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
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
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
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 order to optimize the microwave-assisted extraction technology of polyphenols from Loropetalum chinense (R. Br.) Oliv., the effects of microwave power, ethanol concentration, solid to liquid ratio and extraction ...In order to optimize the microwave-assisted extraction technology of polyphenols from Loropetalum chinense (R. Br.) Oliv., the effects of microwave power, ethanol concentration, solid to liquid ratio and extraction time on polyphenols extraction rate were investigated. On the basis of single-factor test, a four-factor and three-level orthogonal test was designed by response surface method to establish a mathematical model between the response value and various factors. The results showed that the intensity of effect of different influencing factor on polyphenols ex- traction rate ranked as microwave power's〉solid to liquid ratio's〉extraction time's〉 ethanol concentration's. The optimum microwave-assisted extraction conditions for polyphenols from L. chinense were as follows: extraction power 254 W, ethanol concentration 60%, extraction time 12.5 rain and solid to liquid ratio 1:17. Under the optimum extraction conditions, the extraction rate of polyphenols from L. chinense was 19.17%.展开更多
Teng Junjie has pioneered a new paradigm for Chinese opera films through his exceptional narrative techniques and groundbreaking technological innovations.By skillfully integrating 3D,panoramic sound,and 8K technology...Teng Junjie has pioneered a new paradigm for Chinese opera films through his exceptional narrative techniques and groundbreaking technological innovations.By skillfully integrating 3D,panoramic sound,and 8K technology,he has brought about a transformative development in both the visual and auditory dimensions of traditional Chinese opera.While preserving the cultural essence of opera,Teng offers audiences an impactful and immersive artistic experience.This paper explores how Teng’s precise narrative pacing and emotional expression deeply reveal the inner world of opera characters,infusing them with renewed artistic vitality.Furthermore,it examines his successful strategies for international dissemination,highlighting how Teng has helped propel Chinese opera films onto the global stage,thereby enhancing China’s cultural soft power.展开更多
Background: Augmented reality(AR) technology is used to reconstruct three-dimensional(3D) images of hepatic and biliary structures from computed tomography and magnetic resonance imaging data, and to superimpose the v...Background: Augmented reality(AR) technology is used to reconstruct three-dimensional(3D) images of hepatic and biliary structures from computed tomography and magnetic resonance imaging data, and to superimpose the virtual images onto a view of the surgical field. In liver surgery, these superimposed virtual images help the surgeon to visualize intrahepatic structures and therefore, to operate precisely and to improve clinical outcomes.Data Sources: The keywords "augmented reality", "liver", "laparoscopic" and "hepatectomy" were used for searching publications in the Pub Med database. The primary source of literatures was from peer-reviewed journals up to December 2016. Additional articles were identified by manual search of references found in the key articles.Results: In general, AR technology mainly includes 3D reconstruction, display, registration as well as tracking techniques and has recently been adopted gradually for liver surgeries including laparoscopy and laparotomy with video-based AR assisted laparoscopic resection as the main technical application. By applying AR technology, blood vessels and tumor structures in the liver can be displayed during surgery,which permits precise navigation during complex surgical procedures. Liver transformation and registration errors during surgery were the main factors that limit the application of AR technology.Conclusions: With recent advances, AR technologies have the potential to improve hepatobiliary surgical procedures. However, additional clinical studies will be required to evaluate AR as a tool for reducing postoperative morbidity and mortality and for the improvement of long-term clinical outcomes. Future research is needed in the fusion of multiple imaging modalities, improving biomechanical liver modeling,and enhancing image data processing and tracking technologies to increase the accuracy of current AR methods.展开更多
The range of coal-mine underground goaf has continuously expanded over time.Caving,fracture,and deformation zones have also changed,thereby inducing coal-mine water inrush and other environmental disasters.In this stu...The range of coal-mine underground goaf has continuously expanded over time.Caving,fracture,and deformation zones have also changed,thereby inducing coal-mine water inrush and other environmental disasters.In this study,4 D seismic monitoring technology that is effective in reservoir development was used to monitor abnormal changes in coal-mine underground goaf to explore the feasibility of the method.Taking a coal mine in Hancheng,Shaanxi as an example,we used the aforementioned technology to dynamically monitor the abnormal changes in the goaf.Based on the 4 D seismic data obtained in the experiment and the abnormal change characteristics of the coal-mine goaf,the method of 4 D seismic data processing in reservoir was improved.A set of 4 D data processing flow for the goaf was established,and the anomalies in the surface elevation and overlying strata velocity caused by collapse were corrected.We have made the following improvements to the method of 4 D seismic data processing in the reservoir:(1)the static correction problem caused by the changes of surface elevation and destruction of the low-velocity layer has been solved through fusion static correction to comb the low-frequency components of elevation statics with the high-frequency components of refraction statics;(2)the problem of overlying strata velocity changes in the goaf caused by collapse has been solved through the velocity consistency method;(3)the problem of reflection event pull-down in the disturbance area has been solved through space-varying moveout correction based on cross-correlation;and(4)amplitude anomalies in the coal seam caused by the goaf have been addressed using the correction method of space-varying amplitude.Results show that the 4 D seismic data processing and interpretation method established in this study is reasonable and effective.展开更多
Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has...Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has been widely used in various fields of logistics,production automation,and e-commerce,but it also has brought about a series of safety problems. Based on evolutionary encryption technology,this paper improved algorithm of traditional 2D barcode generation,to improve forgery- proof performance of 2D barcode. This algorithm is applied to agricultural products quality and safety traceability system and the results show that it is effective.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
For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surrounding rock disp...For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surrounding rock displacement, plastic zone and stress distribution in rectangular, circle arch and arch wall sections, respectively. Based on the mining depth and thickness of the coal seam, roadway support technology solutions with different buried depth and thickness of coal seam are proposed. Support schemes are amended and optimized in time through monitoring data of the deformation of roadway, roof separation, l-beam bracket, bolt and anchor cable force to ensure the long-term stability and security of the roadway surrounding rock and support structure. The monitoring results show that mine roadway support schemes for different buried depth and section can be adapted to the characteristics of ground pressure and deformation of the surrounding rock in different depth well, effectively control the roadway surrounding rock deformation and the floor heave and guarantee the safety of construction and basic stability of surrounding rock and support structure.展开更多
This work aims to implement expert and collaborative group recommendation services through an analysis of expertise and network relations NTIS. First of all, expertise database has been constructed by extracting keywo...This work aims to implement expert and collaborative group recommendation services through an analysis of expertise and network relations NTIS. First of all, expertise database has been constructed by extracting keywords after indexing national R&D information in Korea (human resources, project and outcome) and applying expertise calculation algorithm. In consideration of the characteristics of national R&D information, weight values have been selected. Then, expertise points were calculated by applying weighted values. In addition, joint research and collaborative relations were implemented in a knowledge map format through network analysis using national R&D information.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
Purpose: This paper introduces an approach to technology evolution analysis using patent information based on Subject-Action-Object(SAO) structures.Design/methodology/approach: First, SAO structures were extracted fro...Purpose: This paper introduces an approach to technology evolution analysis using patent information based on Subject-Action-Object(SAO) structures.Design/methodology/approach: First, SAO structures were extracted from patent documents and were cleaned. Second, several dimension-reduction techniques were used to generate technology topics. Then, the hierarchical relationships between technology topics were calculated based on patent clustering. Finally, technology evolution maps were drawn by adding a timeline.Findings: This approach can reveal technology evolution processes from multiple perspectives than other approaches.Research limitations: The semantic annotation of an SAO type is not very accurate and the semantic types of technology topics need to be enriched.Practical implications: The approach can be applied to draw technology evolution maps using different types of technology topics such as problem or solution.Originality/value: This approach offers an analytical dimension and more details than existing techniques, and it helps identify fundamental and emerging technologies more accurately and comprehensively.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 constraints of energy supply have been a long-term threat to the sustainable development of China. Technological progress and innovation are essential to helping solve this problem. Research and development (R&D...The constraints of energy supply have been a long-term threat to the sustainable development of China. Technological progress and innovation are essential to helping solve this problem. Research and development (R&D) stock plays a key role in technological progress and innovation. Through comparisons with some other countries, it is found that China has fallen behind in the R&D stock for energy technology. The R&D stock can be improved by two means: one is putting capital and human resources in those strategically key fields; the other is taking advantage of the R&D resources from abroad. The strategically key fields include energy saving techniques, energy materials, the manufacture of key equipment and new energy resources.展开更多
Environmental technology (ET) refers to the processes and techniques for environmental prevention, reduction, recycling, reuse and rehabilitation. Since 1978, China has launched a series of R&D programs in promoti...Environmental technology (ET) refers to the processes and techniques for environmental prevention, reduction, recycling, reuse and rehabilitation. Since 1978, China has launched a series of R&D programs in promoting environmental science and technology development. Uneven spatial distribution and sectoral structure give us a profile of the present status of ET in China. Both opportunities and constraints are analyzed for the development of ET, and strategies for its future development are presented in this paper.展开更多
As advanced functional materials,piezoelectric ceramics are widely used in various fields,including the medical,aviation,and military industries.With the advancement of science and technology,the piezoelectric ceramic...As advanced functional materials,piezoelectric ceramics are widely used in various fields,including the medical,aviation,and military industries.With the advancement of science and technology,the piezoelectric ceramics needed in special fields have become more intelligent,diverse and lightweight.The shapes and structures of piezoelectric ceramics are becoming more complex.Traditional piezoelectric ceramic preparation technology has been unable to meet the high-speed and complex production demands of various industries.Considering this situation,3D printing technology has attracted much attention in the field of piezoelectric ceramics.In this paper,the applications of several main 3D printing techniques in the field of piezoelectric ceramics are mainly introduced,and their development statuses,process characteristics and achievements are summarized.The advantages and disadvantages of each printing technique are summarized and compared.The challenges and possible future trends of 3D printing when manufacturing piezoelectric ceramics are summarized and proposed.展开更多
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.
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.
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 Open Funds for Innovation Platforms of Colleges and Universities in Hunan Province(15K066)National College Students'Innovative Entrepreneuria Training Program(201510553003)Research Study and Innovative Experiment Plan Project for College Students in Hunan Province(2015-499)~~
文摘In order to optimize the microwave-assisted extraction technology of polyphenols from Loropetalum chinense (R. Br.) Oliv., the effects of microwave power, ethanol concentration, solid to liquid ratio and extraction time on polyphenols extraction rate were investigated. On the basis of single-factor test, a four-factor and three-level orthogonal test was designed by response surface method to establish a mathematical model between the response value and various factors. The results showed that the intensity of effect of different influencing factor on polyphenols ex- traction rate ranked as microwave power's〉solid to liquid ratio's〉extraction time's〉 ethanol concentration's. The optimum microwave-assisted extraction conditions for polyphenols from L. chinense were as follows: extraction power 254 W, ethanol concentration 60%, extraction time 12.5 rain and solid to liquid ratio 1:17. Under the optimum extraction conditions, the extraction rate of polyphenols from L. chinense was 19.17%.
文摘Teng Junjie has pioneered a new paradigm for Chinese opera films through his exceptional narrative techniques and groundbreaking technological innovations.By skillfully integrating 3D,panoramic sound,and 8K technology,he has brought about a transformative development in both the visual and auditory dimensions of traditional Chinese opera.While preserving the cultural essence of opera,Teng offers audiences an impactful and immersive artistic experience.This paper explores how Teng’s precise narrative pacing and emotional expression deeply reveal the inner world of opera characters,infusing them with renewed artistic vitality.Furthermore,it examines his successful strategies for international dissemination,highlighting how Teng has helped propel Chinese opera films onto the global stage,thereby enhancing China’s cultural soft power.
基金supported by grants from the Mission Plan Program of Beijing Municipal Administration of Hospitals(SML20152201)Beijing Municipal Administration of Hospitals Clinical Medicine Development of Special Funding(ZYLX201712)+1 种基金the National Natural Science Foundation of China(81427803)Beijing Tsinghua Changgung Hospital Fund(12015C1039)
文摘Background: Augmented reality(AR) technology is used to reconstruct three-dimensional(3D) images of hepatic and biliary structures from computed tomography and magnetic resonance imaging data, and to superimpose the virtual images onto a view of the surgical field. In liver surgery, these superimposed virtual images help the surgeon to visualize intrahepatic structures and therefore, to operate precisely and to improve clinical outcomes.Data Sources: The keywords "augmented reality", "liver", "laparoscopic" and "hepatectomy" were used for searching publications in the Pub Med database. The primary source of literatures was from peer-reviewed journals up to December 2016. Additional articles were identified by manual search of references found in the key articles.Results: In general, AR technology mainly includes 3D reconstruction, display, registration as well as tracking techniques and has recently been adopted gradually for liver surgeries including laparoscopy and laparotomy with video-based AR assisted laparoscopic resection as the main technical application. By applying AR technology, blood vessels and tumor structures in the liver can be displayed during surgery,which permits precise navigation during complex surgical procedures. Liver transformation and registration errors during surgery were the main factors that limit the application of AR technology.Conclusions: With recent advances, AR technologies have the potential to improve hepatobiliary surgical procedures. However, additional clinical studies will be required to evaluate AR as a tool for reducing postoperative morbidity and mortality and for the improvement of long-term clinical outcomes. Future research is needed in the fusion of multiple imaging modalities, improving biomechanical liver modeling,and enhancing image data processing and tracking technologies to increase the accuracy of current AR methods.
基金funded by the National Key Research and Development Program Subject(No.2018YFC0807804)。
文摘The range of coal-mine underground goaf has continuously expanded over time.Caving,fracture,and deformation zones have also changed,thereby inducing coal-mine water inrush and other environmental disasters.In this study,4 D seismic monitoring technology that is effective in reservoir development was used to monitor abnormal changes in coal-mine underground goaf to explore the feasibility of the method.Taking a coal mine in Hancheng,Shaanxi as an example,we used the aforementioned technology to dynamically monitor the abnormal changes in the goaf.Based on the 4 D seismic data obtained in the experiment and the abnormal change characteristics of the coal-mine goaf,the method of 4 D seismic data processing in reservoir was improved.A set of 4 D data processing flow for the goaf was established,and the anomalies in the surface elevation and overlying strata velocity caused by collapse were corrected.We have made the following improvements to the method of 4 D seismic data processing in the reservoir:(1)the static correction problem caused by the changes of surface elevation and destruction of the low-velocity layer has been solved through fusion static correction to comb the low-frequency components of elevation statics with the high-frequency components of refraction statics;(2)the problem of overlying strata velocity changes in the goaf caused by collapse has been solved through the velocity consistency method;(3)the problem of reflection event pull-down in the disturbance area has been solved through space-varying moveout correction based on cross-correlation;and(4)amplitude anomalies in the coal seam caused by the goaf have been addressed using the correction method of space-varying amplitude.Results show that the 4 D seismic data processing and interpretation method established in this study is reasonable and effective.
基金Supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2012BAD35B04)
文摘Two-dimensional(2D) barcode technology is an electronic tagging technology based on combination of computer and optical technology. It is an important way of information collection and input. 2D barcode technology has been widely used in various fields of logistics,production automation,and e-commerce,but it also has brought about a series of safety problems. Based on evolutionary encryption technology,this paper improved algorithm of traditional 2D barcode generation,to improve forgery- proof performance of 2D barcode. This algorithm is applied to agricultural products quality and safety traceability system and the results show that it is effective.
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.
基金Financial support for this work, provided by the Major Program of the National Natural Science Foundation of China (Nos. 51174196 and 51204168)the Program for New Century Excellent Talents in University by Ministry of Education of China (No. NCET-07-0519)
文摘For the engineering geology conditions of bad mine roadway roof and floor lithology in extremely weak cemented strata, the best section shape of the roadway is determined from the study of tunnel surrounding rock displacement, plastic zone and stress distribution in rectangular, circle arch and arch wall sections, respectively. Based on the mining depth and thickness of the coal seam, roadway support technology solutions with different buried depth and thickness of coal seam are proposed. Support schemes are amended and optimized in time through monitoring data of the deformation of roadway, roof separation, l-beam bracket, bolt and anchor cable force to ensure the long-term stability and security of the roadway surrounding rock and support structure. The monitoring results show that mine roadway support schemes for different buried depth and section can be adapted to the characteristics of ground pressure and deformation of the surrounding rock in different depth well, effectively control the roadway surrounding rock deformation and the floor heave and guarantee the safety of construction and basic stability of surrounding rock and support structure.
基金Project(N-12-NM-LU01-C01) supported by Construction of NTIS (National Science & Technology Information Service) Program Funded by the National Science & Technology Commission (NSTC), Korea
文摘This work aims to implement expert and collaborative group recommendation services through an analysis of expertise and network relations NTIS. First of all, expertise database has been constructed by extracting keywords after indexing national R&D information in Korea (human resources, project and outcome) and applying expertise calculation algorithm. In consideration of the characteristics of national R&D information, weight values have been selected. Then, expertise points were calculated by applying weighted values. In addition, joint research and collaborative relations were implemented in a knowledge map format through network analysis using national R&D information.
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Purpose: This paper introduces an approach to technology evolution analysis using patent information based on Subject-Action-Object(SAO) structures.Design/methodology/approach: First, SAO structures were extracted from patent documents and were cleaned. Second, several dimension-reduction techniques were used to generate technology topics. Then, the hierarchical relationships between technology topics were calculated based on patent clustering. Finally, technology evolution maps were drawn by adding a timeline.Findings: This approach can reveal technology evolution processes from multiple perspectives than other approaches.Research limitations: The semantic annotation of an SAO type is not very accurate and the semantic types of technology topics need to be enriched.Practical implications: The approach can be applied to draw technology evolution maps using different types of technology topics such as problem or solution.Originality/value: This approach offers an analytical dimension and more details than existing techniques, and it helps identify fundamental and emerging technologies more accurately and comprehensively.
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.
基金Supported by the National Social Science Project (05BTJ018)
文摘The constraints of energy supply have been a long-term threat to the sustainable development of China. Technological progress and innovation are essential to helping solve this problem. Research and development (R&D) stock plays a key role in technological progress and innovation. Through comparisons with some other countries, it is found that China has fallen behind in the R&D stock for energy technology. The R&D stock can be improved by two means: one is putting capital and human resources in those strategically key fields; the other is taking advantage of the R&D resources from abroad. The strategically key fields include energy saving techniques, energy materials, the manufacture of key equipment and new energy resources.
文摘Environmental technology (ET) refers to the processes and techniques for environmental prevention, reduction, recycling, reuse and rehabilitation. Since 1978, China has launched a series of R&D programs in promoting environmental science and technology development. Uneven spatial distribution and sectoral structure give us a profile of the present status of ET in China. Both opportunities and constraints are analyzed for the development of ET, and strategies for its future development are presented in this paper.
基金This work was financially supported by the Scientific Research Fund-ing Project of the Educational Department of Liaoning Province in 2020,grant number LQ2020008.
文摘As advanced functional materials,piezoelectric ceramics are widely used in various fields,including the medical,aviation,and military industries.With the advancement of science and technology,the piezoelectric ceramics needed in special fields have become more intelligent,diverse and lightweight.The shapes and structures of piezoelectric ceramics are becoming more complex.Traditional piezoelectric ceramic preparation technology has been unable to meet the high-speed and complex production demands of various industries.Considering this situation,3D printing technology has attracted much attention in the field of piezoelectric ceramics.In this paper,the applications of several main 3D printing techniques in the field of piezoelectric ceramics are mainly introduced,and their development statuses,process characteristics and achievements are summarized.The advantages and disadvantages of each printing technique are summarized and compared.The challenges and possible future trends of 3D printing when manufacturing piezoelectric ceramics are summarized and proposed.