Developing circularly polarized organic light-emitting diodes(CP-OLEDs)that simultaneously achieve a high electroluminescence dissymmetry factor(gEL)and a high external quantum efficiency(EQE)remains a central challen...Developing circularly polarized organic light-emitting diodes(CP-OLEDs)that simultaneously achieve a high electroluminescence dissymmetry factor(gEL)and a high external quantum efficiency(EQE)remains a central challenge in polarized optoelectronics.Here,we report a general composite strategy for constructing full-color CP-OLEDs by integrating a 5CB-based chiral nematic liquid crystal(N*-LC)layer with OLEDs based on achiral emitters.The resulting CP-OLEDs exhibit both high polarization purity and high electroluminescence efficiency,with|gEL|values of up to 1.9,EQEs reaching 26.9%,and Q-factors as high as 0.48.Notably,contrary to the conventional assumption that N*-LC integration causes severe optical losses(>50%)due to Bragg reflection,the EQE of the devices is preserved mainly in this composite architecture.This behavior is attributed to an internal photon-recycling process enabled by the reflection of light within the device structure.To the best of our knowledge,these CP-OLEDs represent the highest comprehensive performance reported to date.Furthermore,the practical utility of these high-performance devices is demonstrated through the encryption and decryption of information based on circularly polarized electroluminescence.展开更多
Achieving rational control over polarization states and color of circularly polarized luminescence(CPL)through simple modulation poses a challenging yet highly practical problem.To address this issue,we developed a me...Achieving rational control over polarization states and color of circularly polarized luminescence(CPL)through simple modulation poses a challenging yet highly practical problem.To address this issue,we developed a mechano-responsive chiral supramolecular system based on a cyclohexanediamide-derived gelator CCPy.This molecule exhibited a strong blue fluorescence accompanied by a distinct CPL signal upon forming a supramolecular gel in toluene.However,upon the application of mechanical force,the gel rapidly transformed into a faintly emissive suspension with a silent CPL signal,along with a notable morphological alteration.Furthermore,by implementing the circularly polarized Förster resonance energy transfer(CP-FRET)strategy,the mechano-responsiveness was effectively imparted to binary systems through the incorporation of dyes Nile red(NR)and coumarin 7(C7),thus realizing mechanical force-switchable green and red CPL systems.It was particularly noteworthy that by adjusting the ratio of CCPy,C7 and NR,a ternary mechanical force-induced CPL ON-OFF switch that emitted a standard white emission was achieved through sequential CP-FRET.Following this,an information encryption experiment was performed.This work provided a paradigm for fabricating smart multi-color and white-light CPL materials.展开更多
This paper presents a circularly polarized(CP)multiple-input multiple-output(MIMO)antenna with wideband and compact size characteristics.The proposed MIMO antenna consists of two wideband dual-CP radiating elements,wh...This paper presents a circularly polarized(CP)multiple-input multiple-output(MIMO)antenna with wideband and compact size characteristics.The proposed MIMO antenna consists of two wideband dual-CP radiating elements,which are positioned in proximity and decoupled by shorting vias.Accordingly,only two radiating elements are required for a 4-port MIMO array.It distinguishes the proposed design approach from the others,in which 4-port MIMO antennas commonly need four radiating elements.The measured results confirm the wideband performance of the proposed antenna with 10 dB isolation operating bandwidth of 15%(4.68–5.44 GHz),and 15 dB isolation operating bandwidth of 8.2%(4.68–5.08 GHz).Besides,4-port MIMO antenna can be realized with compact dimensions of 0.84λ×0.46λ×0.05λat 4.68 GHz.In comparison with the related CP MIMO antennas,the proposed antenna can work with a higher number of operating ports while achieving smaller overall dimensions.Besides,large operating bandwidth is also another advantage of the proposed work compared to the others.展开更多
A novel thia[8]helicene(BN[8]H)withB,N heteroatoms incorporated in the molecular skeleton was synthesized via Suzuki coupling reaction and intramolecular direct electrophilic C-H borylation.Its helical structure was c...A novel thia[8]helicene(BN[8]H)withB,N heteroatoms incorporated in the molecular skeleton was synthesized via Suzuki coupling reaction and intramolecular direct electrophilic C-H borylation.Its helical structure was confirmed by X-ray crystal analysis.Enantiomers BN[8]H showed the interesting responses to fluoride ion stimulation with novel sign inversion of electronic circular dichroism(ECD)and circularly polarized luminescence(CPL).TD-DFT calculations revealed that the fluoride ions significant influence the transition dipole moments andθu,m,resulting in circularly polarized luminescence reversal.展开更多
In contrast to conventional neutron imaging by measuring the attenuation contrast,polarized-neutron imaging(PNI)has proved to be a powerful tool for investigating the spatial distribution of magnetic fields inside and...In contrast to conventional neutron imaging by measuring the attenuation contrast,polarized-neutron imaging(PNI)has proved to be a powerful tool for investigating the spatial distribution of magnetic fields inside and around bulk samples owing to the intrinsic magnetic moment of neutrons.This technique benefits from the measurement of the cumulative precession of the neutron polarization passing through a magnetic field.We report the recent development of the PNI capability at the China Advanced Research Reactor(CARR),where two neutron imaging instruments(thermal and cold)have been established.To further develop and realize the PNI technique,a PNI facility consisting of a double-crystal pyrolytic graphite monochromator,supermirror polarizer with three parallel V-shaped cavities and an in situ optically pumped 3He neutron spin filter as a neutron spin analyzer was successfully developed and tested based on an established cold neutron imaging instrument.This setup will be beneficial for enhancing neutron imaging and neutron optics in CARR in the future.展开更多
Aqueously dispersed nanomaterials exhibiting circularly polarized luminescence(CPL)hold great potentials in biological fields due to the inherent chirality of biological systems and its excellent biocompatibility.Howe...Aqueously dispersed nanomaterials exhibiting circularly polarized luminescence(CPL)hold great potentials in biological fields due to the inherent chirality of biological systems and its excellent biocompatibility.However,the limited availability of biodegradable CPL nanoparticles in aqueous media has severely constrained the development of biomedical CPL.Here,we present a facile strategy for achieving tunable CPL of aqueously dispersed nanotoroids through the co-assembly of a homopolypeptide with three achiral triphenylamine derivatives,showing a CPL performance depending on the architecture and doping content of small molecules.Remarkably,a deep-red CPL can be achieved with a record luminescence dissymmetry factor(glum=1.1×10-2)among aqueously polypeptide-based nanoparticles.Furthermore,the densely packed nanostructure completely suppressed the intrinsic reactive oxygen species generation of the chromophores by restricting oxygen diffusion and quenching exciton-energy transfer,thereby eliminating phototoxic risks while preserving imaging fidelity.Overall,this work not only provides a facile method for achieving aqueous CPL from achiral molecules but also establishes a structure-property relationship between chromophore geometry and supramolecular CPL performance,advancing their potential in biological fields.展开更多
Circularly polarized light(CPL)detection is critical to emerging technologies in optical communication,chiral sensing,and bio-inspired imaging.However,current devices rely on intrinsically chiral semiconductors that a...Circularly polarized light(CPL)detection is critical to emerging technologies in optical communication,chiral sensing,and bio-inspired imaging.However,current devices rely on intrinsically chiral semiconductors that are synthetically complex and costly to scale.Here,we demonstrate robust CPL detection in achiral organic semiconductors by exploiting chiral plasmonic resonance(CPR).A self-assembled monolayer of L-phenylalanine–modified gold nanoparticles imparts optical chirality to adjacent semiconductors while enhancing photocurrent through plasmon-induced hot-carrier processes.The resulting hybrid devices exhibit nearly tenfold responsivity enhancement and a high dissymmetry factor of 0.35 at 515 nm.Mechanistic analysis reveals a field-driven,hot-carrier-assisted route to helicity sensitivity.This solution-processable approach merges plasmonic chirality with organic semiconductor versatility,providing a scalable platform for next-generation on-chip chiroptoelectronic and polarization-imaging technologies.展开更多
High-energy,high-yield structured spin-polarized positron beams have important applications in nuclear physics,high-energy physics,and information storage.However,their generation remains a significant challenge.Here,...High-energy,high-yield structured spin-polarized positron beams have important applications in nuclear physics,high-energy physics,and information storage.However,their generation remains a significant challenge.Here,we put forward a scheme to generate these beams using a dense relativistic electron beam interacting with a gas-filled cone-channel target.The interaction induces composite focusing fields comprising the electric field from a plasma bubble and skin-layer magnetic fields from the electron beam and displacement currents.These fields compress the seed beam to ultrahigh density,thereby inducing extreme fields that enable efficient-photon emission and subsequent pair production,leading to a high positron yield.Furthermore,the azimuthal topology of these fields is imprinted onto the generated positrons,creating unique azimuthal polarization.Our simulations demonstrate the generation of an azimuthally polarized positron beam with a charge of 0.63 nC,a polarization approaching 60%,and an energy conversion efficiency exceeding 3%.Our method provides a highly efficient pathway for generating azimuthally polarized positrons,paving the way for their potential applications.展开更多
Chirality-dependent optoelectronics and biological interactions have both attracted significant attention over the past several decades.However,interdisciplinary synergy between these two fields remains limited,largel...Chirality-dependent optoelectronics and biological interactions have both attracted significant attention over the past several decades.However,interdisciplinary synergy between these two fields remains limited,largely due to the lack of theoretical support and practical demonstrations.Herein,we report the fabrication of biomolecule-tailored chiral PbS films via a solid-state ligand exchange method,enabling the achievement of a maximum chiroptical anisotropic factor(g-factor)of 2.36×10−3.These chiral PbS films were integrated into circularly polarized short-wave infrared(CP-SWIR)photodetectors,exhibiting a high responsivity beyond 0.3 A/W and a detectivity beyond 8.6×1011 Jones under the irradiation(L-PbS film under left-handed CP-SWIR).More importantly,such chirality-mediated phenomenon enables antibacterial activity through a photo-microcurrent generation effect.It eventually provides a significant 39%difference in E.coli mortality rate when the L-PbS-based photosensitive device is subject to homochiral versus heterochiral CP-SWIR illumination.This strategy offers a robust platform for cross-collaborations between chiroptical optoelectronic devices and chirality-related biological issues.展开更多
Chiral nanocomposites have attracted much attention due to their fascinating size-dependent characteristics.Such nanomaterials could be precisely synthesized by templates from randomly coiled unimolecular micelles wit...Chiral nanocomposites have attracted much attention due to their fascinating size-dependent characteristics.Such nanomaterials could be precisely synthesized by templates from randomly coiled unimolecular micelles with poor chiroptical activities.Helical polymers possessing secondary chirality usually display stronger chiral induction than random-coiled polymers do.However,the controllable preparation of helical unimolecular micelles still remains challenging,which hinders the investigation into the effect of morphology and size on chiroptical properties.In this study,multiarmed star-shaped poly(phenylacetylene)s(PPAs)with target composition,molecular weight,and size were precisely prepared from the multisited initiator via living polymerization.Based on acid−base interactions,chiral transfer from PPAs to various dyes was accomplished in composite membranes and suspension.Notably,the chiral nanocomposites consisting of starshaped PPAs displayed enhanced helical stability,Cotton effect,and circularly polarized luminescence(CPL)compared with linear analogues.Furthermore,this system displayed the triple-mode(photoluminescence,circular dichroism,and CPL)detection toward the volatile organic compound for environmental monitoring.展开更多
Structural anisotropy of celery stalks was studied using T2 anisotropy in microscopic MRI(μMRI)and supplemented by quantitative polarized light microscopy(PLM)at optical resolutions.Parenchyma,which is the ground ...Structural anisotropy of celery stalks was studied using T2 anisotropy in microscopic MRI(μMRI)and supplemented by quantitative polarized light microscopy(PLM)at optical resolutions.Parenchyma,which is the ground tissue in celery and has a diameter in the range of 50–90μm,was found to have isotropic T2;in contrast,collenchyma,which is the structural part of the ground tissue in celery and has a diameter in the range of 8–12μm,was found to have strong anisotropic T2.Substantial size variations within each porous structure and substantial co-existences of more than one type of structural tissues within a singleμMRI voxel were noticed in the optical images,which can contribute to the less clear anisotropies in the smaller vascular structures(e.g.,phloem(approximately 2–6μm in diameter)and xylem(approximately 5–15μm in diameter)).Celery could be used as a simple plant model to study the relationships between tissue microstructures and nuclear spin relaxation in fibrous and porous specimens.展开更多
Ultrafast phenomena initiated by strong-field ionization are commonly interpreted within classical or semiclassical frameworks based on electron trajectories.In this work,we theoretically investigate the energy-resolv...Ultrafast phenomena initiated by strong-field ionization are commonly interpreted within classical or semiclassical frameworks based on electron trajectories.In this work,we theoretically investigate the energy-resolved photoelectron angular distributions in above-threshold ionization(ATI)induced by elliptically polarized ultraviolet(UV)pulses and unravel the underlying dynamics from the perspective of quantum-pathway interference.By numerically solving the threedimensional time-dependent Schrodinger equation,we extract the contributions of the quantum pathways for an electron transitioning from the ground state to the continuum under pulses with different ellipticities.Our results demonstrate that for close-to-circularly polarized UV pulses,two quantum pathways govern the angular distribution for each ATI peak,and their interference produces a cosinusoidal oscillation in the photoelectron angular distributions,which is distinct from the Gaussian characteristic predicted by the traditional tunneling framework.In particular,the corresponding offset angle is shown to depend on the relative phase between these two dominant channels.As the ellipticity decreases,the increasing number of contributing pathways leads to a multiple-peak structure in the photoelectron angular distribution.The present study provides a quantum-mechanical perspective for understanding the angular streaking of nonadiabatic ionization in rotating fields.展开更多
Discrete 2:2 host–guest complexes provide a well-defined platform for correlating supramolecular structure with emergent photophysical behavior.Althoughγ-cyclodextrin(γ-CD)is widely used in aqueous host–guest chem...Discrete 2:2 host–guest complexes provide a well-defined platform for correlating supramolecular structure with emergent photophysical behavior.Althoughγ-cyclodextrin(γ-CD)is widely used in aqueous host–guest chemistry,structurally well-defined 2:2 complexes and their formation mechanisms remain poorly understood.Here we report aγ-CD-mediated 2:2 host–guest complex formed with 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene tetrasodium salt(TCP)and systematically elucidate its structural,mechanistic,and photophysical characteristics.Combined1H NMR,2D NMR,and DOSY analyses resolve the 2:2 architecture,while thermodynamic and kinetic studies reveal a multistep complexation network involving 1:1,1:2,and 2:2 species,with dimerization providing the dominant thermodynamic driving force.The resulting 2:2 complex exhibits enhanced fluorescence emission and pronounced chiroptical responses,including circular dichroism and circularly polarized luminescence,arising from supramolecular chirality induced by the chiralγ-CD cavities.Importantly,analogousγ-CD-mediated 2:2 complexation and associated photophysical features are also observed for a tetraphenylethylene-based guest,indicating that this binding mode is not limited to a single chromophoric scaffold.This study clarifies how 2:2 host–guest complexes can form inγ-CD systems and provides mechanistic insight into the emergence of chiral photophysical properties in such complexes.展开更多
A millimeter-wave(mm-Wave)dual circularly polarized(CP)antenna in gap waveguide(GWG)technology with high port isolation is proposed in this paper.It is consisted of a simplified orthomode transducer(OMT)and an improve...A millimeter-wave(mm-Wave)dual circularly polarized(CP)antenna in gap waveguide(GWG)technology with high port isolation is proposed in this paper.It is consisted of a simplified orthomode transducer(OMT)and an improved multi-section hexagonal waveguide CP horn antenna.The OMT is composed of two metal layers without the traditional septum or iris,which makes the structure simpler.The CP horn antenna can be easily integrated with the OMT without mode conversion.The principle analysis as well as the simulated and measured results of the proposed antenna are given in this paper.The simulated and measured results agree very well with each other.The port isolation of more than 27 dB over bandwidth of 26.5-31 GHz(|S11|<-15 dB)is achieved with relative bandwidth of 15.7%.The axial ratio(AR)lower than 2.5 dB for both left-hand and righthand CP(LHCP and RHCP)are achieved over the bandwidth.The proposed antenna is a candidate for mm-Wave satellite communications or beyond fifth-generation(5G)communications applications.展开更多
Photocatalytic oxidative dehydrogenation of biomass feedstocks offers the possibility for synthesizing value-added chemicals,but the sluggish transport kinetics and rapid recombination of photogenerated charge carrier...Photocatalytic oxidative dehydrogenation of biomass feedstocks offers the possibility for synthesizing value-added chemicals,but the sluggish transport kinetics and rapid recombination of photogenerated charge carriers constrain photocatalysis efficiency.Spin-polarized photocatalysts,by accelerating the separation of photogenerated electrons and holes,offer a promising strategy for selective biomass valorization.Herein,polarization unit Mo was incorporated into ZnIn2S4(ZIS)with S-vacancy through Mo-S4coordination(Mo-Vs-ZIS)to enhance hole and proton-coupled electron transfer(PCET).Mo-Vs-ZIS spin polarized photocatalyst applied to 5-hydroxymethylfurfural(HMF)afforded a 2,5-diformylfuran(DFF)selectivity of 92.3%at a production rate of 1105.3μmol gcat-1h-1,attributed to carrier transport and reaction processes.The Mo-Vs-ZIS photocatalyst efficiently(100 min)converted benzyl and furfuryl alcohols,aromatic alcohols bearing electron-rich substituents,and halogen-substituted aromatic alcohols into their corresponding aldehydes.Piezoelectric force microscopy(PFM)and Kelvin probe force microscopy analyses(KPFM)revealed that the full-space polarized electric field was formed to drive directional transfer of photogenerated carriers,facilitating bulk-to-surface charge separation.Moreover,Mo-Vs-ZIS showed high Bader charge transfer to O2,where Mo atomic sites functioned as an electron reservoir,driving the activation of O2to form•O2,a kinetically favorable step for HMF oxidation and induced transfer of holes to activate C(sp3)-H bonds,which is a rate-determining step.Then,the critical step of PCET(O2+H+→•OOH)over Mo-Vs-ZIS gave•OOH for O-H activation to complete the reaction sequence.This spin-polarized modification strategy featuring atomic-level catalytic sites enables its application to other semiconductor photocatalysts for biomass conversion.展开更多
This paper designs an ultra-wideband(UWB)circularly polarized antenna based on Angle of Arrival(AOA)positioning technology.The antenna element adopts a rectangular dual-feed microstrip patch structure,and realizes rig...This paper designs an ultra-wideband(UWB)circularly polarized antenna based on Angle of Arrival(AOA)positioning technology.The antenna element adopts a rectangular dual-feed microstrip patch structure,and realizes right-hand circular polarization(RHCP)radiation through a 90°feeding network,which effectively suppresses vehicle multipath interference and polarization mismatch problems;a compact L-shaped three-antenna array is built based on the elements,and the array layout and feeding network are optimized to ensure phase and amplitude consistency.The simulation analysis results show that the operating frequency band of the antenna element can completely cover 6.24~8.24 GHz,with a return loss of≤-10 dB and an axial ratio of≤3.0 dB within this band;the isolation between ports is≤-21dB,the gain is stable at 3.55-5.05 dBi,and the AOA positioning error is≤1.4°(positioning distance 0.5-5 m).The overall size is controlled at 42mm×30mm×2mm,which fully meets the application requirements of automotive digital keys for miniaturization,high precision,and anti-interference.It can be directly integrated into digital key terminals,improving the reliability of contactless unlocking and the security of anti-theft authentication.展开更多
Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge ...Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge lies in the absence of well-developed strategies for designing materials that combine these two exceptional optical properties.展开更多
The effects of initial spin orientation on the final electron beam polarization in laser wakefield acceleration in a pre-polarized plasma are investigated theoretically and numerically.From the results of variation of...The effects of initial spin orientation on the final electron beam polarization in laser wakefield acceleration in a pre-polarized plasma are investigated theoretically and numerically.From the results of variation of the initial spin direction,the spin dynamics of the electron beam are found to depend on the self-injection mechanism.The effects of wakefields and laser fields are studied using test particle dynamics and particle-in-cell simulations based on the Thomas-Bargmann-Michel-Telegdi equation.Compared with transverse injection,longitudinal injection is found to be preferable for obtaining a highly polarized electron beam.展开更多
KSSOLV(Kohn−Sham solver)is a MAT-LAB(Matrix Laboratory)toolbox de-signed for solving the Kohn-Sham density functional theory(DFT)equations by us-ing the plane-wave basis set.Leveraging the powerful capabilities of MAT...KSSOLV(Kohn−Sham solver)is a MAT-LAB(Matrix Laboratory)toolbox de-signed for solving the Kohn-Sham density functional theory(DFT)equations by us-ing the plane-wave basis set.Leveraging the powerful capabilities of MATLAB’s parallel computing toolbox and an ad-vanced,optimized calculation workflow,KSSOLV uniquely enables efficient graph-ics processing unit(GPU)acceleration,making DFT calculations accessible on standard personal computing hardware.Here,KSSOLV-GPU 2.0,as the latest release,demonstrates substantial computational gains.In benchmarks,particularly involving calculations such as hybrid functionals and spin-polar-ized systems for complex band structure analysis,KSSOLV-GPU 2.0 achieves a speedup of more than an order of magnitude compared to conventional central processing unit based im-plementations.This significant acceleration marks a pivotal advancement in performing com-plex materials simulations,making KS-DFT increasingly accessible on personal computing platforms.展开更多
Strong feld-induced nonsequential double ionization(NSDI)is a signifcant multi-electron phenomenon that provides crucial insights into understanding electron correlation and multiple ionization of atoms and molecules,...Strong feld-induced nonsequential double ionization(NSDI)is a signifcant multi-electron phenomenon that provides crucial insights into understanding electron correlation and multiple ionization of atoms and molecules,but it is typically unattainable in a circularly polarized laser pulse,especially for long-wavelength lasers.We present evidence that NSDI can occur in the presence of a near-infrared or beyond laser pulse by introducing a bowtie-nanotip.The laser-induced local plasmon can alter the local ellipticity of the feld,thereby enabling NSDI through elliptical trajectories that facilitate recollisions with parent atoms.An oval-shaped momentum distribution of recoiled ions provides evidence for the modifcation of trajectories by the aligned nanotips.Our study introduces an innovative control knob to manipulate NSDI and electron dynamics through the utilization of nanostructures.展开更多
基金supported by the National Natural Science Foundation of China(92256304,22371277)the National Key Research and Development Program of China(2022YFA1204401)the Beijing National Laboratory for Molecular Sciences(BNLMS-CXXM-202105)。
摘要Developing circularly polarized organic light-emitting diodes(CP-OLEDs)that simultaneously achieve a high electroluminescence dissymmetry factor(gEL)and a high external quantum efficiency(EQE)remains a central challenge in polarized optoelectronics.Here,we report a general composite strategy for constructing full-color CP-OLEDs by integrating a 5CB-based chiral nematic liquid crystal(N*-LC)layer with OLEDs based on achiral emitters.The resulting CP-OLEDs exhibit both high polarization purity and high electroluminescence efficiency,with|gEL|values of up to 1.9,EQEs reaching 26.9%,and Q-factors as high as 0.48.Notably,contrary to the conventional assumption that N*-LC integration causes severe optical losses(>50%)due to Bragg reflection,the EQE of the devices is preserved mainly in this composite architecture.This behavior is attributed to an internal photon-recycling process enabled by the reflection of light within the device structure.To the best of our knowledge,these CP-OLEDs represent the highest comprehensive performance reported to date.Furthermore,the practical utility of these high-performance devices is demonstrated through the encryption and decryption of information based on circularly polarized electroluminescence.
基金financialsupport from the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0770101)the National Key R&D Program of China(No.2023YFA1508900)the National Natural Science Foundation of China(Nos.22202211 and 52321006).
摘要Achieving rational control over polarization states and color of circularly polarized luminescence(CPL)through simple modulation poses a challenging yet highly practical problem.To address this issue,we developed a mechano-responsive chiral supramolecular system based on a cyclohexanediamide-derived gelator CCPy.This molecule exhibited a strong blue fluorescence accompanied by a distinct CPL signal upon forming a supramolecular gel in toluene.However,upon the application of mechanical force,the gel rapidly transformed into a faintly emissive suspension with a silent CPL signal,along with a notable morphological alteration.Furthermore,by implementing the circularly polarized Förster resonance energy transfer(CP-FRET)strategy,the mechano-responsiveness was effectively imparted to binary systems through the incorporation of dyes Nile red(NR)and coumarin 7(C7),thus realizing mechanical force-switchable green and red CPL systems.It was particularly noteworthy that by adjusting the ratio of CCPy,C7 and NR,a ternary mechanical force-induced CPL ON-OFF switch that emitted a standard white emission was achieved through sequential CP-FRET.Following this,an information encryption experiment was performed.This work provided a paradigm for fabricating smart multi-color and white-light CPL materials.
摘要This paper presents a circularly polarized(CP)multiple-input multiple-output(MIMO)antenna with wideband and compact size characteristics.The proposed MIMO antenna consists of two wideband dual-CP radiating elements,which are positioned in proximity and decoupled by shorting vias.Accordingly,only two radiating elements are required for a 4-port MIMO array.It distinguishes the proposed design approach from the others,in which 4-port MIMO antennas commonly need four radiating elements.The measured results confirm the wideband performance of the proposed antenna with 10 dB isolation operating bandwidth of 15%(4.68–5.44 GHz),and 15 dB isolation operating bandwidth of 8.2%(4.68–5.08 GHz).Besides,4-port MIMO antenna can be realized with compact dimensions of 0.84λ×0.46λ×0.05λat 4.68 GHz.In comparison with the related CP MIMO antennas,the proposed antenna can work with a higher number of operating ports while achieving smaller overall dimensions.Besides,large operating bandwidth is also another advantage of the proposed work compared to the others.
基金financially supported by the National Natural Science Foundation of China(Nos.22471061,U2004213,22475063)Natural Science Foundation of Henan(Nos.242300421607,242300421611,252300420754)+1 种基金China Postdoctoral Science Foundation(No.2023M730951)Open Foundation project of Henan University(No.DCSHENU2420).
摘要A novel thia[8]helicene(BN[8]H)withB,N heteroatoms incorporated in the molecular skeleton was synthesized via Suzuki coupling reaction and intramolecular direct electrophilic C-H borylation.Its helical structure was confirmed by X-ray crystal analysis.Enantiomers BN[8]H showed the interesting responses to fluoride ion stimulation with novel sign inversion of electronic circular dichroism(ECD)and circularly polarized luminescence(CPL).TD-DFT calculations revealed that the fluoride ions significant influence the transition dipole moments andθu,m,resulting in circularly polarized luminescence reversal.
基金supported by the National Key Research and Development Program of China(No.2020YFA0406004)the key scientific instrument by National Natural Science Foundation of China(No.11527810)Development of the guide field and magnetic simulation is sponsored by National Natural Science Foundation of China(Nos.12075265 and U2032219)。
摘要In contrast to conventional neutron imaging by measuring the attenuation contrast,polarized-neutron imaging(PNI)has proved to be a powerful tool for investigating the spatial distribution of magnetic fields inside and around bulk samples owing to the intrinsic magnetic moment of neutrons.This technique benefits from the measurement of the cumulative precession of the neutron polarization passing through a magnetic field.We report the recent development of the PNI capability at the China Advanced Research Reactor(CARR),where two neutron imaging instruments(thermal and cold)have been established.To further develop and realize the PNI technique,a PNI facility consisting of a double-crystal pyrolytic graphite monochromator,supermirror polarizer with three parallel V-shaped cavities and an in situ optically pumped 3He neutron spin filter as a neutron spin analyzer was successfully developed and tested based on an established cold neutron imaging instrument.This setup will be beneficial for enhancing neutron imaging and neutron optics in CARR in the future.
基金supported by the National Natural Science Foundation of China(Nos.22471198,22101208,22335005)Innovation Program of Shanghai Municipal Education Commission(No.2023ZKZD28)the Fundamental Research Funds for the Central Universities。
摘要Aqueously dispersed nanomaterials exhibiting circularly polarized luminescence(CPL)hold great potentials in biological fields due to the inherent chirality of biological systems and its excellent biocompatibility.However,the limited availability of biodegradable CPL nanoparticles in aqueous media has severely constrained the development of biomedical CPL.Here,we present a facile strategy for achieving tunable CPL of aqueously dispersed nanotoroids through the co-assembly of a homopolypeptide with three achiral triphenylamine derivatives,showing a CPL performance depending on the architecture and doping content of small molecules.Remarkably,a deep-red CPL can be achieved with a record luminescence dissymmetry factor(glum=1.1×10-2)among aqueously polypeptide-based nanoparticles.Furthermore,the densely packed nanostructure completely suppressed the intrinsic reactive oxygen species generation of the chromophores by restricting oxygen diffusion and quenching exciton-energy transfer,thereby eliminating phototoxic risks while preserving imaging fidelity.Overall,this work not only provides a facile method for achieving aqueous CPL from achiral molecules but also establishes a structure-property relationship between chromophore geometry and supramolecular CPL performance,advancing their potential in biological fields.
基金supported by the National Natural Science Foundation of China(52273193 and 52073206)the Haihe Laboratory of Sustainable Chemical Transformations。
摘要Circularly polarized light(CPL)detection is critical to emerging technologies in optical communication,chiral sensing,and bio-inspired imaging.However,current devices rely on intrinsically chiral semiconductors that are synthetically complex and costly to scale.Here,we demonstrate robust CPL detection in achiral organic semiconductors by exploiting chiral plasmonic resonance(CPR).A self-assembled monolayer of L-phenylalanine–modified gold nanoparticles imparts optical chirality to adjacent semiconductors while enhancing photocurrent through plasmon-induced hot-carrier processes.The resulting hybrid devices exhibit nearly tenfold responsivity enhancement and a high dissymmetry factor of 0.35 at 515 nm.Mechanistic analysis reveals a field-driven,hot-carrier-assisted route to helicity sensitivity.This solution-processable approach merges plasmonic chirality with organic semiconductor versatility,providing a scalable platform for next-generation on-chip chiroptoelectronic and polarization-imaging technologies.
基金supported by the National Natural Science Foundation of China(Grant Nos.12135009,12375244,12425510,12441506,12505235,and U2267204)the Natural Science Foundation of Hunan Province of China(Grant No.2025JJ30002)+5 种基金the National Key Research and Development(R&D)Program(Grant No.2024YFA1610900)the Science Challenge Project(No.TZ2025012)the Innovative Scientific Program of CNNC,the China Postdoctoral Science Foundation(Grant No.2024M762568)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20252248)the Fundamental Research Funds for the Central Universities of Ministry of Education of China(Grant No.xzy012025079)the Hunan Provincial Research and Innovation Foundation for Graduate Students(Grant No.CX20220048).
摘要High-energy,high-yield structured spin-polarized positron beams have important applications in nuclear physics,high-energy physics,and information storage.However,their generation remains a significant challenge.Here,we put forward a scheme to generate these beams using a dense relativistic electron beam interacting with a gas-filled cone-channel target.The interaction induces composite focusing fields comprising the electric field from a plasma bubble and skin-layer magnetic fields from the electron beam and displacement currents.These fields compress the seed beam to ultrahigh density,thereby inducing extreme fields that enable efficient-photon emission and subsequent pair production,leading to a high positron yield.Furthermore,the azimuthal topology of these fields is imprinted onto the generated positrons,creating unique azimuthal polarization.Our simulations demonstrate the generation of an azimuthally polarized positron beam with a charge of 0.63 nC,a polarization approaching 60%,and an energy conversion efficiency exceeding 3%.Our method provides a highly efficient pathway for generating azimuthally polarized positrons,paving the way for their potential applications.
基金supported by the National Natural Science Foundation of China(Grant nos.:62261136552 and 62204107)the Shenzhen Science and Technology Program(Grant no.:JCYJ20240813113240052)+1 种基金the Natural Science Foundation of Top Talent of SZTU(Grant no.:GDRC202344)the National Natural Science Foundation of Hubei Province(Grant nos.:2020CFB200 and 2023AFB635).
摘要Chirality-dependent optoelectronics and biological interactions have both attracted significant attention over the past several decades.However,interdisciplinary synergy between these two fields remains limited,largely due to the lack of theoretical support and practical demonstrations.Herein,we report the fabrication of biomolecule-tailored chiral PbS films via a solid-state ligand exchange method,enabling the achievement of a maximum chiroptical anisotropic factor(g-factor)of 2.36×10−3.These chiral PbS films were integrated into circularly polarized short-wave infrared(CP-SWIR)photodetectors,exhibiting a high responsivity beyond 0.3 A/W and a detectivity beyond 8.6×1011 Jones under the irradiation(L-PbS film under left-handed CP-SWIR).More importantly,such chirality-mediated phenomenon enables antibacterial activity through a photo-microcurrent generation effect.It eventually provides a significant 39%difference in E.coli mortality rate when the L-PbS-based photosensitive device is subject to homochiral versus heterochiral CP-SWIR illumination.This strategy offers a robust platform for cross-collaborations between chiroptical optoelectronic devices and chirality-related biological issues.
基金the National Science Foundation of China(Grant No.52273217 to Xinchang Pang,Grant No.22105179 to Ge Shi,Grant No.52173209 to Yanjie He)Key Scientific Research Projects of Colleges and Universities in Henan Province(Fundamental Research Project 2022)(Grant 22ZX001 to Xinchang Pang)+2 种基金Postdoctoral Foundation of Henan Province(No.304348 to Ge Shi)scientific and technological research projects in Henan Province(No.242102520004 to Xiaoguang Qiao)Postgraduate Education Reform and Quality Improvement Project of Henan Province(No.YJS2025GZZ03 to Zhe Cui)are greatly appreciated.
摘要Chiral nanocomposites have attracted much attention due to their fascinating size-dependent characteristics.Such nanomaterials could be precisely synthesized by templates from randomly coiled unimolecular micelles with poor chiroptical activities.Helical polymers possessing secondary chirality usually display stronger chiral induction than random-coiled polymers do.However,the controllable preparation of helical unimolecular micelles still remains challenging,which hinders the investigation into the effect of morphology and size on chiroptical properties.In this study,multiarmed star-shaped poly(phenylacetylene)s(PPAs)with target composition,molecular weight,and size were precisely prepared from the multisited initiator via living polymerization.Based on acid−base interactions,chiral transfer from PPAs to various dyes was accomplished in composite membranes and suspension.Notably,the chiral nanocomposites consisting of starshaped PPAs displayed enhanced helical stability,Cotton effect,and circularly polarized luminescence(CPL)compared with linear analogues.Furthermore,this system displayed the triple-mode(photoluminescence,circular dichroism,and CPL)detection toward the volatile organic compound for environmental monitoring.
基金supported by a BSF grant from the United States-Israel Binational Science Foundation(2019033)a grant from the National Institutes of Health(R01 AR 69047).
摘要Structural anisotropy of celery stalks was studied using T2 anisotropy in microscopic MRI(μMRI)and supplemented by quantitative polarized light microscopy(PLM)at optical resolutions.Parenchyma,which is the ground tissue in celery and has a diameter in the range of 50–90μm,was found to have isotropic T2;in contrast,collenchyma,which is the structural part of the ground tissue in celery and has a diameter in the range of 8–12μm,was found to have strong anisotropic T2.Substantial size variations within each porous structure and substantial co-existences of more than one type of structural tissues within a singleμMRI voxel were noticed in the optical images,which can contribute to the less clear anisotropies in the smaller vascular structures(e.g.,phloem(approximately 2–6μm in diameter)and xylem(approximately 5–15μm in diameter)).Celery could be used as a simple plant model to study the relationships between tissue microstructures and nuclear spin relaxation in fibrous and porous specimens.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFA1406800)the National Natural Science Foundation of China(Grant Nos.12174133,11874163,and 12021004)the Innovation Project of Optics Valley Laboratory(Grant No.OVL2021ZD001)。
摘要Ultrafast phenomena initiated by strong-field ionization are commonly interpreted within classical or semiclassical frameworks based on electron trajectories.In this work,we theoretically investigate the energy-resolved photoelectron angular distributions in above-threshold ionization(ATI)induced by elliptically polarized ultraviolet(UV)pulses and unravel the underlying dynamics from the perspective of quantum-pathway interference.By numerically solving the threedimensional time-dependent Schrodinger equation,we extract the contributions of the quantum pathways for an electron transitioning from the ground state to the continuum under pulses with different ellipticities.Our results demonstrate that for close-to-circularly polarized UV pulses,two quantum pathways govern the angular distribution for each ATI peak,and their interference produces a cosinusoidal oscillation in the photoelectron angular distributions,which is distinct from the Gaussian characteristic predicted by the traditional tunneling framework.In particular,the corresponding offset angle is shown to depend on the relative phase between these two dominant channels.As the ellipticity decreases,the increasing number of contributing pathways leads to a multiple-peak structure in the photoelectron angular distribution.The present study provides a quantum-mechanical perspective for understanding the angular streaking of nonadiabatic ionization in rotating fields.
基金Th supported by the National Key R&D Program of China(Grant No.:2021YFA1501600 for G.W.)the National Natural Science Foundation of China(Grant No.:22250004 for X.C.,Grant No.:22171103 for G.W.,Grant No.:22301010 for Y.S.)+1 种基金the Natural Science Foun-dation of Jilin Province(Grant No.:***202301002 for G.W.)the Fundamental and Interdisciplinary Disciplines Breakthrough Plan of the Ministry of Education of China(Grant No.:JYB2025XDXM401).
摘要Discrete 2:2 host–guest complexes provide a well-defined platform for correlating supramolecular structure with emergent photophysical behavior.Althoughγ-cyclodextrin(γ-CD)is widely used in aqueous host–guest chemistry,structurally well-defined 2:2 complexes and their formation mechanisms remain poorly understood.Here we report aγ-CD-mediated 2:2 host–guest complex formed with 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene tetrasodium salt(TCP)and systematically elucidate its structural,mechanistic,and photophysical characteristics.Combined1H NMR,2D NMR,and DOSY analyses resolve the 2:2 architecture,while thermodynamic and kinetic studies reveal a multistep complexation network involving 1:1,1:2,and 2:2 species,with dimerization providing the dominant thermodynamic driving force.The resulting 2:2 complex exhibits enhanced fluorescence emission and pronounced chiroptical responses,including circular dichroism and circularly polarized luminescence,arising from supramolecular chirality induced by the chiralγ-CD cavities.Importantly,analogousγ-CD-mediated 2:2 complexation and associated photophysical features are also observed for a tetraphenylethylene-based guest,indicating that this binding mode is not limited to a single chromophoric scaffold.This study clarifies how 2:2 host–guest complexes can form inγ-CD systems and provides mechanistic insight into the emergence of chiral photophysical properties in such complexes.
基金supported by China Postdoctoral Foundation(2023M731680)the Youth Foundation of Jiangsu Province(BK20230919)。
摘要A millimeter-wave(mm-Wave)dual circularly polarized(CP)antenna in gap waveguide(GWG)technology with high port isolation is proposed in this paper.It is consisted of a simplified orthomode transducer(OMT)and an improved multi-section hexagonal waveguide CP horn antenna.The OMT is composed of two metal layers without the traditional septum or iris,which makes the structure simpler.The CP horn antenna can be easily integrated with the OMT without mode conversion.The principle analysis as well as the simulated and measured results of the proposed antenna are given in this paper.The simulated and measured results agree very well with each other.The port isolation of more than 27 dB over bandwidth of 26.5-31 GHz(|S11|<-15 dB)is achieved with relative bandwidth of 15.7%.The axial ratio(AR)lower than 2.5 dB for both left-hand and righthand CP(LHCP and RHCP)are achieved over the bandwidth.The proposed antenna is a candidate for mm-Wave satellite communications or beyond fifth-generation(5G)communications applications.
基金National Natural Science Foundation of China(22578226,22178181 and 22508200)Natural Science Fund of Tianjin(No.25JCZDJC01000)Fundamental Research Funds for the Central Universities(Nankai University,63253204)。
摘要Photocatalytic oxidative dehydrogenation of biomass feedstocks offers the possibility for synthesizing value-added chemicals,but the sluggish transport kinetics and rapid recombination of photogenerated charge carriers constrain photocatalysis efficiency.Spin-polarized photocatalysts,by accelerating the separation of photogenerated electrons and holes,offer a promising strategy for selective biomass valorization.Herein,polarization unit Mo was incorporated into ZnIn2S4(ZIS)with S-vacancy through Mo-S4coordination(Mo-Vs-ZIS)to enhance hole and proton-coupled electron transfer(PCET).Mo-Vs-ZIS spin polarized photocatalyst applied to 5-hydroxymethylfurfural(HMF)afforded a 2,5-diformylfuran(DFF)selectivity of 92.3%at a production rate of 1105.3μmol gcat-1h-1,attributed to carrier transport and reaction processes.The Mo-Vs-ZIS photocatalyst efficiently(100 min)converted benzyl and furfuryl alcohols,aromatic alcohols bearing electron-rich substituents,and halogen-substituted aromatic alcohols into their corresponding aldehydes.Piezoelectric force microscopy(PFM)and Kelvin probe force microscopy analyses(KPFM)revealed that the full-space polarized electric field was formed to drive directional transfer of photogenerated carriers,facilitating bulk-to-surface charge separation.Moreover,Mo-Vs-ZIS showed high Bader charge transfer to O2,where Mo atomic sites functioned as an electron reservoir,driving the activation of O2to form•O2,a kinetically favorable step for HMF oxidation and induced transfer of holes to activate C(sp3)-H bonds,which is a rate-determining step.Then,the critical step of PCET(O2+H+→•OOH)over Mo-Vs-ZIS gave•OOH for O-H activation to complete the reaction sequence.This spin-polarized modification strategy featuring atomic-level catalytic sites enables its application to other semiconductor photocatalysts for biomass conversion.
摘要This paper designs an ultra-wideband(UWB)circularly polarized antenna based on Angle of Arrival(AOA)positioning technology.The antenna element adopts a rectangular dual-feed microstrip patch structure,and realizes right-hand circular polarization(RHCP)radiation through a 90°feeding network,which effectively suppresses vehicle multipath interference and polarization mismatch problems;a compact L-shaped three-antenna array is built based on the elements,and the array layout and feeding network are optimized to ensure phase and amplitude consistency.The simulation analysis results show that the operating frequency band of the antenna element can completely cover 6.24~8.24 GHz,with a return loss of≤-10 dB and an axial ratio of≤3.0 dB within this band;the isolation between ports is≤-21dB,the gain is stable at 3.55-5.05 dBi,and the AOA positioning error is≤1.4°(positioning distance 0.5-5 m).The overall size is controlled at 42mm×30mm×2mm,which fully meets the application requirements of automotive digital keys for miniaturization,high precision,and anti-interference.It can be directly integrated into digital key terminals,improving the reliability of contactless unlocking and the security of anti-theft authentication.
基金supported by NSFC(22271282)the Self-deployment Project Research Program of Haixi Institutes,Chinese Academy of Sciences with the grant number of CXZX-2022-JQ04.
摘要Circularly polarized luminescence(CPL)and two-photon absorption(TPA)materials have garnered considerable attentions due to their minimal energy loss and superior optical penetration[1,2].However,the current challenge lies in the absence of well-developed strategies for designing materials that combine these two exceptional optical properties.
基金supported by the National Natural Science Foundation of China(Grant Nos.11804348,11775056,11975154,12225505,and 12405281)the Science Challenge(Project No.TZ2018005)+2 种基金supported by the Shanghai Pujiang Program(Grant No.23PJ1414600)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB0890203)supported by the Accelerator Technology Helmholtz Infrastructure consortium ATHENA.
摘要The effects of initial spin orientation on the final electron beam polarization in laser wakefield acceleration in a pre-polarized plasma are investigated theoretically and numerically.From the results of variation of the initial spin direction,the spin dynamics of the electron beam are found to depend on the self-injection mechanism.The effects of wakefields and laser fields are studied using test particle dynamics and particle-in-cell simulations based on the Thomas-Bargmann-Michel-Telegdi equation.Compared with transverse injection,longitudinal injection is found to be preferable for obtaining a highly polarized electron beam.
基金partly supported by the National Natural Science Foundation of China(42550106,22503093,22288201,22173093,21688102)the Innovation Program for Quantum Science and Technology(2021ZD0303306)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB1170000,XDB0450101)the National Key Research and Development Program of China(2016YFA0200604,2021YFB0300600)the Anhui Province Science and Technology Innovation Project(202423k09020010)the University of Science and Technology of China-Southwest University of Science and Technology Counterpart Cooperation and Development Joint Fund(KY2490002501)the Dream Set Off-Kunpeng&Ascend Seed Program。
摘要KSSOLV(Kohn−Sham solver)is a MAT-LAB(Matrix Laboratory)toolbox de-signed for solving the Kohn-Sham density functional theory(DFT)equations by us-ing the plane-wave basis set.Leveraging the powerful capabilities of MATLAB’s parallel computing toolbox and an ad-vanced,optimized calculation workflow,KSSOLV uniquely enables efficient graph-ics processing unit(GPU)acceleration,making DFT calculations accessible on standard personal computing hardware.Here,KSSOLV-GPU 2.0,as the latest release,demonstrates substantial computational gains.In benchmarks,particularly involving calculations such as hybrid functionals and spin-polar-ized systems for complex band structure analysis,KSSOLV-GPU 2.0 achieves a speedup of more than an order of magnitude compared to conventional central processing unit based im-plementations.This significant acceleration marks a pivotal advancement in performing com-plex materials simulations,making KS-DFT increasingly accessible on personal computing platforms.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFE0134200)the National Natural Science Foundation of China(Grant Nos.12474343,12174147,and 12074142)the Natural Science Foundation of Jilin Province,China(Grant No.20220101016JC)。
摘要Strong feld-induced nonsequential double ionization(NSDI)is a signifcant multi-electron phenomenon that provides crucial insights into understanding electron correlation and multiple ionization of atoms and molecules,but it is typically unattainable in a circularly polarized laser pulse,especially for long-wavelength lasers.We present evidence that NSDI can occur in the presence of a near-infrared or beyond laser pulse by introducing a bowtie-nanotip.The laser-induced local plasmon can alter the local ellipticity of the feld,thereby enabling NSDI through elliptical trajectories that facilitate recollisions with parent atoms.An oval-shaped momentum distribution of recoiled ions provides evidence for the modifcation of trajectories by the aligned nanotips.Our study introduces an innovative control knob to manipulate NSDI and electron dynamics through the utilization of nanostructures.