The boundness and compactness of products of multiplication,composition and differentiation on weighted Bergman spaces in the unit ball are studied.We define the differentiation operator on the space of holomorphic fu...The boundness and compactness of products of multiplication,composition and differentiation on weighted Bergman spaces in the unit ball are studied.We define the differentiation operator on the space of holomorphic functions in the unit ball by radial derivative.Then we extend the Sharma's results.展开更多
Background:Climate change is accelerating alterations in forest species and community composition worldwide,especially following extreme events like severe droughts and windstorms.Understanding these effects on subtro...Background:Climate change is accelerating alterations in forest species and community composition worldwide,especially following extreme events like severe droughts and windstorms.Understanding these effects on subtropical forests is crucial for conservation and forest management,but it remains unclear whether the impacts are stochastic or deterministic.Methods:We analyzed a unique dataset from a 1-ha permanent plot in a subtropical monsoon broadleaf evergreen forest in China,monitored over 26 years with six surveys from 1994 to 2020.The forest has been free from anthropogenic disturbances for over 400 years.In each survey,we measured all trees with a diameter at breast height(DBH)≥1 cm,and recorded 11 plant functional traits relating to photosynthesis,wood properties,water use,and nutrient dynamics.Using this data,we calculated species and trait dispersion,assessing short-term(~5years)and long-term(26 years)trends in species and trait composition following severe droughts and windstorm events.Results:Severe droughts,and subsequent droughts,increased both species and trait dispersion,while species composition converged,and trait dispersion remained relatively stable throughout the recovery period.Windstorm events led to increased species dispersion but decreased trait dispersion.We observed a clear directional shift in both species and trait composition under these climatic stressors,with a more pronounced increase in trait dispersion compared to species dispersion.Conclusion:In the short term(~5 years),severe droughts and windstorms increased species composition divergence,while trait composition responses varied.Over 26 years,deterministic processes mainly drove community composition changes,especially for trait composition,although stochastic processes also played a role.These findings suggest enhancing forest resilience to climatic stressors by protecting adaptive species or increasing species diversity in management practices.展开更多
In recent decades, the application of antifouling paints to watercrafts has emerged as a significant concern in coastal ecosystems, including coral reefs. Diuron, a booster biocide commonly used as an antifouling agen...In recent decades, the application of antifouling paints to watercrafts has emerged as a significant concern in coastal ecosystems, including coral reefs. Diuron, a booster biocide commonly used as an antifouling agent, is persistent in soil, water, and groundwater. Although it exhibits moderate toxicity to mammals and birds, its primary breakdown product, 3,4-dichloroaniline, is highly toxic and environmentally persistent. The secondary toxicity of Diuron emphasizes its potential to contaminate groundwater. This investigation determined the 96-hour LC50 value for Diuron to be 1.627 ± 0.181 mg/L in Lates calcarifer. A 21-day sublethal exposure of Lates calcarifer to diuron did not yield statistically significant differences (P > 0.05) in fatty acid composition between the fresh and control groups. Both groups demonstrated polyunsaturated fatty acids (PUFAs) as the most abundant fatty acids, followed by saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs). However, significant variations (P Lates calcarifer exposed to varying diuron concentrations (50%, 30%, and 10% of the LC50 value). The magnitude of these effects increased with increasing exposure levels. The results of this study indicate that diuron, even at concentrations considered safe, can adversely affect marine organisms, including alterations to their fatty acid composition.展开更多
Scientific knowledge on the chemical compositions of fine particulate matter(PM_(2.5)) is essential for properly assessing its health and climate effects,and for decisionmakers to develop efficient mitigation strategi...Scientific knowledge on the chemical compositions of fine particulate matter(PM_(2.5)) is essential for properly assessing its health and climate effects,and for decisionmakers to develop efficient mitigation strategies.A high-resolution PM_(2.5) chemical composition dataset(CAQRA-aerosol)is developed in this study,which provides hourly maps of organic carbon,black carbon,ammonium,nitrate,and sulfate in China from 2013 to 2020 with a horizontal resolution of 15 km.This paper describes the method,access,and validation results of this dataset.It shows that CAQRA-aerosol has good consistency with observations and achieves higher or comparable accuracy with previous PM_(2.5) composition datasets.Based on CAQRA-aerosol,spatiotemporal changes of different PM_(2.5) compositions were investigated from a national viewpoint,which emphasizes different changes of nitrate from other compositions.The estimated annual rate of population-weighted concentrations of nitrate is 0.23μg m^(−3)yr^(−1) from 2015 to 2020,compared with−0.19 to−1.1μg m^(−3)yr^(−1) for other compositions.The whole dataset is freely available from the China Air Pollution Data Center(https://doi.org/10.12423/capdb_PKU.2023.DA).展开更多
[Objectives]To investigate the chemical composition,antioxidant property,and nematicidal activity of Cucumis metuliferus and establish a theoretical foundation for the development of botanical nematicides.[Methods]The...[Objectives]To investigate the chemical composition,antioxidant property,and nematicidal activity of Cucumis metuliferus and establish a theoretical foundation for the development of botanical nematicides.[Methods]The compounds were isolated and purified using silica gel,reversed-phase medium,low-pressure gel Sephadex LH-20 column chromatography,and preparative high-performance liquid chromatography.Their identification was based on physicochemical properties,various spectral analyses,and data reported in the literature.Subsequently,the nematicidal and antioxidant activities of the isolated compounds were evaluated.[Results]A total of four compounds were isolated from C.metuliferus,which were identified as isovitexin-2″-O-glucoside(compound 1),9E,11E-(13-oxo)tridecadienoic acid(compound 2),2E,4E-tridecadienedioic acid(compound 3),and 9E,11E-(13-hydroxy)tridecadienoic acid(compound 4).Compound 1 demonstrated a notable degree of antioxidant activity,achieving a DPPH scavenging rate of 49.40%at a mass concentration of 1 mg/mL.Additionally,compounds 1,3,and 4 exhibited varying levels of nematicidal activity.Specifically,compound 1 displayed strong nematicidal activity at a concentration of 2.0 mg/mL,resulting in a mortality rate of 90.5%against nematodes.Furthermore,compounds 3 and 4 achieved a mortality rate of 100%against nematodes at a concentration of 0.25 mg/mL.[Conclusions]This study reports the first isolation of four compounds:isovitexin-2″-O-glucoside,9E,11E-(13-oxo)tridecadienoic acid,2E,4E-tridecadienedioic acid,and 9E,11E-(13-hydroxy)tridecadienoic acid from C.metuliferus.Notably,2E,4E-tridecadienedioic acid and 9E,11E-(13-oxo)tridecadienoic acid are identified as novel natural products.Among these compounds,isovitexin-2″-O-glucoside,9E,11E-(13-oxo)tridecadienoic acid,and 9E,11E-(13-hydroxy)tridecadienoic acid exhibit nematicidal activity,whereas isovitexin-2″-O-glucoside demonstrates antioxidant properties.展开更多
Plant community composition typically undergoes progressive changes along environmental gradients.However,most experimental studies have focused on individual communities,so it remains unclear how exogenous nutrient i...Plant community composition typically undergoes progressive changes along environmental gradients.However,most experimental studies have focused on individual communities,so it remains unclear how exogenous nutrient inputs affect the stability of plant communities along environmental gradients.Along a rainfall gradient on the northern Tibetan Plateau,we conducted an 8-year nitrogen(N)addition experiment in four alpine grasslands:alpine desert steppe(ADS),alpine steppe(AS),alpine meadow steppe(AMS),alpine meadow(AM),and we used twoway ANOVA to examine the effects of N addition on the temporal stability of these different alpine grasslands.We found that community aboveground biomass showed saturation trends in AM and AMS with increasing N gradients,while there was no change in AS and a gradual increase in ADS.The temporal stability showed different patterns of gradual decreases in ADS and AM,and a unimodal trend in AMS with increasing N gradients.However,N addition had no effect on the temporal stability of AS.Dominant species stability was the controlling factor for alpine grasslands along the transect,while the effect of asynchrony gradually increased with decreasing precipitation.These findings highlight that community composition,especially the dominant species,along the environmental gradient can mediate the effects of N inputs on community temporal stability.Thus,the conservation and restoration of the dominant species are particularly important under future scenarios of increased atmospheric N deposition.展开更多
Fullerene derivatives[6,6]-phenyl-C61-butyric acid methyl ester(PC_(61)BM)has been routinely used as the electron transport layer(ETL)in perovskite solar cells due to its suitable energy levels and good solution proce...Fullerene derivatives[6,6]-phenyl-C61-butyric acid methyl ester(PC_(61)BM)has been routinely used as the electron transport layer(ETL)in perovskite solar cells due to its suitable energy levels and good solution processability.However,its electron mobility and conductivity still need to be further enhanced for constructing high performance perovskite solar cells(PSCs).Herein,by doping the PC_(61)BM with a p-type polymer PM6 and n-type molecule ITIC,efficient wide-bandgap perovskite solar cells with improved efficiency and operational/storage stability are obtained.Further spectroscopy and electric measurements indicate PM6 and ITIC can both passivate defects at the perovskite/ETL interface,meanwhile ITIC can elevate the Fermi level of PC_(61)BM to enhance conductivity and PM6 can improve the photo-induced electron mobility of the ETL,facilitating charge extraction and reducing charge recombination.As the results,Cs_(0.17)FA_(0.83)Pb(I_(0.83)Br_(0.17))_(3)wide-bandgap PSCs with PM6:PC_(61)BM:ITIC as the ETL demonstrates a superior efficiency of 22.95%,compared to 20.89%of the PC_(61)BM assisted device.展开更多
Jing Fang granules(JFG)are a modern Chinese medicinal formulation derived from Jing Fang Defeating Toxin San(JFDS).JFG primarily contains bioactive compounds such as flavonoids/flavonoid glycosides,coumarins and other...Jing Fang granules(JFG)are a modern Chinese medicinal formulation derived from Jing Fang Defeating Toxin San(JFDS).JFG primarily contains bioactive compounds such as flavonoids/flavonoid glycosides,coumarins and other components,which have various activities:anti-inflammatory,immune system regulation,antiviral,anti-aging,detoxification,and protection of the liver,lungs,and kidneys.JFG has broad potential therapeutic applications.The mechanisms of JFG’s actions are primarily associated with signaling pathways such as TLR4/NF-κB,PI3K/AKT,and MAPK.This article reviews the research progress on JFG,including chemical composition,pharmacologic effects,mechanism of action,safety,clinical application,etc.,serving as a foundation for future research and clinical applications.展开更多
In this paper,we study composition operators on weighted Bergman spaces of Dirichlet series.We first establish some Littlewood-type inequalities for generalized mean counting functions.Then we give sufficient conditio...In this paper,we study composition operators on weighted Bergman spaces of Dirichlet series.We first establish some Littlewood-type inequalities for generalized mean counting functions.Then we give sufficient conditions for a composition operator with zero characteristic to be bounded or compact on weighted Bergman spaces of Dirichlet series.The corresponding sufficient condition for compactness in the case of positive characteristics is also obtained.展开更多
The three-dimensional(3D)imaging of structural and compositional features at the nanometer and atomic scale is crucial for advancing the applications of nanomaterials in energy storageand catalysis.Transmission electr...The three-dimensional(3D)imaging of structural and compositional features at the nanometer and atomic scale is crucial for advancing the applications of nanomaterials in energy storageand catalysis.Transmission electron microscopy,particularly in scanning mode,has traditionally provided atomicresolution structural insights.However,achieving high-resolution 3D compositional imaging of beam-sensitive materials remains formidably challenging due to the limitation of electron dose.Recent innovations in hardware and computational methods,such as data-fusing and deep learning,have enabled 3D compositional imaging at the sub-nanometer scale with significantly reduced electrondoses.This review highlightstheprinciples,advancements,and applications of electron tomography and associated techniques for 3D compositional imaging,summarizes state-of-the-art progress achieved by multimodal tomography and model-free reconstructions,and underscores the transformative potential of these developments for 3D high-resolution characterizations of beam-sensitivematerials.展开更多
This paper combines a variety of physicochemical nondestructive techniques to obtain a knowledge of the chemical and mineralogical composition of the scarce fossil bones from the Húmera paleontological site(Madri...This paper combines a variety of physicochemical nondestructive techniques to obtain a knowledge of the chemical and mineralogical composition of the scarce fossil bones from the Húmera paleontological site(Madrid,Spain).The main classification of the samples has distinguished six colors:red,gray,blue,white,light yellow and green.μ-XRD and Raman spectroscopy have been correlated to study the structure and to distinguish between fluorapatite,chlorapatite,bioapatite and carbonated bones.The bones have further been classified in three main types.Type I includes gray,green,white,and blue samples,classified as fluorapatite and chlorapatite containing organic matter and adsorbed water.Type II,includes the red sample classified as bioapatite,showing broad Raman bands andμ-XRD peaks due to the lattice disorder created by the B-type substitutions emerging from a high matter content.Type III sample(yellow)shows a complete replacement of apatite by calcite which induce the high porosity of the sample.Diagenetic changes add further complexity to the structure of fossil bones,not only by new ionic substitutions but also in terms of biogenic or authigenic phases that form in the fossilizing bone.The multi-technique approach from a broad interdisciplinary perspective enables a better understanding of bone fossilization.展开更多
In this paper,we study asymptotic power series of the composition f(x)=h(g(x)),where g(x)=∑_(n=0)^(∞)b_(n)x^(-n),b_(n)∈R,and h is a given elementary function.The asymptotic expansions have been obtained for the com...In this paper,we study asymptotic power series of the composition f(x)=h(g(x)),where g(x)=∑_(n=0)^(∞)b_(n)x^(-n),b_(n)∈R,and h is a given elementary function.The asymptotic expansions have been obtained for the composition with an exponential or logarithmic function.Using the re-cursive method,we present the asymptotic expansions for the composition with seven trigonometric functions,respectively.As an application,the asymptotic expansions of roots of some equations are given.Computational results show that our recursive formula is more efficient than the method of Lagrange's inverse theorem.展开更多
The unique multilayer, multiscale structure of teakwood results in excellent mechanical and long-term environmental stability, providing inspiration for the biomimetic design of environmental barrier coating (EBC) str...The unique multilayer, multiscale structure of teakwood results in excellent mechanical and long-term environmental stability, providing inspiration for the biomimetic design of environmental barrier coating (EBC) structures. However, achieving the desired biomimetic structure control in high-temperature plasma spraying is a challenging task that requires new technological breakthroughs. In this study, a multiscale nano Yb_(2)Si_(2)O_(7)–Yb_(2)SiO_(5) (YbDS–YbMS) composite EBC with a teakwood-like lamellar structure was realized via a novel alternating vapor/liquid phase deposition method involving plasma spraying-physical vapor deposition (PS-PVD). Volatilized waste SiO_(2) from Yb_(2)Si_(2)O_(7) (YbDS) was reused and deposited on the coating surface during the spraying process, where a regularly arranged multilayer structure was formed in the coating by the alternate deposition of gaseous SiO_(2) and droplet YbDS. In addition, SiO_(2) on the coated surface formed nanoclusters and dome-shaped nanocrystals via homogeneous and heterogeneous nucleation, respectively, and some of them gradually formed a continuous nanofilm as the arc current increased. The deposited SiO_(2) reacted in situ with the decomposed phase YbMS in the coating to form YbDS, preserving its multiscale nanostructure after heat treatment and enabling the preparation of the YbDS–YbMS composite coating. This work provides a new design strategy and method for the preparation of coatings using YbDS and other spray powders with similar decomposition and volatilization characteristics during the plasma spraying process.展开更多
Generative AI technology for human-assisted tools has made great strides in recent years,and studying the impact of this technology on students'compositional abilities plays an important role in promoting changes ...Generative AI technology for human-assisted tools has made great strides in recent years,and studying the impact of this technology on students'compositional abilities plays an important role in promoting changes in music education.Previous studies have focused on the performance of music composition software itself in terms of composition,with less consideration given to the impact of creators'compositional ability after using assistive composition tools.Thus,this paper designs a controlled experiment to investigate the changes in students'compositional ability before and after using AI composition tools.This paper finds that students'compositional abilities in all areas of composition improved to varying degrees after using AI composition tools.This paper compares the differences in compositional abilities of students with and without the education of AI composition tools,which has practical implications for vigorously promoting the adoption of AI composition tools in university music education teaching.展开更多
Microwave absorbing materials(MAMs)characterized by high absorption efficiency and good environmental tolerance are highly desirable in practical applications.Both silicon carbide and carbon are considered as stable M...Microwave absorbing materials(MAMs)characterized by high absorption efficiency and good environmental tolerance are highly desirable in practical applications.Both silicon carbide and carbon are considered as stable MAMs under some rigorous conditions,while their composites still fail to produce satisfactory microwave absorption performance regardless of the improvements as compared with the individuals.Herein,we have successfully implemented compositional and structural engineering to fabricate hollow Si C/C microspheres with controllable composition.The simultaneous modulation on dielectric properties and impedance matching can be easily achieved as the change in the composition of these composites.The formation of hollow structure not only favors lightweight feature,but also generates considerable contribution to microwave attenuation capacity.With the synergistic effect of composition and structure,the optimized SiC/C composite exhibits excellent performance,whose the strongest reflection loss intensity and broadest effective absorption reach-60.8 dB and 5.1 GHz,respectively,and its microwave absorption properties are actually superior to those of most SiC/C composites in previous studies.In addition,the stability tests of microwave absorption capacity after exposure to harsh conditions and Radar Cross Section simulation data demonstrate that hollow SiC/C microspheres from compositional and structural optimization have a bright prospect in practical applications.展开更多
In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active ...In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active sites as exemplified by diatomic metals anchored graphdiyne via the combination of hierarchical high-throughput screening,first-principles calculations,and molecular dynamics simulations.Totally 43 highly efficient catalysts feature ultralow onset potentials(|U_(onset)|≤0.40 V)with Rh-Hf and Rh-Ta showing negligible onset potentials of 0 and-0.04 V,respectively.Extremely high catalytic activities of Rh-Hf and Rh-Ta can be ascribed to the synergistic effects.When forming heteronuclears,the combinations of relatively weak(such as Rh)and relatively strong(such as Hf or Ta)components usually lead to the optimal strengths of adsorption Gibbs free energies of reaction intermediates.The origin can be ascribed to the mediate d-band centers of Rh-Hf and Rh-Ta,which lead to the optimal adsorption strengths of intermediates,thereby bringing the high catalytic activities.Our work provides a new and general strategy toward the architecture of highly efficient catalysts not only for electrocatalytic nitrogen reduction reaction(eNRR)but also for other important reactions.We expect that our work will boost both experimental and theoretical efforts in this direction.展开更多
BACKGROUND In recent years,the prevalence of obesity and metabolic syndrome in type 1 diabetes(T1DM)patients has gradually increased.Insulin resistance in T1DM deserves attention.It is necessary to clarify the relatio...BACKGROUND In recent years,the prevalence of obesity and metabolic syndrome in type 1 diabetes(T1DM)patients has gradually increased.Insulin resistance in T1DM deserves attention.It is necessary to clarify the relationship between body composition,metabolic syndrome and insulin resistance in T1DM to guide clinical treatment and intervention.AIM To assess body composition(BC)in T1DM patients and evaluate the relationship between BC,metabolic syndrome(MS),and insulin resistance in these indi-viduals.METHODS A total of 101 subjects with T1DM,aged 10 years or older,and with a disease duration of over 1 year were included.Bioelectrical impedance analysis using the Tsinghua-Tongfang BC Analyzer BCA-1B was employed to measure various BC parameters.Clinical and laboratory data were collected,and insulin resistance was calculated using the estimated glucose disposal rate(eGDR).RESULTS MS was diagnosed in 16/101 patients(15.84%),overweight in 16/101 patients(15.84%),obesity in 4/101(3.96%),hypertension in 34/101(33.66%%)and dyslip-idemia in 16/101 patients(15.84%).Visceral fat index(VFI)and trunk fat mass were significantly and negatively correlated with eGDR(both P<0.001).Female patients exhibited higher body fat percentage and visceral fat ratio compared to male patients.Binary logistic regression analysis revealed that significant factors for MS included eGDR[P=0.017,odds ratio(OR)=0.109],VFI(P=0.030,OR=3.529),and a family history of diabetes(P=0.004,OR=0.228).Significant factors for hypertension included eGDR(P<0.001,OR=0.488)and skeletal muscle mass(P=0.003,OR=1.111).Significant factors for dyslipidemia included trunk fat mass(P=0.033,OR=1.202)and eGDR(P=0.037,OR=0.708).CONCLUSION Visceral fat was found to be a superior predictor of MS compared to conventional measures such as body mass index and waist-to-hip ratio in Chinese individuals with T1DM.BC analysis,specifically identifying visceral fat(trunk fat),may play an important role in identifying the increased risk of MS in non-obese patients with T1DM.展开更多
Bidens pilosa is recognized as one of the major invasive plants in China.Its invasion has been associated with significant losses in agriculture,forestry,husbandry,and biodiversity.Soil ecosystems play an important ro...Bidens pilosa is recognized as one of the major invasive plants in China.Its invasion has been associated with significant losses in agriculture,forestry,husbandry,and biodiversity.Soil ecosystems play an important role in alien plant invasion.Microorganisms within the soil act as intermediaries between plants and soil ecological functions,playing a role in regulating soil enzyme activities and nutrient dynamics.Understanding the interactions between invasive plants,soil microorganisms,and soil ecological processes is vital for managing and mitigating the impacts of invasive species on the environment.In this study,we conducted a systematic analysis focusing on B.pilosa and Setaria viridis,a common native companion plant in the invaded area.To simulate the invasion process of B.pilosa,we constructed homogeneous plots consisting of B.pilosa and S.viridis grown separately as monocultures,as well as in mixtures.The rhizosphere and bulk soils were collected from the alien plant B.pilosa and the native plant S.viridis.In order to focus on the soil ecological functional mechanisms that contribute to the successful invasion of B.pilosa,we analyzed the effects of B.pilosa on the composition of soil microbial communities and soil ecological functions.The results showed that the biomass of B.pilosa increased by 27.51% and that of S.viridis was significantly reduced by 66.56%.The organic matter contents in the bulk and rhizosphere soils of B.pilosa were approximately 1.30 times those in the native plant soils.The TN and NO_(3)^(-)contents in the rhizosphere soil of B.pilosa were 1.30 to 2.71 times those in the native plant soils.The activities of acid phosphatase,alkaline phosphatase,and urease in the rhizosphere soil of B.pilosa were 1.98-2.25 times higher than in the native plant soils.Using high-throughput sequencing of the16S rRNA gene,we found that B.pilosa altered the composition of the soil microbial community.Specifically,many genera in Actinobacteria and Proteobacteria were enriched in B.pilosa soils.Further correlation analyses verified that these genera had significantly positive relationships with soil nutrients and enzyme activities.Plant biomass,soil p H,and the contents of organic matter,TN,NO_(3)^(-),TP,AP,TK,and AK were the main factors affecting soil microbial communities.This study showed that the invasion of B.pilosa led to significant alterations in the composition of the soil microbial communities.These changes were closely linked to modifications in plant traits as well as soil physical and chemical properties.Some microbial species related to C,N and P cycling were enriched in the soil invaded by B.pilosa.These findings provide additional support for the hypothesis of soil-microbe feedback in the successful invasion of alien plants.They also offer insights into the ecological mechanism by which soil microbes contribute to the successful invasion of B.pilosa.Overall,our research contributes to a better understanding of the complex interactions between invasive plants,soil microbial communities,and ecosystem dynamics.展开更多
Despite the presence of Li F components in the solid electrolyte interphase(SEI)formed on the graphite anode surface by conventional electrolyte,these Li F components primarily exist in an amorphous state,rendering th...Despite the presence of Li F components in the solid electrolyte interphase(SEI)formed on the graphite anode surface by conventional electrolyte,these Li F components primarily exist in an amorphous state,rendering them incapable of effectively inhibiting the exchange reaction between lithium ions and transition metal ions in the electrolyte.Consequently,nearly all lithium ions within the SEI film are replaced by transition metal ions,resulting in an increase in interphacial impedance and a decrease in stability.Herein,we demonstrate that the SEI film,constructed by fluoroethylene carbonate(FEC)additive rich in crystalline Li F,effectively inhibits the undesired Li^(+)/Co^(2+)ion exchange reaction,thereby suppressing the deposition of cobalt compounds and metallic cobalt.Furthermore,the deposited cobalt compounds exhibit enhanced structural stability and reduced catalytic activity with minimal impact on the interphacial stability of the graphite anode.Our findings reveal the crucial influence of SEI film composition and structure on the deposition and hazards associated with transition metal ions,providing valuable guidance for designing next-generation electrolytes.展开更多
Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pret...Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pretreat-ment has been needed for each proxy.Here,we developed a method by which each proxy can be measured in the same sample.First,the sample is polished for ring width meas-urement.After obtaining the ring width data,the sample is cut to form a 1-mm-thick wood plate.The sample is then mounted in a vertical sample holder,and gradually scanned by an X-ray beam.Simultaneously,the count rates of the fluorescent photons of elements(for chemical characteriza-tion)and a radiographic grayscale image(for wood density)are obtained,i.e.the density and the element content are obtained.Then,cellulose is isolated from the 1-mm wood plate by removal of lignin,and hemicellulose.After producing this cellulose plate,cellulose subsamples are separated by knife under the microscope for inter-annual and intra-annual stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)analysis.Based on this method,RW,density,elemental composition,δ^(13)C,and δ^(18)O can be measured from the same sample,which reduces sample amount and treatment time,and is helpful for multi-proxy comparison and combination research.展开更多
基金Supported by Natural Science Foundation of Guangdong Province in China(2018KTSCX161)。
文摘The boundness and compactness of products of multiplication,composition and differentiation on weighted Bergman spaces in the unit ball are studied.We define the differentiation operator on the space of holomorphic functions in the unit ball by radial derivative.Then we extend the Sharma's results.
基金supported by National Natural Science Foundation of China(Nos.42130506,42071031)the Special Technology Innovation Fund of Carbon Peak and Carbon Neutrality in Jiangsu Province(No.BK20231515)。
文摘Background:Climate change is accelerating alterations in forest species and community composition worldwide,especially following extreme events like severe droughts and windstorms.Understanding these effects on subtropical forests is crucial for conservation and forest management,but it remains unclear whether the impacts are stochastic or deterministic.Methods:We analyzed a unique dataset from a 1-ha permanent plot in a subtropical monsoon broadleaf evergreen forest in China,monitored over 26 years with six surveys from 1994 to 2020.The forest has been free from anthropogenic disturbances for over 400 years.In each survey,we measured all trees with a diameter at breast height(DBH)≥1 cm,and recorded 11 plant functional traits relating to photosynthesis,wood properties,water use,and nutrient dynamics.Using this data,we calculated species and trait dispersion,assessing short-term(~5years)and long-term(26 years)trends in species and trait composition following severe droughts and windstorm events.Results:Severe droughts,and subsequent droughts,increased both species and trait dispersion,while species composition converged,and trait dispersion remained relatively stable throughout the recovery period.Windstorm events led to increased species dispersion but decreased trait dispersion.We observed a clear directional shift in both species and trait composition under these climatic stressors,with a more pronounced increase in trait dispersion compared to species dispersion.Conclusion:In the short term(~5 years),severe droughts and windstorms increased species composition divergence,while trait composition responses varied.Over 26 years,deterministic processes mainly drove community composition changes,especially for trait composition,although stochastic processes also played a role.These findings suggest enhancing forest resilience to climatic stressors by protecting adaptive species or increasing species diversity in management practices.
文摘In recent decades, the application of antifouling paints to watercrafts has emerged as a significant concern in coastal ecosystems, including coral reefs. Diuron, a booster biocide commonly used as an antifouling agent, is persistent in soil, water, and groundwater. Although it exhibits moderate toxicity to mammals and birds, its primary breakdown product, 3,4-dichloroaniline, is highly toxic and environmentally persistent. The secondary toxicity of Diuron emphasizes its potential to contaminate groundwater. This investigation determined the 96-hour LC50 value for Diuron to be 1.627 ± 0.181 mg/L in Lates calcarifer. A 21-day sublethal exposure of Lates calcarifer to diuron did not yield statistically significant differences (P > 0.05) in fatty acid composition between the fresh and control groups. Both groups demonstrated polyunsaturated fatty acids (PUFAs) as the most abundant fatty acids, followed by saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs). However, significant variations (P Lates calcarifer exposed to varying diuron concentrations (50%, 30%, and 10% of the LC50 value). The magnitude of these effects increased with increasing exposure levels. The results of this study indicate that diuron, even at concentrations considered safe, can adversely affect marine organisms, including alterations to their fatty acid composition.
基金support from the National Key Scientific and Technological Infrastructure project “Earth System Science Numerical Simulator Facility” (Earth Lab)sponsored by the National Natural Science Foundation of China (Grant Nos. 42175132, 92044303, and 42205119)+2 种基金the National Key R&D Program (Grant Nos. 2020YFA0607802 and 2022YFC3703003)the CAS Information Technology Program (Grant No. CAS-WX2021SF-0107-02)the fellowship of China Postdoctoral Science Foundation (Grant No. 2022M723093)
文摘Scientific knowledge on the chemical compositions of fine particulate matter(PM_(2.5)) is essential for properly assessing its health and climate effects,and for decisionmakers to develop efficient mitigation strategies.A high-resolution PM_(2.5) chemical composition dataset(CAQRA-aerosol)is developed in this study,which provides hourly maps of organic carbon,black carbon,ammonium,nitrate,and sulfate in China from 2013 to 2020 with a horizontal resolution of 15 km.This paper describes the method,access,and validation results of this dataset.It shows that CAQRA-aerosol has good consistency with observations and achieves higher or comparable accuracy with previous PM_(2.5) composition datasets.Based on CAQRA-aerosol,spatiotemporal changes of different PM_(2.5) compositions were investigated from a national viewpoint,which emphasizes different changes of nitrate from other compositions.The estimated annual rate of population-weighted concentrations of nitrate is 0.23μg m^(−3)yr^(−1) from 2015 to 2020,compared with−0.19 to−1.1μg m^(−3)yr^(−1) for other compositions.The whole dataset is freely available from the China Air Pollution Data Center(https://doi.org/10.12423/capdb_PKU.2023.DA).
基金Supported by Natural Science Foundation Project of Xinjiang Uygur Autonomous Region(2021D01B59)Youth Science and Technology Backbone Project of Xinjiang Academy of Agricultural Sciences(XJNKQ-2021011)+2 种基金General Program of Hainan Natural Science Foundation(319MS109)Major Science and Technology Program of Hainan Province(ZDKJ2021005)Specific Research Fund of the Innovation Platform for Academicians of Hainan Province(YSPTZX202141).
文摘[Objectives]To investigate the chemical composition,antioxidant property,and nematicidal activity of Cucumis metuliferus and establish a theoretical foundation for the development of botanical nematicides.[Methods]The compounds were isolated and purified using silica gel,reversed-phase medium,low-pressure gel Sephadex LH-20 column chromatography,and preparative high-performance liquid chromatography.Their identification was based on physicochemical properties,various spectral analyses,and data reported in the literature.Subsequently,the nematicidal and antioxidant activities of the isolated compounds were evaluated.[Results]A total of four compounds were isolated from C.metuliferus,which were identified as isovitexin-2″-O-glucoside(compound 1),9E,11E-(13-oxo)tridecadienoic acid(compound 2),2E,4E-tridecadienedioic acid(compound 3),and 9E,11E-(13-hydroxy)tridecadienoic acid(compound 4).Compound 1 demonstrated a notable degree of antioxidant activity,achieving a DPPH scavenging rate of 49.40%at a mass concentration of 1 mg/mL.Additionally,compounds 1,3,and 4 exhibited varying levels of nematicidal activity.Specifically,compound 1 displayed strong nematicidal activity at a concentration of 2.0 mg/mL,resulting in a mortality rate of 90.5%against nematodes.Furthermore,compounds 3 and 4 achieved a mortality rate of 100%against nematodes at a concentration of 0.25 mg/mL.[Conclusions]This study reports the first isolation of four compounds:isovitexin-2″-O-glucoside,9E,11E-(13-oxo)tridecadienoic acid,2E,4E-tridecadienedioic acid,and 9E,11E-(13-hydroxy)tridecadienoic acid from C.metuliferus.Notably,2E,4E-tridecadienedioic acid and 9E,11E-(13-oxo)tridecadienoic acid are identified as novel natural products.Among these compounds,isovitexin-2″-O-glucoside,9E,11E-(13-oxo)tridecadienoic acid,and 9E,11E-(13-hydroxy)tridecadienoic acid exhibit nematicidal activity,whereas isovitexin-2″-O-glucoside demonstrates antioxidant properties.
基金financially supported by the National Natural Science Foundation of China(42071066)the West Light Foundation of the Chinese Academy of Sciences(2021)+1 种基金the National Key Research and Development Program of China(2023YFF1304304)the Natural Science Foundation of XizangAutonomous Region,China(XZ202201ZR0026G)。
文摘Plant community composition typically undergoes progressive changes along environmental gradients.However,most experimental studies have focused on individual communities,so it remains unclear how exogenous nutrient inputs affect the stability of plant communities along environmental gradients.Along a rainfall gradient on the northern Tibetan Plateau,we conducted an 8-year nitrogen(N)addition experiment in four alpine grasslands:alpine desert steppe(ADS),alpine steppe(AS),alpine meadow steppe(AMS),alpine meadow(AM),and we used twoway ANOVA to examine the effects of N addition on the temporal stability of these different alpine grasslands.We found that community aboveground biomass showed saturation trends in AM and AMS with increasing N gradients,while there was no change in AS and a gradual increase in ADS.The temporal stability showed different patterns of gradual decreases in ADS and AM,and a unimodal trend in AMS with increasing N gradients.However,N addition had no effect on the temporal stability of AS.Dominant species stability was the controlling factor for alpine grasslands along the transect,while the effect of asynchrony gradually increased with decreasing precipitation.These findings highlight that community composition,especially the dominant species,along the environmental gradient can mediate the effects of N inputs on community temporal stability.Thus,the conservation and restoration of the dominant species are particularly important under future scenarios of increased atmospheric N deposition.
基金supported by the National Natural Science Foundation of China(22279098,52102295)。
文摘Fullerene derivatives[6,6]-phenyl-C61-butyric acid methyl ester(PC_(61)BM)has been routinely used as the electron transport layer(ETL)in perovskite solar cells due to its suitable energy levels and good solution processability.However,its electron mobility and conductivity still need to be further enhanced for constructing high performance perovskite solar cells(PSCs).Herein,by doping the PC_(61)BM with a p-type polymer PM6 and n-type molecule ITIC,efficient wide-bandgap perovskite solar cells with improved efficiency and operational/storage stability are obtained.Further spectroscopy and electric measurements indicate PM6 and ITIC can both passivate defects at the perovskite/ETL interface,meanwhile ITIC can elevate the Fermi level of PC_(61)BM to enhance conductivity and PM6 can improve the photo-induced electron mobility of the ETL,facilitating charge extraction and reducing charge recombination.As the results,Cs_(0.17)FA_(0.83)Pb(I_(0.83)Br_(0.17))_(3)wide-bandgap PSCs with PM6:PC_(61)BM:ITIC as the ETL demonstrates a superior efficiency of 22.95%,compared to 20.89%of the PC_(61)BM assisted device.
基金supported by the Key R&D Program of Shandong Province,China(No.2024TZXD067,2022SFGC0105)Natural Science Foundation of Shandong Province(No.ZR2023QB021)+2 种基金Young Taishan Scholarship to Xuekui Xia(No.tsqn202103100)Jinan Talent Project for Universities(No.2021GXRC062,202228088)Key innovation Project and Science,Education and Industry Integration Innovation Pilot Project of Qilu University of Technology(Shandong Academy of Sciences)(No.2022JBZ01-06,2024ZDZX03,2023RCKY214).
文摘Jing Fang granules(JFG)are a modern Chinese medicinal formulation derived from Jing Fang Defeating Toxin San(JFDS).JFG primarily contains bioactive compounds such as flavonoids/flavonoid glycosides,coumarins and other components,which have various activities:anti-inflammatory,immune system regulation,antiviral,anti-aging,detoxification,and protection of the liver,lungs,and kidneys.JFG has broad potential therapeutic applications.The mechanisms of JFG’s actions are primarily associated with signaling pathways such as TLR4/NF-κB,PI3K/AKT,and MAPK.This article reviews the research progress on JFG,including chemical composition,pharmacologic effects,mechanism of action,safety,clinical application,etc.,serving as a foundation for future research and clinical applications.
基金supported by the National Natural Science Foundation of China(12171373)Chen's work also supported by the Fundamental Research Funds for the Central Universities of China(GK202207018).
文摘In this paper,we study composition operators on weighted Bergman spaces of Dirichlet series.We first establish some Littlewood-type inequalities for generalized mean counting functions.Then we give sufficient conditions for a composition operator with zero characteristic to be bounded or compact on weighted Bergman spaces of Dirichlet series.The corresponding sufficient condition for compactness in the case of positive characteristics is also obtained.
基金supported by the National Natural Science Foundation of China(No.52473234)the Fundamental Research Funds for the Central Universities of China,the GJYC Program of Guangzhou City,China(No.2024D03J0001)the Open Research Fund of Songshan Lake Materials Laboratory,China(No.2023SLABFK04).
文摘The three-dimensional(3D)imaging of structural and compositional features at the nanometer and atomic scale is crucial for advancing the applications of nanomaterials in energy storageand catalysis.Transmission electron microscopy,particularly in scanning mode,has traditionally provided atomicresolution structural insights.However,achieving high-resolution 3D compositional imaging of beam-sensitive materials remains formidably challenging due to the limitation of electron dose.Recent innovations in hardware and computational methods,such as data-fusing and deep learning,have enabled 3D compositional imaging at the sub-nanometer scale with significantly reduced electrondoses.This review highlightstheprinciples,advancements,and applications of electron tomography and associated techniques for 3D compositional imaging,summarizes state-of-the-art progress achieved by multimodal tomography and model-free reconstructions,and underscores the transformative potential of these developments for 3D high-resolution characterizations of beam-sensitivematerials.
基金supported by the Ministry of Science,Innovation and Universities(CIENCIA)(Spain)under projects CGL2013-47988-C2-01-P and CGL2016-77138-C2-1-P.
文摘This paper combines a variety of physicochemical nondestructive techniques to obtain a knowledge of the chemical and mineralogical composition of the scarce fossil bones from the Húmera paleontological site(Madrid,Spain).The main classification of the samples has distinguished six colors:red,gray,blue,white,light yellow and green.μ-XRD and Raman spectroscopy have been correlated to study the structure and to distinguish between fluorapatite,chlorapatite,bioapatite and carbonated bones.The bones have further been classified in three main types.Type I includes gray,green,white,and blue samples,classified as fluorapatite and chlorapatite containing organic matter and adsorbed water.Type II,includes the red sample classified as bioapatite,showing broad Raman bands andμ-XRD peaks due to the lattice disorder created by the B-type substitutions emerging from a high matter content.Type III sample(yellow)shows a complete replacement of apatite by calcite which induce the high porosity of the sample.Diagenetic changes add further complexity to the structure of fossil bones,not only by new ionic substitutions but also in terms of biogenic or authigenic phases that form in the fossilizing bone.The multi-technique approach from a broad interdisciplinary perspective enables a better understanding of bone fossilization.
基金Supported by The Innovation Fund of Postgraduate,Sichuan University of Science&Engineering(Y2024336)NSF of Sichuan Province(2023NSFSC0065).
文摘In this paper,we study asymptotic power series of the composition f(x)=h(g(x)),where g(x)=∑_(n=0)^(∞)b_(n)x^(-n),b_(n)∈R,and h is a given elementary function.The asymptotic expansions have been obtained for the composition with an exponential or logarithmic function.Using the re-cursive method,we present the asymptotic expansions for the composition with seven trigonometric functions,respectively.As an application,the asymptotic expansions of roots of some equations are given.Computational results show that our recursive formula is more efficient than the method of Lagrange's inverse theorem.
基金support from the National Natural Science Foundation of China(Nos.52322104,52172067,and 92160202)the Natural Science Foundation of Guangdong Province(No.2021B1515020038)+2 种基金the Guangdong Special Support Program(No.2019BT02C629)the Guangdong Provincial Science and Technology Program(No.2023A0505010017)the Science Center for Gas Turbine Project(No.P2023-C-IV-002-001).
文摘The unique multilayer, multiscale structure of teakwood results in excellent mechanical and long-term environmental stability, providing inspiration for the biomimetic design of environmental barrier coating (EBC) structures. However, achieving the desired biomimetic structure control in high-temperature plasma spraying is a challenging task that requires new technological breakthroughs. In this study, a multiscale nano Yb_(2)Si_(2)O_(7)–Yb_(2)SiO_(5) (YbDS–YbMS) composite EBC with a teakwood-like lamellar structure was realized via a novel alternating vapor/liquid phase deposition method involving plasma spraying-physical vapor deposition (PS-PVD). Volatilized waste SiO_(2) from Yb_(2)Si_(2)O_(7) (YbDS) was reused and deposited on the coating surface during the spraying process, where a regularly arranged multilayer structure was formed in the coating by the alternate deposition of gaseous SiO_(2) and droplet YbDS. In addition, SiO_(2) on the coated surface formed nanoclusters and dome-shaped nanocrystals via homogeneous and heterogeneous nucleation, respectively, and some of them gradually formed a continuous nanofilm as the arc current increased. The deposited SiO_(2) reacted in situ with the decomposed phase YbMS in the coating to form YbDS, preserving its multiscale nanostructure after heat treatment and enabling the preparation of the YbDS–YbMS composite coating. This work provides a new design strategy and method for the preparation of coatings using YbDS and other spray powders with similar decomposition and volatilization characteristics during the plasma spraying process.
文摘Generative AI technology for human-assisted tools has made great strides in recent years,and studying the impact of this technology on students'compositional abilities plays an important role in promoting changes in music education.Previous studies have focused on the performance of music composition software itself in terms of composition,with less consideration given to the impact of creators'compositional ability after using assistive composition tools.Thus,this paper designs a controlled experiment to investigate the changes in students'compositional ability before and after using AI composition tools.This paper finds that students'compositional abilities in all areas of composition improved to varying degrees after using AI composition tools.This paper compares the differences in compositional abilities of students with and without the education of AI composition tools,which has practical implications for vigorously promoting the adoption of AI composition tools in university music education teaching.
基金supported by the National Natural Science Foundation of China(No.21676065 and No.52373262)China Postdoctoral Science Foundation(2021MD703944,2022T150782).
文摘Microwave absorbing materials(MAMs)characterized by high absorption efficiency and good environmental tolerance are highly desirable in practical applications.Both silicon carbide and carbon are considered as stable MAMs under some rigorous conditions,while their composites still fail to produce satisfactory microwave absorption performance regardless of the improvements as compared with the individuals.Herein,we have successfully implemented compositional and structural engineering to fabricate hollow Si C/C microspheres with controllable composition.The simultaneous modulation on dielectric properties and impedance matching can be easily achieved as the change in the composition of these composites.The formation of hollow structure not only favors lightweight feature,but also generates considerable contribution to microwave attenuation capacity.With the synergistic effect of composition and structure,the optimized SiC/C composite exhibits excellent performance,whose the strongest reflection loss intensity and broadest effective absorption reach-60.8 dB and 5.1 GHz,respectively,and its microwave absorption properties are actually superior to those of most SiC/C composites in previous studies.In addition,the stability tests of microwave absorption capacity after exposure to harsh conditions and Radar Cross Section simulation data demonstrate that hollow SiC/C microspheres from compositional and structural optimization have a bright prospect in practical applications.
基金support from the National Natural Science Foundation of China(22073033,21873032,21673087,21903032)startup fund(2006013118 and 3004013105)from Huazhong University of Science and Technology+1 种基金the Fundamental Research Funds for the Central Universities(2019kfyRCPY116)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)
文摘In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active sites as exemplified by diatomic metals anchored graphdiyne via the combination of hierarchical high-throughput screening,first-principles calculations,and molecular dynamics simulations.Totally 43 highly efficient catalysts feature ultralow onset potentials(|U_(onset)|≤0.40 V)with Rh-Hf and Rh-Ta showing negligible onset potentials of 0 and-0.04 V,respectively.Extremely high catalytic activities of Rh-Hf and Rh-Ta can be ascribed to the synergistic effects.When forming heteronuclears,the combinations of relatively weak(such as Rh)and relatively strong(such as Hf or Ta)components usually lead to the optimal strengths of adsorption Gibbs free energies of reaction intermediates.The origin can be ascribed to the mediate d-band centers of Rh-Hf and Rh-Ta,which lead to the optimal adsorption strengths of intermediates,thereby bringing the high catalytic activities.Our work provides a new and general strategy toward the architecture of highly efficient catalysts not only for electrocatalytic nitrogen reduction reaction(eNRR)but also for other important reactions.We expect that our work will boost both experimental and theoretical efforts in this direction.
基金Supported by the“SDF-sweet doctor cultivation”Project of Sinocare Diabetes Foundation,No.2022SD11 and No.2021SD09.
文摘BACKGROUND In recent years,the prevalence of obesity and metabolic syndrome in type 1 diabetes(T1DM)patients has gradually increased.Insulin resistance in T1DM deserves attention.It is necessary to clarify the relationship between body composition,metabolic syndrome and insulin resistance in T1DM to guide clinical treatment and intervention.AIM To assess body composition(BC)in T1DM patients and evaluate the relationship between BC,metabolic syndrome(MS),and insulin resistance in these indi-viduals.METHODS A total of 101 subjects with T1DM,aged 10 years or older,and with a disease duration of over 1 year were included.Bioelectrical impedance analysis using the Tsinghua-Tongfang BC Analyzer BCA-1B was employed to measure various BC parameters.Clinical and laboratory data were collected,and insulin resistance was calculated using the estimated glucose disposal rate(eGDR).RESULTS MS was diagnosed in 16/101 patients(15.84%),overweight in 16/101 patients(15.84%),obesity in 4/101(3.96%),hypertension in 34/101(33.66%%)and dyslip-idemia in 16/101 patients(15.84%).Visceral fat index(VFI)and trunk fat mass were significantly and negatively correlated with eGDR(both P<0.001).Female patients exhibited higher body fat percentage and visceral fat ratio compared to male patients.Binary logistic regression analysis revealed that significant factors for MS included eGDR[P=0.017,odds ratio(OR)=0.109],VFI(P=0.030,OR=3.529),and a family history of diabetes(P=0.004,OR=0.228).Significant factors for hypertension included eGDR(P<0.001,OR=0.488)and skeletal muscle mass(P=0.003,OR=1.111).Significant factors for dyslipidemia included trunk fat mass(P=0.033,OR=1.202)and eGDR(P=0.037,OR=0.708).CONCLUSION Visceral fat was found to be a superior predictor of MS compared to conventional measures such as body mass index and waist-to-hip ratio in Chinese individuals with T1DM.BC analysis,specifically identifying visceral fat(trunk fat),may play an important role in identifying the increased risk of MS in non-obese patients with T1DM.
基金funded by the National Key R&D Program of China(2022YFC2601100,2021YFD1400100 and 2021YFC2600400)the National Natural Science Foundation of China(42207162)。
文摘Bidens pilosa is recognized as one of the major invasive plants in China.Its invasion has been associated with significant losses in agriculture,forestry,husbandry,and biodiversity.Soil ecosystems play an important role in alien plant invasion.Microorganisms within the soil act as intermediaries between plants and soil ecological functions,playing a role in regulating soil enzyme activities and nutrient dynamics.Understanding the interactions between invasive plants,soil microorganisms,and soil ecological processes is vital for managing and mitigating the impacts of invasive species on the environment.In this study,we conducted a systematic analysis focusing on B.pilosa and Setaria viridis,a common native companion plant in the invaded area.To simulate the invasion process of B.pilosa,we constructed homogeneous plots consisting of B.pilosa and S.viridis grown separately as monocultures,as well as in mixtures.The rhizosphere and bulk soils were collected from the alien plant B.pilosa and the native plant S.viridis.In order to focus on the soil ecological functional mechanisms that contribute to the successful invasion of B.pilosa,we analyzed the effects of B.pilosa on the composition of soil microbial communities and soil ecological functions.The results showed that the biomass of B.pilosa increased by 27.51% and that of S.viridis was significantly reduced by 66.56%.The organic matter contents in the bulk and rhizosphere soils of B.pilosa were approximately 1.30 times those in the native plant soils.The TN and NO_(3)^(-)contents in the rhizosphere soil of B.pilosa were 1.30 to 2.71 times those in the native plant soils.The activities of acid phosphatase,alkaline phosphatase,and urease in the rhizosphere soil of B.pilosa were 1.98-2.25 times higher than in the native plant soils.Using high-throughput sequencing of the16S rRNA gene,we found that B.pilosa altered the composition of the soil microbial community.Specifically,many genera in Actinobacteria and Proteobacteria were enriched in B.pilosa soils.Further correlation analyses verified that these genera had significantly positive relationships with soil nutrients and enzyme activities.Plant biomass,soil p H,and the contents of organic matter,TN,NO_(3)^(-),TP,AP,TK,and AK were the main factors affecting soil microbial communities.This study showed that the invasion of B.pilosa led to significant alterations in the composition of the soil microbial communities.These changes were closely linked to modifications in plant traits as well as soil physical and chemical properties.Some microbial species related to C,N and P cycling were enriched in the soil invaded by B.pilosa.These findings provide additional support for the hypothesis of soil-microbe feedback in the successful invasion of alien plants.They also offer insights into the ecological mechanism by which soil microbes contribute to the successful invasion of B.pilosa.Overall,our research contributes to a better understanding of the complex interactions between invasive plants,soil microbial communities,and ecosystem dynamics.
基金supported by the National Natural Science Foundation of China(21972049,21573080)。
文摘Despite the presence of Li F components in the solid electrolyte interphase(SEI)formed on the graphite anode surface by conventional electrolyte,these Li F components primarily exist in an amorphous state,rendering them incapable of effectively inhibiting the exchange reaction between lithium ions and transition metal ions in the electrolyte.Consequently,nearly all lithium ions within the SEI film are replaced by transition metal ions,resulting in an increase in interphacial impedance and a decrease in stability.Herein,we demonstrate that the SEI film,constructed by fluoroethylene carbonate(FEC)additive rich in crystalline Li F,effectively inhibits the undesired Li^(+)/Co^(2+)ion exchange reaction,thereby suppressing the deposition of cobalt compounds and metallic cobalt.Furthermore,the deposited cobalt compounds exhibit enhanced structural stability and reduced catalytic activity with minimal impact on the interphacial stability of the graphite anode.Our findings reveal the crucial influence of SEI film composition and structure on the deposition and hazards associated with transition metal ions,providing valuable guidance for designing next-generation electrolytes.
基金supported the National Natural Science Foundation of China (42022059,41888101)the Strategic Priority Research Program of the Chinese Academy of Sciences,China (Grant No.XDB26020000)+1 种基金the Key Research Program of the Institute of Geology and Geophysics (CAS Grant IGGCAS-201905)the CAS Youth Interdisciplinary Team (JCTD-2021-05).
文摘Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pretreat-ment has been needed for each proxy.Here,we developed a method by which each proxy can be measured in the same sample.First,the sample is polished for ring width meas-urement.After obtaining the ring width data,the sample is cut to form a 1-mm-thick wood plate.The sample is then mounted in a vertical sample holder,and gradually scanned by an X-ray beam.Simultaneously,the count rates of the fluorescent photons of elements(for chemical characteriza-tion)and a radiographic grayscale image(for wood density)are obtained,i.e.the density and the element content are obtained.Then,cellulose is isolated from the 1-mm wood plate by removal of lignin,and hemicellulose.After producing this cellulose plate,cellulose subsamples are separated by knife under the microscope for inter-annual and intra-annual stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)analysis.Based on this method,RW,density,elemental composition,δ^(13)C,and δ^(18)O can be measured from the same sample,which reduces sample amount and treatment time,and is helpful for multi-proxy comparison and combination research.
