| 1. |
- Li, Xian, et al.
(författare)
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GCDB-UNet : A novel robust cloud detection approach for remote sensing images
- 2022
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Ingår i: Knowledge-Based Systems. - : Elsevier BV. - 0950-7051 .- 1872-7409. ; 238
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Tidskriftsartikel (refereegranskat)abstract
- Cloud detection is a prerequisite in many remote sensing applications, and it has been tackled through different approaches from simple thresholding to complicated deep network training. On the other hand, existing approaches are susceptible to failures while handling thin clouds, largely because of their small sizes, sparse distributions, as well as high transparency and similarity to the non-cloud background regions. This paper presents global context dense block U-Net (GCDB-UNet), a robust cloud detection network that embeds global context dense block (GCDB) into the U-Net framework and is capable of detecting thin clouds effectively. GCDB consists of two feature extraction units for addressing the challenges in thin cloud detection, namely, a non-local self-attention unit that extracts sample correlation features by aggregating the sparsely distributed thin clouds and a squeeze excitation unit that extracts channel correlated features by differentiating their importance. In addition, a dense connection scheme is designed to exploit the multi-level fine-grained representations from the two types of extracted features and a recurrent refinement module is introduced for gradual enhancement of the predicted classification map. We also created a fully annotated cloud detection MODIS dataset that consists of 1192 training images, 80 validation images and 150 test images. Extensive experiments on Landsat8, SPARCS and MODIS datasets show that the proposed GCDB-UNet achieves superior cloud detection performance as compared with state-of-the-art methods. Our created MODIS cloud detection dataset is available at https://github.com/xiachangxue/MODIS-Dataset-for-Cloud-Detection.
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| 2. |
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| 3. |
- Tian, Fu-Yang, et al.
(författare)
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A novel potential : the interlayer potential for the fcc (111) plane family
- 2012
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Ingår i: Journal of Physics. - : IOP Publishing. - 0953-8984 .- 1361-648X. ; 24:4, s. 045001-
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Tidskriftsartikel (refereegranskat)abstract
- We propose a novel interlayer potential, which is different from usual interatomic potentials. The interlayer potential represents the interaction between atomic layers in a layered material. Based on the Chen-Mobius inversion method in combination with ab initio calculations, the interlayer interactions are obtained for the face centered cubic (fcc) (111) planes. In order to check the validity of our interlayer potential, we calculate the intrinsic stacking fault energy (gamma(sf)) and the surface energy (gamma(s)) of five metals: Al, Ni, Cu, Ag and Au. The predicted gamma(sf) and gamma(s) values are compared with the theoretical results obtained from direct calculations and also with the available experimental data. Using the interlayer potentials, we also investigate the phonon dispersion and phonon density of state in the fcc (111) plane family of the considered metals.
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| 4. |
- Tian, Fu-Yang, et al.
(författare)
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Interlayer potentials for fcc (111) planes of Pd-Ag random alloys
- 2012
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Ingår i: Computational materials science. - : Elsevier BV. - 0927-0256 .- 1879-0801. ; 63, s. 20-27
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Tidskriftsartikel (refereegranskat)abstract
- Using ab initio alloy theory in combination with the Chen-Mobius inversion method, we obtain the interaction potentials between layers of the face centered cubic (fcc) (111) plane family for elemental Pd and Ag metals and for Pd0.5Ag0.5 random alloy. Based on the interlayer potentials, we investigate properties related to the fcc (111) planes, such as the stacking fault energy, shear elastic constant, surface energy, surface relaxations, and phonon dispersion along the fcc [111] direction. The results agree well with those obtained by fully self-consistent ab initio calculations and also with the available experimental data, indicating that the properties related to the close-packed planes are well described by the interlayer potentials.
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| 5. |
- Tian, Gui-Xian, et al.
(författare)
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Facile Hydrothermal Synthesis of Highly Efficient and Durable Ternary PtPdCu Electrocatalysts for the Methanol Oxidation Reaction
- 2023
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Ingår i: Advanced Energy & Sustainability Research. - : Wiley. - 2699-9412.
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Tidskriftsartikel (refereegranskat)abstract
- Precious metal Pt-based electrocatalysts have been widely used in the methanol catalytic oxidation anodes in direct methanol fuel cells. However, decreasing their cost and improving their efficiency and durability have still been challenging. Herein, ternary PtPdCu nanocatalysts are synthesized through a facile one-step hydrothermal synthesis method. When KI is present with a suitable amount in the synthesis, PtPdCu nanospheres with surface-embedded CuI clusters (CuI/PtPdCu) are fabricated. However, without KI, the prepared PtPdCu catalysts show a distinct hollow structure (h-PtPtCu). CuI/PtPdCu displays the highest specific activity with enhancement 4 times higher than commercial Pt/C for the methanol oxidation reaction in an alkaline medium. The superior activity can be attributed to two aspects: 1) the electronic effect originating from the highly alloyed PtPdCu; 2) the synergetic effect resulting from surface inlaid CuI clusters, which can promote the CO intermediate removal. Furthermore, because of the stable Pt-Pd-rich surface and its special linked hollow structure, the h-PtPtCu catalyst exhibits good durability with only a 3.6% decay in the specific activity.
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| 6. |
- Tian, Shan Xi, et al.
(författare)
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Coherent interference in the resonant dissociative electron attachment to carbon monoxide
- 2013
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 88:1, s. 012708-
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Tidskriftsartikel (refereegranskat)abstract
- Dissociative electron attachment to carbon monoxide, e(-) + CO -> C + O-, at 9.5, 10.0, and 10.6 eV is investigated by using the anion velocity time-sliced map imaging technique. The completely backward scattering distributions of the fast O- fragment are observed at 10.0 and 10.6 eV. The single electron-molecule resonance model fails in interpretation to these unusual angular distributions, while a quantum interference model including two (at 10.0 eV) or three (at 10.6 eV) dissociative outgoing waves is consequently proposed and provides the satisfying results about the experimental data fittings. Moreover, coherent interference among the (2)Pi, (2)Delta, and (2)Phi resonant states of CO- at 10.6 eV could be further established, based on the fact that the sum of the phase-shift fitting values equals pi rad.
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| 7. |
- Yang, Miao, et al.
(författare)
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Kinetics and Mechanism of Reactions between H2O2 and Tungsten Powder
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- In this work, the reaction between H2O2 and tungsten powder in the presence of Tris(hydroxymethyl) aminomethane was studied experimentally. The production of hydroxyl radicals can be quantified indirectly by quantifying the scavenging product formaldehyde (CH2O). XRD, XPS and SEM analysis shows that no significant structural or compositional changes occur after reaction. We compared H2O2 consumption and CH2O formation in both heterogeneous W(s)/H2O2/Tris system and homogenous W(aq)/H2O2/Tris system. Increasing the amount of W powder leads to the increase in dissolution rate of W species, insignificant increase of H2O2 consumption rate and the decrease of final CH2O production. By contrast, the consumption rate of H2O2 increases as increasing the concentration of dissolved W species. Based on the experimental results, a mechanism of H2O2 reacting with W powder in the presence of Tris is proposed. The mechanism well explained the relationship between surface reactions and homogeneous Haber-Weiss reactions.
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| 8. |
- Yang, Miao, et al.
(författare)
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Kinetics and Mechanism of the Reaction between H2O2 and Tungsten Powder in Water
- 2015
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 119:39, s. 22560-22569
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the reaction between H2O2 and tungsten powder in the presence of Tris(hydroxymethyl) aminomethane was studied experimentally. The production of hydroxyl radicals can be quantified indirectly by quantifying the scavenging product formaldehyde (CH2O). XRD, XPS, and SEM analysis shows that no significant structural or compositional changes occur after reaction. We compared H2O2 consumption and CH2O formation in both heterogeneous W(s)/H2O2/Tris system and homogeneous W(aq)/H2O2/Tris system. Increasing the amount of W powder leads to the increase in dissolution rate of W species, insignificant increase of H2O2 consumption rate and the decrease of final CH2O production. By contrast, the consumption rate of H2O2 increases as increasing the concentration of dissolved W species. Based on the experimental results, a mechanism of H2O2 reacting with W powder in the presence of Tris is proposed. The mechanism well explained the relationship between surface reactions and homogeneous Haber–Weiss peroxide chain breakdown.
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