Purpose–The intelligent Central Traffic Control(CTC)system plays a vital role in establishing an intelligent high-speed railway(HSR)system.As the core of HSR transportation command,the intelligent CTC system is a new...Purpose–The intelligent Central Traffic Control(CTC)system plays a vital role in establishing an intelligent high-speed railway(HSR)system.As the core of HSR transportation command,the intelligent CTC system is a new HSR dispatching command system that integrates the widely used CTC in China with the practical service requirements of intelligent dispatching.This paper aims to propose key technologies and applications for intelligent dispatching command in HSR in China.Design/methodology/approach–This paper first briefly introduces the functions and configuration of the intelligent CTC system.Some new servers,terminals and interfaces are introduced,which are plan adjustment server/terminal,interface for automatic train operation(ATO),interface for Dynamic Monitoring System of Train Control Equipment(DMS),interface for Power Supervisory Control and Data Acquisition(PSCADA),interface for Disaster Monitoring,etc.Findings–The key technologies applied in the intelligent CTC system include automatic adjustment of train operation plans,safety control of train routes and commands,traffic information data platform,integrated simulation of traffic dispatching and ATO function.These technologies have been applied in the Beijing-Zhangjiakou HSR,which commenced operations at the end of 2019.Implementing these key intelligent functions has improved the train dispatching command capacity,ensured the safe operation of intelligent HSR,reduced the labor intensity of dispatching operators and enhanced the intelligence level of China’s dispatching system.Originality/value–This paper provides further challenges and research directions for the intelligent dispatching command of HSR.To achieve the objectives,new measures need to be conducted,including the development of advanced technologies for intelligent dispatching command,coping with new requirements with the development of China’s railway signaling system,the integration of traffic dispatching and train control and the application of AI and data-driven modeling and methods.展开更多
This is a review of high-speed train development in the sense of technology advances all over the world. Three generations of high-speed trains are classified according to their technical characteristics and maximum o...This is a review of high-speed train development in the sense of technology advances all over the world. Three generations of high-speed trains are classified according to their technical characteristics and maximum operating speed. Emphasis is given to the newly developed high-speed train in China, CRH380. The theoretical foundations and future development of CRH380 are briefly discussed.展开更多
The stability control of longwall coalface is the key technology of large-cutting-height mining method.Therefore,a systematic study of the factors that affect coalface stability and its control technology is required ...The stability control of longwall coalface is the key technology of large-cutting-height mining method.Therefore,a systematic study of the factors that affect coalface stability and its control technology is required in the development of large-cutting-height mining method in China. After the practical field observation and years of study,it was found that the more than 95% of failures in coalface are shear failure. The shear failure analysis model of coalface has been established,that can perform systematic study among factors such as mining height,coal mass strength,roof load,support resistance,and face flipper protecting plate horizontal force. Meanwhile,sensitivity analysis of factors influencing coalface stability showed that improving support capacity,cohesion of coal mass and decreasing roof load of coalface are the key to improve coalface stability. Numerical simulation of the factors affecting coalface stability has been performed using UDEC software and the results are consistent with the theoretical analysis. The coalface reinforcement technology of large-cutting-height mining method using the grouting combined with coir rope is presented. Laboratory tests have been carried out to verify its reinforcement effect and practical application has been implemented in several coal mines with good results.It has now become the main technology to reduce longwall coalface failure of large-cutting-height mining method.展开更多
This paper mainly introduces the scientific cutting and hoisting construction technology before the large spherical tank(hereinafter referred to as spherical tank)moving and loading,so as to better ensure the construc...This paper mainly introduces the scientific cutting and hoisting construction technology before the large spherical tank(hereinafter referred to as spherical tank)moving and loading,so as to better ensure the construction quality of field assembly and welding in the process of spherical tank moving and loading.展开更多
Precision, Productivity and Performance def ine the GERBERcutter? Z7Tolland, Conn., USA – Gerber Technology, a business unit of Gerber Scientific, Inc. (NYSE: GRB), and the world leader in providing innovative integr...Precision, Productivity and Performance def ine the GERBERcutter? Z7Tolland, Conn., USA – Gerber Technology, a business unit of Gerber Scientific, Inc. (NYSE: GRB), and the world leader in providing innovative integrated software and hardware automation systems to展开更多
Based on the construction of high risk tunnels in Guiguang-Guangzhou high-speed railway, several new technologies were developed for high-risk tunnel con- struction. First, an integrated advanced geological predic- ti...Based on the construction of high risk tunnels in Guiguang-Guangzhou high-speed railway, several new technologies were developed for high-risk tunnel con- struction. First, an integrated advanced geological predic- tion was developed for tunneling in karst area. Then, a new system of ventilation by involving the dedusting technol- ogy was proposed and used in the field, which received a good air quality. Finally, a method to minimize the dis- tance between the working face and the invert installation was proposed by optimizing the invert installation and adopting the micro bench method. Applying the method to the project obtained an excellent result. The achievement obtained for this study would be able to provide a valuable reference to similar projects in the future.展开更多
5G technology is indispensable for developing comprehensive perception and ubiquitous interconnection of intelligent high-speed railways(HSRs),and can be applied to many scenarios in intelligent construction,intellige...5G technology is indispensable for developing comprehensive perception and ubiquitous interconnection of intelligent high-speed railways(HSRs),and can be applied to many scenarios in intelligent construction,intelligent equipment,intelligent operation and in other fields.In order to promote the standardized application of 5G technology in intelligent HSRs in a scientific and orderly manner and to avoid redundant construction and wasteful investment,it is imperative to carry out a systematical top-level design of the application scenarios at the initial stage.To this end,after investigating and analyzing the 5G application demands in different aspects of HSRs and the general structure of the railway 5G network,this paper formulates an overall planning of 5G technology application scenarios and proposes solutions to some typical application scenarios in the intelligent HSR system,based on the architecture and requirements of the intelligent HSR system.展开更多
In the present paper, continuum fracture mechanics is used to analyze the Smart-Cut process, a recently established ion cut technology which enables highly efficient fabrication of various silicon-on-insulator (SOI)...In the present paper, continuum fracture mechanics is used to analyze the Smart-Cut process, a recently established ion cut technology which enables highly efficient fabrication of various silicon-on-insulator (SOI) wafers of high uniformity in thickness. Using integral transform and Cauchy singular integral equation methods, the mode-I and mode-II stress intensity factors, energy release rate, and crack opening displacements are derived in order to examine several important fracture mechanisms involved in the Smart-Cut process. The effects of defect interaction and stiffening wafer on defect growth are investigated. The numerical results indi- cate that a stiffener/handle wafer can effectively prevent the donor wafer from blistering and exfoliation, but it slows down the defect growth by decreasing the magnitudes of SIF's. Defect interaction also plays an important role in the splitting process of SOI wafers, but its contribution depends strongly on the size, interval and internal pressure of defects. Finally, an analytical formula is derived to estimate the implantation dose required for splitting a SOI wafer.展开更多
In Part 2 of the paper on the Smart-Cut process, the effects of bonding flaws characterized by the size and internal pressure before and after splitting are studied by using fracture mechanics models. It is found that...In Part 2 of the paper on the Smart-Cut process, the effects of bonding flaws characterized by the size and internal pressure before and after splitting are studied by using fracture mechanics models. It is found that the bonding flaws with large size are prone to cause severe deviation of defect growth, leading to a non-transferred area of thin layer when splitting. In a practical Smart-Cut process where the internal pressure of bonding flaws is very small, large interfacial defects always promote defect growth in the splitting process. Meanwhile, increasing the internal pressure of the bonding flaws decreases the defect growth and its deviation before splitting. The mechanism of relaxation of stiffener constraint is proposed to clarify the effect of bonding flaws. Moreover, the progress of the splitting process is analyzed when bonding flaws are present. After splitting, those bonding flaws with large size and high internal pressure are vulnerable for the blistering of the thin film during high-temperature annealing.展开更多
One of the promising methods for rock cutting technology is the use of high-speed water jets.In order to improve the cutting capacity of water jets without increasing the hydraulic power of equipment,pulsed water jets...One of the promising methods for rock cutting technology is the use of high-speed water jets.In order to improve the cutting capacity of water jets without increasing the hydraulic power of equipment,pulsed water jets are basically used to increase the rock cutting efficiency.However,there are no mature recommendations for selection of rational parameters,and the relationship between indicators of rock cutting efficiency and parameters of pulsed water jet is still not established.In this context,we aimed at developing a generalized equation for calculating rock cutting efficiency,in which all the major parameters in consideration of rock cutting process are included.Then,a calibration of the rational parameters of rock cutting by pulsed water jets was conducted.The results are likely helpful for increasing productivity and reducing energy consumption.展开更多
Gap cutting consists of the removal of all trees growing on a small surface, varying in size from 200 to 600 m2. In Italy, gap cutting has been successfully tested for introducing the natural regeneration of native sp...Gap cutting consists of the removal of all trees growing on a small surface, varying in size from 200 to 600 m2. In Italy, gap cutting has been successfully tested for introducing the natural regeneration of native species into softwood plantations, thus ac- celerating the transition towards climax hardwood stands. Depending on plantation types and conditions, gap cutting should be start- ed at an age between 70 and 80 years and the system should include at least 12 to 15 gaps, in order to produce enough wood to cover costs. Generally, natural regeneration is firmly established within 5-7 years from treatment. Gap cutting also offers superior results to selection thinning, the latter producing about 35% less value and incurring 25% to 30% more costs. As for all regeneration cuts, the success of gap cutting depends on wildlife control in order to prevent extensive damage to the regeneration.展开更多
Two main types of in situ grain harvesttng machine are introduced. The comparison of their working principles and advantages are given. The limitations and prospects for stripper header are discussed.
Paper-cutting is one of the most fantastic Chinese folk arts. With the aid of computers, digital paper-cutting has become a popular topic in the field of NPR research. This paper will make a comprehensive survey of re...Paper-cutting is one of the most fantastic Chinese folk arts. With the aid of computers, digital paper-cutting has become a popular topic in the field of NPR research. This paper will make a comprehensive survey of related references in four as- pects-image-based paper-cutting, paper-cutting based on computer graphics, paper architectures and paper-cutting animation and it shows that the imitation of the masters' artistic styles of paper-cutting will be the trend of future study.展开更多
基金This work was supported in part by the National Natural Science Foundation of China under Grant 62203468Young Elite Scientist Sponsorship Program by CAST under Grant 2022QNRC001+1 种基金Foundation of China State Railway Group Co.,Ltd.under Grant K2021X001Foundation of China Academy of Railway Sciences Corporation Limited under Grant 2021YJ315.
文摘Purpose–The intelligent Central Traffic Control(CTC)system plays a vital role in establishing an intelligent high-speed railway(HSR)system.As the core of HSR transportation command,the intelligent CTC system is a new HSR dispatching command system that integrates the widely used CTC in China with the practical service requirements of intelligent dispatching.This paper aims to propose key technologies and applications for intelligent dispatching command in HSR in China.Design/methodology/approach–This paper first briefly introduces the functions and configuration of the intelligent CTC system.Some new servers,terminals and interfaces are introduced,which are plan adjustment server/terminal,interface for automatic train operation(ATO),interface for Dynamic Monitoring System of Train Control Equipment(DMS),interface for Power Supervisory Control and Data Acquisition(PSCADA),interface for Disaster Monitoring,etc.Findings–The key technologies applied in the intelligent CTC system include automatic adjustment of train operation plans,safety control of train routes and commands,traffic information data platform,integrated simulation of traffic dispatching and ATO function.These technologies have been applied in the Beijing-Zhangjiakou HSR,which commenced operations at the end of 2019.Implementing these key intelligent functions has improved the train dispatching command capacity,ensured the safe operation of intelligent HSR,reduced the labor intensity of dispatching operators and enhanced the intelligence level of China’s dispatching system.Originality/value–This paper provides further challenges and research directions for the intelligent dispatching command of HSR.To achieve the objectives,new measures need to be conducted,including the development of advanced technologies for intelligent dispatching command,coping with new requirements with the development of China’s railway signaling system,the integration of traffic dispatching and train control and the application of AI and data-driven modeling and methods.
文摘This is a review of high-speed train development in the sense of technology advances all over the world. Three generations of high-speed trains are classified according to their technical characteristics and maximum operating speed. Emphasis is given to the newly developed high-speed train in China, CRH380. The theoretical foundations and future development of CRH380 are briefly discussed.
基金financial support from National Basic Research Program of China (No.2013CB227903)the National Natural Science Foundation of General Program of China (No.51574244)the Joint Funds of the National Natural Science Foundation of China (No.U1361209) are greatly appreciated
文摘The stability control of longwall coalface is the key technology of large-cutting-height mining method.Therefore,a systematic study of the factors that affect coalface stability and its control technology is required in the development of large-cutting-height mining method in China. After the practical field observation and years of study,it was found that the more than 95% of failures in coalface are shear failure. The shear failure analysis model of coalface has been established,that can perform systematic study among factors such as mining height,coal mass strength,roof load,support resistance,and face flipper protecting plate horizontal force. Meanwhile,sensitivity analysis of factors influencing coalface stability showed that improving support capacity,cohesion of coal mass and decreasing roof load of coalface are the key to improve coalface stability. Numerical simulation of the factors affecting coalface stability has been performed using UDEC software and the results are consistent with the theoretical analysis. The coalface reinforcement technology of large-cutting-height mining method using the grouting combined with coir rope is presented. Laboratory tests have been carried out to verify its reinforcement effect and practical application has been implemented in several coal mines with good results.It has now become the main technology to reduce longwall coalface failure of large-cutting-height mining method.
文摘This paper mainly introduces the scientific cutting and hoisting construction technology before the large spherical tank(hereinafter referred to as spherical tank)moving and loading,so as to better ensure the construction quality of field assembly and welding in the process of spherical tank moving and loading.
文摘Precision, Productivity and Performance def ine the GERBERcutter? Z7Tolland, Conn., USA – Gerber Technology, a business unit of Gerber Scientific, Inc. (NYSE: GRB), and the world leader in providing innovative integrated software and hardware automation systems to
文摘Based on the construction of high risk tunnels in Guiguang-Guangzhou high-speed railway, several new technologies were developed for high-risk tunnel con- struction. First, an integrated advanced geological predic- tion was developed for tunneling in karst area. Then, a new system of ventilation by involving the dedusting technol- ogy was proposed and used in the field, which received a good air quality. Finally, a method to minimize the dis- tance between the working face and the invert installation was proposed by optimizing the invert installation and adopting the micro bench method. Applying the method to the project obtained an excellent result. The achievement obtained for this study would be able to provide a valuable reference to similar projects in the future.
文摘5G technology is indispensable for developing comprehensive perception and ubiquitous interconnection of intelligent high-speed railways(HSRs),and can be applied to many scenarios in intelligent construction,intelligent equipment,intelligent operation and in other fields.In order to promote the standardized application of 5G technology in intelligent HSRs in a scientific and orderly manner and to avoid redundant construction and wasteful investment,it is imperative to carry out a systematical top-level design of the application scenarios at the initial stage.To this end,after investigating and analyzing the 5G application demands in different aspects of HSRs and the general structure of the railway 5G network,this paper formulates an overall planning of 5G technology application scenarios and proposes solutions to some typical application scenarios in the intelligent HSR system,based on the architecture and requirements of the intelligent HSR system.
基金the Australian Research Council (ARC),the National Natural Science Foundation of China (10525210 and 10732050) 973 Project (2004CB619303)
文摘In the present paper, continuum fracture mechanics is used to analyze the Smart-Cut process, a recently established ion cut technology which enables highly efficient fabrication of various silicon-on-insulator (SOI) wafers of high uniformity in thickness. Using integral transform and Cauchy singular integral equation methods, the mode-I and mode-II stress intensity factors, energy release rate, and crack opening displacements are derived in order to examine several important fracture mechanisms involved in the Smart-Cut process. The effects of defect interaction and stiffening wafer on defect growth are investigated. The numerical results indi- cate that a stiffener/handle wafer can effectively prevent the donor wafer from blistering and exfoliation, but it slows down the defect growth by decreasing the magnitudes of SIF's. Defect interaction also plays an important role in the splitting process of SOI wafers, but its contribution depends strongly on the size, interval and internal pressure of defects. Finally, an analytical formula is derived to estimate the implantation dose required for splitting a SOI wafer.
基金supported by the Australian Research Council (ARC), the National Natural Science Foundation of China (10525210 and 10732050) 973 Project (2004CB619303)
文摘In Part 2 of the paper on the Smart-Cut process, the effects of bonding flaws characterized by the size and internal pressure before and after splitting are studied by using fracture mechanics models. It is found that the bonding flaws with large size are prone to cause severe deviation of defect growth, leading to a non-transferred area of thin layer when splitting. In a practical Smart-Cut process where the internal pressure of bonding flaws is very small, large interfacial defects always promote defect growth in the splitting process. Meanwhile, increasing the internal pressure of the bonding flaws decreases the defect growth and its deviation before splitting. The mechanism of relaxation of stiffener constraint is proposed to clarify the effect of bonding flaws. Moreover, the progress of the splitting process is analyzed when bonding flaws are present. After splitting, those bonding flaws with large size and high internal pressure are vulnerable for the blistering of the thin film during high-temperature annealing.
文摘One of the promising methods for rock cutting technology is the use of high-speed water jets.In order to improve the cutting capacity of water jets without increasing the hydraulic power of equipment,pulsed water jets are basically used to increase the rock cutting efficiency.However,there are no mature recommendations for selection of rational parameters,and the relationship between indicators of rock cutting efficiency and parameters of pulsed water jet is still not established.In this context,we aimed at developing a generalized equation for calculating rock cutting efficiency,in which all the major parameters in consideration of rock cutting process are included.Then,a calibration of the rational parameters of rock cutting by pulsed water jets was conducted.The results are likely helpful for increasing productivity and reducing energy consumption.
基金supported by the Giunta Regionale delVeneto-Servizi Forestali Regionali di Verona andby the Regione Calabria-Ministero dell'Istruzione,dell'Universitàe della Ricerca
文摘Gap cutting consists of the removal of all trees growing on a small surface, varying in size from 200 to 600 m2. In Italy, gap cutting has been successfully tested for introducing the natural regeneration of native species into softwood plantations, thus ac- celerating the transition towards climax hardwood stands. Depending on plantation types and conditions, gap cutting should be start- ed at an age between 70 and 80 years and the system should include at least 12 to 15 gaps, in order to produce enough wood to cover costs. Generally, natural regeneration is firmly established within 5-7 years from treatment. Gap cutting also offers superior results to selection thinning, the latter producing about 35% less value and incurring 25% to 30% more costs. As for all regeneration cuts, the success of gap cutting depends on wildlife control in order to prevent extensive damage to the regeneration.
文摘Two main types of in situ grain harvesttng machine are introduced. The comparison of their working principles and advantages are given. The limitations and prospects for stripper header are discussed.
文摘Paper-cutting is one of the most fantastic Chinese folk arts. With the aid of computers, digital paper-cutting has become a popular topic in the field of NPR research. This paper will make a comprehensive survey of related references in four as- pects-image-based paper-cutting, paper-cutting based on computer graphics, paper architectures and paper-cutting animation and it shows that the imitation of the masters' artistic styles of paper-cutting will be the trend of future study.