2),which is 2.39 times as that of the single mode device.In addition,it has strong durability,remaining 95.7%after over 271 k cycles,and it can continuously power electronics by harvesting wind energy.This work provides a strategy for achieving the improvement on output performance and durability and expands the application of TENG.展开更多
The net capturing method holds great potential for space debris removal due to its adaptability to the various target shapes and high fault tolerance.However,the capture mechanisms of current rope nets,which rely sole...The net capturing method holds great potential for space debris removal due to its adaptability to the various target shapes and high fault tolerance.However,the capture mechanisms of current rope nets,which rely solely on a passive wrap-ping mechanism,limit their capacity to capture objects within a specific size range and make it challenging to handle unexpected situations.Inspired by spider webs,which combine wrapping and adhering to capture prey of various sizes,we present a new type of net(envelope diameter:208.49 mm)for on-orbit capture.This net adopts a spiral symmetric structure similar to spider webs,incorporates electrostatic-microstructure hybrid adhesives,and increases the maximum contact area by 38.31%,allowing it to capture debris ranging from fragments smaller than the mesh size(envelope diam-eter:2.7 mm-4.4 mm)to larger objects(envelope diameter:270 mm),and effectively grasps flexible items(450 mm2),planar items(350 mm2)and three-dimensional items(160 mm3).Moreover,to validate the net's capability for wrapping and adhesion,simulations and experiments are demonstrated that this dual capture method can effectively handle various targets.展开更多
Al/NH_(4)CoF_(3)-Φ(Φ=0.5,1.0,1.5,2.0,and 3.0)binary composites and Al-NH_(4)CoF_(3)@P(VDF-HFP)ternary composites are fabricated via ultrasonication-assisted blending and electrostatic spraying.The effect of equivale...Al/NH_(4)CoF_(3)-Φ(Φ=0.5,1.0,1.5,2.0,and 3.0)binary composites and Al-NH_(4)CoF_(3)@P(VDF-HFP)ternary composites are fabricated via ultrasonication-assisted blending and electrostatic spraying.The effect of equivalence ratio(Φ)on the reaction properties is systematically investigated in the binary Al/NH_(4)CoF_(3)system.For ternary systems,electrostatic spraying allows both components to be efficiently encapsulated by P(VDF-HFP)and to achieve structural stabilization and enhanced reactivity through synergistic interfacial interactions.Morphological analysis using SEM/TEM revealed that P(VDF-HFP)formed a protective layer on Al and NH_(4)CoF_(3)particles,improving dispersion,hydrophobicity(water contact angle increased by 80.5%compared to physically mixed composites),and corrosion resistance.Thermal decomposition of NH_(4)CoF_(3)occurred at 265℃,releasing NH_(3)and HF,which triggered exothermic reactions with Al.The ternary composites exhibited a narrowed main reaction temperature range and concentrated heat release,attributed to improved interfacial contact and polymer decomposition.Combustion tests demonstrated that Al-NH_(4)CoF_(3)@P(VDF-HFP)achieved self-sustaining combustion.In addition,a simple validation was done by replacing the Al component in the aluminium-containing propellant,demonstrating its potential application in the propellant field.This work establishes a novel strategy for designing stable,high-energy composites with potential applications in advanced propulsion systems.展开更多
As a type of emerging electro-mechanical conversion technology,triboelectric nanogenerators(TENGs)were widely applied in high-entropy energy harvesting,Internet of Things sensing,and biomedical fields due to the chara...As a type of emerging electro-mechanical conversion technology,triboelectric nanogenerators(TENGs)were widely applied in high-entropy energy harvesting,Internet of Things sensing,and biomedical fields due to the characteristics of lightweight,cheap,and high voltage.Among them,the rotating TENG has been extensively researched for its advantages,such as high-precision electrical signals,high electro-mechanical conversion efficiency,and effective output power.In this paper,the working mechanisms of four different rotating TENG modes were introduced in detail.Subsequently,a large amount of research works on the strengthening performance of rotating TENGs were comprehensively introduced and summarized by three gradient classifications.In addition,in view of the many applications of rotating TENGs,they were also systematically divided and generalized into three dimensions.Finally,the problems as well as challenges faced by the current rotating TENG research in the above 16 specific research directions were deeply analyzed,and the possible development directions and the solutions to the above problems were reasonably prospected in the next years.This review hopes to effectively promote the progress of rotating TENG on the road to commercialization.展开更多
Computing electrostatic interaction on non-cooperative targets with unknown meshes is crucial for electrostatic-based space on-orbit services.Although meshes for electrostatic interaction computations can be reconstru...Computing electrostatic interaction on non-cooperative targets with unknown meshes is crucial for electrostatic-based space on-orbit services.Although meshes for electrostatic interaction computations can be reconstructed from point clouds,they are usually too dense,leading to high computational costs.This paper presents an optimization method for converting dense meshes into optimal meshes,enabling fast and accurate computation of the electrostatic interaction by point clouds.First,the dense mesh reconstructed from point clouds is simplified into a coarse mesh using local operators.Second,the simplified mesh is refined by an iterative strategy that integrates a lightweight method of moments and an impedance matrix inheritance technique,ultimately yielding an optimal mesh for computing the electrostatic interaction.Simulation results show that our method effectively optimizes dense meshes,making electrostatic interaction computations using point clouds approximately 63.4 times more efficient than the previous method.展开更多
Although amide-and hydrazide-based nucleating agents have been extensively used to enhance the crystallization performance of poly(lactic acid)(PLA),structurally similar nucleating agents exhibit significant differenc...Although amide-and hydrazide-based nucleating agents have been extensively used to enhance the crystallization performance of poly(lactic acid)(PLA),structurally similar nucleating agents exhibit significant differences in their crystallization-promoting efficiency,and the underlying mechanism remains unclear.In this study,a series of nucleating agents,including N,N-diphenylterephthalamide(DPTA),N,N,N-triphenyl-1,3,5-benzenetricarboxamide(TPTA),N,N-diphenyl terephthalohydrazide(DBTA),and N,N,N-tribenzoyl-1,3,5-benzenetricarbohydrazide(TBTA),were designed and synthesized to investigate the differences in their effects on the crystallization performance of PLA.Density functional theory(DFT)and molecular dynamics(MD)simulations showed that DBTA had a smaller electrostatic potential difference(66.2 kcal/mol).During the cooling process,DBTA could stably form more intermolecular hydrogen bonds with PLA and exhibit a higher interaction energy,thus theoretically enabling more efficient promotion of PLA crystallization.Further differential scanning calorimetry(DSC)results revealed that at a 0.5wt%loading of DBTA,the crystallization peak temperature of the PLA-DBTA composite reached 118.1℃during cooling,whereas no distinct crystallization peak was observed for pure PLA under identical conditions.The crystallinity of the composite was significantly increased to 58.4%compared to 14.6%of pure PLA.Moreover,under isothermal crystallization at 130℃,DBTA reduced the half-crystallization time of PLA to 2.9min,while the half-crystallization time for pure PLA was 27.4 min.Time-resolved Fourier transform infrared spectroscopy(FTIR)results also confirmed that DBTA promoted the formation of gt conformational isomers of PLA during the crystallization process.This study elucidates the mechanism behind the performance differences between structurally similar nucleating agents in regulating PLA crystallization from the perspective of molecular electrostatic potential and hydrogen bonding interactions,providing a theoretical basis for the molecular design of efficient nucleating agents.展开更多
Developing advanced cathode modification strategies to address the inherent high charge density of Al^(3+) is essential for achieving high-energy-density and long-cycle-life rechargeable aluminum batteries(RABs).Herei...Developing advanced cathode modification strategies to address the inherent high charge density of Al^(3+) is essential for achieving high-energy-density and long-cycle-life rechargeable aluminum batteries(RABs).Herein,we engineer tetraethylammonium(TEA)cation intercalation as a dual-function strategy that concurrently enables interlayer distance enlargement and electrostatic shielding effects,resolving Al^(3+) polarization-induced sluggish kinetics and cathode degradation in RABs.TEA intercalation triggers exceptional V2O5 interlayer expansion from 4.37 to 13.10Å,while the modulated charge distribution generates an electrostatic shielding effect that significantly weakens the Coulombic interactions between Al^(3+) and V2O5 frameworks.This dual mechanism collectively enhances ion diffusion kinetics and suppresses lattice stress accumulation.Ex situ X-ray diffraction and transmission electron microscopy analyses confirm that the“molecular pillar effect”of TEA enables minimal and highly reversible structural deformation of the cathode(<2.0%volume change after 200 cycles),demonstrating zero-strain aluminum-storage behavior.The optimized cathode delivers a high reversible capacity of 258 mAh g^(−1) at 0.5 A g^(−1),maintains 99%capacity retention at 5.0 A g^(−1),and exhibits an ultralow capacity decay rate of 0.01%per cycle over 6000 cycles.This work opens new pathways for designing stable high-performance RAB cathodes through synergistic modulation of electronic and lattice structures.展开更多
Ion migration capability and interfacial chemistry of solid polymer electrolytes(SPEs)in all-solid-state sodium metal batteries(ASSMBs)are closely related to the Na^(+)coordination environment.Herein,an electrostatic ...Ion migration capability and interfacial chemistry of solid polymer electrolytes(SPEs)in all-solid-state sodium metal batteries(ASSMBs)are closely related to the Na^(+)coordination environment.Herein,an electrostatic engineering strategy is proposed to regulate the Na^(+)coordinated structure by employing a fluorinated metal–organic framework as an electron-rich model.Theoretical and experimental results revealed that the abundant electron-rich F sites can accelerate the disassociation of Na-salt through electrostatic attraction to release free Na^(+),while forcing anions into a Na^(+)coordination structure though electrostatic repulsion to weaken the Na^(+)coordination with polymer,thus promoting rapid Na^(+)transport.The optimized anion-rich weak solvation structure fosters a stable inorganic-dominated solid–electrolyte interphase,significantly enhancing the interfacial stability toward Na anode.Consequently,the Na/Na symmetric cell delivered stable Na plating/stripping over 2500 h at 0.1 mA cm^(−2).Impressively,the assembled ASSMBs demonstrated stable performance of over 2000 cycles even under high rate of 2 C with capacity retention nearly 100%,surpassing most reported ASSMBs using various solid-state electrolytes.This work provides a new avenue for regulating the Na^(+)coordination structure of SPEs by exploration of electrostatic effect engineering to achieve high-performance all-solid-state alkali metal batteries.展开更多
Aqueous zinc-ion batteries(AZIBs)are facing challenges of severe parasitic side reactions and uncontrolled Zn dendrite growth in promoting commercial applications.Here,rare earth metal neodymium ions(Nd^(3+))have been...Aqueous zinc-ion batteries(AZIBs)are facing challenges of severe parasitic side reactions and uncontrolled Zn dendrite growth in promoting commercial applications.Here,rare earth metal neodymium ions(Nd^(3+))have been introduced into the conventional Zn SO_4 electrolyte as an electrolyte additive to improve the stability and reversibility of AZIBs.Combining experimental characterization and theoretical calculations,Nd^(3+)ions are adsorbed at the active sites of zinc crystal growth,forming a positively charged shielding layer on the Zn anode surface that effectively prevents lateral reactions and induces uniform Zn deposition.Meanwhile,Nd^(3+)ions preferentially adsorb on(100)and(101)planes of Zn,thus facilitating preferential deposition on the(002)plane and achieving a dendrite-free Zn anode.Consequently,a Zn//Zn symmetric cell with the Nd^(3+)-modified electrolyte exhibits an ultralong lifespan of 3000 h at0.5 m A cm^(-2),and a Zn//Cu asymmetric cell realizes an impressive Coulombic efficiency of 99.47%for Zn stripping and plating over 550 cycles at 1.0 mA cm^(-2).Impressively,Zn//CNT@MnO_(2) full cell reaches a considerably stable long cycle performance over 2500 cycles at 1.0 A g^(-1).This work offers an effective solution to the challenges faced by Zn anode and expands the application scope of metallic ions in metalbased energy storage devices.展开更多
Wepresent a new approach to constructmachine-learned interatomic potentials including long-range electrostatic interactions based on a charge equilibration scheme.This new approach can accurately describe the potentia...Wepresent a new approach to constructmachine-learned interatomic potentials including long-range electrostatic interactions based on a charge equilibration scheme.This new approach can accurately describe the potential energy surface of systems with ionic and covalent interactions as well as systems with multiple charge states.Moreover,it can either be regressed against known atomic charge decompositions or trained without charge targets,without compromising the accuracy of energy and forces.We benchmark our approach against other state-of-the-art models and prove it to have equivalent performances on a set of simple reference systems while being less computationally expensive.Finally,we demonstrate the accuracy of our approach on complex systems:solid and liquid state sodium chloride.We attain accuracy in energy and forces better than the model based on local descriptors and show that our electrostatic approach can capture the density functional theory tail of the potential energy surface of the isolated Na-Cl dimer,which the local descriptor-based model fails to describe.展开更多
A mobile Coulomb gas permeating a fixed background crystalline lattice of charged colloidal crystals is subject to an electrostatic-elastic coupling,which we study on the continuum level by introducing a minimal coupl...A mobile Coulomb gas permeating a fixed background crystalline lattice of charged colloidal crystals is subject to an electrostatic-elastic coupling,which we study on the continuum level by introducing a minimal coupling between electrostatic and displacement fields.We derive linearized,Debye–Hückel-like mean-field equations that can be analytically solved,incorporating the minimal coupling between electrostatic and displacement fields leading to an additional effective attractive interaction between mobile charges that depends in general on the strength of the coupling between the electrostatic and displacement fields.By analyzing the Gaussian fluctuations around the mean-field solution we also identify and quantify the region of its stability in terms of the electrostatic-elastic screening length.This detailed continuum theory incorporating the standard lattice elasticity and electrostatics of mobile charges provides a baseline to investigate the electrostatic-elastic coupling for microscopic models in colloid science and materials science.展开更多
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
Magnetic metal has broad application prospects in the field of electromagnetic wave(EMW)absorption due to its excellent dielectric and magnetic properties.However,high density and poor chemical stability constrain the...Magnetic metal has broad application prospects in the field of electromagnetic wave(EMW)absorption due to its excellent dielectric and magnetic properties.However,high density and poor chemical stability constrain their development potential.The combination of magnetic metals with other lightweight carbon materials is an effective solution.In this work,magnetic nanoparticle fiber composites were prepared by electrostatic spinning and high-temperature annealing processes.By adjusting the preparation process and annealing temperature,Co/Co7 Fe_(3)/CF-800 fiber composites containing double-shell hollow structured nanocubes were cleverly synthesized.The material is mixed with paraffin wax and has a minimum reflection loss(RL)of-52.14 dB and a maximum effective absorption bandwidth(EAB)of 6.16 GHz at a load of 10 wt%.By analyzing the electromagnetic parameters of the material,it was demonstrated that the material absorbs EMW through the synergistic effect of dielectric and magnetic losses.Electrochemical testing in a simulated seawater environment demonstrated that the material also has a degree of self-anticorrosion capability.This work provides new strategies for designing materials with excellent electromagnetic wave absorption and self-anticorrosion properties.展开更多
文摘In this paper,the local fractional natural decomposition method(LFNDM)is used for solving a local fractional Poisson equation.The local fractional Poisson equation plays a significant role in the study of a potential field due to a fixed electric charge or mass density distribution.Numerical examples with computer simulations are presented in this paper.The obtained results show that LFNDM is effective and convenient for application.
文摘Any polyhedron accommodates a type of potential theoretic skeleton called a mother body. The study of such mother bodies was originally from Mathematical Physics, initiated by Zidarov [1] and developed by Björn Gustafson and Makoto Sakai [2]. In this paper, we attempt to apply the brilliant idea of mother body to Electrostatics to compute the potentials of electric fields.
文摘The national standardization technical committee on electrostatics,SAC/TC 597,was set up by Standardization Administration of China(SAC)recently.The Ministry of Industry and Information Technology(MIIT)is in charge of its routine management and operational guidance,and China Electronics Standardization Institute(CESl)undertakes the secretariat.
基金supported by the National Natural Science Foundation of China(grant nos.52293472 and 51833005)the National Key Research and Development Program of China(grant no.2021YFC2102800)start-up funding by Tsinghua University(grant no.53330100120).
文摘Janus polymer nanorods with tunable compositions and microstructures possess directionally specific interactions,enabling their self-assembly into hierarchically structured materials(e.g.,biomimetic pillared nanostructures).Traditional synthesis methods usually require highly dilute conditions(<1 mg/mL)to prevent aggregation.Herein,we report the synthesis of Janus polymer nanorods by electrostatics-mediated reversible addition-fragmentation chain transfer copolymerization of cross-linkers and monomers from polymer bottlebrushes.This method achieves an unprecedentedly high solid content over 100 mg/mL,that is,two orders of magnitude higher than that attainable by conventional approaches.The composition,microstructure(e.g.,multilayered architecture),and characteristic dimension of the nanorods are broadly tunable.As a representative example,AB-type Janus nanorods are derived by orthogonal modifications of the end blocks,introducing desired functional groups to drive directional interactions.The Janus nanorods serve as building blocks to self-assemble into diverse superstructures from nanowires to continuous networks,providing a facile platform for the in-situ construction of functional materials within suitable matrices.
基金supported by Singapore’s MOE Tier I grant WBS No.A-800022-00-00。
文摘Non-hermiticity presents a vast newly opened territory that harbors new physics and applications such as lasing and sensing.However,only non-Hermitian systems with real eigenenergies are stable,and great efforts have been devoted in designing them through enforcing parity-time(PT)symmetry.In this work,we exploit a lesser-known dynamical mechanism for enforcing real-spectra,and develop a comprehensive and versatile approach for designing new classes of parent Hamiltonians with real spectra.Our design approach is based on a new electrostatics analogy for modifed non-Hermitian bulk-boundary correspondence,where electrostatic charge corresponds to density of states and electric felds correspond to complex spectral fow.As such,Hamiltonians of any desired spectra and state localization profle can be reverse-engineered,particularly those without any guiding symmetry principles.By recasting the diagonalization of non-Hermitian Hamiltonians as a Poisson boundary value problem,our electrostatics analogy also transcends the gain/loss-induced compounding of foating-point errors in traditional numerical methods,thereby allowing access to far larger system sizes.
基金the National Natural Science Foundation of China(92050102)the National Key Research and Development Program of China(2020YFA0710100)+1 种基金the National Natural Science Foundation of China(11874311)the FundamentalResearch Funds for the Central Universities(20720200074 and20720190049)。
文摘We present a novel method for designing transformation optical devices based on electrostatics.An arbi-trary transformation of electrostatic field can lead to a new refractive index distribution,where wave-fronts and energy flux lines correspond to equipotential surfaces and electrostatic flux lines,respectively.Owing to scalar wave propagating exactly following an eikonal equation,wave optics and geometric optics share the same solutions in the devices.The method is utilized to design multipole lenses derived from multipoles in electrostatics.The source and drain in optics are considered as corre-sponding to positive charge and negative charge in the static field.By defining winding numbers in vir-tual and physical spaces,we explain the reason for some multipole lenses with illusion effects.Besides,we introduce an equipotential absorber to replace the drain to correspond to a negative charge with a grounded conductor.Therefore,it is a very general platform to design intriguing devices based on the combination of electrostatics and transformation optics.
基金funded in part by the National Institutes of Health through the NIH Director’s New Innovator Award Program 1-DP2-OD007237through the NSF TeraGrid Supercomputer resources grant LRAC CHE060073N to R.E.A.supported by a grant from the Institute of General Medical Sciences,National Institutes of Health,award number 1R01GM093937-01.
文摘A new VMD plugin that interfaces with DelPhi to provide ensemble-averaged electrostatic calculations using the Poisson-Boltzmann equation is presented.The general theory and context of this approach are discussed,and examples of the plugin interface and calculations are presented.This new tool is applied to systems of current biological interest,obtaining the ensemble-averaged electrostatic properties of the two major influenza virus glycoproteins,hemagglutinin and neuraminidase,from explicitly solvated all-atom molecular dynamics trajectories.The differences between the ensemble-averaged electrostatics and those obtained from a single structure are examined in detail for these examples,revealing how the plugin can be a powerful tool in facilitating the modeling of electrostatic interactions in biological systems.
基金supported by the Natural Science Foundation of Chongqing(Grant No.CSTB2024NSCQMSX0440)the National Key R&D Project from Minister of Science and Technology(2021YFA1201602)+2 种基金the Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202400506)the Doctor Scientific Research Fund of Chongqing Normal University(Grant No.23XLB017)the Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJZD-K202200505)。
文摘Improving the electric output and durability of triboelectric nanogenerator(TENG)remains a great challenge.In sliding-mode TENG,surface charge dissipation and charge leakage caused by the volume effect result in serious energy waste.In this work,a durable dual output mode TENG(DDO-TENG),which includes alteranting current and direct current output modes,is designed to capture the dissipating charges in the surface of charge space accumulation area and the inner leakage charge in porous network to further improve the output performance of sliding TENGs.The output charge density of DDO-TENG reaches 0.847 mC m^(-2),which is 2.39 times as that of the single mode device.In addition,it has strong durability,remaining 95.7%after over 271 k cycles,and it can continuously power electronics by harvesting wind energy.This work provides a strategy for achieving the improvement on output performance and durability and expands the application of TENG.
基金the New Chongqing Innovative Young Talent Project under Grant 2024NSCQ-qncxX0468Dreams Foundation of Jianghuai Advance Technology Center under Grant 2023-ZM01Z007.
文摘The net capturing method holds great potential for space debris removal due to its adaptability to the various target shapes and high fault tolerance.However,the capture mechanisms of current rope nets,which rely solely on a passive wrap-ping mechanism,limit their capacity to capture objects within a specific size range and make it challenging to handle unexpected situations.Inspired by spider webs,which combine wrapping and adhering to capture prey of various sizes,we present a new type of net(envelope diameter:208.49 mm)for on-orbit capture.This net adopts a spiral symmetric structure similar to spider webs,incorporates electrostatic-microstructure hybrid adhesives,and increases the maximum contact area by 38.31%,allowing it to capture debris ranging from fragments smaller than the mesh size(envelope diam-eter:2.7 mm-4.4 mm)to larger objects(envelope diameter:270 mm),and effectively grasps flexible items(450 mm2),planar items(350 mm2)and three-dimensional items(160 mm3).Moreover,to validate the net's capability for wrapping and adhesion,simulations and experiments are demonstrated that this dual capture method can effectively handle various targets.
基金supported by the National Natural Science Foundation of China(No.51706105)。
文摘Al/NH_(4)CoF_(3)-Φ(Φ=0.5,1.0,1.5,2.0,and 3.0)binary composites and Al-NH_(4)CoF_(3)@P(VDF-HFP)ternary composites are fabricated via ultrasonication-assisted blending and electrostatic spraying.The effect of equivalence ratio(Φ)on the reaction properties is systematically investigated in the binary Al/NH_(4)CoF_(3)system.For ternary systems,electrostatic spraying allows both components to be efficiently encapsulated by P(VDF-HFP)and to achieve structural stabilization and enhanced reactivity through synergistic interfacial interactions.Morphological analysis using SEM/TEM revealed that P(VDF-HFP)formed a protective layer on Al and NH_(4)CoF_(3)particles,improving dispersion,hydrophobicity(water contact angle increased by 80.5%compared to physically mixed composites),and corrosion resistance.Thermal decomposition of NH_(4)CoF_(3)occurred at 265℃,releasing NH_(3)and HF,which triggered exothermic reactions with Al.The ternary composites exhibited a narrowed main reaction temperature range and concentrated heat release,attributed to improved interfacial contact and polymer decomposition.Combustion tests demonstrated that Al-NH_(4)CoF_(3)@P(VDF-HFP)achieved self-sustaining combustion.In addition,a simple validation was done by replacing the Al component in the aluminium-containing propellant,demonstrating its potential application in the propellant field.This work establishes a novel strategy for designing stable,high-energy composites with potential applications in advanced propulsion systems.
基金supported by the China National Postdoctoral Program for Innovative Talents(BX20230037)Talent Fund of Beijing Jiaotong University(2023XKRC034)+1 种基金China Postdoctoral Science Foundation(2023M730205)China Scholarship Council(202407090030)。
文摘As a type of emerging electro-mechanical conversion technology,triboelectric nanogenerators(TENGs)were widely applied in high-entropy energy harvesting,Internet of Things sensing,and biomedical fields due to the characteristics of lightweight,cheap,and high voltage.Among them,the rotating TENG has been extensively researched for its advantages,such as high-precision electrical signals,high electro-mechanical conversion efficiency,and effective output power.In this paper,the working mechanisms of four different rotating TENG modes were introduced in detail.Subsequently,a large amount of research works on the strengthening performance of rotating TENGs were comprehensively introduced and summarized by three gradient classifications.In addition,in view of the many applications of rotating TENGs,they were also systematically divided and generalized into three dimensions.Finally,the problems as well as challenges faced by the current rotating TENG research in the above 16 specific research directions were deeply analyzed,and the possible development directions and the solutions to the above problems were reasonably prospected in the next years.This review hopes to effectively promote the progress of rotating TENG on the road to commercialization.
基金supported by the National Natural Science Foundation of China(No.62003269).
文摘Computing electrostatic interaction on non-cooperative targets with unknown meshes is crucial for electrostatic-based space on-orbit services.Although meshes for electrostatic interaction computations can be reconstructed from point clouds,they are usually too dense,leading to high computational costs.This paper presents an optimization method for converting dense meshes into optimal meshes,enabling fast and accurate computation of the electrostatic interaction by point clouds.First,the dense mesh reconstructed from point clouds is simplified into a coarse mesh using local operators.Second,the simplified mesh is refined by an iterative strategy that integrates a lightweight method of moments and an impedance matrix inheritance technique,ultimately yielding an optimal mesh for computing the electrostatic interaction.Simulation results show that our method effectively optimizes dense meshes,making electrostatic interaction computations using point clouds approximately 63.4 times more efficient than the previous method.
基金supported by the Project of the National Science Foundation of China(Nos.52173033,51773044 and 51603047)Foshan Science and Technology Innovation Project(No.FS0AA-KJ919-4402-0145)。
文摘Although amide-and hydrazide-based nucleating agents have been extensively used to enhance the crystallization performance of poly(lactic acid)(PLA),structurally similar nucleating agents exhibit significant differences in their crystallization-promoting efficiency,and the underlying mechanism remains unclear.In this study,a series of nucleating agents,including N,N-diphenylterephthalamide(DPTA),N,N,N-triphenyl-1,3,5-benzenetricarboxamide(TPTA),N,N-diphenyl terephthalohydrazide(DBTA),and N,N,N-tribenzoyl-1,3,5-benzenetricarbohydrazide(TBTA),were designed and synthesized to investigate the differences in their effects on the crystallization performance of PLA.Density functional theory(DFT)and molecular dynamics(MD)simulations showed that DBTA had a smaller electrostatic potential difference(66.2 kcal/mol).During the cooling process,DBTA could stably form more intermolecular hydrogen bonds with PLA and exhibit a higher interaction energy,thus theoretically enabling more efficient promotion of PLA crystallization.Further differential scanning calorimetry(DSC)results revealed that at a 0.5wt%loading of DBTA,the crystallization peak temperature of the PLA-DBTA composite reached 118.1℃during cooling,whereas no distinct crystallization peak was observed for pure PLA under identical conditions.The crystallinity of the composite was significantly increased to 58.4%compared to 14.6%of pure PLA.Moreover,under isothermal crystallization at 130℃,DBTA reduced the half-crystallization time of PLA to 2.9min,while the half-crystallization time for pure PLA was 27.4 min.Time-resolved Fourier transform infrared spectroscopy(FTIR)results also confirmed that DBTA promoted the formation of gt conformational isomers of PLA during the crystallization process.This study elucidates the mechanism behind the performance differences between structurally similar nucleating agents in regulating PLA crystallization from the perspective of molecular electrostatic potential and hydrogen bonding interactions,providing a theoretical basis for the molecular design of efficient nucleating agents.
基金supported by the Key R&D Program of Zaozhuang city,China(2024GH12)the Zaozhuang Gathering of Talents Program。
文摘Developing advanced cathode modification strategies to address the inherent high charge density of Al^(3+) is essential for achieving high-energy-density and long-cycle-life rechargeable aluminum batteries(RABs).Herein,we engineer tetraethylammonium(TEA)cation intercalation as a dual-function strategy that concurrently enables interlayer distance enlargement and electrostatic shielding effects,resolving Al^(3+) polarization-induced sluggish kinetics and cathode degradation in RABs.TEA intercalation triggers exceptional V2O5 interlayer expansion from 4.37 to 13.10Å,while the modulated charge distribution generates an electrostatic shielding effect that significantly weakens the Coulombic interactions between Al^(3+) and V2O5 frameworks.This dual mechanism collectively enhances ion diffusion kinetics and suppresses lattice stress accumulation.Ex situ X-ray diffraction and transmission electron microscopy analyses confirm that the“molecular pillar effect”of TEA enables minimal and highly reversible structural deformation of the cathode(<2.0%volume change after 200 cycles),demonstrating zero-strain aluminum-storage behavior.The optimized cathode delivers a high reversible capacity of 258 mAh g^(−1) at 0.5 A g^(−1),maintains 99%capacity retention at 5.0 A g^(−1),and exhibits an ultralow capacity decay rate of 0.01%per cycle over 6000 cycles.This work opens new pathways for designing stable high-performance RAB cathodes through synergistic modulation of electronic and lattice structures.
基金supported by the National Natural Science Foundation of China(No.52473213 and No.52203261)。
文摘Ion migration capability and interfacial chemistry of solid polymer electrolytes(SPEs)in all-solid-state sodium metal batteries(ASSMBs)are closely related to the Na^(+)coordination environment.Herein,an electrostatic engineering strategy is proposed to regulate the Na^(+)coordinated structure by employing a fluorinated metal–organic framework as an electron-rich model.Theoretical and experimental results revealed that the abundant electron-rich F sites can accelerate the disassociation of Na-salt through electrostatic attraction to release free Na^(+),while forcing anions into a Na^(+)coordination structure though electrostatic repulsion to weaken the Na^(+)coordination with polymer,thus promoting rapid Na^(+)transport.The optimized anion-rich weak solvation structure fosters a stable inorganic-dominated solid–electrolyte interphase,significantly enhancing the interfacial stability toward Na anode.Consequently,the Na/Na symmetric cell delivered stable Na plating/stripping over 2500 h at 0.1 mA cm^(−2).Impressively,the assembled ASSMBs demonstrated stable performance of over 2000 cycles even under high rate of 2 C with capacity retention nearly 100%,surpassing most reported ASSMBs using various solid-state electrolytes.This work provides a new avenue for regulating the Na^(+)coordination structure of SPEs by exploration of electrostatic effect engineering to achieve high-performance all-solid-state alkali metal batteries.
基金supported by the National Natural Science Foundation of China(Grant No.51702081)。
文摘Aqueous zinc-ion batteries(AZIBs)are facing challenges of severe parasitic side reactions and uncontrolled Zn dendrite growth in promoting commercial applications.Here,rare earth metal neodymium ions(Nd^(3+))have been introduced into the conventional Zn SO_4 electrolyte as an electrolyte additive to improve the stability and reversibility of AZIBs.Combining experimental characterization and theoretical calculations,Nd^(3+)ions are adsorbed at the active sites of zinc crystal growth,forming a positively charged shielding layer on the Zn anode surface that effectively prevents lateral reactions and induces uniform Zn deposition.Meanwhile,Nd^(3+)ions preferentially adsorb on(100)and(101)planes of Zn,thus facilitating preferential deposition on the(002)plane and achieving a dendrite-free Zn anode.Consequently,a Zn//Zn symmetric cell with the Nd^(3+)-modified electrolyte exhibits an ultralong lifespan of 3000 h at0.5 m A cm^(-2),and a Zn//Cu asymmetric cell realizes an impressive Coulombic efficiency of 99.47%for Zn stripping and plating over 550 cycles at 1.0 mA cm^(-2).Impressively,Zn//CNT@MnO_(2) full cell reaches a considerably stable long cycle performance over 2500 cycles at 1.0 A g^(-1).This work offers an effective solution to the challenges faced by Zn anode and expands the application scope of metallic ions in metalbased energy storage devices.
基金supported by the European Commission through the MaX Centre of Excellence(grant number 824143)supported by the European Commission through the MAX Centre of Excellence for supercomputing applications(grant numbers 10109337 and 824143)by the Italian MUR,through the Italian National Centre from HPC,Big Data,and Quantum Computing(grant number CN00000013).
文摘Wepresent a new approach to constructmachine-learned interatomic potentials including long-range electrostatic interactions based on a charge equilibration scheme.This new approach can accurately describe the potential energy surface of systems with ionic and covalent interactions as well as systems with multiple charge states.Moreover,it can either be regressed against known atomic charge decompositions or trained without charge targets,without compromising the accuracy of energy and forces.We benchmark our approach against other state-of-the-art models and prove it to have equivalent performances on a set of simple reference systems while being less computationally expensive.Finally,we demonstrate the accuracy of our approach on complex systems:solid and liquid state sodium chloride.We attain accuracy in energy and forces better than the model based on local descriptors and show that our electrostatic approach can capture the density functional theory tail of the potential energy surface of the isolated Na-Cl dimer,which the local descriptor-based model fails to describe.
基金HW is partially supported by the open research fund of Songshan Lake Materials Laboratory No.2023SLABFN20the General Program of National Natural Science Foundation of China(NSFC)under Grant No.12374210+2 种基金the startup fund under Grant No.WIUCASQD2022005 from Wenzhou Institute University of Chinese Academy of Sciences(WIU-CAS)Z-CO-Y was supported by the Major Program of the NSFC under Grant No.22193032RP acknowledges the support of UCAS and funding from the Key Program of NSFC under Grant No.12034019.
文摘A mobile Coulomb gas permeating a fixed background crystalline lattice of charged colloidal crystals is subject to an electrostatic-elastic coupling,which we study on the continuum level by introducing a minimal coupling between electrostatic and displacement fields.We derive linearized,Debye–Hückel-like mean-field equations that can be analytically solved,incorporating the minimal coupling between electrostatic and displacement fields leading to an additional effective attractive interaction between mobile charges that depends in general on the strength of the coupling between the electrostatic and displacement fields.By analyzing the Gaussian fluctuations around the mean-field solution we also identify and quantify the region of its stability in terms of the electrostatic-elastic screening length.This detailed continuum theory incorporating the standard lattice elasticity and electrostatics of mobile charges provides a baseline to investigate the electrostatic-elastic coupling for microscopic models in colloid science and materials science.
基金financially supported by the National Natural Science Foundation of China(No.52377026 and No.52301192)Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)+4 种基金Postdoctoral Fellowship Program of CPSF under Grant Number(No.GZB20240327)Shandong Postdoctoral Science Foundation(No.SDCXZG-202400275)Qingdao Postdoctoral Application Research Project(No.QDBSH20240102023)China Postdoctoral Science Foundation(No.2024M751563)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites).
文摘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.
基金supported by the National Natural Science Foundation of China(Nos.52377026 and 52301192)Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites).
文摘Magnetic metal has broad application prospects in the field of electromagnetic wave(EMW)absorption due to its excellent dielectric and magnetic properties.However,high density and poor chemical stability constrain their development potential.The combination of magnetic metals with other lightweight carbon materials is an effective solution.In this work,magnetic nanoparticle fiber composites were prepared by electrostatic spinning and high-temperature annealing processes.By adjusting the preparation process and annealing temperature,Co/Co7 Fe_(3)/CF-800 fiber composites containing double-shell hollow structured nanocubes were cleverly synthesized.The material is mixed with paraffin wax and has a minimum reflection loss(RL)of-52.14 dB and a maximum effective absorption bandwidth(EAB)of 6.16 GHz at a load of 10 wt%.By analyzing the electromagnetic parameters of the material,it was demonstrated that the material absorbs EMW through the synergistic effect of dielectric and magnetic losses.Electrochemical testing in a simulated seawater environment demonstrated that the material also has a degree of self-anticorrosion capability.This work provides new strategies for designing materials with excellent electromagnetic wave absorption and self-anticorrosion properties.
