Polycyclic Aromatic Hydrocarbons(PAHs),along with their derivatives nitro-PAHs and oxy-PAHs,are globally recognized toxic pollutants.This research conducted daily PM_(2.5)sampling in winter 2021 at three urban(YNCE,SW...Polycyclic Aromatic Hydrocarbons(PAHs),along with their derivatives nitro-PAHs and oxy-PAHs,are globally recognized toxic pollutants.This research conducted daily PM_(2.5)sampling in winter 2021 at three urban(YNCE,SWP,and NG)and three suburban sites(HC,CTV,and YNE)in the Ili River Valley(IRV).For the first time in the IRV,a comprehensive study on 39 PAHs and derivatives was carried out.The results showed that the average∑_(16)PAHs concentration was 130.21±98.94 ng/m^(3),with 16PAHs constituting the dominant fraction(112.51±86.48 ng/m^(3)).The mean BaP and the total BaP equivalent quotient(TEQ)concentrations were 10.28±8.85 ng/m^(3)and 19.74±16.70 ng/m^(3),respectively.Approximately 88%of the daily BaP averages and 98%of the daily TEQ averages exceeded the national daily average standard of BaP(2.5 ng/m^(3)),indicating severe local BaP pollution.Urban sites had notably higher∑PAHs and TEQ concentrations than suburban sites,attributed to increased vehicular traffic and coal combustion in urban areas.PMF results showed that traffic emissions(32.7%-60.5%),coal combustion(13.9%-24.3%)and secondary formation(14.7%-22.7%)were the primary contributors to∑PAHs.Urban sites experienced a greater influence from traffic,while suburban sites were more impacted by coal and biomass burning.On polluted days,traffic sources’contributions increased significantly at HC,YNE,NG and YNCE sites,and secondary formation sources’contributions grew at CTV and YNCE sites.The sourcedependent BaPeq results underscored the role of secondary-formed PAH derivatives in TEQ.展开更多
Nitrated polycyclic aromatic hydrocarbons(NPAHs)have toxic potentials that are higher than those of their corresponding parent polycyclic aromatic hydrocarbons(PAHs)and thus have received increasing attention in recen...Nitrated polycyclic aromatic hydrocarbons(NPAHs)have toxic potentials that are higher than those of their corresponding parent polycyclic aromatic hydrocarbons(PAHs)and thus have received increasing attention in recent years.In this study,the occurrence,distribution,source,and human health risk assessment of 15 NPAHs and 16 PAHs were investigated in the surface water from 20 sampling sites of Lake Taihu during the dry,normal,and flood seasons of 2018.The PAH concentrations ranged from 255 to 7298 ng/L and the NPAH concentrations ranged from not-detected(ND)to 212 ng/L.Among the target analytes,2-nitrofluorene(2-n Flu)was the predominant NPAH,with a detection frequency ranging from 85%to 90%and a maximum concentration of 56.2 ng/L.The three-ringed and four-ringed NPAHs and PAHs comprised the majority of the detected compounds.In terms of seasonal variation,the highest levels of the NPAHs and PAHs were in the dry season and flood season,respectively.Diagnostic ratio analysis indicated that the prime source of NPAHs was direct combustion,whereas in the case of PAHs the contribution was predominantly from a mixed pattern including pollution from unburned petroleum and petroleum combustion.The human health risk of NPAHs and PAHs was evaluated using a lifetime carcinogenic risk assessment model.The carcinogenic risk level of the targets ranged from 2.09×10^(-7)to 5.75×10^(-5)and some surface water samples posed a potential health risk.展开更多
Polycyclic aromatic hydrocarbons(PAHs)and their nitrated derivatives(NPAHs)attract continuous attention due to their outstanding carcinogenicity and mutagenicity.In order to investigate the diurnal variations,sources,...Polycyclic aromatic hydrocarbons(PAHs)and their nitrated derivatives(NPAHs)attract continuous attention due to their outstanding carcinogenicity and mutagenicity.In order to investigate the diurnal variations,sources,formation mechanism,and health risk assessment of them in heating season,particulate matter(PM)were collected in Beijing urban area from December 26,2017 to January 17,2018.PAHs and NPAHs in PM were quantitatively analyzed via gas chromatography-mass spectrometry(GC-MS).Average daily concentrations of PAHs and NPAHs were(78±54)ng/m^(3)and(783±684)pg/m^(3),respectively.The concentrations of them were significantly higher at nighttime than at daytime,and NPAHs concentrations were 1-2 orders of magnitude lower than PAHs concentrations.In the heating season,the dominant species of PAHs include benzo[b]fluoranthene,fluoranthene,pyrene,and chrysene,while 9-nitroanthracene,2+3-nitrofluoranthene,and 2-nitropyrene were dominant species for NPAHs.NPAHs were found to have a single peak during heating and to be primarily distributed in the 0.4-0.7μm particle size.Primary emissions such as biomass burning,coal combustion,and traffic emissions were the major sources of PAHs.NPAHs were produced by the primary source of vehicle emissions and the secondary reaction triggered by OH radicals,as well as biomass burning during daytime.According to the health risk assessment,the total carcinogenic risk was higher in adults than in children.While upon oral ingestion,the carcinogenic risk in children was higher than that of adults,but the risk of adults was higher than children through skin contact and respiratory inhalation.展开更多
Intensive daytime and nighttime sampling was carried out from 23 Oct to 31 Dec 2008 to investigate the occurrence of nitrated polycyclic aromatic hydrocarbons （NPAHs） in PM1o at a roadside site in Xiamen, China. At ...Intensive daytime and nighttime sampling was carried out from 23 Oct to 31 Dec 2008 to investigate the occurrence of nitrated polycyclic aromatic hydrocarbons （NPAHs） in PM1o at a roadside site in Xiamen, China. At the same time, six PMt0 samples were collected from a nearby roadway tunnel for comparison. Six NPAHs, namely 9-nitroanthracene, 2- and 3-nitrofluoranthene, 1- nitropyrene, 7-nitrobenz[a]anthracene, and 6-nitrobenzo[a]pyrene, were identified and quantified using GC/MS in negative ion chemical ionization mode. The average total concentration of six NPAHs （~NPAHs） in the cold season （26 Nov-31 Dec） was 2.3 （daytime） and 9.9 （nighttime） times higher than those in the warm season. Significant statistical difference （p 〈 0.01, 2-tailed） of ∑NPAHs between daytime and nighttime was found during both the warm and cold seasons. NPAHs were significantly positively correlated with their parent PAHs and nitrogen dioxide but negatively correlated with ambient temperature. The ratio of 2 ＋ 3-nitrofluoranthene to 1- nitropyrene exhibited a similar diurnal pattern as ZNPAHs and was generally greater than 5, indicating the importance of secondary atmospheric formation. The diurnal variations of NPAHs were all influenced by the diurnal variations of PAHs, nitrogen dioxide, sunlight, and temperature. The daily inhalable exposure to the six NPAHs in the tunnel was much higher than the roadside values in the warm season but only slightly higher than those in the cold season.展开更多
Air pollutants can potentially lead to nitration of allergic proteins,thus promoting sensitization of these allergens.However,little is currently known about the nitration status of house dust mite(HDM)allergens.We id...Air pollutants can potentially lead to nitration of allergic proteins,thus promoting sensitization of these allergens.However,little is currently known about the nitration status of house dust mite(HDM)allergens.We identified the occurrence of nitrated products of two major HDM allergens Der f 1 and Der p 1 in dust samples collected from college dormitories in eastern China and assessed their associated health risk.The results showed that both non-nitrated and nitrated forms of the two allergens were detected in the dust in the range of non-detected(ND)-10.6,1.44-15.4,ND-22.4,ND-7.28μg/g for non-nitrated Der f 1,nitrated Der f 1,non-nitrated Der p 1 and nitrated Der p 1,respectively.The median rates of nitration were determined as 74.0%for Der f 1 and 20.4% for Der p 1 at consideration of one nitration site.Further analysis reveals that the levels of HDM allergens and their nitrated products were found to be generally higher during winter,in dormitories of lower altitude and with female occupants.Furthermore,the calculated risk indexes were at considerably high levels.Our findings suggest that nitrated HDM allergens have already accumulated in the environment at such significant levels and their associated health risk calls for our immediate attention.展开更多
Previous studies documented increased nitrative stress and susceptibility to air pollution among individuals with chronic inflammatory conditions.This study examines the role of anti-inflammatory and cardioprotective ...Previous studies documented increased nitrative stress and susceptibility to air pollution among individuals with chronic inflammatory conditions.This study examines the role of anti-inflammatory and cardioprotective nitrated fatty acids(i.e.,NO2-cLA)in chronic obstructive pulmonary disease(COPD)'s and ischemic heart disease(IHD)'s susceptibility to air pollution.In a randomized crossover study,40 healthy,40 COPD,and 39 IHD adults underwent a 2 h walk in a more polluted street or a less polluted park.We measured urinary NO2-cLA before and 24 h after the walk,as well as respiratory inflammatory biomarkers,lung function,airway resistance,and arterial stiffness.Baseline NO2-cLA levels were 2.56(95%CI:1.20-5.43)-fold higher among COPD participants than healthy participants,which can be explained by higher fractional exhaled nitric oxide and sputum myeloperoxidase levels.Among COPD but not healthy or IHD participants,the street walk,compared to park,led to a 57.7%(95%CI:7.6-80.6%)decrease in NO2-cLA levels and sputum biomarker changes indicative of decreased neutrophil inflammation and proresolving responses.Decreased NO2-cLA levels were associated with exposure to black carbon and ultrafine particles and worsened lung function and arterial stiffness.Taken together,nitrated fatty acids partially mediate COPD patients'cardiorespiratory responses to air pollution,explaining their susceptibility.展开更多
Cmyc,a proto-oncogene,is expressed at extremely low levels in mature neurons and is traditionally thought to have no function in these cells.However,recent studies suggest that Cmyc may play a crucial role in maintain...Cmyc,a proto-oncogene,is expressed at extremely low levels in mature neurons and is traditionally thought to have no function in these cells.However,recent studies suggest that Cmyc may play a crucial role in maintaining the health and function of mature dopaminergic neurons.This study assessed the role of Cmyc in dopaminergic neurons and its significance in Parkinson’s disease.We used a conditional knockout approach to specifically delete Cmyc in substantia nigra dopaminergic neurons of adult mice.Our findings showed that Cmyc deletion led to progressive neuron loss,Parkinson’s disease-like symptoms,downregulation of Klotho,and upregulation of senescence-associated inflammatory factors,along with enhanced oxidative stress and nitrated alpha-synuclein accumulation,ultimately causing neuronal death.In vitro experiments confirmed increased senescence in C-MYC knockout cells,which was partially reversible by KLOTHO overexpression.We conclude that low-level Cmyc expression is essential for maintaining the health of mature dopaminergic neurons and preventing neurodegeneration,and suggest the c-Myc/Klotho axis as a potential therapeutic target for age-related neurodegenerative diseases,including Parkinson’s disease.Our study introduces a novel mouse model for Parkinson’s disease that replicates a condition associated with normal aging,offering a valuable tool for future research into disease mechanisms and therapeutic strategies.展开更多
Ammonium toxicity in plants remains poorly understood despite extensive research.While nitrate is known to benefit plant growth,the synergistic effects of nitrate in mitigating ammonium toxicity,even at low concentrat...Ammonium toxicity in plants remains poorly understood despite extensive research.While nitrate is known to benefit plant growth,the synergistic effects of nitrate in mitigating ammonium toxicity,even at low concentrations,are not fully elucidated.This review delves into the physiological and molecular nature of this phenomenon.To date,nitrate-dependent alleviation of ammonium toxicity is the result of cumulative consequences of the role of nitrate as a nutrient and signal in plant performance.The ability to counteract the ammonium-induced acidification through nitrate uptake and metabolism,the enhancement of potassium uptake as an essential nitrate counterion,and the nitratedependent signaling of key factors involved in ammonium assimilation,ROS scavenging,and growth hormone biosynthesis,are the most relevant hallmarks.In addition,evidence suggests that the availability of nitrate and ammonium has driven ecological selection in plants,determining current N preferences,and may have led to the selection of nitrate-dependent and ammonium-sensitive domesticated crops and the inefficient use of N fertilizers in agriculture.As ammonium toxicity limits N fertilization options and reduces agricultural yields,when it could be a more sustainable and cheaper alternative to nitrate,this review provides a better understanding of how plants use nitrate to counteract the problematic aspects of ammonium nutrition.展开更多
In comparison with their 2D and 3D counterparts,1D covalent organic frameworks(COFs)have rarely been investigated due to the synthetic challenge arising from the strict necessary matching in the molecular symmetry bet...In comparison with their 2D and 3D counterparts,1D covalent organic frameworks(COFs)have rarely been investigated due to the synthetic challenge arising from the strict necessary matching in the molecular symmetry between corresponding building blocks and linking units in addition to the unmanageable packing of 1D organic chains once formed.Herein,two novel imide-linked 1D COFs with phthalocyanine building blocks,namely NiPc-CZDM-COF and NiPc-CZDL-COF,were fabricated from the hydrothermal synthesis reaction of 2,3,9,10,16,17,23,24-octacarboxyphthalocyaninato nickel(II)(NiPc(COOH)_(8))with 9H-carbazole-3,6-diamine(CZDM)and 4,4′-(9H-carbazole-3,6-diyl)dianiline(CZDL),respectively.Two COFs have high crystallinity on the basis of powder X-ray diffraction analysis and high-resolution transmission electron microscopy.Due to their high ratio of exposed active centers on the edge sites of porous ribbons,both NiPc-CZDM-COF and NiPc-CZDL-COF electrodes display high utilization efficiency of NiPc electroactive sites of 8.0%and 7.5% according to the electrochemical measurement,resulting in their excellent capacity toward electrocatalytic nitrate reduction with the nitrate-to-NH3 Faradaic efficiency of nearly 100%.In particular,NiPc-CZDM-COF electrode exhibits superior electrocatalytic performance with high NH3 partial current density of−246 mA/cm^(2),ammonia yield rate of 19.5 mg cm^(−2) h^(−1),and turnover frequency of 5.8 s^(−1) at−1.2 V in an H-type cell associated with its higher conductivity.This work reveals the good potential of 1D porous crystalline materials in electrocatalysis.展开更多
Exploring high-performance electrocatalysts for the nitrate reduction reaction(NO_(3)RR)is crucial for environmental nitrate removal and ammonia synthesis.Single-atom collaboration with cluster can provide sufficient ...Exploring high-performance electrocatalysts for the nitrate reduction reaction(NO_(3)RR)is crucial for environmental nitrate removal and ammonia synthesis.Single-atom collaboration with cluster can provide sufficient active sites for catalysts to promote NO_(3)RR,yet the unclear synergistic effect between the two hinders their rational design.Herein,a series of Ir_(3)clusters and metal single atoms co-embedded in graphitic carbon nitride(g-CN)catalysts(Ir_(3)M1)were constructed,and the synergistic effects of Ir_(3)clusters and M1 single atoms on the NO_(3)RR catalytic mechanism and activity were systematically explored using density functional theory(DFT)calculations combined with machine learning.Comprehensive evaluations of structural stability and catalytic activity demonstrate that the synergy between single atoms and clusters effectively balances the adsorption energies of key intermediates,yielding exceptional catalytic performance(the limiting potential of Ir_(3)Ti_(1)can reach−0.22 V).Machine learning models further clarify the synergistic mechanism,where the geometric configurations of clusters serve as critical features for modulating the catalytic activity of single-atom sites,whereas the electronic structures of single atoms directly govern the reactivity of cluster sites.This DFT-machine learning approach provides theoretical guidelines for catalyst design and a predictive framework for efficient NO_(3)RR electrocatalysts.展开更多
To address the deficiencies in comprehensive surface contamination prevention strategies within China's nitrate-affected regions,this research innovatively proposes the DITAPH model-a systematic framework integrat...To address the deficiencies in comprehensive surface contamination prevention strategies within China's nitrate-affected regions,this research innovatively proposes the DITAPH model-a systematic framework integrating groundwater nitrate vulnerability assessment and Nitrate Vulnerable Zones(NVZs)delineation through optimization of hydrogeological parameters.Based on detailed hydrogeological and hydrochemical investigations,the DITAPH model was applied in the plain areas of Quanzhou to evaluate its applicability.The model selected hydrogeological parameters(depth of groundwater,lithology of the vadose zone,topographic slope,aquifer water yield property),one climatic parameter(precipitation),and two anthropogenic parameters(land use type and population density)as assessment indicators.The results of the groundwater nitrate vulnerability assessment showed that the low,relatively low,relatively high,and high groundwater nitrate vulnerability zones in the study area accounted for 5.96%,35.44%,53.74%and 4.86%of the total area,respectively.Groundwater nitrate vulnerability was most strongly influenced by human activities,followed by groundwater depth and topographic slope.The high vulnerability zone is mainly affected by domestic and industrial wastewater,whereas the relatively high groundwater nitrate vulnerability zone is primarily influenced by agricultural activities.Validation of the DITAPH model revealed a significant positive correlation between the DITAPH index(DI)and nitrate concentration(ρ(NO3−)).The results of the NVZs delineated by the DITAPH model are reliable and can serve as a tool for water resource management planning,guiding the development of targeted measures in the NVZs to prevent groundwater contamination.展开更多
Electrocatalytic nitrate-to-ammonia conversion offers dual environmental and sustainable synthesis benefits,but achieving high efficiency with low-cost catalysts remains a major challenge.This review focuses on cobalt...Electrocatalytic nitrate-to-ammonia conversion offers dual environmental and sustainable synthesis benefits,but achieving high efficiency with low-cost catalysts remains a major challenge.This review focuses on cobalt-based electrocatalysts,emphasizing their structural engineering for enhanced the performance of electrocatalytic nitrate reduction reaction(NO3RR)through dimensional control,compositional tuning,and coordination microenvironment modulation.Notably,by critically analyzing metallic cobalt,cobalt alloys,cobalt compounds,cobalt single atom and molecular catalyst configurations,we firstly establish correlations between atomic-scale structural features and catalytic performance in a coordination environment perspective for NO3RR,including the dynamic reconstruction during operation and its impact on active site.Synergizing experimental breakthroughs with computational modeling,we decode mechanisms underlying competitive hydrogen evolution suppression,intermediate adsorption-energy optimization,and durability enhancement in complex aqueous environments.The development of cobalt-based catalysts was summarized and prospected,and the emerging opportunities of machine learning in accelerating the research and development of high-performance catalysts and the configuration of series reactors for scalable nitrate-to-ammonia systems were also introduced.Bridging surface science and applications,it outlines a framework for designing multifunctional electrocatalysts to restore nitrogen cycle balance sustainably.展开更多
The electrocatalytic reduction of nitrate to ammonia(NO_(3)^(−)RR)offers a sustainable alternative to energy-intensive industrial NH3 synthesis.Tandem catalysis has shown promise in overcoming the multi-step complexit...The electrocatalytic reduction of nitrate to ammonia(NO_(3)^(−)RR)offers a sustainable alternative to energy-intensive industrial NH3 synthesis.Tandem catalysis has shown promise in overcoming the multi-step complexity of NO_(3)^(−)RR,yet challenges remain in optimizing performance and elucidating tandem mechanisms.Herein,we report a Cu@Co/CoFe-P tandem electrocatalyst featuring a phosphorus-doped heterostructure with dual active sites(Cu-P and Co/CoFe-P).This catalyst achieves an exceptional NH_(3)yield of 175.40 mg h^(−1)cm^(−2)and a record-high current density exceeding 2 A cm^(−2),with the electro-synthesized NH3 directly converted into NH4Cl.In situ spectroscopic analysis and density functional theory(DFT)calculations reveal a novel desorption-reactivation tandem mechanism:(1)the Cu-P domain preferentially reduces NO_(3)^(−)to*NO_(2),which desorbs as stable NO_(2)^(−);(2)the Co/CoFe-P domain subsequently reactivates NO_(2)^(−),and converts it efficiently into NH3.Moreover,phosphorus doping enhances*H supply,while Fe alloying with Co promotes NO_(2)^(−)hydrogenation,ensuring an efficient and synchronized tandem pathway for NO_(3)^(−)RR.The proposed*NO_(2)desorption-reactivation mechanism deepens the understanding of NO_(3)^(−)RR tandem process,thereby paving the way for designing more efficient tandem electrocatalysts.展开更多
Electrically controlled solid propellant(ECSP)offers multiple ignition and adjustable burning rate,serving as fuel for next-generation intelligent propulsion systems.To further enhance the combustion performance of EC...Electrically controlled solid propellant(ECSP)offers multiple ignition and adjustable burning rate,serving as fuel for next-generation intelligent propulsion systems.To further enhance the combustion performance of ECSP,a method utilizing electrochemical and thermal decomposition catalysts has been proposed.In this work,we investigated the combustion characteristics of hydroxylamine nitrate(HAN)-based ECSP incorporating cerium oxide(CeO_(2))and graphene oxide(GO)by using an electrically controlled combustion test system.Electrochemical impedance spectroscopy(EIS)and linear sweep voltammetry(LSV)were used to measure the electrical conductibility and overpotential of ECSP with various additives,and Tafel curves were calculated.Thermogravimetric analysis coupled with differential scanning calorimetry(TG-DSC)was employed to investigate the thermal decomposition behavior of ECSP.While the addition of CeO_(2) and GO reduced the conductivity of ECSP,both catalysts exhibited strong electrocatalytic properties and facilitated the thermal decomposition of ECSP.Between two catalysts,GO demonstrated superior electrochemical catalytic performance but weaker thermal decomposition catalytic ability than CeO_(2).The addition of catalysts significantly enhanced the combustion performance of HAN-based ECSP.Specifically,the ignition delay time was shortened by 10%~20%.CeO_(2) raised the burning rate by approximately 20%but GO exhibited a remarkable boost of 40%in burning rate at high voltage.The combination of GO and PVA produced a flame-retardant substance that negatively impacted the ignition delay of ECSP and resulted in a smaller increase in the burning rate of ECSP at low ignition voltages.展开更多
Lithium metal batteries(LMBs)have been regarded as one of the most promising alternatives in the post-lithium battery era due to their high energy density,which meets the needs of light-weight electronic devices and l...Lithium metal batteries(LMBs)have been regarded as one of the most promising alternatives in the post-lithium battery era due to their high energy density,which meets the needs of light-weight electronic devices and long-range electric vehicles.However,technical barriers such as dendrite growth and poor Li plating/stripping reversibility severely hinder the practical application of LMBs.However,lithium nitrate(LiNO_(3))is found to be able to stabilize the Li/electrolyte interface and has been used to address the above challenges.To date,considerable research efforts have been devoted toward understanding the roles of LiNO_(3) in regulating the surface properties of Li anodes and toward the development of many effective strategies.These research efforts are partially mentioned in some articles on LMBs and yet have not been reviewed systematically.To fill this gap,we discuss the recent advances in fundamental and technological research on LiNO_(3) and its derivatives for improving the performances of LMBs,particularly for Li-sulfur(S),Li-oxygen(O),and Li-Li-containing transition-metal oxide(LTMO)batteries,as well as LiNO_(3)-containing recipes for precursors in battery materials and interphase fabrication.This review pays attention to the effects of LiNO_(3) in lithium-based batteries,aiming to provide scientific guidance for the optimization of electrode/electrolyte interfaces and enrich the design of advanced LMBs.展开更多
Although previous studies have demonstrated the involvement of nitrated a-synuclein in neurodegenerative disorders(synucleinopathies),the effects of nitrated α-synuclein and the molecular mechanisms underlying its t...Although previous studies have demonstrated the involvement of nitrated a-synuclein in neurodegenerative disorders(synucleinopathies),the effects of nitrated α-synuclein and the molecular mechanisms underlying its toxicity are still unclear.In the present study,nitrated α-synuclein with four 3-nitrotyrosines(Tyr^(39),Tyr^(125),Tyr^(133),and Tyr^(136))was obtained non-enzymatically by incubation with nitrite.The nitrated protein existed as a mixture of monomers,dimers,and polymers in solution.The nitrated a-synuclein could induce cell death in a time-and concentration-dependent manner when SH-SY5Y cells(a human neuroblastoma cell line)were incubated with the dimers and polymers.Treatment with anti-integrin α5β1 antibody partially rescued the SH-SY5Y cells from the cell death.Dot blotting and immunoprecipitation revealed that the nitrated protein bound to integrin on the cell membranes.Level of nitric oxide(NO)and calcium-independent inducible NO synthase(iNOS)activity increased during the initial stages of the treatment.The expression of phosphorylated focal adhesion kinase(FAK)decreased in the cells.Subsequently,an increase in caspase 3 activity was observed in SH-SY5Y cells.Our results demonstrate that activation of iNOS and inhibition of FAK may both be responsible for the cell death induced by nitrated α-synuclein.These data suggest that the cytotoxicity of nitrated a-synuclein is mediated via an integrin-iNOS/-FAK signaling pathway,and that the nitration of α-synuclein plays a role in neuronal degeneration.展开更多
Ammonia is the cornerstone of modern agriculture,providing a critical nitrogen source for global food production and serving as a key raw material for numerous industrial chemicals.Electrocatalytic nitrate reduction,a...Ammonia is the cornerstone of modern agriculture,providing a critical nitrogen source for global food production and serving as a key raw material for numerous industrial chemicals.Electrocatalytic nitrate reduction,as an environmentally friendly method for synthesizing ammonia,not only mitigates the reliance on current ammonia synthesis processes fed by traditional fossil fuels but also effectively reduces nitrate pollution resulting from agricultural and industrial activities.This review explores the fundamental principles of electrocata lytic nitrate reduction,focusing on the key steps of electron transfer and ammonia formation.Additionally,it summarizes the critical factors influencing the performance and selectivity of the reaction,including the properties of the electrolyte,operating voltage,electrode materials,and design of the electrolytic cell.Further discussion of recent advances in electrocatalysts,including pure metal catalysts,metal oxide catalysts,non-metallic catalysts,and composite catalysts,highlights their significant roles in enhancing both the efficiency and selectivity of electrocata lytic nitrate to ammonia(NRA)reactions.Critical challenges for the industrial NRA trials and further outlooks are outlined to propel this strategy toward real-world applications.Overall,the review provides an in-depth overview and comprehensive understanding of electrocata lytic NRA technology,thereby promoting further advancements and innovations in this domain.展开更多
The present work aims to stabilize the room temperature allotropic transition of ammonium nitrate(AN)particles utilizing a microencapsulation technique,which involves solvent/non-solvent in which nitrocellulose(NC)has...The present work aims to stabilize the room temperature allotropic transition of ammonium nitrate(AN)particles utilizing a microencapsulation technique,which involves solvent/non-solvent in which nitrocellulose(NC)has been employed as a coating agent.The SEM micrographs revealed distinct features of both pure AN and NC,contrasting with the irregular granular surface topography of the coated AN particles,demonstrating the adherence of NC on the AN surface.Structural analysis via infrared spectroscopy(IR)demonstrated a successful association of AN and NC,with slight shifts observed in IR bands indicating interfacial interactions.Powder X-ray Diffraction(PXRD)analysis further elucidated the structural changes induced by the coating process,revealing that the NC coating altered the crystallization pattern of its pure form.Thermal analysis demonstrates distinct profiles for pure and coated AN,for which the coated sample exhibits a temperature increase and an enthalpy decrease of the room temperature allotropic transition by 6℃,and 36%,respectively.Furthermore,the presence of NC coating alters the intermolecular forces within the composite system,leading to a reduction in melting enthalpy of coated AN by~39%compared to pure AN.The thermal decomposition analysis shows a two-step thermolysis process for coated AN,with a significant increase in the released heat by about 78%accompanied by an increase in the activation barrier of NC and AN thermolysis,demonstrating a stabilized reactivity of the AN-NC particles.These findings highlight the synergistic effect of NC coating on AN particles,which contributed to a structural and reactive stabilization of both AN and NC,proving the potential application of NC-coated AN as a strategically advantageous oxidizer in composite solid propellant formulations.展开更多
Nitrate contamination of groundwater is a worldwide problem, particularly in agricultural countries. Exposure to high levels of nitrates in groundwater can have adverse effects on the health of residents who use groun...Nitrate contamination of groundwater is a worldwide problem, particularly in agricultural countries. Exposure to high levels of nitrates in groundwater can have adverse effects on the health of residents who use groundwater for drinking. This study aims to assess the health risk associated with the ingestion of nitrates in well water in the town of M’bahiakro. Health risk maps were created on the basis of hazard quotients (HQ) using the US Environmental Protection Agency (USEPA) health risk assessment model. The results indicate that residents of the Koko, Dougouba and Baoulekro neighbourhoods, whatever their age, are potentially exposed to the toxic effects of NO3−during their daily intake of nitrate-contaminated well water, with reference to hazard quotients (HQ) greater than 1. Nitrate concentrations in the groundwater should therefore be controlled in order to prevent their harmful effects on the health of the population and guarantee its use in rice-growing activities in M’Bahiakro.展开更多
基金supported by the National Key R&D Program of China(No.2017YFC0212501)the Fundamental Research Funds for the Central Universities(No.2021YJSMT09)the research project on deep source apportionment of urban air pollution and pollution control strategies in the core area of the Ili River Valley。
文摘Polycyclic Aromatic Hydrocarbons(PAHs),along with their derivatives nitro-PAHs and oxy-PAHs,are globally recognized toxic pollutants.This research conducted daily PM_(2.5)sampling in winter 2021 at three urban(YNCE,SWP,and NG)and three suburban sites(HC,CTV,and YNE)in the Ili River Valley(IRV).For the first time in the IRV,a comprehensive study on 39 PAHs and derivatives was carried out.The results showed that the average∑_(16)PAHs concentration was 130.21±98.94 ng/m^(3),with 16PAHs constituting the dominant fraction(112.51±86.48 ng/m^(3)).The mean BaP and the total BaP equivalent quotient(TEQ)concentrations were 10.28±8.85 ng/m^(3)and 19.74±16.70 ng/m^(3),respectively.Approximately 88%of the daily BaP averages and 98%of the daily TEQ averages exceeded the national daily average standard of BaP(2.5 ng/m^(3)),indicating severe local BaP pollution.Urban sites had notably higher∑PAHs and TEQ concentrations than suburban sites,attributed to increased vehicular traffic and coal combustion in urban areas.PMF results showed that traffic emissions(32.7%-60.5%),coal combustion(13.9%-24.3%)and secondary formation(14.7%-22.7%)were the primary contributors to∑PAHs.Urban sites experienced a greater influence from traffic,while suburban sites were more impacted by coal and biomass burning.On polluted days,traffic sources’contributions increased significantly at HC,YNE,NG and YNCE sites,and secondary formation sources’contributions grew at CTV and YNCE sites.The sourcedependent BaPeq results underscored the role of secondary-formed PAH derivatives in TEQ.
基金supported by the National Natural Science Foundation of China(No.41671493)the State Key Laboratory of Pollution Control and Resource Reuse Foundation(No.PCRRF17030)the National Major Project of the Science and Technology Ministry of China(No.2017ZX07202-004 and 2017X07301002-3)。
文摘Nitrated polycyclic aromatic hydrocarbons(NPAHs)have toxic potentials that are higher than those of their corresponding parent polycyclic aromatic hydrocarbons(PAHs)and thus have received increasing attention in recent years.In this study,the occurrence,distribution,source,and human health risk assessment of 15 NPAHs and 16 PAHs were investigated in the surface water from 20 sampling sites of Lake Taihu during the dry,normal,and flood seasons of 2018.The PAH concentrations ranged from 255 to 7298 ng/L and the NPAH concentrations ranged from not-detected(ND)to 212 ng/L.Among the target analytes,2-nitrofluorene(2-n Flu)was the predominant NPAH,with a detection frequency ranging from 85%to 90%and a maximum concentration of 56.2 ng/L.The three-ringed and four-ringed NPAHs and PAHs comprised the majority of the detected compounds.In terms of seasonal variation,the highest levels of the NPAHs and PAHs were in the dry season and flood season,respectively.Diagnostic ratio analysis indicated that the prime source of NPAHs was direct combustion,whereas in the case of PAHs the contribution was predominantly from a mixed pattern including pollution from unburned petroleum and petroleum combustion.The human health risk of NPAHs and PAHs was evaluated using a lifetime carcinogenic risk assessment model.The carcinogenic risk level of the targets ranged from 2.09×10^(-7)to 5.75×10^(-5)and some surface water samples posed a potential health risk.
基金supported by the National Natural Science Foundation of China(No.41907197)the Fundamental Research Funds for Central Public Welfare Scientific Research Institutes of China,Chinese Research Academy of Environmental Sciences(No.2019YSKY-018)+1 种基金the National Key R&D Program of China(No.2019YFC0214800)the Standard System and Key Standards Research of National Ecological Environment Protection and Risk Prevention(No.2020YFC18063)。
文摘Polycyclic aromatic hydrocarbons(PAHs)and their nitrated derivatives(NPAHs)attract continuous attention due to their outstanding carcinogenicity and mutagenicity.In order to investigate the diurnal variations,sources,formation mechanism,and health risk assessment of them in heating season,particulate matter(PM)were collected in Beijing urban area from December 26,2017 to January 17,2018.PAHs and NPAHs in PM were quantitatively analyzed via gas chromatography-mass spectrometry(GC-MS).Average daily concentrations of PAHs and NPAHs were(78±54)ng/m^(3)and(783±684)pg/m^(3),respectively.The concentrations of them were significantly higher at nighttime than at daytime,and NPAHs concentrations were 1-2 orders of magnitude lower than PAHs concentrations.In the heating season,the dominant species of PAHs include benzo[b]fluoranthene,fluoranthene,pyrene,and chrysene,while 9-nitroanthracene,2+3-nitrofluoranthene,and 2-nitropyrene were dominant species for NPAHs.NPAHs were found to have a single peak during heating and to be primarily distributed in the 0.4-0.7μm particle size.Primary emissions such as biomass burning,coal combustion,and traffic emissions were the major sources of PAHs.NPAHs were produced by the primary source of vehicle emissions and the secondary reaction triggered by OH radicals,as well as biomass burning during daytime.According to the health risk assessment,the total carcinogenic risk was higher in adults than in children.While upon oral ingestion,the carcinogenic risk in children was higher than that of adults,but the risk of adults was higher than children through skin contact and respiratory inhalation.
基金supported by the National Natural Science Foundation of China (No. 40971257,41171365)the Environmental Nonprofit Research and Special Project of China (No. 201009004)the Program for Changjiang Scholars and Innovative Research Team in University (No.IRT0941)
文摘Intensive daytime and nighttime sampling was carried out from 23 Oct to 31 Dec 2008 to investigate the occurrence of nitrated polycyclic aromatic hydrocarbons （NPAHs） in PM1o at a roadside site in Xiamen, China. At the same time, six PMt0 samples were collected from a nearby roadway tunnel for comparison. Six NPAHs, namely 9-nitroanthracene, 2- and 3-nitrofluoranthene, 1- nitropyrene, 7-nitrobenz[a]anthracene, and 6-nitrobenzo[a]pyrene, were identified and quantified using GC/MS in negative ion chemical ionization mode. The average total concentration of six NPAHs （~NPAHs） in the cold season （26 Nov-31 Dec） was 2.3 （daytime） and 9.9 （nighttime） times higher than those in the warm season. Significant statistical difference （p 〈 0.01, 2-tailed） of ∑NPAHs between daytime and nighttime was found during both the warm and cold seasons. NPAHs were significantly positively correlated with their parent PAHs and nitrogen dioxide but negatively correlated with ambient temperature. The ratio of 2 ＋ 3-nitrofluoranthene to 1- nitropyrene exhibited a similar diurnal pattern as ZNPAHs and was generally greater than 5, indicating the importance of secondary atmospheric formation. The diurnal variations of NPAHs were all influenced by the diurnal variations of PAHs, nitrogen dioxide, sunlight, and temperature. The daily inhalable exposure to the six NPAHs in the tunnel was much higher than the roadside values in the warm season but only slightly higher than those in the cold season.
基金financially supported by the National Natural Science Foundation of China (No. 41977341)Natural Science Foundation of Zhejiang Province, China (No. LGF21B070007)Research Center for Air Pollution and Health, Zhejiang University (No. I21405-11)
文摘Air pollutants can potentially lead to nitration of allergic proteins,thus promoting sensitization of these allergens.However,little is currently known about the nitration status of house dust mite(HDM)allergens.We identified the occurrence of nitrated products of two major HDM allergens Der f 1 and Der p 1 in dust samples collected from college dormitories in eastern China and assessed their associated health risk.The results showed that both non-nitrated and nitrated forms of the two allergens were detected in the dust in the range of non-detected(ND)-10.6,1.44-15.4,ND-22.4,ND-7.28μg/g for non-nitrated Der f 1,nitrated Der f 1,non-nitrated Der p 1 and nitrated Der p 1,respectively.The median rates of nitration were determined as 74.0%for Der f 1 and 20.4% for Der p 1 at consideration of one nitration site.Further analysis reveals that the levels of HDM allergens and their nitrated products were found to be generally higher during winter,in dormitories of lower altitude and with female occupants.Furthermore,the calculated risk indexes were at considerably high levels.Our findings suggest that nitrated HDM allergens have already accumulated in the environment at such significant levels and their associated health risk calls for our immediate attention.
基金funded by the British Heart Foundation(PGF/10/82/28608).
文摘Previous studies documented increased nitrative stress and susceptibility to air pollution among individuals with chronic inflammatory conditions.This study examines the role of anti-inflammatory and cardioprotective nitrated fatty acids(i.e.,NO2-cLA)in chronic obstructive pulmonary disease(COPD)'s and ischemic heart disease(IHD)'s susceptibility to air pollution.In a randomized crossover study,40 healthy,40 COPD,and 39 IHD adults underwent a 2 h walk in a more polluted street or a less polluted park.We measured urinary NO2-cLA before and 24 h after the walk,as well as respiratory inflammatory biomarkers,lung function,airway resistance,and arterial stiffness.Baseline NO2-cLA levels were 2.56(95%CI:1.20-5.43)-fold higher among COPD participants than healthy participants,which can be explained by higher fractional exhaled nitric oxide and sputum myeloperoxidase levels.Among COPD but not healthy or IHD participants,the street walk,compared to park,led to a 57.7%(95%CI:7.6-80.6%)decrease in NO2-cLA levels and sputum biomarker changes indicative of decreased neutrophil inflammation and proresolving responses.Decreased NO2-cLA levels were associated with exposure to black carbon and ultrafine particles and worsened lung function and arterial stiffness.Taken together,nitrated fatty acids partially mediate COPD patients'cardiorespiratory responses to air pollution,explaining their susceptibility.
基金supported by the National Natural Science Foundation of China,No.81671263(to XX)Scientific Research and Innovation Team,Education Department of Anhui Province,China,No.2023AH010072(to XX)+1 种基金the Natural Science Foundation of Anhui Province,No.2208085MH221(to XX)The Key Projects for National Science Research of Education Department of Anhui Province,No.KJ2021A0851(to YD).
文摘Cmyc,a proto-oncogene,is expressed at extremely low levels in mature neurons and is traditionally thought to have no function in these cells.However,recent studies suggest that Cmyc may play a crucial role in maintaining the health and function of mature dopaminergic neurons.This study assessed the role of Cmyc in dopaminergic neurons and its significance in Parkinson’s disease.We used a conditional knockout approach to specifically delete Cmyc in substantia nigra dopaminergic neurons of adult mice.Our findings showed that Cmyc deletion led to progressive neuron loss,Parkinson’s disease-like symptoms,downregulation of Klotho,and upregulation of senescence-associated inflammatory factors,along with enhanced oxidative stress and nitrated alpha-synuclein accumulation,ultimately causing neuronal death.In vitro experiments confirmed increased senescence in C-MYC knockout cells,which was partially reversible by KLOTHO overexpression.We conclude that low-level Cmyc expression is essential for maintaining the health of mature dopaminergic neurons and preventing neurodegeneration,and suggest the c-Myc/Klotho axis as a potential therapeutic target for age-related neurodegenerative diseases,including Parkinson’s disease.Our study introduces a novel mouse model for Parkinson’s disease that replicates a condition associated with normal aging,offering a valuable tool for future research into disease mechanisms and therapeutic strategies.
基金funding from Deutsche Forschungsgemeinschaft (DFG)supported by an MCIN Ry C Programme MCIN/ AEI/10.13039/501100011033+2 种基金by the ‘European Union Next Generation EU/PRTR’ under grant no. RYC2021-032345-Isupported by the AEI (grant no. PID2019-107463RJ-I00/ AEI/10.13039/501100011033)the Regional Research and Development Programme of the Government of Navarre (call 2019, project Nitro Healthy, PC068)
文摘Ammonium toxicity in plants remains poorly understood despite extensive research.While nitrate is known to benefit plant growth,the synergistic effects of nitrate in mitigating ammonium toxicity,even at low concentrations,are not fully elucidated.This review delves into the physiological and molecular nature of this phenomenon.To date,nitrate-dependent alleviation of ammonium toxicity is the result of cumulative consequences of the role of nitrate as a nutrient and signal in plant performance.The ability to counteract the ammonium-induced acidification through nitrate uptake and metabolism,the enhancement of potassium uptake as an essential nitrate counterion,and the nitratedependent signaling of key factors involved in ammonium assimilation,ROS scavenging,and growth hormone biosynthesis,are the most relevant hallmarks.In addition,evidence suggests that the availability of nitrate and ammonium has driven ecological selection in plants,determining current N preferences,and may have led to the selection of nitrate-dependent and ammonium-sensitive domesticated crops and the inefficient use of N fertilizers in agriculture.As ammonium toxicity limits N fertilization options and reduces agricultural yields,when it could be a more sustainable and cheaper alternative to nitrate,this review provides a better understanding of how plants use nitrate to counteract the problematic aspects of ammonium nutrition.
基金supported by the Natural Science Foundation(NSF)of China(Nos.22205015,22175020,and 22235001)the National Postdoctoral Program for Innovative Talents(No.BX20220032)+2 种基金the China Postdoctoral Science Foundation Funded Project(No.2022BG013)the Fundamental Research Funds for the Central Universities(Nos.00007709,00007770,and FRFBR-23-02B)University of Science and Technology Beijing is gratefully acknowledged.
文摘In comparison with their 2D and 3D counterparts,1D covalent organic frameworks(COFs)have rarely been investigated due to the synthetic challenge arising from the strict necessary matching in the molecular symmetry between corresponding building blocks and linking units in addition to the unmanageable packing of 1D organic chains once formed.Herein,two novel imide-linked 1D COFs with phthalocyanine building blocks,namely NiPc-CZDM-COF and NiPc-CZDL-COF,were fabricated from the hydrothermal synthesis reaction of 2,3,9,10,16,17,23,24-octacarboxyphthalocyaninato nickel(II)(NiPc(COOH)_(8))with 9H-carbazole-3,6-diamine(CZDM)and 4,4′-(9H-carbazole-3,6-diyl)dianiline(CZDL),respectively.Two COFs have high crystallinity on the basis of powder X-ray diffraction analysis and high-resolution transmission electron microscopy.Due to their high ratio of exposed active centers on the edge sites of porous ribbons,both NiPc-CZDM-COF and NiPc-CZDL-COF electrodes display high utilization efficiency of NiPc electroactive sites of 8.0%and 7.5% according to the electrochemical measurement,resulting in their excellent capacity toward electrocatalytic nitrate reduction with the nitrate-to-NH3 Faradaic efficiency of nearly 100%.In particular,NiPc-CZDM-COF electrode exhibits superior electrocatalytic performance with high NH3 partial current density of−246 mA/cm^(2),ammonia yield rate of 19.5 mg cm^(−2) h^(−1),and turnover frequency of 5.8 s^(−1) at−1.2 V in an H-type cell associated with its higher conductivity.This work reveals the good potential of 1D porous crystalline materials in electrocatalysis.
基金the financial support from the Shandong Province colleges and universities youth innovation technology plan innovation team project(2022KJ285)the Natural Science Foundation of Shandong Province(ZR2022QE076)+1 种基金the National Natural Science Foundation of China(52202092)the Science and Technology Support Plan for Youth Innovation of Colleges and Universities of Shandong Province of China(2023KJ104).
文摘Exploring high-performance electrocatalysts for the nitrate reduction reaction(NO_(3)RR)is crucial for environmental nitrate removal and ammonia synthesis.Single-atom collaboration with cluster can provide sufficient active sites for catalysts to promote NO_(3)RR,yet the unclear synergistic effect between the two hinders their rational design.Herein,a series of Ir_(3)clusters and metal single atoms co-embedded in graphitic carbon nitride(g-CN)catalysts(Ir_(3)M1)were constructed,and the synergistic effects of Ir_(3)clusters and M1 single atoms on the NO_(3)RR catalytic mechanism and activity were systematically explored using density functional theory(DFT)calculations combined with machine learning.Comprehensive evaluations of structural stability and catalytic activity demonstrate that the synergy between single atoms and clusters effectively balances the adsorption energies of key intermediates,yielding exceptional catalytic performance(the limiting potential of Ir_(3)Ti_(1)can reach−0.22 V).Machine learning models further clarify the synergistic mechanism,where the geometric configurations of clusters serve as critical features for modulating the catalytic activity of single-atom sites,whereas the electronic structures of single atoms directly govern the reactivity of cluster sites.This DFT-machine learning approach provides theoretical guidelines for catalyst design and a predictive framework for efficient NO_(3)RR electrocatalysts.
基金supported by the National Key Research and Development Program of China(No.2022YFF1301301)the Natural Science Foundation of Xiamen Municipality(No.3502Z202472047)the Geological Survey Program of China Geological Survey(DD20190303).
文摘To address the deficiencies in comprehensive surface contamination prevention strategies within China's nitrate-affected regions,this research innovatively proposes the DITAPH model-a systematic framework integrating groundwater nitrate vulnerability assessment and Nitrate Vulnerable Zones(NVZs)delineation through optimization of hydrogeological parameters.Based on detailed hydrogeological and hydrochemical investigations,the DITAPH model was applied in the plain areas of Quanzhou to evaluate its applicability.The model selected hydrogeological parameters(depth of groundwater,lithology of the vadose zone,topographic slope,aquifer water yield property),one climatic parameter(precipitation),and two anthropogenic parameters(land use type and population density)as assessment indicators.The results of the groundwater nitrate vulnerability assessment showed that the low,relatively low,relatively high,and high groundwater nitrate vulnerability zones in the study area accounted for 5.96%,35.44%,53.74%and 4.86%of the total area,respectively.Groundwater nitrate vulnerability was most strongly influenced by human activities,followed by groundwater depth and topographic slope.The high vulnerability zone is mainly affected by domestic and industrial wastewater,whereas the relatively high groundwater nitrate vulnerability zone is primarily influenced by agricultural activities.Validation of the DITAPH model revealed a significant positive correlation between the DITAPH index(DI)and nitrate concentration(ρ(NO3−)).The results of the NVZs delineated by the DITAPH model are reliable and can serve as a tool for water resource management planning,guiding the development of targeted measures in the NVZs to prevent groundwater contamination.
基金supported by the National Natural Science Foundation of China(Grant Nos.:21825201,52401244 and 52201227)Henan Province Key Research and Development and Promotion Program(Scientific and Technological Breakthrough Project:232102240088 and 252102230078)+3 种基金the Key Research&Development and Promotion of Special Project(Scientific Problem Tackling)of Henan Province(252102230078)Doctoral Research Startup Fund Project of Henan Open University(BSJH-2025-04)Zhejiang Provincial Natural Science Foundation of China(LQ24B020005,LQ23B030001)China Postdoctoral Science Foundation(2024M762442).
文摘Electrocatalytic nitrate-to-ammonia conversion offers dual environmental and sustainable synthesis benefits,but achieving high efficiency with low-cost catalysts remains a major challenge.This review focuses on cobalt-based electrocatalysts,emphasizing their structural engineering for enhanced the performance of electrocatalytic nitrate reduction reaction(NO3RR)through dimensional control,compositional tuning,and coordination microenvironment modulation.Notably,by critically analyzing metallic cobalt,cobalt alloys,cobalt compounds,cobalt single atom and molecular catalyst configurations,we firstly establish correlations between atomic-scale structural features and catalytic performance in a coordination environment perspective for NO3RR,including the dynamic reconstruction during operation and its impact on active site.Synergizing experimental breakthroughs with computational modeling,we decode mechanisms underlying competitive hydrogen evolution suppression,intermediate adsorption-energy optimization,and durability enhancement in complex aqueous environments.The development of cobalt-based catalysts was summarized and prospected,and the emerging opportunities of machine learning in accelerating the research and development of high-performance catalysts and the configuration of series reactors for scalable nitrate-to-ammonia systems were also introduced.Bridging surface science and applications,it outlines a framework for designing multifunctional electrocatalysts to restore nitrogen cycle balance sustainably.
基金supported financially by the Key Project of the National Ministry of Science and Technology (No.2022YFC3705005)the Open Foundation of Key Laboratory of Industrial Ecology and Environmental Engineering,MOE (KLIEEE-22-05)
文摘The electrocatalytic reduction of nitrate to ammonia(NO_(3)^(−)RR)offers a sustainable alternative to energy-intensive industrial NH3 synthesis.Tandem catalysis has shown promise in overcoming the multi-step complexity of NO_(3)^(−)RR,yet challenges remain in optimizing performance and elucidating tandem mechanisms.Herein,we report a Cu@Co/CoFe-P tandem electrocatalyst featuring a phosphorus-doped heterostructure with dual active sites(Cu-P and Co/CoFe-P).This catalyst achieves an exceptional NH_(3)yield of 175.40 mg h^(−1)cm^(−2)and a record-high current density exceeding 2 A cm^(−2),with the electro-synthesized NH3 directly converted into NH4Cl.In situ spectroscopic analysis and density functional theory(DFT)calculations reveal a novel desorption-reactivation tandem mechanism:(1)the Cu-P domain preferentially reduces NO_(3)^(−)to*NO_(2),which desorbs as stable NO_(2)^(−);(2)the Co/CoFe-P domain subsequently reactivates NO_(2)^(−),and converts it efficiently into NH3.Moreover,phosphorus doping enhances*H supply,while Fe alloying with Co promotes NO_(2)^(−)hydrogenation,ensuring an efficient and synchronized tandem pathway for NO_(3)^(−)RR.The proposed*NO_(2)desorption-reactivation mechanism deepens the understanding of NO_(3)^(−)RR tandem process,thereby paving the way for designing more efficient tandem electrocatalysts.
基金supported by the National Natural Science Foundation of China(Grant No.12074187).
文摘Electrically controlled solid propellant(ECSP)offers multiple ignition and adjustable burning rate,serving as fuel for next-generation intelligent propulsion systems.To further enhance the combustion performance of ECSP,a method utilizing electrochemical and thermal decomposition catalysts has been proposed.In this work,we investigated the combustion characteristics of hydroxylamine nitrate(HAN)-based ECSP incorporating cerium oxide(CeO_(2))and graphene oxide(GO)by using an electrically controlled combustion test system.Electrochemical impedance spectroscopy(EIS)and linear sweep voltammetry(LSV)were used to measure the electrical conductibility and overpotential of ECSP with various additives,and Tafel curves were calculated.Thermogravimetric analysis coupled with differential scanning calorimetry(TG-DSC)was employed to investigate the thermal decomposition behavior of ECSP.While the addition of CeO_(2) and GO reduced the conductivity of ECSP,both catalysts exhibited strong electrocatalytic properties and facilitated the thermal decomposition of ECSP.Between two catalysts,GO demonstrated superior electrochemical catalytic performance but weaker thermal decomposition catalytic ability than CeO_(2).The addition of catalysts significantly enhanced the combustion performance of HAN-based ECSP.Specifically,the ignition delay time was shortened by 10%~20%.CeO_(2) raised the burning rate by approximately 20%but GO exhibited a remarkable boost of 40%in burning rate at high voltage.The combination of GO and PVA produced a flame-retardant substance that negatively impacted the ignition delay of ECSP and resulted in a smaller increase in the burning rate of ECSP at low ignition voltages.
基金supported by the Yunnan Fundamental Research Projects(Grant Nos.202401AU070163 and 202501AT070298)the Yunnan Engineering Research Center Innovation Ability Construction and Enhancement Projects(Grant No.2023-XMDJ-00617107)+5 种基金the University Service Key Industry Project of Yunnan Province(Grant No.FWCY-ZD2024005)the Expert Workstation Support Project of Yunnan Province(Grant No.202405AF140069)the Scientific Research Foundation of Kunming University of Science and Technology(Grant No.20220122)the Analysis and Test Foundation of Kunming University of Science and Technology(Grant No.2023T20220122)the Natural Science Foundation of Inner Mongolia Autonomous Region of China(Grant No.2025QN02057)the Ordos City Strategic Pioneering Science and Technology Special Program for New Energy(Grant No.DC2400003365).
文摘Lithium metal batteries(LMBs)have been regarded as one of the most promising alternatives in the post-lithium battery era due to their high energy density,which meets the needs of light-weight electronic devices and long-range electric vehicles.However,technical barriers such as dendrite growth and poor Li plating/stripping reversibility severely hinder the practical application of LMBs.However,lithium nitrate(LiNO_(3))is found to be able to stabilize the Li/electrolyte interface and has been used to address the above challenges.To date,considerable research efforts have been devoted toward understanding the roles of LiNO_(3) in regulating the surface properties of Li anodes and toward the development of many effective strategies.These research efforts are partially mentioned in some articles on LMBs and yet have not been reviewed systematically.To fill this gap,we discuss the recent advances in fundamental and technological research on LiNO_(3) and its derivatives for improving the performances of LMBs,particularly for Li-sulfur(S),Li-oxygen(O),and Li-Li-containing transition-metal oxide(LTMO)batteries,as well as LiNO_(3)-containing recipes for precursors in battery materials and interphase fabrication.This review pays attention to the effects of LiNO_(3) in lithium-based batteries,aiming to provide scientific guidance for the optimization of electrode/electrolyte interfaces and enrich the design of advanced LMBs.
基金supported by the grants from the China Postdoctoral Science Foundation(20070410153,200801120)the National Science Foundation of China(30970695)+1 种基金the Major State Basic Research Development Program of China(973 Program)(2010CB912303)the Chinese Academy of Sciences(KSCX2-YW-R-119,KSCX2-YW-R-256).
文摘Although previous studies have demonstrated the involvement of nitrated a-synuclein in neurodegenerative disorders(synucleinopathies),the effects of nitrated α-synuclein and the molecular mechanisms underlying its toxicity are still unclear.In the present study,nitrated α-synuclein with four 3-nitrotyrosines(Tyr^(39),Tyr^(125),Tyr^(133),and Tyr^(136))was obtained non-enzymatically by incubation with nitrite.The nitrated protein existed as a mixture of monomers,dimers,and polymers in solution.The nitrated a-synuclein could induce cell death in a time-and concentration-dependent manner when SH-SY5Y cells(a human neuroblastoma cell line)were incubated with the dimers and polymers.Treatment with anti-integrin α5β1 antibody partially rescued the SH-SY5Y cells from the cell death.Dot blotting and immunoprecipitation revealed that the nitrated protein bound to integrin on the cell membranes.Level of nitric oxide(NO)and calcium-independent inducible NO synthase(iNOS)activity increased during the initial stages of the treatment.The expression of phosphorylated focal adhesion kinase(FAK)decreased in the cells.Subsequently,an increase in caspase 3 activity was observed in SH-SY5Y cells.Our results demonstrate that activation of iNOS and inhibition of FAK may both be responsible for the cell death induced by nitrated α-synuclein.These data suggest that the cytotoxicity of nitrated a-synuclein is mediated via an integrin-iNOS/-FAK signaling pathway,and that the nitration of α-synuclein plays a role in neuronal degeneration.
基金supported by the National Key Research and Development Program of China(2023YFE0120900)the National Natural Science Foundation of China(52377160)+2 种基金the National Natural Science Foundation of China National Young Talents Project(GYKP010)Shaanxi Provincial Natural Science Program(2023-JCYB-425)Xi’an Jiaotong University Young Top Talents Program。
文摘Ammonia is the cornerstone of modern agriculture,providing a critical nitrogen source for global food production and serving as a key raw material for numerous industrial chemicals.Electrocatalytic nitrate reduction,as an environmentally friendly method for synthesizing ammonia,not only mitigates the reliance on current ammonia synthesis processes fed by traditional fossil fuels but also effectively reduces nitrate pollution resulting from agricultural and industrial activities.This review explores the fundamental principles of electrocata lytic nitrate reduction,focusing on the key steps of electron transfer and ammonia formation.Additionally,it summarizes the critical factors influencing the performance and selectivity of the reaction,including the properties of the electrolyte,operating voltage,electrode materials,and design of the electrolytic cell.Further discussion of recent advances in electrocatalysts,including pure metal catalysts,metal oxide catalysts,non-metallic catalysts,and composite catalysts,highlights their significant roles in enhancing both the efficiency and selectivity of electrocata lytic nitrate to ammonia(NRA)reactions.Critical challenges for the industrial NRA trials and further outlooks are outlined to propel this strategy toward real-world applications.Overall,the review provides an in-depth overview and comprehensive understanding of electrocata lytic NRA technology,thereby promoting further advancements and innovations in this domain.
文摘The present work aims to stabilize the room temperature allotropic transition of ammonium nitrate(AN)particles utilizing a microencapsulation technique,which involves solvent/non-solvent in which nitrocellulose(NC)has been employed as a coating agent.The SEM micrographs revealed distinct features of both pure AN and NC,contrasting with the irregular granular surface topography of the coated AN particles,demonstrating the adherence of NC on the AN surface.Structural analysis via infrared spectroscopy(IR)demonstrated a successful association of AN and NC,with slight shifts observed in IR bands indicating interfacial interactions.Powder X-ray Diffraction(PXRD)analysis further elucidated the structural changes induced by the coating process,revealing that the NC coating altered the crystallization pattern of its pure form.Thermal analysis demonstrates distinct profiles for pure and coated AN,for which the coated sample exhibits a temperature increase and an enthalpy decrease of the room temperature allotropic transition by 6℃,and 36%,respectively.Furthermore,the presence of NC coating alters the intermolecular forces within the composite system,leading to a reduction in melting enthalpy of coated AN by~39%compared to pure AN.The thermal decomposition analysis shows a two-step thermolysis process for coated AN,with a significant increase in the released heat by about 78%accompanied by an increase in the activation barrier of NC and AN thermolysis,demonstrating a stabilized reactivity of the AN-NC particles.These findings highlight the synergistic effect of NC coating on AN particles,which contributed to a structural and reactive stabilization of both AN and NC,proving the potential application of NC-coated AN as a strategically advantageous oxidizer in composite solid propellant formulations.
文摘Nitrate contamination of groundwater is a worldwide problem, particularly in agricultural countries. Exposure to high levels of nitrates in groundwater can have adverse effects on the health of residents who use groundwater for drinking. This study aims to assess the health risk associated with the ingestion of nitrates in well water in the town of M’bahiakro. Health risk maps were created on the basis of hazard quotients (HQ) using the US Environmental Protection Agency (USEPA) health risk assessment model. The results indicate that residents of the Koko, Dougouba and Baoulekro neighbourhoods, whatever their age, are potentially exposed to the toxic effects of NO3−during their daily intake of nitrate-contaminated well water, with reference to hazard quotients (HQ) greater than 1. Nitrate concentrations in the groundwater should therefore be controlled in order to prevent their harmful effects on the health of the population and guarantee its use in rice-growing activities in M’Bahiakro.
