This paper presents an analogical study between electromagnetic and elastic wave fields,with a one-to-one correspondence principle established regarding the basic wave equations,the physical quantities and the differe...This paper presents an analogical study between electromagnetic and elastic wave fields,with a one-to-one correspondence principle established regarding the basic wave equations,the physical quantities and the differential operations.Using the electromagnetic-to-elastic substitution,the analogous relations of the conservation laws of energy and momentum are investigated between these two physical fields.Moreover,the energy-based and momentum-based reciprocity theorems for an elastic wave are also derived in the time-harmonic state,which describe the interaction between two elastic wave systems from the perspectives of energy and momentum,respectively.The theoretical results obtained in this analysis can not only improve our understanding of the similarities of these two linear systems,but also find potential applications in relevant fields such as medical imaging,non-destructive evaluation,acoustic microscopy,seismology and exploratory geophysics.展开更多
Transition metal sulfides have high theoretical capacities and are considered as potential anode materials for sodium-ion batteries.However,due to low inherent conductivity and significant volume expansion,the electro...Transition metal sulfides have high theoretical capacities and are considered as potential anode materials for sodium-ion batteries.However,due to low inherent conductivity and significant volume expansion,the electrochemical performance is greatly limited.In this study,a nickel/manganese sulfide material(Ni_(0.96)S_(x)/MnS_(y)-NC)with adjustable sulfur vacancies and heterogeneous hollow spheres was prepared using a simple method.The introduction of a concentration-adjustable sulfur vacancy enables the generation of a heterogeneous interface between bimetallic sulfide and sulfur vacancies.This interface collectively creates an internal electric field,improving the mobility of electrons and ions,increasing the number of electrochemically active sites,and further optimizing the performance of Na~+storage.The direction of electron flow is confirmed by Density functional theory(DFT)calculations.The hollow nano-spherical material provides a buffer for expansion,facilitating rapid transfer kinetics.Our innovative discovery involves the interaction between the ether-based electrolyte and copper foil,leading to the formation of Cu_9S_5,which grafts the active material and copper current collector,reinforcing mechanical supporting.This results in a new heterostructure of Cu_9S_5 with Ni_(0.96)S_(x)/MnS_(y),contributing to the stabilization of structural integrity for long-cycle performance.Therefore,Ni_(0.96)S_(x)/MnS_(y)-NC exhibits excellent electrochemical properties following our modification route.Regarding stability performance,Ni0_(.96)S_(x)/MnS_(y)-NC demonstrates an average decay rate of 0.00944%after 10,000 cycles at an extremely high current density of 10000 mA g^(-1),A full cell with a high capacity of 304.2 mA h g^(-1)was also successfully assembled by using Na_(3)V_(2)(PO_(4))_(3)/C as the cathode.This study explores a novel strategy for interface/vacancy co-modification in the fabrication of high-performance sodium-ion batteries electrode.展开更多
By using one-dimensional tight-binding model modified to include electron-electric field interaction and electron-electron interaction,we theoretically explore the polarization process of exciton and biexciton in cis-...By using one-dimensional tight-binding model modified to include electron-electric field interaction and electron-electron interaction,we theoretically explore the polarization process of exciton and biexciton in cis-polyacetylene.The dynamical simulation is performed by adopting the non-adiabatic evolution approach.The results show that under the effect of moderate electric field,when the strength of electron-electron interaction is weak,the singlet exciton is stable but its polarization presents obvious oscillation.With the enhancement of interaction,it is dissociated into polaron pairs,the spin-flip of which can be observed through modulating the interaction strength.For the triplet exciton,the strong electron-electron interaction restrains its normal polarization,but it is still stable.In the case of biexciton,the strong electron-electron interaction not only dissociate it,but also flip its charge distribution.The yield of the possible states formed after the dissociation of exciton and biexciton is also calculated.展开更多
Magnesium ion batteries(MIBs)are a potential field for the energy storage of the future but are restricted by insufficient rate capability and rapid capacity degradation.Magnesium-sodium hybrid ion batteries(MSHBs)are...Magnesium ion batteries(MIBs)are a potential field for the energy storage of the future but are restricted by insufficient rate capability and rapid capacity degradation.Magnesium-sodium hybrid ion batteries(MSHBs)are an effective way to address these problems.Here,we report a new type of MSHBs that use layered sodium vanadate((Na,Mn)V_(8)O_(20)·5H_(2)O,Mn-NVO)cathodes coupled with an organic 3,4,9,10-perylenetetracarboxylic diimide(PTCDI)anode in Mg^(2+)/Na^(+)hybrid electrolytes.During electrochemical cycling,Mg^(2+)and Na^(+)co-participate in the cathode reactions,and the introduction of Na^(+)promotes the structural stability of the Mn-NVO cathode,as cleared by several ex-situ characterizations.Consequently,the Mn-NVO cathode presents great specific capacity(249.9 mA h g^(−1)at 300 mA g^(−1))and cycling(1500 cycles at 1500 mA g^(−1))in the Mg^(2+)/Na^(+)hybrid electrolytes.Besides,full battery displays long lifespan with 10,000 cycles at 1000 mA g^(−1).The rate performance and cycling stability of MSHBs have been improved by an economical and scalable method,and the mechanism for these improvements is discussed.展开更多
Wide-bandgap(WBG)perovskite solar cells(PSCs)play a fundamental role in perovskite-based tandem solar cells.However,the efficiency of WBG PSCs is limited by significant open-circuit voltage losses,which are primarily ...Wide-bandgap(WBG)perovskite solar cells(PSCs)play a fundamental role in perovskite-based tandem solar cells.However,the efficiency of WBG PSCs is limited by significant open-circuit voltage losses,which are primarily caused by surface defects.In this study,we present a novel method for modifying surfaces using the multifunctional S-ethylisothiourea hydrobromide(SEBr),which can passivate both Pb^(-1)and FA^(-1)terminated surfaces,Moreover,the SEBr upshifted the Fermi level at the perovskite interface,thereby promoting carrier collection.This proposed method was effective for both 1.67 and 1.77 eV WBG PSCs,achieving power conversion efficiencies(PCEs)of 22.47%and 19.90%,respectively,with V_(OC)values of 1.28 and 1.33 V,along with improved film and device stability.With this advancement,we were able to fabricate monolithic all-perovskite tandem solar cells with a champion PCE of 27.10%,This research offers valuable insights for passivating the surface trap states of WBG perovskite through rational multifunctional molecular engineering.展开更多
Discovery of the X(3872)meson in 2003 ignited intense interest in exotic(neither qq nor qqq)hadrons,but a cc interpretation of this state was difficult to exclude.An unequivocal exotic was discovered in the Z_(c)(3900...Discovery of the X(3872)meson in 2003 ignited intense interest in exotic(neither qq nor qqq)hadrons,but a cc interpretation of this state was difficult to exclude.An unequivocal exotic was discovered in the Z_(c)(3900)^(+)meson—a charged charmonium-like state.A variety of models of exotic structure have been advanced but consensus is elusive.The grand lesson from heavy quarkonia was that heavy quarks bring clarity.Thus,the recently reported triplet of all-charm tetraquark candidates—X(6600),X(6900),and X(7100)—decaying to J/ψJ/ψ is a great boon,promising important insights.We review some history of exotics,chronicle the road to prospective all-charm tetraquarks,discuss in some detail the divergent modeling of J/ψJ/ψ structures,and offer some inferences about them.These states form a Regge trajectory and appear to be a family of radial excitations.A reported,but unexplained,threshold excess could hint at a fourth family member.We close with a brief look at a step beyond:all-bottom tetraquarks.展开更多
A kind of sandwich-like NiCo_2O_4/rGO/NiO heterostructure composite has been successfully anchored on nickel foam substrate via a three-step hydrothermal method with successive annealing treatment. The smart combinati...A kind of sandwich-like NiCo_2O_4/rGO/NiO heterostructure composite has been successfully anchored on nickel foam substrate via a three-step hydrothermal method with successive annealing treatment. The smart combination of NiCo_2O_4, reduced graphene oxide(rGO), and NiO nanostructure in the sandwich-like nano architecture shows a promising synergistic effect for supercapacitors with greatly enhanced electrochemical performance. For serving as supercapacitor electrode, the NiCo_2O_4/rGO/NiO heterostructure materials exhibit remarkable specific capacitance of 2644 mF cm^(-2)at current density of 1 mA cm^(-2),and excellent capacitance retentions of 97.5% after 3000 cycles. It is expected that the present heterostructure will be a promising electrode material for high-performance supercapacitors.展开更多
An approximate Fokker-Planck equation for the logistic growth model which is driven by coloured correlated noises is derived by applying the Novikov theorem and the Fox approximation. The steady-state probability dist...An approximate Fokker-Planck equation for the logistic growth model which is driven by coloured correlated noises is derived by applying the Novikov theorem and the Fox approximation. The steady-state probability distribution （SPD） and the mean of the tumour cell number are analysed. It is found that the SPD is the single extremum configuration when the degree of correlation between the multiplicative and additive noises, λ is in -1 〈λ≤0 and can be the double extrema in 0〈λ〈1. A configuration transition occurs because of the variation of noise parameters. A minimum appears in the curve of the mean of the steady-state tumour cell number, （x）, versus λ The position and the value of the minimum are controlled by the noise-correlated times.展开更多
TiBN coatings have huge potential applications as they have excellent properties with increasing modem industrial requirements.Nanocomposite TiBN coatings were synthesized on cemented carbide,high speed steel and Si s...TiBN coatings have huge potential applications as they have excellent properties with increasing modem industrial requirements.Nanocomposite TiBN coatings were synthesized on cemented carbide,high speed steel and Si substrates by using cathodic arc plasma ion plating from pure TiB2 ceramic targets.The structure and mechanical properties of the TiBN coatings were significantly influenced by the nitrogen partial pressure.Rutherford backscattering spectrometry demonstrates that the nitrogen content of the coating varied from 2.8% to 34.5% and highresolution electron microscopy images reveal that all coatings have the characteristic of nanocrystals embedded in an amorphous matrix.The root-mean-square roughness of the coatings increases from 3.73 to 14.64 nm and the coefficients of friction of the coatings at room temperature vary from 0.54 to 0.73 with increasing nitrogen partial pressure.The microhardness of the coating increases up to 35.7 GPa at 10 sccm N2 flow rate.The smallest wear rate is 2.65 ×10^-15m^3N^-1m^-1 which indicates that TiBN coatings have excellent wear resistance.The adhesion test revealed that the TiBN coatings have good adhesion at low nitrogen partial pressure.展开更多
This paper proposes a simple scheme to generate a four-atom entangled cluster state in cavity quantum electrodynamics. With the assistantce of a strong classical field the cavity is only virtually excited and no quant...This paper proposes a simple scheme to generate a four-atom entangled cluster state in cavity quantum electrodynamics. With the assistantce of a strong classical field the cavity is only virtually excited and no quantum information will be transferred from the atoms to the cavity during the preparation for a four-atom entangled cluster state, and thus the scheme is insensitive to the cavity field states and cavity decay. Assuming that deviation of laser intensity is 0.01 and that of simultaneity for the interaction is 0.01, it shows that the fidelity of the resulting four-atom entangled cluster state is about 0.9886. The scheme can also be used to generate a four-ion entangled cluster state in a hot trapped-ion system. Assuming that deviation of laser intensity is 0.01, it shows that the fidelity of the resulting four-ion entangled cluster state is about 0.9990. Experimental feasibility for achieving this scheme is also discussed.展开更多
Optofluidics is a rising technology that combines microfluidics and optics.Its goal is to manipulate light and flowing liquids on the micro/nanoscale and exploiting their interaction in optofluidic chips.The fluid flo...Optofluidics is a rising technology that combines microfluidics and optics.Its goal is to manipulate light and flowing liquids on the micro/nanoscale and exploiting their interaction in optofluidic chips.The fluid flow in the on-chip devices is reconfigurable,non-uniform and usually transports substances being analyzed,offering a new idea in the accurate manipulation of lights and biochemical samples.In this paper,we summarized the light modulation in heterogeneous media by unique fluid dynamic properties such as molecular diffusion,heat conduction,centrifugation effect,light-matter interaction and others.By understanding the novel phenomena due to the interaction of light and flowing liquids,quantities of tunable and reconfigurable optofluidic devices such as waveguides,lenses,and lasers are introduced.Those novel applications bring us firm conviction that optofluidics would provide better solutions to high-efficient and high-quality lab-on-chip systems in terms of biochemical analysis and environment monitoring.展开更多
An ion beam analysis system was established on a 1.7 MV tandem accelerator, enabling Rutherford backscattering(RBS), elastic recoil detection(ERD), nuclear reaction analysis(NRA) and channeling measurements. The syste...An ion beam analysis system was established on a 1.7 MV tandem accelerator, enabling Rutherford backscattering(RBS), elastic recoil detection(ERD), nuclear reaction analysis(NRA) and channeling measurements. The system was tested by performing qualitative and quantitative analysis of Si, Ni/Si, Bi Fe O3:La/Si,Mo C/Mo/Si and Ti BN/Si samples. RBS of a Bi Fe O3:La film was used as system calibration. Tested by ion beam channeling, a Si(100) is of good crystallinity(χmin= 3.01%). For thin film samples, the measured thickness agrees well with simulation results by SIMNRA. In particular, composition of a Mo C/Mo/Si and Ti BN film samples were analyzed by RBS and non-Rutherford elastic backscattering.展开更多
CrTiAlN/TiAlN composite coatings were deposited on cemented carbide by using a home-made industrial scale multi-arc ion plating system. The samples were studied by X-ray diffraction, scanning electron microscopy （SEM...CrTiAlN/TiAlN composite coatings were deposited on cemented carbide by using a home-made industrial scale multi-arc ion plating system. The samples were studied by X-ray diffraction, scanning electron microscopy （SEM）, microhardness and ball-on-disk testing. The properties of the CrTiAlN/TiAlN coatings were significantly influenced by the microstructure and the deposition time ratio of TiAlN over CrTiAlN layers. With the increase of deposition time ratio, the microhardness of CrTiAlN/TiAlN increased from 28.6 GPa to 37.5 GPa, much higher than that of CrTiAlN coatings. The friction coefficients of the CrTiAlN/TiAlN coatings were higher than those of CrTiAlN coatings against a cemented carbide ball. The microhardness of the CrTiAlN/TiAlN coatings was changed after annealing at 800 ℃, and the friction coefficients of the annealed coatings were increased against the cemented carbide ball.展开更多
We investigate the effect of CH-doped and F-doped on dielectric properties of SiCOH films deposited by de- camethylcyclopentasiloxane （DMCPS） electron cyclotron resonance plasma. The dielectric constant k is closely...We investigate the effect of CH-doped and F-doped on dielectric properties of SiCOH films deposited by de- camethylcyclopentasiloxane （DMCPS） electron cyclotron resonance plasma. The dielectric constant k is closely related to the configurations of films. For the films deposited only using DMCPS, the minimum k is as low as 2.88. By adding CH4 in the precursor, the k value can be reduced to 2.45 due to the film density decreasing by incorporating large size CHx groups. By adding CHF3 in the precursor, the k value can also be reduced to 2.48 due to the incorporation of the weak-polarization F atom. Thus the dielectric constant for SiCOH films depends on not only the film density but also the polarization of atoms. By increasing the film density or by reducing the polarization of atoms under the condition of a lower film density, the low dielectric constant SiCOH films can be obtained.展开更多
We investigate the ground-state phases and spin textures of spin-orbit-coupled dipolar pseudo-spin-1/2 Bose-Einstein condensates in a rotating two-dimensional toroidal potential.The combined effects of dipole-dipole i...We investigate the ground-state phases and spin textures of spin-orbit-coupled dipolar pseudo-spin-1/2 Bose-Einstein condensates in a rotating two-dimensional toroidal potential.The combined effects of dipole-dipole interaction(DDI),spin-orbit coupling(SOC),rotation,and interatomic interactions on the ground-state structures and topological defects of the system are analyzed systematically.For fixed SOC strength and rotation frequency,we provide a set of phase diagrams as a function of the DDI strength and the ratio between inter-and intra-species interactions.The system can show rich quantum phases including a half-quantum vortex,symmetrical(asymmetrical)phase with quantum droplets(QDs),asymmetrical segregated phase with hidden vortices(ASH phase),annular condensates with giant vortices,triangular(square)vortex lattice with QDs,and criss-cross vortex string lattice,depending on the competition between DDI and contact interaction.For given DDI strength and rotation frequency,the increase of the SOC strength leads to a structural phase transition from an ASH phase to a tetragonal vortex lattice then to a pentagonal vortex lattice and finally to a vortex necklace,which is also demonstrated by the momentum distributions.Without rotation,the interplay of DDI and SOC may result in the formation of a unique trumpet-shaped Bloch domain wall.In addition,the rotation effect is discussed.Furthermore,the system supports exotic topological excitations,such as a half-skyrmion(meron)string,triangular skyrmion lattice,skyrmion-halfskyrmion lattice,skyrmion-meron cluster,skyrmion-meron layered necklace,skyrmion-giant-skyrmion necklace lattice,and half-skyrmion-half-antiskyrmion necklace.展开更多
Micrometer-scale gold nanoplates have been synthesized in high yield through a polyol process.The morphology,crystal structure and linear optical extinction of the gold nanoplates have been characterized.These gold na...Micrometer-scale gold nanoplates have been synthesized in high yield through a polyol process.The morphology,crystal structure and linear optical extinction of the gold nanoplates have been characterized.These gold nanoplates are single-crystalline with triangular,truncated triangular and hexagonal shapes,exhibiting strong surface plasmon resonance(SPR)extinction in the visible and near-infrared(NIR)region.The linear optical properties of gold nanoplates are also investigated by theoretical calculations.We further investigate the nonlinear optical properties of the gold nanoplates in solution by Z-scan technique.The nonlinear absorption(NLA)coefficient and nonlinear refraction(NLR)index are measured to be 1.18×10^(2)cm/GW and-1.04×10^(-3)cm^(2)/GW,respectively.展开更多
In this work, BaWO4 nanospheres were successfully prepared by hydrothermal process. The bipolar resistive switching behavior of Ag/BaWO4/FTO device is observed. Moreover, this resistive switching behavior can be modul...In this work, BaWO4 nanospheres were successfully prepared by hydrothermal process. The bipolar resistive switching behavior of Ag/BaWO4/FTO device is observed. Moreover, this resistive switching behavior can be modulated by white light. The device can maintain superior stability in the dark and under white-light illumination. This study is useful for developing the light-controlled nonvolatile memory devices.展开更多
To investigate the coercivity,corrosion resistance,and thermal stability of Nd-Fe-B magnets,their properties were investigated at room and high temperature before and after doping with Dy（80）Ga（20）（at.%） powder....To investigate the coercivity,corrosion resistance,and thermal stability of Nd-Fe-B magnets,their properties were investigated at room and high temperature before and after doping with Dy（80）Ga（20）（at.%） powder.The coercivity of the magnets increased from the undoped value of 12.72 kOe to a doped value of 21.44 kOe.A micro-structural analysis indicates that a well-developed core-shell structure forms in the magnets doped with Dy（80）Ga（20） powder.The improvement in magnetic properties is believed to be related to the refined and uniform matrix grains,continuous grain boundaries,and a hardened（Nd,Dy）2Fe（14）B shell surrounding the matrix grains.Additionally,the doped magnets exhibit an obvious improvement in thermal stability.For the magnets with added Dy（80）Ga（20） powder,the temperature coefficients of remanence（α） and coercivity（β） increased to-0.106%℃-（-1） and-0.60%℃-（-1） over the range 20-100 ℃,compared to temperature coefficients of-0.117%℃-（-1）（α） and-0.74%℃-（-1）（β） in the regular magnets without Dy（80）Ga（20） powder.The irreversible loss of magnetic flux（Hirr） was investigated at different temperatures.After being exposed to 150 ℃ for 2 h,the Hirr of magnets with 4 wt.%Dy（80）Ga（20） decreased by -95%compared to that of the undoped magnets.The enhanced temperature coefficients and Hirr indicate improved thermal stability in the doped Nd-Fe-B magnets.The intergranular addition of Dy（80）Ga（20） also improved the corrosion resistance of the magnets because of the enhanced intergranular phase.In a corrosive atmosphere for 96 h,the mass loss of the sintered magnets with 4 wt.%Dy（80）Ga（20） was 2.68 mg/cm-2,less than 10%of that suffered by the undoped magnets（28.1 mg/cm-2）.展开更多
Effect of low-frequency power on F, CF2 relative density and F/CF2 ratio, in C2F6, C4F8 and CHF3 dual-frequency capacitively couple discharge driven by the power of 13.56 MHz/2 MHz, was investigated by using optical e...Effect of low-frequency power on F, CF2 relative density and F/CF2 ratio, in C2F6, C4F8 and CHF3 dual-frequency capacitively couple discharge driven by the power of 13.56 MHz/2 MHz, was investigated by using optical emission spectroscopy. High F, CF2 relative density and high F/CF2 ratio were obtained in a CHF3 plasma. But for C2F6 and C4Fs plasmas, the F, CF2 relative density and F/CF2 ratio all decreased significantly due to the difference in both reactive paths and reactive energy. The increase of LF power caused simultaneous increase of F and CF2 radical relative densities in C4Fs and CHF3 plasmas, but led to increase of F with the decrease in CF2 relative densities in C2F6 plasma due to the increase of lower energy electrons and the decrease of higher energy electrons in electron energy distribution function （EEDF）.展开更多
We investigate the temporal evolution of the current pulses from an ac Fie cold plasma jet at atmospheric pressure and with driving frequency in the range 14.76-15.30 kHz. The driving frequency is used as the plasma s...We investigate the temporal evolution of the current pulses from an ac Fie cold plasma jet at atmospheric pressure and with driving frequency in the range 14.76-15.30 kHz. The driving frequency is used as the plasma system＇s bifurcation parameter in analogy with the evolution in which the current pulses undergoes multiplication and chaos. Such time-domain nonlineaxity is important for controlling instabilities in atmospheric glow discharges. In addition, the observation can provide some data to support the simulation results reported previously [Appl. Phys. Lett. 90 （2007） 071501].展开更多
基金funded by the National Natural Science Foundation of China(Grant No.12404507)the Natural Science Research of Jiangsu Higher Education Institutions of China(Grant No.24KJB140013)the Scientific Startup Foundation of Nanjing Normal University(Grant No.184080H201B49).
文摘This paper presents an analogical study between electromagnetic and elastic wave fields,with a one-to-one correspondence principle established regarding the basic wave equations,the physical quantities and the differential operations.Using the electromagnetic-to-elastic substitution,the analogous relations of the conservation laws of energy and momentum are investigated between these two physical fields.Moreover,the energy-based and momentum-based reciprocity theorems for an elastic wave are also derived in the time-harmonic state,which describe the interaction between two elastic wave systems from the perspectives of energy and momentum,respectively.The theoretical results obtained in this analysis can not only improve our understanding of the similarities of these two linear systems,but also find potential applications in relevant fields such as medical imaging,non-destructive evaluation,acoustic microscopy,seismology and exploratory geophysics.
基金financially supported by the National Nature Science Foundation of Jiangsu Province(BK20221259)。
文摘Transition metal sulfides have high theoretical capacities and are considered as potential anode materials for sodium-ion batteries.However,due to low inherent conductivity and significant volume expansion,the electrochemical performance is greatly limited.In this study,a nickel/manganese sulfide material(Ni_(0.96)S_(x)/MnS_(y)-NC)with adjustable sulfur vacancies and heterogeneous hollow spheres was prepared using a simple method.The introduction of a concentration-adjustable sulfur vacancy enables the generation of a heterogeneous interface between bimetallic sulfide and sulfur vacancies.This interface collectively creates an internal electric field,improving the mobility of electrons and ions,increasing the number of electrochemically active sites,and further optimizing the performance of Na~+storage.The direction of electron flow is confirmed by Density functional theory(DFT)calculations.The hollow nano-spherical material provides a buffer for expansion,facilitating rapid transfer kinetics.Our innovative discovery involves the interaction between the ether-based electrolyte and copper foil,leading to the formation of Cu_9S_5,which grafts the active material and copper current collector,reinforcing mechanical supporting.This results in a new heterostructure of Cu_9S_5 with Ni_(0.96)S_(x)/MnS_(y),contributing to the stabilization of structural integrity for long-cycle performance.Therefore,Ni_(0.96)S_(x)/MnS_(y)-NC exhibits excellent electrochemical properties following our modification route.Regarding stability performance,Ni0_(.96)S_(x)/MnS_(y)-NC demonstrates an average decay rate of 0.00944%after 10,000 cycles at an extremely high current density of 10000 mA g^(-1),A full cell with a high capacity of 304.2 mA h g^(-1)was also successfully assembled by using Na_(3)V_(2)(PO_(4))_(3)/C as the cathode.This study explores a novel strategy for interface/vacancy co-modification in the fabrication of high-performance sodium-ion batteries electrode.
基金Project supported by the Natural Science Foundation of Shandong Province,China(Grant No.ZR2020MA070).
文摘By using one-dimensional tight-binding model modified to include electron-electric field interaction and electron-electron interaction,we theoretically explore the polarization process of exciton and biexciton in cis-polyacetylene.The dynamical simulation is performed by adopting the non-adiabatic evolution approach.The results show that under the effect of moderate electric field,when the strength of electron-electron interaction is weak,the singlet exciton is stable but its polarization presents obvious oscillation.With the enhancement of interaction,it is dissociated into polaron pairs,the spin-flip of which can be observed through modulating the interaction strength.For the triplet exciton,the strong electron-electron interaction restrains its normal polarization,but it is still stable.In the case of biexciton,the strong electron-electron interaction not only dissociate it,but also flip its charge distribution.The yield of the possible states formed after the dissociation of exciton and biexciton is also calculated.
基金the financial support from the National Natural Science Foundation of China, China (22005207, 52261160384)the Guangdong Basic and Applied Basic Research Foundation, Guangdong Province, China (2019A1515011819)+2 种基金the Outstanding Youth Basic Research Project of Shenzhen, Shenzhen, China (RCYX20221008092934093)the Joint Funds of the National Natural Science Foundation of China, China (U22A20140)the Science and Technology Development Fund, Macao SAR (0090/2021/A2 and 0049/2021/AGJ)
文摘Magnesium ion batteries(MIBs)are a potential field for the energy storage of the future but are restricted by insufficient rate capability and rapid capacity degradation.Magnesium-sodium hybrid ion batteries(MSHBs)are an effective way to address these problems.Here,we report a new type of MSHBs that use layered sodium vanadate((Na,Mn)V_(8)O_(20)·5H_(2)O,Mn-NVO)cathodes coupled with an organic 3,4,9,10-perylenetetracarboxylic diimide(PTCDI)anode in Mg^(2+)/Na^(+)hybrid electrolytes.During electrochemical cycling,Mg^(2+)and Na^(+)co-participate in the cathode reactions,and the introduction of Na^(+)promotes the structural stability of the Mn-NVO cathode,as cleared by several ex-situ characterizations.Consequently,the Mn-NVO cathode presents great specific capacity(249.9 mA h g^(−1)at 300 mA g^(−1))and cycling(1500 cycles at 1500 mA g^(−1))in the Mg^(2+)/Na^(+)hybrid electrolytes.Besides,full battery displays long lifespan with 10,000 cycles at 1000 mA g^(−1).The rate performance and cycling stability of MSHBs have been improved by an economical and scalable method,and the mechanism for these improvements is discussed.
基金financially supported by the National Natural Science Foundation of China(52330004)the Fundamental Research Funds for the Central Universities(WUT:2023IVA075 and 2023IVB009)+3 种基金the financial support from RISE project Grant(Q-CDBK)Start-up Fund for RAPs under the Strategic Hiring Scheme(PoluU)(1-BD1H)PRI Strategic Grant(1-CD7X)RI-iWEAR Strategic Supporting Scheme(1-CD94)。
文摘Wide-bandgap(WBG)perovskite solar cells(PSCs)play a fundamental role in perovskite-based tandem solar cells.However,the efficiency of WBG PSCs is limited by significant open-circuit voltage losses,which are primarily caused by surface defects.In this study,we present a novel method for modifying surfaces using the multifunctional S-ethylisothiourea hydrobromide(SEBr),which can passivate both Pb^(-1)and FA^(-1)terminated surfaces,Moreover,the SEBr upshifted the Fermi level at the perovskite interface,thereby promoting carrier collection.This proposed method was effective for both 1.67 and 1.77 eV WBG PSCs,achieving power conversion efficiencies(PCEs)of 22.47%and 19.90%,respectively,with V_(OC)values of 1.28 and 1.33 V,along with improved film and device stability.With this advancement,we were able to fabricate monolithic all-perovskite tandem solar cells with a champion PCE of 27.10%,This research offers valuable insights for passivating the surface trap states of WBG perovskite through rational multifunctional molecular engineering.
基金supported by the Research Start-Up Funding Project of Nanjing Normal Universitythe National Natural Science Foundation of China(Grant Nos.12075123 and 12061141002)the National Science Research and Development Program of China(Grant No.2023YFA1605804)。
文摘Discovery of the X(3872)meson in 2003 ignited intense interest in exotic(neither qq nor qqq)hadrons,but a cc interpretation of this state was difficult to exclude.An unequivocal exotic was discovered in the Z_(c)(3900)^(+)meson—a charged charmonium-like state.A variety of models of exotic structure have been advanced but consensus is elusive.The grand lesson from heavy quarkonia was that heavy quarks bring clarity.Thus,the recently reported triplet of all-charm tetraquark candidates—X(6600),X(6900),and X(7100)—decaying to J/ψJ/ψ is a great boon,promising important insights.We review some history of exotics,chronicle the road to prospective all-charm tetraquarks,discuss in some detail the divergent modeling of J/ψJ/ψ structures,and offer some inferences about them.These states form a Regge trajectory and appear to be a family of radial excitations.A reported,but unexplained,threshold excess could hint at a fourth family member.We close with a brief look at a step beyond:all-bottom tetraquarks.
基金supported by the Special Fund for the Development of Strategic Emerging Industries of Shenzhen City of China(No.JCYJ20140419141154246)the National Nature Science Foundation of China(No.11174227)Chinese Universities Scientific Fund
文摘A kind of sandwich-like NiCo_2O_4/rGO/NiO heterostructure composite has been successfully anchored on nickel foam substrate via a three-step hydrothermal method with successive annealing treatment. The smart combination of NiCo_2O_4, reduced graphene oxide(rGO), and NiO nanostructure in the sandwich-like nano architecture shows a promising synergistic effect for supercapacitors with greatly enhanced electrochemical performance. For serving as supercapacitor electrode, the NiCo_2O_4/rGO/NiO heterostructure materials exhibit remarkable specific capacitance of 2644 mF cm^(-2)at current density of 1 mA cm^(-2),and excellent capacitance retentions of 97.5% after 3000 cycles. It is expected that the present heterostructure will be a promising electrode material for high-performance supercapacitors.
基金Supported by the National Natural Science Foundation of China under Grant No 10275025, and the Key Project of Education Bureau of Hubei Province under Grant No Z200612001.
文摘An approximate Fokker-Planck equation for the logistic growth model which is driven by coloured correlated noises is derived by applying the Novikov theorem and the Fox approximation. The steady-state probability distribution （SPD） and the mean of the tumour cell number are analysed. It is found that the SPD is the single extremum configuration when the degree of correlation between the multiplicative and additive noises, λ is in -1 〈λ≤0 and can be the double extrema in 0〈λ〈1. A configuration transition occurs because of the variation of noise parameters. A minimum appears in the curve of the mean of the steady-state tumour cell number, （x）, versus λ The position and the value of the minimum are controlled by the noise-correlated times.
基金supported by National Natural Science Foundation of China under grant 11375135International Cooperation Program of the Ministry of Science and Technology under grant 2015DFR00720
文摘TiBN coatings have huge potential applications as they have excellent properties with increasing modem industrial requirements.Nanocomposite TiBN coatings were synthesized on cemented carbide,high speed steel and Si substrates by using cathodic arc plasma ion plating from pure TiB2 ceramic targets.The structure and mechanical properties of the TiBN coatings were significantly influenced by the nitrogen partial pressure.Rutherford backscattering spectrometry demonstrates that the nitrogen content of the coating varied from 2.8% to 34.5% and highresolution electron microscopy images reveal that all coatings have the characteristic of nanocrystals embedded in an amorphous matrix.The root-mean-square roughness of the coatings increases from 3.73 to 14.64 nm and the coefficients of friction of the coatings at room temperature vary from 0.54 to 0.73 with increasing nitrogen partial pressure.The microhardness of the coating increases up to 35.7 GPa at 10 sccm N2 flow rate.The smallest wear rate is 2.65 ×10^-15m^3N^-1m^-1 which indicates that TiBN coatings have excellent wear resistance.The adhesion test revealed that the TiBN coatings have good adhesion at low nitrogen partial pressure.
基金Project supported by the Postdoctal Foundation of Central South University of Chinathe Important Program of Hunan Provincial Education Department of China (Grant No. 06A038)+1 种基金Department of Education of Hunan Province of China (Grant No. 06C080)Hunan Provincial Natural Science Foundation,China (Grant No. 07JJ3013)
文摘This paper proposes a simple scheme to generate a four-atom entangled cluster state in cavity quantum electrodynamics. With the assistantce of a strong classical field the cavity is only virtually excited and no quantum information will be transferred from the atoms to the cavity during the preparation for a four-atom entangled cluster state, and thus the scheme is insensitive to the cavity field states and cavity decay. Assuming that deviation of laser intensity is 0.01 and that of simultaneity for the interaction is 0.01, it shows that the fidelity of the resulting four-atom entangled cluster state is about 0.9886. The scheme can also be used to generate a four-ion entangled cluster state in a hot trapped-ion system. Assuming that deviation of laser intensity is 0.01, it shows that the fidelity of the resulting four-ion entangled cluster state is about 0.9990. Experimental feasibility for achieving this scheme is also discussed.
基金This work is financially supported by National Natural Science Foundation of China(No.11774274)National Key R&D Program of China(2018YFC1003200)+1 种基金Open Financial Grant from Qingdao National Laboratory for Marine Science and Technology(No.QNLM2016ORP0410)Foundation Research Fund of Shenzhen Science and Technology Program(No.JCYJ20170818112939064).
文摘Optofluidics is a rising technology that combines microfluidics and optics.Its goal is to manipulate light and flowing liquids on the micro/nanoscale and exploiting their interaction in optofluidic chips.The fluid flow in the on-chip devices is reconfigurable,non-uniform and usually transports substances being analyzed,offering a new idea in the accurate manipulation of lights and biochemical samples.In this paper,we summarized the light modulation in heterogeneous media by unique fluid dynamic properties such as molecular diffusion,heat conduction,centrifugation effect,light-matter interaction and others.By understanding the novel phenomena due to the interaction of light and flowing liquids,quantities of tunable and reconfigurable optofluidic devices such as waveguides,lenses,and lasers are introduced.Those novel applications bring us firm conviction that optofluidics would provide better solutions to high-efficient and high-quality lab-on-chip systems in terms of biochemical analysis and environment monitoring.
基金Supported by the National Natural Science Foundation of China(No.11405117)the State Key Lab of Advanced Welding and Joining of Harbin Institute of Technology(No.AWJ-M13-03)
文摘An ion beam analysis system was established on a 1.7 MV tandem accelerator, enabling Rutherford backscattering(RBS), elastic recoil detection(ERD), nuclear reaction analysis(NRA) and channeling measurements. The system was tested by performing qualitative and quantitative analysis of Si, Ni/Si, Bi Fe O3:La/Si,Mo C/Mo/Si and Ti BN/Si samples. RBS of a Bi Fe O3:La film was used as system calibration. Tested by ion beam channeling, a Si(100) is of good crystallinity(χmin= 3.01%). For thin film samples, the measured thickness agrees well with simulation results by SIMNRA. In particular, composition of a Mo C/Mo/Si and Ti BN film samples were analyzed by RBS and non-Rutherford elastic backscattering.
基金supported by the International Cooperation Program of the Ministry of Science and Technology of China(No.2011DFR50580)Basic Research Funds of the Central Universities of China(No.2012202020217)
文摘CrTiAlN/TiAlN composite coatings were deposited on cemented carbide by using a home-made industrial scale multi-arc ion plating system. The samples were studied by X-ray diffraction, scanning electron microscopy （SEM）, microhardness and ball-on-disk testing. The properties of the CrTiAlN/TiAlN coatings were significantly influenced by the microstructure and the deposition time ratio of TiAlN over CrTiAlN layers. With the increase of deposition time ratio, the microhardness of CrTiAlN/TiAlN increased from 28.6 GPa to 37.5 GPa, much higher than that of CrTiAlN coatings. The friction coefficients of the CrTiAlN/TiAlN coatings were higher than those of CrTiAlN coatings against a cemented carbide ball. The microhardness of the CrTiAlN/TiAlN coatings was changed after annealing at 800 ℃, and the friction coefficients of the annealed coatings were increased against the cemented carbide ball.
文摘We investigate the effect of CH-doped and F-doped on dielectric properties of SiCOH films deposited by de- camethylcyclopentasiloxane （DMCPS） electron cyclotron resonance plasma. The dielectric constant k is closely related to the configurations of films. For the films deposited only using DMCPS, the minimum k is as low as 2.88. By adding CH4 in the precursor, the k value can be reduced to 2.45 due to the film density decreasing by incorporating large size CHx groups. By adding CHF3 in the precursor, the k value can also be reduced to 2.48 due to the incorporation of the weak-polarization F atom. Thus the dielectric constant for SiCOH films depends on not only the film density but also the polarization of atoms. By increasing the film density or by reducing the polarization of atoms under the condition of a lower film density, the low dielectric constant SiCOH films can be obtained.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11475144 and 11047033)the Natural Science Foundation of Hebei Province,China(Grant Nos.A2019203049 and A2015203037)+2 种基金the University Science and Technology Foundation of Hebei Provincial Department of Education,China(Grant No.Z2017056)Science and Technology Plan Projects of Tangshan City,China(Grant No.19130220g)Research Foundation of Yanshan University,China(Grant No.B846).
文摘We investigate the ground-state phases and spin textures of spin-orbit-coupled dipolar pseudo-spin-1/2 Bose-Einstein condensates in a rotating two-dimensional toroidal potential.The combined effects of dipole-dipole interaction(DDI),spin-orbit coupling(SOC),rotation,and interatomic interactions on the ground-state structures and topological defects of the system are analyzed systematically.For fixed SOC strength and rotation frequency,we provide a set of phase diagrams as a function of the DDI strength and the ratio between inter-and intra-species interactions.The system can show rich quantum phases including a half-quantum vortex,symmetrical(asymmetrical)phase with quantum droplets(QDs),asymmetrical segregated phase with hidden vortices(ASH phase),annular condensates with giant vortices,triangular(square)vortex lattice with QDs,and criss-cross vortex string lattice,depending on the competition between DDI and contact interaction.For given DDI strength and rotation frequency,the increase of the SOC strength leads to a structural phase transition from an ASH phase to a tetragonal vortex lattice then to a pentagonal vortex lattice and finally to a vortex necklace,which is also demonstrated by the momentum distributions.Without rotation,the interplay of DDI and SOC may result in the formation of a unique trumpet-shaped Bloch domain wall.In addition,the rotation effect is discussed.Furthermore,the system supports exotic topological excitations,such as a half-skyrmion(meron)string,triangular skyrmion lattice,skyrmion-halfskyrmion lattice,skyrmion-meron cluster,skyrmion-meron layered necklace,skyrmion-giant-skyrmion necklace lattice,and half-skyrmion-half-antiskyrmion necklace.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61008043 and 10874134the National Program on Key Science Research(No 2007CB935300)the Fundamental Research Funds for the Central Universities(Nos 1101024 and 20102020101000025).
文摘Micrometer-scale gold nanoplates have been synthesized in high yield through a polyol process.The morphology,crystal structure and linear optical extinction of the gold nanoplates have been characterized.These gold nanoplates are single-crystalline with triangular,truncated triangular and hexagonal shapes,exhibiting strong surface plasmon resonance(SPR)extinction in the visible and near-infrared(NIR)region.The linear optical properties of gold nanoplates are also investigated by theoretical calculations.We further investigate the nonlinear optical properties of the gold nanoplates in solution by Z-scan technique.The nonlinear absorption(NLA)coefficient and nonlinear refraction(NLR)index are measured to be 1.18×10^(2)cm/GW and-1.04×10^(-3)cm^(2)/GW,respectively.
基金supported by the National Nature Science Foundation of China (Grant No. 51372209)
文摘In this work, BaWO4 nanospheres were successfully prepared by hydrothermal process. The bipolar resistive switching behavior of Ag/BaWO4/FTO device is observed. Moreover, this resistive switching behavior can be modulated by white light. The device can maintain superior stability in the dark and under white-light illumination. This study is useful for developing the light-controlled nonvolatile memory devices.
基金Project supported by the Ministry of Science and Technology of China(Grant Nos.2014DFB50130 and 2011CB612304)the National Natural Science Foundation of China(Grant Nos.51172168 and 51072139)
文摘To investigate the coercivity,corrosion resistance,and thermal stability of Nd-Fe-B magnets,their properties were investigated at room and high temperature before and after doping with Dy（80）Ga（20）（at.%） powder.The coercivity of the magnets increased from the undoped value of 12.72 kOe to a doped value of 21.44 kOe.A micro-structural analysis indicates that a well-developed core-shell structure forms in the magnets doped with Dy（80）Ga（20） powder.The improvement in magnetic properties is believed to be related to the refined and uniform matrix grains,continuous grain boundaries,and a hardened（Nd,Dy）2Fe（14）B shell surrounding the matrix grains.Additionally,the doped magnets exhibit an obvious improvement in thermal stability.For the magnets with added Dy（80）Ga（20） powder,the temperature coefficients of remanence（α） and coercivity（β） increased to-0.106%℃-（-1） and-0.60%℃-（-1） over the range 20-100 ℃,compared to temperature coefficients of-0.117%℃-（-1）（α） and-0.74%℃-（-1）（β） in the regular magnets without Dy（80）Ga（20） powder.The irreversible loss of magnetic flux（Hirr） was investigated at different temperatures.After being exposed to 150 ℃ for 2 h,the Hirr of magnets with 4 wt.%Dy（80）Ga（20） decreased by -95%compared to that of the undoped magnets.The enhanced temperature coefficients and Hirr indicate improved thermal stability in the doped Nd-Fe-B magnets.The intergranular addition of Dy（80）Ga（20） also improved the corrosion resistance of the magnets because of the enhanced intergranular phase.In a corrosive atmosphere for 96 h,the mass loss of the sintered magnets with 4 wt.%Dy（80）Ga（20） was 2.68 mg/cm-2,less than 10%of that suffered by the undoped magnets（28.1 mg/cm-2）.
基金supported by National Natural Science Foundation of China (Nos.10975105, 10575074, 10635010)
文摘Effect of low-frequency power on F, CF2 relative density and F/CF2 ratio, in C2F6, C4F8 and CHF3 dual-frequency capacitively couple discharge driven by the power of 13.56 MHz/2 MHz, was investigated by using optical emission spectroscopy. High F, CF2 relative density and high F/CF2 ratio were obtained in a CHF3 plasma. But for C2F6 and C4Fs plasmas, the F, CF2 relative density and F/CF2 ratio all decreased significantly due to the difference in both reactive paths and reactive energy. The increase of LF power caused simultaneous increase of F and CF2 radical relative densities in C4Fs and CHF3 plasmas, but led to increase of F with the decrease in CF2 relative densities in C2F6 plasma due to the increase of lower energy electrons and the decrease of higher energy electrons in electron energy distribution function （EEDF）.
文摘We investigate the temporal evolution of the current pulses from an ac Fie cold plasma jet at atmospheric pressure and with driving frequency in the range 14.76-15.30 kHz. The driving frequency is used as the plasma system＇s bifurcation parameter in analogy with the evolution in which the current pulses undergoes multiplication and chaos. Such time-domain nonlineaxity is important for controlling instabilities in atmospheric glow discharges. In addition, the observation can provide some data to support the simulation results reported previously [Appl. Phys. Lett. 90 （2007） 071501].
