Low surface photogenerated charge concentration is a critical limitation hindering conventional graphitic carbon nitride(CN)from efficiently reducing CO_(2)to high-value products.In this work,a pollution-free oxygen o...Low surface photogenerated charge concentration is a critical limitation hindering conventional graphitic carbon nitride(CN)from efficiently reducing CO_(2)to high-value products.In this work,a pollution-free oxygen oxidation strategy was devised to enhance the surface charge enrichment sites of CN.This approach led to the successful fabrication of a tubular CN photocatalyst functionalized with oxygen-containing groups(C-O-C and C-OH),named O-TCN.The introduction of oxygen functional groups not only effectively widen the light absorption range and narrowed the bandgap but also optimized the surface electronic structure,realizing substantial photogenerated charge accumulation on the O-TCN surface.Photocatalytic performance evaluations revealed that O-TCN achieved exceptional catalytic activity and selectivity in CO_(2)reduction,stably converting CO_(2)to CO.The average CO yield of O-TCN reaches 49.8μmol g^(-1)h^(-1),representing enhancements of 5.5-fold and 7.7-fold compared to TCN and the classical bulk CN,respectively.This work highlights the potential of surface oxygen functionalization as a powerful strategy to boost the photocatalytic activity of CN-based materials,offering new insights for advancing sustainable energy conversion technologies.展开更多
Ischemic stroke is a major cause of neurological deficits and high disability rate.As the primary immune cells of the central nervous system,microglia play dual roles in neuroinflammation and tissue repair following a...Ischemic stroke is a major cause of neurological deficits and high disability rate.As the primary immune cells of the central nervous system,microglia play dual roles in neuroinflammation and tissue repair following a stroke.Their dynamic activation and polarization states are key factors that influence the disease process and treatment outcomes.This review article investigates the role of microglia in ischemic stroke and explores potential intervention strategies.Microglia exhibit a dynamic functional state,transitioning between pro-inflammatory(M1)and anti-inflammatory(M2)phenotypes.This duality is crucial in ischemic stroke,as it maintains a balance between neuroinflammation and tissue repair.Activated microglia contribute to neuroinflammation through cytokine release and disruption of the blood-brain barrier,while simultaneously promoting tissue repair through anti-inflammatory responses and regeneration.Key pathways influencing microglial activation include Toll-like receptor 4/nuclear factor kappa B,mitogen-activated protein kinases,Janus kinase/signal transducer and activator of transcription,and phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathways.These pathways are targets for various experimental therapies aimed at promoting M2 polarization and mitigating damage.Potential therapeutic agents include natural compounds found in drugs such as minocycline,as well as traditional Chinese medicines.Drugs that target these regulatory mechanisms,such as small molecule inhibitors and components of traditional Chinese medicines,along with emerging technologies such as single-cell RNA sequencing and spatial transcriptomics,offer new therapeutic strategies and clinical translational potential for ischemic stroke.展开更多
Stroke,particularly ischemic stroke,is the leading cause of long-term disability and mortality worldwide.It occurs due to the occlusion of the cerebral arteries,which significantly reduces the delivery of blood,oxygen...Stroke,particularly ischemic stroke,is the leading cause of long-term disability and mortality worldwide.It occurs due to the occlusion of the cerebral arteries,which significantly reduces the delivery of blood,oxygen,and essential nutrients to brain tissues.This deprivation triggers a cascade of cellular events that ultimately leads to neuronal death.Recent studies have clarified the multifactorial pathogenesis of ischemic stroke,highlighting the roles of energy failure,excitotoxicity,oxidative stress,neuroinflammation,and apoptosis.This review aimed to provide a comprehensive insight into the fundamental mechanisms driving neuronal death triggered by ischemia and to examine the progress of neuroprotective therapeutic approaches designed to mitigate neuronal loss and promote neurological recovery after a stroke.Additionally,we explored widely accepted findings regarding the potential pathways implicated in neuronal death during ischemic stroke,including the interplay of apoptosis,autophagy,pyroptosis,ferroptosis,and necrosis,which collectively influence neuronal fate.We also discussed advancements in neuroprotective therapeutics,encompassing a range of interventions from pharmacological modulation to stem cell-based therapies,aimed at reducing neuronal injury and enhancing functional recovery following ischemic stroke.Despite these advancements,challenges remain in translating mechanistic insights into effective clinical therapies.Although neuroprotective strategies have shown promise in preclinical models,their efficacy in human trials has been inconsistent,often due to the complex pathology of ischemic stroke and the timing of interventions.In conclusion,this review synthesizes mechanistic insights into the intricate interplay of molecular and cellular pathways driving neuronal death post-ischemia.It sheds light on cutting-edge advancements in potential neuroprotective therapeutics,underscores the promise of regenerative medicine,and offers a forward-looking perspective on potential clinical breakthroughs.The ongoing evolution of precision-targeted interventions is expected to significantly enhance preventative strategies and improve clinical outcomes.展开更多
The cure rate for chronic neurodegenerative diseases remains low,creating an urgent need for improved intervention methods.Recent studies have shown that enhancing mitochondrial function can mitigate the effects of th...The cure rate for chronic neurodegenerative diseases remains low,creating an urgent need for improved intervention methods.Recent studies have shown that enhancing mitochondrial function can mitigate the effects of these diseases.This paper comprehensively reviews the relationship between mitochondrial dysfunction and chronic neurodegenerative diseases,aiming to uncover the potential use of targeted mitochondrial interventions as viable therapeutic options.We detail five targeted mitochondrial intervention strategies for chronic neurodegenerative diseases that act by promoting mitophagy,inhibiting mitochondrial fission,enhancing mitochondrial biogenesis,applying mitochondria-targeting antioxidants,and transplanting mitochondria.Each method has unique advantages and potential limitations,making them suitable for various therapeutic situations.Therapies that promote mitophagy or inhibit mitochondrial fission could be particularly effective in slowing disease progression,especially in the early stages.In contrast,those that enhance mitochondrial biogenesis and apply mitochondria-targeting antioxidants may offer great benefits during the middle stages of the disease by improving cellular antioxidant capacity and energy metabolism.Mitochondrial transplantation,while still experimental,holds great promise for restoring the function of damaged cells.Future research should focus on exploring the mechanisms and effects of these intervention strategies,particularly regarding their safety and efficacy in clinical settings.Additionally,the development of innovative mitochondria-targeting approaches,such as gene editing and nanotechnology,may provide new solutions for treating chronic neurodegenerative diseases.Implementing combined therapeutic strategies that integrate multiple intervention methods could also enhance treatment outcomes.展开更多
Stroke is a major cause of death and disability worldwide.It is characterized by a highly interconnected and multiphasic neuropathological cascade of events,in which an intense and protracted inflammatory response pla...Stroke is a major cause of death and disability worldwide.It is characterized by a highly interconnected and multiphasic neuropathological cascade of events,in which an intense and protracted inflammatory response plays a crucial role in worsening brain injury.Neuroinflammation,a key player in the pathophysiology of stroke,has a dual role.In the acute phase of stroke,neuroinflammation exacerbates brain injury,contributing to neuronal damage and blood–brain barrier disruption.This aspect of neuroinflammation is associated with poor neurological outcomes.Conversely,in the recovery phase following stroke,neuroinflammation facilitates brain repair processes,including neurogenesis,angiogenesis,and synaptic plasticity.The transition of neuroinflammation from a harmful to a reparative role is not well understood.Therefore,this review seeks to explore the mechanisms underlying this transition,with the goal of informing the development of therapeutic interventions that are both time-and context-specific.This review aims to elucidate the complex and dual role of neuroinflammation in stroke,highlighting the main actors,biomarkers of the disease,and potential therapeutic approaches.展开更多
Neuronal cell death is a common outcome of multiple pathophysiological processes and a key factor in neurological dysfunction after subarachnoid hemorrhage.Neuronal ferroptosis in particular plays an important role in...Neuronal cell death is a common outcome of multiple pathophysiological processes and a key factor in neurological dysfunction after subarachnoid hemorrhage.Neuronal ferroptosis in particular plays an important role in early brain injury.Bromodomain-containing protein 4,a member of the bromo and extraterminal domain family of proteins,participated in multiple cell death pathways,but the mechanisms by which it regulates ferroptosis remain unclear.The primary aim of this study was to investigate how bromodomain-containing protein 4 affects neuronal ferroptosis following subarachnoid hemorrhage in vivo and in vitro.Our findings revealed that endogenous bromodomain-containing protein 4 co-localized with neurons,and its expression was decreased 48 hours after subarachnoid hemorrhage of the cerebral cortex in vivo.In addition,ferroptosis-related pathways were activated in vivo and in vitro after subarachnoid hemorrhage.Targeted inhibition of bromodomain-containing protein 4 in neurons increased lipid peroxidation and intracellular ferrous iron accumulation via ferritinophagy and ultimately led to neuronal ferroptosis.Using cleavage under targets and tagmentation analysis,we found that bromodomain-containing protein 4 enrichment in the Raf-1 promoter region decreased following oxyhemoglobin stimulation in vitro.Furthermore,treating bromodomain-containing protein 4-knockdown HT-22 cell lines with GW5074,a Raf-1 inhibitor,exacerbated neuronal ferroptosis by suppressing the Raf-1/ERK1/2 signaling pathway.Moreover,targeted inhibition of neuronal bromodomain-containing protein 4 exacerbated early and long-term neurological function deficits after subarachnoid hemorrhage.Our findings suggest that bromodomain-containing protein 4 may have neuroprotective effects after subarachnoid hemorrhage,and that inhibiting ferroptosis could help treat subarachnoid hemorrhage.展开更多
Strokes include both ischemic stroke,which is mediated by a blockade or reduction in the blood supply to the brain,and hemorrhagic stroke,which comprises intracerebral hemorrhage and subarachnoid hemorrhage and is cha...Strokes include both ischemic stroke,which is mediated by a blockade or reduction in the blood supply to the brain,and hemorrhagic stroke,which comprises intracerebral hemorrhage and subarachnoid hemorrhage and is characterized by bleeding within the brain.Stroke is a lifethreatening cerebrovascular condition characterized by intricate pathophysiological mechanisms,including oxidative stress,inflammation,mitochondrial dysfunction,and neuronal injury.Critical transcription factors,such as nuclear factor erythroid 2-related factor 2 and nuclear factor kappa B,play central roles in the progression of stroke.Nuclear factor erythroid 2-related factor 2 is sensitive to changes in the cellular redox status and is crucial in protecting cells against oxidative damage,inflammatory responses,and cytotoxic agents.It plays a significant role in post-stroke neuroprotection and repair by influencing mitochondrial function,endoplasmic reticulum stress,and lysosomal activity and regulating metabolic pathways and cytokine expression.Conversely,nuclear factor-kappa B is closely associated with mitochondrial dysfunction,the generation of reactive oxygen species,oxidative stress exacerbation,and inflammation.Nuclear factor-kappa B contributes to neuronal injury,apoptosis,and immune responses following stroke by modulating cell adhesion molecules and inflammatory mediators.The interplay between these pathways,potentially involving crosstalk among various organelles,significantly influences stroke pathophysiology.Advancements in single-cell sequencing and spatial transcriptomics have greatly improved our understanding of stroke pathogenesis and offer new opportunities for the development of targeted,individualized,cell typespecific treatments.In this review,we discuss the mechanisms underlying the involvement of nuclear factor erythroid 2-related factor 2 and nuclear factor-kappa B in both ischemic and hemorrhagic stroke,with an emphasis on their roles in oxidative stress,inflammation,and neuroprotection.展开更多
Ischemia–reperfusion injury is a common pathophysiological mechanism in retinal degeneration.PANoptosis is a newly defined integral form of regulated cell death that combines the key features of pyroptosis,apoptosis,...Ischemia–reperfusion injury is a common pathophysiological mechanism in retinal degeneration.PANoptosis is a newly defined integral form of regulated cell death that combines the key features of pyroptosis,apoptosis,and necroptosis.Oligomerization of mitochondrial voltage-dependent anion channel 1 is an important pathological event in regulating cell death in retinal ischemia–reperfusion injury.However,its role in PANoptosis remains largely unknown.In this study,we demonstrated that voltage-dependent anion channel 1 oligomerization-mediated mitochondrial dysfunction was associated with PANoptosis in retinal ischemia–reperfusion injury.Inhibition of voltage-dependent anion channel 1 oligomerization suppressed mitochondrial dysfunction and PANoptosis in retinal cells subjected to ischemia–reperfusion injury.Mechanistically,mitochondria-derived reactive oxygen species played a central role in the voltagedependent anion channel 1-mediated regulation of PANoptosis by promoting PANoptosome assembly.Moreover,inhibiting voltage-dependent anion channel 1 oligomerization protected against PANoptosis in the retinas of rats subjected to ischemia–reperfusion injury.Overall,our findings reveal the critical role of voltage-dependent anion channel 1 oligomerization in regulating PANoptosis in retinal ischemia–reperfusion injury,highlighting voltage-dependent anion channel 1 as a promising therapeutic target.展开更多
To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretre...To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.展开更多
In order to explore the reduction pathways of zinc oxide in LiCl molten salt and the optimal process,experiments were conducted in an alumina crucible using metallic lithium as the reducing agent and lithium chloride ...In order to explore the reduction pathways of zinc oxide in LiCl molten salt and the optimal process,experiments were conducted in an alumina crucible using metallic lithium as the reducing agent and lithium chloride molten salt as the reaction medium at 923 K.The study assessed the effects of lithium thermochemical reduction and electrolytic reduction of ZnO.The volatilization behavior of metal oxides in molten salts,the equivalent of a reducing agent,reduction time,amount of molten salt,stirring time,and the method of reduction feed were investigated for their impacts on the reduction yield and product composition.X-ray powder diffraction(XRD)analysis of the products showed that lithium reduction of ZnO not only produced metallic Zn but also formed a LiZn alloy.Electrolytic reduction can be used to obtain the metallic Zn product by controlling the potential below-2.2 V(vs Ag/Ag^(+)).Moreover,sintered oxides and higher electrode potentials could enhance the efficiency of electrolysis.Under the optimal reaction conditions determined experimentally,the lithium reduction experiment achieved a yield of 77.2%after a 12-h test,and the electrolytic reduction reached a yield of 85.4%after a 6-h test.展开更多
In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented...In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.展开更多
It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,...It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).展开更多
Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent f...Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent for fragrances,cosmetics,food additives,and detergents,and can also be served as a moisturizer in cosmetics,showing broad application prospects.The distribution of DPG isomers in the products synthesized from PO and PG has a significant impactΔrGΔrHΔfHθΔfGθPO+PG⇌DPG PO+DPG⇌TPG PG+PG⇌DPG+H_(2)O PG+DPG⇌TPG+H_(2)O on the quality of the products.Therefore,conducting thermodynamic calculation on the reaction of PO and PG to synthesize DPG can provide a theoretical basis for practical operations and product distribution regulation.So,in this paper,the thermodynamic parameters of PO,1,2-PG,H_(2)O,tripropylene glycol(TPG)and three isomers of DPG under different reaction conditions is calculated.Additionally,the,and lnK for four potential reactions at various reaction temperatures and pressures are calculated.By designing isodesmic reactions and combining the results of thermodynamic calculations,the and for the isomers of DPG are obtained,and the relative error is less than 7%.The results show that in the process of preparing DPG by PO and PG,when PO∶PG=1,the reaction temperature ranges from 298.15 to 413.15 K,and the pressure ranges from 101.325 to 506.625 kPa,the reactions of and are thermodynamically spontaneous.While the reactions of and are thermodynamically unspontaneous.The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa.The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions.The accuracy of the computational results is verified through experimental design,and based on this,the factors affecting product distribution are analyzed.展开更多
Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatin...Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatings on C/CA to address its susceptibility to oxidation is a feasible approach to promote its application in oxidative environments.However,the currently reported coatings on C/CA mainly focus on improving the ablation performance and coating preparation process typically necessitating high-temperature heat treatment.This procedure can increase its thermal conductivity and reduce its thermal insulation ability.In this study,a series of ceramic-resin coatings were fabricated on C/CA through a simple slurry brushing-drying approach at room temperature.The effects of phenolic resin content on the coating structure,residual stress,thermal shock,and oxidation behaviors were investigated.Due to the adhesive properties and curing-induced shrinkage,the PR-7.5 coating(containing 7.5%(in mass)phenolic resin in the slurry)exhibits bonding strength close to fracture strength of the substrate and residual compressive stress of 0.853 GPa,which is beneficial for resisting thermal shock cracking.However,excessive resin content(PR-10.0 containing 10.0%(in mass)phenolic resin in the slurry)induces tensile stress due to uneven curing shrinkage,thereby leading to thermal shock cracking.Meanwhile,oxidation tests reveal significantly reduced weight losses for PR-7.5(17.46%at 800℃/100 min,8.15%at 1000℃/120 min,3.15%at 1200℃/120 min)versus uncoated C/CA’s 44.60%loss at 800℃/20 min.This work provides a brand-new and simple approach to improving the anti-oxidation performance of C/CA and expands its application in mild oxidative environments.展开更多
Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon ...Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon steel substrates via photo-assisted electrodeposition.A systematic investigation was conducted on the effects of cerium ion concentration and nano-ceria(CeO_(2))particle content in the electrolyte on the coating properties,along with an analysis of the temporal evolution of coating’s corrosion resistance.When the cerium ion concentration in the electrolyte was 0.05 mol/L,the coating exhibited a uniform black appearance with a light absorption rate of 95%,an emissivity of 0.87,maximum impedance,and the lowest corrosion tendency,demonstrating optimal comprehensive performance.The coating prepared with a nano-ceria concentration of 6 g/L in the electrolyte exhibited an emissivity of 0.9,achieved a 5B adhesion grade(ASTM D3359-09),and demonstrated a one-order-of-magnitude reduction in corrosion current density compared to coatings fabricated without nano-ceria in the electrolyte.With prolonged storage time,the coating's impedance slightly increased,leading to improved corrosion resistance.展开更多
The present work provides a facile and efficient method for producing ultrafine copper powders.Ultrafine copper powders were synthesized through a solvothermal method,utilizing ethanol both as a solvent and a reducing...The present work provides a facile and efficient method for producing ultrafine copper powders.Ultrafine copper powders were synthesized through a solvothermal method,utilizing ethanol both as a solvent and a reducing agent.Specifically,by exploiting the weak reducing property of ethanol,the copper precursor is first converted to copper oxide and then further reduced to cuprous oxide and pure copper.Such a method can effectively control the morphology and particle size of the copper powder,reduce particle aggregation,and enhance oxidation resistance.It is cost-effective and produces fewer toxic by-products.Spherical copper particles with an average particle size of about 180 nm were obtained.The initial oxidation temperature is approximately 150℃,and the resulting copper powders can be stored stably under ambient conditions for at least 5 months,demonstrating excellent oxidation resistance and thermal stability.展开更多
As a key component of shale oil,petroleum fractions,and chemical products,the oxidative pyrolysis behavior of paraffin directly influences energy conversion efficiency and the direction of process optimization.A deep ...As a key component of shale oil,petroleum fractions,and chemical products,the oxidative pyrolysis behavior of paraffin directly influences energy conversion efficiency and the direction of process optimization.A deep understanding of its oxidative pyrolysis mechanism is crucial for addressing wax deposition in oil and gas extraction,enhancing product selectivity in cracking processes,and advancing novel clean fuel technologies.Traditional experimental methods face challenges in capturing transient free-radical reaction pathways at high temperatures,whereas molecular dynamics simulations offer a powerful approach to bridge the research gap in elucidating atomic-scale dynamic mechanisms.This database is constructed based on high-precision molecular dynamics simulations,comprising oxidative pyrolysis trajectory data for three paraffin models featuring different straight-chain hydrocarbon distributions within the temperature range of 2100-2500 K.The COMPASS force field was employed to optimize the initial structures,and the ReaxFF reactive force field was used to simulate the oxidative pyrolysis process.The database includes atomic trajectories,species evolution information,and reaction network analysis results for both heating and isothermal cracking processes,with a total data volume of approximately 141 GB(including 150000 atomic configuration frames).The data is stored in a hierarchical directory structure,supporting multi-scale oxidative pyrolysis mechanism studies and providing atomic-scale dynamic evidence for revealing carbon chain length effects and temperature sensitivity.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
The aim of this research was to synthesize a new totally bio wood adhesive entailing the use of oxidized starch(OST),urea,and oxidized lignin(OL).For this reason,non-modified(L)and oxidized lignin(OL)at different cont...The aim of this research was to synthesize a new totally bio wood adhesive entailing the use of oxidized starch(OST),urea,and oxidized lignin(OL).For this reason,non-modified(L)and oxidized lignin(OL)at different contents(20%,30%,and 40%)were used to prepare the starch-urea-lignin(SUL)and starch-urea-oxidized lignin(SUOL)resin.Sodium persulfate(SPS)as oxidizer was employed to oxidize both starch and lignin.Urea was just used as a low cost and effective crosslinker in the resin composition.The properties of the synthesized resins and the plywood panels bonded with themweremeasured according to relevant standards.The viscosity and gel time of the SUOL resins containing oxidized lignin are respectively higher and faster than for non-modified lignin(SUL).The lignin phenolic hydroxyl groups(-OH)proportion was markedly increased by oxidation as shown by Fourier Transform Infrared(FTIR)spectrometry.The molecular mass and the polydispersity of the lignin did also decrease by its oxidization pretreatment.DSC analysis showed a decrease of the glass transition temperature of the lignin(Tg)due to its oxidation.The thermal analysis of the oxidized lignin SUOL resin also showed that it had a lower peak temperature than the SUL equivalent non-modified lignin resin.The plywood panels bonded with oxidized lignin gave acceptable bending modulus,bending strength,peak temperature by thermal analysis and dry shear strength as well as a better plywood dimensional stability when used in the SUOL formulation.The synthesized SUOL adhesive is a lignin-derived,totally bio,no-aldehyde added,inexpensive resin applicable to bond plywood.展开更多
The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical pr...The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical properties,can significantly enhance the oxidation resistance of Mg alloys.Based on our previous study,we conclude that REs such as Gd,Y,and Ce enhance the oxidation resistance of Mg-RE alloys.This article comprehensively reviews recent research progress on high-temperature oxidation behavior and the potential mechanism in Mg-RE alloys.Based on the thermodynamic and kinetic analyses,the evolution of the complex oxide system formed during the high-temperature oxidation of Mg-RE alloys is first summarized.The diffusion behavior and concentration control mechanisms of REs during the oxidation process and how these mechanisms affect the sustained growth of the oxide film and antioxidant properties were elucidated.Moreover,the different structures of the oxide films were classified,and their properties were discussed.Finally,this paper introduces the applications of commonly used REs in Mg alloys and frontier research on their oxidation mechanisms.Based on the above review,we propose that future research perspectives can be explored in terms of expanding the experimental temperature range for oxidation tests,optimizing the chemical composition by adding trace REs to study their synergistic mechanism,revealing the underlying oxidation mechanism through advanced in situ microscopic characterization methods,and investigating the mechanical properties of oxide films using diverse approaches.展开更多
基金supported by the National Natural Science Foundation of China(21901154)the Shanghai Pujiang Program(21PJD022)+1 种基金the Hunan Provincial Natural Science Foundation(2023JJ60522)supported by the Shanghai Technical Service Center of Science and Engineering Computing,Shanghai University。
文摘Low surface photogenerated charge concentration is a critical limitation hindering conventional graphitic carbon nitride(CN)from efficiently reducing CO_(2)to high-value products.In this work,a pollution-free oxygen oxidation strategy was devised to enhance the surface charge enrichment sites of CN.This approach led to the successful fabrication of a tubular CN photocatalyst functionalized with oxygen-containing groups(C-O-C and C-OH),named O-TCN.The introduction of oxygen functional groups not only effectively widen the light absorption range and narrowed the bandgap but also optimized the surface electronic structure,realizing substantial photogenerated charge accumulation on the O-TCN surface.Photocatalytic performance evaluations revealed that O-TCN achieved exceptional catalytic activity and selectivity in CO_(2)reduction,stably converting CO_(2)to CO.The average CO yield of O-TCN reaches 49.8μmol g^(-1)h^(-1),representing enhancements of 5.5-fold and 7.7-fold compared to TCN and the classical bulk CN,respectively.This work highlights the potential of surface oxygen functionalization as a powerful strategy to boost the photocatalytic activity of CN-based materials,offering new insights for advancing sustainable energy conversion technologies.
基金supported by the National Natural Science Foundation of China,82471345(to LC)the Key Research and Development Program for Social Development by the Jiangsu Provincial Department of Science and Technology.No.BE2022668(to LC).
文摘Ischemic stroke is a major cause of neurological deficits and high disability rate.As the primary immune cells of the central nervous system,microglia play dual roles in neuroinflammation and tissue repair following a stroke.Their dynamic activation and polarization states are key factors that influence the disease process and treatment outcomes.This review article investigates the role of microglia in ischemic stroke and explores potential intervention strategies.Microglia exhibit a dynamic functional state,transitioning between pro-inflammatory(M1)and anti-inflammatory(M2)phenotypes.This duality is crucial in ischemic stroke,as it maintains a balance between neuroinflammation and tissue repair.Activated microglia contribute to neuroinflammation through cytokine release and disruption of the blood-brain barrier,while simultaneously promoting tissue repair through anti-inflammatory responses and regeneration.Key pathways influencing microglial activation include Toll-like receptor 4/nuclear factor kappa B,mitogen-activated protein kinases,Janus kinase/signal transducer and activator of transcription,and phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathways.These pathways are targets for various experimental therapies aimed at promoting M2 polarization and mitigating damage.Potential therapeutic agents include natural compounds found in drugs such as minocycline,as well as traditional Chinese medicines.Drugs that target these regulatory mechanisms,such as small molecule inhibitors and components of traditional Chinese medicines,along with emerging technologies such as single-cell RNA sequencing and spatial transcriptomics,offer new therapeutic strategies and clinical translational potential for ischemic stroke.
基金supported by the National Natural Science Foundation of China,Nos.82171387 and 31830111(both to SL).
文摘Stroke,particularly ischemic stroke,is the leading cause of long-term disability and mortality worldwide.It occurs due to the occlusion of the cerebral arteries,which significantly reduces the delivery of blood,oxygen,and essential nutrients to brain tissues.This deprivation triggers a cascade of cellular events that ultimately leads to neuronal death.Recent studies have clarified the multifactorial pathogenesis of ischemic stroke,highlighting the roles of energy failure,excitotoxicity,oxidative stress,neuroinflammation,and apoptosis.This review aimed to provide a comprehensive insight into the fundamental mechanisms driving neuronal death triggered by ischemia and to examine the progress of neuroprotective therapeutic approaches designed to mitigate neuronal loss and promote neurological recovery after a stroke.Additionally,we explored widely accepted findings regarding the potential pathways implicated in neuronal death during ischemic stroke,including the interplay of apoptosis,autophagy,pyroptosis,ferroptosis,and necrosis,which collectively influence neuronal fate.We also discussed advancements in neuroprotective therapeutics,encompassing a range of interventions from pharmacological modulation to stem cell-based therapies,aimed at reducing neuronal injury and enhancing functional recovery following ischemic stroke.Despite these advancements,challenges remain in translating mechanistic insights into effective clinical therapies.Although neuroprotective strategies have shown promise in preclinical models,their efficacy in human trials has been inconsistent,often due to the complex pathology of ischemic stroke and the timing of interventions.In conclusion,this review synthesizes mechanistic insights into the intricate interplay of molecular and cellular pathways driving neuronal death post-ischemia.It sheds light on cutting-edge advancements in potential neuroprotective therapeutics,underscores the promise of regenerative medicine,and offers a forward-looking perspective on potential clinical breakthroughs.The ongoing evolution of precision-targeted interventions is expected to significantly enhance preventative strategies and improve clinical outcomes.
基金partly supported by the Yan’an University Qin Chuanyuan“Scientist+Engineer”Team Special Fund,No.2023KXJ-012(to YL)Yan’an University Transformation of Scientific and Technological Achievements Fund,No.2023CGZH-001(to YL)+2 种基金College Students Innovation and Entrepreneurship Training Program,Nos.D2023158,202410719056(to XS,JM)Yan’an University Production and Cultivation Project,No.CXY202001(to YL)Kweichow Moutai Hospital Research and Talent Development Fund Project,No.MTyk2022-25(to XO)。
文摘The cure rate for chronic neurodegenerative diseases remains low,creating an urgent need for improved intervention methods.Recent studies have shown that enhancing mitochondrial function can mitigate the effects of these diseases.This paper comprehensively reviews the relationship between mitochondrial dysfunction and chronic neurodegenerative diseases,aiming to uncover the potential use of targeted mitochondrial interventions as viable therapeutic options.We detail five targeted mitochondrial intervention strategies for chronic neurodegenerative diseases that act by promoting mitophagy,inhibiting mitochondrial fission,enhancing mitochondrial biogenesis,applying mitochondria-targeting antioxidants,and transplanting mitochondria.Each method has unique advantages and potential limitations,making them suitable for various therapeutic situations.Therapies that promote mitophagy or inhibit mitochondrial fission could be particularly effective in slowing disease progression,especially in the early stages.In contrast,those that enhance mitochondrial biogenesis and apply mitochondria-targeting antioxidants may offer great benefits during the middle stages of the disease by improving cellular antioxidant capacity and energy metabolism.Mitochondrial transplantation,while still experimental,holds great promise for restoring the function of damaged cells.Future research should focus on exploring the mechanisms and effects of these intervention strategies,particularly regarding their safety and efficacy in clinical settings.Additionally,the development of innovative mitochondria-targeting approaches,such as gene editing and nanotechnology,may provide new solutions for treating chronic neurodegenerative diseases.Implementing combined therapeutic strategies that integrate multiple intervention methods could also enhance treatment outcomes.
基金supported by European Union-NextGeneration EU under the Italian University and Research(MUR)National Innovation Ecosystem grant ECS00000041-VITALITY-CUP E13C22001060006(to MdA)。
文摘Stroke is a major cause of death and disability worldwide.It is characterized by a highly interconnected and multiphasic neuropathological cascade of events,in which an intense and protracted inflammatory response plays a crucial role in worsening brain injury.Neuroinflammation,a key player in the pathophysiology of stroke,has a dual role.In the acute phase of stroke,neuroinflammation exacerbates brain injury,contributing to neuronal damage and blood–brain barrier disruption.This aspect of neuroinflammation is associated with poor neurological outcomes.Conversely,in the recovery phase following stroke,neuroinflammation facilitates brain repair processes,including neurogenesis,angiogenesis,and synaptic plasticity.The transition of neuroinflammation from a harmful to a reparative role is not well understood.Therefore,this review seeks to explore the mechanisms underlying this transition,with the goal of informing the development of therapeutic interventions that are both time-and context-specific.This review aims to elucidate the complex and dual role of neuroinflammation in stroke,highlighting the main actors,biomarkers of the disease,and potential therapeutic approaches.
基金supported by the National Natural Science Foundation of China,Nos.82371310(to YJ),82271306(to JP)the Sichuan Science and Technology Support Program,Nos.2023YFH0069(to JP),2023NSFSC0028(to YJ),2023NSFSC1559(to YJ),2022YFS0615(to JP),2022NSFSC1421(to JP)+1 种基金Scientific Research Project of Sichuan Provincial Health Commission,No.23LCYJ040(to YJ)Youth Foundation of Southwestern Medical University and Southwest Medical University Project,Nos.2020ZRQNA038(to JP),2021ZKZD013(to JP),2021LZXNYD-P01(to YJ),2023QN014(to JP).
文摘Neuronal cell death is a common outcome of multiple pathophysiological processes and a key factor in neurological dysfunction after subarachnoid hemorrhage.Neuronal ferroptosis in particular plays an important role in early brain injury.Bromodomain-containing protein 4,a member of the bromo and extraterminal domain family of proteins,participated in multiple cell death pathways,but the mechanisms by which it regulates ferroptosis remain unclear.The primary aim of this study was to investigate how bromodomain-containing protein 4 affects neuronal ferroptosis following subarachnoid hemorrhage in vivo and in vitro.Our findings revealed that endogenous bromodomain-containing protein 4 co-localized with neurons,and its expression was decreased 48 hours after subarachnoid hemorrhage of the cerebral cortex in vivo.In addition,ferroptosis-related pathways were activated in vivo and in vitro after subarachnoid hemorrhage.Targeted inhibition of bromodomain-containing protein 4 in neurons increased lipid peroxidation and intracellular ferrous iron accumulation via ferritinophagy and ultimately led to neuronal ferroptosis.Using cleavage under targets and tagmentation analysis,we found that bromodomain-containing protein 4 enrichment in the Raf-1 promoter region decreased following oxyhemoglobin stimulation in vitro.Furthermore,treating bromodomain-containing protein 4-knockdown HT-22 cell lines with GW5074,a Raf-1 inhibitor,exacerbated neuronal ferroptosis by suppressing the Raf-1/ERK1/2 signaling pathway.Moreover,targeted inhibition of neuronal bromodomain-containing protein 4 exacerbated early and long-term neurological function deficits after subarachnoid hemorrhage.Our findings suggest that bromodomain-containing protein 4 may have neuroprotective effects after subarachnoid hemorrhage,and that inhibiting ferroptosis could help treat subarachnoid hemorrhage.
基金supported by grants from the Zhejiang Provincial TCM Science and Technology Plan Project,No.2023ZL156(to YH)Ningbo Top Medical and Health Research Program,No.2022020304(to XG)+1 种基金the Natural Science Foundation of Ningbo,No.2023J019(to YH)Key Laboratory of Precision Medicine for Atherosclerotic Diseases of Zhejiang Province,No.2022E10026(to YH)。
文摘Strokes include both ischemic stroke,which is mediated by a blockade or reduction in the blood supply to the brain,and hemorrhagic stroke,which comprises intracerebral hemorrhage and subarachnoid hemorrhage and is characterized by bleeding within the brain.Stroke is a lifethreatening cerebrovascular condition characterized by intricate pathophysiological mechanisms,including oxidative stress,inflammation,mitochondrial dysfunction,and neuronal injury.Critical transcription factors,such as nuclear factor erythroid 2-related factor 2 and nuclear factor kappa B,play central roles in the progression of stroke.Nuclear factor erythroid 2-related factor 2 is sensitive to changes in the cellular redox status and is crucial in protecting cells against oxidative damage,inflammatory responses,and cytotoxic agents.It plays a significant role in post-stroke neuroprotection and repair by influencing mitochondrial function,endoplasmic reticulum stress,and lysosomal activity and regulating metabolic pathways and cytokine expression.Conversely,nuclear factor-kappa B is closely associated with mitochondrial dysfunction,the generation of reactive oxygen species,oxidative stress exacerbation,and inflammation.Nuclear factor-kappa B contributes to neuronal injury,apoptosis,and immune responses following stroke by modulating cell adhesion molecules and inflammatory mediators.The interplay between these pathways,potentially involving crosstalk among various organelles,significantly influences stroke pathophysiology.Advancements in single-cell sequencing and spatial transcriptomics have greatly improved our understanding of stroke pathogenesis and offer new opportunities for the development of targeted,individualized,cell typespecific treatments.In this review,we discuss the mechanisms underlying the involvement of nuclear factor erythroid 2-related factor 2 and nuclear factor-kappa B in both ischemic and hemorrhagic stroke,with an emphasis on their roles in oxidative stress,inflammation,and neuroprotection.
基金supported by the National Natural Science Foundation of China,Nos.82172196(to KX),82372507(to KX)the Natural Science Foundation of Hunan Province,China,No.2023JJ40804(to QZ)the Key Laboratory of Emergency and Trauma(Hainan Medical University)of the Ministry of Education,China,No.KLET-202210(to QZ)。
文摘Ischemia–reperfusion injury is a common pathophysiological mechanism in retinal degeneration.PANoptosis is a newly defined integral form of regulated cell death that combines the key features of pyroptosis,apoptosis,and necroptosis.Oligomerization of mitochondrial voltage-dependent anion channel 1 is an important pathological event in regulating cell death in retinal ischemia–reperfusion injury.However,its role in PANoptosis remains largely unknown.In this study,we demonstrated that voltage-dependent anion channel 1 oligomerization-mediated mitochondrial dysfunction was associated with PANoptosis in retinal ischemia–reperfusion injury.Inhibition of voltage-dependent anion channel 1 oligomerization suppressed mitochondrial dysfunction and PANoptosis in retinal cells subjected to ischemia–reperfusion injury.Mechanistically,mitochondria-derived reactive oxygen species played a central role in the voltagedependent anion channel 1-mediated regulation of PANoptosis by promoting PANoptosome assembly.Moreover,inhibiting voltage-dependent anion channel 1 oligomerization protected against PANoptosis in the retinas of rats subjected to ischemia–reperfusion injury.Overall,our findings reveal the critical role of voltage-dependent anion channel 1 oligomerization in regulating PANoptosis in retinal ischemia–reperfusion injury,highlighting voltage-dependent anion channel 1 as a promising therapeutic target.
基金National Natural Science Foundation of China(52071274)Key Research and Development Projects of Shaanxi Province(2023-YBGY-442)Science and Technology Nova Project-Innovative Talent Promotion Program of Shaanxi Province(2020KJXX-062)。
文摘To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.
文摘In order to explore the reduction pathways of zinc oxide in LiCl molten salt and the optimal process,experiments were conducted in an alumina crucible using metallic lithium as the reducing agent and lithium chloride molten salt as the reaction medium at 923 K.The study assessed the effects of lithium thermochemical reduction and electrolytic reduction of ZnO.The volatilization behavior of metal oxides in molten salts,the equivalent of a reducing agent,reduction time,amount of molten salt,stirring time,and the method of reduction feed were investigated for their impacts on the reduction yield and product composition.X-ray powder diffraction(XRD)analysis of the products showed that lithium reduction of ZnO not only produced metallic Zn but also formed a LiZn alloy.Electrolytic reduction can be used to obtain the metallic Zn product by controlling the potential below-2.2 V(vs Ag/Ag^(+)).Moreover,sintered oxides and higher electrode potentials could enhance the efficiency of electrolysis.Under the optimal reaction conditions determined experimentally,the lithium reduction experiment achieved a yield of 77.2%after a 12-h test,and the electrolytic reduction reached a yield of 85.4%after a 6-h test.
基金Supported by the National Key Research and Development Program of Traditional Chinese Medicine Modernization Project,China(No.2023YFC3504000)the Science and Technology Development Project of Jilin Province,China(No.20240404043ZP)the Science and Technology Innovation Cooperation Project of Changchun Science and Technology Bureau and Chinese Academy of Sciences,China(No.23SH14)。
文摘In this study,a novel polysaccharide GPA-G 2-H was derived from ginseng.Furthermore,the coherent study of its structural characteristics,fermented characteristics in vitro,as well as antioxidant mechanism of fermented product FGPA-G 2-H on Aβ25-35-induced PC 12 cells were explored.The structure of GPA-G 2-H was determined by means of zeta potential analysis,FTIR,HPLC,XRD,GC-MS and NMR.The backbone of GPA-G 2-H was mainly composed of→4)-α-D-Glcp-(1→with branches substituted at O-3.Notably,GPA-G 2-H was degraded by intestinal microbiota in vitro with total sugar content and pH value decreasing,and short-chain fatty acids(SCFAs)increasing.Moreover,GPA-G 2-H significantly promoted the proliferation of Lactobacillus,Muribaculaceae and Weissella,thereby making positive alterations in intestinal microbiota composition.Additionally,FGPA-G 2-H activated the Nrf 2/HO-1 signaling pathway,enhanced HO-1,NQO 1,SOD and GSH-Px,while inhabited Keap 1,MDA and LDH,which alleviated Aβ-induced oxidative stress in PC 12 cells.These provide a solid theoretical basis for the further development of ginseng polysaccharides as functional food and antioxidant drugs.
文摘It is crucial to develop arsenic removal adsorbents with strong sulfur resistance under middle-low-temperature flue gas conditions(<400℃).In this work,five Fe-Ce-La oxides were prepared by co-precipitation method,and FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbents were prepared by coupling fly ash-based Si-Al carriers.The active components Fe-Ce-La oxides and Si-Al carriers were characterized by TPD,TG,XRF,BET and XPS,respectively.The effects of temperature,Si/Al ratio and FeCeLaO loading rate on the sulfur resistance were investigated.Results show that the SO_(2) promotes the arsenic removal of Fe_(2)O_(3),CeLaO and FeCeLaO.At 400℃,the arsenic removal efficiencies of the three oxides increase from 45.3%,72.5% and 81.3% without SO_(2) to 62.6%,80.5%and 91.0%,respectively.The SO_(2) inhibits the arsenic removal of La_(2)O_(2)CO_(3) and FeLaO,and the inhibition effect is pronounced at high temperatures.The sulfur poisoning resistance of Si-Al carriers increases with the increase of Si/Al ratio.When the Si/Al ratio is increased to 9.74,the arsenic removal efficiency in the SO_(2) environment is 13.9% higher than that in the absence of SO_(2).Introducing FeCeLaO active components is beneficial for enhancing the SO_(2) poisoning resistance of Si-Al carriers.The strong sulfur resistance of the FeCeLaO/SiO_(2)-Al_(2)O_(3) composite adsorbent results from multiple factors:protective effects of Ce on Fe,La and Al;sulfation-induced generation of Ce^(3+)and surface-adsorbed oxygen;and strong surface acidity of SiO_(2).
基金Supported by the Natural Science Foundation of Shanxi Province(202203021221303)the Science and Technology Major Project of Shanxi Province(202005D121002)the Science and Technology Cooperation and Communication Project of Shanxi Province(202304041101016)。
文摘Propylene oxide(PO)is an important petrochemical materials used to produce downstream products such as propylene glycol(PG),polyether polyols,and dipropylene glycol(DPG).Among these,DPG is commonly used as a solvent for fragrances,cosmetics,food additives,and detergents,and can also be served as a moisturizer in cosmetics,showing broad application prospects.The distribution of DPG isomers in the products synthesized from PO and PG has a significant impactΔrGΔrHΔfHθΔfGθPO+PG⇌DPG PO+DPG⇌TPG PG+PG⇌DPG+H_(2)O PG+DPG⇌TPG+H_(2)O on the quality of the products.Therefore,conducting thermodynamic calculation on the reaction of PO and PG to synthesize DPG can provide a theoretical basis for practical operations and product distribution regulation.So,in this paper,the thermodynamic parameters of PO,1,2-PG,H_(2)O,tripropylene glycol(TPG)and three isomers of DPG under different reaction conditions is calculated.Additionally,the,and lnK for four potential reactions at various reaction temperatures and pressures are calculated.By designing isodesmic reactions and combining the results of thermodynamic calculations,the and for the isomers of DPG are obtained,and the relative error is less than 7%.The results show that in the process of preparing DPG by PO and PG,when PO∶PG=1,the reaction temperature ranges from 298.15 to 413.15 K,and the pressure ranges from 101.325 to 506.625 kPa,the reactions of and are thermodynamically spontaneous.While the reactions of and are thermodynamically unspontaneous.The optimal reaction temperature and pressure are 413.15 K and 101.325 kPa.The thermodynamic stability of the three isomers is DPG1>DPG2>DPG3 under standard conditions.The accuracy of the computational results is verified through experimental design,and based on this,the factors affecting product distribution are analyzed.
基金National Natural Science Foundation of China(52272075,52472053)Research Fund of Youth Innovation Promotion Association of CAS,China(2021190)Defense Industrial Technology Development Program(JCKY2021130B007)。
文摘Carbon fiber-reinforced carbon aerogel(C/CA)composites are one of the most promising candidates for applications requiring both thermal insulation and load bearing capabilities.The preparation of anti-oxidation coatings on C/CA to address its susceptibility to oxidation is a feasible approach to promote its application in oxidative environments.However,the currently reported coatings on C/CA mainly focus on improving the ablation performance and coating preparation process typically necessitating high-temperature heat treatment.This procedure can increase its thermal conductivity and reduce its thermal insulation ability.In this study,a series of ceramic-resin coatings were fabricated on C/CA through a simple slurry brushing-drying approach at room temperature.The effects of phenolic resin content on the coating structure,residual stress,thermal shock,and oxidation behaviors were investigated.Due to the adhesive properties and curing-induced shrinkage,the PR-7.5 coating(containing 7.5%(in mass)phenolic resin in the slurry)exhibits bonding strength close to fracture strength of the substrate and residual compressive stress of 0.853 GPa,which is beneficial for resisting thermal shock cracking.However,excessive resin content(PR-10.0 containing 10.0%(in mass)phenolic resin in the slurry)induces tensile stress due to uneven curing shrinkage,thereby leading to thermal shock cracking.Meanwhile,oxidation tests reveal significantly reduced weight losses for PR-7.5(17.46%at 800℃/100 min,8.15%at 1000℃/120 min,3.15%at 1200℃/120 min)versus uncoated C/CA’s 44.60%loss at 800℃/20 min.This work provides a brand-new and simple approach to improving the anti-oxidation performance of C/CA and expands its application in mild oxidative environments.
文摘Black nickel coatings have emerged as a research hotspot in materials science due to their excellent performance and broad application prospects.In this study,nickel-based black coatings were fabricated on low-carbon steel substrates via photo-assisted electrodeposition.A systematic investigation was conducted on the effects of cerium ion concentration and nano-ceria(CeO_(2))particle content in the electrolyte on the coating properties,along with an analysis of the temporal evolution of coating’s corrosion resistance.When the cerium ion concentration in the electrolyte was 0.05 mol/L,the coating exhibited a uniform black appearance with a light absorption rate of 95%,an emissivity of 0.87,maximum impedance,and the lowest corrosion tendency,demonstrating optimal comprehensive performance.The coating prepared with a nano-ceria concentration of 6 g/L in the electrolyte exhibited an emissivity of 0.9,achieved a 5B adhesion grade(ASTM D3359-09),and demonstrated a one-order-of-magnitude reduction in corrosion current density compared to coatings fabricated without nano-ceria in the electrolyte.With prolonged storage time,the coating's impedance slightly increased,leading to improved corrosion resistance.
文摘The present work provides a facile and efficient method for producing ultrafine copper powders.Ultrafine copper powders were synthesized through a solvothermal method,utilizing ethanol both as a solvent and a reducing agent.Specifically,by exploiting the weak reducing property of ethanol,the copper precursor is first converted to copper oxide and then further reduced to cuprous oxide and pure copper.Such a method can effectively control the morphology and particle size of the copper powder,reduce particle aggregation,and enhance oxidation resistance.It is cost-effective and produces fewer toxic by-products.Spherical copper particles with an average particle size of about 180 nm were obtained.The initial oxidation temperature is approximately 150℃,and the resulting copper powders can be stored stably under ambient conditions for at least 5 months,demonstrating excellent oxidation resistance and thermal stability.
基金Supported by Natural Science Foundation of Shanxi Province (202203021221219)Research on the Construction of Scientific and Technological Innovation Think Tank of Shanxi Association for Science and Technology (KXKT202542)Planning Project under Commerce Statistical Society of China (2025STY122)。
文摘As a key component of shale oil,petroleum fractions,and chemical products,the oxidative pyrolysis behavior of paraffin directly influences energy conversion efficiency and the direction of process optimization.A deep understanding of its oxidative pyrolysis mechanism is crucial for addressing wax deposition in oil and gas extraction,enhancing product selectivity in cracking processes,and advancing novel clean fuel technologies.Traditional experimental methods face challenges in capturing transient free-radical reaction pathways at high temperatures,whereas molecular dynamics simulations offer a powerful approach to bridge the research gap in elucidating atomic-scale dynamic mechanisms.This database is constructed based on high-precision molecular dynamics simulations,comprising oxidative pyrolysis trajectory data for three paraffin models featuring different straight-chain hydrocarbon distributions within the temperature range of 2100-2500 K.The COMPASS force field was employed to optimize the initial structures,and the ReaxFF reactive force field was used to simulate the oxidative pyrolysis process.The database includes atomic trajectories,species evolution information,and reaction network analysis results for both heating and isothermal cracking processes,with a total data volume of approximately 141 GB(including 150000 atomic configuration frames).The data is stored in a hierarchical directory structure,supporting multi-scale oxidative pyrolysis mechanism studies and providing atomic-scale dynamic evidence for revealing carbon chain length effects and temperature sensitivity.
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.
基金funded by Semnan University,research grant No.226/1403/T140211.
文摘The aim of this research was to synthesize a new totally bio wood adhesive entailing the use of oxidized starch(OST),urea,and oxidized lignin(OL).For this reason,non-modified(L)and oxidized lignin(OL)at different contents(20%,30%,and 40%)were used to prepare the starch-urea-lignin(SUL)and starch-urea-oxidized lignin(SUOL)resin.Sodium persulfate(SPS)as oxidizer was employed to oxidize both starch and lignin.Urea was just used as a low cost and effective crosslinker in the resin composition.The properties of the synthesized resins and the plywood panels bonded with themweremeasured according to relevant standards.The viscosity and gel time of the SUOL resins containing oxidized lignin are respectively higher and faster than for non-modified lignin(SUL).The lignin phenolic hydroxyl groups(-OH)proportion was markedly increased by oxidation as shown by Fourier Transform Infrared(FTIR)spectrometry.The molecular mass and the polydispersity of the lignin did also decrease by its oxidization pretreatment.DSC analysis showed a decrease of the glass transition temperature of the lignin(Tg)due to its oxidation.The thermal analysis of the oxidized lignin SUOL resin also showed that it had a lower peak temperature than the SUL equivalent non-modified lignin resin.The plywood panels bonded with oxidized lignin gave acceptable bending modulus,bending strength,peak temperature by thermal analysis and dry shear strength as well as a better plywood dimensional stability when used in the SUOL formulation.The synthesized SUOL adhesive is a lignin-derived,totally bio,no-aldehyde added,inexpensive resin applicable to bond plywood.
基金supported by the Key R&D Program of Shandong Province,China(No.2025CXGC 010412)the National Key Research and Development Program of China(No.2022YFB3709300)the National Natural Science Foundation of China(No.U21A2048).
文摘The limited high-temperature oxidation resistance of Mg alloys is a key factor restricting their development and application.The addition of some rare earth elements(REs),owing to their unique physical and chemical properties,can significantly enhance the oxidation resistance of Mg alloys.Based on our previous study,we conclude that REs such as Gd,Y,and Ce enhance the oxidation resistance of Mg-RE alloys.This article comprehensively reviews recent research progress on high-temperature oxidation behavior and the potential mechanism in Mg-RE alloys.Based on the thermodynamic and kinetic analyses,the evolution of the complex oxide system formed during the high-temperature oxidation of Mg-RE alloys is first summarized.The diffusion behavior and concentration control mechanisms of REs during the oxidation process and how these mechanisms affect the sustained growth of the oxide film and antioxidant properties were elucidated.Moreover,the different structures of the oxide films were classified,and their properties were discussed.Finally,this paper introduces the applications of commonly used REs in Mg alloys and frontier research on their oxidation mechanisms.Based on the above review,we propose that future research perspectives can be explored in terms of expanding the experimental temperature range for oxidation tests,optimizing the chemical composition by adding trace REs to study their synergistic mechanism,revealing the underlying oxidation mechanism through advanced in situ microscopic characterization methods,and investigating the mechanical properties of oxide films using diverse approaches.
