To elucidate the variations in volatile organic compounds(VOCs)among widely cultivated japonica rice varieties in China and offer novel perspectives on flavor formation during rice-based beer brewing,nine prevalent Ch...To elucidate the variations in volatile organic compounds(VOCs)among widely cultivated japonica rice varieties in China and offer novel perspectives on flavor formation during rice-based beer brewing,nine prevalent Chinese japonica rice variaties were selected as experimental materials.Comprehensive analyses were conducted to investigate three key aspects:differences in VOCs among the selected japonica rice varieties,the retention of rice VOCs after beer brewing,and the influence of rice additives on beer sensory characteristics.Results showed that the total contents of VOCs in Wuyoudao 4(WYD4)and Nangeng 9108(NG9108)were significantly higher than those in the other varieties(P<0.05).The popcorn-flavor compound 2-acetyl-1-pyrroline(2-AP)was detected in Suigeng 27(SG27,26.80 ng/g),WYD4(25.25 ng/g),NG9108(21.18 ng/g),and Suigeng 18(SG18,11.62 ng/g),with the levels in the first three varieties significantly higher than those in SG18.Circular heatmap analysis classified the nine japonica varieties into three major categories:fragrant japonica from North China(WYD4),fragrant japonica from South China(NG9108),and others.Ten characteristic VOCs across the japonica varieties were identified by headspace solid-phase microextraction gas chromatography-mass spectrometry(HS-SPME-GC-MS).Using beer brewed with whole wheat as the control,we analyzed the VOCs and sensory characteristics of beer brewed with fragrant japonica rice as an additive.We found that rice VOCs were not detected in beer brewed with fragrant japonica rice as an additive.Adding rice promoted the formation of banana-like flavors and reduced the beer’s richness and mellowness.展开更多
Temperature has a substantial impact on the emission of biogenic volatile organic compounds(BVOCs).Moder-ate warm temperatures,e.g.,30–40°C,could boost plant metabolism,increasing BVOC emissions.Against the back...Temperature has a substantial impact on the emission of biogenic volatile organic compounds(BVOCs).Moder-ate warm temperatures,e.g.,30–40°C,could boost plant metabolism,increasing BVOC emissions.Against the backdrop of global warming,plants emit more BVOCs to cope with thermal stress,leading to elevated concen-trations of tropospheric ozone(O_(3))and secondary organic aerosols(SOA).In recent years,a considerable body of research has explored the interaction between tree species and BVOCs under the influence of various environ-mental factors.Although many studies have examined explored the temperature dependence of BVOC emissions in the past,few studies have conducted a comprehensive and in-depth investigation into the impacts of tempera-ture.This review summarizes the relevant studies on BVOCs in the past decade,including the main biosynthetic pathways,emission observation techniques and emission inventories,as well as how temperature affects isoprene and monoterpene emission rates and the formation of O_(3) and SOA.Our work offers a theoretical foundation and guidance for future efforts to advance the comprehension of BVOC emission characteristics and develop strategies to mitigate secondary pollution.展开更多
The volatile chemical components of flowers,leaves,stems,and roots of Rabdosia rubescens were extracted by solid-phase microextraction method,and the extracts were analyzed by gas chromatography-mass spectrometry.A to...The volatile chemical components of flowers,leaves,stems,and roots of Rabdosia rubescens were extracted by solid-phase microextraction method,and the extracts were analyzed by gas chromatography-mass spectrometry.A total of 40 chemical constituents were identified from the essential oils of the roots,stems,leaves,and flowers of R.rubescens.Among them,15,24,15,and 17 chemical components were identified from the roots,stems,leaves,and flowers of.rubescens respectively.In the roots,camphene(38.29%),calarene(7.25%),o-cymene(5.31%),elsholtzia ketone(4.49%)were identified as the major constituents.In the stems,the main components were benzaldehyde(37.81%),elsholtzia ketone(26.14%),β-caryophyllene(5.03%).The leaves were characterized primarily by elsholtzia ketone(73.85%),β-caryophyllene(5.95%)and benzaldehyde(3.31%).In the flowers,elsholtzia ketone(63.18%),β-caryophyllene(10.68%),bicyclogermacrene(4.90%)and benzaldehyde(4.58%)were identified to be the predominant compounds.These results indicate that the essential oils from different organs of R.rubescens exhibit distinct chemical compositions.The differences were particularly between the aboveground and belowground organs.展开更多
Auxin is a phytohormone that is critical for plant growth and development.The molecular mechanisms underlying auxin biosynthesis,transport,and signaling are well understood.However,the complex mechanism by which auxin...Auxin is a phytohormone that is critical for plant growth and development.The molecular mechanisms underlying auxin biosynthesis,transport,and signaling are well understood.However,the complex mechanism by which auxin regulates plant volatile biosynthesis has seldom been studied.A growing array of unique auxin-related plant volatiles have recently been discovered.This study comprehensively reviews recent findings on auxin and auxin-related genes and their roles in the formation of plant volatiles.This study highlights the implications of exogenous auxin application,genes involved in auxin signaling transduction,and hormonal crosstalk during volatile compound biosynthesis in plants.Plant hormones facilitate the integration of multiple volatile signals to enable specific and appropriate responses to environmental changes.This will improve our overall understanding of the role of auxins in plant volatile compound metabolic pathways.Recent studies have delineated the considerable advancements in elucidating the intricate methods by which plants employ auxin regulatory pathways to modulate the release of volatile chemicals during development and growth,along with prospective research paths.展开更多
Edible oils derived from aquatic products are rich in lipids beneficial to human health.However,the volatile flavor characteristics of flesh oil and liver oil from Doederleinia berycoides remain unclear.In this study,...Edible oils derived from aquatic products are rich in lipids beneficial to human health.However,the volatile flavor characteristics of flesh oil and liver oil from Doederleinia berycoides remain unclear.In this study,flesh oil and liver oil were extracted from Doederleinia berycoides,revealing different fatty acid compositions and contents.Lipidomics analysis identified a total of 124 differential lipids between the flesh oil and liver oil,including 42 glycerophospholipids(GPs),33 glycerolipids(GLs),23 free fatty acids(FAs),13 sphingolipids(SPs),10 sterols(STs),and 3 prenol lipids(PRs).Analysis using HS-GC-IMS identified 12 key volatile compounds that significantly contributed to the distinct volatile flavors of the flesh and liver oils.The volatile flavors originated from these volatile compounds,which had different Relative Odor Activity Values(ROAVs).Further results from HSSPME-GC-MS showed that the volatile flavors of the flesh oil and liver oil were respectively attributed to 64 and 35 volatile compounds,each with unique key volatile compounds exhibiting different ROAVs.There were significant positive or negative correlations between 18 key differential lipids and 24 volatile compounds in both flesh oil and liver oil.Therefore,the complex lipid profiles are responsible for the unique volatile flavors of flesh oil and liver oil,and the differential lipids play a central role in their volatile flavor formation.These findings provide a foundation for understanding the volatile flavor differences in fish oils and hold promise for further exploration of the molecular mechanisms underlying oil volatile flavors.展开更多
Cyclic volatile methyl siloxanes(cVMSs)are widely used in industrial and consumer products because of their thermal stability,low reactivity,and reduced surface tension[1].Their extensive use has resulted in environme...Cyclic volatile methyl siloxanes(cVMSs)are widely used in industrial and consumer products because of their thermal stability,low reactivity,and reduced surface tension[1].Their extensive use has resulted in environmental pollution globally.Recognized as very persistent and very bioaccumulative(vPvB),compounds such as octamethylcyclotetrasiloxane(D4),decamethylcyclopentasiloxane(D5),and dodecamethylcyclohexasiloxane(D6)are regulated in the European Union[2]and are monitored worldwide.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
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
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
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
Tomato is an important economic crop all over the world.Volatile flavors in tomato fruit are key factors influencing consumer liking and commercial quality.However,the regulatory mechanism controlling the volatile fla...Tomato is an important economic crop all over the world.Volatile flavors in tomato fruit are key factors influencing consumer liking and commercial quality.However,the regulatory mechanism controlling the volatile flavors of tomatoes is still not clear.Here,we integrated the metabolome and transcriptome of the volatile flavors in tomato fruit to explore the regulatory mechanism of volatile flavor formation,using wild and cultivated tomatoes with significant differences in flavors.A total of 35 volatile flavor compounds were identified,based on the solid phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS).The content of the volatiles,affecting fruit flavor,significantly increased in the transition from breaker to red ripe fruit stage.Moreover,the total content of the volatiles in wild tomatoes was much higher than that in the cultivated tomatoes.The content variations of all volatile flavors were clustered into 10 groups by hierarchical cluster and Pearson coefficient correlation(PCC)analysis.The fruit transcriptome was also patterned into 10 groups,with significant variations both from the mature green to breaker fruit stage and from the breaker to red ripe fruit stage.Combining the metabolome and the transcriptome of the same developmental stage of fruits by co-expression analysis,we found that the expression level of 1182 genes was highly correlated with the content of volatile flavor compounds,thereby constructing two regulatory pathways of important volatile flavors.One pathway is tetrahydrothiazolidine N-hydroxylase(SlTNH1)-dependent,which is regulated by two transcription factors(TFs)from the bHLH and AP2/ERF families,controlling the synthesis of 2-isobutylthiazole in amino acid metabolism.The other is lipoxygenase(Sl LOX)-dependent,which is regulated by one TF from the HD-Zip family,controlling the synthesis of hexanal and(Z)-2-heptenal in fatty acid metabolism.Dual-luciferase assay confirmed the binding of b HLH and AP2/ERF to their structural genes.The findings of this study provide new insights into volatile flavor formation in tomato fruit,which can be useful for tomato flavor improvement.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
Vertical detection of volatile organic compounds(VOCs)is essential to expend our understanding of the distribution characteristics of VOCs and improve the predictive ability of existing air qualitymodels.In this work,...Vertical detection of volatile organic compounds(VOCs)is essential to expend our understanding of the distribution characteristics of VOCs and improve the predictive ability of existing air qualitymodels.In this work,we report the development of a sorbent tube sampler based on an unmanned aerial vehicle(UAV)platform.Vertical profile measurement of VOCs with a vertical resolution of 25mwas achieved.The sampler consists of five lightweight VOC sorbent tubes and a 5-way solenoid valve,making it available for collecting five atmospheric VOC samples in a single flight with a time response of less than 30min.The samplerweighed∼1.45 kg and had dimensions of 240mm×220mm×100mmwith small penetration loss(<10%)under 4-liter sampling conditions(flow rate of 200 mL/min).Commercialized SUMMA canisters were used as experimental controls to investigate the possible loss of self-made sampler for target compounds in the same sampling process.Comparison experiment on the ground showed that the concentration differences for all VOC species were lower than 0.14μg/m3,proving the good reliability for VOCs measurements using sorbent tube sampler.The UAV platform also incorporated online instruments for meteorological parameters and O_(3) measurement.The sampler was successfully applied to characterize the vertical profiles of VOCs up to 100 m in October 2023 in the Huaihe River Basin of China.The UAV platform and the sorbent tube sampler demonstrate good performance and will be a valuable and reliable tool for vertical VOCs measurement.展开更多
Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in China.In vine tea processing,a large amount of broken tea is produced,which has low commercial value.Methods:This study investigat...Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in China.In vine tea processing,a large amount of broken tea is produced,which has low commercial value.Methods:This study investigates the influence of different extraction methods(room temperature water extraction,boiling water extraction,ultrasonic-assisted room temperature water extraction,and ultrasonic-assisted boiling water extraction,referred to as room temperature water extraction(RE),boiling water extraction(BE),ultrasonic assistance at room temperature water extraction(URE),and ultrasonic assistance in boiling water extraction(UBE))on the yield,dihydromyricetin(DMY)content,free amino acid composition,volatile aroma components,and antioxidant properties of vine tea extracts.Results:A notable influence of extraction temperature on the yield of vine tea extracts(P<0.05),with BE yielding the highest at 43.13±0.26%,higher than that of RE(34.29±0.81%).Ultrasound-assisted extraction significantly increased the DMY content of the extracts(P<0.05),whereas DMY content in the RE extracts was 59.94±1.70%,that of URE reached 66.14±2.78%.Analysis revealed 17 amino acids,with L-serine and aspartic acid being the most abundant in the extracts,nevertheless ultrasound-assisted extraction reduced total free amino acid content.Gas chromatography-mass spectrometry analysis demonstrated an increase in the diversity and quantity of compounds in the vine tea water extracts obtained through ultrasonic-assisted extraction.Specifically,69 and 68 volatile compounds were found in URE and UBE extracts,which were higher than the number found in RE and BE extracts.In vitro,antioxidant activity assessments revealed varying antioxidant capacities among different extraction methods,with RE exhibiting the highest DPPH scavenging rate,URE leading in ABTS•+free radical scavenging,and BE demonstrating superior ferric ion reducing antioxidant activity.Conclusion:The findings suggest that extraction methods significantly influence the chemical composition and antioxidant properties of vine tea extracts.Ultrasonic-assisted extraction proved instrumental in elevating the DMY content in vine tea extracts,thereby enriching its flavor profile while maintaining its antioxidant properties.展开更多
Halide perovskites is a recently emerged platform for the creation of efficient memristors.In turn,single-crystal inorganic perovskite would be new low-cost and flexible memory devices because of their excellent resis...Halide perovskites is a recently emerged platform for the creation of efficient memristors.In turn,single-crystal inorganic perovskite would be new low-cost and flexible memory devices because of their excellent resistive switching(RS)properties,without risk of chemical and mechanical stress-generated degradation,compared with the operational instability of general thin-film perovskite memristors.Moreover,miniaturization of perovskite memristors would be useful for creating high-density memory devices.Here we demonstrate the smallest CsPbBr3 perovskite nanomemristor with volatile unipolar RS characteristics which depends on the size of a single-crystal as a resistive layer due to its overall structural stability and low sensitivity to atmosphere conditions that helps to keep the stable RS switching over 1500 times with the lowest consumption power of 70 nW.To better understand the RS mechanism,we provide a comprehensive simulation of the evolution of mixed ionic-electronic charge carriers under current-voltage(I-V)tests using a one-dimensional drift-diffusion model.Because of the nonreactive nature of the contacts,the main mechanism of resistive state switching is potential barrier modulation of the Schottky contacts through the accumulation of migrating ions at the interfaces.Our findings pave the way for ultracompact memristors as well as shed light on RS mechanism in non-filamentary perovskitebased memory devices.展开更多
The anaerobic acid production experiments were conducted with the pretreated kitchen waste under pH adjustment.The results showed that pH 8 was considered to be the most suitable condition for acid production,especial...The anaerobic acid production experiments were conducted with the pretreated kitchen waste under pH adjustment.The results showed that pH 8 was considered to be the most suitable condition for acid production,especially for the formation of acetic acid and propionic acid.The average value of total volatile fatty acid at pH 8 was 8814 mg COD/L,1.5 times of that under blank condition.The average yield of acetic acid and propionic acid was 3302 mg COD/L and 2891 mg COD/L,respectively.The activities of key functional enzymes such as phosphotransacetylase,acetokinase,oxaloacetate transcarboxylase and succinylcoA transferase were all enhanced.To further explore the regulatory mechanisms within the system,the distribution of microorganisms at different levels in the fermentation system was obtained by microbial sequencing,results indicating that the relative abundances of Clostridiales,Bacteroidales,Chloroflexi,Clostridium,Bacteroidetes and Propionibacteriales,which were great contributors for the hydrolysis and acidification,increased rapidly at pH 8 compared with the blank group.Besides,the proportion of genes encoding key enzymes was generally increased,which further verified the mechanism of hydrolytic acidification and acetic acid production of organic matter under pH regulation.展开更多
Volatile organic chemicals(VOC)have been identified as hazardous pollutants impairing human health.While whether the VOC exposure was associated with hyperuricemia is yet clarified.All the data was acquired from 6 sur...Volatile organic chemicals(VOC)have been identified as hazardous pollutants impairing human health.While whether the VOC exposure was associated with hyperuricemia is yet clarified.All the data was acquired from 6 survey cycles of the National Health and Nutrition Examination Survey(NHANES)program(2005–2006,2011–2012,2013–2014,2015–2016,2017–2018,2017–2020).Hyperuricemia was defined as a serum uric acid(SUA)concentration exceeding 7 mg/mL in men or 6 mg/mL in women.Three quantile logistic regression modelswith varied covariateswere developed to analyze the correlation between hyperuricemia and volatile organic chemical metabolites(VOCs)in urine,and three quantile linear regression models were used for examining the correlation between VOCs and SUA.N-acetyl-S-(2-carboxyethyl)-l-cysteine(CEMA),N-acetyl-S-(3,4-dihydroxybutyl)-l-cysteine(DHBM),and phenylglyoxylic acid(PHGA)were identified to associated positively with increased hyperuricemia risk and uric acid level.Meanwhile,the weighted quantile sum(WQS)model suggested a positive association between VOCs exposure and hyperuricemia.These data indicate that VOC exposure potentially increases hyperuricemia risk,necessitating policies to mitigate VOC exposure.展开更多
Volatile organic compounds(VOCs)present significant risks to both human health and the environment.As a result,there has been increasing research on their formation processes,emission patterns,and emission reduction t...Volatile organic compounds(VOCs)present significant risks to both human health and the environment.As a result,there has been increasing research on their formation processes,emission patterns,and emission reduction technologies.Sintered ore,a key raw material in ironmaking,requires substantial amounts of fossil fuels such as coal and coke in its production,leading to significant VOC emissions.However,research on VOC emission patterns during the sintering process remains limited.Thus,the influence of factors such as moisture content in the sintering mixture,fuel type,fuel ratio,and coal-to-coke ratio on VOC emissions was investigated through sintering cup experiments.Additionally,the reaction pathways of hydrocarbons within the sintering bed were analyzed using temperature distribution and thermodynamic calculations.In the sintering process using coke powder,the emissions of total volatile organic compounds and non-methane hydrocarbons per ton of sintered ore are 18.78 and 11.14 g,respectively,whereas emissions from coal are substantially higher at 378.27 and 32.55 g.VOC emissions exhibit a linear correlation with the total volatile matter input during sintering,with most VOCs originating from volatile matter.The improved heat transfer conditions reduce the preheating zone thickness,allowing more VOCs to remain in the high-temperature region.展开更多
Serious fine particulate matter(PM_(2.5))pollution and rapidly increasing of ground-level ozone(O_(3))concentrations are concern issues in China.To achieve the comprehensive control of PM_(2.5)-O_(3) composite air pol...Serious fine particulate matter(PM_(2.5))pollution and rapidly increasing of ground-level ozone(O_(3))concentrations are concern issues in China.To achieve the comprehensive control of PM_(2.5)-O_(3) composite air pollution,exploring the common sources of PM_(2.5) and VOCs is essential.However,previous researches most carried out either PM_(2.5) or VOCs source appointment.In this study,we applied the ensemble source apportionment method to explore the impacts of common sources on PM_(2.5)-VOCs.Subsequently,we obtained the ensemble source impacts on O_(3) combining the extracted VOCs source profile and ozone formation potential.We found that the focus of environmentalmanagement and source control should be varied accordingly for different pollutants.Vehicle emission was the largest contributor(41%)to PM_(2.5)-VOCs,while industrial emission was the main common source(51%)to O_(3).The result showed that the O_(3) production rate is not only related to the VOCs emission,but also to the reactivity of VOCs.In addition,sensitivity tests revealed that temperature was the main factor affecting O_(3) formation.The study provides a framework to explore the common sources impact on PM_(2.5) and VOCs,which is benefit to address both PM_(2.5) and O_(3) mitigations.展开更多
The BZ oilfield in the Bohai Sea is a rare,highly volatile reservoir with fractures in the metamorphic rocks of buried hills.Clarifying the mechanism of gas injection for improving oil recovery and determining the opt...The BZ oilfield in the Bohai Sea is a rare,highly volatile reservoir with fractures in the metamorphic rocks of buried hills.Clarifying the mechanism of gas injection for improving oil recovery and determining the optimal way to deploy injection-production well networks are critical issues that must be urgently addressed for efficient oilfield development.Experimental research on the mixed-phase displacement mechanism through gas injection into indoor formation fluids was conducted to guide the efficient development of gas injection in oil fields.We established a model of dual-medium reservoir composition and researched the deployment strategy for a three-dimensional well network for gas injection development.The coupling relationship between key influencing factors of the well network and fracture development was also quantitatively analyzed.The results show that the solubility of the associated gas and strong volatile oil system injected into the BZ oilfield is high.This high solubility demonstrates a mixed-phase displacement mechanism involving intermediate hydrocarbons,dissolution and condensation of medium components,and coexistence of extraction processes.Injecting gas and crude oil can achieve a favorable mixing effect when the local formation pressure is greater than 35.79 MPa.Associated gas reinjection is recommended to supplement energy for developing the highly volatile oil reservoirs in the fractured buried hills of the BZ oilfield.This recommendation involves fully utilizing the structural position and gravity-assisted oil displacement mechanism to deploy an injection-production well network.Gas injection points should be constructed at the top of high areas,and oil production points should be placed at the middle and lower parts of low areas.This approach forms a spatial threedimensional well network.By adopting high inclination well development,the oil production well forms a 45°angle with the fracture direction,which increases the drainage area and enhances single-well production capacity.The optimal injection-production well spacing along the fracture direction is approximately 1000 m,while the reasonable well spacing in the vertical fracture direction is approximately 800 m.The research results were applied to the development practice of the buried hills in the BZ oilfield,which achieved favorable development results.These outcomes provide a valuable reference for the formulation of development plans and efficient gas injection development in similar oil and gas fields in buried hills.展开更多
基金supported by the Natural Science Foundation of Zhejiang Province,China(Grant No.LTGN24C020004)the Enterprise Cooperation Project,China(Grant No.HRJYH-202330)+1 种基金the Zhejiang Province Pioneer and Bellwethers Research&Development Project of Science and Technology,China(Grant No.2023C02014)the Central Public-Interest Scientific Institution Basal Research Fund,China(Grant No.CPSIBRFCNRRI-202303).
文摘To elucidate the variations in volatile organic compounds(VOCs)among widely cultivated japonica rice varieties in China and offer novel perspectives on flavor formation during rice-based beer brewing,nine prevalent Chinese japonica rice variaties were selected as experimental materials.Comprehensive analyses were conducted to investigate three key aspects:differences in VOCs among the selected japonica rice varieties,the retention of rice VOCs after beer brewing,and the influence of rice additives on beer sensory characteristics.Results showed that the total contents of VOCs in Wuyoudao 4(WYD4)and Nangeng 9108(NG9108)were significantly higher than those in the other varieties(P<0.05).The popcorn-flavor compound 2-acetyl-1-pyrroline(2-AP)was detected in Suigeng 27(SG27,26.80 ng/g),WYD4(25.25 ng/g),NG9108(21.18 ng/g),and Suigeng 18(SG18,11.62 ng/g),with the levels in the first three varieties significantly higher than those in SG18.Circular heatmap analysis classified the nine japonica varieties into three major categories:fragrant japonica from North China(WYD4),fragrant japonica from South China(NG9108),and others.Ten characteristic VOCs across the japonica varieties were identified by headspace solid-phase microextraction gas chromatography-mass spectrometry(HS-SPME-GC-MS).Using beer brewed with whole wheat as the control,we analyzed the VOCs and sensory characteristics of beer brewed with fragrant japonica rice as an additive.We found that rice VOCs were not detected in beer brewed with fragrant japonica rice as an additive.Adding rice promoted the formation of banana-like flavors and reduced the beer’s richness and mellowness.
基金supported by the National Key R&D Program of China(No.2024YFC3714200)Guangxi Key Research and Development Program,China(No.Guike AB24010074)+2 种基金the National Natural Science Foundation of China(Nos.22276099,U24A20515 and 22361162668)the Natural Science Foundation of Jiangsu Province(No.BK20240036)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX24_1529).
文摘Temperature has a substantial impact on the emission of biogenic volatile organic compounds(BVOCs).Moder-ate warm temperatures,e.g.,30–40°C,could boost plant metabolism,increasing BVOC emissions.Against the backdrop of global warming,plants emit more BVOCs to cope with thermal stress,leading to elevated concen-trations of tropospheric ozone(O_(3))and secondary organic aerosols(SOA).In recent years,a considerable body of research has explored the interaction between tree species and BVOCs under the influence of various environ-mental factors.Although many studies have examined explored the temperature dependence of BVOC emissions in the past,few studies have conducted a comprehensive and in-depth investigation into the impacts of tempera-ture.This review summarizes the relevant studies on BVOCs in the past decade,including the main biosynthetic pathways,emission observation techniques and emission inventories,as well as how temperature affects isoprene and monoterpene emission rates and the formation of O_(3) and SOA.Our work offers a theoretical foundation and guidance for future efforts to advance the comprehension of BVOC emission characteristics and develop strategies to mitigate secondary pollution.
文摘The volatile chemical components of flowers,leaves,stems,and roots of Rabdosia rubescens were extracted by solid-phase microextraction method,and the extracts were analyzed by gas chromatography-mass spectrometry.A total of 40 chemical constituents were identified from the essential oils of the roots,stems,leaves,and flowers of R.rubescens.Among them,15,24,15,and 17 chemical components were identified from the roots,stems,leaves,and flowers of.rubescens respectively.In the roots,camphene(38.29%),calarene(7.25%),o-cymene(5.31%),elsholtzia ketone(4.49%)were identified as the major constituents.In the stems,the main components were benzaldehyde(37.81%),elsholtzia ketone(26.14%),β-caryophyllene(5.03%).The leaves were characterized primarily by elsholtzia ketone(73.85%),β-caryophyllene(5.95%)and benzaldehyde(3.31%).In the flowers,elsholtzia ketone(63.18%),β-caryophyllene(10.68%),bicyclogermacrene(4.90%)and benzaldehyde(4.58%)were identified to be the predominant compounds.These results indicate that the essential oils from different organs of R.rubescens exhibit distinct chemical compositions.The differences were particularly between the aboveground and belowground organs.
基金supported by the National Natural Science Foundation of China(Grant Nos.W2433051,32272663,32302520,and 32060655)National Key Research and Development Program(Grant No.2023YFD2300800)+3 种基金the Guangzhou Science and Technology Project(Grant No.202206010023)Yunnan Provincial Science and Technology Department Local Universities Joint Project(Grant No.202101BA070001-166)China Litchi and Longan Industry Technology Research System(CARS-32-08),Talent Introduction Project of Kunming University(Grant No.XJ20220003)Yunnan Provincial Natural Science Basic Research Fund General Program(Grant No.202501AT070058).
文摘Auxin is a phytohormone that is critical for plant growth and development.The molecular mechanisms underlying auxin biosynthesis,transport,and signaling are well understood.However,the complex mechanism by which auxin regulates plant volatile biosynthesis has seldom been studied.A growing array of unique auxin-related plant volatiles have recently been discovered.This study comprehensively reviews recent findings on auxin and auxin-related genes and their roles in the formation of plant volatiles.This study highlights the implications of exogenous auxin application,genes involved in auxin signaling transduction,and hormonal crosstalk during volatile compound biosynthesis in plants.Plant hormones facilitate the integration of multiple volatile signals to enable specific and appropriate responses to environmental changes.This will improve our overall understanding of the role of auxins in plant volatile compound metabolic pathways.Recent studies have delineated the considerable advancements in elucidating the intricate methods by which plants employ auxin regulatory pathways to modulate the release of volatile chemicals during development and growth,along with prospective research paths.
基金supported by the R&D Projects in Key Areas of Guangdong Province(2023B0202080003)the National Natural Science Foundation of China(32472272,32302135,32072291)+1 种基金“Pioneer”and“Leading Goose”R&D Program of Zhejiang(2023C02006)Youth S&T Talent Support Programme of Guangdong Provincial Association for Science and Technology(SKXRC202401)。
文摘Edible oils derived from aquatic products are rich in lipids beneficial to human health.However,the volatile flavor characteristics of flesh oil and liver oil from Doederleinia berycoides remain unclear.In this study,flesh oil and liver oil were extracted from Doederleinia berycoides,revealing different fatty acid compositions and contents.Lipidomics analysis identified a total of 124 differential lipids between the flesh oil and liver oil,including 42 glycerophospholipids(GPs),33 glycerolipids(GLs),23 free fatty acids(FAs),13 sphingolipids(SPs),10 sterols(STs),and 3 prenol lipids(PRs).Analysis using HS-GC-IMS identified 12 key volatile compounds that significantly contributed to the distinct volatile flavors of the flesh and liver oils.The volatile flavors originated from these volatile compounds,which had different Relative Odor Activity Values(ROAVs).Further results from HSSPME-GC-MS showed that the volatile flavors of the flesh oil and liver oil were respectively attributed to 64 and 35 volatile compounds,each with unique key volatile compounds exhibiting different ROAVs.There were significant positive or negative correlations between 18 key differential lipids and 24 volatile compounds in both flesh oil and liver oil.Therefore,the complex lipid profiles are responsible for the unique volatile flavors of flesh oil and liver oil,and the differential lipids play a central role in their volatile flavor formation.These findings provide a foundation for understanding the volatile flavor differences in fish oils and hold promise for further exploration of the molecular mechanisms underlying oil volatile flavors.
基金supported by the Shanghai 3-year Public Health Action Plan(grant number:GWVI-11.1-39).
文摘Cyclic volatile methyl siloxanes(cVMSs)are widely used in industrial and consumer products because of their thermal stability,low reactivity,and reduced surface tension[1].Their extensive use has resulted in environmental pollution globally.Recognized as very persistent and very bioaccumulative(vPvB),compounds such as octamethylcyclotetrasiloxane(D4),decamethylcyclopentasiloxane(D5),and dodecamethylcyclohexasiloxane(D6)are regulated in the European Union[2]and are monitored worldwide.
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 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.
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 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 Natural Science Foundation of China(Grant Nos.32120103010,32002050)Beijing Joint Research Program for Germplasm Innovation and New Variety Breeding(Grant No.G20220628003-03)the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences。
文摘Tomato is an important economic crop all over the world.Volatile flavors in tomato fruit are key factors influencing consumer liking and commercial quality.However,the regulatory mechanism controlling the volatile flavors of tomatoes is still not clear.Here,we integrated the metabolome and transcriptome of the volatile flavors in tomato fruit to explore the regulatory mechanism of volatile flavor formation,using wild and cultivated tomatoes with significant differences in flavors.A total of 35 volatile flavor compounds were identified,based on the solid phase microextraction-gas chromatography-mass spectrometry(SPME-GC-MS).The content of the volatiles,affecting fruit flavor,significantly increased in the transition from breaker to red ripe fruit stage.Moreover,the total content of the volatiles in wild tomatoes was much higher than that in the cultivated tomatoes.The content variations of all volatile flavors were clustered into 10 groups by hierarchical cluster and Pearson coefficient correlation(PCC)analysis.The fruit transcriptome was also patterned into 10 groups,with significant variations both from the mature green to breaker fruit stage and from the breaker to red ripe fruit stage.Combining the metabolome and the transcriptome of the same developmental stage of fruits by co-expression analysis,we found that the expression level of 1182 genes was highly correlated with the content of volatile flavor compounds,thereby constructing two regulatory pathways of important volatile flavors.One pathway is tetrahydrothiazolidine N-hydroxylase(SlTNH1)-dependent,which is regulated by two transcription factors(TFs)from the bHLH and AP2/ERF families,controlling the synthesis of 2-isobutylthiazole in amino acid metabolism.The other is lipoxygenase(Sl LOX)-dependent,which is regulated by one TF from the HD-Zip family,controlling the synthesis of hexanal and(Z)-2-heptenal in fatty acid metabolism.Dual-luciferase assay confirmed the binding of b HLH and AP2/ERF to their structural genes.The findings of this study provide new insights into volatile flavor formation in tomato fruit,which can be useful for tomato flavor improvement.
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(Nos.42022051,U21A2028,and 42305124)the Youth Innovation Promotion Association CAS(No.Y202089)the HFIPS Director’s Fund(Nos.BJPY2023A02,YZJJ202101,and YZJJ2023QN01).
文摘Vertical detection of volatile organic compounds(VOCs)is essential to expend our understanding of the distribution characteristics of VOCs and improve the predictive ability of existing air qualitymodels.In this work,we report the development of a sorbent tube sampler based on an unmanned aerial vehicle(UAV)platform.Vertical profile measurement of VOCs with a vertical resolution of 25mwas achieved.The sampler consists of five lightweight VOC sorbent tubes and a 5-way solenoid valve,making it available for collecting five atmospheric VOC samples in a single flight with a time response of less than 30min.The samplerweighed∼1.45 kg and had dimensions of 240mm×220mm×100mmwith small penetration loss(<10%)under 4-liter sampling conditions(flow rate of 200 mL/min).Commercialized SUMMA canisters were used as experimental controls to investigate the possible loss of self-made sampler for target compounds in the same sampling process.Comparison experiment on the ground showed that the concentration differences for all VOC species were lower than 0.14μg/m3,proving the good reliability for VOCs measurements using sorbent tube sampler.The UAV platform also incorporated online instruments for meteorological parameters and O_(3) measurement.The sampler was successfully applied to characterize the vertical profiles of VOCs up to 100 m in October 2023 in the Huaihe River Basin of China.The UAV platform and the sorbent tube sampler demonstrate good performance and will be a valuable and reliable tool for vertical VOCs measurement.
基金supported by the Key Research and Development Program of Hunan Province of China(No.2022NK2036)Xiangxi Prefecture Science and Technology Plan Project"School-Local Integration"Special Project(No.2022001)the scientific research project of Hunan Provincial Department of Education(No.22B0520).
文摘Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in China.In vine tea processing,a large amount of broken tea is produced,which has low commercial value.Methods:This study investigates the influence of different extraction methods(room temperature water extraction,boiling water extraction,ultrasonic-assisted room temperature water extraction,and ultrasonic-assisted boiling water extraction,referred to as room temperature water extraction(RE),boiling water extraction(BE),ultrasonic assistance at room temperature water extraction(URE),and ultrasonic assistance in boiling water extraction(UBE))on the yield,dihydromyricetin(DMY)content,free amino acid composition,volatile aroma components,and antioxidant properties of vine tea extracts.Results:A notable influence of extraction temperature on the yield of vine tea extracts(P<0.05),with BE yielding the highest at 43.13±0.26%,higher than that of RE(34.29±0.81%).Ultrasound-assisted extraction significantly increased the DMY content of the extracts(P<0.05),whereas DMY content in the RE extracts was 59.94±1.70%,that of URE reached 66.14±2.78%.Analysis revealed 17 amino acids,with L-serine and aspartic acid being the most abundant in the extracts,nevertheless ultrasound-assisted extraction reduced total free amino acid content.Gas chromatography-mass spectrometry analysis demonstrated an increase in the diversity and quantity of compounds in the vine tea water extracts obtained through ultrasonic-assisted extraction.Specifically,69 and 68 volatile compounds were found in URE and UBE extracts,which were higher than the number found in RE and BE extracts.In vitro,antioxidant activity assessments revealed varying antioxidant capacities among different extraction methods,with RE exhibiting the highest DPPH scavenging rate,URE leading in ABTS•+free radical scavenging,and BE demonstrating superior ferric ion reducing antioxidant activity.Conclusion:The findings suggest that extraction methods significantly influence the chemical composition and antioxidant properties of vine tea extracts.Ultrasonic-assisted extraction proved instrumental in elevating the DMY content in vine tea extracts,thereby enriching its flavor profile while maintaining its antioxidant properties.
基金supported by the Russian Science Foundation(project number 24-62-00022)for data analysis and by Priority 2030 Federal Academic Leadership Program for samples synthesis.
文摘Halide perovskites is a recently emerged platform for the creation of efficient memristors.In turn,single-crystal inorganic perovskite would be new low-cost and flexible memory devices because of their excellent resistive switching(RS)properties,without risk of chemical and mechanical stress-generated degradation,compared with the operational instability of general thin-film perovskite memristors.Moreover,miniaturization of perovskite memristors would be useful for creating high-density memory devices.Here we demonstrate the smallest CsPbBr3 perovskite nanomemristor with volatile unipolar RS characteristics which depends on the size of a single-crystal as a resistive layer due to its overall structural stability and low sensitivity to atmosphere conditions that helps to keep the stable RS switching over 1500 times with the lowest consumption power of 70 nW.To better understand the RS mechanism,we provide a comprehensive simulation of the evolution of mixed ionic-electronic charge carriers under current-voltage(I-V)tests using a one-dimensional drift-diffusion model.Because of the nonreactive nature of the contacts,the main mechanism of resistive state switching is potential barrier modulation of the Schottky contacts through the accumulation of migrating ions at the interfaces.Our findings pave the way for ultracompact memristors as well as shed light on RS mechanism in non-filamentary perovskitebased memory devices.
基金supported by the National Key Research and Development Program of China(No.2019YFC1906304).
文摘The anaerobic acid production experiments were conducted with the pretreated kitchen waste under pH adjustment.The results showed that pH 8 was considered to be the most suitable condition for acid production,especially for the formation of acetic acid and propionic acid.The average value of total volatile fatty acid at pH 8 was 8814 mg COD/L,1.5 times of that under blank condition.The average yield of acetic acid and propionic acid was 3302 mg COD/L and 2891 mg COD/L,respectively.The activities of key functional enzymes such as phosphotransacetylase,acetokinase,oxaloacetate transcarboxylase and succinylcoA transferase were all enhanced.To further explore the regulatory mechanisms within the system,the distribution of microorganisms at different levels in the fermentation system was obtained by microbial sequencing,results indicating that the relative abundances of Clostridiales,Bacteroidales,Chloroflexi,Clostridium,Bacteroidetes and Propionibacteriales,which were great contributors for the hydrolysis and acidification,increased rapidly at pH 8 compared with the blank group.Besides,the proportion of genes encoding key enzymes was generally increased,which further verified the mechanism of hydrolytic acidification and acetic acid production of organic matter under pH regulation.
基金supported by the National Natural Science Foundation of China(No.82360437)the Key Research and Development Program of Hunan Province(No.2021SK2012).
文摘Volatile organic chemicals(VOC)have been identified as hazardous pollutants impairing human health.While whether the VOC exposure was associated with hyperuricemia is yet clarified.All the data was acquired from 6 survey cycles of the National Health and Nutrition Examination Survey(NHANES)program(2005–2006,2011–2012,2013–2014,2015–2016,2017–2018,2017–2020).Hyperuricemia was defined as a serum uric acid(SUA)concentration exceeding 7 mg/mL in men or 6 mg/mL in women.Three quantile logistic regression modelswith varied covariateswere developed to analyze the correlation between hyperuricemia and volatile organic chemical metabolites(VOCs)in urine,and three quantile linear regression models were used for examining the correlation between VOCs and SUA.N-acetyl-S-(2-carboxyethyl)-l-cysteine(CEMA),N-acetyl-S-(3,4-dihydroxybutyl)-l-cysteine(DHBM),and phenylglyoxylic acid(PHGA)were identified to associated positively with increased hyperuricemia risk and uric acid level.Meanwhile,the weighted quantile sum(WQS)model suggested a positive association between VOCs exposure and hyperuricemia.These data indicate that VOC exposure potentially increases hyperuricemia risk,necessitating policies to mitigate VOC exposure.
基金supported by the National Key Research and Development Program of China(2022YFC3901405)the National Program for Supporting Postdoctoral Researchers of China(GZC20230016)the 2023 Provincial Quality Project Program for Nurturing People in the New Era(Graduate Education)(2023xscx065).
文摘Volatile organic compounds(VOCs)present significant risks to both human health and the environment.As a result,there has been increasing research on their formation processes,emission patterns,and emission reduction technologies.Sintered ore,a key raw material in ironmaking,requires substantial amounts of fossil fuels such as coal and coke in its production,leading to significant VOC emissions.However,research on VOC emission patterns during the sintering process remains limited.Thus,the influence of factors such as moisture content in the sintering mixture,fuel type,fuel ratio,and coal-to-coke ratio on VOC emissions was investigated through sintering cup experiments.Additionally,the reaction pathways of hydrocarbons within the sintering bed were analyzed using temperature distribution and thermodynamic calculations.In the sintering process using coke powder,the emissions of total volatile organic compounds and non-methane hydrocarbons per ton of sintered ore are 18.78 and 11.14 g,respectively,whereas emissions from coal are substantially higher at 378.27 and 32.55 g.VOC emissions exhibit a linear correlation with the total volatile matter input during sintering,with most VOCs originating from volatile matter.The improved heat transfer conditions reduce the preheating zone thickness,allowing more VOCs to remain in the high-temperature region.
基金supported by the National Key Research and Development Program of China(Nos.2023YFC3709500,2023YFC3709502 and 2022YFC3703400)the National Natural Science Foundation of China(No.42077191)+1 种基金the Fundamental Research Funds for the Central Universities(No.63233054)Tianjin Science and Technology Plan Project(No.18PTZWHZ00120).
文摘Serious fine particulate matter(PM_(2.5))pollution and rapidly increasing of ground-level ozone(O_(3))concentrations are concern issues in China.To achieve the comprehensive control of PM_(2.5)-O_(3) composite air pollution,exploring the common sources of PM_(2.5) and VOCs is essential.However,previous researches most carried out either PM_(2.5) or VOCs source appointment.In this study,we applied the ensemble source apportionment method to explore the impacts of common sources on PM_(2.5)-VOCs.Subsequently,we obtained the ensemble source impacts on O_(3) combining the extracted VOCs source profile and ozone formation potential.We found that the focus of environmentalmanagement and source control should be varied accordingly for different pollutants.Vehicle emission was the largest contributor(41%)to PM_(2.5)-VOCs,while industrial emission was the main common source(51%)to O_(3).The result showed that the O_(3) production rate is not only related to the VOCs emission,but also to the reactivity of VOCs.In addition,sensitivity tests revealed that temperature was the main factor affecting O_(3) formation.The study provides a framework to explore the common sources impact on PM_(2.5) and VOCs,which is benefit to address both PM_(2.5) and O_(3) mitigations.
文摘The BZ oilfield in the Bohai Sea is a rare,highly volatile reservoir with fractures in the metamorphic rocks of buried hills.Clarifying the mechanism of gas injection for improving oil recovery and determining the optimal way to deploy injection-production well networks are critical issues that must be urgently addressed for efficient oilfield development.Experimental research on the mixed-phase displacement mechanism through gas injection into indoor formation fluids was conducted to guide the efficient development of gas injection in oil fields.We established a model of dual-medium reservoir composition and researched the deployment strategy for a three-dimensional well network for gas injection development.The coupling relationship between key influencing factors of the well network and fracture development was also quantitatively analyzed.The results show that the solubility of the associated gas and strong volatile oil system injected into the BZ oilfield is high.This high solubility demonstrates a mixed-phase displacement mechanism involving intermediate hydrocarbons,dissolution and condensation of medium components,and coexistence of extraction processes.Injecting gas and crude oil can achieve a favorable mixing effect when the local formation pressure is greater than 35.79 MPa.Associated gas reinjection is recommended to supplement energy for developing the highly volatile oil reservoirs in the fractured buried hills of the BZ oilfield.This recommendation involves fully utilizing the structural position and gravity-assisted oil displacement mechanism to deploy an injection-production well network.Gas injection points should be constructed at the top of high areas,and oil production points should be placed at the middle and lower parts of low areas.This approach forms a spatial threedimensional well network.By adopting high inclination well development,the oil production well forms a 45°angle with the fracture direction,which increases the drainage area and enhances single-well production capacity.The optimal injection-production well spacing along the fracture direction is approximately 1000 m,while the reasonable well spacing in the vertical fracture direction is approximately 800 m.The research results were applied to the development practice of the buried hills in the BZ oilfield,which achieved favorable development results.These outcomes provide a valuable reference for the formulation of development plans and efficient gas injection development in similar oil and gas fields in buried hills.
