With in-depth development of the Internet of Things(IoT)in various industries,the informatization process of various industries has also entered the fast lane.This article aims to solve the supply chain process proble...With in-depth development of the Internet of Things(IoT)in various industries,the informatization process of various industries has also entered the fast lane.This article aims to solve the supply chain process problem in e-commerce,focusing on the specific application of Internet of Things technology in e-commerce.Warehousing logistics is an important link in today’s e-commerce transactions.This article proposes a distributed analysis method for RFID-based e-commerce warehousing process optimization and an e-commerce supply chain management process based on Internet of Things technology.This article first introduces the advantages and disadvantages of shared IoT identification technology and the IoT resource sharing platform based on the three-layer abstract data model and representational state transfer(REST)style.Combining actual IoT applications and the characteristics of an existing platform,a REST-based IoT resource sharing platform is proposed.Combined with actual projects,a REST-based IoT resource sharing platform was built,and key technology experiments were conducted for verification.Finally,optimizing the e-commerce supply chain management process under Internet of Things technology and explaining the advantages of optimized e-commerce supply chain management are discussed.Research on this subject provides a theoretical basis for the application of the Internet of Things in e-commerce and has practical significance and practical value for managing service capabilities and service levels in e-commerce.展开更多
[Objectives]This study was conducted to investigate the effect of compound fresh-keeping liquid on the browning and quality of fresh-cut yam during the cold chain process.[Methods]Under the simulated cold chain condit...[Objectives]This study was conducted to investigate the effect of compound fresh-keeping liquid on the browning and quality of fresh-cut yam during the cold chain process.[Methods]Under the simulated cold chain condition of 4℃,a uniform design(U6*(64))experiment was carried out to optimize the compound preservative formula,and a better compound preservative formula was obtained using the regression equation.[Results]The compound preservative formula was:AA 0.25%,CA 0.5%,Nisin 0.09%,GSH 0.15%.The compound fresh-keeping liquid effectively delayed the browning of fresh-cut yam and the accumulation of MDA,maintained the content of TSS,inhibited the activity of PAL and delayed the appearance of the maximum activity of POD and POD.[Conclusions]This study provides technical support for the actual extension of the shelf life of fresh-cut yam.展开更多
This paper presents a digital model for the powder metallurgical(PM)production chain of high-performance sintered gears based on an integrated computational materials engineering(ICME)platform.Discrete and finite elem...This paper presents a digital model for the powder metallurgical(PM)production chain of high-performance sintered gears based on an integrated computational materials engineering(ICME)platform.Discrete and finite element methods(DEM and FEM)were combined to describe the macroscopic material response to the thermomechanical loads and process conditions during the entire production process.The microstructural evolution during the sintering process was predicted on the meso-scale using a Monte-Carlo Model.The effective elastic properties were determined by a homogenization method based on modelling a representative volume element(RVE).The results were subsequently used for the FE modelling of the heat treatment process.Through the development of multi-scale models,it was possible obtain characteristics of the microstructural features.The predicted hardness and residual stress distributions allowed the calculation of the tooth root load bearing capacity of the heat-treated sintered gears.展开更多
Rotation sintering, also known as slush molding, is used to manufacture molded skins, such as dashboards or door interior panels for cars. At present, approximately 80% of such molded skins are manufactured using elec...Rotation sintering, also known as slush molding, is used to manufacture molded skins, such as dashboards or door interior panels for cars. At present, approximately 80% of such molded skins are manufactured using electroforms to achieve the complex free-form surfaces, and surface structures, such as leather graining that the industry demands. The manufacture of these electroforms is, however, time-consuming and expensive. This project aims to replace conventional electroforms with laser-drilled molds. Holes in tool molds should be drilled by using laser radiation as part of an automated process. The system consists of a robot with a fiber-laser beam source. A CAx (computer-aided x) process chain has been developed for this purpose in which the CAD (computer-aided design) data of the tool molds are processed, drill hole fields generated, and a machine-specific RC (robot control) program created. Process-specific fundamentals, such as suitable process windows and process control, have been devised to manufacture holes using fiber laser radiation The advantages of the new laser-drilled tool molds may result in substituting them for conventional electroforms, allowing old markets to be re-entered or additional markets to be created and targeted through new molds or lower costs.展开更多
The final quality of complex conical-section rings depends on co-design of multiple processes in forming process chain.In this study,for a complex aeroengine casing ring with a large slope and a flange on its end,a co...The final quality of complex conical-section rings depends on co-design of multiple processes in forming process chain.In this study,for a complex aeroengine casing ring with a large slope and a flange on its end,a co-design method of the forming process chain is put forward towards the objective of precision forming,which not only proposes a standard process route composed of multiple processes of upsetting,punching,rectangular ring rolling,loose tooling forging and profiled ring rolling,but also presents co-design methods of dies and blanks for all the processes.For profiled ring rolling,a design method of preformed blank that makes the blank and the target conical-section ring have the same axial volume distribution is proposed.By the method,the axial metal redistribution during the process can be alleviated greatly thus improving the forming stability and precision of the ring.Based on the geometric features of designed preformed blank,design methods of blanks and dies for loose tolling forging,rectangular ring rolling,punching and upsetting are proposed sequentially.In view of the key roles of loose tooling forging(manufacturing the preformed blank)and profiled ring rolling on the final quality of the conical ring parts,inherited FE simulations for these two processes are performed to verify the proposed design methods and determine appropriate design parameter.It is demonstrated that the proposed design method has significant advantages in improving forming precision.Besides,a suggestive value 1.5 of the rolling ratio for profiled ring rolling(a key design parameter)is given based on comprehensive consideration of multiple indicators such as ring roundness,deformation uniformity and forming load.The corresponding industrial experiments performed illustrate that a high forming precision of the conical-section aeroengine casing ring is achieved.展开更多
This paper discusses an organizational model to be used for both conventional and virtual organizations. The model deals with variable relationships within an organization and provides a framework for overall organiza...This paper discusses an organizational model to be used for both conventional and virtual organizations. The model deals with variable relationships within an organization and provides a framework for overall organizational design that may include relationship among different design variables and external relationship with environment. Based on the researches of virtual organization, this paper also illustrates the new model of organization in the real world such as Beijing 2008 Olympic games and Dongfeng Automobile group.展开更多
All known results on large deviations of occupation measures of Markov processes are based on the assumption of (essential) irreducibility. In this paper we establish the weak* large deviation principle of occupati...All known results on large deviations of occupation measures of Markov processes are based on the assumption of (essential) irreducibility. In this paper we establish the weak* large deviation principle of occupation measures for any countable Markov chain with arbitrary initial measures. The new rate function that we obtain is not convex and depends on the initial measure, contrary to the (essentially) irreducible case.展开更多
Residual processing defects during the contact processing processes greatly reduce the anti-ultraviolet(UV)laser damage performance of fused silica optics,which significantly limited development of high-energy laser s...Residual processing defects during the contact processing processes greatly reduce the anti-ultraviolet(UV)laser damage performance of fused silica optics,which significantly limited development of high-energy laser systems.In this study,we demonstrate the manufacturing of fused silica optics with a high damage threshold using a CO_(2)laser process chain.Based on theoretical and experimental studies,the proposed uniform layer-by-layer laser ablation technique can be used to characterize the subsurface mechanical damage in three-dimensional full aperture.Longitudinal ablation resolutions ranging from nanometers to micrometers can be realized;the minimum longitudinal resolution is<5 nm.This technique can also be used as a crack-free grinding tool to completely remove subsurface mechanical damage,and as a cleaning tool to effectively clean surface/subsurface contamination.Through effective control of defects in the entire chain,the laser-induced damage thresholds of samples fabricated by the CO_(2)laser process chain were 41%(0%probability)and 65.7%(100%probability)higher than those of samples fabricated using the conventional process chain.This laser-based defect characterization and removal process provides a new tool to guide optimization of the conventional finishing process and represents a new direction for fabrication of highly damage-resistant fused silica optics for high-energy laser applications.展开更多
文摘With in-depth development of the Internet of Things(IoT)in various industries,the informatization process of various industries has also entered the fast lane.This article aims to solve the supply chain process problem in e-commerce,focusing on the specific application of Internet of Things technology in e-commerce.Warehousing logistics is an important link in today’s e-commerce transactions.This article proposes a distributed analysis method for RFID-based e-commerce warehousing process optimization and an e-commerce supply chain management process based on Internet of Things technology.This article first introduces the advantages and disadvantages of shared IoT identification technology and the IoT resource sharing platform based on the three-layer abstract data model and representational state transfer(REST)style.Combining actual IoT applications and the characteristics of an existing platform,a REST-based IoT resource sharing platform is proposed.Combined with actual projects,a REST-based IoT resource sharing platform was built,and key technology experiments were conducted for verification.Finally,optimizing the e-commerce supply chain management process under Internet of Things technology and explaining the advantages of optimized e-commerce supply chain management are discussed.Research on this subject provides a theoretical basis for the application of the Internet of Things in e-commerce and has practical significance and practical value for managing service capabilities and service levels in e-commerce.
基金Natural Science Foundation of Guangxi(2017GXNSFAA198082)Guangxi Aquatic Vegetable Fresh-keeping and Processing Engineering Research Center Project(GXSSSCBXYJGZX1912)。
文摘[Objectives]This study was conducted to investigate the effect of compound fresh-keeping liquid on the browning and quality of fresh-cut yam during the cold chain process.[Methods]Under the simulated cold chain condition of 4℃,a uniform design(U6*(64))experiment was carried out to optimize the compound preservative formula,and a better compound preservative formula was obtained using the regression equation.[Results]The compound preservative formula was:AA 0.25%,CA 0.5%,Nisin 0.09%,GSH 0.15%.The compound fresh-keeping liquid effectively delayed the browning of fresh-cut yam and the accumulation of MDA,maintained the content of TSS,inhibited the activity of PAL and delayed the appearance of the maximum activity of POD and POD.[Conclusions]This study provides technical support for the actual extension of the shelf life of fresh-cut yam.
基金Supported by the German Research Foundation DFG(Project-ID:390621612)within the Cluster of Excellence Inter-net of Production(IoP).
文摘This paper presents a digital model for the powder metallurgical(PM)production chain of high-performance sintered gears based on an integrated computational materials engineering(ICME)platform.Discrete and finite element methods(DEM and FEM)were combined to describe the macroscopic material response to the thermomechanical loads and process conditions during the entire production process.The microstructural evolution during the sintering process was predicted on the meso-scale using a Monte-Carlo Model.The effective elastic properties were determined by a homogenization method based on modelling a representative volume element(RVE).The results were subsequently used for the FE modelling of the heat treatment process.Through the development of multi-scale models,it was possible obtain characteristics of the microstructural features.The predicted hardness and residual stress distributions allowed the calculation of the tooth root load bearing capacity of the heat-treated sintered gears.
文摘Rotation sintering, also known as slush molding, is used to manufacture molded skins, such as dashboards or door interior panels for cars. At present, approximately 80% of such molded skins are manufactured using electroforms to achieve the complex free-form surfaces, and surface structures, such as leather graining that the industry demands. The manufacture of these electroforms is, however, time-consuming and expensive. This project aims to replace conventional electroforms with laser-drilled molds. Holes in tool molds should be drilled by using laser radiation as part of an automated process. The system consists of a robot with a fiber-laser beam source. A CAx (computer-aided x) process chain has been developed for this purpose in which the CAD (computer-aided design) data of the tool molds are processed, drill hole fields generated, and a machine-specific RC (robot control) program created. Process-specific fundamentals, such as suitable process windows and process control, have been devised to manufacture holes using fiber laser radiation The advantages of the new laser-drilled tool molds may result in substituting them for conventional electroforms, allowing old markets to be re-entered or additional markets to be created and targeted through new molds or lower costs.
基金the National Natural Science Foundation of China(52275378).
文摘The final quality of complex conical-section rings depends on co-design of multiple processes in forming process chain.In this study,for a complex aeroengine casing ring with a large slope and a flange on its end,a co-design method of the forming process chain is put forward towards the objective of precision forming,which not only proposes a standard process route composed of multiple processes of upsetting,punching,rectangular ring rolling,loose tooling forging and profiled ring rolling,but also presents co-design methods of dies and blanks for all the processes.For profiled ring rolling,a design method of preformed blank that makes the blank and the target conical-section ring have the same axial volume distribution is proposed.By the method,the axial metal redistribution during the process can be alleviated greatly thus improving the forming stability and precision of the ring.Based on the geometric features of designed preformed blank,design methods of blanks and dies for loose tolling forging,rectangular ring rolling,punching and upsetting are proposed sequentially.In view of the key roles of loose tooling forging(manufacturing the preformed blank)and profiled ring rolling on the final quality of the conical ring parts,inherited FE simulations for these two processes are performed to verify the proposed design methods and determine appropriate design parameter.It is demonstrated that the proposed design method has significant advantages in improving forming precision.Besides,a suggestive value 1.5 of the rolling ratio for profiled ring rolling(a key design parameter)is given based on comprehensive consideration of multiple indicators such as ring roundness,deformation uniformity and forming load.The corresponding industrial experiments performed illustrate that a high forming precision of the conical-section aeroengine casing ring is achieved.
文摘This paper discusses an organizational model to be used for both conventional and virtual organizations. The model deals with variable relationships within an organization and provides a framework for overall organizational design that may include relationship among different design variables and external relationship with environment. Based on the researches of virtual organization, this paper also illustrates the new model of organization in the real world such as Beijing 2008 Olympic games and Dongfeng Automobile group.
文摘All known results on large deviations of occupation measures of Markov processes are based on the assumption of (essential) irreducibility. In this paper we establish the weak* large deviation principle of occupation measures for any countable Markov chain with arbitrary initial measures. The new rate function that we obtain is not convex and depends on the initial measure, contrary to the (essentially) irreducible case.
基金supported by the National Key Research and Development Project(2022YFB3403400)Shanghai Sailing Program(20YF1454800)+2 种基金National Natural Science Youth Foundation of China(62205352)Natural Science Foundation of Shanghai(21ZR1472000)Key Projects of the Joint Fund for Astronomy of the National Natural Science Funding of China(U1831211),and the Youth Innovation Promotion Association of the Chinese Academy of Sciences.
文摘Residual processing defects during the contact processing processes greatly reduce the anti-ultraviolet(UV)laser damage performance of fused silica optics,which significantly limited development of high-energy laser systems.In this study,we demonstrate the manufacturing of fused silica optics with a high damage threshold using a CO_(2)laser process chain.Based on theoretical and experimental studies,the proposed uniform layer-by-layer laser ablation technique can be used to characterize the subsurface mechanical damage in three-dimensional full aperture.Longitudinal ablation resolutions ranging from nanometers to micrometers can be realized;the minimum longitudinal resolution is<5 nm.This technique can also be used as a crack-free grinding tool to completely remove subsurface mechanical damage,and as a cleaning tool to effectively clean surface/subsurface contamination.Through effective control of defects in the entire chain,the laser-induced damage thresholds of samples fabricated by the CO_(2)laser process chain were 41%(0%probability)and 65.7%(100%probability)higher than those of samples fabricated using the conventional process chain.This laser-based defect characterization and removal process provides a new tool to guide optimization of the conventional finishing process and represents a new direction for fabrication of highly damage-resistant fused silica optics for high-energy laser applications.