More space truss construction has been planned to develop and utilize space resources.These trusses are designed in the way of large-scale,complex,modular,and on-orbit assembly.To meet the upcoming challenge of large-...More space truss construction has been planned to develop and utilize space resources.These trusses are designed in the way of large-scale,complex,modular,and on-orbit assembly.To meet the upcoming challenge of large-scale space infrastructure construction,it is necessary to study space truss automation design and robotic construction.This paper proposes an ordinal finite screw adjacency matrix model(OFSAMM),focusing on the relationship between assembly motions,to express and compute a space truss structure.In this model,a space truss is abstracted as a set of ordered assembly motions,each of which is recorded as a finite screw as the basic element of the truss and its assembly.The operation of truss transformation is also derived under this model.Therefore,the truss configuration,the assembly sequence,the truss sub-assembly,the truss components,and the on-orbit assembly task can be expressed and calculated in a unified model,which is calculated and stores the truss topology and assembly with the minimum storage cost.At the end of this paper,we introduce how to synthesize and optimize space truss design through two cases.The study will help to improve design efficiency.Furthermore,it provides a theoretical basis for the automatic construction of space truss structures,especially in the next stage.展开更多
With the increasing size of space facilities,on-orbit assembly requires robots to move on different heights of trusses.This paper proposes a bio-inspired attachment mechanism for robot feet to enable climbing on diffe...With the increasing size of space facilities,on-orbit assembly requires robots to move on different heights of trusses.This paper proposes a bio-inspired attachment mechanism for robot feet to enable climbing on different heights of trusses.Inspired by the attachment and grasping abilities of Dynastes Hercules,we utilize its foot microstructures,such as microhooks and setae,to achieve efficient contact and firm grip with the surface.The morphology and arrangement of these structures can inspire the design of robot feet to improve their grasping and stability performance.We study the biological structure of Dynastes Hercules,design and optimize the bio-inspired structure,analyze the influence of various factors from theoretical and experimental perspectives,and verify the feasibility of the scheme through simulation.We propose an ideal climbing strategy that provides useful reference for robot applications in practice.Moreover,the influence laws of various factors in this paper can be applied to robot foot design to improve their operation ability and stability performance in the space environment.This bio-inspired mechanism can improve robot working range and efficiency,which is critical for on-orbit assemblyin space.展开更多
An approach to sequence planning for on-orbit assembly of large space truss structures in a multirobot environment is presented. A hierarchical representation of large space truss structures at the structural volume e...An approach to sequence planning for on-orbit assembly of large space truss structures in a multirobot environment is presented. A hierarchical representation of large space truss structures at the structural volume element level and strut level is adopted. The representation of connectivity matrix and directed graph is respectively presented at the strut level and SVE level. The multirobot environment that consists of autonomous space robots and struts is supposed. Then the multirobot serial assembly strategy,assembly states,assembly tasks and assembly sequences are described. The assembly sequence planning algorithms at the strut level and SVE level are respectively discussed. The results of the simulations show that this approach is feasible and efficient. Two extensions of this approach include more accurate assessment of the efficiency representation and improvements in planning algorithm. In the future,the assembly sequence planning of more large space truss structures and complex multirobot environments and assembly tasks will be considered.展开更多
The coupling dynamics problem between the walking robot and large space structures during on-orbit assembly is investigated in this paper.The quadruped walking robot is first chosen as the assembly robot,which is equi...The coupling dynamics problem between the walking robot and large space structures during on-orbit assembly is investigated in this paper.The quadruped walking robot is first chosen as the assembly robot,which is equivalent to a spring-mass-damper system with seven degrees of freedom.The primary goal of the robot is to stably walk on a large space structure while carrying an assembly module to a designated location for assembly.Combining with the characteristic of incrementally increasing of the large space structure,a revival dynamic modeling method is then presented.On this basis,the coupled dynamic model of the robot and the space truss structure is developed.To simulate robot walking,the motion gait of the quadruped walking robot is designed as a diagonal alternating gait.The moving load are considered as disturbance inputs associated with the truss,and an active vibration controller is developed to deal with the disturbance.The numerical simulation of a quadruped walking robot moving on a space truss structure is finally presented with different cases.The results demonstrate that the quadruped walking robot movement has a significant influence on the space truss structure,and the mutual disturbances between the two are effectively suppressed by the proposed controller.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
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
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
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
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
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
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
Cellular spheroids,closely resembling native tissue microenvironments,have emerged as pivotal constructs in biomedicine as they can facilitate complex cell-cell and cell-matrix interactions.However,current methods for...Cellular spheroids,closely resembling native tissue microenvironments,have emerged as pivotal constructs in biomedicine as they can facilitate complex cell-cell and cell-matrix interactions.However,current methods for constructing spheroid assembloids with spatial arrangement or heterogeneous structures are limited,which has become a barrier for studying tissue engineering and in vitro disease modeling.Here,we demonstrate an acoustofluidic pick-and-place operation system capable of spatially assembling of spheroids into desired patterns in both two dimensional(2D)and three dimensional(3D)spaces.The underlying physical mechanism of the device is systematically studied to explain the interrelationship between trapping cell spheroids,acoustic streaming,and the acoustic radiation force(ARF)induced by the acoustically activated microneedle.We exploit these mechanisms to successfully transfer cellular spheroids into hydrogel solutions,enabling them to be precisely patterned and fused into assembloids of predefined shapes.Besides,we demonstrate arranging MC3T3-E1 cellular spheroids into a ring shape to fabricate the osteogenic tissues.Besides,a co-culture model involving tumor cells(MCF-7)and normal human dermal fibroblasts(NHDFs)is constructed to validate our method’s ability to reconstruct heterogeneous tumor model,revealing that the fibroblast spheroids promote tumor spheroid invasion.Our method holds significant potential prospects in regenerative medicine,disease model construction and drug screening.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
The buckling-guided three-dimensional(3D)assembly method has arisen increasing attention for its advantages in forming complex 3D architectures with a rich diversity of geometric shapes in a broad spectrum of inorgani...The buckling-guided three-dimensional(3D)assembly method has arisen increasing attention for its advantages in forming complex 3D architectures with a rich diversity of geometric shapes in a broad spectrum of inorganic functional materials.Such an assembly method relies on the controlled lateral bucking of a 2D precursor structure integrated with a pre-stretched substrate at selective regions.In the assembly process,the preservation or break-ing of rotational symmetry is crucial for understanding the mechanism of 2D-to-3D geometric transformation.Here,we present a fundamental study on the rotational symmetry of 3D spoke double-ring structures formed through buckling-guided assembly.An energetic method is introduced to analyze the rotational symmetry and to understand the symmetry-breaking mechanism.Such symmetry-breaking phenomenon is validated by experi-ments and finite element analyses(FEA).Phase diagrams of the deformation mode are established to shed light on the influences of various geometric parameters(e.g.,initial rotational symmetry order,radius ratio,and lo-cation of bonding sites).This work offers new insights into the underlying mechanism of 2D-to-3D geometric transformation in ribbon-type structures formed by compressive buckling.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
Black phosphorus(BP),as a rising star of 2D nanomaterials has drawn considerable attention in cancer therapy.However,the poor stability under ambient conditions limits their practical applications.Herein,a multiple su...Black phosphorus(BP),as a rising star of 2D nanomaterials has drawn considerable attention in cancer therapy.However,the poor stability under ambient conditions limits their practical applications.Herein,a multiple supramolecular assembly composed of adamantane-modified hyaluronic acid(HAADA),ferrocene-modified cinnamaldehyde(Fc-CA),guanidinium-functionalizedβ-cyclodextrin(Guano-CD),and black phosphorus(BP)nanosheets was successfully fabricated through cooperative host-vip and electrostatic interactions.Owing to the cooperative contribution of these building blocks,the obtained supramolecular assembly simultaneously possesses multiple functions including excellent stability,good biocompatibility and targeting property,and a high inhibition effect toward cancer cells.We believe that this work might provide new insights into designing a new generation of cancer theranostic protocols for potential clinical applications.展开更多
In response to the deficiencies of commonly used optimization methods for assembly lines,a production demand-oriented optimization method for assembly lines is proposed.Taking a certain compressor assembly line as an ...In response to the deficiencies of commonly used optimization methods for assembly lines,a production demand-oriented optimization method for assembly lines is proposed.Taking a certain compressor assembly line as an example,the production rhythm and the number of workstations are calculated based on production requirements and working systems.With assembly rhythm and smoothing index as optimization goals,an improved particle swarm optimization algorithm is employed for process allocation.Subsequently,Flexsim simulation is used to analyze the assembly line.The final results show that after optimization using the improved particle swarm algorithm,the assembly line balance rate increased from 71.1%to 85.9%,and the assembly line smoothing index decreased from 47.4 to 29.8,significantly enhancing assembly efficiency.This demonstrates the effectiveness of the proposed optimization method for the assembly line and provides a reference for other products in the same industry.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
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
基金financial support under the Manned Aerospace Research Project(Grant No.040102)。
文摘More space truss construction has been planned to develop and utilize space resources.These trusses are designed in the way of large-scale,complex,modular,and on-orbit assembly.To meet the upcoming challenge of large-scale space infrastructure construction,it is necessary to study space truss automation design and robotic construction.This paper proposes an ordinal finite screw adjacency matrix model(OFSAMM),focusing on the relationship between assembly motions,to express and compute a space truss structure.In this model,a space truss is abstracted as a set of ordered assembly motions,each of which is recorded as a finite screw as the basic element of the truss and its assembly.The operation of truss transformation is also derived under this model.Therefore,the truss configuration,the assembly sequence,the truss sub-assembly,the truss components,and the on-orbit assembly task can be expressed and calculated in a unified model,which is calculated and stores the truss topology and assembly with the minimum storage cost.At the end of this paper,we introduce how to synthesize and optimize space truss design through two cases.The study will help to improve design efficiency.Furthermore,it provides a theoretical basis for the automatic construction of space truss structures,especially in the next stage.
基金supported in part by the National Nature Science Foundation of China[No.62073229]Jiangsu Policy Guidance Program(International Science and Technology Cooperation)The Belt and Road Initiative Innovative Cooperation Projects(No.BZ2021016)EDL fund of Beijing Institute of Space Mechanics and Electricity(Grant No.EDL19092127).
文摘With the increasing size of space facilities,on-orbit assembly requires robots to move on different heights of trusses.This paper proposes a bio-inspired attachment mechanism for robot feet to enable climbing on different heights of trusses.Inspired by the attachment and grasping abilities of Dynastes Hercules,we utilize its foot microstructures,such as microhooks and setae,to achieve efficient contact and firm grip with the surface.The morphology and arrangement of these structures can inspire the design of robot feet to improve their grasping and stability performance.We study the biological structure of Dynastes Hercules,design and optimize the bio-inspired structure,analyze the influence of various factors from theoretical and experimental perspectives,and verify the feasibility of the scheme through simulation.We propose an ideal climbing strategy that provides useful reference for robot applications in practice.Moreover,the influence laws of various factors in this paper can be applied to robot foot design to improve their operation ability and stability performance in the space environment.This bio-inspired mechanism can improve robot working range and efficiency,which is critical for on-orbit assemblyin space.
文摘An approach to sequence planning for on-orbit assembly of large space truss structures in a multirobot environment is presented. A hierarchical representation of large space truss structures at the structural volume element level and strut level is adopted. The representation of connectivity matrix and directed graph is respectively presented at the strut level and SVE level. The multirobot environment that consists of autonomous space robots and struts is supposed. Then the multirobot serial assembly strategy,assembly states,assembly tasks and assembly sequences are described. The assembly sequence planning algorithms at the strut level and SVE level are respectively discussed. The results of the simulations show that this approach is feasible and efficient. Two extensions of this approach include more accurate assessment of the efficiency representation and improvements in planning algorithm. In the future,the assembly sequence planning of more large space truss structures and complex multirobot environments and assembly tasks will be considered.
基金supported by the National Natural Science Foundation of China(grant numbers 12472049,12232015)Guangdong Basic and Applied Basic Research Foundation(2024A1515010634).
文摘The coupling dynamics problem between the walking robot and large space structures during on-orbit assembly is investigated in this paper.The quadruped walking robot is first chosen as the assembly robot,which is equivalent to a spring-mass-damper system with seven degrees of freedom.The primary goal of the robot is to stably walk on a large space structure while carrying an assembly module to a designated location for assembly.Combining with the characteristic of incrementally increasing of the large space structure,a revival dynamic modeling method is then presented.On this basis,the coupled dynamic model of the robot and the space truss structure is developed.To simulate robot walking,the motion gait of the quadruped walking robot is designed as a diagonal alternating gait.The moving load are considered as disturbance inputs associated with the truss,and an active vibration controller is developed to deal with the disturbance.The numerical simulation of a quadruped walking robot moving on a space truss structure is finally presented with different cases.The results demonstrate that the quadruped walking robot movement has a significant influence on the space truss structure,and the mutual disturbances between the two are effectively suppressed by the proposed controller.
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.
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.
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 National Natural Science Foundation of China(Grant No.12032015,12121002,and 12402062)Natural Science Foundation of Shanghai(Grant No.24ZR1434900)+4 种基金The Innovation Program of Shanghai Municipal Education Commission(Grant No.2019-01-07-00-02-E00030)Shanghai Pilot Program for Basic Research—Shanghai Jiao Tong University(Grant No.21TQ1400203)the Open Research Project Programme of the Science and Technology Development Fund(Grant No.006/2022/ALC)the Macao Centre for Research and Development in Advanced Materials(University of Macao)(Grant.No.MCRDAM-IAPME(UM)-2022-2024/ORP/002/2023)the Science and Technology Commission of Shanghai Municipality(Grant No.20DZ2220400).
文摘Cellular spheroids,closely resembling native tissue microenvironments,have emerged as pivotal constructs in biomedicine as they can facilitate complex cell-cell and cell-matrix interactions.However,current methods for constructing spheroid assembloids with spatial arrangement or heterogeneous structures are limited,which has become a barrier for studying tissue engineering and in vitro disease modeling.Here,we demonstrate an acoustofluidic pick-and-place operation system capable of spatially assembling of spheroids into desired patterns in both two dimensional(2D)and three dimensional(3D)spaces.The underlying physical mechanism of the device is systematically studied to explain the interrelationship between trapping cell spheroids,acoustic streaming,and the acoustic radiation force(ARF)induced by the acoustically activated microneedle.We exploit these mechanisms to successfully transfer cellular spheroids into hydrogel solutions,enabling them to be precisely patterned and fused into assembloids of predefined shapes.Besides,we demonstrate arranging MC3T3-E1 cellular spheroids into a ring shape to fabricate the osteogenic tissues.Besides,a co-culture model involving tumor cells(MCF-7)and normal human dermal fibroblasts(NHDFs)is constructed to validate our method’s ability to reconstruct heterogeneous tumor model,revealing that the fibroblast spheroids promote tumor spheroid invasion.Our method holds significant potential prospects in regenerative medicine,disease model construction and drug screening.
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 Natural Science Foundation of China(Grant Nos.12225206,11921002,and 12202233)the New Cornerstone Science Foundation through the XPLORER PRIZE,the Tsinghua National Laboratory for Information Science and Technology,a grant from the Institute for Guo Qiang,Tsinghua University(Grant No.2021GQG1009)。
文摘The buckling-guided three-dimensional(3D)assembly method has arisen increasing attention for its advantages in forming complex 3D architectures with a rich diversity of geometric shapes in a broad spectrum of inorganic functional materials.Such an assembly method relies on the controlled lateral bucking of a 2D precursor structure integrated with a pre-stretched substrate at selective regions.In the assembly process,the preservation or break-ing of rotational symmetry is crucial for understanding the mechanism of 2D-to-3D geometric transformation.Here,we present a fundamental study on the rotational symmetry of 3D spoke double-ring structures formed through buckling-guided assembly.An energetic method is introduced to analyze the rotational symmetry and to understand the symmetry-breaking mechanism.Such symmetry-breaking phenomenon is validated by experi-ments and finite element analyses(FEA).Phase diagrams of the deformation mode are established to shed light on the influences of various geometric parameters(e.g.,initial rotational symmetry order,radius ratio,and lo-cation of bonding sites).This work offers new insights into the underlying mechanism of 2D-to-3D geometric transformation in ribbon-type structures formed by compressive buckling.
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 Program for improving the Scientific Research Ability of Youth Teachers of Inner Mongolia Agricultural University(No.BR220140)the National Natural Science Foundation of China(No.52263013)+2 种基金the Natural Science Foundation of Inner Mongolia Autonomous Region(No.2021MS02023)the Grassland Talents program of Inner Mongolia Autonomous Regionthe Program of Higher-level Talents of Inner Mongolia Agricultural University(No.NDGCC2016-21)。
文摘Black phosphorus(BP),as a rising star of 2D nanomaterials has drawn considerable attention in cancer therapy.However,the poor stability under ambient conditions limits their practical applications.Herein,a multiple supramolecular assembly composed of adamantane-modified hyaluronic acid(HAADA),ferrocene-modified cinnamaldehyde(Fc-CA),guanidinium-functionalizedβ-cyclodextrin(Guano-CD),and black phosphorus(BP)nanosheets was successfully fabricated through cooperative host-vip and electrostatic interactions.Owing to the cooperative contribution of these building blocks,the obtained supramolecular assembly simultaneously possesses multiple functions including excellent stability,good biocompatibility and targeting property,and a high inhibition effect toward cancer cells.We believe that this work might provide new insights into designing a new generation of cancer theranostic protocols for potential clinical applications.
文摘In response to the deficiencies of commonly used optimization methods for assembly lines,a production demand-oriented optimization method for assembly lines is proposed.Taking a certain compressor assembly line as an example,the production rhythm and the number of workstations are calculated based on production requirements and working systems.With assembly rhythm and smoothing index as optimization goals,an improved particle swarm optimization algorithm is employed for process allocation.Subsequently,Flexsim simulation is used to analyze the assembly line.The final results show that after optimization using the improved particle swarm algorithm,the assembly line balance rate increased from 71.1%to 85.9%,and the assembly line smoothing index decreased from 47.4 to 29.8,significantly enhancing assembly efficiency.This demonstrates the effectiveness of the proposed optimization method for the assembly line and provides a reference for other products in the same industry.
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(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.
