The well-known Yau＇s uniformization conjecture states that any complete noncompact Kahler manifold with positive bisectional curvature is bi-holomorphic to the Euclidean space. The conjecture for the case of maximal ...The well-known Yau＇s uniformization conjecture states that any complete noncompact Kahler manifold with positive bisectional curvature is bi-holomorphic to the Euclidean space. The conjecture for the case of maximal volume growth has been recently confirmed, by G. Liu in [23]. In the first part, we will give a survey on thc progress. In the second part, we will consider Yau＇s conjecture for manifolds with non-maximal volume growth. We will show that the finiteness of the first Chern number Cn1 is an essential condition to solve Yau＇s conjecture by using algebraic embedding method. Moreover, we prove that, under bounded curvature conditions, Cn1 is automatically finite provided that there exists a positive line bundle with finite Chern number. In particular, we obtain a partial answer to Yau＇s uniformization conjecture on Kahler manifolds with minimal volume growth.展开更多
In this article, we show that the universal covering of any complete normal Kähler space of constant holomorphic sectional curvature on the regular locus is exactly biholomorphic to one of the complex projective ...In this article, we show that the universal covering of any complete normal Kähler space of constant holomorphic sectional curvature on the regular locus is exactly biholomorphic to one of the complex projective space, the complex Euclidean space or the complex Euclidean ball. Moreover, we also prove that in a normal Stein space any bounded domain with complete Bergman metric of constant holomorphic sectional curvature on the regular locus is necessarily biholomorphic to the complex Euclidean ball, by which we generalize the classical Lu Qi-Keng uniformization theorem to the singular setting.展开更多
This paper deals with the global boundedness of a two-competing-species chemotaxis model with indirect signal production in a three-dimensional bounded domain.The current work extends prior results by ZHENG et al.(202...This paper deals with the global boundedness of a two-competing-species chemotaxis model with indirect signal production in a three-dimensional bounded domain.The current work extends prior results by ZHENG et al.(2022)who established global existence and boundedness of classical solution under the parameter constraintsµ_(1)µ_(2)a_(2)≥χ1(4+µ_(2)^(2)a _(2)^(2)),µ_(1)µ_(2)a_(1)≥χ2(4+µ_(1)^(2)a_(1)^( 2)).Our main contribution demonstrates that these technical conditions can be significantly relaxed toµ1≥5χ_(1),µ2≥5χ_(2),thereby expanding the admissible parameter space for solution boundedness.展开更多
The excimer laser has important applications in many fields. Because of its non-uniform intensity distribution there are some limits in applications. This paper introduces rotational lens array to improve intensity di...The excimer laser has important applications in many fields. Because of its non-uniform intensity distribution there are some limits in applications. This paper introduces rotational lens array to improve intensity distributions. The intensity variation is reduced to 1 percent by computer simulation.展开更多
The increasing pursuit of ultra-high resolution displays has driven the demand for thin film transistors(TFTs)with higher mobility,especially on flexible substrates.In this work,we developed indium tin oxide(ITO)TFTs ...The increasing pursuit of ultra-high resolution displays has driven the demand for thin film transistors(TFTs)with higher mobility,especially on flexible substrates.In this work,we developed indium tin oxide(ITO)TFTs on flexible substrates for the first time and achieved a remarkable average mobility of 39.1 cm^(2)·V^(-1)·s^(-1),via mass-production compatible processes uti-lizing SiO_(2)gate dielectric.Benefiting from the ultra-flat surface and extremely low coefficient of thermal expansion(CTE)of our PI substrate,the ITO TFTs exhibit excellent large-scale uniformity.Additionally,the TFTs generate minor variations of-5.5%and+0.45 V in mobility and threshold voltage under a bending radius of 7 mm,respectively.They stay fully functional even after a dynamic bending test up to 13000 cycles,observing no obvious degradation in mobility and threshold voltage.The reliable mechanical flexibility and robust bending durability demonstrate their great potential for ultra-high resolution flexible displays in the future.展开更多
Aqueous zinc-ion batteries have emerged as highly promising energy storage devices due to their high theoretical capacity,low cost,and high safety.However,they still suffer from dendrite growth and parasitic side reac...Aqueous zinc-ion batteries have emerged as highly promising energy storage devices due to their high theoretical capacity,low cost,and high safety.However,they still suffer from dendrite growth and parasitic side reactions caused by reactive aqueous electrolytes,which not only compromise reversibility but may also lead to internal short circuits,severely limiting practical applications.Herein,inulin(INU),a hydroxyl-rich polysaccharide,is proposed as a multifunctional electrolyte additive.Experimental and density functional theory calculations reveal that INU molecules effectively disrupt the original hydrogen-bond network,facilitating Zn^(2+)desolvation and rapid migration,thereby effectively resisting hydrogen evolution reaction,Zn corrosion,and by-products formation.Additionally,INU preferentially adsorbs on the Zn(002)crystal plane,forming a hydrophobic protective layer and guiding uniform Zn^(2+)deposition,thus inhibiting random dendritic growth.The presence of INU also effectively retards the dissolution process of V_(2)O_(5).As a result,the Zn‖Zn symmetric cell assembled with INU-3 electrolyte achieves an extended cycling life of 2400 h at a current density of 0.5 mA cm^(-2) and an areal capacity of0.5 mAh m^(-2).Furthermore,the Zn‖V_(2)O_(5) full cell exhibits a high capacity of 386.0 mAh g^(-1) at0.5 A g^(-1) and a high capacity retention of 55.26%at 8 A g^(-1).The full cell maintains remarkable capacity retention of 73%after 500 cycles at 1 A g^(-1) and 91%after 1000 cycles at 3 A g^(-1).This work inspires the study of electrolyte additives for aqueous zinc-ion batteries.展开更多
Based on the split hopkinson pressure bar(SHPB)tests results,the cubic specimens have been numerically modeled in this paper to investigate the impact of key factors,such as the rise time,duration,and incident pulse s...Based on the split hopkinson pressure bar(SHPB)tests results,the cubic specimens have been numerically modeled in this paper to investigate the impact of key factors,such as the rise time,duration,and incident pulse shape,on achieving stress uniformity.After analysis,the paper provides actionable methods aimed at optimizing the conditions for stress uniformity within the cubic specimen.Finally,the lateral inertia effect of cubic specimen has been scrutinized to address the existing gap in this academic area.展开更多
The goal of this paper is to investigate the long-time dynamics of solutions to a Kirchhoff type suspension bridge equation with nonlinear damping and memory term.For this problem we establish the well-posedness and e...The goal of this paper is to investigate the long-time dynamics of solutions to a Kirchhoff type suspension bridge equation with nonlinear damping and memory term.For this problem we establish the well-posedness and existence of uniform attractor under some suitable assumptions on the nonlinear term g(u),the nonlinear damping f(u_(t))and the external force h(x,t).Specifically,the asymptotic compactness of the semigroup is verified by the energy reconstruction method.展开更多
Laser-induced periodic surface structures(LIPSS)have gained increasing attention in the field of micro/nano fabrication,although achieving sub-100-nm period LIPSS with high uniformity remains a significant challenge.I...Laser-induced periodic surface structures(LIPSS)have gained increasing attention in the field of micro/nano fabrication,although achieving sub-100-nm period LIPSS with high uniformity remains a significant challenge.In this work,towards deep-subwavelength LIPSS on highly oriented pyrolytic graphite(HOPG),we demonstrate that ultra-uniform nanogratings of sub-50-nm periods and near-10-nm groove widths can be stably prepared via 800-nm femtosecond laser scanning irradiation with a high-NA objective lens under water immersion.The resulting nanogratings of strong polarization dependence,exhibiting exceptional surface flatness,period stability,and structural integrity,tend to appear at near-damage-threshold fluence regime with an appropriate effective pulse number.It turns out that the water immersion condition can significantly reduce the thermal effects of femtosecond laser ablation on HOPG,and thus via a mild,incubation-like scanning ablation process occurring in the nanogrooves with a continuous or jumping manner,this deep-subwavelength grating can achieve robust elongation growth,ensuring its long-range uniformity as well as minimal deposited debris and structural defects.Interestingly,the different incubation extension mechanisms for the mutually perpendicular and parallel settings between scanning direction and laser polarization bring not only distinct effective-pulse-number windows and somewhat different grating qualities,but also different extension stabilities in nanograting stitching via overlapping scanning lines and thus the optimal scanning strategy of parallel setting for large-area processing.In short,this study presents a convenient laser-processing approach for high precision fabrication of sub-50-nm gratings on HOPG,which would provide new insights into micro/nano-fabrication for optoelectronic metasurfaces and physics of the interaction between ultrafast laser and graphite.展开更多
The random distribution of one-dimensional nanofillers in composite polymer electrolytes(CPEs) typically results in tortuous ion transport pathways,severely limiting ionic conductivity and Li^(+) flux uniformity.Herei...The random distribution of one-dimensional nanofillers in composite polymer electrolytes(CPEs) typically results in tortuous ion transport pathways,severely limiting ionic conductivity and Li^(+) flux uniformity.Herein,an innovative electric field-assisted strategy is proposed to construct vertically aligned ion channels in CPEs using lithiated halloysite nano tubes(HNTs-SO_(3)Li)embedded within a polyurethane acrylate/polyethylene glycol diacrylate(PUA/PEGDA) matrix.Under an alternating electric field,the nanotubes orient perpendicularly,forming continuous,low-tortuosity pathways that significantly enhance roomtemperature ionic conductivity.The aligned structure not only shortens Li+transport distances but also homogenizes ion flux at the electrode interface,effectively suppressing lithium dendrite growth.Electrochemical characterization reveals exceptional stability.Three-dimensional structural reconstruction and ion transport simulations further demonstrate that the ordered channels promote uniform Li+distribution and faster ion kinetics compared to disordered systems.This study provides a scalable and efficient approach to designing high-performance CPEs for next-generation solid-state batteries,addressing critical challenges in ionic conductivity,interfacial stability,and dendrite suppression.展开更多
To address the challenges of complexity,power consumption,and cost constraints in traditional display driver integrated circuits(DDICs)caused by external NOR Flash and SRAM,this work proposes an embedded resistive ran...To address the challenges of complexity,power consumption,and cost constraints in traditional display driver integrated circuits(DDICs)caused by external NOR Flash and SRAM,this work proposes an embedded resistive random-access memory(RRAM)integration solution based on a 40 nm high-voltage CMOS logic platform.Targeting the yield fluctuations and stability challenges during RRAM mass production,systematic process optimizations are implemented to achieve synergistic improvements in RRAM performance and yield.Through modifications to the film sputtering and pre-deposition treatment,the withinwafer resistance uniformity(RSU)of the oxygen-deficient layer(ODL)thin film is improved from 11%to 8%,while inter-wafer process stability variation reduces from 23%to below 6%.Consequently,the yield of 8 Mb RRAM embedded mass production products increases from 87%to 98.5%.In terms of device performance,the RRAM demonstrates a fast 4.8 ns read speed,exceptional read disturb immunity of 3×10^(8) cycles at 95℃,10^(3) write/erase endurance cycles for the 1 Mb cells,and data retention of 12.5 years at 125℃.Post high-temperature operating life(HTOL)testing exhibits stable high/low resistance window.This study provides process optimization strategies and a reliability assurance framework for the mass production of highly integrated,low-power embedded RRAM display driver IC.展开更多
Rotating Single-Baseline Interferometer(RSBI)systems have attracted considerable attention for Direct Position Determination(DPD)due to their simplicity and high localization accuracy.Nevertheless,the growing complexi...Rotating Single-Baseline Interferometer(RSBI)systems have attracted considerable attention for Direct Position Determination(DPD)due to their simplicity and high localization accuracy.Nevertheless,the growing complexity of electromagnetic environments has led to scenarios with multiple time-frequency aliased sources,rendering conventional DPD methods for RSBI systems ineffective.Previous studies have predominantly concentrated on deploying antenna arrays and applying related signal-processing techniques for localization.Typically,these approaches necessitate that the number of physical antennas exceeds the number of sources.For RSBI systems already in practical operation,this would entail the installation of additional physical antennas,which implies equipment recycling and hardware upgrades.In numerous cases,such modifications are unfeasible.This paper proposes a novel Relative Offset-based Direct Position Determination(RO-DPD)method for RSBI systems that can handle multiple time-frequency aliased sources.The proposed method overcomes the challenge of simultaneous positioning without requiring hardware modifications by leveraging time accumulation and algorithmic enhancements.The implementation of the method involves three key steps.Firstly,the rotation of the interferometer is synthesized into a virtual Uniform Circular Array(UCA).Secondly,a novel estimation variable,termed relative offset,is introduced.The variable serves as an intermediate parameter to establish correlation equations between the positions of multiple time-frequency aliased sources and the intercepted signals.Thirdly,the relative offset model in the UCA is transformed into a virtual Uniform Linear Array(ULA)model,from which the cost function can be derived via the Spatial Smoothing(SS)MUSIC algorithm.Theoretical analysis and simulation results verify the effectiveness of the proposed method.Compared with traditional approaches,the RO-DPD method maintains the low complexity of RSBI systems while demonstrating robust performance in complex electromagnetic environments.展开更多
Improving plasma uniformity is a critical issue in the development of large-area radio-frequency(RF)inductively coupled plasma(ICP)sources.In this work,the effects of coil structure and electromagnetic shielding on th...Improving plasma uniformity is a critical issue in the development of large-area radio-frequency(RF)inductively coupled plasma(ICP)sources.In this work,the effects of coil structure and electromagnetic shielding on the spatial distribution and uniformity of the plasma are systematically investigated using a three-dimensional fluid model.The model integrates plasma and electromagnetic field modules to simulate the discharge characteristics of a large-area RF ICP source with dimensions of 100 cm×50 cm.The results reveal that the electron density distribution varies significantly with the coil structure.For the rotating and translating coil structures,the electron density is high at off-axis positions and low at the center.In contrast,the mirror coil structure exhibits a significantly higher electron density at the chamber center,resulting in a high-center and low-edge density distribution.Among the three configurations,the rotating coil structure provides the best plasma uniformity.The incorporation of electromagnetic shielding further improves plasma uniformity,particularly for the mirror coil structure.For the rotating and translating coil structures,the electron density exhibits a saddle-shaped distribution regardless of electromagnetic shielding.However,introducing electromagnetic shielding into the mirror coil structure reduces the electron density at the chamber center and decreases the non-uniformity degree by 18.4%.Overall,the mirror coil structure with electromagnetic shielding achieves the highest uniformity,with an exceptional plasma uniformity of 94%.This work offers valuable insights for the design of large-area ICP sources in advanced plasma processing systems.展开更多
Let n≥2 be a natural number,1≤p≤∞and X a Banach space.We prove that if X^(*)containsλ-uniformly copies of l^(k)^(p),then:P(^(n)X) contains cKλ^(n)-uniformly copies of■.in the case p^(*)>n(ii)P(^(n)X) contain...Let n≥2 be a natural number,1≤p≤∞and X a Banach space.We prove that if X^(*)containsλ-uniformly copies of l^(k)^(p),then:P(^(n)X) contains cKλ^(n)-uniformly copies of■.in the case p^(*)>n(ii)P(^(n)X) containsλ^(n)-uniformly copies of l^(k)_(∞)in the case p^(*)≤n.This complete a result of S.Dineen’s from 1995.展开更多
Achieving uniform X-ray irradiation in indirect-drive inertial confinement fusion(ICF)is a key challenge for successful capsule implosion.Spherical hohlraums,particularly those with octahedral laser entrance holes(LEH...Achieving uniform X-ray irradiation in indirect-drive inertial confinement fusion(ICF)is a key challenge for successful capsule implosion.Spherical hohlraums,particularly those with octahedral laser entrance holes(LEHs),are an alternative to the cylindrical hohlraums currently considered for ICF at NIF(USA)and LMJ(France).These spherical hohlraums are advantageous in terms of irradiation uniformity on the fusion capsule because,owing to their octahedral symmetry,low-order asymmetries cancel out intrinsically.However,they may be less favorable from an energetic point of view,primarily owing to radiation losses through their multiple LEHs.The net balance of these advantages and disadvantages is difficult to determine,because,unlike cylindrical hohlraums,they require fully 3D modeling.To address this,a new version of the MULTI-3D simulation code has been developed.MULTI-3D is a 3D radiation-hydrodynamics code with arbitrary Langrangian-Eulerian(ALE)hydrodynamics,multigroup SN radiation transport,and ray-tracing laser deposition.Using this tool,several aspects of the behavior of spherical hohlraums have been analyzed,with special attention to phenomena inaccessible to 2D modeling.In these targets,laser beams strike the inner walls at very oblique angles,and the expansion of plasma significantly alters the locations where primary X rays are produced.Furthermore,the complex distribution of laser hot spots leads to mutual interactions,where plasma bubbles from one beam intersect the path of another.The laser-to-X-ray energy conversion efficiency has been analyzed as a function of key parameters.The symmetry on the capsule has also been evaluated,revealing nonuniformities of less than 1%.展开更多
The(010)orientation ofβ-Ga_(2)O_(3)is a highly promising platform for next-generation lateral power electronics due to its superior theoretical transport properties.However,progress has been impeded by the unavailabi...The(010)orientation ofβ-Ga_(2)O_(3)is a highly promising platform for next-generation lateral power electronics due to its superior theoretical transport properties.However,progress has been impeded by the unavailability of large-area substrates,limiting studies to small-scale samples.Leveraging the recent emergence of 2-inch wafers,we report the first demonstration of homoepitaxial growth on a 2-inch,Fe-doped semi-insulating(010)β-Ga_(2)O_(3)substrate by metal-organic chemical vapor deposition(MOCVD).A systematic,wafer-scale characterization reveals the successful growth of a highquality epitaxial film.High-resolution x-ray diffraction shows an excellent crystalline structure,with a rocking curve full-width ranging from 21.0 arcsec to 103.0 arcsec.Atomic force microscopy confirms an atomically smooth surface with a root-mean-square roughness below 1.53 nm,displaying a distinct step-flow growth mode across the wafer.Furthermore,mercury-probe capacitance-voltage mapping indicates a well-controlled carrier concentration of~2×10~(18)cm~(-3)with a RSD of 5.12%.This work provides the first comprehensive assessment of 2-inch(010)Ga_(2)O_(3)epitaxial wafers,validating a critical material platform for the development and future manufacturing of high-performance power devices.展开更多
Recently,uniform circular array(UCA)based orbital angular momentum(OAM)beam steering schemes have been proposed to overcome the limitations of coaxial transmission.Unlike the traditional multiple-input-multiple-output...Recently,uniform circular array(UCA)based orbital angular momentum(OAM)beam steering schemes have been proposed to overcome the limitations of coaxial transmission.Unlike the traditional multiple-input-multiple-output(MIMO)beam steering,OAM beam steering includes both the OAM generation and the beam steering.Generally,the true time delay(TTD)or the phase shifter(PS)are required for beam steering in the radio domain.Previous studies suggest that TTD is preferred for wideband MIMO beam steering to avoid beam squint caused by PS.However,in this paper,we theoretically prove that to generate the OAM beam ideally,PS should be used,while TTD deteriorates the mode orthogonality,which is influenced by the relative bandwidth.Once the ideal OAM beam is generated,TTD is required to prevent beam squint.Based on this analysis,we propose to use the two-stage phase-shifting(TSPS)architecture for OAM beam steering:PS for OAM generation and TTD for beam steering.Simulation results suggest that compared to the spectrum efficiency(SE)of PS based OAM communication,the SE based on the TTD significantly declines as the relative bandwidth increases.Furthermore,OAM beam steering using the TSPS architecture greatly outperforms systems that adopt a single TTD or PS network.展开更多
The suppression of ablative Rayleigh–Taylor instability(ARTI)by a spatially modulated laser in inertial confinement fusion(ICF)is studied through numerical simulations.The results show that in the acceleration phase ...The suppression of ablative Rayleigh–Taylor instability(ARTI)by a spatially modulated laser in inertial confinement fusion(ICF)is studied through numerical simulations.The results show that in the acceleration phase of ICF implosion,the growth of ARTI can be suppressed by using a short-wavelength spatially modulated laser.The ARTI growth rate decreases as the wavelength of the spatially modulated laser decreases,and ARTI is completely suppressed after a certain wavelength has been reached.A spatially uniform laser is introduced to keep the state of motion of the implosion fluid consistent,and it is found that the proportion of the spatially modulated laser required for complete suppression of ARTI decreases as the wavelength continues to decrease.We also optimize the spatial intensity distribution of the spatially modulated laser.In addition,as the duration of the spatially modulated laser decreases,the proportion required for completely suppressing ARTI increases,but the required energy decreases.When the perturbation wavenumber decreases,the wavelength of the spatially modulated laser required for complete suppression of ARTI becomes longer.In the case of multimode perturbation,ARTI can also be significantly suppressed by a spatially modulated laser,and the perturbation amplitude can be reduced to less than 10% of that without a spatially modulated laser.We believe that the conclusions drawn from our simulations can provide the basis for new approaches to control ARTI in ICF.展开更多
Knowledge distillation aims to distill knowledge from teacher networks to train student networks.Distilling intermediate features has attracted much attention in recent years as it can beflexibly applied in variousfiel...Knowledge distillation aims to distill knowledge from teacher networks to train student networks.Distilling intermediate features has attracted much attention in recent years as it can beflexibly applied in variousfields such as image classification,object detection and semantic segmentation.A critical obstacle of feature-based knowledge distillation is the dimension gap between the intermediate features of teacher and student,and plenty of methods have been proposed to resolve this problem.However,these works usually implement feature uniformization in an unsupervised way,lacking guidance to help the student network learn meaningful mapping functions in the uniformization process.Moreover,the dimension uniformization process of the student and teacher network is usually not equivalent as the mapping functions are different.To this end,some factors of the feature are discarded during parametric feature alignment,or some factors are blended in some non-parametric operations.In this paper,we propose a novel semantic-aware knowledge distillation scheme to solve these problems.We build a standalone feature-based classification branch to extract semantic-aware knowledge for better guiding the learning process of the student network.In addition,to avoid the inequivalence of feature uniformization between teacher and student,we design a novel parameter-free self-attention operation that can convert features of different dimensions into vectors of the same length.Experimental results show that the proposed knowledge distillation scheme outperforms existing feature-based distillation methods on the widely used CIFAR-100 and CINIC-10 datasets.展开更多
For the fuzzy topological group (ftg) (Science Bulletin, 29(1984), 651—653), we introduce a new fuzzy uniformity (fu) which is different from L(?)wen’s sense.
文摘The well-known Yau＇s uniformization conjecture states that any complete noncompact Kahler manifold with positive bisectional curvature is bi-holomorphic to the Euclidean space. The conjecture for the case of maximal volume growth has been recently confirmed, by G. Liu in [23]. In the first part, we will give a survey on thc progress. In the second part, we will consider Yau＇s conjecture for manifolds with non-maximal volume growth. We will show that the finiteness of the first Chern number Cn1 is an essential condition to solve Yau＇s conjecture by using algebraic embedding method. Moreover, we prove that, under bounded curvature conditions, Cn1 is automatically finite provided that there exists a positive line bundle with finite Chern number. In particular, we obtain a partial answer to Yau＇s uniformization conjecture on Kahler manifolds with minimal volume growth.
基金supported by the National Key R&D Program of China(Grant No.2021YFA1002600)NSFC(Grant No.12201060)。
文摘In this article, we show that the universal covering of any complete normal Kähler space of constant holomorphic sectional curvature on the regular locus is exactly biholomorphic to one of the complex projective space, the complex Euclidean space or the complex Euclidean ball. Moreover, we also prove that in a normal Stein space any bounded domain with complete Bergman metric of constant holomorphic sectional curvature on the regular locus is necessarily biholomorphic to the complex Euclidean ball, by which we generalize the classical Lu Qi-Keng uniformization theorem to the singular setting.
基金Supported by the National Natural Science Foundation of China(12301631)the Natural Science Foundation of Qinghai Province(2023-ZJ-949Q)。
文摘This paper deals with the global boundedness of a two-competing-species chemotaxis model with indirect signal production in a three-dimensional bounded domain.The current work extends prior results by ZHENG et al.(2022)who established global existence and boundedness of classical solution under the parameter constraintsµ_(1)µ_(2)a_(2)≥χ1(4+µ_(2)^(2)a _(2)^(2)),µ_(1)µ_(2)a_(1)≥χ2(4+µ_(1)^(2)a_(1)^( 2)).Our main contribution demonstrates that these technical conditions can be significantly relaxed toµ1≥5χ_(1),µ2≥5χ_(2),thereby expanding the admissible parameter space for solution boundedness.
文摘The excimer laser has important applications in many fields. Because of its non-uniform intensity distribution there are some limits in applications. This paper introduces rotational lens array to improve intensity distributions. The intensity variation is reduced to 1 percent by computer simulation.
基金supported in part by the National Natural Science Foundation of China(62274033)Natural Science Foundation of Jiangsu Province(BK20221453)Fundamental Research Funds for the Central Universities.
文摘The increasing pursuit of ultra-high resolution displays has driven the demand for thin film transistors(TFTs)with higher mobility,especially on flexible substrates.In this work,we developed indium tin oxide(ITO)TFTs on flexible substrates for the first time and achieved a remarkable average mobility of 39.1 cm^(2)·V^(-1)·s^(-1),via mass-production compatible processes uti-lizing SiO_(2)gate dielectric.Benefiting from the ultra-flat surface and extremely low coefficient of thermal expansion(CTE)of our PI substrate,the ITO TFTs exhibit excellent large-scale uniformity.Additionally,the TFTs generate minor variations of-5.5%and+0.45 V in mobility and threshold voltage under a bending radius of 7 mm,respectively.They stay fully functional even after a dynamic bending test up to 13000 cycles,observing no obvious degradation in mobility and threshold voltage.The reliable mechanical flexibility and robust bending durability demonstrate their great potential for ultra-high resolution flexible displays in the future.
基金the financial support by the National Natural Science Foundation of China(No.52573221,U2330124,U20A2072,52072352,21875226)the Foundation for the Youth S&T Innovation Team of Sichuan Province(2020JDTD0035)+1 种基金the Scientific Research Funds for Central Universities(ZYGX2025XJ016)the Sichuan Science and Technology Program(2023ZYD0026)。
文摘Aqueous zinc-ion batteries have emerged as highly promising energy storage devices due to their high theoretical capacity,low cost,and high safety.However,they still suffer from dendrite growth and parasitic side reactions caused by reactive aqueous electrolytes,which not only compromise reversibility but may also lead to internal short circuits,severely limiting practical applications.Herein,inulin(INU),a hydroxyl-rich polysaccharide,is proposed as a multifunctional electrolyte additive.Experimental and density functional theory calculations reveal that INU molecules effectively disrupt the original hydrogen-bond network,facilitating Zn^(2+)desolvation and rapid migration,thereby effectively resisting hydrogen evolution reaction,Zn corrosion,and by-products formation.Additionally,INU preferentially adsorbs on the Zn(002)crystal plane,forming a hydrophobic protective layer and guiding uniform Zn^(2+)deposition,thus inhibiting random dendritic growth.The presence of INU also effectively retards the dissolution process of V_(2)O_(5).As a result,the Zn‖Zn symmetric cell assembled with INU-3 electrolyte achieves an extended cycling life of 2400 h at a current density of 0.5 mA cm^(-2) and an areal capacity of0.5 mAh m^(-2).Furthermore,the Zn‖V_(2)O_(5) full cell exhibits a high capacity of 386.0 mAh g^(-1) at0.5 A g^(-1) and a high capacity retention of 55.26%at 8 A g^(-1).The full cell maintains remarkable capacity retention of 73%after 500 cycles at 1 A g^(-1) and 91%after 1000 cycles at 3 A g^(-1).This work inspires the study of electrolyte additives for aqueous zinc-ion batteries.
基金Funded by the National Natural Science Foundation of China(Nos.52278518 and 51938011)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.24KJB560021)。
文摘Based on the split hopkinson pressure bar(SHPB)tests results,the cubic specimens have been numerically modeled in this paper to investigate the impact of key factors,such as the rise time,duration,and incident pulse shape,on achieving stress uniformity.After analysis,the paper provides actionable methods aimed at optimizing the conditions for stress uniformity within the cubic specimen.Finally,the lateral inertia effect of cubic specimen has been scrutinized to address the existing gap in this academic area.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11961059,1210502)the University Innovation Project of Gansu Province(Grant No.2023B-062)the Gansu Province Basic Research Innovation Group Project(Grant No.23JRRA684).
文摘The goal of this paper is to investigate the long-time dynamics of solutions to a Kirchhoff type suspension bridge equation with nonlinear damping and memory term.For this problem we establish the well-posedness and existence of uniform attractor under some suitable assumptions on the nonlinear term g(u),the nonlinear damping f(u_(t))and the external force h(x,t).Specifically,the asymptotic compactness of the semigroup is verified by the energy reconstruction method.
基金supported by grants from Natural Science Foundation of Guangdong Province(Grant No.2021A1515012335)National Natural Science Foundation of China(NSFC)(Grant No.11274400)+2 种基金Pearl River S&T Nova Program of Guangzhou(Grant No.201506010059)State Key Laboratory of Optoelectronic Materials and Technologies(Sun Yat-Sen University)(Grant No.OEMT-2024-ZTS-01)State Key Laboratory of High Field Laser Physics(Shanghai Institute of Optics and Fine Mechanics)。
文摘Laser-induced periodic surface structures(LIPSS)have gained increasing attention in the field of micro/nano fabrication,although achieving sub-100-nm period LIPSS with high uniformity remains a significant challenge.In this work,towards deep-subwavelength LIPSS on highly oriented pyrolytic graphite(HOPG),we demonstrate that ultra-uniform nanogratings of sub-50-nm periods and near-10-nm groove widths can be stably prepared via 800-nm femtosecond laser scanning irradiation with a high-NA objective lens under water immersion.The resulting nanogratings of strong polarization dependence,exhibiting exceptional surface flatness,period stability,and structural integrity,tend to appear at near-damage-threshold fluence regime with an appropriate effective pulse number.It turns out that the water immersion condition can significantly reduce the thermal effects of femtosecond laser ablation on HOPG,and thus via a mild,incubation-like scanning ablation process occurring in the nanogrooves with a continuous or jumping manner,this deep-subwavelength grating can achieve robust elongation growth,ensuring its long-range uniformity as well as minimal deposited debris and structural defects.Interestingly,the different incubation extension mechanisms for the mutually perpendicular and parallel settings between scanning direction and laser polarization bring not only distinct effective-pulse-number windows and somewhat different grating qualities,but also different extension stabilities in nanograting stitching via overlapping scanning lines and thus the optimal scanning strategy of parallel setting for large-area processing.In short,this study presents a convenient laser-processing approach for high precision fabrication of sub-50-nm gratings on HOPG,which would provide new insights into micro/nano-fabrication for optoelectronic metasurfaces and physics of the interaction between ultrafast laser and graphite.
基金the Program of National Key Research and Development of China (No.2022YFB3603702, No. 2023YFC3905301)Hubei Provincial Natural Science Foundation of China (No. 2025AFA025)the Research Fund of Jianghan University (No. 2023KJZX01)。
文摘The random distribution of one-dimensional nanofillers in composite polymer electrolytes(CPEs) typically results in tortuous ion transport pathways,severely limiting ionic conductivity and Li^(+) flux uniformity.Herein,an innovative electric field-assisted strategy is proposed to construct vertically aligned ion channels in CPEs using lithiated halloysite nano tubes(HNTs-SO_(3)Li)embedded within a polyurethane acrylate/polyethylene glycol diacrylate(PUA/PEGDA) matrix.Under an alternating electric field,the nanotubes orient perpendicularly,forming continuous,low-tortuosity pathways that significantly enhance roomtemperature ionic conductivity.The aligned structure not only shortens Li+transport distances but also homogenizes ion flux at the electrode interface,effectively suppressing lithium dendrite growth.Electrochemical characterization reveals exceptional stability.Three-dimensional structural reconstruction and ion transport simulations further demonstrate that the ordered channels promote uniform Li+distribution and faster ion kinetics compared to disordered systems.This study provides a scalable and efficient approach to designing high-performance CPEs for next-generation solid-state batteries,addressing critical challenges in ionic conductivity,interfacial stability,and dendrite suppression.
文摘To address the challenges of complexity,power consumption,and cost constraints in traditional display driver integrated circuits(DDICs)caused by external NOR Flash and SRAM,this work proposes an embedded resistive random-access memory(RRAM)integration solution based on a 40 nm high-voltage CMOS logic platform.Targeting the yield fluctuations and stability challenges during RRAM mass production,systematic process optimizations are implemented to achieve synergistic improvements in RRAM performance and yield.Through modifications to the film sputtering and pre-deposition treatment,the withinwafer resistance uniformity(RSU)of the oxygen-deficient layer(ODL)thin film is improved from 11%to 8%,while inter-wafer process stability variation reduces from 23%to below 6%.Consequently,the yield of 8 Mb RRAM embedded mass production products increases from 87%to 98.5%.In terms of device performance,the RRAM demonstrates a fast 4.8 ns read speed,exceptional read disturb immunity of 3×10^(8) cycles at 95℃,10^(3) write/erase endurance cycles for the 1 Mb cells,and data retention of 12.5 years at 125℃.Post high-temperature operating life(HTOL)testing exhibits stable high/low resistance window.This study provides process optimization strategies and a reliability assurance framework for the mass production of highly integrated,low-power embedded RRAM display driver IC.
基金partially supported by the National Natural Science Foundation of China(Nos.61901494,62101563)。
文摘Rotating Single-Baseline Interferometer(RSBI)systems have attracted considerable attention for Direct Position Determination(DPD)due to their simplicity and high localization accuracy.Nevertheless,the growing complexity of electromagnetic environments has led to scenarios with multiple time-frequency aliased sources,rendering conventional DPD methods for RSBI systems ineffective.Previous studies have predominantly concentrated on deploying antenna arrays and applying related signal-processing techniques for localization.Typically,these approaches necessitate that the number of physical antennas exceeds the number of sources.For RSBI systems already in practical operation,this would entail the installation of additional physical antennas,which implies equipment recycling and hardware upgrades.In numerous cases,such modifications are unfeasible.This paper proposes a novel Relative Offset-based Direct Position Determination(RO-DPD)method for RSBI systems that can handle multiple time-frequency aliased sources.The proposed method overcomes the challenge of simultaneous positioning without requiring hardware modifications by leveraging time accumulation and algorithmic enhancements.The implementation of the method involves three key steps.Firstly,the rotation of the interferometer is synthesized into a virtual Uniform Circular Array(UCA).Secondly,a novel estimation variable,termed relative offset,is introduced.The variable serves as an intermediate parameter to establish correlation equations between the positions of multiple time-frequency aliased sources and the intercepted signals.Thirdly,the relative offset model in the UCA is transformed into a virtual Uniform Linear Array(ULA)model,from which the cost function can be derived via the Spatial Smoothing(SS)MUSIC algorithm.Theoretical analysis and simulation results verify the effectiveness of the proposed method.Compared with traditional approaches,the RO-DPD method maintains the low complexity of RSBI systems while demonstrating robust performance in complex electromagnetic environments.
基金supported by the National Natural Science Foundation of China(Grant Nos.12075049 and 11935005)。
文摘Improving plasma uniformity is a critical issue in the development of large-area radio-frequency(RF)inductively coupled plasma(ICP)sources.In this work,the effects of coil structure and electromagnetic shielding on the spatial distribution and uniformity of the plasma are systematically investigated using a three-dimensional fluid model.The model integrates plasma and electromagnetic field modules to simulate the discharge characteristics of a large-area RF ICP source with dimensions of 100 cm×50 cm.The results reveal that the electron density distribution varies significantly with the coil structure.For the rotating and translating coil structures,the electron density is high at off-axis positions and low at the center.In contrast,the mirror coil structure exhibits a significantly higher electron density at the chamber center,resulting in a high-center and low-edge density distribution.Among the three configurations,the rotating coil structure provides the best plasma uniformity.The incorporation of electromagnetic shielding further improves plasma uniformity,particularly for the mirror coil structure.For the rotating and translating coil structures,the electron density exhibits a saddle-shaped distribution regardless of electromagnetic shielding.However,introducing electromagnetic shielding into the mirror coil structure reduces the electron density at the chamber center and decreases the non-uniformity degree by 18.4%.Overall,the mirror coil structure with electromagnetic shielding achieves the highest uniformity,with an exceptional plasma uniformity of 94%.This work offers valuable insights for the design of large-area ICP sources in advanced plasma processing systems.
文摘Let n≥2 be a natural number,1≤p≤∞and X a Banach space.We prove that if X^(*)containsλ-uniformly copies of l^(k)^(p),then:P(^(n)X) contains cKλ^(n)-uniformly copies of■.in the case p^(*)>n(ii)P(^(n)X) containsλ^(n)-uniformly copies of l^(k)_(∞)in the case p^(*)≤n.This complete a result of S.Dineen’s from 1995.
基金supported by the Project Nos.PID2022-137339OB-C22 of the“Plan Estatal 2021-2023R”of the Spanish Government and ENR-IFE.01.CEA of EUROFUSION.
文摘Achieving uniform X-ray irradiation in indirect-drive inertial confinement fusion(ICF)is a key challenge for successful capsule implosion.Spherical hohlraums,particularly those with octahedral laser entrance holes(LEHs),are an alternative to the cylindrical hohlraums currently considered for ICF at NIF(USA)and LMJ(France).These spherical hohlraums are advantageous in terms of irradiation uniformity on the fusion capsule because,owing to their octahedral symmetry,low-order asymmetries cancel out intrinsically.However,they may be less favorable from an energetic point of view,primarily owing to radiation losses through their multiple LEHs.The net balance of these advantages and disadvantages is difficult to determine,because,unlike cylindrical hohlraums,they require fully 3D modeling.To address this,a new version of the MULTI-3D simulation code has been developed.MULTI-3D is a 3D radiation-hydrodynamics code with arbitrary Langrangian-Eulerian(ALE)hydrodynamics,multigroup SN radiation transport,and ray-tracing laser deposition.Using this tool,several aspects of the behavior of spherical hohlraums have been analyzed,with special attention to phenomena inaccessible to 2D modeling.In these targets,laser beams strike the inner walls at very oblique angles,and the expansion of plasma significantly alters the locations where primary X rays are produced.Furthermore,the complex distribution of laser hot spots leads to mutual interactions,where plasma bubbles from one beam intersect the path of another.The laser-to-X-ray energy conversion efficiency has been analyzed as a function of key parameters.The symmetry on the capsule has also been evaluated,revealing nonuniformities of less than 1%.
基金supported by the National Natural Science Foundation of China(Grant Nos.U23A20358,62474170,61925110,62404214,and 62234007)the University of Science and Technology of China(USTC)Research Funds of the Double First-Class Initiative(Grant No.WK2100000055)+2 种基金the Project of the 46t hResearch Institute of CETC(Grant No.WDZC202446007)the JieBang Headed Project of Changsha City Hunan Province(Grant No.kq2301006)the Opening Project and the Key Laboratory of Nano devices and Applications in Suzhou Institute of Nano-Tech and NanoBionics of CAS。
文摘The(010)orientation ofβ-Ga_(2)O_(3)is a highly promising platform for next-generation lateral power electronics due to its superior theoretical transport properties.However,progress has been impeded by the unavailability of large-area substrates,limiting studies to small-scale samples.Leveraging the recent emergence of 2-inch wafers,we report the first demonstration of homoepitaxial growth on a 2-inch,Fe-doped semi-insulating(010)β-Ga_(2)O_(3)substrate by metal-organic chemical vapor deposition(MOCVD).A systematic,wafer-scale characterization reveals the successful growth of a highquality epitaxial film.High-resolution x-ray diffraction shows an excellent crystalline structure,with a rocking curve full-width ranging from 21.0 arcsec to 103.0 arcsec.Atomic force microscopy confirms an atomically smooth surface with a root-mean-square roughness below 1.53 nm,displaying a distinct step-flow growth mode across the wafer.Furthermore,mercury-probe capacitance-voltage mapping indicates a well-controlled carrier concentration of~2×10~(18)cm~(-3)with a RSD of 5.12%.This work provides the first comprehensive assessment of 2-inch(010)Ga_(2)O_(3)epitaxial wafers,validating a critical material platform for the development and future manufacturing of high-performance power devices.
基金Shanghai 20246G Technology Innovation and Future Industry Development Project under grant 24DP1501204。
文摘Recently,uniform circular array(UCA)based orbital angular momentum(OAM)beam steering schemes have been proposed to overcome the limitations of coaxial transmission.Unlike the traditional multiple-input-multiple-output(MIMO)beam steering,OAM beam steering includes both the OAM generation and the beam steering.Generally,the true time delay(TTD)or the phase shifter(PS)are required for beam steering in the radio domain.Previous studies suggest that TTD is preferred for wideband MIMO beam steering to avoid beam squint caused by PS.However,in this paper,we theoretically prove that to generate the OAM beam ideally,PS should be used,while TTD deteriorates the mode orthogonality,which is influenced by the relative bandwidth.Once the ideal OAM beam is generated,TTD is required to prevent beam squint.Based on this analysis,we propose to use the two-stage phase-shifting(TSPS)architecture for OAM beam steering:PS for OAM generation and TTD for beam steering.Simulation results suggest that compared to the spectrum efficiency(SE)of PS based OAM communication,the SE based on the TTD significantly declines as the relative bandwidth increases.Furthermore,OAM beam steering using the TSPS architecture greatly outperforms systems that adopt a single TTD or PS network.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.12074399,12204500,and 12004403)the Key Projects of Intergovernmental International Scientific and Technological Innovation Cooperation(No.2021YFE0116700)+1 种基金the Shanghai Natural Science Foundation(No.20ZR1464400)the Shanghai Sailing Program(No.22YF1455300).
文摘The suppression of ablative Rayleigh–Taylor instability(ARTI)by a spatially modulated laser in inertial confinement fusion(ICF)is studied through numerical simulations.The results show that in the acceleration phase of ICF implosion,the growth of ARTI can be suppressed by using a short-wavelength spatially modulated laser.The ARTI growth rate decreases as the wavelength of the spatially modulated laser decreases,and ARTI is completely suppressed after a certain wavelength has been reached.A spatially uniform laser is introduced to keep the state of motion of the implosion fluid consistent,and it is found that the proportion of the spatially modulated laser required for complete suppression of ARTI decreases as the wavelength continues to decrease.We also optimize the spatial intensity distribution of the spatially modulated laser.In addition,as the duration of the spatially modulated laser decreases,the proportion required for completely suppressing ARTI increases,but the required energy decreases.When the perturbation wavenumber decreases,the wavelength of the spatially modulated laser required for complete suppression of ARTI becomes longer.In the case of multimode perturbation,ARTI can also be significantly suppressed by a spatially modulated laser,and the perturbation amplitude can be reduced to less than 10% of that without a spatially modulated laser.We believe that the conclusions drawn from our simulations can provide the basis for new approaches to control ARTI in ICF.
基金supported in part by Key-Area Research and Development Program of Guangdong Province(Grant No.2021B0101200001)the National Natural Science Foundation of China(Grant No.62293543)+1 种基金the National Natural Science Foundation of China(Grant No.U21B2048)the Open Research Projects of Zhejiang Lab(Grant No.2019KD0AD01/010).
文摘Knowledge distillation aims to distill knowledge from teacher networks to train student networks.Distilling intermediate features has attracted much attention in recent years as it can beflexibly applied in variousfields such as image classification,object detection and semantic segmentation.A critical obstacle of feature-based knowledge distillation is the dimension gap between the intermediate features of teacher and student,and plenty of methods have been proposed to resolve this problem.However,these works usually implement feature uniformization in an unsupervised way,lacking guidance to help the student network learn meaningful mapping functions in the uniformization process.Moreover,the dimension uniformization process of the student and teacher network is usually not equivalent as the mapping functions are different.To this end,some factors of the feature are discarded during parametric feature alignment,or some factors are blended in some non-parametric operations.In this paper,we propose a novel semantic-aware knowledge distillation scheme to solve these problems.We build a standalone feature-based classification branch to extract semantic-aware knowledge for better guiding the learning process of the student network.In addition,to avoid the inequivalence of feature uniformization between teacher and student,we design a novel parameter-free self-attention operation that can convert features of different dimensions into vectors of the same length.Experimental results show that the proposed knowledge distillation scheme outperforms existing feature-based distillation methods on the widely used CIFAR-100 and CINIC-10 datasets.
文摘For the fuzzy topological group (ftg) (Science Bulletin, 29(1984), 651—653), we introduce a new fuzzy uniformity (fu) which is different from L(?)wen’s sense.
