Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N de...Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N deposition affects specific key soil enzymes that mediate plant-soil feedback of grassland.Here,with a meta-analysis on 1446 cases from field observations in China,we show that N deposition differently affects soil enzymes associated with soil biochemical processes.Specifically,N-promoted C,N,and P-acquiring hydrolase activities significantly increased by 8.73%,7.67%,and 8.69%,respectively,related to an increase in microbial-specific enzyme secretion.The increased relative N availability and soil acidification were two potential mechanisms accounting for the changes in soil enzyme activities with N enrichment.The mixed N addition in combination of NH_(4)NO_(3) and urea showed greater stimulation effect on soil enzyme activities.However,the high rate and long-term N addition tended to weaken the positive responses of soil C-,Nand P-acquiring hydrolase activities to N enrichment.Spatially increased mean annual precipitation and temperature primarily promoted the positive effects of N enrichment on N-and P-acquiring hydrolase activities,and the stimulation of C-and N-acquiring hydrolase activities by N enrichment was intensified with the increase in soil depth.Finally,multimodal inference showed that grassland type was the most important regulator of responses of microbial C,N,and P-acquiring hydrolase activities to N enrichment.This meta-analysis provides a comprehensive insight into understanding the key role of N enrichment in shaping soil enzyme activities of grassland ecosystems.展开更多
The problem of corruption represents one of the biggest and most dangerous social,legal and security challenges of today,which is especially present in countries that are going through the transition process.We are ta...The problem of corruption represents one of the biggest and most dangerous social,legal and security challenges of today,which is especially present in countries that are going through the transition process.We are talking about countries that until recently were organized according to the principles of communism and socialism,and then,after global changes,transitioned to a capitalist arrangement,which also caused numerous accompanying problems and difficulties.Corruption is certainly one of those problems.The countries of Southeast Europe have struggled,and are still struggling,with the dangerous problem of corruption.Hardly acceptable changes and resistance to them still allow corruption to be maintained and persist,despite serious efforts to eradicate it,or at least put it within reasonable limits.展开更多
This study aims to determine the phytochemical composition and antioxidant activity(AA)of different plant parts(bulbs,stalk,leaves and flowers)of wild rosy garlic(Allium roseum)from Montenegro.The flower exhibited the...This study aims to determine the phytochemical composition and antioxidant activity(AA)of different plant parts(bulbs,stalk,leaves and flowers)of wild rosy garlic(Allium roseum)from Montenegro.The flower exhibited the highest concentration of total phenols(55.7 GAE/g d.e.),followed by the leaf(25.6mg GAE/g d.e.).The leaf displayed the highest concentration of total flavonoids(41.48 mg RE/g d.e.),followed by the flower(36.26 mg RE/g d.e.)and top part of the stalk(26.80 mg RE/g d.e.).The AA of different parts of A.roseum after 60 min of incubation decreased in the following order:flower(0.15mg/cm^(3))>upper stalk(0.32mg/cm^(3))>leaf(0.36mg/cm^(3))>basal stalk(0.80mg/cm^(3))>bulb(1.53 mg/cm^(3)).The flowers exhibited the lowest EC_(50) values,indicating the highest antioxidant potential throughout the entire incubation period.Among all plant parts analyzed,the flowers demonstrated the highest ferric reducing antioxidant power(FRAP),reaching 24.99 mg Fe^(2+)/g,thereby indicating their superior antioxidant potential.Given their edibility,pleasant flavor,and high nutritional value,A.roseum flowers may be considered a promising natural additive for functional food products or culinary applications,including dish enhancement and decoration.展开更多
Semitransparent organic photovoltaics(ST-OPVs)for building integration represent a pivotal direction in the development of photovoltaic industry.Solution-processed silver nanowires(AgNWs)are considered promising candi...Semitransparent organic photovoltaics(ST-OPVs)for building integration represent a pivotal direction in the development of photovoltaic industry.Solution-processed silver nanowires(AgNWs)are considered promising candidates for transparent electrodes in semitransparent devices due to their high transparency-conductivity-efficiency merit,large-scale processability,and low cost.In this work,we develop two solution-processed organic–inorganic hybrid electrodes,named AgNWs-PD and AgNWsPC,utilizing AgNWs as the conductive framework and aliphatic amine-functionalized perylene-diimide(PDINN)as the sandwiched material,while AgNWs-PC exhibits significantly improved electrical conductivity and enhanced contact area with the underlying electron transport layer.The optimized device achieves a power conversion efficiency of 9.45%with an open circuit voltage of 0.846 V,a high filling factor of 75.4%,and an average visible transmittance(AVT)of 44.0%,delivering an outstanding light utilization efficiency(LUE)of 4.16%,which is the highest reported value for all solution-processed ST-OPVs.In addition,by coupling a 30-nm tellurium dioxide atop AgNWs-PC,the bifaciality factor of derivative devices improves from 73.7%to 99.4%,while maintaining a high bifacial LUE over 3.7%.Our results emphasize the superiority and effectiveness of PDINN-sandwiched AgNWs electrodes for highperformance and all solution-processed ST-OPVs.展开更多
Perovskite materials have emerged as promising candidates for various optoelectronic applications owing to their remarkable optoelectronic properties and easy solution processing.Metal halide perovskites,as direct-ban...Perovskite materials have emerged as promising candidates for various optoelectronic applications owing to their remarkable optoelectronic properties and easy solution processing.Metal halide perovskites,as direct-bandgap semiconductors,show an excellent class of optical gain media,which makes them applicable to the development of low-threshold or even thresholdless lasers.This mini review explores recent advances in perovskite-based laser technology,which have led to chiral single-mode microlasers,low-threshold,external-cavity-free lasing devices at room temperature,and other innovative device architectures.Including self-assembled CsPbBr3 microwires that enable edge lasing.Realized continuous-wave(CW)pumped lasing by perovskite material pushes the research of electrically driven perovskite lasers.The capacity to regulate charge transport in halide perovskites further enhances their applicability in optoelectronic systems.The ongoing integration of perovskite materials with advanced photonic structures holds excellent potential for future innovations in laser technology and photovoltaics.We also highlight the transformative potential of perovskite materials in advancing the next generation of efficient and integrated optoelectronic devices.展开更多
Wide-bandgap mixed-halide perovskites,particularly CsPbIBr_(2),hold great promise for multi-junction solar cells due to their well-matched bandgap and all-inorganic material system.However,their inherent susceptibilit...Wide-bandgap mixed-halide perovskites,particularly CsPbIBr_(2),hold great promise for multi-junction solar cells due to their well-matched bandgap and all-inorganic material system.However,their inherent susceptibility to light-induced phase segregation(LIPS)limits efficiency and stability.In this work,we investigate the effect of three organic additives-4-cyclopentene-1,3-dione(CPD),maleimide(HPD),and 3,4-dibromo-1H-pyrrole-2,5(2H,5H)-dione(BrPD)-on LIPS in wide-bandgap CsPbIBr_(2)perovskite films.The additives form various chemical interactions,including coordination bonds,hydrogen bonds,and ionic bonds,with I^(-)and undercoordinated Pb^(2+)ions,among which BrPD has the strongest interaction.This interaction regulates crystallization and improves film morphology.The BrPD-modified films have the largest grain size and the highest light stability,suppressing LIPS,enhancing carrier transfer,and improving device performance.BrPD-modified CsPbIBr_(2)-based solar cells achieve a power conversion efficiency(PCE)of 11.34%,outperforming the control(8.96%)and other additives.Moreover,BrPDmodified devices show excellent stability,retaining 94%of their initial PCE after 60 min of continuous light exposure.This work highlights the potential of strategically selected organic additives to enhance the stability and performance of perovskite solar cells,offering valuable insights for the design of high-efficiency and long-lasting perovskite-based optoelectronic devices.展开更多
Coal pillar design has historically assigned a factor of safety(Fo S) or stability factor(SF) according to their estimated strength and the assumed overburden load acting on them. Acceptable Fo S values have been assi...Coal pillar design has historically assigned a factor of safety(Fo S) or stability factor(SF) according to their estimated strength and the assumed overburden load acting on them. Acceptable Fo S values have been assigned based on past mining experience or a statistical link between Fo S and probability of failure(Po F). Pillar width-to-height(w/h) ratio has long been established as having a material influence on both pillar strength and its potential failure mode. However, there has been significant disagreement on using both factor of safety(Fo S) and w/h as part of pillar system stability criterion, as compared to using Fo S in isolation. This paper will argue that there are valid technical reasons to bring w/h ratio into system stability criteria(other than its influence on pillar strength), as it is related to the post-failure stiffness of the pillar, as measured in situ, and its interaction with overburden stiffness. When overburden stiffness is also brought into pillar system stability considerations, two issues emerge. The first is the width-todepth(W/D) ratio of the panel and whether it is sub-critical or super-critical from a surface subsidence perspective. The second relates to a re-evaluation of pillar Fo S based on whether the pillar is in an elastic or non-elastic(i.e., post-yield) state in its as-designed condition, as this is relevant to maintaining overburden stiffness at the highest possible level. The significance of the model is the potential to maximise both reserve recovery and mining efficiencies without any discernible increase in geotechnical risk, particularly in thick seams and higher depth of cover mining situations. At a time when mining economics are, at best, marginal, removing potentially unnecessary design conservatism is of interest to all mine operators and is an important topic for discussion amongst the geotechnical community.展开更多
The Jinchuan Ni-Cu-PGE deposit（〉500 Mt @1.2%Ni,0.7%Cu,～0.4 g/t PGE）,one of the largest magmatic sulphide deposits in the world,is located within the westernmost terrane of the North China Craton.It is hosted withi...The Jinchuan Ni-Cu-PGE deposit（〉500 Mt @1.2%Ni,0.7%Cu,～0.4 g/t PGE）,one of the largest magmatic sulphide deposits in the world,is located within the westernmost terrane of the North China Craton.It is hosted within the 6.5 km long,Neoproterozoic（～0.83 Ga） Jinchuan ultramafic intrusion,emplaced as a sill-like body into a Palaeoproterozoic suite of gneisses,migmatites,marbles and amphibolites,below an active intracratonic rift.The parental magma was high-Mg basalt,generated through melting of subcrustal lithospheric mantle by a mantle plume during the initiation of Rodinia supercontinent breakup.The lower Palaeozoic collision of the exotic Qilian Block with the breakup-related southern margin of the craton accreted a subduction complex,and emplaced voluminous granitic intrusions and foreland basin sequences within the craton,to as far north as Jinchuan.During the Cainozoic,allochthonous lower Palaeozoic rocks were thrust up to 300 km to the northeast over cratonic basement,to within 25 km of the Jinchuan deposit.The Jinchuan ultramafic intrusion was injected into three interconnected sub-chambers,each containing a separate orebody.It essentially comprises an olivine-orthopyroxene-chromite cumulate,with interstitial orthopyroxene,clinopyroxene,plagioclase and phlogopite,and is predominantly composed of lherzolite（～80%）,with an outer rim of olivine pyroxenite and cores of mineralised dunite.Mineralisation occurs as disseminated and net-textured sulphides,predominantly within the dunite,with lesser,PGE rich lenses,late massive sulphide accumulations,small copper rich pods and limited mineralised diopside skarn in wall rock marbles.The principal ore minerals are pyrrhotite（the dominant sulphide）,pentlandite,chalcopyrite,cubanite,mackinawite and pyrite,with a variety of platinum group minerals and minor gold.The deposit underwent significant post-magmatic tremolite-actinolite,chlorite,serpentine and magnetite alteration.The volume of thejinchuan intrusion accounts for 〈3% of the total parental magma required to generate the contained olivine and sulphide.It is postulated that mafic melt,intruded into the lower crust,hydraulically supported by density contrast buoyancy from below the Moho,ponded in a large staging chamber,where crystallisation and settling formed a lower sulphide rich mush.This mush was subsequently injected into nearby shallow dipping faults to form the Jinchuan intrusion.展开更多
Human activities alter land use patterns and affect landscape sustainability. It is therefore very important to investigate the relationship between land use change and human activities. This study focuses on the dete...Human activities alter land use patterns and affect landscape sustainability. It is therefore very important to investigate the relationship between land use change and human activities. This study focuses on the detection of changing land use patterns in the Yanhe River Basin in northern Loess Plateau of China between 1995 and 2008. Landscape metrics were used to analyze the changing land use patterns and to explore the related anthropogenic driving forces. Results show that:1) Totally, 186 590 ha of croplands were converted into alternate land-use types (equivalent to 61.7% of the original cropland area). The majority of cropland areas were found to be converted into grassland and woodland areas (accounting for 55.9% and 4.9% respectively of the original cropland areas). 2) Both cropland and woodland demonstrated an increasing fragmentation tendency while grasslands showed a decreasing fragmentation tendency. 3) Multiple driving forces of land use change were thought to act together to changes in landscape metrics in the Yanhe River Basin. The anthropogenic driving forces were analyzed from four perspectives:ecological conservation policy, labor force transfer, industrial development, and rural settlement. The policy of the GfG (Grain for Green) project was the main driving factor which expedited the conversion from cropland to woodland and grassland. Industrial development was also found to affect land use change through the direct impact of economic activities such as oil exploration and agricultural production, or through indirect impacts such as the industrial structures readjustment. Labor force transfer from rural to urban areas was found to follow the industrial structure readjustment and further drove land use change from cropland to off-farm land use. Establishment of new tile-roofed houses instead of cave-type dwellings in rural settlements has helped to aggregate the original scattered land-use type of construction.展开更多
The main objective of the present study was to model the kinetics of essential oil extraction from swelled ground juniper berries by classic hydrodistillation(HD) and microwave-assisted hydrodistillation(MAHD). A new ...The main objective of the present study was to model the kinetics of essential oil extraction from swelled ground juniper berries by classic hydrodistillation(HD) and microwave-assisted hydrodistillation(MAHD). A new phenomenological kinetic model was developed on the basis of the juniper essential oil extraction mechanism that assumed three mass transfer processes occurring simultaneously: washing, unhindered diffusion and hindered diffusion. The new model was compared to the existing kinetic models. Among the tested models,the new model had the smallest mean relative percentage deviation and the highest corrected Akaike information criterion value. In addition, that, the new model was verified for HD and MAHD of essential oils from some other plant materials. On the basis of the above-mentioned facts, the new model can be recommended for modeling the kinetics of essential oil extraction by both HD and MAHD.展开更多
Objective:To determine the prevalence and risk factors associated with drug resistant tuberculosis(TB) in South West Nigeria.Methods:A retrospective study conducted among pulmonary tuberculosis(PTB) patients from Oyo ...Objective:To determine the prevalence and risk factors associated with drug resistant tuberculosis(TB) in South West Nigeria.Methods:A retrospective study conducted among pulmonary tuberculosis(PTB) patients from Oyo and Osun States in South West Nigeria who had their culture and drug susceptibility test performed at the institute of tropical medicine Antwerp, Belgium between 2007 and 2009.Data on the patient’s characteristics were retrieved from the TB treatment card.Univariate analysis was performed to assess the risk factors for drug resistant tuberculosis.The Level of significance was at P【0.05.Results:Among the 88 patients who had drug-susceptibility test result,there were 50 males and 38 females.Of the 88 patients,55(62.5%) had strains resistant to at least one or more anti-drugs.The proportion of TB cases with resistance to a single drug was 12.7%.The multi-drug resistant TB(MDR-TB) rate was 76.4%.The only significant factor for the development of drug resistance and MDR was the history of previous anti TB treatment(P【0.01).Other factors such as age[OR 0.86(0.35-2.13);P=0.72]and gender[OR 1.24 (0.49-3.14);P=0.62]were not significantly associated with drug resistance TB.Conclusions:The study highlighted a high prevalence of MDR-TB among the study population.History of previous TB treatment was associated with MDR-TB.There is an urgent need to conduct a national TB drug resistance survey to determine the actual burden and risk factors associated with drug resistance TB in the country.展开更多
There have been many design practices utilised within the coal mining industry to arrive at the minimum densities of primary ground support required during roadway development. This paper demonstrates the practical us...There have been many design practices utilised within the coal mining industry to arrive at the minimum densities of primary ground support required during roadway development. This paper demonstrates the practical use of empirical databases, and focuses on the main drivers for ground support as demonstrated in conceptual models. （;older Associates＇ empirical databases used for ground support include a primary roof support database and a primary fib support database. Both are based on successful ground support designs installed in mines in Australia, the US, the LIK, South Africa, New Zealand, and Europe. The term ＂successful＂ refers to those designs that were used on a repeated basis for the purpose of roadway devel- opment. The primary roof support database indicates that the major factors influencing successful roof support designs are roof competency, expressed as the coal mine roof rating （CMRR）, and in situ stress. In regard to the primary rib support database, it is evident from the current database that the primary factors affecting the capacity of rib support required for a successful design are roadway height and depth of cover. These databases have been used to help determine the minimum primary ground support designs required at many mine sites in Australasia, Europe, and the US. This paper will demonstrate the effectiveness and practicality of these databases at two selected mines in Australia and the US. In order to improve the primary rib support database, this paper will also propose a new rib deformation rating based on the addition of site specific coal strength data for the Australian mines. The proposed rat- ing attempts to capture the main variables that define the behaviour of a buckling column.展开更多
A bench-scale biopiling experiment was conducted to hydrocarbon bioremediation in a chronically contaminated soil compare the ability of different techniques to enhance petroleum After 195 days, 10%-32% removal of TP...A bench-scale biopiling experiment was conducted to hydrocarbon bioremediation in a chronically contaminated soil compare the ability of different techniques to enhance petroleum After 195 days, 10%-32% removal of TPHs （total petroleum hydrocarbons） occurred in unamended soil （control）. Biostimulation by inorganic nutrient addition enhanced TPH removal （49%） confirming that bioremediation was nutrient limited and the soil contained a well-adapted hydrocarbonoclastic microbial community. The addition of organic amendments including green waste at 25% and 50% （w/w） and a commercial product called DaramendTM had a further biostimulatory effect （50%-66%, 34%-59% and 69%-80% TPH removal respectively）. Bioaugmentation using two commercially available petroleum hydrocarbon degrading microbial cultures with nutrients enhanced TPH removal in the case of RemActivTM （60%-69%）, but had a marginal effect using Recycler 102 （49%-55%）. The effect of a non-ionic surfactant in green waste amended soil was variable （52%-72% TPH reduction）, but its potential to enhance biodegradation presumably by promoting contaminant bioavailability was demonstrated. High degradation of artificially added polycyclic aromatic hydrocarbons （PAHs） occurred after 106 days （75%-84%）, but significant differences between the control and treatments were unapparent, suggesting that spiked soils do not reflect the behavior of contaminants in genuinely polluted and weathered soil.展开更多
Background： This experiment was conducted to test the hypothesis that vitamin E（Vit E） and acetylsalicylic acid（ASA）, a cyclooxygenase-2（COX-2） inhibitor, will additively reduce the production of the immunosupp...Background： This experiment was conducted to test the hypothesis that vitamin E（Vit E） and acetylsalicylic acid（ASA）, a cyclooxygenase-2（COX-2） inhibitor, will additively reduce the production of the immunosuppressive molecule prostaglandin E_2（PGE_2） and hence reduce inflammatory responses in weaner pigs experimentally infected with an enterotoxigenic strain of E. coli.Methods： The experiment was conducted in a research facility with 192 individually-housed male weaner pigs（Landrace × Large White） weighing 6.6 ± 0.04 kg（mean ± SEM）. The pigs were experimentally infected with an enterotoxigenic strain of E. coli and were allocated to a 2 × 3 factorial design with the respective factors being without and with 125 ppm ASA and three levels of Vit E supplementation（50, 100 or 200 IU/kg diet, dl-α-tocopheryl acetate）.Results： Acetylsalicylic acid supplementation improved average daily gain（P 〈 0.05） and tended to improve feed：gain ratio（P 〈 0.10） during the first 14 d after weaning. Acetylsalicylic acid supplementation also improved（P 〈 0.001） amino acid utilization efficiency（as assessed by plasma urea level） and tended to decrease（P 〈 0.10） PGE2 production in the liver without affecting smal intestinal histology and tight junction protein mR NA expression in the jejunal epithelium. Vitamin E supplementation greater than 100 IU/kg diet sustained both the plasma Vit E concentration（P 〈 0.001） and plasma haptoglobin content（P 〈 0.001） after weaning. However, there was no additive effects of the combined supplementation of ASA and Vit E on performance, intestinal barrier function and inflammatory responses of weaned pigs.Conclusions： Although ASA and vitamin E improved amino acid utilization efficiency and reduced acute inflammatory responses, ASA and vitamin E did not additively reduce production of PGE2 and inflammatory responses in weaner pigs experimental y infected with an enterotoxigenic strain of E. coli.展开更多
Wheat grown under rain-fed conditions is often affected by drought worldwide. Future projections from a climate simulation model predict that the combined effects of increasing temperature and changing rainfall patter...Wheat grown under rain-fed conditions is often affected by drought worldwide. Future projections from a climate simulation model predict that the combined effects of increasing temperature and changing rainfall patterns will aggravate this drought scenario and may significantly reduce wheat yields unless appropriate varieties are adopted. Wheat is adapted to a wide range of environments due to the diversity in its phenology genes. Wheat phenology offers the opportunity to fight against drought by modifying crop developmental phases according to water availability in target environments. This review summa- rizes recent advances in wheat phenology research, including vernalization （Vrn）, photoperiod （Ppd）, and also dwarfing （Rht） genes. The alleles, haplotypes, and copy number variation identified for Vrn and Ppd genes respond differently in different climatic conditions, and thus could alter not only the development phases but also the yield. Compared with the model plant Arabidopsis, more phenology genes have not yet been identified in wheat; quantifying their effects in target environments would benefit the breeding of wheat for improved drought tolerance. Hence, there is scope to maximize yields in water-limited envi-ronments by deploying appropriate phenology gene combinations along with Rht genes and other important physiological traits that are associated with drought resistance.展开更多
Although it first appeared almost two years ago,the COVID-19 pandemic continues to have an impact on a global scale,in part due to newly emerging SARS-CoV-2 variants such as Delta and Lambda.The B.1.621 variant,first ...Although it first appeared almost two years ago,the COVID-19 pandemic continues to have an impact on a global scale,in part due to newly emerging SARS-CoV-2 variants such as Delta and Lambda.The B.1.621 variant,first identified in Colombia in January 2021,was classified as a variant of interest(VOI)and designated as Mu by the World Health Organization(WHO)in August 2021.However,its infectivity and resistance to neutralizing antibodies remain largely unknown.Here,in comparison to Delta,the Mu variant showed an unexpectedly enhanced immune resistance to inactivated vaccine-elicited antibodies.Nevertheless,Mu demonstrated less infectivity than Delta,implying a biological trade-off between viral transmission and immune escape.This study strongly calls for urgent evaluation of the protective efficacy of current COVID-19 vaccines against the Mu variant.Variants of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)are of concern regarding control of the global COVID-19 pandemic(Wang et al.,2021).The SARS-CoV-2 B.1.621 variant was first identified in Colombia in January 2021.Considering its epidemiological prevalence,the WHO defined B.1.621(named Mu)as a VOI on 30 August 2021.As of September 2021,the WHO has classified four variants of concern(VOC),i.e.,Alpha(B.1.1.7),Beta(B.1.351),Gamma(P.1),and Delta(B.1.617.2),and two VOI,i.e.,Lambda(C.37)and Mu(B.1.621)(Supplementary Figure S1A).展开更多
Atmospheric aerosol particle samples were collected using an Ambient Eight Stage（Non-Viable） Cascade Impactor Sampler in a typical urban area of Beijing from 27 th Sep.to 5th Oct.,2009.The surface chemistry of these...Atmospheric aerosol particle samples were collected using an Ambient Eight Stage（Non-Viable） Cascade Impactor Sampler in a typical urban area of Beijing from 27 th Sep.to 5th Oct.,2009.The surface chemistry of these aerosol particles was analyzed using Static Time of Flight-Secondary Ion Mass Spectrometry（Static TOF-SIMS）.The factors influencing surface compositions were evaluated in conjunction with the air pollution levels,meteorological factors,and air mass transport for the sampling period.The results show that a variety of organic ion groups and inorganic ions/ion groups were accumulated on the surfaces of aerosol particles in urban areas of Beijing;and hydrophobic organic compounds with short-or middle-chain alkyl as well as hydrophilic secondary inorganic compounds were observed.All these compounds have the potential to affect the atmospheric behavior of urban aerosol particles.PM1.1–2.1and PM3.3–4.7had similar elements on their surfaces,but some molecules and ionic groups demonstrated differences in Time of Flight-Secondary Ion Mass Spectrometry spectra.This suggests that the quantities of elements varied between PM1.1–2.1and PM3.3–4.7.In particular,more intense research efforts into fluoride pollution are required,because the fluorides on aerosol surfaces have the potential to harm human health.The levels of air pollution had the most significant influence on the surface compositions of aerosol particles in our study.Hence,heavier air pollution was associated with more complex surface compositions on aerosol particles.In addition,wind,rainfall,and air masses from the south also greatly influenced the surface compositions of these urban aerosol particles.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA28110300)National Natural Science Foundation of China(No.U23A2004)+3 种基金Natural Science Foundation of Jilin Province,China(No.YDZJ202201ZYTS522)Science and Technology Cooperation Program between Jilin Province and Chinese Academy of Sciences(No.2023SYHZ0053)Innovation Team Program of Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(No.2023CXTD02)the European Commission under Marie Sk?odowska-Curie(No.101034371)。
文摘Nitrogen(N)enrichment has resulted in widespread alteration of grassland ecosystem processes and functions mainly through disturbance in soil enzyme activities.However,we lack a comprehensive understanding of how N deposition affects specific key soil enzymes that mediate plant-soil feedback of grassland.Here,with a meta-analysis on 1446 cases from field observations in China,we show that N deposition differently affects soil enzymes associated with soil biochemical processes.Specifically,N-promoted C,N,and P-acquiring hydrolase activities significantly increased by 8.73%,7.67%,and 8.69%,respectively,related to an increase in microbial-specific enzyme secretion.The increased relative N availability and soil acidification were two potential mechanisms accounting for the changes in soil enzyme activities with N enrichment.The mixed N addition in combination of NH_(4)NO_(3) and urea showed greater stimulation effect on soil enzyme activities.However,the high rate and long-term N addition tended to weaken the positive responses of soil C-,Nand P-acquiring hydrolase activities to N enrichment.Spatially increased mean annual precipitation and temperature primarily promoted the positive effects of N enrichment on N-and P-acquiring hydrolase activities,and the stimulation of C-and N-acquiring hydrolase activities by N enrichment was intensified with the increase in soil depth.Finally,multimodal inference showed that grassland type was the most important regulator of responses of microbial C,N,and P-acquiring hydrolase activities to N enrichment.This meta-analysis provides a comprehensive insight into understanding the key role of N enrichment in shaping soil enzyme activities of grassland ecosystems.
文摘The problem of corruption represents one of the biggest and most dangerous social,legal and security challenges of today,which is especially present in countries that are going through the transition process.We are talking about countries that until recently were organized according to the principles of communism and socialism,and then,after global changes,transitioned to a capitalist arrangement,which also caused numerous accompanying problems and difficulties.Corruption is certainly one of those problems.The countries of Southeast Europe have struggled,and are still struggling,with the dangerous problem of corruption.Hardly acceptable changes and resistance to them still allow corruption to be maintained and persist,despite serious efforts to eradicate it,or at least put it within reasonable limits.
基金funded by the Ministry of Education Science and Technological Development of the Republic of Serbia with grant numbers 451-03-47/2025-01/200133 and 451-34403-47/2025-01/200189.
文摘This study aims to determine the phytochemical composition and antioxidant activity(AA)of different plant parts(bulbs,stalk,leaves and flowers)of wild rosy garlic(Allium roseum)from Montenegro.The flower exhibited the highest concentration of total phenols(55.7 GAE/g d.e.),followed by the leaf(25.6mg GAE/g d.e.).The leaf displayed the highest concentration of total flavonoids(41.48 mg RE/g d.e.),followed by the flower(36.26 mg RE/g d.e.)and top part of the stalk(26.80 mg RE/g d.e.).The AA of different parts of A.roseum after 60 min of incubation decreased in the following order:flower(0.15mg/cm^(3))>upper stalk(0.32mg/cm^(3))>leaf(0.36mg/cm^(3))>basal stalk(0.80mg/cm^(3))>bulb(1.53 mg/cm^(3)).The flowers exhibited the lowest EC_(50) values,indicating the highest antioxidant potential throughout the entire incubation period.Among all plant parts analyzed,the flowers demonstrated the highest ferric reducing antioxidant power(FRAP),reaching 24.99 mg Fe^(2+)/g,thereby indicating their superior antioxidant potential.Given their edibility,pleasant flavor,and high nutritional value,A.roseum flowers may be considered a promising natural additive for functional food products or culinary applications,including dish enhancement and decoration.
基金financially supported by the National Natural Science Foundation of China(21905137)the Research Grants Council of Hong Kong(15307922,C5037-18G,C4005-22Y)+1 种基金RGC Senior Research Fellowship Scheme(SRFS2223-5S01)the Hong Kong Polytechnic University:Sir Sze-yuen Chung Endowed Professorship Fund(8-8480)。
文摘Semitransparent organic photovoltaics(ST-OPVs)for building integration represent a pivotal direction in the development of photovoltaic industry.Solution-processed silver nanowires(AgNWs)are considered promising candidates for transparent electrodes in semitransparent devices due to their high transparency-conductivity-efficiency merit,large-scale processability,and low cost.In this work,we develop two solution-processed organic–inorganic hybrid electrodes,named AgNWs-PD and AgNWsPC,utilizing AgNWs as the conductive framework and aliphatic amine-functionalized perylene-diimide(PDINN)as the sandwiched material,while AgNWs-PC exhibits significantly improved electrical conductivity and enhanced contact area with the underlying electron transport layer.The optimized device achieves a power conversion efficiency of 9.45%with an open circuit voltage of 0.846 V,a high filling factor of 75.4%,and an average visible transmittance(AVT)of 44.0%,delivering an outstanding light utilization efficiency(LUE)of 4.16%,which is the highest reported value for all solution-processed ST-OPVs.In addition,by coupling a 30-nm tellurium dioxide atop AgNWs-PC,the bifaciality factor of derivative devices improves from 73.7%to 99.4%,while maintaining a high bifacial LUE over 3.7%.Our results emphasize the superiority and effectiveness of PDINN-sandwiched AgNWs electrodes for highperformance and all solution-processed ST-OPVs.
文摘Perovskite materials have emerged as promising candidates for various optoelectronic applications owing to their remarkable optoelectronic properties and easy solution processing.Metal halide perovskites,as direct-bandgap semiconductors,show an excellent class of optical gain media,which makes them applicable to the development of low-threshold or even thresholdless lasers.This mini review explores recent advances in perovskite-based laser technology,which have led to chiral single-mode microlasers,low-threshold,external-cavity-free lasing devices at room temperature,and other innovative device architectures.Including self-assembled CsPbBr3 microwires that enable edge lasing.Realized continuous-wave(CW)pumped lasing by perovskite material pushes the research of electrically driven perovskite lasers.The capacity to regulate charge transport in halide perovskites further enhances their applicability in optoelectronic systems.The ongoing integration of perovskite materials with advanced photonic structures holds excellent potential for future innovations in laser technology and photovoltaics.We also highlight the transformative potential of perovskite materials in advancing the next generation of efficient and integrated optoelectronic devices.
基金supported financially by the National Key R&D Program of China(Grant No.2023YFE0111500)the National Natural Science Foundation of China(Grant Nos.52321006,T2394480,T2394484,22109143,22475196,22479131)+11 种基金the Research Grants Council of Hong Kong(CRF C4005-22YRGC Senior Research Fellowship Scheme(SRFS2223-5S01))the Joint Fund for Provincial Science and Technology R&D Program of Henan(grant no.242301420051)the Opening Project of the State Key Laboratory of Advanced Technology for Float Glass(grant no.2022KF04)the China Postdoctoral Innovative Talent Support Program(grant no.BX2021271)the China Postdoctoral Science Foundation(grant no.2022M712851)the Graduate Education Reform Project of Henan Province(Grant No.2023SJGLX136Y)the Key R&D Special Program of Henan Province(Grant No.241111242000)the Program for Science&Technology Innovation Talents in Universities of Henan Province(Grant No.25HASTIT005)the Training Plan for Young Backbone Teachers of Zhengzhou University(Grant No.2023ZDGGJS017)the Joint Research Project of Puyang ShengtongJuyuan New Materials Co.Ltd.(Grant No.20230128A)。
文摘Wide-bandgap mixed-halide perovskites,particularly CsPbIBr_(2),hold great promise for multi-junction solar cells due to their well-matched bandgap and all-inorganic material system.However,their inherent susceptibility to light-induced phase segregation(LIPS)limits efficiency and stability.In this work,we investigate the effect of three organic additives-4-cyclopentene-1,3-dione(CPD),maleimide(HPD),and 3,4-dibromo-1H-pyrrole-2,5(2H,5H)-dione(BrPD)-on LIPS in wide-bandgap CsPbIBr_(2)perovskite films.The additives form various chemical interactions,including coordination bonds,hydrogen bonds,and ionic bonds,with I^(-)and undercoordinated Pb^(2+)ions,among which BrPD has the strongest interaction.This interaction regulates crystallization and improves film morphology.The BrPD-modified films have the largest grain size and the highest light stability,suppressing LIPS,enhancing carrier transfer,and improving device performance.BrPD-modified CsPbIBr_(2)-based solar cells achieve a power conversion efficiency(PCE)of 11.34%,outperforming the control(8.96%)and other additives.Moreover,BrPDmodified devices show excellent stability,retaining 94%of their initial PCE after 60 min of continuous light exposure.This work highlights the potential of strategically selected organic additives to enhance the stability and performance of perovskite solar cells,offering valuable insights for the design of high-efficiency and long-lasting perovskite-based optoelectronic devices.
文摘Coal pillar design has historically assigned a factor of safety(Fo S) or stability factor(SF) according to their estimated strength and the assumed overburden load acting on them. Acceptable Fo S values have been assigned based on past mining experience or a statistical link between Fo S and probability of failure(Po F). Pillar width-to-height(w/h) ratio has long been established as having a material influence on both pillar strength and its potential failure mode. However, there has been significant disagreement on using both factor of safety(Fo S) and w/h as part of pillar system stability criterion, as compared to using Fo S in isolation. This paper will argue that there are valid technical reasons to bring w/h ratio into system stability criteria(other than its influence on pillar strength), as it is related to the post-failure stiffness of the pillar, as measured in situ, and its interaction with overburden stiffness. When overburden stiffness is also brought into pillar system stability considerations, two issues emerge. The first is the width-todepth(W/D) ratio of the panel and whether it is sub-critical or super-critical from a surface subsidence perspective. The second relates to a re-evaluation of pillar Fo S based on whether the pillar is in an elastic or non-elastic(i.e., post-yield) state in its as-designed condition, as this is relevant to maintaining overburden stiffness at the highest possible level. The significance of the model is the potential to maximise both reserve recovery and mining efficiencies without any discernible increase in geotechnical risk, particularly in thick seams and higher depth of cover mining situations. At a time when mining economics are, at best, marginal, removing potentially unnecessary design conservatism is of interest to all mine operators and is an important topic for discussion amongst the geotechnical community.
文摘The Jinchuan Ni-Cu-PGE deposit（〉500 Mt @1.2%Ni,0.7%Cu,～0.4 g/t PGE）,one of the largest magmatic sulphide deposits in the world,is located within the westernmost terrane of the North China Craton.It is hosted within the 6.5 km long,Neoproterozoic（～0.83 Ga） Jinchuan ultramafic intrusion,emplaced as a sill-like body into a Palaeoproterozoic suite of gneisses,migmatites,marbles and amphibolites,below an active intracratonic rift.The parental magma was high-Mg basalt,generated through melting of subcrustal lithospheric mantle by a mantle plume during the initiation of Rodinia supercontinent breakup.The lower Palaeozoic collision of the exotic Qilian Block with the breakup-related southern margin of the craton accreted a subduction complex,and emplaced voluminous granitic intrusions and foreland basin sequences within the craton,to as far north as Jinchuan.During the Cainozoic,allochthonous lower Palaeozoic rocks were thrust up to 300 km to the northeast over cratonic basement,to within 25 km of the Jinchuan deposit.The Jinchuan ultramafic intrusion was injected into three interconnected sub-chambers,each containing a separate orebody.It essentially comprises an olivine-orthopyroxene-chromite cumulate,with interstitial orthopyroxene,clinopyroxene,plagioclase and phlogopite,and is predominantly composed of lherzolite（～80%）,with an outer rim of olivine pyroxenite and cores of mineralised dunite.Mineralisation occurs as disseminated and net-textured sulphides,predominantly within the dunite,with lesser,PGE rich lenses,late massive sulphide accumulations,small copper rich pods and limited mineralised diopside skarn in wall rock marbles.The principal ore minerals are pyrrhotite（the dominant sulphide）,pentlandite,chalcopyrite,cubanite,mackinawite and pyrite,with a variety of platinum group minerals and minor gold.The deposit underwent significant post-magmatic tremolite-actinolite,chlorite,serpentine and magnetite alteration.The volume of thejinchuan intrusion accounts for 〈3% of the total parental magma required to generate the contained olivine and sulphide.It is postulated that mafic melt,intruded into the lower crust,hydraulically supported by density contrast buoyancy from below the Moho,ponded in a large staging chamber,where crystallisation and settling formed a lower sulphide rich mush.This mush was subsequently injected into nearby shallow dipping faults to form the Jinchuan intrusion.
基金Under the auspices of National Natural Science Foundation of China(No.40930528)State Forestry Administration of China(No.201004058)External Cooperation Program of Chinese Academy of Sciences(No.29GJHZ0948)
文摘Human activities alter land use patterns and affect landscape sustainability. It is therefore very important to investigate the relationship between land use change and human activities. This study focuses on the detection of changing land use patterns in the Yanhe River Basin in northern Loess Plateau of China between 1995 and 2008. Landscape metrics were used to analyze the changing land use patterns and to explore the related anthropogenic driving forces. Results show that:1) Totally, 186 590 ha of croplands were converted into alternate land-use types (equivalent to 61.7% of the original cropland area). The majority of cropland areas were found to be converted into grassland and woodland areas (accounting for 55.9% and 4.9% respectively of the original cropland areas). 2) Both cropland and woodland demonstrated an increasing fragmentation tendency while grasslands showed a decreasing fragmentation tendency. 3) Multiple driving forces of land use change were thought to act together to changes in landscape metrics in the Yanhe River Basin. The anthropogenic driving forces were analyzed from four perspectives:ecological conservation policy, labor force transfer, industrial development, and rural settlement. The policy of the GfG (Grain for Green) project was the main driving factor which expedited the conversion from cropland to woodland and grassland. Industrial development was also found to affect land use change through the direct impact of economic activities such as oil exploration and agricultural production, or through indirect impacts such as the industrial structures readjustment. Labor force transfer from rural to urban areas was found to follow the industrial structure readjustment and further drove land use change from cropland to off-farm land use. Establishment of new tile-roofed houses instead of cave-type dwellings in rural settlements has helped to aggregate the original scattered land-use type of construction.
文摘The main objective of the present study was to model the kinetics of essential oil extraction from swelled ground juniper berries by classic hydrodistillation(HD) and microwave-assisted hydrodistillation(MAHD). A new phenomenological kinetic model was developed on the basis of the juniper essential oil extraction mechanism that assumed three mass transfer processes occurring simultaneously: washing, unhindered diffusion and hindered diffusion. The new model was compared to the existing kinetic models. Among the tested models,the new model had the smallest mean relative percentage deviation and the highest corrected Akaike information criterion value. In addition, that, the new model was verified for HD and MAHD of essential oils from some other plant materials. On the basis of the above-mentioned facts, the new model can be recommended for modeling the kinetics of essential oil extraction by both HD and MAHD.
文摘Objective:To determine the prevalence and risk factors associated with drug resistant tuberculosis(TB) in South West Nigeria.Methods:A retrospective study conducted among pulmonary tuberculosis(PTB) patients from Oyo and Osun States in South West Nigeria who had their culture and drug susceptibility test performed at the institute of tropical medicine Antwerp, Belgium between 2007 and 2009.Data on the patient’s characteristics were retrieved from the TB treatment card.Univariate analysis was performed to assess the risk factors for drug resistant tuberculosis.The Level of significance was at P【0.05.Results:Among the 88 patients who had drug-susceptibility test result,there were 50 males and 38 females.Of the 88 patients,55(62.5%) had strains resistant to at least one or more anti-drugs.The proportion of TB cases with resistance to a single drug was 12.7%.The multi-drug resistant TB(MDR-TB) rate was 76.4%.The only significant factor for the development of drug resistance and MDR was the history of previous anti TB treatment(P【0.01).Other factors such as age[OR 0.86(0.35-2.13);P=0.72]and gender[OR 1.24 (0.49-3.14);P=0.62]were not significantly associated with drug resistance TB.Conclusions:The study highlighted a high prevalence of MDR-TB among the study population.History of previous TB treatment was associated with MDR-TB.There is an urgent need to conduct a national TB drug resistance survey to determine the actual burden and risk factors associated with drug resistance TB in the country.
文摘There have been many design practices utilised within the coal mining industry to arrive at the minimum densities of primary ground support required during roadway development. This paper demonstrates the practical use of empirical databases, and focuses on the main drivers for ground support as demonstrated in conceptual models. （;older Associates＇ empirical databases used for ground support include a primary roof support database and a primary fib support database. Both are based on successful ground support designs installed in mines in Australia, the US, the LIK, South Africa, New Zealand, and Europe. The term ＂successful＂ refers to those designs that were used on a repeated basis for the purpose of roadway devel- opment. The primary roof support database indicates that the major factors influencing successful roof support designs are roof competency, expressed as the coal mine roof rating （CMRR）, and in situ stress. In regard to the primary rib support database, it is evident from the current database that the primary factors affecting the capacity of rib support required for a successful design are roadway height and depth of cover. These databases have been used to help determine the minimum primary ground support designs required at many mine sites in Australasia, Europe, and the US. This paper will demonstrate the effectiveness and practicality of these databases at two selected mines in Australia and the US. In order to improve the primary rib support database, this paper will also propose a new rib deformation rating based on the addition of site specific coal strength data for the Australian mines. The proposed rat- ing attempts to capture the main variables that define the behaviour of a buckling column.
文摘A bench-scale biopiling experiment was conducted to hydrocarbon bioremediation in a chronically contaminated soil compare the ability of different techniques to enhance petroleum After 195 days, 10%-32% removal of TPHs （total petroleum hydrocarbons） occurred in unamended soil （control）. Biostimulation by inorganic nutrient addition enhanced TPH removal （49%） confirming that bioremediation was nutrient limited and the soil contained a well-adapted hydrocarbonoclastic microbial community. The addition of organic amendments including green waste at 25% and 50% （w/w） and a commercial product called DaramendTM had a further biostimulatory effect （50%-66%, 34%-59% and 69%-80% TPH removal respectively）. Bioaugmentation using two commercially available petroleum hydrocarbon degrading microbial cultures with nutrients enhanced TPH removal in the case of RemActivTM （60%-69%）, but had a marginal effect using Recycler 102 （49%-55%）. The effect of a non-ionic surfactant in green waste amended soil was variable （52%-72% TPH reduction）, but its potential to enhance biodegradation presumably by promoting contaminant bioavailability was demonstrated. High degradation of artificially added polycyclic aromatic hydrocarbons （PAHs） occurred after 106 days （75%-84%）, but significant differences between the control and treatments were unapparent, suggesting that spiked soils do not reflect the behavior of contaminants in genuinely polluted and weathered soil.
基金support by Australian Cooperative Research Centre for High Integrity Australian Pork(Award number 2C-110 1213)
文摘Background： This experiment was conducted to test the hypothesis that vitamin E（Vit E） and acetylsalicylic acid（ASA）, a cyclooxygenase-2（COX-2） inhibitor, will additively reduce the production of the immunosuppressive molecule prostaglandin E_2（PGE_2） and hence reduce inflammatory responses in weaner pigs experimentally infected with an enterotoxigenic strain of E. coli.Methods： The experiment was conducted in a research facility with 192 individually-housed male weaner pigs（Landrace × Large White） weighing 6.6 ± 0.04 kg（mean ± SEM）. The pigs were experimentally infected with an enterotoxigenic strain of E. coli and were allocated to a 2 × 3 factorial design with the respective factors being without and with 125 ppm ASA and three levels of Vit E supplementation（50, 100 or 200 IU/kg diet, dl-α-tocopheryl acetate）.Results： Acetylsalicylic acid supplementation improved average daily gain（P 〈 0.05） and tended to improve feed：gain ratio（P 〈 0.10） during the first 14 d after weaning. Acetylsalicylic acid supplementation also improved（P 〈 0.001） amino acid utilization efficiency（as assessed by plasma urea level） and tended to decrease（P 〈 0.10） PGE2 production in the liver without affecting smal intestinal histology and tight junction protein mR NA expression in the jejunal epithelium. Vitamin E supplementation greater than 100 IU/kg diet sustained both the plasma Vit E concentration（P 〈 0.001） and plasma haptoglobin content（P 〈 0.001） after weaning. However, there was no additive effects of the combined supplementation of ASA and Vit E on performance, intestinal barrier function and inflammatory responses of weaned pigs.Conclusions： Although ASA and vitamin E improved amino acid utilization efficiency and reduced acute inflammatory responses, ASA and vitamin E did not additively reduce production of PGE2 and inflammatory responses in weaner pigs experimental y infected with an enterotoxigenic strain of E. coli.
文摘Wheat grown under rain-fed conditions is often affected by drought worldwide. Future projections from a climate simulation model predict that the combined effects of increasing temperature and changing rainfall patterns will aggravate this drought scenario and may significantly reduce wheat yields unless appropriate varieties are adopted. Wheat is adapted to a wide range of environments due to the diversity in its phenology genes. Wheat phenology offers the opportunity to fight against drought by modifying crop developmental phases according to water availability in target environments. This review summa- rizes recent advances in wheat phenology research, including vernalization （Vrn）, photoperiod （Ppd）, and also dwarfing （Rht） genes. The alleles, haplotypes, and copy number variation identified for Vrn and Ppd genes respond differently in different climatic conditions, and thus could alter not only the development phases but also the yield. Compared with the model plant Arabidopsis, more phenology genes have not yet been identified in wheat; quantifying their effects in target environments would benefit the breeding of wheat for improved drought tolerance. Hence, there is scope to maximize yields in water-limited envi-ronments by deploying appropriate phenology gene combinations along with Rht genes and other important physiological traits that are associated with drought resistance.
基金This work was supported by start-up funding from the Kunming Institute of Zoology,Chinese Academy of Sciences to J.X.Z.
文摘Although it first appeared almost two years ago,the COVID-19 pandemic continues to have an impact on a global scale,in part due to newly emerging SARS-CoV-2 variants such as Delta and Lambda.The B.1.621 variant,first identified in Colombia in January 2021,was classified as a variant of interest(VOI)and designated as Mu by the World Health Organization(WHO)in August 2021.However,its infectivity and resistance to neutralizing antibodies remain largely unknown.Here,in comparison to Delta,the Mu variant showed an unexpectedly enhanced immune resistance to inactivated vaccine-elicited antibodies.Nevertheless,Mu demonstrated less infectivity than Delta,implying a biological trade-off between viral transmission and immune escape.This study strongly calls for urgent evaluation of the protective efficacy of current COVID-19 vaccines against the Mu variant.Variants of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)are of concern regarding control of the global COVID-19 pandemic(Wang et al.,2021).The SARS-CoV-2 B.1.621 variant was first identified in Colombia in January 2021.Considering its epidemiological prevalence,the WHO defined B.1.621(named Mu)as a VOI on 30 August 2021.As of September 2021,the WHO has classified four variants of concern(VOC),i.e.,Alpha(B.1.1.7),Beta(B.1.351),Gamma(P.1),and Delta(B.1.617.2),and two VOI,i.e.,Lambda(C.37)and Mu(B.1.621)(Supplementary Figure S1A).
基金supported by the Project of National Natural Science Foundation of China (Nos.41175111,20677054,21177078)the Strategic Pilot Science and Technology Project of the Chinese Academy of Sciences (Class B) (No.XDB05010200)
文摘Atmospheric aerosol particle samples were collected using an Ambient Eight Stage（Non-Viable） Cascade Impactor Sampler in a typical urban area of Beijing from 27 th Sep.to 5th Oct.,2009.The surface chemistry of these aerosol particles was analyzed using Static Time of Flight-Secondary Ion Mass Spectrometry（Static TOF-SIMS）.The factors influencing surface compositions were evaluated in conjunction with the air pollution levels,meteorological factors,and air mass transport for the sampling period.The results show that a variety of organic ion groups and inorganic ions/ion groups were accumulated on the surfaces of aerosol particles in urban areas of Beijing;and hydrophobic organic compounds with short-or middle-chain alkyl as well as hydrophilic secondary inorganic compounds were observed.All these compounds have the potential to affect the atmospheric behavior of urban aerosol particles.PM1.1–2.1and PM3.3–4.7had similar elements on their surfaces,but some molecules and ionic groups demonstrated differences in Time of Flight-Secondary Ion Mass Spectrometry spectra.This suggests that the quantities of elements varied between PM1.1–2.1and PM3.3–4.7.In particular,more intense research efforts into fluoride pollution are required,because the fluorides on aerosol surfaces have the potential to harm human health.The levels of air pollution had the most significant influence on the surface compositions of aerosol particles in our study.Hence,heavier air pollution was associated with more complex surface compositions on aerosol particles.In addition,wind,rainfall,and air masses from the south also greatly influenced the surface compositions of these urban aerosol particles.
