In times of digitalisation, visual assistance systems in assembly are increasingly important. The design of these assembly systems needs to be highly complex to meet the requirements. Due to the increasing number of v...In times of digitalisation, visual assistance systems in assembly are increasingly important. The design of these assembly systems needs to be highly complex to meet the requirements. Due to the increasing number of variants in production processes, as well as shorter innovation and product life cycles, assistance systems should improve quality and reduce complexity of assembly processes. However, many large kitchen manufacturers still assemble kitchen cabinets manually, due to the high variety of components, such as rails and fittings. This paper focuses on the analysis and evaluation of virtual assistance systems to improve quality and usability in individualised kitchen cabinet assembly processes at a large German manufacturer. A solution is identified and detailed.展开更多
The controlled assembly of nanomaterials has demon-strated significant potential in advancing technological devices.However,achieving highly efficient and low-loss assembly technique for nanomate-rials,enabling the cr...The controlled assembly of nanomaterials has demon-strated significant potential in advancing technological devices.However,achieving highly efficient and low-loss assembly technique for nanomate-rials,enabling the creation of hierarchical structures with distinctive func-tionalities,remains a formidable challenge.Here,we present a method for nanomaterial assembly enhanced by ionic liquids,which enables the fabrication of highly stable,flexible,and transparent electrodes featuring an organized layered structure.The utilization of hydrophobic and non-volatile ionic liquids facilitates the production of stable interfaces with water,effectively preventing the sedimentation of 1D/2D nanomaterials assembled at the interface.Furthermore,the interfacially assembled nanomaterial monolayer exhibits an alternate self-climbing behavior,enabling layer-by-layer transfer and the formation of a well-ordered MXene-wrapped silver nanowire network film.The resulting composite film not only demonstrates exceptional photoelectric performance with a sheet resistance of 9.4Ωsq^(-1) and 93%transmittance,but also showcases remarkable environmental stability and mechanical flexibility.Particularly noteworthy is its application in transparent electromagnetic interference shielding materials and triboelectric nanogenerator devices.This research introduces an innovative approach to manufacture and tailor functional devices based on ordered nanomaterials.展开更多
There are lots of researches on fixture layout optimization for large thin-walled parts.Current researches focus on the positioning problem,i.e.,optimizing the positions of a constant number of fixtures.However,how to...There are lots of researches on fixture layout optimization for large thin-walled parts.Current researches focus on the positioning problem,i.e.,optimizing the positions of a constant number of fixtures.However,how to determine the number of fixtures is ignored.In most cases,the number of fixtures located on large thin-walled parts is determined based on engineering experience,which leads to huge fixture number and extra waste.Therefore,this paper constructs an optimization model to minimize the number of fixtures.The constraints are set in the optimization model to ensure that the part deformation is within the surface profile tolerance.In addition,the assembly gap between two parts is also controlled.To conduct the optimization,this paper develops an improved particle swarm optimization(IPSO)algorithm by integrating the shrinkage factor and adaptive inertia weight.In the algorithm,particles are encoded according to the fixture position.Each dimension of the particle is assigned to a sub-region by constraining the optional position range of each fixture to improve the optimization efficiency.Finally,a case study on ship curved panel assembly is provided to prove that our method can optimize the number of fixtures while meeting the assembly quality requirements.This research proposes a method to optimize the number of fixtures,which can reduce the number of fixtures and achieve deformation control at the same time.展开更多
Accurate genomic information is essential for advancing genetic breeding research in specific rice varieties.This study presented a gapless genome assembly of the indica rice cultivar Zhonghui 8015(ZH8015)using Pac Bi...Accurate genomic information is essential for advancing genetic breeding research in specific rice varieties.This study presented a gapless genome assembly of the indica rice cultivar Zhonghui 8015(ZH8015)using Pac Bio HiFi,Hi-C,and ONT(Oxford Nanopore Technologies)ultra-long sequencing technologies,annotating 43037 gene structures.Subsequently,utilizing this genome along with transcriptomic and metabolomic techniques,we explored ZH8015's response to brown planthopper(BPH)infestation.Continuous transcriptomic sampling indicated significant changes in gene expression levels around 48 h after BPH feeding.Enrichment analysis revealed particularly significant alterations in genes related to reactive oxygen species scavenging and cell wall formation.Metabolomic results demonstrated marked increases in levels of several monosaccharides,which are components of the cell wall and dramatic changes in flavonoid contents.Omics association analysis identified differentially expressed genes associated with key metabolites,shedding light on ZH8015's response to BPH infestation.In summary,this study constructed a reliable genome sequence resource for ZH8015,and the preliminary multi-omics results will guide future insect-resistant breeding research.展开更多
Hapalogenys analis(order Lobotiformes)is an economically and ecologically significant fish species.It is a typical sedentary rocky reef fish and is primarily found in the northern Pacific Ocean.Here,we used Hi-C and P...Hapalogenys analis(order Lobotiformes)is an economically and ecologically significant fish species.It is a typical sedentary rocky reef fish and is primarily found in the northern Pacific Ocean.Here,we used Hi-C and PacBio sequencing technique to assemble a high-quality,chromosome-level genome for this species.The 539 Mb genome had a contig N50 with a size of 3.43 Mb,while 755 contigs clustered into 24 chromosomal groups with an anchoring rate of 99.02%.Of the total genomic sequence,132.74Mb(24.39%)were annotated as repeat elements.A total of 21360 protein-coding genes were identified,of which 20787 genes(97.32%)were successfully annotated to public databases.The BUSCO evaluation indicated that 96.90%of the total orthologous genes were matched.The phylogenetic tree representing H.analis and 14 other bony fish species indicated that the H.analis genome contained 364 expanded gene families related to olfactory receptor activity,compared with the common ancestor of H.analis and Sciaenidae.Comparative genomic analysis further identified 3584 contracted gene families.Branch-site modeling identified 277 genes experiencing positive selection,which may facilitate the adaptation to rocky reef environments.The genome reported here is helpful for ecological and evolutionary studies of H.analis.展开更多
Proton exchange membrane fuel cell(PEMFC)is of paramount significance to the development of clean energy.The components of PEMFC are assembled using many pairs of nuts and bolts.The assembly champing bolt torque is cr...Proton exchange membrane fuel cell(PEMFC)is of paramount significance to the development of clean energy.The components of PEMFC are assembled using many pairs of nuts and bolts.The assembly champing bolt torque is critical to the electrochemical performance and mechanical stability of PEMFC.In this paper,a PEMFC with the threechannel serpentine flow field was used and studied.The different assembly clamping bolt torques were applied to the PEMFC in three uniform assembly bolt torque and six non-uniform assembly bolt torque conditions,respectively.And then,the electrochemical performance experiments were performed to study the effect of the assembly bolt torque on the electrochemical performance.The test results show that the assembly bolt torque significantly affected the electrochemical performance of the PEMFC.In uniform assembly bolt torque conditions,the maximal power density increased initially as the assembly bolt torque increased,and then decreased on further increasing the assembly torque.It existed the optimum assembly torque which was found to be 3.0 N·m in this work.In non-uniform assembly clamping bolt torque conditions,the optimum electrochemical performance appeared in the condition where the assembly torque of each bolt was closer to be 3.0 N·m.This could be due to the change of the contact resistance between the gas diffusion layer and bipolar plate and mass transport resistance for the hydrogen and oxygen towards the catalyst layers.This work could optimize the assembly force conditions and provide useful information for the practical PEMFC stack assembly.展开更多
Soybean(Glycine max)stands as a globally significant agricultural crop,and the comprehensive assembly of its genome is of paramount importance for unraveling its biological characteristics and evolutionary history.Nev...Soybean(Glycine max)stands as a globally significant agricultural crop,and the comprehensive assembly of its genome is of paramount importance for unraveling its biological characteristics and evolutionary history.Nevertheless,previous soybean genome assemblies have harbored gaps and incompleteness,which have constrained in-depth investigations into soybean.Here,we present Telomere-to-Telomere(T2T)assembly of the Chinese soybean cultivar Zhonghuang 13(ZH13)genome,termed ZH13-T2T,utilizing PacBio Hifi and ONT ultralong reads.We employed a multi-assembler approach,integrating Hifiasm,NextDenovo,and Canu,to minimize biases and enhance assembly accuracy.The assembly spans 1,015,024,879 bp,effectively resolving all 393 gaps that previously plagued the reference genome.Our annotation efforts identified 50,564 high-confidence protein-coding genes,707 of which are novel.ZH13-T2T revealed longer chromosomes,421 not-aligned regions(NARs),112 structure variations(SVs),and a substantial expansion of repetitive element compared to earlier assemblies.Specifically,we identified 25.67 Mb of tandem repeats,an enrichment of 5S and 48S rDNAs,and characterized their genotypic diversity.In summary,we deliver the first complete Chinese soybean cultivar T2T genome.The comprehensive annotation,along with precise centromere and telomere characterization,as well as insights into structural variations,further enhance our understanding of soybean genetics and evolution.展开更多
Adequate vascularization is a critical determinant for the successful construction and clinical implementation of complex organotypic tissue models. Currently, low cell and vessel density and insufficient vascular mat...Adequate vascularization is a critical determinant for the successful construction and clinical implementation of complex organotypic tissue models. Currently, low cell and vessel density and insufficient vascular maturation make vascularized organotypic tissue construction difficult,greatly limiting its use in tissue engineering and regenerative medicine. To address these limitations, recent studies have adopted pre-vascularized microtissue assembly for the rapid generation of functional tissue analogs with dense vascular networks and high cell density. In this article, we summarize the development of module assembly-based vascularized organotypic tissue construction and its application in tissue repair and regeneration, organ-scale tissue biomanufacturing, as well as advanced tissue modeling.展开更多
Tau protein is encoded by the microtubuleassociated protein tau(MAPT)gene and stabilizes microtubules in the neurons.Tau has unique biophysical properties that make it both highly water-soluble and positively charged....Tau protein is encoded by the microtubuleassociated protein tau(MAPT)gene and stabilizes microtubules in the neurons.Tau has unique biophysical properties that make it both highly water-soluble and positively charged.Although tau is an intrinsically disordered protein lacking defined secondary structures,it can acquire highly organized-sheet structures and stack into a filamentous inclusion such as a paired helical filament(PHF).展开更多
Sorghum(Sorghum bicolor(L.)Moench)is a world cereal crop used in China for producing Baijiu,a distilled spirit.We report a telomere-to-telomere genome assembly of the Baijiu cultivar Hongyingzi,HYZ-T2T,using ultralong...Sorghum(Sorghum bicolor(L.)Moench)is a world cereal crop used in China for producing Baijiu,a distilled spirit.We report a telomere-to-telomere genome assembly of the Baijiu cultivar Hongyingzi,HYZ-T2T,using ultralong reads.The 10 chromosome pairs contained 33,462 genes,of which 93%were functionally annotated.The 20 telomeres and 10 centromeric regions on the HYZ-T2T chromosomes were predicted and two consecutive large inversions on chromosome 2 were characterized.A 65-gene reconstruction of the metabolic pathway of tannins,the flavor substances in Baijiu,was performed and may advance the breeding of sorghum cultivars for Baijiu production.展开更多
The quality and aroma of strong-flavor Baijiu are mainly dependent on Daqu,pit mud(PM),and the interaction of both.However,little is known about how their combination patterns affect the microbiome and metabolome of Z...The quality and aroma of strong-flavor Baijiu are mainly dependent on Daqu,pit mud(PM),and the interaction of both.However,little is known about how their combination patterns affect the microbiome and metabolome of Zaopei,especially the metabolic function of rare taxa.Here,an experiment on industrial size was designed to assess the effects of 6 combinations(3 kinds of Daqu×2 kinds of PM)on the composition and assembly of different taxa,as well as the flavor profile.The results showed that Zaopei's microbiota was composed of a few abundant taxa and enormous rare taxa,and rare bacterial and abundant fungal subcommunities were significantly affected by combination patterns.The assembly processes of abundant/rare taxa and bacterial/fungal communities were distinct,and environmental changes mediated the balance between stochastic and deterministic processes in rare bacteria assembly.Furthermore,specific combination patterns improved the flavor quality of Zaopei by enhancing the interspecies interaction,which was closely related to rare taxa,especially rare bacteria.These findings highlighted that rare bacteria might be the keystone in involving community interaction and maintaining metabolic function,which provided a scientific foundation for better understanding and regulating the brewing microbiota from the viewpoint of microbial ecology.展开更多
As the take-off of China’s macro economy,as well as the rapid development of infrastructure construction,real estate industry,and highway logistics transportation industry,the demand for heavy vehicles is increasing ...As the take-off of China’s macro economy,as well as the rapid development of infrastructure construction,real estate industry,and highway logistics transportation industry,the demand for heavy vehicles is increasing rapidly,the competition is becoming increasingly fierce,and the digital transformation of the production line is imminent.As one of themost important components of heavy vehicles,the transmission front andmiddle case assembly lines have a high degree of automation,which can be used as a pilot for the digital transformation of production.To ensure the visualization of digital twins(DT),consistent control logic,and real-time data interaction,this paper proposes an experimental digital twin modeling method for the transmission front and middle case assembly line.Firstly,theDT-based systemarchitecture is designed,and theDT model is created by constructing the visualization model,logic model,and data model of the assembly line.Then,a simulation experiment is carried out in a virtual space to analyze the existing problems in the current assembly line.Eventually,some improvement strategies are proposed and the effectiveness is verified by a new simulation experiment.展开更多
As computer graphics technology continues to advance,Collision Detection(CD)has emerged as a critical element in fields such as virtual reality,computer graphics,and interactive simulations.CD is indispensable for ens...As computer graphics technology continues to advance,Collision Detection(CD)has emerged as a critical element in fields such as virtual reality,computer graphics,and interactive simulations.CD is indispensable for ensuring the fidelity of physical interactions and the realism of virtual environments,particularly within complex scenarios like virtual assembly,where both high precision and real-time responsiveness are imperative.Despite ongoing developments,current CD techniques often fall short in meeting these stringent requirements,resulting in inefficiencies and inaccuracies that impede the overall performance of virtual assembly systems.To address these limitations,this study introduces a novel algorithm that leverages the capabilities of a Backpropagation Neural Network(BPNN)to optimize the structural composition of the Hybrid Bounding Volume Tree(HBVT).Through this optimization,the research proposes a refined Hybrid Hierarchical Bounding Box(HHBB)framework,which is specifically designed to enhance the computational efficiency and precision of CD processes.The HHBB framework strategically reduces the complexity of collision detection computations,thereby enabling more rapid and accurate responses to collision events.Extensive experimental validation within virtual assembly environments reveals that the proposed algorithm markedly improves the performance of CD,particularly in handling complex models.The optimized HBVT architecture not only accelerates the speed of collision detection but also significantly diminishes error rates,presenting a robust and scalable solution for real-time applications in intricate virtual systems.These findings suggest that the proposed approach offers a substantial advancement in CD technology,with broad implications for its application in virtual reality,computer graphics,and related fields.展开更多
Currently, the electrochemical CO_(2) reduction reaction (CO_(2) RR) can realize the resource conversion of CO_(2) , which is a promising approach to carbon resource use. Important advancements have been made in explo...Currently, the electrochemical CO_(2) reduction reaction (CO_(2) RR) can realize the resource conversion of CO_(2) , which is a promising approach to carbon resource use. Important advancements have been made in exploring the CO_(2) RR performance and mechanism because of the rational design of electrolyzer systems, such as H-cells, flow cells, and catalysts. Considering the future development direction of this technology and large-scale application needs, membrane electrode assembly (MEA) systems can improve energy use efficiency and achieve large-scale CO_(2) conversion, which is considered the most promising technology for industrial applications. This review will concentrate on the research progress and present situation of the MEA component structure. This paper begins with the composition and construction of a gas diff usion electrode. Then, the application of ion-exchange membranes in MEA is introduced. Furthermore, the eff ects of pH and the anion and cation of the anolyte on MEA performance are explored. Additionally, we present the anode reaction type in MEA. Finally, the challenges in this field are summarized, and upcoming trends are projected. This review should offer researchers a clearer picture of MEA systems and provide important, timely, and valuable insights into rational electrolyzer design to facilitate further development of CO_(2) electrochemical reduction.展开更多
The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope capable of observing an energy range from 0.5 keV to 2 keV to study hot baryon evolution. In this paper, we report the latest progres...The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope capable of observing an energy range from 0.5 keV to 2 keV to study hot baryon evolution. In this paper, we report the latest progress in the design and construction of nested X-ray telescopes which were designed to use a three-stage conic-approximation type assembly to simplify the manufacturing process. The mirror substrate is made using the thermal glass slumping method, with mirrors characterized by a root-mean-square roughness of 0.3 nm, with expected high reflectivity and good thermal stability. We also discuss methods of telescope construction and conduct a deformation analysis of the manufactured mirror. The in situ measurement system program is developed to guide the telescope assembly process.展开更多
Mercury ion(Hg^(2+)),a highly noxious of heavy metalion,has detrimental effects on the ecological environment and human health.Herein,we have developed an exonuclease III(Exo III)assisted catalytic hairpin assembly fo...Mercury ion(Hg^(2+)),a highly noxious of heavy metalion,has detrimental effects on the ecological environment and human health.Herein,we have developed an exonuclease III(Exo III)assisted catalytic hairpin assembly formation of a trivalent G-quadruplex/hemin DNAzyme for colorimetric detection of Hg^(2+).A hairpin DNA(Hr)was designed with thymine-Hg^(2+)-thymine pairs that catalyzed by Exo III is prompted to happen upon binding Hg^(2+).A released DNA fragment triggers the catalytic assembly of other three hairpins(H1,H2,and H3)to form many trivalent G-quadruplex/hemin DNA enzymes for signal output.The developed sensor shows a dynamic range from 2 pM to 2μM,with an impressively low detection limit of 0.32 pM for Hg^(2+)detection.Such a sensor also has good selectivity toward Hg^(2+)detection in the presence of other common metal ions.This strategy shows the great potential for visual detection with portable type.展开更多
Kiwifruit is an economically and nutritionally important fruit crop with extremely high contents of vitamin C.However,the previously released versions of kiwifruit genomes all have a mass of unanchored or missing regi...Kiwifruit is an economically and nutritionally important fruit crop with extremely high contents of vitamin C.However,the previously released versions of kiwifruit genomes all have a mass of unanchored or missing regions.Here,we report a highly continuous and completely gap-free reference genome of Actinidia chinensis cv.‘Hongyang’,named Hongyang v4.0,which is the first to achieve two de novo haploid-resolved haplotypes,HY4P and HY4A.HY4P and HY4A have a total length of 606.1 and 599.6 Mb,respectively,with almost the entire telomeres and centromeres assembled in each haplotype.In comparison with Hongyang v3.0,the integrity and contiguity of Hongyang v4.0 is markedly improved by filling all unclosed gaps and correcting some misoriented regions,resulting in∼38.6–39.5 Mb extra sequences,which might affect 4263 and 4244 protein-coding genes in HY4P and HY4A,respectively.Furthermore,our gap-free genome assembly provides the first clue for inspecting the structure and function of centromeres.Globally,centromeric regions are characterized by higher-order repeats that mainly consist of a 153-bp conserved centromere-specific monomer(Ach-CEN153)with different copy numbers among chromosomes.Functional enrichment analysis of the genes located within centromeric regions demonstrates that chromosome centromeres may not only play physical roles for linking a pair of sister chromatids,but also have genetic features for participation in the regulation of cell division.The availability of the telomere-to-telomere and gap-free Hongyang v4.0 reference genome lays a solid foundation not only for illustrating genome structure and functional genomics studies but also for facilitating kiwifruit breeding and improvement.展开更多
A high-quality genome is the basis for studies on functional,evolutionary,and comparative genomics.The majority of attention has been paid to the solution of complex chromosome structures and highly repetitive sequenc...A high-quality genome is the basis for studies on functional,evolutionary,and comparative genomics.The majority of attention has been paid to the solution of complex chromosome structures and highly repetitive sequences,along with the emergence of a new‘telomere-to-telomere(T2T)assembly’era.However,the bioinformatic tools for the automatic construction and/or characterization of T2T genome are limited.Here,we developed a user-friendly web toolkit,quarTeT,which currently includes four modules:AssemblyMapper,GapFiller,TeloExplorer,and CentroMiner.First,AssemblyMapper is designed to assemble phased contigs into the chromosome-level genome by referring to a closely related genome.Then,GapFiller would endeavor to fill all unclosed gaps in a given genome with the aid of additional ultra-long sequences.Finally,TeloExplorer and CentroMiner are applied to identify candidate telomere and centromere as well as their localizations on each chromosome.These four modules can be used alone or in combination with each other for T2T genome assembly and characterization.As a case study,by adopting the entire modular functions of quarTeT,we have achieved the Actinidia chinensis genome assembly that is of a quality comparable to the reported genome Hongyang v4.0,which was assembled with the addition of manual handling.Further evaluation of CentroMiner by searching centromeres in Arabidopsis thaliana and Oryza sativa genomes showed that quarTeT is capable of identifying all the centromeric regions that have been previously detected by experimental methods.Collectively,quarTeT is an efficient toolkit for studies of large-scale T2T genomes and can be accessed at http://www.atcgn.com:8080/quarTeT/home.html without registration.展开更多
A fuel cell is an energy conversion device that can continuously input fuel and oxidant into the device through an electrochemical reaction to release electrical energy.Although noble metals show good activity in fuel...A fuel cell is an energy conversion device that can continuously input fuel and oxidant into the device through an electrochemical reaction to release electrical energy.Although noble metals show good activity in fuel cell-related electrochemical reactions,their ever-increasing price considerably hinders their industrial application.Improvement of atom utilization efficiency is considered one of the most effective strategies to improve the mass activity of catalysts,and this allows for the use of fewer catalysts,saving greatly on the cost.Thus,single-atom catalysts(SACs)with an atom utilization efficiency of 100%have been widely developed,which show remarkable performance in fuel cells.In this review,we will describe recent progress on the development of SACs for membrane electrode assembly of fuel cell applications.First,we will introduce several effective routes for the synthesis of SACs.The reaction mechanism of the involved reactions will also be introduced as it is highly determinant of the final activity.Then,we will systematically summarize the application of Pt group metal(PGM)and nonprecious group metal(non-PGM)catalysts in membrane electrode assembly of fuel cells.This review will offer numerous experiences for developing potential industrialized fuel cell catalysts in the future.展开更多
Spatial and environmental processes are two ecological processes that have attracted considerable attention in plant community assembly,depending on sampling scale and life history.However,the processes that determine...Spatial and environmental processes are two ecological processes that have attracted considerable attention in plant community assembly,depending on sampling scale and life history.However,the processes that determine community assembly have not been studied in the karst region of southwest China.In this study,a 25-ha(500 m×500 m)monitoring plot within the subtropical climax forest in the karst region was established and canonical correspondence analysis was used to reveal the effects of topography and soil on the spatial patterns of tree community assembly.Our study suggests that spatial processes dominate species composition and the combined effects of spatial and environmental processes play an important role.Overall interpretation rate increases with enlarging the sampling scale.However,the pattern of variation partitioning was similar in different life stages.Environmental variables significantly affected species composition at different sampling sizes and life histories and had a higher interpretation rate of species composition on larger s ampling sizes.Topographic wetness index was the most important variable to explain species composition of the environmental variables.These results suggest that it is necessary to consider the relative importance of environmental and spatial factors on community assembly to better understand,conserve,and manage subtropical karst forests.展开更多
文摘In times of digitalisation, visual assistance systems in assembly are increasingly important. The design of these assembly systems needs to be highly complex to meet the requirements. Due to the increasing number of variants in production processes, as well as shorter innovation and product life cycles, assistance systems should improve quality and reduce complexity of assembly processes. However, many large kitchen manufacturers still assemble kitchen cabinets manually, due to the high variety of components, such as rails and fittings. This paper focuses on the analysis and evaluation of virtual assistance systems to improve quality and usability in individualised kitchen cabinet assembly processes at a large German manufacturer. A solution is identified and detailed.
基金This work was supported by the National Natural Science Foundation of China(nos.21988102,and 22305026)the China Postdoctoral Science Foundation(2019M650433).
文摘The controlled assembly of nanomaterials has demon-strated significant potential in advancing technological devices.However,achieving highly efficient and low-loss assembly technique for nanomate-rials,enabling the creation of hierarchical structures with distinctive func-tionalities,remains a formidable challenge.Here,we present a method for nanomaterial assembly enhanced by ionic liquids,which enables the fabrication of highly stable,flexible,and transparent electrodes featuring an organized layered structure.The utilization of hydrophobic and non-volatile ionic liquids facilitates the production of stable interfaces with water,effectively preventing the sedimentation of 1D/2D nanomaterials assembled at the interface.Furthermore,the interfacially assembled nanomaterial monolayer exhibits an alternate self-climbing behavior,enabling layer-by-layer transfer and the formation of a well-ordered MXene-wrapped silver nanowire network film.The resulting composite film not only demonstrates exceptional photoelectric performance with a sheet resistance of 9.4Ωsq^(-1) and 93%transmittance,but also showcases remarkable environmental stability and mechanical flexibility.Particularly noteworthy is its application in transparent electromagnetic interference shielding materials and triboelectric nanogenerator devices.This research introduces an innovative approach to manufacture and tailor functional devices based on ordered nanomaterials.
基金Supported by National Natural Science Foundation of China(Grant No.52005371)Shanghai Pujiang Program of China(Grant No.2020PJD071)+1 种基金Shanghai Municipal Natural Science Foundation of China(Grant No.22ZR1463900)Fundamental Research Funds for the Central Universities of China.
文摘There are lots of researches on fixture layout optimization for large thin-walled parts.Current researches focus on the positioning problem,i.e.,optimizing the positions of a constant number of fixtures.However,how to determine the number of fixtures is ignored.In most cases,the number of fixtures located on large thin-walled parts is determined based on engineering experience,which leads to huge fixture number and extra waste.Therefore,this paper constructs an optimization model to minimize the number of fixtures.The constraints are set in the optimization model to ensure that the part deformation is within the surface profile tolerance.In addition,the assembly gap between two parts is also controlled.To conduct the optimization,this paper develops an improved particle swarm optimization(IPSO)algorithm by integrating the shrinkage factor and adaptive inertia weight.In the algorithm,particles are encoded according to the fixture position.Each dimension of the particle is assigned to a sub-region by constraining the optional position range of each fixture to improve the optimization efficiency.Finally,a case study on ship curved panel assembly is provided to prove that our method can optimize the number of fixtures while meeting the assembly quality requirements.This research proposes a method to optimize the number of fixtures,which can reduce the number of fixtures and achieve deformation control at the same time.
基金supported by the Chinese Academy of Agricultural Sciences Innovation Project(Grant No.CAASASTIP-2013CNRRI)Fundamental Research Funds for Central Public Welfare Research Institutes of Chinese Rice Research Institute(Grant No.CPSIBRF-CNRRI-202102)。
文摘Accurate genomic information is essential for advancing genetic breeding research in specific rice varieties.This study presented a gapless genome assembly of the indica rice cultivar Zhonghui 8015(ZH8015)using Pac Bio HiFi,Hi-C,and ONT(Oxford Nanopore Technologies)ultra-long sequencing technologies,annotating 43037 gene structures.Subsequently,utilizing this genome along with transcriptomic and metabolomic techniques,we explored ZH8015's response to brown planthopper(BPH)infestation.Continuous transcriptomic sampling indicated significant changes in gene expression levels around 48 h after BPH feeding.Enrichment analysis revealed particularly significant alterations in genes related to reactive oxygen species scavenging and cell wall formation.Metabolomic results demonstrated marked increases in levels of several monosaccharides,which are components of the cell wall and dramatic changes in flavonoid contents.Omics association analysis identified differentially expressed genes associated with key metabolites,shedding light on ZH8015's response to BPH infestation.In summary,this study constructed a reliable genome sequence resource for ZH8015,and the preliminary multi-omics results will guide future insect-resistant breeding research.
基金supported by the Province Key Research and Development Program of Zhejiang (No.2021C02047)the Special Projects of Zhejiang Provincial Science and Technology Department (Nos.HYS-CZ-004,HYS-CZ-202208)the‘San Nong Jiu Fang’Science and Technology Cooperation Project of Zhejiang Province (No.2022 SN JF073)。
文摘Hapalogenys analis(order Lobotiformes)is an economically and ecologically significant fish species.It is a typical sedentary rocky reef fish and is primarily found in the northern Pacific Ocean.Here,we used Hi-C and PacBio sequencing technique to assemble a high-quality,chromosome-level genome for this species.The 539 Mb genome had a contig N50 with a size of 3.43 Mb,while 755 contigs clustered into 24 chromosomal groups with an anchoring rate of 99.02%.Of the total genomic sequence,132.74Mb(24.39%)were annotated as repeat elements.A total of 21360 protein-coding genes were identified,of which 20787 genes(97.32%)were successfully annotated to public databases.The BUSCO evaluation indicated that 96.90%of the total orthologous genes were matched.The phylogenetic tree representing H.analis and 14 other bony fish species indicated that the H.analis genome contained 364 expanded gene families related to olfactory receptor activity,compared with the common ancestor of H.analis and Sciaenidae.Comparative genomic analysis further identified 3584 contracted gene families.Branch-site modeling identified 277 genes experiencing positive selection,which may facilitate the adaptation to rocky reef environments.The genome reported here is helpful for ecological and evolutionary studies of H.analis.
基金Supported by National Natural Science Foundation of China (Grant No.52275152)。
文摘Proton exchange membrane fuel cell(PEMFC)is of paramount significance to the development of clean energy.The components of PEMFC are assembled using many pairs of nuts and bolts.The assembly champing bolt torque is critical to the electrochemical performance and mechanical stability of PEMFC.In this paper,a PEMFC with the threechannel serpentine flow field was used and studied.The different assembly clamping bolt torques were applied to the PEMFC in three uniform assembly bolt torque and six non-uniform assembly bolt torque conditions,respectively.And then,the electrochemical performance experiments were performed to study the effect of the assembly bolt torque on the electrochemical performance.The test results show that the assembly bolt torque significantly affected the electrochemical performance of the PEMFC.In uniform assembly bolt torque conditions,the maximal power density increased initially as the assembly bolt torque increased,and then decreased on further increasing the assembly torque.It existed the optimum assembly torque which was found to be 3.0 N·m in this work.In non-uniform assembly clamping bolt torque conditions,the optimum electrochemical performance appeared in the condition where the assembly torque of each bolt was closer to be 3.0 N·m.This could be due to the change of the contact resistance between the gas diffusion layer and bipolar plate and mass transport resistance for the hydrogen and oxygen towards the catalyst layers.This work could optimize the assembly force conditions and provide useful information for the practical PEMFC stack assembly.
基金This work has been supported by the National Key Research and Development Program of China(2021YFF1200105)National Natural Science Foundation of China(62172125,62371161).
文摘Soybean(Glycine max)stands as a globally significant agricultural crop,and the comprehensive assembly of its genome is of paramount importance for unraveling its biological characteristics and evolutionary history.Nevertheless,previous soybean genome assemblies have harbored gaps and incompleteness,which have constrained in-depth investigations into soybean.Here,we present Telomere-to-Telomere(T2T)assembly of the Chinese soybean cultivar Zhonghuang 13(ZH13)genome,termed ZH13-T2T,utilizing PacBio Hifi and ONT ultralong reads.We employed a multi-assembler approach,integrating Hifiasm,NextDenovo,and Canu,to minimize biases and enhance assembly accuracy.The assembly spans 1,015,024,879 bp,effectively resolving all 393 gaps that previously plagued the reference genome.Our annotation efforts identified 50,564 high-confidence protein-coding genes,707 of which are novel.ZH13-T2T revealed longer chromosomes,421 not-aligned regions(NARs),112 structure variations(SVs),and a substantial expansion of repetitive element compared to earlier assemblies.Specifically,we identified 25.67 Mb of tandem repeats,an enrichment of 5S and 48S rDNAs,and characterized their genotypic diversity.In summary,we deliver the first complete Chinese soybean cultivar T2T genome.The comprehensive annotation,along with precise centromere and telomere characterization,as well as insights into structural variations,further enhance our understanding of soybean genetics and evolution.
文摘Adequate vascularization is a critical determinant for the successful construction and clinical implementation of complex organotypic tissue models. Currently, low cell and vessel density and insufficient vascular maturation make vascularized organotypic tissue construction difficult,greatly limiting its use in tissue engineering and regenerative medicine. To address these limitations, recent studies have adopted pre-vascularized microtissue assembly for the rapid generation of functional tissue analogs with dense vascular networks and high cell density. In this article, we summarize the development of module assembly-based vascularized organotypic tissue construction and its application in tissue repair and regeneration, organ-scale tissue biomanufacturing, as well as advanced tissue modeling.
基金supported by grants from the National Research Foundation of Korea (2021 R1A2C2008023,2020R1A5A 1019023RS-2023-00261784 to MJL2021R1/1A1A 01051245to JHL)。
文摘Tau protein is encoded by the microtubuleassociated protein tau(MAPT)gene and stabilizes microtubules in the neurons.Tau has unique biophysical properties that make it both highly water-soluble and positively charged.Although tau is an intrinsically disordered protein lacking defined secondary structures,it can acquire highly organized-sheet structures and stack into a filamentous inclusion such as a paired helical filament(PHF).
基金supported by the Scientific Research Project of Kweichow Moutai Liquor Co.,Ltd.(MTGF2023007)the National Natural Science Foundation of China(32160459,32172036)+2 种基金the Guizhou Natural Science Foundation of China(QKHJC[2023]YB169)the Innovation Capacity Building Project of Guizhou Scientific Institutions(QKFQ[2022]007])the Guizhou Academy of Agricultural Sciences Project(Guizhou Agricultural Germplasm Resources(2023)06)。
文摘Sorghum(Sorghum bicolor(L.)Moench)is a world cereal crop used in China for producing Baijiu,a distilled spirit.We report a telomere-to-telomere genome assembly of the Baijiu cultivar Hongyingzi,HYZ-T2T,using ultralong reads.The 10 chromosome pairs contained 33,462 genes,of which 93%were functionally annotated.The 20 telomeres and 10 centromeric regions on the HYZ-T2T chromosomes were predicted and two consecutive large inversions on chromosome 2 were characterized.A 65-gene reconstruction of the metabolic pathway of tannins,the flavor substances in Baijiu,was performed and may advance the breeding of sorghum cultivars for Baijiu production.
基金supported by the Cooperation Project of Luzhou Laojiao Co.,Ltd.Sichuan University (21H0997)。
文摘The quality and aroma of strong-flavor Baijiu are mainly dependent on Daqu,pit mud(PM),and the interaction of both.However,little is known about how their combination patterns affect the microbiome and metabolome of Zaopei,especially the metabolic function of rare taxa.Here,an experiment on industrial size was designed to assess the effects of 6 combinations(3 kinds of Daqu×2 kinds of PM)on the composition and assembly of different taxa,as well as the flavor profile.The results showed that Zaopei's microbiota was composed of a few abundant taxa and enormous rare taxa,and rare bacterial and abundant fungal subcommunities were significantly affected by combination patterns.The assembly processes of abundant/rare taxa and bacterial/fungal communities were distinct,and environmental changes mediated the balance between stochastic and deterministic processes in rare bacteria assembly.Furthermore,specific combination patterns improved the flavor quality of Zaopei by enhancing the interspecies interaction,which was closely related to rare taxa,especially rare bacteria.These findings highlighted that rare bacteria might be the keystone in involving community interaction and maintaining metabolic function,which provided a scientific foundation for better understanding and regulating the brewing microbiota from the viewpoint of microbial ecology.
基金supported by China National Heavy Duty Truck Group Co.,Ltd.(Grant No.YF03221048P)the Shanghai Municipal Bureau of Market Supervision and Administration(Grant No.2022-35)New Young TeachersResearch Start-Up Foundation of Shanghai Jiao Tong University(Grant No.22X010503668).
文摘As the take-off of China’s macro economy,as well as the rapid development of infrastructure construction,real estate industry,and highway logistics transportation industry,the demand for heavy vehicles is increasing rapidly,the competition is becoming increasingly fierce,and the digital transformation of the production line is imminent.As one of themost important components of heavy vehicles,the transmission front andmiddle case assembly lines have a high degree of automation,which can be used as a pilot for the digital transformation of production.To ensure the visualization of digital twins(DT),consistent control logic,and real-time data interaction,this paper proposes an experimental digital twin modeling method for the transmission front and middle case assembly line.Firstly,theDT-based systemarchitecture is designed,and theDT model is created by constructing the visualization model,logic model,and data model of the assembly line.Then,a simulation experiment is carried out in a virtual space to analyze the existing problems in the current assembly line.Eventually,some improvement strategies are proposed and the effectiveness is verified by a new simulation experiment.
文摘As computer graphics technology continues to advance,Collision Detection(CD)has emerged as a critical element in fields such as virtual reality,computer graphics,and interactive simulations.CD is indispensable for ensuring the fidelity of physical interactions and the realism of virtual environments,particularly within complex scenarios like virtual assembly,where both high precision and real-time responsiveness are imperative.Despite ongoing developments,current CD techniques often fall short in meeting these stringent requirements,resulting in inefficiencies and inaccuracies that impede the overall performance of virtual assembly systems.To address these limitations,this study introduces a novel algorithm that leverages the capabilities of a Backpropagation Neural Network(BPNN)to optimize the structural composition of the Hybrid Bounding Volume Tree(HBVT).Through this optimization,the research proposes a refined Hybrid Hierarchical Bounding Box(HHBB)framework,which is specifically designed to enhance the computational efficiency and precision of CD processes.The HHBB framework strategically reduces the complexity of collision detection computations,thereby enabling more rapid and accurate responses to collision events.Extensive experimental validation within virtual assembly environments reveals that the proposed algorithm markedly improves the performance of CD,particularly in handling complex models.The optimized HBVT architecture not only accelerates the speed of collision detection but also significantly diminishes error rates,presenting a robust and scalable solution for real-time applications in intricate virtual systems.These findings suggest that the proposed approach offers a substantial advancement in CD technology,with broad implications for its application in virtual reality,computer graphics,and related fields.
基金The financial assistance for this work was provided by the National Natural Science Foundation of China (Nos. 51773092, 21975124, 20210283, and 22109070)the Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure (No. SKL201911SIC).
文摘Currently, the electrochemical CO_(2) reduction reaction (CO_(2) RR) can realize the resource conversion of CO_(2) , which is a promising approach to carbon resource use. Important advancements have been made in exploring the CO_(2) RR performance and mechanism because of the rational design of electrolyzer systems, such as H-cells, flow cells, and catalysts. Considering the future development direction of this technology and large-scale application needs, membrane electrode assembly (MEA) systems can improve energy use efficiency and achieve large-scale CO_(2) conversion, which is considered the most promising technology for industrial applications. This review will concentrate on the research progress and present situation of the MEA component structure. This paper begins with the composition and construction of a gas diff usion electrode. Then, the application of ion-exchange membranes in MEA is introduced. Furthermore, the eff ects of pH and the anion and cation of the anolyte on MEA performance are explored. Additionally, we present the anode reaction type in MEA. Finally, the challenges in this field are summarized, and upcoming trends are projected. This review should offer researchers a clearer picture of MEA systems and provide important, timely, and valuable insights into rational electrolyzer design to facilitate further development of CO_(2) electrochemical reduction.
基金supported by National Key R&D Program of China (2022YFF0709101)China National Space Administration (D050104)National Natural Science Foundation of China (62105244 and U2030111)。
文摘The Hot Universe Baryon Surveyor (HUBS) mission will carry a nested X-ray telescope capable of observing an energy range from 0.5 keV to 2 keV to study hot baryon evolution. In this paper, we report the latest progress in the design and construction of nested X-ray telescopes which were designed to use a three-stage conic-approximation type assembly to simplify the manufacturing process. The mirror substrate is made using the thermal glass slumping method, with mirrors characterized by a root-mean-square roughness of 0.3 nm, with expected high reflectivity and good thermal stability. We also discuss methods of telescope construction and conduct a deformation analysis of the manufactured mirror. The in situ measurement system program is developed to guide the telescope assembly process.
基金Supported by The Science and Technology Project of General Administration of Quality Supervision,Inspection and Quarantine (2015IK126)The Science and Technology Project of Changsha City of Hunan Province of China (KQ1602124).
文摘Mercury ion(Hg^(2+)),a highly noxious of heavy metalion,has detrimental effects on the ecological environment and human health.Herein,we have developed an exonuclease III(Exo III)assisted catalytic hairpin assembly formation of a trivalent G-quadruplex/hemin DNAzyme for colorimetric detection of Hg^(2+).A hairpin DNA(Hr)was designed with thymine-Hg^(2+)-thymine pairs that catalyzed by Exo III is prompted to happen upon binding Hg^(2+).A released DNA fragment triggers the catalytic assembly of other three hairpins(H1,H2,and H3)to form many trivalent G-quadruplex/hemin DNA enzymes for signal output.The developed sensor shows a dynamic range from 2 pM to 2μM,with an impressively low detection limit of 0.32 pM for Hg^(2+)detection.Such a sensor also has good selectivity toward Hg^(2+)detection in the presence of other common metal ions.This strategy shows the great potential for visual detection with portable type.
基金supported by funds from the National Natural Science Foundation of China(31972474,90717110)Hubei Natural Science Fund for Distinguished Young Scholars(2020CFA062).
文摘Kiwifruit is an economically and nutritionally important fruit crop with extremely high contents of vitamin C.However,the previously released versions of kiwifruit genomes all have a mass of unanchored or missing regions.Here,we report a highly continuous and completely gap-free reference genome of Actinidia chinensis cv.‘Hongyang’,named Hongyang v4.0,which is the first to achieve two de novo haploid-resolved haplotypes,HY4P and HY4A.HY4P and HY4A have a total length of 606.1 and 599.6 Mb,respectively,with almost the entire telomeres and centromeres assembled in each haplotype.In comparison with Hongyang v3.0,the integrity and contiguity of Hongyang v4.0 is markedly improved by filling all unclosed gaps and correcting some misoriented regions,resulting in∼38.6–39.5 Mb extra sequences,which might affect 4263 and 4244 protein-coding genes in HY4P and HY4A,respectively.Furthermore,our gap-free genome assembly provides the first clue for inspecting the structure and function of centromeres.Globally,centromeric regions are characterized by higher-order repeats that mainly consist of a 153-bp conserved centromere-specific monomer(Ach-CEN153)with different copy numbers among chromosomes.Functional enrichment analysis of the genes located within centromeric regions demonstrates that chromosome centromeres may not only play physical roles for linking a pair of sister chromatids,but also have genetic features for participation in the regulation of cell division.The availability of the telomere-to-telomere and gap-free Hongyang v4.0 reference genome lays a solid foundation not only for illustrating genome structure and functional genomics studies but also for facilitating kiwifruit breeding and improvement.
基金This work was supported by funds from the National Natural Science Foundation of China(31972474,31471157)the Open Fund of State Key Laboratory of Tea Plant Biology and Utilization(SKLTOF20150103).
文摘A high-quality genome is the basis for studies on functional,evolutionary,and comparative genomics.The majority of attention has been paid to the solution of complex chromosome structures and highly repetitive sequences,along with the emergence of a new‘telomere-to-telomere(T2T)assembly’era.However,the bioinformatic tools for the automatic construction and/or characterization of T2T genome are limited.Here,we developed a user-friendly web toolkit,quarTeT,which currently includes four modules:AssemblyMapper,GapFiller,TeloExplorer,and CentroMiner.First,AssemblyMapper is designed to assemble phased contigs into the chromosome-level genome by referring to a closely related genome.Then,GapFiller would endeavor to fill all unclosed gaps in a given genome with the aid of additional ultra-long sequences.Finally,TeloExplorer and CentroMiner are applied to identify candidate telomere and centromere as well as their localizations on each chromosome.These four modules can be used alone or in combination with each other for T2T genome assembly and characterization.As a case study,by adopting the entire modular functions of quarTeT,we have achieved the Actinidia chinensis genome assembly that is of a quality comparable to the reported genome Hongyang v4.0,which was assembled with the addition of manual handling.Further evaluation of CentroMiner by searching centromeres in Arabidopsis thaliana and Oryza sativa genomes showed that quarTeT is capable of identifying all the centromeric regions that have been previously detected by experimental methods.Collectively,quarTeT is an efficient toolkit for studies of large-scale T2T genomes and can be accessed at http://www.atcgn.com:8080/quarTeT/home.html without registration.
基金National Natural Science Foundation of China,Grant/Award Numbers:22075203,22279079,21905179Guangdong Science and Technology Department Program,Grant/Award Number:2021QN02L252+1 种基金Shenzhen Science and Technology Department Program,Grant/Award Numbers:20220810133521001,20220809165014001Natural Science Foundation of SZU,Grant/Award Numbers:000002111605,000002112215。
文摘A fuel cell is an energy conversion device that can continuously input fuel and oxidant into the device through an electrochemical reaction to release electrical energy.Although noble metals show good activity in fuel cell-related electrochemical reactions,their ever-increasing price considerably hinders their industrial application.Improvement of atom utilization efficiency is considered one of the most effective strategies to improve the mass activity of catalysts,and this allows for the use of fewer catalysts,saving greatly on the cost.Thus,single-atom catalysts(SACs)with an atom utilization efficiency of 100%have been widely developed,which show remarkable performance in fuel cells.In this review,we will describe recent progress on the development of SACs for membrane electrode assembly of fuel cell applications.First,we will introduce several effective routes for the synthesis of SACs.The reaction mechanism of the involved reactions will also be introduced as it is highly determinant of the final activity.Then,we will systematically summarize the application of Pt group metal(PGM)and nonprecious group metal(non-PGM)catalysts in membrane electrode assembly of fuel cells.This review will offer numerous experiences for developing potential industrialized fuel cell catalysts in the future.
基金supported by the National Natural Science Foundation of China (42071073,31971487)Youth Innovation Promotion Association of the Chinese Academy of Sciences (2021366)+2 种基金Guangxi Key Research and Development Program (AB17129009)the Hechi Distinguished Expert Program to Fuping Zengthe Guangxi Bagui Scholarship Program to Dejun Li。
文摘Spatial and environmental processes are two ecological processes that have attracted considerable attention in plant community assembly,depending on sampling scale and life history.However,the processes that determine community assembly have not been studied in the karst region of southwest China.In this study,a 25-ha(500 m×500 m)monitoring plot within the subtropical climax forest in the karst region was established and canonical correspondence analysis was used to reveal the effects of topography and soil on the spatial patterns of tree community assembly.Our study suggests that spatial processes dominate species composition and the combined effects of spatial and environmental processes play an important role.Overall interpretation rate increases with enlarging the sampling scale.However,the pattern of variation partitioning was similar in different life stages.Environmental variables significantly affected species composition at different sampling sizes and life histories and had a higher interpretation rate of species composition on larger s ampling sizes.Topographic wetness index was the most important variable to explain species composition of the environmental variables.These results suggest that it is necessary to consider the relative importance of environmental and spatial factors on community assembly to better understand,conserve,and manage subtropical karst forests.