To address the challenges of insufficient visualization in the industrial robot assembly operation system and the limitation of visualizing only geometric attributes of physical properties,a method is proposed for con...To address the challenges of insufficient visualization in the industrial robot assembly operation system and the limitation of visualizing only geometric attributes of physical properties,a method is proposed for constructing an industrial robot assembly system based on virtual reality technology.Focusing on the shaft hole assembly,the mechanical characteristics of the industrial robot shaft hole assembly process are analyzed and a dynamic model is established for shaft hole assembly operations.The key elements of virtual assembly operations for industrial robots are summarized and a five-dimensional model is proposed for industrial robot virtual operations.Utilizing the Unity3D engine based on the 5-D model for industrial robot virtual operations,an industrial robot shaft hole assembly system is developed.This system enables virtual assembly operations,displays physical attributes,and provides valuable references for the research of virtual systems.展开更多
Despite the gradual transformation of traditional manufacturing by the Human-Robot Collaboration Assembly(HRCA),challenges remain in the robot’s ability to understand and predict human assembly intentions.This study ...Despite the gradual transformation of traditional manufacturing by the Human-Robot Collaboration Assembly(HRCA),challenges remain in the robot’s ability to understand and predict human assembly intentions.This study aims to enhance the robot’s comprehension and prediction capabilities of operator assembly intentions by capturing and analyzing operator behavior and movements.We propose a video feature extraction method based on the Temporal Shift Module Network(TSM-ResNet50)to extract spatiotemporal features from assembly videos and differentiate various assembly actions using feature differences between video frames.Furthermore,we construct an action recognition and segmentation model based on the Refined-Multi-Scale Temporal Convolutional Network(Refined-MS-TCN)to identify assembly action intervals and accurately acquire action categories.Experiments on our self-built reducer assembly action dataset demonstrate that our network can classify assembly actions frame by frame,achieving an accuracy rate of 83%.Additionally,we develop a HiddenMarkovModel(HMM)integrated with assembly task constraints to predict operator assembly intentions based on the probability transition matrix and assembly task constraints.The experimental results show that our method for predicting operator assembly intentions can achieve an accuracy of 90.6%,which is a 13.3%improvement over the HMM without task constraints.展开更多
Membrane electrode assembly(MEA)is widely considered to be the most promising type of electrolyzer for the practical application of electrochemical CO_(2) reduction reaction(CO_(2)RR).In MEAs,a square-shaped cross-sec...Membrane electrode assembly(MEA)is widely considered to be the most promising type of electrolyzer for the practical application of electrochemical CO_(2) reduction reaction(CO_(2)RR).In MEAs,a square-shaped cross-section in the flow channel is normally adopted,the configuration optimization of which could potentially enhance the performance of the electrolyzer.This paper describes the numerical simulation study on the impact of the flow-channel cross-section shapes in the MEA electrolyzer for CO_(2)RR.The results show that wide flow channels with low heights are beneficial to the CO_(2)RR by providing a uniform flow field of CO_(2),especially at high current densities.Moreover,the larger the electrolyzer,the more significant the effect is.This study provides a theoretical basis for the design of high-performance MEA electrolyzers for CO_(2)RR.展开更多
Juglans sigillata is an economically valuable nut crop renowned for its nutritional richness,including essential nutrients,antioxidants,and healthy fats,which boost human cardial,brain and gut health.Despite its impor...Juglans sigillata is an economically valuable nut crop renowned for its nutritional richness,including essential nutrients,antioxidants,and healthy fats,which boost human cardial,brain and gut health.Despite its importance,the lack of a complete genome assembly has been a stumbling block in its biological breeding process.Therefore,we generated deep coverage ultralong Oxford Nanopore Technology(ONT)and PacBio HiFi reads to construct a telomere-to-telomere(T2T)genome assembly.The final assembly spans 537.27 Mb with no gaps,demonstrating a remarkable completeness of 98.1%.We utilized a combination of transcriptome data and homologous proteins to annotate the genome,identifying 36018 protein-coding genes.Furthermore,we profiled global cytosine DNA methylations using ONT sequencing data.Global methylome analysis revealed high methylation levels in transposable element(TE)-rich chromosomal regions juxtaposed with comparatively lower methylation in gene-rich areas.By integrating a detailed multi-omics data analysis,we obtained valuable insights into the mechanism underlying endopleura coloration.This investigation led to the identification of eight candidate genes(e.g.ANR)involved in anthocyanin biosynthesis pathways,which are crucial for the development of color in plants.The comprehensive genome assembly and the understanding of the genetic basis of important traits like endopleura coloration will open avenues for more efficient breeding programs and improved crop quality.展开更多
A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefo...A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefore,this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers.This study measured Electrochemical Surface Area(ECSA),Electrochemical Impedance Spectroscopy(EIS),X-ray Diffraction analysis(XRD),and X-ray Fluorescence(XRF).Furthermore,the round-trip efficiency(RTE)of the MEA,as w ell as the performance in FC and WE mode,was measured.In comparison,The ECSA values of Pt-Ru/C and Pt/C with three catalyst layers were higher than the single catalyst layer.This result was supported by electrode characterization data for XRD and XRF.The respective electrical conductivity values of Pt-Ru/C and Pt/C with three catalyst layers are also higher than the single cata-lyst layer,and the performance of URFC using MEA with three catalyst layers has the highest value of RTE among the MEA performances of URFC,which is 100%at a current density of 4 mA·cm-2.展开更多
Soil microbiomes are significant for biodiversity,crucial for ecosystem functions,and vital for the health of various organisms.Nevertheless,the impacts of season and plant species shifts on soil microbial diversity a...Soil microbiomes are significant for biodiversity,crucial for ecosystem functions,and vital for the health of various organisms.Nevertheless,the impacts of season and plant species shifts on soil microbial diversity and community assembly are still poorly understood.This study explored soil bacterial,fungal,and protistan communities during summer and winter in a coastal wetland affected by Spartina alterniflora invasion and subsequent Cyperus malaccensis or Kandelia obovata restoration.The results showed that bacterial,fungal,and protistan diversity were 2.63%,40.3%,and 9.90%higher in winter than in summer,respectively.Plant species had a distinct impact on microbial diversity.Notably,K.obovata restoration significantly increased bacterial diversity,but decreased protistan diversity,with no effect on fungal diversity when compared to S.alterniflora invasion.Season and plant species both significantly influenced the community structure of bacteria,fungi,and protists.However,protistan community structure was more sensitive to season compared to the structure of bacterial and fungal communities.The complexity of co-occurrence networks within or among bacteria,fungi,and protists was higher in winter than in summer.Bacterial and protistan community assembly was primarily driven by stochastic processes,while fungal assembly was dominated by deterministic processes.Bacterial and protistan community assembly exhibited lower stochasticity in winter compared to summer,suggesting a more deterministic assembly of communities during winter.Our findings highlight the critical role of season and plant species in regulating microbial communities,revealing higher microbial diversity,network complexity,and determinism in community assembly during winter compared to summer in a subtropical coastal wetland.展开更多
Molecular recognition of fullerene using various host compounds is well-known in literature.But most studies focus on host-vip complexation in solution using host compounds with a single binding cavity.Herein,we rep...Molecular recognition of fullerene using various host compounds is well-known in literature.But most studies focus on host-vip complexation in solution using host compounds with a single binding cavity.Herein,we report a series of highly preorganized janusarene derivatives with homoditopic binding sites.These novel janusarenes can bind and align various fullerenes such as C_(60),C_(70),C_(84),and Gd@C_(82)in a highly efficient manner.Robust shape complementary association and assembly are observed in solution,in the bulk solid state,in the liquid crystalline state,or on surface,and the assembled structures are characterized by nuclear magnetic resonance(NMR)titration,X-ray diffraction,polarized optical microscopy,and scanning tunneling microscopy.展开更多
Common bean(Phaseolus vulgaris L.)is a vital source of protein and essential nutrients for human consumption and plays a key role in sustainable agriculture due to its nitrogen-fixing ability(Nadeem et al.,2021).Kidne...Common bean(Phaseolus vulgaris L.)is a vital source of protein and essential nutrients for human consumption and plays a key role in sustainable agriculture due to its nitrogen-fixing ability(Nadeem et al.,2021).Kidney beans,a subcategory of dry common beans,are highly valued for their rich protein,dietary fiber,low fat content,and various trace elements(Garcia-Cordero et al.,2021).Despite the release of several de novo genome assemblies(Goodstein et al.,2012;Schmutz et al.,2014;Vlasova et al.,2016;Cortinovis et al.,2024),existing common bean genomes remain incomplete,particularly in complex regions such as centromeres and telomeres,limiting a comprehensive understanding of the genomic landscape.展开更多
Carbon dots(CDs)-based composites have shown impressive performance in fields of information encryption and sensing,however,a great challenge is to simultaneously implement multi-mode luminescence and room-temperature...Carbon dots(CDs)-based composites have shown impressive performance in fields of information encryption and sensing,however,a great challenge is to simultaneously implement multi-mode luminescence and room-temperature phosphorescence(RTP)detection in single system due to the formidable synthesis.Herein,a multifunctional composite of Eu&CDs@p RHO has been designed by co-assembly strategy and prepared via a facile calcination and impregnation treatment.Eu&CDs@p RHO exhibits intense fluorescence(FL)and RTP coming from two individual luminous centers,Eu3+in the free pores and CDs in the interrupted structure of RHO zeolite.Unique four-mode color outputs including pink(Eu^(3+),ex.254 nm),light violet(CDs,ex.365 nm),blue(CDs,254 nm off),and green(CDs,365 nm off)could be realized,on the basis of it,a preliminary application of advanced information encoding has been demonstrated.Given the free pores of matrix and stable RTP in water of confined CDs,a visual RTP detection of Fe^(3+)ions is achieved with the detection limit as low as 9.8μmol/L.This work has opened up a new perspective for the strategic amalgamation of luminous vips with porous zeolite to construct the advanced functional materials.展开更多
A renewable fluorescent material(GСCP5L)has been constructed via supramolecular assembly between a new derivative of pillararene,namely leggero pillar[5]arene,as the host molecule(CP5L)and a tetraphenylethylene(TPE)-...A renewable fluorescent material(GСCP5L)has been constructed via supramolecular assembly between a new derivative of pillararene,namely leggero pillar[5]arene,as the host molecule(CP5L)and a tetraphenylethylene(TPE)-based ditopic vip(G).This new material can simultaneously perform efficient detection and separation of silver(I)from aqueous environments.Possessing an electron-rich cavity and two cytosine groups modified on both rims,CP5L functions as the host-vip binding site for G and offers exclusive coordination sites for further interaction with Ag+.Adding Ag+to the system undergoes dramatic fluorescence enhancement due to the mechanism of supramolecular assembly-induced enhanced emission(SAIEE).This fluorescence enhancement allows for efficient and visualized detection following a“light-up”pattern,achieving a limit of detection(LOD)of 1.3×10^(-7)mol/L,which is fully in line with the World Health Organization's drinking water standard of 9×10^(-7)mol/L.In addition,GСCP5L also shows strong anti-interference capability against other cationic species.For the separation of Ag+from aqueous systems,GСCP5L displays exceptional adsorption efficiency(97%)and reliable recovery performance,demonstrating excellent recyclability after five experimental cycles without compromising its adsorption activity.展开更多
phoD and pqqC gene occurrence in bacteria allows them to mobilize phosphorus(P)by mineralizing organic P(Po)and solubilizing inorganic P(Pi),respectively.Community characteristics of phoD-and pqqC-harboring bacteria(p...phoD and pqqC gene occurrence in bacteria allows them to mobilize phosphorus(P)by mineralizing organic P(Po)and solubilizing inorganic P(Pi),respectively.Community characteristics of phoD-and pqqC-harboring bacteria(phoD-and pqqC-HB,respectively)mediate P cycling.However,whether the microbial community assembly and keystone taxa of phoD-and pqqC-HB regulate P availability and distinct regulatory pathways between these two genes remain unclear.In this study,soil microbial community characteristics and P availability were investigated in four long-term(38-year)fertilization regimes:control with no fertilizer(CK),P fertilizer(PF),nitrogen(N)and P fertilizers(NP),and N fertilizer,P fertilizer,and manure(NPM).The N addition treatments(NP and NPM)significantly changed the community composition and increased the abundances of phoD-and pqqC-HB compared to the no-N addition treatments(CK and PF).Stochastic processes dominated the community assembly of both phoD-and pqqC-HB,and the relative contributions of stochasticity increased with N addition.Furthermore,the N addition treatments resulted in greater network complexity and higher abundances of keystone taxa of phoD-and pqqC-HB compared to those of the no-N addition treatments.The keystone taxa implicated in P cycling were also associated with carbon(C)and N cycling processes.Microbial community composition and assembly processes were the main factors driving labile Pi for phoD-HB,whereas keystone taxa contributed the most to labile Pi for pqqC-HB.These results emphasize that distinct mechanisms of phoD-and pqqC-HB regulate P availability under fertilization management and underline the significance of microbial community assembly and keystone taxa in soil ecological functions,offering fresh perspectives on comprehending the biological processes facilitated by microorganisms in enhancing soil quality.展开更多
Bacterial communities play a crucial role in permafrost biogeochemical cycling and ecosystem function maintenance.Bacterial interaction is one of the main factors in shaping soil bacterial communities.However,how woul...Bacterial communities play a crucial role in permafrost biogeochemical cycling and ecosystem function maintenance.Bacterial interaction is one of the main factors in shaping soil bacterial communities.However,how would bacterial interaction influence the bacterial communities in permafrost of the Qinghai-Tibet Plateau(QTP)remains largely unknown.Here we collected paired soil samples from both the active and permafrost layers of two typical QTP permafrost regions in October 2020 for Tuotuohe River(TTH)and May 2022 for Aerjin(ARJ),and investigated the bacterial communities and the role of interactions in structuring the bacterial community and its assembly process through amplicon sequencing of the 16S rRNA gene.Our study revealed distinct bacterial communities,with significant differences in the relative abundances of Proteobacteria(P<0.05),Acidobacteriota(P<0.001),Bacteroidota(P<0.05),and Planctomycetota(P<0.001)between the active layer and the permafrost layer.More importantly,we found that interspecies interactions,including both positive and negative associations,were strongly correlated with bacterial alpha-diversity and played a significant role in community variation and assembly process.Our findings also showed that the community assembly in both the active and permafrost layers was primarily driven by homogeneous selection of deterministic processes,with interspecies interactions accounting for more than 58%and 63%of all assembly mechanisms,respectively.This is the first study to quantify the contribution of bacterial interactions in shaping the bacterial community and its assembly process in permafrost of QTP,highlighting the importance of considering interspecies interactions in future modeling efforts.Our work also emphasizes the necessity of including interspecies interactions in microbial process projections to reduce uncertainty.展开更多
The environmental impacts of acid mine drainage(AMD)from open-pit mining are profoundly detrimental,yet knowledge about its effects on paddy soil microbial communities,especially at greater depths,remains limited.In t...The environmental impacts of acid mine drainage(AMD)from open-pit mining are profoundly detrimental,yet knowledge about its effects on paddy soil microbial communities,especially at greater depths,remains limited.In this investigation,we compared soils affected by AMD versus unaffected soil depth profiles in terms of bacterial diversity and community assembly.The profiles in AMD-polluted soils exhibited tight geochemical gradients,characterized by increased acidity,SO_(4)^(2-),NO_(3)^(-),and heavy metal content compared to unpolluted soils.Notably,AMD significantly diminished soil bacterial biodiversity.A depthwise analysis showed distinct microbial stratification,with certain bacteria like Candidatus_Solibacter and Candidatus_Koribacter predominated in polluted soils,while others like Haliangium and Nitrospira were more prevalent in control soils.Interestingly,despite variable soil conditions,predictedmetabolic pathways,particularly those involving carbon,nitrogen,and sulfur,showed relative stability.AMD pollution induced the upregulation of methylcoenzyme M reductase and sulfate reductase genes.Bacterial communities were more responsive to pH and nutrient content rather than heavy metals,with pH and SO_(4)^(2-)being the primary drivers of microbial diversity and distribution.Additionally,pHwas identified as the most significant influence on the predicted methane,sulfur,and nitrogen metabolism.Furthermore,deterministic processes played a more significant role in community assembly of polluted soils,while heterogeneous selection gained importance with increasing depth in control soils.Additionally,microbial co-occurrences,particularly positive interactions,were more prevalent in the polluted soils with reduced network modularity and keystone taxa.These findings offer insights into sustaining microbial diversity in extreme environments.展开更多
Diazotrophs make important contributions to nitrogen(N) inputs in agricultural ecosystems. However, strong evidence of the effects of conservation tillage(CT) on the coexistence and assembly of soil diazotrophic commu...Diazotrophs make important contributions to nitrogen(N) inputs in agricultural ecosystems. However, strong evidence of the effects of conservation tillage(CT) on the coexistence and assembly of soil diazotrophic community and related mechanisms is lacking. Here, a long-term experiment was conducted to study the impacts of CT on the coexistence and assembly patterns of soil diazotrophic community in Lishu County, Jilin Province, North China. Compared to traditional tillage(control, CK), CT significantly reduced both the N fixation rate in top 0–10 cm soil and the alpha diversity of diazotrophic community while increasing the density of diazotrophic and overall bacterial communities. Conservation tillage also reduced the competitive relationships within the diazotrophic community and enhanced network stability. Furthermore, diazotroph assembly was dominated by deterministic processes(relative influence =68.63%) under CK and stochastic processes(relative influence = 58.82%) under CT. Soil depth and total N(TN) were identified as crucial predictors shaping the assembly processes of diazotrophic community under different tillage practices. The relative influence of stochastic processes on diazotrophic community under CT varied more significantly with increasing soil depth. Overall, tillage practice and soil depth had significant influences on the coexistence and assembly processes of soil diazotrophic community. Moreover, long-term CT may impact the selection of N fixation agents and the specific taxa associated with N fixers. Our results indicated that in CT systems, relatively sufficient nutrient availability led to a reduction in interspecies competition, an increase in network stability, and a greater influence of stochastic processes on community assembly. These findings may help us better understand biological N fixation in sustainable agricultural systems.展开更多
Effective vegetation reconstruction plays a vital role in the restoration of desert ecosystems.However,in reconstruction of different vegetation types,the community characteristics,assembly processes,and functions of ...Effective vegetation reconstruction plays a vital role in the restoration of desert ecosystems.However,in reconstruction of different vegetation types,the community characteristics,assembly processes,and functions of different soil microbial taxa under environmental changes are still disputed,which limits the understanding of the sustainability of desert restoration.Hence,we investigated the soil microbial community characteristics and functional attributes of grassland desert(GD),desert steppe(DS),typical steppe(TS),and artificial forest(AF)in the Mu Us Desert,China.Our findings confirmed the geographical conservation of soil microbial composition but highlighted decreased microbial diversity in TS.Meanwhile,the abundance of rare taxa and microbial community stability in TS improved.Heterogeneous and homogeneous selection determined the assembly of rare and abundant bacterial taxa,respectively,with both being significantly influenced by soil moisture.In contrast,fungal communities displayed stochastic processes and exhibited sensitivity to soil nutrient conditions.Furthermore,our investigation revealed a noteworthy augmentation in bacterial metabolic functionality in TS,aligning with improved vegetation restoration and the assemblage of abundant bacterial taxa.However,within nutrient-limited soils(GD,DS,and AF),the assembly dynamics of rare fungal taxa assumed a prominent role in augmenting their metabolic capacity and adaptability to desert ecosystems.These results highlighted the variations in the assembly processes and metabolic functions of soil microorganisms during vegetation reestablishment and provided corresponding theoretical support for anthropogenic revegetation of desert ecosystems.展开更多
Gear assembly errors can lead to the increase of vibration and noise of the system,which affect the stability of system.The influence can be compensated by tooth modification.Firstly,an improved three-dimensional load...Gear assembly errors can lead to the increase of vibration and noise of the system,which affect the stability of system.The influence can be compensated by tooth modification.Firstly,an improved three-dimensional loaded tooth contact analysis(3D-LTCA)method which can consider tooth modification and coupling assembly errors is proposed,and mesh stiffness calculated by proposed method is verified by MASTA software.Secondly,based on neural network,the surrogate model(SM)that maps the relationship between modification parameters and mesh mechanical parameters is established,and its accuracy is verified.Finally,SM is introduced to establish an optimization model with the target of minimizing mesh stiffness variations and obtaining more even load distribution on mesh surface.The results show that even considering training time,the efficiency of gear pair optimization by surrogate model is still much higher than that by LTCA method.After optimization,the mesh stiffness fluctuation of gear pair with coupling assembly error is reduced by 34.10%,and difference in average contact stresses between left and right regions of the mesh surface is reduced by 62.84%.展开更多
As one of the important wintering areas along the East Asian-Australasian Flyway,wetlands in the Yangtze River floodplain face threats from land-use changes,yet its effects on wintering waterbirds at the landscape lev...As one of the important wintering areas along the East Asian-Australasian Flyway,wetlands in the Yangtze River floodplain face threats from land-use changes,yet its effects on wintering waterbirds at the landscape level remain understudied,impeding conservation practice.Here,using survey data collected across 14 inland lakes in Jiangsu Province in 2022,we calculated wintering waterbirds diversity(taxonomic,functional,phylogenetic)and assembly patterns(MPD/MNTD of functional and phylogenetic).Then,we interpreted satellite imagery of lake areas and buffer zones(5 km),and partitioned them into three land-use and landscape index categories(anthropogenic,ecological,and lake landscape).Finally,we employed multiple linear regression and hierarchical partitioning to explain the influence of landscape scales on wintering waterbird communities.Our results showed that the diversity and assembly of regional wintering waterbird communities tended to be consistent across taxonomic,functional,and phylogenetic dimensions.The standardized diversity indices indicated that functional assembly of communities tends to be clustered at both local and regional scale.In contrast,the phylogenetic structure showed a predominantly overdispersed pattern in most lakes at the local scale,while neutral processes dominated at the regional scale.Modeling showed that selected variables explained waterbird diversity and assembly well.Lake fragmentation increased species evenness but reduced other diversity indices,while landscape evenness was negatively associated with functional and phylogenetic assembly.Among anthropogenic factors,aquaculture ponds and impervious surfaces reduced all diversity dimensions,whereas cropland connectivity enhanced phylogenetic diversity.These factors had consistent effects on community assembly.For ecological variables,grassland area enhanced functional and phylogenetic diversity but led to more clustered functional assembly.Overall,maintaining the integrity and connectivity of lakes and their surrounding landscapes is essential for sustaining waterbird diversity and guiding wetland restoration.展开更多
Biological nitrogen fixation(BNF)is a crucial process that provides bioavailable nitrogen and supports primary production in freshwater lake ecosystems.However,the characteristics of diazotrophic community and nitroge...Biological nitrogen fixation(BNF)is a crucial process that provides bioavailable nitrogen and supports primary production in freshwater lake ecosystems.However,the characteristics of diazotrophic community and nitrogenase activity in freshwater lake sediments remain poorly understood.Here,we investigated the diazotrophic communities and nitrogenase activities in the sediments of three large river-connected freshwater lakes in eastern China using 15N-isotope tracing and nifH sequencing.The sediments in these lakes contained diverse nitrogenase genes that were phylogenetically grouped into Clusters I and III.The diazotrophic communities in the sedimentswere dominated by stochastic processes in Hongze Lake and Taihu Lake,which had heterogeneous habitats and shallower water depths,while in Poyang Lake,which had deeper water and a shorter hydraulic retention time,the assembly of the diazotrophic community in the sediments was dominated by homogeneous selection processes.Temperature and water depth were also found the key environmental factors affecting the sediment diazotrophic communities.Sediment nitrogenase activities varied in the three lakes and within distinct regions of an individual lake,ranging from 0 to 14.58 nmol/(kg·hr).Nitrogenase activity was significantly correlated with ferric iron,total phosphorus,and organic matter contents.Our results suggested that freshwater lake sediment contain high diversity of nitrogen-fixing microorganisms with potential metabolic diversity,and the community assembly patterns and nitrogenase activities varied with the lake habitat.展开更多
Acoustic-vortex(AV)tweezers ensure stable particle trapping at a zero-pressure center,while particle assembly between two vortex cores is still prevented by the high-potential barrier.Although a one-dimensional low-pr...Acoustic-vortex(AV)tweezers ensure stable particle trapping at a zero-pressure center,while particle assembly between two vortex cores is still prevented by the high-potential barrier.Although a one-dimensional low-pressure attractive path of particle assembly can be constructed by the interference between two independent cylindrical Bessel beams,it remains challenging to create two-dimensional(2D)neighboring vortexes using a source array in practical applications.In this paper,a three-step phase-reversal strategy of 2D particle assembly based on the synchronized evolution of a centrosymmetric array of M off-axis acoustic vortexes(OA-AVs)with a preset radial offset is proposed based on a ring array of planar sources.By introducing initial vortex phase differences of-2π/M and+2π/M to the vortex array,low-pressure patterns of an M-sided regular polygon and M-branched star are formed by connecting the vortex cores and the field center before and after the tangent state of adjacent OA-AVs.Center-oriented particle assembly is finally realized by a central AV constructed by coincident in-phase OA-AVs.The capability of particle manipulation in the lateral and radial directions is demonstrated by low-pressure patterns with acoustic radiation forces pointing to the field center during a synchronized central approach.The field evolution is certified by experimental field measurements for OA-AVs with different vo rtex numbers,initial vortex phase differences,and radial offsets using a ring array of 16 planar sources.The feasibility of particle assembly in two dimensions is also verified by the accurate manipulation of four particles using the low-pressure patterns of a four-sided polygon,a four-branched star,and a central AV in experiments.The three-step strategy paves a new way for 2D particle assembly based on the synchronize d evolution of centrosymmetric OA-AVs using a simplified single-sided source array,exhibiting excellent potential for the precise navigation and manipulation of cells and particles in biomedical applications.展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.52005003)the Science and Technology Planning Project of Wuhu City(Grant No.2022jc41)。
文摘To address the challenges of insufficient visualization in the industrial robot assembly operation system and the limitation of visualizing only geometric attributes of physical properties,a method is proposed for constructing an industrial robot assembly system based on virtual reality technology.Focusing on the shaft hole assembly,the mechanical characteristics of the industrial robot shaft hole assembly process are analyzed and a dynamic model is established for shaft hole assembly operations.The key elements of virtual assembly operations for industrial robots are summarized and a five-dimensional model is proposed for industrial robot virtual operations.Utilizing the Unity3D engine based on the 5-D model for industrial robot virtual operations,an industrial robot shaft hole assembly system is developed.This system enables virtual assembly operations,displays physical attributes,and provides valuable references for the research of virtual systems.
文摘Despite the gradual transformation of traditional manufacturing by the Human-Robot Collaboration Assembly(HRCA),challenges remain in the robot’s ability to understand and predict human assembly intentions.This study aims to enhance the robot’s comprehension and prediction capabilities of operator assembly intentions by capturing and analyzing operator behavior and movements.We propose a video feature extraction method based on the Temporal Shift Module Network(TSM-ResNet50)to extract spatiotemporal features from assembly videos and differentiate various assembly actions using feature differences between video frames.Furthermore,we construct an action recognition and segmentation model based on the Refined-Multi-Scale Temporal Convolutional Network(Refined-MS-TCN)to identify assembly action intervals and accurately acquire action categories.Experiments on our self-built reducer assembly action dataset demonstrate that our network can classify assembly actions frame by frame,achieving an accuracy rate of 83%.Additionally,we develop a HiddenMarkovModel(HMM)integrated with assembly task constraints to predict operator assembly intentions based on the probability transition matrix and assembly task constraints.The experimental results show that our method for predicting operator assembly intentions can achieve an accuracy of 90.6%,which is a 13.3%improvement over the HMM without task constraints.
基金the National Key R&D Program of China(No.2021YFA1501503)the National Natural Science Foundation of China(Nos.22250008,22121004,22108197)+3 种基金the Haihe Laboratory of Sustainable Chemical Transformations(No.CYZC202107)the Natural Science Foundation of Tianjin City(No.21JCZXJC00060)the Program of Introducing Talents of Discipline to Universities(No.BP0618007)the Xplorer Prize for financial support。
文摘Membrane electrode assembly(MEA)is widely considered to be the most promising type of electrolyzer for the practical application of electrochemical CO_(2) reduction reaction(CO_(2)RR).In MEAs,a square-shaped cross-section in the flow channel is normally adopted,the configuration optimization of which could potentially enhance the performance of the electrolyzer.This paper describes the numerical simulation study on the impact of the flow-channel cross-section shapes in the MEA electrolyzer for CO_(2)RR.The results show that wide flow channels with low heights are beneficial to the CO_(2)RR by providing a uniform flow field of CO_(2),especially at high current densities.Moreover,the larger the electrolyzer,the more significant the effect is.This study provides a theoretical basis for the design of high-performance MEA electrolyzers for CO_(2)RR.
基金supported by the Yunnan Seed Laboratory,China(202205AR070001-15)the National Natural Science Foundation of China,China(Grant No.32160697)。
文摘Juglans sigillata is an economically valuable nut crop renowned for its nutritional richness,including essential nutrients,antioxidants,and healthy fats,which boost human cardial,brain and gut health.Despite its importance,the lack of a complete genome assembly has been a stumbling block in its biological breeding process.Therefore,we generated deep coverage ultralong Oxford Nanopore Technology(ONT)and PacBio HiFi reads to construct a telomere-to-telomere(T2T)genome assembly.The final assembly spans 537.27 Mb with no gaps,demonstrating a remarkable completeness of 98.1%.We utilized a combination of transcriptome data and homologous proteins to annotate the genome,identifying 36018 protein-coding genes.Furthermore,we profiled global cytosine DNA methylations using ONT sequencing data.Global methylome analysis revealed high methylation levels in transposable element(TE)-rich chromosomal regions juxtaposed with comparatively lower methylation in gene-rich areas.By integrating a detailed multi-omics data analysis,we obtained valuable insights into the mechanism underlying endopleura coloration.This investigation led to the identification of eight candidate genes(e.g.ANR)involved in anthocyanin biosynthesis pathways,which are crucial for the development of color in plants.The comprehensive genome assembly and the understanding of the genetic basis of important traits like endopleura coloration will open avenues for more efficient breeding programs and improved crop quality.
基金support from the Ministry of Higher Education Malaysia under grant HICOE-2023-005.
文摘A unitized regenerative fuel cell(URFC)is a device that may function reversibly as either a fuel cell(FC)or water elec-trolysis(WE).An important component of this device is the Membrane electrode assembly(MEA).Therefore,this study aimed to compare the performance outcomes of MEA using electrodes with single and three catalyst layers.This study measured Electrochemical Surface Area(ECSA),Electrochemical Impedance Spectroscopy(EIS),X-ray Diffraction analysis(XRD),and X-ray Fluorescence(XRF).Furthermore,the round-trip efficiency(RTE)of the MEA,as w ell as the performance in FC and WE mode,was measured.In comparison,The ECSA values of Pt-Ru/C and Pt/C with three catalyst layers were higher than the single catalyst layer.This result was supported by electrode characterization data for XRD and XRF.The respective electrical conductivity values of Pt-Ru/C and Pt/C with three catalyst layers are also higher than the single cata-lyst layer,and the performance of URFC using MEA with three catalyst layers has the highest value of RTE among the MEA performances of URFC,which is 100%at a current density of 4 mA·cm-2.
基金supported by the Natural Resources Science and Technology Innovation Project of Fujian Province,China(No.KY-090000-04-2022-012)the National Natural Science Foundation of China(Nos.42077041 and 42377301)+1 种基金the National Natural Science Foundation of Fujian Province,China(No.2021J011038)the Talent Introduction Program of Minjiang University,China(No.MJY20012).
文摘Soil microbiomes are significant for biodiversity,crucial for ecosystem functions,and vital for the health of various organisms.Nevertheless,the impacts of season and plant species shifts on soil microbial diversity and community assembly are still poorly understood.This study explored soil bacterial,fungal,and protistan communities during summer and winter in a coastal wetland affected by Spartina alterniflora invasion and subsequent Cyperus malaccensis or Kandelia obovata restoration.The results showed that bacterial,fungal,and protistan diversity were 2.63%,40.3%,and 9.90%higher in winter than in summer,respectively.Plant species had a distinct impact on microbial diversity.Notably,K.obovata restoration significantly increased bacterial diversity,but decreased protistan diversity,with no effect on fungal diversity when compared to S.alterniflora invasion.Season and plant species both significantly influenced the community structure of bacteria,fungi,and protists.However,protistan community structure was more sensitive to season compared to the structure of bacterial and fungal communities.The complexity of co-occurrence networks within or among bacteria,fungi,and protists was higher in winter than in summer.Bacterial and protistan community assembly was primarily driven by stochastic processes,while fungal assembly was dominated by deterministic processes.Bacterial and protistan community assembly exhibited lower stochasticity in winter compared to summer,suggesting a more deterministic assembly of communities during winter.Our findings highlight the critical role of season and plant species in regulating microbial communities,revealing higher microbial diversity,network complexity,and determinism in community assembly during winter compared to summer in a subtropical coastal wetland.
基金supported by the National Natural Science Foundation of China(Nos.22325111,2220312,21871298,91956118)Guangdong Basic Research Center of Excellence for Functional Molecular Engineeringthe Sun Yat-sen University。
文摘Molecular recognition of fullerene using various host compounds is well-known in literature.But most studies focus on host-vip complexation in solution using host compounds with a single binding cavity.Herein,we report a series of highly preorganized janusarene derivatives with homoditopic binding sites.These novel janusarenes can bind and align various fullerenes such as C_(60),C_(70),C_(84),and Gd@C_(82)in a highly efficient manner.Robust shape complementary association and assembly are observed in solution,in the bulk solid state,in the liquid crystalline state,or on surface,and the assembled structures are characterized by nuclear magnetic resonance(NMR)titration,X-ray diffraction,polarized optical microscopy,and scanning tunneling microscopy.
基金supported by the National Natural Science Foundation of China(32241045,32241046,32241038)the Major Special Science and Technology Projects in Shanxi Province(202101140601027)+3 种基金Shanxi Provincial Agricultural Key Technologies Breakthrough Project(NYGG01)Doctoral Research Starting Project at Shanxi Agricultural University(2024BQ77)the National Key Research and Development Program of China(2023YFD1202705/2023YFD120270503,2023YFD1202703/2023YFD1202703-4)Shanxi HouJi Laboratory Self-proposed Research Project(202304010930003/202304010930003-03).
文摘Common bean(Phaseolus vulgaris L.)is a vital source of protein and essential nutrients for human consumption and plays a key role in sustainable agriculture due to its nitrogen-fixing ability(Nadeem et al.,2021).Kidney beans,a subcategory of dry common beans,are highly valued for their rich protein,dietary fiber,low fat content,and various trace elements(Garcia-Cordero et al.,2021).Despite the release of several de novo genome assemblies(Goodstein et al.,2012;Schmutz et al.,2014;Vlasova et al.,2016;Cortinovis et al.,2024),existing common bean genomes remain incomplete,particularly in complex regions such as centromeres and telomeres,limiting a comprehensive understanding of the genomic landscape.
基金supported by the National Natural Science Foundation of China(No.22288101)the 111 Project(No.B17020)。
文摘Carbon dots(CDs)-based composites have shown impressive performance in fields of information encryption and sensing,however,a great challenge is to simultaneously implement multi-mode luminescence and room-temperature phosphorescence(RTP)detection in single system due to the formidable synthesis.Herein,a multifunctional composite of Eu&CDs@p RHO has been designed by co-assembly strategy and prepared via a facile calcination and impregnation treatment.Eu&CDs@p RHO exhibits intense fluorescence(FL)and RTP coming from two individual luminous centers,Eu3+in the free pores and CDs in the interrupted structure of RHO zeolite.Unique four-mode color outputs including pink(Eu^(3+),ex.254 nm),light violet(CDs,ex.365 nm),blue(CDs,254 nm off),and green(CDs,365 nm off)could be realized,on the basis of it,a preliminary application of advanced information encoding has been demonstrated.Given the free pores of matrix and stable RTP in water of confined CDs,a visual RTP detection of Fe^(3+)ions is achieved with the detection limit as low as 9.8μmol/L.This work has opened up a new perspective for the strategic amalgamation of luminous vips with porous zeolite to construct the advanced functional materials.
基金the Natural Science Foundation of Jilin Province(No.20230101052JC)the National Natural Science Foundation of China(No.52173200)Hangzhou Jingshi Technology Co.,Ltd.,and Hangzhou Xuhui Technology Co.,Ltd.for financial support。
文摘A renewable fluorescent material(GСCP5L)has been constructed via supramolecular assembly between a new derivative of pillararene,namely leggero pillar[5]arene,as the host molecule(CP5L)and a tetraphenylethylene(TPE)-based ditopic vip(G).This new material can simultaneously perform efficient detection and separation of silver(I)from aqueous environments.Possessing an electron-rich cavity and two cytosine groups modified on both rims,CP5L functions as the host-vip binding site for G and offers exclusive coordination sites for further interaction with Ag+.Adding Ag+to the system undergoes dramatic fluorescence enhancement due to the mechanism of supramolecular assembly-induced enhanced emission(SAIEE).This fluorescence enhancement allows for efficient and visualized detection following a“light-up”pattern,achieving a limit of detection(LOD)of 1.3×10^(-7)mol/L,which is fully in line with the World Health Organization's drinking water standard of 9×10^(-7)mol/L.In addition,GСCP5L also shows strong anti-interference capability against other cationic species.For the separation of Ag+from aqueous systems,GСCP5L displays exceptional adsorption efficiency(97%)and reliable recovery performance,demonstrating excellent recyclability after five experimental cycles without compromising its adsorption activity.
基金supported by the National Key Research and Development Program of China(No.2022YFD 1901601)the National Natural Science Foundation of China(No.42107360)the Fundamental Research Funds for the Central Universities,China(No.2452021032).
文摘phoD and pqqC gene occurrence in bacteria allows them to mobilize phosphorus(P)by mineralizing organic P(Po)and solubilizing inorganic P(Pi),respectively.Community characteristics of phoD-and pqqC-harboring bacteria(phoD-and pqqC-HB,respectively)mediate P cycling.However,whether the microbial community assembly and keystone taxa of phoD-and pqqC-HB regulate P availability and distinct regulatory pathways between these two genes remain unclear.In this study,soil microbial community characteristics and P availability were investigated in four long-term(38-year)fertilization regimes:control with no fertilizer(CK),P fertilizer(PF),nitrogen(N)and P fertilizers(NP),and N fertilizer,P fertilizer,and manure(NPM).The N addition treatments(NP and NPM)significantly changed the community composition and increased the abundances of phoD-and pqqC-HB compared to the no-N addition treatments(CK and PF).Stochastic processes dominated the community assembly of both phoD-and pqqC-HB,and the relative contributions of stochasticity increased with N addition.Furthermore,the N addition treatments resulted in greater network complexity and higher abundances of keystone taxa of phoD-and pqqC-HB compared to those of the no-N addition treatments.The keystone taxa implicated in P cycling were also associated with carbon(C)and N cycling processes.Microbial community composition and assembly processes were the main factors driving labile Pi for phoD-HB,whereas keystone taxa contributed the most to labile Pi for pqqC-HB.These results emphasize that distinct mechanisms of phoD-and pqqC-HB regulate P availability under fertilization management and underline the significance of microbial community assembly and keystone taxa in soil ecological functions,offering fresh perspectives on comprehending the biological processes facilitated by microorganisms in enhancing soil quality.
基金supported by grants from the National Natural Science Foundation of China for Excellent Young Scientists Fund Program(No.42222105)the National Natural Science Foundation of China General Program(No.42171144)+1 种基金the Assessment of Ecosystem Carbon Stock and Turnover Patterns in Qinghai Province(No.2021-SFA7-1-1)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(No.2021QZKK0100)。
文摘Bacterial communities play a crucial role in permafrost biogeochemical cycling and ecosystem function maintenance.Bacterial interaction is one of the main factors in shaping soil bacterial communities.However,how would bacterial interaction influence the bacterial communities in permafrost of the Qinghai-Tibet Plateau(QTP)remains largely unknown.Here we collected paired soil samples from both the active and permafrost layers of two typical QTP permafrost regions in October 2020 for Tuotuohe River(TTH)and May 2022 for Aerjin(ARJ),and investigated the bacterial communities and the role of interactions in structuring the bacterial community and its assembly process through amplicon sequencing of the 16S rRNA gene.Our study revealed distinct bacterial communities,with significant differences in the relative abundances of Proteobacteria(P<0.05),Acidobacteriota(P<0.001),Bacteroidota(P<0.05),and Planctomycetota(P<0.001)between the active layer and the permafrost layer.More importantly,we found that interspecies interactions,including both positive and negative associations,were strongly correlated with bacterial alpha-diversity and played a significant role in community variation and assembly process.Our findings also showed that the community assembly in both the active and permafrost layers was primarily driven by homogeneous selection of deterministic processes,with interspecies interactions accounting for more than 58%and 63%of all assembly mechanisms,respectively.This is the first study to quantify the contribution of bacterial interactions in shaping the bacterial community and its assembly process in permafrost of QTP,highlighting the importance of considering interspecies interactions in future modeling efforts.Our work also emphasizes the necessity of including interspecies interactions in microbial process projections to reduce uncertainty.
基金supported by the Educational Commission of Anhui Province of China(No.KJ2021A0168)the Research Fund of Anhui Agricultural University(No.rc422112).
文摘The environmental impacts of acid mine drainage(AMD)from open-pit mining are profoundly detrimental,yet knowledge about its effects on paddy soil microbial communities,especially at greater depths,remains limited.In this investigation,we compared soils affected by AMD versus unaffected soil depth profiles in terms of bacterial diversity and community assembly.The profiles in AMD-polluted soils exhibited tight geochemical gradients,characterized by increased acidity,SO_(4)^(2-),NO_(3)^(-),and heavy metal content compared to unpolluted soils.Notably,AMD significantly diminished soil bacterial biodiversity.A depthwise analysis showed distinct microbial stratification,with certain bacteria like Candidatus_Solibacter and Candidatus_Koribacter predominated in polluted soils,while others like Haliangium and Nitrospira were more prevalent in control soils.Interestingly,despite variable soil conditions,predictedmetabolic pathways,particularly those involving carbon,nitrogen,and sulfur,showed relative stability.AMD pollution induced the upregulation of methylcoenzyme M reductase and sulfate reductase genes.Bacterial communities were more responsive to pH and nutrient content rather than heavy metals,with pH and SO_(4)^(2-)being the primary drivers of microbial diversity and distribution.Additionally,pHwas identified as the most significant influence on the predicted methane,sulfur,and nitrogen metabolism.Furthermore,deterministic processes played a more significant role in community assembly of polluted soils,while heterogeneous selection gained importance with increasing depth in control soils.Additionally,microbial co-occurrences,particularly positive interactions,were more prevalent in the polluted soils with reduced network modularity and keystone taxa.These findings offer insights into sustaining microbial diversity in extreme environments.
基金funded by the Strategic Priority Research Program of Chinese Academy of Sciences (No. XDA28020202)the National Natural Science Foundation of China (No. 42277336)+3 种基金the Natural Science Foundation of Jiangsu Province, China (No. BK20221561)the China Agriculture Research System (Nos. CARS-03 and CARS52)the National Key Research and Development Program of China (No. 2022YFD1500401)the Jiangsu Agricultural Science and Technology Innovation Fund of China (No. CX(24)1003)。
文摘Diazotrophs make important contributions to nitrogen(N) inputs in agricultural ecosystems. However, strong evidence of the effects of conservation tillage(CT) on the coexistence and assembly of soil diazotrophic community and related mechanisms is lacking. Here, a long-term experiment was conducted to study the impacts of CT on the coexistence and assembly patterns of soil diazotrophic community in Lishu County, Jilin Province, North China. Compared to traditional tillage(control, CK), CT significantly reduced both the N fixation rate in top 0–10 cm soil and the alpha diversity of diazotrophic community while increasing the density of diazotrophic and overall bacterial communities. Conservation tillage also reduced the competitive relationships within the diazotrophic community and enhanced network stability. Furthermore, diazotroph assembly was dominated by deterministic processes(relative influence =68.63%) under CK and stochastic processes(relative influence = 58.82%) under CT. Soil depth and total N(TN) were identified as crucial predictors shaping the assembly processes of diazotrophic community under different tillage practices. The relative influence of stochastic processes on diazotrophic community under CT varied more significantly with increasing soil depth. Overall, tillage practice and soil depth had significant influences on the coexistence and assembly processes of soil diazotrophic community. Moreover, long-term CT may impact the selection of N fixation agents and the specific taxa associated with N fixers. Our results indicated that in CT systems, relatively sufficient nutrient availability led to a reduction in interspecies competition, an increase in network stability, and a greater influence of stochastic processes on community assembly. These findings may help us better understand biological N fixation in sustainable agricultural systems.
基金supported by the National Natural Science Foundation of China(No.42007428)the National Forage Industry Technology System Program of China(No.CARS34)+1 种基金the Key Research and Development Program of Shaanxi,China(No.2022SF-285)Shaanxi Province Forestry Science and Technology Innovation Program,China(No.SXLK2022-02-14)。
文摘Effective vegetation reconstruction plays a vital role in the restoration of desert ecosystems.However,in reconstruction of different vegetation types,the community characteristics,assembly processes,and functions of different soil microbial taxa under environmental changes are still disputed,which limits the understanding of the sustainability of desert restoration.Hence,we investigated the soil microbial community characteristics and functional attributes of grassland desert(GD),desert steppe(DS),typical steppe(TS),and artificial forest(AF)in the Mu Us Desert,China.Our findings confirmed the geographical conservation of soil microbial composition but highlighted decreased microbial diversity in TS.Meanwhile,the abundance of rare taxa and microbial community stability in TS improved.Heterogeneous and homogeneous selection determined the assembly of rare and abundant bacterial taxa,respectively,with both being significantly influenced by soil moisture.In contrast,fungal communities displayed stochastic processes and exhibited sensitivity to soil nutrient conditions.Furthermore,our investigation revealed a noteworthy augmentation in bacterial metabolic functionality in TS,aligning with improved vegetation restoration and the assemblage of abundant bacterial taxa.However,within nutrient-limited soils(GD,DS,and AF),the assembly dynamics of rare fungal taxa assumed a prominent role in augmenting their metabolic capacity and adaptability to desert ecosystems.These results highlighted the variations in the assembly processes and metabolic functions of soil microorganisms during vegetation reestablishment and provided corresponding theoretical support for anthropogenic revegetation of desert ecosystems.
基金Project(11972112)supported by the National Natural Science Foundation of ChinaProject(N2103024)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(J2019-IV-0018-0086)supported by the National Science and Technology Major Project,China。
文摘Gear assembly errors can lead to the increase of vibration and noise of the system,which affect the stability of system.The influence can be compensated by tooth modification.Firstly,an improved three-dimensional loaded tooth contact analysis(3D-LTCA)method which can consider tooth modification and coupling assembly errors is proposed,and mesh stiffness calculated by proposed method is verified by MASTA software.Secondly,based on neural network,the surrogate model(SM)that maps the relationship between modification parameters and mesh mechanical parameters is established,and its accuracy is verified.Finally,SM is introduced to establish an optimization model with the target of minimizing mesh stiffness variations and obtaining more even load distribution on mesh surface.The results show that even considering training time,the efficiency of gear pair optimization by surrogate model is still much higher than that by LTCA method.After optimization,the mesh stiffness fluctuation of gear pair with coupling assembly error is reduced by 34.10%,and difference in average contact stresses between left and right regions of the mesh surface is reduced by 62.84%.
基金funded by the National Natural Science Foundation of China(Grant No.42271116)。
文摘As one of the important wintering areas along the East Asian-Australasian Flyway,wetlands in the Yangtze River floodplain face threats from land-use changes,yet its effects on wintering waterbirds at the landscape level remain understudied,impeding conservation practice.Here,using survey data collected across 14 inland lakes in Jiangsu Province in 2022,we calculated wintering waterbirds diversity(taxonomic,functional,phylogenetic)and assembly patterns(MPD/MNTD of functional and phylogenetic).Then,we interpreted satellite imagery of lake areas and buffer zones(5 km),and partitioned them into three land-use and landscape index categories(anthropogenic,ecological,and lake landscape).Finally,we employed multiple linear regression and hierarchical partitioning to explain the influence of landscape scales on wintering waterbird communities.Our results showed that the diversity and assembly of regional wintering waterbird communities tended to be consistent across taxonomic,functional,and phylogenetic dimensions.The standardized diversity indices indicated that functional assembly of communities tends to be clustered at both local and regional scale.In contrast,the phylogenetic structure showed a predominantly overdispersed pattern in most lakes at the local scale,while neutral processes dominated at the regional scale.Modeling showed that selected variables explained waterbird diversity and assembly well.Lake fragmentation increased species evenness but reduced other diversity indices,while landscape evenness was negatively associated with functional and phylogenetic assembly.Among anthropogenic factors,aquaculture ponds and impervious surfaces reduced all diversity dimensions,whereas cropland connectivity enhanced phylogenetic diversity.These factors had consistent effects on community assembly.For ecological variables,grassland area enhanced functional and phylogenetic diversity but led to more clustered functional assembly.Overall,maintaining the integrity and connectivity of lakes and their surrounding landscapes is essential for sustaining waterbird diversity and guiding wetland restoration.
基金supported by the National Natural Science Foundation of China(Nos.51839011,42203079,and U2240208)the Carbon Peak/Neutralization Technology Innovation Project of Jiangsu Province,China(No.BK20220043)the Excellent Postdoctoral Project of Jiangsu Province,China(No.2022ZB452).
文摘Biological nitrogen fixation(BNF)is a crucial process that provides bioavailable nitrogen and supports primary production in freshwater lake ecosystems.However,the characteristics of diazotrophic community and nitrogenase activity in freshwater lake sediments remain poorly understood.Here,we investigated the diazotrophic communities and nitrogenase activities in the sediments of three large river-connected freshwater lakes in eastern China using 15N-isotope tracing and nifH sequencing.The sediments in these lakes contained diverse nitrogenase genes that were phylogenetically grouped into Clusters I and III.The diazotrophic communities in the sedimentswere dominated by stochastic processes in Hongze Lake and Taihu Lake,which had heterogeneous habitats and shallower water depths,while in Poyang Lake,which had deeper water and a shorter hydraulic retention time,the assembly of the diazotrophic community in the sediments was dominated by homogeneous selection processes.Temperature and water depth were also found the key environmental factors affecting the sediment diazotrophic communities.Sediment nitrogenase activities varied in the three lakes and within distinct regions of an individual lake,ranging from 0 to 14.58 nmol/(kg·hr).Nitrogenase activity was significantly correlated with ferric iron,total phosphorus,and organic matter contents.Our results suggested that freshwater lake sediment contain high diversity of nitrogen-fixing microorganisms with potential metabolic diversity,and the community assembly patterns and nitrogenase activities varied with the lake habitat.
基金funded by the National Nature Science Foundation of China(11934009,12174198,and 12227808)the Natural Science Foundation of Jiangsu Province,China(BE2022814)+2 种基金the Universal Technology for Primary and Secondary Schoolsthe National Research Institute for Teaching Materialsthe Qing Lan Project of Jiangsu Province,China。
文摘Acoustic-vortex(AV)tweezers ensure stable particle trapping at a zero-pressure center,while particle assembly between two vortex cores is still prevented by the high-potential barrier.Although a one-dimensional low-pressure attractive path of particle assembly can be constructed by the interference between two independent cylindrical Bessel beams,it remains challenging to create two-dimensional(2D)neighboring vortexes using a source array in practical applications.In this paper,a three-step phase-reversal strategy of 2D particle assembly based on the synchronized evolution of a centrosymmetric array of M off-axis acoustic vortexes(OA-AVs)with a preset radial offset is proposed based on a ring array of planar sources.By introducing initial vortex phase differences of-2π/M and+2π/M to the vortex array,low-pressure patterns of an M-sided regular polygon and M-branched star are formed by connecting the vortex cores and the field center before and after the tangent state of adjacent OA-AVs.Center-oriented particle assembly is finally realized by a central AV constructed by coincident in-phase OA-AVs.The capability of particle manipulation in the lateral and radial directions is demonstrated by low-pressure patterns with acoustic radiation forces pointing to the field center during a synchronized central approach.The field evolution is certified by experimental field measurements for OA-AVs with different vo rtex numbers,initial vortex phase differences,and radial offsets using a ring array of 16 planar sources.The feasibility of particle assembly in two dimensions is also verified by the accurate manipulation of four particles using the low-pressure patterns of a four-sided polygon,a four-branched star,and a central AV in experiments.The three-step strategy paves a new way for 2D particle assembly based on the synchronize d evolution of centrosymmetric OA-AVs using a simplified single-sided source array,exhibiting excellent potential for the precise navigation and manipulation of cells and particles in biomedical applications.
