A new adsorbent was successfully prepared by hydrothermal treatment and chemical activation through coal gasification fine slag(CGFS)and blue algae(BA)as raw materials and used for CO_(2)capture.The CO_(2)chemisorptio...A new adsorbent was successfully prepared by hydrothermal treatment and chemical activation through coal gasification fine slag(CGFS)and blue algae(BA)as raw materials and used for CO_(2)capture.The CO_(2)chemisorption capacity of the adsorbent was further enhanced by taking advantage of the nitrogenous bases contained in the BA.In the hydrothermal process,the addition of BA significantly increased the content of pyrrole nitrogen in the adsorbent.In the activation process,pyrrole nitrogen gradually changed into pyridine nitrogen and graphite nitrogen.Increased BA addition result in a higher specific surface area and microporosity of the adsorbent.The CO_(2)adsorption performance test proved that the CGFS-50%-CA sample has the strongest CO_(2)adsorption capacity at low temperature,up to 15.59 cm^(3)/g,which is mainly through physical adsorption,and the CGFS-10%-CA sample has the strongest CO_(2)adsorption capacity at high temperature,up to 7.31 cm^(3)/g,which is mainly through chemical adsorption.CO_(2)uptake of the CGFS-10%-CA sample was well maintained after 10 cycles,with regeneration efficiencies above 99%.The results indicate that the novel adsorbents with coexistence of physical and chemical adsorption have great potential for CO_(2)adsorption applications.展开更多
Nitrogen-containing organic compounds(NOCs)may potentially contribute to aqueous secondary organic aerosols,yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear.With the in-situ ...Nitrogen-containing organic compounds(NOCs)may potentially contribute to aqueous secondary organic aerosols,yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear.With the in-situ measurements performed at a mountain site(1690 m a.s.l.)in southern China,we investigated the formation of NOCs in the cloud droplets and the cloud-free particles,based on their mixing state information of NOCscontaining particles by single particle mass spectrometry.The relative abundance of NOCs in the cloud-free particles was significantly higher than those in cloud residual(cloud RES)particles.NOCs were highly correlated with carbonyl compounds(including glyoxalate and methylglyoxal)in the cloud-free particles,however,limited correlation was observed for cloud RES particles.Analysis of their mixing state and temporal variations highlights that NOCs was mainly formed from the carbonyl compounds and ammonium in the cloud-free particles,rather than in the cloud RES particles.The results support that the formation of NOCs from carbonyl compounds is facilitated in concentrated solutions in wet aerosols,rather than cloud droplets.In addition,we have identified the transport of biomass burning particles that facilitate the formation of NOCs,and that the observed NOCs is most likely contributed to the light absorption.These findings have implications for the evaluation of NOCs formation and their contribution to light absorption.展开更多
Covalent organic frameworks(COFs)are crystalline porous polymeric materials composed of organic monomers connected by strong covalent bonds and offer high stability,good crystallinity,a large specific surface area,and...Covalent organic frameworks(COFs)are crystalline porous polymeric materials composed of organic monomers connected by strong covalent bonds and offer high stability,good crystallinity,a large specific surface area,and controllable structures.COFs are widely used in the fields of adsorption and separation,catalysis,photovoltaics,and drug-delivery.The structural regulation and performance optimization of COFs can be realized through the modification of ligands and the selection of linkage methods.In which,the types of linkage are closely related to the stability and performance of COFs.In this review,nitrogencontaining linkage-bonds(NCLBs)in COFs are divided into N-containing double bonds,N-containing conjugated rings and N-containing unconjugated rings.The association between structure and performance of COFs is elaborated and the synthesis methods of COFs are systematically summarized.Moreover,the structural design,theoretical prediction and machinable application of COFs are prospected.展开更多
The influence of nitrogen-containing polycyclic aromatic hydrocarbons(NC-PAH)on the formation of carbonaceous mesophase remains enigmatic,despite extensive research on the production of carbonaceous materials from aro...The influence of nitrogen-containing polycyclic aromatic hydrocarbons(NC-PAH)on the formation of carbonaceous mesophase remains enigmatic,despite extensive research on the production of carbonaceous materials from aromatic-rich oils.Molecular dynamics simulation was used to investigate the variations in pyrolysis behavior between PAH and NC-PAH based on the composition analysis.Through adjusting the content of NC-PAH,the influence of NC-PAH on the thermal stability of slurry oils(SOs)was evaluated by thermogravimetry,viscosity,coke value,and quinoline insoluble(QI).The morphology and structure of mesocarbon microbeads(MCMBs)prepared with SOs were measured by a polarized-light microscope,SEM,XRD,and Raman.Simulation results indicate that NC-PAH possesses much higher reactivity and tends to produce highly condensed solid and coke products.It corresponds to the QI and high viscosity in thermal stability experiments.Therefore,high concentrations of NC-PAH result in nonuniform morphology and disordered structures.In a system with low viscosity and few QIs,SO,which has a low nitrogen content(475 ppm),reacts gently to produce MCMBs with a uniform particle size(10-40μm)and an excellent spherical shape.As NC-PAH content decreases,the crystalline size of graphitization elevates,as evidenced by parallel layers(10.472-11.764)and stack height(3.269-3.701 nm).The graphitization degree becomes worse and nonuniform with the increase of the content of NC-PAH,and the best is 20.58%evaluated by Raman spectra area ratio(AG/Aall).Overall,this work suggests a nitrogen content reference and a controlling technology of nitrogen for the preparation of superior MCMB.展开更多
Current evidence for oligodendrocyte precursor cell involvement in Parkinson’s disease:Oligodendroglial cells comprise a large cell population in the substantia nigra(SN).We recently reported a stable portion of olig...Current evidence for oligodendrocyte precursor cell involvement in Parkinson’s disease:Oligodendroglial cells comprise a large cell population in the substantia nigra(SN).We recently reported a stable portion of oligodendrocyte precursor cells(OPCs)in the SN pars compacta(SNpc)in a 1:1 ratio with dopaminergic neurons:15%of cells in neonate and young mice,rising to 20%in aged mice.Moreover,this portion represents only 45%of all oligodendroglial cells in the SNpc and 54%of all oligodendroglial cells in the SN pars reticulata(SNpr)(Fitzgerald et al.,2025).The SN is a deeply located area of the midbrain and the site of dopaminergic degeneration in Parkinson’s disease(PD).Recent advancement of single-cell transcriptomics revealed the involvement of non-neuronal cells in PD,with PD risk variants being strongly associated with oligodendroglia(reviewed by Salazar Campos et al.,2025).展开更多
Oligodendrocyte precursor cells(OPCs)tile the central nervous system ubiquitously,accounting for about 5%of the total cell population in the central nervous system.Beyond their role in myelination,OPCs actively shape ...Oligodendrocyte precursor cells(OPCs)tile the central nervous system ubiquitously,accounting for about 5%of the total cell population in the central nervous system.Beyond their role in myelination,OPCs actively shape neural circuits(Fang and Bai,2023),by releasing neuromodulators,pruning synapses,maintaining the homeostasis of extracellular potassium concentration,and interacting with endothelial cells.展开更多
The recycling of waste activated carbon is of great significance in environmental protection.Porous mullite ceramics were prepared by impregnating the mullite precursor with activated carbon,adding a pore-forming agen...The recycling of waste activated carbon is of great significance in environmental protection.Porous mullite ceramics were prepared by impregnating the mullite precursor with activated carbon,adding a pore-forming agent,and adopting aluminum sulfate octahydrate,ammonia and silica micropowder as raw materials,waste activated carbon after heat treatment as the pore-forming agent,and sodium polyacrylate(PAAS)as the dispersant.The effects of the activated carbon additions(1.5%,3.0%,5.2%,and 7.8%,by mass)and PAAS additions(1%,2%,and 3%,extra adding,by mass)on the physical properties,phase composition and microstructure of the porous ceramics were studied.The results show that:(1)as a pore-forming agent,activated carbon promotes the formation of pores inside the samples,while the apparent porosity of the samples increases significantly with the increasing activated carbon addition;when the activated carbon addition is 7.8%,the apparent porosity of the sample is 65.7%,the cold compressive strength is 4.62 MPa,the peak pore size is around 3.5μm,and the pore size distribution is uniform;(2)appropriate PAAS helps to improve the dispersion of activated carbon in the samples and the comprehensive performance of the porous mullite ceramics;when the PAAS addition is 2%,the apparent porosity of the sample is 71.8%,the cold compressive strength is 5.53 MPa,the peak pore size is around 3μm,and the pore size distribution is optimized;however,excessive PAAS increases the liquid phase in the system,resulting in over sintering of mullite and a decrease in the porosity.展开更多
Investigating the damage evolution of surrounding rock under thermal shock cycles is crucial for ensuring the stability of engineering rock masses.This study performed Brazilian splitting tests on granite specimens un...Investigating the damage evolution of surrounding rock under thermal shock cycles is crucial for ensuring the stability of engineering rock masses.This study performed Brazilian splitting tests on granite specimens under varying temperature and cycle conditions,employing acoustic emission monitoring,digital image correlation,and three-dimensional scanning technology.A systematic analysis was conducted on the patterns of damage evolution,failure precursor,and response mechanisms under combined thermal and cyclic loading.Experimental results show that both P-wave velocity and tensile strength degrade significantly with increasing temperature and cycle count,with temperature having a more pronounced effect than cycle count.Notably,damage evolution exhibits a dual-threshold behavior in which degradation accelerates markedly above 400℃ and stabilizes after 5 thermal cycles.Fracture surfaces evolve from initially planar to rugged morphologies,with peak-valley height differences at 600℃ being approximately three times greater than those at 200℃.Furthermore,based on acoustic emission energy entropy analysis,we introduce a novel failure precursor indicator where the sustained increase and critical surge in average entropy serve as reliable early-warning signals for impending rock failure.These findings establish a solid theoretical basis and practical methodology for damage assessment and instability early-warning systems in high-temperature rock engineering.展开更多
Ceramic 4D printing,which integrates dynamic deformation with additive manufacturing,demonstrates significant potential in intelligent manufacturing,on-demand shaping of complex structures,and multifunctional device d...Ceramic 4D printing,which integrates dynamic deformation with additive manufacturing,demonstrates significant potential in intelligent manufacturing,on-demand shaping of complex structures,and multifunctional device development.Its core advantage lies in endowing materials with environmentally responsive dynamic deformation capabilities.However,current technologies still face limitations in responsiveness,reversibility,and mechanical performance.To address these challenges,this study proposes a programmable ceramic precursor system based on synergistic reinforcement of phase-separating hydrogels and shape memory polymers,combined with a nano-ceramic particle enhancement strategy.Using stereolithography 3D printing,high-precision fabrication of complex structures was achieved.By adjusting precursor composition,programming time,and structural thickness,the phase-separation kinetics-driven delayed recovery mechanism was elucidated,enabling precise control over recovery onset time.Furthermore,the thermal response mechanism of the precursor materials is explored,along with their potential for multi-shape transformation in biomedical applications,which is further extended to shape memory polymer systems.By employing a layered printing strategy,the autonomous reversible deformation of ceramic precursors is realized,providing new possibilities for specific applications.展开更多
0 INTRODUCTION Due to the sudden and highly destructive nature of slope rock collapse,developing effective early warning systems has become an urgent challenge in geotechnical engineering(Cai and Detournay,2024;Loew e...0 INTRODUCTION Due to the sudden and highly destructive nature of slope rock collapse,developing effective early warning systems has become an urgent challenge in geotechnical engineering(Cai and Detournay,2024;Loew et al.,2017).Traditional monitoring methods primarily target the acceleration stage preceding disasters(such as displacement monitoring for landslides and debris flows),which is effective for early warning of plastic collapse disasters but often inadequate for brittle failure modes(Walter et al.,2019;Chao et al.,2018;Crosta et al.,2017).展开更多
This study systematically investigates the cyclization reaction mechanisms between n-C_(4)H_(3)(1-buten-3-yn-1-yl)and i-C_(4)H_(3)(2-buten-3-yn-1-yl)radicals with acetylene(C_(2)H_(2))using density functional theory(D...This study systematically investigates the cyclization reaction mechanisms between n-C_(4)H_(3)(1-buten-3-yn-1-yl)and i-C_(4)H_(3)(2-buten-3-yn-1-yl)radicals with acetylene(C_(2)H_(2))using density functional theory(DFT)and transition state theory(TST).The results reveal that the reaction of n-C_(4)H_(3)with acetylene proceeds via a radical chain mechanism through an additioncyclization pathway,yielding phenyl(sixmembered ring),fulvenyl(five-membered ring),and four-membered ring intermediates.The product formation rates follow the order:fulvenyl(five-membered ring)>phenyl(six-membered ring)>four-membered ring.For i-C_(4)H_(3),the intermediate structures depend on the carbon position of i-C_(4)H_(3)where acetylene addition occurs:addition at the C2 position predominantly generates fulvenyl(five-membered ring)as the primary product,whereas addition at the C4 position may lead to phenyl(six-membered ring),fulvenyl(five-membered ring),or four-membered ring intermediates,with the four-membered ring forming most rapidly and the six-membered ring the slowest.Theoretical analyses demonstrate that the selectivity of reaction pathways is primarily governed by structural differences between the isomers.This work provides atomic-scale insights into the cyclization processes between acetylene and C_(4)H_(3)species,establishing a foundation for refining models of soot precursor formation.展开更多
Many nitrogen-containing aromatic compounds （NACs）, such as nitrobenzene （NB）, 4-nitrophenol （4-NP）, aniline （AN）, and 2,4-dinitrophenol （2,4-DNP）, are environmentally hazardous, and their removal from conta...Many nitrogen-containing aromatic compounds （NACs）, such as nitrobenzene （NB）, 4-nitrophenol （4-NP）, aniline （AN）, and 2,4-dinitrophenol （2,4-DNP）, are environmentally hazardous, and their removal from contaminated water is one of the main challenges facing wastewater treatment plants. In this study, synthetic wastewater containing NB, 4-NP, 2,4-DNP, and AN at concentrations ranging from 50 to 180 mg/L was fed into a sequencing batch reactor （SBR）. Analyses of the SBR system indicated that it simultaneously removed more than 99% of the NACs at loading rates of 0.36 kg NB/（m^3·d）, 0.3 kg 4-NP/（m^3·d）, 0.25 kg AN/（m^3·d）, and 0.1 kg 2,4-DNP/（m^3·d）. Bacterial groups of Bacteriodetes, Candidate division TM7, α-Proteobacteria, and β-Proteobacteria were dominant in the clone libraries of 16S rRNA genes retrieved from the microbial communities in the SBR system. ＂Cycle tests＂ designed to alter feeding and aeration parameters of the SBR system demonstrated that the resident microbial biome of the SBR system responded rapidly to changing conditions. Consumption of O2 was concomitant with the apparent mineralization of NACs. Aromatic ring-cleaving dioxygenase activities suggested that （1） AN and NB were degraded via catechol 2,3-dioxygenase; （2） 4-NP was degraded via 1,2,4-benzentriol 1,2-dioxygenase; and （3） 2,4-DNP was degraded via an unresolved pathway.展开更多
Soluble portions(SPs) 1-4(SP1-SP4) were afforded from sequentially dissolution and alkanolyses of Baiyinhua lignite(BL) in cyclohexane,CH3OH,CH3CH2OH,and(CH3)2CHOH at 300℃.They were analyzed with a gas chromatograph/...Soluble portions(SPs) 1-4(SP1-SP4) were afforded from sequentially dissolution and alkanolyses of Baiyinhua lignite(BL) in cyclohexane,CH3OH,CH3CH2OH,and(CH3)2CHOH at 300℃.They were analyzed with a gas chromatograph/mass spectrometer and quadrupole exactive orbitrap mass spectrometer(QEOTMS) with an atmosphere pressure chemical ionization source in positive-ion mode,while BL was characterized with an X-ray photoelectron spectrometer(XRPES).The results show that the yields of SP2 and SP3 are much higher than those of SP1 and SP4,and the total SP yield is ca.39.0%.According to the analysis with XRPES,pyrrolic nitrogen atoms are the most abundant nitrogen existing forms in BL.Thousands of nitrogen-containing aromatics(NCAs) were resolved with QEOTMS and their molecular masses are mainly in the range of 200-450 u.The main NCAs are N1O1 and N1O2 class species with double bond equivalent values of 4-18 and carbon numbers of 7-30.The nitrogen atoms appear in pyridine s,quinolines,benzoquinolines or acridine,and dibenzoquinolines or naphthoquinolines,while the oxygen atoms exist in methoxy and furan rings.展开更多
Nitrogen-containing organic pollutants(quinoline,pyridine and indole)are widely distributed in coking wastewater,and bioaugmentation with specific microorganisms may enhance the removal of these recalcitrant pollutant...Nitrogen-containing organic pollutants(quinoline,pyridine and indole)are widely distributed in coking wastewater,and bioaugmentation with specific microorganisms may enhance the removal of these recalcitrant pollutants.The bioaugmented system(group B)was constructed through inoculation of two aromatics-degrading bacteria,Comamonas sp.Z1(quinoline degrader)and Acinetobacter sp.JW(indole degrader),into the activated sludge for treatment of quinoline,indole and pyridine,and the non-bioaugmented activated sludge was used as the control(group C).Both groups maintained high efficiencies(>94%)for removal of nitrogen-containing organic pollutants and chemical oxygen demand(COD)during the long-term operation,and group B was highly effective at the starting period and the operation stage fed with raw wastewater.High-throughput sequencing analysis indicated that nitrogen-containing organic pollutants could shape the microbial community structure,and communities of bioaugmented group B were clearly separated from those of non-bioaugmented group C as observed in non-metric multidimensional scaling(NMDS)plot.Although the inoculants did not remain their dominance in group B,bioaugmentation could induce the formation of effective microbial community,and the indigenous microbes might play the key role in removal of nitrogen-containing organic pollutants,including Dokdonella,Comamonas and Pseudoxanthomonas.Phylogenetic Investigation of Communities by Reconstruction of Unobserved States(PICRUSt)analysis suggested that bioaugmentation could facilitate the enrichment of functional genes related to xenobiotics biodegradation and metabolism,probably leading to the improved performance in group B.This study indicated that bioaugmentation could promote the removal of nitrogen-containing organic pollutants,which should be an effective strategy for wastewater treatment.展开更多
The adsorptive denitrogenation from fuels over three metal-organic frameworks(MIL-96(Al),MIL-53(Al)and MIL-101(Cr))was studied by batch adsorption experiments.Four nitrogen-containing compounds(NCCs)pyridine,pyrrole,q...The adsorptive denitrogenation from fuels over three metal-organic frameworks(MIL-96(Al),MIL-53(Al)and MIL-101(Cr))was studied by batch adsorption experiments.Four nitrogen-containing compounds(NCCs)pyridine,pyrrole,quinoline and indole were used as model NCCs in fuels to study the adsorption mechanism.The physicochemical properties of the adsorbents were characterized by XRD,N2physical adsorption,FT-IR spectrum and Hammett indicator method.The metal-organic frameworks(MOFs),especially the MIL-101(Cr)containing Lewis acid sites as well as high specific surface area,can adsorb large quantities of NCCs from fuels.In addition,the adsorptive capacity over MIL-101(Cr)will be different for NCCs with different basicity.The stronger basicity of the NCC is,the more it can be absorbed over MIL-101(Cr).Furthermore,pore size and shape also affect the adsorption capacity for a given adsorbate,which can be proved by the adsorption over MIL-53(Al)and MIL-96(Al).The pseudo-second-order kinetic model and Langmuir equation can be used to describe kinetics and thermodynamics of the adsorption process,respectively.Finally,the regeneration of the used adsorbent has been conducted successfully by just washing it with ethanol.展开更多
Stress corrosion cracking （SCC） of stainless steels and Ni-based alloys in high temperature water coolant is one of the key problems affecting the safe operation of nuclear power plants （NPPs）. The nitrogen-added ...Stress corrosion cracking （SCC） of stainless steels and Ni-based alloys in high temperature water coolant is one of the key problems affecting the safe operation of nuclear power plants （NPPs）. The nitrogen-added stainless steel is a kind of possible candidate materials for mitigating SCC since reducing the carbon content and adding nitrogen to offset the loss in strength caused by the decrease in carbon content can mitigate the problem of sensitization. However, the reports of SCC of nitrogen-added stainless steels in high temperature water are few available. The effects of applied potential and sensitization treatment on the SCC of a newly developed nitrogen-containing stainless steel （SS） 316LN in high temperature water doped with chloride at 250 ℃ were studied by using slow strain rate tests （SSRTs）. The SSRT results are compared with our data previously published for 316 SS without nitrogen and 304NG SS with nitrogen, and the possible mechanism affecting the SCC behaviors of the studied steels is also discussed based on SSRT and microstucture analysis results. The susceptibility to cracking of 316LN SS normally increases with increasing potential. The susceptibility to SCC of 316LN SS was less than that of 316 SS and 304NG SS. Sensitization treatment at 700℃ for 30 h showed little effect on the S CC of 316LN S S and significant effect on the S CC of 316 S S. The predominant cracking mode for the 316LN S S in both annealed state and the state after the sensitization treatment was transgranular. The presented conditions of mitigating stress corrosion cracking are some useful information for the safe use of 316LN SS in NPPs.展开更多
A new nitrogen-containing epoxy resin (XT resin) was synthesized from chain extension of xylenephenolformaldehyde resin (XPF) and triglycidyl isocyanurate (TGIC) in the presence of base catalyst. FT-IR and H-NMR ana...A new nitrogen-containing epoxy resin (XT resin) was synthesized from chain extension of xylenephenolformaldehyde resin (XPF) and triglycidyl isocyanurate (TGIC) in the presence of base catalyst. FT-IR and H-NMR analysis confirmed the chemical structure of XT resin. It was 1 cured with dicyandiamide (DICY) and diaminodiphenyl sulfone (DDS). Dynamic mechanical analysis (DMA) results showed that the introduction of triazine ring provides epoxy polymer with good thermal stability. Furthermore, high char yields at 800℃ in thermogravimetric (TGA) analysis indicated that XT resin had potential flame retardance.展开更多
We synthesized a series of hydrazones,a novel type of nitrogen-containing prostaglandins,from different aromatic hydrazines and variant 2-substituted amino-3-hydroxy bicycle[3.2.0]hept-6-ones IV.
The DFT-based （density fimctional theory） ab initio quantum mechanical methods have been applied to study the basicity of the nitrogen-containing compounds in petroleum. The results have indicated that there is a di...The DFT-based （density fimctional theory） ab initio quantum mechanical methods have been applied to study the basicity of the nitrogen-containing compounds in petroleum. The results have indicated that there is a distinct relationship between the protonation energy of nitrogen-containing compounds and their basicity. The more negative the protonation energy, the stronger the basicity is. It has been also found that aliphatic amines are more basic than pyridines or aromatic amines, and all these compounds are more basic than pyrroles. The addition of the aromatic rings can influence the basicity of anilines, while the 5- and 6-membered heterocyclic compounds function differently. The solvent properties may affect the basicity of these nitrogen-containing compounds.展开更多
To elucidate the effects of Fe_(2)O_(3) on nitrogen transformation during sludge pyrolysis,thermogravimetry coupled with mass spectrometry(TG-MS)was used to investigate the influences of Fe_(2)O_(3) on the pyrolysis c...To elucidate the effects of Fe_(2)O_(3) on nitrogen transformation during sludge pyrolysis,thermogravimetry coupled with mass spectrometry(TG-MS)was used to investigate the influences of Fe_(2)O_(3) on the pyrolysis characteristics and the release of important gaseous NO_(x) precursors such as HCN and NH_(3) during pyrolysis of three typical amino acids in urban sludge.The results show that after Fe_(2)O_(3) addition,the total weight loss rate of the three amino acids and the initial decomposition temperature of proline are reduced.The release amounts of NH_(3),HCN,CH_(3)CN,and HNCO from these three representative amino acids—glumatic,arginine,and proline,decrease in the order of arginine,glutamic,proline.The generation of Fe-N complexes,reduces the generation of NH_(3),HCN,CH_(3)CN,and HNCO while the catalysis effects of Fe_(2)O_(3) on the formation of H and H2 play a promoting role in the generation of NH_(3),HCN,CH_(3)CN,and HNCO.The results would provide an experimental and theoretical basis for subsequent research on the NOx precursor formation mechanisms during pyrolysis or combustion of Fe-containing sludge or sludge with additives containing Fe.展开更多
基金supported by the National Natural Science Foundation of China(22168032)the National Key Research and Development Program of China(2023YFC3904302,2023YFB4103500)the Key Projects of Ning Dong Energy and Chemical Industry Base(2023NDKJXMLX022).
文摘A new adsorbent was successfully prepared by hydrothermal treatment and chemical activation through coal gasification fine slag(CGFS)and blue algae(BA)as raw materials and used for CO_(2)capture.The CO_(2)chemisorption capacity of the adsorbent was further enhanced by taking advantage of the nitrogenous bases contained in the BA.In the hydrothermal process,the addition of BA significantly increased the content of pyrrole nitrogen in the adsorbent.In the activation process,pyrrole nitrogen gradually changed into pyridine nitrogen and graphite nitrogen.Increased BA addition result in a higher specific surface area and microporosity of the adsorbent.The CO_(2)adsorption performance test proved that the CGFS-50%-CA sample has the strongest CO_(2)adsorption capacity at low temperature,up to 15.59 cm^(3)/g,which is mainly through physical adsorption,and the CGFS-10%-CA sample has the strongest CO_(2)adsorption capacity at high temperature,up to 7.31 cm^(3)/g,which is mainly through chemical adsorption.CO_(2)uptake of the CGFS-10%-CA sample was well maintained after 10 cycles,with regeneration efficiencies above 99%.The results indicate that the novel adsorbents with coexistence of physical and chemical adsorption have great potential for CO_(2)adsorption applications.
基金supported by the National Key Research and Development Program of China(No.2022YFC3701103)the National Natural Science Foundation of China(No.42222705)+1 种基金the Youth Innovation Promotion Association CAS(No.2021354)Guangdong Foundation for Program of Science and Technology Research(No.2023B1212060049).
文摘Nitrogen-containing organic compounds(NOCs)may potentially contribute to aqueous secondary organic aerosols,yet the different formation of NOCs in aerosol particles and cloud droplets remains unclear.With the in-situ measurements performed at a mountain site(1690 m a.s.l.)in southern China,we investigated the formation of NOCs in the cloud droplets and the cloud-free particles,based on their mixing state information of NOCscontaining particles by single particle mass spectrometry.The relative abundance of NOCs in the cloud-free particles was significantly higher than those in cloud residual(cloud RES)particles.NOCs were highly correlated with carbonyl compounds(including glyoxalate and methylglyoxal)in the cloud-free particles,however,limited correlation was observed for cloud RES particles.Analysis of their mixing state and temporal variations highlights that NOCs was mainly formed from the carbonyl compounds and ammonium in the cloud-free particles,rather than in the cloud RES particles.The results support that the formation of NOCs from carbonyl compounds is facilitated in concentrated solutions in wet aerosols,rather than cloud droplets.In addition,we have identified the transport of biomass burning particles that facilitate the formation of NOCs,and that the observed NOCs is most likely contributed to the light absorption.These findings have implications for the evaluation of NOCs formation and their contribution to light absorption.
基金supported by the National Key Research and Development Program of China(Nos.2022YFD1700800 and 2023YFC3905903)the Science and Technology Project of Education Department of Jiangxi Province(No.GJJ2201103)+2 种基金the Fund of Nanchang Hangkong University(Nos.EA202201110 and EA202201065)National Undergraduate Innovation and Entrepreneurship Training Program(No.202310406023)the National Natural Science Foundation of China(No.52470149)。
文摘Covalent organic frameworks(COFs)are crystalline porous polymeric materials composed of organic monomers connected by strong covalent bonds and offer high stability,good crystallinity,a large specific surface area,and controllable structures.COFs are widely used in the fields of adsorption and separation,catalysis,photovoltaics,and drug-delivery.The structural regulation and performance optimization of COFs can be realized through the modification of ligands and the selection of linkage methods.In which,the types of linkage are closely related to the stability and performance of COFs.In this review,nitrogencontaining linkage-bonds(NCLBs)in COFs are divided into N-containing double bonds,N-containing conjugated rings and N-containing unconjugated rings.The association between structure and performance of COFs is elaborated and the synthesis methods of COFs are systematically summarized.Moreover,the structural design,theoretical prediction and machinable application of COFs are prospected.
基金support of National Natural Science Foundation of P.R.China(22308104).
文摘The influence of nitrogen-containing polycyclic aromatic hydrocarbons(NC-PAH)on the formation of carbonaceous mesophase remains enigmatic,despite extensive research on the production of carbonaceous materials from aromatic-rich oils.Molecular dynamics simulation was used to investigate the variations in pyrolysis behavior between PAH and NC-PAH based on the composition analysis.Through adjusting the content of NC-PAH,the influence of NC-PAH on the thermal stability of slurry oils(SOs)was evaluated by thermogravimetry,viscosity,coke value,and quinoline insoluble(QI).The morphology and structure of mesocarbon microbeads(MCMBs)prepared with SOs were measured by a polarized-light microscope,SEM,XRD,and Raman.Simulation results indicate that NC-PAH possesses much higher reactivity and tends to produce highly condensed solid and coke products.It corresponds to the QI and high viscosity in thermal stability experiments.Therefore,high concentrations of NC-PAH result in nonuniform morphology and disordered structures.In a system with low viscosity and few QIs,SO,which has a low nitrogen content(475 ppm),reacts gently to produce MCMBs with a uniform particle size(10-40μm)and an excellent spherical shape.As NC-PAH content decreases,the crystalline size of graphitization elevates,as evidenced by parallel layers(10.472-11.764)and stack height(3.269-3.701 nm).The graphitization degree becomes worse and nonuniform with the increase of the content of NC-PAH,and the best is 20.58%evaluated by Raman spectra area ratio(AG/Aall).Overall,this work suggests a nitrogen content reference and a controlling technology of nitrogen for the preparation of superior MCMB.
文摘Current evidence for oligodendrocyte precursor cell involvement in Parkinson’s disease:Oligodendroglial cells comprise a large cell population in the substantia nigra(SN).We recently reported a stable portion of oligodendrocyte precursor cells(OPCs)in the SN pars compacta(SNpc)in a 1:1 ratio with dopaminergic neurons:15%of cells in neonate and young mice,rising to 20%in aged mice.Moreover,this portion represents only 45%of all oligodendroglial cells in the SNpc and 54%of all oligodendroglial cells in the SN pars reticulata(SNpr)(Fitzgerald et al.,2025).The SN is a deeply located area of the midbrain and the site of dopaminergic degeneration in Parkinson’s disease(PD).Recent advancement of single-cell transcriptomics revealed the involvement of non-neuronal cells in PD,with PD risk variants being strongly associated with oligodendroglia(reviewed by Salazar Campos et al.,2025).
基金supported by DeutscheForschungsgemeinschaft(BA 8014/1-1 to XB)University of Saarland(NanoBioMed Young Investigatorgrant 2021 to XB,Anschubsfinanzierung2024to XB,HOMFORExzellenz2025 andAnschubsfinanzierung2025 to LPF)the ChinaPharmaceutical University(UndergraduateInternship Program to YZ).
文摘Oligodendrocyte precursor cells(OPCs)tile the central nervous system ubiquitously,accounting for about 5%of the total cell population in the central nervous system.Beyond their role in myelination,OPCs actively shape neural circuits(Fang and Bai,2023),by releasing neuromodulators,pruning synapses,maintaining the homeostasis of extracellular potassium concentration,and interacting with endothelial cells.
文摘The recycling of waste activated carbon is of great significance in environmental protection.Porous mullite ceramics were prepared by impregnating the mullite precursor with activated carbon,adding a pore-forming agent,and adopting aluminum sulfate octahydrate,ammonia and silica micropowder as raw materials,waste activated carbon after heat treatment as the pore-forming agent,and sodium polyacrylate(PAAS)as the dispersant.The effects of the activated carbon additions(1.5%,3.0%,5.2%,and 7.8%,by mass)and PAAS additions(1%,2%,and 3%,extra adding,by mass)on the physical properties,phase composition and microstructure of the porous ceramics were studied.The results show that:(1)as a pore-forming agent,activated carbon promotes the formation of pores inside the samples,while the apparent porosity of the samples increases significantly with the increasing activated carbon addition;when the activated carbon addition is 7.8%,the apparent porosity of the sample is 65.7%,the cold compressive strength is 4.62 MPa,the peak pore size is around 3.5μm,and the pore size distribution is uniform;(2)appropriate PAAS helps to improve the dispersion of activated carbon in the samples and the comprehensive performance of the porous mullite ceramics;when the PAAS addition is 2%,the apparent porosity of the sample is 71.8%,the cold compressive strength is 5.53 MPa,the peak pore size is around 3μm,and the pore size distribution is optimized;however,excessive PAAS increases the liquid phase in the system,resulting in over sintering of mullite and a decrease in the porosity.
基金supported by National Natural Science Foundation of China (Nos.52264006,52364004,and 52464005)the Guizhou Provincial Science and Technology Foundation (No.GCC[2022]005-1)。
文摘Investigating the damage evolution of surrounding rock under thermal shock cycles is crucial for ensuring the stability of engineering rock masses.This study performed Brazilian splitting tests on granite specimens under varying temperature and cycle conditions,employing acoustic emission monitoring,digital image correlation,and three-dimensional scanning technology.A systematic analysis was conducted on the patterns of damage evolution,failure precursor,and response mechanisms under combined thermal and cyclic loading.Experimental results show that both P-wave velocity and tensile strength degrade significantly with increasing temperature and cycle count,with temperature having a more pronounced effect than cycle count.Notably,damage evolution exhibits a dual-threshold behavior in which degradation accelerates markedly above 400℃ and stabilizes after 5 thermal cycles.Fracture surfaces evolve from initially planar to rugged morphologies,with peak-valley height differences at 600℃ being approximately three times greater than those at 200℃.Furthermore,based on acoustic emission energy entropy analysis,we introduce a novel failure precursor indicator where the sustained increase and critical surge in average entropy serve as reliable early-warning signals for impending rock failure.These findings establish a solid theoretical basis and practical methodology for damage assessment and instability early-warning systems in high-temperature rock engineering.
基金supported by the National Natural Science Foundation of China(Grant Nos.52025053 and 52235006)the Jilin Provincial Scientific and Technological Development Program(20220204119YY)the Natural Science Foundation of Shandong Province(ZR2023ME154)。
文摘Ceramic 4D printing,which integrates dynamic deformation with additive manufacturing,demonstrates significant potential in intelligent manufacturing,on-demand shaping of complex structures,and multifunctional device development.Its core advantage lies in endowing materials with environmentally responsive dynamic deformation capabilities.However,current technologies still face limitations in responsiveness,reversibility,and mechanical performance.To address these challenges,this study proposes a programmable ceramic precursor system based on synergistic reinforcement of phase-separating hydrogels and shape memory polymers,combined with a nano-ceramic particle enhancement strategy.Using stereolithography 3D printing,high-precision fabrication of complex structures was achieved.By adjusting precursor composition,programming time,and structural thickness,the phase-separation kinetics-driven delayed recovery mechanism was elucidated,enabling precise control over recovery onset time.Furthermore,the thermal response mechanism of the precursor materials is explored,along with their potential for multi-shape transformation in biomedical applications,which is further extended to shape memory polymer systems.By employing a layered printing strategy,the autonomous reversible deformation of ceramic precursors is realized,providing new possibilities for specific applications.
基金supported by the National Key R&D Program of China(No.2023YFC3081400)the National Natural Science Foundation of China(No.41702371)+3 种基金the Open Fund Project of State Key Laboratory of Mining Response and Disaster Prevention in Deep Coal Mines(No.SKLMRDPC22KF13)the Supported by State key Laboratory of Mining Disaster Prevention and Control(Shandong University of Science and Technology),Ministry of Education(No.DPEPM202502)the Open Fund Research Project Supported by State Key Laboratory of Strata Intelligent Control and Green Mining Co-founded by Shandong Province and the Ministry of Science and Technology(No.SICGM202503)the Fund of Chongqing Key Laboratory of Facility Damage Mechanism and Protection in Highland Mountain Environment(No.LQ24KFJJ09)。
文摘0 INTRODUCTION Due to the sudden and highly destructive nature of slope rock collapse,developing effective early warning systems has become an urgent challenge in geotechnical engineering(Cai and Detournay,2024;Loew et al.,2017).Traditional monitoring methods primarily target the acceleration stage preceding disasters(such as displacement monitoring for landslides and debris flows),which is effective for early warning of plastic collapse disasters but often inadequate for brittle failure modes(Walter et al.,2019;Chao et al.,2018;Crosta et al.,2017).
基金Supported by the National Key Research and Development Program of China(2022YFB4301400)the Basic Science(Natural Science)Research Project for Higher Education Institutions in Jiangsu Province(24KJD580001)。
文摘This study systematically investigates the cyclization reaction mechanisms between n-C_(4)H_(3)(1-buten-3-yn-1-yl)and i-C_(4)H_(3)(2-buten-3-yn-1-yl)radicals with acetylene(C_(2)H_(2))using density functional theory(DFT)and transition state theory(TST).The results reveal that the reaction of n-C_(4)H_(3)with acetylene proceeds via a radical chain mechanism through an additioncyclization pathway,yielding phenyl(sixmembered ring),fulvenyl(five-membered ring),and four-membered ring intermediates.The product formation rates follow the order:fulvenyl(five-membered ring)>phenyl(six-membered ring)>four-membered ring.For i-C_(4)H_(3),the intermediate structures depend on the carbon position of i-C_(4)H_(3)where acetylene addition occurs:addition at the C2 position predominantly generates fulvenyl(five-membered ring)as the primary product,whereas addition at the C4 position may lead to phenyl(six-membered ring),fulvenyl(five-membered ring),or four-membered ring intermediates,with the four-membered ring forming most rapidly and the six-membered ring the slowest.Theoretical analyses demonstrate that the selectivity of reaction pathways is primarily governed by structural differences between the isomers.This work provides atomic-scale insights into the cyclization processes between acetylene and C_(4)H_(3)species,establishing a foundation for refining models of soot precursor formation.
基金Project supported by the Pilot Project of Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-G-009)the National Natural Science Foundation of China (No. 20577067, 30230010).
文摘Many nitrogen-containing aromatic compounds （NACs）, such as nitrobenzene （NB）, 4-nitrophenol （4-NP）, aniline （AN）, and 2,4-dinitrophenol （2,4-DNP）, are environmentally hazardous, and their removal from contaminated water is one of the main challenges facing wastewater treatment plants. In this study, synthetic wastewater containing NB, 4-NP, 2,4-DNP, and AN at concentrations ranging from 50 to 180 mg/L was fed into a sequencing batch reactor （SBR）. Analyses of the SBR system indicated that it simultaneously removed more than 99% of the NACs at loading rates of 0.36 kg NB/（m^3·d）, 0.3 kg 4-NP/（m^3·d）, 0.25 kg AN/（m^3·d）, and 0.1 kg 2,4-DNP/（m^3·d）. Bacterial groups of Bacteriodetes, Candidate division TM7, α-Proteobacteria, and β-Proteobacteria were dominant in the clone libraries of 16S rRNA genes retrieved from the microbial communities in the SBR system. ＂Cycle tests＂ designed to alter feeding and aeration parameters of the SBR system demonstrated that the resident microbial biome of the SBR system responded rapidly to changing conditions. Consumption of O2 was concomitant with the apparent mineralization of NACs. Aromatic ring-cleaving dioxygenase activities suggested that （1） AN and NB were degraded via catechol 2,3-dioxygenase; （2） 4-NP was degraded via 1,2,4-benzentriol 1,2-dioxygenase; and （3） 2,4-DNP was degraded via an unresolved pathway.
基金Supported by the Key Project of Joint Fund from National Natural Science Foundation of China and the Government of Xinjiang Uygur Autonomous Region(U1503293)the National Key Research and Development Program of China(2018YFB0604602)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Soluble portions(SPs) 1-4(SP1-SP4) were afforded from sequentially dissolution and alkanolyses of Baiyinhua lignite(BL) in cyclohexane,CH3OH,CH3CH2OH,and(CH3)2CHOH at 300℃.They were analyzed with a gas chromatograph/mass spectrometer and quadrupole exactive orbitrap mass spectrometer(QEOTMS) with an atmosphere pressure chemical ionization source in positive-ion mode,while BL was characterized with an X-ray photoelectron spectrometer(XRPES).The results show that the yields of SP2 and SP3 are much higher than those of SP1 and SP4,and the total SP yield is ca.39.0%.According to the analysis with XRPES,pyrrolic nitrogen atoms are the most abundant nitrogen existing forms in BL.Thousands of nitrogen-containing aromatics(NCAs) were resolved with QEOTMS and their molecular masses are mainly in the range of 200-450 u.The main NCAs are N1O1 and N1O2 class species with double bond equivalent values of 4-18 and carbon numbers of 7-30.The nitrogen atoms appear in pyridine s,quinolines,benzoquinolines or acridine,and dibenzoquinolines or naphthoquinolines,while the oxygen atoms exist in methoxy and furan rings.
基金supported by the National Natural Science Foundation of China(Nos.31970107 and 51508068)the Fundamental Research Funds for the Central Universities(No.DUT19JC17)the Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.QAK201943)。
文摘Nitrogen-containing organic pollutants(quinoline,pyridine and indole)are widely distributed in coking wastewater,and bioaugmentation with specific microorganisms may enhance the removal of these recalcitrant pollutants.The bioaugmented system(group B)was constructed through inoculation of two aromatics-degrading bacteria,Comamonas sp.Z1(quinoline degrader)and Acinetobacter sp.JW(indole degrader),into the activated sludge for treatment of quinoline,indole and pyridine,and the non-bioaugmented activated sludge was used as the control(group C).Both groups maintained high efficiencies(>94%)for removal of nitrogen-containing organic pollutants and chemical oxygen demand(COD)during the long-term operation,and group B was highly effective at the starting period and the operation stage fed with raw wastewater.High-throughput sequencing analysis indicated that nitrogen-containing organic pollutants could shape the microbial community structure,and communities of bioaugmented group B were clearly separated from those of non-bioaugmented group C as observed in non-metric multidimensional scaling(NMDS)plot.Although the inoculants did not remain their dominance in group B,bioaugmentation could induce the formation of effective microbial community,and the indigenous microbes might play the key role in removal of nitrogen-containing organic pollutants,including Dokdonella,Comamonas and Pseudoxanthomonas.Phylogenetic Investigation of Communities by Reconstruction of Unobserved States(PICRUSt)analysis suggested that bioaugmentation could facilitate the enrichment of functional genes related to xenobiotics biodegradation and metabolism,probably leading to the improved performance in group B.This study indicated that bioaugmentation could promote the removal of nitrogen-containing organic pollutants,which should be an effective strategy for wastewater treatment.
基金supported by the Program for New Century Excellent Talents in University (NCET-04-0270)National Basic Research Program of China (2011CB201301)
文摘The adsorptive denitrogenation from fuels over three metal-organic frameworks(MIL-96(Al),MIL-53(Al)and MIL-101(Cr))was studied by batch adsorption experiments.Four nitrogen-containing compounds(NCCs)pyridine,pyrrole,quinoline and indole were used as model NCCs in fuels to study the adsorption mechanism.The physicochemical properties of the adsorbents were characterized by XRD,N2physical adsorption,FT-IR spectrum and Hammett indicator method.The metal-organic frameworks(MOFs),especially the MIL-101(Cr)containing Lewis acid sites as well as high specific surface area,can adsorb large quantities of NCCs from fuels.In addition,the adsorptive capacity over MIL-101(Cr)will be different for NCCs with different basicity.The stronger basicity of the NCC is,the more it can be absorbed over MIL-101(Cr).Furthermore,pore size and shape also affect the adsorption capacity for a given adsorbate,which can be proved by the adsorption over MIL-53(Al)and MIL-96(Al).The pseudo-second-order kinetic model and Langmuir equation can be used to describe kinetics and thermodynamics of the adsorption process,respectively.Finally,the regeneration of the used adsorbent has been conducted successfully by just washing it with ethanol.
基金supported by National Basic Research Program of China (973 Program, Grant No. 2006CB605005)Shanghai Municipal Committee of Science and Technology of china(Grant No. 005207019,Grant No. 08520708000)
文摘Stress corrosion cracking （SCC） of stainless steels and Ni-based alloys in high temperature water coolant is one of the key problems affecting the safe operation of nuclear power plants （NPPs）. The nitrogen-added stainless steel is a kind of possible candidate materials for mitigating SCC since reducing the carbon content and adding nitrogen to offset the loss in strength caused by the decrease in carbon content can mitigate the problem of sensitization. However, the reports of SCC of nitrogen-added stainless steels in high temperature water are few available. The effects of applied potential and sensitization treatment on the SCC of a newly developed nitrogen-containing stainless steel （SS） 316LN in high temperature water doped with chloride at 250 ℃ were studied by using slow strain rate tests （SSRTs）. The SSRT results are compared with our data previously published for 316 SS without nitrogen and 304NG SS with nitrogen, and the possible mechanism affecting the SCC behaviors of the studied steels is also discussed based on SSRT and microstucture analysis results. The susceptibility to cracking of 316LN SS normally increases with increasing potential. The susceptibility to SCC of 316LN SS was less than that of 316 SS and 304NG SS. Sensitization treatment at 700℃ for 30 h showed little effect on the S CC of 316LN S S and significant effect on the S CC of 316 S S. The predominant cracking mode for the 316LN S S in both annealed state and the state after the sensitization treatment was transgranular. The presented conditions of mitigating stress corrosion cracking are some useful information for the safe use of 316LN SS in NPPs.
文摘A new nitrogen-containing epoxy resin (XT resin) was synthesized from chain extension of xylenephenolformaldehyde resin (XPF) and triglycidyl isocyanurate (TGIC) in the presence of base catalyst. FT-IR and H-NMR analysis confirmed the chemical structure of XT resin. It was 1 cured with dicyandiamide (DICY) and diaminodiphenyl sulfone (DDS). Dynamic mechanical analysis (DMA) results showed that the introduction of triazine ring provides epoxy polymer with good thermal stability. Furthermore, high char yields at 800℃ in thermogravimetric (TGA) analysis indicated that XT resin had potential flame retardance.
基金Project(39470824)was supported by the National Natural Science Foundation of China.
文摘We synthesized a series of hydrazones,a novel type of nitrogen-containing prostaglandins,from different aromatic hydrazines and variant 2-substituted amino-3-hydroxy bicycle[3.2.0]hept-6-ones IV.
基金supported by the"973"project envisaged in the State Key Basic R&D Program(2006CB202505).
文摘The DFT-based （density fimctional theory） ab initio quantum mechanical methods have been applied to study the basicity of the nitrogen-containing compounds in petroleum. The results have indicated that there is a distinct relationship between the protonation energy of nitrogen-containing compounds and their basicity. The more negative the protonation energy, the stronger the basicity is. It has been also found that aliphatic amines are more basic than pyridines or aromatic amines, and all these compounds are more basic than pyrroles. The addition of the aromatic rings can influence the basicity of anilines, while the 5- and 6-membered heterocyclic compounds function differently. The solvent properties may affect the basicity of these nitrogen-containing compounds.
文摘To elucidate the effects of Fe_(2)O_(3) on nitrogen transformation during sludge pyrolysis,thermogravimetry coupled with mass spectrometry(TG-MS)was used to investigate the influences of Fe_(2)O_(3) on the pyrolysis characteristics and the release of important gaseous NO_(x) precursors such as HCN and NH_(3) during pyrolysis of three typical amino acids in urban sludge.The results show that after Fe_(2)O_(3) addition,the total weight loss rate of the three amino acids and the initial decomposition temperature of proline are reduced.The release amounts of NH_(3),HCN,CH_(3)CN,and HNCO from these three representative amino acids—glumatic,arginine,and proline,decrease in the order of arginine,glutamic,proline.The generation of Fe-N complexes,reduces the generation of NH_(3),HCN,CH_(3)CN,and HNCO while the catalysis effects of Fe_(2)O_(3) on the formation of H and H2 play a promoting role in the generation of NH_(3),HCN,CH_(3)CN,and HNCO.The results would provide an experimental and theoretical basis for subsequent research on the NOx precursor formation mechanisms during pyrolysis or combustion of Fe-containing sludge or sludge with additives containing Fe.
