With the continuous advancement of technology,the application of 3D printing technology in the field of dental medicine is becoming increasingly widespread.This article aims to explore the current applications and fut...With the continuous advancement of technology,the application of 3D printing technology in the field of dental medicine is becoming increasingly widespread.This article aims to explore the current applications and future potential of 3D printing technology in dental medicine and to analyze its benefits and challenges.It first introduces the current state of 3D printing technology in dental implants,crowns,bridges,orthodontics,and maxillofacial surgery.It then discusses the potential applications of 3D printing technology in oral tissue engineering,drug delivery systems,personalized dental prosthetics,and surgical planning.Finally,it analyzes the benefits of 3D printing technology in dental medicine,such as improving treatment accuracy and patient comfort,and shortening treatment times,while also highlighting the challenges faced,such as costs,material choices,and technical limitations.This article aims to provide a reference for professionals in the field of dental medicine and to promote the further application and development of 3D printing technology in this area.展开更多
In recent years,the government has issued a series of documents to promote the construction of digital campuses.This initiative serves to encourage the deep integration of information technology and intelligent techno...In recent years,the government has issued a series of documents to promote the construction of digital campuses.This initiative serves to encourage the deep integration of information technology and intelligent technology education and digital reform,the combination of virtual reality and campus management is the need for innovative thinking and economic and social development,and then better change our learning style and living environment.The construction of the digital campus is based on virtual reality technology,BIM,GIS,and three-dimensional modeling technology to provide an immersive platform for students,promote the integration of virtual reality technology and education,help teachers,students,and parents to understand all kinds of education information and resources,to achieve their interoperability.From the off-campus environment to the school teaching equipment,teachers to teaching quality certification,and learning,to extracurricular entertainment,opening ceremonies to graduation parties,to bring more efficient,convenient,and safe campus life for teachers,students,and staff in school,and break the traditional information restrictions.展开更多
With the development and progress of science and technology,road and bridge design has experienced rapid development,from the initial manual drawing design to the popularity of Computer-Aided Design(CAD),and then to t...With the development and progress of science and technology,road and bridge design has experienced rapid development,from the initial manual drawing design to the popularity of Computer-Aided Design(CAD),and then to today’s digital software design era.Early designers relied on hand-drawn paper design forms which was time-consuming and error-prone.Digital support for road and bridge design not only saves the design time but the design quality has also achieved a qualitative leap.This paper engages in the application of digital technology in road and bridge design,to provide technical reference for China’s road and bridge engineering design units,to promote the popularity of Civil3D and other advanced design software in the field of engineering design and development,ultimately contributing to the sustainable development of China’s road and bridge engineering.展开更多
Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent...Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses.In this paper,soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP)sand core technology.Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology.The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels.As the stress level increases,the effect of creep stress on its creep anisotropy increases significantly,and the dip angle is no longer the main factor.The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°,which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°.The tests results are verified by comparing with theoretical and other published studies.The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research.展开更多
After more than 30 years of scientific and social development, surveying and mapping technology by leaps and bounds, engineering surveying technology has undergone tremendous changes. In the process of protecting anci...After more than 30 years of scientific and social development, surveying and mapping technology by leaps and bounds, engineering surveying technology has undergone tremendous changes. In the process of protecting ancient buildings, it is necessary to obtain the precise dimensions of architectural details. In this study, the path of 3D laser scanning combined with BIM technology is explored. Taking the observation and protection of the ancestral hall of the Liu family as an example, this study aims to draw drawings that reflect the relevant information about the ancient buildings, the accurate three-dimensional model of ancient buildings is established with BIM technology, which provides new methods and ideas for the research and protection of ancient buildings. .展开更多
The informatization of higher vocational education is the future development trend,and it is also encouraged and promoted by the Ministry of Education.This article focuses on the road and bridge major,combined with th...The informatization of higher vocational education is the future development trend,and it is also encouraged and promoted by the Ministry of Education.This article focuses on the road and bridge major,combined with the author’s experience in introducing virtual simulation and three-dimensional(3D)animation technology into relevant course teaching in recent years,discusses the application of virtual simulation and 3D animation technology in higher vocational education and promotes classroom revolution,to obtain better teaching effect.展开更多
The application of virtual reality technology has become more and more influential in garden design. Quest3D as a significant software to realize the virtual reality technology is utilized in this study to make a gard...The application of virtual reality technology has become more and more influential in garden design. Quest3D as a significant software to realize the virtual reality technology is utilized in this study to make a garden roaming demonstration system with the gardening design of a classical courtyard as an example. Besides, the advantages and disadvantages of applying Quest3D technology in garden landscape design are elaborated from the perspective of the selection of Quest3D technology, basic procedures for the selection and establishment of software and hardware.展开更多
Facial wound segmentation plays a crucial role in preoperative planning and optimizing patient outcomes in various medical applications.In this paper,we propose an efficient approach for automating 3D facial wound seg...Facial wound segmentation plays a crucial role in preoperative planning and optimizing patient outcomes in various medical applications.In this paper,we propose an efficient approach for automating 3D facial wound segmentation using a two-stream graph convolutional network.Our method leverages the Cir3D-FaIR dataset and addresses the challenge of data imbalance through extensive experimentation with different loss functions.To achieve accurate segmentation,we conducted thorough experiments and selected a high-performing model from the trainedmodels.The selectedmodel demonstrates exceptional segmentation performance for complex 3D facial wounds.Furthermore,based on the segmentation model,we propose an improved approach for extracting 3D facial wound fillers and compare it to the results of the previous study.Our method achieved a remarkable accuracy of 0.9999993% on the test suite,surpassing the performance of the previous method.From this result,we use 3D printing technology to illustrate the shape of the wound filling.The outcomes of this study have significant implications for physicians involved in preoperative planning and intervention design.By automating facial wound segmentation and improving the accuracy ofwound-filling extraction,our approach can assist in carefully assessing and optimizing interventions,leading to enhanced patient outcomes.Additionally,it contributes to advancing facial reconstruction techniques by utilizing machine learning and 3D bioprinting for printing skin tissue implants.Our source code is available at https://github.com/SIMOGroup/WoundFilling3D.展开更多
The catalyst layers(CLs) electrode is the key component of the membrane electrode assembly(MEA) in proton exchange membrane fuel cells(PEMFCs). Conventional electrodes for PEMFCs are composed of carbon-supported, iono...The catalyst layers(CLs) electrode is the key component of the membrane electrode assembly(MEA) in proton exchange membrane fuel cells(PEMFCs). Conventional electrodes for PEMFCs are composed of carbon-supported, ionomer, and Pt nanoparticles, all immersed together and sprayed with a micron-level thickness of CLs. They have a performance trade-off where increasing the Pt loading leads to higher performance of abundant triple-phase boundary areas but increases the electrode cost. Major challenges must be overcome before realizing its wide commercialization. Literature research revealed that it is impossible to achieve performance and durability targets with only high-performance catalysts, so the controllable design of CLs architecture in MEAs for PEMFCs must now be the top priority to meet industry goals. From this perspective, a 3D ordered electrode circumvents this issue with a support-free architecture and ultrathin thickness while reducing noble metal Pt loadings. Herein, we discuss the motivation in-depth and summarize the necessary CLs structural features for designing ultralow Pt loading electrodes. Critical issues that remain in progress for 3D ordered CLs must be studied and characterized. Furthermore, approaches for 3D ordered CLs architecture electrode development, involving material design, structure optimization, preparation technology, and characterization techniques, are summarized and are expected to be next-generation CLs for PEMFCs. Finally, the review concludes with perspectives on possible research directions of CL architecture to address the significant challenges in the future.展开更多
In order to study the successive deposition and solidification processes of uniform alloy droplets during the drop-on-demand three dimensional(3D) printing method,based on the volume of fluid(VOF) method,a 3D nume...In order to study the successive deposition and solidification processes of uniform alloy droplets during the drop-on-demand three dimensional(3D) printing method,based on the volume of fluid(VOF) method,a 3D numerical model was employed.In this model,the 7075 alloy with larger temperature range for phase change was used.The simulation results show that the successive deposition and solidification processes of uniform 7075 alloy droplets can be well characterized by this model.Simulated droplets shapes agree well with SEM images under the same condition.The effects of deposition and solidification of droplets result in vertical and L-shaped ridges on the surface of droplets,and tips of dendrites appear near the overlap of droplets due to rapid solidification.展开更多
In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently,which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor...In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently,which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor to ensure the invert stability by regulating the external water pressure(EWP). By means of a threedimensional(3D) printing model, this paper experimentally investigates the deformation behavior of the invert for the tunnels with the traditional drainage system(TDS) widely used in China and its optimized drainage system(ODS) with bottom drainage function. Six test groups with a total of 110 test conditions were designed to consider the design factors and environmental factors in engineering practice,including layout of the drainage system, blockage of the drainage system and groundwater level fluctuation. It was found that there are significant differences in the water discharge, EWP and invert stability for the tunnels with the two drainage systems. Even with a dense arrangement of the external blind tubes, TDS was still difficult to eliminate the excessive EWP below the invert, which is the main cause for the invert instability. Blockage of drainage system further increased the invert uplift and aggravated the track irregularity, especially when the blockage degree is more than 50%. However, ODS can prevent these invert anomalies by reasonably controlling the EWP at tunnel bottom. Even when the groundwater level reached 60 m and the blind tubes were fully blocked, the invert stability can still be maintained and the railway track experienced a settlement of only 1.8 mm. Meanwhile, the on-site monitoring under several rainstorms further showed that the average EWP of the invert was controlled within 84 k Pa, while the maximum settlement of the track slab was only 0.92 mm, which also was in good agreement with the results of model test.展开更多
3D stereoscopic visualization technology is coming into more and more common use in the field of entertainment,and this technology is also beginning to cut a striking figure in casting industry and scientific research...3D stereoscopic visualization technology is coming into more and more common use in the field of entertainment,and this technology is also beginning to cut a striking figure in casting industry and scientific research.The history,fundamental principle,and devices of 3D stereoscopic visualization technology are reviewed in this paper.The authors’research achievements on the 3D stereoscopic visualization technology in the modeling and simulation of the casting process are presented.This technology can be used for the observation of complex 3D solid models of castings and the simulated results of solidification processes such as temperature,fluid flow,displacement,stress strain and microstructure,as well as the predicted defects such as shrinkage/porosity,cracks,and deformation.It can also be used for other areas relating to 3D models,such as assembling of dies,cores,etc.Several cases are given to compare the illustration of simulated results by traditional images and red-blue 3D stereoscopic images.The spatial shape is observed better by the new method.The prospect of3D stereoscopic visualization in the casting aspect is discussed as well.The need for aided-viewing devices is still the most prominent problem of 3D stereoscopic visualization technology.However,3D stereoscopic visualization represents the tendency of visualization technology in the future;and as the problem is solved in the years ahead,great breakthroughs will certainly be made for its application in casting design and modeling and simulation of the casting processes.展开更多
The recent advances of 3D seismic technique applied in geological study of sedimentary basin analysis were reviewed.The achievements in the study of the sedimentology,structural analysis, fluid-rock interaction and ig...The recent advances of 3D seismic technique applied in geological study of sedimentary basin analysis were reviewed.The achievements in the study of the sedimentology,structural analysis, fluid-rock interaction and igneous geology were summarized.Because 3D seismic resolution and interpretation technology are enhanced surprisingly。展开更多
The study of wind erosion processes is of great importance to the prevention and control of soil wind erosion.In this study,three structurally intact soil samples were collected from the steppe of Inner Mongolia Auton...The study of wind erosion processes is of great importance to the prevention and control of soil wind erosion.In this study,three structurally intact soil samples were collected from the steppe of Inner Mongolia Autonomous Region,China and placed in a wind tunnel where they were subjected to six different wind speeds(10,15,17,20,25,and 30 m/s)to simulate wind erosion in the wind tunnel.After each test,the soil surfaces were scanned by a 3D laser scanner to create a high-resolution Digital Elevation Model(DEM),and the changes in wind erosion mass and microtopography were quantified.Based on this,we performed further analysis of wind erosion-controlling factors.The study results showed that the average measurement error between the 3D laser scanning method and weighing method was 6.23%for the three undisturbed soil samples.With increasing wind speed,the microtopography on the undisturbed soil surface first became smooth,and then fine stripes and pits gradually developed.In the initial stage of wind erosion processes,the ability of the soil to resist wind erosion was mainly affected by the soil hardness.In the late stage of wind erosion processes,the degree of soil erosion was mainly affected by soil organic matter and CaCO_(3)content.The results of this study are expected to provide a theoretical basis for soil wind erosion control and promote the application of 3D laser scanners in wind erosion monitoring.展开更多
3D printing technology is an innovative manufacturing technology used in several disciplines, whose number and diversity are growing day by day. The development of devices to improve the accessibility of buildings an...3D printing technology is an innovative manufacturing technology used in several disciplines, whose number and diversity are growing day by day. The development of devices to improve the accessibility of buildings and urban spaces for people with disabilities through 3D priming technology is still not broadly explored. The present study is focused on filling this gap, with the realization of a tactile map of the MTE (Museum of Electrical Technology) of the University of Pavia (Italy) for blind and visually impaired people. The tactile map represents the building plan with all the information to guide the visit. The device is the result of a research process which is made by several steps and experimental tests, aimed at setting the best 3D priming profiles to meet all the requirements of the end-users. This paper describes methods and strategies applied to reach these goals: it underlines the social and technical approaches, the experimental phases and its possible future developments.展开更多
Nowadays, a large amount of thinking and inspiration which can't be expressed by words and drawings has been realized because of the rapid development of computer graphics. 3D is one of the technology drawn much atte...Nowadays, a large amount of thinking and inspiration which can't be expressed by words and drawings has been realized because of the rapid development of computer graphics. 3D is one of the technology drawn much attention in the field of interior design, in the meantime, 3D technology is also the development direction of Chinese interior design in new age. Those design concepts which can only be expressed with words will be accomplished by computer through 3D modeling technology. The interior design applying 3D technology meets psychological need of people's indoor life quality, environment atmosphere, and style.This paper made a design of the medium and small house model has been realized through the application platform of the Auto CAD, 3 D Max, Vray, and Premiere Pro.展开更多
The shift towards sustainability in the fashion industry has become an urgent necessity and a national duty, where the life cycle of garments poses a negative impact on the environment, which increases strongly with t...The shift towards sustainability in the fashion industry has become an urgent necessity and a national duty, where the life cycle of garments poses a negative impact on the environment, which increases strongly with the huge increase in the daily consumption of garments and fast fashion. One of the most prominent solutions that have been proposed is to change the manufacturing system in a way that would help reduce costs, reduce supply and provide products that are more closely related to the individual customer need. Accessories such as (closers) are an important part of the fashion industry, and therefore, this study aimed to produce closers using (FDM) technology, which is one of the least expensive and most widespread 3D printing technologies. These closers are then tested in the laboratory according to AATCC standard specifications for garments and closers to ensure the applicability of this technology in the implementation of closers for designers and manufacturers in medium and small facilities. This study relied on the experimental exploratory approach, and the results proved the success of the proposed closers, as the implemented models passed the standard tests with distinction.展开更多
Objective:To explore the clinical method and effect of 3D printing in the treatment of cerebral aneurysms.Methods:The authors research work on the hospital,work time in February 2019-February 2020,this study selected ...Objective:To explore the clinical method and effect of 3D printing in the treatment of cerebral aneurysms.Methods:The authors research work on the hospital,work time in February 2019-February 2020,this study selected patients of cerebral aneurysms,this period are selected for treatment of 100 cases of patients,randomly divided into two groups,a group to give simple intervention,named as the control group,another group for the interventional therapy under the guidance of 3 D printing,named as experimental group,analyze the effect of two groups of patients with clinical intervention.Results:The length of hospital stay in the experimental group was shorter than that in the control group.Meanwhile,the incidence of complications and adverse reactions in the experimental group and the control group were 6.00%and 18.00%,the experimental group was better(P<0.05).Conclusion:3D printing technology can be applied in the treatment of patients with cerebral aneurysms to provide guidance for interventional surgical treatment.It has significant effect,can reduce the incidence complications in patients,has significant clinical effect,and can be popularized.展开更多
This paper taking Wuzhou arcade naturalist city as design sight spot, made a on location shoot on the streetscape of arcade naturalist city. then synthesized them by software in panoramic way. to create a multimedia v...This paper taking Wuzhou arcade naturalist city as design sight spot, made a on location shoot on the streetscape of arcade naturalist city. then synthesized them by software in panoramic way. to create a multimedia virtual exhibition platform. This paper has explored the used digital software and forms of artistic expression in this system, summed up the experience in the production of shooting, image stitching, and image post-processing as well ss art design, and finally combined with the Lingnan culture features to design the arcade naturalist city show platform.展开更多
Coal working face is damaged more and more seriously by water below the coal face floor. Therefore, floor water detection is a must in the process of extraction. This article aims to introducing application and princi...Coal working face is damaged more and more seriously by water below the coal face floor. Therefore, floor water detection is a must in the process of extraction. This article aims to introducing application and principle of the two-gateways parallel 3-D electrical technology and the arrangement of the observation system. The authors use this method to detect the water under the floor of a mine in north of Anhui. The results show that the two-gateways parallel 3-D electrical technology can accurately locate the water-rich areas, providing the basis for drilling drainage and grouting construction.展开更多
文摘With the continuous advancement of technology,the application of 3D printing technology in the field of dental medicine is becoming increasingly widespread.This article aims to explore the current applications and future potential of 3D printing technology in dental medicine and to analyze its benefits and challenges.It first introduces the current state of 3D printing technology in dental implants,crowns,bridges,orthodontics,and maxillofacial surgery.It then discusses the potential applications of 3D printing technology in oral tissue engineering,drug delivery systems,personalized dental prosthetics,and surgical planning.Finally,it analyzes the benefits of 3D printing technology in dental medicine,such as improving treatment accuracy and patient comfort,and shortening treatment times,while also highlighting the challenges faced,such as costs,material choices,and technical limitations.This article aims to provide a reference for professionals in the field of dental medicine and to promote the further application and development of 3D printing technology in this area.
文摘In recent years,the government has issued a series of documents to promote the construction of digital campuses.This initiative serves to encourage the deep integration of information technology and intelligent technology education and digital reform,the combination of virtual reality and campus management is the need for innovative thinking and economic and social development,and then better change our learning style and living environment.The construction of the digital campus is based on virtual reality technology,BIM,GIS,and three-dimensional modeling technology to provide an immersive platform for students,promote the integration of virtual reality technology and education,help teachers,students,and parents to understand all kinds of education information and resources,to achieve their interoperability.From the off-campus environment to the school teaching equipment,teachers to teaching quality certification,and learning,to extracurricular entertainment,opening ceremonies to graduation parties,to bring more efficient,convenient,and safe campus life for teachers,students,and staff in school,and break the traditional information restrictions.
文摘With the development and progress of science and technology,road and bridge design has experienced rapid development,from the initial manual drawing design to the popularity of Computer-Aided Design(CAD),and then to today’s digital software design era.Early designers relied on hand-drawn paper design forms which was time-consuming and error-prone.Digital support for road and bridge design not only saves the design time but the design quality has also achieved a qualitative leap.This paper engages in the application of digital technology in road and bridge design,to provide technical reference for China’s road and bridge engineering design units,to promote the popularity of Civil3D and other advanced design software in the field of engineering design and development,ultimately contributing to the sustainable development of China’s road and bridge engineering.
基金the support of the National Natural Science Foundation of China(Grant Nos.42207199,52179113,42272333)Zhejiang Postdoctoral Scientific Research Project(Grant Nos.ZJ2022155,ZJ2022156)。
文摘Three-dimensional(3D)printing technology is increasingly used in experimental research of geotechnical engineering.Compared to other materials,3D layer-by-layer printing specimens are extremely similar to the inherent properties of natural layered rock masses.In this paper,soft-hard interbedded rock masses with different dip angles were prepared based on 3D printing(3DP)sand core technology.Uniaxial compression creep tests were conducted to investigate its anisotropic creep behavior based on digital imaging correlation(DIC)technology.The results show that the anisotropic creep behavior of the 3DP soft-hard interbedded rock mass is mainly affected by the dip angles of the weak interlayer when the stress is at low levels.As the stress level increases,the effect of creep stress on its creep anisotropy increases significantly,and the dip angle is no longer the main factor.The minimum value of the long-term strength and creep failure strength always appears in the weak interlayer within 30°–60°,which explains why the failure of the layered rock mass is controlled by the weak interlayer and generally emerges at 45°.The tests results are verified by comparing with theoretical and other published studies.The feasibility of the 3DP soft-hard interbedded rock mass provides broad prospects and application values for 3DP technology in future experimental research.
文摘After more than 30 years of scientific and social development, surveying and mapping technology by leaps and bounds, engineering surveying technology has undergone tremendous changes. In the process of protecting ancient buildings, it is necessary to obtain the precise dimensions of architectural details. In this study, the path of 3D laser scanning combined with BIM technology is explored. Taking the observation and protection of the ancestral hall of the Liu family as an example, this study aims to draw drawings that reflect the relevant information about the ancient buildings, the accurate three-dimensional model of ancient buildings is established with BIM technology, which provides new methods and ideas for the research and protection of ancient buildings. .
基金2021 Chongqing Energy Vocational College Science and Technology Department Teaching Reform Project"Discussion and Practice of Teaching Reform of"Bridge and Culvert Engineering Construction Technology"Based on Road and Bridge Simulation Software"(202106)。
文摘The informatization of higher vocational education is the future development trend,and it is also encouraged and promoted by the Ministry of Education.This article focuses on the road and bridge major,combined with the author’s experience in introducing virtual simulation and three-dimensional(3D)animation technology into relevant course teaching in recent years,discusses the application of virtual simulation and 3D animation technology in higher vocational education and promotes classroom revolution,to obtain better teaching effect.
文摘The application of virtual reality technology has become more and more influential in garden design. Quest3D as a significant software to realize the virtual reality technology is utilized in this study to make a garden roaming demonstration system with the gardening design of a classical courtyard as an example. Besides, the advantages and disadvantages of applying Quest3D technology in garden landscape design are elaborated from the perspective of the selection of Quest3D technology, basic procedures for the selection and establishment of software and hardware.
文摘Facial wound segmentation plays a crucial role in preoperative planning and optimizing patient outcomes in various medical applications.In this paper,we propose an efficient approach for automating 3D facial wound segmentation using a two-stream graph convolutional network.Our method leverages the Cir3D-FaIR dataset and addresses the challenge of data imbalance through extensive experimentation with different loss functions.To achieve accurate segmentation,we conducted thorough experiments and selected a high-performing model from the trainedmodels.The selectedmodel demonstrates exceptional segmentation performance for complex 3D facial wounds.Furthermore,based on the segmentation model,we propose an improved approach for extracting 3D facial wound fillers and compare it to the results of the previous study.Our method achieved a remarkable accuracy of 0.9999993% on the test suite,surpassing the performance of the previous method.From this result,we use 3D printing technology to illustrate the shape of the wound filling.The outcomes of this study have significant implications for physicians involved in preoperative planning and intervention design.By automating facial wound segmentation and improving the accuracy ofwound-filling extraction,our approach can assist in carefully assessing and optimizing interventions,leading to enhanced patient outcomes.Additionally,it contributes to advancing facial reconstruction techniques by utilizing machine learning and 3D bioprinting for printing skin tissue implants.Our source code is available at https://github.com/SIMOGroup/WoundFilling3D.
基金funded by the Natural Science Foundation of Shandong Province, China (ZR2023MB049)the China Postdoctoral Science Foundation (2020M670483)the Science Foundation of Weifang University (2023BS11)。
文摘The catalyst layers(CLs) electrode is the key component of the membrane electrode assembly(MEA) in proton exchange membrane fuel cells(PEMFCs). Conventional electrodes for PEMFCs are composed of carbon-supported, ionomer, and Pt nanoparticles, all immersed together and sprayed with a micron-level thickness of CLs. They have a performance trade-off where increasing the Pt loading leads to higher performance of abundant triple-phase boundary areas but increases the electrode cost. Major challenges must be overcome before realizing its wide commercialization. Literature research revealed that it is impossible to achieve performance and durability targets with only high-performance catalysts, so the controllable design of CLs architecture in MEAs for PEMFCs must now be the top priority to meet industry goals. From this perspective, a 3D ordered electrode circumvents this issue with a support-free architecture and ultrathin thickness while reducing noble metal Pt loadings. Herein, we discuss the motivation in-depth and summarize the necessary CLs structural features for designing ultralow Pt loading electrodes. Critical issues that remain in progress for 3D ordered CLs must be studied and characterized. Furthermore, approaches for 3D ordered CLs architecture electrode development, involving material design, structure optimization, preparation technology, and characterization techniques, are summarized and are expected to be next-generation CLs for PEMFCs. Finally, the review concludes with perspectives on possible research directions of CL architecture to address the significant challenges in the future.
基金Projects (51005186,51221001) supported by the National Natural Science Foundation of ChinaProject (85-TZ-2013) supported by the Research Fund of the State Key Laboratory of Solidification Processing(NWPU),ChinaProject (20126102110022) supported by the Doctoral Fund of Ministry of Education of China
文摘In order to study the successive deposition and solidification processes of uniform alloy droplets during the drop-on-demand three dimensional(3D) printing method,based on the volume of fluid(VOF) method,a 3D numerical model was employed.In this model,the 7075 alloy with larger temperature range for phase change was used.The simulation results show that the successive deposition and solidification processes of uniform 7075 alloy droplets can be well characterized by this model.Simulated droplets shapes agree well with SEM images under the same condition.The effects of deposition and solidification of droplets result in vertical and L-shaped ridges on the surface of droplets,and tips of dendrites appear near the overlap of droplets due to rapid solidification.
基金supported by the National Natural Science Foundation of China (Grant No. U1934211)the Open Foundation of National Engineering Research Center of High-speed Railway Construction Technology (Grant No. HSR202005)Scientific Research Project of Hunan Education Department (Grant No.20B596)。
文摘In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently,which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor to ensure the invert stability by regulating the external water pressure(EWP). By means of a threedimensional(3D) printing model, this paper experimentally investigates the deformation behavior of the invert for the tunnels with the traditional drainage system(TDS) widely used in China and its optimized drainage system(ODS) with bottom drainage function. Six test groups with a total of 110 test conditions were designed to consider the design factors and environmental factors in engineering practice,including layout of the drainage system, blockage of the drainage system and groundwater level fluctuation. It was found that there are significant differences in the water discharge, EWP and invert stability for the tunnels with the two drainage systems. Even with a dense arrangement of the external blind tubes, TDS was still difficult to eliminate the excessive EWP below the invert, which is the main cause for the invert instability. Blockage of drainage system further increased the invert uplift and aggravated the track irregularity, especially when the blockage degree is more than 50%. However, ODS can prevent these invert anomalies by reasonably controlling the EWP at tunnel bottom. Even when the groundwater level reached 60 m and the blind tubes were fully blocked, the invert stability can still be maintained and the railway track experienced a settlement of only 1.8 mm. Meanwhile, the on-site monitoring under several rainstorms further showed that the average EWP of the invert was controlled within 84 k Pa, while the maximum settlement of the track slab was only 0.92 mm, which also was in good agreement with the results of model test.
文摘3D stereoscopic visualization technology is coming into more and more common use in the field of entertainment,and this technology is also beginning to cut a striking figure in casting industry and scientific research.The history,fundamental principle,and devices of 3D stereoscopic visualization technology are reviewed in this paper.The authors’research achievements on the 3D stereoscopic visualization technology in the modeling and simulation of the casting process are presented.This technology can be used for the observation of complex 3D solid models of castings and the simulated results of solidification processes such as temperature,fluid flow,displacement,stress strain and microstructure,as well as the predicted defects such as shrinkage/porosity,cracks,and deformation.It can also be used for other areas relating to 3D models,such as assembling of dies,cores,etc.Several cases are given to compare the illustration of simulated results by traditional images and red-blue 3D stereoscopic images.The spatial shape is observed better by the new method.The prospect of3D stereoscopic visualization in the casting aspect is discussed as well.The need for aided-viewing devices is still the most prominent problem of 3D stereoscopic visualization technology.However,3D stereoscopic visualization represents the tendency of visualization technology in the future;and as the problem is solved in the years ahead,great breakthroughs will certainly be made for its application in casting design and modeling and simulation of the casting processes.
文摘The recent advances of 3D seismic technique applied in geological study of sedimentary basin analysis were reviewed.The achievements in the study of the sedimentology,structural analysis, fluid-rock interaction and igneous geology were summarized.Because 3D seismic resolution and interpretation technology are enhanced surprisingly。
基金supported by National Natural Science Foundation of China(41871010)The Second Comprehensive Scientific Expedition to the Qinghai-Tibet Plateau of China(2019QZKK0906)。
文摘The study of wind erosion processes is of great importance to the prevention and control of soil wind erosion.In this study,three structurally intact soil samples were collected from the steppe of Inner Mongolia Autonomous Region,China and placed in a wind tunnel where they were subjected to six different wind speeds(10,15,17,20,25,and 30 m/s)to simulate wind erosion in the wind tunnel.After each test,the soil surfaces were scanned by a 3D laser scanner to create a high-resolution Digital Elevation Model(DEM),and the changes in wind erosion mass and microtopography were quantified.Based on this,we performed further analysis of wind erosion-controlling factors.The study results showed that the average measurement error between the 3D laser scanning method and weighing method was 6.23%for the three undisturbed soil samples.With increasing wind speed,the microtopography on the undisturbed soil surface first became smooth,and then fine stripes and pits gradually developed.In the initial stage of wind erosion processes,the ability of the soil to resist wind erosion was mainly affected by the soil hardness.In the late stage of wind erosion processes,the degree of soil erosion was mainly affected by soil organic matter and CaCO_(3)content.The results of this study are expected to provide a theoretical basis for soil wind erosion control and promote the application of 3D laser scanners in wind erosion monitoring.
文摘3D printing technology is an innovative manufacturing technology used in several disciplines, whose number and diversity are growing day by day. The development of devices to improve the accessibility of buildings and urban spaces for people with disabilities through 3D priming technology is still not broadly explored. The present study is focused on filling this gap, with the realization of a tactile map of the MTE (Museum of Electrical Technology) of the University of Pavia (Italy) for blind and visually impaired people. The tactile map represents the building plan with all the information to guide the visit. The device is the result of a research process which is made by several steps and experimental tests, aimed at setting the best 3D priming profiles to meet all the requirements of the end-users. This paper describes methods and strategies applied to reach these goals: it underlines the social and technical approaches, the experimental phases and its possible future developments.
文摘Nowadays, a large amount of thinking and inspiration which can't be expressed by words and drawings has been realized because of the rapid development of computer graphics. 3D is one of the technology drawn much attention in the field of interior design, in the meantime, 3D technology is also the development direction of Chinese interior design in new age. Those design concepts which can only be expressed with words will be accomplished by computer through 3D modeling technology. The interior design applying 3D technology meets psychological need of people's indoor life quality, environment atmosphere, and style.This paper made a design of the medium and small house model has been realized through the application platform of the Auto CAD, 3 D Max, Vray, and Premiere Pro.
文摘The shift towards sustainability in the fashion industry has become an urgent necessity and a national duty, where the life cycle of garments poses a negative impact on the environment, which increases strongly with the huge increase in the daily consumption of garments and fast fashion. One of the most prominent solutions that have been proposed is to change the manufacturing system in a way that would help reduce costs, reduce supply and provide products that are more closely related to the individual customer need. Accessories such as (closers) are an important part of the fashion industry, and therefore, this study aimed to produce closers using (FDM) technology, which is one of the least expensive and most widespread 3D printing technologies. These closers are then tested in the laboratory according to AATCC standard specifications for garments and closers to ensure the applicability of this technology in the implementation of closers for designers and manufacturers in medium and small facilities. This study relied on the experimental exploratory approach, and the results proved the success of the proposed closers, as the implemented models passed the standard tests with distinction.
文摘Objective:To explore the clinical method and effect of 3D printing in the treatment of cerebral aneurysms.Methods:The authors research work on the hospital,work time in February 2019-February 2020,this study selected patients of cerebral aneurysms,this period are selected for treatment of 100 cases of patients,randomly divided into two groups,a group to give simple intervention,named as the control group,another group for the interventional therapy under the guidance of 3 D printing,named as experimental group,analyze the effect of two groups of patients with clinical intervention.Results:The length of hospital stay in the experimental group was shorter than that in the control group.Meanwhile,the incidence of complications and adverse reactions in the experimental group and the control group were 6.00%and 18.00%,the experimental group was better(P<0.05).Conclusion:3D printing technology can be applied in the treatment of patients with cerebral aneurysms to provide guidance for interventional surgical treatment.It has significant effect,can reduce the incidence complications in patients,has significant clinical effect,and can be popularized.
文摘This paper taking Wuzhou arcade naturalist city as design sight spot, made a on location shoot on the streetscape of arcade naturalist city. then synthesized them by software in panoramic way. to create a multimedia virtual exhibition platform. This paper has explored the used digital software and forms of artistic expression in this system, summed up the experience in the production of shooting, image stitching, and image post-processing as well ss art design, and finally combined with the Lingnan culture features to design the arcade naturalist city show platform.
文摘Coal working face is damaged more and more seriously by water below the coal face floor. Therefore, floor water detection is a must in the process of extraction. This article aims to introducing application and principle of the two-gateways parallel 3-D electrical technology and the arrangement of the observation system. The authors use this method to detect the water under the floor of a mine in north of Anhui. The results show that the two-gateways parallel 3-D electrical technology can accurately locate the water-rich areas, providing the basis for drilling drainage and grouting construction.