Accurate prediction of sea surface temperature (SST) is extremely important for forecasting oceanic environmental events and for ocean studies. However, the existing SST prediction methods do not consider the seasonal...
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Accurate prediction of sea surface temperature (SST) is extremely important for forecasting oceanic environmental events and for ocean studies. However, the existing SST prediction methods do not consider the seasonal periodicity and abnormal fluctuation characteristics of SST or the importance of historical SST data from different times;thus, these methods suffer from low prediction accuracy. To solve this problem, we comprehensively consider the effects of seasonal periodicity and abnormal fluctuation characteristics of SST data, as well as the influence of historical data in different periods, on prediction accuracy. We propose a novel ensemble learning approach that combines the Predictive Recurrent Neural Network(PredRNN) network and an attention mechanism for effective SST field prediction. In this approach, the XGBoost model is used to learn the long-period fluctuation law of SST and to extract seasonal periodic features from SST data. The exponential smoothing method is used to mitigate the impact of severely abnormal SST fluctuations and extract the a priori features of SST data. The outputs of the two aforementioned models and the original SST data are stacked and used as inputs for the next model, the PredRNN network. PredRNN is the most recently developed spatiotemporal deep learning network, which simulates both spatial and temporal representations and is capable of transferring memory across layers and time steps. Therefore, we used it to extract the spatiotemporal correlations of SST data and predict future SSTs. Finally, an attention mechanism is added to capture the importance of different historical SST data, weigh the output of each step of the PredRNN network, and improve the prediction accuracy. The experimental results on two ocean datasets confirm that the proposed approach achieves higher training efficiency and prediction accuracy than the existing SST field prediction approaches do.
Enantiomeric molecules generally play distinct functions in chemistry,biology,and *** physical and chemical properties of chiral analytes lay difficulty in discrimination and quantification of the *** report herein an...
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Enantiomeric molecules generally play distinct functions in chemistry,biology,and *** physical and chemical properties of chiral analytes lay difficulty in discrimination and quantification of the *** report herein an efficient approach of increasing the chiral sensing ability ofβ-cyclodextrin(β-CD),a widely used host molecule,in the hostguest chemistry by magnetic anisotropy.A rigid and chiral lanthanide binding tag was attached to theβ-CD to amplify the changes of nuclear magnetic resonance(NMR)signals in the host-guest recognition *** installation of the paramagnetic lanthanide ion inβ-CD greatly enhances the enantiomeric discrimination up to 30-fold in comparison with the diamagneticβ-CD *** addition,the magnitude of the paramagnetic effects is tunable according to the diverse range of paramagnetic strength of the lanthanide *** reported method significantly increases the chiral sensing ability ofβ-CD,which can be applied to other host *** transferred paramagnetic effects,pseudocontact shifts(PCSs)and paramagnetic relaxation enhancements(PREs),from the host to the guest molecules,are valuable structural restraints to determine the absolute stereochemistry of the chiral *** strategy does not need modification of the analytes and is complementary to the reported analytical methods that rely on the functionalization of the chiral analytes.
The microstructure of electrodes significantly affects the performance of lithium-ion batteries(LiBs),and using bi-diameter active particles is a simple but effective way to regulate the microstructure of commercial L...
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The microstructure of electrodes significantly affects the performance of lithium-ion batteries(LiBs),and using bi-diameter active particles is a simple but effective way to regulate the microstructure of commercial LiB ***,to optimize the LiB cathode of bi-diameter active particles,a microstructure-resolved model is developed and *** results indicate that randomly packing of bi-diameter active particles is optimal when the electrolyte diffusion limitation is mild,as it provides the highest volume fraction of active *** strong electrolyte diffusion limitations,layered packing with small particles near the separator is *** is because particles near the current collector have a low lithiation ***,optimizing the random packing can further improve the energy *** energy-oriented LiBs,a low volume fraction of small particles(0.2)is preferred due to the higher volume fraction of active *** power-oriented LiBs,a high volume fraction of small particles(0.8)is better because it reduces diffusion *** work should serve to guide the optimal design of electrode microstructure for achieving high-performance LiBs.
The flexible pressure sensor has been credited for leading performance including higher sensitivity,faster response/recovery,wider detection range and higher mechanical durability,thus driving the development of novel...
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The flexible pressure sensor has been credited for leading performance including higher sensitivity,faster response/recovery,wider detection range and higher mechanical durability,thus driving the development of novel sensing materials enabled by new processing *** atomic layer infiltration,Pt nanocrystals with dimensions on the order of a few nanometers can be infiltrated into the compressible lamellar structure of Ti3C2Tx MXene,allowing a modulation of its interlayer spacing,electrical conductivity and piezoresistive *** flexible piezoresistive sensor is further developed from the Pt-infiltrated MXene on a paper *** is demonstrated that Pt infiltration leads to a significant enhancement of the pressure-sensing performance of the sensor,including increase of sensitivity from 0.08 kPa^(-1)to 0.5 kPa^(-1),extension of detection limit from 5 kPa to 9 kPa,decrease of response time from 200 ms to 20 ms,and reduction of recovery time from 230 ms to 50 *** mechanical durability of the flexible sensor is also improved,with the piezoresistive performance stable over 1000 cycles of flexure *** atomic layer infiltration process offers new possibilities for the structure modification of MXene for advanced sensor applications.
Commercial V_(2)O_(5)-based catalysts have been successfully applied in NH_(3) selective catalytic reduction(NH_(3)-SCR)of NO_(x) from power stations,but their poor alkali-resistance restrains the wider application in...
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Commercial V_(2)O_(5)-based catalysts have been successfully applied in NH_(3) selective catalytic reduction(NH_(3)-SCR)of NO_(x) from power stations,but their poor alkali-resistance restrains the wider application in nonelectrical *** this study,NO_(x) reduction against alkali poisoning over V_(2)O_(5)/TiO_(2) is greatly improved via Ce(SO_(4))_(2) *** has been originally demonstrated that Ce^(4+)-SO_(4)^(2−)pair sites play crucial roles in improving NO_(x) reduction against alkali poisoning over V_(2)O_(5)/TiO_(2) *** strong interaction between V species and Ce sites of Ce^(4+)-SO_(4)^(2−)pairs triggers the reaction between NH_(4)^(+) species and gaseous NO via Eley-Rideal(E-R)reaction *** K-poisoning,the SO_(4)^(2−)sites of Ce^(4+)-SO_(4)^(2−)pairs as protective sites strongly bond with K and thus maintain the high reaction efficiency via the E-R reaction *** work demonstrates an effective strategy to enhance NO_(x) reduction against alkali poisoning over catalysts via constructing Ce^(4+)-SO_(4)^(2−)pair sites,contributing to developing alkali-resistant SCR catalysts for practical application in nonelectrical industries.
Reinforcement Learning(RL)has emerged as a promising data-driven solution for wargaming ***,two domain challenges still exist:(1)dealing with discrete-continuous hybrid wargaming control and(2)accelerating RL deployme...
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Reinforcement Learning(RL)has emerged as a promising data-driven solution for wargaming ***,two domain challenges still exist:(1)dealing with discrete-continuous hybrid wargaming control and(2)accelerating RL deployment with rich offline *** RL methods fail to handle these two issues simultaneously,thereby we propose a novel offline RL method targeting hybrid action space.A new constrained action representation technique is developed to build a bidirectional mapping between the original hybrid action space and a latent space in a semantically consistent *** allows learning a continuous latent policy with offline RL with better exploration feasibility and scalability and reconstructing it back to a needed hybrid ***,a novel offline RL optimization objective with adaptively adjusted constraints is designed to balance the alleviation and generalization of out-of-distribution *** method demonstrates superior performance and generality across different tasks,particularly in typical realistic wargaming scenarios.
In this paper, a series of kelp-derived porous carbon(KPC) materials were prepared from kelp by using a pyrolysisactivation method, where KOH with a fixed ratio was applied as the activator under varying activation ...
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In this paper, a series of kelp-derived porous carbon(KPC) materials were prepared from kelp by using a pyrolysisactivation method, where KOH with a fixed ratio was applied as the activator under varying activation temperature. Eventually, the KPC-based capacitive deionization(CDI) system showed excellent desalination performance, and the desalination capacity of KPC with an activation temperature of 800°C was highest, reaching 51.33 mgNaClg-1at 1.2 V. This work implies the trade-off effect of the activation temperature for the preparation and application of biomass-derived carbon materials, and provides some insights for carbon-based CDI materials.
Software-Defined Data Center Networks (SDDCNs) utilizes Software Defined Networking (SDN) as a network architecture to achieve highly flexible, programmable, and automated management of Data Center Networks (DCNs). Th...
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With the intensification of informatization and mobility, various web security threats are emerging. Cross-site scripting (XSS) attack is the most common type of web attack. Most traditional detection methods have bee...
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With the depletion of high-quality iron ore resources,high-phosphorus oolitic hematite(HPOH)has attracted great attention due to its large reserve and relatively high iron ***,HPOH is very difficult to be used in iron...
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With the depletion of high-quality iron ore resources,high-phosphorus oolitic hematite(HPOH)has attracted great attention due to its large reserve and relatively high iron ***,HPOH is very difficult to be used in ironmaking process due to its special structure.A two-step method of gas-based direct reduction and magnetic separation was thus proposed to recover iron and reduce *** results showed that the powdery reduced iron produced contained 92.31%iron and 0.1%phosphorus,and the iron recovery was 92.65%under optimum reduction condition,which is suitable for following *** apatite will be reduced under long reduction time and a large reducing gas flow rate,resulting in more phosphorus found in the metallic *** the hydrogen–carbon ratio will inhibit the formation and growth of iron particles and prevent the breakage of oolitic *** adjustment of reduction temperature is recommended as it affects the oolitic structure and reduction.
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