Augmented Reality(AR)is a new mode of interactive media that is becoming increasingly popular.Few universities,however,offer courses specifically in AR.This raises questions on appropriate teaching paradigms for this ...Augmented Reality(AR)is a new mode of interactive media that is becoming increasingly popular.Few universities,however,offer courses specifically in AR.This raises questions on appropriate teaching paradigms for this fast-developing area.This paper,therefore,discusses current challenges for teaching AR including a shortage of teaching staff,segmented teaching materials,and theory-driven assessment methods.As such,we present several strategies currently used in the AR technology and application course at Xiamen University.To improve teaching performance,we introduced part-time tutors who are currently employed within the AR industry.Furthermore,we improved the systematic presentation of our course materials to allow an integrative understanding of them.Students developed AR projects using Huawei,the most popular mobile platform in China.This paper concludes that students who underwent this teaching paradigm developed effective skills and knowledge in AR and successfully advanced their careers.展开更多
This special issue is devoted to the celebration of the century anniversary of Xiamen University(XMU)(6 April 2021)and the establishment of the LSA Editorial Office in Xiamen(3 July 2021),a collection to highlight the...This special issue is devoted to the celebration of the century anniversary of Xiamen University(XMU)(6 April 2021)and the establishment of the LSA Editorial Office in Xiamen(3 July 2021),a collection to highlight the recent exciting research works performed in XMU or by XMU alumni,from all aspects of optics and photonics,including basic,applied and engineering research and applications.The vip editors are three XMU alumni who are active researchers in these areas:Professor Minghui Hong from National University of Singapore,Professor Zhongqun Tian and Professor Junyong Kang from XMU.展开更多
The toxicity of PM_(2.5)does not necessarily change synchronously with its mass concentration.In this study,the chemical composition(carbonaceous species,water-soluble ions,and metals)and oxidative potential(dithiothr...The toxicity of PM_(2.5)does not necessarily change synchronously with its mass concentration.In this study,the chemical composition(carbonaceous species,water-soluble ions,and metals)and oxidative potential(dithiothreitol assay,DTT)of PM_(2.5)were investigated in 2017/2018 and 2022 in Xiamen,China.The decrease rate of volume-normalized DTT(DTTv)(38%)was lower than that of PM_(2.5)(55%)between the two sampling periods.However,the mass-normalized DTT(DTTm)increased by 44%.Clear seasonal patterns with higher levels in winter were found for PM_(2.5),most chemical constituents and DTTv but not for DTTm.The large decrease in DTT activity(84%−92%)after the addition of EDTA suggested that watersoluble metals were the main contributors to DTT in Xiamen.The increased gap between the reconstructed and measured DTTv and the stronger correlations between the reconstructed/measured DTT ratio and carbonaceous species in 2022were observed.The decrease rates of the hazard index(32.5%)and lifetime cancer risk(9.1%)differed from those of PM_(2.5)and DTTv due to their different main contributors.The PMF-MLR model showed that the contributions(nmol/(min·m^(3)))of vehicle emission,coal+biomass burning,ship emission and secondary aerosol to DTTv in 2022 decreased by 63.0%,65.2%,66.5%,and 22.2%,respectively,compared to those in 2017/2018,which was consistent with the emission reduction of vehicle exhaust and coal consumption,the adoption of low-sulfur fuel oil used on board ships and the reduced production of WSOC.However,the contributions of dust+sea salt and industrial emission increased.展开更多
Achieving mutual benefits in the process of city cluster integration is the core of sustainable regional economic development.This means the core city is driving and avoids the siphon effect.Therefore,it is crucial to...Achieving mutual benefits in the process of city cluster integration is the core of sustainable regional economic development.This means the core city is driving and avoids the siphon effect.Therefore,it is crucial to analyse which factors affect the differences in integration outcomes.In this paper,for the 28 districts and counties of Xiamen-Zhangzhou-Quanzhou City Cluster,we use FsQCA to analyse the configuration of the impacts of five conditions,namely,urbanization,infrastructure development,level of public services,degree of government intervention,and industrial structure,on the intensity of the districts and counties’economic linkages.This paper obtains four group conditions of high economic linkage intensity and seven paths leading to low economic linkage intensity.And in this regard,it puts forward suggestions such as constructing a mechanism for coordinated development of regional industries and accelerating the convenient sharing of public services.展开更多
Coastal ecosystems are plagued by high levels of microplastic pollution.Conducting baseline surveys is crucial to comprehend the distribution and influencing factors of this pollution.The present study investigates th...Coastal ecosystems are plagued by high levels of microplastic pollution.Conducting baseline surveys is crucial to comprehend the distribution and influencing factors of this pollution.The present study investigates the spatiotemporal variation and diversity of microplastic on the coastal beaches in Xiamen City,China,considering the combined effects of seasons,human activities,and physicochemical properties of sediments.It is detected that the abundance of microplastics in Xiamen beaches was 0.271±0.01 items/g.The abundance of microplastics in dry season was significantly higher than in rainy season.In terms of spatial variation,the beaches that attracted a larger number of tourists exhibited significantly higher microplastic abundance.The temporal pattern of microplastic distribution on different beaches varied greatly due to region-specific human activities(e.g.,mangrove restoration project)and sedimentary properties(e.g.,bulk density).When the assemblage of microplastics in the coastal area was viewed as a biological community,the Shannon-Wiener index and Pielou's index were higher in rainy season and in the beaches with high intensity of tourist activities,which suggests that the human activities and the surface runoff may contribute to the diversity of microplastics on coastal beaches.Future investigations are encouraged to combine controlled experiments and long-term monitoring at multiple scales to elucidate the underlying mechanisms and factors associated with microplastic pollution in coastal zone.展开更多
Among various architectures of polymers,end-group-free rings have attracted growing interests due to their distinct physicochemical performances over the linear counterparts which are exemplified by reduced hydrodynam...Among various architectures of polymers,end-group-free rings have attracted growing interests due to their distinct physicochemical performances over the linear counterparts which are exemplified by reduced hydrodynamic size and slower degradation.It is key to develop facile methods to large-scale synthesis of polymer rings with tunable compositions and microstructures.Recent progresses in large-scale synthesis of polymer rings against single-chain dynamic nanoparticles,and the example applications in synchronous enhancing toughness and strength of polymer nanocomposites are summarized.Once there is the breakthrough in rational design and effective large-scale synthesis of polymer rings and their functional derivatives,a family of cyclic functional hybrids would be available,thus providing a new paradigm in developing polymer science and engineering.展开更多
Low-density superalloys often exhibit low yield strength in the intermediate temperature range(300−650℃).To enhance yield performance in this range,the CALPHAD method was used to design a new Co-based superalloy.The ...Low-density superalloys often exhibit low yield strength in the intermediate temperature range(300−650℃).To enhance yield performance in this range,the CALPHAD method was used to design a new Co-based superalloy.The Co−30Ni−10Al−3V−6Ti−2Ta alloy,designed based onγʹphase dissolution temperature and phase fraction,was synthesized via arc melting and heat treatment.Phase transition temperatures,microstructure evolution,and hightemperature mechanical properties were characterized by differential scanning calorimetry,scanning electron microscopy,dual-beam TEM,and compression tests.Results show that the alloy has low density(8.15 g/cm^(3))and highγʹdissolution temperature(1234℃),along with unique yield strength retention from room temperature to 650℃.The yield strength anomaly(YSA)is attributed to high stacking fault energy and activation of the Kear−Wilsdorf locking mechanism,contributing to superior high-temperature stability of the alloy.The yield strength of this alloy outperforms other lowdensity Co-based superalloys in the temperature range of 23−650℃.展开更多
BACKGROUND Ischemic stroke is one of the leading global causes of disability and death.Despite advances in modern medical technology that improve acute treatment and rehabilitation measures,post-stroke anxiety and dep...BACKGROUND Ischemic stroke is one of the leading global causes of disability and death.Despite advances in modern medical technology that improve acute treatment and rehabilitation measures,post-stroke anxiety and depression(PSD)do not receive sufficient attention.AIM To systematically evaluate risk factors and early identification markers for PSD for more precise screening and intervention strategies in clinical practice.METHODS This retrospective study analyzed clinical data from 112 patients with ischemic stroke admitted between January 2022 and December 2024.Based on assessments using the Hamilton Rating Scale for Anxiety(HAMA)and Hamilton Rating Scale for Depression(HAMD)at 2 weeks(±3 days)post-stroke,patients were classified into the PSD group(HAMA≥7 and/or HAMD≥7)and the non-PSD group(HAMA<7 and HAMD<7).Observation indicators included psychological assessment,demographic and clinical characteristics,stroke-related clinical indicators,neuroimaging assessments,and laboratory biomarkers.Multivariate logistic regression analysis was used to identify independent risk factors for PSD,and receiver operating characteristic curve analysis was used to evaluate the diagnostic value of potential biomarkers.RESULTS Of the 112 patients,46(41.1%)were diagnosed with PSD.Multivariate analysis identified five independent risk factors:Female gender[Odds ratio(OR)=2.32,95%confidence interval(CI):1.56-3.45],history of mental disorders prior to stroke(OR=3.17,95%CI:1.89-5.32),infarct location in the frontal lobe or limbic system(OR=2.86,95%CI:1.73-4.71),stroke severity with National Institutes of Health Stroke Scale≥8 at admission(OR=2.54,95%CI:1.62-3.99),and low social support(Social Support Rating Scale<35,OR=2.18,95%CI:1.42-3.36).Subgroup analysis showed that depression patients more commonly had left hemisphere lesions(68.4%vs 45.2%),while anxiety patients more frequently presented with right hemisphere lesions(59.5%vs 39.5%).The PSD group exhibited larger infarct volumes(8.7 cm^(3) vs 5.3 cm^(3)),more severe white matter hyperintensities,and more pronounced frontal lobe atrophy.Analysis of inflammatory markers showed significantly elevated levels of interleukin-6(7.8 pg/mL vs 4.5 pg/mL)and tumor necrosis factor-alpha(15.6 pg/mL vs 9.8 pg/mL)in the PSD group,while hypothalamicpituitary-adrenal axis function assessment revealed higher cortisol levels(386.5±92.3 nmol/L vs 328.7±75.6 nmol/L)and flattened diurnal rhythm in the PSD group.CONCLUSION PSD is a complex neuropsychiatric consequence of stroke involving disruption of the frontal-limbic circuitry,neuroinflammatory responses,and dysfunction of the hypothalamic-pituitary-adrenal axis.展开更多
Crystalline silicon(c-Si)solar cells,though dominating the photovoltaic market,are nearing their theoretical power conversion efficiencies(PCE)limit of 29.4%,necessitating the adoption of multi-junction technology to ...Crystalline silicon(c-Si)solar cells,though dominating the photovoltaic market,are nearing their theoretical power conversion efficiencies(PCE)limit of 29.4%,necessitating the adoption of multi-junction technology to achieve higher performance.Among these,perovskiteon-silicon-based multi-junction solar cells have emerged as a promising alternative,where the perovskite offering tunable bandgaps,superior optoelectronic properties,and cost-effective manufacturing.Recent announced double-junction solar cells(PSDJSCs)have achieved the PCE of 34.85%,surpassing all other double-junction technologies.Encouragingly,the rapid advancements in PSDJSCs have spurred increased research interest in perovskite/perovskite/silicon triple-junction solar cells(PSTJSCs)in 2024.This triple-junction solar cell configuration demonstrates immense potential due to their optimum balance between achieving a high PCE limit and managing device complexity.This review provides a comprehensive analysis of PSTJSCs,covering fundamental principles,and technological milestones.Current challenges,including current mismatch,open-circuit voltage deficits,phase segregation,and stability issues,and their corresponding strategies are also discussed,alongside future directions to achieve long-term stability and high PCE.This work aims to advance the understanding of the development in PSTJSCs,paving the way for their practical implementation.展开更多
While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance re...While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance remains underexplored in field investigations.To evaluate the practical applicability of this emerging technique in adverse shallow sea channels,a field experiment was conducted using three communication modes:orthogonal frequency division multiplexing(OFDM),M-ary frequency-shift keying(MFSK),and direct sequence spread spectrum(DSSS)for reinforcement learning-driven adaptive modulation.Specifically,a Q-learning method is used to select the optimal modulation mode according to the channel quality quantified by signal-to-noise ratio,multipath spread length,and Doppler frequency offset.Experimental results demonstrate that the reinforcement learning-based adaptive modulation scheme outperformed fixed threshold detection in terms of total throughput and average bit error rate,surpassing conventional adaptive modulation strategies.展开更多
Interferon-related genes are involved in antiviral responses,inflammation,and immunity,which are closely related to sepsis-associated acute respiratory distress syndrome(ARDS).We analyzed 1972 participants with genoty...Interferon-related genes are involved in antiviral responses,inflammation,and immunity,which are closely related to sepsis-associated acute respiratory distress syndrome(ARDS).We analyzed 1972 participants with genotype data and 681 participants with gene expression data from the Molecular Epidemiology of ARDS(MEARDS),the Molecular Epidemiology of Sepsis in the ICU(MESSI),and the Molecular Diagnosis and Risk Stratification of Sepsis(MARS)cohorts in a three-step study focusing on sepsis-associated ARDS and sepsis-only controls.First,we identified and validated interferon-related genes associated with sepsis-associated ARDS risk using genetically regulated gene expression(GReX).Second,we examined the association of the confirmed gene(interferon regulatory factor 1,IRF1)with ARDS risk and survival and conducted a mediation analysis.Through discovery and validation,we found that the GReX of IRF1 was associated with ARDS risk(odds ratio[OR_(MEARDS)]=0.84,P=0.008;OR_(MESSI)=0.83,P=0.034).Furthermore,individual-level measured IRF1 expression was associated with reduced ARDS risk(OR=0.58,P=8.67×10^(-4)),and improved overall survival in ARDS patients(hazard ratio[HR_(28-day)]=0.49,P=0.009)and sepsis patients(HR_(28-day)=0.76,P=0.008).Mediation analysis revealed that IRF1 may enhance immune function by regulating the major histocompatibility complex,including HLA-F,which mediated more than 70%of protective effects of IRF1 on ARDS.The findings were validated by in vitro biological experiments including time-series infection dynamics,overexpression,knockout,and chromatin immunoprecipitation sequencing.Early prophylactic interventions to activate IRF1 in sepsis patients,thereby regulating HLA-F,may reduce the risk of ARDS and mortality,especially in severely ill patients.展开更多
Long-term changes of phytoplankton community by water sampling method in Xiagu Sea waters of Xiamen,China,were investigated in this study.Species composition of the phytoplankton community in these waters changed grea...Long-term changes of phytoplankton community by water sampling method in Xiagu Sea waters of Xiamen,China,were investigated in this study.Species composition of the phytoplankton community in these waters changed greatly since the 1950s.The numbers of Dinophyta species increased significantly,although Bacillariophyta species are generally dominant.The succession of dominant species in phytoplankton community is obvious： large-size dominant species such as Biddulphia sinensis of the 1950s were gradually replaced by small-size ones such as Cyclotella striata and Nitzschia closterium,and species that still maintain dominant such as Skeletonema costatum are also small ones,leading the whole phytoplankton community of smaller size.Cell density of phytoplankton community increased greatly,among which cell density of the most dominant species Skeletonema costatum have been increasing in exponent function.Margalef index of phytoplankton community decreased,indicating decline of biodiversity of the community,and dominant character of Skeletonema costatum increased.Generally,the structure of the entire phytoplankton community is becoming more and more singular and unstable,which makes the occurrence of red tides more frequent.The succession in the phytoplankton community is related to the long-term changes in marine environment,influenced by human activities and global climate changes,especially the increases of nutrient content.展开更多
Based on the survey of surface sediment in Xiamen Bay in October 2011, the speciation, distribution, and potential ecological risk assessment of heavy metals （Cu, Pb, Zn, Cd, and Cr） in this area were studied us-ing...Based on the survey of surface sediment in Xiamen Bay in October 2011, the speciation, distribution, and potential ecological risk assessment of heavy metals （Cu, Pb, Zn, Cd, and Cr） in this area were studied us-ing the sequential extraction method and ecological risk assessment method. The results indicated：（1） the total concentrations of these heavy metals were influenced by runoff, industrial wastewater, and sewage, and were all higher in the coastal area than the offshore area while the highest area of Pb was a little far-ther away from the coastal water due to atmosphere deposition;（2） sequential extractions suggested that Cu was mainly composed with residual and Fe/Mn-oxide bound fractions, Pb was bound to Fe/Mn-oxide, Zn and Cr were dominated by residual, and Cd bound to exchangeable and carbonate fractions; （3） the order of migration and transformation sequence was Cd＆gt;Pb＆gt;Cu＆gt;Zn＆gt;Cr and the degree of pollution was Cd＆gt;Pb＆gt;Cu＆gt;Zn＆gt;Cr;and （4） the ratios of the secondary and primary phases showed that Zn and Cr were both clean, Cu may be polluted, Pb was moderately polluted, while Cd was heavily polluted.展开更多
To compare meiofaunal community in the two mangrove wetlands in Tong＇an Bay, Xiamen, China, and probe the response of meiofauna to high organic matter, sampling was carried out in Fenglin and Xiang＇an mangrove wetla...To compare meiofaunal community in the two mangrove wetlands in Tong＇an Bay, Xiamen, China, and probe the response of meiofauna to high organic matter, sampling was carried out in Fenglin and Xiang＇an mangrove wetlands in the bay. The results showed that the Ne/Co ratio （nematode to benthic copepod） and organic matter in Fenglin mangrove wetland were higher than those in Xiang＇an mangrove wetland. The meiofaunal abundance in Fenglin mangrove was all lower than that in Xiang＇an mangrove wetland in summer, autumn and spring, while the meiofaunal abundance in Fenglin mangrove was higher than that in Xiang＇an mangrove wetland in winter. Two-way ANOVA results showed that the meiofaunal abundance and nematode abundance were significantly different between regions, seasons and regionxseason. With all the results in the present study, we confirmed that the positive response of meiofaunal and nematode abundance were only detected for medium organic matter contents according to the Xiang＇an wetland＇s level, and that the distribution of meiofaunal abundance would be influenced by sand content. Higher copepod abundance and lower N/C value usually suggest better environmental quality.展开更多
Intensive daytime and nighttime sampling was carried out from 23 Oct to 31 Dec 2008 to investigate the occurrence of nitrated polycyclic aromatic hydrocarbons （NPAHs） in PM1o at a roadside site in Xiamen, China. At ...Intensive daytime and nighttime sampling was carried out from 23 Oct to 31 Dec 2008 to investigate the occurrence of nitrated polycyclic aromatic hydrocarbons （NPAHs） in PM1o at a roadside site in Xiamen, China. At the same time, six PMt0 samples were collected from a nearby roadway tunnel for comparison. Six NPAHs, namely 9-nitroanthracene, 2- and 3-nitrofluoranthene, 1- nitropyrene, 7-nitrobenz[a]anthracene, and 6-nitrobenzo[a]pyrene, were identified and quantified using GC/MS in negative ion chemical ionization mode. The average total concentration of six NPAHs （~NPAHs） in the cold season （26 Nov-31 Dec） was 2.3 （daytime） and 9.9 （nighttime） times higher than those in the warm season. Significant statistical difference （p 〈 0.01, 2-tailed） of ∑NPAHs between daytime and nighttime was found during both the warm and cold seasons. NPAHs were significantly positively correlated with their parent PAHs and nitrogen dioxide but negatively correlated with ambient temperature. The ratio of 2 ＋ 3-nitrofluoranthene to 1- nitropyrene exhibited a similar diurnal pattern as ZNPAHs and was generally greater than 5, indicating the importance of secondary atmospheric formation. The diurnal variations of NPAHs were all influenced by the diurnal variations of PAHs, nitrogen dioxide, sunlight, and temperature. The daily inhalable exposure to the six NPAHs in the tunnel was much higher than the roadside values in the warm season but only slightly higher than those in the cold season.展开更多
The levels and distribution of mercury （Hg） species, including total mercury （THg） and methylmercury （MeHg） in the topsoil and dust collected from twenty sampling stations located in different land function area...The levels and distribution of mercury （Hg） species, including total mercury （THg） and methylmercury （MeHg） in the topsoil and dust collected from twenty sampling stations located in different land function areas of Xiamen, China, were investigated. The THg concentrations in topsoil ranged from 0.071 to 1.2 mg/kg, and in dust ranged from of 0.034 to 1.4 mg/kg. For stations where the THg of dust was less than 0.31 mg/kg, THg concentrations in the topsoil were significantly correlated to those in the corresponding dust （r = 0.597, n = 16, P = 0.014）. The MeHg concentrations in topsoil were varied between 0.14 and 5.7 μg/kg. The ratios of MeHg/THg in the topsoil ranged from 0.069% to 0.74%. The range of MeHg concentration in the dust were 0.092-2.3 μg/kg. The ratios of MeHg/THg in the dust were at the same level as those in the topsoil. The MeHg concentrations in both topsoil and dust were linked to corresponding THg concentrations and soil organic matter. Neither THg nor MeHg concentration in the topsoil and dust was obviously linked to the land function.展开更多
Water samples were collected at 20 sites on 4 occasions in 2009 （twice in May, and once in both August and November） along the Jiulong River, South China to examine how nutrient inputs from the Jiulong River could a...Water samples were collected at 20 sites on 4 occasions in 2009 （twice in May, and once in both August and November） along the Jiulong River, South China to examine how nutrient inputs from the Jiulong River could affect the nutrient status of the Xiamen Water. Samples were analyzed for nitrite （NO2-N）, nitrate （NO3-N）, ammonium （NH4-N）, phosphate （PO4-P）, silicate （SiO3-Si）, salinity, and temperature, to determine the nutrient and trophic status of the river. The results indicate that nutrients are derived mainly from river runoff. NO3-N was the main form of DIN in most parts of the river. In addition, NO3-N, DIN, and SiO3-Si behave conservatively. There is a surplus of DIN and SiO3-Si in the river, and PO4-P is a limitation on phytoplankton growth. The concentration of DIN is typically above 0.60 mg/dm3, and higher than 1.00 mg/dm3 in most parts of the river. The concentration of PO4-P is typically above 0.02 mg/dm3, while the concentration of SiO3-Si is higher than 1.00 rag/din3. Between 2003 and 2008, samples were collected 3 times per year （May, August and November） at 27 sites in the Xiamen Water and analyzed for NO2-N, NO3-N, NH4-N, PO4-P, salinity, and temperature. We discovered that the Jiulong River was the key source of DIN into the Xiamen Water, but not PO4-P, indicating the reason of the N/P molar ratio imbalance in the Xiamen Water. In the future, the effects of high DIN concentrations on the phytoplankton communities and marine ecosystems of the Xiamen Water shall be studied.展开更多
Applying the methods of on-site observation and dynamic model, the research on the fronts at the Jiulong Estuary has been carried out, during which spatial and temporal distribution, dynamic characteristics and format...Applying the methods of on-site observation and dynamic model, the research on the fronts at the Jiulong Estuary has been carried out, during which spatial and temporal distribution, dynamic characteristics and formation mechanism of salinity fronts are analyzed and discussed. The research shows that the estuarine fronts mainly lie in the area from the Jiyu Islet to the Haimen Island, outside of Yuweizai to Hulishan cross-section, the near coast of Yuweizai and the south of the Songyu-Gulangyu Channel. The fronts in the former two regions are formed directly by plume, while the one near the coast of Yuweizai is a tidal intrusion front caused by flood current and the one at the south of the Songyu-Gulangyu Channel is the result of current shear transformation. Under normal circumstances, fresh water of the Jiulong River mainly influences the inside of the Xiamen Bay, and when it is in typhoon seasons, plume front can affect the Taiwan Strait and has an effect on the biogeochemical Drocesses in the strait.展开更多
Mangroves are unique in their biodiversity,but studies on their meiobenthic biodiversity in China are scarce.Despite the importance of mangroves,little work has been done on the classification of nematodes in mangrove...Mangroves are unique in their biodiversity,but studies on their meiobenthic biodiversity in China are scarce.Despite the importance of mangroves,little work has been done on the classification of nematodes in mangrove wetlands.Fujian Province is the most northern point of China’s natural mangrove distribution,and it is also one of the provinces with the earliest constructed mangrove forest.In this paper,two new free-living marine nematode species of Desmodoridae from the Xiamen mangrove wetlands in China are described.Metachromadora xiamenensis sp.nov.is characterized by a cylindrical body,and smooth head capsule set off from the rest of the body.The cuticle is finely annulated and thickened at the midbody.Lateral ridges run from the posterior end of the pharynx to the middle of the tail.The amphid foveae is loop shaped and opens at the top with a double contour amphidial,pharynx with bipartite cuticularized internal cavity.There are 18 tubular precloacal supplements and tail with three small protuberances.Molgolaimus euryformis sp.nov.is characterized by a relatively short and plump body with finely annulated cuticle,which is particularly obvious in the tail.The head is small and wide with intensive striates.The inner and outer labial sensilla are indistinct with short spicules and ventral apophysis,a gubernaculum with a block-shaped hook,a swollen conical-cylindrical tail and an absence of precloacal supplements.展开更多
Objective Cr（VI） removal from industrial effluents and sediments has attracted the attention of environmental researchers. In the present study, we aimed to isolate bacteria for Cr（VI） bioremediation from sediment...Objective Cr（VI） removal from industrial effluents and sediments has attracted the attention of environmental researchers. In the present study, we aimed to isolate bacteria for Cr（VI） bioremediation from sediment samples and to optimize parameters of biodegradation. Methods Strains with the ability to tolerate Cr（VI） were obtained by serial dilution and spread plate methods and characterized by morphology, 16 S r DNA identification, and phylogenetic analysis. Cr（VI） was determined using the 1,5-diphenylcarbazide method, and the optimum p H and temperature for degradation were studied using a multiple-factor mixed experimental design. Statistical analysis methods were used to analyze the results. Results Fifty-five strains were obtained, and one strain（Sporosarcina saromensis M52; patent application number： 201410819443.3） having the ability to tolerate 500 mg Cr（VI）/L was selected to optimize the degradation conditions. M52 was found be able to efficiently remove 50-200 mg Cr（VI）/L in 24 h, achieving the highest removal efficiency at p H 7.0-8.5 and 35 °C. Moreover, M52 could completely degrade 100 mg Cr（VI）/L at p H 8.0 and 35 °C in 24 h. The mechanism involved in the reduction of Cr（VI） was considered to be bioreduction rather than absorption. Conclusion The strong degradation ability of S. saromensis M52 and its advantageous functional characteristics support the potential use of this organism for bioremediation of heavy metal pollution.展开更多
文摘Augmented Reality(AR)is a new mode of interactive media that is becoming increasingly popular.Few universities,however,offer courses specifically in AR.This raises questions on appropriate teaching paradigms for this fast-developing area.This paper,therefore,discusses current challenges for teaching AR including a shortage of teaching staff,segmented teaching materials,and theory-driven assessment methods.As such,we present several strategies currently used in the AR technology and application course at Xiamen University.To improve teaching performance,we introduced part-time tutors who are currently employed within the AR industry.Furthermore,we improved the systematic presentation of our course materials to allow an integrative understanding of them.Students developed AR projects using Huawei,the most popular mobile platform in China.This paper concludes that students who underwent this teaching paradigm developed effective skills and knowledge in AR and successfully advanced their careers.
文摘This special issue is devoted to the celebration of the century anniversary of Xiamen University(XMU)(6 April 2021)and the establishment of the LSA Editorial Office in Xiamen(3 July 2021),a collection to highlight the recent exciting research works performed in XMU or by XMU alumni,from all aspects of optics and photonics,including basic,applied and engineering research and applications.The vip editors are three XMU alumni who are active researchers in these areas:Professor Minghui Hong from National University of Singapore,Professor Zhongqun Tian and Professor Junyong Kang from XMU.
基金supported by the Science and Technology Program of Fujian Province,China(No.2023R1014002)the National Natural Science Foundation of China(No.41471390).
文摘The toxicity of PM_(2.5)does not necessarily change synchronously with its mass concentration.In this study,the chemical composition(carbonaceous species,water-soluble ions,and metals)and oxidative potential(dithiothreitol assay,DTT)of PM_(2.5)were investigated in 2017/2018 and 2022 in Xiamen,China.The decrease rate of volume-normalized DTT(DTTv)(38%)was lower than that of PM_(2.5)(55%)between the two sampling periods.However,the mass-normalized DTT(DTTm)increased by 44%.Clear seasonal patterns with higher levels in winter were found for PM_(2.5),most chemical constituents and DTTv but not for DTTm.The large decrease in DTT activity(84%−92%)after the addition of EDTA suggested that watersoluble metals were the main contributors to DTT in Xiamen.The increased gap between the reconstructed and measured DTTv and the stronger correlations between the reconstructed/measured DTT ratio and carbonaceous species in 2022were observed.The decrease rates of the hazard index(32.5%)and lifetime cancer risk(9.1%)differed from those of PM_(2.5)and DTTv due to their different main contributors.The PMF-MLR model showed that the contributions(nmol/(min·m^(3)))of vehicle emission,coal+biomass burning,ship emission and secondary aerosol to DTTv in 2022 decreased by 63.0%,65.2%,66.5%,and 22.2%,respectively,compared to those in 2017/2018,which was consistent with the emission reduction of vehicle exhaust and coal consumption,the adoption of low-sulfur fuel oil used on board ships and the reduced production of WSOC.However,the contributions of dust+sea salt and industrial emission increased.
文摘Achieving mutual benefits in the process of city cluster integration is the core of sustainable regional economic development.This means the core city is driving and avoids the siphon effect.Therefore,it is crucial to analyse which factors affect the differences in integration outcomes.In this paper,for the 28 districts and counties of Xiamen-Zhangzhou-Quanzhou City Cluster,we use FsQCA to analyse the configuration of the impacts of five conditions,namely,urbanization,infrastructure development,level of public services,degree of government intervention,and industrial structure,on the intensity of the districts and counties’economic linkages.This paper obtains four group conditions of high economic linkage intensity and seven paths leading to low economic linkage intensity.And in this regard,it puts forward suggestions such as constructing a mechanism for coordinated development of regional industries and accelerating the convenient sharing of public services.
基金Supported by the Natural Science Foundation of Fujian Province(No.2022J05278)the Marine and Fishery Development Special Fund of Xiamen(No.23YYST064QCB36)。
文摘Coastal ecosystems are plagued by high levels of microplastic pollution.Conducting baseline surveys is crucial to comprehend the distribution and influencing factors of this pollution.The present study investigates the spatiotemporal variation and diversity of microplastic on the coastal beaches in Xiamen City,China,considering the combined effects of seasons,human activities,and physicochemical properties of sediments.It is detected that the abundance of microplastics in Xiamen beaches was 0.271±0.01 items/g.The abundance of microplastics in dry season was significantly higher than in rainy season.In terms of spatial variation,the beaches that attracted a larger number of tourists exhibited significantly higher microplastic abundance.The temporal pattern of microplastic distribution on different beaches varied greatly due to region-specific human activities(e.g.,mangrove restoration project)and sedimentary properties(e.g.,bulk density).When the assemblage of microplastics in the coastal area was viewed as a biological community,the Shannon-Wiener index and Pielou's index were higher in rainy season and in the beaches with high intensity of tourist activities,which suggests that the human activities and the surface runoff may contribute to the diversity of microplastics on coastal beaches.Future investigations are encouraged to combine controlled experiments and long-term monitoring at multiple scales to elucidate the underlying mechanisms and factors associated with microplastic pollution in coastal zone.
基金Supported by the National Natural Science Foundation of China(Nos.52293472,22473096 and 22471164)。
文摘Among various architectures of polymers,end-group-free rings have attracted growing interests due to their distinct physicochemical performances over the linear counterparts which are exemplified by reduced hydrodynamic size and slower degradation.It is key to develop facile methods to large-scale synthesis of polymer rings with tunable compositions and microstructures.Recent progresses in large-scale synthesis of polymer rings against single-chain dynamic nanoparticles,and the example applications in synchronous enhancing toughness and strength of polymer nanocomposites are summarized.Once there is the breakthrough in rational design and effective large-scale synthesis of polymer rings and their functional derivatives,a family of cyclic functional hybrids would be available,thus providing a new paradigm in developing polymer science and engineering.
基金supported by the National Natural Science Foundation of China(Nos.51831007,52101135)the Shenzhen Science and Technology Program,China(No.SGDX20210823104002016)the Guangdong Basic and Applied Basic Research Foundation,China(Nos.2021B1515120071,JCYJ20220531095217039)。
文摘Low-density superalloys often exhibit low yield strength in the intermediate temperature range(300−650℃).To enhance yield performance in this range,the CALPHAD method was used to design a new Co-based superalloy.The Co−30Ni−10Al−3V−6Ti−2Ta alloy,designed based onγʹphase dissolution temperature and phase fraction,was synthesized via arc melting and heat treatment.Phase transition temperatures,microstructure evolution,and hightemperature mechanical properties were characterized by differential scanning calorimetry,scanning electron microscopy,dual-beam TEM,and compression tests.Results show that the alloy has low density(8.15 g/cm^(3))and highγʹdissolution temperature(1234℃),along with unique yield strength retention from room temperature to 650℃.The yield strength anomaly(YSA)is attributed to high stacking fault energy and activation of the Kear−Wilsdorf locking mechanism,contributing to superior high-temperature stability of the alloy.The yield strength of this alloy outperforms other lowdensity Co-based superalloys in the temperature range of 23−650℃.
文摘BACKGROUND Ischemic stroke is one of the leading global causes of disability and death.Despite advances in modern medical technology that improve acute treatment and rehabilitation measures,post-stroke anxiety and depression(PSD)do not receive sufficient attention.AIM To systematically evaluate risk factors and early identification markers for PSD for more precise screening and intervention strategies in clinical practice.METHODS This retrospective study analyzed clinical data from 112 patients with ischemic stroke admitted between January 2022 and December 2024.Based on assessments using the Hamilton Rating Scale for Anxiety(HAMA)and Hamilton Rating Scale for Depression(HAMD)at 2 weeks(±3 days)post-stroke,patients were classified into the PSD group(HAMA≥7 and/or HAMD≥7)and the non-PSD group(HAMA<7 and HAMD<7).Observation indicators included psychological assessment,demographic and clinical characteristics,stroke-related clinical indicators,neuroimaging assessments,and laboratory biomarkers.Multivariate logistic regression analysis was used to identify independent risk factors for PSD,and receiver operating characteristic curve analysis was used to evaluate the diagnostic value of potential biomarkers.RESULTS Of the 112 patients,46(41.1%)were diagnosed with PSD.Multivariate analysis identified five independent risk factors:Female gender[Odds ratio(OR)=2.32,95%confidence interval(CI):1.56-3.45],history of mental disorders prior to stroke(OR=3.17,95%CI:1.89-5.32),infarct location in the frontal lobe or limbic system(OR=2.86,95%CI:1.73-4.71),stroke severity with National Institutes of Health Stroke Scale≥8 at admission(OR=2.54,95%CI:1.62-3.99),and low social support(Social Support Rating Scale<35,OR=2.18,95%CI:1.42-3.36).Subgroup analysis showed that depression patients more commonly had left hemisphere lesions(68.4%vs 45.2%),while anxiety patients more frequently presented with right hemisphere lesions(59.5%vs 39.5%).The PSD group exhibited larger infarct volumes(8.7 cm^(3) vs 5.3 cm^(3)),more severe white matter hyperintensities,and more pronounced frontal lobe atrophy.Analysis of inflammatory markers showed significantly elevated levels of interleukin-6(7.8 pg/mL vs 4.5 pg/mL)and tumor necrosis factor-alpha(15.6 pg/mL vs 9.8 pg/mL)in the PSD group,while hypothalamicpituitary-adrenal axis function assessment revealed higher cortisol levels(386.5±92.3 nmol/L vs 328.7±75.6 nmol/L)and flattened diurnal rhythm in the PSD group.CONCLUSION PSD is a complex neuropsychiatric consequence of stroke involving disruption of the frontal-limbic circuitry,neuroinflammatory responses,and dysfunction of the hypothalamic-pituitary-adrenal axis.
基金supported by the National Natural Science Foundation of China under Grants 62404185the industry-academia joint laboratory collaboration between Hiking PV and Xiamen University(20243160C0010)J.Z.is supported by Nanqiang Outstanding Young Talents Program X2450215 of Xiamen University.
文摘Crystalline silicon(c-Si)solar cells,though dominating the photovoltaic market,are nearing their theoretical power conversion efficiencies(PCE)limit of 29.4%,necessitating the adoption of multi-junction technology to achieve higher performance.Among these,perovskiteon-silicon-based multi-junction solar cells have emerged as a promising alternative,where the perovskite offering tunable bandgaps,superior optoelectronic properties,and cost-effective manufacturing.Recent announced double-junction solar cells(PSDJSCs)have achieved the PCE of 34.85%,surpassing all other double-junction technologies.Encouragingly,the rapid advancements in PSDJSCs have spurred increased research interest in perovskite/perovskite/silicon triple-junction solar cells(PSTJSCs)in 2024.This triple-junction solar cell configuration demonstrates immense potential due to their optimum balance between achieving a high PCE limit and managing device complexity.This review provides a comprehensive analysis of PSTJSCs,covering fundamental principles,and technological milestones.Current challenges,including current mismatch,open-circuit voltage deficits,phase segregation,and stability issues,and their corresponding strategies are also discussed,alongside future directions to achieve long-term stability and high PCE.This work aims to advance the understanding of the development in PSTJSCs,paving the way for their practical implementation.
基金funding from the National Key Research and Development Program of China(No.2018YFE0110000)the National Natural Science Foundation of China(No.11274259,No.11574258)the Science and Technology Commission Foundation of Shanghai(21DZ1205500)in support of the present research.
文摘While reinforcement learning-based underwater acoustic adaptive modulation shows promise for enabling environment-adaptive communication as supported by extensive simulation-based research,its practical performance remains underexplored in field investigations.To evaluate the practical applicability of this emerging technique in adverse shallow sea channels,a field experiment was conducted using three communication modes:orthogonal frequency division multiplexing(OFDM),M-ary frequency-shift keying(MFSK),and direct sequence spread spectrum(DSSS)for reinforcement learning-driven adaptive modulation.Specifically,a Q-learning method is used to select the optimal modulation mode according to the channel quality quantified by signal-to-noise ratio,multipath spread length,and Doppler frequency offset.Experimental results demonstrate that the reinforcement learning-based adaptive modulation scheme outperformed fixed threshold detection in terms of total throughput and average bit error rate,surpassing conventional adaptive modulation strategies.
基金supported by the National Natural Science Foundation of China(Grant No.82220108002 to F.C.and Grant No.82273737 to R.Z.)the U.S.National Institutes of Health(Grant Nos.CA209414,HL060710,and ES000002 to D.C.C.,Grant Nos.CA209414 and CA249096 to Y.L.)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)supported by the Qing Lan Project of the Higher Education Institutions of Jiangsu Province and the Outstanding Young Level Academic Leadership Training Program of Nanjing Medical University.
文摘Interferon-related genes are involved in antiviral responses,inflammation,and immunity,which are closely related to sepsis-associated acute respiratory distress syndrome(ARDS).We analyzed 1972 participants with genotype data and 681 participants with gene expression data from the Molecular Epidemiology of ARDS(MEARDS),the Molecular Epidemiology of Sepsis in the ICU(MESSI),and the Molecular Diagnosis and Risk Stratification of Sepsis(MARS)cohorts in a three-step study focusing on sepsis-associated ARDS and sepsis-only controls.First,we identified and validated interferon-related genes associated with sepsis-associated ARDS risk using genetically regulated gene expression(GReX).Second,we examined the association of the confirmed gene(interferon regulatory factor 1,IRF1)with ARDS risk and survival and conducted a mediation analysis.Through discovery and validation,we found that the GReX of IRF1 was associated with ARDS risk(odds ratio[OR_(MEARDS)]=0.84,P=0.008;OR_(MESSI)=0.83,P=0.034).Furthermore,individual-level measured IRF1 expression was associated with reduced ARDS risk(OR=0.58,P=8.67×10^(-4)),and improved overall survival in ARDS patients(hazard ratio[HR_(28-day)]=0.49,P=0.009)and sepsis patients(HR_(28-day)=0.76,P=0.008).Mediation analysis revealed that IRF1 may enhance immune function by regulating the major histocompatibility complex,including HLA-F,which mediated more than 70%of protective effects of IRF1 on ARDS.The findings were validated by in vitro biological experiments including time-series infection dynamics,overexpression,knockout,and chromatin immunoprecipitation sequencing.Early prophylactic interventions to activate IRF1 in sepsis patients,thereby regulating HLA-F,may reduce the risk of ARDS and mortality,especially in severely ill patients.
基金The Scientific Research Foundation of Third Institute of Oceanography,State Oceanic Administration under contract Nos TIO 2007009 and TIO 2009007the River basin-Estuary ecological security assessment and Management strategy under contract No.200805064+4 种基金the Natural Science Foundation of Fujian Province under contract No.2010J01260the "908" Project under contract No.908-02-02-01 special subjectthe Program of Chinese Marine Chemistry Investigation and Research under contract No.908-ZC-I-03the Special Fund of State Oceanic Administration under contract No.908-02-01-02the Major State Basic Research Development Program of China (973 Program) under contract Nos 2010CB428704 and 2005CB422305
文摘Long-term changes of phytoplankton community by water sampling method in Xiagu Sea waters of Xiamen,China,were investigated in this study.Species composition of the phytoplankton community in these waters changed greatly since the 1950s.The numbers of Dinophyta species increased significantly,although Bacillariophyta species are generally dominant.The succession of dominant species in phytoplankton community is obvious： large-size dominant species such as Biddulphia sinensis of the 1950s were gradually replaced by small-size ones such as Cyclotella striata and Nitzschia closterium,and species that still maintain dominant such as Skeletonema costatum are also small ones,leading the whole phytoplankton community of smaller size.Cell density of phytoplankton community increased greatly,among which cell density of the most dominant species Skeletonema costatum have been increasing in exponent function.Margalef index of phytoplankton community decreased,indicating decline of biodiversity of the community,and dominant character of Skeletonema costatum increased.Generally,the structure of the entire phytoplankton community is becoming more and more singular and unstable,which makes the occurrence of red tides more frequent.The succession in the phytoplankton community is related to the long-term changes in marine environment,influenced by human activities and global climate changes,especially the increases of nutrient content.
基金The Fundamental Research Project of Third Institute Oceanography of State Oceanic Administration under contract No.2011014the Public Welfare Project of the State Oceanic Administration under contract No.2011418015
文摘Based on the survey of surface sediment in Xiamen Bay in October 2011, the speciation, distribution, and potential ecological risk assessment of heavy metals （Cu, Pb, Zn, Cd, and Cr） in this area were studied us-ing the sequential extraction method and ecological risk assessment method. The results indicated：（1） the total concentrations of these heavy metals were influenced by runoff, industrial wastewater, and sewage, and were all higher in the coastal area than the offshore area while the highest area of Pb was a little far-ther away from the coastal water due to atmosphere deposition;（2） sequential extractions suggested that Cu was mainly composed with residual and Fe/Mn-oxide bound fractions, Pb was bound to Fe/Mn-oxide, Zn and Cr were dominated by residual, and Cd bound to exchangeable and carbonate fractions; （3） the order of migration and transformation sequence was Cd＆gt;Pb＆gt;Cu＆gt;Zn＆gt;Cr and the degree of pollution was Cd＆gt;Pb＆gt;Cu＆gt;Zn＆gt;Cr;and （4） the ratios of the secondary and primary phases showed that Zn and Cr were both clean, Cu may be polluted, Pb was moderately polluted, while Cd was heavily polluted.
基金supported by the National Natural Science Foundation of China(Grant No.41176089)supported by WEL(abbreviation of Key Laboratory of the Coastal and Wetland Ecosystems,Ministry of Education)Visiting Fellowship Program from Xiamen University
文摘To compare meiofaunal community in the two mangrove wetlands in Tong＇an Bay, Xiamen, China, and probe the response of meiofauna to high organic matter, sampling was carried out in Fenglin and Xiang＇an mangrove wetlands in the bay. The results showed that the Ne/Co ratio （nematode to benthic copepod） and organic matter in Fenglin mangrove wetland were higher than those in Xiang＇an mangrove wetland. The meiofaunal abundance in Fenglin mangrove was all lower than that in Xiang＇an mangrove wetland in summer, autumn and spring, while the meiofaunal abundance in Fenglin mangrove was higher than that in Xiang＇an mangrove wetland in winter. Two-way ANOVA results showed that the meiofaunal abundance and nematode abundance were significantly different between regions, seasons and regionxseason. With all the results in the present study, we confirmed that the positive response of meiofaunal and nematode abundance were only detected for medium organic matter contents according to the Xiang＇an wetland＇s level, and that the distribution of meiofaunal abundance would be influenced by sand content. Higher copepod abundance and lower N/C value usually suggest better environmental quality.
基金supported by the National Natural Science Foundation of China (No. 40971257,41171365)the Environmental Nonprofit Research and Special Project of China (No. 201009004)the Program for Changjiang Scholars and Innovative Research Team in University (No.IRT0941)
文摘Intensive daytime and nighttime sampling was carried out from 23 Oct to 31 Dec 2008 to investigate the occurrence of nitrated polycyclic aromatic hydrocarbons （NPAHs） in PM1o at a roadside site in Xiamen, China. At the same time, six PMt0 samples were collected from a nearby roadway tunnel for comparison. Six NPAHs, namely 9-nitroanthracene, 2- and 3-nitrofluoranthene, 1- nitropyrene, 7-nitrobenz[a]anthracene, and 6-nitrobenzo[a]pyrene, were identified and quantified using GC/MS in negative ion chemical ionization mode. The average total concentration of six NPAHs （~NPAHs） in the cold season （26 Nov-31 Dec） was 2.3 （daytime） and 9.9 （nighttime） times higher than those in the warm season. Significant statistical difference （p 〈 0.01, 2-tailed） of ∑NPAHs between daytime and nighttime was found during both the warm and cold seasons. NPAHs were significantly positively correlated with their parent PAHs and nitrogen dioxide but negatively correlated with ambient temperature. The ratio of 2 ＋ 3-nitrofluoranthene to 1- nitropyrene exhibited a similar diurnal pattern as ZNPAHs and was generally greater than 5, indicating the importance of secondary atmospheric formation. The diurnal variations of NPAHs were all influenced by the diurnal variations of PAHs, nitrogen dioxide, sunlight, and temperature. The daily inhalable exposure to the six NPAHs in the tunnel was much higher than the roadside values in the warm season but only slightly higher than those in the cold season.
基金supported by the National Natural Sci-ence Foundation of China (No 20777063) China Postdoctoral Science Foundation (No 20080440731)
文摘The levels and distribution of mercury （Hg） species, including total mercury （THg） and methylmercury （MeHg） in the topsoil and dust collected from twenty sampling stations located in different land function areas of Xiamen, China, were investigated. The THg concentrations in topsoil ranged from 0.071 to 1.2 mg/kg, and in dust ranged from of 0.034 to 1.4 mg/kg. For stations where the THg of dust was less than 0.31 mg/kg, THg concentrations in the topsoil were significantly correlated to those in the corresponding dust （r = 0.597, n = 16, P = 0.014）. The MeHg concentrations in topsoil were varied between 0.14 and 5.7 μg/kg. The ratios of MeHg/THg in the topsoil ranged from 0.069% to 0.74%. The range of MeHg concentration in the dust were 0.092-2.3 μg/kg. The ratios of MeHg/THg in the dust were at the same level as those in the topsoil. The MeHg concentrations in both topsoil and dust were linked to corresponding THg concentrations and soil organic matter. Neither THg nor MeHg concentration in the topsoil and dust was obviously linked to the land function.
基金Supported by the Scientific Research Foundation of Third Institute of Oceanography,SOA(Nos.TIO2007009,TIO2009007)the River Basin-Estuary Ecological Security Assessment and Management Strategy(No.200805064)+3 种基金the Natural Science Foundation of Fujian Province(Nos.2006J0362,2010J01260,2012Y0048)the National Department Public Benefit Research Foundation:Protection Technique of Beach and Demonstration Project in China(No.200905008)a Sub-task of the National Commonweal Marine Research Project:Typical Semi-enclosed Bay Eutrophication Immediate Report and Ecological Effect Assessment(No.201105014-6)the Special Social Commonweal Foundation for Research Institutes:Primary Red Tide Warning Index System of Physical and Chemical Research for Enclosed Bay(No.2004DIB3J084)
文摘Water samples were collected at 20 sites on 4 occasions in 2009 （twice in May, and once in both August and November） along the Jiulong River, South China to examine how nutrient inputs from the Jiulong River could affect the nutrient status of the Xiamen Water. Samples were analyzed for nitrite （NO2-N）, nitrate （NO3-N）, ammonium （NH4-N）, phosphate （PO4-P）, silicate （SiO3-Si）, salinity, and temperature, to determine the nutrient and trophic status of the river. The results indicate that nutrients are derived mainly from river runoff. NO3-N was the main form of DIN in most parts of the river. In addition, NO3-N, DIN, and SiO3-Si behave conservatively. There is a surplus of DIN and SiO3-Si in the river, and PO4-P is a limitation on phytoplankton growth. The concentration of DIN is typically above 0.60 mg/dm3, and higher than 1.00 mg/dm3 in most parts of the river. The concentration of PO4-P is typically above 0.02 mg/dm3, while the concentration of SiO3-Si is higher than 1.00 rag/din3. Between 2003 and 2008, samples were collected 3 times per year （May, August and November） at 27 sites in the Xiamen Water and analyzed for NO2-N, NO3-N, NH4-N, PO4-P, salinity, and temperature. We discovered that the Jiulong River was the key source of DIN into the Xiamen Water, but not PO4-P, indicating the reason of the N/P molar ratio imbalance in the Xiamen Water. In the future, the effects of high DIN concentrations on the phytoplankton communities and marine ecosystems of the Xiamen Water shall be studied.
文摘Applying the methods of on-site observation and dynamic model, the research on the fronts at the Jiulong Estuary has been carried out, during which spatial and temporal distribution, dynamic characteristics and formation mechanism of salinity fronts are analyzed and discussed. The research shows that the estuarine fronts mainly lie in the area from the Jiyu Islet to the Haimen Island, outside of Yuweizai to Hulishan cross-section, the near coast of Yuweizai and the south of the Songyu-Gulangyu Channel. The fronts in the former two regions are formed directly by plume, while the one near the coast of Yuweizai is a tidal intrusion front caused by flood current and the one at the south of the Songyu-Gulangyu Channel is the result of current shear transformation. Under normal circumstances, fresh water of the Jiulong River mainly influences the inside of the Xiamen Bay, and when it is in typhoon seasons, plume front can affect the Taiwan Strait and has an effect on the biogeochemical Drocesses in the strait.
基金funded by the National Natural Science Foundation of China (No. 41606119)the Provincial Natural Science Foundation of Fujian (No. 2017J05068)the New Century Outstanding Talents Support Program for Institutions of Higher Learning in Fujian Province and Building Ecological Security for Urban Agglomeration and Integrating Ecological Restoration Techniques for Coastal Zones in Fujian River Deltas (No. 2016YFC0502900)
文摘Mangroves are unique in their biodiversity,but studies on their meiobenthic biodiversity in China are scarce.Despite the importance of mangroves,little work has been done on the classification of nematodes in mangrove wetlands.Fujian Province is the most northern point of China’s natural mangrove distribution,and it is also one of the provinces with the earliest constructed mangrove forest.In this paper,two new free-living marine nematode species of Desmodoridae from the Xiamen mangrove wetlands in China are described.Metachromadora xiamenensis sp.nov.is characterized by a cylindrical body,and smooth head capsule set off from the rest of the body.The cuticle is finely annulated and thickened at the midbody.Lateral ridges run from the posterior end of the pharynx to the middle of the tail.The amphid foveae is loop shaped and opens at the top with a double contour amphidial,pharynx with bipartite cuticularized internal cavity.There are 18 tubular precloacal supplements and tail with three small protuberances.Molgolaimus euryformis sp.nov.is characterized by a relatively short and plump body with finely annulated cuticle,which is particularly obvious in the tail.The head is small and wide with intensive striates.The inner and outer labial sensilla are indistinct with short spicules and ventral apophysis,a gubernaculum with a block-shaped hook,a swollen conical-cylindrical tail and an absence of precloacal supplements.
基金supported by the Xiamen Science and Technology Project of China[3502Z20123003]Fundamental Research Funds for the Central Universities of China[2011121006]National Undergraduate Training Program for Innovation and Entrepreneurship[201510384140]
文摘Objective Cr（VI） removal from industrial effluents and sediments has attracted the attention of environmental researchers. In the present study, we aimed to isolate bacteria for Cr（VI） bioremediation from sediment samples and to optimize parameters of biodegradation. Methods Strains with the ability to tolerate Cr（VI） were obtained by serial dilution and spread plate methods and characterized by morphology, 16 S r DNA identification, and phylogenetic analysis. Cr（VI） was determined using the 1,5-diphenylcarbazide method, and the optimum p H and temperature for degradation were studied using a multiple-factor mixed experimental design. Statistical analysis methods were used to analyze the results. Results Fifty-five strains were obtained, and one strain（Sporosarcina saromensis M52; patent application number： 201410819443.3） having the ability to tolerate 500 mg Cr（VI）/L was selected to optimize the degradation conditions. M52 was found be able to efficiently remove 50-200 mg Cr（VI）/L in 24 h, achieving the highest removal efficiency at p H 7.0-8.5 and 35 °C. Moreover, M52 could completely degrade 100 mg Cr（VI）/L at p H 8.0 and 35 °C in 24 h. The mechanism involved in the reduction of Cr（VI） was considered to be bioreduction rather than absorption. Conclusion The strong degradation ability of S. saromensis M52 and its advantageous functional characteristics support the potential use of this organism for bioremediation of heavy metal pollution.
