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Electromagnetic (EM) wave absorber with broad and robust absorption performance over wide incident angle range is persistently desired in specific applications. In this work, we propose and demonstrate a broadband and wide-angle metamaterial absorber (MA) based on a hybrid of stereo spoof surface plasmonic polariton (SSPP) structure and planar resistive metasurface. At first, we design a broadband SSPP absorber by adjusting the dispersion and loss of the artificial plasmonic structure (PS) simultaneously. Furthermore, owing to utilize its spatial phase manipulation ability, we integrate a resistive metasurface on top of the PS to construct a modified circuit analog (CA) absorber with a dispersive metamaterial spacer. The absorption mechanism of the hybrid structure is analyzed theoretically. The results indicate that the hybrid MA is equipped with broad and robust absorption performance over a wide incident angle range due to the synergistic absorption of the PS and metasurface. Finally, a prototype of the hybrid MA is fabricated by silk-printing technic and its absorption performances are measured. The experimental results can verify the theoretic ones and indicate that proposed hybrid MA can achieve 90% absorptivity from 3.9 GHz to 10.6 GHz with thickness of 7.0 mm, which is only 106% times of the ultimate thickness corresponding to the absorption performance of MA. In general, the concept and design offer a distinct approach of utilizing SSPP to design absorbers with excellent performances from radio frequency to optic band, which are promising for extensive applications.

In this paper, by integrating resistive stereo metamaterial and metasurface, a metamaterial absorber (MA) with wideband microwave absorption and wide-angle performance is proposed. The intersecting dielectric substrates are printed with standing lossy rectangular rings, which indicates that stereo metamaterial has advantages of polarization-insensitiveness and light-weight. Metasurface as a covering consists of resistive film and dielectric substrate. We fabricated a prototype of proposed composite metamaterial and verify its absorption performances by experiment. The proposed MA can achieve broadband absorption with the efficiency over 90% in the frequency band of 2.78-21.00 GHz with the thickness of 9 mm.

Broadband electromagnetic (EM) wave absorbers are persistently desired in the past decades due to their extensive applications in different fields. In this paper, we proposed and demonstrated a metamaterial absorber (MA) based on a hybrid structure of stereo and planar resistive metamaterial elements. In principle, this hybrid MA is a combination of the Dallenbach layer absorber and circuit analog (CA) absorber. By adjusting its dispersion feature, the stereo metamaterial based on standing resistive patch can work as a broadband artificial Dallenbach layer absorber for C, X and Ku bands. Such stereo metamaterial was also utilized as a dispersive dielectric spacer and a metasurface consisting of resistive circle rings was deployed on the top of it to implement an improved CA absorber for S and C bands. By combing them together, the proposed hybrid MA can achieve absorption over 90% in an ultra-broad bandwidth from S to Ku band (2.59–16.80 GHz). Since our design takes full advantage of the physical space, the hybrid MA achieves an actual thickness as only 1.075 times of the ultimate thickness corresponding to its absorption performance. Furthermore, the hybrid MA has comprehensive advantages in terms of stability against oblique incidence, easy processing and light-weight. The MA prototype was fabricated assisted by the silk screen printing process and its ultra-broadband absorption performance was experimentally validated by the measured results. The new concept of hybrid MA and specific design scheme proposed here provide a promising approach for broadband, low-profile and light weight EM absorber.

We reported a rational design of branched NiCo 2 O 4 @NiMoO 4 nanofilm core/shell arrays on Ni foam by two steps of facile hydrothermal processing for the first time, and Ni foam was directly utilized for supercapacitive investigation. The supercapacitor based on NiCo 2 O 4 @NiMoO 4 nanofilm core/shell arrays yielded outstanding electrochemical performance with a high specific capacitance of 6.29 F cm −2 at a current density of 5 mA cm −2 and 3.58 F cm −2 at 100 mA cm −2 . Moreover, the hybrid electrode exhibit an excellent cycling stability (87% areal capacitance retention after 5000 charge-discharge cycles). Such remarkably electrochemical performance implied that this 3D honeycomb-like structure electrode could be a promising candidate for supercapacitors.

We have developed a one-step method to produce three-dimensional honeycomb-like nitrogen-doped graphene. Interlaminated hybrid composites of phthalocyanine (Pc) and graphene oxide (GO) swell up when hydrogen is released from the layers during the solid-state pyrolysis process, producing the three-dimensional graphene. The unique micro-structural features of the honeycomb-like nitrogen-doped graphene possesses a high surface area of ∼230 m2 g−1 and a substantial content of nitrogen (∼4.03%). The planar-N configuration is found to significantly enhance the electrochemical property, due to the improved electrical conductivity and enhanced capacitance in KOH aqueous electrolyte in reversible Faradic redox reactions. The supercapacitor based on the honeycomb-like nitrogen-doped graphene presented outstanding specific capacitance (175 F·g−1 at 0.5 A·g−1) and a long cycle life of more than 5000 cycles. This work provides an opportunity for the mass production of 3D nitrogen-doped graphene for industrial application.

The Chrysanthemum morifolium flower is widely used in China and Japan as a food, beverage, and medicine for many diseases. In our work, two new caffeoylquinic acid derivatives (1, 2), a new flavanone glycoside (3), and six reported flavanones (4&ndash, 9) were isolated and identified from the flowers of C. morifolium. The chemical structures of all isolates were elucidated by the analysis of comprehensive spectroscopic data as well as by comparison with previously reported data. The isolated constituents 1&ndash, 8 were evaluated for their neuroprotective activity, and compounds 3 and 4 displayed neuroprotective effects against hydrogen peroxide-induced neurotoxicity in human neuroblastoma SH-SY5Y cells.