Tyrosine residues in proteins can be nitrated to form 3-nitrotyrosine(3-NT)under the influence of ozone(O_(3))and nitrogen dioxide(NO_(2))in the air,which may introduce health impacts.A selective and sensitive enzyme-...Tyrosine residues in proteins can be nitrated to form 3-nitrotyrosine(3-NT)under the influence of ozone(O_(3))and nitrogen dioxide(NO_(2))in the air,which may introduce health impacts.A selective and sensitive enzyme-linked-immunoassay(ELISA)method was developed to determine 3-NT in modified model protein(bovine serum albumin,BSA)and ambient aerosol samples.The nitration degrees(NDs)of BSA in the exposure experiments with different durations were detected by both the ELISA and spectrophotometric methods(i.e.,ND_(ELISA) and ND_(SEC-PDA)),which show good coincidence.The kinetic investigation by both ΔND_(ELISA) and ΔND_(SEC-PDA) in the exposure experiments shows that the rate coefficients(k)of the pseudo-first-order kinetic rate reactions of protein nitration were comparable.These results indicate that direct detection of 3-NT by the ELISA method can be applied for laboratory exposure samples analysis for kinetic studies.Based on the selective detection of 3-NT,ND_(ELISA) provides a promising measure for the assessment of ND in model proteins.3-NT was alsomeasured in PM_(2.5) samples in summer in Guangzhou,southern China,ranging from 10.1 to 404 pg/m^(3),providing clear evidence of protein nitration in ambient aerosols.We further proposed that 3-NT/protein can be used as a proxy to evaluate protein nitration in ambient aerosols.A significant correlationwas observed between 3-NT/protein and O_(3),confirming the crucial role of O_(3) in protein nitration.Our results show that the direct detection of 3-NT by the ELISA method can be more widely applied in the laboratory and field-based studies for understanding the mechanisms of protein nitration.展开更多
Light exposure can accelerate phase transformation of Schwertmannite(Sch)coexisting with lowmolecular-weight organic acids(LMWOAs),affecting the cycling of Fe in acid mine drainage(AMD).However,it is still unclear how...Light exposure can accelerate phase transformation of Schwertmannite(Sch)coexisting with lowmolecular-weight organic acids(LMWOAs),affecting the cycling of Fe in acid mine drainage(AMD).However,it is still unclear how this process relates to the fate of heavy metal contaminants.The study comprehensively reports the significant role and speciation redistribution of Cu(Ⅱ)during the photochemical transformation of a Sch/tartaric acid(TA)system.Based on X-ray diffractometer and Fourier transform infrared spectra results,the presence of TA in simulated AMD significantly promoted photoreductive dissolution and phase transformation of Sch to magnetite(Mt)and goethite(Gt)under anoxic and oxic conditions,respectively.With the addition of 10-30 mg/L Cu(Ⅱ),this transformation of Sch/TA system was significantly inhibited,i.e.,only Gt occurred as product under anoxic conditions and even no phase transformation under oxic conditions.The results of EPR and adsorbed Fe(Ⅱ)indicated that the coexistence of Cu(Ⅱ)suppressed the amount of adsorbed Fe(Ⅱ)available for the transformation of Sch via competitive adsorption with Fe(Ⅱ)and inhibition of ligand-to-metal charge transfer(LMCT)of Sch-TA complexes.Chemical speciation and X-ray photoelectron spectroscopy analysis revealed the proportions of adsorbed and structural Cu(Ⅱ)of Sch/TA system were observably enhanced due to an increase in pH and recrystallization/nucleation growth of newly formed Gt.Under anoxic conditions,62.7%-75.88%of Cu(Ⅱ)was adsorbed on the mineral surface,and during the nucleation and growth of secondary mineral phases,15.49%-17.01%of Cu(Ⅱ)was incorporated into their crystal structure.The changes in distribution of Cu(Ⅱ)further suggested the photochemical transformation of Sch facilitated the sequestration of heavy metals and reduced their bioavailability.These findings enhance the understanding of role and redistribution of Cu(Ⅱ)during the transformation of Sch/LMWOA system in euphotic zone of AMD and provid insights of exploring engineered strategies of AMD remediation.展开更多
The reduction of carbon emissions in the steel industry is a significant challenge,and utilizing CO_(2) from carbon intensive steel industry off-gases for methanol production is a promising strategy for decarbonizatio...The reduction of carbon emissions in the steel industry is a significant challenge,and utilizing CO_(2) from carbon intensive steel industry off-gases for methanol production is a promising strategy for decarbonization.However,steelwork off-gases typically contain various impurities,including H_(2)S,which can deactivate commercial methanol synthesis catalysts,Cu/ZnO/Al_(2)O_(3)(CZA).Reverse water-gas shift(RWGS)reaction is the predominant side reaction in CO_(2) hydrogenation to methanol which can occur at ambient pressure,enabling the decouple of RWGS from methanol production at high pressure.Then,a series of activated CZA catalysts has been in-situ pretreated in 400 ppm H_(2)S/Ar at 250℃and tested for both RWGS reaction at ambient pressure and CO_(2) hydrogenation to methanol at high pressure.An innovative decoupling strategy was employed to isolate the RWGS reaction from the methanol synthesis process,enabling the investigation of the evolution of active site structures and the poisoning mechanism through elemental analysis,X-ray Diffraction,X-ray Photoelectron Spectroscopy,Fourier Transform Infrared Spectroscopy,Temperature Programmed Reduction and CO_(2) Temperature Programmed Desorption.The results indicate that there are different dynamic migration behaviors of ZnO_(x) in the two reaction systems,leading to different poisoning mechanisms.These interesting findings are beneficial to develop sulfur resistant and durable highly efficient catalysts for CO_(2) hydrogenation to methanol,promoting the carbon emission reduction in steel industry.展开更多
Colloidal synthesis of metal nanoclusters will inevitably lead to the blockage of catalytically active sites by organic ligands.Here,taking[Au_(25)(PET)_(18)]-(PET=2-phenylethanethiol)nanocluster as a model catalyst,t...Colloidal synthesis of metal nanoclusters will inevitably lead to the blockage of catalytically active sites by organic ligands.Here,taking[Au_(25)(PET)_(18)]-(PET=2-phenylethanethiol)nanocluster as a model catalyst,this work reports a feasible procedure to achieve the controllably partial removal of thiolate ligands from unsupported[Au_(25)(PET)_(18)]-nanoclusters with the preservation of the core structure.This procedure shortens the processing duration by rapid heating and cooling on the basis of traditional annealing treatment,avoiding the reconfiguration or agglomeration of Au_(25)nanoclusters,where the degree of dethiolation can be regulated by the control of duration.This work finds that a moderate degree of dethiolation can expose the Au active sites while maintaining the suppression of the competing hydrogen evolution reaction.Consequently,the activity and selectivity towards CO formation in electrochemical CO_(2)reduction reaction of Au_(25)nanoclusters can be promoted.This work provides a new approach for the removal of thiolate ligands from atomically precise gold nanoclusters.展开更多
Chemical modifications of proteins induced by ambient ozone(O_(3))and nitrogen oxides(NOx)are of public health concerns due to their potential to trigger respiratory diseases.The laboratory and environmental exposure ...Chemical modifications of proteins induced by ambient ozone(O_(3))and nitrogen oxides(NOx)are of public health concerns due to their potential to trigger respiratory diseases.The laboratory and environmental exposure systems have been widely used to investigate their relevant mechanism in the atmosphere.Using bovine serum albumin(BSA)as a model protein,we evaluated the two systems and aimed to reduce the uncertainties of both the reactants and products in the corresponding kinetic study.In the laboratory simulation system,the generated gaseous pollutants showed negligible losses.Ten layers of BSA were coated on the flow tube with protein extraction recovery of 87.4%.For environmental exposure experiment,quartz fiber filter was selected as the upper filter with low gaseous O_(3)(8.0%)and NO_(2)(1.7%)losses,and cellulose acetate filter was appropriate for the lower filter with protein extraction efficiency of 95.2%.The protein degradation process was observed without the exposure to atmospheric oxidants and contributed to the loss of protein monomer mass fractions,while environmental factors(e.g.,molecular oxygen and ultraviolet)may cause greater protein monomer losses.Based on the evaluation,the study exemplarily applied the two systems to protein modification and both showed that O_(3) promotes the protein oligomerization and nitration,while increased temperature can accelerate the oligomerization and increased relative humidity can inhibit the nitration in the environmental exposure samples.The developed laboratory and environmental systems are suitable for studying protein modifications formed under different atmospheric conditions.A combination of the two will further reveal the actual mechanism of protein modifications.展开更多
Electrochemical nitrate reduction(NO_(3)RR)offers a promising avenue for treating nitrate-contaminated water and recovering ammonia(NH_(3)),yet the complexities of direct electron transfer(DET)and hydrogen atom transf...Electrochemical nitrate reduction(NO_(3)RR)offers a promising avenue for treating nitrate-contaminated water and recovering ammonia(NH_(3)),yet the complexities of direct electron transfer(DET)and hydrogen atom transfer(HAT)mechanisms crucial for efficiency remain elusive.This study bridges the gap with a combined experimental and theoretical approach,elucidating the impact of catalyst structure on NO3RR pathways.We discover that catalysts favoring strong NO_(3^(-))adsorption and efficient water dissociation were more inclined towards DET,enhancing denitrification.The Fe@Fe_(3)O_(4)/FF cathode,leveraging the synergistic interplay between metallic Fe and Fe_(3)O_(4),excelled in NO3RR via DET,achieving an NH3yield of 0.28 mmol h-1cm-2and a Faradaic efficiency of 95.7%for NH3at-1.6 V(vs.SCE),with minimal nitrite accumulation at 100 mmol/L nitrate.Conversely,the Fe/FF and Fe_(3)O_(4)/CC cathodes showed reduced NH3production and increased nitrite levels,attributed to the lack of Fe_(3)O_(4)and metallic Fe,respectively,resulting in a dominant HAT mechanism.Moreover,Fe@Fe_(3)O_(4)/FF facilitated complete denitrification in real wastewater treatment by harnessing Cl^(-)for electrochemically mediated breakpoint chlorination.This research not only deepens our understanding of NO3RR mechanisms but also paves the way for designing superior nitrate reduction catalysts.展开更多
Microplastics loaded with phenanthrene and derivatives are widely detected in aquatic environments,and the coating of natural minerals or organic macromolecules may change the environmental behavior of microplastics.I...Microplastics loaded with phenanthrene and derivatives are widely detected in aquatic environments,and the coating of natural minerals or organic macromolecules may change the environmental behavior of microplastics.In this study,three kinds of composites with different coverage were prepared by coating goethite on the surface of polyvinyl chloride microplastics to investigate the adsorption and desorption behavior of phenanthrene(PHE)and 1-hydroxyphenanthrene(1-OHPHE),and the effect of mucin on desorption was inves-tigated.The results showed that goethite promoted the adsorption of PHE and 1-OHPHE by increasing the specific surface area of the composites.With the increase of the cover de-gree,the adsorption of PHE decreased because of the decrease in hydrophobicity;while the adsorption of 1-OHPHE initially increased and then decreased with the contributions of hydrophobic interaction and hydrogen bond.The adsorption of 1-OHPHE could be influenced by the pH and ionic strength primarily through electrostatic interactions and Ca2+bridg-ing.The goethite significantly increased the desorption hysteresis for two chemicals due to the complicated pore structures and increased adsorption affinity.Mucin promoted the desorption of PHE through competitive adsorption,and inhibit the desorption of 1-OHPHE through hydrophobic interaction,hydrogen bonding and Ca2+bridging.This study elucidated the effects of natural minerals on the adsorption and desorption behavior of organic pollutants on microplastics,briefly discussed the effects of organic macromolecules on the desorption behavior of pollutants with different properties,and emphasized the different environmental behaviors of pollutants.展开更多
Designing efficient and durable hydrogen evolution reaction(HER)catalysts for seawater electrolysis is crucial for large-scale hydrogen production.Here,we introduce a theory-driven design of metal/WN electrocatalysts,...Designing efficient and durable hydrogen evolution reaction(HER)catalysts for seawater electrolysis is crucial for large-scale hydrogen production.Here,we introduce a theory-driven design of metal/WN electrocatalysts,with metal strongly coupled to lattice-matched WN.Theoretical calculations for Pt/WN reveal that W sites enhance H_(2)O adsorption/dissociation,optimizing Pt's H binding.The prepared Pt/WN@CP nanorods can catalyze HER with low overpotentials of 107 and 113 mV at 500 mA cm^(-2)in alkaline water/seawater,respectively,surpassing Pt/C.Extended calculations and experiments show that the optimized Ni/WN@CP-90 achieves an optimal ΔG_(H*)and overpotential of 219 mV at 500 mA cm^(-2)in alkaline seawater,demonstrating the versatility of the WN support to promote HER activity.Notably,the anion exchange membrane water electrolyzer(AEMWE)constructed by Pt/WN@CP or Ni/WN@CP-90 with NiFe-LDH@NF demonstrates outstanding hydrogen production activity with excellent Faraday efficiency(~100%)and durability(120 h),indicating the potential application of WN-supported catalysts for efficient and stable seawater electrolysis.展开更多
Preparing rare earth carbonates from rare earth chlorides is a common step in the smelting process for all rare earth ores;however,it produces large amounts of ammoniacal nitrogen wastewater and a chloriderich precipi...Preparing rare earth carbonates from rare earth chlorides is a common step in the smelting process for all rare earth ores;however,it produces large amounts of ammoniacal nitrogen wastewater and a chloriderich precipitate.This study proposes a novel,green and simple process for preparing low-chlorine lanthanum carbonate via a multi-membrane electroconversion approach.The effects of the CO_(2) flow rate,current density,lanthanum chloride concentration,and electroconversion time on the electroconversion process were systematically explored.Under the optimal process conditions(CO_(2) flow rate=0.5 L/min,current density=25 mA/cm^(2),LaCl_(3) concentration=0.3 mol/L,electroconversion time=60 min),a current efficiency of 75.77% was obtained,along with a unit energy consumption of5.44 kWh/kg.X-ray diffraction,Fourier transform infrared spectroscopy,thermogravimetric analysis,and laser particle size analysis results indicate that a pure La_(2)(CO_(3))_(3)·8H_(2)O product is obtained with a median particle size of 6.53 μm and chlorine content of 0.0021%.In addition,scanning electron microscopy and transmission electron microscopy observations indicate that the crystallisation and growth of La_(2)(CO_(3))_(3)·8H_(2)O conform to the oriented attachment and Ostwald ripening mechanisms.Thus,the proposed multi-membrane electroconversion method provides guidance toward the clean transformation of rare earth chlorides to low-chlorine lanthanum carbonates.展开更多
Dexamethasone is a common glucocorticoid medication with adverse effects that can cause muscle atrophy,but no drug intervention has been approved or recommended for this condition.KF-8 is a rice bran-derived anti-oxid...Dexamethasone is a common glucocorticoid medication with adverse effects that can cause muscle atrophy,but no drug intervention has been approved or recommended for this condition.KF-8 is a rice bran-derived anti-oxidant peptide that extends the lifespan of Caenorhabditis elegans.We established a C.elegans model of dexamethasone-induced myopathy to evaluate the potential therapeutic effects of KF-8 in this model.C.elegans muscle function was assessed in terms of locomotory behaviors including crawling,swimming,burrowing,pharyngeal pumping,and head swing.Muscle actin filament integrity was evaluated using fluorescence imaging.The molecular mechanisms of KF-8 were investigated using transcriptome sequencing,quantitative real-time PCR(qRT-PCR),RNA interference,and Western blot analysis.Dexamethasone disrupted actin filaments in the striated muscles of the body wall and inhibited C.elegans crawling,swimming,burrowing,pharyngeal pumping,and head swing.KF-8 reversed the actin filament disruption and locomotor dysfunction induced by dexamethasone.Transcriptome sequencing,pathway enrichment,and qRT-PCR analyses revealed that KF-8 regulated the locomotion-related genes W04G5.10,vha-12,and ddr-1,as well as age-1(the catalytic subunit ortholog of phosphatidylinositol 3-kinase(PI3K)),and akt1.RNA interference,conducted using a genetically engineered Escherichia coli HT115 strain as a food source,confirmed age-1 as a key regulator of locomotor function of C.elegans.Further mechanistic studies with C2C12 myotubes showed that KF-8 regulated the IRS-PI3K-Akt pathway,the master regulator of protein synthesis and degradation.Together,these findings suggest that KF-8 protects against dexamethasoneinduced myopathy in C.elegans by regulating locomotion-related genes and the IRS-PI3K-Akt pathway.展开更多
Guangdong’s carbon emissions have surpassed the world’s 11th largest emitter.It is indispensable for this province to find a robust cost-effective strategy for reducing carbon emissions.This study employed the Low E...Guangdong’s carbon emissions have surpassed the world’s 11th largest emitter.It is indispensable for this province to find a robust cost-effective strategy for reducing carbon emissions.This study employed the Low Emissions Analysis Platform model,marginal cost curves,and Monte Carlo methods to simulate the energy consumption,carbon emissions,and economic benefits of emission reduction in Guangdong Province from 2020 to 2030 under the application of various structural optimization policies and energy-saving technologies.The main findings are as follows:In 2030,Guangdong Province is projected to achieve a carbon emission reduction of 273.6 to 304.6million t CO_(2eq),with a total reduction cost ranging from 1030.9 to 1452.2 billion yuan.Increasing the share of renewable energy,which still has significant growth potential,can lead to a 1.4 times greater reduction in carbon emissions compared to the application of energy-saving technologies,despite the latter yielding 2.3 times more energy savings.The emission reduction measures with net-cost can contribute 71.4%to the total carbon reduction of the province,being much larger than those with net benefits.The power sector plays a critical role in carbon emission reduction within Guangdong Province,with its various measures exerting the most substantial impact on emission reduction quantity and cost,contributing cumulative variance contributions of 90.1%and 84.3%,respectively.It has relatively large potential for emission reduction and relatively low cost of structural adjustment.展开更多
Polyethersulfone(PES) is widely used as biomaterials due to its thermal stability,mechanical strength,and chemical inertness.Nevertheless,their blood compatibility is still not adequate for hemodialysis and blood puri...Polyethersulfone(PES) is widely used as biomaterials due to its thermal stability,mechanical strength,and chemical inertness.Nevertheless,their blood compatibility is still not adequate for hemodialysis and blood purification.In this study,the sulfonated polyethersulfone(SPES) was synthesized through an electrophilic substitution reaction,and PES/SPES blending membranes were prepared.The characterization of the SPES was studied by FTIR.The water adsorption and water contact angle experiments show that the hydrophilicity of PES/SPES blend membrane was improved as for the sulfonate group existing in the SPES.Moreover,PES/SPES blend membrane could effectively reduce bovine serum albumin adsorption and prolong the blood coagulation time compared with the PES membrane,thereby improving blood compatibility.展开更多
The super high strength aluminum alloy ingots with 100 mm in diameter were cast by the process of low-frequency electromagnetic horizontal continuous casting (LFEHC) and the effect of electromagnetic field on the as-c...The super high strength aluminum alloy ingots with 100 mm in diameter were cast by the process of low-frequency electromagnetic horizontal continuous casting (LFEHC) and the effect of electromagnetic field on the as-cast microstructure was studied. Results show that microstructure of the sample prepared by the LFEHC process was greatly refined. Microstructures at the border and the center of the ingots were fine, uniform and rosette-shaped. Electromagnetic frequency plays a key role in microstructure refining. Fine and uniform microstructures can be obtained with optimal electromagnetic frequency. In this experiment, under a frequency of 30 Hz the microstructure was the finest and the most uniform.展开更多
The kinetics of heat-facilitated persulfate oxidation of p-chloroaniline（PCA） in aqueous solutions was measured at five different temperature conditions and at four different oxidant concentrations.The PCA degradati...The kinetics of heat-facilitated persulfate oxidation of p-chloroaniline（PCA） in aqueous solutions was measured at five different temperature conditions and at four different oxidant concentrations.The PCA degradation was found to follow a pseudo-first-order decay model when the persulfate was excessive.The pseudo-first-order rate constants of PCA degradation by persulfate（50 mmol/ L） at pH 7.0 are 0.12×10^-4,0.28×10^-4,0.43×10^-4,0.83×10^-4,1.32×10^-4 s^-1 at 10,20,30,40 and 50℃,respectively. Under the above reaction conditions,the reaction has activation energy of 49.97 kJ/mol.The observed rate was found to be function of temperature and oxidant concentration.Raising temperature and increasing persulfate concentration can significantly accelerate the PCA degradation.展开更多
Quasi-columnar structure 7YSZ（yttria stabilized zirconia） thermal barrier coatings（TBCs） are prepared by plasma spray-physical vapor deposition（PS-PVD） onto pretreated and un-pretreated bond coating, respectivel...Quasi-columnar structure 7YSZ（yttria stabilized zirconia） thermal barrier coatings（TBCs） are prepared by plasma spray-physical vapor deposition（PS-PVD） onto pretreated and un-pretreated bond coating, respectively. An isothermal oxidation experiment of 7YSZ TBCs is carried out in the atmosphere of 950 °C in order to simulate the high-temperature oxidation process of engine blades. The isothermal oxidation process of 7YSZ thermal barrier coatings is investigated systematically by impedance spectroscopy. The electrochemical physical model and equivalent circuit of columnar 7YSZ coatings are established. Results show that the isothermal oxidation kinetic curve of columnar 7YSZ thermal barrier coatings appears to follow the parabolic law. A pretreatment of bond coating can reduce the growth rate of the thermally grown oxide（TGO） layer, restraining the initiation and propagation of microcracks between YSZ and TGO layers. The oxidation rate constants of 7YSZ coatings with pretreated and un-pretreated bond coating are 0.101×10^（-12） cm^2·s^（-1） and 0.115 × 10^（-13） cm^2 ·s^（-1）, respectively. Impedance analysis shows that the content of oxygen vacancies decreases and the density increases after the TGO layer is oxidized for 150 h. In addition, shrinkage microcracks formed by sintering during the oxidation process is the main reason for an increase of the capacitance and a decrease of the resistance in the grain boundary of YSZ.展开更多
The toxicity of trace elements （TEs）, such as copper （Cu）, zinc （Zn）, and cadmium （Cd）, often restrict land application of sewage sludge （SS） and there was little information about soil-plant transfer of TEs...The toxicity of trace elements （TEs）, such as copper （Cu）, zinc （Zn）, and cadmium （Cd）, often restrict land application of sewage sludge （SS） and there was little information about soil-plant transfer of TEs in SS from field experiments in China. In this study pot and field experiments were carried out for 2 years to investigate the phytoavailability of TEs in calcareous soils amended with SS. The results of the pot experiment showed that the phytoavailability of Zn and Cu in the SS was equal to 53.4%-80.9% and 54.8%-91.1% of corresponding water-soluble metal salts, respectively. The results from the field experiment showed that the contents of total Zn, Cu, and Cd in the soils increased linearly with SS application rates. With increasing SS application rates, the contents of Zn and Cu in the wheat grains initially increased and then reached a plateau, while there was no significant change of Cd content in the maize grains. The bioconcentration factors of the metals in the grains of wheat and maize were found to he in the order of Zn 〉 Cu 〉 Cd, but for the straw the order was Cd 〉 Cu 〉 Zn. It was also found that wheat grains could accumulate more metals compared with maize grains. The results will be helpful in developing the critical loads of sewage sludge applied to calcareous soils.展开更多
The ecological characteristics and fiber structure of the colored cotton were introduced briefly. The color changing mechanisms of the pigments extracted from colored cottons and some plants were discussed with the re...The ecological characteristics and fiber structure of the colored cotton were introduced briefly. The color changing mechanisms of the pigments extracted from colored cottons and some plants were discussed with the results of different experiments, which could offer an academic reference for the color fixations of the colored cotton textile produces and promote the development of the natural colored cotton industry.展开更多
FgGCN5,a GCN5 homolog in Fusarium graminearum,plays a critical role in hyphal vegetative growth,asexual and sexual reproduction,deoxynivalenol(DON)biosynthesis and plant infection.For nuclear localized GCN5,four conse...FgGCN5,a GCN5 homolog in Fusarium graminearum,plays a critical role in hyphal vegetative growth,asexual and sexual reproduction,deoxynivalenol(DON)biosynthesis and plant infection.For nuclear localized GCN5,four conserved sequence motifs(I-IV)are presented in the catalytic domain and a bromodomain in the carboxy-terminus.As a lysine acetyltransferase,conserved negatively charged residues are present to neutralize the protons from lysine substrates.However,the role of conserved motifs/domains and residues in FgGCN5 are unclear.Here,we generated deletion mutant strains for each the conserved motifs/domains and a glutamate residue 130(E130)replacement mutant.Deletion of each conserved motif in the catalytic domain and replacement of E130 site resulted in manifold defects in hyphae growth,asexual and sexual development,DON biosynthesis,and plant infection.Phenotypic defects in the mutant strains were similar to deletion mutants.The deletion of the bromodomain led a significant reduction in DON production and virulence,with no effects on hyphae growth,asexual or sexual reproduction.FgGCN5 was further found to localize to the nucleus in conidia and hyphae cells.In conclusion,FgGCN5 encodes a nuclear localized acetyltransferase.The conserved motifs in the catalytic domain and E130 are essential for correct functions of the gene.The conserved bromodomain is impotant for DON production and pathogen virulence.This was the first report to identify the functions of conserved motifs/domains in FgGCN5,which will contribute to our understanding of the mechanism(s)by which FgGCN5 regulates F.graminearum.展开更多
In the present work,selective laser melting(SLM)technology was utilized for manufacturing CX stainless steel samples under a series of laser parameters.The effect of laser linear energy density on the microstructure c...In the present work,selective laser melting(SLM)technology was utilized for manufacturing CX stainless steel samples under a series of laser parameters.The effect of laser linear energy density on the microstructure characteristics,phase distribution,crystallographic orientation and mechanical properties of these CX stainless steel samples were investigated theoretically and experimentally via scanning electron microscope(SEM),X-ray diffraction(XRD),electron backscatter diffraction(EBSD)and transmission electron microscope(TEM).Based on the systematic study,the SLM CX stainless steel sample with best surface roughness(Ra=4.05±1.8μm)and relative density(Rd=99.72%±0.22%)under the optimal linear density(η=245 J/m)can be obtained.SLM CX stainless steel was primarily constituted by a large number of fine martensite(α’phase)structures(i.e.,cell structures,cellular dendrites and blocky grains)and a small quantity of austenite(γphase)structures.The pre ferred crystallographic orientation(i.e.,<111>direction)can be determined in the XZ plane of the SLM CX sample.Furthermore,under the optimal linear energy density,the good combinations with the highest ultimate tensile strength(UTS=1068.0%±5.9%)and the best total elongation(TE=15.70%±0.26%)of the SLM CX sample can be attained.Dislocation strengthening dominates the strengthening mechanism of the SLM CX sample in as-built state.展开更多
Highly efficient and sustainable conversion technologies to generate uniform sodalite(Na8(AlSiO4)6(OH)2)zeolite micro spheres with low-grade waste natural diatomite as raw materials via a solution-mediated crystalliza...Highly efficient and sustainable conversion technologies to generate uniform sodalite(Na8(AlSiO4)6(OH)2)zeolite micro spheres with low-grade waste natural diatomite as raw materials via a solution-mediated crystallization route were developed in the present study.The synthesis process can be considered as an in-situ zeolitization of diatomite precursor without involving any me so scale template and any post-synthetic modification.The mass ratios of diatomite and AlCl3·6 H2 O have remarkable effect on the morphology,crystal structure and porosity of sodalite zeolite product.The preferred sodalite microspheres with uniform mesoporous of size 3.5-5.5 nm and large surface area of 162.5 m2/g exhibit well removal performance for heavy metal ions(Pb(II),Cd(II),Zn(II),and Cu(II)),with the highest adsorption abilities for Pb(II)ions of 365 mg/g.In addition,the effect of contact time,initial ion concentration,competitive adsorption and solution pH were evaluated.The removal performance results from synergistic effects of dominating cation-exchange and additional surface chemisorption.The study may broadly help unveil chemical control reactions of the zeolitization processes of diatomite,and thus facilitates the development of promising zeolite materials for the use in natural and engineered aquatic environments by recvcling waste diatomite resources.展开更多
基金supported by the National Natural Science Foundation of China(No.41975156).
文摘Tyrosine residues in proteins can be nitrated to form 3-nitrotyrosine(3-NT)under the influence of ozone(O_(3))and nitrogen dioxide(NO_(2))in the air,which may introduce health impacts.A selective and sensitive enzyme-linked-immunoassay(ELISA)method was developed to determine 3-NT in modified model protein(bovine serum albumin,BSA)and ambient aerosol samples.The nitration degrees(NDs)of BSA in the exposure experiments with different durations were detected by both the ELISA and spectrophotometric methods(i.e.,ND_(ELISA) and ND_(SEC-PDA)),which show good coincidence.The kinetic investigation by both ΔND_(ELISA) and ΔND_(SEC-PDA) in the exposure experiments shows that the rate coefficients(k)of the pseudo-first-order kinetic rate reactions of protein nitration were comparable.These results indicate that direct detection of 3-NT by the ELISA method can be applied for laboratory exposure samples analysis for kinetic studies.Based on the selective detection of 3-NT,ND_(ELISA) provides a promising measure for the assessment of ND in model proteins.3-NT was alsomeasured in PM_(2.5) samples in summer in Guangzhou,southern China,ranging from 10.1 to 404 pg/m^(3),providing clear evidence of protein nitration in ambient aerosols.We further proposed that 3-NT/protein can be used as a proxy to evaluate protein nitration in ambient aerosols.A significant correlationwas observed between 3-NT/protein and O_(3),confirming the crucial role of O_(3) in protein nitration.Our results show that the direct detection of 3-NT by the ELISA method can be more widely applied in the laboratory and field-based studies for understanding the mechanisms of protein nitration.
基金financially supported by the National Natural Science Foundation of China(No.U21A2034)the Guangdong Special Support Plan for Innovation Teams(No.2019BT02L218).
文摘Light exposure can accelerate phase transformation of Schwertmannite(Sch)coexisting with lowmolecular-weight organic acids(LMWOAs),affecting the cycling of Fe in acid mine drainage(AMD).However,it is still unclear how this process relates to the fate of heavy metal contaminants.The study comprehensively reports the significant role and speciation redistribution of Cu(Ⅱ)during the photochemical transformation of a Sch/tartaric acid(TA)system.Based on X-ray diffractometer and Fourier transform infrared spectra results,the presence of TA in simulated AMD significantly promoted photoreductive dissolution and phase transformation of Sch to magnetite(Mt)and goethite(Gt)under anoxic and oxic conditions,respectively.With the addition of 10-30 mg/L Cu(Ⅱ),this transformation of Sch/TA system was significantly inhibited,i.e.,only Gt occurred as product under anoxic conditions and even no phase transformation under oxic conditions.The results of EPR and adsorbed Fe(Ⅱ)indicated that the coexistence of Cu(Ⅱ)suppressed the amount of adsorbed Fe(Ⅱ)available for the transformation of Sch via competitive adsorption with Fe(Ⅱ)and inhibition of ligand-to-metal charge transfer(LMCT)of Sch-TA complexes.Chemical speciation and X-ray photoelectron spectroscopy analysis revealed the proportions of adsorbed and structural Cu(Ⅱ)of Sch/TA system were observably enhanced due to an increase in pH and recrystallization/nucleation growth of newly formed Gt.Under anoxic conditions,62.7%-75.88%of Cu(Ⅱ)was adsorbed on the mineral surface,and during the nucleation and growth of secondary mineral phases,15.49%-17.01%of Cu(Ⅱ)was incorporated into their crystal structure.The changes in distribution of Cu(Ⅱ)further suggested the photochemical transformation of Sch facilitated the sequestration of heavy metals and reduced their bioavailability.These findings enhance the understanding of role and redistribution of Cu(Ⅱ)during the transformation of Sch/LMWOA system in euphotic zone of AMD and provid insights of exploring engineered strategies of AMD remediation.
基金supported by the National Natural Science Foundation of China(Nos.22276060 and 21976059)Guangdong Basic and Applied Basic Research Foundation(No.2024A1515012636)China Scholarship Council Scholarship(No.201906155006)。
文摘The reduction of carbon emissions in the steel industry is a significant challenge,and utilizing CO_(2) from carbon intensive steel industry off-gases for methanol production is a promising strategy for decarbonization.However,steelwork off-gases typically contain various impurities,including H_(2)S,which can deactivate commercial methanol synthesis catalysts,Cu/ZnO/Al_(2)O_(3)(CZA).Reverse water-gas shift(RWGS)reaction is the predominant side reaction in CO_(2) hydrogenation to methanol which can occur at ambient pressure,enabling the decouple of RWGS from methanol production at high pressure.Then,a series of activated CZA catalysts has been in-situ pretreated in 400 ppm H_(2)S/Ar at 250℃and tested for both RWGS reaction at ambient pressure and CO_(2) hydrogenation to methanol at high pressure.An innovative decoupling strategy was employed to isolate the RWGS reaction from the methanol synthesis process,enabling the investigation of the evolution of active site structures and the poisoning mechanism through elemental analysis,X-ray Diffraction,X-ray Photoelectron Spectroscopy,Fourier Transform Infrared Spectroscopy,Temperature Programmed Reduction and CO_(2) Temperature Programmed Desorption.The results indicate that there are different dynamic migration behaviors of ZnO_(x) in the two reaction systems,leading to different poisoning mechanisms.These interesting findings are beneficial to develop sulfur resistant and durable highly efficient catalysts for CO_(2) hydrogenation to methanol,promoting the carbon emission reduction in steel industry.
基金the financial support of the Training Program of the Major Research Plan of the National Natural Science Foundation of China(92061124)the National Natural Science Foundation of China(21975292,21978331,22068008,and 52101186)+3 种基金the Guangdong Basic and Applied Basic Research Foundation(2021A1515010167 and 2022A1515011196)the Guangzhou Key R&D Program/Plan Unveiled Flagship Project(20220602JBGS02)the Guangzhou Basic and Applied Basic Research Project(202201011449)the Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology(FC202220 and FC202216)。
文摘Colloidal synthesis of metal nanoclusters will inevitably lead to the blockage of catalytically active sites by organic ligands.Here,taking[Au_(25)(PET)_(18)]-(PET=2-phenylethanethiol)nanocluster as a model catalyst,this work reports a feasible procedure to achieve the controllably partial removal of thiolate ligands from unsupported[Au_(25)(PET)_(18)]-nanoclusters with the preservation of the core structure.This procedure shortens the processing duration by rapid heating and cooling on the basis of traditional annealing treatment,avoiding the reconfiguration or agglomeration of Au_(25)nanoclusters,where the degree of dethiolation can be regulated by the control of duration.This work finds that a moderate degree of dethiolation can expose the Au active sites while maintaining the suppression of the competing hydrogen evolution reaction.Consequently,the activity and selectivity towards CO formation in electrochemical CO_(2)reduction reaction of Au_(25)nanoclusters can be promoted.This work provides a new approach for the removal of thiolate ligands from atomically precise gold nanoclusters.
基金supported by the National Natural Science Foundation of China(Nos.41975156,41675119)。
文摘Chemical modifications of proteins induced by ambient ozone(O_(3))and nitrogen oxides(NOx)are of public health concerns due to their potential to trigger respiratory diseases.The laboratory and environmental exposure systems have been widely used to investigate their relevant mechanism in the atmosphere.Using bovine serum albumin(BSA)as a model protein,we evaluated the two systems and aimed to reduce the uncertainties of both the reactants and products in the corresponding kinetic study.In the laboratory simulation system,the generated gaseous pollutants showed negligible losses.Ten layers of BSA were coated on the flow tube with protein extraction recovery of 87.4%.For environmental exposure experiment,quartz fiber filter was selected as the upper filter with low gaseous O_(3)(8.0%)and NO_(2)(1.7%)losses,and cellulose acetate filter was appropriate for the lower filter with protein extraction efficiency of 95.2%.The protein degradation process was observed without the exposure to atmospheric oxidants and contributed to the loss of protein monomer mass fractions,while environmental factors(e.g.,molecular oxygen and ultraviolet)may cause greater protein monomer losses.Based on the evaluation,the study exemplarily applied the two systems to protein modification and both showed that O_(3) promotes the protein oligomerization and nitration,while increased temperature can accelerate the oligomerization and increased relative humidity can inhibit the nitration in the environmental exposure samples.The developed laboratory and environmental systems are suitable for studying protein modifications formed under different atmospheric conditions.A combination of the two will further reveal the actual mechanism of protein modifications.
基金support from the National Natural Science Foundation of China(Nos.U21A2034 and 21876052)the Guangdong Special Support Plan for Innovation Teams(No.2019BT02L218)+1 种基金the Guangdong Special Support Plan for Young Top-notch Talents(No.2019TQ05L179)the Natural Science Foundation of Guangdong Province,China(No.2021B1515120077)。
文摘Electrochemical nitrate reduction(NO_(3)RR)offers a promising avenue for treating nitrate-contaminated water and recovering ammonia(NH_(3)),yet the complexities of direct electron transfer(DET)and hydrogen atom transfer(HAT)mechanisms crucial for efficiency remain elusive.This study bridges the gap with a combined experimental and theoretical approach,elucidating the impact of catalyst structure on NO3RR pathways.We discover that catalysts favoring strong NO_(3^(-))adsorption and efficient water dissociation were more inclined towards DET,enhancing denitrification.The Fe@Fe_(3)O_(4)/FF cathode,leveraging the synergistic interplay between metallic Fe and Fe_(3)O_(4),excelled in NO3RR via DET,achieving an NH3yield of 0.28 mmol h-1cm-2and a Faradaic efficiency of 95.7%for NH3at-1.6 V(vs.SCE),with minimal nitrite accumulation at 100 mmol/L nitrate.Conversely,the Fe/FF and Fe_(3)O_(4)/CC cathodes showed reduced NH3production and increased nitrite levels,attributed to the lack of Fe_(3)O_(4)and metallic Fe,respectively,resulting in a dominant HAT mechanism.Moreover,Fe@Fe_(3)O_(4)/FF facilitated complete denitrification in real wastewater treatment by harnessing Cl^(-)for electrochemically mediated breakpoint chlorination.This research not only deepens our understanding of NO3RR mechanisms but also paves the way for designing superior nitrate reduction catalysts.
基金supported by the National Natural Science Foundation of China(Nos.42077337 and 42277228)the Guangdong Basic and Applied Basic Research Foundation(No.2020A1515011560)the Science and Technology Planning Project of Guangzhou(Nos.202002030297 and 202002020072).
文摘Microplastics loaded with phenanthrene and derivatives are widely detected in aquatic environments,and the coating of natural minerals or organic macromolecules may change the environmental behavior of microplastics.In this study,three kinds of composites with different coverage were prepared by coating goethite on the surface of polyvinyl chloride microplastics to investigate the adsorption and desorption behavior of phenanthrene(PHE)and 1-hydroxyphenanthrene(1-OHPHE),and the effect of mucin on desorption was inves-tigated.The results showed that goethite promoted the adsorption of PHE and 1-OHPHE by increasing the specific surface area of the composites.With the increase of the cover de-gree,the adsorption of PHE decreased because of the decrease in hydrophobicity;while the adsorption of 1-OHPHE initially increased and then decreased with the contributions of hydrophobic interaction and hydrogen bond.The adsorption of 1-OHPHE could be influenced by the pH and ionic strength primarily through electrostatic interactions and Ca2+bridg-ing.The goethite significantly increased the desorption hysteresis for two chemicals due to the complicated pore structures and increased adsorption affinity.Mucin promoted the desorption of PHE through competitive adsorption,and inhibit the desorption of 1-OHPHE through hydrophobic interaction,hydrogen bonding and Ca2+bridging.This study elucidated the effects of natural minerals on the adsorption and desorption behavior of organic pollutants on microplastics,briefly discussed the effects of organic macromolecules on the desorption behavior of pollutants with different properties,and emphasized the different environmental behaviors of pollutants.
基金financial support of the National Natural Science Foundation of China(22478450,22478451,22408408)Guangdong Basic and Applied Basic Research Foundation(2024A1515012565,2021A1515010167,2022A1515011196)+3 种基金Guangzhou Key R&D Program/Plan Unveiled Flagship Project(20220602JBGS02)Guangzhou Basic and Applied Basic Research Project(202201011449)Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology(FC202220,FC202216)100 Talent Research Foundation of Sun Yat-sen University(76110-12230029)。
文摘Designing efficient and durable hydrogen evolution reaction(HER)catalysts for seawater electrolysis is crucial for large-scale hydrogen production.Here,we introduce a theory-driven design of metal/WN electrocatalysts,with metal strongly coupled to lattice-matched WN.Theoretical calculations for Pt/WN reveal that W sites enhance H_(2)O adsorption/dissociation,optimizing Pt's H binding.The prepared Pt/WN@CP nanorods can catalyze HER with low overpotentials of 107 and 113 mV at 500 mA cm^(-2)in alkaline water/seawater,respectively,surpassing Pt/C.Extended calculations and experiments show that the optimized Ni/WN@CP-90 achieves an optimal ΔG_(H*)and overpotential of 219 mV at 500 mA cm^(-2)in alkaline seawater,demonstrating the versatility of the WN support to promote HER activity.Notably,the anion exchange membrane water electrolyzer(AEMWE)constructed by Pt/WN@CP or Ni/WN@CP-90 with NiFe-LDH@NF demonstrates outstanding hydrogen production activity with excellent Faraday efficiency(~100%)and durability(120 h),indicating the potential application of WN-supported catalysts for efficient and stable seawater electrolysis.
基金supported by the Postdoctoral Research Project of Henan Province (HN2022004)Zhongyuan Critical Metals Laboratory(GJJSGFYQ202319,GJJSGFYQ202328)+2 种基金Open Fund project of Key Laboratory of Ecological Metallurgy of Multi-Metal Intergrown Ores of Ministry of Education(NEMM2022003)Guangxi Science and Technology Major Project (Guike AA22068078)National Key R&D Program of China (2021YFC2902604)。
文摘Preparing rare earth carbonates from rare earth chlorides is a common step in the smelting process for all rare earth ores;however,it produces large amounts of ammoniacal nitrogen wastewater and a chloriderich precipitate.This study proposes a novel,green and simple process for preparing low-chlorine lanthanum carbonate via a multi-membrane electroconversion approach.The effects of the CO_(2) flow rate,current density,lanthanum chloride concentration,and electroconversion time on the electroconversion process were systematically explored.Under the optimal process conditions(CO_(2) flow rate=0.5 L/min,current density=25 mA/cm^(2),LaCl_(3) concentration=0.3 mol/L,electroconversion time=60 min),a current efficiency of 75.77% was obtained,along with a unit energy consumption of5.44 kWh/kg.X-ray diffraction,Fourier transform infrared spectroscopy,thermogravimetric analysis,and laser particle size analysis results indicate that a pure La_(2)(CO_(3))_(3)·8H_(2)O product is obtained with a median particle size of 6.53 μm and chlorine content of 0.0021%.In addition,scanning electron microscopy and transmission electron microscopy observations indicate that the crystallisation and growth of La_(2)(CO_(3))_(3)·8H_(2)O conform to the oriented attachment and Ostwald ripening mechanisms.Thus,the proposed multi-membrane electroconversion method provides guidance toward the clean transformation of rare earth chlorides to low-chlorine lanthanum carbonates.
基金supported by funding from the National Key Research and Development Program of China(2022YFF1100203)National Natural Science Foundation of China(32372349)+1 种基金Science and Technology Innovation Talent Project of Hunan Province(2022RC3056)Key Research and Development Program of Hunan Province(2024AQ2020)。
文摘Dexamethasone is a common glucocorticoid medication with adverse effects that can cause muscle atrophy,but no drug intervention has been approved or recommended for this condition.KF-8 is a rice bran-derived anti-oxidant peptide that extends the lifespan of Caenorhabditis elegans.We established a C.elegans model of dexamethasone-induced myopathy to evaluate the potential therapeutic effects of KF-8 in this model.C.elegans muscle function was assessed in terms of locomotory behaviors including crawling,swimming,burrowing,pharyngeal pumping,and head swing.Muscle actin filament integrity was evaluated using fluorescence imaging.The molecular mechanisms of KF-8 were investigated using transcriptome sequencing,quantitative real-time PCR(qRT-PCR),RNA interference,and Western blot analysis.Dexamethasone disrupted actin filaments in the striated muscles of the body wall and inhibited C.elegans crawling,swimming,burrowing,pharyngeal pumping,and head swing.KF-8 reversed the actin filament disruption and locomotor dysfunction induced by dexamethasone.Transcriptome sequencing,pathway enrichment,and qRT-PCR analyses revealed that KF-8 regulated the locomotion-related genes W04G5.10,vha-12,and ddr-1,as well as age-1(the catalytic subunit ortholog of phosphatidylinositol 3-kinase(PI3K)),and akt1.RNA interference,conducted using a genetically engineered Escherichia coli HT115 strain as a food source,confirmed age-1 as a key regulator of locomotor function of C.elegans.Further mechanistic studies with C2C12 myotubes showed that KF-8 regulated the IRS-PI3K-Akt pathway,the master regulator of protein synthesis and degradation.Together,these findings suggest that KF-8 protects against dexamethasoneinduced myopathy in C.elegans by regulating locomotion-related genes and the IRS-PI3K-Akt pathway.
基金supported by Hainan Provincial Natural Science Foundation of China(No.721RC525).
文摘Guangdong’s carbon emissions have surpassed the world’s 11th largest emitter.It is indispensable for this province to find a robust cost-effective strategy for reducing carbon emissions.This study employed the Low Emissions Analysis Platform model,marginal cost curves,and Monte Carlo methods to simulate the energy consumption,carbon emissions,and economic benefits of emission reduction in Guangdong Province from 2020 to 2030 under the application of various structural optimization policies and energy-saving technologies.The main findings are as follows:In 2030,Guangdong Province is projected to achieve a carbon emission reduction of 273.6 to 304.6million t CO_(2eq),with a total reduction cost ranging from 1030.9 to 1452.2 billion yuan.Increasing the share of renewable energy,which still has significant growth potential,can lead to a 1.4 times greater reduction in carbon emissions compared to the application of energy-saving technologies,despite the latter yielding 2.3 times more energy savings.The emission reduction measures with net-cost can contribute 71.4%to the total carbon reduction of the province,being much larger than those with net benefits.The power sector plays a critical role in carbon emission reduction within Guangdong Province,with its various measures exerting the most substantial impact on emission reduction quantity and cost,contributing cumulative variance contributions of 90.1%and 84.3%,respectively.It has relatively large potential for emission reduction and relatively low cost of structural adjustment.
基金Supported by the Special Fund for International Cooperation Projects of China (2005DFA50160)
文摘Polyethersulfone(PES) is widely used as biomaterials due to its thermal stability,mechanical strength,and chemical inertness.Nevertheless,their blood compatibility is still not adequate for hemodialysis and blood purification.In this study,the sulfonated polyethersulfone(SPES) was synthesized through an electrophilic substitution reaction,and PES/SPES blending membranes were prepared.The characterization of the SPES was studied by FTIR.The water adsorption and water contact angle experiments show that the hydrophilicity of PES/SPES blend membrane was improved as for the sulfonate group existing in the SPES.Moreover,PES/SPES blend membrane could effectively reduce bovine serum albumin adsorption and prolong the blood coagulation time compared with the PES membrane,thereby improving blood compatibility.
基金National "863" project (NO.2001AA332030) of China
文摘The super high strength aluminum alloy ingots with 100 mm in diameter were cast by the process of low-frequency electromagnetic horizontal continuous casting (LFEHC) and the effect of electromagnetic field on the as-cast microstructure was studied. Results show that microstructure of the sample prepared by the LFEHC process was greatly refined. Microstructures at the border and the center of the ingots were fine, uniform and rosette-shaped. Electromagnetic frequency plays a key role in microstructure refining. Fine and uniform microstructures can be obtained with optimal electromagnetic frequency. In this experiment, under a frequency of 30 Hz the microstructure was the finest and the most uniform.
基金supported financially by the Foundation of Science and Technology Planning Project of Guangdong Province(No2007A020100001-13)the Key Laboratory of Environmental Protection and Eco-Remediation of Guangdong Higher Education Institutions(China)
文摘The kinetics of heat-facilitated persulfate oxidation of p-chloroaniline（PCA） in aqueous solutions was measured at five different temperature conditions and at four different oxidant concentrations.The PCA degradation was found to follow a pseudo-first-order decay model when the persulfate was excessive.The pseudo-first-order rate constants of PCA degradation by persulfate（50 mmol/ L） at pH 7.0 are 0.12×10^-4,0.28×10^-4,0.43×10^-4,0.83×10^-4,1.32×10^-4 s^-1 at 10,20,30,40 and 50℃,respectively. Under the above reaction conditions,the reaction has activation energy of 49.97 kJ/mol.The observed rate was found to be function of temperature and oxidant concentration.Raising temperature and increasing persulfate concentration can significantly accelerate the PCA degradation.
基金financial supports from National Key Research Program (No. 2017YFB0306100)Guangdong Academy of Sciences (No. 2017GDASCX-0843)+3 种基金Guang-dong Technical Research Program (No’s. 201707010385, 2014B070706026, and 2013B061800053)Guangdong Natural Science Foundation (No. 2016A030312015)National Natural Science Foundation of China (No. 51501044)Guangzhou Technical Research Program (No. 201707010385)
文摘Quasi-columnar structure 7YSZ（yttria stabilized zirconia） thermal barrier coatings（TBCs） are prepared by plasma spray-physical vapor deposition（PS-PVD） onto pretreated and un-pretreated bond coating, respectively. An isothermal oxidation experiment of 7YSZ TBCs is carried out in the atmosphere of 950 °C in order to simulate the high-temperature oxidation process of engine blades. The isothermal oxidation process of 7YSZ thermal barrier coatings is investigated systematically by impedance spectroscopy. The electrochemical physical model and equivalent circuit of columnar 7YSZ coatings are established. Results show that the isothermal oxidation kinetic curve of columnar 7YSZ thermal barrier coatings appears to follow the parabolic law. A pretreatment of bond coating can reduce the growth rate of the thermally grown oxide（TGO） layer, restraining the initiation and propagation of microcracks between YSZ and TGO layers. The oxidation rate constants of 7YSZ coatings with pretreated and un-pretreated bond coating are 0.101×10^（-12） cm^2·s^（-1） and 0.115 × 10^（-13） cm^2 ·s^（-1）, respectively. Impedance analysis shows that the content of oxygen vacancies decreases and the density increases after the TGO layer is oxidized for 150 h. In addition, shrinkage microcracks formed by sintering during the oxidation process is the main reason for an increase of the capacitance and a decrease of the resistance in the grain boundary of YSZ.
基金Supported by the Beijing Drainage Group Co. Ltd. and the Special Fund for Agro-Scientific Research in the Public Interest of China (No. 200903015)
文摘The toxicity of trace elements （TEs）, such as copper （Cu）, zinc （Zn）, and cadmium （Cd）, often restrict land application of sewage sludge （SS） and there was little information about soil-plant transfer of TEs in SS from field experiments in China. In this study pot and field experiments were carried out for 2 years to investigate the phytoavailability of TEs in calcareous soils amended with SS. The results of the pot experiment showed that the phytoavailability of Zn and Cu in the SS was equal to 53.4%-80.9% and 54.8%-91.1% of corresponding water-soluble metal salts, respectively. The results from the field experiment showed that the contents of total Zn, Cu, and Cd in the soils increased linearly with SS application rates. With increasing SS application rates, the contents of Zn and Cu in the wheat grains initially increased and then reached a plateau, while there was no significant change of Cd content in the maize grains. The bioconcentration factors of the metals in the grains of wheat and maize were found to he in the order of Zn 〉 Cu 〉 Cd, but for the straw the order was Cd 〉 Cu 〉 Zn. It was also found that wheat grains could accumulate more metals compared with maize grains. The results will be helpful in developing the critical loads of sewage sludge applied to calcareous soils.
文摘The ecological characteristics and fiber structure of the colored cotton were introduced briefly. The color changing mechanisms of the pigments extracted from colored cottons and some plants were discussed with the results of different experiments, which could offer an academic reference for the color fixations of the colored cotton textile produces and promote the development of the natural colored cotton industry.
基金Supported by the open project of the State Key Laboratory of Crop Stress Biology for Arid Areas,Northwest A&F University,China(CSBAA2016001).
文摘FgGCN5,a GCN5 homolog in Fusarium graminearum,plays a critical role in hyphal vegetative growth,asexual and sexual reproduction,deoxynivalenol(DON)biosynthesis and plant infection.For nuclear localized GCN5,four conserved sequence motifs(I-IV)are presented in the catalytic domain and a bromodomain in the carboxy-terminus.As a lysine acetyltransferase,conserved negatively charged residues are present to neutralize the protons from lysine substrates.However,the role of conserved motifs/domains and residues in FgGCN5 are unclear.Here,we generated deletion mutant strains for each the conserved motifs/domains and a glutamate residue 130(E130)replacement mutant.Deletion of each conserved motif in the catalytic domain and replacement of E130 site resulted in manifold defects in hyphae growth,asexual and sexual development,DON biosynthesis,and plant infection.Phenotypic defects in the mutant strains were similar to deletion mutants.The deletion of the bromodomain led a significant reduction in DON production and virulence,with no effects on hyphae growth,asexual or sexual reproduction.FgGCN5 was further found to localize to the nucleus in conidia and hyphae cells.In conclusion,FgGCN5 encodes a nuclear localized acetyltransferase.The conserved motifs in the catalytic domain and E130 are essential for correct functions of the gene.The conserved bromodomain is impotant for DON production and pathogen virulence.This was the first report to identify the functions of conserved motifs/domains in FgGCN5,which will contribute to our understanding of the mechanism(s)by which FgGCN5 regulates F.graminearum.
基金supported financially by the Sciences Platform Environment and Capacity Building Projects of GDAS(No.2019GDASYL-0502006)the Key R&D Program of Guangdong Province(No.2020B090923002)+3 种基金the Guangdong Academy of Science Projects(No.2021GDASYL-20210102005)the Guangdong Province Science and Technology Plan Projects(No.2020A1515011096)the Guangzhou Project of Science&Technology(Nos.202007020008 and 201807010030)the support from the Program of CSC(No.201801810106)。
文摘In the present work,selective laser melting(SLM)technology was utilized for manufacturing CX stainless steel samples under a series of laser parameters.The effect of laser linear energy density on the microstructure characteristics,phase distribution,crystallographic orientation and mechanical properties of these CX stainless steel samples were investigated theoretically and experimentally via scanning electron microscope(SEM),X-ray diffraction(XRD),electron backscatter diffraction(EBSD)and transmission electron microscope(TEM).Based on the systematic study,the SLM CX stainless steel sample with best surface roughness(Ra=4.05±1.8μm)and relative density(Rd=99.72%±0.22%)under the optimal linear density(η=245 J/m)can be obtained.SLM CX stainless steel was primarily constituted by a large number of fine martensite(α’phase)structures(i.e.,cell structures,cellular dendrites and blocky grains)and a small quantity of austenite(γphase)structures.The pre ferred crystallographic orientation(i.e.,<111>direction)can be determined in the XZ plane of the SLM CX sample.Furthermore,under the optimal linear energy density,the good combinations with the highest ultimate tensile strength(UTS=1068.0%±5.9%)and the best total elongation(TE=15.70%±0.26%)of the SLM CX sample can be attained.Dislocation strengthening dominates the strengthening mechanism of the SLM CX sample in as-built state.
基金supported by the National Key R&D Program of China(No.2017YFB0310804)the Scientific and Technological Developing Scheme of Jilin Province(No.20190303119SF)+1 种基金the National Natural Science Foundation of China(No.51974011)the Key R&D Program of Ningxia Hui Autonomous Region(No.2019BFG02032)
文摘Highly efficient and sustainable conversion technologies to generate uniform sodalite(Na8(AlSiO4)6(OH)2)zeolite micro spheres with low-grade waste natural diatomite as raw materials via a solution-mediated crystallization route were developed in the present study.The synthesis process can be considered as an in-situ zeolitization of diatomite precursor without involving any me so scale template and any post-synthetic modification.The mass ratios of diatomite and AlCl3·6 H2 O have remarkable effect on the morphology,crystal structure and porosity of sodalite zeolite product.The preferred sodalite microspheres with uniform mesoporous of size 3.5-5.5 nm and large surface area of 162.5 m2/g exhibit well removal performance for heavy metal ions(Pb(II),Cd(II),Zn(II),and Cu(II)),with the highest adsorption abilities for Pb(II)ions of 365 mg/g.In addition,the effect of contact time,initial ion concentration,competitive adsorption and solution pH were evaluated.The removal performance results from synergistic effects of dominating cation-exchange and additional surface chemisorption.The study may broadly help unveil chemical control reactions of the zeolitization processes of diatomite,and thus facilitates the development of promising zeolite materials for the use in natural and engineered aquatic environments by recvcling waste diatomite resources.
