Cationized pulp fibers （CPF） were prepared by the adsorption of a novel biodegradable cationic ester quaternary ammonium salt （31441） on bleached softwood kraft pulp fibers. The optimized conditions for the CPF pr...Cationized pulp fibers （CPF） were prepared by the adsorption of a novel biodegradable cationic ester quaternary ammonium salt （31441） on bleached softwood kraft pulp fibers. The optimized conditions for the CPF preparation were： 4% of 31441 （based on oven-dry pulp）, 80℃ and 30 rain. The CPF was characterized by FT-IR, SEM and XPS. Experimental results showed that the CPF improved the retention of precipitated calcium carbonate （PCC） filler significantly. With 0.9% CPF （based on oven-dry pulp）, the retention of PCC increased from 57.53% to 72.21%. The physical properties of paper were also slightly improved. The tensile strength and burst strength of the paper with CPF were higher than those with CPAM. CPF addition had no effect on the stock drainage.展开更多
In this work, melamine-formaldehyde resin was cationized by adding modifiers so that the fibers closely bonded to improve their usability and the wet strength of paper was greatly improved. Triethanolamine and dimethy...In this work, melamine-formaldehyde resin was cationized by adding modifiers so that the fibers closely bonded to improve their usability and the wet strength of paper was greatly improved. Triethanolamine and dimethylamine were added to modify the melamine-formaldehyde resin,respectively.The mechanism of the cationized resin was explored and the possible chemical reactions were deduced. It was concluded that,with the use of triethanolamine,the most optimum product was obtained by hydroxymethylation for 30 min with a temperature of 85℃ and p H of 9. 0 where n( melamine) ∶ n( formaldehyde) ∶ n( methanol) ∶ n( triethanolamine) was 100 ∶ 330 ∶ 450 ∶ 15. With the combined use of dimethylamine and methanol,the optimal product was acquired by condensation for 30 min at a temperature of 50℃ and p H of 2. 0 at melamine, formaldehyde, methanol, and dimethylamine molar ratio of100∶ 330∶ 350∶ 20. With the only use of dimethylamine,the optimal product was obtained by condensation at melamine,formaldehyde,dimethylamine molar ratio of 100∶ 330∶ 10. The wet tensile strength of fruit-bagging paper was improved by adding cationized melamine-formaldehyde resin. The zeta potential,charge density,and conductivity of the melamine-formaldehyde resin were also studied.展开更多
The rapid advancement of modern science and technology,coupled with the recent surge in new-energy electric vehicles,has significantly boosted the demand for lithium.This has promoted the development and efficient uti...The rapid advancement of modern science and technology,coupled with the recent surge in new-energy electric vehicles,has significantly boosted the demand for lithium.This has promoted the development and efficient utilization of lepidolite as a lithium source.Therefore,the processes for the flotation of lepidolite have been studied in depth,particularly the development and use of lepidolite flotation collectors and the action mechanism of the collectors on the lepidolite surface.Based on the crystal-structure characteristics of lepidolite minerals,this review focuses on the application of anionic collectors,amine cationic collectors(primary amines,quaternary ammonium salts,ether amines,and Gemini amines),and combined collectors to the flotation behavior of lepidolite as well as the adsorption mechanisms.New directions and technologies for the controllable flotation of lepidolite are proposed,including process improvement,reagent synthesis,and mechanistic research.This analysis demonstrates the need for the further study of the complex environment inside lepidolite and pulp.By using modern analytical detection methods and quantum chemical calculations,research on reagents for the flotation of lepidolite has expanded,providing new concepts and references for the efficient flotation recovery and utilization of lepidolite.展开更多
NiFe-layered double hydroxides(NiFe-LDHs)are among the most promising earth-abundant electrocatalysts for the oxygen evolution reaction(OER)in alkaline media.However,their practical application is hindered by intrinsi...NiFe-layered double hydroxides(NiFe-LDHs)are among the most promising earth-abundant electrocatalysts for the oxygen evolution reaction(OER)in alkaline media.However,their practical application is hindered by intrinsic activity limitations and poor stability,primarily due to the asymmetric adsorption of oxygen intermediates.To overcome this,the binding strength must be synergistically tuned to a moderate level to optimize catalytic performance.Here,we engineered NiFeCoCr LDH through Co doping to enhance electrical conductivity and controlled Cr leaching to introduce cationic vacancies for modulating intermediate binding strength in NiFe LDH.X-ray absorption near-edge structure and extended X-ray absorption fine structure analyses reveal that NiFe-LDH with Co doping and Cr vacancies modulates the Ni oxidation state and local coordination environment,leading to a balanced electronic structure and enhanced structural complexity around the Ni sites.Additionally,these vacancies can trap OH^(-)/H_(2)O species,which can serve as a reservoir for OH^(-) transfer,facilitating the rapid formation of OER intermediates and enhancing catalytic performance at high current densities.As a result,V_(Cr)-NiFeCo LDH achieves 1.6 A cm^(-2)current density at 1.7 V vs.RHE while maintaining stable operation for over 1000 h at 500 mA cm^(-2).Density functional theory(DFT)calculations validate the synergistic effects of Co doping and Cr-induced vacancies on intermediate binding energies and improved OER kinetics.Overall,this work presents a rational design strategy to simultaneously enhance the activity and durability of NiFe-based OER catalysts for their application in high-performance alkaline water electrolysis.展开更多
Cataract is the leading cause of reversible blindness worldwide,affecting millions,particularly the elderly.Over 65 million people suffer from significant visual impairment due to cataracts,with the burden being highe...Cataract is the leading cause of reversible blindness worldwide,affecting millions,particularly the elderly.Over 65 million people suffer from significant visual impairment due to cataracts,with the burden being highest in low-and middle-income countries where access to surgery is limited.Cataract surgery,one of the most commonly performed and cost-effective procedures,has evolved significantly.Traditional extracapsular cataract extraction(ECCE)has been largely replaced by phacoemulsifi cation,which uses ultrasonic energy through a small incision,reducing recovery time and complications.More recently,femtosecond laser-assisted cataract surgery(FLACS)has emerged,off ering enhanced precision but with ongoing evaluation of its cost-eff ectiveness.Intraocular lenses(IOLs)now allow for customized visual outcomes,addressing distance,near,and intermediate vision.Despite its safety,cataract surgery can still result in complications such as corneal edema and posterior capsular opacifi cation,requiring careful surgical management and patient education.展开更多
The development of synthetic hybrid biological systems integrating photosynthetic organisms with organic-abiotic functional materials holds significant promise for enhancing photosynthetic processes.The artificial reg...The development of synthetic hybrid biological systems integrating photosynthetic organisms with organic-abiotic functional materials holds significant promise for enhancing photosynthetic processes.The artificial regulation of the state transition between photosystem I(PSI)and photosystem II(PSII)represents a strategic and promising approach for improving the efficiency of natural photosynthesis.In this study,we demonstrate that poly(benzimidazolium-phenylthiophene)(CP4)featuring a flexible cationic backbone exhibits superior ultraviolet light-harvesting capability.The polymer CP4 enhanced PSI activity in Chlorella pyrenoidosa(C.pyrenoidosa),subsequently promoting PSII activity and augmenting overall photosynthetic performance.During light-dependent reactions,CP4 significantly accelerated photosynthetic electron transfer,resulting in a 330%increase in the production of oxygen and 93%and 96%increases in the ATP and NADPH contents,respectively.In the context of dark reactions,CP4 facilitated the conversion and utilization of light energy,leading to a 6%increase in both carbohydrate and protein contents.These findings indicate that synthetic light-harvesting polymer materials exhibit considerable application potential in the field of biomass production through enhancement of natural photosynthetic efficiency.展开更多
Sodium layered oxides stand out as one of the most promising cathodes for sodium-ion batteries due to their high energy density,elemental abundance,and scalability.However,their practical applications are restricted b...Sodium layered oxides stand out as one of the most promising cathodes for sodium-ion batteries due to their high energy density,elemental abundance,and scalability.However,their practical applications are restricted by interplanar gliding,cation migration,and the formation of intragranular microcracks,which collectively lead to rapid structural degradation and capacity loss.Herein,we rationally design an ultrastable O3-type Na_(0.94)Ca_(0.03)Ni_(1/3)Fe_(1/3)Mn_(1/3)O_(2) cathode,in which Ca^(2+)cations act as pillars within the NaO_(2)slabs,suppressing the irreversible phase transitions and Na/TM cation migration commonly observed in layered oxides.Multiscale in situ and ex situ techniques,combined with post-mortem analysis,reveal that the Ca-pillared pinning effect not only effectively suppresses the interplanar gliding and stress accumulation within the crystal phase but also restrains Na/TM cation migration and surface reconstruction in near-surface regions.Benefiting from the combined effects of structural stabilization,the Ca-pillared cathode exhibits a superior cycling stability,retaining 81.6%of its capacity after 1000 cycles at 2 C within the voltage range of 2.0-4.0 V,along with significantly enhanced wide-temperature(from-40 to 80℃)performance.This work highlights another critical role of Ca pillars in suppressing cation migration and surface structural degradation beyond preventing adverse interplanar gliding,offering valuable insights for designing long-life and wide-temperature layered oxide cathodes.展开更多
Climate warming is significantly altering the distribution of tree species,which holds crucial implications for China’s Larix species as they are important afforestation efforts.Understanding their optimal habitats a...Climate warming is significantly altering the distribution of tree species,which holds crucial implications for China’s Larix species as they are important afforestation efforts.Understanding their optimal habitats and environmental constraints is vital for predicting range shifts and guiding adaptive forest management.Previous studies prioritized changing climate impacts on horizontal range shifts of Larix,neglecting the influence of soil factors and range shift along altitudinal gradients.To address this,we applied an optimized MaxEnt model to assess current and future SSP126/SSP585 scenarios,three-dimensional habitat suitability(latitude,longitude,altitude)for four major Larix species(L.principis-rupprechtii,L.gmelinii,L.kaempferi,L.olgensis),while identifying key environmental drivers.Our results indicate that elevation and extreme moisture conditions universally constrain their distribution.Soil chemistry properties exhibited species-specific influences:cation exchange capacity critically shaped L.principis-rupprechtii and L.gmelinii ranges,whereas exchangeable aluminum determined L.kaempferi and L.olgensis distribution.Under future climate scenarios,habitat areas show divergent trajectories-L.principis-rupprechtii maximum gains 5.1%under SSP126,while L.kaempferi maximum expands 15.1%.Conversely,SSP585 triggered a 3.7% decline for L.gmelinii during the 2040s−2100s,and L.olgensis faces a net reduction to 0.4% by 2100s despite transient gains.Spatially,three species(L.kaempferi,L.gmelinii,L.olgensis)shifted northward,while L.principis-rupprechtii migrated northwest.All species distribution ascended altitudinally reflecting thermal adaptation strategies.These multidimensional insights enable targeted species selection for climate-resilient afforestation and underscore the need for soil-inclusive management planning.展开更多
Converting CO_(2) into methanol(CH_(3)OH),a high-value-added liquid-phase product,through efficient and highly selective photocatalysis remains a significant challenge.Herein,we present a straightforward cation exchan...Converting CO_(2) into methanol(CH_(3)OH),a high-value-added liquid-phase product,through efficient and highly selective photocatalysis remains a significant challenge.Herein,we present a straightforward cation exchange strategy for the in-situ growth of BiVO_(4) on an InVO_(4) substrate to generate a Z-scheme heterojunction of InVO_(4)/BiVO_(4) .This in-situ partial transformation approach endows the InVO_(4)/BiVO_(4) heterojunction with a tightly connected interface,resulting in a significant improvement in charge separation efficiency between InVO_(4) and BiVO_(4).Moreover,the construction of the heterojunction reduces the formation energy barrier of the ^(*)COOH intermediate during the photoreduction of CO_(2) and increases the desorption energy barrier of the ^(*)CO intermediate,facilitating the deep reduction of ^(*)CO.Consequently,the InVO_(4)/BiVO_(4) heterojunction is capable of photocatalytic CO_(2) reduction to CH_(3)OH with high efficiency and selectivity.Under conditions where water serves as the electron source and a light intensity of 100 m W/cm^(2),the yield of CH_(3)OH reaches 130.5 μmol g^(-1)h^(-1) with a selectivity of 92 %,outperforming photocatalysts reported under similar conditions.展开更多
The dynamics of calcium(Ca)and magnesium(Mg)in the forest floor and topsoil caused by anthropogenic and natural processes continue to be a concern in temperate forests.However,the impacts of abiotic and biotic variabl...The dynamics of calcium(Ca)and magnesium(Mg)in the forest floor and topsoil caused by anthropogenic and natural processes continue to be a concern in temperate forests.However,the impacts of abiotic and biotic variables as well as their interactions remain unclear,especially in areas undergoing long-term forest restoration.In this study,Ca and Mg concentrations in the forest floor and topsoil from 239 forest plots across the Loess Plateau were measured,and the effects of forest types,climate,soil properties,stand characteristics and nitrogen deposition were explored.The results showed significantly higher Ca concentrations in the forest floor(20.68±8.04 mg/g)than in the topsoil(13.28±12.83 mg/g),whereas Mg exhibited the inverse pattern(3.64±1.09 and 10.11±2.51 mg/g,respectively).The effect of forest types was only significant on forest floor Ca,and Ca concentrations were higher in broadleaf and mixed forests than in coniferous forests.Overall,Ca and Mg concentrations in forest floor and topsoil increased with latitudes while decreased with elevations,and the significance of the trends varied among forest types.Forest floor Ca and Mg were mainly influenced by environmental variables aboveground,i.e.,basal area(BA)and mean annual precipitation(MAP),respectively;topsoil Ca and Mg were more affected by soil properties(soil C/N and pH,respectively).Those suggested a depletion of Ca belowground was associated with forest growth and enriched soil nitrogen,and the leaching of mobile Mg was correlated with rainfall and soil acidification.Besides,the impact of environmental variables on Ca-Mg balance(Ca/Mg ratio)belowground was primarily through the regulation of Ca.Elucidating the influence of environmental variables will improve our ability to predict future changes in base cations and thus forest soil health in the greening vegetated Loess Plateau.展开更多
Background:Home accessibility modifi cations are crucial for promoting independent living and quality of life among persons with disabilities.While developed countries have established comprehensive policy frameworks,...Background:Home accessibility modifi cations are crucial for promoting independent living and quality of life among persons with disabilities.While developed countries have established comprehensive policy frameworks,developing nations like China face unique challenges in program design and implementation.Objective:This study conducts a systematic comparative analysis of home accessibility modification policies across China,Japan,Germany,and Sweden,identifying key policy dimensions and proposing evidence-based recommendations for strengthening China’s policy framework.Methods:We employed a multi-dimensional analytical framework examining legislative foundations,eligibility criteria,funding mechanisms,and service delivery models.Data were collected from primary legislation,governmental regulations,official statistics,and peer-reviewed literature.Results:Significant cross-national variations exist in policy approaches.Japan and Germany utilize social insurance models with standardized assessments,Sweden adopts a universal rights-based approach,while China employs a targeted assistance model focused on economically disadvantaged households.China completed 1.28 million household renovations during its 14th Five-Year Plan,demonstrating strong implementation capacity;future policy refi nement could draw on international experience to strengthen assessment standardization,broaden eff ective coverage,and improve the sustainability of fi nancing.Conclusions:China can benefi t from international experience in developing standardized assessment protocols,diversifying funding mechanisms,and establishing professional service delivery systems,while acknowledging contextual constraints unique to developing country settings.展开更多
The scaling-up of electrochemical CO_(2)reduction requires circumventing the CO_(2)loss as carbonates under alkaline conditions.Zero-gap MEA cell configurations with a proton exchange membrane represent an alternative...The scaling-up of electrochemical CO_(2)reduction requires circumventing the CO_(2)loss as carbonates under alkaline conditions.Zero-gap MEA cell configurations with a proton exchange membrane represent an alternative solution in a pure acidic system,but the catalyst layer in direct contact with the hydrated proton environment usually leads to H_(2)evolution dominating.Herein,we show that polydimethyldiallyl-ammonium-chloride-coated Ag(Ag@PDDA)electrode exhibits outstanding performance with a FE of 86%,a single-pass conversion of 72%,and a stability of 28 h for CO production in pure-acid MEA compared with ammonium poly(N-methyl-piperidine-co-pterphenyl)decorated Ag(Ag/QAPPT)and cetyltrimethylammonium bromide decorated Ag(Ag/CTAB).The in situ ATR-SEIRAS reveal that PDDA creates a positive charge-rich protective outer layer and an N-rich hybrid inner layer,which not only suppresses the migration of H+during the electrolysis process and blocks the direct contact between H2O and Ag catalyst,but also promotes the generation from CO_(2)to*COOH in a pure-acid system.This work highlights the importance of polyelectrolyte engineering in regulating the electrocatalytic interface and accelerates the development of proton exchange membrane CO_(2)electrolysis.展开更多
Formamidinium lead iodide(FAPbI_(3))perovskite exhibits an impressive X-ray absorption coefficient and a large carrier mobility-lifetime product(μτ),making it as a highly promising candidate for X-ray detection appl...Formamidinium lead iodide(FAPbI_(3))perovskite exhibits an impressive X-ray absorption coefficient and a large carrier mobility-lifetime product(μτ),making it as a highly promising candidate for X-ray detection application.However,the presence of larger FA^(+)cation induces to an expansion of the Pb-I octahedral framework,which unfortunately affects both the stability and charge carrier mobility of the corresponding devices.To address this challenge,we develop a novel low-dimensional(HtrzT)PbI_(3) perovskite featuring a conjugated organic cation(1H-1,2,4-Triazole-3-thiol,HtrzT^(+))which matches well with theα-FAPbI_(3) lattices in two-dimensional plane.Benefiting from the matched lattice between(HtrzT)PbI_(3) andα-FAPbI_(3),the anchored lattice enhances the Pb-I bond strength and effectively mitigates the inherent tensile strain of theα-FAPbI_(3) crystal lattice.The X-ray detector based on(HtrzT)PbI_(3)(1.0)/FAPbI_(3) device achieves a remarkable sensitivity up to 1.83×10^(5)μC Gy_(air)^(−1) cm^(−2),along with a low detection limit of 27.6 nGy_(air) s^(−1),attributed to the release of residual stress,and the enhancement in carrier mobility-lifetime product.Furthermore,the detector exhibits outstanding stability under X-ray irradiation with tolerating doses equivalent to nearly 1.17×10^(6) chest imaging doses.展开更多
Aqueous zinc-ion batteries(AZIBs) have advantages including low economic cost and high safety.Nevertheless,the serious hydrogen evolution reactions(HER) and rampant growth of Zn dendrite hinder their further developme...Aqueous zinc-ion batteries(AZIBs) have advantages including low economic cost and high safety.Nevertheless,the serious hydrogen evolution reactions(HER) and rampant growth of Zn dendrite hinder their further development.Herein,potassium acetate(KAc) additive with cation/anion synergy effect is added into the ZnSO_(4) electrolyte to effectively promote the oriented uniform Zn deposition and suppress side reactions.According to density functional theory calculation and experimental results,CH_(3)COO^(-)(Ac^(-))anions are capable of forming stronger hydrogen bonds with H_(2)O molecules,leading to an expanded electrochemical stability window,reduced the reactivity of H_(2)O,and hence suppressing HER.Meanwhile,Ac-anions can also preferentially adsorb onto the Zn anode,promoting dense deposition towards the(100) crystal plane.Besides,dissociated K^(+) ions serve as electrostatic shielding cations,which significantly promote uniform Zn deposition and prevent dendrite formation.Thus,the Zn||Zn symmetric cell demonstrates an impressive cycle lifespan of 3000 h at 1.0 m A/cm^(2).Furthermore,the Zn||MnO_(2) full battery exhibits superior stability with a capacity retention of 86.95 % at 2.0 A/g after 4000 cycles.Therefore,the cation/anion synergy effect in KAc additive offers a viable solution to address HER and hinder dendrite growth at the interface of Zn anodes.展开更多
Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters accordi...Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.展开更多
In recent years, the research advancements have high-lighted the critical role of the A-site cation in determining the optoelectronic and physicochemical properties of organicinorganic lead halide perovskites. Mixed-c...In recent years, the research advancements have high-lighted the critical role of the A-site cation in determining the optoelectronic and physicochemical properties of organicinorganic lead halide perovskites. Mixed-cation perovskites(MCPs) have been extensively used as absorber thin films in perovskite solar cells(PSCs), achieving high power conversion efficiencies(PCE) over 26%^([1, 2]).展开更多
The recent commercialization of gene products has sparked significant interest in gene therapy,necessitating efficient and precise gene delivery via various vectors.Currently,viral vectors and lipid-based nanocarriers...The recent commercialization of gene products has sparked significant interest in gene therapy,necessitating efficient and precise gene delivery via various vectors.Currently,viral vectors and lipid-based nanocarriers are the predominant choices and have been extensively investigated and reviewed.Beyond these vectors,polymeric nanocarriers also hold the promise in therapeutic gene delivery owing to their versatile functionalities,such as improving the stability,cellar uptake and endosomal escape of nucleic acid drugs,along with precise delivery to targeted tissues.This review presents a brief overview of the status quo of the emerging polymeric nanocarriers for therapeutic gene delivery,focusing on key cationic polymers,nanocarrier types,and preparation methods.It also highlights targeted diseases,strategies to improve delivery efficiency,and potential future directions in this research area.The review is hoped to inspire the development,optimization,and clinical translation of highly efficient polymeric nanocarriers for therapeutic gene delivery.展开更多
Although the Mg-air battery with high theoretical energy density is desirable for the energy supply of marine engineering equipment,its applications remain limited due to the low actual discharge voltage and inferior ...Although the Mg-air battery with high theoretical energy density is desirable for the energy supply of marine engineering equipment,its applications remain limited due to the low actual discharge voltage and inferior Mg anode utilization rate.In addition to the microstructure of Mg alloy anodes,the properties of discharge product films are of great importance to the discharge performance.Herein,the discharge behaviors of Mg-Y-Zn alloys are first studied mainly from the perspective of film properties.Through contrastive analysis,it is found that the sufficient Y^(3+) produced during the discharge process can substitute Mg^(2+) in Mg(OH)_(2) to introduce effective cation vacancies.The Mg-Y-Zn anode with profuse cation vacancies in the product film shows a synergy of potential and efficiency,and this can be attributed to an increase in the migration pathway for Mg^(2+),reducing the diffusion over-potential caused by the protective product film.This study is expected to provide a new strategy from the perspective of cation vacancy design of discharge film for developing high-performance Mg-air batteries.展开更多
The development of flexible zinc-ion batteries(ZIBs)faces a threeway trade-off among the ionic conductivity,Zn^(2+)mobility,and the electrochemical stability of hydrogel electrolytes.To address this challenge,we desig...The development of flexible zinc-ion batteries(ZIBs)faces a threeway trade-off among the ionic conductivity,Zn^(2+)mobility,and the electrochemical stability of hydrogel electrolytes.To address this challenge,we designed a cationic hydrogel named PAPTMA to holistically improve the reversibility of ZIBs.The long cationic branch chains in the polymeric matrix construct express pathways for rapid Zn^(2+)transport through an ionic repulsion mechanism,achieving simultaneously high Zn^(2+)transference number(0.79)and high ionic conductivity(28.7 mS cm−1).Additionally,the reactivity of water in the PAPTMA hydrogels is significantly inhibited,thus possessing a strong resistance to parasitic reactions.Mechanical characterization further reveals the superior tensile and adhesion strength of PAPTMA.Leveraging these properties,symmetric batteries employing PAPTMA hydrogel deliver exceeding 6000 h of reversible cycling at 1 mA cm^(−2) and maintain stable operation for 1000 h with a discharge of depth of 71%.When applied in 4×4 cm2 pouch cells with MnO_(2) as the cathode material,the device demonstrates remarkable operational stability and mechanical robustness through 150 cycles.This work presents an eclectic strategy for designing advanced hydrogels that combine high ionic conductivity,enhanced Zn^(2+)mobility,and strong resistance to parasitic reactions,paving the way for long-lasting flexible ZIBs.展开更多
Hydrogen fuel cells are expected to play a central role in the next-generation energy paradigm.However,owing to practical limitations,hydrogen is supplied in the form of refined hydrocarbons or alcohols in industrial ...Hydrogen fuel cells are expected to play a central role in the next-generation energy paradigm.However,owing to practical limitations,hydrogen is supplied in the form of refined hydrocarbons or alcohols in industrial applications.Among them,methanol is widely used as a hydrogen source,and CO is inevitably generated during its oxidation process.Even a small amount of CO(∼20 ppm)strongly binds to Pt used as a catalyst,and deactivates it.In addition to CO,surface adsorption of organic cations by binder or ionomer use in alkaline fuel cells is also one of the poisoning issues to be overcome.Herein,we propose FePt bimetallic catalysts that can resist unavoidable CO and organic cation poisoning.Our synthetic strategy,including annealing and acid treatment,allows the catalysts to possess different alloying degrees and surface structures,which in turn induce different levels of resistance to CO and organic-cation poisonings.The correlation between the surface and bulk structures of the catalysts and poisoning resistance was elucidated through X-ray photoemission spectroscopy and electrochemical analysis.The results revealed that an FePt catalyst having an ordered atomic arrangement displayed a better poisoning resistance than that having a disordered arrangement.展开更多
基金the Key Scientific and Technological Project of Heilongjiang Province (GB06B501-1)
文摘Cationized pulp fibers （CPF） were prepared by the adsorption of a novel biodegradable cationic ester quaternary ammonium salt （31441） on bleached softwood kraft pulp fibers. The optimized conditions for the CPF preparation were： 4% of 31441 （based on oven-dry pulp）, 80℃ and 30 rain. The CPF was characterized by FT-IR, SEM and XPS. Experimental results showed that the CPF improved the retention of precipitated calcium carbonate （PCC） filler significantly. With 0.9% CPF （based on oven-dry pulp）, the retention of PCC increased from 57.53% to 72.21%. The physical properties of paper were also slightly improved. The tensile strength and burst strength of the paper with CPF were higher than those with CPAM. CPF addition had no effect on the stock drainage.
文摘In this work, melamine-formaldehyde resin was cationized by adding modifiers so that the fibers closely bonded to improve their usability and the wet strength of paper was greatly improved. Triethanolamine and dimethylamine were added to modify the melamine-formaldehyde resin,respectively.The mechanism of the cationized resin was explored and the possible chemical reactions were deduced. It was concluded that,with the use of triethanolamine,the most optimum product was obtained by hydroxymethylation for 30 min with a temperature of 85℃ and p H of 9. 0 where n( melamine) ∶ n( formaldehyde) ∶ n( methanol) ∶ n( triethanolamine) was 100 ∶ 330 ∶ 450 ∶ 15. With the combined use of dimethylamine and methanol,the optimal product was acquired by condensation for 30 min at a temperature of 50℃ and p H of 2. 0 at melamine, formaldehyde, methanol, and dimethylamine molar ratio of100∶ 330∶ 350∶ 20. With the only use of dimethylamine,the optimal product was obtained by condensation at melamine,formaldehyde,dimethylamine molar ratio of 100∶ 330∶ 10. The wet tensile strength of fruit-bagging paper was improved by adding cationized melamine-formaldehyde resin. The zeta potential,charge density,and conductivity of the melamine-formaldehyde resin were also studied.
基金financially supported by the Excellent Youth Scholars Program of State Key Laboratory of Complex Nonferrous Metal Resource Clean Utilization,Kunming University of Science and Technology,China(No.YXQN-2024003)the Central Government-Guided Local Science and Technology Development Fund Project,China(No.202407AB110022)。
文摘The rapid advancement of modern science and technology,coupled with the recent surge in new-energy electric vehicles,has significantly boosted the demand for lithium.This has promoted the development and efficient utilization of lepidolite as a lithium source.Therefore,the processes for the flotation of lepidolite have been studied in depth,particularly the development and use of lepidolite flotation collectors and the action mechanism of the collectors on the lepidolite surface.Based on the crystal-structure characteristics of lepidolite minerals,this review focuses on the application of anionic collectors,amine cationic collectors(primary amines,quaternary ammonium salts,ether amines,and Gemini amines),and combined collectors to the flotation behavior of lepidolite as well as the adsorption mechanisms.New directions and technologies for the controllable flotation of lepidolite are proposed,including process improvement,reagent synthesis,and mechanistic research.This analysis demonstrates the need for the further study of the complex environment inside lepidolite and pulp.By using modern analytical detection methods and quantum chemical calculations,research on reagents for the flotation of lepidolite has expanded,providing new concepts and references for the efficient flotation recovery and utilization of lepidolite.
基金supported by the Natural Science Foundation of China Grant No.52272289 and 5240223,and JSPS(Japan Society for the Promotion of Science)of Grant No.22K19088,23H00313,24H02202,and 24H02205。
文摘NiFe-layered double hydroxides(NiFe-LDHs)are among the most promising earth-abundant electrocatalysts for the oxygen evolution reaction(OER)in alkaline media.However,their practical application is hindered by intrinsic activity limitations and poor stability,primarily due to the asymmetric adsorption of oxygen intermediates.To overcome this,the binding strength must be synergistically tuned to a moderate level to optimize catalytic performance.Here,we engineered NiFeCoCr LDH through Co doping to enhance electrical conductivity and controlled Cr leaching to introduce cationic vacancies for modulating intermediate binding strength in NiFe LDH.X-ray absorption near-edge structure and extended X-ray absorption fine structure analyses reveal that NiFe-LDH with Co doping and Cr vacancies modulates the Ni oxidation state and local coordination environment,leading to a balanced electronic structure and enhanced structural complexity around the Ni sites.Additionally,these vacancies can trap OH^(-)/H_(2)O species,which can serve as a reservoir for OH^(-) transfer,facilitating the rapid formation of OER intermediates and enhancing catalytic performance at high current densities.As a result,V_(Cr)-NiFeCo LDH achieves 1.6 A cm^(-2)current density at 1.7 V vs.RHE while maintaining stable operation for over 1000 h at 500 mA cm^(-2).Density functional theory(DFT)calculations validate the synergistic effects of Co doping and Cr-induced vacancies on intermediate binding energies and improved OER kinetics.Overall,this work presents a rational design strategy to simultaneously enhance the activity and durability of NiFe-based OER catalysts for their application in high-performance alkaline water electrolysis.
文摘Cataract is the leading cause of reversible blindness worldwide,affecting millions,particularly the elderly.Over 65 million people suffer from significant visual impairment due to cataracts,with the burden being highest in low-and middle-income countries where access to surgery is limited.Cataract surgery,one of the most commonly performed and cost-effective procedures,has evolved significantly.Traditional extracapsular cataract extraction(ECCE)has been largely replaced by phacoemulsifi cation,which uses ultrasonic energy through a small incision,reducing recovery time and complications.More recently,femtosecond laser-assisted cataract surgery(FLACS)has emerged,off ering enhanced precision but with ongoing evaluation of its cost-eff ectiveness.Intraocular lenses(IOLs)now allow for customized visual outcomes,addressing distance,near,and intermediate vision.Despite its safety,cataract surgery can still result in complications such as corneal edema and posterior capsular opacifi cation,requiring careful surgical management and patient education.
基金supported by the National Key R&D Program of China(Nos.2023YFC3404200,2023YFC34042012023YFC3404202)+1 种基金the National Natural Science Foundation of China(No.22575253)the Beijing Natural Science Foundation(No.Z220025)。
文摘The development of synthetic hybrid biological systems integrating photosynthetic organisms with organic-abiotic functional materials holds significant promise for enhancing photosynthetic processes.The artificial regulation of the state transition between photosystem I(PSI)and photosystem II(PSII)represents a strategic and promising approach for improving the efficiency of natural photosynthesis.In this study,we demonstrate that poly(benzimidazolium-phenylthiophene)(CP4)featuring a flexible cationic backbone exhibits superior ultraviolet light-harvesting capability.The polymer CP4 enhanced PSI activity in Chlorella pyrenoidosa(C.pyrenoidosa),subsequently promoting PSII activity and augmenting overall photosynthetic performance.During light-dependent reactions,CP4 significantly accelerated photosynthetic electron transfer,resulting in a 330%increase in the production of oxygen and 93%and 96%increases in the ATP and NADPH contents,respectively.In the context of dark reactions,CP4 facilitated the conversion and utilization of light energy,leading to a 6%increase in both carbohydrate and protein contents.These findings indicate that synthetic light-harvesting polymer materials exhibit considerable application potential in the field of biomass production through enhancement of natural photosynthetic efficiency.
基金supported by the National Key R&D Program of China(2023YFB2406000)the National Natural Science Foundation of China(22479057,52172201,51732005)。
文摘Sodium layered oxides stand out as one of the most promising cathodes for sodium-ion batteries due to their high energy density,elemental abundance,and scalability.However,their practical applications are restricted by interplanar gliding,cation migration,and the formation of intragranular microcracks,which collectively lead to rapid structural degradation and capacity loss.Herein,we rationally design an ultrastable O3-type Na_(0.94)Ca_(0.03)Ni_(1/3)Fe_(1/3)Mn_(1/3)O_(2) cathode,in which Ca^(2+)cations act as pillars within the NaO_(2)slabs,suppressing the irreversible phase transitions and Na/TM cation migration commonly observed in layered oxides.Multiscale in situ and ex situ techniques,combined with post-mortem analysis,reveal that the Ca-pillared pinning effect not only effectively suppresses the interplanar gliding and stress accumulation within the crystal phase but also restrains Na/TM cation migration and surface reconstruction in near-surface regions.Benefiting from the combined effects of structural stabilization,the Ca-pillared cathode exhibits a superior cycling stability,retaining 81.6%of its capacity after 1000 cycles at 2 C within the voltage range of 2.0-4.0 V,along with significantly enhanced wide-temperature(from-40 to 80℃)performance.This work highlights another critical role of Ca pillars in suppressing cation migration and surface structural degradation beyond preventing adverse interplanar gliding,offering valuable insights for designing long-life and wide-temperature layered oxide cathodes.
基金supported by the National Key Research and Development Program of China(2022YFD2200501).
文摘Climate warming is significantly altering the distribution of tree species,which holds crucial implications for China’s Larix species as they are important afforestation efforts.Understanding their optimal habitats and environmental constraints is vital for predicting range shifts and guiding adaptive forest management.Previous studies prioritized changing climate impacts on horizontal range shifts of Larix,neglecting the influence of soil factors and range shift along altitudinal gradients.To address this,we applied an optimized MaxEnt model to assess current and future SSP126/SSP585 scenarios,three-dimensional habitat suitability(latitude,longitude,altitude)for four major Larix species(L.principis-rupprechtii,L.gmelinii,L.kaempferi,L.olgensis),while identifying key environmental drivers.Our results indicate that elevation and extreme moisture conditions universally constrain their distribution.Soil chemistry properties exhibited species-specific influences:cation exchange capacity critically shaped L.principis-rupprechtii and L.gmelinii ranges,whereas exchangeable aluminum determined L.kaempferi and L.olgensis distribution.Under future climate scenarios,habitat areas show divergent trajectories-L.principis-rupprechtii maximum gains 5.1%under SSP126,while L.kaempferi maximum expands 15.1%.Conversely,SSP585 triggered a 3.7% decline for L.gmelinii during the 2040s−2100s,and L.olgensis faces a net reduction to 0.4% by 2100s despite transient gains.Spatially,three species(L.kaempferi,L.gmelinii,L.olgensis)shifted northward,while L.principis-rupprechtii migrated northwest.All species distribution ascended altitudinally reflecting thermal adaptation strategies.These multidimensional insights enable targeted species selection for climate-resilient afforestation and underscore the need for soil-inclusive management planning.
基金financially supported the National Key R&D Program of China (No.2022YFA1502902)the National Natural Science Foundation of China (NSFC,Nos.22475152 and U21A20286)the 111 Project of China (No.D17003)。
文摘Converting CO_(2) into methanol(CH_(3)OH),a high-value-added liquid-phase product,through efficient and highly selective photocatalysis remains a significant challenge.Herein,we present a straightforward cation exchange strategy for the in-situ growth of BiVO_(4) on an InVO_(4) substrate to generate a Z-scheme heterojunction of InVO_(4)/BiVO_(4) .This in-situ partial transformation approach endows the InVO_(4)/BiVO_(4) heterojunction with a tightly connected interface,resulting in a significant improvement in charge separation efficiency between InVO_(4) and BiVO_(4).Moreover,the construction of the heterojunction reduces the formation energy barrier of the ^(*)COOH intermediate during the photoreduction of CO_(2) and increases the desorption energy barrier of the ^(*)CO intermediate,facilitating the deep reduction of ^(*)CO.Consequently,the InVO_(4)/BiVO_(4) heterojunction is capable of photocatalytic CO_(2) reduction to CH_(3)OH with high efficiency and selectivity.Under conditions where water serves as the electron source and a light intensity of 100 m W/cm^(2),the yield of CH_(3)OH reaches 130.5 μmol g^(-1)h^(-1) with a selectivity of 92 %,outperforming photocatalysts reported under similar conditions.
基金supported by the National Natural Science Foundation of China(42401054)Natural Science Foundation of Hebei Province(D2024205019)Science and Technology Project of Hebei Education Department(BJ2025014).
文摘The dynamics of calcium(Ca)and magnesium(Mg)in the forest floor and topsoil caused by anthropogenic and natural processes continue to be a concern in temperate forests.However,the impacts of abiotic and biotic variables as well as their interactions remain unclear,especially in areas undergoing long-term forest restoration.In this study,Ca and Mg concentrations in the forest floor and topsoil from 239 forest plots across the Loess Plateau were measured,and the effects of forest types,climate,soil properties,stand characteristics and nitrogen deposition were explored.The results showed significantly higher Ca concentrations in the forest floor(20.68±8.04 mg/g)than in the topsoil(13.28±12.83 mg/g),whereas Mg exhibited the inverse pattern(3.64±1.09 and 10.11±2.51 mg/g,respectively).The effect of forest types was only significant on forest floor Ca,and Ca concentrations were higher in broadleaf and mixed forests than in coniferous forests.Overall,Ca and Mg concentrations in forest floor and topsoil increased with latitudes while decreased with elevations,and the significance of the trends varied among forest types.Forest floor Ca and Mg were mainly influenced by environmental variables aboveground,i.e.,basal area(BA)and mean annual precipitation(MAP),respectively;topsoil Ca and Mg were more affected by soil properties(soil C/N and pH,respectively).Those suggested a depletion of Ca belowground was associated with forest growth and enriched soil nitrogen,and the leaching of mobile Mg was correlated with rainfall and soil acidification.Besides,the impact of environmental variables on Ca-Mg balance(Ca/Mg ratio)belowground was primarily through the regulation of Ca.Elucidating the influence of environmental variables will improve our ability to predict future changes in base cations and thus forest soil health in the greening vegetated Loess Plateau.
基金funded by the China Disabled Persons’Federation under its 2024 research project(Grant No.2024CDPFAT-47)the Yancheng Social Science Foundation(Grant No.25skB252).
文摘Background:Home accessibility modifi cations are crucial for promoting independent living and quality of life among persons with disabilities.While developed countries have established comprehensive policy frameworks,developing nations like China face unique challenges in program design and implementation.Objective:This study conducts a systematic comparative analysis of home accessibility modification policies across China,Japan,Germany,and Sweden,identifying key policy dimensions and proposing evidence-based recommendations for strengthening China’s policy framework.Methods:We employed a multi-dimensional analytical framework examining legislative foundations,eligibility criteria,funding mechanisms,and service delivery models.Data were collected from primary legislation,governmental regulations,official statistics,and peer-reviewed literature.Results:Significant cross-national variations exist in policy approaches.Japan and Germany utilize social insurance models with standardized assessments,Sweden adopts a universal rights-based approach,while China employs a targeted assistance model focused on economically disadvantaged households.China completed 1.28 million household renovations during its 14th Five-Year Plan,demonstrating strong implementation capacity;future policy refi nement could draw on international experience to strengthen assessment standardization,broaden eff ective coverage,and improve the sustainability of fi nancing.Conclusions:China can benefi t from international experience in developing standardized assessment protocols,diversifying funding mechanisms,and establishing professional service delivery systems,while acknowledging contextual constraints unique to developing country settings.
基金financial support of the National Natural Science Foundation of China(NSFC)(52394202,52021004,52301232,and 52476056)the Natural Science Foundation of Chongqing Province(2024NSCQ-MSX1109).
文摘The scaling-up of electrochemical CO_(2)reduction requires circumventing the CO_(2)loss as carbonates under alkaline conditions.Zero-gap MEA cell configurations with a proton exchange membrane represent an alternative solution in a pure acidic system,but the catalyst layer in direct contact with the hydrated proton environment usually leads to H_(2)evolution dominating.Herein,we show that polydimethyldiallyl-ammonium-chloride-coated Ag(Ag@PDDA)electrode exhibits outstanding performance with a FE of 86%,a single-pass conversion of 72%,and a stability of 28 h for CO production in pure-acid MEA compared with ammonium poly(N-methyl-piperidine-co-pterphenyl)decorated Ag(Ag/QAPPT)and cetyltrimethylammonium bromide decorated Ag(Ag/CTAB).The in situ ATR-SEIRAS reveal that PDDA creates a positive charge-rich protective outer layer and an N-rich hybrid inner layer,which not only suppresses the migration of H+during the electrolysis process and blocks the direct contact between H2O and Ag catalyst,but also promotes the generation from CO_(2)to*COOH in a pure-acid system.This work highlights the importance of polyelectrolyte engineering in regulating the electrocatalytic interface and accelerates the development of proton exchange membrane CO_(2)electrolysis.
基金supports from the National Natural Science Foundation of China(22375220,U2001214,22471302)the Guangdong Basic and Applied Basic Research Foundation(2024B1515020101)Open Project Fund from State Key Laboratory of Optoelectronic Materials and Technologies(OEMT-2024-KF-08).
文摘Formamidinium lead iodide(FAPbI_(3))perovskite exhibits an impressive X-ray absorption coefficient and a large carrier mobility-lifetime product(μτ),making it as a highly promising candidate for X-ray detection application.However,the presence of larger FA^(+)cation induces to an expansion of the Pb-I octahedral framework,which unfortunately affects both the stability and charge carrier mobility of the corresponding devices.To address this challenge,we develop a novel low-dimensional(HtrzT)PbI_(3) perovskite featuring a conjugated organic cation(1H-1,2,4-Triazole-3-thiol,HtrzT^(+))which matches well with theα-FAPbI_(3) lattices in two-dimensional plane.Benefiting from the matched lattice between(HtrzT)PbI_(3) andα-FAPbI_(3),the anchored lattice enhances the Pb-I bond strength and effectively mitigates the inherent tensile strain of theα-FAPbI_(3) crystal lattice.The X-ray detector based on(HtrzT)PbI_(3)(1.0)/FAPbI_(3) device achieves a remarkable sensitivity up to 1.83×10^(5)μC Gy_(air)^(−1) cm^(−2),along with a low detection limit of 27.6 nGy_(air) s^(−1),attributed to the release of residual stress,and the enhancement in carrier mobility-lifetime product.Furthermore,the detector exhibits outstanding stability under X-ray irradiation with tolerating doses equivalent to nearly 1.17×10^(6) chest imaging doses.
基金financially supported by the National Natural Science Foundation of China (No.52372188)the 111 Project (No.D17007)2023 Introduction of studying abroad talent program。
文摘Aqueous zinc-ion batteries(AZIBs) have advantages including low economic cost and high safety.Nevertheless,the serious hydrogen evolution reactions(HER) and rampant growth of Zn dendrite hinder their further development.Herein,potassium acetate(KAc) additive with cation/anion synergy effect is added into the ZnSO_(4) electrolyte to effectively promote the oriented uniform Zn deposition and suppress side reactions.According to density functional theory calculation and experimental results,CH_(3)COO^(-)(Ac^(-))anions are capable of forming stronger hydrogen bonds with H_(2)O molecules,leading to an expanded electrochemical stability window,reduced the reactivity of H_(2)O,and hence suppressing HER.Meanwhile,Ac-anions can also preferentially adsorb onto the Zn anode,promoting dense deposition towards the(100) crystal plane.Besides,dissociated K^(+) ions serve as electrostatic shielding cations,which significantly promote uniform Zn deposition and prevent dendrite formation.Thus,the Zn||Zn symmetric cell demonstrates an impressive cycle lifespan of 3000 h at 1.0 m A/cm^(2).Furthermore,the Zn||MnO_(2) full battery exhibits superior stability with a capacity retention of 86.95 % at 2.0 A/g after 4000 cycles.Therefore,the cation/anion synergy effect in KAc additive offers a viable solution to address HER and hinder dendrite growth at the interface of Zn anodes.
基金supported by the Innovation Foundation of Provincial Education Department of Gansu(2024B-005)the Gansu Province National Science Foundation(22YF7GA182)the Fundamental Research Funds for the Central Universities(No.lzujbky2022-kb01)。
文摘Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.
基金financially supported by the National Natural Science Foundation of China (52462032, 62274018, 52462031)Natural Science Foundation of Yunnan Province (202501AT070353, 202101BE070001-049)+2 种基金the Xinjiang Construction Corps Key Areas of Science and Technology Research Project (2023AB029)the Tianchi Talent Program of Xinjiang Uygur Autonomous Region (2024, Jiangzhao Chen)the Key Project of Chongqing Overseas Students Returning to China Entrepreneurship and Innovation Support Plan (cx2023006)。
文摘In recent years, the research advancements have high-lighted the critical role of the A-site cation in determining the optoelectronic and physicochemical properties of organicinorganic lead halide perovskites. Mixed-cation perovskites(MCPs) have been extensively used as absorber thin films in perovskite solar cells(PSCs), achieving high power conversion efficiencies(PCE) over 26%^([1, 2]).
基金supported by National Natural Science Foundation of China(82104082)Natural Science Foundation of Qinghai Province(2024-ZJ-911).
文摘The recent commercialization of gene products has sparked significant interest in gene therapy,necessitating efficient and precise gene delivery via various vectors.Currently,viral vectors and lipid-based nanocarriers are the predominant choices and have been extensively investigated and reviewed.Beyond these vectors,polymeric nanocarriers also hold the promise in therapeutic gene delivery owing to their versatile functionalities,such as improving the stability,cellar uptake and endosomal escape of nucleic acid drugs,along with precise delivery to targeted tissues.This review presents a brief overview of the status quo of the emerging polymeric nanocarriers for therapeutic gene delivery,focusing on key cationic polymers,nanocarrier types,and preparation methods.It also highlights targeted diseases,strategies to improve delivery efficiency,and potential future directions in this research area.The review is hoped to inspire the development,optimization,and clinical translation of highly efficient polymeric nanocarriers for therapeutic gene delivery.
基金support of the Natural Science Foundation of Heilongjiang Province of China(No.LH2023E059)the National Natural Science Foundation of China(No.52071093)the Opening Project of Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology(No.ASMA202205).
文摘Although the Mg-air battery with high theoretical energy density is desirable for the energy supply of marine engineering equipment,its applications remain limited due to the low actual discharge voltage and inferior Mg anode utilization rate.In addition to the microstructure of Mg alloy anodes,the properties of discharge product films are of great importance to the discharge performance.Herein,the discharge behaviors of Mg-Y-Zn alloys are first studied mainly from the perspective of film properties.Through contrastive analysis,it is found that the sufficient Y^(3+) produced during the discharge process can substitute Mg^(2+) in Mg(OH)_(2) to introduce effective cation vacancies.The Mg-Y-Zn anode with profuse cation vacancies in the product film shows a synergy of potential and efficiency,and this can be attributed to an increase in the migration pathway for Mg^(2+),reducing the diffusion over-potential caused by the protective product film.This study is expected to provide a new strategy from the perspective of cation vacancy design of discharge film for developing high-performance Mg-air batteries.
基金financially supported by the General Research Fund(CityU 11315622 and CityU 11310123)National Natural Science Foundation(NSFC 52372229 and NSFC 52172241)+3 种基金Green Tech Fund(GTF202220105)Guangdong Basic and Applied Basic Research Foundation(2024A1515011008)City University of Hong Kong(No.9020002)the Shenzhen Research Institute of City University of Hong Kong.
文摘The development of flexible zinc-ion batteries(ZIBs)faces a threeway trade-off among the ionic conductivity,Zn^(2+)mobility,and the electrochemical stability of hydrogel electrolytes.To address this challenge,we designed a cationic hydrogel named PAPTMA to holistically improve the reversibility of ZIBs.The long cationic branch chains in the polymeric matrix construct express pathways for rapid Zn^(2+)transport through an ionic repulsion mechanism,achieving simultaneously high Zn^(2+)transference number(0.79)and high ionic conductivity(28.7 mS cm−1).Additionally,the reactivity of water in the PAPTMA hydrogels is significantly inhibited,thus possessing a strong resistance to parasitic reactions.Mechanical characterization further reveals the superior tensile and adhesion strength of PAPTMA.Leveraging these properties,symmetric batteries employing PAPTMA hydrogel deliver exceeding 6000 h of reversible cycling at 1 mA cm^(−2) and maintain stable operation for 1000 h with a discharge of depth of 71%.When applied in 4×4 cm2 pouch cells with MnO_(2) as the cathode material,the device demonstrates remarkable operational stability and mechanical robustness through 150 cycles.This work presents an eclectic strategy for designing advanced hydrogels that combine high ionic conductivity,enhanced Zn^(2+)mobility,and strong resistance to parasitic reactions,paving the way for long-lasting flexible ZIBs.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(Nos.2022M3J1A1063917 and 2021M3H4A3A02086681).
文摘Hydrogen fuel cells are expected to play a central role in the next-generation energy paradigm.However,owing to practical limitations,hydrogen is supplied in the form of refined hydrocarbons or alcohols in industrial applications.Among them,methanol is widely used as a hydrogen source,and CO is inevitably generated during its oxidation process.Even a small amount of CO(∼20 ppm)strongly binds to Pt used as a catalyst,and deactivates it.In addition to CO,surface adsorption of organic cations by binder or ionomer use in alkaline fuel cells is also one of the poisoning issues to be overcome.Herein,we propose FePt bimetallic catalysts that can resist unavoidable CO and organic cation poisoning.Our synthetic strategy,including annealing and acid treatment,allows the catalysts to possess different alloying degrees and surface structures,which in turn induce different levels of resistance to CO and organic-cation poisonings.The correlation between the surface and bulk structures of the catalysts and poisoning resistance was elucidated through X-ray photoemission spectroscopy and electrochemical analysis.The results revealed that an FePt catalyst having an ordered atomic arrangement displayed a better poisoning resistance than that having a disordered arrangement.
