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Broadband and conformal metamaterial absorber

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Frontiers of Optoelectronics 2017年第2期10卷 124-131页

作者： Xiangkun KONG Junyi XU Jin-jun MO shaobin liu Key Laboratory of Radar Imaging and Microwave Photonics Ministry of Education College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China State Key Laboratory of Millimeter Waves Southeast University Nanjing 210096 China College of Electronic Science and Engineering National University of Defense Technology Changsha 410073 China

In this study, a new broadband and conformal metamaterial absorber using two flexible substrates was proposed. Simulation results showed that the proposed absorber exhibited an absorption band from 6.08 to 13.04 GHz and a high absorption of 90%, because it was planar. The absorber was broadband as its relative absorption bandwidth was 72.8%. Moreover, the proposed absorber was insensitive to the polarization of the TE and TM waves. The absorber was ultra-thin; its total thickness was only 0.072 at the lowest operating frequency. Furthermore, different regions of absorption can be adjusted by lumping and loading two resistors onto the polyimide film, respectively. Moreover, compared with the conventional microwave absorber, the absorption bandwidth of the proposed absorber can be broadened and enhanced when it was bent and conformed to the surface of objects. Experimental and simulation results were in agreement. The proposed absorber is a promising absorbing element in scientific and technical applications because of its broad- band absorption, polarization insensitivity, and flexible substrates.

关键词： absorber metamaterials flexible broadband,conformal

Problems and Solutions in Ideological and Political Education under the Training Mode of Excellent and Innovative Talents in Colleges and Universities

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Asian Agricultural Research 2022年第10期14卷 51-53,57页

作者： Chenghao JIN Jing LI Yang XI Tong HAN shaobin liu Yinghua LUO Rongan CAO Guinan SHEN Heilongjiang Bayi Agricultural University Daqing 163319China

By grasping the characteristics and laws of the growth of excellent talents,this paper objectively analyzes the current situation of ideological and political education and the problems existing in the innovation process of ideological and political education.In accordance with the inherent requirements of the innovation of ideological and political education in colleges and universities,efforts should be made to build a specific path for the innovation of ideological and political education in colleges and universities,which is consistent with the training mode of excellent and innovative talents.

关键词： Excellent and innovative talents Training mode Ideological and political education

Nest complexity correlates with larger brain size but smaller body mass across bird species

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Integrative Zoology 2024年第3期19卷 496-504页

作者： shaobin LI Yuxin liu Xiaolong DU Guopan LI Wenbo LIAO College of Life Science Yangtze UniversityJingzhouChina Key Laboratory of Southwest China Wildlife Resources Conservation(Ministry of Education) China West Normal UniversityNanchongChina

Amniotes differ substantially in absolute and relative brain size after controlling for allometry,and numerous hypotheses have been proposed to explain brain size evolution.Brain size is thought to correlate with processing capacity and the brain’s ability to support complex manipulation such as nest-building skills.The increased complexity of nest structure is supposed to be a measure of an ability to manipulate nesting material into the required shape.The degree of nest-structure complexity is also supposed to be associated with body mass,partly because small species lose heat faster and delicate and insulated nests are more crucial for temperature control of eggs during incubation by small birds.Here,we conducted comparative analyses to test these hypotheses by investigating whether the complexity of species-typical nest structure can be explained by brain size and body mass(a covariate also to control for allometric effects on brain size)across 1353 bird species from 147 families.Consistent with these hypotheses,our results revealed that avian brain size increases as the complexity of the nest structure increases after controlling for a significant effect of body size,and also that a negative relationship exists between nest complexity and body mass.

关键词： body size brain size comparative analysis nest building nest type reproductive investment

Investigations and prospects of Fabry-Perot antennas:a review

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Journal of Systems Engineering and Electronics 2021年第4期32卷 731-747页

作者： liu Zhiming BORNEMANN Jens liu shaobin KONG Xiangkun Department of Electrical and Computer Engineering University of VictoriaVictoria V8W 2Y2Canada College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Fabry-Perot(FP)antennas have characteristics of planar structures combined with high gain,and they have been widely used in wireless communications.With the progress of ongoing research,FP antennas have achieved various capabilities,but many of them are still under development,such as lowprofile,wideband,circular polarization,multi-band,low-radar cross section(RCS)and reconfigurable features.This paper discusses the theoretical analysis methods and research progress of FP antennas,and explains the realization methods of different features of FP antennas.In order to indicate different technologies for realizing various capabilities,the key technologies and features of some of the latest designs are described.Finally,the research situation and prospects of FP antennas are summarized to guide their research directions in the future.

关键词： Fabry-Perot(FP)antenna partially reflective surface research situation research direction

Wentzel-Kramer-Brillouin and finite-difierence time-domain analysis of Terahertz band electromagnetic characteristics of target coated with unmagnetized plasma

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Journal of Systems Engineering and Electronics 2008年第1期19卷 15-20页

作者： liu shaobin Zhou Tao liu Meilin Hong Wei State Key Lab. of Millimeter Waves Southeast Univ. Nanjing 210096 P. R. China Coll. of Information Science &: Technology Nanjing Univ. of Aeronautics & Astronautics Nanjing 210016 P. R. China

We investigate computationally the attenuation and reflection of Terahertz （THz） wave using targets coated with plasmas. The simulators are the Wentzel-Kramer-Brillouin （WKB） method and finite-difference timedomain （FDTD） method. The relation between the frequency of the incident electromagnetic （EM） wave and the attenuation caused by unmagnitized plasma is analyzed. The results demonstrate that the amount of absorbed power is a decreasing function of the EM wave frequency and the plasma collision frequency. For THz band incident wave, the attenuation that is caused by plasma is small when the plasma has common density and the collision frequency. This conclusion has fine applying foreground for plasma anti stealth.

关键词： frequency dispersion WKB method FDTD methods unmagnetized plasma Terahertz wave

Piecewise linear recursive convolution FDTD method for magnetized plasmas

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Journal of Systems Engineering and Electronics 2006年第2期17卷 290-295页

作者： liu Song Zhong Shuangying liu shaobin School of Sciences Nanchang Univ. Nanchang 330047 P. R. China

The piecewise linear recursive convolution （PLRC） finite-different time-domain （FDTD） method greatly improves accuracy over the original recursive convolution （RC） FDTD approach but retains its speed and efficiency advantages. A PLRC-FDTD formulation for magnetized plasma which incorporates both anisotropy and frequency dispersion at the same time is presented, enabled the transient analysis of magnetized plasma media. The technique is illustrated by numerical simulations the reflection and transmission coefficients through a magnetized plasma layer. The results show that the PLRC-FDTD method has significantly improved the accuracy over the original RC method.

关键词： electromagnetic wave FDTD methods piecewise linear recursive convolution magnetized plasma.

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近坝岸坡滑坡涌浪演化规律及工程影响模拟

西北水电 2024年第1期 67-72页

作者：李鹏峰贺翠玲史蝶刘少斌张若羽荆海晓中国电建西北勘测设计研究院有限公司西安710065 西安理工大学西北旱区生态水利国家重点实验室西安710048 陕西省河湖生态保护与修复“四主体一联合”工程技术研究中心西安710065 陕西省水生态环境工程技术研究中心西安710065

近坝库区滑坡涌浪严重威胁大坝及周边人员安全,明晰库区涌浪演化规律是该类型灾害预警的首要任务。以黄河上游某水电站工程大坝左岸4号倾倒变形体为对象,建立了基于Flow-3D Hydro原型尺度三维数值模型,分析了4号倾倒变形体不同部位原位... 详细信息

近坝库区滑坡涌浪严重威胁大坝及周边人员安全,明晰库区涌浪演化规律是该类型灾害预警的首要任务。以黄河上游某水电站工程大坝左岸4号倾倒变形体为对象,建立了基于Flow-3D Hydro原型尺度三维数值模型,分析了4号倾倒变形体不同部位原位失稳时的涌浪特性及传播演化特性。结果表明:近坝岸坡4号倾倒变形体失稳产生的涌浪类型为弱非线性震荡波,这种波型经过演化后往往次生波表现出最大波高、最大爬高等特征;如果将4号倾倒变形体分不同部位原位失稳,多宗龙洼沟侧整体下滑对坝前及坝下游建筑物无影响,可不做工程处理;但黄河侧原位整体下滑时,右坝肩最大浪高14.19 m,左坝肩最大浪高16.40 m,坝前爬坡高程约至3 009.00 m,超过防浪墙顶高程,严重危害面板堆石坝的安全,需要进一步的工程减灾措施。该研究成果可为库区滑坡涌浪灾害预警提供技术支撑。

关键词：近坝岸坡滑坡涌浪流固耦合波浪传播数值模拟

A novel polarization converter based on the band-stop frequency selective surface

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Chinese Physics B 2022年第2期31卷 380-386页

作者：廖昆孙世宁郑昕原邵纤纤孔祥鲲刘少斌 College of Electronic and Information Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Aviation Key Laboratory of Science and Technology on High Performance Electromagnetic Windows Jinan 250023China Pingxiang Health Vocational College Pingxiang 337006China

A dual-passband single-polarized converter based on the band-stop frequency selective surface(FSS)with a low radar cross-section(RCS)is designed in this article.The unit cell of the proposed converter is formed by a polarization layer attached to the band-stop frequency selective surface.The simulation results reveal that the co-polarization reflection coefficients below-10 d B are achieved in 3.82–13.64 GHz with a 112.4%fractional bandwidth(the ratio of the signal bandwidth to the central frequency).Meanwhile,a polarization conversion band is realized from 8.14 GHz to 9.27 GHz with a polarization conversion ratio which is over 80%.Moreover,the 1 d B transmission window is obtained in two nonadjacent bands of 3.42–7.02 GHz and 10.04–13.91 GHz corresponding to the relative bandwidths of 68.9%and 32.3%,respectively.Furthermore,the radar cross-section of the designed structure can be reduced in the wideband from 2.28 GHz to 14 GHz,and the 10 d B RCS reduction in the range of 4.10–13.35 GHz is achieved.In addition,the equivalent circuit model of this converter is established,and the simulation results of the Advanced Design System(ADS)match well with those of CST Microwave Studio(CST).The archetype of the designed converter is manufactured and measured.The experiment results match the simulation results well,which proves the reliability of the simulation results.

关键词： dual-passband single-polarized converter polarization radar cross-section(RCS)

等离子体覆盖目标散射特性的RKETD-FDTD分析

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南京航空航天大学学报 2009年第4期41卷 532-535页

作者：刘崧刘少斌南京航空航天大学信息科学与技术学院南京210016 南昌大学理学院南昌330031

采用一种既保证计算的高效率,又有较高的计算精度的龙格库塔指数时程差分时域有限差分法(RKETD-FDTD)研究了等离子体的散射特性。该算法解决了电磁波在色散介质中传播的计算问题,导出了在等离子体介质中RKETD-FDTD迭代公式。文中分别计... 详细信息

采用一种既保证计算的高效率,又有较高的计算精度的龙格库塔指数时程差分时域有限差分法(RKETD-FDTD)研究了等离子体的散射特性。该算法解决了电磁波在色散介质中传播的计算问题,导出了在等离子体介质中RKETD-FDTD迭代公式。文中分别计算了等离子体平板的反射系数和非均匀等离子体覆盖导体柱的散射特性,所得结果与解析结果相符合,并且表明等离子体涂层选择合适的碰撞频率,能有效地减小目标的雷达散射截面(RCS)。

关键词：等离子体散射特性时域有限差分法电磁波