在充分研究USB2.0设备接口协议的基础上,提出了一种基于TMS320C5402 DSP与CY7C68001 EZ USB SX2的USB2.0系统的硬件接口逻辑及软件系统。通过 CPLD设计,克服了DSP I/O口功能弱的缺点,提高了DSP的控制能力,增强了系统设计的成功率和灵活...在充分研究USB2.0设备接口协议的基础上,提出了一种基于TMS320C5402 DSP与CY7C68001 EZ USB SX2的USB2.0系统的硬件接口逻辑及软件系统。通过 CPLD设计,克服了DSP I/O口功能弱的缺点,提高了DSP的控制能力,增强了系统设计的成功率和灵活性。用所设计的软件接口实现了控制状态寄存器的访问、中断源的读取、设备枚举处理及命令节点的处理。现场使用和试验表明,该系统具有速度快和可靠性强等优点。展开更多
The hot forming behavior,failure mechanism,and microstructure evolution of in-situ TiB_(2)particle-reinforced 7075 aluminum matrix composite were investigated by isothermal compression test under different deformation...The hot forming behavior,failure mechanism,and microstructure evolution of in-situ TiB_(2)particle-reinforced 7075 aluminum matrix composite were investigated by isothermal compression test under different deformation conditions of deformation temperatures of 300−450℃ and strain rates of 0.001^(−1)s^(−1).The results demonstrate that the failure behavior of the composite exhibits both particle fracture and interface debonding at low temperature and high strain rate,and dimple rupture of the matrix at high temperature and low strain rate.Full dynamic recrystallization,which improves the composite formability,occurs under conditions of high temperature(450℃)and low strain rate(0.001 s^(−1));the grain size of the matrix after hot compression was significantly smaller than that of traditional 7075Al and ex-situ particle reinforced 7075Al matrix composite.Based on the flow stress curves,a constitutive model describing the relationship of the flow stress,true strain,strain rate and temperature was proposed.Furthermore,the processing maps based on both the dynamic material modeling(DMM)and modified DMM(MDMM)were established to analyze flow instability domain of the composite and optimize hot forming processing parameters.The optimum processing domain was determined at temperatures of 425−450℃ and strain rates of 0.001−0.01 s^(−1),in which the fine grain microstructure can be gained and particle crack and interface debonding can be avoided.展开更多
Lithium cobalt oxide(LiCoO_(2),LCO)dominates in 3C(computer,communication,and consumer)electronics-based batteries with the merits of extraordinary volumetric and gravimetric energy density,high-voltage plateau,and fa...Lithium cobalt oxide(LiCoO_(2),LCO)dominates in 3C(computer,communication,and consumer)electronics-based batteries with the merits of extraordinary volumetric and gravimetric energy density,high-voltage plateau,and facile synthesis.Currently,the demand for lightweight and longer standby smart portable electronic products drives the development of the upper cut-off voltage of LCO-based batteries to further improve the energy density.However,several challenges,including irreversible structural transformation,surface degradation,cobalt dissolution and oxygen evolution along with detrimental side reactions with the electrolyte remain with charging to a high cut-off voltage(>4.2 V vs.Li/Li+),resulting in rapid capacity decay and safety issues.Based on the degradation mechanisms and latest advances of the high-voltage LCO,this review summarizes modification strategies in view of the LCO structure,artificial interface design and electrolytes optimization.Meanwhile,many advanced characterization and monitoring techniques utilized to clarify the structural and interfacial evolution of LCO during charge/discharge process are critically emphasized.Moreover,the perspectives in terms of integrating multiple modification strategies,applying gel and solid-state electrolytes,optimizing the recovery process and scalable production are presented.展开更多
Green energy generation is an indispensable task to concurrently resolve fossil fuel depletion and environmental issues to align with the global goals of achieving carbon neutrality.Photocatalysis,a process that trans...Green energy generation is an indispensable task to concurrently resolve fossil fuel depletion and environmental issues to align with the global goals of achieving carbon neutrality.Photocatalysis,a process that transforms solar energy into clean fuels through a photocatalyst,represents a felicitous direction toward sustainability.Eco-rich metal-free graphitic carbon nitride(g-C_(3)N_(4))is profiled as an attractive photocatalyst due to its fascinating properties,including excellent chemical and thermal stability,moderate band gap,visible light-active nature,and ease of fabrication.Nonetheless,the shortcomings of g-C_(3)N_(4)include fast charge recombination and limited surface-active sites,which adversely affect photocatalytic reactions.Among the modification strategies,point-to-face contact engineering of 2D g-C_(3)N_(4)with 0D nanomaterials represents an innovative and promising synergy owing to several intriguing attributes such as the high specific surface area,short effective charge-transfer pathways,and quantum confinement effects.This review introduces recent advances achieved in experimental and computational studies on the interfacial design of 0D nanostructures on 2D g-C_(3)N_(4)in the construction of point-to-face heterojunction interfaces.Notably,0D materials such as metals,metal oxides,metal sulfides,metal selenides,metal phosphides,and nonmetals on g-C_(3)N_(4)with different charge-transfer mechanisms are systematically discussed along with controllable synthesis strategies.The applications of 0D/2D g-C_(3)N_(4)-based photocatalysts are focused on solar-to-energy conversion via the hydrogen evolution reaction,the CO_(2)reduction reaction,and the N2 reduction reaction to evaluate the photocatalyst activity and elucidate reaction pathways.Finally,future perspectives for developing high-efficiency 0D/2D photocatalysts are proposed to explore potential emerging carbon nitride allotropes,large-scale production,machine learning integration,and multidisciplinary advances for technological breakthroughs.展开更多
文摘在充分研究USB2.0设备接口协议的基础上,提出了一种基于TMS320C5402 DSP与CY7C68001 EZ USB SX2的USB2.0系统的硬件接口逻辑及软件系统。通过 CPLD设计,克服了DSP I/O口功能弱的缺点,提高了DSP的控制能力,增强了系统设计的成功率和灵活性。用所设计的软件接口实现了控制状态寄存器的访问、中断源的读取、设备枚举处理及命令节点的处理。现场使用和试验表明,该系统具有速度快和可靠性强等优点。
基金the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2018-ZX04044001-008)the National Natural Science Foundation of China(No.52075328).
文摘The hot forming behavior,failure mechanism,and microstructure evolution of in-situ TiB_(2)particle-reinforced 7075 aluminum matrix composite were investigated by isothermal compression test under different deformation conditions of deformation temperatures of 300−450℃ and strain rates of 0.001^(−1)s^(−1).The results demonstrate that the failure behavior of the composite exhibits both particle fracture and interface debonding at low temperature and high strain rate,and dimple rupture of the matrix at high temperature and low strain rate.Full dynamic recrystallization,which improves the composite formability,occurs under conditions of high temperature(450℃)and low strain rate(0.001 s^(−1));the grain size of the matrix after hot compression was significantly smaller than that of traditional 7075Al and ex-situ particle reinforced 7075Al matrix composite.Based on the flow stress curves,a constitutive model describing the relationship of the flow stress,true strain,strain rate and temperature was proposed.Furthermore,the processing maps based on both the dynamic material modeling(DMM)and modified DMM(MDMM)were established to analyze flow instability domain of the composite and optimize hot forming processing parameters.The optimum processing domain was determined at temperatures of 425−450℃ and strain rates of 0.001−0.01 s^(−1),in which the fine grain microstructure can be gained and particle crack and interface debonding can be avoided.
基金financial support from the National Key R&D Program of China(2018YFA0209600)the National Natural Science Foundation of China(22022813 and 21878268)the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2019R01006)。
文摘Lithium cobalt oxide(LiCoO_(2),LCO)dominates in 3C(computer,communication,and consumer)electronics-based batteries with the merits of extraordinary volumetric and gravimetric energy density,high-voltage plateau,and facile synthesis.Currently,the demand for lightweight and longer standby smart portable electronic products drives the development of the upper cut-off voltage of LCO-based batteries to further improve the energy density.However,several challenges,including irreversible structural transformation,surface degradation,cobalt dissolution and oxygen evolution along with detrimental side reactions with the electrolyte remain with charging to a high cut-off voltage(>4.2 V vs.Li/Li+),resulting in rapid capacity decay and safety issues.Based on the degradation mechanisms and latest advances of the high-voltage LCO,this review summarizes modification strategies in view of the LCO structure,artificial interface design and electrolytes optimization.Meanwhile,many advanced characterization and monitoring techniques utilized to clarify the structural and interfacial evolution of LCO during charge/discharge process are critically emphasized.Moreover,the perspectives in terms of integrating multiple modification strategies,applying gel and solid-state electrolytes,optimizing the recovery process and scalable production are presented.
基金Ministry of Higher Education,Malaysia,Grant/Award Number:FRGS/1/2020/TK0/XMU/02/1Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2021A1515111019+1 种基金Hengyuan International Sdn.Bhd.,Grant/Award Number:EENG/0003Xiamen University Malaysia,Grant/Award Numbers:IENG/0038,ICOE/0001,XMUMRF/2019-C3/IENG/0013,XMUMRF/2021-C8/IENG/0041。
文摘Green energy generation is an indispensable task to concurrently resolve fossil fuel depletion and environmental issues to align with the global goals of achieving carbon neutrality.Photocatalysis,a process that transforms solar energy into clean fuels through a photocatalyst,represents a felicitous direction toward sustainability.Eco-rich metal-free graphitic carbon nitride(g-C_(3)N_(4))is profiled as an attractive photocatalyst due to its fascinating properties,including excellent chemical and thermal stability,moderate band gap,visible light-active nature,and ease of fabrication.Nonetheless,the shortcomings of g-C_(3)N_(4)include fast charge recombination and limited surface-active sites,which adversely affect photocatalytic reactions.Among the modification strategies,point-to-face contact engineering of 2D g-C_(3)N_(4)with 0D nanomaterials represents an innovative and promising synergy owing to several intriguing attributes such as the high specific surface area,short effective charge-transfer pathways,and quantum confinement effects.This review introduces recent advances achieved in experimental and computational studies on the interfacial design of 0D nanostructures on 2D g-C_(3)N_(4)in the construction of point-to-face heterojunction interfaces.Notably,0D materials such as metals,metal oxides,metal sulfides,metal selenides,metal phosphides,and nonmetals on g-C_(3)N_(4)with different charge-transfer mechanisms are systematically discussed along with controllable synthesis strategies.The applications of 0D/2D g-C_(3)N_(4)-based photocatalysts are focused on solar-to-energy conversion via the hydrogen evolution reaction,the CO_(2)reduction reaction,and the N2 reduction reaction to evaluate the photocatalyst activity and elucidate reaction pathways.Finally,future perspectives for developing high-efficiency 0D/2D photocatalysts are proposed to explore potential emerging carbon nitride allotropes,large-scale production,machine learning integration,and multidisciplinary advances for technological breakthroughs.
