Designing logic circuits using complementary metal-oxide-semiconductor(CMOS)technology at the nano scale has been faced with various challenges recently.Undesirable leakage currents,the short-effect channel,and high e...Designing logic circuits using complementary metal-oxide-semiconductor(CMOS)technology at the nano scale has been faced with various challenges recently.Undesirable leakage currents,the short-effect channel,and high energy dissipation are some of the concerns.Quantum-dot cellular automata(QCA)represent an appropriate alternative for possible CMOS replacement in the future because it consumes an insignificant amount of energy compared to the standard CMOS.The key point of designing arithmetic circuits is based on the structure of a 1-bit full adder.A low-complexity full adder block is beneficial for developing various intricate structures.This paper represents scalable 1-bit QCA full adder structures based on cell interaction.Our proposed full adders encompass preference aspects of QCA design,such as a low number of cells used,low latency,and small area occupation.Also,the proposed structures have been expanded to larger circuits,including a 4-bit ripple carry adder(RCA),a 4-bit ripple borrow subtractor(RBS),an add/sub circuit,and a 2-bit array multiplier.All designs were simulated and verified using QCA Designer-E version 2.2.This tool can estimate the energy dissipation as well as evaluate the performance of the circuits.Simulation results showed that the proposed designs are efficient in complexity,area,latency,cost,and energy dissipation.展开更多
Understanding the phenology and productivity of Populus species is crucial for effective management and conservation strategies amid climate change.We investigated leaf budbreak timing,susceptibility to cold damage,le...Understanding the phenology and productivity of Populus species is crucial for effective management and conservation strategies amid climate change.We investigated leaf budbreak timing,susceptibility to cold damage,leaf dynamics,and biomass production of 168 Populus genotypes with diverse provenances in the southeastern United States.Our study revealed significant variation in budbreak timing across different taxa and years,with genotypes inheriting traits adapted to their parents’local climates.Temperature emerged as a key factor triggering budbreak,while leaf development depended on other environmental cues such as photoperiod.Notably,budbreak occurred approximately 20 days earlier in 2023 compared to 2022 due to higher accumulated degree days(ADDs).Short-rotation-coppice(SRC)management delayed budbreak by five to ten days.Cold damage was significant in 2023,particularly for genotypes from northern provenances and those with P.maximowiczii parentage.Severe damage was also observed in eastern cottonwood(Populus deltoides×Populus deltoides(D×D))genotypes,despite most having southeastern US parentages.Leaf dynamics,including leaf duration and leaf area index(LAI),varied across taxa and sites,with earlier budbreak correlating with extended growing seasons and increased LAI.Biomass production was intricately linked to phenological events,with earlier budbreak leading to increased biomass production and greater susceptibility to cold damage.Our findings highlight the importance of genetics,environment,and coppicing management in understanding and managing Populus phenology and biomass production.These insights provide valuable guidance for developing effective breeding,conservation,and management strategies for Populus species in the context of climate change.展开更多
A duxianqin musician needs only a single string stretched across an elongated(细长的)soundboard and a feather⁃shaped rod to deliver a diverse repertoire,whether pop or classical,Chinese or Western.In his Zen⁃style stu...A duxianqin musician needs only a single string stretched across an elongated(细长的)soundboard and a feather⁃shaped rod to deliver a diverse repertoire,whether pop or classical,Chinese or Western.In his Zen⁃style studio adorned with folding screens,Wei Qingbing,39,sits on a bamboo mat and plucks(弹拨)the string of his duxianqin with his right hand,while his left hand slides across the rod to adjust the pitch and add vibrato.展开更多
利用无源车辆ISD(inerter spring damper)悬架系统可有效抑制车身低频振动的特性,结合经典加速度驱动阻尼(acceleration driven damping,ADD)控制可抑制车身中高频振动的特点,提出基于ADD正实网络的车辆ISD悬架综合优化设计方法,将车辆...利用无源车辆ISD(inerter spring damper)悬架系统可有效抑制车身低频振动的特性,结合经典加速度驱动阻尼(acceleration driven damping,ADD)控制可抑制车身中高频振动的特点,提出基于ADD正实网络的车辆ISD悬架综合优化设计方法,将车辆ISD悬架的宽频域振动抑制问题转化为基于ADD网络综合的正实优化控制问题。分别构建一阶和二阶正实网络的悬架动态模型,基于鱼群算法优化悬架结构参数,仿真分析ADD控制与正实网络的耦合作用机理和正实网络阶次对悬架性能的影响。结果表明:悬架的隔振性能随正实网络阶次的升高而提升,ADD网络综合的方法可以有效的实现车辆ISD悬架的宽频域的振动抑制,进一步拓展车辆ISD悬架主动控制的思路。展开更多
文摘Designing logic circuits using complementary metal-oxide-semiconductor(CMOS)technology at the nano scale has been faced with various challenges recently.Undesirable leakage currents,the short-effect channel,and high energy dissipation are some of the concerns.Quantum-dot cellular automata(QCA)represent an appropriate alternative for possible CMOS replacement in the future because it consumes an insignificant amount of energy compared to the standard CMOS.The key point of designing arithmetic circuits is based on the structure of a 1-bit full adder.A low-complexity full adder block is beneficial for developing various intricate structures.This paper represents scalable 1-bit QCA full adder structures based on cell interaction.Our proposed full adders encompass preference aspects of QCA design,such as a low number of cells used,low latency,and small area occupation.Also,the proposed structures have been expanded to larger circuits,including a 4-bit ripple carry adder(RCA),a 4-bit ripple borrow subtractor(RBS),an add/sub circuit,and a 2-bit array multiplier.All designs were simulated and verified using QCA Designer-E version 2.2.This tool can estimate the energy dissipation as well as evaluate the performance of the circuits.Simulation results showed that the proposed designs are efficient in complexity,area,latency,cost,and energy dissipation.
基金funded by the USDA National Institute of Food and Agriculture(USDA-NIFA)through the APPS grant(Advancing Populus Pathways in the Southeast,2018-68005-27636)United States Department of Energy(DOE)through the PoSIES(Populus in the Southeast for Integrated Ecosystem Services,DE-EE0009280)USDA-NIFA McIntire Stennis grant(MISZ-067050).
文摘Understanding the phenology and productivity of Populus species is crucial for effective management and conservation strategies amid climate change.We investigated leaf budbreak timing,susceptibility to cold damage,leaf dynamics,and biomass production of 168 Populus genotypes with diverse provenances in the southeastern United States.Our study revealed significant variation in budbreak timing across different taxa and years,with genotypes inheriting traits adapted to their parents’local climates.Temperature emerged as a key factor triggering budbreak,while leaf development depended on other environmental cues such as photoperiod.Notably,budbreak occurred approximately 20 days earlier in 2023 compared to 2022 due to higher accumulated degree days(ADDs).Short-rotation-coppice(SRC)management delayed budbreak by five to ten days.Cold damage was significant in 2023,particularly for genotypes from northern provenances and those with P.maximowiczii parentage.Severe damage was also observed in eastern cottonwood(Populus deltoides×Populus deltoides(D×D))genotypes,despite most having southeastern US parentages.Leaf dynamics,including leaf duration and leaf area index(LAI),varied across taxa and sites,with earlier budbreak correlating with extended growing seasons and increased LAI.Biomass production was intricately linked to phenological events,with earlier budbreak leading to increased biomass production and greater susceptibility to cold damage.Our findings highlight the importance of genetics,environment,and coppicing management in understanding and managing Populus phenology and biomass production.These insights provide valuable guidance for developing effective breeding,conservation,and management strategies for Populus species in the context of climate change.
文摘A duxianqin musician needs only a single string stretched across an elongated(细长的)soundboard and a feather⁃shaped rod to deliver a diverse repertoire,whether pop or classical,Chinese or Western.In his Zen⁃style studio adorned with folding screens,Wei Qingbing,39,sits on a bamboo mat and plucks(弹拨)the string of his duxianqin with his right hand,while his left hand slides across the rod to adjust the pitch and add vibrato.
文摘利用无源车辆ISD(inerter spring damper)悬架系统可有效抑制车身低频振动的特性,结合经典加速度驱动阻尼(acceleration driven damping,ADD)控制可抑制车身中高频振动的特点,提出基于ADD正实网络的车辆ISD悬架综合优化设计方法,将车辆ISD悬架的宽频域振动抑制问题转化为基于ADD网络综合的正实优化控制问题。分别构建一阶和二阶正实网络的悬架动态模型,基于鱼群算法优化悬架结构参数,仿真分析ADD控制与正实网络的耦合作用机理和正实网络阶次对悬架性能的影响。结果表明:悬架的隔振性能随正实网络阶次的升高而提升,ADD网络综合的方法可以有效的实现车辆ISD悬架的宽频域的振动抑制,进一步拓展车辆ISD悬架主动控制的思路。
