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Mesoscale eddies have attracted increased attention due to their central role in ocean energy and mass transport. The observations of their three-dimensional structure will facilitate the understanding of nonlinear eddy dynamics. In this paper, we propose a novel framework, the mesoscale eddy characterization from ordinal modalities recurrence networks method (MeC-OMRN), that utilizes a Petrel-II underwater glider for in situ observations and vertical structure characterization of a moving mesoscale eddy in the northern South China Sea. First, higher resolution continuous observation profile data collected throughout the traversal by the underwater glider are acquired and preprocessed. Subsequently, we analyze and compute these nonlinear data. To further amplify the hidden structural features of the mesoscale eddy, we construct ordinal modalities sequences rich in spatiotemporal characteristics based on the measured vertical density of the mesoscale eddy. Based on this, we employ ordinal modalities recurrence plots (OMRPs) to depict the vertical structure inside and outside the eddy, revealing significant differences in the OMRPs and the unevenness of density stratification within the eddy. To validate our intriguing findings from the perspective of complex network theory, we build the multivariate weighted ordinal modalities recurrence networks, through which network measures exhibit a more random distribution of vertical density stratification within the eddy, possibly due to more intense vertical convection and oscillations within the eddy's seawater micelles. These framework and intriguing findings are anticipated to be applied to more data-driven in situ observation tasks of oceanic phenomena. [ABSTRACT FROM AUTHOR]

As a new type of unmanned autonomous marine observation platform, underwater gliders (UGs) offer advantages such as low energy consumption and long operational ranges. However, during the gliding process, the complex marine environment often leads to abrupt changes in short-term control parameters, complicating the data and rendering them more challenging to predict. This typically poses difficulties in adjusting control parameters based on human experience, thereby significantly reducing UG control efficiency. To address this issue, this paper proposes a novel method termed DFFormer, aimed at enhancing the predictive accuracy of the rudder angles during UG motion. The proposed method integrates discrete wavelet transform (DWT) for rudder angle signal decomposition and employs a fast Fourier transform-based attention mechanism (FFT-Attention) to effectively capture and analyze its frequency- and time-domain characteristics. Notably, the method leverages a Transformer architecture to process the decomposed signals through multiple parallel pathways, substantially improving the capability to forecast the complex and variable control parameters of UGs. The effectiveness and practicality of the proposed method are demonstrated through actual sea trials. The experimental results indicate that the proposed method surpasses traditional approaches in terms of accuracy and computational efficiency, exhibiting superior performance in predicting UG control parameters and, to some extent, enhancing their heading-keeping ability. [ABSTRACT FROM AUTHOR]

The generation of medium‐scale traveling ionospheric disturbances (MSTIDs) in the mid‐latitude F region ionosphere, particularly in the presence of sporadic E (Es) layers or geomagnetically conjugate features, has been the focus of extensive investigation using both observational and numerical modeling approaches. Recent observations have revealed the occurrence of nighttime MSTIDs over the continental US during storm conditions even without invoking the Es instability. While this phenomenon is considered to be electrified and likely associated with the Perkins instability, the influences of storm‐enhanced density (SED), electric fields, and winds on the excitation of nighttime MSTIDs remain a complicated issue and require further quantitative analysis. In this study, we develop a two‐dimensional numerical model of the nighttime ionospheric electrodynamics at midlatitudes using the ionospheric ion continuity equation and the electric field Poisson equation to investigate the characteristics of MSTIDs in the SED base region during storm conditions. We demonstrate that the magnetic inclination effect can explain the lower latitude preference of the MSTIDs during magnetic storms, while the development of MSTIDs is primarily influenced by intense storm electric fields under the background ionospheric condition of large density gradients associated with SED. However, the impact of neutral winds on the MSTIDs growth varies, depending on their specific direction determined by the strongly dynamic spatiotemporal variation of the thermosphere and ionosphere during storms. Therefore, the MSTIDs stormtime scenario results from a combination of multiple important factors. Key Points: The medium‐scale traveling ionospheric disturbances (MSTIDs) evolution under stormtime electrodynamic forcing is simulated for the first timeThe effect of stormtime large horizontal density gradients associated with storm‐enhanced density (SED) is considered in two‐dimensional MSTIDs simulationsThe development of MSTIDs is primarily influenced by storm electric fields and SED‐related density gradients [ABSTRACT FROM AUTHOR]

The p–n type Sm2WO6-Co9S8 heterojunction with two-dimensional coupling interface was successfully synthesized by electrostatic self-assembly. The unique rhombic morphology of Sm2WO6 and Co9S8 nanoparticles also effectively improve the light utilization efficiency. The intervention of Co9S8 enhances the visible light absorption capacity of m2WO6/Co9S8. The Sm2WO6/Co9S8 greatly increases the specific surface area and provides a rich reaction site. Recombination of photogenerated carriers in Sm2WO6/Co9S8 heterojunctions is effectively inhibited. The p–n type Sm2WO6-Co9S8 heterojunction results show that the optimized Sm2WO6/Co9S8 heterojunction exhibits significant hydrogen evolution activity, and the optimal Sm2WO6/Co9S8-25 composite has 117.5 μmol hydrogen evolution activity, it's close to four times Co9S8, close to 143 times Sm2WO6. The stability of the composite Sm2WO6/Co9S8 is the better. Under the built-in electric field induced by p–n heterojunction, using of p–n heterojunction interactions and electron transport modes, the Sm2WO6/Co9S8 can effectively achieve the remarkable effect of its internal carrier separation. This work also provides new opportunities for studying rare earth element tungstate photocatalysts. [ABSTRACT FROM AUTHOR]

Photocatalytic hydrogen production is one of the effective ways of global energy conservation and emission reduction. Herein, we report the successful embedding of flower ball MoS2 into Sm2WO6 using the hydrothermal method, and p-n heterojunction is obtained successfully. Due to the narrow band gap of MoS2, the Sm2WO6/ MoS2 composite photocatalyst effectively improves the photogenerated carrier separation. The better redox capacity of Sm2WO6 itself also promotes the reduction capacity of Sm2WO6/MoS2. The petals on MoS2 are closely bound to Sm2WO6, which enhances the electron transport efficiency and is one of the main factors for improving photocatalytic hydrogen evolution (HER). To explore the performance of Sm2WO6/ MoS2 by various means of representation. And the HER performance of Sm2WO6/ MoS2 is evaluated using eosin Y (EY) as sensitizer and TEOA as sacrifice agent. Compared with pure Sm2WO6, Sm2WO6/ MoS2 has improved HER performance, and its optimal activity is 142.7 µmol, which is nearly 140 times that of pure Sm2WO6. This study demonstrates a novel morphology design strategy for composite photocatalysts to promote efficient photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

In the context of national efforts to promote country-wide distributed photovoltaics (DPVs), the installation of distributed energy storage systems (DESSs) can solve the current problems of DPV consumption, peak shaving, and valley filling, as well as operation optimization faced by medium-voltage distribution networks (DN). In this paper, firstly, a price elasticity matrix based on the peak and valley tariff mechanism is introduced to establish a master–slave game framework for DN-DESSs under the DPV multi-point access environment. Secondly, the main model optimizes the pricing strategy of peak and valley tariffs with the objective of the lowest annual operating cost of the DN, and the slave model establishes a two-layer optimization model of DESSs with the objective of the maximum investment return of the DESSs and the lowest daily operating costs and call the CPLEX solver and particle swarm optimization algorithm for solving. Finally, the IEEE33 node system is used as a prototype for simulation verification. The results show that the proposed model can not only effectively reduce the operating cost of the distribution network but also play a role in improving the energy storage revenue and DPV consumption capacity, which has a certain degree of rationality and practicality. [ABSTRACT FROM AUTHOR]