Wei Hu

Bio: Wei Hu is an academic researcher from Nanjing University. The author has contributed to research in topics: Liquid crystal & Materials science. The author has an hindex of 58, co-authored 683 publications receiving 12907 citations. Previous affiliations of Wei Hu include Beijing Institute of Technology & Jilin University.

A Flexible and Highly Pressure‐Sensitive Graphene–Polyurethane Sponge Based on Fractured Microstructure Design

Abstract: A fractured microstructure design: A new type of piezoresistive sensor with ultra-high-pressure sensitivity (0.26 kPa(-1) ) in low pressure range (<2 kPa) and minimum detectable pressure of 9 Pa has been fabricated using a fractured microstructure design in a graphene-nanosheet-wrapped polyurethane (PU) sponge. This low-cost and easily scalable graphene-wrapped PU sponge pressure sensor has potential application in high-spatial-resolution, artificial skin without complex nanostructure design.

Cobalt in Nitrogen-Doped Graphene as Single-Atom Catalyst for High-Sulfur Content Lithium–Sulfur Batteries

Abstract: Because of their high theoretical energy density and low cost, lithium–sulfur (Li–S) batteries are promising next-generation energy storage devices. The electrochemical performance of Li–S batteries largely depends on the efficient reversible conversion of Li polysulfides to Li2S in discharge and to elemental S during charging. Here, we report on our discovery that monodisperse cobalt atoms embedded in nitrogen-doped graphene (Co–N/G) can trigger the surface-mediated reaction of Li polysulfides. Using a combination of operando X-ray absorption spectroscopy and first-principles calculation, we reveal that the Co–N–C coordination center serves as a bifunctional electrocatalyst to facilitate both the formation and the decomposition of Li2S in discharge and charge processes, respectively. The S@Co–N/G composite, with a high S mass ratio of 90 wt %, can deliver a gravimetric capacity of 1210 mAh g–1, and it exhibits an areal capacity of 5.1 mAh cm–2 with capacity fading rate of 0.029% per cycle over 100 cycles...

Atomic-level insight into super-efficient electrocatalytic oxygen evolution on iron and vanadium co-doped nickel (oxy)hydroxide.

Abstract: It is of great importance to understand the origin of high oxygen-evolving activity of state-of-the-art multimetal oxides/(oxy)hydroxides at atomic level. Herein we report an evident improvement of oxygen evolution reaction activity via incorporating iron and vanadium into nickel hydroxide lattices. X-ray photoelectron/absorption spectroscopies reveal the synergistic interaction between iron/vanadium dopants and nickel in the host matrix, which subtly modulates local coordination environments and electronic structures of the iron/vanadium/nickel cations. Further, in-situ X-ray absorption spectroscopic analyses manifest contraction of metal-oxygen bond lengths in the activated catalyst, with a short vanadium-oxygen bond distance. Density functional theory calculations indicate that the vanadium site of the iron/vanadium co-doped nickel (oxy)hydroxide gives near-optimal binding energies of oxygen evolution reaction intermediates and has lower overpotential compared with nickel and iron sites. These findings suggest that the doped vanadium with distorted geometric and disturbed electronic structures makes crucial contribution to high activity of the trimetallic catalyst.

Aromatic Poly(ether ketone)s with Pendant Sulfonic Acid Phenyl Groups Prepared by a Mild Sulfonation Method for Proton Exchange Membranes

Abstract: The sulfonation selectivity of seven poly(ether ether ketone)s (PEEKs) was investigated, and several possessed targeted single- or double-substituted sites per repeated unit on pendant phenyl groups via the postsulfonation approach. The presence of the various pendant groups enabled postsulfonation to occur under mild reaction conditions, in much shorter times than required for the sulfonation of commercial PEEK. A series of poly(ether ketone)s (PEKs) with ion exchange capacity of 2.23−0.84 mequiv/g could be realized by controlling the length of unsulfonated segments of both homopolymers and copolymers. These side-group sulfonation polymers had excellent mechanical properties, good thermal and oxidative stability, and good dimensional stability in hot water. The methanol permeability values of Me-SPEEKK, Me-SPEEKDK, Ph-SPEEKK, and Ph-SPEEKDK at room temperature were in the range 3.31 × 10-7−9.55 × 10-8 cm2/s, which is several times lower than that of Nafion 117. Me-SPEEKK and Ph-SPEEKK also exhibited high...

Intrinsic Electric Fields in Two-dimensional Materials Boost the Solar-to-Hydrogen Efficiency for Photocatalytic Water Splitting

Abstract: Two-dimensional (2D) materials with the vertical intrinsic electric fields show great promise in inhibiting the recombination of photogenerated carriers and widening light absorption region for the photocatalytic applications For the first time, we investigated the potential feasibility of the experimentally attainable 2D M2X3 (M = Al, Ga, In; X = S, Se, Te) family featuring out-of-plane ferroelectricity used in photocatalytic water splitting By using first-principles calculations, all the nine members of 2D M2X3 are verified to be available photocatalysts for overall water splitting The predicted solar-to-hydrogen efficiency of Al2Te3, Ga2Se3, Ga2Te3, In2S3, In2Se3, and In2Te3 are larger than 10% Excitingly, In2Te3 is manifested to be an infrared-light driven photocatalyst, and its solar-to-hydrogen efficiency limit using the full solar spectrum even reaches up to 321%, which breaks the conventional theoretical efficiency limit

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

A Comprehensive Survey on Graph Neural Networks

Abstract: Deep learning has revolutionized many machine learning tasks in recent years, ranging from image classification and video processing to speech recognition and natural language understanding. The data in these tasks are typically represented in the Euclidean space. However, there is an increasing number of applications, where data are generated from non-Euclidean domains and are represented as graphs with complex relationships and interdependency between objects. The complexity of graph data has imposed significant challenges on the existing machine learning algorithms. Recently, many studies on extending deep learning approaches for graph data have emerged. In this article, we provide a comprehensive overview of graph neural networks (GNNs) in data mining and machine learning fields. We propose a new taxonomy to divide the state-of-the-art GNNs into four categories, namely, recurrent GNNs, convolutional GNNs, graph autoencoders, and spatial–temporal GNNs. We further discuss the applications of GNNs across various domains and summarize the open-source codes, benchmark data sets, and model evaluation of GNNs. Finally, we propose potential research directions in this rapidly growing field.