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NOISE AMPLIFICATION ANALYSIS AND COMPARISON OF TWO PERIODIC NONUNIFORM SAMPLING RECONSTRUCTION METHODS USED IN DPCA SAR

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Journal of Electronics(China) 2008年第6期25卷 786-796页

作者： song xiufeng Yu Weidong Institute of Electronics Chinese Academy of Sciences Beijing 100190 China Graduate University of Chinese Academy of Sciences Beijing 100030 China

General Sampling Expansion Reconstruction Method (GSERM) and Digital Spectrum Reconstruction Method (DSRM), which prove effective to reconstruct azimuth signal of Displaced Phase Center Apertures (DPCA) Synthetic Aperture Radar (SAR) system from its Periodic Non-Uniform Sampling (PNUS) data sequences, would amplify the noise and sidelobe clutter simultaneously in the reconstruction. This paper formulates the relation of the system transfer matrixes of the above two methods, gives the properties, such as periodicity, symmetry, and time-shift property, of their Noise and Sidelobe Clutter Amplification Factor (NSCAF), and discovers that DSRM is more sensitive than GSERM in the white noise environment. In addition, criteria based on initial sampling point analysis for the robust PRF selection are suggested. Computer simulation results support these con-clusions.

关键词： Synthetic Aperture Radar (SAR) Displaced Phase Center Apertures (DPCA) Periodic NonUniform Sampling (PNUS) Noise Sidelobe clutter

RECONSTRUCT AZIMUTH SIGNAL AND SUPPRESS INTERBEAM AMBIGUITIES OF SPCMB SAR WITH HYBRID FILTERBANK

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Journal of Electronics(China) 2008年第3期25卷 324-329页

作者： song xiufeng Yu Weidong Institute of Electronics Chinese Academy of Sciences Beijing 100190 China Graduate School of Chinese Academy of Sciences Beijing 100039 China

Conventional Synthetic Aperture Radar (SAR) systems cannot obtain high-resolution and wide-swath illumination area due to the well-known minimum antenna area constraint. Single Phase Center MultiBeam (SPCMB) technique can overcome this limitation by adding spatial sampling through multiple receivers in azimuth direction. Unfortunately, this approach will lead to an increase of azimuth ambiguities (interbeam ambiguities), because each receive beam’s mainlobe overlaps with the other ones’ sidelobes. This paper proves that the front part of SPCMB SAR systems can be considered to be a hybrid filterbank. Therefore, the azimuth signal can be reconstructed and the interbeam am- biguities can be effectively suppressed by a well-designed hybrid filterbank.

关键词： Synthetic Aperture Radar (SAR) High-resolution wide-swath Signal Phase Center MultiBeam (SPCMB) Signal reconstruction Hybrid filterbank

Optical detection of quantum geometric tensor in intrinsic semiconductors

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Science China(Physics,Mechanics & Astronomy) 2021年第10期64卷 82-87页

作者： Zhi Li Shengli Zhang Takami Tohyama xiufeng song Yu Gu Toshiaki Iitaka Haibin Su Haibo Zeng MIIT Key Lxiboratory of Advanced Display Materials and Devices Ministry of Industry and Information TechnologyInstitute of Optoelectronics&NanomaterialsNanjing University of Science and TechnologyNanjing 210094China Department of Applied Physics Tokyo University of ScienceKatsushikaTokyo 125-8585Japan Discrete Event Simulation Research Team R/KEN Center for Computational ScienceWako 351-0198Japan Department of Chemistry The Hong Kong University of Science and TechnologyHong KongChina

Quantum geometric tensor, including a symmetric real part defined as quantum metric and an antisymmetric part defined as Berry curvature, is essential for understanding many phenomena. In this study, we investigated the photogalvanic efect of semiconductors with time-reversal-invariant and spatial inversion symmetries using the quantum kinetic equation. We concluded that the integral of the symmetric(antisymmetric) part of quantum geometric tensor on the equal energy surface in momentum space, satisfying the resonance condition, is related to the generation rate of carriers in semiconductors under linearly(circularly) polarized light. Under additional bias voltage, the dc photocurrent is proportional to the bias voltage. Our study provided an alternative interpretation for the photogalvanic efect in the view of quantum geometric tensor. Additionally, it classified the intrinsic diference between linearly and circularly polarized optical fields.

关键词： quantum geometry photovoltaic efect nonlinear optics

Two-Dimensional Pnictogen for Field-Effect Transistors

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Research 2019年第1期2019卷 348-368页

作者： Wenhan Zhou Jiayi Chen Pengxiang Bai Shiying Guo Shengli Zhang xiufeng song Li Tao Haibo Zeng Key Laboratory of Advanced Display Materials and Devices Ministry of Industry and Information TechnologyCollege of Material Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Jiangsu Key Laboratory of Advanced Metallic Materials School of Materials Science and EngineeringSoutheast UniversityNanjing 211189China

Two-dimensional(2D)layered materials hold great promise for various future electronic and optoelectronic devices that traditional semiconductors cannot afford.2D pnictogen,group-VA atomic sheet(including phosphorene,arsenene,antimonene,and bismuthene)is believed to be a competitive candidate for next-generation logic *** is due to their intriguing physical and chemical properties,such as tunable midrange bandgap and controllable *** the first black phosphorus fieldeffect transistor(FET)demo in 2014,there has been abundant exciting research advancement on the fundamental properties,preparation methods,and related electronic applications of 2D ***,we review the recent progress in both material and device aspects of 2D pnictogen *** includes a brief survey on the crystal structure,electronic properties and synthesis,or growth *** more device orientation,this review emphasizes experimental fabrication,performance enhancing approaches,and configuration engineering of 2D pnictogen *** the end,this review outlines current challenges and prospects for 2D pnictogen FETs as a potential platform for novel nanoelectronics.

关键词： optoelectronic bismuth competitive

1.7 kV normally-off p-GaN gate high-electron-mobility transistors on a semi-insulating SiC substrate

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Science China(Information Sciences) 2023年第2期66卷 250-255页

作者： Shenglei ZHAO Jincheng ZHANG Yachao ZHANG Lansheng FENG Shuang LIU xiufeng song Yixin YAO Jun LUO Zhihong LIU Shengrui XU Yue HAO Key Lab of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices School of Microelectronics Xidian University School of Mechano-Electronic Engineering Xidian University Testing Center Sichuan Institute of Solid-State CircuitsChina Electronics Technology Group Corporation

A study of 1.7 kV normally-off p-GaN gate high-electron-mobility transistors(HEMTs) on SiC substrates is presented. The fabricated p-GaN HEMT with a gate-drain spacing LGD = 5 μm exhibited a threshold voltage of 1.10 V, a maximum drain current of 235 mA/mm, an ON/OFF ratio of 108, and a breakdown voltage of 440 V. Benefiting from the semi-insulating and high-critical-electric-field substrate, the p-GaN HEMT with LGD = 23 μm achieved the remarkably high breakdown voltage of 1740 V with substrate grounded. This breakdown voltage is very high compared with the reported values for p-GaN HEMTs on silicon substrates with substrate grounded. The vertical breakdown voltage for the p-GaN-on-SiC material exceeded 3 kV with substrate grounded. In addition, the maximum drain current at 500 K was 48% of that at 300 K with a negligible threshold voltage shift. These results indicate the substantial potential of p-GaN gate HEMTs on SiC substrates for high-voltage power applications.

关键词： p-GaN gate HEMTs high voltage SiC substrate

Functional magnetic resonance imaging evaluation of visual cortex activation in patients with anterior visual pathway lesions

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Neural Regeneration Research 2012年第9期7卷 692-696页

作者： xiufeng song Guohua Wang Tong Zhang Lei Feng Peng An Yueli Zhu Department of Radiology Qingdao Municipal HospitalQingdao 266071Shandong ProvinceChina

The aim of this study was to examine the secondary visual cortex functional disorder in patients with glaucoma and large pituitary adenoma by functional magnetic resonance imaging, and to determine the correlation between visual field defect and primary visual cortex activation. Results showed that single eye stimulation resulted in bilateral visual cortex activation in patients with glaucoma or large pituitary adenoma. Compared with the normal control group, the extent and intensity of visual cortex activation was decreased after left and right eye stimulation, and functional magnetic resonance imaging revealed a correlation between visual field defects and visual cortex activation in patients with glaucoma and large pituitary adenoma. These functional magnetic resonance imaging data suggest that anterior optic pathway lesions can cause secondary functional disorder of the visual cortex, and that visual defects are correlated with visual cortex activation.

关键词： functional magnetic resonance imaging glaucoma pituitary adenoma anterior visual pathway visual cortex

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优化江苏高等教育结构的对策思考

江苏高教 2007年第3期 48-51页

作者：宋旭峰江苏省教育科学研究院高教所

适应全面达小康、建设新江苏的需要,实现由高等教育大省向高等教育强省转变,需要在加强质量内涵建设的同时,进一步协调各类高等教育的关系,促使高等学校合理定位,加快建设一批内部组织结构新颖、办学特色显著的新制大学,推动高等教育实... 详细信息

适应全面达小康、建设新江苏的需要,实现由高等教育大省向高等教育强省转变,需要在加强质量内涵建设的同时,进一步协调各类高等教育的关系,促使高等学校合理定位,加快建设一批内部组织结构新颖、办学特色显著的新制大学,推动高等教育实质性地迈入新的发展阶段。

关键词：江苏区域高等教育高等教育结构

First-principle study of puckered arsenene MOSFET

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Journal of Semiconductors 2020年第8期41卷 75-80页

作者： Hengze Qu Ziwei Lin Ruijuan Guo Xiyu Ming Wenhan Zhou Shiying Guo xiufeng song Shengli Zhang Haibo Zeng Key Laboratory of Advanced Display Materials and Devices Ministry of Industry and Information TechnologyCollege of Material Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China

Two-dimensional material has been regarded as a competitive silicon-alternative with a gate length approaching sub-10 nm,due to its unique atomic thickness and outstanding electronic ***,we provide a comprehensively study on the electronic and ballistic transport properties of the puckered arsenene by the density functional theory coupled with nonequilibrium Green’s function *** puckered arsenene exhibits an anisotropic characteristic,as effective mass for the electron/hole in the armchair and zigzag directions is 0.35/0.16 m0 and 1.26/0.32 *** it also holds a high electron mobility,as the highest value can reach 20045 cm2V–1s–***,the puckered arsenene FETs with a 10-nm channel length possess high on/off ratio above 105 and a steep subthreshold swing below 75 mV/dec,which have the potential to design high-performance electronic ***,the channel length limit for arsenene FETs can reach ***,the benchmarking of the intrinsic arsenene FETs and the 32-bit arithmetic logic unit circuits also shows that the devices possess high switching speed and low energy dissipation,which can be comparable to the CMOS technologies and other CMOS ***,the puckered arsenene is an attractive channel material in next-generation electronics.

关键词： first principle two-dimensional material electronic properties arsenene MOSFET

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科研数据再利用过程模型研究

情报理论与实践 2021年第6期44卷 61-68页

作者：宋秀芬周茜李立睿魏银珍湖北警官学院法庭科学湖北省重点实验室湖北武汉430034 西南大学计算机与信息科学学院重庆400715 黄冈师范学院计算机学院湖北黄冈438000

[目的/意义]旨在厘清数据共享、发布、再利用三者之间的关系,为国内数据再利用实践提供参考与借鉴。[方法/过程]在明确数据概念基础上,比较数据共享、发布、再利用的异同,构建与分析数据再利用过程模型。[结果/结论]从增强数据共享程度... 详细信息

[目的/意义]旨在厘清数据共享、发布、再利用三者之间的关系,为国内数据再利用实践提供参考与借鉴。[方法/过程]在明确数据概念基础上,比较数据共享、发布、再利用的异同,构建与分析数据再利用过程模型。[结果/结论]从增强数据共享程度、创建高质量元数据、质量控制、数据长期保存、开放数据许可5个方面提出数据再利用提升策略。[局限]下一步研究工作需用定量方法研究数据再利用过程模型中关键影响要素的作用效果。

关键词：科研数据数据再利用数据发布数据共享数据监护人员