39 soil samples surrounding a lead-zinc mining area in Guangxi were collected,and the contents of Pb,Hg,Cd,Cr,As,Cu,Zn,and Ni were determined to investigate the pollution characteristics and sources of heavy metals.Ar...39 soil samples surrounding a lead-zinc mining area in Guangxi were collected,and the contents of Pb,Hg,Cd,Cr,As,Cu,Zn,and Ni were determined to investigate the pollution characteristics and sources of heavy metals.ArcGIS inverse distance weight difference method was used to analyze the characteristics of pollution distribution,and single-factor pollution index,Nemerow comprehensive pollution index,ground accumulation index,and potential ecological risk index were selected to evaluate the characteristics of heavy metal pollution.Based on correlation analysis,the absolute principal component-multiple linear regression(APCS-MLR)and positive definite matrix factorization(PMF)models were used to analyze the sources of soil heavy metals.The results showed that the average concentrations of all eight heavy metals exceeded both national and Guangxi soil background values.Hg,Cd,and Zn exhibited high variation(greater than 0.5),indicating significant external disturbances,and their spatial distribution was closely related to mining activity locations.The single-factor pollution index evaluation indicated varying degrees of pollution risk for Cd,Zn,and As,with Cd and Zn being the most severe pollutants,as 69.23%and 30.77%of the samples fell into the moderate pollution or higher category.The geoaccumulation index analysis ranked the mean pollution levels of the eight elements as follows:Zn>Cd>Ni>Pb>Cu>Cr>Hg>As,with Cd and Zn showing the most severe contamination,and 51.28%of the samples exhibiting moderate or higher pollution levels.The Nemerow comprehensive pollution index evaluation showed that 74.35%of soil samples were classified as moderate to heavy pollution.The potential ecological risk index assessment indicated significant ecological risks posed by Cd and Zn,with 82.05%and 5.12%of the samples classified as causing strong to extreme ecological risks,respectively.The source apportionment analysis revealed minor differences between the two models.The APCS-MLR model identified three pollution sources and their contribution rates:anthropogenic mining sources(31.13%),parent material sources(40.38%),and unidentified sources(28.49%).The PMF model identified three pollution sources with contribution rates of anthropogenic mining sources(26.10%),parent material sources(46.96%),and a combined traffic and agricultural source(26.61%).Pb,Hg,Cd,and Zn mainly originated from mining activities;Cr,As,and Ni were primarily derived from the parent material,while Cu was predominantly attributed to traffic and agricultural sources.These findings provide a scientific basis for the prevention and control of heavy metal pollution in mining areas.展开更多
Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durabili...Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durability,and corrosion resistance.These metals have body-centered cubic crystal structure,characterized by limited slip systems and impeded dislocation motion,resulting in significant low-temperature brittleness,which poses challenges for the conventional processing.Additive manufacturing technique provides an innovative approach,enabling the production of intricate parts without molds,which significantly improves the efficiency of material usage.This review provides a comprehensive overview of the advancements in additive manufacturing techniques for the production of refractory metals,such as W,Ta,Mo,and Nb,particularly the laser powder bed fusion.In this review,the influence mechanisms of key process parameters(laser power,scan strategy,and powder characteristics)on the evolution of material microstructure,the formation of metallurgical defects,and mechanical properties were discussed.Generally,optimizing powder characteristics,such as sphericity,implementing substrate preheating,and formulating alloying strategies can significantly improve the densification and crack resistance of manufactured parts.Meanwhile,strictly controlling the oxygen impurity content and optimizing the energy density input are also the key factors to achieve the simultaneous improvement in strength and ductility of refractory metals.Although additive manufacturing technique provides an innovative solution for processing refractory metals,critical issues,such as residual stress control,microstructure and performance anisotropy,and process stability,still need to be addressed.This review not only provides a theoretical basis for the additive manufacturing of high-performance refractory metals,but also proposes forward-looking directions for their industrial application.展开更多
Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materi...Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.展开更多
T he residual stray magnetic fields present in ferromagnetic casting slabs were investigated in this work,which result from the magnetic fields generated during the steel casting process.Existing optical detection met...T he residual stray magnetic fields present in ferromagnetic casting slabs were investigated in this work,which result from the magnetic fields generated during the steel casting process.Existing optical detection methods face challenges owing to surface oxide scales,and conventional high-precision magnetic sensors are ineffective at high temperatures.To overcome these limitations,a small coil sensor was employed to measure the residual magnetism strength in oscillation traces,using metal magnetic memory and electromagnetic induction methods,which can carry out detection without an external excitation source.Using this technology,the proposed scheme successfully detects defects at high tempe-ratures(up to 670℃)without a cooling device.The key findings include the ability to detect both surface and near-surface defects,such as cracks and oscillation marks,with an enhanced signal-to-noise ratio(SNR)of 7.2 dB after signal processing.The method’s practicality was validated in a steel mill environment,where testing on casting slabs effectively detected defects,providing a foundation for improving industrial quality control.The proposed detection scheme offers a significant advancement in nondestructive testing(NDT)for high-temperature applications,contributing to more efficient and accurate monitoring of ferromagnetic material integrity.展开更多
Biomass-derived carbon materials are favored for their abundance and sustainability,and ease of preparation and modification.By surface activation and modification they can have a good electrical conductivity,excellen...Biomass-derived carbon materials are favored for their abundance and sustainability,and ease of preparation and modification.By surface activation and modification they can have a good electrical conductivity,excellent catalytic activity,a remarkable adsorption capacity,and different interfacial physicochemical functionalities.Surface-modified biochars have found wide applications in energy storage,environmental remediation,and catalysis.However,achieving precise and controllable modification of their active sites remains a challenge.Recent advances and future prospects for controlling their surface morphology,defect engineering,and surface coating strategies,with particular attention to their means of fabrication,are reviewed.展开更多
Herein,manganese(Mn)‑doped poly(1,5‑diaminonaphthalene)(PN)electrode material(Mn@PN)was synthesized via chemical oxidative polymerization.The material′s distinctive vesicular architecture enables rapid ion transport ...Herein,manganese(Mn)‑doped poly(1,5‑diaminonaphthalene)(PN)electrode material(Mn@PN)was synthesized via chemical oxidative polymerization.The material′s distinctive vesicular architecture enables rapid ion transport while maintaining the structural stability of the electrode under continuous charge‑discharge cycles.Electrochemical characterization under a three‑electrode system revealed exceptional rate capability:Mn@PN delivered an ultrahigh specific capacitance of 10318 F·g^(-1) at a low current density of 3 A·g^(-1) and retained 9415 F·g^(-1)(91.2%retention compared to the value at 3 A·g^(-1))even at an ultrahigh current density of 50 A·g^(-1).Moreover,the material exhibited 97.4%capacitance retention after 9000 cycles at 30 A·g^(-1),corresponding with a low capacitance decay rate of 0.003‰per cycle,significantly outperforming conventional conductive polymers like polyaniline(PANI).An asymmetric supercapacitor assembled with Mn@PN as the positive electrode(Mn@PN||AC)achieved an energy density of 328 Wh·kg^(-1) at 15 A·g^(-1) and retained 80.7%of its initial specific capacitance after 4000 cycles at 20 A·g^(-1).展开更多
The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically in...The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically investigated.The structural characteristics and nickel anchoring capacity were analyzed using XRD,BET,FT-IR,H2-TPR,and ICP-OES.The results demonstrated that the crystallization temperature significantly affected the framework order of SBA-15 and the surface anchoring efficiency of Ni ions.The nickel utilization efficiency increased from 8.4%at 80℃ to 60.49%at 140℃,but then decreased to 47.25%at 160℃,indicating an optimal crystallization temperature window.This provides crucial guidance for tailoring high-performance metal-doped molecular sieves.The optimal catalyst exhibited excellent performance in the hydrogenation of 1,4-butynediol(BYD):the BYD conversion reached 97.25%with 88.99%selectivity of 1,4-butenediol(BED)within 5 h,and reached 99.73%with 87.34%selectivity of 1,4-butanediol(BDO)after 20 h reaction.These results revealed the critical role of crystallization temperature in metal utilization and provided theoretical support for designing highly active molecular sieve catalysts.展开更多
In this study,using 3,5‑di(3′,5′‑dicarboxylphenyl)‑1H‑1,2,4‑triazole(H4L)as ligands,a gadolinia‑based organic framework complex{[GdNa(L)(H_(2)O)3]·2H_(2)O}_(n)(Gd‑Na‑MOF)was successfully designed and synthesize...In this study,using 3,5‑di(3′,5′‑dicarboxylphenyl)‑1H‑1,2,4‑triazole(H4L)as ligands,a gadolinia‑based organic framework complex{[GdNa(L)(H_(2)O)3]·2H_(2)O}_(n)(Gd‑Na‑MOF)was successfully designed and synthesized by hydrothermal method.The structure and properties were systematically characterized and tested by techniques such as single‑crystal X‑ray diffraction,powder X‑ray diffraction,thermogravimetric analysis,infrared spectroscopy,and fluorescence spectroscopy.The results indicate that this complex has a unique 3D structure,excellent thermal stability,and outstanding luminescent performance.Based on its luminescent properties,a polymer‑embedding method was employed to fabricate the Gd‑Na‑MOF into a flexible,washable composite fluorescent film,Gd‑Na‑MOF@PMMA/BMA(PMMA=polymethyl methacrylate,BMA=butyl methacrylate).This fluorescent film exhibited highly sensitive recognition capability for tyramine,with a low detection limit of 1.66μmol·L^(-1).It was used for the detection of tyramine in bananas,with a recovery rate of 96.92%‑100.26%.CCDC:2466949.展开更多
Crystallized lithium fluoride(LiF)melts at 848℃ upon heating,and evaporates subsequently at a remarkably high temperature of 1673℃,characterizing its excellent thermally stability as one of the most representative m...Crystallized lithium fluoride(LiF)melts at 848℃ upon heating,and evaporates subsequently at a remarkably high temperature of 1673℃,characterizing its excellent thermally stability as one of the most representative metal halides.The marriage between Li F and rechargeable batteries dates back to early activities related to the electrochemical properties of lithium metal(Li°)negative electrodes,in which the nonaqueous electrolytes containing fluorinated salts were generally employed,e.g.,lithium tetrafluoroborate(LiBF_(4)),lithium hexafluoroarsenate(LiAsF_(6)),lithium trifluoromethanesulfonate(CF_(3)SO_(3)Li)[1].展开更多
[Objectives]To analyze the current status of heavy metal contamination in soils of vegetable cultivation bases located in Huichuan District,Zunyi City.[Methods]Soil samples from various depths within the vegetable cul...[Objectives]To analyze the current status of heavy metal contamination in soils of vegetable cultivation bases located in Huichuan District,Zunyi City.[Methods]Soil samples from various depths within the vegetable cultivation bases of Guanba Village,Sidu Village,and Banqiao Village in Huichuan District,Zunyi City,were selected as the subjects of this study.The concentrations of five heavy metals,including lead(Pb),mercury(Hg),cadmium(Cd),arsenic(As),and chromium(Cr),were measured at different soil depths.The Nemerow comprehensive pollution index method was employed to assess heavy metal contamination,and the analysis was conducted in accordance with the farmland environmental quality evaluation standards for edible agricultural products.[Results]The concentrations of Cd and As at the sample collection sites were relatively elevated.The pollution level of Cd reached grade III or above,indicating moderate contamination in certain topsoil areas.Most As concentrations corresponded to grade II and grade III pollution levels.In contrast,Hg,Pb,and Cr concentrations remained within the safety standards established for agricultural products.However,Cd and As levels predominantly surpassed these safety thresholds.Notably,Guanba Village and Sidu Village exhibited significant pollution levels,warranting comprehensive investigations into the sources of contamination.[Conclusions]This study offers valuable insights for advancing the sustainable development of local agriculture and for the prevention and management of soil contamination.展开更多
Driven by the increasing demand for high-energy-density batteries in electric vehicles and portable electronics,lithium metal batteries have made significant breakthroughs[1–3].While critical challenges associated wi...Driven by the increasing demand for high-energy-density batteries in electric vehicles and portable electronics,lithium metal batteries have made significant breakthroughs[1–3].While critical challenges associated with lithium metal anodes in liquid electrolytes(e.g.,dendrite growth,interface instability)have hindered commercialization[4–6],solid electrolyte systems have shown promise in mitigating these issues.Among these,solid polymer electrolytes(SPEs)have emerged as a viable solution for enabling stable quasisolid-state lithium metal batteries[7–9].展开更多
Aqueous zinc ion batteries(AZIBs)are considered promising candidates owing to their inherent safety and low cost.However,the conventional glass fiber(GF)separator used in AZIBs suffers from poor physicochemical proper...Aqueous zinc ion batteries(AZIBs)are considered promising candidates owing to their inherent safety and low cost.However,the conventional glass fiber(GF)separator used in AZIBs suffers from poor physicochemical properties,leading to uncontrolled zinc(Zn)dendrite formation and undesirable side reactions.To address these limitations and enhance the electrochemical performance of AZIBs,a precisely designed functional separator is developed by incorporating UiO-66-(COOH)_(2)into a poly(vinylidene fluoride)(PVDF)framework(U-PVDF)via a direct in situ growth method.This approach enables uniform distribution of UiO-66-(COOH)_(2)both on the surface and within the PVDF backbone,without increasing separator thickness.Owing to the strong interaction between Zn^(2+)and the abundant carboxyl groups in UiO-66-(COOH)_(2),the U-PVDF separator regulates the Zn^(2+)solvation structure toward a contact ion pair-dominated structure by reducing coordinated water molecules,which effectively mitigates water-induced parasitic reactions and promotes compact Zn deposition.Consequently,a Zn/Zn symmetric cell employing the U-PVDF separator demonstrates superior cycling stability over 1500 cycles without internal short-circuiting at a current density of 6 mA cm^(−2)and an areal capacity of 2 mAh cm^(−2).Moreover,Zn/NaV_(3)O_(8)·xH_(2)O(NVO)cell with the U-PVDF separator exhibits markedly improved cyclability and rate performance compared with those using conventional GF separator.展开更多
Zero-dimensional(0D)organic-inorganic metal halide perovskite is one of the hot research topics in the field of optoelectronic materials.Their structure generally consists of discrete metal halide octahedra entirely i...Zero-dimensional(0D)organic-inorganic metal halide perovskite is one of the hot research topics in the field of optoelectronic materials.Their structure generally consists of discrete metal halide octahedra entirely isolated by surrounding organic cations,forming independent luminescent centers[1,2].Such a configuration results in high exciton binding energy and exceptional luminescence efficiency,due to strong quantum confinement[3,4].展开更多
Vitamin D deficiency(VDD)represents a significant nutritional concern among children and adolescents.The estimated prevalence of VDD in China is 46.8%in this population^([1]).VDD during childhood and adolescence has b...Vitamin D deficiency(VDD)represents a significant nutritional concern among children and adolescents.The estimated prevalence of VDD in China is 46.8%in this population^([1]).VDD during childhood and adolescence has been associated with the onset of various conditions,including acute respiratory infections,asthma,atopic dermatitis,and food allergies^([2]).Multiple factors,including age,sun exposure,adiposity,and genetics,influence vitamin D levels^([2,3]).Increasing attention has been directed toward understanding the environmental determinants that may influence vitamin D status.Given the potential of metallic pollutants to disrupt endocrine function and their ubiquity in the environment,investigating the effects of metal exposure on human vitamin D status,particularly in vulnerable populations,is imperative.展开更多
Metal ion homeostasis plays a pivotal role in maintaining cellular functions,and its disruption can initiate regulated cell death pathways.Despite its therapeutic potential,metal ion therapy for breast cancer has been...Metal ion homeostasis plays a pivotal role in maintaining cellular functions,and its disruption can initiate regulated cell death pathways.Despite its therapeutic potential,metal ion therapy for breast cancer has been hampered by inefficient ion delivery and the intrinsic resistance mechanisms of cancer cells.In this work,a cuproptosis amplifier of copper-telaglenastat coordinate(denoted as Cu-CB) is developed to trigger cell ferroptosis for synergistic breast cancer treatment.Telaglenastat(CB-839),a glutaminase inhibitor,is identified as an effective copper ionophore that facilitates the formation of Cu-CB.Specially,Cu-CB can promote the aggregation of lipoylated proteins to initiate cuproptosis,while also inhibiting glutathione(GSH) synthesis and downregulating glutathione peroxidase 4(GPX4) to trigger ferroptosis.The interplay between these cuproptosis and apoptosis pathways,mediated by Cu-CB,significantly amplifies reactive oxygen species(ROS) production and lipid peroxidation,culminating in the synergistic suppression of breast cancer.Both in vitro and in vivo studies validate the superior antitumor effects of Cu-CB through the induction of cuproptosis and ferroptosis,which may provide a new insight for metal ion delivery systems and metal ion-based tumor therapies.展开更多
Liquid metals have garnered widespread attention in the fields of electronics and materials science due to their unique combination of fluidity and electrical conductivity.Conventional liquid metal droplet generators ...Liquid metals have garnered widespread attention in the fields of electronics and materials science due to their unique combination of fluidity and electrical conductivity.Conventional liquid metal droplet generators typically rely on piezoelectric actuators to impose mechanical perturbations on the jet to control droplet formation.In this work,we present a new method for generating a uniform and controllable stream of liquid metal microdroplets by applying periodic electrostatic perturbations to the jet.Using a nozzle with an inner diameter of 25??m,we achieved continuous generation of droplets approximately 51μm in diameter at a frequency of 110 kHz.By adjusting the nozzle diameter,flow rate,and the frequency of the applied voltage,the size and spacing of the droplets can be effectively tuned.Moreover,a comparison between experimental observations and theoretical predictions under various conditions demonstrates that the Rayleigh-Plateau instability theory accurately describes the disturbance growth and droplet formation under electric field excitation.Our study provides both theoretical and experimental foundations for the controlled generation of gallium-based liquid metal droplets.展开更多
Peptides play important roles in chemistry,medicinal chemistry and life science,due to their high efficiency and specificity,unusual biological and therapeutic properties.As naturally occurring peptides often face wit...Peptides play important roles in chemistry,medicinal chemistry and life science,due to their high efficiency and specificity,unusual biological and therapeutic properties.As naturally occurring peptides often face with their intrinsic limitations including metabolic instability and low membrane permeability,the strategies for synthesizing unnatural amino acids and peptides are explored.Among the methods for modifying amino acids and peptides,chemo-and site-selective approaches are preferred because of the ability to fine-tuning structural features.Recently,transition metal-catalyzed Csingle bondH activation has been employed for the functionalization of amino acids and peptides.Through domino Csingle bondH activation/annulation,a series of structurally complex and diverse amino acids and peptides is constructed.This review highlights recent advances in the synthesis of unnatural amino acids and peptides via transition metal-catalyzed Csingle bondH activation/annulation.展开更多
The recovery of precious metals(PMs)from secondary resources is critical for addressing global supply-chain vulnerabilities and sustainable resource utilization.This review systematically examines the transformative p...The recovery of precious metals(PMs)from secondary resources is critical for addressing global supply-chain vulnerabilities and sustainable resource utilization.This review systematically examines the transformative potential of metal-organic frameworks(MOFs)as next-generation adsorbents for PM recovery,focusing on their synthesis,functionalization,and multiscale adsorption mechanisms.We critically analyze conventional pyrometallurgical and hydrometallurgical methods and highlight their limitations in terms of selectivity,energy consumption,and secondary pollution.In contrast,MOFs offer tunable porosity,abundant active sites,and tunable surface chemistry,enabling efficient PM capture via synergistic physical and chemical adsorption.Advanced modification techniques,including direct synthesis and post-synthetic modification,are reviewed to propose strategies for enhancing the adsorption kinetics and selectivity for Au,Ag,Pt,and Pd.Key structure-property relationships are established through multiscale characterization and thermodynamic models,revealing the critical roles of hierarchical porosity,soft donor atoms,and framework stability.Industrial challenges,such as aqueous stability and scalability,are addressed via Zr-O bond strengthening,hydrophobic functionalization,and support immobilization.This study consolidates the experimental and theoretical advances in MOF-based PM recovery and provides a roadmap for translating laboratory innovations into practical applications within the circular-economy framework.展开更多
Heavy metal(HM)contamination severely impacts global agricultural production.HMs toxicity effectively damaged the physiological functions such as imbalanced redox homeostasis,altered antioxidant enzyme activity,damage...Heavy metal(HM)contamination severely impacts global agricultural production.HMs toxicity effectively damaged the physiological functions such as imbalanced redox homeostasis,altered antioxidant enzyme activity,damage root system architecture,hindered photosynthetic apparatus,cellular toxicity,restricted mineral accumulation,and changed the metabolite production.Using phytohormones may be a successful strategy for enhancing and stimulating plant tolerance to HMs toxicity without affecting the environment.Melatonin(MT),a novel plant growth regulator,and powerful antioxidant molecule,enhances plant resilience to HMs stress by enhancing seedling growth,protecting the photosynthetic system,increasing nutritional status,balanced redox homeostasis,and restricting HMs accumulation from root to shoot.In addition,MT enhances the activity of antioxidant enzymes and triggers the ascorbate-glutathione(AsA-GSH)cycle,which helps remove excessive ROS.MT improves RuBisCO activity to improve photosynthesis and reduce the breakdown of chlorophyll.To identify future research needs,it is crucial to understand the comprehensive and intricate regulatory mechanisms of exogenous and endogenous MT-mediated reduction of heavy metal toxicity in plants.Melatonin has several functions,and this review sheds light on those functions and the molecular processes by which it alleviates HMs toxicity.More research is needed to fully understand how melatonin affects plant tolerance to heavy metals stress.展开更多
文摘39 soil samples surrounding a lead-zinc mining area in Guangxi were collected,and the contents of Pb,Hg,Cd,Cr,As,Cu,Zn,and Ni were determined to investigate the pollution characteristics and sources of heavy metals.ArcGIS inverse distance weight difference method was used to analyze the characteristics of pollution distribution,and single-factor pollution index,Nemerow comprehensive pollution index,ground accumulation index,and potential ecological risk index were selected to evaluate the characteristics of heavy metal pollution.Based on correlation analysis,the absolute principal component-multiple linear regression(APCS-MLR)and positive definite matrix factorization(PMF)models were used to analyze the sources of soil heavy metals.The results showed that the average concentrations of all eight heavy metals exceeded both national and Guangxi soil background values.Hg,Cd,and Zn exhibited high variation(greater than 0.5),indicating significant external disturbances,and their spatial distribution was closely related to mining activity locations.The single-factor pollution index evaluation indicated varying degrees of pollution risk for Cd,Zn,and As,with Cd and Zn being the most severe pollutants,as 69.23%and 30.77%of the samples fell into the moderate pollution or higher category.The geoaccumulation index analysis ranked the mean pollution levels of the eight elements as follows:Zn>Cd>Ni>Pb>Cu>Cr>Hg>As,with Cd and Zn showing the most severe contamination,and 51.28%of the samples exhibiting moderate or higher pollution levels.The Nemerow comprehensive pollution index evaluation showed that 74.35%of soil samples were classified as moderate to heavy pollution.The potential ecological risk index assessment indicated significant ecological risks posed by Cd and Zn,with 82.05%and 5.12%of the samples classified as causing strong to extreme ecological risks,respectively.The source apportionment analysis revealed minor differences between the two models.The APCS-MLR model identified three pollution sources and their contribution rates:anthropogenic mining sources(31.13%),parent material sources(40.38%),and unidentified sources(28.49%).The PMF model identified three pollution sources with contribution rates of anthropogenic mining sources(26.10%),parent material sources(46.96%),and a combined traffic and agricultural source(26.61%).Pb,Hg,Cd,and Zn mainly originated from mining activities;Cr,As,and Ni were primarily derived from the parent material,while Cu was predominantly attributed to traffic and agricultural sources.These findings provide a scientific basis for the prevention and control of heavy metal pollution in mining areas.
基金National MCF Energy R&D Program(2024YFE03260300)。
文摘Refractory metals,including tungsten(W),tantalum(Ta),molybdenum(Mo),and niobium(Nb),play a vital role in industries,such as nuclear energy and aerospace,owing to their exceptional melting temperatures,thermal durability,and corrosion resistance.These metals have body-centered cubic crystal structure,characterized by limited slip systems and impeded dislocation motion,resulting in significant low-temperature brittleness,which poses challenges for the conventional processing.Additive manufacturing technique provides an innovative approach,enabling the production of intricate parts without molds,which significantly improves the efficiency of material usage.This review provides a comprehensive overview of the advancements in additive manufacturing techniques for the production of refractory metals,such as W,Ta,Mo,and Nb,particularly the laser powder bed fusion.In this review,the influence mechanisms of key process parameters(laser power,scan strategy,and powder characteristics)on the evolution of material microstructure,the formation of metallurgical defects,and mechanical properties were discussed.Generally,optimizing powder characteristics,such as sphericity,implementing substrate preheating,and formulating alloying strategies can significantly improve the densification and crack resistance of manufactured parts.Meanwhile,strictly controlling the oxygen impurity content and optimizing the energy density input are also the key factors to achieve the simultaneous improvement in strength and ductility of refractory metals.Although additive manufacturing technique provides an innovative solution for processing refractory metals,critical issues,such as residual stress control,microstructure and performance anisotropy,and process stability,still need to be addressed.This review not only provides a theoretical basis for the additive manufacturing of high-performance refractory metals,but also proposes forward-looking directions for their industrial application.
文摘Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.
文摘T he residual stray magnetic fields present in ferromagnetic casting slabs were investigated in this work,which result from the magnetic fields generated during the steel casting process.Existing optical detection methods face challenges owing to surface oxide scales,and conventional high-precision magnetic sensors are ineffective at high temperatures.To overcome these limitations,a small coil sensor was employed to measure the residual magnetism strength in oscillation traces,using metal magnetic memory and electromagnetic induction methods,which can carry out detection without an external excitation source.Using this technology,the proposed scheme successfully detects defects at high tempe-ratures(up to 670℃)without a cooling device.The key findings include the ability to detect both surface and near-surface defects,such as cracks and oscillation marks,with an enhanced signal-to-noise ratio(SNR)of 7.2 dB after signal processing.The method’s practicality was validated in a steel mill environment,where testing on casting slabs effectively detected defects,providing a foundation for improving industrial quality control.The proposed detection scheme offers a significant advancement in nondestructive testing(NDT)for high-temperature applications,contributing to more efficient and accurate monitoring of ferromagnetic material integrity.
文摘Biomass-derived carbon materials are favored for their abundance and sustainability,and ease of preparation and modification.By surface activation and modification they can have a good electrical conductivity,excellent catalytic activity,a remarkable adsorption capacity,and different interfacial physicochemical functionalities.Surface-modified biochars have found wide applications in energy storage,environmental remediation,and catalysis.However,achieving precise and controllable modification of their active sites remains a challenge.Recent advances and future prospects for controlling their surface morphology,defect engineering,and surface coating strategies,with particular attention to their means of fabrication,are reviewed.
文摘Herein,manganese(Mn)‑doped poly(1,5‑diaminonaphthalene)(PN)electrode material(Mn@PN)was synthesized via chemical oxidative polymerization.The material′s distinctive vesicular architecture enables rapid ion transport while maintaining the structural stability of the electrode under continuous charge‑discharge cycles.Electrochemical characterization under a three‑electrode system revealed exceptional rate capability:Mn@PN delivered an ultrahigh specific capacitance of 10318 F·g^(-1) at a low current density of 3 A·g^(-1) and retained 9415 F·g^(-1)(91.2%retention compared to the value at 3 A·g^(-1))even at an ultrahigh current density of 50 A·g^(-1).Moreover,the material exhibited 97.4%capacitance retention after 9000 cycles at 30 A·g^(-1),corresponding with a low capacitance decay rate of 0.003‰per cycle,significantly outperforming conventional conductive polymers like polyaniline(PANI).An asymmetric supercapacitor assembled with Mn@PN as the positive electrode(Mn@PN||AC)achieved an energy density of 328 Wh·kg^(-1) at 15 A·g^(-1) and retained 80.7%of its initial specific capacitance after 4000 cycles at 20 A·g^(-1).
文摘The Ni/SBA-15 catalysts were synthesized using the in situ method and the influence of crystallization temperature on nickel utilization efficiency-a critical factor in mesoporous material design-was systematically investigated.The structural characteristics and nickel anchoring capacity were analyzed using XRD,BET,FT-IR,H2-TPR,and ICP-OES.The results demonstrated that the crystallization temperature significantly affected the framework order of SBA-15 and the surface anchoring efficiency of Ni ions.The nickel utilization efficiency increased from 8.4%at 80℃ to 60.49%at 140℃,but then decreased to 47.25%at 160℃,indicating an optimal crystallization temperature window.This provides crucial guidance for tailoring high-performance metal-doped molecular sieves.The optimal catalyst exhibited excellent performance in the hydrogenation of 1,4-butynediol(BYD):the BYD conversion reached 97.25%with 88.99%selectivity of 1,4-butenediol(BED)within 5 h,and reached 99.73%with 87.34%selectivity of 1,4-butanediol(BDO)after 20 h reaction.These results revealed the critical role of crystallization temperature in metal utilization and provided theoretical support for designing highly active molecular sieve catalysts.
文摘In this study,using 3,5‑di(3′,5′‑dicarboxylphenyl)‑1H‑1,2,4‑triazole(H4L)as ligands,a gadolinia‑based organic framework complex{[GdNa(L)(H_(2)O)3]·2H_(2)O}_(n)(Gd‑Na‑MOF)was successfully designed and synthesized by hydrothermal method.The structure and properties were systematically characterized and tested by techniques such as single‑crystal X‑ray diffraction,powder X‑ray diffraction,thermogravimetric analysis,infrared spectroscopy,and fluorescence spectroscopy.The results indicate that this complex has a unique 3D structure,excellent thermal stability,and outstanding luminescent performance.Based on its luminescent properties,a polymer‑embedding method was employed to fabricate the Gd‑Na‑MOF into a flexible,washable composite fluorescent film,Gd‑Na‑MOF@PMMA/BMA(PMMA=polymethyl methacrylate,BMA=butyl methacrylate).This fluorescent film exhibited highly sensitive recognition capability for tyramine,with a low detection limit of 1.66μmol·L^(-1).It was used for the detection of tyramine in bananas,with a recovery rate of 96.92%‑100.26%.CCDC:2466949.
文摘Crystallized lithium fluoride(LiF)melts at 848℃ upon heating,and evaporates subsequently at a remarkably high temperature of 1673℃,characterizing its excellent thermally stability as one of the most representative metal halides.The marriage between Li F and rechargeable batteries dates back to early activities related to the electrochemical properties of lithium metal(Li°)negative electrodes,in which the nonaqueous electrolytes containing fluorinated salts were generally employed,e.g.,lithium tetrafluoroborate(LiBF_(4)),lithium hexafluoroarsenate(LiAsF_(6)),lithium trifluoromethanesulfonate(CF_(3)SO_(3)Li)[1].
基金Supported by Undergraduate Innovation and Entrepreneurship Training Program of Guizhou Province(2024106640823)Natural Science Research Project of Guizhou Provincial Department of Education(QJJ[2023]043)Zunyi Science and Technology Innovation Team Project(ZKCTD008).
文摘[Objectives]To analyze the current status of heavy metal contamination in soils of vegetable cultivation bases located in Huichuan District,Zunyi City.[Methods]Soil samples from various depths within the vegetable cultivation bases of Guanba Village,Sidu Village,and Banqiao Village in Huichuan District,Zunyi City,were selected as the subjects of this study.The concentrations of five heavy metals,including lead(Pb),mercury(Hg),cadmium(Cd),arsenic(As),and chromium(Cr),were measured at different soil depths.The Nemerow comprehensive pollution index method was employed to assess heavy metal contamination,and the analysis was conducted in accordance with the farmland environmental quality evaluation standards for edible agricultural products.[Results]The concentrations of Cd and As at the sample collection sites were relatively elevated.The pollution level of Cd reached grade III or above,indicating moderate contamination in certain topsoil areas.Most As concentrations corresponded to grade II and grade III pollution levels.In contrast,Hg,Pb,and Cr concentrations remained within the safety standards established for agricultural products.However,Cd and As levels predominantly surpassed these safety thresholds.Notably,Guanba Village and Sidu Village exhibited significant pollution levels,warranting comprehensive investigations into the sources of contamination.[Conclusions]This study offers valuable insights for advancing the sustainable development of local agriculture and for the prevention and management of soil contamination.
基金supported by the National Natural Science Foundation of China(22279028,21975063,22421001)the Natural Science Foundation of Hebei Province(B2021205019)the 333 Project of Hebei Province(C20231106)。
文摘Driven by the increasing demand for high-energy-density batteries in electric vehicles and portable electronics,lithium metal batteries have made significant breakthroughs[1–3].While critical challenges associated with lithium metal anodes in liquid electrolytes(e.g.,dendrite growth,interface instability)have hindered commercialization[4–6],solid electrolyte systems have shown promise in mitigating these issues.Among these,solid polymer electrolytes(SPEs)have emerged as a viable solution for enabling stable quasisolid-state lithium metal batteries[7–9].
基金supported by the Basic Science Research Program(RS-2024-00455177)through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT.
文摘Aqueous zinc ion batteries(AZIBs)are considered promising candidates owing to their inherent safety and low cost.However,the conventional glass fiber(GF)separator used in AZIBs suffers from poor physicochemical properties,leading to uncontrolled zinc(Zn)dendrite formation and undesirable side reactions.To address these limitations and enhance the electrochemical performance of AZIBs,a precisely designed functional separator is developed by incorporating UiO-66-(COOH)_(2)into a poly(vinylidene fluoride)(PVDF)framework(U-PVDF)via a direct in situ growth method.This approach enables uniform distribution of UiO-66-(COOH)_(2)both on the surface and within the PVDF backbone,without increasing separator thickness.Owing to the strong interaction between Zn^(2+)and the abundant carboxyl groups in UiO-66-(COOH)_(2),the U-PVDF separator regulates the Zn^(2+)solvation structure toward a contact ion pair-dominated structure by reducing coordinated water molecules,which effectively mitigates water-induced parasitic reactions and promotes compact Zn deposition.Consequently,a Zn/Zn symmetric cell employing the U-PVDF separator demonstrates superior cycling stability over 1500 cycles without internal short-circuiting at a current density of 6 mA cm^(−2)and an areal capacity of 2 mAh cm^(−2).Moreover,Zn/NaV_(3)O_(8)·xH_(2)O(NVO)cell with the U-PVDF separator exhibits markedly improved cyclability and rate performance compared with those using conventional GF separator.
文摘Zero-dimensional(0D)organic-inorganic metal halide perovskite is one of the hot research topics in the field of optoelectronic materials.Their structure generally consists of discrete metal halide octahedra entirely isolated by surrounding organic cations,forming independent luminescent centers[1,2].Such a configuration results in high exciton binding energy and exceptional luminescence efficiency,due to strong quantum confinement[3,4].
基金supported by grants from the National Natural Science Foundation of China(G.F.Wang,grant number 82204071)(P.Y.Su,grant numbers 81874268 and 82473655)the Research Funds of the Center for Big Data and Population Health of IHM(P.Y.Su,No.JKS2023016)Anhui Provincial Health Commission Scientific Research Project(Y.Zhou,No.AHWJ2023A30027)。
文摘Vitamin D deficiency(VDD)represents a significant nutritional concern among children and adolescents.The estimated prevalence of VDD in China is 46.8%in this population^([1]).VDD during childhood and adolescence has been associated with the onset of various conditions,including acute respiratory infections,asthma,atopic dermatitis,and food allergies^([2]).Multiple factors,including age,sun exposure,adiposity,and genetics,influence vitamin D levels^([2,3]).Increasing attention has been directed toward understanding the environmental determinants that may influence vitamin D status.Given the potential of metallic pollutants to disrupt endocrine function and their ubiquity in the environment,investigating the effects of metal exposure on human vitamin D status,particularly in vulnerable populations,is imperative.
基金supported by the National Natural Science Foundation of China (Nos.82302355,32371394)Guangdong Basic and Applied Basic Research Foundation (No.2023A1515012628)+1 种基金the Characteristic Innovation Projects of General Colleges and Universities in Guangdong Province (No.2024KTSCX120)the Science and Technology Program of Guangzhou (Nos.2024A04J3324,2024A03J0078)。
文摘Metal ion homeostasis plays a pivotal role in maintaining cellular functions,and its disruption can initiate regulated cell death pathways.Despite its therapeutic potential,metal ion therapy for breast cancer has been hampered by inefficient ion delivery and the intrinsic resistance mechanisms of cancer cells.In this work,a cuproptosis amplifier of copper-telaglenastat coordinate(denoted as Cu-CB) is developed to trigger cell ferroptosis for synergistic breast cancer treatment.Telaglenastat(CB-839),a glutaminase inhibitor,is identified as an effective copper ionophore that facilitates the formation of Cu-CB.Specially,Cu-CB can promote the aggregation of lipoylated proteins to initiate cuproptosis,while also inhibiting glutathione(GSH) synthesis and downregulating glutathione peroxidase 4(GPX4) to trigger ferroptosis.The interplay between these cuproptosis and apoptosis pathways,mediated by Cu-CB,significantly amplifies reactive oxygen species(ROS) production and lipid peroxidation,culminating in the synergistic suppression of breast cancer.Both in vitro and in vivo studies validate the superior antitumor effects of Cu-CB through the induction of cuproptosis and ferroptosis,which may provide a new insight for metal ion delivery systems and metal ion-based tumor therapies.
基金supported by the National Natural Science Foundation of China(Grant Nos.U2341281,12272026,12502287)the Natural Science Foundation of Beijing Municipality(Grant No.L248008)。
文摘Liquid metals have garnered widespread attention in the fields of electronics and materials science due to their unique combination of fluidity and electrical conductivity.Conventional liquid metal droplet generators typically rely on piezoelectric actuators to impose mechanical perturbations on the jet to control droplet formation.In this work,we present a new method for generating a uniform and controllable stream of liquid metal microdroplets by applying periodic electrostatic perturbations to the jet.Using a nozzle with an inner diameter of 25??m,we achieved continuous generation of droplets approximately 51μm in diameter at a frequency of 110 kHz.By adjusting the nozzle diameter,flow rate,and the frequency of the applied voltage,the size and spacing of the droplets can be effectively tuned.Moreover,a comparison between experimental observations and theoretical predictions under various conditions demonstrates that the Rayleigh-Plateau instability theory accurately describes the disturbance growth and droplet formation under electric field excitation.Our study provides both theoretical and experimental foundations for the controlled generation of gallium-based liquid metal droplets.
基金supported by the Natural Science Foundation of Jiangsu Province(No.BK20220409)the National Natural Science Foundation of China(No.22401153)+2 种基金the FWO[Fund for Scientific Research-Flanders(Belgium)]for financial support(recipient Erik V.Van der Eycken)the Research Council of the KU Leuven(recipient Erik V.Van der Eycken)the support of the"RUDN University Strategic Academic Leadership Program"(recipient Erik V.Van der Eycken).
文摘Peptides play important roles in chemistry,medicinal chemistry and life science,due to their high efficiency and specificity,unusual biological and therapeutic properties.As naturally occurring peptides often face with their intrinsic limitations including metabolic instability and low membrane permeability,the strategies for synthesizing unnatural amino acids and peptides are explored.Among the methods for modifying amino acids and peptides,chemo-and site-selective approaches are preferred because of the ability to fine-tuning structural features.Recently,transition metal-catalyzed Csingle bondH activation has been employed for the functionalization of amino acids and peptides.Through domino Csingle bondH activation/annulation,a series of structurally complex and diverse amino acids and peptides is constructed.This review highlights recent advances in the synthesis of unnatural amino acids and peptides via transition metal-catalyzed Csingle bondH activation/annulation.
基金supported by the National Natural Science Foundation of China(No.52304329)the Yunnan Fundamental Research Projects(No.202201BE070001-003),Guo Lin would like to acknowledge Xing Dian talent support program of Yunnan Province.
文摘The recovery of precious metals(PMs)from secondary resources is critical for addressing global supply-chain vulnerabilities and sustainable resource utilization.This review systematically examines the transformative potential of metal-organic frameworks(MOFs)as next-generation adsorbents for PM recovery,focusing on their synthesis,functionalization,and multiscale adsorption mechanisms.We critically analyze conventional pyrometallurgical and hydrometallurgical methods and highlight their limitations in terms of selectivity,energy consumption,and secondary pollution.In contrast,MOFs offer tunable porosity,abundant active sites,and tunable surface chemistry,enabling efficient PM capture via synergistic physical and chemical adsorption.Advanced modification techniques,including direct synthesis and post-synthetic modification,are reviewed to propose strategies for enhancing the adsorption kinetics and selectivity for Au,Ag,Pt,and Pd.Key structure-property relationships are established through multiscale characterization and thermodynamic models,revealing the critical roles of hierarchical porosity,soft donor atoms,and framework stability.Industrial challenges,such as aqueous stability and scalability,are addressed via Zr-O bond strengthening,hydrophobic functionalization,and support immobilization.This study consolidates the experimental and theoretical advances in MOF-based PM recovery and provides a roadmap for translating laboratory innovations into practical applications within the circular-economy framework.
文摘Heavy metal(HM)contamination severely impacts global agricultural production.HMs toxicity effectively damaged the physiological functions such as imbalanced redox homeostasis,altered antioxidant enzyme activity,damage root system architecture,hindered photosynthetic apparatus,cellular toxicity,restricted mineral accumulation,and changed the metabolite production.Using phytohormones may be a successful strategy for enhancing and stimulating plant tolerance to HMs toxicity without affecting the environment.Melatonin(MT),a novel plant growth regulator,and powerful antioxidant molecule,enhances plant resilience to HMs stress by enhancing seedling growth,protecting the photosynthetic system,increasing nutritional status,balanced redox homeostasis,and restricting HMs accumulation from root to shoot.In addition,MT enhances the activity of antioxidant enzymes and triggers the ascorbate-glutathione(AsA-GSH)cycle,which helps remove excessive ROS.MT improves RuBisCO activity to improve photosynthesis and reduce the breakdown of chlorophyll.To identify future research needs,it is crucial to understand the comprehensive and intricate regulatory mechanisms of exogenous and endogenous MT-mediated reduction of heavy metal toxicity in plants.Melatonin has several functions,and this review sheds light on those functions and the molecular processes by which it alleviates HMs toxicity.More research is needed to fully understand how melatonin affects plant tolerance to heavy metals stress.
