在循证医学时代下,依托规范的技术方法和标准化的操作规程发掘中医药独特优势,是实现中医药现代化、国际化发展并惠泽人类的必由之路。中医理论、人用经验和研究证据三结合证据体系的提出标志着中医药特色评价体系思维方法取得了重要进...在循证医学时代下,依托规范的技术方法和标准化的操作规程发掘中医药独特优势,是实现中医药现代化、国际化发展并惠泽人类的必由之路。中医理论、人用经验和研究证据三结合证据体系的提出标志着中医药特色评价体系思维方法取得了重要进步,经过恰当方法整合后的多元证据体是中医药临床指南推荐意见和循证卫生决策的有力支撑。本文基于当前国际证据合成与分级方法学前沿进展,初步提出中医药多元证据整合的方法学框架——MERGE(Merge Evidence-based Research and artificial intelliGence to support smart dEcision)框架,以期为中医药循证医学方法学体系的完善和发展提供借鉴和参考。展开更多
In the modern society,there is a strong demand for semiconductor chips,and the 4H polytype silicon carbide(4H-SiC)power device is a promising candidate for the next generation semiconductor chip,which can be used in v...In the modern society,there is a strong demand for semiconductor chips,and the 4H polytype silicon carbide(4H-SiC)power device is a promising candidate for the next generation semiconductor chip,which can be used in various power electronic systems.In order to improve the performance of the 4H-SiC power device,a novel ultrahigh-voltage(UHV)4H-SiC merged p-type/intrinsic/n-type(PiN)Schottky(MPS)diode with three-dimensional(3D)p-type buried layers(PBL)(3D-PBL MPS)is proposed and investigated by numerical simulation.The static forward conduction characteristics of the 3D-PBL MPS are similar to those of the conventional 4H-SiC MPS diode without the PBL(PBL-free MPS).However,when the 3D-PBL MPS is in the reverse blocking state,the 3D PBL can transfer the peak electric field(E_(peak))into a deeper position in the body of the epitaxial layer,and enhance the ability of the device to shield the high electric field at the Schottky contact interface(E_(S)),so that the reverse leakage current of the 3D-PBL MPS at 10 kV is only 0.002%of that of the PBL-free MPS.Meanwhile,the novel 3D-PBL MPS has overcome the disadvantage in the 4H-SiC MPS diode with the two-dimensional PBL(2D-PBL MPS),and the forward conduction characteristic of the 3D-PBL MPS will not get degenerated after the device converts from the reverse blocking state to the forward conduction state because of the special depletion layer variation mechanism depending on the 3D PBL.All the simulation results show that the novel UHV 3D-PBL MPS has excellent device performance.展开更多
为精确刻画匝道合流区客货混行条件下的车辆微观换道行为,本文以量化客货交互为切入点,构建并验证考虑货车影响的微观换道模型。首先,引入“压迫”概念,构建改进Morse势函数模型描述周边货车行驶对小汽车横纵驾驶行为产生的“压迫”影响...为精确刻画匝道合流区客货混行条件下的车辆微观换道行为,本文以量化客货交互为切入点,构建并验证考虑货车影响的微观换道模型。首先,引入“压迫”概念,构建改进Morse势函数模型描述周边货车行驶对小汽车横纵驾驶行为产生的“压迫”影响;随后,分析小汽车换道过程中的横纵向“压迫”变化,提出一种考虑货车“压迫”影响的车辆换道决策模型(Modified Morse-Based Lane-Changing model,MMBLC);最后,基于实测轨迹数据进行数值仿真,验证模型的稳定性与有效性,并进一步利用Python与SUMO(Simulation of Urban Mobility)联合仿真,对比MMBLC模型和现有换道模型在交通流中的表现。结果表明:在稳定性分析中,MMBLC模型对交通流的影响更小,恢复稳定的速度更快;在货车占比30%和交通量3600 veh·h-1的主路3车道客货混行匝道合流区中,MMBLC模型相比LC2013和MOBIL(Model of Optimal Control Based on Interacting Trajectories)模型,换道成功率分别提高11.9%和53.1%,危险场景占比分别降低10.5%和52.8%。展开更多
文摘在循证医学时代下,依托规范的技术方法和标准化的操作规程发掘中医药独特优势,是实现中医药现代化、国际化发展并惠泽人类的必由之路。中医理论、人用经验和研究证据三结合证据体系的提出标志着中医药特色评价体系思维方法取得了重要进步,经过恰当方法整合后的多元证据体是中医药临床指南推荐意见和循证卫生决策的有力支撑。本文基于当前国际证据合成与分级方法学前沿进展,初步提出中医药多元证据整合的方法学框架——MERGE(Merge Evidence-based Research and artificial intelliGence to support smart dEcision)框架,以期为中医药循证医学方法学体系的完善和发展提供借鉴和参考。
基金Project(F2020210016) supported by the Natural Science Foundation of Hebei,ChinaProject(620004153) supported by the National Natural Science Foundation of China。
文摘In the modern society,there is a strong demand for semiconductor chips,and the 4H polytype silicon carbide(4H-SiC)power device is a promising candidate for the next generation semiconductor chip,which can be used in various power electronic systems.In order to improve the performance of the 4H-SiC power device,a novel ultrahigh-voltage(UHV)4H-SiC merged p-type/intrinsic/n-type(PiN)Schottky(MPS)diode with three-dimensional(3D)p-type buried layers(PBL)(3D-PBL MPS)is proposed and investigated by numerical simulation.The static forward conduction characteristics of the 3D-PBL MPS are similar to those of the conventional 4H-SiC MPS diode without the PBL(PBL-free MPS).However,when the 3D-PBL MPS is in the reverse blocking state,the 3D PBL can transfer the peak electric field(E_(peak))into a deeper position in the body of the epitaxial layer,and enhance the ability of the device to shield the high electric field at the Schottky contact interface(E_(S)),so that the reverse leakage current of the 3D-PBL MPS at 10 kV is only 0.002%of that of the PBL-free MPS.Meanwhile,the novel 3D-PBL MPS has overcome the disadvantage in the 4H-SiC MPS diode with the two-dimensional PBL(2D-PBL MPS),and the forward conduction characteristic of the 3D-PBL MPS will not get degenerated after the device converts from the reverse blocking state to the forward conduction state because of the special depletion layer variation mechanism depending on the 3D PBL.All the simulation results show that the novel UHV 3D-PBL MPS has excellent device performance.
文摘为精确刻画匝道合流区客货混行条件下的车辆微观换道行为,本文以量化客货交互为切入点,构建并验证考虑货车影响的微观换道模型。首先,引入“压迫”概念,构建改进Morse势函数模型描述周边货车行驶对小汽车横纵驾驶行为产生的“压迫”影响;随后,分析小汽车换道过程中的横纵向“压迫”变化,提出一种考虑货车“压迫”影响的车辆换道决策模型(Modified Morse-Based Lane-Changing model,MMBLC);最后,基于实测轨迹数据进行数值仿真,验证模型的稳定性与有效性,并进一步利用Python与SUMO(Simulation of Urban Mobility)联合仿真,对比MMBLC模型和现有换道模型在交通流中的表现。结果表明:在稳定性分析中,MMBLC模型对交通流的影响更小,恢复稳定的速度更快;在货车占比30%和交通量3600 veh·h-1的主路3车道客货混行匝道合流区中,MMBLC模型相比LC2013和MOBIL(Model of Optimal Control Based on Interacting Trajectories)模型,换道成功率分别提高11.9%和53.1%,危险场景占比分别降低10.5%和52.8%。
