Recent studies have shown that stereo matching can be considered a supervised learning task, in which several left and right images serve as inputs to the convolutional neural network for training, ...and a detailed disparity map can be obtained. However, the existing architecture for stereo matching is not suitable for estimating the depth of ill-posed regions. To address this problem, we propose a multiple attention network (MA-Net) for stereo matching, which mainly consists of four processes: feature extraction, cost volume construction, cost aggregation, and disparity prediction. For feature extraction, an hourglass position attention module that can effectively aggregate global context and multi-scale information at every position is adopted. In the cost volume construction, we combine cross-correlation volumes with concatenation volumes to ensure that the cost volume can provide efficient representations for measuring feature similarities. In cost aggregation, a multiscale disparity attention module is designed, which can aggregate the feature information of different scales and different disparity dimensions. As in other end-to-end methods, the final disparity is obtained through regression in the disparity prediction. Experimental results obtained on Scene Flow, KITT2012 and KITTI2015 benchmarks show that the proposed method has several advantages in terms of accuracy and speed.
Aluminum (Al), the most abundant metallic element on the earth crust, has been reckoned as a promising battery material for its the highest theoretical volume capacity (8046 mAh cm−3). Being ...rechargeable in ionic liquid electrolytes, however, the Al anode and battery case suffer from corrosion. On the other hand, Al is irreversible in aqueous electrolyte with severe hydrogen evolution reaction. Here, we demonstrate a water-in-salt aluminum ion electrolyte (WISE) based on Al and lithium salts to tackle the above challenges. In the WISE system, water molecules can be confined within the Li+ solvation structures. This diminished Al3+-H2O interaction essentially eliminates the hydrolysis effect, effectively protecting Al anode from corrosion. Therefore, long-term Al plating/stripping can be realized. Furthermore, two types of high-performance full batteries have been demonstrated using copper hexacyanoferrate (CuHCF, a Prussian Blue Analogues) and LiNi0.8Co0.1Mn0.1O2 (NCM) as cathodes. The reversibility of Al anode laid the foundation for low cost rechargeable batteries suffering for large-scale energy storage.
Broader context: Al batteries are expected to become a safe and sustainable alternative to lithium batteries. For decades, chase for a feasible Al secondary battery has not been successful. The key challenge is to find suitable cathode and electrolyte materials, together with which Al anode battery can function reversibly. Currently, fatal drawbacks have impeded the practical application of Al metal batteries (AMBs), such as sustained corrosion of Al anode and battery case in ionic liquid electrolytes, irreversibility issues as well as severe hydrogen evolution reaction during cycling in aqueous electrolyte. Therefore, electrolyte and their electrochemical kinetics play a vital role in the performance and environmental operating limitations of high-energy Al metal batteries. In this work, we demonstrate a nearly neutral Al ion water-in-salt electrolyte (WISE) to tackle the above challenges. The WISE shows excellent stability in the open atmosphere. The distinct solvation-sheath structure of Al3+ in the WISE system would protect Al metal anodes from corrosion and eliminate hydrogen evolution reaction effectively, further promoting the reversibility of Al metal anodes with dendrite-free morphology. Moreover, such a WISE exhibits superior compatibility with LiNi0.3Co0.3Mn0.3O2 (NCM) and copper hexacyanoferrate (CuHCF) cathodes and long-term stabilities with high coulombic efficiency (CE) can be attained for full batteries with the WISE. The approach in this study can furnish an opportunity to develop reversible AMBs and lay the foundation for other potential multivalent-metal-based secondary batteries suffering from interface passivation and poor reversibility, which suggest the promise of multivalent metal batteries and their applications in large-scale energy storage.
•In water-in-salt Al ion electrolyte (Al-WISE), water molecules can be confined within the Li+ solvation structures.•The solvation-sheath structure of Al3+ would protect Al anodes from corrosion and eliminate hydrogen evolution reaction.•The solvation-sheath structure of Al3+ promotes the reversibility of Al metal anodes with dendrite-free morphology.
A reversible Al metal secondary battery configuration based on WISE. Display omitted
Multitask sparse representation method improves the detection performance by constructing multiple associated sub-sparse representation tasks and jointly learning multiple sub-sparse representation ...tasks, and this method can make use of the spectral information. However, the using of spatial information needs to be improved. This paper designs a hyperspectral image target detection method which can both make use of spectral and spatial information, that is a weighted joint k-nearest neighbor and multitask learning sparse representation method (WJNN-MTL-SR) is proposed. This method mainly consists of the following steps:1) using multitask sparse representation to obtain the representation residuals. 2) weighted joint k-nearest neighbor is used into the joint region of test pixels to obtain the weighted joint Euclidean distance. 3) a decision function, combining the weighted joint Euclidean distance and residuals of the multitask sparse representation, is used to get target detection result. Experimental results demonstrate that the proposed method show better detection performance than state-of-the-art methods.
The H.264/AVC was designed mainly for lossy video coding, the lossless coding of H.264 use bypass mode for DCT and quantization. Although sample-by-sample DPCM improves performance of coding, the ...benět is limited in intra. In this paper, a new adaptive transform is proposed based on the character of 4×4 block residual coefčient's distribution, which can be used both in intra and inter coding. The greatest strength of the proposed transform is the decorrelation without in ation versus dynamic range of input matrix. Due to the random distribution of residual coefčcients, a specič transform is hard to play a positive impact on them. Therefore, several transforms of different directions will be implemented simultaneously, and the most efčient one will be determined by a proposed mechanism. Then, by means of statistic method, a new scan order is designed for CAVLC entropy encoder, cooperating with corresponding transform. The simulation results show that based on the fast algorithm of proposed method, the bit saving achieves about 7.41% bit saving in intra coding and 10.47% in inter, compared with H.264-LS.
Direct use of metals with low redox potential and high capacity as anodes can enable high energy density batteries. Mg metal has been considered as an ideal anode for its high critical current ...density and earth‐abundance, but its development has been impeded by the lacking of Mg‐compatible yet cost‐effective electrolyte. Artificial layers that prevent direct Mg‐electrolyte contact while permit Mg2+ to transport through, mitigate the anode–electrolyte incompatibility and allow industrial Li battery electrolyte analog to implement. However, charge transport through these artificial layers remains elusive, let alone to quantitatively design the layer thickness, components, and their distribution. Here it is shown that by using a gradient mixed ion‐electron conducting layer, which is prepared by a transferable perovskite film, the ion/electron transport path can be individually and continually tuned. It is found that a high Coulombic efficiency of 99.2% can be obtained for Mg anode in 0.5 M Mg(TFSI)2/DME electrolyte. It is also shown that long cycling full cells with a low N/P ratio (N/P ≈ 3.42 for Mg|Mo6S8, N/P ≈ 2.06 for Mg|Cu2‐xS) can be achieved. It is suggested that rational interfacial engineering will open new way to design practical Mg metal batteries.
Rationally designed gradient perovskite mixed ionic–electronic conducting heterointerphases facilitate non‐passivation, fast Mg2+ diffusion, and homogeneous ionic/electronic distribution simultaneously, enabling deep cycling Mg anode in commercially acceptable electrolyte.
A Moisture‐Assisted Rechargeable Mg−CO2 Battery Zhang, Chenyue; Wang, Aoxuan; Guo, Longyuan ...
Angewandte Chemie International Edition,
April 19, 2022, Volume:
61, Issue:
17
Journal Article
Peer reviewed
New sustainable energy conversion and storage technologies are required to address the energy crisis and CO2 emission. Among various metal–CO2 batteries that utilize CO2 and offer high energy ...density, rechargeable Mg−CO2 batteries based on earth‐abundant and safe magnesium (Mg) metal have been limited due to the lack of a compatible electrolyte, operation atmosphere, and unambiguous reaction process. Herein, the first rechargeable nonaqueous Mg−CO2 batteries have been proposed with moisture assistance in a CO2 atmosphere. These display more than 250 h cycle life and maintain the discharge voltage over 1 V at 200 mA g−1. Combining with the experimental observations and theoretical calculations, the reaction in the moisture‐assisted Mg−CO2 battery is revealed to be 2 Mg+3 CO2+6 H2O↔2 MgCO3⋅3 H2O+C. It is anticipated that the moisture‐assisted rechargeable Mg−CO2 batteries would stimulate the development of multivalent metal‐CO2 batteries and extend CO2 fixation and utilization for carbon neutrality.
Rechargeable nonaqueous Mg−CO2 batteries have been realized in a moisture‐assisted CO2 atmosphere exhibiting superior cycling life (250 h) and good reversibility. Compared with the anhydrous CO2 atmosphere, the humid system improves battery performance through the formation of discharge products which have a stronger interaction with the cathode substrate. The rechargeable battery reaction can be verified as 2 Mg+3 CO2+6 H2O↔2 MgCO3⋅3 H2O+C.
New sustainable energy conversion and storage technologies are required to address the energy crisis and CO
emission. Among various metal-CO
batteries that utilize CO
and offer high energy density, ...rechargeable Mg-CO
batteries based on earth-abundant and safe magnesium (Mg) metal have been limited due to the lack of a compatible electrolyte, operation atmosphere, and unambiguous reaction process. Herein, the first rechargeable nonaqueous Mg-CO
batteries have been proposed with moisture assistance in a CO
atmosphere. These display more than 250 h cycle life and maintain the discharge voltage over 1 V at 200 mA g
. Combining with the experimental observations and theoretical calculations, the reaction in the moisture-assisted Mg-CO
battery is revealed to be 2 Mg+3 CO
+6 H
O↔2 MgCO
⋅3 H
O+C. It is anticipated that the moisture-assisted rechargeable Mg-CO
batteries would stimulate the development of multivalent metal-CO
batteries and extend CO
fixation and utilization for carbon neutrality.
This letter presents the hyperspectral imagery (HSI) noisy label detection using a spectral angle and the local outlier factor (SALOF) algorithm. The noisy label is caused by a mislabeled training ...pixel, and thus, noisy training samples mixed with correct and incorrect labels are formed in the supervised classification. The LOF algorithm is first used in the noisy label detection of the HSI to improve the supervised classification accuracy. The proposed method SALOF mainly includes the following steps. First, <inline-formula> <tex-math notation="LaTeX">k </tex-math></inline-formula> nearest neighbors of different training samples of each class are calculated based on the spectral angle mapper. Second, the reachability distance and local reachability density of all training samples are obtained. Third, the LOF is determined among different classes of training samples. Then, a segmentation threshold of the LOF is established to achieve an abnormal probability of these training samples. Finally, the support vector machines are applied to measure the detection efficiency of the proposed method. The experiments performed on the Kennedy Space Center data set demonstrate that the proposed method can effectively detect noisy labels.
Rechargeable magnesium batteries (RMBs) have garnered significant attention due to the abundant natural availability, safety and high volumetric capacity of magnesium (Mg) anode. However, the ...practical application has been hindered by the pronounced passivation layer and sluggish charge transfer kinetics of Mg anode in commercial conventional electrolytes. Herein, a superb Mg2+-conducting and electron-blocking interphase is in-situ constructed on Mg anode facilely through the spontaneous magnetization reaction with SbBr3 added in cost-effective Mg(TFSI)2 electrolyte. The interphase with high ionic conductivity and electronic resistivity endows Mg anode a stable long-cycling lifespan of 1600 h with a low overpotential (<0.3 V) at 0.5 mA cm−2 and 0.5 mAh cm−2. Benefitting from the deep cycling Mg anode, the Mg||CuS cell delivers an impressive specific capacity 85.2 mAh g−1 over 300 cycles at 1000 mA g−1 with a capacity retention of 82.8 %, as well as the Mg||Mo6S8 cell can be cycled over 500 cycles at 2C. This research provides valuable insight into the interphase construction and presents a feasible way to develop reliable Mg metal anode for high-performance RMBs.
Display omitted
•A Sb-based interphase is in-situ formed on Mg surface via ion exchange reaction.•Mg anode exhibits superior kinetics, long-term lifespan and high-rate performance.•Mg.||CuS cell exhibits a high delivery capacity of 231.9 mAh g−1 at 100 mA g−1.
Mg−CO2 battery has been considered as an ideal system for energy conversion and CO2 fixation. However, its practical application is significantly limited by the poor reversibility and sluggish ...kinetics of CO2 cathode and Mg anode. Here, a new amine mediated chemistry strategy is proposed to realize a highly reversible and high‐rate Mg−CO2 battery in conventional electrolyte. Judiciously combined experimental characterization and theoretical computation unveiled that the introduced amine could simultaneously modify the reactant state of CO2 and Mg2+ to accelerate CO2 cathodic reactions on the thermodynamic‐kinetic levels and facilitate the formation of Mg2+‐conductive solid‐electrolyte interphase (SEI) to enable highly reversible Mg anode. As a result, the Mg−CO2 battery exhibits boosted stable cyclability (70 cycles, more than 400 h at 200 mA g−1) and high‐rate capability (from 100 to 2000 mA g−1 with 1.5 V overpotential) even at −15 °C. This work opens a newly promising avenue for advanced metal‐CO2 batteries.
A non‐aqueous Mg−CO2 battery with high reversibility and enhanced kinetics is utilized using an amine molecular mediator that tunes the CO2 reduction pathways as well as the Mg anode. It not only modifies the reactant state of CO2 and Mg2+ to promote CO2 cathodic reaction kinetics but also facilitates Mg2+‐conducting interphase formation to enable the reversible cycling of Mg anode.
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