During the initial impoundment period of a canyon-shaped reservoir,the water body fluctuated violently regarding water level,hydrological condition,and thermal stratification.These variations may alter the structure o...During the initial impoundment period of a canyon-shaped reservoir,the water body fluctuated violently regarding water level,hydrological condition,and thermal stratification.These variations may alter the structure of phytoplankton community,resulting in algal blooms and seriously threatening the ecological security of the reservoir.It is of great significance to understand the continuous changes of phytoplankton in the initial impoundment period for the protection of reservoir water quality.Therefore,a two-year in-situ monitoring study was conducted on water quality and phytoplankton in a representative canyonshaped reservoir named Sanhekou and the interannual changes of phytoplankton community and its response to environmental changes during the initial impoundment period were discussed at taxonomic versus functional classification levels.The results showed that the total nitrogen and permanganate index levels were relatively high in the first year due to rapid water storage and heavy rainfall input,and the more stable hydrological conditions in the second year promoted the increase of algae density and the transformation of community,and the proportion of cyanobacteria increased significantly.The succession order of phytoplankton in the first year of the initial impoundment periodwas Chlorophyta-Bacillariophyta-Chlorophyta,or J/F/X1-P/MP/W1-A/X1/MP,respectively.And the succession order in the second year was Cyanobacteria/Chlorophyta-Bacillariophyta-Chlorophyta,or L_(M)/G/P-P/A/X1-X1/J/G.Water temperature,relativewater column stability,mixing depth,and pHwere crucial factors affecting phytoplankton community succession.This study revealed the interannual succession law and driving factors of phytoplankton in the initial impoundment period and provided an important reference for the operation management and ecological protection of canyon-shaped reservoirs.展开更多
Difunctionalization of unsaturated hydrocarbons is a pivotal synthetic strategy enabling the conversion of alkenes and alkynes into high value-added compounds.It allows for the introduction of two functional groups in...Difunctionalization of unsaturated hydrocarbons is a pivotal synthetic strategy enabling the conversion of alkenes and alkynes into high value-added compounds.It allows for the introduction of two functional groups into the unsaturated bond in a single step,facilitating the efficient construction of complex molecular architectures,which has been widely utilized in material chemistry,pharmaceutical and fine chemical synthesis.Recently,significant progress has been made via free radical-mediated difunctionalization due to the extensive application of photocatalysis.However,highly selective difunc-tionalization reactions still remain challenging.The research progress of selective difunctionalization of unsaturated hydro-carbons using a free radical addition/functional group migration strategy over the past decade is summarized,and synthetic strategies and key reaction steps are systematically elaborated.展开更多
Multi-criteria decision-making(MCDM)is essential for handling complex decision problems under uncertainty,especially in fields such as criminal justice,healthcare,and environmental management.Traditional fuzzy MCDM te...Multi-criteria decision-making(MCDM)is essential for handling complex decision problems under uncertainty,especially in fields such as criminal justice,healthcare,and environmental management.Traditional fuzzy MCDM techniques have failed to deal with problems where uncertainty or vagueness is involved.To address this issue,we propose a novel framework that integrates group and overlap functions with Aczel-Alsina(AA)operational laws in the intuitionistic fuzzy set(IFS)environment.Overlap functions capture the degree to which two inputs share common features and are used to find how closely two values or criteria match in uncertain environments,while the Group functions are used to combine different expert opinions into a single collective result.This study introduces four new aggregation operators:Group Overlap function-based intuitionistic fuzzy Aczel-Alsina(GOF-IFAA)Weighted Averaging(GOF-IFAAWA)operator,intuitionistic fuzzy Aczel-Alsina(GOF-IFAA)Weighted Geometric(GOF-IFAAWG),intuitionistic fuzzy Aczel-Alsina(GOF-IFAA)OrderedWeighted Averaging(GOF-IFAAOWA),and intuitionistic fuzzy Aczel-Alsina(GOF-IFAA)Ordered Weighted Geometric(GOF-IFAAOWG),which are rigorously defined and mathematically analyzed and offer improved flexibility in managing overlapping,uncertain,and hesitant information.The properties of these operators are discussed in detail.Further,the effectiveness,validity,activeness,and ability to capture the uncertain information,the developed operators are applied to the AI-based Criminal Justice Policy Selection problem.At last,the comparison analysis between prior and proposed studies has been displayed,and then followed by the conclusion of the result.展开更多
As a new electrochemical technology,capacitive deionization(CDI)has been increasingly applied in environmental water treatment and seawater desalination.In this study,functional groups modified porous hollow carbon(HC...As a new electrochemical technology,capacitive deionization(CDI)has been increasingly applied in environmental water treatment and seawater desalination.In this study,functional groups modified porous hollow carbon(HC)were synthesized as CDI electrode material for removing Na^(+)and Cl^(−)in salty water.Results showed that the average diameter of HC was approximately 180 nm,and the infrared spectrum showed that its surface was successfully modified with sulfonic and amino groups,respectively.The sulfonic acid functionalized HC(HC-S)showed better electrochemical and desalting performance than the amino-functionalized HC(HC–N),with a maximum Faradic capacity of 287.4 F/g and an adsorptive capacity of 112.97 mg/g for NaCl.Additionally,92.63%capacity retention after 100 adsorption/desorption cycles demonstrates the excellent stability of HC-S.The main findings prove that HC-S is viable as an electrodematerial for desalination by high-performance CDI applications.展开更多
Amyloid-like proteins are critical for interfacial adhesion across various marine organisms and bacteria.However,the specific contributions of different functional residues remain unclear.Herein,we introduce an approa...Amyloid-like proteins are critical for interfacial adhesion across various marine organisms and bacteria.However,the specific contributions of different functional residues remain unclear.Herein,we introduce an approach to deconstruct and mimic these residues using synthetic homopolymers and random copolymers with phenyl,amino,carboxyl,and hydroxyl functional groups using reversible addition-fragmentation chain transfer(RAFT)polymerization.The resulting polymers,designed with comparable molecular weights(M_(n):10–20 kDa)and narrow dispersities(PDI<1.3),mimic the diverse surface chemistry of amyloid-like proteins,enabling systematic investigation of their adhesive properties.The interfacial adhesion forces of different polymer films were quantified using atomic force microscopy(AFM)with a colloidal probe.Remarkably copolymers with multiple functional groups demonstrated significantly enhanced adhesion compared to homopolymers,a trend corroborated by macroscopic shear strength and stability tests.These results highlight that the synergistic effects of multiple functional groups are crucial for achieving universal interfacial adhesion of macromolecules,offering insights into protein adhesion mechanisms,and guiding polymer-based interfacial modifications.展开更多
Macrocyclic hosts play a crucial role in supramolecular chemistry and the development of supramolecular functional materials.Their well-defined cavities and diverse host-vip interactions endow macrocycles with excel...Macrocyclic hosts play a crucial role in supramolecular chemistry and the development of supramolecular functional materials.Their well-defined cavities and diverse host-vip interactions endow macrocycles with excellent stimuli responsiveness,facilitating efficient assembly construction.However,the limited availability of functional groups in conventional macrocycles restricts their ability to meet the demand for fabricating materials with multiple functionalities.To address this limitation,several research groups have introduced tetraphenylethylene(TPE),a well-known building block renowned for its remarkable aggregation-induced emission(AIE)effect,into the macrocycle framework.Herein,this paper summarizes the combination strategies and synergistic approaches that achieve multi-functionality by integrating TPE and macrocyclic architectures.The emission characteristics of TPE-embedded macrocycles are elucidated,and it is anticipated that more AIE-type macrocycles with innovative backbones and broad applications will emerge.展开更多
Stable carbon isotopes(δ^(13)C)are extensively utilized to study intrinsic water use efficiency(iWUE)at the leaf-scale in terrestrial ecosystems,serving as a crucial metric for assessing plant adaptation to climate c...Stable carbon isotopes(δ^(13)C)are extensively utilized to study intrinsic water use efficiency(iWUE)at the leaf-scale in terrestrial ecosystems,serving as a crucial metric for assessing plant adaptation to climate change.However,there is currently a lack of consensus regarding the leaf-scale iWUE variation characteristics among different functional types.In this study,we measured theδ^(13)Cleaf and iWUE values of different functional plants(i.e.,life forms,leaf types,and mycorrhizal types)from 120 species across distinct habitat types(i.e.,hillside,nearpeak,and peak)in a subtropical forest on the western slope of Wuyi Mountains,southern China.The results showed that theδ^(13)Cleaf values of plants on the western slope of Wuyi Mountains ranged from-34.63‰to-30.04‰,and iWUE ranged from 5.93μmol mol^(-1)to 57.34μmol mol^(-1).Theδ^(13)Cleaf and iWUE values differed significantly among plant life forms,following the order of herbs>vine plants>shrubs>trees.Theδ^(13)Cleaf and iWUE values of ectomycorrhizal(ECM)species were greater than those of arbuscular mycorrhizal(AM)species despite there being no significant difference between plants with different leaf types(Simple leaves(SL)vs.Compound leaves(CL)).From the hillside to the peak,both at the community level and at the species level,theδ^(13)C values of leaves and iWUE values of plants exhibited an upward trend.The regression analysis revealed that leaf-scale iWUE was significantly negatively correlated with soil water content and significantly positively correlated with leaf phosphorus content.The findings indicated that leaf carbon isotope fractionation and corresponding iWUE can be influenced by life form,mycorrhizal type,and soil water availability.These insights provide a deeper understanding of the coupling mechanisms of carbon,water,and nutrients among different functional plant types in subtropical forests,and offer insights into predicting plant adaptability under climate change.展开更多
Taking the Lower Silurian Longmaxi Formation shale in the Sichuan Basin as an example,this study employs atomic force microscopy-based infrared(AFM-IR)spectroscopy to analyze the submicron-scale molecular functional g...Taking the Lower Silurian Longmaxi Formation shale in the Sichuan Basin as an example,this study employs atomic force microscopy-based infrared(AFM-IR)spectroscopy to analyze the submicron-scale molecular functional groups of different types and occurrences of organic matter.Combined with the quantitative evaluation of pore development via scanning electron microscopy(SEM),the response of organic pore formation and evolution mechanisms to chemical composition and structural evolution of organic matter in overmature marine shale is investigated.The results indicate that the AFM-IR spectra of graptolite periderms and pyrobitumen in shale are dominated by the stretching vibrations of conjugated C=C bonds in aromatic compounds at approximately 1600 cm-1,with weak absorption peaks near 1375,1450 and 1720 cm-1,corresponding to aliphatic chains and carbonyl/carboxyl functional groups.Overall,the AFM-IR structural indices(A and C factors)of organic matter show a strong correlation with visible porosity in shales of equivalent maturity.Lower A and C factor values correlate with enhanced development of organic pores,which is associated with the detachment of more aliphatic chains and oxygen-containing functional groups during thermal evolution.Pyrobitumen-clay mineral composites generally exhibit superior pore development,likely attributable to clay mineral dehydration participating in hydrocarbon generation reactions that promote the removal of more functional groups.Additionally,hydrocarbon generation within organic-clay composites during high-over mature stages may induce volumetric expansion,resulting in microfracturing and hydrocarbon expulsion.The associated higher hydrocarbon expulsion rates promote the formation of larger pores and fracture-shaped pores along the flake-shaped clay minerals.This study highlights that the research of submicron-scale molecular functional groups provides a deeper understanding of organic matter evolution and pores development mechanisms in overmature shales,thereby offering critical theoretical parameters for reservoir evaluation in shale oil and gas exploration.展开更多
In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method...In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method involving high-pressure processing,stirring,and immiscible solutions,sub-100 nm MXene flake thickness is achieved within the MXene film on the Si-wafer.Functionalization control is achieved by defunctionalizing MXene at 650℃ under vacuum and H2 gas in a CVD furnace,followed by refunctionalization with iodine and bromine vaporization from a bubbler attached to the CVD.Notably,the introduction of iodine,which has a larger atomic size,lower electronegativity,reduce shielding effect,and lower hydrophilicity(contact angle:99°),profoundly affecting MXene.It improves the surface area(36.2 cm^(2) g^(-1)),oxidation stability in aqueous/ambient environments(21 days/80 days),and film conductivity(749 S m^(-1)).Additionally,it significantly enhances the gas-sensing performance,including the sensitivity(0.1119Ωppm^(-1)),response(0.2% and 23%to 50 ppb and 200 ppm NO_(2)),and response/recovery times(90/100 s).The reduced shielding effect of the–I-terminals and the metallic characteristics of MXene enhance the selectivity of I-MXene toward NO2.This approach paves the way for the development of stable and high-performance gas-sensing two-dimensional materials with promising prospects for future studies.展开更多
To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were investigated.First,the correlation betwe...To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were investigated.First,the correlation between the surface characteristics of four different alumina and the existing Mo species states was established.It was found that the Mo equilibrium adsorption capacity can be used as a specific descriptor to quantitatively evaluate the changes in surface characteristics of different alumina.A lower Mo equilibrium adsorption capacity for alumina means weaker metal-support interaction and the loaded Mo species are easier to transform into MoS2.However,the Mo-O-Al bonds still exist at the metal-support interface.The introduction of cationic surfactant hecadecyl trimethyl ammonium bromide(CTAB)can further improve Mo species dispersion through electrostatic attraction with Mo anions and interaction of its alkyl chain with the alumina surface;meanwhile,the introduction of ethylenediamine tetraacetic acid(EDTA)can complex with Ni ions to enhance the Ni-promoting effect on Mo.Therefore,the NiMo catalyst designed using alumina with lower Mo equilibrium adsorption capacity and the simultaneous addition of EDTA and CTAB exhibits the highest hydrodesulfurization activity for 4,6-dimethyl dibenzothiophene because of its proper metal-support interaction and more well-dispersed Ni-Mo-S active phases.展开更多
Global warming has caused an increase in the frequency and duration of droughts worldwide.Droughts could trigger large changes in physico-chemical conditions and phytoplankton community in waterbodies,resulting in a s...Global warming has caused an increase in the frequency and duration of droughts worldwide.Droughts could trigger large changes in physico-chemical conditions and phytoplankton community in waterbodies,resulting in a shift in the phytoplankton community.Spring diatom blooms in reservoirs have been increasingly observed in the past decade in the Taihu Lake basin.The aim of the present study is to elucidate the impacts of droughts on aquatic environment and to determine the driving factors for the succession of the phytoplankton functional groups based on the analysis of data collected during spring from 2009 to 2020 in the Daxi Reservoir.The unimodal relationship between 1-month aggregated precipitation index and phytoplankton species richness indicated the competitive exclusion occurred in extremely drought period.The structural equation modeling indicated that drought-related low water level conditions intensified sediment resuspension,and increased the phosphorus-enriched nonalgal turbidity in the Daxi Reservoir.Concurrently,a steady shift in the Reynolds phytoplankton functional groups from L 0,TD,J,X 2,and A(phytoplankton taxa preferring low turbidity and nutrient conditions)to TB(pennate diatoms being adapt to turbid and nutrient-rich conditions)was observed.The increased TP and non-algal turbidity in addition to the lowered disturbance contribute to the prevalence of Group TB.Considering the difficulties in nutrient control,timely water replenishment is often a feasible method of controlling the dominance of harmful algae for reservoir management.Finally,alternative water sources are in high demand for ensuring ecological safety and water availability when dealing with drought.展开更多
Mercury ion(Hg^(2+)),as one of the most toxic heavy metal ions,accumulates easily in the environment,which can generate potential hazards to the ecosystem and human health.To effectively detect and remove Hg^(2+),we f...Mercury ion(Hg^(2+)),as one of the most toxic heavy metal ions,accumulates easily in the environment,which can generate potential hazards to the ecosystem and human health.To effectively detect and remove Hg^(2+),we fabricated four types of carbon dots(CDs)using carboxymethyl nanocellulose as a carbon source doped with different elements using a hydrothermal method.All the CDs exhibited a strong fluorescence emission,excitation-dependent emission and possessed good water dispersibility.Moreover,the four fluorescent CDs were used for Hg^(2+)recognition in aqueous solution,where the CDs-N exhibited better sensitivity and selectivity for Hg^(2+)detection,with a low limit of detection of 8.29×10^(-6)mol/L.It was determined that the fluorescence quenching could be ascribed to a photoinduced charge-transfer processes between Hg^(2+)and the CDs.In addition,the CDs-N were used as a smart invisible ink for anticounterfeiting,information encryption and decryption.Furthermore,the CDs-N were immersed into a cellulose(CMC)-based hydrogel network to prepare fluorescent hydrogels capable of simultaneously detecting and adsorbing Hg^(2+).We anticipate that this research will open possibilities for a green method to synthesize fluorescent CDs for metal ion detection and fluorescent ink production.展开更多
Anthropogenic disturbances are widespread in tropical forests and influence the species composition in the overstory.However,the impacts of historical disturbance on tropical forest overstory recovery are unclear due ...Anthropogenic disturbances are widespread in tropical forests and influence the species composition in the overstory.However,the impacts of historical disturbance on tropical forest overstory recovery are unclear due to a lack of disturbance data,and previous studies have focused on understory species.In this study,the purpose was to deter-mine the influence of historical disturbance on the diver-sity,composition and regeneration of overstory species in present forests.In the 20-ha Xishuangbanna tropical sea-sonal rainforest dynamics plot in southwestern China,the historical disturbance boundaries were delineated based on panchromatic photographs from 1965.Factors that drove species clustering in the overstory layer(DBH≥40 cm)were analyzed and the abundance,richness and composition of these species were compared among different tree groups based on multiple regression tree analysis.The coefficient of variation of the brightness value in historical panchro-matic photographs from 1965 was the primary driver of spe-cies clustering in the overstory layer.The abundance and richness of overstory species throughout the regeneration process were similar,but species composition was always different.Although the proportion of large-seeded and vigorous-sprouting species showed no significant differ-ence between disturbed and undisturbed forests in the tree-let layer(DBH<20 cm),the difference became significant when DBH increased.The findings highlight that historical disturbances have strong legacy effects on functional group composition in the overstory and the recovery of overstory species was multidimensional.Functional group composi-tion can better indicate the dynamics of overstory species replacement during secondary succession.展开更多
To understand the distribution of phytoplankton functional groups(PFGs)and key factors on their compositions in different watersheds of the Huanghe(Yellow)River basin,25 river sites and 25 lake-reservoirs sites were s...To understand the distribution of phytoplankton functional groups(PFGs)and key factors on their compositions in different watersheds of the Huanghe(Yellow)River basin,25 river sites and 25 lake-reservoirs sites were selected.The contents of nephelometric turbidity(NTU),total nitrogen(TN),and total phosphorus(TP)were significantly higher in rivers than that in lakes or reservoirs,whereas the pH and CODMn(chemical oxygen demand or potassium permanganate index)were lower.Results show that,27 PFGs,namely,assemblages A,B,C,D,E,F,G,H,J,K,LM,Lo,M,MP,N,P,S1,S2,T,TC,W1,W2,X1,X2,X3,XPh,and Y,were identified.Additionally,ANOSIM correlation analysis demonstrated significant differences in PFG composition between the riverine and lake-reservoir sections in the Huanghe River basin.In the riverine watersheds,the group MP was dominant,while assemblages B and J were prevalent in lakes and reservoirs.The Mantel correlation tests and RDA analysis showed that environmental variables,such as NTU,water temperature(WT),conductivity(Cond),and TP,were key driving factors of shaping the dominant PFGs of the study area.Using the Venn diagram based on variation partitioning analysis,PFGs were mainly influenced by WT and TP in lake-reservoir sites,while in the river sites were affected mainly by geo-climatic variables.This study helps understanding the PFGs in river ecosystems,and unraveling the key driving factors in different watersheds,which shall be important for the protection and management of entire Huanghe River basin.展开更多
The education and management of college student Party members is the focus of student Party building work in colleges and universities.In the context of students second classroom being conducted in the academy,the man...The education and management of college student Party members is the focus of student Party building work in colleges and universities.In the context of students second classroom being conducted in the academy,the management of student Party members should enhance their Party spirit cultivation through improving their self-management and self-monitoring.After the comprehensive reform of Ningxia University,Runze College targeted the characteristics of agricultural majors and set up functional Party groups to enable student Party members to play a pioneering and exemplary role in the second classroom.Runze College relies on the academy system and breaks through the traditional one-way management mode led by Party branch teachers in the second classroom of college students.It leverages the role of functional Party groups in off campus science and technology academies,and integrates Party building work into daily teaching and research and solving agricultural production technology problems for local villagers,achieving the goal of promoting and integrating Party building and business work,and improving each other.展开更多
All-vanadium flow batteries(VFBs)are one of the most promising large-scale energy storage technologies.Conducting an operando quantitative analysis of the polarizations in VFBs under different conditions is essential ...All-vanadium flow batteries(VFBs)are one of the most promising large-scale energy storage technologies.Conducting an operando quantitative analysis of the polarizations in VFBs under different conditions is essential for developing high power density batteries.Here,we employ an operando decoupling method to quantitatively analyze the polarizations in each electrochemical and chemical reaction of VFBs under different catalytic conditions.Results show that the reduction reaction of V^(3+)presents the largest activation polarization,while the reduction reaction of VO_(2)^(+)primarily contributes to concentration polarizations due to the formation of the intermediate product V_(2)O_(3)^(3+).Additionally,it is found that the widely used electrode catalytic methods,incorporating oxygen functional groups and electrodepositing Bi,not only enhance the reaction kinetics but also exacerbate concentration polarizations simultaneously,especially during the discharge process.Specifically,in the battery with the high oxygen-containing electrodes,the negative side still accounts for the majority of activation loss(75.3%)at 200 mA cm^(-2),but it comes down to 36,9% after catalyzing the negative reactions with bismuth.This work provides an effective way to probe the limiting steps in flow batteries under various working conditions and offers insights for effectively enhancing battery performance for future developments.展开更多
[Objective]The aim was to carry out stoichiometry on the early-spring herbs functional group in subtropical artificial wetland.[Method]UV-Vis spectrophotometer was used for the determination of nitrate-nitrogen,ammoni...[Objective]The aim was to carry out stoichiometry on the early-spring herbs functional group in subtropical artificial wetland.[Method]UV-Vis spectrophotometer was used for the determination of nitrate-nitrogen,ammonium nitrogen and phosphorus concentrations.Potassium persulfate absorptiometry was used for the measurement of total N content,while the flame photometer was used to detect the potassium and sodium concentration in plants.All the nutrient determination of plant samples were repeated for four times.[Result]The four nutrient concentrations in almost all samples were in the normal range of natural plant nutrition concentrations;in early-spring herbs functional groups,different species showed diversity on the nutrient concentrations;plant height had no significant effect on the nutrient concentrations in plants;the nutrient concentrations of non-grass group plants were higher than that of grass group plants;the nutrient concentrations of the annual herb were higher than that of perennial herbs.[Conclusion]The study had provided basis for the understanding of the effects of changes in nutritional conditions on species diversity,community structure and succession of the system.展开更多
Increasing nitrogen and phosphorus discharge and decreasing sediment input have made silicon(Si)a limiting element for diatoms in estuaries.Disturbances in nutrient structure and salinity fluctuation can greatly affec...Increasing nitrogen and phosphorus discharge and decreasing sediment input have made silicon(Si)a limiting element for diatoms in estuaries.Disturbances in nutrient structure and salinity fluctuation can greatly affect metal uptake by estuarine diatoms.However,the combined effects of Si and salinity on metal accumulation in these diatoms have not been evaluated.In this study,we aimed to investigate how salinity and Si availability combine to influence the adsorption of metals by a widely distributed diatom Phaeodactylum tricornutum.Our data indicate that replete Si and low salinity in seawater can enhance cadmium and copper adsorption onto the diatom surface.At the single-cell level,surface potential was a dominant factor determining metal adsorption,while surface roughness also contributed to the highermetal loading capacity at lower salinities.Using a combination of noninvasive micro-test technology,atomic force microscopy,X-ray photoelectron spectroscopy,and Fourier transform infrared spectroscopy,we demonstrate that the diversity and abundance of the functional groups embedded in diatom cell walls vary with salinity and Si supply.This results in a change in the cell surface potential and transient metal influx.Our study provides novel mechanisms to explain the highly variable metal adsorption capacity of a model estuarine diatom.展开更多
Understanding the response of the phytoplankton community to climate change is essential for reservoir management.We analyzed a long-term data series(2009–2020)on the phytoplankton community in a large mesotrophic re...Understanding the response of the phytoplankton community to climate change is essential for reservoir management.We analyzed a long-term data series(2009–2020)on the phytoplankton community in a large mesotrophic reservoir in the wet season to investigate the impacts of temperature and precipitation increases caused by climate change on the functioning and trait composition of the phytoplankton community.Over the last twelve years,the 3-month accumulative precipitation increased from 291.03 mm to 590.91 mm,and the surface water temperature increased from 25.06℃to 26.49℃in wet season,respectively.These changes caused a higher water level,stronger thermal stratification and lower nitrogen concentration in Daxi Reservoir.The dynamic equilibrium model indicated that the increased precipitation and water temperature-related environmental changes would result in a more diverse and productive phytoplankton community.The effects of increasing water temperature and precipitation on the niche complementarity and selection effects within the phytoplankton community were analyzed using structural equation model by means of the functional divergence index and functional evenness index,respectively,elucidating the reasons for the increase in cyanobacteria in the absence of a significant increase in nutrient levels.Based on these results,it is advisable that more stringent phosphorus control standards might be conducted to reduce the risks of cyanobacteria proliferation in the context of global warming.展开更多
The effects of different kinds of ionic liquids(ILs)on the caking property of Shenhua long-flame coal(SHLC)were studied.SHLC and its residue after[N_(4441)][Cl]treatment under optimum conditions were characterized by ...The effects of different kinds of ionic liquids(ILs)on the caking property of Shenhua long-flame coal(SHLC)were studied.SHLC and its residue after[N_(4441)][Cl]treatment under optimum conditions were characterized by Fourier transform infrared spectroscopy(FT-IR),thermogravimetric analysis(TG),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Raman spectroscopy,and pyrolysis-gas chromatography and mass-spectrometric analysis(Py-GC/MS).The results showed that the ILs used could extract the poorly-caking components from SHLC,and[N_(4441)][Cl]with C_(3)H_(6)O as a solvent exhibited the best effect among the ILs and solvents used.[N_(4441)][Cl]could destroy the H bonds in SHLC,and the structure of the cross-linked macromolecules of SHLC was loosed,leading to the release of the small molecules within the macromolecular framework of SHLC.Additionally,[N_(4441)][Cl]could easily penetrate into the interior of the relaxed SHLC and break the weak covalent bonds(e.g.,C-O bonds)of the macromolecules of SHLC.As a result,aromatic hydrocarbons with 3‒5 rings and aliphatic side chains,which are the precursor of the poorly-caking components,were formed and were then extracted from SHLC by C_(3)H_(6)O.Consequently,[N_(4441)][Cl]treatment could decrease the caking property,thermal ability,and macromolecular size of SHLC.展开更多
基金supported by the National Key R&D Program of China(No.2022YFC3203602)the Natural Science Foundation of China(No.52370018)+1 种基金Shaanxi Provincial Youth Innovation Team Project(No.22JP040)Shaanxi Provincial Key Scientific and Technological Innovation Team(No.2023-CX-TD-32).
文摘During the initial impoundment period of a canyon-shaped reservoir,the water body fluctuated violently regarding water level,hydrological condition,and thermal stratification.These variations may alter the structure of phytoplankton community,resulting in algal blooms and seriously threatening the ecological security of the reservoir.It is of great significance to understand the continuous changes of phytoplankton in the initial impoundment period for the protection of reservoir water quality.Therefore,a two-year in-situ monitoring study was conducted on water quality and phytoplankton in a representative canyonshaped reservoir named Sanhekou and the interannual changes of phytoplankton community and its response to environmental changes during the initial impoundment period were discussed at taxonomic versus functional classification levels.The results showed that the total nitrogen and permanganate index levels were relatively high in the first year due to rapid water storage and heavy rainfall input,and the more stable hydrological conditions in the second year promoted the increase of algae density and the transformation of community,and the proportion of cyanobacteria increased significantly.The succession order of phytoplankton in the first year of the initial impoundment periodwas Chlorophyta-Bacillariophyta-Chlorophyta,or J/F/X1-P/MP/W1-A/X1/MP,respectively.And the succession order in the second year was Cyanobacteria/Chlorophyta-Bacillariophyta-Chlorophyta,or L_(M)/G/P-P/A/X1-X1/J/G.Water temperature,relativewater column stability,mixing depth,and pHwere crucial factors affecting phytoplankton community succession.This study revealed the interannual succession law and driving factors of phytoplankton in the initial impoundment period and provided an important reference for the operation management and ecological protection of canyon-shaped reservoirs.
文摘Difunctionalization of unsaturated hydrocarbons is a pivotal synthetic strategy enabling the conversion of alkenes and alkynes into high value-added compounds.It allows for the introduction of two functional groups into the unsaturated bond in a single step,facilitating the efficient construction of complex molecular architectures,which has been widely utilized in material chemistry,pharmaceutical and fine chemical synthesis.Recently,significant progress has been made via free radical-mediated difunctionalization due to the extensive application of photocatalysis.However,highly selective difunc-tionalization reactions still remain challenging.The research progress of selective difunctionalization of unsaturated hydro-carbons using a free radical addition/functional group migration strategy over the past decade is summarized,and synthetic strategies and key reaction steps are systematically elaborated.
基金supported by“1 Decembrie 1918”University of Alba Iulia,510009 Alba Iuliasupported in part by the HEC-NRPU project,under the grant No.14566.
文摘Multi-criteria decision-making(MCDM)is essential for handling complex decision problems under uncertainty,especially in fields such as criminal justice,healthcare,and environmental management.Traditional fuzzy MCDM techniques have failed to deal with problems where uncertainty or vagueness is involved.To address this issue,we propose a novel framework that integrates group and overlap functions with Aczel-Alsina(AA)operational laws in the intuitionistic fuzzy set(IFS)environment.Overlap functions capture the degree to which two inputs share common features and are used to find how closely two values or criteria match in uncertain environments,while the Group functions are used to combine different expert opinions into a single collective result.This study introduces four new aggregation operators:Group Overlap function-based intuitionistic fuzzy Aczel-Alsina(GOF-IFAA)Weighted Averaging(GOF-IFAAWA)operator,intuitionistic fuzzy Aczel-Alsina(GOF-IFAA)Weighted Geometric(GOF-IFAAWG),intuitionistic fuzzy Aczel-Alsina(GOF-IFAA)OrderedWeighted Averaging(GOF-IFAAOWA),and intuitionistic fuzzy Aczel-Alsina(GOF-IFAA)Ordered Weighted Geometric(GOF-IFAAOWG),which are rigorously defined and mathematically analyzed and offer improved flexibility in managing overlapping,uncertain,and hesitant information.The properties of these operators are discussed in detail.Further,the effectiveness,validity,activeness,and ability to capture the uncertain information,the developed operators are applied to the AI-based Criminal Justice Policy Selection problem.At last,the comparison analysis between prior and proposed studies has been displayed,and then followed by the conclusion of the result.
基金supported by the National Science Foundation of China(No.21606191)the Natural Science Foundation of Shandong Province(No.ZR2020ME024).
文摘As a new electrochemical technology,capacitive deionization(CDI)has been increasingly applied in environmental water treatment and seawater desalination.In this study,functional groups modified porous hollow carbon(HC)were synthesized as CDI electrode material for removing Na^(+)and Cl^(−)in salty water.Results showed that the average diameter of HC was approximately 180 nm,and the infrared spectrum showed that its surface was successfully modified with sulfonic and amino groups,respectively.The sulfonic acid functionalized HC(HC-S)showed better electrochemical and desalting performance than the amino-functionalized HC(HC–N),with a maximum Faradic capacity of 287.4 F/g and an adsorptive capacity of 112.97 mg/g for NaCl.Additionally,92.63%capacity retention after 100 adsorption/desorption cycles demonstrates the excellent stability of HC-S.The main findings prove that HC-S is viable as an electrodematerial for desalination by high-performance CDI applications.
基金supported by the National Natural Science Foundation of China(Nos.22375122 and 22105065)the National Science Fund for Distinguished Young Scholars(No.52225301)+3 种基金the National Key R&D Program of China(Nos.2020YFA0710400 and 2020YFA0710402)the 111 Project(No.B14041)Fundamental Research Funds for Central Universities(No.GK202304040)Open Project of the State Key Laboratory of Supramolecular Structure and Materials(No.sklssm2024023)。
文摘Amyloid-like proteins are critical for interfacial adhesion across various marine organisms and bacteria.However,the specific contributions of different functional residues remain unclear.Herein,we introduce an approach to deconstruct and mimic these residues using synthetic homopolymers and random copolymers with phenyl,amino,carboxyl,and hydroxyl functional groups using reversible addition-fragmentation chain transfer(RAFT)polymerization.The resulting polymers,designed with comparable molecular weights(M_(n):10–20 kDa)and narrow dispersities(PDI<1.3),mimic the diverse surface chemistry of amyloid-like proteins,enabling systematic investigation of their adhesive properties.The interfacial adhesion forces of different polymer films were quantified using atomic force microscopy(AFM)with a colloidal probe.Remarkably copolymers with multiple functional groups demonstrated significantly enhanced adhesion compared to homopolymers,a trend corroborated by macroscopic shear strength and stability tests.These results highlight that the synergistic effects of multiple functional groups are crucial for achieving universal interfacial adhesion of macromolecules,offering insights into protein adhesion mechanisms,and guiding polymer-based interfacial modifications.
基金the National Natural Science Foundation of China(No.22271154)the Science Fund for Distinguished Young Scholars of Jiangsu Province(No.BK20240078).
文摘Macrocyclic hosts play a crucial role in supramolecular chemistry and the development of supramolecular functional materials.Their well-defined cavities and diverse host-vip interactions endow macrocycles with excellent stimuli responsiveness,facilitating efficient assembly construction.However,the limited availability of functional groups in conventional macrocycles restricts their ability to meet the demand for fabricating materials with multiple functionalities.To address this limitation,several research groups have introduced tetraphenylethylene(TPE),a well-known building block renowned for its remarkable aggregation-induced emission(AIE)effect,into the macrocycle framework.Herein,this paper summarizes the combination strategies and synergistic approaches that achieve multi-functionality by integrating TPE and macrocyclic architectures.The emission characteristics of TPE-embedded macrocycles are elucidated,and it is anticipated that more AIE-type macrocycles with innovative backbones and broad applications will emerge.
基金supported by the Open Research Fund of Jiangxi Provincial Academy of Water Resources Sciences(2022SKTR05&2022SKTR03)the National Natural Science Foundation of China(42067049&42367049),the Jiangxi Provincial Natural Science Foundation(20242BAB25350)+5 种基金the Research Project of the Jiangxi Provincial Department of Forestry(CXZX(2025)14 and JXTG(2023)15)the Ganpo Juncai Plan(QN2023018)the Ganpo Yingcai Plan(gpyc20240038)the Double Thousand Plan of Jiangxi Province(jxsq2023102213 and jxsq2023102214)the Jiangxi Province“Science and Technology+Water Resources”Joint Plan Project(2023KSG01001)the Major Discipline Academic and Technical Leaders Training Program of Jiangxi Province(20243BCE51025).
文摘Stable carbon isotopes(δ^(13)C)are extensively utilized to study intrinsic water use efficiency(iWUE)at the leaf-scale in terrestrial ecosystems,serving as a crucial metric for assessing plant adaptation to climate change.However,there is currently a lack of consensus regarding the leaf-scale iWUE variation characteristics among different functional types.In this study,we measured theδ^(13)Cleaf and iWUE values of different functional plants(i.e.,life forms,leaf types,and mycorrhizal types)from 120 species across distinct habitat types(i.e.,hillside,nearpeak,and peak)in a subtropical forest on the western slope of Wuyi Mountains,southern China.The results showed that theδ^(13)Cleaf values of plants on the western slope of Wuyi Mountains ranged from-34.63‰to-30.04‰,and iWUE ranged from 5.93μmol mol^(-1)to 57.34μmol mol^(-1).Theδ^(13)Cleaf and iWUE values differed significantly among plant life forms,following the order of herbs>vine plants>shrubs>trees.Theδ^(13)Cleaf and iWUE values of ectomycorrhizal(ECM)species were greater than those of arbuscular mycorrhizal(AM)species despite there being no significant difference between plants with different leaf types(Simple leaves(SL)vs.Compound leaves(CL)).From the hillside to the peak,both at the community level and at the species level,theδ^(13)C values of leaves and iWUE values of plants exhibited an upward trend.The regression analysis revealed that leaf-scale iWUE was significantly negatively correlated with soil water content and significantly positively correlated with leaf phosphorus content.The findings indicated that leaf carbon isotope fractionation and corresponding iWUE can be influenced by life form,mycorrhizal type,and soil water availability.These insights provide a deeper understanding of the coupling mechanisms of carbon,water,and nutrients among different functional plant types in subtropical forests,and offer insights into predicting plant adaptability under climate change.
基金Supported by the National Natural Science Foundation of China(42172148,42172142)。
文摘Taking the Lower Silurian Longmaxi Formation shale in the Sichuan Basin as an example,this study employs atomic force microscopy-based infrared(AFM-IR)spectroscopy to analyze the submicron-scale molecular functional groups of different types and occurrences of organic matter.Combined with the quantitative evaluation of pore development via scanning electron microscopy(SEM),the response of organic pore formation and evolution mechanisms to chemical composition and structural evolution of organic matter in overmature marine shale is investigated.The results indicate that the AFM-IR spectra of graptolite periderms and pyrobitumen in shale are dominated by the stretching vibrations of conjugated C=C bonds in aromatic compounds at approximately 1600 cm-1,with weak absorption peaks near 1375,1450 and 1720 cm-1,corresponding to aliphatic chains and carbonyl/carboxyl functional groups.Overall,the AFM-IR structural indices(A and C factors)of organic matter show a strong correlation with visible porosity in shales of equivalent maturity.Lower A and C factor values correlate with enhanced development of organic pores,which is associated with the detachment of more aliphatic chains and oxygen-containing functional groups during thermal evolution.Pyrobitumen-clay mineral composites generally exhibit superior pore development,likely attributable to clay mineral dehydration participating in hydrocarbon generation reactions that promote the removal of more functional groups.Additionally,hydrocarbon generation within organic-clay composites during high-over mature stages may induce volumetric expansion,resulting in microfracturing and hydrocarbon expulsion.The associated higher hydrocarbon expulsion rates promote the formation of larger pores and fracture-shaped pores along the flake-shaped clay minerals.This study highlights that the research of submicron-scale molecular functional groups provides a deeper understanding of organic matter evolution and pores development mechanisms in overmature shales,thereby offering critical theoretical parameters for reservoir evaluation in shale oil and gas exploration.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT)(No. 2021R1I1A1A0105621313, No. 2022R1F1A1074441, No. 2022K1A3A1A20014496, and No. 2022R1F1A1074083)supported by the Ministry of Education Funding (No. RIS 2021-004)supported by the Brain Pool program funded by the Ministry of Science and ICT through the National Research Foundation of Korea (RS-2023-00284318).
文摘In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method involving high-pressure processing,stirring,and immiscible solutions,sub-100 nm MXene flake thickness is achieved within the MXene film on the Si-wafer.Functionalization control is achieved by defunctionalizing MXene at 650℃ under vacuum and H2 gas in a CVD furnace,followed by refunctionalization with iodine and bromine vaporization from a bubbler attached to the CVD.Notably,the introduction of iodine,which has a larger atomic size,lower electronegativity,reduce shielding effect,and lower hydrophilicity(contact angle:99°),profoundly affecting MXene.It improves the surface area(36.2 cm^(2) g^(-1)),oxidation stability in aqueous/ambient environments(21 days/80 days),and film conductivity(749 S m^(-1)).Additionally,it significantly enhances the gas-sensing performance,including the sensitivity(0.1119Ωppm^(-1)),response(0.2% and 23%to 50 ppb and 200 ppm NO_(2)),and response/recovery times(90/100 s).The reduced shielding effect of the–I-terminals and the metallic characteristics of MXene enhance the selectivity of I-MXene toward NO2.This approach paves the way for the development of stable and high-performance gas-sensing two-dimensional materials with promising prospects for future studies.
基金funding of the National Key Research and Development Plan(Grant 2017YFB0306600)the Project of SINOPEC(NO.117006).
文摘To prepare a highly efficient NiMo/Al_(2)O_(3) hydrodesulfurization catalyst,the combined effects of specific organic functional groups and alumina surface characteristics were investigated.First,the correlation between the surface characteristics of four different alumina and the existing Mo species states was established.It was found that the Mo equilibrium adsorption capacity can be used as a specific descriptor to quantitatively evaluate the changes in surface characteristics of different alumina.A lower Mo equilibrium adsorption capacity for alumina means weaker metal-support interaction and the loaded Mo species are easier to transform into MoS2.However,the Mo-O-Al bonds still exist at the metal-support interface.The introduction of cationic surfactant hecadecyl trimethyl ammonium bromide(CTAB)can further improve Mo species dispersion through electrostatic attraction with Mo anions and interaction of its alkyl chain with the alumina surface;meanwhile,the introduction of ethylenediamine tetraacetic acid(EDTA)can complex with Ni ions to enhance the Ni-promoting effect on Mo.Therefore,the NiMo catalyst designed using alumina with lower Mo equilibrium adsorption capacity and the simultaneous addition of EDTA and CTAB exhibits the highest hydrodesulfurization activity for 4,6-dimethyl dibenzothiophene because of its proper metal-support interaction and more well-dispersed Ni-Mo-S active phases.
基金Supported by the National Natural Science Foundation of China(Nos.U22A20616,32071573)。
文摘Global warming has caused an increase in the frequency and duration of droughts worldwide.Droughts could trigger large changes in physico-chemical conditions and phytoplankton community in waterbodies,resulting in a shift in the phytoplankton community.Spring diatom blooms in reservoirs have been increasingly observed in the past decade in the Taihu Lake basin.The aim of the present study is to elucidate the impacts of droughts on aquatic environment and to determine the driving factors for the succession of the phytoplankton functional groups based on the analysis of data collected during spring from 2009 to 2020 in the Daxi Reservoir.The unimodal relationship between 1-month aggregated precipitation index and phytoplankton species richness indicated the competitive exclusion occurred in extremely drought period.The structural equation modeling indicated that drought-related low water level conditions intensified sediment resuspension,and increased the phosphorus-enriched nonalgal turbidity in the Daxi Reservoir.Concurrently,a steady shift in the Reynolds phytoplankton functional groups from L 0,TD,J,X 2,and A(phytoplankton taxa preferring low turbidity and nutrient conditions)to TB(pennate diatoms being adapt to turbid and nutrient-rich conditions)was observed.The increased TP and non-algal turbidity in addition to the lowered disturbance contribute to the prevalence of Group TB.Considering the difficulties in nutrient control,timely water replenishment is often a feasible method of controlling the dominance of harmful algae for reservoir management.Finally,alternative water sources are in high demand for ensuring ecological safety and water availability when dealing with drought.
基金supported by the National Natural Science Foundation of China(Nos.52370110 and 21607044)supported by the Fundamental Research Funds for the Central Universities(No.2023MS146)the Open Research Fund of the School of Chemistry and Chemical Engineering,Henan Normal University for support(Nos.2020ZD01 and 2021YB07)。
文摘Mercury ion(Hg^(2+)),as one of the most toxic heavy metal ions,accumulates easily in the environment,which can generate potential hazards to the ecosystem and human health.To effectively detect and remove Hg^(2+),we fabricated four types of carbon dots(CDs)using carboxymethyl nanocellulose as a carbon source doped with different elements using a hydrothermal method.All the CDs exhibited a strong fluorescence emission,excitation-dependent emission and possessed good water dispersibility.Moreover,the four fluorescent CDs were used for Hg^(2+)recognition in aqueous solution,where the CDs-N exhibited better sensitivity and selectivity for Hg^(2+)detection,with a low limit of detection of 8.29×10^(-6)mol/L.It was determined that the fluorescence quenching could be ascribed to a photoinduced charge-transfer processes between Hg^(2+)and the CDs.In addition,the CDs-N were used as a smart invisible ink for anticounterfeiting,information encryption and decryption.Furthermore,the CDs-N were immersed into a cellulose(CMC)-based hydrogel network to prepare fluorescent hydrogels capable of simultaneously detecting and adsorbing Hg^(2+).We anticipate that this research will open possibilities for a green method to synthesize fluorescent CDs for metal ion detection and fluorescent ink production.
基金supported by the Natural Science Foundation of Yunnan Province(Grant No:202301AT070356)the Open Fund of the Key Laboratory of Tropical Forest Ecology,Chinese Academy of Sciences,National Science Foundation of China(Grant No.32061123003)+1 种基金the Joint Fund of the National Natural Science Foundation of China-Yunnan Province(Grant No.U1902203)the Field Station Foundation of the Chinese Academy of Sciences.
文摘Anthropogenic disturbances are widespread in tropical forests and influence the species composition in the overstory.However,the impacts of historical disturbance on tropical forest overstory recovery are unclear due to a lack of disturbance data,and previous studies have focused on understory species.In this study,the purpose was to deter-mine the influence of historical disturbance on the diver-sity,composition and regeneration of overstory species in present forests.In the 20-ha Xishuangbanna tropical sea-sonal rainforest dynamics plot in southwestern China,the historical disturbance boundaries were delineated based on panchromatic photographs from 1965.Factors that drove species clustering in the overstory layer(DBH≥40 cm)were analyzed and the abundance,richness and composition of these species were compared among different tree groups based on multiple regression tree analysis.The coefficient of variation of the brightness value in historical panchro-matic photographs from 1965 was the primary driver of spe-cies clustering in the overstory layer.The abundance and richness of overstory species throughout the regeneration process were similar,but species composition was always different.Although the proportion of large-seeded and vigorous-sprouting species showed no significant differ-ence between disturbed and undisturbed forests in the tree-let layer(DBH<20 cm),the difference became significant when DBH increased.The findings highlight that historical disturbances have strong legacy effects on functional group composition in the overstory and the recovery of overstory species was multidimensional.Functional group composi-tion can better indicate the dynamics of overstory species replacement during secondary succession.
基金Supported by the Young Backbone Teachers Project of Henan Province (No. 2020GGJS064)the Key Scientific and Technological Project of Henan Province (No. 232102321056)+1 种基金the Scientific Fund of Henan Normal University (No. 2020QK02)the Project of Huanghe River Fisheries Resources and Environment Investigation from the MARA,China,and the Observation and Research Station on Water Ecosystem in Danjiangkou Reservoir of Henan Province
文摘To understand the distribution of phytoplankton functional groups(PFGs)and key factors on their compositions in different watersheds of the Huanghe(Yellow)River basin,25 river sites and 25 lake-reservoirs sites were selected.The contents of nephelometric turbidity(NTU),total nitrogen(TN),and total phosphorus(TP)were significantly higher in rivers than that in lakes or reservoirs,whereas the pH and CODMn(chemical oxygen demand or potassium permanganate index)were lower.Results show that,27 PFGs,namely,assemblages A,B,C,D,E,F,G,H,J,K,LM,Lo,M,MP,N,P,S1,S2,T,TC,W1,W2,X1,X2,X3,XPh,and Y,were identified.Additionally,ANOSIM correlation analysis demonstrated significant differences in PFG composition between the riverine and lake-reservoir sections in the Huanghe River basin.In the riverine watersheds,the group MP was dominant,while assemblages B and J were prevalent in lakes and reservoirs.The Mantel correlation tests and RDA analysis showed that environmental variables,such as NTU,water temperature(WT),conductivity(Cond),and TP,were key driving factors of shaping the dominant PFGs of the study area.Using the Venn diagram based on variation partitioning analysis,PFGs were mainly influenced by WT and TP in lake-reservoir sites,while in the river sites were affected mainly by geo-climatic variables.This study helps understanding the PFGs in river ecosystems,and unraveling the key driving factors in different watersheds,which shall be important for the protection and management of entire Huanghe River basin.
基金School-level Theoretical Research Project on Grassroots Party Building at Ningxia University in 2023(NXDXDJ202335).
文摘The education and management of college student Party members is the focus of student Party building work in colleges and universities.In the context of students second classroom being conducted in the academy,the management of student Party members should enhance their Party spirit cultivation through improving their self-management and self-monitoring.After the comprehensive reform of Ningxia University,Runze College targeted the characteristics of agricultural majors and set up functional Party groups to enable student Party members to play a pioneering and exemplary role in the second classroom.Runze College relies on the academy system and breaks through the traditional one-way management mode led by Party branch teachers in the second classroom of college students.It leverages the role of functional Party groups in off campus science and technology academies,and integrates Party building work into daily teaching and research and solving agricultural production technology problems for local villagers,achieving the goal of promoting and integrating Party building and business work,and improving each other.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(2023B0303000002)the National Natural Science Foundation of China(No.52206089)+3 种基金the Guangdong Basic and Applied Basic Research Foundation(2024A1515010288,2023B1515120005)the Natural Science Foundation of Shenzhen(JCYJ20230807093315033)the Shenzhen Engineering Research Center,Southern University of Science and Technology(No.XMHT20230208003)high level of special funds(G03034K001)。
文摘All-vanadium flow batteries(VFBs)are one of the most promising large-scale energy storage technologies.Conducting an operando quantitative analysis of the polarizations in VFBs under different conditions is essential for developing high power density batteries.Here,we employ an operando decoupling method to quantitatively analyze the polarizations in each electrochemical and chemical reaction of VFBs under different catalytic conditions.Results show that the reduction reaction of V^(3+)presents the largest activation polarization,while the reduction reaction of VO_(2)^(+)primarily contributes to concentration polarizations due to the formation of the intermediate product V_(2)O_(3)^(3+).Additionally,it is found that the widely used electrode catalytic methods,incorporating oxygen functional groups and electrodepositing Bi,not only enhance the reaction kinetics but also exacerbate concentration polarizations simultaneously,especially during the discharge process.Specifically,in the battery with the high oxygen-containing electrodes,the negative side still accounts for the majority of activation loss(75.3%)at 200 mA cm^(-2),but it comes down to 36,9% after catalyzing the negative reactions with bismuth.This work provides an effective way to probe the limiting steps in flow batteries under various working conditions and offers insights for effectively enhancing battery performance for future developments.
基金Supported by National Natural Science Foundation of China(30370146)~~
文摘[Objective]The aim was to carry out stoichiometry on the early-spring herbs functional group in subtropical artificial wetland.[Method]UV-Vis spectrophotometer was used for the determination of nitrate-nitrogen,ammonium nitrogen and phosphorus concentrations.Potassium persulfate absorptiometry was used for the measurement of total N content,while the flame photometer was used to detect the potassium and sodium concentration in plants.All the nutrient determination of plant samples were repeated for four times.[Result]The four nutrient concentrations in almost all samples were in the normal range of natural plant nutrition concentrations;in early-spring herbs functional groups,different species showed diversity on the nutrient concentrations;plant height had no significant effect on the nutrient concentrations in plants;the nutrient concentrations of non-grass group plants were higher than that of grass group plants;the nutrient concentrations of the annual herb were higher than that of perennial herbs.[Conclusion]The study had provided basis for the understanding of the effects of changes in nutritional conditions on species diversity,community structure and succession of the system.
基金supported by the National Natural Science Foundation of China (Nos.U23A2048,42376152,41976140,and 42076148)the Special Program of Key Sectors in Guangdong Universities (Nos.2022ZDZX4040 and 2023KCXTD028).
文摘Increasing nitrogen and phosphorus discharge and decreasing sediment input have made silicon(Si)a limiting element for diatoms in estuaries.Disturbances in nutrient structure and salinity fluctuation can greatly affect metal uptake by estuarine diatoms.However,the combined effects of Si and salinity on metal accumulation in these diatoms have not been evaluated.In this study,we aimed to investigate how salinity and Si availability combine to influence the adsorption of metals by a widely distributed diatom Phaeodactylum tricornutum.Our data indicate that replete Si and low salinity in seawater can enhance cadmium and copper adsorption onto the diatom surface.At the single-cell level,surface potential was a dominant factor determining metal adsorption,while surface roughness also contributed to the highermetal loading capacity at lower salinities.Using a combination of noninvasive micro-test technology,atomic force microscopy,X-ray photoelectron spectroscopy,and Fourier transform infrared spectroscopy,we demonstrate that the diversity and abundance of the functional groups embedded in diatom cell walls vary with salinity and Si supply.This results in a change in the cell surface potential and transient metal influx.Our study provides novel mechanisms to explain the highly variable metal adsorption capacity of a model estuarine diatom.
基金Supported by the National Natural Science Foundation of China(Nos.U22A20616,32071573)。
文摘Understanding the response of the phytoplankton community to climate change is essential for reservoir management.We analyzed a long-term data series(2009–2020)on the phytoplankton community in a large mesotrophic reservoir in the wet season to investigate the impacts of temperature and precipitation increases caused by climate change on the functioning and trait composition of the phytoplankton community.Over the last twelve years,the 3-month accumulative precipitation increased from 291.03 mm to 590.91 mm,and the surface water temperature increased from 25.06℃to 26.49℃in wet season,respectively.These changes caused a higher water level,stronger thermal stratification and lower nitrogen concentration in Daxi Reservoir.The dynamic equilibrium model indicated that the increased precipitation and water temperature-related environmental changes would result in a more diverse and productive phytoplankton community.The effects of increasing water temperature and precipitation on the niche complementarity and selection effects within the phytoplankton community were analyzed using structural equation model by means of the functional divergence index and functional evenness index,respectively,elucidating the reasons for the increase in cyanobacteria in the absence of a significant increase in nutrient levels.Based on these results,it is advisable that more stringent phosphorus control standards might be conducted to reduce the risks of cyanobacteria proliferation in the context of global warming.
基金supported by the National Natural Science Foundation of China(22278001 and 22308006)the Natural Science Foundation of Anhui Provincial Education Department(KJ2021A0407).
文摘The effects of different kinds of ionic liquids(ILs)on the caking property of Shenhua long-flame coal(SHLC)were studied.SHLC and its residue after[N_(4441)][Cl]treatment under optimum conditions were characterized by Fourier transform infrared spectroscopy(FT-IR),thermogravimetric analysis(TG),X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Raman spectroscopy,and pyrolysis-gas chromatography and mass-spectrometric analysis(Py-GC/MS).The results showed that the ILs used could extract the poorly-caking components from SHLC,and[N_(4441)][Cl]with C_(3)H_(6)O as a solvent exhibited the best effect among the ILs and solvents used.[N_(4441)][Cl]could destroy the H bonds in SHLC,and the structure of the cross-linked macromolecules of SHLC was loosed,leading to the release of the small molecules within the macromolecular framework of SHLC.Additionally,[N_(4441)][Cl]could easily penetrate into the interior of the relaxed SHLC and break the weak covalent bonds(e.g.,C-O bonds)of the macromolecules of SHLC.As a result,aromatic hydrocarbons with 3‒5 rings and aliphatic side chains,which are the precursor of the poorly-caking components,were formed and were then extracted from SHLC by C_(3)H_(6)O.Consequently,[N_(4441)][Cl]treatment could decrease the caking property,thermal ability,and macromolecular size of SHLC.
