Unfixed reactive dyes stained on cotton fabric could be removed using Fe-tetra-amido macro-cyclic ligands( TAML) / H_2O_2 catalyzed oxidation system( COS). The colored washing-off wastewater also could be decolorized ...Unfixed reactive dyes stained on cotton fabric could be removed using Fe-tetra-amido macro-cyclic ligands( TAML) / H_2O_2 catalyzed oxidation system( COS). The colored washing-off wastewater also could be decolorized simultaneously in the same system. The decolourization kinetics showed that the decolourization ratio of reactive dyes in water could reach at least 80% at room temperature in 10 min,which followed the law of pseudo-first order reaction kinetics. The effects of the COS washing-off process parameters on the decolourization ratio,chemical oxygen demand( COD) of wastewater,K/S value,color fastness,color difference,and bursting strength were investigated in detail. The results showed that color fastness properties and final shade of fabric treated by COS were very similar to conventional soaping. The reactive dye molecules in wash-off bath were destroyed using the COS,potentially reduced COD which generated during conventional washing-off procedure.展开更多
A pulse current technique was conducted in a boron-doped diamond （BDD） anode system for electrochemical waste- water treatment. Due to the strong generation and weak absorption of hydroxyl radicals on the diamond su...A pulse current technique was conducted in a boron-doped diamond （BDD） anode system for electrochemical waste- water treatment. Due to the strong generation and weak absorption of hydroxyl radicals on the diamond surface, the BDD elec- trode possesses a powerful capability of electrochemical oxidation of organic compounds, especially in the pulse current mode. The influences of pulse current parameters such as current density, pulse duty cycle, and frequency were investigated in terms of chemical oxygen demand （COD） removal, average current efficiency, and specific energy consumption. The results demon- strated that the relatively high COD removal and low specific energy consumption were obtained simultaneously only if the current density or pulse duty cycle was adjusted to a reasonable value. Increasing the frequency slightly enhanced the COD re- moval and average current efficiency. A pulse-BDD anode system showed a stronger energy saving ability than a constant-BDD anode system when the electrochemical oxidation of phenol of the two systems was compared. The results prove that the pulse current technique is more cost-effective and more suitable for a BDD anode system for real wastewater treatment. A kinetic analysis was presented to explain the above results.展开更多
In this study,nitrogen removal performance of the denitrifying ammonium oxidation(DAO)process was investigated when treating sulfamethoxazole(SMX)-laden secondary wastewater effluent.The influent SMX concentration sho...In this study,nitrogen removal performance of the denitrifying ammonium oxidation(DAO)process was investigated when treating sulfamethoxazole(SMX)-laden secondary wastewater effluent.The influent SMX concentration showed negligible effect on efficiencies for removal of nitrate and COD.However,the ammonium ions removal rate was moderately reduced,when the influent SMX concentration in wastewater reached 6 mg/L.Total nitrogen removal efficiency remained as high as 76.77%towards the day 158 at the end of experiment.Candidatus_Brocadia and Candidatus_Kuenenia were the functional anammox strains.The unclassified_f__Rhodobacteraceae sp.was predominant heterotrophic denitrifying strain in the studied reactor.The concentrations of soluble extracellular polymeric substances in sludge obviously increased from 16.76 mg/g VSS to 32.31 mg/g VSS,which might protect the nitrogen removal strains from high-concentration SMX.This result provides a theoretical and technical foundation for the application of denitrifying ammonium oxidation process in treating sulfamethoxazole-laden secondary wastewater effluent.展开更多
Layered transition metal hydroxides show distinct advantages in separately co-catalyzing CO_(2)reduction and H_(2)O oxidation at the electron-accumulating and hole-accumulating sites of wrapped heterojunction photocat...Layered transition metal hydroxides show distinct advantages in separately co-catalyzing CO_(2)reduction and H_(2)O oxidation at the electron-accumulating and hole-accumulating sites of wrapped heterojunction photocatalysts,while concurrently preventing side reactions and photocorrosion on the semiconductor surface.Herein,Ni-Co bimetallic hydroxides with varying Ni/Co molar ratios(Ni_(x)Co_(1-x)(OH)_(2),x=1,0.75,0.5,0.25,and 0)were grown in situ on a model 2D/2D S-scheme heterojunction composed of Cu_(2)O nanosheets and Fe_(2)O_(3)nanoplates to form a series of Cu_(2)O/Fe_(2)O_(3)@Ni_(x)Co_(1-x)(OH)_(2)(CF@NiCo)photocatalysts.The combined experimental and theoretical investigation demonstrates that incorporating an appropriate amount of Co into Ni(OH)_(2)not only modulates the energy band structure of Ni_(x)Co_(1-x)(OH)_(2),balances the electron-and hole-trapping abilities of the bifunctional cocatalyst and maximizes the charge separation efficiency of the heterojunction,but also regulates the d-band center of Ni_(x)Co_(1-x)(OH)_(2),reinforcing the adsorption and activation of CO_(2)and H_(2)O on the cocatalyst surface and lowering the rate-limiting barriers in the CO_(2)-to-CO and H_(2)O-to-O_(2)conversion.Benefiting from the Ni-Co synergy,the redox reactions proceed stoichiometrically.The optimized CF@Ni_(0.75)Co_(0.25)achieves CO and O_(2)yields of 552.7 and 313.0μmol gcat^(-1)h^(-1),respectively,11.3/9.9,1.6/1.7,and 4.5/5.9-fold higher than those of CF,CF@Ni,and CF@Co.This study offers valuable insights into the design of bifunctional noble-metal-free cocatalysts for high-performance artificial photosynthesis.展开更多
The environmental threat posed by stibnite is an important geoenvironmental issue of current concern.To better understand stibnite oxidation pathways,aerobic abiotic batch experiments were conducted in aqueous solutio...The environmental threat posed by stibnite is an important geoenvironmental issue of current concern.To better understand stibnite oxidation pathways,aerobic abiotic batch experiments were conducted in aqueous solution with varyingδ^(18)O_(H_(2)O) value at initial neutral pH for different lengths of time(15-300 days).The sulfate oxygen and sulfur isotope compositions as well as concentrations of sulfur and antimony species were determined.The sulfur isotope fractionation factor(△^(34)S_(SO4-stibnite))values decreased from 0.8‰to-2.1‰during the first 90 days,and increased to 2.6‰at the 180 days,indicating the dominated intermediate sulfur species such as S_(2)O_(3)^(2-),S0,and H_(2)S(g)involved in Sb2S3 oxidation processes.The incorporation of O into sulfate derived from O_(2)(~100%)indicated that the dissociated O_(2)was only directly adsorbed on the stibnite-S sites in the initial stage(0-90 days).The proportion of O incorporation into sulfate from water(27%-52%)increased in the late stage(90-300 days),which suggested the oxidation mechanism changed to hydroxyl attack on stibnite-S sites promoted by nearby adsorbed O_(2)on stibnite-Sb sites.The exchange of oxygen between sulfite and water may also contributed to the increase of water derived O into SO42-.The new insight of stibnite oxidation pathway contributes to the understanding of sulfide oxidation mechanism and helps to interpret field data.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
Fine-grained nuclear graphite is a key material in high-temperature gas-cooled reactors(HTGRs).During air ingress accidents,core graphite components undergo severe oxidation,threatening structural integrity.Therefore,...Fine-grained nuclear graphite is a key material in high-temperature gas-cooled reactors(HTGRs).During air ingress accidents,core graphite components undergo severe oxidation,threatening structural integrity.Therefore,understanding the oxidation behavior of nuclear graphite is essential for reactor safety.The influence of oxidation involves multiple factors,including temperature,sample size,oxidant,impurities,filler type and size,etc.The size of the filler particles plays a crucial role in this study.Five ultrafine-and superfine-grained nuclear graphite samples(5.9-34.4μm)are manufactured using identical raw materials and manufacturing processes.Isothermal oxidation tests conducted at 650℃-750℃ are used to study the oxidation behavior.Additionally,comprehensive characterization is performed to analyze the crystal structure,surface morphology,and nanoscale to microscale pore structure of the samples.Results indicate that oxidation behavior cannot be predicted solely based on filler grain size.Reactive site concentration,characterized by active surface area,dominates the chemical reaction kinetics,whereas pore tortuosity,quantified by the structural parameterΨ,plays a key role in regulating oxidant diffusion.These findings clarify the dual role of microstructure in oxidation mechanisms and establish a theoretical and experimental basis for the design of high-performance nuclear graphite capable of long-term service in high-temperature gas-cooled reactors.展开更多
In this work,we constructed a three-dimensional electrochemical system(3D-ECO),which included the cathode and anode electrode plates,as well as the screening of three-dimensional particle electrodes and parameter opti...In this work,we constructed a three-dimensional electrochemical system(3D-ECO),which included the cathode and anode electrode plates,as well as the screening of three-dimensional particle electrodes and parameter opti-mization,for the degradation of landfill leachate(LL)containing elevated levels of tetracycline(TC),and explored its mechanism of action.Firstly,titanium-based ruthenium-iridium(Ti/RuO_(2)-IrO_(2)),titanium-based ruthenium-iridium-platinum(Ti/Pt-RuO_(2)-IrO_(2)),and titanium-based tin-antimony(Ti/SnO_(2)-Sb_(2)O_(3))were employed as an-odes in the electrocatalytic oxidation system,with titanium and stainless steel plates serving as cathodes,to construct the optimal two-dimensional electrocatalytic oxidation system(2D-ECO)through cross-comparison ex-periments.Subsequently,using granular activated carbon(GAC),coconut shell biochar(CBC),walnut shell carbon(WBC),and bamboo charcoal(BBC)as particle electrodes,a 3D-ECO system was developed.The influence of var-ious operational parameters on treating TC-containing LL was investigated.The optimal operating parameters obtained from the study was:pH=5,current density of 30 mA/cm^(2),particle dosage of 7 g/L,particle size ranging from 1.70 to 2.00 mm,and electrode spacing of 4 cm.Under these conditions,the COD removal rate of 3D-ECO within three hours was 90.25%,the TC removal rate was 72.41%,and the NH_(3)-N removal rate was 39.52%.The removal of TC followed a pseudo-first-order kinetic model.Additionally,degradation mechanisms were elucidated through electron paramagnetic resonance(EPR)spectrometer and Tert-Butanol(TBA)quenching experiments,indicating that the degradation primarily occurred through a non-radical(1O_(2))pathway.This re-search offers a comprehensive analysis of the simultaneous breakdown of intricate LL matrices and TC,enhancing our comprehension of the degradation processes and underlying mechanisms.展开更多
TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing Ti...TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.展开更多
Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electro...Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electrocatalytic oxidations of saturated alcohols(C_(1)-C_(6))to selectively form formate using Ni Co hydroxide(Ni Co-OH)derived Ni Co_(2)O_(4)solid-acid electrocatalysts with balanced Lewis acid(LASs)and Brønsted acid sites(BASs).Thermal treatment transforms BASs-rich(89.6%)Ni Co-OH into Ni Co_(2)O_(4)with nearly equal distribution of LASs(53.1%)and BASs(46.9%)which synergistically promote adsorption and activation of OH-and alcohol molecules for enhanced oxidation activity.In contrast,BASs-enriched Ni Co-OH facilitates formation of higher valence metal sites,beneficial for water oxidation.The combined experimental studies and theoretical calculation imply the oxidation ability of C1-C6alcohols increases as increased number of hydroxyl groups and decreased HOMO-LUMO gaps:methanol(C_(1))<ethylene glycol(C_(2))<glycerol(C3)<meso-erythritol(C4)<xylitol(C5)<sorbitol(C6),while the formate selectivity shows the opposite trend from 100 to 80%.This study unveils synergistic roles of LASs and BASs,as well as hydroxyl group effect in electro-upgrading of alcohols using solid-acid electrocatalysts.展开更多
Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pa...Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pathological factor contributing to the progression of sarcopenia.However,the morphological and functional changes in mitochondria and their interplay in the degeneration of the neuromuscular junction during aging remain poorly understood.A defined systematic search of the Pub Med,Web of Science and Embase databases(last accessed on October 30,2024)was conducted with search terms including'mitochondria','aging'and'NMJ'.Clinical and preclinical studies of mitochondrial dysfunction and neuromuscular junction degeneration during aging.Twentyseven studies were included in this systematic review.This systematic review provides a summary of morphological,functional and biological changes in neuromuscular junction,mitochondrial morphology,biosynthesis,respiratory chain function,and mitophagy during aging.We focus on the interactions and mechanisms underlying the relationship between mitochondria and neuromuscular junctions during aging.Aging is characterized by significant reductions in mitochondrial fusion/fission cycles,biosynthesis,and mitochondrial quality control,which may lead to neuromuscular junction dysfunction,denervation and poor physical performance.Motor nerve terminals that exhibit redox sensitivity are among the first to exhibit abnormalities,ultimately leading to an early decline in muscle strength through impaired neuromuscular junction transmission function.Parg coactivator 1 alpha is a crucial molecule that regulates mitochondrial biogenesis and modulates various pathways,including the mitochondrial respiratory chain,energy deficiency,oxidative stress,and inflammation.Mitochondrial dysfunction is correlated with neuromuscular junction denervation and acetylcholine receptor fragmentation,resulting in muscle atrophy and a decrease in strength during aging.Physical therapy,pharmacotherapy,and gene therapy can alleviate the structural degeneration and functional deterioration of neuromuscular junction by restoring mitochondrial function.Therefore,mitochondria are considered potential targets for preserving neuromuscular junction morphology and function during aging to treat sarcopenia.展开更多
Lakes are carbon dioxide(CO_(2))and methane(CH_(4))emission hotspots,whose associated flux is spatially vari-able.Many studies have investigated the impact of microorganisms and environmental factors on CO_(2) and CH_...Lakes are carbon dioxide(CO_(2))and methane(CH_(4))emission hotspots,whose associated flux is spatially vari-able.Many studies have investigated the impact of microorganisms and environmental factors on CO_(2) and CH_(4) emissions between different lakes.However,the carbon emissions and their influencing factors of different areas within a single lake remain poorly understood.Accordingly,this study investigates CO_(2) and CH_(4) emission hetero-geneity in a large floodplain lake system and distribution characteristics of associated functional microorganisms.Findings show that mean CO_(2) and CH_(4) flux values in the sub lake area were 62.03±24.21 mg/(m2·day)and 5.97±3.2μg/(m2·day),which were greater by factors of 1.78 and 2.96 compared to the water channel and the main lake area,respectively.The alpha diversity of methanogens in the sub lake area was lower than that in the main lake and water channel areas.The abundance of methanogens in bottom water layer was higher compared with the middle and surface layers.Conversely,the abundance of methane(CH_(4))-oxidizing bacteria in the surface layer was higher than that in the bottom layer.Additionally,the composition of methanogen and CH_(4)-oxidizing bacterial community,chlorophyll a(Chl-a),pH,total phosphorus(TP)and dissolved organic carbon(DOC)con-tent constituted the dominate driving factors affecting lake C emissions.Results from this study can be used to improve our understanding of lake spatial heterogeneous of CO_(2) and CH_(4) emission and the driving mechanisms within floodplain lakes under the coupling effects of functional C microorganisms and environmental factors.展开更多
Stroke remains a leading cause of death and disability worldwide,and electroacupuncture has a long history of use in stroke treatment.This meta-analysis and systematic review aimed to evaluate the efficacy of electroa...Stroke remains a leading cause of death and disability worldwide,and electroacupuncture has a long history of use in stroke treatment.This meta-analysis and systematic review aimed to evaluate the efficacy of electroacupuncture and explore its potential mechanisms in animal models of ischemic stroke.The PubMed,EMBASE,Web of Science,CENTRAL,and CINAHL databases were comprehensively searched up to May 1,2024.This review included articles on preclinical investigations of the efficacy and mechanisms of electroacupuncture in treating ischemic stroke.Data from 70 eligible studies were analyzed in Stata 18.0,using a random-effects model to calculate the standardized mean difference(Hedge’s g).The risk of bias was assessed using RevMan 5.4 software,and the quality of evidence was rated according to the Grading of Recommendations,Assessment,Development,and Evaluation(GRADE)system.Subgroup analyses were conducted to test the consistency of the results and sensitivity analyses were used to assess their robustness.The quality assessment revealed that most studies adequately handled incomplete data and selective reporting.However,several methodological limitations were identified:only 4 studies demonstrated a low risk of allocation concealment,26 achieved a low risk of outcome assessment bias,and 9 had a high risk of randomization bias.Additionally,there was an unclear risk regarding participant blinding and other methodological aspects.The GRADE assessment rated 12 outcomes as moderate quality and 6 as low quality.The mechanisms of electroacupuncture treatment for ischemic stroke can be categorized as five primary pathways:(1)Electroacupuncture significantly reduced infarct volume and apoptotic cell death(P<0.01)in ischemic stroke models;(2)electroacupuncture significantly decreased the levels of pro-inflammatory factors(P<0.01)while increasing the levels of anti-inflammatory factors(P=0.02);(3)electroacupuncture reduced the levels of oxidative stress indicators(P<0.01)and enhanced the expression of antioxidant enzymes(P<0.01);(4)electroacupuncture significantly promoted nerve regeneration(P<0.01);and(5)electroacupuncture influenced blood flow remodeling(P<0.01)and angiogenesis(P<0.01).Subgroup analyses indicated that electroacupuncture was most effective in the transient middle cerebral artery occlusion model(P<0.01)and in post-middle cerebral artery occlusion intervention(P<0.01).Dispersive waves were found to outperform continuous waves with respect to neuroprotection and anti-inflammatory effects(P<0.01),while scalp acupoints demonstrated greater efficacy than body acupoints(P<0.01).The heterogeneity among the included studies was minimal,and sensitivity analyses indicated stable results.Their methodological quality was generally satisfactory.In conclusion,electroacupuncture is effective in treating cerebral ischemia by modulating cell apoptosis,oxidative stress,inflammation,stroke-induced nerve regeneration,blood flow remodeling,and angiogenesis.The efficacy of electroacupuncture may be influenced by factors such as the middle cerebral artery occlusion model,the timing of intervention onset,waveform,and acupoint selection.Despite the moderate to low quality of evidence,these findings suggest that electroacupuncture has clinical potential for improving outcomes in ischemic stroke.展开更多
A laboratory-scale well-mixed thermostatic reactor with continuously blasting air was used to investigate the oxidation inhibition of sulfite in dual alkali flue gas desulfurization （FGD） system. The effects of oper...A laboratory-scale well-mixed thermostatic reactor with continuously blasting air was used to investigate the oxidation inhibition of sulfite in dual alkali flue gas desulfurization （FGD） system. The effects of operating parameters such as pH value and catalyst concentration on the oxidation were studied. Sodium thiosulfate was used in the system, and was found that it significantly inhabited the sulfite oxidation. In the absence of catalyst, sodium thiosulfate at 12.67 mmol/L had an inhibition efficiency of approximately 98%. While in the presence of catalyst, sodium thiosulfate at 26.72 mmol/L had an inhibition efficiency less than 85.0%. The oxidation reaction order of sulfite in the sodium thiosulfate was determined to be -1.90 and 4）.55 in the absence and presence of the catalyst, respectively. Apparent activation energy of oxidation inhibition was calculated to be 53.9 kJ/mol. Pilot tests showed that the consumption rate of thiosulfate agreed well with the laboratory-scale experimental results.展开更多
To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal （SNDPR）, a whole course of SNDPR damage and recovery was...To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal （SNDPR）, a whole course of SNDPR damage and recovery was studied in a pilot-scale, anaerobicanoxic oxidation ditch （OD）, where the volumes of anaerobic zone, anoxic zone, and ditches zone of the OD system were 7, 21, and 280 L, respectively. The reactor was fed with municipal wastewater with a flow rate of 336 L/d. The concept of simultaneous nitrification and denitrification （SND） rate （rSND） was put forward to quantify SND. The results indicate that： （1） high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase, total nitrogen （TN） and total phosphate （TP） removal rates were 80% and 85%, respectively; （2） when the system was aerated excessively, the stability of SND was damaged, and rSND dropped from 80% to 20% or less; （3） the natural logarithm of the ratio of NOx to NH4^＋ in the effluent had a linear correlation to oxidation-reduction potential （ORP）; （4） when NO3^- was less than 6 mg/L, high phosphorus removal efficiency could be achieved; （5） denitrifying phosphorus removal （DNPR） could take place in the anaerobic-anoxic OD system. The major innovation was that the SND rate was devised and quantified.展开更多
Oxidation pressure leaching was proposed to selectively dissolve Li from spent LiFePO_(4)batteries in a stoichiometric sulfuric acid solution.Using O_(2)as an oxidant and stoichiometric sulfuric acid as leaching agent...Oxidation pressure leaching was proposed to selectively dissolve Li from spent LiFePO_(4)batteries in a stoichiometric sulfuric acid solution.Using O_(2)as an oxidant and stoichiometric sulfuric acid as leaching agent,above 97%of Li was leached into the solution,whereas more than 99%of Fe remained in the leaching residue,enabling a relatively low cost for one-step separation of Li and Fe.And then,by adjusting the pH of leachate,above 95%of Li was recovered in the form of the Li_(3)PO_(4)product through iron removal and chemical precipitation of phosphate.展开更多
Nb-16Si-24Ti-6Cr-6A1-2Hf-xCe （x =0, 0.05, 0.1,02.5, 0.5, 1 （%, atom fraction）） in situ composites were prepared by arc melting The microstmcture and the effect of rare earth element cerium on 1250℃ oxidation resi...Nb-16Si-24Ti-6Cr-6A1-2Hf-xCe （x =0, 0.05, 0.1,02.5, 0.5, 1 （%, atom fraction）） in situ composites were prepared by arc melting The microstmcture and the effect of rare earth element cerium on 1250℃ oxidation resistance of the composites were investigated with scanning electron microscopy （SEM） and X-ray energy disperse spectrum （EDS）, as well as X-ray diffraction （XRD）. The experimental results showed that the high temperature oxidation resistance of the alloy was improved by adding a proper amount of cerium （Ce）. The effect of Ce was considered as the concurrent of the following three factors： first, the oxide of Ce formed in the interface reduced the internal oxidation rate; second, the lath shaped oxide containing Ce increased the cracking resistance and reduced the expansion of the oxide scale; and third, the decrease of the sificide volume fraction on account of Ce addition reduces the power of the sample resisting oxygen penetration.展开更多
Thiophene (C4H4S) and 3-methylthiophene(3-MC4H4S) are typical thiophenenic sulfur compounds that exist in fluid catalytic cracking (FCC) gasoline. Oxidation of C4H4S and 3-MC4H4S were conducted in hydrogen peroxide (H...Thiophene (C4H4S) and 3-methylthiophene(3-MC4H4S) are typical thiophenenic sulfur compounds that exist in fluid catalytic cracking (FCC) gasoline. Oxidation of C4H4S and 3-MC4H4S were conducted in hydrogen peroxide (H2O2) and formic acid system over a series of silica gel loaded with metal oxide. The silica gel loaded with copper and cobalt (1:1) oxide was found very active for the model compound oxidation using H2O2/formic acid, while the silica gel unloaded with metal oxide was less active. The sulfur removal rate of thiophenes was different as solvent was changed. And the conversation of C4H4S and 3-MC4H4S was improved at higher temperature,but reduced when olefin was added. The sulfur removal rate of model sulfur compounds was enhanced when the phase transfer catalyst emulsifier polyethylene glycol octyl phenyl ether or tetrabutylammonium bromide(TBAB)in a H2O2 and formic acid system with the addition of TBAB, a bromine substitution trend appeared in the oxidation of thiophenes, suggesting the influence of TBAB.展开更多
Micro-arc oxidation （MAO） process was cartied out in an optimized dual electrolyte system to fabricate a compact, smooth, and corrosion resistant coating on ZK60 Mg alloy. The microstructural characteristics of coat...Micro-arc oxidation （MAO） process was cartied out in an optimized dual electrolyte system to fabricate a compact, smooth, and corrosion resistant coating on ZK60 Mg alloy. The microstructural characteristics of coating were investigated by scanning electron microscopy （SEM） coupled with an energy dispersive spectrometer （EDS） and X-ray diffraction （XRD）. Test of mass loss was conducted at a 3.5 % NaCl solution to assess the resistance to corrosion. The bonding strength between the coating and ZK60 substrate was evaluated using scratch experiment. The results reveal that MgA1204 and MgO are the main phases of ceramic coating obtained in the dual electrolyte system. The corrosion rate of coating prepared in the optimized dual electrolyte is only 0.0061 g.m-2.h-1, which demonstrates excellent corrosion resistance. This is mainly due to the compact, uniform coating with high bonding strength.展开更多
Uranium exploration breakthrough was extremely rare in an aeolian depositional system.In order to know the complicate characteristics of oxidation associated closely with uranium mineralization in the aeolian depositi...Uranium exploration breakthrough was extremely rare in an aeolian depositional system.In order to know the complicate characteristics of oxidation associated closely with uranium mineralization in the aeolian depositional system,petrology and mineralogy markers of the oxidation and its genetic mechanisms are identified and illustrated by fieldwork,thin section analysis and scanning electron microscopy test,based on 2 field outcrops in Zhenyuan County in the southwest of the Tianhuan depression in the Ordos Basin and the core of 2 wells in the north and south of Ordos Basin.The results showed:the typical macroscopic indicator of primary oxidation was the red fine sediments in the aeolian interdune with a thickness of 10-50 cm,and the microscopic characteristics of primary oxidation were the minerals such as hematite,ilmenite,and the irony matrix rich in fine-grained dolomite and biotite;the phreatic oxidation was manifested as the red sandstone with limonite horizontal layer with a thickness of 1-4 cm and a width of 60 cm-1 m,and the circular limonite nodules with a diameter of 3-7 cm,in which there was intergranular limonite cement;the interlayer oxidation was characterized by lenticular tongue and tapered red sandstone with a length of 1-10 m and a width of 10 cm-5m,in which detrital particles are coated with hematite and hematite was distributed inside the rhombus dolomite.The paleoclimate of the sedimentary period,the water-table movement and the pore and permeability conditions of the sand body were the key factors for the formation of different oxidation types in the aeolian depositional system.展开更多
基金National Key Technology R&D Program,China(No.2011BAE07B08)the Fundamental Research Funds for the Central Universities,China(No.2232013D3-26)
文摘Unfixed reactive dyes stained on cotton fabric could be removed using Fe-tetra-amido macro-cyclic ligands( TAML) / H_2O_2 catalyzed oxidation system( COS). The colored washing-off wastewater also could be decolorized simultaneously in the same system. The decolourization kinetics showed that the decolourization ratio of reactive dyes in water could reach at least 80% at room temperature in 10 min,which followed the law of pseudo-first order reaction kinetics. The effects of the COS washing-off process parameters on the decolourization ratio,chemical oxygen demand( COD) of wastewater,K/S value,color fastness,color difference,and bursting strength were investigated in detail. The results showed that color fastness properties and final shade of fabric treated by COS were very similar to conventional soaping. The reactive dye molecules in wash-off bath were destroyed using the COS,potentially reduced COD which generated during conventional washing-off procedure.
基金supported by the Ph.D. Programs Foundation of the Ministry of Education of China (No. 20110006110011)the National Natural Science Foundation of China (No. 51272024)
文摘A pulse current technique was conducted in a boron-doped diamond （BDD） anode system for electrochemical waste- water treatment. Due to the strong generation and weak absorption of hydroxyl radicals on the diamond surface, the BDD elec- trode possesses a powerful capability of electrochemical oxidation of organic compounds, especially in the pulse current mode. The influences of pulse current parameters such as current density, pulse duty cycle, and frequency were investigated in terms of chemical oxygen demand （COD） removal, average current efficiency, and specific energy consumption. The results demon- strated that the relatively high COD removal and low specific energy consumption were obtained simultaneously only if the current density or pulse duty cycle was adjusted to a reasonable value. Increasing the frequency slightly enhanced the COD re- moval and average current efficiency. A pulse-BDD anode system showed a stronger energy saving ability than a constant-BDD anode system when the electrochemical oxidation of phenol of the two systems was compared. The results prove that the pulse current technique is more cost-effective and more suitable for a BDD anode system for real wastewater treatment. A kinetic analysis was presented to explain the above results.
基金This research was supported by the Natural Science Foundation of Shandong Province(ZR2019MEE038)the Fundamental Research Funds for the Central Universities(19CX02038A).
文摘In this study,nitrogen removal performance of the denitrifying ammonium oxidation(DAO)process was investigated when treating sulfamethoxazole(SMX)-laden secondary wastewater effluent.The influent SMX concentration showed negligible effect on efficiencies for removal of nitrate and COD.However,the ammonium ions removal rate was moderately reduced,when the influent SMX concentration in wastewater reached 6 mg/L.Total nitrogen removal efficiency remained as high as 76.77%towards the day 158 at the end of experiment.Candidatus_Brocadia and Candidatus_Kuenenia were the functional anammox strains.The unclassified_f__Rhodobacteraceae sp.was predominant heterotrophic denitrifying strain in the studied reactor.The concentrations of soluble extracellular polymeric substances in sludge obviously increased from 16.76 mg/g VSS to 32.31 mg/g VSS,which might protect the nitrogen removal strains from high-concentration SMX.This result provides a theoretical and technical foundation for the application of denitrifying ammonium oxidation process in treating sulfamethoxazole-laden secondary wastewater effluent.
文摘Layered transition metal hydroxides show distinct advantages in separately co-catalyzing CO_(2)reduction and H_(2)O oxidation at the electron-accumulating and hole-accumulating sites of wrapped heterojunction photocatalysts,while concurrently preventing side reactions and photocorrosion on the semiconductor surface.Herein,Ni-Co bimetallic hydroxides with varying Ni/Co molar ratios(Ni_(x)Co_(1-x)(OH)_(2),x=1,0.75,0.5,0.25,and 0)were grown in situ on a model 2D/2D S-scheme heterojunction composed of Cu_(2)O nanosheets and Fe_(2)O_(3)nanoplates to form a series of Cu_(2)O/Fe_(2)O_(3)@Ni_(x)Co_(1-x)(OH)_(2)(CF@NiCo)photocatalysts.The combined experimental and theoretical investigation demonstrates that incorporating an appropriate amount of Co into Ni(OH)_(2)not only modulates the energy band structure of Ni_(x)Co_(1-x)(OH)_(2),balances the electron-and hole-trapping abilities of the bifunctional cocatalyst and maximizes the charge separation efficiency of the heterojunction,but also regulates the d-band center of Ni_(x)Co_(1-x)(OH)_(2),reinforcing the adsorption and activation of CO_(2)and H_(2)O on the cocatalyst surface and lowering the rate-limiting barriers in the CO_(2)-to-CO and H_(2)O-to-O_(2)conversion.Benefiting from the Ni-Co synergy,the redox reactions proceed stoichiometrically.The optimized CF@Ni_(0.75)Co_(0.25)achieves CO and O_(2)yields of 552.7 and 313.0μmol gcat^(-1)h^(-1),respectively,11.3/9.9,1.6/1.7,and 4.5/5.9-fold higher than those of CF,CF@Ni,and CF@Co.This study offers valuable insights into the design of bifunctional noble-metal-free cocatalysts for high-performance artificial photosynthesis.
基金supported by the National Natural Science Foundation of China(No.41672245)the National Key Research and Development Program of China(No.2022YFC3702201).
文摘The environmental threat posed by stibnite is an important geoenvironmental issue of current concern.To better understand stibnite oxidation pathways,aerobic abiotic batch experiments were conducted in aqueous solution with varyingδ^(18)O_(H_(2)O) value at initial neutral pH for different lengths of time(15-300 days).The sulfate oxygen and sulfur isotope compositions as well as concentrations of sulfur and antimony species were determined.The sulfur isotope fractionation factor(△^(34)S_(SO4-stibnite))values decreased from 0.8‰to-2.1‰during the first 90 days,and increased to 2.6‰at the 180 days,indicating the dominated intermediate sulfur species such as S_(2)O_(3)^(2-),S0,and H_(2)S(g)involved in Sb2S3 oxidation processes.The incorporation of O into sulfate derived from O_(2)(~100%)indicated that the dissociated O_(2)was only directly adsorbed on the stibnite-S sites in the initial stage(0-90 days).The proportion of O incorporation into sulfate from water(27%-52%)increased in the late stage(90-300 days),which suggested the oxidation mechanism changed to hydroxyl attack on stibnite-S sites promoted by nearby adsorbed O_(2)on stibnite-Sb sites.The exchange of oxygen between sulfite and water may also contributed to the increase of water derived O into SO42-.The new insight of stibnite oxidation pathway contributes to the understanding of sulfide oxidation mechanism and helps to interpret field data.
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.
基金supported by the National Key Research and Development Program of China(2024YFA1612900)the National Natural Science Foundation of China(Grant No.52103365 and No.12375270)the Guangdong Innovative and Entrepreneurial Research Team Program,China(Grant No.2021ZT09L227).
文摘Fine-grained nuclear graphite is a key material in high-temperature gas-cooled reactors(HTGRs).During air ingress accidents,core graphite components undergo severe oxidation,threatening structural integrity.Therefore,understanding the oxidation behavior of nuclear graphite is essential for reactor safety.The influence of oxidation involves multiple factors,including temperature,sample size,oxidant,impurities,filler type and size,etc.The size of the filler particles plays a crucial role in this study.Five ultrafine-and superfine-grained nuclear graphite samples(5.9-34.4μm)are manufactured using identical raw materials and manufacturing processes.Isothermal oxidation tests conducted at 650℃-750℃ are used to study the oxidation behavior.Additionally,comprehensive characterization is performed to analyze the crystal structure,surface morphology,and nanoscale to microscale pore structure of the samples.Results indicate that oxidation behavior cannot be predicted solely based on filler grain size.Reactive site concentration,characterized by active surface area,dominates the chemical reaction kinetics,whereas pore tortuosity,quantified by the structural parameterΨ,plays a key role in regulating oxidant diffusion.These findings clarify the dual role of microstructure in oxidation mechanisms and establish a theoretical and experimental basis for the design of high-performance nuclear graphite capable of long-term service in high-temperature gas-cooled reactors.
基金supported by the National Natural Science Foundation of China(Nos.42477406 and 51878617)the Horizontal Scientific Research Project(No.KYY-HX-20220803)the Engineering Research Center of Ministry of Education for Renewable Energy Infrastructure Construction Technology.
文摘In this work,we constructed a three-dimensional electrochemical system(3D-ECO),which included the cathode and anode electrode plates,as well as the screening of three-dimensional particle electrodes and parameter opti-mization,for the degradation of landfill leachate(LL)containing elevated levels of tetracycline(TC),and explored its mechanism of action.Firstly,titanium-based ruthenium-iridium(Ti/RuO_(2)-IrO_(2)),titanium-based ruthenium-iridium-platinum(Ti/Pt-RuO_(2)-IrO_(2)),and titanium-based tin-antimony(Ti/SnO_(2)-Sb_(2)O_(3))were employed as an-odes in the electrocatalytic oxidation system,with titanium and stainless steel plates serving as cathodes,to construct the optimal two-dimensional electrocatalytic oxidation system(2D-ECO)through cross-comparison ex-periments.Subsequently,using granular activated carbon(GAC),coconut shell biochar(CBC),walnut shell carbon(WBC),and bamboo charcoal(BBC)as particle electrodes,a 3D-ECO system was developed.The influence of var-ious operational parameters on treating TC-containing LL was investigated.The optimal operating parameters obtained from the study was:pH=5,current density of 30 mA/cm^(2),particle dosage of 7 g/L,particle size ranging from 1.70 to 2.00 mm,and electrode spacing of 4 cm.Under these conditions,the COD removal rate of 3D-ECO within three hours was 90.25%,the TC removal rate was 72.41%,and the NH_(3)-N removal rate was 39.52%.The removal of TC followed a pseudo-first-order kinetic model.Additionally,degradation mechanisms were elucidated through electron paramagnetic resonance(EPR)spectrometer and Tert-Butanol(TBA)quenching experiments,indicating that the degradation primarily occurred through a non-radical(1O_(2))pathway.This re-search offers a comprehensive analysis of the simultaneous breakdown of intricate LL matrices and TC,enhancing our comprehension of the degradation processes and underlying mechanisms.
基金supported by the Original Exploratory Program of the National Natural Science Foundation of China(No.52450012)。
文摘TiB_(2)coatings can significantly enhance the high-temperature oxidation resistance of molybdenum,which would broaden the application range of molybdenum and alloys thereof.However,traditional methods for preparing TiB_(2)coatings have disadvantages such as high equipment costs,complicated processes,and highly toxic gas emissions.This paper proposes an environmentally friendly method,which requires inexpensive equipment and simple processing,for preparing TiB_(2)coating on molybdenum via electrophoretic deposition within Na3AlF6-based molten salts.The produced TiB_(2)layer had an approximate thickness of 60μm and exhibited high density,outstanding hardness(38.2 GPa)and robust adhesion strength(51 N).Additionally,high-temperature oxidation experiments revealed that,at900℃,the TiB_(2)coating provided effective protection to the molybdenum substrate against oxidation for 3 h.This result indicates that the TiB_(2)coating prepared on molybdenum using molten salt electrophoretic deposition possesses good high-temperature oxidation resistance.
基金the financial support from the National Natural Science Foundation of China(52172110,52472231,52311530113)Shanghai"Science and Technology Innovation Action Plan"intergovernmental international science and technology cooperation project(23520710600)+1 种基金Science and Technology Commission of Shanghai Municipality(22DZ1205600)the Central Guidance on Science and Technology Development Fund of Zhejiang Province(2024ZY01011)。
文摘Investigating structural and hydroxyl group effects in electrooxidation of alcohols to value-added products by solid-acid electrocatalysts is essential for upgrading biomass alcohols.Herein,we report efficient electrocatalytic oxidations of saturated alcohols(C_(1)-C_(6))to selectively form formate using Ni Co hydroxide(Ni Co-OH)derived Ni Co_(2)O_(4)solid-acid electrocatalysts with balanced Lewis acid(LASs)and Brønsted acid sites(BASs).Thermal treatment transforms BASs-rich(89.6%)Ni Co-OH into Ni Co_(2)O_(4)with nearly equal distribution of LASs(53.1%)and BASs(46.9%)which synergistically promote adsorption and activation of OH-and alcohol molecules for enhanced oxidation activity.In contrast,BASs-enriched Ni Co-OH facilitates formation of higher valence metal sites,beneficial for water oxidation.The combined experimental studies and theoretical calculation imply the oxidation ability of C1-C6alcohols increases as increased number of hydroxyl groups and decreased HOMO-LUMO gaps:methanol(C_(1))<ethylene glycol(C_(2))<glycerol(C3)<meso-erythritol(C4)<xylitol(C5)<sorbitol(C6),while the formate selectivity shows the opposite trend from 100 to 80%.This study unveils synergistic roles of LASs and BASs,as well as hydroxyl group effect in electro-upgrading of alcohols using solid-acid electrocatalysts.
基金supported by grants from Collaborative Research Fund(Ref:C4032-21GF)General Research Grant(Ref:14114822)+1 种基金Group Research Scheme(Ref:3110146)Area of Excellence(Ref:Ao E/M-402/20)。
文摘Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pathological factor contributing to the progression of sarcopenia.However,the morphological and functional changes in mitochondria and their interplay in the degeneration of the neuromuscular junction during aging remain poorly understood.A defined systematic search of the Pub Med,Web of Science and Embase databases(last accessed on October 30,2024)was conducted with search terms including'mitochondria','aging'and'NMJ'.Clinical and preclinical studies of mitochondrial dysfunction and neuromuscular junction degeneration during aging.Twentyseven studies were included in this systematic review.This systematic review provides a summary of morphological,functional and biological changes in neuromuscular junction,mitochondrial morphology,biosynthesis,respiratory chain function,and mitophagy during aging.We focus on the interactions and mechanisms underlying the relationship between mitochondria and neuromuscular junctions during aging.Aging is characterized by significant reductions in mitochondrial fusion/fission cycles,biosynthesis,and mitochondrial quality control,which may lead to neuromuscular junction dysfunction,denervation and poor physical performance.Motor nerve terminals that exhibit redox sensitivity are among the first to exhibit abnormalities,ultimately leading to an early decline in muscle strength through impaired neuromuscular junction transmission function.Parg coactivator 1 alpha is a crucial molecule that regulates mitochondrial biogenesis and modulates various pathways,including the mitochondrial respiratory chain,energy deficiency,oxidative stress,and inflammation.Mitochondrial dysfunction is correlated with neuromuscular junction denervation and acetylcholine receptor fragmentation,resulting in muscle atrophy and a decrease in strength during aging.Physical therapy,pharmacotherapy,and gene therapy can alleviate the structural degeneration and functional deterioration of neuromuscular junction by restoring mitochondrial function.Therefore,mitochondria are considered potential targets for preserving neuromuscular junction morphology and function during aging to treat sarcopenia.
基金supported by the National Natural Science Foundation of China(No.42225103).
文摘Lakes are carbon dioxide(CO_(2))and methane(CH_(4))emission hotspots,whose associated flux is spatially vari-able.Many studies have investigated the impact of microorganisms and environmental factors on CO_(2) and CH_(4) emissions between different lakes.However,the carbon emissions and their influencing factors of different areas within a single lake remain poorly understood.Accordingly,this study investigates CO_(2) and CH_(4) emission hetero-geneity in a large floodplain lake system and distribution characteristics of associated functional microorganisms.Findings show that mean CO_(2) and CH_(4) flux values in the sub lake area were 62.03±24.21 mg/(m2·day)and 5.97±3.2μg/(m2·day),which were greater by factors of 1.78 and 2.96 compared to the water channel and the main lake area,respectively.The alpha diversity of methanogens in the sub lake area was lower than that in the main lake and water channel areas.The abundance of methanogens in bottom water layer was higher compared with the middle and surface layers.Conversely,the abundance of methane(CH_(4))-oxidizing bacteria in the surface layer was higher than that in the bottom layer.Additionally,the composition of methanogen and CH_(4)-oxidizing bacterial community,chlorophyll a(Chl-a),pH,total phosphorus(TP)and dissolved organic carbon(DOC)con-tent constituted the dominate driving factors affecting lake C emissions.Results from this study can be used to improve our understanding of lake spatial heterogeneous of CO_(2) and CH_(4) emission and the driving mechanisms within floodplain lakes under the coupling effects of functional C microorganisms and environmental factors.
基金supported by the National Natural Science Foundation of China,Nos.82174496(to NW),82374574(to NW),82302865(to LL)Shanghai Science and Technology Committee Sailing Program,Nos.23YF1403800(to LL),23YF1405200(to YX)Shanghai Hospital Development Center Foundation-Shanghai Municipal Hospital Rehabilitation Medicine Specialty Alliance,No.SHDC22023304(to YW).
文摘Stroke remains a leading cause of death and disability worldwide,and electroacupuncture has a long history of use in stroke treatment.This meta-analysis and systematic review aimed to evaluate the efficacy of electroacupuncture and explore its potential mechanisms in animal models of ischemic stroke.The PubMed,EMBASE,Web of Science,CENTRAL,and CINAHL databases were comprehensively searched up to May 1,2024.This review included articles on preclinical investigations of the efficacy and mechanisms of electroacupuncture in treating ischemic stroke.Data from 70 eligible studies were analyzed in Stata 18.0,using a random-effects model to calculate the standardized mean difference(Hedge’s g).The risk of bias was assessed using RevMan 5.4 software,and the quality of evidence was rated according to the Grading of Recommendations,Assessment,Development,and Evaluation(GRADE)system.Subgroup analyses were conducted to test the consistency of the results and sensitivity analyses were used to assess their robustness.The quality assessment revealed that most studies adequately handled incomplete data and selective reporting.However,several methodological limitations were identified:only 4 studies demonstrated a low risk of allocation concealment,26 achieved a low risk of outcome assessment bias,and 9 had a high risk of randomization bias.Additionally,there was an unclear risk regarding participant blinding and other methodological aspects.The GRADE assessment rated 12 outcomes as moderate quality and 6 as low quality.The mechanisms of electroacupuncture treatment for ischemic stroke can be categorized as five primary pathways:(1)Electroacupuncture significantly reduced infarct volume and apoptotic cell death(P<0.01)in ischemic stroke models;(2)electroacupuncture significantly decreased the levels of pro-inflammatory factors(P<0.01)while increasing the levels of anti-inflammatory factors(P=0.02);(3)electroacupuncture reduced the levels of oxidative stress indicators(P<0.01)and enhanced the expression of antioxidant enzymes(P<0.01);(4)electroacupuncture significantly promoted nerve regeneration(P<0.01);and(5)electroacupuncture influenced blood flow remodeling(P<0.01)and angiogenesis(P<0.01).Subgroup analyses indicated that electroacupuncture was most effective in the transient middle cerebral artery occlusion model(P<0.01)and in post-middle cerebral artery occlusion intervention(P<0.01).Dispersive waves were found to outperform continuous waves with respect to neuroprotection and anti-inflammatory effects(P<0.01),while scalp acupoints demonstrated greater efficacy than body acupoints(P<0.01).The heterogeneity among the included studies was minimal,and sensitivity analyses indicated stable results.Their methodological quality was generally satisfactory.In conclusion,electroacupuncture is effective in treating cerebral ischemia by modulating cell apoptosis,oxidative stress,inflammation,stroke-induced nerve regeneration,blood flow remodeling,and angiogenesis.The efficacy of electroacupuncture may be influenced by factors such as the middle cerebral artery occlusion model,the timing of intervention onset,waveform,and acupoint selection.Despite the moderate to low quality of evidence,these findings suggest that electroacupuncture has clinical potential for improving outcomes in ischemic stroke.
基金Preoject supported by the Hi-Tech Research and Development Program (863) of China (No. 2001AA642030-1)the Key Research Project of Zhejiang Province (No. 2004C23028)New Century Excellent Scholar Program of Ministry of Education of the People's Republic of China (No.NCET-04-0549)
文摘A laboratory-scale well-mixed thermostatic reactor with continuously blasting air was used to investigate the oxidation inhibition of sulfite in dual alkali flue gas desulfurization （FGD） system. The effects of operating parameters such as pH value and catalyst concentration on the oxidation were studied. Sodium thiosulfate was used in the system, and was found that it significantly inhabited the sulfite oxidation. In the absence of catalyst, sodium thiosulfate at 12.67 mmol/L had an inhibition efficiency of approximately 98%. While in the presence of catalyst, sodium thiosulfate at 26.72 mmol/L had an inhibition efficiency less than 85.0%. The oxidation reaction order of sulfite in the sodium thiosulfate was determined to be -1.90 and 4）.55 in the absence and presence of the catalyst, respectively. Apparent activation energy of oxidation inhibition was calculated to be 53.9 kJ/mol. Pilot tests showed that the consumption rate of thiosulfate agreed well with the laboratory-scale experimental results.
文摘To achieve high efficiency of nitrogen and phosphorus removal and to investigate the rule of simultaneous nitrification and denitrification phosphorus removal （SNDPR）, a whole course of SNDPR damage and recovery was studied in a pilot-scale, anaerobicanoxic oxidation ditch （OD）, where the volumes of anaerobic zone, anoxic zone, and ditches zone of the OD system were 7, 21, and 280 L, respectively. The reactor was fed with municipal wastewater with a flow rate of 336 L/d. The concept of simultaneous nitrification and denitrification （SND） rate （rSND） was put forward to quantify SND. The results indicate that： （1） high nitrogen and phosphorus removal efficiencies were achieved during the stable SND phase, total nitrogen （TN） and total phosphate （TP） removal rates were 80% and 85%, respectively; （2） when the system was aerated excessively, the stability of SND was damaged, and rSND dropped from 80% to 20% or less; （3） the natural logarithm of the ratio of NOx to NH4^＋ in the effluent had a linear correlation to oxidation-reduction potential （ORP）; （4） when NO3^- was less than 6 mg/L, high phosphorus removal efficiency could be achieved; （5） denitrifying phosphorus removal （DNPR） could take place in the anaerobic-anoxic OD system. The major innovation was that the SND rate was devised and quantified.
基金the financial supports from the National Natural Science Foundation of China(Nos.51804083,52104395,21906031)the Natural Science Foundation of Guangdong Province,China(No.2019A1515011628)+1 种基金the Science and Technology Planning Project of Guangdong Province,China(No.2017B090907026)the Special Program of Guangdong Academy of Sciences,China(Nos.2019GDASYL-0103069,2020GDASYL-0104027,2020GDASYL-0302004,2020GDASYL-0302009,2021GDASYL-0302004)。
文摘Oxidation pressure leaching was proposed to selectively dissolve Li from spent LiFePO_(4)batteries in a stoichiometric sulfuric acid solution.Using O_(2)as an oxidant and stoichiometric sulfuric acid as leaching agent,above 97%of Li was leached into the solution,whereas more than 99%of Fe remained in the leaching residue,enabling a relatively low cost for one-step separation of Li and Fe.And then,by adjusting the pH of leachate,above 95%of Li was recovered in the form of the Li_(3)PO_(4)product through iron removal and chemical precipitation of phosphate.
基金Project supported by the National"863"Project (2003AA305810)
文摘Nb-16Si-24Ti-6Cr-6A1-2Hf-xCe （x =0, 0.05, 0.1,02.5, 0.5, 1 （%, atom fraction）） in situ composites were prepared by arc melting The microstmcture and the effect of rare earth element cerium on 1250℃ oxidation resistance of the composites were investigated with scanning electron microscopy （SEM） and X-ray energy disperse spectrum （EDS）, as well as X-ray diffraction （XRD）. The experimental results showed that the high temperature oxidation resistance of the alloy was improved by adding a proper amount of cerium （Ce）. The effect of Ce was considered as the concurrent of the following three factors： first, the oxide of Ce formed in the interface reduced the internal oxidation rate; second, the lath shaped oxide containing Ce increased the cracking resistance and reduced the expansion of the oxide scale; and third, the decrease of the sificide volume fraction on account of Ce addition reduces the power of the sample resisting oxygen penetration.
基金Supported by the National Natural Science Foundation of China (No.20276015) and the Natural Science Foundation of Hebei Province (No.203364).
文摘Thiophene (C4H4S) and 3-methylthiophene(3-MC4H4S) are typical thiophenenic sulfur compounds that exist in fluid catalytic cracking (FCC) gasoline. Oxidation of C4H4S and 3-MC4H4S were conducted in hydrogen peroxide (H2O2) and formic acid system over a series of silica gel loaded with metal oxide. The silica gel loaded with copper and cobalt (1:1) oxide was found very active for the model compound oxidation using H2O2/formic acid, while the silica gel unloaded with metal oxide was less active. The sulfur removal rate of thiophenes was different as solvent was changed. And the conversation of C4H4S and 3-MC4H4S was improved at higher temperature,but reduced when olefin was added. The sulfur removal rate of model sulfur compounds was enhanced when the phase transfer catalyst emulsifier polyethylene glycol octyl phenyl ether or tetrabutylammonium bromide(TBAB)in a H2O2 and formic acid system with the addition of TBAB, a bromine substitution trend appeared in the oxidation of thiophenes, suggesting the influence of TBAB.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions and the Key Laboratory of Advanced Welding Technology of Jiangsu Province, China (No. JSAWT-11)
文摘Micro-arc oxidation （MAO） process was cartied out in an optimized dual electrolyte system to fabricate a compact, smooth, and corrosion resistant coating on ZK60 Mg alloy. The microstructural characteristics of coating were investigated by scanning electron microscopy （SEM） coupled with an energy dispersive spectrometer （EDS） and X-ray diffraction （XRD）. Test of mass loss was conducted at a 3.5 % NaCl solution to assess the resistance to corrosion. The bonding strength between the coating and ZK60 substrate was evaluated using scratch experiment. The results reveal that MgA1204 and MgO are the main phases of ceramic coating obtained in the dual electrolyte system. The corrosion rate of coating prepared in the optimized dual electrolyte is only 0.0061 g.m-2.h-1, which demonstrates excellent corrosion resistance. This is mainly due to the compact, uniform coating with high bonding strength.
基金supported by the National Key Research and Development Program of China (No.2018YFC0604202)from the Ministry of Science and Technology of China and the International Geosciences Program (No.IGCP675)
文摘Uranium exploration breakthrough was extremely rare in an aeolian depositional system.In order to know the complicate characteristics of oxidation associated closely with uranium mineralization in the aeolian depositional system,petrology and mineralogy markers of the oxidation and its genetic mechanisms are identified and illustrated by fieldwork,thin section analysis and scanning electron microscopy test,based on 2 field outcrops in Zhenyuan County in the southwest of the Tianhuan depression in the Ordos Basin and the core of 2 wells in the north and south of Ordos Basin.The results showed:the typical macroscopic indicator of primary oxidation was the red fine sediments in the aeolian interdune with a thickness of 10-50 cm,and the microscopic characteristics of primary oxidation were the minerals such as hematite,ilmenite,and the irony matrix rich in fine-grained dolomite and biotite;the phreatic oxidation was manifested as the red sandstone with limonite horizontal layer with a thickness of 1-4 cm and a width of 60 cm-1 m,and the circular limonite nodules with a diameter of 3-7 cm,in which there was intergranular limonite cement;the interlayer oxidation was characterized by lenticular tongue and tapered red sandstone with a length of 1-10 m and a width of 10 cm-5m,in which detrital particles are coated with hematite and hematite was distributed inside the rhombus dolomite.The paleoclimate of the sedimentary period,the water-table movement and the pore and permeability conditions of the sand body were the key factors for the formation of different oxidation types in the aeolian depositional system.
