Here we report on simultaneous lidar observations of sporadic Ni(Nis)layers and sporadic Na(Nas)layers in the atmosphere over Yanqing,Beijing(40.42°N,116.02°E)from April 2019 to October 2022.During 343 night...Here we report on simultaneous lidar observations of sporadic Ni(Nis)layers and sporadic Na(Nas)layers in the atmosphere over Yanqing,Beijing(40.42°N,116.02°E)from April 2019 to October 2022.During 343 nights of observation,68 Nis and 56 Nas were observed.The seasonal variation of Nis and Nas was also obtained,with the highest occurrence of Nis being in July(43%)and that of Nas being in June(61%).We found that the seasonal variation of Nis is similar to that of Nas and that both occur more frequently in summer than in winter.In addition,we found 23 events in which Nis and Nas occur simultaneously.The average peak altitude of Nas is approximately 1 km higher than that of Nis,and the peak density ratio of Nas to Nis is approximately 5,which is half the density ratio of the two main layers.Additionally,the strength factor for Nas is smaller than that for Nis.Through data analysis of sporadic E layers(Es),we found that Nis and Nas has a significant correlation with Es.The neutralization rates of Ni^(+)/Na^(+)were calculated according to the dissociative recombination reaction of Ni^(+)/Na^(+)and the WACCM-Ni(Whole Atmosphere Community Climate Model of Ni).The production rates of Ni and Na were estimated to be approximately 1:4.4,which is consistent with the density ratio of Nis to Nas.The results showed that the neutralization reaction of Ni+,Na+,and electrons in Es is the main reason for the formation of the Nis layer and the Nas layer.展开更多
This study introduces a new ocean surface friction velocity scheme and a modified Thompson cloud microphysics parameterization scheme into the CMA-TYM model.The impact of these two parameterization schemes on the pred...This study introduces a new ocean surface friction velocity scheme and a modified Thompson cloud microphysics parameterization scheme into the CMA-TYM model.The impact of these two parameterization schemes on the prediction of the movement track and intensity of Typhoon Kompasu in 2021 is examined.Additionally,the possible reasons for their effects on tropical cyclone(TC)intensity prediction are analyzed.Statistical results show that both parameterization schemes improve the predictions of Typhoon Kompasu’s track and intensity.The influence on track prediction becomes evident after 60 h of model integration,while the significant positive impact on intensity prediction is observed after 66 h.Further analysis reveals that these two schemes affect the timing and magnitude of extreme TC intensity values by influencing the evolution of the TC’s warm-core structure.展开更多
The atmospheric surface layer of the tropical coastal ocean is commonly very unstable and experiences weakwind conditions.How the latent(LE)and sensible(H)heat fluxes behave under such conditions are unclear because o...The atmospheric surface layer of the tropical coastal ocean is commonly very unstable and experiences weakwind conditions.How the latent(LE)and sensible(H)heat fluxes behave under such conditions are unclear because of the lack of observation stations in the tropics.Thus,this study aims to analyze LE and H and the microclimate parameters influencing them.The authors deployed an eddy covariance system in a tropical coastal region for seven months.The microclimate parameters investigated were wind speed(U),vapor pressure deficit(Δe),temperature difference(ΔT),wind-vapor pressure deficit(UΔe),wind-temperature difference(UΔT),and atmospheric stability(z/L),where z is height and L is the Monin–Obukhov length.On the daily time scale,the results show that LE was more associated with U thanΔe,while H was more related toΔT than U.Cross-wavelet analysis revealed the strong coherence in the LE-U relationship for periods between one and two days,and for H–ΔT,0.5 to 1 day.Correlation and regression analyses confirmed the time series analyses results,where strong positive correlation coefficients(r)were obtained between LE and U(r=0.494)and H andΔT(r=0.365).Compared to other water bodies,the transfer coefficient of moisture(CE N)was found to be small(=0.40×10^(-3))and independent of stability;conversely,the transfer coefficient of heat(CH N)was closer to literature values(=1.00×10^(-3))and a function of stability.展开更多
Layered oxides have attracted significant attention as cathodes for sodium-ion batteries(SIBs)due to their compositional versatility and tuneable electrochemical performance.However,these materials still face challeng...Layered oxides have attracted significant attention as cathodes for sodium-ion batteries(SIBs)due to their compositional versatility and tuneable electrochemical performance.However,these materials still face challenges such as structural phase transitions,Na^(+)/vacancy ordering,and Jahn–Teller distortion effect,resulting in severe capacity decay and sluggish ion kinetics.We develop a novel Cu/Y dual-doping strategy that leads to the formation of"Na–Y"interlayer aggregates,which act as structural pillars within alkali metal layers,enhancing structural stability and disrupting the ordered arrangement of Na^(+)/vacancies.This disruption leads to a unique coexistence of ordered and disordered Na^(+)/vacancy states with near-zero strain,which significantly improves Na^(+)diffusion kinetics.This structural innovation not only mitigates the unfavorable P2–O2 phase transition but also facilitates rapid ion transport.As a result,the doped material demonstrates exceptional electrochemical performance,including an ultra-long cycle life of 3000 cycles at 10 C and an outstanding high-rate capability of~70 mAh g^(−1)at 50 C.The discovery of this novel interlayer pillar,along with its role in modulating Na^(+)/vacancy arrangements,provides a fresh perspective on engineering layered oxides.It opens up promising new pathways for the structural design of advanced cathode materials toward efficient,stable,and high-rate SIBs.展开更多
The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter per...The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.展开更多
The transition to sustainable energy systems necessitates efficient hydrogen production via water electrolysis,with anion-exchange membrane water electrolyzers(AEMWEs)emerging as a cost-effective alternative by combin...The transition to sustainable energy systems necessitates efficient hydrogen production via water electrolysis,with anion-exchange membrane water electrolyzers(AEMWEs)emerging as a cost-effective alternative by combining the merits of alkaline water electrolyzers(AWEs)and proton-exchange membrane water electrolyzers(PEMWEs).However,challenges persist in membrane stability,oxygen evolution reaction(OER)kinetics,and mass transport efficiency.This review highlights the pivotal role of transition metal-based layered double hydroxides(LDHs)as high-performance,non-precious OER catalysts for AEMWEs,emphasizing their tunable electronic structures,abundant active sites,and alkaline stability.We systematically outline LDHs synthesis strategies(top-down/bottom-up approaches,and self-supporting LDHs engineering on the conductive substrates),and AEMWE component design,including membraneelectrode assembly optimization and ionomer-free architectures.Standardized evaluation protocols-short-circuit inspection,impedance spectroscopy,and durability assessment are detailed to benchmark performance.Moreover,recent advances in LDHs modification(cation/anion doping,heterojunction design,three-dimensional(3D)electrode structuring)are discussed for alkaline-fed systems,alongside emerging applications in seawater and pure-water electrolysis.By correlating material innovations with device-level metrics,this work provides a roadmap to address scalability challenges,offering perspectives on advancing AEMWEs for sustainable,large-scale hydrogen production.展开更多
The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges be...The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges between 0.2 and 0.4.This enhancement prompts a critical question:to what extent can quantum wells(QWs)be strained while still preserving the fundamental QSHI phase?In this study,we demonstrate the controlled molecular beam epitaxial growth of highly strained-layer QWs with an indium composition of x=0.5.These structures possess a substantial compressive strain within the In_(0.5)Ga_(0.5)Sb QW.Detailed crystal structure analyses confirm the exceptional quality of the resulting epitaxial films,indicating coherent lattice structures and the absence of visible dislocations.Transport measurements further reveal that the QSHI phase in InAs/In_(0.5)Ga_(0.5)Sb QWs is robust and protected by time-reversal symmetry.Notably,the edge states in these systems exhibit giant magnetoresistance when subjected to a modest perpendicular magnetic field.This behavior is in agreement with the𝑍2 topological property predicted by the Bernevig–Hughes–Zhang model,confirming the preservation of topologically protected edge transport in the presence of enhanced bulk strain.展开更多
Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding str...Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective.展开更多
Layer pseudospins,exhibiting quantum coherence and precise multistate controllability,present significant potential for the advancement of future computing technologies.In this work,we propose an in-memory probabilist...Layer pseudospins,exhibiting quantum coherence and precise multistate controllability,present significant potential for the advancement of future computing technologies.In this work,we propose an in-memory probabilistic computing scheme based on the electrical manipulation of layer pseudospins in layered materials,by exploiting the interaction between real spins and layer pseudospins.展开更多
Background Postoperative delirium is one of the most common complications in the older surgical population,but its pathogenesis and biomarkers are largely undetermined.Retinal layer thickness has been demonstrated to ...Background Postoperative delirium is one of the most common complications in the older surgical population,but its pathogenesis and biomarkers are largely undetermined.Retinal layer thickness has been demonstrated to be associated with cognitive function in mild cognitive impairment and patients with Alzheimer’s disease.However,relatively little is known about possible retinal layer thickness among patients with postoperative delirium.Aims We aimed to investigate the relationship between retinal layer thickness and postoperative delirium in this cross-sectional study.Methods The participants(≥65 years old)having elective surgery under general anaesthesia were screened via medical records from Shanghai 10th People’s Hospital.Preoperative macular thickness and peripapillary retinal nerve fibre layer(RNFL)thickness were measured using optical coherence tomography(OCT).The Confusion Assessment Method(CAM)algorithm and CAM-Severity(CAM-S)were used to assess the incidence and severity of postoperative delirium on the first,second and third days after surgery.Results Among 169 participants(mean(standard deviation(SD)71.15(4.36)years),40(24%)developed postoperative delirium.Notably,individuals who developed postoperative delirium exhibited thicker preoperative macular thickness in the right eye compared with those who did not(mean(SD)283.35(27.97)µm vs 273.84(20.14)µm,p=0.013).Furthermore,the thicker preoperative macular thickness of the right eye was associated with a higher incidence of postoperative delirium(adjusted odds ratio 1.593,95%confidence interval(CI)1.093 to 2.322,p=0.015)and greater severity(adjusted mean difference(β)=0.256,95%CI 0.037 to 0.476,p=0.022)after adjustment for age,sex and Mini-Mental State Examination(MMSE)scores.However,such a difference or association did not appear in the left macular or bilateral peripapillary RNFL thicknesses.Conclusions Current findings demonstrated that preoperative macular thickness might serve as a potential non-invasive marker for the vulnerability of developing postoperative delirium in older surgical patients.Further large-scale validation studies should be performed to confirm these results.展开更多
Recent advances in two-dimensional layered systems have greatly enriched electronic transport studies, particularly in inter-layer Coulomb drag research. Here, systematic transport measurements were conducted in graph...Recent advances in two-dimensional layered systems have greatly enriched electronic transport studies, particularly in inter-layer Coulomb drag research. Here, systematic transport measurements were conducted in graphene-based electronic double-layer structures, revealing giant yet reproducible drag fluctuations at cryogenic temperatures. These fluctuations' characteristics, including amplitude and peak/valley spacing, are mainly determined by the drag layer's carrier dynamics rather than the drive layer's, resulting in violation of the Onsager reciprocity relation. Notably, the drag fluctuations remain observable up to 35 K, far exceeding universal conductance fluctuations within individual layers. This suggests enhanced phase coherence in inter-layer drag compared to single-layer transport, as further confirmed by quantitative analysis of auto-correlation fields of fluctuations under magnetic fields. Our findings provide new insights into quantum interference effects and their interplay with Coulomb interactions in solids. The observations of significant drag fluctuations could potentially help address chaotic signals between nearby components in nanoscale devices.展开更多
Separator modification is an effective approach to suppress dendrite growth to realize high-energy sodium metal batteries(SMBs)in practical applications,however,its success is mainly subject to surface modification.He...Separator modification is an effective approach to suppress dendrite growth to realize high-energy sodium metal batteries(SMBs)in practical applications,however,its success is mainly subject to surface modification.Herein,a separator with multifunctional layers composed of N-doped mesoporous hollow carbon spheres(HCS)as the inner layer and sodium fluoride(NaF)as the outer layer on commercial polypropylene separator(PP)is proposed(PP@HCS-NaF)to achieve stable cycling in SMB.At the molecular level,the inner HCS layer with a high content of pyrrolic-N induces the uniform Na^(+)flux as a potential Na^(+)redistributor for homogenous deposition,whereas its hollow mesoporous structure offers nanoporous buffers and ion channels to regulate Na^(+)ion distribution and uniform deposition.The outer layer(NaF)constructs the NaF-enriched robust solid electrolyte interphase layer,significantly lowering the Na^(+)ions diffusion barrier.Benefiting from these merits,higher electrochemical performances are achieved with multifunctional double-layered PP@HCS-NaF separators compared with single-layered separators(i.e.PP@HCS or PP@NaF)in SMBs.The Na‖Cu half-cell with PP@HCS-NaF offers stable cycling(280 cycles)with a high CE(99.6%),and Na‖Na symmetric cells demonstrate extended lifespans for over 6000 h at 1 mA cm^(-2)with a progressively stable overpotential of 9 mV.Remarkably,in Na‖NVP full-cells,the PP@HCS-NaF separator grants a stable capacity of~81 mA h g^(-1)after 3500 cycles at 1 C and an impressive rate capability performance(~70 mA h g^(-1)at 15 C).展开更多
Nickel-rich(Ni≥90%)layered oxides materials have emerged as a promising candidate for nextgeneration high-energy-density lithium-ion batteries(LIBs).However,their widespread application is hindered by structural fati...Nickel-rich(Ni≥90%)layered oxides materials have emerged as a promising candidate for nextgeneration high-energy-density lithium-ion batteries(LIBs).However,their widespread application is hindered by structural fatigue and lattice oxygen loss.In this work,an epitaxial surface rock-salt nanolayer is successfully developed on the LiNi_(0.9)Co_(0.1)O_(2)sub-surface via heteroatom anchoring utilizing high-valence element molybdenum modification.This in-situ formed conformal buffer phase with a thickness of 1.2 nm effectively suppresses the continuous interphase side-reactions,and thus maintains the excellent structure integrity at high voltage.Furthermore,theoretical calculations indicate that the lattice oxygen reversibility in the anion framework of the optimized sample is obviously enhanced due to the higher content of O 2p states near the Fermi level than that of the pristine one.Meanwhile,the stronger Mo-O bond further reduces cell volume alteration,which improves the bulk structure stability of modified materials.Besides,the detailed charge compensation mechanism suggests that the average oxidation state of Ni is reduced,which induces more active Li+participating in the redox reactions,boosting the cell energy density.As a result,the uniquely designed cathode materials exhibit an extraordinary discharge capacity of 245.4 mAh g^(-1)at 0.1 C,remarkable rate performance of 169.3 mAh g^(-1)at 10 C at 4.5 V,and a high capacity retention of 70.5% after 1000 cycles in full cells at a high cut-off voltage of 4.4 V.This strategy provides an valuable insight into constructing distinctive heterostructure on highperformance Ni-rich layered cathodes for LIBs.展开更多
Optical data storage(ODS)is a low-cost and high-durability counterpart of traditional electronic or mag-netic storage.As a means of enhancing ODS capacity,the multiple recording layer(MRL)method is more promising than...Optical data storage(ODS)is a low-cost and high-durability counterpart of traditional electronic or mag-netic storage.As a means of enhancing ODS capacity,the multiple recording layer(MRL)method is more promising than other approaches such as reducing the recording volume and multiplexing technology.However,the architecture of current MRLs is identical to that of recording data into physical layers with rigid space,which leads to either severe interlayer crosstalk or finite recording layers constrained by the short working distances of the objectives.Here,we propose the concept of hybrid-layer ODS,which can record optical information into a physical layer and multiple virtual layers by using high-orthogonality random meta-channels.In the virtual layer,32 images are experimentally reconstructed through holog-raphy,where their holographic phases are encoded into 16 printed images and complementary images in the physical layer,yielding a capacity of 2.5 Tbit cm^(-3).A higher capacity is achievable with more virtual layers,suggesting hybrid-layer ODS as a possible candidate for next-generation ODS.展开更多
Aqueous zinc batteries offer significant potential for large-scale energy storage,wearable devices,and medium-to low-speed transportation due to their safety,affordability,and environmental friendliness.However,the un...Aqueous zinc batteries offer significant potential for large-scale energy storage,wearable devices,and medium-to low-speed transportation due to their safety,affordability,and environmental friendliness.However,the uneven zinc deposition at the anode side caused by localized reaction activity from the passivation layer presents challenges that significantly impact the battery's stability and lifespan.In this study,we have proposed an expandable and maneuverable gel sustained-release(GSR)treatment to polish the Zn metal,which in situ converts its native passivation layer into a composite interphase layer with nanocrystal zinc phosphate and flexible polyvinyl alcohol.Such a thin and uniform interface contributes to fast and homogeneous Zn ion transport and improved anti-corrosion ability,enabling uniform zinc deposition without dendrite growth and thereby improving the battery performance with high-rate ability and long cycle life.This GSR treatment method,characterized by its simplicity,low cost,and universality,facilitates the widespread application of aqueous zinc batteries.展开更多
Due to the coexistence of compressibility,viscosity,and threedimensional effects,laminar flow is difficult to maintain for high-speed boundary layer on complex geometries.The unstable disturbance waves in the boundary...Due to the coexistence of compressibility,viscosity,and threedimensional effects,laminar flow is difficult to maintain for high-speed boundary layer on complex geometries.The unstable disturbance waves in the boundary layer are excited and rapidly increase during the receptivity process,so sufficiently large Reynolds stress causes the basic flow velocity profile to change,and the formation of turbulence is inevitable.展开更多
Two-dimensional transition metal carbon/nitrides(MXenes)have emerged as prominent materials in the development of high-performance electromagnetic interference(EMI)shielding films owing to their ex-ceptional electrica...Two-dimensional transition metal carbon/nitrides(MXenes)have emerged as prominent materials in the development of high-performance electromagnetic interference(EMI)shielding films owing to their ex-ceptional electrical conductivity,special layered structure,and chemically active surfaces.Substantial ef-forts have been devoted to addressing the poor mechanical strength and limited functionality of pure MXene films through structural design and interfacial reinforcement.However,there is a notable lack of a systematic review of the research on MXene-based EMI shielding films with multi-layer structures,which could provide a theoretical foundation and technical guidance for the development and application of shielding films.This review aims to summarize the recent advancements in MXene-based layered films for EMI shielding.First,the structure and properties of MXene nanosheets are systematically introduced.Next,the optimization of layered structures and interfacial reinforcement strategies in MXene-based EMI shielding films are objectively reviewed,followed by a discussion of their multifunctional compatibility.Finally,future prospects and challenges for MXene-based layered EMI shielding films are highlighted.展开更多
AIM:To evaluate parameters measured using the tear film imager(TFI)prototype,a new technology that enables to quantify the tear film thickness of lipid and mucoaqueous layers.METHODS:In this cross-sectional study,pati...AIM:To evaluate parameters measured using the tear film imager(TFI)prototype,a new technology that enables to quantify the tear film thickness of lipid and mucoaqueous layers.METHODS:In this cross-sectional study,patients with dry eye,meibomian gland dysfunction(MGD),and non-dry eye/MGD from February 2020 to January 2021 were analyzed.Quantified TFI outputs included lipid layer thickness(LLT),mucoaqueous layer thickness(MALT),MALT rate of change(MALTR),and lipid breakup time.Two other interferometry devices,LipiView2 and DR-1α,were used for comparison.TFI outputs and other clinical parameters were analyzed using correlation coefficients.Each patient underwent one or several study visits.Baseline values of three device outputs,other clinical parameters,and their changes were examined.RESULTS:This study involved 28 patients(8 patients with dry eyes,13 with MGD,and 7 with non-dry eye/MGD).Baseline TFI,LipiView2,and DR-1αvalues were associated with various clinical parameters.The LLT values estimated using TFI had a correlation with the plugging score in the upper eyelid(r=−0.42).Several TFI values have correlated better than LipiView2 and DR-1α,particularly with questionnaire scores.MALTR by TFI revealed a correlation between standardized patient evaluation on eye dryness(SPEED)and dry eye-related quality of life score(DEQS)scores(r=0.59,0.43),respectively.CONCLUSION:TFI enabled to quantify the LLT and MALT separately over time and shows the moderate correlations between TFI measurements and clinical parameters,which yields the potential for TFI to serve as a complementary tool for assessing dry eye and MGD.展开更多
Layered rocks are widely distributed in sedimentary and metamorphic rocks and show anisotropic deformation and strength due to the layered structures with apparent weak surfaces.This study summarizes the findings on t...Layered rocks are widely distributed in sedimentary and metamorphic rocks and show anisotropic deformation and strength due to the layered structures with apparent weak surfaces.This study summarizes the findings on the deformation and damage characteristics of layered rock masses and surrounding rocks.The physicomechanical properties of layered rocks with different properties(e.g.inclination,shear strength,tensile strength,shear stiffness,roughness,and layer spacing)and different lithological and stress conditions are analyzed.The results revealed that with increasing layer inclination angles,the deformation and strength parameters of the rock masses present U-shaped,W-shaped,incremental,decremental,and basically unchanged trends,which are closely related to their strength and stress conditions.The increase in layer strength and confining pressure effectively suppresses the deformation and strength anisotropy caused by layer weakening,and the rock mass shifts from“structure-controlled”to“stress-structure-controlled”deformation mode.Water will increase the anisotropic behavior of layered rock masses due to the degradation of bedding and bedrock performance.The anisotropic behavior of the layered surrounding rocks is analyzed to reveal how it affects the deformation and failure behaviors of tunnels.The asymmetric characteristics of surrounding rock deformation are closely related to the layer weakening,layer thickness,and in situ stress.These findings are crucial for understanding layered rock mass deformation and failure mechanisms,facilitating prediction and control of tunnel deformation.展开更多
Developing cathode catalyst layers(CCL)with efficient mass transport capability is crucial to developing ultra-low Pt loading(<50μg·cm^(-2))proton exchange membrane fuel cells(PEMFCs).Herein,CCLs with various...Developing cathode catalyst layers(CCL)with efficient mass transport capability is crucial to developing ultra-low Pt loading(<50μg·cm^(-2))proton exchange membrane fuel cells(PEMFCs).Herein,CCLs with various pore distributions were constructed by depositing Pt onto the integrated carbonaceous films consisting of carbon nanoparticles(CNs),three-dimensional(3D)graphene nanosheets(GNs),and nanocomposites of CNs and GNs(CNs-GNs),respectively.The hierarchical mesoporous pore distributions of CCLs strongly affect the effective exposure of Pt active sites,proton-transfer resistance,and oxygen mass transport efficiencies related to Knudsen diffusion and local resistance at the Pt/ionomer interface.The CCL with Pt/CNs-GNs(50.0μgPt·cm^(-2))features a unique tri-modal pore distribution concentrated at 10.2,20.4,and 43.7 nm,providing efficient three-phase boundaries with a significantly higher active surface area of 49.67 m2·g^(-1),lower oxygen transport resistance and proton resistance of down to 18.68 s·m^(-1) and 0.0603Ω·cm^(2),compared with Pt/CNs(31.48 m^(2)·g^(-1),41.17 s·m^(-1),and 0.0702Ω·cm^(2))with a single-modal pore distribution at 9.5 nm and Pt/GNs(38.21 m^(2)·g^(-1),33.40 s·m^(-1),and 0.0654Ω·cm^(2))with a bi-modal pore distribution at 9.8 and 20.9 nm.Correspondingly,the cell with Pt/CNs-GNs delivers a high power output of up to 1.01 W·cm^(-2) and presents a high durability that satisfies the 2025 targets set by the U.S.Department of Energy.This work provides new insights into the critical role of hierarchically mesoporous pore distribution of CCL for constructing high-performance PEMFCs with ultra-low Pt loading<50μg·cm^(-2).展开更多
基金supported by the Specialized Research Fund for State Key Laboratories,Chinese Meridian Project,the Specialized Research Fund for the State Key Laboratory of Solar Activity and Space Weather,postgraduate Education Reform and Quality Improvement Project of Henan Province(Grant No.YJS2024JD32)Natural Science Foundation Project of Henan Province(Grant No.242300420253)National Natural Science Foundation of China for Young Scientists(Grant No.42504156)funding.
文摘Here we report on simultaneous lidar observations of sporadic Ni(Nis)layers and sporadic Na(Nas)layers in the atmosphere over Yanqing,Beijing(40.42°N,116.02°E)from April 2019 to October 2022.During 343 nights of observation,68 Nis and 56 Nas were observed.The seasonal variation of Nis and Nas was also obtained,with the highest occurrence of Nis being in July(43%)and that of Nas being in June(61%).We found that the seasonal variation of Nis is similar to that of Nas and that both occur more frequently in summer than in winter.In addition,we found 23 events in which Nis and Nas occur simultaneously.The average peak altitude of Nas is approximately 1 km higher than that of Nis,and the peak density ratio of Nas to Nis is approximately 5,which is half the density ratio of the two main layers.Additionally,the strength factor for Nas is smaller than that for Nis.Through data analysis of sporadic E layers(Es),we found that Nis and Nas has a significant correlation with Es.The neutralization rates of Ni^(+)/Na^(+)were calculated according to the dissociative recombination reaction of Ni^(+)/Na^(+)and the WACCM-Ni(Whole Atmosphere Community Climate Model of Ni).The production rates of Ni and Na were estimated to be approximately 1:4.4,which is consistent with the density ratio of Nis to Nas.The results showed that the neutralization reaction of Ni+,Na+,and electrons in Es is the main reason for the formation of the Nis layer and the Nas layer.
基金supported by the National Key R&D Program of China[grant number 2023YFC3008004]。
文摘This study introduces a new ocean surface friction velocity scheme and a modified Thompson cloud microphysics parameterization scheme into the CMA-TYM model.The impact of these two parameterization schemes on the prediction of the movement track and intensity of Typhoon Kompasu in 2021 is examined.Additionally,the possible reasons for their effects on tropical cyclone(TC)intensity prediction are analyzed.Statistical results show that both parameterization schemes improve the predictions of Typhoon Kompasu’s track and intensity.The influence on track prediction becomes evident after 60 h of model integration,while the significant positive impact on intensity prediction is observed after 66 h.Further analysis reveals that these two schemes affect the timing and magnitude of extreme TC intensity values by influencing the evolution of the TC’s warm-core structure.
基金supported by a PETRONAS-Academia Collabora-tion Dialogue 2022 Grant[Grant number PACD 2022]from PETRONAS Research Sdn.Bhd。
文摘The atmospheric surface layer of the tropical coastal ocean is commonly very unstable and experiences weakwind conditions.How the latent(LE)and sensible(H)heat fluxes behave under such conditions are unclear because of the lack of observation stations in the tropics.Thus,this study aims to analyze LE and H and the microclimate parameters influencing them.The authors deployed an eddy covariance system in a tropical coastal region for seven months.The microclimate parameters investigated were wind speed(U),vapor pressure deficit(Δe),temperature difference(ΔT),wind-vapor pressure deficit(UΔe),wind-temperature difference(UΔT),and atmospheric stability(z/L),where z is height and L is the Monin–Obukhov length.On the daily time scale,the results show that LE was more associated with U thanΔe,while H was more related toΔT than U.Cross-wavelet analysis revealed the strong coherence in the LE-U relationship for periods between one and two days,and for H–ΔT,0.5 to 1 day.Correlation and regression analyses confirmed the time series analyses results,where strong positive correlation coefficients(r)were obtained between LE and U(r=0.494)and H andΔT(r=0.365).Compared to other water bodies,the transfer coefficient of moisture(CE N)was found to be small(=0.40×10^(-3))and independent of stability;conversely,the transfer coefficient of heat(CH N)was closer to literature values(=1.00×10^(-3))and a function of stability.
基金supported by the“Pioneer”and“Leading Goose”R&D Program of Zhejiang Province of China(No.2024C01056)。
文摘Layered oxides have attracted significant attention as cathodes for sodium-ion batteries(SIBs)due to their compositional versatility and tuneable electrochemical performance.However,these materials still face challenges such as structural phase transitions,Na^(+)/vacancy ordering,and Jahn–Teller distortion effect,resulting in severe capacity decay and sluggish ion kinetics.We develop a novel Cu/Y dual-doping strategy that leads to the formation of"Na–Y"interlayer aggregates,which act as structural pillars within alkali metal layers,enhancing structural stability and disrupting the ordered arrangement of Na^(+)/vacancies.This disruption leads to a unique coexistence of ordered and disordered Na^(+)/vacancy states with near-zero strain,which significantly improves Na^(+)diffusion kinetics.This structural innovation not only mitigates the unfavorable P2–O2 phase transition but also facilitates rapid ion transport.As a result,the doped material demonstrates exceptional electrochemical performance,including an ultra-long cycle life of 3000 cycles at 10 C and an outstanding high-rate capability of~70 mAh g^(−1)at 50 C.The discovery of this novel interlayer pillar,along with its role in modulating Na^(+)/vacancy arrangements,provides a fresh perspective on engineering layered oxides.It opens up promising new pathways for the structural design of advanced cathode materials toward efficient,stable,and high-rate SIBs.
基金supported by the National Natural Science Foundation of China(52471240)the Natural Science Foundation of Zhejiang Province(LZ23B030003)+2 种基金the Fundamental Research Funds for the Central Universities(226-2024-00075)support from the Engineering and Physical Sciences Research Council(EPSRC,UK)RiR grant-RIR18221018-1EU COST CA23155。
文摘The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.
基金supported by the National Natural Science Foundation of China(Nos.52122308 and 22305225)the Postdoctoral Fellowship Program of CPSF(No.GZC20232391).
文摘The transition to sustainable energy systems necessitates efficient hydrogen production via water electrolysis,with anion-exchange membrane water electrolyzers(AEMWEs)emerging as a cost-effective alternative by combining the merits of alkaline water electrolyzers(AWEs)and proton-exchange membrane water electrolyzers(PEMWEs).However,challenges persist in membrane stability,oxygen evolution reaction(OER)kinetics,and mass transport efficiency.This review highlights the pivotal role of transition metal-based layered double hydroxides(LDHs)as high-performance,non-precious OER catalysts for AEMWEs,emphasizing their tunable electronic structures,abundant active sites,and alkaline stability.We systematically outline LDHs synthesis strategies(top-down/bottom-up approaches,and self-supporting LDHs engineering on the conductive substrates),and AEMWE component design,including membraneelectrode assembly optimization and ionomer-free architectures.Standardized evaluation protocols-short-circuit inspection,impedance spectroscopy,and durability assessment are detailed to benchmark performance.Moreover,recent advances in LDHs modification(cation/anion doping,heterojunction design,three-dimensional(3D)electrode structuring)are discussed for alkaline-fed systems,alongside emerging applications in seawater and pure-water electrolysis.By correlating material innovations with device-level metrics,this work provides a roadmap to address scalability challenges,offering perspectives on advancing AEMWEs for sustainable,large-scale hydrogen production.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (Grant Nos.XDB28000000 and XDB0460000)the Quantum Science and Technology-National Science and Technology Major Project (Grant No.2021ZD0302600)the National Key Research and Development Program of China(Grant No.2024YFA1409002)。
文摘The hybridization gap in strained-layer InAs/In_(x)Ga_(1−x) Sb quantum spin Hall insulators(QSHIs)is significantly enhanced compared to binary InAs/GaSb QSHI structures,where the typical indium composition,x,ranges between 0.2 and 0.4.This enhancement prompts a critical question:to what extent can quantum wells(QWs)be strained while still preserving the fundamental QSHI phase?In this study,we demonstrate the controlled molecular beam epitaxial growth of highly strained-layer QWs with an indium composition of x=0.5.These structures possess a substantial compressive strain within the In_(0.5)Ga_(0.5)Sb QW.Detailed crystal structure analyses confirm the exceptional quality of the resulting epitaxial films,indicating coherent lattice structures and the absence of visible dislocations.Transport measurements further reveal that the QSHI phase in InAs/In_(0.5)Ga_(0.5)Sb QWs is robust and protected by time-reversal symmetry.Notably,the edge states in these systems exhibit giant magnetoresistance when subjected to a modest perpendicular magnetic field.This behavior is in agreement with the𝑍2 topological property predicted by the Bernevig–Hughes–Zhang model,confirming the preservation of topologically protected edge transport in the presence of enhanced bulk strain.
基金supported by the National Key R&D Program of China (No. 2018YFA0707300)the National Natural Science Foundation of China (No. 52374376)the Introduction Plan for High end Foreign Experts, China (No. G2023105001L)。
文摘Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective.
基金supported by the National Natural Science Foundation of China(Grant Nos.12322407,62122036,and 62034004)the Natural Science Foundation of Jiangsu Province(Grant No.BK20233001)+5 种基金the National Key R&D Program of China(Grant Nos.2023YFF0718400 and 2023YFF1203600)the Leading-edge Technology Program of Jiangsu Natural Science Foundation(Grant No.BK20232004)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB44000000)Innovation Program for Quantum Science and Technologysupport from the Fundamental Research Funds for the Central Universities(Grant Nos.020414380227,020414380240,and 020414380242)the e-Science Center of Collaborative Innovation Center of Advanced Microstructures。
文摘Layer pseudospins,exhibiting quantum coherence and precise multistate controllability,present significant potential for the advancement of future computing technologies.In this work,we propose an in-memory probabilistic computing scheme based on the electrical manipulation of layer pseudospins in layered materials,by exploiting the interaction between real spins and layer pseudospins.
基金supported by grants from National Natural Science Foundation of China(81720108012,82001118)Ministry of Science and Technology of China(2021ZD0202003)+1 种基金Shanghai‘Rising Stars of Medical Talents’Youth Development Program(SHWSRS(2023)-62)Henry K.Beecher Professorship from Harvard University。
文摘Background Postoperative delirium is one of the most common complications in the older surgical population,but its pathogenesis and biomarkers are largely undetermined.Retinal layer thickness has been demonstrated to be associated with cognitive function in mild cognitive impairment and patients with Alzheimer’s disease.However,relatively little is known about possible retinal layer thickness among patients with postoperative delirium.Aims We aimed to investigate the relationship between retinal layer thickness and postoperative delirium in this cross-sectional study.Methods The participants(≥65 years old)having elective surgery under general anaesthesia were screened via medical records from Shanghai 10th People’s Hospital.Preoperative macular thickness and peripapillary retinal nerve fibre layer(RNFL)thickness were measured using optical coherence tomography(OCT).The Confusion Assessment Method(CAM)algorithm and CAM-Severity(CAM-S)were used to assess the incidence and severity of postoperative delirium on the first,second and third days after surgery.Results Among 169 participants(mean(standard deviation(SD)71.15(4.36)years),40(24%)developed postoperative delirium.Notably,individuals who developed postoperative delirium exhibited thicker preoperative macular thickness in the right eye compared with those who did not(mean(SD)283.35(27.97)µm vs 273.84(20.14)µm,p=0.013).Furthermore,the thicker preoperative macular thickness of the right eye was associated with a higher incidence of postoperative delirium(adjusted odds ratio 1.593,95%confidence interval(CI)1.093 to 2.322,p=0.015)and greater severity(adjusted mean difference(β)=0.256,95%CI 0.037 to 0.476,p=0.022)after adjustment for age,sex and Mini-Mental State Examination(MMSE)scores.However,such a difference or association did not appear in the left macular or bilateral peripapillary RNFL thicknesses.Conclusions Current findings demonstrated that preoperative macular thickness might serve as a potential non-invasive marker for the vulnerability of developing postoperative delirium in older surgical patients.Further large-scale validation studies should be performed to confirm these results.
基金supported by the National Natural Science Foundation of China (Grant Nos.12474051 and 92165201)the Chinese Academy of Sciences Project for Young Scientists in Basic Research (Grant No.YSBR-046)+1 种基金the National Key Research and Development Program of China (Grant No.2023YFA1406300)the Anhui Provincial Natural Science Foundation (Grant Nos.2308085J11 and2308085QA14)。
文摘Recent advances in two-dimensional layered systems have greatly enriched electronic transport studies, particularly in inter-layer Coulomb drag research. Here, systematic transport measurements were conducted in graphene-based electronic double-layer structures, revealing giant yet reproducible drag fluctuations at cryogenic temperatures. These fluctuations' characteristics, including amplitude and peak/valley spacing, are mainly determined by the drag layer's carrier dynamics rather than the drive layer's, resulting in violation of the Onsager reciprocity relation. Notably, the drag fluctuations remain observable up to 35 K, far exceeding universal conductance fluctuations within individual layers. This suggests enhanced phase coherence in inter-layer drag compared to single-layer transport, as further confirmed by quantitative analysis of auto-correlation fields of fluctuations under magnetic fields. Our findings provide new insights into quantum interference effects and their interplay with Coulomb interactions in solids. The observations of significant drag fluctuations could potentially help address chaotic signals between nearby components in nanoscale devices.
基金supported by the National Natural Science Foundation of China(Grant Number 22350410379)Zhejiang Provincial Natural Science Foundation of China(LZ23B030003)+1 种基金the Fundamental Research Funds for the Central Universities(226-202400075)Ten Thousand Talent Program of Zhejiang Province.
文摘Separator modification is an effective approach to suppress dendrite growth to realize high-energy sodium metal batteries(SMBs)in practical applications,however,its success is mainly subject to surface modification.Herein,a separator with multifunctional layers composed of N-doped mesoporous hollow carbon spheres(HCS)as the inner layer and sodium fluoride(NaF)as the outer layer on commercial polypropylene separator(PP)is proposed(PP@HCS-NaF)to achieve stable cycling in SMB.At the molecular level,the inner HCS layer with a high content of pyrrolic-N induces the uniform Na^(+)flux as a potential Na^(+)redistributor for homogenous deposition,whereas its hollow mesoporous structure offers nanoporous buffers and ion channels to regulate Na^(+)ion distribution and uniform deposition.The outer layer(NaF)constructs the NaF-enriched robust solid electrolyte interphase layer,significantly lowering the Na^(+)ions diffusion barrier.Benefiting from these merits,higher electrochemical performances are achieved with multifunctional double-layered PP@HCS-NaF separators compared with single-layered separators(i.e.PP@HCS or PP@NaF)in SMBs.The Na‖Cu half-cell with PP@HCS-NaF offers stable cycling(280 cycles)with a high CE(99.6%),and Na‖Na symmetric cells demonstrate extended lifespans for over 6000 h at 1 mA cm^(-2)with a progressively stable overpotential of 9 mV.Remarkably,in Na‖NVP full-cells,the PP@HCS-NaF separator grants a stable capacity of~81 mA h g^(-1)after 3500 cycles at 1 C and an impressive rate capability performance(~70 mA h g^(-1)at 15 C).
基金financially supported by the National Natural Science Foundation of China(No.52202228,52402298)funded by the Science Research Project of Hebei Education Department(No.BJK2022011)+3 种基金the Central Funds Guiding the Local Science and Technology Development of Hebei Province(No.236Z4404G)the Beijing Tianjin Hebei Basic Research Cooperation Special Project(No.E2024202273)the Science and Technology Correspondent Project of Tianjin(24YDTPJC00240)supported by the U.S.Department of Energy’s Office of Science,Office of Basic Energy Science,Materials Sciences and Engineering Division。
文摘Nickel-rich(Ni≥90%)layered oxides materials have emerged as a promising candidate for nextgeneration high-energy-density lithium-ion batteries(LIBs).However,their widespread application is hindered by structural fatigue and lattice oxygen loss.In this work,an epitaxial surface rock-salt nanolayer is successfully developed on the LiNi_(0.9)Co_(0.1)O_(2)sub-surface via heteroatom anchoring utilizing high-valence element molybdenum modification.This in-situ formed conformal buffer phase with a thickness of 1.2 nm effectively suppresses the continuous interphase side-reactions,and thus maintains the excellent structure integrity at high voltage.Furthermore,theoretical calculations indicate that the lattice oxygen reversibility in the anion framework of the optimized sample is obviously enhanced due to the higher content of O 2p states near the Fermi level than that of the pristine one.Meanwhile,the stronger Mo-O bond further reduces cell volume alteration,which improves the bulk structure stability of modified materials.Besides,the detailed charge compensation mechanism suggests that the average oxidation state of Ni is reduced,which induces more active Li+participating in the redox reactions,boosting the cell energy density.As a result,the uniquely designed cathode materials exhibit an extraordinary discharge capacity of 245.4 mAh g^(-1)at 0.1 C,remarkable rate performance of 169.3 mAh g^(-1)at 10 C at 4.5 V,and a high capacity retention of 70.5% after 1000 cycles in full cells at a high cut-off voltage of 4.4 V.This strategy provides an valuable insight into constructing distinctive heterostructure on highperformance Ni-rich layered cathodes for LIBs.
基金the National Key Research and Development Program of China(2022YFB3607300)the National Natural Science Foundation of China(62322512 and 12134013)+3 种基金the Chinese Acad-emy of Sciences Project for Young Scientists in Basic Research(YSBR-049)support from the University of Science and Technology of China’s Center for Micro and Nanoscale Research and Fabricationsupported by the China Postdoctoral Science Foundation(2023M743364)supercomputing system in Hefei Advanced Computing Center and the Supercomputing Center of University of Science and Technology of China.
文摘Optical data storage(ODS)is a low-cost and high-durability counterpart of traditional electronic or mag-netic storage.As a means of enhancing ODS capacity,the multiple recording layer(MRL)method is more promising than other approaches such as reducing the recording volume and multiplexing technology.However,the architecture of current MRLs is identical to that of recording data into physical layers with rigid space,which leads to either severe interlayer crosstalk or finite recording layers constrained by the short working distances of the objectives.Here,we propose the concept of hybrid-layer ODS,which can record optical information into a physical layer and multiple virtual layers by using high-orthogonality random meta-channels.In the virtual layer,32 images are experimentally reconstructed through holog-raphy,where their holographic phases are encoded into 16 printed images and complementary images in the physical layer,yielding a capacity of 2.5 Tbit cm^(-3).A higher capacity is achievable with more virtual layers,suggesting hybrid-layer ODS as a possible candidate for next-generation ODS.
基金supported by the National Key R&D Program of China(Grant 2022YFB2402200)National Natural Science Foundation of China(Grant 92372206,52271140,52171194)+2 种基金Jilin Province Science and Technology Development Plan Funding Project(Grant YDZJ202301-ZYTS545)National Natural Science Foundation of China Excellent Young Scientists(Overseas)Youth Innovation Promotion Association CAS(Grant 2020230)。
文摘Aqueous zinc batteries offer significant potential for large-scale energy storage,wearable devices,and medium-to low-speed transportation due to their safety,affordability,and environmental friendliness.However,the uneven zinc deposition at the anode side caused by localized reaction activity from the passivation layer presents challenges that significantly impact the battery's stability and lifespan.In this study,we have proposed an expandable and maneuverable gel sustained-release(GSR)treatment to polish the Zn metal,which in situ converts its native passivation layer into a composite interphase layer with nanocrystal zinc phosphate and flexible polyvinyl alcohol.Such a thin and uniform interface contributes to fast and homogeneous Zn ion transport and improved anti-corrosion ability,enabling uniform zinc deposition without dendrite growth and thereby improving the battery performance with high-rate ability and long cycle life.This GSR treatment method,characterized by its simplicity,low cost,and universality,facilitates the widespread application of aqueous zinc batteries.
文摘Due to the coexistence of compressibility,viscosity,and threedimensional effects,laminar flow is difficult to maintain for high-speed boundary layer on complex geometries.The unstable disturbance waves in the boundary layer are excited and rapidly increase during the receptivity process,so sufficiently large Reynolds stress causes the basic flow velocity profile to change,and the formation of turbulence is inevitable.
基金supported by the Key Research and Development Project of Henan Province of China(No.241111232300)the National Natural Science Foundation of China(Nos.52303113 and 5227308)the Open Project Program of Yaoshan Laboratory(No.2024003).
文摘Two-dimensional transition metal carbon/nitrides(MXenes)have emerged as prominent materials in the development of high-performance electromagnetic interference(EMI)shielding films owing to their ex-ceptional electrical conductivity,special layered structure,and chemically active surfaces.Substantial ef-forts have been devoted to addressing the poor mechanical strength and limited functionality of pure MXene films through structural design and interfacial reinforcement.However,there is a notable lack of a systematic review of the research on MXene-based EMI shielding films with multi-layer structures,which could provide a theoretical foundation and technical guidance for the development and application of shielding films.This review aims to summarize the recent advancements in MXene-based layered films for EMI shielding.First,the structure and properties of MXene nanosheets are systematically introduced.Next,the optimization of layered structures and interfacial reinforcement strategies in MXene-based EMI shielding films are objectively reviewed,followed by a discussion of their multifunctional compatibility.Finally,future prospects and challenges for MXene-based layered EMI shielding films are highlighted.
基金Supported by Topcon Corporation and Santen Pharmaceutical Co.Ltd.
文摘AIM:To evaluate parameters measured using the tear film imager(TFI)prototype,a new technology that enables to quantify the tear film thickness of lipid and mucoaqueous layers.METHODS:In this cross-sectional study,patients with dry eye,meibomian gland dysfunction(MGD),and non-dry eye/MGD from February 2020 to January 2021 were analyzed.Quantified TFI outputs included lipid layer thickness(LLT),mucoaqueous layer thickness(MALT),MALT rate of change(MALTR),and lipid breakup time.Two other interferometry devices,LipiView2 and DR-1α,were used for comparison.TFI outputs and other clinical parameters were analyzed using correlation coefficients.Each patient underwent one or several study visits.Baseline values of three device outputs,other clinical parameters,and their changes were examined.RESULTS:This study involved 28 patients(8 patients with dry eyes,13 with MGD,and 7 with non-dry eye/MGD).Baseline TFI,LipiView2,and DR-1αvalues were associated with various clinical parameters.The LLT values estimated using TFI had a correlation with the plugging score in the upper eyelid(r=−0.42).Several TFI values have correlated better than LipiView2 and DR-1α,particularly with questionnaire scores.MALTR by TFI revealed a correlation between standardized patient evaluation on eye dryness(SPEED)and dry eye-related quality of life score(DEQS)scores(r=0.59,0.43),respectively.CONCLUSION:TFI enabled to quantify the LLT and MALT separately over time and shows the moderate correlations between TFI measurements and clinical parameters,which yields the potential for TFI to serve as a complementary tool for assessing dry eye and MGD.
基金support of the National Natural Science Foundation of China(Grant No.42207199)Zhejiang Provincial Natural Science Foundation of China(Grant Nos.ZCLMS25D0201 and LQ23D010002).
文摘Layered rocks are widely distributed in sedimentary and metamorphic rocks and show anisotropic deformation and strength due to the layered structures with apparent weak surfaces.This study summarizes the findings on the deformation and damage characteristics of layered rock masses and surrounding rocks.The physicomechanical properties of layered rocks with different properties(e.g.inclination,shear strength,tensile strength,shear stiffness,roughness,and layer spacing)and different lithological and stress conditions are analyzed.The results revealed that with increasing layer inclination angles,the deformation and strength parameters of the rock masses present U-shaped,W-shaped,incremental,decremental,and basically unchanged trends,which are closely related to their strength and stress conditions.The increase in layer strength and confining pressure effectively suppresses the deformation and strength anisotropy caused by layer weakening,and the rock mass shifts from“structure-controlled”to“stress-structure-controlled”deformation mode.Water will increase the anisotropic behavior of layered rock masses due to the degradation of bedding and bedrock performance.The anisotropic behavior of the layered surrounding rocks is analyzed to reveal how it affects the deformation and failure behaviors of tunnels.The asymmetric characteristics of surrounding rock deformation are closely related to the layer weakening,layer thickness,and in situ stress.These findings are crucial for understanding layered rock mass deformation and failure mechanisms,facilitating prediction and control of tunnel deformation.
基金supported by the National Natural Science Foundation of China(No.22379031)the Guangxi Science and Technology Project of China(No.AB16380030)。
文摘Developing cathode catalyst layers(CCL)with efficient mass transport capability is crucial to developing ultra-low Pt loading(<50μg·cm^(-2))proton exchange membrane fuel cells(PEMFCs).Herein,CCLs with various pore distributions were constructed by depositing Pt onto the integrated carbonaceous films consisting of carbon nanoparticles(CNs),three-dimensional(3D)graphene nanosheets(GNs),and nanocomposites of CNs and GNs(CNs-GNs),respectively.The hierarchical mesoporous pore distributions of CCLs strongly affect the effective exposure of Pt active sites,proton-transfer resistance,and oxygen mass transport efficiencies related to Knudsen diffusion and local resistance at the Pt/ionomer interface.The CCL with Pt/CNs-GNs(50.0μgPt·cm^(-2))features a unique tri-modal pore distribution concentrated at 10.2,20.4,and 43.7 nm,providing efficient three-phase boundaries with a significantly higher active surface area of 49.67 m2·g^(-1),lower oxygen transport resistance and proton resistance of down to 18.68 s·m^(-1) and 0.0603Ω·cm^(2),compared with Pt/CNs(31.48 m^(2)·g^(-1),41.17 s·m^(-1),and 0.0702Ω·cm^(2))with a single-modal pore distribution at 9.5 nm and Pt/GNs(38.21 m^(2)·g^(-1),33.40 s·m^(-1),and 0.0654Ω·cm^(2))with a bi-modal pore distribution at 9.8 and 20.9 nm.Correspondingly,the cell with Pt/CNs-GNs delivers a high power output of up to 1.01 W·cm^(-2) and presents a high durability that satisfies the 2025 targets set by the U.S.Department of Energy.This work provides new insights into the critical role of hierarchically mesoporous pore distribution of CCL for constructing high-performance PEMFCs with ultra-low Pt loading<50μg·cm^(-2).
