bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sulfur Dioxide Transported From the Residual Layer Drives Atmospheric Nucleation During Haze Periods in Beijing
Authors: Wang Yonghong , Ma Yongjing , Yan Chao , Yao Lei , Cai Runlong , Li Shuying , Lin Zhuohui , Zhao Xiujuan , Yin Rujing , Deng Chenjuan , Kangasluoma Juha , He Xu‐Cheng , Hakala Simo , Fan Xiaolong , Chen Siyu , Ma Qingxin , Kerminen Veli‐Matti , Petäjä Tuukka , Xin Jinyuan , Wang Lin , Liu Baoxian , Wang Weigang , Ge Maofa , Jiang Jingkun , Liu Yongchun , Bianchi Federico , Chu Biwu , Donahue Neil M. , Martin Scot T. , He Hong , Kulmala Markku 
Published: March 2023

AbstractNew particle formation (NPF) is a global phenomenon that significantly influences climate. NPF also contributes to haze, with pronounced negative impacts on human health. Theory and observations both show that nucleation is favored during clean days and inhibited during haze episodes due to a high pre‐existing condensation sink (CS). Here we show that the surprising occurrence of NPF during haze days in Beijing is associated with a high concentration of sulfuric acid dimers. With both field observations and model simulations, we demonstrate that downward mixing of sulfur dioxide (SO2) from the residual layer aloft enhances ground level SO2, which in turn elevates sulfuric acid dimer after rapid SO2 oxidation in the polluted air. Our results address a key gap between the source of SO2 and its atmospheric oxidation products during haze conditions in a megacity, Beijing, providing a missing link in a complete chain describing NPF in the polluted atmosphere.
Real‐Time Forecast of Catastrophic Landslides via Dragon‐King Detection
Authors: Lei Qinghua , Sornette Didier , Yang Haonan , Loew Simon 
Published: March 2023

AbstractCatastrophic landslides characterized by runaway slope failures remain difficult to predict. Here, we develop a physics‐based framework to prospectively assess slope failure potential. Our method builds upon the physics of extreme events in natural systems: the extremes so‐called “dragon‐kings” (e.g., slope tertiary creeps prior to failure) exhibit statistically different properties than other smaller‐sized events (e.g., slope secondary creeps). We develop statistical tools to detect the emergence of dragon‐kings during landslide evolution, with the secondary‐to‐tertiary creep transition quantitatively captured. We construct a phase diagram characterizing the detectability of dragon‐kings against “black‐swans” and informing on whether the slope evolves toward a catastrophic or slow landslide. We test our method on synthetic and real data sets, demonstrating how it might have been used to forecast three representative historical landslides. Our method can in principle considerably reduce the number of false alarms and identify with high confidence the presence of true hazards of catastrophic landslides.
The Shape of Jupiter and Saturn Based on Atmospheric Dynamics, Radio Occultations and Gravity Measurements
Authors: Galanti E. , Kaspi Y. , Guillot T. 
Published: March 2023

AbstractThe shape of the two gas giants, Jupiter and Saturn, is determined primarily by their rotation rate, and interior density distribution. It is also affected by their zonal winds, causing an anomaly of O(10 km) at low latitudes. However, uncertainties in the observed cloud‐level wind and the polar radius, translate to an uncertainty in the shape with the same order of magnitude. The Juno (Jupiter) and Cassini (Saturn) missions gave unprecedented accurate gravity measurements, constraining better the uncertainty in the wind structure. Using an accurate shape calculation, and a joint optimization, given both gravity and radio‐occultation measurements, we calculate the possible range of dynamical height for both planets. We find that for Saturn there is an excellent match to the radio‐occultation measurements, while at Jupiter such a match is not achieved. This may point to deviations from a barotropic flow above the cloud level, which might be tested with the forthcoming radio‐occultation measurements by Juno.
Energetic Bottom Current at the Equatorial Gap of the Ninety East Ridge in the Indian Ocean Based on Mooring Data
Authors: Ye Ruijie , Zhou Feng , Ma Xiao , Zhou Beifeng , Zeng Dingyong , Liu Chenggang , Meng Qicheng , Lin Feilong , Xu Mingquan , Li Hongliang , Shou Lu 
Published: March 2023

AbstractBottom current at the equatorial gap of the Ninety East Ridge is revealed by long‐term bottom mooring observations from 24 December 2019 to 2 April 2021. It is found that the observed bottom current has significant intraseasonal variability (ISV) with a dominant time scale of ∼33 days, which becomes enhanced in the boreal summer and winter. Variability of the bottom current was explored by using the Mercator Ocean outputs, which revealed that the enhancement of ISV of the bottom current is closely related to the westward propagation of Rossby waves originating from the eastern boundary, with their ray paths vertically propagating into the deep layer. Considering the importance of water mass transport through the gaps in the Ninety East Ridge to the renewal of deep water and modification of deep circulation in the Central Indian Basin (CIB) and West Australian Basin (WAB), our study provides in‐situ evidence for previously unrevealed energetic variation of water mass exchange between the CIB and WAB, and it further helps us gain a comprehensive understanding of the pathway and variation of the deep meridional overturning circulation in the Indian Ocean.
Diverse Dispersion Effects and Parameterization of Relative Dispersion in Urban Fog in Eastern China
Authors: Wang Yuan , Lu Chunsong , Niu Shengjie , Lv Jingjing , Jia Xingcan , Xu Xiaoqi , Xue Yuqi , Zhu Lei , Yan Shuqi 
Published: March 2023

AbstractUnderstanding cloud droplet relative dispersion is critical for mitigating the confounding effect of aerosol‐cloud interactions in the simulation of the global climatic patterns. Diverse dispersion effects, meaning that the correlation between relative dispersion (ε) and fog droplet number concentration (Nf) changes from positive to negative as Nf increases at a fixed liquid water content (LWC) condition, were found in the urban fog observed during the winters of 2017 and 2018 in Nanjing, China. The dominant microphysical processes driving the diverse dispersion effects were found to be activation, condensation, deactivation, evaporation, and sedimentation. The critical first bin (diameter range of 2–4 μm) strength and volume‐mean diameter (Dv) for classifying the diverse dispersion effects are 0.3–0.4 and 10–12 μm, respectively. The mean dispersion offset (DO) was −27.6% for weakening the Twomey effect and 27.5% for enhancing it. Assuming the Gamma distribution for the fog droplet number size distribution, the mean dispersion effect was significantly underestimated at DO < 0. Based on the measured nonmonotonic relationship between ε and Dv, we establish ε parameterization using a Nelder function, which can be applied to the diverse dispersion effects. The mean deviation for diagnosing DO was less than 10% for DO > 0 and less than 50% for DO < 0. These results could shed new light on understanding the diverse dispersion effects, which cloud help reduce the uncertainties in the simulation of aerosol‐cloud interactions.
Projection of Flash Droughts in the Headstream Area of Tarim River Basin Under Climate Change Through Bayesian Uncertainty Analysis
Authors: Yu Xiaohan , Zeng Xiankui , Gui Dongwei , Li Xiaolan , Gou Qiqi , Wang Dong , Wu Jichun 
Published: March 2023

AbstractThe Tarim River, the largest inland river in China, sits in the Tarim River Basin (TRB), which is an arid area with the ecosystem primarily sustained by water from melting snow and glaciers in the headstream area. To evaluate the pressures of natural disasters in this climate‐change‐sensitive basin, this study projected flash droughts in the headstream area of the TRB. We used the variable infiltration capacity (VIC) model to describe the hydrological processes of the study area, Markov chain Monte Carlo to quantify the parameter uncertainty of the VIC model. Ten downscaled general circulation models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) were used to drive the VIC model, and the standardized evaporative stress ratio was applied to identify flash droughts. The results demonstrated that the VIC model after Bayesian parameters uncertainty analysis can efficiently describe the hydrological processes of the study area. In the future (2021–2100), compared with the plain region, the alpine region has higher flash drought frequency and intensity. Compared with the historical period (1961–2014), the frequency, duration, and intensity of flash droughts tend to increase throughout the study area, especially for the alpine area. Moreover, based on variance decomposition, CMIP6 model is the most important uncertainty source for flash drought projection, followed by the shared socioeconomic pathway of climate change scenario and VIC model parameters.
Geometry of Freezing Impacts Ice Composition: Implications for Icy Satellites
Authors: Buffo J. J. , Meyer C. R. , Chivers C. J. , Walker C. C. , Huber C. , Schmidt B. E. 
Published: March 2023

AbstractNon‐ice impurities within the ice shells of ocean worlds (e.g., Europa, Enceladus, Titan, Ganymede) are believed to play a fundamental role in their geophysics and habitability and may become a surface expression of subsurface ocean properties. Heterogeneous entrainment and distribution of impurities within planetary ice shells have been proposed as mechanisms that can drive ice shell overturns, generate diverse geological features, and facilitate ocean‐surface material transport critical for maintaining a habitable subsurface ocean. However, current models of ice shell composition suggest that impurity rejection at the ice‐ocean interface of thick contemporary ice shells will be exceptionally efficient, resulting in relatively pure, homogeneous ice. As such, additional mechanisms capable of facilitating enhanced and heterogeneous impurity entrainment are needed to reconcile the observed physicochemical diversity of planetary ice shells. Here we investigate the potential for hydrologic features within planetary ice shells (sills and basal fractures), and the unique freezing geometries they promote, to provide such a mechanism. By simulating the two‐dimensional thermal and physicochemical evolution of these hydrological features as they solidify, we demonstrate that bottom‐up solidification at sill floors and horizontal solidification at fracture walls generate distinct ice compositions and provide mechanisms for both enhanced and heterogeneous impurity entrainment. We compare our results with magmatic and metallurgic analogs that exhibit similar micro‐ and macroscale chemical zonation patterns during solidification. Our results suggest variations in ice‐ocean/brine interface geometry could play a fundamental role in introducing compositional heterogeneities into planetary ice shells and cryoconcentrating impurities in (re)frozen hydrologic features.
Incoherency in Central American Hydroclimate Proxy Records Spanning the Last Millennium
Authors: Obrist‐Farner Jonathan , Steinman Byron A. , Stansell Nathan D. , Maurer Jeremy 
Published: March 2023

AbstractContinued global warming is expected to result in reduced precipitation and a drier climate in Central America. Projections of future changes are highly uncertain, however, due to the spatial resolution limitations of models and insufficient observational data coverage across space and time. Paleoclimate proxy data are therefore critical for understanding regional climate responses during times of global climate reorganization. Here we present two lake‐sediment based records of precipitation variability in Guatemala along with a synthesis of Central American hydroclimate records spanning the last millennium (800–2000 CE). The synthesis reveals that regional climate changes have been strikingly heterogeneous, even over relatively short distances. Our analysis further suggests that shifts in the mean position of the Intertropical Convergence Zone, which have been invoked by numerous studies to explain variability in Central American and circum‐Caribbean proxy records, cannot alone explain the observed pattern of hydroclimate variability. Instead, interactions between several ocean‐atmosphere processes and their disparate influences across variable topography appear to have resulted in complex precipitation responses. These complexities highlight the difficulty of reconstructing past precipitation changes across Central America and point to the need for additional paleo‐record development and analysis before the relationships between external forcing and hydroclimate change can be robustly determined. Such efforts should help anchor model‐based predictions of future responses to continued global warming.
Trapping photons with optical black hole
Authors: Chen You-Ling , Cao Qi-Tao , Xiao Yun-Feng 
Published: March 2023

AbstractAn optical black-hole cavity based on transformation optics enables Q-factor enhancement and strong field confinement, by eliminating the intrinsic radiation loss of the conventional whispering-gallery modes, holding potential for applications in energy harvesting and optoelectronics.
Structural dynamics in the evolution of SARS-CoV-2 spike glycoprotein
Authors: Calvaresi Valeria , Wrobel Antoni G. , Toporowska Joanna , Hammerschmid Dietmar , Doores Katie J. , Bradshaw Richard T. , Parsons Ricardo B. , Benton Donald J. , Roustan Chloë , Reading Eamonn , Malim Michael H. , Gamblin Steve J. , Politis Argyris 
Published: March 2023

AbstractSARS-CoV-2 spike glycoprotein mediates receptor binding and subsequent membrane fusion. It exists in a range of conformations, including a closed state unable to bind the ACE2 receptor, and an open state that does so but displays more exposed antigenic surface. Spikes of variants of concern (VOCs) acquired amino acid changes linked to increased virulence and immune evasion. Here, using HDX-MS, we identified changes in spike dynamics that we associate with the transition from closed to open conformations, to ACE2 binding, and to specific mutations in VOCs. We show that the RBD-associated subdomain plays a role in spike opening, whereas the NTD acts as a hotspot of conformational divergence of VOC spikes driving immune evasion. Alpha, beta and delta spikes assume predominantly open conformations and ACE2 binding increases the dynamics of their core helices, priming spikes for fusion. Conversely, substitutions in omicron spike lead to predominantly closed conformations, presumably enabling it to escape antibodies. At the same time, its core helices show characteristics of being pre-primed for fusion even in the absence of ACE2. These data inform on SARS-CoV-2 evolution and omicron variant emergence.
Sustainable methane utilization technology via photocatalytic halogenation with alkali halides
Authors: Ma Jun , Zhu Can , Mao Keke , Jiang Wenbin , Low Jingxiang , Duan Delong , Ju Huanxin , Liu Dong , Wang Kun , Zang Yijing , Chen Shuangming , Zhang Hui , Qi Zeming , Long Ran , Liu Zhi , Song Li , Xiong Yujie 
Published: March 2023

AbstractMethyl halides are versatile platform molecules, which have been widely adopted as precursors for producing value-added chemicals and fuels. Despite their high importance, the green and economical synthesis of the methyl halides remains challenging. Here we demonstrate sustainable and efficient photocatalytic methane halogenation for methyl halide production over copper-doped titania using alkali halides as a widely available and noncorrosive halogenation agent. This approach affords a methyl halide production rate of up to 0.61 mmol h−1m−2for chloromethane or 1.08 mmol h−1m−2for bromomethane with a stability of 28 h, which are further proven transformable to methanol and pharmaceutical intermediates. Furthermore, we demonstrate that such a reaction can also operate solely using seawater and methane as resources, showing its high practicability as general technology for offshore methane exploitation. This work opens an avenue for the sustainable utilization of methane from various resources and toward designated applications.
An integrated evaluation approach of wearable lower limb exoskeletons for human performance augmentation
Authors: Zhang Xiao , Chen Xue , Huo Bo , Liu Chenglin , Zhu Xiaorong , Zu Yuanyuan , Wang Xiliang , Chen Xiao , Sun Qing 
Published: March 2023

AbstractWearable robots have been growing exponentially during the past years and it is crucial to quantify the performance effectiveness and to convert them into practical benchmarks. Although there exist some common metrics such as metabolic cost, many other characteristics still needs to be presented and demonstrated. In this study, we developed an integrated evaluation (IE) approach of wearable exoskeletons of lower limb focusing on human performance augmentation. We proposed a novel classification of trial tasks closely related to exoskeleton functions, which were divided into three categories, namely, basic trial at the preliminary phase, semi-reality trial at the intermediate phase, and reality trial at the advanced phase. In the present study, the IE approach has been exercised with a subject who wore an active power-assisted knee (APAK) exoskeleton with three types of trial tasks, including walking on a treadmill at a certain angle, walking up and down on three-step stairs, and ascending in 11-storey stairs. Three wearable conditions were carried out in each trial task, i.e. with unpowered exoskeleton, with powered exoskeleton, and without the exoskeleton. Nine performance indicators (PIs) for evaluating performance effectiveness were adopted basing on three aspects of goal-level, task-based kinematics, and human–robot interactions. Results indicated that compared with other conditions, the powered APAK exoskeleton make generally lesser heart rate (HR), Metabolic equivalent (METs), biceps femoris (BF) and rectus femoris (RF) muscles activation of the subject at the preliminary phase and intermediate phase, however, with minimal performance augmentation at advanced phase, suggesting that the APAK exoskeleton is not suitable for marketing and should be further improved. In the future, continuous iterative optimization for the IE approach may help the robot community to attain a comprehensive benchmarking methodology for robot-assisted locomotion more efficiently.
Automated prediction of COVID-19 severity upon admission by chest X-ray images and clinical metadata aiming at accuracy and explainability
Authors: Olar Alex , Biricz András , Bedőházi Zsolt , Sulyok Bendegúz , Pollner Péter , Csabai István 
Published: March 2023

AbstractIn the past few years COVID-19 posed a huge threat to healthcare systems around the world. One of the first waves of the pandemic hit Northern Italy severely resulting in high casualties and in the near breakdown of primary care. Due to these facts, theCovid CXR Hackathon—Artificial Intelligence for Covid-19 prognosis: aiming at accuracy and explainabilitychallenge had been launched at the beginning of February 2022, releasing a new imaging dataset with additional clinical metadata for each accompanying chest X-ray (CXR). In this article we summarize our techniques at correctly diagnosing chest X-ray images collected upon admission for severity of COVID-19 outcome. In addition to X-ray imagery, clinical metadata was provided and the challenge also aimed at creating an explainable model. We created a best-performing, as well as, an explainable model that makes an effort to map clinical metadata to image features whilst predicting the prognosis. We also did many ablation studies in order to identify crucial parts of the models and the predictive power of each feature in the datasets. We conclude that CXRs at admission do not help the predicting power of the metadata significantly by itself and contain mostly information that is also mutually present in the blood samples and other clinical factors collected at admission.
Arsenic causing gallbladder cancer disease in Bihar
Authors: Kumar Arun , Ali Mohammad , Raj Vivek , Kumari Arti , Rachamalla Mahesh , Niyogi Som , Kumar Dhruv , Sharma Ashok , Saxena Amit , Panjawani Ghanish , Jain Preeti , Vidyarthi Ajay , Kumar Navin , Kumar Mukesh , Niraj Pintoo Kumar , Rahman Md. Samiur , Bishwapriya Akhouri , Kumar Ranjit , Sakamoto Maiko , Kumar Santosh , Singh Manisha , Ghosh Ashok Kumar 
Published: March 2023

AbstractIn recent times Gallbladder cancer (GBC) incidences increased many folds in India and are being reported from arsenic hotspots identified in Bihar. The study aims to establish association between arsenic exposure and gallbladder carcinogenesis. In the present study, n = 200 were control volunteers and n = 152 confirmed gallbladder cancer cases. The studied GBC patient’s biological samples-gallbladder tissue, gallbladder stone, bile, blood and hair samples were collected for arsenic estimation. Moreover, n = 512 gallbladder cancer patients blood samples were also evaluated for the presence of arsenic to understand exposure level in the population. A significantly high arsenic concentration (p < 0.05) was detected in the blood samples with maximum concentration 389 µg/L in GBC cases in comparison to control. Similarly, in the gallbladder cancer patients, there was significantly high arsenic concentration observed in gallbladder tissue with highest concentration of 2166 µg/kg, in gallbladder stones 635 µg/kg, in bile samples 483 µg/L and in hair samples 6980 µg/kg respectively. Moreover, the n = 512 gallbladder cancer patient’s blood samples study revealed very significant arsenic concentration in the population of Bihar with maximum arsenic concentration as 746 µg/L. The raised arsenic concentration in the gallbladder cancer patients’ biological samples—gallbladder tissue, gallbladder stone, bile, blood, and hair samples was significantly very high in the arsenic exposed area. The study denotes that the gallbladder disease burden is very high in the arsenic exposed area of Bihar. The findings do provide a strong link between arsenic contamination and increased gallbladder carcinogenesis.
Design and fabrication of a Wilkinson power divider with harmonic suppression for LTE and GSM applications
Authors: Moloudian Gholamhosein , Soltani Sepehr , Bahrami Sirous , Buckley John L. , O’Flynn Brendan , Lalbakhsh Ali 
Published: March 2023

AbstractConventional Wilkinson power dividers (WPDs) can provide acceptable performance close to the nominal center frequency. However, these WPDs can also exhibit poor out-of-band performance while requiring a large footprint. In order to improve on the current state of the art, a modified microstrip WPD is proposed that exhibits a substantially improved stopband and high isolation. A lowpass filter (LPF) structure is utilized in both branches of the power divider to provide harmonic suppression. According to the obtained results, the input return loss (|S11|), output return loss (|S22|), output insertion loss (|S21|) and isolation (|S32|) are better than 34.2 dB, 26.2 dB, 3.52 dB and 31.2 dB, respectively. The proposed modified WPD has a wide 20 dB stopband (from 2.54 GHz to 13.48 GHz) and filters the second to seventh harmonics with attenuation levels of greater than 20 dB. The proposed WPD has a small size of 33.8 mm × 27 mm (0.42 λg × 0.33 λg), where λg is the guided wavelength at the operating frequency of 1.8 GHz. The WPD has been fabricated and tested and shows good agreement between simulated and measured results and the proposed design has desirable characteristics for LTE and GSM applications.