Nanjing University of Science and Technology

About: Nanjing University of Science and Technology is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 31581 authors who have published 36390 publications receiving 525474 citations. The organization is also known as: Nánjīng Lǐgōng Dàxué & Nánlǐgōng.

Few-Layer Antimonene: Anisotropic Expansion and Reversible Crystalline-Phase Evolution Enable Large-Capacity and Long-Life Na-Ion Batteries.

Abstract: Two-dimensional (2D) antimonene is a promising anode material in sodium-ion batteries (SIBs) because of its high theoretical capacity of 660 mAh g–1 and enlarged surface active sites. However, its Na storage properties and sodiation/desodiation mechanism have not been fully explored. Herein, we propose the sodiation/desodiation reaction mechanism of 2D few-layer antimonene (FLA) based on results acquired by in situ synchrotron X-ray diffraction, ex situ selected-area electron diffraction, and theoretical simulations. Our study shows that the FLA undergoes anisotropic volume expansion along the a/b plane and exhibits reversible crystalline phase evolution (Sb ⇋ NaSb ⇋ Na3Sb) during cycling. Density-functional theory calculations demonstrate that the FLA has a small Na-ion diffusion barrier of 0.14 eV. The FLA delivers a larger capacity of 642 mAh g–1 at 0.1 C (1 C = 660 mA g–1) and a high rate capability of 429 mAh g–1 at 5 C and maintains a stable capacity of 620 mA g–1 at 0.5 C with 99.7% capacity retent...

Narrowband Wireless Access for Low-Power Massive Internet of Things: A Bandwidth Perspective

Abstract: LPWAN is a type of wireless telecommunication network designed to allow long range communications with relaxed requirements on data rate and latency between the core network and a high-volume of battery-operated devices This article first reviews the leading LPWAN technologies on both unlicensed spectrum (SIGFOX, and LoRa) and licensed spectrum (LTE-M and NB-IoT) Although these technologies differ in many aspects, they do have one thing in common: they all utilize the narrow-band transmission mechanism as a leverage to achieve three fundamental goals, that is, high system capacity, long battery life, and wide coverage This article introduces an effective bandwidth concept that ties these goals together with the transmission bandwidth, such that these contradicting goals are balanced for best overall system performance

Spatial-Spectral Kernel Sparse Representation for Hyperspectral Image Classification

Abstract: Kernel sparse representation classification (KSRC), a nonlinear extension of sparse representation classification, shows its good performance for hyperspectral image classification. However, KSRC only considers the spectra of unordered pixels, without incorporating information on the spatially adjacent data. This paper proposes a neighboring filtering kernel to spatial-spectral kernel sparse representation for enhanced classification of hyperspectral images. The novelty of this work consists in: 1) presenting a framework of spatial-spectral KSRC; and 2) measuring the spatial similarity by means of neighborhood filtering in the kernel feature space. Experiments on several hyperspectral images demonstrate the effectiveness of the presented method, and the proposed neighboring filtering kernel outperforms the existing spatial-spectral kernels. In addition, the proposed spatial-spectral KSRC opens a wide field for future developments in which filtering methods can be easily incorporated.