The level of automation in the manufacture of recreational aluminum boats is very low. Robotized welding is rarely utilized, although it is commonly considered as the most effective way to reduce costs and increase co...The level of automation in the manufacture of recreational aluminum boats is very low. Robotized welding is rarely utilized, although it is commonly considered as the most effective way to reduce costs and increase competitiveness. A reason for the under-exploitation of robotics can be found in the construction of aluminum boats;boat models and their detailed structures are almost without exception individual pieces. A new stiffener structure for an aluminum recreational boat hull is developed in this work. Construction of the stiffener as a module allows exploitation of the advantages of modularization. The number of different parts is reduced and the structure simplified improves the applicability of robotic welding and provides benefits accruing from mass production. The same module can be used in several boat models. The modularity also makes it possible to use the same advanced robot welding fixture for a variety of boat models.展开更多
Solid-state nanopores with controllable pore size and morphology have huge application potential.However,it has been very challenging to process sub-10 nm silicon nanopore arrays with high efficiency and high quality ...Solid-state nanopores with controllable pore size and morphology have huge application potential.However,it has been very challenging to process sub-10 nm silicon nanopore arrays with high efficiency and high quality at low cost.In this study,a method combining metal-assisted chemical etching and machine learning is proposed to fabricate sub-10 nm nanopore arrays on silicon wafers with various dopant types and concentrations.Through a SVM algorithm,the relationship between the nanopore structures and the fabrication conditions,including the etching solution,etching time,dopant type,and concentration,was modeled and experimentally verified.Based on this,a processing parameter window for generating regular nanopore arrays on silicon wafers with variable doping types and concentrations was obtained.The proposed machine-learning-assisted etching method will provide a feasible and economical way to process high-quality silicon nanopores,nanostructures,and devices.展开更多
Multispecies solid-state fermentation is a traditional processing technique for the traditional Chinese food,such as cereal vinegar,Baijiu,etc.Generally,few abundant and many rare microbes were involved in such proces...Multispecies solid-state fermentation is a traditional processing technique for the traditional Chinese food,such as cereal vinegar,Baijiu,etc.Generally,few abundant and many rare microbes were involved in such processes,and the necessity and roles of the latter are less studied.Here the co-occurrence patterns of abundant and rare bacterial community and abiotic factors infuencing their community assembly were investigated in acetic acid fermentation following starter inoculation,using Zhenjiang aromatic vinegar as a model system.Abundant taxa that contribute to the function of accumulating acid exhibited a ubiquitous distribution while the distribution of rare taxa along the fermentation process unraveled.The species composition of the rare taxa signifcantly altered,but abundant taxa were maintained after inoculation.Moreover,the diversity of rare taxa changed more signifcantly than that of abundant taxa.Both abundant and rare sub-communities,which were contributed more with species turnover than species richness,were demonstrated to be driven by pH,acetic acid,ammonium nitrogen,and ethanol.Stochastic processes regulated the assembly of both sub-communities,but more prominent on rare sub-communities.Co-occurrence network was more governed by rare sub-communities,and the co-variations between microbial communities were predominantly positive,implying that rare taxa played more important role in the fermentation stability and network robustness.Furthermore,seven network connectors were identifed,and three of them belonged to rare taxa.These microbes of diferent modules were enriched at particular phases of fermentation.These results demonstrate the ecological signifcance of rare bacteria and provide new insights into understanding the abiotic factors infuence microbial structure in traditional fermented foods.展开更多
文摘The level of automation in the manufacture of recreational aluminum boats is very low. Robotized welding is rarely utilized, although it is commonly considered as the most effective way to reduce costs and increase competitiveness. A reason for the under-exploitation of robotics can be found in the construction of aluminum boats;boat models and their detailed structures are almost without exception individual pieces. A new stiffener structure for an aluminum recreational boat hull is developed in this work. Construction of the stiffener as a module allows exploitation of the advantages of modularization. The number of different parts is reduced and the structure simplified improves the applicability of robotic welding and provides benefits accruing from mass production. The same module can be used in several boat models. The modularity also makes it possible to use the same advanced robot welding fixture for a variety of boat models.
基金supported by the National Natural Science Foundation of China[Grant Nos.51975127,U20A6004]the Guangdong-Hong Kong Technology Coopeartion[Grant No.GHP/112/19GD]from Hong Kong Innovation and Technology Commission+1 种基金Research and Development Program of Guangdong Province[Grant No.2020A0505140008]the Fund of Key-Area Research and Development Program of Guangdong Province[Grant No.2018B090906002]。
文摘Solid-state nanopores with controllable pore size and morphology have huge application potential.However,it has been very challenging to process sub-10 nm silicon nanopore arrays with high efficiency and high quality at low cost.In this study,a method combining metal-assisted chemical etching and machine learning is proposed to fabricate sub-10 nm nanopore arrays on silicon wafers with various dopant types and concentrations.Through a SVM algorithm,the relationship between the nanopore structures and the fabrication conditions,including the etching solution,etching time,dopant type,and concentration,was modeled and experimentally verified.Based on this,a processing parameter window for generating regular nanopore arrays on silicon wafers with variable doping types and concentrations was obtained.The proposed machine-learning-assisted etching method will provide a feasible and economical way to process high-quality silicon nanopores,nanostructures,and devices.
基金This work was supported by National Key R&D Program of China(2018YFC1603800 and 2018YFC1603802)Natural Science Foundation of China(NSFC)(No.31771967)We thank Jiangsu Hengshun Vinegar Industry Co,Ltd,for the samples provided.
文摘Multispecies solid-state fermentation is a traditional processing technique for the traditional Chinese food,such as cereal vinegar,Baijiu,etc.Generally,few abundant and many rare microbes were involved in such processes,and the necessity and roles of the latter are less studied.Here the co-occurrence patterns of abundant and rare bacterial community and abiotic factors infuencing their community assembly were investigated in acetic acid fermentation following starter inoculation,using Zhenjiang aromatic vinegar as a model system.Abundant taxa that contribute to the function of accumulating acid exhibited a ubiquitous distribution while the distribution of rare taxa along the fermentation process unraveled.The species composition of the rare taxa signifcantly altered,but abundant taxa were maintained after inoculation.Moreover,the diversity of rare taxa changed more signifcantly than that of abundant taxa.Both abundant and rare sub-communities,which were contributed more with species turnover than species richness,were demonstrated to be driven by pH,acetic acid,ammonium nitrogen,and ethanol.Stochastic processes regulated the assembly of both sub-communities,but more prominent on rare sub-communities.Co-occurrence network was more governed by rare sub-communities,and the co-variations between microbial communities were predominantly positive,implying that rare taxa played more important role in the fermentation stability and network robustness.Furthermore,seven network connectors were identifed,and three of them belonged to rare taxa.These microbes of diferent modules were enriched at particular phases of fermentation.These results demonstrate the ecological signifcance of rare bacteria and provide new insights into understanding the abiotic factors infuence microbial structure in traditional fermented foods.
