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
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
NiMo-based catalysts show significant potential for the hydrogen evolution reaction(HER).Optimizing the electronic structure and enhancing mass transfer are two critical factors for improving catalytic performance,but...NiMo-based catalysts show significant potential for the hydrogen evolution reaction(HER).Optimizing the electronic structure and enhancing mass transfer are two critical factors for improving catalytic performance,but they remain significant challenges.Herein,we present a route for synthesizing two-dimensional(2D)porous Mo_(2)N-Ni heterojunction nanosheets with tuned Ni-Mo ratio for enhanced alkaline HER performance.A precursor can be easily synthesized by assembling polyoxometalate clusters(PMo_(12))with layered hydroxy oxides(Ni(OH)_(2)).It is found that the interaction between PMo_(12)and Ni(OH)_(2)can effectively protect the particles from significant agglomeration during pyrolysis,resulting in the formation of 2D porous sheets composed of small Mo_(2)N-Ni units.The transfer of electrons from Ni to Mo_(2)N results in the redistribution of electrons at the heterojunction,optimizing the adsorption and desorption of intermediates.Moreover,the 2D porous structure comprised of small particles enhances mass transfer,thereby reducing the impedance of the catalyst.Consequently,the catalyst with an optimized Mo/Ni ratio exhibits an overpotential of 19 mV at 10 mA cm^(-2),being comparable to that of commercial Pt/C catalyst.The anion exchange membrane(AEM)electrolyzer,consisting of optimized Mo_(2)N-Ni and NiFe-LDH,achieves a current density of 500 mA cm^(-2)at 1.80 V and can operate stably for 300 h.This assembly method offers an effective strategy for the large-scale preparation of efficient catalysts.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
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
Solvation structures fundamentally control the ion-transport dynamics and mechanical properties of polymer electrolytes.However,there is a lack of strategies to rationally regulate the solvation structures and fundame...Solvation structures fundamentally control the ion-transport dynamics and mechanical properties of polymer electrolytes.However,there is a lack of strategies to rationally regulate the solvation structures and fundamental understanding on how they control the electrochemical performances.Herein,by harnessing the electrostatic adsorption of one-dimensional nanofiller(i.e.,surface-charged halloysite nanotubes,d-HNTs),we successfully fabricate a high-performance polymer nanocomposite electrolyte enabled by strong surface adsorption,referred as adsorption-state polymer electrolyte(ASPE).This ASPE shows fast ion transport(0.71±0.05 mS cm^(-1)at room temperature),high mechanical strength and toughness(10.3±0.05 MPa;15.73 MJ m^(-3)),improved lithium-ion transference number,and long cycle life with lithium metal anode,in comparison with the sample without the d-HNT adsorption effect.To fundamentally understand these high performances,an anion-rich asymmetric solvent structure model is further proposed and evidenced by both experiments and simulation studies.Results show that the electrostatic adsorption among the d-HNT,ionic liquid electrolyte,and polymer chain generates a nano filler-supported fast ion-conduction pathway with asymmetric Li+-coordination microenvironment.Meanwhile,the anion-rich asymmetric solvent structure model of ASPE also generates a fast de-solvation and anion-derived stable solid-electrolyte interphase for lithium metal anode.The high performance and understanding of the mechanism for ASPE provide a promising path to develop advanced polymer electrolytes.展开更多
Cerium oxide(CeO_(2)) has attracted much attention in recent years owing to its reversible switch ability in Ce^(3+)/Ce^(4+)redox to produce improved antioxidation properties for biomedical applications.Here,we report...Cerium oxide(CeO_(2)) has attracted much attention in recent years owing to its reversible switch ability in Ce^(3+)/Ce^(4+)redox to produce improved antioxidation properties for biomedical applications.Here,we report to embed the CeO_(2)nanospheres into the organic polymer network using electrostatic spinning technology to prepare polyvinyl alcohol(PVA)-encapsulated CeO_(2)nanospheres composite nanofibrous membranes(PVA-CeO_(2)) for the first time,which is beneficial to improving the dispersion and biocompatibility of CeO_(2)nanosphere without altering the original antioxidant properties of CeO_(2).Detailed characterization of the as-prepared composite nanofibrous membranes reveals that CeO_(2)was successfully introduced into the PVA fibers with strong interactions,thus enhancing the thermal stability and fracture toughness of the nanoifbers.As a result,PVA-CeO_(2)exhibits superior UV shielding performance,antioxidant performance and bacteriostatic performance.Meaningfully,PVA-CeO_(2)has strong absorbance in both UVA and UVB bands when the CeO_(2)concentration in the nanoifber membrane reaches 1.5 wt%,and shows an excellent scavenging effect on the 2,2-diphenyl-1-picrylhydrazyl(DPPH)radicals with a scavenging rate of 86.52%.Moreover,the Kirby-Bauer(K-B) method of agar diffusion test further confirms that PVA-CeO_(2)has antimicrobial ability against three types of representative strains,including Gram-positive bacteria(Staphylococcus aureus),Gram-negative bacteria(Escherichia coli) and fungi(Candida albicans).Importantly,no obvious cytotoxicity is observed for PVA-CeO_(2)even though the amount of embedded CeO_(2)nanosphere reaches as high as 1.5 wt%.This study reveals new avenues for improving the future smart design of CeO_(2)-based nanoifber membrane composite materials for biological antioxidants.展开更多
To study the influence of silicon(Si)on 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20),NC/CL-20 composite explosives and Si/NC/CL-20 composite explosives were prepared by the electrostatic spraying ...To study the influence of silicon(Si)on 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20),NC/CL-20 composite explosives and Si/NC/CL-20 composite explosives were prepared by the electrostatic spraying method.The morphology,structure and thermal decomposition properties of the samples were analyzed using scanning electron microscopy(SEM),X-ray energy spectroscopy(EDS),infrared spectroscopy(FT-IR),and simultaneous thermal analyzer(TG-DSC).Additionally,the combustion process of the samples was tested using a high-speed camera.The results show that the addition of nano-Si contributes to the formation of composite explosives with regular morphology and smaller particle size.The Si/NC/CL-20 composite explosive has better and more uniform sphericity,with an average particle size of 73.4 nm,compared to the NC/CL-20 composite explosive.The Si/NC/CL-20 composite explosive which produced by the electrostatic spraying method,achieves physically uniform distribution of the components including NC,CL-20,Si.The addition of Si promotes the thermal decomposition of CL-20.In comparison to the NC/CL-20 composite explosive,the activation energy of the Si/NC/CL-20 composite explosive decreases by 16.78 kJ/mol,and the self-accelerated decomposition temperature and the critical temperature of thermal explosion decreases by 3.12 K and 2.61 K,respectively.Furthermore,Si/NC/CL-20 composite explosive has shorter ignition delay time and faster combustion rate compared to the NC/CL-20 composite explosive,which shows that Si can improve the combustion performance of CL-20.展开更多
Preferential oxidation of CO(CO-PROX)in H_(2)-rich streams is highly important for purifying the industrial grade H_(2)used in proton-exchange-membrane fuel cells(PEMFC),but it is still limited to a relatively narrow ...Preferential oxidation of CO(CO-PROX)in H_(2)-rich streams is highly important for purifying the industrial grade H_(2)used in proton-exchange-membrane fuel cells(PEMFC),but it is still limited to a relatively narrow operation temperature window.In this study,the trace amounts of Cu are used to modify a Pt/Al_(2)O_(3)catalyst.The introduced Cu_(2+)species are atomically anchored on Pt nanoparticles through strong electrostatic adsorption.展开更多
The liquid Zr_(100-x)V_(x)(x=8.6,16.5,30)alloys were undercooled to the maximum undercooling of 364 K(0.18 T_(L)),405 K(0.21 T_(L)),and 375 K(0.21 T_(L)),respectively,by using electrostatic levitation technique.The Zr...The liquid Zr_(100-x)V_(x)(x=8.6,16.5,30)alloys were undercooled to the maximum undercooling of 364 K(0.18 T_(L)),405 K(0.21 T_(L)),and 375 K(0.21 T_(L)),respectively,by using electrostatic levitation technique.The Zr_(91.4)V_(8.6) and Zr_(83.5)V_(16.5) alloys present only one recalescence during liquid/solid phase transition,while the Zr_(70)V_(30) alloy presents a transformation from two recalescence to one recalescence phenomenon with a critical undercooling of approximately 300 K.According to the LKT/BCT model,the calculated results of the primary β-Zr dendrite growth velocity in undercooled liquid Zr_(91.4)V_(8.6) and Zr_(83.5)V_(16.5) alloys agree well with the experiments.The velocity inflection points at 119 K of Zr_(91.4)V_(8.6) alloy and 201 K of Zr_(83.5)V_(16.5) alloy could be explained by the competition between solutal undercooling control and thermal undercooling control modes.For Zr_(70)V_(30) alloy solidified in the P1 with twice recalescence,a critical second undercooling of 253 K and corresponding undercooling of 65 and 244 K are obtained.When the un-dercooling is in the range of 65-244 K,the second undercooling would be greater than 253 K,and the residual liquid phase would solidify into anomalous eutectic microstructure for Zr_(70)V_(30) alloy.The Vickers hardness of Zr_(100-x)V_(x)(x=8.6,16.5,30)alloys all show a quadratic relationship with undercooling.Under electrostatic levitation condition,the mechanical property of Zr-V alloys could be significantly regulated through solidifying the alloys at different undercoolings.展开更多
To explore the electrostatic discharge behavior of charged powders in industrial silos,discharge experiments are conducted based on a full-size industrial silo discharge platform.Electrostatic discharge mode,frequency...To explore the electrostatic discharge behavior of charged powders in industrial silos,discharge experiments are conducted based on a full-size industrial silo discharge platform.Electrostatic discharge mode,frequency,and energy are investigated for powders of different polarities.Although the powders have low charge-to-mass ratios(+0.087μC/kg for the positively charged powders and−0.26μC/kg for the negatively charged ones),electrostatic discharges occur approximately every 10 s,with the maximum discharge energy being 800 mJ.Powder polarity considerably influences discharge energy.The positive powders exhibit higher discharge energy than the negative ones,although discharge frequency remains similar for both.Effects of powder charge,humidity,and mass flow on discharge frequency and discharge energy are quantitatively analyzed,providing important insights for the improvement of safety in industrial powder handling.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 National Key R&D Program of China(2022YFA1503002,2022YFA1503003)the National Natural Science Foundation of China(22271081)+2 种基金the Natural Science Foundation of Heilongjiang Province(PL2024B017)the Postdoctoral Science Foundation of Heilongjiang Province(LBH-Z22240)the Heilongjiang University Excellent Youth Foundation。
文摘NiMo-based catalysts show significant potential for the hydrogen evolution reaction(HER).Optimizing the electronic structure and enhancing mass transfer are two critical factors for improving catalytic performance,but they remain significant challenges.Herein,we present a route for synthesizing two-dimensional(2D)porous Mo_(2)N-Ni heterojunction nanosheets with tuned Ni-Mo ratio for enhanced alkaline HER performance.A precursor can be easily synthesized by assembling polyoxometalate clusters(PMo_(12))with layered hydroxy oxides(Ni(OH)_(2)).It is found that the interaction between PMo_(12)and Ni(OH)_(2)can effectively protect the particles from significant agglomeration during pyrolysis,resulting in the formation of 2D porous sheets composed of small Mo_(2)N-Ni units.The transfer of electrons from Ni to Mo_(2)N results in the redistribution of electrons at the heterojunction,optimizing the adsorption and desorption of intermediates.Moreover,the 2D porous structure comprised of small particles enhances mass transfer,thereby reducing the impedance of the catalyst.Consequently,the catalyst with an optimized Mo/Ni ratio exhibits an overpotential of 19 mV at 10 mA cm^(-2),being comparable to that of commercial Pt/C catalyst.The anion exchange membrane(AEM)electrolyzer,consisting of optimized Mo_(2)N-Ni and NiFe-LDH,achieves a current density of 500 mA cm^(-2)at 1.80 V and can operate stably for 300 h.This assembly method offers an effective strategy for the large-scale preparation of efficient catalysts.
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 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financial support from the National Natural Science Foundation of China(52203123)the Sichuan Science and Technology Program(2023NSFSC0991)+2 种基金the State Key Laboratory of Polymer Materials Engineering(sklpme 2023-1-05 and sklpme 2024-2-04)the Fundamental Research Funds for the Central Universitiespartially sponsored by the Double First-Class Construction Funds of Sichuan University。
文摘Solvation structures fundamentally control the ion-transport dynamics and mechanical properties of polymer electrolytes.However,there is a lack of strategies to rationally regulate the solvation structures and fundamental understanding on how they control the electrochemical performances.Herein,by harnessing the electrostatic adsorption of one-dimensional nanofiller(i.e.,surface-charged halloysite nanotubes,d-HNTs),we successfully fabricate a high-performance polymer nanocomposite electrolyte enabled by strong surface adsorption,referred as adsorption-state polymer electrolyte(ASPE).This ASPE shows fast ion transport(0.71±0.05 mS cm^(-1)at room temperature),high mechanical strength and toughness(10.3±0.05 MPa;15.73 MJ m^(-3)),improved lithium-ion transference number,and long cycle life with lithium metal anode,in comparison with the sample without the d-HNT adsorption effect.To fundamentally understand these high performances,an anion-rich asymmetric solvent structure model is further proposed and evidenced by both experiments and simulation studies.Results show that the electrostatic adsorption among the d-HNT,ionic liquid electrolyte,and polymer chain generates a nano filler-supported fast ion-conduction pathway with asymmetric Li+-coordination microenvironment.Meanwhile,the anion-rich asymmetric solvent structure model of ASPE also generates a fast de-solvation and anion-derived stable solid-electrolyte interphase for lithium metal anode.The high performance and understanding of the mechanism for ASPE provide a promising path to develop advanced polymer electrolytes.
基金Project supported by the National Natural Science Foundation of China (22301012)the R&D Program of Beijing Municipal Education Commission (KM202310011005)。
文摘Cerium oxide(CeO_(2)) has attracted much attention in recent years owing to its reversible switch ability in Ce^(3+)/Ce^(4+)redox to produce improved antioxidation properties for biomedical applications.Here,we report to embed the CeO_(2)nanospheres into the organic polymer network using electrostatic spinning technology to prepare polyvinyl alcohol(PVA)-encapsulated CeO_(2)nanospheres composite nanofibrous membranes(PVA-CeO_(2)) for the first time,which is beneficial to improving the dispersion and biocompatibility of CeO_(2)nanosphere without altering the original antioxidant properties of CeO_(2).Detailed characterization of the as-prepared composite nanofibrous membranes reveals that CeO_(2)was successfully introduced into the PVA fibers with strong interactions,thus enhancing the thermal stability and fracture toughness of the nanoifbers.As a result,PVA-CeO_(2)exhibits superior UV shielding performance,antioxidant performance and bacteriostatic performance.Meaningfully,PVA-CeO_(2)has strong absorbance in both UVA and UVB bands when the CeO_(2)concentration in the nanoifber membrane reaches 1.5 wt%,and shows an excellent scavenging effect on the 2,2-diphenyl-1-picrylhydrazyl(DPPH)radicals with a scavenging rate of 86.52%.Moreover,the Kirby-Bauer(K-B) method of agar diffusion test further confirms that PVA-CeO_(2)has antimicrobial ability against three types of representative strains,including Gram-positive bacteria(Staphylococcus aureus),Gram-negative bacteria(Escherichia coli) and fungi(Candida albicans).Importantly,no obvious cytotoxicity is observed for PVA-CeO_(2)even though the amount of embedded CeO_(2)nanosphere reaches as high as 1.5 wt%.This study reveals new avenues for improving the future smart design of CeO_(2)-based nanoifber membrane composite materials for biological antioxidants.
基金National Natural Science Foundation of China(No.22275150)。
文摘To study the influence of silicon(Si)on 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20),NC/CL-20 composite explosives and Si/NC/CL-20 composite explosives were prepared by the electrostatic spraying method.The morphology,structure and thermal decomposition properties of the samples were analyzed using scanning electron microscopy(SEM),X-ray energy spectroscopy(EDS),infrared spectroscopy(FT-IR),and simultaneous thermal analyzer(TG-DSC).Additionally,the combustion process of the samples was tested using a high-speed camera.The results show that the addition of nano-Si contributes to the formation of composite explosives with regular morphology and smaller particle size.The Si/NC/CL-20 composite explosive has better and more uniform sphericity,with an average particle size of 73.4 nm,compared to the NC/CL-20 composite explosive.The Si/NC/CL-20 composite explosive which produced by the electrostatic spraying method,achieves physically uniform distribution of the components including NC,CL-20,Si.The addition of Si promotes the thermal decomposition of CL-20.In comparison to the NC/CL-20 composite explosive,the activation energy of the Si/NC/CL-20 composite explosive decreases by 16.78 kJ/mol,and the self-accelerated decomposition temperature and the critical temperature of thermal explosion decreases by 3.12 K and 2.61 K,respectively.Furthermore,Si/NC/CL-20 composite explosive has shorter ignition delay time and faster combustion rate compared to the NC/CL-20 composite explosive,which shows that Si can improve the combustion performance of CL-20.
基金financially supported by the National Key Research and Development Program of China(No.2022YFB3504200)the National Natural Science Foundation of China(Nos.U21A20326 and 22376063)+4 种基金the fund of the National Engineering Laboratory for Mobile Source Emission Control Technology(No.NELMS2020A05)the Fundamental Research Funds for the Central Universitiesthe funding received from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 897197.Y.L.(CSC No.202006740085)is grateful for thegrant from the China Scholarship Councilthe ICREA Academia program and grants MICINN/FEDER PID2021124572OB-C31 and GC 2021 SGR 01061part of Maria de Maeztu Units of Excellence Programme CEX2023-001300-M/funded by MCIN/AEI/https://doi.org/10.13039/501100011033
文摘Preferential oxidation of CO(CO-PROX)in H_(2)-rich streams is highly important for purifying the industrial grade H_(2)used in proton-exchange-membrane fuel cells(PEMFC),but it is still limited to a relatively narrow operation temperature window.In this study,the trace amounts of Cu are used to modify a Pt/Al_(2)O_(3)catalyst.The introduced Cu_(2+)species are atomically anchored on Pt nanoparticles through strong electrostatic adsorption.
基金supported by the National Natural Science Foundation of China(Grant No.52088101)the Space Utilization System of China Manned Space Engineering(Grant No.KJZ-YY-NCL02)+1 种基金the National Key R&D Program of China(Grant No.2021YFA0716301)the Shannxi Key Science and Technology Program(Grant Nos.2023-ZDLGY-36,2024JC-ZDXM-24).
文摘The liquid Zr_(100-x)V_(x)(x=8.6,16.5,30)alloys were undercooled to the maximum undercooling of 364 K(0.18 T_(L)),405 K(0.21 T_(L)),and 375 K(0.21 T_(L)),respectively,by using electrostatic levitation technique.The Zr_(91.4)V_(8.6) and Zr_(83.5)V_(16.5) alloys present only one recalescence during liquid/solid phase transition,while the Zr_(70)V_(30) alloy presents a transformation from two recalescence to one recalescence phenomenon with a critical undercooling of approximately 300 K.According to the LKT/BCT model,the calculated results of the primary β-Zr dendrite growth velocity in undercooled liquid Zr_(91.4)V_(8.6) and Zr_(83.5)V_(16.5) alloys agree well with the experiments.The velocity inflection points at 119 K of Zr_(91.4)V_(8.6) alloy and 201 K of Zr_(83.5)V_(16.5) alloy could be explained by the competition between solutal undercooling control and thermal undercooling control modes.For Zr_(70)V_(30) alloy solidified in the P1 with twice recalescence,a critical second undercooling of 253 K and corresponding undercooling of 65 and 244 K are obtained.When the un-dercooling is in the range of 65-244 K,the second undercooling would be greater than 253 K,and the residual liquid phase would solidify into anomalous eutectic microstructure for Zr_(70)V_(30) alloy.The Vickers hardness of Zr_(100-x)V_(x)(x=8.6,16.5,30)alloys all show a quadratic relationship with undercooling.Under electrostatic levitation condition,the mechanical property of Zr-V alloys could be significantly regulated through solidifying the alloys at different undercoolings.
基金The National Natural Science Foundation of China(No.51976039)。
文摘To explore the electrostatic discharge behavior of charged powders in industrial silos,discharge experiments are conducted based on a full-size industrial silo discharge platform.Electrostatic discharge mode,frequency,and energy are investigated for powders of different polarities.Although the powders have low charge-to-mass ratios(+0.087μC/kg for the positively charged powders and−0.26μC/kg for the negatively charged ones),electrostatic discharges occur approximately every 10 s,with the maximum discharge energy being 800 mJ.Powder polarity considerably influences discharge energy.The positive powders exhibit higher discharge energy than the negative ones,although discharge frequency remains similar for both.Effects of powder charge,humidity,and mass flow on discharge frequency and discharge energy are quantitatively analyzed,providing important insights for the improvement of safety in industrial powder handling.
