Dalian University of Technology

About: Dalian University of Technology is a education organization based out in Dalian, China. It is known for research contribution in the topics: Catalysis & Finite element method. The organization has 60890 authors who have published 71921 publications receiving 1188356 citations. The organization is also known as: Dàlián Lǐgōng Dàxué.

Global Second-Order Pooling Convolutional Networks

Abstract: Deep Convolutional Networks (ConvNets) are fundamental to, besides large-scale visual recognition, a lot of vision tasks. As the primary goal of the ConvNets is to characterize complex boundaries of thousands of classes in a high-dimensional space, it is critical to learn higher-order representations for enhancing non-linear modeling capability. Recently, Global Second-order Pooling (GSoP), plugged at the end of networks, has attracted increasing attentions, achieving much better performance than classical, first-order networks in a variety of vision tasks. However, how to effectively introduce higher-order representation in earlier layers for improving non-linear capability of ConvNets is still an open problem. In this paper, we propose a novel network model introducing GSoP across from lower to higher layers for exploiting holistic image information throughout a network. Given an input 3D tensor outputted by some previous convolutional layer, we perform GSoP to obtain a covariance matrix which, after nonlinear transformation, is used for tensor scaling along channel dimension. Similarly, we can perform GSoP along spatial dimension for tensor scaling as well. In this way, we can make full use of the second-order statistics of the holistic image throughout a network. The proposed networks are thoroughly evaluated on large-scale ImageNet-1K, and experiments have shown that they outperform non-trivially the counterparts while achieving state-of-the-art results.

Photocatalytic oxidation of aqueous ammonia using atomic single layer graphitic-C3N4.

Abstract: Direct utilization of solar energy for photocatalytic removal of ammonia from water is a topic of strong interest. However, most of the photocatalysts with effective performance are solely metal-based semiconductors. Here, we report for the first time that a new type of atomic single layer graphitic-C3N4 (SL g-C3N4), a metal-free photocatalyst, has an excellent photocatalytic activity for total ammonia nitrogen (TAN) removal from water. The results demonstrated that over 80% of TAN (initial concentration 1.50 mg·L–1) could be removed in 6 h under Xe lamp irradiation (195 mW·cm–2). Furthermore, the SL g-C3N4 exhibited a higher photocatalytic activity in alkaline solution than that in neutral or acidic solutions. The investigation suggested that both photogenerated holes and hydroxyl radicals were involved the TAN photocatalytic oxidation process and that the major oxidation product was NO3–-N. In addition, SL g-C3N4 exhibited good photocatalytic stability in aqueous solution. This work highlights the appea...

Visible Light-Driven Electron Transfer and Hydrogen Generation Catalyzed by Bioinspired [2Fe2S] Complexes

Abstract: Complexes [{(μ-SCH2)2NCH2C6H5}{Fe(CO)2L1}{Fe(CO)2L2}] (L1 = CO, L2 = P(Pyr)3, 2; L1 = L2 = P(Pyr)3, 3) were prepared, which have the lowest reduction potentials for the mono- and double-CO-displaced diiron complexes reported so far. Hydrogen evolution, driven by visible light, was successfully observed for a three-component system, consisting of a ruthenium polypyridine complex, the biomimetic model complex 2 or 3, and ascorbic acid as both electron and proton donor in CH3CN/H2O. The electron transfer from photogenerated Ru(bpy)3+ to 2 or 3 was detected by laser flash photolysis. Under optimal conditions, the total turnover number for hydrogen evolution was 4.3 based on 2 and 86 based on Ru(bpy)32+ in a three-hour photolysis.

Controllable Fabrication and Photocatalytic Activity of ZnO Nanobelt Arrays

Abstract: Well-aligned single-crystalline ZnO nanobelt arrays were fabricated on a Si wafer by a carbothermal reduction route with the assistance of a SnO2/Sn species. The as-prepared ZnO nanobelt arrays were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, UV−vis spectroscopy, and photoluminescence spectroscopy. The photocatalytic activity for methyl orange on the ZnO nanobelt arrays was also investigated under UV irradiation. The ZnO nanobelts are several tens of nanometers in thickness, 100−500 nm in width, and have a length of up to several micrometers. It has been found that the ZnO nanobelt arrays form on a substrate only when the thickness of the SnO2 coating is less than 100 nm. The rod-/comb-like ZnO nanostructures and the ZnO film can be obtained by increasing the SnO2 loading or the temperature, respectively. The ZnO nanobelts grow from the active surface at the nanobelt root via a vapor−liquid−solid mechanism. The Z...