bluuebunny/crossref_metadata_2025_split huggingface dataset:
Marine Heatwaves/Cold‐Spells Associated With Mixed Layer Depth Variation Globally
Authors: Sun Wenjin , Wang Yindi , Yang Yifei , Yang Jingsong , Ji Jinlin , Dong Changming 
Published: December 2024

AbstractMarine heatwaves (MHWs) and cold‐spells (MCSs) are extreme sea surface temperature events with significant impacts on marine ecosystems. However, the connection between these events and mixed layer depth (MLD) variations, as well as how their intensity relates to MLD changes, remains unclear. Integrating OISST V2.1 data with Argo profiles, this analysis finds that during MHWs, MLD decreases by 8.10% globally, while during MCSs, it increases by 8.13%. In 5° × 5° bins, 80.46% of ocean regions show MLD shallowing during MHWs, while 67.69% show deepening during MCSs. A significant global correlation between the intensity of MHWs/MCSs and MLD changes, with coefficients of −0.85 and −0.86, respectively. MHWs are more common in mesoscale anticyclonic eddies (AEs) (19.45%) than in cyclonic eddies (CEs) (10.11%). For MCSs, the pattern reverses, with 8.57% in AEs and 20.82% in CEs. Restratification and mesoscale eddies are two important factors driving MLD changes during these events.
Melting of B1‐Phase MgO From Simultaneous True Radiative Shock Temperature and Sound Speed Measurements to 250 GPa on Samples Preheated to 2300 K
Authors: Fat’yanov O. V. , Asimow P. D. 
Published: December 2024

AbstractTo refine the melting curve, equation of state, and physical properties of MgO we performed plate impact experiments spanning 170–250 GPa on MgO single crystals, preheated to 2300 K. A controlled thermal gradient in 20 mm long samples enabled radiative temperature (3%–4%) and rarefaction overtake observations (yielding sound speed 2%) close to the hot Mo driver with a free surface below 2000 K that minimized evaporation. Ta flyers were launched by two‐stage light‐gas gun up to 7.6 km/s and sample radiance was recorded with a 6‐channel (500–850 nm) pyrometer. Shock front reflectivity was measured at 198 and 243 GPa using 50/50 sapphire beam‐splitters. Most experiments show monotonic increases of shock temperature with pressure, from (168 GPa, 7100 K) to (243 GPa, 9400 K), in good agreement with predictions of our MgO B1 phase equation of state. Measured sound speeds are parallel to but 10% higher than model predictions for bulk sound speed of solid B1 MgO, confirming ductile behavior of preheated MgO. Two experiments, at 238 and 246 GPa, showed anomalously low shock temperature and sound speed, suggesting melting. Using reported MgO melting data up to 120 GPa and our data at 232–246 GPa, we constructed a maximum‐likelihood Simon‐Glatzel fit. At Earth's core‐mantle boundary pressure (135 GPa), our best‐fit interpolated MgO melting point is K. Our proposed melting line falls within the envelope of theoretical predictions but does not completely agree with any particular model curve. Our results reduce the uncertainty on MgO melting temperature at Earth's core‐mantle boundary by a factor of 17 and provide an anchor for extension to multicomponent systems.
Impact of Temperature and Stratification, Modulated by Warming Tsushima Warm Current, on the Spatiotemporal Distribution of Picoplankton in the Northern East China Sea
Authors: Kang Yoonja , Kwon Chan‐Woo , Lee Eunbi , Oh Yeongji , Cho Yang‐Ki , Lee Chung Il , Kwon Hyeong Kyu , Kim Guebuem , Lee Minji , Lim Weol‐Ae , Kang Chang‐Keun 
Published: December 2024

AbstractThe northern East China Sea is one of the Large Marine Ecosystems, which experiences the fastest ocean warming across the globe. With the anticipation of stimulated Tsushima Warm Current (TWC) transport and rapid ocean warming, the importance of picoplankton will increase in this ecosystem. Thus, the spatiotemporal distribution of picoplankton was investigated in the northern East China Sea, where variability of TWC can modulate temperature and stratification. High contributions of warm and less saline Tsushima Surface Warm Water (TSWW) increased water temperature and stratification. Picoplankton were responsible for 75% of the relative contribution of chl a. PicoC:PicoChla ratios increased with distance from the coasts and fluctuated with depth, indicating that an elevated contribution of Tsushima Warm Water diminished the photosynthetic activity of picoplankton. Synechococcus I population decreased with salinity. High contribution of TSWW increased Prochlorococcus and Synechococcus II population, related with stratification and rising temperature driven by TSWW, respectively. Picoplankton‐derived carbon contents were mostly attributed either to picoeukaryotes or to Synechococcus depending on the TSWW contribution. This suggests that the rising TSWW contribution can intensify the role of Synechococcus in picoplankton‐derived organic matter in the northern East China Sea.
Mixing of Top‐Down and Bottom‐Up Diffusing Reactive Tracers Within the Ocean Mixed Layer and Its Application to Autumn Phytoplankton Blooms
Authors: Noh Y. , Seunu H. J. , Song H. , Choi Y. 
Published: December 2024

AbstractThe mixing of reactive tracers within the ocean mixed layer, phytoplankton transported downwards from the sea surface and nutrients transported upwards from the mixed layer depth (MLD), is investigated using large eddy simulation coupled to a Lagrangian plankton model. The study focuses on how vertical and horizontal heterogeneity in tracer distribution is generated and how it influences an autumn phytoplankton bloom. The vertical gradient appears in the profiles of horizontal mean phytoplankton and nutrient concentrations, P and N, and it reduces phytoplankton production by photosynthesis compared to the cases with uniform distributions. The reduction ratio decreases as the mixed‐layer mean N increases, but it remains relatively insensitive to other conditions such as MLD, surface forcing, stratification below the mixed layer, and the initial N. Phytoplankton and nutrient concentrations show a negative correlation in the horizontal plane, which becomes stronger with increasing depth. Its contribution to plankton production by photosynthesis is negligible, however, because the correlation is weak near the sea surface and the reaction time scale is much longer than the turbulent mixing time scale. It is also found that the vertical gradients of P and N are smaller, and the negative correlation is stronger in the convective mixed layer than in the shear‐driven mixed layer. A simple box plankton model, which takes into account the mixing process of tracers, is proposed and used to investigate how mixing affects the prediction of an autumn phytoplankton bloom.
Escalated Risk of Concurrent Eurasian Heatwaves Under Recurrent Rossby Wave Patterns
Authors: FANG Beijing , LU Mengqian 
Published: December 2024

AbstractConcurrent heatwaves, featured by simultaneous occurrences of extreme heat in separate regions, pose significant risks to natural ecosystems and human society. In August 2022, unprecedented heatwaves struck central China and west Russia concurrently, resulting in severe energy crisis, numerous financial losses, and fatalities. Through synoptic‐scale analysis, we identify a pivotal role of recurrent Rossby wave packets (RRWPs) in shaping the event by repeatedly forming ridges and troughs over the same key areas. In this study, we further extend the investigation of the influence of RRWPs on heatwave occurrences in these two targeted regions over the past 44 years. Using a self‐organizing map to identify the RRWP patterns, we find that RRWPs with ridges over central China are closely associated with a marked increase in heatwave probabilities in both central China and western Russia. Specifically, the regional‐mean likelihood of heatwaves increases by factors of 3.0 and 2.6, respectively, relative to the climatology. Notably, the effect of RRWPs on the occurrence of concurrent heatwaves across both regions is more pronounced than on regional events alone. For example, during RRWPs, the likelihood of concurrent heatwaves affecting at least 20% of both target regions exceeds 10 times the climatological average. Our findings underscore the significant role of RRWPs in triggering concurrent Eurasian heatwaves and suggest promising synoptic predictability for such extreme events.
Seasonal Differences in Vegetation Susceptibility to Soil Drought During 2001–2021
Authors: Tang Jiwang , Niu Ben , Peng Jinlong , Hu Zhigang , Zhang Ziwei , Zhang Xianzhou 
Published: December 2024

AbstractDroughts typically exert negative effects on vegetation growth, which largely depend on the timing of drought onset. However, huge inconsistencies exist in the seasonal vegetation response to drought among diverse regions across the globe. Here, using the leaf area index (LAI) and solar‐induced chlorophyll fluorescence (SIF), we quantified the vegetation susceptibility by calculating the coincidence rate between vegetation suppression extremes and soil droughts, and further investigated the spatiotemporal changes of vegetation susceptibility during different seasons from 2001 to 2021. We found the vegetation during summer and dry seasons were most susceptible to soil droughts in the extra‐tropics and tropics, respectively. Temporally, the autumn vegetation susceptibility was strengthening in drought‐susceptible regions of extra‐tropics, albeit with insignificant change during spring, summer and the entire growing season. Both the dry and wet seasons showed evidently increasing vegetation susceptibility on the dry tropical ecosystems, which dominated the enhanced vegetation susceptibility of global drought‐susceptible regions. Our findings determined the spatial pattern of most susceptible seasons to soil droughts across the globe and highlighted the enhanced risk to soil droughts, especially in the dry tropics.
Deep Learning‐Based 3D Microseismic Event Direct Location Using Simultaneous Surface and Borehole Data
Authors: Yang Yuanyuan , Saad Omar M. , Alkhalifah Tariq 
Published: December 2024

AbstractMicroseismic monitoring is crucial for characterizing and assessing fracture systems developed during subsurface operations like geothermal reservoir development, sequestration, and hydraulic fracturing. In such long‐term projects, surface arrays provide a large aperture for accurate epicenter location but struggle with poor event depth estimation and low signal‐to‐noise ratio; while borehole arrays deliver better signal quality and enhanced depth estimation, but have severely limited aperture and azimuthal ambiguity for epicenter location. To bridge the capacities of surface and borehole arrays, we propose a deep learning model to directly locate microseismic events in 3D using seismic recordings from both surface and borehole sensors, based on the elastic medium assumption. Specifically, the DEtection TRansformer (DETR) network is utilized as the base model to identify and locate events simultaneously. The proposed method, based on distinct feature extraction blocks for the surface and borehole data, has potent compatibility for embracing diverse data sets. It is also able to effectively model the complicated dynamics from the moveout patterns of microseismic energy to responsible source locations, and the concerted interactions of these moveout signatures across various sensor layouts. The statistical analysis on results from synthetic passive seismic data demonstrates the efficacy of the method. An application on the field microseismic events from the Utah FORGE site further validates its accuracy and reliability, in which a domain adaptation technique is used to bridge the gap between training on synthetic data and application on field data for better generalization.
On the Performance of a Real‐Time Electron Radiation Belt Specification Model
Authors: Staples Frances , Kellerman Adam , Green Janet 
Published: December 2024

AbstractMaintaining accurate real‐time hindcast and forecast specification of the radiation environment is essential for operators to monitor and mitigate the effects of hazardous radiation on satellite components. The Radiation Belt Forecasting Model and Framework (RBFMF) provides real‐time forecasts and hindcasts of the electron radiation belt environment, which are used as inputs for the Satellite Charging Assessment Tool. We evaluated the long‐term statistical error and bias of the RBFMF by comparing the 10‐hr hindcast of electron phase space densities (PSD) to a multi‐mission data set of PSD observations. We found that, between the years 2016–2018, the RBFMF reproduced the radiation belt environment to within a factor of 1.5. While the error and bias of assimilated observations were found to influence the error and bias of the hindcast, data assimilation resulted in more accurate specification of the radiation belt state than real‐time Van Allen Probe observations alone. Furthermore, when real‐time Van Allen Probe observations were no longer available, the hindcast errors increased by an order of magnitude. This highlights two needs; (a) the development of physics‐based modeling incorporated into this framework, and (b) the need for real‐time observations which span the entire outer radiation belt.
Selectivity promotion of Cu by manganese oxide in hydrogenative ring opening of furfural to pentanediols
Authors: Li Huixiang , Li Huayang , Shen Jun , Liang Changhui , Zhang Xiaoqiang , Zhang Wei , Li Yongxin , Conrad Zhang Z. 
Published: December 2024

Modifying Cu with MnO2 enhances the interaction of the furan ring and C–O–C group in furfural alcohol with catalyst in a preferential flat adsorption configuration thus facilitating the C–O–C activation to produce pentanediols.
Research on a high‐performance signal distribution reconstruction algorithm for wireless communication networks
Authors: Li Zhimeng , Wang Hongjun , Shen Zhexian 
Published: December 2024

AbstractWith the rapid development of communication technology and the increasing demand for coverage refinement in wireless communication networks, the optimization of wireless communication networks is faced with unprecedented challenges. Obtaining the signal distribution map of wireless communication networks efficiently has become a popular area of study in this field. This paper considers a distributed sensing network architecture, a radial basis function neural network is used to process electromagnetic data and optimize the parameters of the random forest model. Then, interpolation processing of incomplete electromagnetic data is achieved by the improved random forest model, based on which a signal distribution map of the wireless communication network is reconstructed. The results indicate that the proposed algorithm yields high interpolation accuracy. The average error between the real signal distribution and the reconstructed signal distribution is 2.7973 dBm when the proportion of sampled nodes is 1%, and the similarity of the reconstructed signal distribution map to the original signal distribution map is good, demonstrating certain application prospects.
Experimental study on temperature control of cable tunnel fire under the combined effect of fine water mist and mechanical ventilation
Authors: Zhu Hui , Ji Jun , Nie Jingkai , Xia Yu 
Published: December 2024

AbstractElectricity is an important energy supply for industry, and long‐distance transmission in China mainly relies on cable tunnels, while cable tunnel fires occur frequently. A 1:1 scale tunnel model with a length of 20 m, a width of 2.5 m, and a height of 2.5 m was used to conduct experimental research on the temperature field of the ceiling of a high‐voltage fine water mist suppression cable tunnel. The article conducted experimental research on parameters, such as nozzle pressure, nozzle position, and longitudinal ventilation speed in high‐pressure water mist systems using n‐hexane as the ignition source. The results indicate that the high‐pressure water mist system can effectively reduce the ceiling temperature during cable tunnel fires. When the mechanical smoke evacuation system is activated, it leads to a reduction in the overall temperature within the tunnel. When the mechanical smoke extraction system is integrated with the high‐pressure water mist system, therefore, it is feasible to integrate the high‐pressure water mist system with the mechanical smoke exhaust system in engineering applications.
PlutoNet: An efficient polyp segmentation network with modified partial decoder and decoder consistency training
Authors: Erol Tugberk , Sarikaya Duygu 
Published: December 2024

AbstractDeep learning models are used to minimize the number of polyps that goes unnoticed by the experts and to accurately segment the detected polyps during interventions. Although state‐of‐the‐art models are proposed, it remains a challenge to define representations that are able to generalize well and that mediate between capturing low‐level features and higher‐level semantic details without being redundant. Another challenge with these models is that they are computation and memory intensive, which can pose a problem with real‐time applications. To address these problems, PlutoNet is proposed for polyp segmentation which requires only 9 FLOPs and 2,626,537 parameters, less than 10% of the parameters required by its counterparts. With PlutoNet, a novel decoder consistency training approach is proposed that consists of a shared encoder, the modified partial decoder, which is a combination of the partial decoder and full‐scale connections that capture salient features at different scales without redundancy, and the auxiliary decoder which focuses on higher‐level semantic features. The modified partial decoder and the auxiliary decoder are trained with a combined loss to enforce consistency, which helps strengthen learned representations. Ablation studies and experiments are performed which show that PlutoNet performs significantly better than the state‐of‐the‐art models, particularly on unseen datasets.
Large disturbance stability analysis method for DC microgrid with virtual DC motor control
Authors: Zhao Fengzhan , Liu Ting , Ju Yuntao , Li Hong 
Published: December 2024

AbstractMixed potential theory is frequently employed for analysing large‐disturbance stability. The precision of the current stability criterion for DC microgrids controlled by virtual DC motors (VDCM), which relies on mixed potential theory, is inadequate. This is primarily because the criterion does not account for the control parameters of the DC bus voltage control link and the virtual DC motor link. To address these issues, the paper initially formulates the control aspect of the VDCM using a controlled current source. Subsequently, it derives the system's mixed potential function from the model, enabling the development of a stability criterion that includes the control parameters of the DC bus voltage control link, the virtual DC motor link, and the current tracking link. It also clarifies how parameters not directly included in the criterion affect system stability. Through simulations and experimental validations, it is demonstrated that the proposed stability criterion effectively captures the impact of control parameters on system stability and precisely delineates the system's power stability boundary, offering insights for system parameter optimization.
Hydrodynamical simulations with strong indirect terms in FARGO-like codes
Authors: Jordan Lucas M. , Rometsch Thomas 
Published: December 2024

Context. Binary star systems allow us to study the planet formation process under extreme conditions. In the early stages, these systems contain a circumbinary disk and a disk around each star. To model the interactions between these disks in the frame of one of the stars, strong fictitious forces must be included in the simulations. The original FARGO and the FARGO3D codes fail to correctly simulate such systems if the indirect term becomes too strong.
Aims. We present a different way to compute the indirect term that, together with a tensor artificial viscosity prescription, allows the FARGO code to simulate the circumbinary disks in a non-inertial frame of reference. In this way, the FARGO code can be used to study interactions between circumstellar and circumbinary disks.
Methods. We first evaluated the accuracy of the standard implementation and our proposed indirect term prescription using a simple N-body test case. We then analytically estimated the effect of the default artificial viscosity used in the FARGO code in the limit of large distances to the N-body system. Finally, we evaluated the effects of the different prescriptions by performing hydrodynamical simulations in a non-inertial frame of reference.
Results. By updating the indirect term prescription and the artificial viscosity, we were able to successfully simulate a circumbinary disk in a frame that is centered on the less massive star. We find that updating the indirect term becomes relevant when the indirect term becomes stronger than the direct gravitational forces, which occurs for mass ratios of q ≳ 5%. The default artificial viscosity used in the FARGO code inherently produces artificial pressure in a non-inertial frame of reference even in the absence of shocks. This leads to artificial mass ejection from the Hill sphere, starting at brown dwarf masses (q ≳ 1%). These problems can be mitigated by using a tensor artificial viscosity formulation. For high mass ratios, q ≳ 1%, it is also becomes important to initialize the disk in the center-of-mass frame. We expect our proposed changes to be relevant for other grid-based hydrodynamic codes where strong indirect terms occur, or for codes that use artificial viscosity.
Molecular gas budget of strongly magnified low-mass star-forming galaxies at cosmic noon
Authors: Catán V. , González-López J. , Solimano M. , Barrientos L. F. , Afruni A. , Aravena M. , Bayliss M. , Hernández J. A. , Ledoux C. , Mahler G. , Sharon K. , Tejos N. 
Published: December 2024

Aims. The aim of this study is to investigate the molecular gas content of strongly magnified low-mass star-forming galaxies (SFGs) around the cosmic noon period (z ∼ 2) through observations of carbon monoxide (CO) emission lines and dust continuum emission, both of which serve as tracers of molecular gas (H2).
Methods. We observed 12 strongly lensed arcs with the Atacama Compact Array (ACA) to detect CO mid-J rotational transitions and dust continuum. Thanks to the strong lensing, we were able to probe the previously understudied low-mass regime. With a compiled set of observations, we recalibrated empirical relations between star formation rate density (ΣSFR) and the CO line ratios. We derived galaxy properties using spectral energy distribution fitting (SED). We also performed galaxy stacking to combine faint signals. In all cases, molecular gas masses were estimated using both tracers.
Results. We detected CO emission in 3 of the 12 arcs and dust continuum emission in another 3. The obtained H2 masses indicate that most of these galaxies (M* < 1010.7 M⊙) have lower molecular gas fractions and shorter depletion times compared to expectations from established scaling relations at these redshifts. We explored several possible explanations for this gas deficit, including uncertainties in mass estimates, effects of low-metallicity environments, larger atomic gas reservoirs in low-mass systems, and the possibility that these represent low-mass analogs of main sequence starburst (MS SBs) galaxies that are undergoing sustained star formation due to gas compaction despite low overall gas fractions.
Conclusions. We conclude that these mass and metallicity regimes present a molecular gas deficit. Our results suggest that this deficit is likely due to a significant amount of atomic gas, which our stacking indicates is about 91% of the total gas. However, this estimation might be an upper limit, as the possibility remains that our galaxies contain CO-dark gas.