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
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
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
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
In the last decade,shell biorefinery,a novel concept referring to the extraction of the main components of crustacean shells and the transformation of each component into valuable products,was proposed and has attract...In the last decade,shell biorefinery,a novel concept referring to the extraction of the main components of crustacean shells and the transformation of each component into valuable products,was proposed and has attracted increasing attentions.Chitin is one of main components of crustacean shells.Owing to the bio-fixed nitrogen element,chitin biomass has been regarded as a good candidate to produce nitrogen-containing chemicals.Among these,3-acetamido-5-acetylfuran(3A5AF)is an interesting furanic compound derived from the hydrolysis and sequential dehydration of chitin.Similar to cellulose-derived platform chemical 5-hydromethylfurfural(HMF),3A5AF is an emerging platform compound and also can be converted into various useful chemicals by oxidation,reduction,hydrolysis,substitution,and so on.This review showcases the recent advances in the synthesis of 3A5AF from chitin and N-acetyl glucosamine(NAG)employing various catalytic systems.The conversion of 3A5AF into valuable compounds was introduced then.There are still some challenges in this area,for example,the rational design of green and efficient catalytic systems for the synthesis of 3A5AF and its derivatives.The outlooks also were discussed at the end of the review.展开更多
Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ...Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ozone pollution as its major precursors.This study analyzed VOC characteristics of roadside,suburban,and rural sites in Hong Kong to investigate their compositions,concentrations,and source contributions.Herewe showthat the TVOC concentrations were 23.05±13.24,12.68±15.36,and 5.16±5.48 ppbv for roadside,suburban,and rural sites between May 2015 to June 2019,respectively.By using Positive Matrix Factorization(PMF)model,six sources were identified at the roadside site over five years:Liquefied petroleum gas(LPG)usage(33%–46%),gasoline evaporation(8%–31%),aged air mass(11%–28%),gasoline exhaust(5%–16%),diesel exhaust(2%–16%)and fuel filling(75–9%).Similarly,six sources were distinguished at the suburban site,including LPG usage(30%–33%),solvent usage(20%–26%),diesel exhaust(14%–26%),gasoline evaporation(8%–16%),aged air mass(4%–11%),and biogenic emissions(2%–5%).At the rural site,four sources were identified,including aged airmass(33%–51%),solvent usage(25%–30%),vehicular emissions(11%–28%),and biogenic emissions(6%–12%).The analysis further revealed that fuel filling and LPG usage were the primary contributors to OFP and OH reactivity at the roadside site,while solvent usage and biogenic emissions accounted for almost half of OFP and OH reactivity at the suburban and rural sites,respectively.These findings highlight the importance of identifying and characterizing VOC sources at different sites to help policymakers develop targeted measures for pollution mitigation in specific areas.展开更多
Furniture is identified as a vital volatile organic compound(VOC)emission source in the indoor environment.Leather has become the most common raw and auxiliary fabric material for upholstered furniture,particularly wi...Furniture is identified as a vital volatile organic compound(VOC)emission source in the indoor environment.Leather has become the most common raw and auxiliary fabric material for upholstered furniture,particularly with extensive consumption in sofas,due to its abundant resources and efficient functions.Despite being widely traded across the world,little research has been conducted on the VOCs released by leathermaterials and their health risk assessment in the indoor environment.Accordingly,this study investigated the VOC emissions of leather with different grades and the health risk of the inhalation exposure.Based on the ultra-fast gas phase electronic nose(EN)and GC-FID/Qtof,the substantial emissions of aliphatic aldehyde ketones(Aks),particularly hexanal,appear to be the cause of off-flavor in medium and low grade(MG and LG)sofa leathers.The health risk assessment indicated that leather materials barely pose non-carcinogenic and carcinogenic effects to residents.Given the abundance of VOC sources and the accumulation of health risks in the indoor environment,more stringent specifications concerning qualitative and quantitative content should be extended to provide VOC treatment basic for the manufacturing industry and obtain better indoor air quality.展开更多
VOCs(Volatile organic compounds)exert a vital role in ozone and secondary organic aerosol production,necessitating investigations into their concentration,chemical characteristics,and source apportionment for the effe...VOCs(Volatile organic compounds)exert a vital role in ozone and secondary organic aerosol production,necessitating investigations into their concentration,chemical characteristics,and source apportionment for the effective implementation of measures aimed at preventing and controlling atmospheric pollution.FromJuly to October 2020,onlinemonitoringwas conducted in the main urban area of Shijiazhuang to collect data on VOCs and analyze their concentrations and reactivity.Additionally,the PMF(positive matrix factorization)method was utilized to identify the VOCs sources.Results indicated that the TVOCs(total VOCs)concentration was(96.7±63.4μg/m^3),with alkanes exhibiting the highest concentration of(36.1±26.4μg/m^3),followed by OVOCs(16.4±14.4μg/m^3).The key active components were alkenes and aromatics,among which xylene,propylene,toluene,propionaldehyde,acetaldehyde,ethylene,and styrene played crucial roles as reactive species.The sources derived from PMF analysis encompassed vehicle emissions,solvent and coating sources,combustion sources,industrial emissions sources,as well as plant sources,the contribution of which were 37.80%,27.93%,16.57%,15.24%,and 2.46%,respectively.Hence,reducing vehicular exhaust emissions and encouraging neighboring industries to adopt low-volatile organic solvents and coatings should be prioritized to mitigate VOCs levels.展开更多
The organic compound composition ofwastewater,serves as a crucial indicator for the operational performance of activated sludge processes and has a major influence on the development of filamentous bulking in activate...The organic compound composition ofwastewater,serves as a crucial indicator for the operational performance of activated sludge processes and has a major influence on the development of filamentous bulking in activated sludge.This study focused on the impact of typical soluble and slowly-biodegradable organic compounds,investigating the pathways through which these substrates affect the occurrence of filamentous bulking in systems operated under both high-and low-oxygen conditions.Results showed that slowly-biodegradable organic compounds lead to a concentrated distribution of microorganisms within flocs,with inward growth of filamentous bacteria.Both Tween-80 and granular starch treated systems exhibited a significant increase in protein content.The glucose system,utilizing soluble substrates,exhibited a markedly higher total polysaccharide content.Microbial communities in the Tween-80 and granular starch treated systems were characterized by a higher abundance of bacteria known to enhance sludge flocculation and settling,such as Competibacter,Xanthomonadaceae and Zoogloea.These findings are of high significance for controlling the operational performance and stability of activated sludge systems,deepening our understanding and providing a novel perspective for the improvement of wastewater treatment processes.展开更多
Ubiquitous contamination of the soil environment with volatile organic compounds(VOCs)has raised considerable concerns.However,there is still limited comprehensive surveying of soil VOCs on a national scale.Herein,65 ...Ubiquitous contamination of the soil environment with volatile organic compounds(VOCs)has raised considerable concerns.However,there is still limited comprehensive surveying of soil VOCs on a national scale.Herein,65 species of VOCswere simultaneously determined in surface soil samples collected from 63 chemical industrial parks(CIPs)across China.The results showed that the total VOC concentrations ranged from 7.15 to 1842 ng/g with a mean concentration of 326 ng/g(median:179 ng/g).Benzene homologs and halogenated hydrocarbons were identified as the dominant contaminant groups.Positive correlations between many VOC species indicated that these compounds probably originated from similar sources.Spatially,the hotspots of VOC pollution were located in eastern and southern China.Soils with higher clay content and a higher fraction of total organic carbon(TOC)content were significantly associated with higher soil VOC concentrations.Precipitation reduces the levels of highly water-soluble substances in surface soils.Both positive matrix factorization(PMF)and principal component analysis-multiple linear regression(PCA-MLR)identified a high proportion of industrial sources(PMF:59.2%and PCA-MLR:66.5%)and traffic emission sources(PMF:32.3%and PCA-MLR:33.5%).PMF,which had a higher R^(2) value(0.7892)than PCA-MLR(0.7683),was the preferred model for quantitative source analysis of soil VOCs.The health risk assessment indicated that the non-carcinogenic and carcinogenic risks of VOCs were at acceptable levels.Overall,this study provides valuable data on the occurrence of VOCs in soil from Chinese CIPs,which is essential for a comprehensive understanding of their environmental behavior.展开更多
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
To explore the potential utilization of Elaeagnus mollis,we conducted a comprehensive assessment of its phytochemical composition,antioxidant properties,cholinesterase inhibition,and anti-HepG2 cell proliferation acti...To explore the potential utilization of Elaeagnus mollis,we conducted a comprehensive assessment of its phytochemical composition,antioxidant properties,cholinesterase inhibition,and anti-HepG2 cell proliferation activity across different plant parts(branch wood,branch bark,and pericarp)using various solvents(water,methanol,ethanol,and n-hexane).Our findings revealed that water extracts displayed superior antioxidant activities in ABTS and RP assays,while methanol extracts exhibited better performance in DPPH and FRAP assays.Moreover,methanol extracts demonstrated the highest effectiveness against anti-HepG2 cell proliferation,whereas n-hexane extracts showed greater efficiency in cholinesterase inhibition.Notably,branch bark extracts exhibited the highest levels of phytochemical compounds,with both branch bark and pericarp extracts demonstrating significant effects in cholinesterase inhibition and anti-HepG2 cell proliferation.Correlation analysis indicated that phytochemical compounds were primarily responsible for the observed biological activities.Overall,extracts from the branch bark and pericarp of E.mollis showed promising potential for antioxidant and anticancer activities,suggesting their suitability for applications in the pharmaceutical industry as health-promoting products.展开更多
Peptic ulcer(PU)is characterized by inflammation,necrosis,and erosion of the gastrointestinal mucosa caused by various pathogenic factors,leading to ulcer formation.The stomach and duodenum are the most commonly affec...Peptic ulcer(PU)is characterized by inflammation,necrosis,and erosion of the gastrointestinal mucosa caused by various pathogenic factors,leading to ulcer formation.The stomach and duodenum are the most commonly affected sites.Bletilla striata,a traditional Chinese medicinal herb,contains diverse chemical constituents and exhibits multiple pharmacological effects.As a key component in various traditional Chinese medicine compound formulations,it has demonstrated notable clinical efficacy.Moreover,it has a solid research foundation and broad application prospects in the treatment of gastrointestinal diseases.This paper systematically elaborates on the clinical efficacy and mechanisms of action of Bletilla striata in the treatment of PUs,drawing from ancient medical literature and traditional formula applications to provide support for clinical use.展开更多
Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely limited.Here we conducted in situ field measurements of BVOCs...Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely limited.Here we conducted in situ field measurements of BVOCs emissions from representative mature evergreen trees by using dynamic branch enclosures at four altitude gradients(600-1690ma.s.l.)in the Nanling Mountains of southern China.Composition characteristics as well as seasonal and altitudinal variations were analyzed.Standardized emission rates and canopyscale emission factors were then calculated.Results showed that BVOCs emission intensities in the wet season were generally higher than those in the dry season.Monoterpenes were the dominant BVOCs emitted from most broad-leaved trees,accounting for over 70%of the total.Schima superba,Yushania basihirsuta and Altingia chinensis had relatively high emission intensities and secondary pollutant formation potentials.The localized emission factors of isoprene were comparable to the defaults in the Model of Emissions of Gases and Aerosols fromNature(MEGAN),while emission factors of monoterpenes and sesquiterpenes were 2 to 58 times of those in the model.Our results can be used to update the current BVOCs emission inventory in MEGAN,thereby reducing the uncertainties of BVOCs emission estimations in forested regions of southern China.展开更多
Visible-light-mediated O-H functionalization reactions of alcohols with diazo compounds have been fully developed in recent years.However,alkenyl and acetylenic alcohols were rarely examined in these reactions due to ...Visible-light-mediated O-H functionalization reactions of alcohols with diazo compounds have been fully developed in recent years.However,alkenyl and acetylenic alcohols were rarely examined in these reactions due to the inevitable side reactions involving cycloaddition.Herein,the visible-light-mediated O-H functionalization reactions of alkenyl alcohols with diazo compounds were developed.This process competed favorably with the cycloaddition reaction.A series of multifunctional ethers were provided in low to high yields with aryldiazoacetates or 3-diazooxindoles.Biologically relevant spirooxindole-fused oxacycle could be easily accessed from the O-H functionalization product of alkenyl alcohol and 3-diazooxindole.展开更多
The Rh(III)-catalyzed C—H functionalization of sulfoxonium ylides and successively annulation with two classes of cyclic diazo compounds has been realized,affording structurally diverse fused-ring or spirocyclic comp...The Rh(III)-catalyzed C—H functionalization of sulfoxonium ylides and successively annulation with two classes of cyclic diazo compounds has been realized,affording structurally diverse fused-ring or spirocyclic compounds under redoxneutral conditions.The reaction proceeds via successive chelation-assisted C—H activation,carbene insertion,and intramolecular[3+3]/[4+1]annulation processes.展开更多
Employing the principle of active moiety concatenation, a novel series of symmetrical triazine compounds were designed. A series of novel triazine compounds were synthesized using cyanuric chloride, amines, and chalco...Employing the principle of active moiety concatenation, a novel series of symmetrical triazine compounds were designed. A series of novel triazine compounds were synthesized using cyanuric chloride, amines, and chalcones as the initial reactants. The structures of these compounds were characterized through FT-IR, 1H-NMR, 13C-NMR, high-resolution mass spectrometry (HRMS) and high performance liquid chromatography (HPLC). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetra- zolium bromide (MTT) assay was employed to evaluate the in vitro anti-proliferative activity of the new s-triazine compounds against human lung cancer cells (A549), human cervical cancer cells (HeLa), human breast cancer cells (MCF-7) and human colon cancer cells (SW620). The findings indicated that several compounds exhibited promising antitumor effects. Notably, (E)-1-(4-((4,6-dimorpholino-1,3,5-triazin-2-yl)oxy)phenyl)-3-(thiophen-2-yl)prop-2-en-1-one (3bg) demonstrated efficacy as a broad-spectrum anticancer agent, exhibiting significant activity against the A549, HeLa, and MCF-7 cell lines. Furthermore, (E)-1-(4-((4,6-dimorpholino-1,3,5-triazin-2-yl)oxy)phenyl)-3-phenylprop-2-en-1-one (3bb) displayed the most potent in vitro antitumor activity against the MCF-7 cell line with an IC_(50) value of 16.4 μmol/L, establishing it as the most active compound in assay.展开更多
Direct enantioselective allylic C—H functionalization has emerged as a powerful strategy for the asymmetric syn-thesis of highly valuable chiral products.Herein,a Rh(III)-catalyzed enantioselective allylic C—H alkyl...Direct enantioselective allylic C—H functionalization has emerged as a powerful strategy for the asymmetric syn-thesis of highly valuable chiral products.Herein,a Rh(III)-catalyzed enantioselective allylic C—H alkylation of unactivated alkenes withα-diazo carbonyl compounds is described,enabling direct access to chiral products with high efficiency(up to 77%yield,92%ee,and>10∶1 B/L(branched/linear)selectivity).This atom-and step-economical protocol directly converts simple,unactivated substrates into valuable enantioenriched products under mild conditions,providing an efficient catalytic system for asymmetric allylic C—H functionalization.展开更多
This research was carried out to identify the most effective plant species for air purification based on environmental factors. The existence of plants beside roadways can be considered a more efficient approach to im...This research was carried out to identify the most effective plant species for air purification based on environmental factors. The existence of plants beside roadways can be considered a more efficient approach to improving air quality and minimizing pollution exposure. The samples for this research were collected from various sites across the streets of Jeddah governorate. The primary sources of air pollution in the research area are vehicle traffic and emissions from cars. Eight species were gathered from various streets in Jeddah governorate, namely, Azadirachta indica, Senna sulfurea, Ziziphus spina-christi, Cordia sebestena, Tecoma stans, Bougainvillea spectabilis, Conocarpus lancifolius, and Ixora coccinea. The leaves of the studied plants were analyzed for secondary compounds using Gas chromatography-mass spectrometry (GC-MS) techniques. Gas-chromatographic analyses revealed that bis (2-ethylhexyl) phthalate was found in every plant. Bis-(2-ethylhexyl) phthalate, a widespread environmental pollutant. Moreover, Cordia sebestena was the sole plant that contained Phenol, 2,2’-methylenebis [6-(1,1-dimethylethyl)-4-methyl] which is part of the phenols category. Environmental conditions can affect the production of secondary metabolites. By tracking the concentrations of these substances, researchers can evaluate the well-being of ecosystems and identify pollution.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
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.
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.
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.
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support of the National Natural Science Foundation of China(22408032)the Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202000826 and KJQN202300836)+2 种基金Research Start-up Funding project of Chongqing Technology and Business University(1856011)Science and Technology Project of Chongqing Technology and Business University(2152027)Graduate Innovative Research Project from Chongqing Technology and Business University(yjscxx2024-284-29).
文摘In the last decade,shell biorefinery,a novel concept referring to the extraction of the main components of crustacean shells and the transformation of each component into valuable products,was proposed and has attracted increasing attentions.Chitin is one of main components of crustacean shells.Owing to the bio-fixed nitrogen element,chitin biomass has been regarded as a good candidate to produce nitrogen-containing chemicals.Among these,3-acetamido-5-acetylfuran(3A5AF)is an interesting furanic compound derived from the hydrolysis and sequential dehydration of chitin.Similar to cellulose-derived platform chemical 5-hydromethylfurfural(HMF),3A5AF is an emerging platform compound and also can be converted into various useful chemicals by oxidation,reduction,hydrolysis,substitution,and so on.This review showcases the recent advances in the synthesis of 3A5AF from chitin and N-acetyl glucosamine(NAG)employing various catalytic systems.The conversion of 3A5AF into valuable compounds was introduced then.There are still some challenges in this area,for example,the rational design of green and efficient catalytic systems for the synthesis of 3A5AF and its derivatives.The outlooks also were discussed at the end of the review.
基金supported by Hong Kong Environment Protection Department(Quotation Ref.18-06532)Hong Kong Innovation and Technology Fund(ITS/193/20FP)Hong Kong Research Grants Council(No.26304921).
文摘Initial success has been achieved in Hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three decades.Volatile organic compounds(VOCs)are important for mitigating ozone pollution as its major precursors.This study analyzed VOC characteristics of roadside,suburban,and rural sites in Hong Kong to investigate their compositions,concentrations,and source contributions.Herewe showthat the TVOC concentrations were 23.05±13.24,12.68±15.36,and 5.16±5.48 ppbv for roadside,suburban,and rural sites between May 2015 to June 2019,respectively.By using Positive Matrix Factorization(PMF)model,six sources were identified at the roadside site over five years:Liquefied petroleum gas(LPG)usage(33%–46%),gasoline evaporation(8%–31%),aged air mass(11%–28%),gasoline exhaust(5%–16%),diesel exhaust(2%–16%)and fuel filling(75–9%).Similarly,six sources were distinguished at the suburban site,including LPG usage(30%–33%),solvent usage(20%–26%),diesel exhaust(14%–26%),gasoline evaporation(8%–16%),aged air mass(4%–11%),and biogenic emissions(2%–5%).At the rural site,four sources were identified,including aged airmass(33%–51%),solvent usage(25%–30%),vehicular emissions(11%–28%),and biogenic emissions(6%–12%).The analysis further revealed that fuel filling and LPG usage were the primary contributors to OFP and OH reactivity at the roadside site,while solvent usage and biogenic emissions accounted for almost half of OFP and OH reactivity at the suburban and rural sites,respectively.These findings highlight the importance of identifying and characterizing VOC sources at different sites to help policymakers develop targeted measures for pollution mitigation in specific areas.
基金supported by the National Key Research and Development Program of China (No.2019YFC1904501).
文摘Furniture is identified as a vital volatile organic compound(VOC)emission source in the indoor environment.Leather has become the most common raw and auxiliary fabric material for upholstered furniture,particularly with extensive consumption in sofas,due to its abundant resources and efficient functions.Despite being widely traded across the world,little research has been conducted on the VOCs released by leathermaterials and their health risk assessment in the indoor environment.Accordingly,this study investigated the VOC emissions of leather with different grades and the health risk of the inhalation exposure.Based on the ultra-fast gas phase electronic nose(EN)and GC-FID/Qtof,the substantial emissions of aliphatic aldehyde ketones(Aks),particularly hexanal,appear to be the cause of off-flavor in medium and low grade(MG and LG)sofa leathers.The health risk assessment indicated that leather materials barely pose non-carcinogenic and carcinogenic effects to residents.Given the abundance of VOC sources and the accumulation of health risks in the indoor environment,more stringent specifications concerning qualitative and quantitative content should be extended to provide VOC treatment basic for the manufacturing industry and obtain better indoor air quality.
基金supported by the Natural Science Foundation of Hebei Province(Nos.D2019106042,D2020304038,and D2021106002)the National Natural Science Foundation of China(No.22276099)+1 种基金the State Environmental Protection Key Laboratory of Formation and Prevention of Urban Air Pollution Complex(No.2021080544)the Environmental Monitoring Research Foundation of Jiangsu Province(No.2211).
文摘VOCs(Volatile organic compounds)exert a vital role in ozone and secondary organic aerosol production,necessitating investigations into their concentration,chemical characteristics,and source apportionment for the effective implementation of measures aimed at preventing and controlling atmospheric pollution.FromJuly to October 2020,onlinemonitoringwas conducted in the main urban area of Shijiazhuang to collect data on VOCs and analyze their concentrations and reactivity.Additionally,the PMF(positive matrix factorization)method was utilized to identify the VOCs sources.Results indicated that the TVOCs(total VOCs)concentration was(96.7±63.4μg/m^3),with alkanes exhibiting the highest concentration of(36.1±26.4μg/m^3),followed by OVOCs(16.4±14.4μg/m^3).The key active components were alkenes and aromatics,among which xylene,propylene,toluene,propionaldehyde,acetaldehyde,ethylene,and styrene played crucial roles as reactive species.The sources derived from PMF analysis encompassed vehicle emissions,solvent and coating sources,combustion sources,industrial emissions sources,as well as plant sources,the contribution of which were 37.80%,27.93%,16.57%,15.24%,and 2.46%,respectively.Hence,reducing vehicular exhaust emissions and encouraging neighboring industries to adopt low-volatile organic solvents and coatings should be prioritized to mitigate VOCs levels.
基金supported by the Opening Project of National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology,and the National Natural Science Foundation of China(No.52270017).
文摘The organic compound composition ofwastewater,serves as a crucial indicator for the operational performance of activated sludge processes and has a major influence on the development of filamentous bulking in activated sludge.This study focused on the impact of typical soluble and slowly-biodegradable organic compounds,investigating the pathways through which these substrates affect the occurrence of filamentous bulking in systems operated under both high-and low-oxygen conditions.Results showed that slowly-biodegradable organic compounds lead to a concentrated distribution of microorganisms within flocs,with inward growth of filamentous bacteria.Both Tween-80 and granular starch treated systems exhibited a significant increase in protein content.The glucose system,utilizing soluble substrates,exhibited a markedly higher total polysaccharide content.Microbial communities in the Tween-80 and granular starch treated systems were characterized by a higher abundance of bacteria known to enhance sludge flocculation and settling,such as Competibacter,Xanthomonadaceae and Zoogloea.These findings are of high significance for controlling the operational performance and stability of activated sludge systems,deepening our understanding and providing a novel perspective for the improvement of wastewater treatment processes.
基金supported by the Medical and Health Projects in Zhejiang Province(No.2022PY049)the Basic Scientific Research Project of Hangzhou Medical College(No.YS2021006)Key Discipline of Zhejiang Province in Public Health and Preventive Medicine(First Class,Category A),Hangzhou Medical College.
文摘Ubiquitous contamination of the soil environment with volatile organic compounds(VOCs)has raised considerable concerns.However,there is still limited comprehensive surveying of soil VOCs on a national scale.Herein,65 species of VOCswere simultaneously determined in surface soil samples collected from 63 chemical industrial parks(CIPs)across China.The results showed that the total VOC concentrations ranged from 7.15 to 1842 ng/g with a mean concentration of 326 ng/g(median:179 ng/g).Benzene homologs and halogenated hydrocarbons were identified as the dominant contaminant groups.Positive correlations between many VOC species indicated that these compounds probably originated from similar sources.Spatially,the hotspots of VOC pollution were located in eastern and southern China.Soils with higher clay content and a higher fraction of total organic carbon(TOC)content were significantly associated with higher soil VOC concentrations.Precipitation reduces the levels of highly water-soluble substances in surface soils.Both positive matrix factorization(PMF)and principal component analysis-multiple linear regression(PCA-MLR)identified a high proportion of industrial sources(PMF:59.2%and PCA-MLR:66.5%)and traffic emission sources(PMF:32.3%and PCA-MLR:33.5%).PMF,which had a higher R^(2) value(0.7892)than PCA-MLR(0.7683),was the preferred model for quantitative source analysis of soil VOCs.The health risk assessment indicated that the non-carcinogenic and carcinogenic risks of VOCs were at acceptable levels.Overall,this study provides valuable data on the occurrence of VOCs in soil from Chinese CIPs,which is essential for a comprehensive understanding of their environmental behavior.
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National Natural Science Foundation of China(Grant No.31600549).
文摘To explore the potential utilization of Elaeagnus mollis,we conducted a comprehensive assessment of its phytochemical composition,antioxidant properties,cholinesterase inhibition,and anti-HepG2 cell proliferation activity across different plant parts(branch wood,branch bark,and pericarp)using various solvents(water,methanol,ethanol,and n-hexane).Our findings revealed that water extracts displayed superior antioxidant activities in ABTS and RP assays,while methanol extracts exhibited better performance in DPPH and FRAP assays.Moreover,methanol extracts demonstrated the highest effectiveness against anti-HepG2 cell proliferation,whereas n-hexane extracts showed greater efficiency in cholinesterase inhibition.Notably,branch bark extracts exhibited the highest levels of phytochemical compounds,with both branch bark and pericarp extracts demonstrating significant effects in cholinesterase inhibition and anti-HepG2 cell proliferation.Correlation analysis indicated that phytochemical compounds were primarily responsible for the observed biological activities.Overall,extracts from the branch bark and pericarp of E.mollis showed promising potential for antioxidant and anticancer activities,suggesting their suitability for applications in the pharmaceutical industry as health-promoting products.
基金Supported by National Science and Technology Major Project,No.2024ZD0521002The Innovation Team Project of Traditional Chinese Medicine of Liaoning Province,No.LNZYYCXTD-CCCX-003+1 种基金General Program of the National Natural Science Foundation of China,No.82074296Construction Project of Inheritance Studios of Famous Chinese Medicine Experts in China,No.[2022]No.75.
文摘Peptic ulcer(PU)is characterized by inflammation,necrosis,and erosion of the gastrointestinal mucosa caused by various pathogenic factors,leading to ulcer formation.The stomach and duodenum are the most commonly affected sites.Bletilla striata,a traditional Chinese medicinal herb,contains diverse chemical constituents and exhibits multiple pharmacological effects.As a key component in various traditional Chinese medicine compound formulations,it has demonstrated notable clinical efficacy.Moreover,it has a solid research foundation and broad application prospects in the treatment of gastrointestinal diseases.This paper systematically elaborates on the clinical efficacy and mechanisms of action of Bletilla striata in the treatment of PUs,drawing from ancient medical literature and traditional formula applications to provide support for clinical use.
基金supported by the National Natural Science Foundation of China (NSFC)Projects (Nos.42205105,42121004,and 42077190)the Science and Technology Project of Shaoguan (No.210811164532141)+3 种基金the National Key R&D Program of China (2022YFC3700604)the Science and Technology Program of Guangzhou City (No.202201010400)the Fundamental Research Funds for the Central Universities (No.21622319)the Research Center of Low Carbon Economy for Guangzhou Region (No.22JNZS50).
文摘Emission characteristics of biogenic volatile organic compounds(BVOCs)from dominant tree species in the subtropical pristine forests of China are extremely limited.Here we conducted in situ field measurements of BVOCs emissions from representative mature evergreen trees by using dynamic branch enclosures at four altitude gradients(600-1690ma.s.l.)in the Nanling Mountains of southern China.Composition characteristics as well as seasonal and altitudinal variations were analyzed.Standardized emission rates and canopyscale emission factors were then calculated.Results showed that BVOCs emission intensities in the wet season were generally higher than those in the dry season.Monoterpenes were the dominant BVOCs emitted from most broad-leaved trees,accounting for over 70%of the total.Schima superba,Yushania basihirsuta and Altingia chinensis had relatively high emission intensities and secondary pollutant formation potentials.The localized emission factors of isoprene were comparable to the defaults in the Model of Emissions of Gases and Aerosols fromNature(MEGAN),while emission factors of monoterpenes and sesquiterpenes were 2 to 58 times of those in the model.Our results can be used to update the current BVOCs emission inventory in MEGAN,thereby reducing the uncertainties of BVOCs emission estimations in forested regions of southern China.
文摘Visible-light-mediated O-H functionalization reactions of alcohols with diazo compounds have been fully developed in recent years.However,alkenyl and acetylenic alcohols were rarely examined in these reactions due to the inevitable side reactions involving cycloaddition.Herein,the visible-light-mediated O-H functionalization reactions of alkenyl alcohols with diazo compounds were developed.This process competed favorably with the cycloaddition reaction.A series of multifunctional ethers were provided in low to high yields with aryldiazoacetates or 3-diazooxindoles.Biologically relevant spirooxindole-fused oxacycle could be easily accessed from the O-H functionalization product of alkenyl alcohol and 3-diazooxindole.
文摘The Rh(III)-catalyzed C—H functionalization of sulfoxonium ylides and successively annulation with two classes of cyclic diazo compounds has been realized,affording structurally diverse fused-ring or spirocyclic compounds under redoxneutral conditions.The reaction proceeds via successive chelation-assisted C—H activation,carbene insertion,and intramolecular[3+3]/[4+1]annulation processes.
文摘Employing the principle of active moiety concatenation, a novel series of symmetrical triazine compounds were designed. A series of novel triazine compounds were synthesized using cyanuric chloride, amines, and chalcones as the initial reactants. The structures of these compounds were characterized through FT-IR, 1H-NMR, 13C-NMR, high-resolution mass spectrometry (HRMS) and high performance liquid chromatography (HPLC). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetra- zolium bromide (MTT) assay was employed to evaluate the in vitro anti-proliferative activity of the new s-triazine compounds against human lung cancer cells (A549), human cervical cancer cells (HeLa), human breast cancer cells (MCF-7) and human colon cancer cells (SW620). The findings indicated that several compounds exhibited promising antitumor effects. Notably, (E)-1-(4-((4,6-dimorpholino-1,3,5-triazin-2-yl)oxy)phenyl)-3-(thiophen-2-yl)prop-2-en-1-one (3bg) demonstrated efficacy as a broad-spectrum anticancer agent, exhibiting significant activity against the A549, HeLa, and MCF-7 cell lines. Furthermore, (E)-1-(4-((4,6-dimorpholino-1,3,5-triazin-2-yl)oxy)phenyl)-3-phenylprop-2-en-1-one (3bb) displayed the most potent in vitro antitumor activity against the MCF-7 cell line with an IC_(50) value of 16.4 μmol/L, establishing it as the most active compound in assay.
文摘Direct enantioselective allylic C—H functionalization has emerged as a powerful strategy for the asymmetric syn-thesis of highly valuable chiral products.Herein,a Rh(III)-catalyzed enantioselective allylic C—H alkylation of unactivated alkenes withα-diazo carbonyl compounds is described,enabling direct access to chiral products with high efficiency(up to 77%yield,92%ee,and>10∶1 B/L(branched/linear)selectivity).This atom-and step-economical protocol directly converts simple,unactivated substrates into valuable enantioenriched products under mild conditions,providing an efficient catalytic system for asymmetric allylic C—H functionalization.
文摘This research was carried out to identify the most effective plant species for air purification based on environmental factors. The existence of plants beside roadways can be considered a more efficient approach to improving air quality and minimizing pollution exposure. The samples for this research were collected from various sites across the streets of Jeddah governorate. The primary sources of air pollution in the research area are vehicle traffic and emissions from cars. Eight species were gathered from various streets in Jeddah governorate, namely, Azadirachta indica, Senna sulfurea, Ziziphus spina-christi, Cordia sebestena, Tecoma stans, Bougainvillea spectabilis, Conocarpus lancifolius, and Ixora coccinea. The leaves of the studied plants were analyzed for secondary compounds using Gas chromatography-mass spectrometry (GC-MS) techniques. Gas-chromatographic analyses revealed that bis (2-ethylhexyl) phthalate was found in every plant. Bis-(2-ethylhexyl) phthalate, a widespread environmental pollutant. Moreover, Cordia sebestena was the sole plant that contained Phenol, 2,2’-methylenebis [6-(1,1-dimethylethyl)-4-methyl] which is part of the phenols category. Environmental conditions can affect the production of secondary metabolites. By tracking the concentrations of these substances, researchers can evaluate the well-being of ecosystems and identify pollution.
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.
