Terminals and their access represent a vulnerable aspect in the security framework of 5G-railway(5G-R)system.To enhance the control of 5G-R terminals and their access to applications,this paper analyzes the applicatio...Terminals and their access represent a vulnerable aspect in the security framework of 5G-railway(5G-R)system.To enhance the control of 5G-R terminals and their access to applications,this paper analyzes the application scenarios,operational modes,services supported by 5G-R terminals,and the data paths between these terminals and the connected railway application service systems.Further analysis concentrates on the security risks posed by the characteristics of intelligent 5G-R handheld terminals,lightweight Internet of Things(IoT)communication terminals,and onboard integrated wireless transmission equipment with public-private convergence.In light of the risks above,this paper presents the terminal security control requirements.Furthermore,based on the planned architecture of the 5G-R system and security technologies such as terminal identity authentication and behavior auditing,the paper proposes a solution package for the 5G-R terminal security control system,including the overall architecture,functional implementation,and interface configuration.These solutions aim to achieve unified control over the admission and access of 5G-R handheld terminals,IoT communication terminals,and onboard integrated wireless communication equipment to railway application systems.Additionally,they enable the security control and analysis of terminal behaviors and application data,facilitate the security management of terminals,and ensure the secure release,download,and installation of mobile applications.展开更多
Two-dimensional (2D) materials, such as MoS2, show exceptional potential for next-generation electronics. However, the poorstability of these materials, particularly under long-term operations and high temperature, im...Two-dimensional (2D) materials, such as MoS2, show exceptional potential for next-generation electronics. However, the poorstability of these materials, particularly under long-term operations and high temperature, impedes their practical applications.Here, we develop a terminal passivation interface decoupling (TPID) strategy to significantly improve the stability of MoS2, bymitigating the interaction between the substrate and the 2D material within the in-situ growth process. Specifically, the strongelectron-withdrawing terminal group hydroxyl, prevalent on the oxide substrate, is passivated by carbon groups. Due to this, thestructure of MoS2 materials remains stable during long-term storage, and its electronic devices, field-effect transistors (FETs),show remarkable operational and high-temperature (400°C) stability over 60 days, with much-improved performance. Forexample, mobility increases from 9.69 to 85 cm2/(V·s), the highest value for bottom-up transfer-free single crystal MoS2 FETs.This work provides a new avenue to solve reliability issues of 2D materials and devices, laying a foundation for their applicationsin the electronic industry.展开更多
The efficient utilization of visible light catalysts for organic reactions necessitates not only the effective separation of photogenerated electrons and holes to participate in the reaction,but also their ability to ...The efficient utilization of visible light catalysts for organic reactions necessitates not only the effective separation of photogenerated electrons and holes to participate in the reaction,but also their ability to form key intermediates with reactant molecules.The present study successfully synthesized a crusiform-like mesoporous structure of nitrogen-doped carbon-coated Cu_(2)O/Cu(Cu_(2)O/Cu/N-C)with a Cu_(2)O/dual electron acceptor interface using etched HKUST-1 as the precursor.A series of theoretical and experimental studies have demonstrated that the Cu_(2)O/Cu/N-C interface in the photocatalytic homo-coupling of terminal alkynes not only effectively enhances the separation of photogenerated electron−hole pairs,but also facilitates the formation of the key intermediate[Cu_(2)O/Cu/N-C]-phenylacetylide and promotes the rearrangement of its internal charges.As a result,the homo-coupling reaction can be effectively facilitated.The primary reason for the functional role of Cu_(2)O/Cu/N-C interface lies in the downward bending of energy band from Cu_(2)O to N-doped C layers,induced by the different work functions of Cu_(2)O,Cu and N-doped C layers.Consequently,Cu_(2)O/Cu/N-C photocatalysts demonstrate exceptional photocatalytic activity in the homo-coupling reaction of terminal alkynes under blue-light irradiation and air atmosphere.The present study presents a novel research methodology for the development of highly efficient visible light catalysts to facilitate organic reactions in future applications.展开更多
Partial discharge caused by interfacial defects of cable terminations is an important factor affecting insulating performance,which will seriously threaten operational safety of high-speed trains by causing a breakdow...Partial discharge caused by interfacial defects of cable terminations is an important factor affecting insulating performance,which will seriously threaten operational safety of high-speed trains by causing a breakdown fault of vehicle-mounted cable terminations.Simulation combined with experimentation is adopted to study the evolution characteristic of interfacial defects inside cable termination for high-speed trains.A simulation model and test samples of high-voltage cable terminations with prefabricated air gap and carbon trace defects are constructed.Results show that maximum field strength(MFS)at the defect is always located at the end of it.Evolution of the defects can be significantly divided into three stages based on the variation law of field strength and characteristics of partial discharge.A new feature of stage III is that volume of discharge in the third quadrant is significantly higher than in the first quadrant.PDEV in this stage is 51.41%lower than that of the defect-free cable termination and lower than operating voltage.Therefore,stage III is critical for detection of insulation state.Findings of the new characteristics and conclusions of the study provide strong support for improving operation and maintenance techniques of vehicle-mounted cable terminations.展开更多
文摘Terminals and their access represent a vulnerable aspect in the security framework of 5G-railway(5G-R)system.To enhance the control of 5G-R terminals and their access to applications,this paper analyzes the application scenarios,operational modes,services supported by 5G-R terminals,and the data paths between these terminals and the connected railway application service systems.Further analysis concentrates on the security risks posed by the characteristics of intelligent 5G-R handheld terminals,lightweight Internet of Things(IoT)communication terminals,and onboard integrated wireless transmission equipment with public-private convergence.In light of the risks above,this paper presents the terminal security control requirements.Furthermore,based on the planned architecture of the 5G-R system and security technologies such as terminal identity authentication and behavior auditing,the paper proposes a solution package for the 5G-R terminal security control system,including the overall architecture,functional implementation,and interface configuration.These solutions aim to achieve unified control over the admission and access of 5G-R handheld terminals,IoT communication terminals,and onboard integrated wireless communication equipment to railway application systems.Additionally,they enable the security control and analysis of terminal behaviors and application data,facilitate the security management of terminals,and ensure the secure release,download,and installation of mobile applications.
基金supported by the National Natural Science Foundation of China(52403243,52225304,52073210,52121002)the China Postdoctoral Science Foundation(2024T170646,2023M742591)the Fundamental Research Funds for the Central Universities.
文摘Two-dimensional (2D) materials, such as MoS2, show exceptional potential for next-generation electronics. However, the poorstability of these materials, particularly under long-term operations and high temperature, impedes their practical applications.Here, we develop a terminal passivation interface decoupling (TPID) strategy to significantly improve the stability of MoS2, bymitigating the interaction between the substrate and the 2D material within the in-situ growth process. Specifically, the strongelectron-withdrawing terminal group hydroxyl, prevalent on the oxide substrate, is passivated by carbon groups. Due to this, thestructure of MoS2 materials remains stable during long-term storage, and its electronic devices, field-effect transistors (FETs),show remarkable operational and high-temperature (400°C) stability over 60 days, with much-improved performance. Forexample, mobility increases from 9.69 to 85 cm2/(V·s), the highest value for bottom-up transfer-free single crystal MoS2 FETs.This work provides a new avenue to solve reliability issues of 2D materials and devices, laying a foundation for their applicationsin the electronic industry.
基金supported by the Xuzhou Key Research and Development Program(Social Development)(No.KC23298)the National Natural Science Foundation of China(No.22271122)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20211549)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_2903).
文摘The efficient utilization of visible light catalysts for organic reactions necessitates not only the effective separation of photogenerated electrons and holes to participate in the reaction,but also their ability to form key intermediates with reactant molecules.The present study successfully synthesized a crusiform-like mesoporous structure of nitrogen-doped carbon-coated Cu_(2)O/Cu(Cu_(2)O/Cu/N-C)with a Cu_(2)O/dual electron acceptor interface using etched HKUST-1 as the precursor.A series of theoretical and experimental studies have demonstrated that the Cu_(2)O/Cu/N-C interface in the photocatalytic homo-coupling of terminal alkynes not only effectively enhances the separation of photogenerated electron−hole pairs,but also facilitates the formation of the key intermediate[Cu_(2)O/Cu/N-C]-phenylacetylide and promotes the rearrangement of its internal charges.As a result,the homo-coupling reaction can be effectively facilitated.The primary reason for the functional role of Cu_(2)O/Cu/N-C interface lies in the downward bending of energy band from Cu_(2)O to N-doped C layers,induced by the different work functions of Cu_(2)O,Cu and N-doped C layers.Consequently,Cu_(2)O/Cu/N-C photocatalysts demonstrate exceptional photocatalytic activity in the homo-coupling reaction of terminal alkynes under blue-light irradiation and air atmosphere.The present study presents a novel research methodology for the development of highly efficient visible light catalysts to facilitate organic reactions in future applications.
基金supported by the National Natural Science Foundation of China(52007158)The Smart Grid Joint Fund and the National Natural Science Foundation of China(U1966602)The Excellent Young Scientists Fund of China(51922090)。
文摘Partial discharge caused by interfacial defects of cable terminations is an important factor affecting insulating performance,which will seriously threaten operational safety of high-speed trains by causing a breakdown fault of vehicle-mounted cable terminations.Simulation combined with experimentation is adopted to study the evolution characteristic of interfacial defects inside cable termination for high-speed trains.A simulation model and test samples of high-voltage cable terminations with prefabricated air gap and carbon trace defects are constructed.Results show that maximum field strength(MFS)at the defect is always located at the end of it.Evolution of the defects can be significantly divided into three stages based on the variation law of field strength and characteristics of partial discharge.A new feature of stage III is that volume of discharge in the third quadrant is significantly higher than in the first quadrant.PDEV in this stage is 51.41%lower than that of the defect-free cable termination and lower than operating voltage.Therefore,stage III is critical for detection of insulation state.Findings of the new characteristics and conclusions of the study provide strong support for improving operation and maintenance techniques of vehicle-mounted cable terminations.
