Hengyang Normal University

About: Hengyang Normal University is a education organization based out in Hengyang, China. It is known for research contribution in the topics: Graphene & Adsorption. The organization has 1087 authors who have published 1280 publications receiving 13850 citations. The organization is also known as: Hengyang Teachers' College & Héngyáng Shīfàn Xuéyuàn.

Pillared Graphene Sheets with High-Rate Performance as Anode Material for Lithium-Ion Batteries.

Abstract: Pillared graphene composite (GP) is prepared by in situ polymerization and subsequent carbonization of graphene oxide (GO) and polyaniline (PANI) precursors. The interlayer spacing of GO layer can reach 1.418 nm with 200% increase compared with the original spacing of 0.706 nm by the intercalation of aniline monomer through π-π conjugate and electrostatic interactions. After carbonization, the graphene composite is reinforced by the intercalated PANI-converted carbon pillars and also has a nitrogen-doped level of ca. 4.49 atom%. Electrochemical characterization studies show that the GP composite exhibits a high reversible capacity of 653 mAh g-1 at a current density of 100 mA g-1 and an excellent rate capability (343 mAh g-1 at a current density of 1 A g-1), which are superior to graphene owing to the unique pillared and the nitrogen-doped structure.

Lipschitz spaces and bounded mean oscillation of harmonic mappings

Abstract: In this paper, we first study the bounded mean oscillation of planar harmonic mappings, then a relationship between Lipschitz-type spaces and equivalent modulus of real harmonic mappings is established. At last, we obtain sharp estimates on Lipschitz number of planar harmonic mappings in terms of bounded mean oscillation norm, which shows that the harmonic Bloch space is isomorphic to $BMO_{2}$ as a Banach space. 10.1017/S0004972712000998

Electron transport properties of boron nitride chains between two-dimensional metallic borophene electrodes

Abstract: Recently, boron nitride (BN) chains have been made from hexagonal BN sheets. However, the BN sheet has a large band gap, which is not suitable to be used as the electrode material of BN chain-based two-dimensional (2D) electronic devices. The successful preparation of borophene sheets opens a possible way for building BN chain-based 2D devices. The borophene is a metal material with strong oxidation resistance. In particular, recent experimental results show that the borophene exists massless Dirac fermions, which makes it a suitable candidate for constructing high-speed low-dissipation devices. Here, we investigate the electron transport properties of boron nitride chains between 2D metallic borophene electrodes by using nonequilibrium Green's functions in combination with the density functional theory. Surprisingly, the BN chain displays metallic characteristic when coupled into 2D borophene electrodes. Inherent negative differential resistance behaviors can be observed in the BN chains sandwiched between 2D metallic borophene. Meanwhile, the current superposition law is studied in BN chain-based 2D circuits. Results show that the current value of BN chain-based system with parallel paths is more than twice that with a single path, which is different from Kirchhoff's circuit laws. Moreover, the effects of strain on the electron transport properties of BN chain-based 2D electronic devices are also studied.

Enhanced optical spatial differential operations via strong spin-orbit interactions in an anisotropic epsilon-near-zero slab

Abstract: Several works on optical higher-order differential operations have recently attracted attention, particularly in image processing for edge detection. However, the inefficient differential operation leads to barriers to practical applications. Here, we report an anisotropic epsilon-near-zero slab to significantly enhance the transmission efficiency of second-order differentiators and discuss the Berry phase mechanism of this optical calculation process. Through a rigorous full-wave analysis of the process, we find that the conversion efficiency of differential operation depends on the spin-orbit interactions. Our scheme can strengthen the spin-orbit interaction by introducing anisotropy, which significantly enhances the transmission efficiency. We finally give transfer functions to reveal how to improve the efficiency and compare the quadratic coefficient among different systems. This highly efficient differentiation operation may develop significant applications in fast, compatible, and power-efficient ultrathin devices for data processing and biological imaging.