检索结果-南通市图书馆

Chinese Physics B 2024年第10期33卷 95-101页

作者： Huan Liu peng-Fei Shao Song-lin Chen Tao Tao Yu yan Zi-Li Xie Bin Liu Dun-Jun Chen Hai Lu Rong Zhang Ke wang Jiangsu Provincial Key Laboratory of Advanced Photonic and electronic Materials School of Electronic Science and EngineeringNanjing UniversityNanjing 210093China Hefei National Laboratory Hefei 230088China Xiamen University Xiamen 361005China

We have investigated homoepitaxy of AlN films grown by molecular beam epitaxy on AlN/sapphire templates byadopting both the continuous growth method and the Al modulation epitaxy(AME)growth *** continuous growthmethod encounters significant challenges in controlling the growth *** the precise Al/N=1.0 ratio is difficult toachieve,either the excessive Al-rich or N-rich growth mode *** contrast,by adopting the AME growth method,sucha difficulty has been effectively *** manipulating the supply time of the Al and nitrogen sources,we were able toproduce AlN films with much improved surface *** first step of the AME method,only supplying Al atoms,is important to wet the surface and the Al adatoms can act as a *** of the initial Al supply time caneffectively reduce the pit density on the grown AlN *** pits density dropped from 12 pits/μm^(2)to 1 pit/μm^(2)andthe surface roughness reduced from 0.72 nm to 0.3 nm in a 2×2μm^(2)area for the AME AlN film homoepitaxially grownon an AlN template.

关键词： Al modulation epitaxy molecular beam epitaxy AlN pits

Observation of spectral lines in the exceptional GRB 221009A

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 187-206页

作者： yan-Qiu Zhang Shao-lin Xiong Ji-Rong Mao Shuang-Nan Zhang wang-Chen Xue Chao Zheng Jia-Cong Liu Zhen Zhang Xi-Lu wang Ming-Yu Ge Shu-Xu Yi Li-Ming Song Zheng-Hua An Ce Cai Xin-Qiao Li Wen-Xi peng Wen-Jun Tan Chen-Wei wang Xiang-yang Wen Yue wang Shuo Xiao Fan Zhang peng Zhang Shi-Jie Zheng Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China Yunnan Observatories Chinese Academy of SciencesKunming 650011China Center for Astronomical Mega-Science Chinese Academy of SciencesBeijing 100012China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China College of Physics and Hebei Key Laboratory of Photophysics Research and Application Hebei Normal UniversityShijiazhuang 050024China Guizhou Provincial Key Laboratory of Radio Astronomy and Data Processing Guizhou Normal UniversityGuiyang 550001China College of electronic and Information engineering Tongji UniversityShanghai 201804China

As the brightest gamma-ray burst ever observed,GRB 221009A provided a precious opportunity to explore spectral line *** this article,we performed a comprehensive spectroscopy analysis of GRB 221009A jointly with GECAM-C and Fermi/GBM data to search for emission and absorption *** the first time we investigated the line feature throughout this GRB including the most bright part where many instruments suffered problems,and identified prominent emission lines in multiple time *** central energy of the Gaussian emission line evolves from about 37 to 6 MeV,with a nearly constant ratio(about 10%)between the line width and central ***,we find that both the central energy and the energy flux of the emission line evolve with time as a power law decay with power law index of–1 and–2,*** suggest that the observed emission lines most likely origin from the blue-shifted electron positron pair annihilation 511 ke V *** find that a standard high latitude emission scenario cannot fully interpret the observation,thus we propose that the emission line comes from some dense clumps with electron positron pairs traveling together with the *** this scenario,we can use the emission line to directly,for the first time,measure the bulk Lorentz factor of the jet(Γ)and reveal its time evolution(i.e.,Γ~t^(-1))during the prompt ***,we find that the flux of the annihilation line in the co-moving frame keeps *** discoveries of the spectral line features shed new and important lights on the physics of GRB and relativistic jet.

关键词： GRB GRB 221009A emission line

Research progress and development tendency on storage mechanism of multi-principal element alloys for hydrogen/tritium storage

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第11期 5549-5572页

作者： Yi-Jie Chen Jian-Wei Zhang Can-Hui Xu Mu-Hong Li Shuang-lin Hu Yue-Xia wang Xiao-Tao Zu Hai-yan Xiao Xiao-Song Zhou Shu-Ming peng Hua-Hai Shen Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics Key Laboratory of Nuclear Physics and Ion-Beam Application (MOE) Institute of Modern PhysicsDepartment of Nuclear Science and TechnologyFudan University School of Physics University of Electronic Science and Technology of China

Sustainable clean energy is gradually replacing traditional fossil energy sources in important industrial applications and is placing higher demands on the technologies of energy storage and *** development of multi-principal element alloys(MPEAs) offers a new idea for safe solid-state hydrogen storage *** to the unique characteristics of complex components and severe lattice distortion,MPEAs are predicted to have better hydrogen storage performance and more probability for modulation and enhancement,allowing them to meet the requirements of different hydrogen storage *** unique structure characteristic potentially devotes the improvement of thermodynamic and kinetic performance,such as the hydrogen storage capacity and hydrogen adsorption/desorption ***,several important modulation factors originating from components and structures facilitate the understanding of the correlation between hydrogen storage properties and ***,we highlight the correlations of hydrogen storage mechanism,with the degree of lattice distortion,the element variation or segregation and valence electron ***,the development tendency on the hydrogen storage mechanism based on the advanced microscopy and computational approach is ***,the chemically short-range ordered structure in MPEAs is predicted as a potential modification factor of the hydrogen/tritium storage properties.

关键词：

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

非完全信息下无人机集群对抗研究综述

电子与信息学报 2024年第4期46卷 1157-1172页

作者：薛健赵琳向贤财吕科宏晨张宝琳岩延王泳中国科学院大学工程科学学院北京100049 鹏程实验室深圳518055 北京联合大学机器人学院北京100101 青岛科技大学自动化与电子工程学院青岛266061 中国科学院大学人工智能学院北京100190

无人机集群以其具备的应用优势及发展前景,成为当前人工智能领域研究者关注的热点之一。而非完全信息下的无人机集群对抗技术,因其集群结构变化的高动态性以及环境信息复杂多变且不能完全感知的特点,成为对集群协同性与智能性要求最高... 详细信息

无人机集群以其具备的应用优势及发展前景,成为当前人工智能领域研究者关注的热点之一。而非完全信息下的无人机集群对抗技术,因其集群结构变化的高动态性以及环境信息复杂多变且不能完全感知的特点,成为对集群协同性与智能性要求最高的研究方向之一。其研究成果可以促进智能化无人系统的快速发展和广泛应用。该文全面回顾了非完全信息环境下无人机集群对抗研究的最新进展,按照包以德循环理论的思路将无人机集群对抗过程划分为态势评估、意图推断、任务规划与机动决策4个相互衔接的关键组成部分,并进一步将其细分为8个子研究目标。通过分析比较近年来的相关研究,着重阐述了无人机集群对抗领域各项任务的研究重点和难点以及已取得的成果,并讨论了无人机集群对抗技术所面临的挑战,包括大规模异构集群的协同控制、非完全信息的处理、复杂决策过程的建模以及实际应用任务的应对等。

关键词：无人机集群非完全信息态势评估意图推断任务规划机动决策

在线全文

学校读者我要写书评

暂无评论

负性向列相液晶电致缺陷的产生与湮灭过程

物理学报 2024年第5期73卷 257-266页

作者：王紫凌叶家耀黄志军宋振鹏李炳祥肖瑞林陆延青南京邮电大学电子与光学工程学院柔性电子(未来技术)学院南京210023 南京大学现代工程与应用科学学院南京210093 鞍山师范学院物理学院鞍山114000

取向有序的液晶材料具有丰富的物理各向异性、外场响应性、物理效应,催生了新一代的光电应用.利用电场可在液晶中产生拓扑缺陷.缺陷动态过程受材料自身特性和外界条件的影响尚未明晰.本文选用介电各向异性△ε在-1.1到-11.5之间的7种向... 详细信息

取向有序的液晶材料具有丰富的物理各向异性、外场响应性、物理效应,催生了新一代的光电应用.利用电场可在液晶中产生拓扑缺陷.缺陷动态过程受材料自身特性和外界条件的影响尚未明晰.本文选用介电各向异性△ε在-1.1到-11.5之间的7种向列相液晶材料,通过施加线性增加的交流电场,研究了负性向列相液晶电致脐点缺陷产生到湮灭过程中材料特性(△ε)和外界条件(温度、外加电场参数)对脐点缺陷的标度规律及湮灭快慢的影响.结果表明:在不同的△ε、温度和电场频率下,缺陷产生过程均满足Kibble-Zurek机制,即缺陷密度与电场变化率之间存在标度关系,且标度指数约为1/2;温度越高,产生缺陷密度越大;△ε越强或电场变化越快,缺陷湮灭速度越快.本文的研究厘清了拓扑缺陷产生湮灭与材料特性和外界条件的依赖关系,有利于对软物质中拓扑缺陷动态过程的认识和理解.

关键词：向列相液晶脐点缺陷电场效应介电各向异性

Adaptive subsequence adjustment with evolutionary asymmetric path-relinking for TDRSS scheduling

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Journal of Systems engineering and electronics 2014年第5期25卷 800-810页

作者： peng lin linling Kuang Xiang Chen Jian yan Jianhua Lu Xiaojuan wang department of electronic engineering Tsinghua University China electronic Equipment of System engineering Institute Tsinghua Space Center Tsinghua University

Due to the limited transmission resources for data relay in the tracking and data relay satellite system （TDRSS）, there are many job requirements in busy days which will be discarded in the conventional job scheduling model. Therefore, the improvement of scheduling efficiency in the TDRSS can not only help to increase the resource utilities, but also to reduce the scheduling failure ratio. A model of nonhomogeneous parallel machines scheduling problems with time window （NPM-TW） is firstly built up for the TDRSS, considering the distinct features of the variable preparation time and the nonhomogeneous transmission rates for different types of antennas on each tracking and data relay satellite （TDRS）. Then, an adaptive subsequence adjustment （ASA） framework with evolutionary asymmetric path-relinking （EvAPR） is proposed to solve this problem, in which an asymmetric progressive crossover operation is involved to overcome the local optima by the conventional job inserting methods. The numerical results show that, compared with the classical greedy randomized adaptive search procedure （GRASP） algorithm, the scheduling failure ratio of jobs can be reduced over 11% on average by the proposed ASA with EvAPR.

关键词： nonhomogeneous parallel machines scheduling problem with time window (NPM-TW) adaptive subsequence adjustment (ASA) asymmetric path-relinking (APR) evolutionary asymmetric path-relinking (EvAPR).

Large circuit models: opportunities and challenges

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第10期67卷 25-66页

作者： Lei CHEN Yiqi CHEN Zhufei CHU Wenji FANG Tsung-Yi HO Ru HUANG Yu HUANG Sadaf KHAN Min LI Xingquan LI Yu LI Yun LIANG Jinwei LIU Yi LIU Yibo lin Guojie LUO Hongyang PAN Zhengyuan SHI Guangyu SUN Dimitrios TSARAS Runsheng wang Ziyi wang Xinming WEI Zhiyao XIE Qiang XU Chenhao XUE Junchi yan Jun yanG Bei YU Mingxuan YUAN Evangeline F.Y.YOUNG Xuan ZENG Haoyi ZHANG Zuodong ZHANG Yuxiang ZHAO Hui-ling ZHEN Ziyang ZHENG Binwu ZHU Keren ZHU Sunan ZOU Huawei Noah’s Ark Lab School of Integrated Circuits Peking University Faculty of Electrical engineering and Computer Science Ningbo University department of electronic and Computer engineering Hong Kong University of Science and Technology department of Computer Science and engineering The Chinese University of Hong Kong School of Integrated Circuits Southeast University Huawei HiSilicon peng Cheng Laboratory School of Computer Science Peking University School of Microelectronics State Key Laboratory of Integrated Chips and System Fudan University School of Artificial Intelligence Shanghai Jiao Tong University

Within the electronic design automation(EDA) domain, artificial intelligence(AI)-driven solutions have emerged as formidable tools, yet they typically augment rather than redefine existing methodologies. These solutions often repurpose deep learning models from other domains, such as vision, text, and graph analytics, applying them to circuit design without tailoring to the unique complexities of electronic circuits. Such an “AI4EDA” approach falls short of achieving a holistic design synthesis and understanding,overlooking the intricate interplay of electrical, logical, and physical facets of circuit data. This study argues for a paradigm shift from AI4EDA towards AI-rooted EDA from the ground up, integrating AI at the core of the design process. Pivotal to this vision is the development of a multimodal circuit representation learning technique, poised to provide a comprehensive understanding by harmonizing and extracting insights from varied data sources, such as functional specifications, register-transfer level(RTL) designs, circuit netlists,and physical layouts. We champion the creation of large circuit models(LCMs) that are inherently multimodal, crafted to decode and express the rich semantics and structures of circuit data, thus fostering more resilient, efficient, and inventive design methodologies. Embracing this AI-rooted philosophy, we foresee a trajectory that transcends the current innovation plateau in EDA, igniting a profound “shift-left” in electronic design methodology. The envisioned advancements herald not just an evolution of existing EDA tools but a revolution, giving rise to novel instruments of design-tools that promise to radically enhance design productivity and inaugurate a new epoch where the optimization of circuit performance, power, and area(PPA) is achieved not incrementally, but through leaps that redefine the benchmarks of electronic systems' capabilities.

关键词： AI-rooted EDA large circuit models (LCMs) multimodal circuit representation learning circuit optimization

Resonances Characteristics of Parallel Plate Waveguide Cavities

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of electronic Science and Technology 2015年第2期13卷 122-129页

作者： lin Chen Dan-Ni wang Yi-Ming Zhu yan peng Shanghai Key Lab of Modern Optical System Engineering Research Center of Optical Instrument and SystemMinistry of EducationUniversity of Shanghai for Science and Technology

The influence of air gaps on the response of transmission for a transverse-electric mode parallel-plate waveguide（TE-PPWG） with a single cavity and double cavities has been studied experimentally. As the air gap is larger than the resonant wavelength of high order cavity mode in the single deep grooved waveguide, only the fundamental cavity mode can be excited and single resonance can be observed in the transmission spectrum. Based on above observations, a tunable multiband terahertz（THz）notch filter has been proposed and the variation of air gap has turned out to be an effective method to select the band number. Experimental data and simulated results verify this band number tunability. This mechanical control mechanism for electromagnetic induced transparency（EIT） will open a door to design the tunable THz devices.

关键词： resonant transparency excited waveguide tunable terahertz verify notch realization optics

Study of hybrid optical burst networks

在线全文

学校读者我要写书评

暂无评论

Frontiers of Electrical and electronic engineering in China 2006年第4期1卷 416-420页

作者： peng peng PAN Yu-yan wang Jun-feng lin Jin-tong Optical Communication Center Beijing University of Posts and TelecommunicationsBeijing 100876China

We propose the hybrid optical burst switching(HOBS),and investigate the HOBS-based ring topology with numerical *** indicate that the packet loss ratio in HOBS is much less than that in optical burst switching(OBS)and its performance depends on some pa-rameters such as the packet proportion,the electronic buffer size and the processing speed in the node.

关键词： HOBS OBS packet proportion