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.

In Situ Passivation of PbBr64– Octahedra toward Blue Luminescent CsPbBr3 Nanoplatelets with Near 100% Absolute Quantum Yield

Abstract: Recently, the pursuit of high photoluminescence quantum yields (PLQYs) for blue emission in perovskite nanocrystals (NCs) has attracted increased attention because the QY of blue NCs lags behind those of green and red ones severely, which is fatal for three-primary-color displays. Here, we propose an in situ PbBr64– octahedra passivation strategy to achieve a 96% absolute QY for the ultrapure (line width = 12 nm) blue emission from CsPbBr3 nanoplatelets (NPLs), and both values rank first among perovskite NCs with blue emission. From the aspect of constructing intact PbBr64– octahedra, additional Br– was introduced to drive the ionic equilibrium to form intact Pb–Br octahedra. The reduced Br vacancy and inhibited nonradiative recombination processes are well proved by reduced Urbach energy, increased Pb–Br bonds, and slower transient absorption delay. Blue light-emitting diodes (LEDs) using NPLs were fabricated, and a high external quantum efficiency (EQE) of 0.124% with an emission line width of ∼12 nm wa...

Reduced graphene oxide (RGO) modified spongelike polypyrrole (PPy) aerogel for excellent electromagnetic absorption

Abstract: A self-assembled spongelike (S) ultralight (ρ ≈ 140 mg cm−3) aerogel was fabricated through polypyrrole (PPy) and reduced graphene oxide (RGO). First, the dispersed graphene oxide (GO) was locked homogeneously in those chains formed by the gelation of PPy. Then, a hydrothermal process was employed to reduce GO to RGO. With a trace content of RGO (0.43 wt% in aerogel), the electromagnetic absorption (EA) performance had been significantly improved. Only with a very low filler loading (10 wt%), the S-PPy/RGO aerogel based composite could reach an effective EA bandwidth (below −10 dB) of 6.76 GHz, and the highest reflection coefficient reached −54.4 dB at 12.76 GHz. It was demonstrated that this aerogel material can be considered as an effective route to design a lightweight and high performance EA material. Furthermore, the S-PPy/RGO aerogel also showed a suitable pollution treatment performance with different solvents and dyes.

Siamese Box Adaptive Network for Visual Tracking

Abstract: Most of the existing trackers usually rely on either a multi-scale searching scheme or pre-defined anchor boxes to accurately estimate the scale and aspect ratio of a target. Unfortunately, they typically call for tedious and heuristic configurations. To address this issue, we propose a simple yet effective visual tracking framework (named Siamese Box Adaptive Network, SiamBAN) by exploiting the expressive power of the fully convolutional network (FCN). SiamBAN views the visual tracking problem as a parallel classification and regression problem, and thus directly classifies objects and regresses their bounding boxes in a unified FCN. The no-prior box design avoids hyper-parameters associated with the candidate boxes, making SiamBAN more flexible and general. Extensive experiments on visual tracking benchmarks including VOT2018, VOT2019, OTB100, NFS, UAV123, and LaSOT demonstrate that SiamBAN achieves state-of-the-art performance and runs at 40 FPS, confirming its effectiveness and efficiency. The code will be available at https://github.com/hqucv/siamban.

High Energy and High Power Lithium‐Ion Capacitors Based on Boron and Nitrogen Dual‐Doped 3D Carbon Nanofibers as Both Cathode and Anode

Abstract: High energy density at high power density is still a challenge for the current Li-ion capacitors (LICs) due to the mismatch of charge-storage capacity and electrode kinetics between capacitor-type cathode and battery-type anode. In this work, B and N dual-doped 3D porous carbon nanofibers are prepared through a facile method as both capacitor-type cathode and battery-type anode for LICs. The B and N dual doping has profound effect in tuning the porosity, functional groups, and electrical conductivity for the porous carbon nanofibers. With rational design, the developed B and N dual-doped carbon nanofibers (BNC) exhibit greatly improved electrochemical performance as both cathode and anode for LICs, which greatly alleviates the mismatch between the two electrodes. For the first time, a 4.5 V “dual carbon” BNC//BNC LIC device is constructed and demonstrated, exhibiting outstanding energy density and power capability compared to previously reported LICs with other configurations. In specific, the present BNC//BNC LIC device can deliver a large energy density of 220 W h kg−1 and a high power density of 22.5 kW kg−1 (at 104 W h kg−1) with reasonably good cycling stability (≈81% retention after 5000 cycles).

Producing Bulk Ultrafine-Grained Materials by Severe Plastic Deformation: Ten Years Later

Abstract: It is now well established that the processing of bulk solids through the application of severe plastic deformation (SPD) leads to exceptional grain refinement to the submicrometer or nanometer level. Extensive research over the last decade has demonstrated that SPD processing also produces unusual phase transformations and leads to the introduction of a range of nanostructural features, including nonequilibrium grain boundaries, deformation twins, dislocation substructures, vacancy agglomerates, and solute segregation and clustering. These many structural changes provide new opportunities for fine tuning the characteristics of SPD metals to attain major improvements in their physical, mechanical, chemical, and functional properties. This review provides a summary of some of these recent developments. Special emphasis is placed on the use of SPD processing in achieving increased electrical conductivity, superconductivity, and thermoelectricity, an improved hydrogen storage capability, materials for use in biomedical applications, and the fabrication of high-strength metal-matrix nanocomposites.