Extraordinary terahertz transmission through subwavelength spindle-like apertures in NbN film

We studied numerically the temperature dependent extraordinary terahertz transmission through niobium nitride(NbN) film perforated with subwavelength spindle-like apertures. Both the resonant frequency and intensity of extraordinary terahertz transmission peaks can be greatly modified by the transition of NbN film from the normal state to the superconducting state. An enhancement of the(±1, 0) NbN/magnesium oxide(MgO) peak intensity as high as 200% is demonstrated due to the combined contribution of both the superconducting transition and the excitation of localized surface plasmons(LSPs) around the apertures. The extraordinary terahertz transmission through spindle-like hole arrays patterned on the NbN film can pave the way for us to explore novel active tuning devices.

Precipitant-free solvothermal construction of spindle-like CoCO3/reduced graphene oxide hybrid anode toward high-performance lithium-ion batteries

Recently,CoCO3 has attracted enormous attention as anodes for lithium-ion batteries(LIBs),benefiting from its high theoretical capacity and simple synthesis.However,the modest electronic conductivity and structural instability over cycling hinder its wider applications.To well address the intrinsic issues,we explored a precipitantfree hydrothermal methodology for mass production of spindle-like CoCO3/reduced graphene oxide(S-CoCO3/rGO)toward advanced LIBs as a hybrid anode.The dimethylformamide plays a significant role of"two birds(i.e.,solvent and precipitant)with one stone"in the formation of the S-CoCO3/rGO,greatly improving its practical applicability.The purposeful introduction of rGO nanosheets as a two-dimensional flexible conductive network enhances the conductivity and stability of the S-CoCO3.It is the structural and compositional merits for LIBs that endow the S-CoCO3/rGO with remarkable lithium-storage performance in terms of enhanced interfacial storage capacity,high-rate reversible capacities(803 mAh·g-1 at 2.0 A·g-1)and long-duration capacity retention of 82.1%over 2000 consecutive cycles at 2.0 A·g-1.More significantly,the simple yet efficient avenue here promises enormous commercial prospect of the S-CoCO3/rGO in next-generation LIBs.

Self-assembly Behavior of Copolymers with Super Segregated Structure Containing Fluorinated Segments

Copolymers with super segregated structure of hydrophilic methoxy poly（ethylene glycol） （mPEG） and fluorophilic poly（1H,1H,2H,2H-perfluorodecyl acrylate） （PFA） were prepared. And just because of this super segregated structure which was resulted from the extremely strong incompatibility between the two blocks, several interesting self- assembly behaviors of the copolymers were displayed and studied under different conditions. Transmission electron microscope （TEM） showed that with the increase of PFA in the polymerization system, the incompatibility in this super segregated structure became stronger, and the self-assembly behavior changed from ball-like or rod-like to vesicles, and finally collapsed to sheet-like. The self-assembly behavior changed likewise when the initial concentration increased. And the interesting formation of these barrel-like and spindle-like vesicles was finally studied with different cooling speeds. It＇s finally found that with this super segregation structure, these new self-assembly morphology might be formed due to the extremely strong incompatibility between mPEG and PFA segments.