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Electromagnetic absorbing technology can effectively suppress the radiation of electromagnetic waves, and has been widely used in military and civilian fields. However, traditional absorbing technology cannot meet the new requirements for modern absorbing materials. The advent of metamaterials provides a solution for this problem Metamaterial absorber has the advantages of simple structure, light weight, high absorption rate, and can realize the flexible control of electromagnetic waves, which has led the electromagnetic absorption research to rapidly develop. In this paper, the research and development of using metamaterials to absorb electromagnetic wave is reviewed. Firstly, the principle, implementation, and presently existing bottlenecks of electromagnetic wave absorption in using metamaterials are outlined. Secondly, recent progress of the aforementioned key issues in three aspects is introduced, including multi-band and broadband, polarization and angle independence, and dynamic tunability. Several typical methods of making metamaterial absorbers are illustrated here. Generally speaking, the prerequisite of broadband metamaterial absorbers is to provide multiple resonances that are close enough to each other. The structure with multiple rotationally symmetric geometry is helpful in achieving polarization- and angle-insensitive properties. The flexible control of absorption performance can be realized by introducing lumped elements such as resistances, capacitances, and diodes. In addition, by means of composite traditional materials or new materials and other methods the dynamic adjustment of the absorption performance can be achieved. Although researchers have done a lot of work on the metamaterial absorbers, there remain many problems and challenges. For the future design, several promising directions are suggested from three perspectives: high performance, multifunctionality, and new structures. In terms of high performance, it is still a challenge to achieve ultra-thin broadband metamaterial absorber for low-frequency which can break through the limitation of wavelength. Integrated multifunctional metamaterials can adapt to the increasingly complex application scenarios and should gradually become the focus of attention. Since three-dimensional (3D) printing technology has proved to be applicable to the preparation of complex metamaterial structures, the new 3D metamerial absorbers will bring more vitality to the development of metamaterials. Finally, as regards the application of metamaterials in stealth, the future development of metamaterial absorbers is further summarized.
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Keywords:
- metamaterial absorber /
- broadband /
- angle-independence
[1] Duan X, Chen X, Zhou Y, Zhou L, Hao S 2018 IEEE Antennas Wirel. Propag. Lett. 17 1617Google Scholar
[2] Li W, Valentine J 2014 Nano Lett. 14 3510Google Scholar
[3] Watts C M, Liu X, Padilla W J 2012 Adv. Mater. 24 OP98
[4] Choi I, Lee D 2015 Compos. Struct. 119 218Google Scholar
[5] 刘顺华, 刘军民, 董星龙 2014 电磁波屏蔽及吸波材料(北京: 化学工业出版社) 第270页
Liu S H, Liu J M, Dong X L 2014 Electromagnetic Shielding and Absorb-ing Materials (Vol. 2) (Beijing: Chemical Industry Press) p270 (in Chinese)
[6] Fante R L, McCormack M T 1988 IEEE Trans. Antennas Propag. 36 1443Google Scholar
[7] Toit D, J L 1994 IEEE Antennas and Propag. Mag. 36 17Google Scholar
[8] Jaggard D, Engheta N, Liu J 1990 Electron. Lett. 26 1332Google Scholar
[9] 王光明, 许河秀, 梁建刚, 蔡通 2015 紧凑型异向介质: 机理、设计与应用(北京: 国防工业出版社)
Wang G M, Xu H X, Liang J G, Cai T 2015 Compact Metamaterials Mechanism, Design and Application (Beijing: National Defense Industry Press) (in Chinese)
[10] Veselago V G 1968 Sov. Phys. Usp. 10 509Google Scholar
[11] Pendry J B, Holden A, Stewart W, Youngs I 1996 Phys. Rev. Lett. 76 4773Google Scholar
[12] Pendry J B, Holden A J, Robbins D J, Stewart W 1999 IEEE Trans. Microw. Theory Tech. 47 2075Google Scholar
[13] Shelby R A, Smith D R, Schultz S 2001 Science 292 77Google Scholar
[14] Seddon N, Bearpark T 2003 Science 302 1537Google Scholar
[15] Lu J, Grzegorczyk T M, Zhang Y, Pacheco Jr J, Wu B I, Kong J A, Chen M 2003 Opt. Express 11 723Google Scholar
[16] Koschny T, Zhang L, Soukoulis C M 2005 Phys. Rev. B 71 121103Google Scholar
[17] Pendry J B 2000 Phys. Rev. Lett. 85 3966Google Scholar
[18] Pendry J B, Schurig D, Smith D R 2006 Science 312 1780Google Scholar
[19] Leonhardt U 2006 Science 312 1777Google Scholar
[20] Schurig D, Mock J J, Justice B, Cummer S A, Pendry J B, Starr A F, Smith D R 2006 Science 314 977Google Scholar
[21] 丰茂昌, 李勇峰, 张介秋, 王甲富, 王超, 马华, 屈绍波 2018 67 198101Google Scholar
Feng M C, Li Y F, Zhang J Q, Wang J F, Wang C, Ma H, Qu S B 2018 Acta Phys. Sin. 67 198101Google Scholar
[22] Yu N, Genevet P, Kats M A, Aieta F, Tetienne J P, Capasso F, Gaburro Z 2011 Science 334 333Google Scholar
[23] 庄亚强, 王光明, 张晨新, 张小宽, 宗彬锋, 马卫东, 王亚伟 2016 65 154101Google Scholar
Zhuang Y Q, Wang G M, Zhang C X, Zhang X K, Zong B F, Ma W D, Wang Y W 2016 Acta Phys. Sin. 65 154101Google Scholar
[24] Cui T J, Qi M Q, Wan X, Zhao J, Cheng Q 2014 Light: Sci. Appl. 3 e218Google Scholar
[25] Tran M C, Pham V H, Ho T H, Nguyen T T, Do H T, Bui X K, Bui S T, Le D T, Pham T L, Vu D L 2020 Sci. Rep. 10 1Google Scholar
[26] Wu H, Liu S, Wan X, Zhang L, Wang D, Li L, Cui T J 2017 Adv. Sci. 4 1700098Google Scholar
[27] Hum S V, Perruisseau-Carrier J 2013 IEEE Trans. Antennas Propag. 62 183Google Scholar
[28] Cai T, Tang S, Wang G, Xu H, Sun S, He Q, Zhou L 2017 Adv. Opt. Mater. 5 1600506Google Scholar
[29] Xu H X, Zhang L, Kim Y, Wang G M, Zhang X K, Sun Y, Ling X, Liu H, Chen Z, Qiu C W 2018 Adv. Opt. Mater. 6 1800010Google Scholar
[30] Yuan F, Xu H X, Jia X Q, Wang G M, Fu Y Q 2020 IEEE Trans. Antennas Propag.68 2463Google Scholar
[31] Sun S, He Q, Hao J, Xiao S, Zhou L 2019 Adv. Opt. Photonics 11 380Google Scholar
[32] Zhang L, Wan X, Liu S, Yin J Y, Zhang Q, Wu H T, Cui T J 2017 IEEE Trans. Antennas Propag. 65 3374Google Scholar
[33] Landy N I, Sajuyigbe S, Mock J J, Smith D R, Padilla W J 2008 Phys. Rev. Lett. 100 207402Google Scholar
[34] Marin P, Cortina D, Hernando A 2008 IEEE Trans. Magn. 44 3934Google Scholar
[35] 刘祥萱, 陈鑫, 王煊军, 刘渊 2013 表面技术 42 104Google Scholar
Liu X X, Chen X, Wang X J, Liu Y 2013 Surf. Technol. 42 104Google Scholar
[36] 周万城, 王婕, 罗发, 朱冬梅, 黄智斌, 卿玉长 2013 中国材料进展 000 463Google Scholar
Zhou W C, Wang J, Luo F, Zhu D M, Huang Z B, Qing Y C 2013 Mater. China 000 463Google Scholar
[37] Costa F, Monorchio A, Manara G 2010 IEEE Trans. Antennas Propag. 58 1551Google Scholar
[38] Wen Q Y, Zhang H W, Xie Y S, Yang Q H, Liu Y L 2009 Appl. Phys. Lett. 95 241111Google Scholar
[39] Hao J, Wang J, Liu X, Padilla W J, Zhou L, Qiu M 2010 Appl. Phys. Lett. 96 251104Google Scholar
[40] Liu X, Starr T, Starr A F, Padilla W J 2010 Phys. Rev. Lett. 104 207403Google Scholar
[41] Aydin K, Ferry V E, Briggs R M, Atwater H A 2011 Nat. Commun. 2 1Google Scholar
[42] Simovski C 2009 Opt. Spectrosc. 107 726Google Scholar
[43] Smith D R, Schultz S, Markoš P, Soukoulis C M 2002 Phys. Rev. B 65 195104Google Scholar
[44] Chen X, Grzegorczyk T M, Wu B I, Pacheco J J, Kong J A 2004 Phys. Rev. E 70 016608Google Scholar
[45] Smith D R, Vier D C, Koschny T, Soukoulis C M 2005 Phys. Rev. E 71 036617Google Scholar
[46] Arslanagić S, Hansen T V, Mortensen N A, Gregersen A H, Sigmund O, Ziolkowski R W, Breinbjerg O 2013 IEEE Antennas and Propag. Mag. 55 91Google Scholar
[47] Costa F, Monorchio A, Manara G 2012 IEEE Antennas and Propag. Mag. 54 35Google Scholar
[48] Chen H T 2012 Opt. Express 20 7165Google Scholar
[49] Peng X Y, Wang B, Lai S, Zhang D H, Teng J H 2012 Opt. Express 20 27756Google Scholar
[50] Liu X, Zhao Q, Lan C, Zhou J 2013 Appl. Phys. Lett. 103 031910Google Scholar
[51] Zheng H, Jin X, Park J, Lu Y, Rhee J Y, Jang W, Cheong H, Lee Y 2012 Opt. Express 20 24002Google Scholar
[52] Im K, Kang J H, Park Q H 2018 Nat. Photonics 12 143Google Scholar
[53] Tao H, Bingham C, Pilon D, Fan K, Strikwerda A, Shrekenhamer D, Padilla W, Zhang X, Averitt R 2010 J. Phys. D: Appl. Phys. 43 225102Google Scholar
[54] Chen K, Adato R, Altug H 2012 ACS Nano 6 7998Google Scholar
[55] Xu H X, Wang G M, Qi M Q, Liang J G, Gong J Q, Xu Z M 2012 Phys. Rev. B 86 205104Google Scholar
[56] Shen X, Cui T J, Zhao J, Ma H F, Jiang W X, Li H 2011 Opt. Express 19 9401Google Scholar
[57] Ma Y, Chen Q, Grant J, Saha S C, Khalid A, Cumming D R 2011 Opt. Lett. 36 945Google Scholar
[58] Jia D, Xu J, Yu X 2018 Opt. Express 26 26227Google Scholar
[59] Huang L, Chowdhury D R, Ramani S, Reiten M T, Luo S N, Taylor A J, Chen H T 2012 Opt. Lett. 37 154Google Scholar
[60] Zhang C, Cheng Q, Yang J, Zhao J, Cui T J 2017 Appl. Phys. Lett. 110 143511Google Scholar
[61] Zhang Y, Li Y, Cao Y, Liu Y, Zhang H 2017 Opt. Commun. 382 281Google Scholar
[62] Su Z, Yin J, Zhao X 2015 Opt. Express 23 1679Google Scholar
[63] Ding F, Cui Y, Ge X, Jin Y, He S 2012 Appl. Phys. Lett. 100 103506Google Scholar
[64] Nguyen T Q H, Phan H L, Phan D T 2017 Microw. Opt. Techn. Lett. 59 1157Google Scholar
[65] Cheng Y Z, Wang Y, Nie Y, Gong R Z, Xiong X, Wang X 2012 J. Appl. Phys. 111 044902Google Scholar
[66] Yuan W, Cheng Y 2014 Appl. Phys. A 117 1915Google Scholar
[67] Kim Y J, Hwang J S, Yoo Y J, Khuyen B X, Rhee J Y, Chen X, Lee Y 2017 J. Phys. D: Appl. Phys. 50 405110Google Scholar
[68] Kundu D, Mohan A, Chakrabarty A 2016 IEEE Antennas Wirel. Propag. Lett. 15 1589Google Scholar
[69] 顾超, 屈绍波, 裴志斌, 徐卓, 林宝勤, 周航, 柏鹏, 顾巍, 彭卫东, 马华 2011 60 087802Google Scholar
Gu C, Qu S B, Pei Z B, Xu Z, Lin B Q, Zhou H, Bai P, Gu W, Peng W D, Ma H 2011 Acta Phys. Sin. 60 087802Google Scholar
[70] Sun L, Cheng H, Zhou Y, Wang J 2012 Opt. Express 20 4675Google Scholar
[71] 莫漫漫, 马武伟, 庞永强, 陈润华, 张笑梅, 柳兆堂, 李想, 郭万涛 2018 67 217801Google Scholar
Mo M M, Ma W W, Pang Y Q, Chen R H, Zhang X M, Liu Z T, Li X, Guo W T 2018 Acta Phys. Sin. 67 217801Google Scholar
[72] Tayde Y, Saikia M, Srivastava K V, Ramakrishna S A 2018 IEEE Antennas Wirel. Propag. Lett. 17 2489Google Scholar
[73] Ji T, Wang Y, Cui Y, Lin Y, Hao Y, Li D 2017 Mater. Today Energy 5 181Google Scholar
[74] Pang Y, Wang J, Ma H, Feng M, Li Y, Xu Z, Xia S, Qu S 2016 Sci. Rep. 6 29429Google Scholar
[75] Fan Y, Wang J, Li Y, Pang Y, Zheng L, Xiang J, Zhang J, Qu S 2018 J. Phys. D: Appl. Phys. 51 215001Google Scholar
[76] Li S J, Wu P X, Xu H X, Zhou Y L, Cao X Y, Han J F, Zhang C, Yang H H, Zhang Z 2018 Nanoscale Res. Lett. 13 386Google Scholar
[77] Pitchappa P, Ho C P, Kropelnicki P, Singh N, Kwong D L, Lee C 2014 J. Appl. Phys. 115 193109Google Scholar
[78] Gu S, Su B, Zhao X 2013 J. Appl. Phys. 114 163702Google Scholar
[79] Yu P, Besteiro L V, Huang Y, Wu J, Fu L, Tan H H, Jagadish C, Wiederrecht G P, Govorov A O, Wang Z 2019 Adv. Opt. Mater. 7 1800995Google Scholar
[80] Landy N I, Bingham C M, Tyler T, Jokerst N, Smith D R, Padilla W J 2009 Phys. Rev. B 79 125104Google Scholar
[81] Zhu B, Wang Z B, Yu Z Z, Zhang Q, Zhao J M, Feng Y J, Jiang T 2009 Chin. Phys. Lett. 26 114102Google Scholar
[82] Li L, Yang Y, Liang C 2011 J. Appl. Phys. 110 063702Google Scholar
[83] Gu C, Qu S B, Pei Z B, Xu Z 2011 Chin. Phys. B 20 037801Google Scholar
[84] Chen J, Hu Z, Wang S, Huang X, Liu M 2016 Eur. Phys. J. B 89 14Google Scholar
[85] Zhu B, Wang Z, Huang C, Feng Y, Zhao J, Jiang T 2010 Prog. Electromagn. Res. 101 231Google Scholar
[86] Wang J, Yang R, Tian J, Chen X, Zhang W 2018 IEEE Antennas Wirel. Propag. Lett. 17 1242Google Scholar
[87] Xu Y Q, Zhou P H, Zhang H B, Chen L, Deng L J 2011 J. Appl. Phys. 110 044102Google Scholar
[88] Wang B, Koschny T, Soukoulis C M 2009 Phys. Rev. B 80 033108Google Scholar
[89] Munk B A, Munk P, Pryor J 2007 IEEE Trans. Antennas Propag. 55 186Google Scholar
[90] Bhattacharyya S, Srivastava K V 2014 J. Appl. Phys. 115 064508Google Scholar
[91] Ghosh S, Nguyen T T, Lim S 2019 EPJ Appl. Metamater. 6 12 064508
[92] Shen Y, Pang Y, Wang J, Ma H, Pei Z, Qu S 2015 J. Phys. D: Appl. Phys. 48 445008Google Scholar
[93] Chen T, Li S J, Cao X Y, Gao J, Guo Z X 2019 Appl. Phys. A 125 232Google Scholar
[94] Chang T, Langley R J, Parker E 1993 IEEE Microwave Guided Wave Lett. 3 387Google Scholar
[95] Shadrivov I V, Morrison S K, Kivshar Y S 2006 Opt. Express 14 9344Google Scholar
[96] Zhu H, Liu X, Cheung S, Yuk T 2013 IEEE Trans. Antennas Propag. 62 80Google Scholar
[97] 李宇涵, 邓联文, 罗衡, 贺龙辉, 贺君, 徐运超, 黄生祥 2019 68 095201Google Scholar
Li Y H, Deng L W, Luo H, He L H, He J, Xu Y C, Huang S X 2019 Acta Phys. Sin. 68 095201Google Scholar
[98] Zhao X, Wang Y, Schalch J, Duan G, Cremin K, Zhang J, Chen C, Averitt R D, Zhang X 2019 ACS Photonics 6 830Google Scholar
[99] Zhai Z, Zhang L, Li X, Xiao S 2019 Opt. Commun. 431 199Google Scholar
[100] 陈俊, 杨茂生, 李亚迪, 程登科, 郭耿亮, 蒋林, 张海婷, 宋效先, 叶云霞, 任云鹏, 任旭东, 张雅婷, 姚建铨 2019 68 247802Google Scholar
Chen J, Yang M S, Li Y D, Cheng D K, Guo G L, Jiang L, Zhang H T, Song X X, Ye Y X, Ren Y P, Ren X D, Zhang Y T, Yao J Q 2019 Acta Phys. Sin. 68 247802Google Scholar
[101] Balci O, Kakenov N, Karademir E, Balci S, Cakmakyapan S, Polat E O, Caglayan H, Özbay E, Kocabas C 2018 Sci. Adv. 4 eaao1749Google Scholar
[102] 毕科, 王旭莹, 兰楚文, 郝亚楠, 周济 2019 中国材料进展 38 1Google Scholar
Bi K, Wang X Y, Lan C W, Hao Y N, Zhou J 2019 Mater. China 38 1Google Scholar
[103] Zhao J, Cheng Q, Chen J, Qi M Q, Jiang W X, Cui T J 2013 New J. Phys. 15 043049Google Scholar
[104] Li M, Yi Z, Luo Y, Muneer B, Zhu Q 2016 IEEE Trans. Antennas Propag. 64 944Google Scholar
[105] Zhang Y, Feng Y, Zhu B, Zhao J, Jiang T 2014 Opt. Express 22 22743Google Scholar
[106] Shrekenhamer D, Chen W C, Padilla W J 2013 Phys. Rev. Lett. 110 177403Google Scholar
[107] Zhang F, Feng S, Qiu K, Liu Z, Fan Y, Zhang W, Zhao Q, Zhou J 2015 Appl. Phys. Lett. 106 091907Google Scholar
[108] Rozanov K N 2000 IEEE Trans. Antennas Propag. 48 1230Google Scholar
[109] Acher O, Dubourg S 2008 Phys. Rev. B 77 104440Google Scholar
[110] 院伟, 杨进, 王一龙, 李维, 官建国 2016 材料导报 30 104Google Scholar
Yuan W, Yang J, Wang Y L, Li W, Guan J G 2016 Mater. Rev. 30 104Google Scholar
[111] Mou J, Shen Z 2017 Sci. Rep. 7 1Google Scholar
[112] Mou J, Shen Z 2016 IEEE Trans. Antennas Propag. 65 696Google Scholar
[113] Banadaki M D, Heidari A A, Nakhkash M 2017 IEEE Antennas Wirel. Propag. Lett. 17 205Google Scholar
[114] Li W, Wei J, Wang W, Hu D, Li Y, Guan J 2016 Mater. Des. 110 27Google Scholar
[115] 程用志, 王莹, 聂彦, 郑栋浩, 龚荣洲, 熊炫, 王鲜 2012 61 134102Google Scholar
Cheng Y Z, Wang Y, Nie Y, Zheng D H, Gong R Z, Xiong X, Wang X 2012 Acta Phys. Sin. 61 134102Google Scholar
[116] Li W, Liu Q, Wang L, Zhou Z, Zheng J, Ying Y, Qiao L, Yu J, Qiao X, Che S 2018 AIP Adv. 8 015318Google Scholar
[117] 许河秀 2019 超表面电磁调控机理与功能器件应用研究 (北京: 科学出版社)
Xu H X 2019 Investigations on Electromagnetic Wave Manipulations and Functional Device Applications Using Metasurfaces (Beijing: Science Press) (in Chinese)
[118] Sun J, Chen K, Ding G, Guo W, Zhao J, Feng Y, Jiang T 2019 IEEE Access 7 93919Google Scholar
[119] Peng L, Li X F, Gao X, Jiang X, Li S M 2019 Opt. Mater. Express 9 687Google Scholar
[120] Chen W, Chen R, Zhou Y, Ma Y 2019 IEEE Photonics Technol. Lett. 31 1187Google Scholar
[121] 沈杨, 王甲富, 张介秋, 李勇峰, 郑麟, 庞永强, 屈绍波 2018 空军工程大学学报 (自然科学版) 19 39Google Scholar
Shen Y, Wang J F, Zhang J Q, Li Y F, Zheng L, Pang Y Q, Qu S B 2018 J. Air Force Engineering Univ. (Nat. Sci. Ed.) 19 39Google Scholar
[122] Wang J F, Qu S B, Xu Z, Fu Z T, Ma H, Yang Y M 2009 J. Phys. D: Appl. Phys. 42 155413Google Scholar
[123] 鲁磊, 屈绍波, 施宏宇, 张安学, 张介秋, 马华 2013 62 158102Google Scholar
Lu Lei, Qu S B, Shi H Y, Zhang A X, Zhang J Q, Ma H 2013 Acta Phys. Sin. 62 158102Google Scholar
[124] Xu H X, Wang G M, Tao Z, Cui T J 2014 Sci. Rep. 4 5744
[125] Xu H X, Wang G M, Ma K, Cui T J 2014 Adv. Opt. Mater. 2 572Google Scholar
[126] 熊益军, 王岩, 王强, 王春齐, 黄小忠, 张芬, 周丁 2018 67 084202Google Scholar
Xiong Y J, Wang Y, Wang Q, Wang C Q, Huang X Z, Zhang F, Zhou D 2018 Acta Phys. Sin. 67 084202Google Scholar
[127] Lim D, Yu S, Lim S 2018 IEEE Access 6 43654Google Scholar
[128] Jiang W, Yan L, Ma H, Fan Y, Wang J, Feng M, Qu S 2018 Sci. Rep. 8 4817Google Scholar
[129] Xie J, Quader S, Xiao F, He C, Liang X, Geng J, Jin R, Zhu W, Rukhlenko I D 2019 IEEE Antennas Wirel. Propag. Lett. 18 536Google Scholar
[130] 田小永, 尚振涛, 尹丽仙, 李涤尘 2019 航空制造技术 62 14Google Scholar
Tian X Y, Shang Z T, Yin L X, Li D C 2019 Aeronaut. Manuf. Technol. 62 14Google Scholar
[131] Rashid A K, Li B, Shen Z 2014 IEEE Antennas and Propag. Mag. 56 43Google Scholar
[132] Yu Y, Shen Z, Deng T, Luo G 2017 IEEE Trans. Antennas Propag. 65 4363Google Scholar
[133] Li W, Wu T, Wang W, Guan J, Zhai P 2014 Appl. Phys. Lett. 104 022903Google Scholar
[134] Li M, Shen L, Jing L, Xu S, Zheng B, Lin X, Yang Y, Wang Z, Chen H 2019 Adv. Sci. 6 1901434Google Scholar
[135] 梁彩云, 王志江 2018 航空材料学报 38 5Google Scholar
Liang C Y, Wang Z J 2018 J. Aeronaut. Mater. 38 5Google Scholar
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图 2 三频带超材料吸波体 (a) 单元拓扑结构; (b) 等效电路模型; (c) 横电波(transverse electric, TE)模式下在不同入射角下测得的吸收率与频率的关系; (d) 横磁波(transverse magnetic, TM)模式下在不同入射角下测得的吸收率与频率的关系[55]
Figure 2. Triple-band metamaterial absorber: (a) Topology structure of the element; (b) equivalent circuit models; (c) measured absorption as a function of frequency for TE mode radiation at different angles of incidence; (d) measured absorption as a function of frequency for TM mode radiation at different angles of incidence[55].
图 4 超宽带完美超材料吸波体单元原理图 (a) 单元三维示意图; (b) 带有开口谐振环II的底层结构; (c) 带有开口谐振环I的第三层结构; (d) 加载集总电阻的第二层结构[76]
Figure 4. Schematic geometry of unit cell for the ultra-broadband perfect metamaterial absorber: (a) the 3 D schematic of a unit cell; (b) the bottom layer with the split ring resonator-II; (c) the third layer with the split ring resonator-I; (d) the third layer with lumped resistances[76].
图 5 极化和角度不敏感超材料吸波体单元结构示意图 (a) 正交排布的极化不敏感单元[81]; (b) 单频带单元[84]; (c) 四个扇形为基础的角度不敏感单元; (d) 八个扇形为基础的角度不敏感单元[91]
Figure 5. Schematic diagram of polarization and angle-independent metamaterial absorber unit cell: (a) Orthogonal polarization insensitive unit cell[81]; (b) single-band metamaterial absorber unit cell[84]; (c) four circular sector-based unit cell; (d) eight circular sector-based unit cell[91].
图 6 动态可调超材料吸波体 (a) 加载变容二极管的超材料吸波体[103]; (b) 加载石墨烯的超材料吸波体单元结构[105]; (c) 液晶可调超材料完美吸波体[106]; (d) 基于机械可调谐的吸波体[107]
Figure 6. Dynamically tunable metamaterial absorber: (a) Tunable metamaterial absorber using varactor diodes[103]; (b) schematic of the unit cell of the graphene based tunable metamaterial absorber[105]; (c) liquid crystal tunable metamaterial perfect absorber[106]; (d) mechanically stretchable and tunable metamaterial absorber[107].
表 1 用于实现多频/宽频吸波体的不同方法总结
Table 1. A summary of methods used to create multiple/broadband absorbers.
方法 工作频率 相对带宽 吸收率 厚度 周期 结构 文献 平面排布 30.6—37.5 THz 20.26% ≥ 80% 0.041 λL 10.8 µm “三明治” [61] 多层堆叠 24.8/25.5 THz N ≥ 90% 0.062 λL 500 nm 多层结构 [62] 多层堆叠 7.8—14.7 GHz 61.33% ≥ 90% 0.130 λL 11 mm 金字塔结构 [63] 集总元件 5.3—11.2 GHz 70.7% ≥ 90% 0.077 λL 13.6 mm 单层结构 [68] 用电阻膜 7.0—27.5 GHz 118.8% ≥ 90% 0.093 λL 5.5 mm “三明治” [69] 用电阻膜 2.0—18.5 GHz 160.97% N 0.082 λL 11 mm 多层结构 [72] 基于SSPP 7.6—14.7 GHz 63.7% ≥ 90% 0.177 λL 14 mm 非平面结构 [74] 混合方法 4.5—25.4 GHz 139.6% ≥ 80% 0.075 λL 8.4 mm 多层结构 [76] 新型结构 9.05—11.4 GHz 23.0% ≥ 80% 0.060 λL 5 mm 分形结构 [78] 注: 相对带宽指10 dB吸收带宽, λL为最低工作频率所对应的工作波长, N代表没有提及. -
[1] Duan X, Chen X, Zhou Y, Zhou L, Hao S 2018 IEEE Antennas Wirel. Propag. Lett. 17 1617Google Scholar
[2] Li W, Valentine J 2014 Nano Lett. 14 3510Google Scholar
[3] Watts C M, Liu X, Padilla W J 2012 Adv. Mater. 24 OP98
[4] Choi I, Lee D 2015 Compos. Struct. 119 218Google Scholar
[5] 刘顺华, 刘军民, 董星龙 2014 电磁波屏蔽及吸波材料(北京: 化学工业出版社) 第270页
Liu S H, Liu J M, Dong X L 2014 Electromagnetic Shielding and Absorb-ing Materials (Vol. 2) (Beijing: Chemical Industry Press) p270 (in Chinese)
[6] Fante R L, McCormack M T 1988 IEEE Trans. Antennas Propag. 36 1443Google Scholar
[7] Toit D, J L 1994 IEEE Antennas and Propag. Mag. 36 17Google Scholar
[8] Jaggard D, Engheta N, Liu J 1990 Electron. Lett. 26 1332Google Scholar
[9] 王光明, 许河秀, 梁建刚, 蔡通 2015 紧凑型异向介质: 机理、设计与应用(北京: 国防工业出版社)
Wang G M, Xu H X, Liang J G, Cai T 2015 Compact Metamaterials Mechanism, Design and Application (Beijing: National Defense Industry Press) (in Chinese)
[10] Veselago V G 1968 Sov. Phys. Usp. 10 509Google Scholar
[11] Pendry J B, Holden A, Stewart W, Youngs I 1996 Phys. Rev. Lett. 76 4773Google Scholar
[12] Pendry J B, Holden A J, Robbins D J, Stewart W 1999 IEEE Trans. Microw. Theory Tech. 47 2075Google Scholar
[13] Shelby R A, Smith D R, Schultz S 2001 Science 292 77Google Scholar
[14] Seddon N, Bearpark T 2003 Science 302 1537Google Scholar
[15] Lu J, Grzegorczyk T M, Zhang Y, Pacheco Jr J, Wu B I, Kong J A, Chen M 2003 Opt. Express 11 723Google Scholar
[16] Koschny T, Zhang L, Soukoulis C M 2005 Phys. Rev. B 71 121103Google Scholar
[17] Pendry J B 2000 Phys. Rev. Lett. 85 3966Google Scholar
[18] Pendry J B, Schurig D, Smith D R 2006 Science 312 1780Google Scholar
[19] Leonhardt U 2006 Science 312 1777Google Scholar
[20] Schurig D, Mock J J, Justice B, Cummer S A, Pendry J B, Starr A F, Smith D R 2006 Science 314 977Google Scholar
[21] 丰茂昌, 李勇峰, 张介秋, 王甲富, 王超, 马华, 屈绍波 2018 67 198101Google Scholar
Feng M C, Li Y F, Zhang J Q, Wang J F, Wang C, Ma H, Qu S B 2018 Acta Phys. Sin. 67 198101Google Scholar
[22] Yu N, Genevet P, Kats M A, Aieta F, Tetienne J P, Capasso F, Gaburro Z 2011 Science 334 333Google Scholar
[23] 庄亚强, 王光明, 张晨新, 张小宽, 宗彬锋, 马卫东, 王亚伟 2016 65 154101Google Scholar
Zhuang Y Q, Wang G M, Zhang C X, Zhang X K, Zong B F, Ma W D, Wang Y W 2016 Acta Phys. Sin. 65 154101Google Scholar
[24] Cui T J, Qi M Q, Wan X, Zhao J, Cheng Q 2014 Light: Sci. Appl. 3 e218Google Scholar
[25] Tran M C, Pham V H, Ho T H, Nguyen T T, Do H T, Bui X K, Bui S T, Le D T, Pham T L, Vu D L 2020 Sci. Rep. 10 1Google Scholar
[26] Wu H, Liu S, Wan X, Zhang L, Wang D, Li L, Cui T J 2017 Adv. Sci. 4 1700098Google Scholar
[27] Hum S V, Perruisseau-Carrier J 2013 IEEE Trans. Antennas Propag. 62 183Google Scholar
[28] Cai T, Tang S, Wang G, Xu H, Sun S, He Q, Zhou L 2017 Adv. Opt. Mater. 5 1600506Google Scholar
[29] Xu H X, Zhang L, Kim Y, Wang G M, Zhang X K, Sun Y, Ling X, Liu H, Chen Z, Qiu C W 2018 Adv. Opt. Mater. 6 1800010Google Scholar
[30] Yuan F, Xu H X, Jia X Q, Wang G M, Fu Y Q 2020 IEEE Trans. Antennas Propag.68 2463Google Scholar
[31] Sun S, He Q, Hao J, Xiao S, Zhou L 2019 Adv. Opt. Photonics 11 380Google Scholar
[32] Zhang L, Wan X, Liu S, Yin J Y, Zhang Q, Wu H T, Cui T J 2017 IEEE Trans. Antennas Propag. 65 3374Google Scholar
[33] Landy N I, Sajuyigbe S, Mock J J, Smith D R, Padilla W J 2008 Phys. Rev. Lett. 100 207402Google Scholar
[34] Marin P, Cortina D, Hernando A 2008 IEEE Trans. Magn. 44 3934Google Scholar
[35] 刘祥萱, 陈鑫, 王煊军, 刘渊 2013 表面技术 42 104Google Scholar
Liu X X, Chen X, Wang X J, Liu Y 2013 Surf. Technol. 42 104Google Scholar
[36] 周万城, 王婕, 罗发, 朱冬梅, 黄智斌, 卿玉长 2013 中国材料进展 000 463Google Scholar
Zhou W C, Wang J, Luo F, Zhu D M, Huang Z B, Qing Y C 2013 Mater. China 000 463Google Scholar
[37] Costa F, Monorchio A, Manara G 2010 IEEE Trans. Antennas Propag. 58 1551Google Scholar
[38] Wen Q Y, Zhang H W, Xie Y S, Yang Q H, Liu Y L 2009 Appl. Phys. Lett. 95 241111Google Scholar
[39] Hao J, Wang J, Liu X, Padilla W J, Zhou L, Qiu M 2010 Appl. Phys. Lett. 96 251104Google Scholar
[40] Liu X, Starr T, Starr A F, Padilla W J 2010 Phys. Rev. Lett. 104 207403Google Scholar
[41] Aydin K, Ferry V E, Briggs R M, Atwater H A 2011 Nat. Commun. 2 1Google Scholar
[42] Simovski C 2009 Opt. Spectrosc. 107 726Google Scholar
[43] Smith D R, Schultz S, Markoš P, Soukoulis C M 2002 Phys. Rev. B 65 195104Google Scholar
[44] Chen X, Grzegorczyk T M, Wu B I, Pacheco J J, Kong J A 2004 Phys. Rev. E 70 016608Google Scholar
[45] Smith D R, Vier D C, Koschny T, Soukoulis C M 2005 Phys. Rev. E 71 036617Google Scholar
[46] Arslanagić S, Hansen T V, Mortensen N A, Gregersen A H, Sigmund O, Ziolkowski R W, Breinbjerg O 2013 IEEE Antennas and Propag. Mag. 55 91Google Scholar
[47] Costa F, Monorchio A, Manara G 2012 IEEE Antennas and Propag. Mag. 54 35Google Scholar
[48] Chen H T 2012 Opt. Express 20 7165Google Scholar
[49] Peng X Y, Wang B, Lai S, Zhang D H, Teng J H 2012 Opt. Express 20 27756Google Scholar
[50] Liu X, Zhao Q, Lan C, Zhou J 2013 Appl. Phys. Lett. 103 031910Google Scholar
[51] Zheng H, Jin X, Park J, Lu Y, Rhee J Y, Jang W, Cheong H, Lee Y 2012 Opt. Express 20 24002Google Scholar
[52] Im K, Kang J H, Park Q H 2018 Nat. Photonics 12 143Google Scholar
[53] Tao H, Bingham C, Pilon D, Fan K, Strikwerda A, Shrekenhamer D, Padilla W, Zhang X, Averitt R 2010 J. Phys. D: Appl. Phys. 43 225102Google Scholar
[54] Chen K, Adato R, Altug H 2012 ACS Nano 6 7998Google Scholar
[55] Xu H X, Wang G M, Qi M Q, Liang J G, Gong J Q, Xu Z M 2012 Phys. Rev. B 86 205104Google Scholar
[56] Shen X, Cui T J, Zhao J, Ma H F, Jiang W X, Li H 2011 Opt. Express 19 9401Google Scholar
[57] Ma Y, Chen Q, Grant J, Saha S C, Khalid A, Cumming D R 2011 Opt. Lett. 36 945Google Scholar
[58] Jia D, Xu J, Yu X 2018 Opt. Express 26 26227Google Scholar
[59] Huang L, Chowdhury D R, Ramani S, Reiten M T, Luo S N, Taylor A J, Chen H T 2012 Opt. Lett. 37 154Google Scholar
[60] Zhang C, Cheng Q, Yang J, Zhao J, Cui T J 2017 Appl. Phys. Lett. 110 143511Google Scholar
[61] Zhang Y, Li Y, Cao Y, Liu Y, Zhang H 2017 Opt. Commun. 382 281Google Scholar
[62] Su Z, Yin J, Zhao X 2015 Opt. Express 23 1679Google Scholar
[63] Ding F, Cui Y, Ge X, Jin Y, He S 2012 Appl. Phys. Lett. 100 103506Google Scholar
[64] Nguyen T Q H, Phan H L, Phan D T 2017 Microw. Opt. Techn. Lett. 59 1157Google Scholar
[65] Cheng Y Z, Wang Y, Nie Y, Gong R Z, Xiong X, Wang X 2012 J. Appl. Phys. 111 044902Google Scholar
[66] Yuan W, Cheng Y 2014 Appl. Phys. A 117 1915Google Scholar
[67] Kim Y J, Hwang J S, Yoo Y J, Khuyen B X, Rhee J Y, Chen X, Lee Y 2017 J. Phys. D: Appl. Phys. 50 405110Google Scholar
[68] Kundu D, Mohan A, Chakrabarty A 2016 IEEE Antennas Wirel. Propag. Lett. 15 1589Google Scholar
[69] 顾超, 屈绍波, 裴志斌, 徐卓, 林宝勤, 周航, 柏鹏, 顾巍, 彭卫东, 马华 2011 60 087802Google Scholar
Gu C, Qu S B, Pei Z B, Xu Z, Lin B Q, Zhou H, Bai P, Gu W, Peng W D, Ma H 2011 Acta Phys. Sin. 60 087802Google Scholar
[70] Sun L, Cheng H, Zhou Y, Wang J 2012 Opt. Express 20 4675Google Scholar
[71] 莫漫漫, 马武伟, 庞永强, 陈润华, 张笑梅, 柳兆堂, 李想, 郭万涛 2018 67 217801Google Scholar
Mo M M, Ma W W, Pang Y Q, Chen R H, Zhang X M, Liu Z T, Li X, Guo W T 2018 Acta Phys. Sin. 67 217801Google Scholar
[72] Tayde Y, Saikia M, Srivastava K V, Ramakrishna S A 2018 IEEE Antennas Wirel. Propag. Lett. 17 2489Google Scholar
[73] Ji T, Wang Y, Cui Y, Lin Y, Hao Y, Li D 2017 Mater. Today Energy 5 181Google Scholar
[74] Pang Y, Wang J, Ma H, Feng M, Li Y, Xu Z, Xia S, Qu S 2016 Sci. Rep. 6 29429Google Scholar
[75] Fan Y, Wang J, Li Y, Pang Y, Zheng L, Xiang J, Zhang J, Qu S 2018 J. Phys. D: Appl. Phys. 51 215001Google Scholar
[76] Li S J, Wu P X, Xu H X, Zhou Y L, Cao X Y, Han J F, Zhang C, Yang H H, Zhang Z 2018 Nanoscale Res. Lett. 13 386Google Scholar
[77] Pitchappa P, Ho C P, Kropelnicki P, Singh N, Kwong D L, Lee C 2014 J. Appl. Phys. 115 193109Google Scholar
[78] Gu S, Su B, Zhao X 2013 J. Appl. Phys. 114 163702Google Scholar
[79] Yu P, Besteiro L V, Huang Y, Wu J, Fu L, Tan H H, Jagadish C, Wiederrecht G P, Govorov A O, Wang Z 2019 Adv. Opt. Mater. 7 1800995Google Scholar
[80] Landy N I, Bingham C M, Tyler T, Jokerst N, Smith D R, Padilla W J 2009 Phys. Rev. B 79 125104Google Scholar
[81] Zhu B, Wang Z B, Yu Z Z, Zhang Q, Zhao J M, Feng Y J, Jiang T 2009 Chin. Phys. Lett. 26 114102Google Scholar
[82] Li L, Yang Y, Liang C 2011 J. Appl. Phys. 110 063702Google Scholar
[83] Gu C, Qu S B, Pei Z B, Xu Z 2011 Chin. Phys. B 20 037801Google Scholar
[84] Chen J, Hu Z, Wang S, Huang X, Liu M 2016 Eur. Phys. J. B 89 14Google Scholar
[85] Zhu B, Wang Z, Huang C, Feng Y, Zhao J, Jiang T 2010 Prog. Electromagn. Res. 101 231Google Scholar
[86] Wang J, Yang R, Tian J, Chen X, Zhang W 2018 IEEE Antennas Wirel. Propag. Lett. 17 1242Google Scholar
[87] Xu Y Q, Zhou P H, Zhang H B, Chen L, Deng L J 2011 J. Appl. Phys. 110 044102Google Scholar
[88] Wang B, Koschny T, Soukoulis C M 2009 Phys. Rev. B 80 033108Google Scholar
[89] Munk B A, Munk P, Pryor J 2007 IEEE Trans. Antennas Propag. 55 186Google Scholar
[90] Bhattacharyya S, Srivastava K V 2014 J. Appl. Phys. 115 064508Google Scholar
[91] Ghosh S, Nguyen T T, Lim S 2019 EPJ Appl. Metamater. 6 12 064508
[92] Shen Y, Pang Y, Wang J, Ma H, Pei Z, Qu S 2015 J. Phys. D: Appl. Phys. 48 445008Google Scholar
[93] Chen T, Li S J, Cao X Y, Gao J, Guo Z X 2019 Appl. Phys. A 125 232Google Scholar
[94] Chang T, Langley R J, Parker E 1993 IEEE Microwave Guided Wave Lett. 3 387Google Scholar
[95] Shadrivov I V, Morrison S K, Kivshar Y S 2006 Opt. Express 14 9344Google Scholar
[96] Zhu H, Liu X, Cheung S, Yuk T 2013 IEEE Trans. Antennas Propag. 62 80Google Scholar
[97] 李宇涵, 邓联文, 罗衡, 贺龙辉, 贺君, 徐运超, 黄生祥 2019 68 095201Google Scholar
Li Y H, Deng L W, Luo H, He L H, He J, Xu Y C, Huang S X 2019 Acta Phys. Sin. 68 095201Google Scholar
[98] Zhao X, Wang Y, Schalch J, Duan G, Cremin K, Zhang J, Chen C, Averitt R D, Zhang X 2019 ACS Photonics 6 830Google Scholar
[99] Zhai Z, Zhang L, Li X, Xiao S 2019 Opt. Commun. 431 199Google Scholar
[100] 陈俊, 杨茂生, 李亚迪, 程登科, 郭耿亮, 蒋林, 张海婷, 宋效先, 叶云霞, 任云鹏, 任旭东, 张雅婷, 姚建铨 2019 68 247802Google Scholar
Chen J, Yang M S, Li Y D, Cheng D K, Guo G L, Jiang L, Zhang H T, Song X X, Ye Y X, Ren Y P, Ren X D, Zhang Y T, Yao J Q 2019 Acta Phys. Sin. 68 247802Google Scholar
[101] Balci O, Kakenov N, Karademir E, Balci S, Cakmakyapan S, Polat E O, Caglayan H, Özbay E, Kocabas C 2018 Sci. Adv. 4 eaao1749Google Scholar
[102] 毕科, 王旭莹, 兰楚文, 郝亚楠, 周济 2019 中国材料进展 38 1Google Scholar
Bi K, Wang X Y, Lan C W, Hao Y N, Zhou J 2019 Mater. China 38 1Google Scholar
[103] Zhao J, Cheng Q, Chen J, Qi M Q, Jiang W X, Cui T J 2013 New J. Phys. 15 043049Google Scholar
[104] Li M, Yi Z, Luo Y, Muneer B, Zhu Q 2016 IEEE Trans. Antennas Propag. 64 944Google Scholar
[105] Zhang Y, Feng Y, Zhu B, Zhao J, Jiang T 2014 Opt. Express 22 22743Google Scholar
[106] Shrekenhamer D, Chen W C, Padilla W J 2013 Phys. Rev. Lett. 110 177403Google Scholar
[107] Zhang F, Feng S, Qiu K, Liu Z, Fan Y, Zhang W, Zhao Q, Zhou J 2015 Appl. Phys. Lett. 106 091907Google Scholar
[108] Rozanov K N 2000 IEEE Trans. Antennas Propag. 48 1230Google Scholar
[109] Acher O, Dubourg S 2008 Phys. Rev. B 77 104440Google Scholar
[110] 院伟, 杨进, 王一龙, 李维, 官建国 2016 材料导报 30 104Google Scholar
Yuan W, Yang J, Wang Y L, Li W, Guan J G 2016 Mater. Rev. 30 104Google Scholar
[111] Mou J, Shen Z 2017 Sci. Rep. 7 1Google Scholar
[112] Mou J, Shen Z 2016 IEEE Trans. Antennas Propag. 65 696Google Scholar
[113] Banadaki M D, Heidari A A, Nakhkash M 2017 IEEE Antennas Wirel. Propag. Lett. 17 205Google Scholar
[114] Li W, Wei J, Wang W, Hu D, Li Y, Guan J 2016 Mater. Des. 110 27Google Scholar
[115] 程用志, 王莹, 聂彦, 郑栋浩, 龚荣洲, 熊炫, 王鲜 2012 61 134102Google Scholar
Cheng Y Z, Wang Y, Nie Y, Zheng D H, Gong R Z, Xiong X, Wang X 2012 Acta Phys. Sin. 61 134102Google Scholar
[116] Li W, Liu Q, Wang L, Zhou Z, Zheng J, Ying Y, Qiao L, Yu J, Qiao X, Che S 2018 AIP Adv. 8 015318Google Scholar
[117] 许河秀 2019 超表面电磁调控机理与功能器件应用研究 (北京: 科学出版社)
Xu H X 2019 Investigations on Electromagnetic Wave Manipulations and Functional Device Applications Using Metasurfaces (Beijing: Science Press) (in Chinese)
[118] Sun J, Chen K, Ding G, Guo W, Zhao J, Feng Y, Jiang T 2019 IEEE Access 7 93919Google Scholar
[119] Peng L, Li X F, Gao X, Jiang X, Li S M 2019 Opt. Mater. Express 9 687Google Scholar
[120] Chen W, Chen R, Zhou Y, Ma Y 2019 IEEE Photonics Technol. Lett. 31 1187Google Scholar
[121] 沈杨, 王甲富, 张介秋, 李勇峰, 郑麟, 庞永强, 屈绍波 2018 空军工程大学学报 (自然科学版) 19 39Google Scholar
Shen Y, Wang J F, Zhang J Q, Li Y F, Zheng L, Pang Y Q, Qu S B 2018 J. Air Force Engineering Univ. (Nat. Sci. Ed.) 19 39Google Scholar
[122] Wang J F, Qu S B, Xu Z, Fu Z T, Ma H, Yang Y M 2009 J. Phys. D: Appl. Phys. 42 155413Google Scholar
[123] 鲁磊, 屈绍波, 施宏宇, 张安学, 张介秋, 马华 2013 62 158102Google Scholar
Lu Lei, Qu S B, Shi H Y, Zhang A X, Zhang J Q, Ma H 2013 Acta Phys. Sin. 62 158102Google Scholar
[124] Xu H X, Wang G M, Tao Z, Cui T J 2014 Sci. Rep. 4 5744
[125] Xu H X, Wang G M, Ma K, Cui T J 2014 Adv. Opt. Mater. 2 572Google Scholar
[126] 熊益军, 王岩, 王强, 王春齐, 黄小忠, 张芬, 周丁 2018 67 084202Google Scholar
Xiong Y J, Wang Y, Wang Q, Wang C Q, Huang X Z, Zhang F, Zhou D 2018 Acta Phys. Sin. 67 084202Google Scholar
[127] Lim D, Yu S, Lim S 2018 IEEE Access 6 43654Google Scholar
[128] Jiang W, Yan L, Ma H, Fan Y, Wang J, Feng M, Qu S 2018 Sci. Rep. 8 4817Google Scholar
[129] Xie J, Quader S, Xiao F, He C, Liang X, Geng J, Jin R, Zhu W, Rukhlenko I D 2019 IEEE Antennas Wirel. Propag. Lett. 18 536Google Scholar
[130] 田小永, 尚振涛, 尹丽仙, 李涤尘 2019 航空制造技术 62 14Google Scholar
Tian X Y, Shang Z T, Yin L X, Li D C 2019 Aeronaut. Manuf. Technol. 62 14Google Scholar
[131] Rashid A K, Li B, Shen Z 2014 IEEE Antennas and Propag. Mag. 56 43Google Scholar
[132] Yu Y, Shen Z, Deng T, Luo G 2017 IEEE Trans. Antennas Propag. 65 4363Google Scholar
[133] Li W, Wu T, Wang W, Guan J, Zhai P 2014 Appl. Phys. Lett. 104 022903Google Scholar
[134] Li M, Shen L, Jing L, Xu S, Zheng B, Lin X, Yang Y, Wang Z, Chen H 2019 Adv. Sci. 6 1901434Google Scholar
[135] 梁彩云, 王志江 2018 航空材料学报 38 5Google Scholar
Liang C Y, Wang Z J 2018 J. Aeronaut. Mater. 38 5Google Scholar
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