Beihang University

About: Beihang University is a education organization based out in Beijing, China. It is known for research contribution in the topics: Computer science & Control theory. The organization has 67002 authors who have published 73507 publications receiving 975691 citations. The organization is also known as: Beijing University of Aeronautics and Astronautics.

High Electrochemical Selectivity of Edge versus Terrace Sites in Two-Dimensional Layered MoS2 Materials

Abstract: Exploring the chemical reactivity of different atomic sites on crystal surface and controlling their exposures are important for catalysis and renewable energy storage. Here, we use two-dimensional layered molybdenum disulfide (MoS2) to demonstrate the electrochemical selectivity of edge versus terrace sites for Li–S batteries and hydrogen evolution reaction (HER). Lithium sulfide (Li2S) nanoparticles decorates along the edges of the MoS2 nanosheet versus terrace, confirming the strong binding energies between Li2S and the edge sites and guiding the improved electrode design for Li–S batteries. We also provided clear comparison of HER activity between edge and terrace sites of MoS2 beyond the previous theoretical prediction and experimental proof.

Forward and Backward Information Retention for Accurate Binary Neural Networks

Abstract: Weight and activation binarization is an effective approach to deep neural network compression and can accelerate the inference by leveraging bitwise operations. Although many binarization methods have improved the accuracy of the model by minimizing the quantization error in forward propagation, there remains a noticeable performance gap between the binarized model and the full-precision one. Our empirical study indicates that the quantization brings information loss in both forward and backward propagation, which is the bottleneck of training accurate binary neural networks. To address these issues, we propose an Information Retention Network (IR-Net) to retain the information that consists in the forward activations and backward gradients. IR-Net mainly relies on two technical contributions: (1) Libra Parameter Binarization (Libra-PB): simultaneously minimizing both quantization error and information loss of parameters by balanced and standardized weights in forward propagation; (2) Error Decay Estimator (EDE): minimizing the information loss of gradients by gradually approximating the sign function in backward propagation, jointly considering the updating ability and accurate gradients. We are the first to investigate both forward and backward processes of binary networks from the unified information perspective, which provides new insight into the mechanism of network binarization. Comprehensive experiments with various network structures on CIFAR-10 and ImageNet datasets manifest that the proposed IR-Net can consistently outperform state-of-the-art quantization methods.

Tunable Magnetism and Extraordinary Sunlight Absorbance in Indium Triphosphide Monolayer.

Abstract: Atomically thin two-dimensional (2D) materials have received considerable research interest due to their extraordinary properties and promising applications. Here we predict the monolayered indium triphosphide (InP3) as a new semiconducting 2D material with a range of favorable functional properties by means of ab initio calculations. The 2D InP3 crystal shows high stability and promise of experimental synthesis. It possesses an indirect band gap of 1.14 eV and a high electron mobility of 1919 cm2 V-1 s-1, which can be strongly manipulated with applied strain. Remarkably, the InP3 monolayer suggests tunable magnetism and half-metallicity under hole doping or defect engineering, which is attributed to the novel Mexican-hat-like bands and van Hove singularities in its electronic structure. A semiconductor-metal transition is also revealed by doping 2D InP3 with electrons. Furthermore, monolayered InP3 exhibits extraordinary optical absorption with significant excitonic effects in the entire range of the visible light spectrum. All these desired properties render 2D InP3 a promising candidate for future applications in a wide variety of technologies, in particular for electronic, spintronic, and photovoltaic devices.