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A Metamaterial with Dual-Band Perfect Terahertz Transmission

IOP Conference Series: materials Science and Engineering 2017年第1期250卷

作者： Guochao Wei Yawei Zheng Xiran Chen Zhengpeng Qin Luman Qin Nangang Zhang Kan Liu Songzhan Li Shengxiang Wang School of Electronic and Electrical Engineering Wuhan Textile University Wuhan 430020 P. R. China Advanced Micro-Nano Textile Innovation Research Center Wuhan Textile University Wuhan 430020 P. R. China State Key Laboratory for Hubei New Textile Materials and Advanced Processing Technology Wuhan Textile University Wuhan 430020 P. R. China

In recent years, the electromagnetic metamaterial has been development rapidly. Meanwhile, its peculiar electromagnetic properties have been widely studied in the fields of electromagnetism and optics. Compared to conventional natural materials, metamaterials show some unusual phenomena, for example, negative refractive index. Because of their exotic properties, metamaterials have been found with many applications, such as perfect lens, cloaking, solar cells and so on. In this paper, we report a metamaterial with dual-band perfect transmission in terahertz range. By tailoring the periodicity of the unit cell, significantly high transmission can be obtained with the metamaterial. The simulation results show that significant transmission peaks at 3.56THz and 7.16THz with the magnitudes of 99.8% and 99.7%, respectively.

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A 3D-printed metamaterial with electromagnetically induced transmission

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IOP Conference Series: materials Science and Engineering 2017年第1期250卷

作者： Zhengpeng Qin Xiran Chen Yawei Zheng Guochao Wei Luman Qin Nangang Zhang Kan Liu Songzhan Li Shengxiang Wang School of Electronic and Electrical Engineering Wuhan Textile University Wuhan 430020 P. R. China Advanced Micro-Nano Textile Innovation Research Center Wuhan Textile University Wuhan 430020 P. R. China State Key Laboratory for Hubei New Textile Materials and Advanced Processing Technology Wuhan Textile University Wuhan 430020 P. R. China

Metamaterials have recently enabled coupling electromagnetic transparency due to interference effects in coupled sub-wavelength resonators. In this work, it presents a three dimensional (3D) metamaterial designed with hollow cube whose simulation shows electromagnetically induced transparency in GHz regime with polarization insensitive to the incident electromagnetic wave due to the ultra-sharp resonance line width as a result of interaction between the constituent meta-atoms. Influences of various parameters including incident angle and frequency have been investigated numerically in detail. The simulation shows significant transmission magnitude of 99.8% at ~12GHz.

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Author Correction: Concise N-doped Carbon Nanosheets/Vanadium Nitride Nanoparticles materials via Intercalative Polymerization for Supercapacitors

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Scientific reports 2018年第1期8卷 6428页

作者： Yongtao Tan Ying Liu Zhenghua Tang Zhe Wang Lingbin Kong Long Kang Zhen Liu Fen Ran State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals Lanzhou University of Technology Lanzhou 730050 P. R. China. School of Material Science and Engineering Lanzhou University of Technology Lanzhou 730050 Gansu P. R. China. Guangzhou Key Laboratory for Surface Chemistry of Energy Materials New Energy Research Institute School of Environment and Energy South China University of Technology Guangzhou Higher Education Mega Centre Guangzhou 510006 China. Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control Guangdong Provincial Engineering and Technology Research Center for Environmental Risk Prevention and Emergency Disposal South China University of Technology Guangzhou Higher Education Mega Centre Guangzhou 510006 China. Department of Chemistry Xavier University of Louisiana New Orleans LA 70125 USA. Department of Physics & Engineering Frostburg State University Frostburg MD 21532-2303 USA. zliu@frostburg.edu. State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals Lanzhou University of Technology Lanzhou 730050 P. R. China. ranfen@***. School of Material Science and Engineering Lanzhou University of Technology Lanzhou 730050 Gansu P. R. China. ranfen@***.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

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Density functional theory investigation of oxygen interaction with boron-doped graphite

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Applied Surface Science 2016年 390卷 273-282页

作者： Juan Liu Chen Wang Tongxiang Liang Wensheng Lai State Key Lab of New Ceramic and Fine Processing Institute of Nuclear and New Energy Technology Tsinghua University Beijing 100084 China Advanced Material Laboratory School of Materials Science & Engineering Tsinghua University Beijing 100084 China

Boron inserted as impurity by substitution of carbon atoms in graphite is known to change (improve or deteriorate) oxidation resistance of nuclear graphite, but the reason for both catalytic and inhibiting oxidation is still uncertain. As a first step, this work is more specially devoted to the adsorption and diffusion of oxygen atoms on the surface and related to the problem of oxygen retention on the pure and boron-containing graphite surfaces. Adsorption energies and energy barriers associated to the diffusion for molecular oxygen recombination are calculated in the density functional theory framework. The existence of boron modifies the electronic structure of the surface, which results in an increase of the adsorption energy for O. However, low boron loading makes it easier for the recombination into molecular oxygen. For high boron concentration, it induces a better O retention capability in graphite because the presence of B-B bonds decreases recombination of the adsorbed oxygen atoms. A possible explanation for both catalytic and inhibiting effects of boron in graphite is proposed.

关键词： Density functional calculations Chemisorption Graphite Boron Oxygen

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Integrated Intercalation-Based and Interfacial Sodium Storage in Graphene-Wrapped Porous Li4Ti5O12 Nanofibers Composite Aerogel

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advanced Energy materials 2016年第13期6卷

作者： Chen, Chaoji Xu, Henghui Zhou, Tengfei Guo, Zaiping Chen, Lineng Yan, Mengyu Mai, Liqiang Hu, Pei Cheng, Shijie Huang, Yunhui Xie, Jia State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan430074 China State Key Laboratory of Materials Processing and Die and Mould Technology School of Materials Science and Engineering Huazhong University of Science and Technology Wuhan430074 China School of Mechanical Materials and Mechatronics Engineering University of Wollongong North WollongongNSW Australia State Key Laboratory of Advanced Technology for Materials Synthesis and Processing WUT-Harvard Joint Nano Key Laboratory Wuhan University of Technology Wuhan430070 China Collaborative Innovation Center of Intelligent New Energy Vehicle Tongji University Shanghai201804 China

Sodium storage in both solid–liquid and solid–solid interfaces is expected to extend the horizon of sodium-ion batteries, leading to a new strategy for developing high-performance energy-storage materials. Here, a novel composite aerogel with porous Li4Ti5O12 (PLTO) nanofibers confined in a highly conductive 3D-interconnected graphene framework (G-PLTO) is designed and fabricated for Na storage. A high capacity of 195 mA h g−1 at 0.2 C and super-long cycle life up to 12 000 cycles are attained. Electrochemical analysis shows that the intercalation-based and interfacial Na storage behaviors take effect simultaneously in the G-PLTO composite aerogel. An integrated Na storage mechanism is proposed. This study ascribes the excellent performance to the unique structure, which not only offers short pathways for Na+ diffusion and conductive networks for electron transport, but also guarantees plenty of PLTO–electrolyte and PLTO–graphene interfacial sites for Na+ adsorption. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

关键词： Storage (materials)

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A three-dimensional model of non-slipping stress corrosion cracking under low loads

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Procedia Structural Integrity 2016年 2卷 612-621页

作者： Zhu Longkui Li Zhengcao Qiao Lijie State Key Laboratory of New Ceramics & Fine Processing Key Laboratory for Advanced Materials of Ministry of Education School of Materials Science and Engineering Tsinghua University Beijing 100084 People’s Republic of China Corrosion and Protection Center Key Laboratory for environmental fracture of Ministry of Education School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100084 People’s Republic of China

Stress corrosion cracking (SCC) of 316L single-crystal austenitic stainless steel subjected to low loads (σ nom = 20-40 MPa) in a 45 % boiling MgCl 2 solution was studied using synchrotron X-ray computed tomography, finite element analysis and so on. Results show that there was no surface slip band around the nucleation sites and the tips of short cracks. Three-dimensional reconstruction of discontinuous zig-zag surface SCC crack indicates that the crack was continuous inside the specimen. The obtaining through two-surface trace analysis manifests, rather than {1 1 1} slip planes, the cracks extended along {1 0 0} planes with the lowest surface energy. It is considered that microcleavage and local dissolution synergistically led to the SCC advance, and microshear was also one of the primarily microscopic SCC mechanisms under the high load. The three-dimensional SCC model was created at the low stress level, where a main SCC crack grew along the MPD due to anodic dissolution, and a microdefect was formed on the crack front. When the microdefect enlarged to a critical size, secondary microcracks nucleated at the stress-concentrated microdefect shoulders. Then, the microcracks propagated to two sides of the MPD through anodic dissolution, microcleavage or mciroshear, resulting in the formation of the river-like fractography and the discontinuous surface SCC cracks with or without surface slipping.

关键词： Single-crystal stainless steel Stress corrosion cracking Three-dimensional model Slip band Discontinuous cracks

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Interaction of boron with graphite: A van der Waals density functional study

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Applied Surface Science 2016年 379卷 402-410页

作者： Juan Liu Chen Wang Tongxiang Liang Wensheng Lai Beijing Key Lab of Fine Ceramics Institute of Nuclear and New Energy Technology Tsinghua University Beijing 100084 China State Key Lab of New Ceramic and Fine Processing Tsinghua University Beijing 100084 China Advanced Material Laboratory School of Materials Science & Engineering Tsinghua University Beijing 100084 China

Boron doping has been widely investigated to improve oxidation resistance of graphite. In this work the interaction of boron with graphite is investigated by a van der Waals density-functional approach (vdW-DF). The traditional density-functional theory (DFT) is well accounted for the binding in boron-substituted graphite. However, to investigate the boron atom on graphite surface and the interstitial impurities require use of a description of graphite interlayer binding. Traditional DFT cannot describe the vdW physics, for instance, GGA calculations show no relevant binding between graphite sheets. LDA shows some binding, but they fail to provide an accurate account of vdW forces. In this paper, we compare the calculation results of graphite lattice constant and cohesive energy by several functionals, it shows that vdW-DF such as two optimized functionals optB88-vdW and optB86b-vdW give much improved results than traditional DFT. The vdW-DF approach is then applied to study the interaction of boron with graphite. Boron adsorption, substitution, and intercalation are discussed in terms of structural parameters and electronic structures. When adsorbing on graphite surface, boron behaves as π electron acceptor. The π electron approaches boron atom because of more electropositive of boron than carbon. For substitution situation, the hole introduced by boron mainly concentrates on boron and the nearest three carbon atoms. The B-doped graphite system with the hole has less ability to offer electrons to oxygen, ultimately resulted in the inhibition of carbon oxidation. For interstitial doping, vdW-DFs show more accurate formation energy than LDA. PBE functional cannot describe the interstitial boron in graphite reasonably because of the ignoring binding of graphite sheets. The investigation of electron structures of boron doped graphite will play an important role in understanding the oxidation mechanism in further study.

关键词： Graphite Boron van der Waals density functional Oxidation

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Aluminum-Doped Zinc Oxide as Highly Stable Electron Collection Layer for Perovskite Solar Cells

Aluminum-Doped Zinc Oxide as Highly Stable Electron Collecti...

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第三届新型太阳能电池学术研讨会

作者： Xingyue Zhao Heping Shen Ye Zhang Xin Li Xiaochong Zhao Meiqian Tai Jingfeng Li Jianbao Li Xin Li Hong Lin State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua University Science and Technology on Surface Physics and Chemistry Laboratory Key Laboratory of Ministry of Education for Advanced Materials in Tropical Island Resources Hainan University Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen University

Although low-temperature,solution-processed zinc oxide（ZnO） has been widely adopted as the electron collection layer（ECL） in perovskite solar cells（PSCs） because of its simple synthesis and excellent electrical properties such as high charge mobility,the thermal stability of the perovskite films deposited atop ZnO layer remains as a major ***,we addressed this problem by employing aluminum-doped zinc oxide（AZO） as the ECL and obtained extraordinarily thermally stable perovskite *** improvement of the thermal stability was ascribed to diminish of the Lewis acid–base chemical reaction between perovskite and ***,the outstanding transmittance and conductivity also render AZO layer as an ideal candidate for transparent conductive electrodes,which enables a simplified cell structure featuring glass/AZO/perovskite/Spiro-OMe TAD/*** of the perovskite layer leads to an excellent and repeatable photovoltaic performance,with the champion cell exhibiting an open-circuit voltage（Voc） of 0.94 V,a short-circuit current（Jsc） of 20.2 m A cm,a fill factor（FF） of 0.67,and an overall power conversion efficiency（PCE） of 12.6% under standard 1 sun *** was also revealed by steady-state and time-resolved photoluminescence that the AZO/perovskite interface resulted in less quenching than that between perovskite and hole transport material.

关键词： Solar cell perovskite zinc oxide aluminum doping thermally stable

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Discontinuous Precipitation Reaction Front of Cellular Recrystallization for a Single-Crystal Superalloy Studied by Electron Microscopy

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Chinese Physics Letters 2015年第7期32卷 106-109页

作者：卓龙超梁淑华王锋刘玉峰熊继春 School of Materials Science and Engineering Xi'an University of Technology Xi'an 710048 National Center for Electron Microscopy in Beijing School of Materials Science and Engineering State Key Laboratory of New Ceramics and Fine Processing Laboratory of Advanced Materials Tsinghua University Beijing 100084 State Key Lab of Power Systems Department of Thermal Engineering Tsinghua University Beijing 100084 Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical Materials Beijing 100095

Combining analytical transmission electron microscopy systematic tilting, scanning transmission electron microscopy mapping and nano-beam electron diffraction operations, we obtain direct experimental proofs on the boundary type, elemental distribution and structure of the cellular reerystallization reaction front for a single- crystal superalloy. It is demonstrated that the cellular recrystallization reaction front usually corresponds to coincidence site lattice boundaries, and a thin layer of γ-forming elements such as Re, Cr, Mo and Co invariably exists in the direct reaction front. Furthermore, the thin layer with γ-forming elements is proved to be γ phase, with the same orientation as the neighboring original matrix.

关键词： CR OM Discontinuous Precipitation Reaction Front of Cellular Recrystallization for a Single-Crystal Superalloy Studied by Electron Microscopy

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Towards polyvalent ion batteries: A zinc-ion battery based on NASICON structured Na 3 V 2 (PO 4 ) 3

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Nano Energy 2016年 25卷 211-217页

作者： Guolong Li Ze Yang Yan Jiang Chuanhong Jin Wei Huang Xuli Ding Yunhui Huang State Key Laboratory of Material Processing and Die & Mould Technology School of Materials Science and Engineering Huazhong University of Science and Technology Wuhan Hubei 430074 China Hubei Collaborative Innovation Center for High-efficient Utilization of Solar Energy Wuhan 430068 China School of Electrical & Electronic Engineering Hubei University of Technology Wuhan 430068 China State Key Laboratory of Silicon Materials Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province School of Materials Science and Engineering Zhejiang University Hangzhou Zhejiang 310027 China Collaborative Innovation Center of Intelligent New Energy Vehicle School of Materials Science and Engineering Tongji University Shanghai 201804 China

Zinc-ion batteries are considered as potential large-scale renewable energy storage devices due to low redox potential, low cost, large capacity, high electric conductivity, nontoxicity and easy processing of zinc metal. However, the development of cathode materials for zinc-ion batteries to date has been mainly limited to tunnel manganese oxides and Prussian blue analogues. Here we have firstly developed NASICON structured Na 3 V 2 (PO 4 ) 3 as cathode material for Zn-ion batteries. To compensate the low conductivity, graphene-like carbon wrapped Na 3 V 2 (PO 4 ) 3 nanoparticles are fabricated. With Na 3 V 2 (PO 4 ) 3 /C as cathode, Zn metal as both counter and reference electrodes, and 0.5 mol L −1 Zn(CH 3 COO) 2 solution as electrolyte, the aqueous Zn-ion battery delivers a reversible capacity of 97 mA h g −1 at 0.5 C and retains 74% capacity after 100 cycles. Meanwhile, the battery can be charged and discharged at high rate up to 10 C. The cyclic voltammogram analysis shows that the Zn-ion storage in Na 3 V 2 (PO 4 ) 3 is a diffusion-controlled kinetic process. A mechanism of Zn ion occupancy variation during cycling is proposed. Our results provide an example for understanding and designing the intercalation process of divalent metal ions in NASICON structured cathode for new type rechargeable divalent metal ion batteries.

关键词： Zn-ion batteries NASICON Na 3 V 2 (PO 4 ) 3 Ion occupancy variation

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