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Lattice dynamics has been widely employed to study various properties of crystalline materials, by revealing the atomic vibration rules with phonon dispersion curves. Modulating lattice‐dynamics‐related factors is an emerging trend in the design of inorganic crystalline solid‐state electrolytes (ICSSEs) with promoted ionic conductivity. Nevertheless, due to complicated interplay of these enormous factors, fundamental understanding of lattice‐dynamics‐influenced ionic transport is still limited. In this review, all related factors are classified into lattice static and dynamic ones based on their variability in ionic transport process, facilitating a methodological evaluation of their individual and interrelated influences. The previous efforts are affirmed to design ICSSEs by constructing potential energy surfaces for ionic transport based on lattice static factors (e.g., ionic arrangement, time‐scale dependent ionic concentration, and lattice softening). As for lattice dynamic factors, the possibility to quantify ionic transport activation energy and to screen the type of migration ions by phonon frequency and amplitude, respectively is validated. Specifically, it is highlighted that the optimization of specific phonon mode and the coupling of both lattice static and dynamic factors are essential to achieve superior ionic transport in ICSSEs. Finally, challenges and opportunities are pointed out in this field, which can potentially guide the future development of ICSSEs. [ABSTRACT FROM AUTHOR]

Achieving precise estimates of battery cycle life is a formidable challenge due to the nonlinear nature of battery degradation. This study explores an approach using machine learning (ML) methods to predict the cycle life of lithium‐metal‐based rechargeable batteries with high mass loading LiNi0.8Mn0.1Co0.1O2 electrode, which exhibits more complicated and electrochemical profile during battery operating conditions than typically studied LiFePO₄/graphite based rechargeable batteries. Extracting diverse features from discharge, charge, and relaxation processes, the intricacies of cell behavior without relying on specific degradation mechanisms are navigated. The best‐performing ML model, after feature selection, achieves an R2 of 0.89, showcasing the application of ML in accurately forecasting cycle life. Feature importance analysis unveils the logarithm of the minimum value of discharge capacity difference between 100 and 10 cycle (Log(|min(ΔDQ 100–10(V))|)) as the most important feature. Despite the inherent challenges, this model demonstrates a remarkable 6.6% test error on unseen data, underscoring its robustness and potential for transformative advancements in battery management systems. This study contributes to the successful application of ML in the realm of cycle life prediction for lithium‐metal‐based rechargeable batteries with practically high energy density design. [ABSTRACT FROM AUTHOR]

Silyl anions have garnered significant attention due to their synthetic abilities. However, previously reported silyl anions have been limited to either trigonal‐pyramidal or trigonal‐planar geometries, which confine them primarily as nucleophiles in substitution reactions. Herein, we report the isolation of the unprecedented T‐shaped planar silyl anion salt 2 by employment of a geometrically constrained triamido pincer ligand. Theoretical calculations disclosed that the silicon centre in 2 possesses both a lone pair of electrons and an empty 3pz orbital. In addition to nucleophilic substitution reactions with Ph3PAuCl and W(CO)6, 2 readily undergoes oxidative additions with CO2 and 2,6‐dimethylphenylisonitrile at room temperature. Furthermore, under mild conditions, compound 2 cleaves Csp2−H, Csp2−H, and H−H bonds in 1,2,4,5‐tetrafluorobenzene, an intramolecular iPr group, and dihydrogen, representing the first examples of C−H and H−H activations mediated by a silyl anion, respectively. This work unveils new reactivity of silyl anions owing to the non‐classical geometry and electronic structure. [ABSTRACT FROM AUTHOR]

Whistler‐mode hiss waves are crucial to the dynamics of Earth's radiation belts, particularly in the scattering and loss of energetic electrons and forming the slot region between the inner and outer belts. The generation of hiss waves involves multiple potential mechanisms, which are under active research. Understanding the role of hiss waves in radiation belt dynamics and their generation mechanisms requires analyzing their temporal and spatial evolutions, especially for strong hiss waves. Therefore, we developed an Imbalanced Regressive Neural Network (IR‐NN) model for predicting hiss amplitudes. This model addresses the challenge posed by the data imbalance of the hiss data set, which consists of predominantly quiet‐time background samples and fewer but significant active‐time intense hiss samples. Notably, the IR‐NN hiss model excels in predicting strong hiss waves (>100 pT). We investigate the temporal and spatial evolution of hiss wave during a geomagnetic storm on 24–27 October 2017. We show that hiss waves occur within the nominal plasmapause, and follow its dynamically evolving shape. They exhibit intensifications with 1 and 2 hr timescale similar to substorms but with a noticeable time delay. The intensifications begin near dawn and progress toward noon and afternoon. During the storm recovery phase, hiss intensifications may occur in the plume. Additionally, we observe no significant latitudinal dependence of the hiss waves within |MLAT| < 20°. In addition to describing the spatiotemporal evolution of hiss waves, this study highlights the importance of imbalanced regressive methods, given the prevalence of imbalanced data sets in space physics and other real‐world applications. Plain Language Summary: Whistler‐mode hiss waves play a crucial role in understanding the dynamics of Earth's radiation belts, particularly scattering and loss of energetic electrons and the formation of the slot region. The underlying generation mechanisms of hiss wave sources remain an active area of research, which needs to quantify the global evolution of these waves, especially powerful ones. We developed an Imbalanced Regressive Neural Network (IR‐NN) model, which excels at accurately predicting strong hiss wave activity, that is of particular interest in radiation belt studies. We analyzed the evolution of hiss waves during a geomagnetically active period in October 2017. We found that these waves predominantly occur within the plasmapause boundary and exhibit dynamics that follow the plasmapause's changes. These waves strengthen on timescales similar to those of magnetospheric substorms, with a slight delay, and move to different local times during different phases of the storm. These waves maintain uniform intensity across low to mid‐latitudes. This study underlines the importance of imbalanced regressive methods in handling imbalanced data sets, a common challenge in space physics and related physical science fields. This approach is not only significant for advancing our understanding of space weather phenomena but also has broader implications in other areas. Key Points: An imbalanced regressive neural network model of hiss amplitude developed that predicts quiet‐time background and active‐time intense wavesHiss waves are well organized inside the plasmapause and follow its dynamic shape, evolving from dawn toward later local time during a stormModeled hiss evolution correlates with chorus, supporting the hypothesis that hiss is generated by evolving chorus waves [ABSTRACT FROM AUTHOR]

Solar steam generation is a promising water purification technology due to its low‐cost and environmentally friendly applications in water purification and desalination. However, hydrophilic or hydrophobic materials alone are insufficient in achieving necessary characteristics for constructing high‐quality solar steam generators with good comprehensive properties. Herein, novel hydrophile/hydrophobe amphipathic Janus nanofibers aerogel is designed and used as a host material for preparing solar steam generators. The product consists of an internal cubic aerogel and an external layer of photothermal materials. The internal aerogel is composed of electrospun amphipathic Janus nanofibers. Owing to the unique composition and structure, the prepared solar steam generator integrates the features of high water evaporation rate (2.944 kg m−2 h−1 under 1 kW m−2 irradiation), self‐floating, salt‐resisting, and fast performance recovery after flipping. Moreover, the product also exhibits excellent properties on desalination and removal of organic pollutants. Compared with traditional hydrophilic aerogel host material, the amphipathic Janus nanofibers aerogel brings much higher water evaporation rate and salt resistance. [ABSTRACT FROM AUTHOR]

Electromagnetic Ion Cyclotron (EMIC) wave scattering has been proved to be responsible for the fast loss of both radiation belt (RB) electrons and ring current (RC) protons. However, its role in the concurrent dropout of these two co‐located populations remains to be quantified. In this work, we study the effect of EMIC wave scattering on both populations during the 27 February 2014 storm by employing the global physics‐based RAM‐SCB model. Throughout this storm event, MeV RB electrons and 100s keV RC protons experienced simultaneous dropout following the occurrence of intense EMIC waves. By implementing data‐driven initial and boundary conditions, we perform simulations for both populations through the interplay with EMIC waves and compare them against Van Allen Probes observations. The results indicate that by including EMIC wave scattering loss, especially by the He‐band EMIC waves, the model aligns closely with data for both populations. Additionally, we investigate the simulated pitch angle distributions (PADs) for both populations. Including EMIC wave scattering in our model predicts a 90° peaked PAD for electrons with stronger losses at lower pitch angles, while protons exhibit an isotropic PAD with enhanced losses at pitch angles above 40°. Furthermore, our model predicts considerable precipitation of both particle populations, predominantly confined to the afternoon to midnight sector (12 hr < MLT < 24 hr) during the storm's main phase, corresponding closely with the presence of EMIC waves. Key Points: An updated RAM‐SCB model is used to study the concurrent dropout of radiation belt (RB) electrons and ring current (RC) protons driven by EMIC wave scatteringRAM‐SCB simulations including Electromagnetic Ion Cyclotron wave scattering better capture the observed losses of both RB electrons and RC protonsSimulated pitch angle distributions (PADs) of electrons peak at 90° with more losses at lower angles; protons show isotropic PADs with enhanced losses above 40° [ABSTRACT FROM AUTHOR]

Using particle and wave measurements from the Van Allen Probes, a 2‐D Fokker‐Planck simulation model driven by the time‐integrated auroral index (AL) value is developed. Simulations for a large sample of 186 storm‐time events are conducted, demonstrating that the AL‐driven model can reproduce flux enhancement of the MeV electrons. More importantly, the relativistic electron flux enhancement is determined by the sustained strong substorm activity. Enhanced substorm activity results in increased chorus wave intensity and reduced background electron density, which creates the required condition for local electron acceleration by chorus waves to MeV energies. The appearance of higher energy electrons in radiation belts requires a higher level of cumulative AL activity after the storm commencement, which acts as a type of switch, turning on progressively higher energies for longer and more intense substorms, at critical thresholds. Plain Language Summary: The Earth's radiation belts are filled with high‐energy electrons (100s keV–10 MeV) that can damage satellites and impact the expanding human presence in space. The flux of these electrons can change by several orders of magnitude in less than a day. Thus, predicting and understanding their dynamics is crucial. We have developed a physical model driven by the integral auroral index (AL), which influences the amplitude of plasma waves and the density of the background plasma. We simulated a large sample of 186 events from 2012 to 2018 for the first time. The results show that this model not only simulates the acceleration of electrons at high energy levels but also reveals that sustained strong substorms act as a switch. High energy electrons are accelerated only when the intensity of sustained substorms exceeds a certain threshold. Key Points: An AL‐driven radiation belt model reproduces the observed MeV electron fluxes for 186 storm‐time events with good performancePost‐storm flux enhancement requires sufficient integrated substorm strength which increases wave activity and decreases plasma densityAccumulated substorm activity is shown to act as a switch, turning on progressively higher energies at certain critical thresholds [ABSTRACT FROM AUTHOR]

Magnetotail earthward‐propagating fast plasma flows provide important pathways for magnetosphere‐ionosphere coupling. This study reexamines a flow‐related red‐line diffuse‐like aurora event previously reported by Liang et al. (2011, https://doi.org/10.1029/2010ja015867), utilizing THEMIS and ground‐based auroral observations from Poker Flat. We find that time domain structures (TDSs) within the flow bursts efficiently drive electron precipitation below a few keV, aligning with predominantly red‐line auroral intensifications in this non‐substorm event. The diffuse‐like auroras sometimes coexisted with or potentially evolved from discrete forms. We forward model red‐line diffuse auroras due to TDS‐driven precipitation, employing the time‐dependent TREx‐ATM auroral transport code. The good correlation (∼0.77) between our modeled and observed red line emissions underscores that TDSs are a primary driver of the red‐line diffuse‐like auroras, though whistler‐mode wave contributions are needed to fully explain the most intense red‐line emissions. Plain Language Summary: Fast plasma flows in the magnetotail, traveling earthward at several hundred kilometers per second, transport energetic particles and magnetic flux into the inner magnetosphere. Upon braking near Earth's high magnetic flux regions, they trigger plasma instabilities and waves, leading to increased electric currents and particle precipitation in the polar regions. This precipitation, depending on its driver, results in either diffuse auroras from electron pitch‐angle scattering, or discrete auroras from field‐aligned electron acceleration and currents. Our case study highlights the important role of time‐domain structures in diffuse‐like aurora generation during flow braking. This reveals a new aspect of magnetosphere‐ionosphere coupling: the generation of diffuse auroras through electron scattering by time‐domain structures in braking flow bursts. Key Points: Predominantly red‐line auroras are linked to flow bursts, TDSs, and <1 keV electron precipitationFor the first time, red‐line diffuse‐like auroras have been forward‐modeled using TREx‐ATM with time domain structure (TDS) inputsA good correlation between forward‐modeled and observed red‐line emissions suggests that TDSs are a major driver [ABSTRACT FROM AUTHOR]

Whistler‐mode waves are commonly observed within the lunar environment, while their variations during Interplanetary (IP) shocks are not fully understood yet. In this paper, we analyze two IP shock events observed by Acceleration, Reconnection, Turbulence and Electrodynamics of the Moons Interaction with the Sun (ARTEMIS) satellites while the Moon was exposed to the solar wind. In the first event, ARTEMIS detected whistler‐mode wave intensification, accompanied by sharply increased hot electron flux and anisotropy across the shock ramp. The potential reflection or backscattering of electrons by the lunar crustal magnetic field is found to be favorable for whistler‐mode wave intensification. In the second event, a magnetic field line rotation around the shock region was observed and correlated with whistler‐mode wave intensification. The wave growth rates calculated using linear theory agree well with the observed wave spectra. Our study highlights the significance of magnetic field variations and anisotropic hot electron distributions in generating whistler‐mode waves in the lunar plasma environment following IP shock arrivals. Plain Language Summary: The surface of the Earth's Moon is frequently exposed to the incoming solar wind flow and IP shocks due to its lack of internal magnetic fields that can deflect the solar wind particles. Within the lunar environment, whistler‐mode waves, characterized by electromagnetic fluctuations with frequencies below the electron gyrofrequency, are commonly present. Interplanetary shocks that are often associated with significant disturbances in electron flux and magnetic field can potentially lead to anisotropic distributions of electrons, which are known to provide free energy source for whistler‐mode wave generation. To assess the whistler wave generation under shock conditions, we conduct an in‐depth analysis of two IP shock events. These events provide clear evidence of shock‐induced enhancements in electron pitch angle anisotropy and flux, as well as a potential rotation of magnetic field around the shock region, resulting in the intensification of whistler‐mode waves downstream of the shock. We calculated a timeseries of linear wave growth rate for the entire duration of shock events, which remarkably accounted for the observed whistler‐mode wave spectra both before and after the shock arrival. Our findings are important for understanding the associated physical process of whistler‐mode wave generation in the lunar plasma environment during IP shock events. Key Points: Two Interplanetary shock events in the lunar environment are analyzed to unveil whistler wave generation around shock regionLinear wave growth calculations show that whistler‐mode waves are generated locally due to enhanced electron anisotropy and fluxMagnetic field line connection to lunar surface is found to be important for enhancing whistler wave intensity [ABSTRACT FROM AUTHOR]

We statistically evaluate the global distribution and energy spectrum of electron precipitation at low‐Earth‐orbit, using unprecedented pitch‐angle and energy resolved data from the Electron Losses and Fields INvestigation CubeSats. Our statistical results indicate that during active conditions, the ∼63 keV electron precipitation ratio peaks at L > 6 at midnight, whereas the spatial distribution of precipitating energy flux peaks between the dawn and noon sectors. ∼1 MeV electron precipitation ratio peaks near midnight at L > ∼6 but is enhanced near dusk during active times. The energy spectrum of the precipitation ratio shows reversal points indicating energy dispersion as a function of L shell in both the slot region and at L > ∼6, consistent with hiss‐driven precipitation and current sheet scattering, respectively. Our findings provide accurate quantification of electron precipitation at various energies in a broad region of the Earth's magnetosphere, which is critical for magnetosphere‐ionosphere coupling. Plain Language Summary: Precipitation into the Earth's upper atmosphere is an important loss process of radiation belt electrons and can change the ionospheric conductance and atmospheric chemistry. Electrons can be moved into the loss cone through either wave‐particle interactions or due to special magnetic field geometries, such as current sheet scattering (CSS). To determine the relative contribution of wave‐particle interactions and CSS, it is crucial to investigate the global distribution and energy spectra of the electron precipitation rate. Previous measurements of energetic electron precipitation at low‐Earth‐orbit either had low resolution in pitch angle and energy or were contaminated by ions and penetrating particles. In this study, we used data from the twin Electron Losses and Fields INvestigation CubeSats, which do not suffer from similar deficiencies, to statistically analyze the dependence of energetic electron precipitation rates on geomagnetic activity, with high resolution in both pitch angle and energy. These findings cast new light on the physical mechanisms that determine the precipitation rate from the magnetosphere into the atmosphere and may have implications for future studies of the ionospheric conductivity and atmospheric chemistry. Key Points: A global survey of electron precipitation is performed using the pitch angle and energy resolved data from Electron Losses and Fields INvestigation CubeSatsAt ∼1 MeV, electron precipitation is strongest at L > ∼6 near midnight and is enhanced near dusk during active timesThe energy spectrum of the precipitation ratio shows reversal points indicating energy dispersion in L shells in the slot region and L > ∼6 [ABSTRACT FROM AUTHOR]

Certain forms of solar wind transients contain significant enhancements of dynamic pressure and may effectively drive magnetosphere dynamics, including substorms and storms. An integral element of such driving is the generation of a wide range of electromagnetic waves within the inner magnetosphere, either by compressionally heated plasma or by substorm plasma sheet injections. Consequently, solar wind transient impacts are traditionally associated with energetic electron scattering and losses into the atmosphere by electromagnetic waves. In this study, we show the first direct measurements of two such transient‐driven precipitation events as measured by the low‐altitude Electron Losses and Fields Investigation CubeSats. The first event demonstrates storm‐time generated electromagnetic ion cyclotron waves efficiently precipitating sub‐relativistic and relativistic electrons from >300 keV to 2 MeV at the duskside. The second event demonstrates whistler‐mode waves leading to scattering of electrons from 50 to 700 keV on the dawnside. These observations confirm the importance of solar wind transients in driving energetic electron losses and subsequent dynamics in the ionosphere. Key Points: A corotating interaction region (CIR) and interplanetary coronal mass ejection (ICME), both including interplanetary shocks, are observed resulting in relativistic electron precipitation from low‐altitude orbitDuskside precipitation after CIR impact is driven by intense electromagnetic ion cyclotron waves, showing distinct energy‐L dispersion from magnetic field distortionDawnside precipitation after ICME impact is driven by intense whistler‐mode waves resonating with electrons at high latitudes [ABSTRACT FROM AUTHOR]

It is reported that earthquakes are accompanied by electromagnetic (EM) anomalies. These anomalies are thought to be caused by earthquakes but their generation mechanism is still unclear. The piezoelectric effect has been proposed as a possible mechanism, particularly in quartz‐rich rocks. However, the EM responses to earthquakes due to such an effect have not been well understood. In this article, we study the EM signals generated by an earthquake source due to the piezoelectric effect. We develop a semi‐analytical method to simulate the EM responses to earthquake sources in a 3‐D layered model and conduct numerical simulations to investigate the characteristics of the EM fields. The results show that the piezoelectric effect in quartz‐rich rocks could be the responsible mechanism for the EM signals recorded during the earthquake. Two kinds of EM signals can be generated by the earthquake, namely, the early EM wave arriving before the seismic waves and the coseismic EM field accompanying the seismic waves. For an Mw 6.1 earthquake, the coseismic electric field is ∼0.1 μV/m and the magnetic field can only reach ∼10−5 nT. We also study the sensitivity of the coseismic EM fields to the rock conductivity. The results indicate that the coseismic EM fields are mainly affected by the conductivity of the shallow layer where the receiver is located, and if the top layer is thin, they are also affected by the conductivity of the deeper layer due to the contribution of the evanescent EM wave created at the interface. Plain Language Summary: When a quartz‐rich rock is under stress, the positive and negative charge centers of quartz crystals are shifted, resulting in a polarization, which manifests macroscopically as the EM radiation. Such a phenomenon is known as the piezoelectric effect. It is a plausible mechanism for the generation of the earthquake‐associated electromagnetic (EM) anomaly. In this paper, we propose a simple method to simulate the EM disturbances generated by an earthquake source arising from the piezoelectric effect. We also conduct numerical simulations to study the properties of the EM fields. The results show that earthquakes can produce two kinds of EM signals. One signal propagates with the speed of the EM wave in the rocks and it arrives earlier than the seismic waves. The other is the coseismic EM field that appears simultaneously with the seismic waves. Such a coseismic signal is restricted to inside of the area disturbed by the seismic wave. Based on the sensitivity analysis, we find that the coseismic EM signal is sensitive not only to the conductivity of shallow rocks, but also to that of the deep rocks. The results also indicate that the electric signals produced by the piezoelectric effect during an earthquake are observable. Key Points: A method is presented to simulate the seismo‐electromagnetic fields due to the piezoelectric effect in quartz‐rich strataAn earthquake source can generate an early electromagnetic (EM) wave and coseismic EM fields due to the piezoelectric effectNumerical results show that the piezoelectric effect is an effective mechanism to produce observable electric signals [ABSTRACT FROM AUTHOR]

Whistler mode waves in the plasmasphere and plumes drive significant losses of energetic electrons from the Earth's radiation belts into the upper atmosphere. In this study, we conducted a survey of amplitude‐dependent whistler wave properties and analyzed their associated background plasma conditions and electron fluxes in the plasmasphere and plumes. Our findings indicate that extremely large amplitude (>400 pT) whistler waves (a) tend to occur at L > 4 over the midnight‐dawn‐noon sectors and have small wave normal angles; (b) are more likely to occur during active geomagnetic conditions associated with higher fluxes of anisotropic electrons at 10 s keV energies; and (c) tend to occur at higher latitudes up to 20° with increasing amplitude. These results suggest that extremely large amplitude whistler waves in the plasmasphere and plumes could be generated locally by injected electrons during substorms and further amplified when propagating to higher latitudes. Plain Language Summary: Whistler mode waves are known as one of the primary drivers of precipitating energetic electrons from the Earth's radiation belts into the upper atmosphere. We utilize plasma wave observations from the Van Allen Probes mission and conduct a survey of whistler mode waves inside the plasmasphere and plumes, which are plasma regions surrounding the Earth and filled with high‐density cold electrons. Statistical results indicate that extremely large amplitude whistler waves are more likely to occur at large L shells (L shell is defined as the distance from magnetic field lines to the center of the Earth at the magnetic equator) in the post‐midnight sectors during active geomagnetic conditions associated with high fluxes of tens of keV electrons exhibiting anisotropic pitch angle distributions (with a flux peak in the direction that is perpendicular to the background magnetic field). These waves tend to occur at higher latitudes with increasing amplitude. Results suggest that these waves could be generated locally by injected electrons during substorm activity and may be further amplified when propagating to higher latitudes. Key Points: Van Allen Probes wave measurements are used to statistically analyze the whistler waves in the plasmasphere or plume regionsExtremely large amplitude (>400 pT) whistler waves tend to occur at L shells >4 over 0–18 hr MLT with small wave normal angles (<10°)Larger amplitude whistler waves are observed during more active substorm activities and higher magnetic latitudes [ABSTRACT FROM AUTHOR]

"Anode‐free" solid‐state battery concepts are explored extensively as they promise a higher energy density with less material consumption and simple anode processing. Here, the homogeneous and uniform electrochemical deposition of alkali metal at the interface between current collector and solid electrolyte plays the central role to form a metal anode within the first cycle. While the cathodic deposition of lithium has been studied intensively, knowledge on sodium deposition is scarce. In this work, dense and uniform sodium layers of several microns thickness are deposited at the Cu|Na3.4Zr2Si2.4P0.6O12 interface with high reproducibility. At current densities of ≈1 mA∙cm−2, relatively uniform coverage is achieved underneath the current collector, as shown by electrochemical impedance spectroscopy and 3D confocal microscopy. In contrast, only slight variations of the coverage are observed at different stack pressures. Early stages of the sodium metal growth are analyzed by in situ transmission electron microscopy revealing oriented growth of sodium. The results demonstrate that reservoir‐free ("anode‐free") sodium‐based batteries are feasible and may stimulate further research efforts in sodium‐based solid‐state batteries. [ABSTRACT FROM AUTHOR]

Glass sagging is a subsequent process to the CVD process used for large‐size and high‐purity silica glass synthesis. Physical phenomena taking place in this process are complicated which need an in‐depth understanding for better control. In this paper, a comprehensive study is conducted for the sagging process using a level‐set and enthalpy‐porosity coupled model. With this model, the deforming behavior of glass ingot and evolution of OH uniformly distributed region are well predicted. Then, two performance indices (the effective yield rate and maximum extension radius of OH uniformly distributed region) are proposed based on different applications, and important factors, including geometrical parameters (the ingot initial length, crucible diameter and pedestal height) and operating parameter (the heater power allocation scheme), are explored for their effects on the two indices. The orthogonal test design method is adopted to further determine the collective effects of the four factors. According to the range analysis results, the initial ingot length has the greatest effect, while the crucible diameter has the least effect on the effective yield rate; and for the maximum extension radius, the crucible diameter becomes the major factor, while the pedestal height is the most insensitive factor. The corresponding optimal schemes are proposed for the two indices finally, which are believed to provide useful guidance for improving the sagging process. [ABSTRACT FROM AUTHOR]

Energetic electron losses by pitch‐angle scattering and precipitation to the atmosphere from the radiation belts are controlled, to a great extent, by resonant wave particle interactions with whistler‐mode waves. The efficacy of such precipitation is primarily modulated by wave intensity, although its relative importance, compared to other wave and plasma parameters, remains unclear. Precipitation spectra from the low‐altitude, polar‐orbiting ELFIN mission have previously been demonstrated to be consistent with energetic precipitation modeling derived from empirical models of field‐aligned wave power across a wide swath of local‐time sectors. However, such modeling could not explain the intense, relativistic electron precipitation observed on the nightside. Therefore, this study aims to additionally consider the contributions of three modifications—wave obliquity, frequency spectrum, and local plasma density—to explain this discrepancy on the nightside. By incorporating these effects into both test particle simulations and quasi‐linear diffusion modeling, we find that realistic implementations of each individual modification result in only slight changes to the electron precipitation spectrum. However, these modifications, when combined, enable more accurate modeling of ELFIN‐observed spectra. In particular, a significant reduction in plasma density enables lower frequency waves, oblique, or even quasi field‐aligned waves to resonate with near ∼1 MeV electrons closer to the equator. We demonstrate that the levels of modification required to accurately reproduce the nightside spectra of whistler‐mode wave‐driven relativistic electron precipitation match empirical expectations and should therefore be included in future radiation belt modeling. Plain Language Summary: Whistler‐mode waves are a type of electromagnetic wave that mediate electron dynamics in Earth's radiation belts and are simultaneously important for energizing electrons and driving loss mechanisms. Most radiation belt models today do not adequately capture the effects of these waves on relativistic electrons, which are important to study because these energetic electrons are often called "Killer Electrons" for their ability to degrade spacecraft electronics. Additionally, when lost into Earth's atmosphere, these electrons can also change atmospheric chemistry and ionospheric properties, making them important input parameters for atmospheric, ionospheric, and magnetospheric modeling. This study uses two different modeling methods to determine which properties of whistler‐mode waves are most important for accurately capturing these wave‐particle interactions on the nightside, where plasma interactions are more dynamic. The results agree well with statistical results from the Electron Losses and Fields INvestigation mission, allowing us to fully explain the mechanisms behind whistler‐mode wave‐driven electron losses on the nightside. Key Points: Comparing Electron Losses and Fields INvestigation data with test particle and quasi‐linear simulations, we investigate whistler‐driven electron precipitation on the nightsideA reduction in background plasma density is key to enabling whistler‐mode waves to efficiently scatter electrons up to 1 MeVA decreasing wave frequency as a function of latitude and wave obliquity are both needed for explaining observed nightside electron losses [ABSTRACT FROM AUTHOR]

The full spatiotemporal distribution of chorus wave‐induced relativistic electron microburst is modeled for chorus waves originated from different L shells and MLTs, based on the newly developed numerical precipitation model (Kang et al., 2022, https://doi.org/10.1029/2022gl100841). The wave‐particle interaction process that induces each microburst is analyzed in detail, and its relation to the chorus wave propagation effects is explained. The global distribution of maximum precipitation fluxes and scale sizes of relativistic microbursts is then obtained by modeling chorus waves at different L‐shells and local times. The characteristics of dawn and midnight sector microbursts have little difference, but the noon sector has much larger maximum flux and much smaller full width at half maximum, which may be due to dayside's low electron flux in the Landau resonance range. This suggests the controlling effect of keV electrons on the MeV electron precipitation intensity and properties and the overall relativistic electron loss in the outer radiation belt. Key Points: Based on statistical chorus and electron distributions, the global distribution of relativistic microburst scale size is modeledDawn and night sectors are fairly similar in precipitation scale size, and dayside has larger maximum precipitation flux and smaller widthThe keV electron populations on dayside play a critical role on the MeV electron precipitation intensity and the microburst scale size [ABSTRACT FROM AUTHOR]

The present study uncovers the fine structures of magnetosonic waves by investigating the EFW waveforms measured by Van Allen Probes. We show that each harmonic of the magnetosonic wave may consist of a series of elementary rising‐tone emissions, implying a nonlinear mechanism for the wave generation. By investigating an elementary rising‐tone magnetosonic wave that spans a wide frequency range, we show that the frequency sweep rate is likely proportional to the wave frequency. We studied compound rising‐tone magnetosonic waves, and found that they typically consist of multiple harmonics in the source region, and may gradually become continuous in frequency as they propagate away from source. Both elementary and compound rising‐tone magnetosonic waves last for ∼1 min which is close to the bounce period of the ring proton distribution, but their relation is not fully understood. Plain Language Summary: Naturally occurring magnetosonic waves are a kind of electromagnetic wave in the Earth's magnetized space. Their frequency spectra typically exhibit a harmonic structure. Sometimes they exhibit a rising‐tone feature, that is, the wave starts at a low pitch and gradually increases its frequency to a high pitch. Using the high‐resolution data measured by Van Allen Probe satellites, the present study uncovers that each harmonic of a magnetosonic wave may have a fine structure: they consist of a series of elementary rising‐tone emissions. The traditionally known rising‐tone magnetosonic waves consist of multiple harmonics, and we name them "compound rising‐tone magnetosonic waves". The compound rising‐tone waves may gradually become continuous in spectrum as they propagate away from source. These findings give new insights to the generation of magnetosonic waves and their impact on space environment. Key Points: Each harmonic of a magnetosonic wave may consist of a series of elementary rising‐tone emissionsThe frequency sweep rate of elementary magnetosonic waves is likely proportional to the frequencyCompound rising‐tone magnetosonic waves consist of harmonics at the source, and gradually develop a continuous spectrum during propagation [ABSTRACT FROM AUTHOR]

C–C chemokine receptor 5 (CCR5) plays a crucial role in the regulation of immune cell activation and migration as well as the progression of many cancers. We performed an in silico analysis using public data resources and found that the lung cancer patients with higher CCR5 expression had a notably better overall survival than those with lower CCR5 expression patients and CCR5 expression level is positive correlated with the infiltration of immune cells, such as B, CD8+ T and CD4+ T cells, in both lung adenocarcinoma and lung squamous cell cancer. In the present study, we investigated the association between the promoter polymorphism of CCR5 and nonsmall cell lung cancer (NSCLC). A case‒control study of 449 NSCLC patients and 516 controls of Chinese Han population was conducted, along with polymorphism detection using a sequencing method. A dual‐luciferase reporter assay system was used to analyse the transcriptional activity of CCR5 promoter variations. Our results showed that the frequency of rs1799987‐AA was significantly higher in the NSCLC group than in the controls in recessive model (p =.007, OR = 1.66 95% confidence interval [CI]: 1.14–2.40, adjusted by sex and age); the G allele showed a significant associated with NSCLC in dominant model (p =.003, OR = 1.64, 95%CI: 1.18–2.28, adjusted by sex and age). Compared with haplotype H1 rs2227010–rs2734648–rs1799987–rs1799988–rs1800023–rs1800024: A‐T‐G‐T‐G‐C, haplotype H5: A‐G‐G‐T‐G‐C increased the risk of NSCLC by over 10‐fold (p <.0001, OR = 16.09, 95%CI: 5.37–48.20, adjusted by sex and age) and notably depressed the transcriptional activity of the CCR5 promoter in 293T, A549, H1299 and HeLa cells. In conclusion, CCR5 promoter polymorphisms are significantly associated with NSCLC by affecting the transcriptional activity of the CCR5 promoter. [ABSTRACT FROM AUTHOR]

Magnetopause shadowing (MPS) effect could drive a concurrent dropout of radiation belt electrons and ring current protons. However, its relative role in the dropout of both plasma populations has not been well quantified. In this work, we study the simultaneous dropout of MeV electrons and 100s keV protons during an intense geomagnetic storm in May 2017. A radial diffusion model with an event‐specific last closed drift shell is used to simulate the MPS loss of both populations. The model well captures the fast shadowing loss of both populations at L* > 4.6, while the loss at L* < 4.6, possibly due to the electromagnetic ion cyclotron wave scattering, is not captured. The observed butterfly pitch angle distributions of electron fluxes in the initial loss phase are well reproduced by the model. The initial proton losses at low pitch angles are underestimated, potentially also contributed by other mechanisms such as field line curvature scattering. Plain Language Summary: Magnetopause shadowing, due to the solar wind compression of the magnetopause combined with outward radial diffusion driven by ultra low frequency waves, is known to be one of the major loss mechanisms for both radiation belt electrons and ring current protons. However, the role of MPS in driving the simultaneous dropout of both populations has not been well quantified. In this study, for the first time, we quantitatively model the fast shadowing loss of radiation belt electrons and ring current protons during a geomagnetic storm event using a radial diffusion model with event‐specific inputs. The results indicate that MPS can efficiently capture the concurrent fast depletion of both populations at high L*. Key Points: A radial diffusion model with event‐specific last closed drift shell is used to simulate the concurrent dropout of electrons and protons due to magnetopause shadowingThe model captures the fast shadowing loss of both populations at high L* but not the loss at low L* possibly from electromagnetic ion cyclotron wave scatteringThe model reproduces the butterfly PAD of electrons in the initial loss phase but underestimates the loss of protons at low pitch angles [ABSTRACT FROM AUTHOR]

We investigate the response of outer radiation belt electron fluxes to different solar wind and geomagnetic indices using an interpretable machine learning method. We reconstruct the electron flux variation during 19 enhancement and 7 depletion events and demonstrate the feature attribution analysis called SHAP (SHapley Additive exPlanations) on the superposed epoch results for the first time. We find that the intensity and duration of the substorm sequence following an initial dropout determine the overall enhancement or depletion of electron fluxes, while the solar wind pressure drives the initial dropout in both types of events. Further statistical results from a data set with 71 events confirm this and show a significant correlation between the resulting flux levels and the average AL index, indicating that the observed "depletion" event can be more accurately described as a "non‐enhancement" event. Our novel SHAP‐Enhanced Superposed Epoch Analysis (SHESEA) method can offer insight in various physical systems. Plain Language Summary: This study examines the responses of relativistic electrons in Earth's radiation belt to various solar wind and geomagnetic disturbances, identifying key influencing factors. We first adopt an explainable machine learning method to understand the importance of different features during 19 enhancement and 7 depletion events. Our results directly reveal that an increase in solar wind dynamic pressure contributes to a sudden decrease in electron fluxes. Additionally, we find that the strength and duration of subsequent substorms determine whether the electron flux increases or decreases. Guided by the importance of these features as determined by our machine learning model, we carry out a statistical analysis, showing a significant correlation between the flux level and the average AL index. Our method offers advantages over traditional superposed epoch analysis since it directly shows the determining factors. Key Points: We use a machine learning feature attribution method to identify key drivers in radiation belt enhancement and depletion eventsThe electron flux depletion, loss, or enhancement is driven by the competition between solar wind Psw and cumulative strength of substormsThe average AL index following the pressure maximum has a significant correlation with the resulting flux level [ABSTRACT FROM AUTHOR]

Low temperature thermal treatment (LTTT) is a technology that can enhance aqueous‐phase degradation reactions for organic constituents in groundwater. Understanding heat transfer in groundwater is important for the design of LTTT applications. In this study, the effect of permeability heterogeneity on temperature distributions during and after the application of heat was investigated by numerical modeling. An enhanced reaction zone was determined for the hydrolysis of 1,1,1‐trichloroethane (1,1,1‐TCA) using an average half‐life considering the temperature history during and after heating. For hydrolysis reactions, the average half‐life could be reduced substantially by reaching a high temperature for a short period of time because their reaction rates increase exponentially with increased temperatures. Results showed that the enhanced reaction zone was shifted downstream of the heater well zone at high groundwater velocities. This suggests that heaters should be shifted upstream of the target treatment zone to fully utilize the applied heat. In addition, permeability heterogeneity leads to greater macroscopic dispersion at higher velocities. This resulted in higher spreading of heat and faster heat dissipation in the simulations with a heterogeneous permeability condition compared with a homogenous permeability condition. As a result, the enhanced reaction zone was smaller in simulations with higher levels of permeability heterogeneity at a mean velocity of 0.3 m/day. [ABSTRACT FROM AUTHOR]

In the inner magnetosphere, fast magnetosonic waves (MS waves) are known to resonantly interact with ring current protons, causing these protons to gain energy preferentially in the direction perpendicular to the background magnetic field. An anisotropic distribution of enhanced ring current protons is a necessary condition to excite electromagnetic ion cyclotron (EMIC) waves which are known to facilitate a rapid depletion of ultra‐relativistic electrons in the outer radiation belt. So, when a simultaneous observation of high‐frequency EMIC (HFEMIC) waves, anisotropic low‐energy protons, and MS waves was first reported, a chain of energy flow from MS waves to HFEMIC waves through proton heating was naturally proposed. In this study, we carry out a statistical analysis using Van Allen Probes data to provide deeper insights into this energy pathway. Our results show that the occurrence of HFEMIC waves exhibits good correlation with the enhanced flux and anisotropy of low‐energy protons, but the correlation between the low‐energy protons and the concurrent MS waves is rather poor. The latter result is given support by quasilinear diffusion analysis, indicating negligible momentum diffusion rates at sub‐keV energies, unless MS wave frequency gets very close to the proton cyclotron frequency (which constitutes only a small number of the cases). The fact that the first chain of the coupling is statistically inconclusive calls for an alternative explanation for the major source of the low‐energy anisotropic proton population in the inner magnetosphere. Key Points: Energy coupling from magnetosonic to high‐frequency electromagnetic ion cyclotron (EMIC) waves through low‐energy proton heating is investigated using correlation analysisHigh‐frequency EMIC wave occurrence correlates well with large anisotropy of 10–100 eV protons, required for the wave generationThe correlation between low‐energy protons and MS waves is rather poor, calling for alternative explanation for the origin of these protons [ABSTRACT FROM AUTHOR]

The development of reliable and affordable all‐solid‐state sodium metal batteries (ASS‐SMBs) requires suitable solid‐state electrolytes with cost‐efficient processing and stabilized electrode/electrolyte interfaces. Here, an integrated porous/dense/porous Na5YSi4O12 (NYS) trilayered scaffold is designed and fabricated by tape casting using aqueous slurries. In this template‐based NYS scaffold, the dense layer in the middle serves as a separator and the porous layers on both sides accommodate the active materials with their volume changes during the charge/discharge processes, increasing the contact area and thus enhancing the utilization rate and homogenizing the current distribution. The Na/NYS/Na symmetric cells with the Pb‐coated NYS scaffold exhibit significantly reduced interfacial impedance and superior critical current density of up to 3.0 mA cm−2 against Na metal owing to enhanced wettability. Furthermore, the assembled Na/NYS/S full cells operated without external pressure at room temperature showed a high initial discharge capacity of 970 mAh g−1 and good cycling stability with a capacity of 600 mAh g−1 after 150 cycles (based on the mass of sulfur). This approach paves the way for the realization of economical and practical ASS‐SMBs from the perspective of ceramic manufacturing. [ABSTRACT FROM AUTHOR]

Recently, all‐solid‐state sodium batteries (Na‐ASSBs) have received increased interest owing to their high safety and potential of high energy density. The potential of Na‐ASSBs based on sodium superionic conductor (NASICON)‐structured Na3V2(PO4)3(Na3VP) cathodes have been proven by their high capacity and a long cycling stability closely related to the microstructural evolution. However, the detailed kinetics of the electrochemical processes in the cathodes is still unclear. In this work, the sodiation/desodiation process of Na3VP is first investigated using in situ high‐resolution transmission electron microscopy (HRTEM). The intermediate Na2V2(PO4)3 (Na2VP) phase with the P21/c space group, which would be inhibited by constant electron beam irradiation, is observed at the atomic scale. With the calculated volume change and the electrode–electrolyte interface after cycling, it can be concluded that the Na2VP phase reduces the lattice mismatch between Na3VP and NaV2(PO4)3 (NaVP), preventing structural collapse. Based on the density functional theory calculation (DFT), the Na+ ion migrates more rapidly in the Na2VP structure, which facilitates the desodiation and sodiation processes. The formation of Na2VP phase lowers the formation energy of NaVP. This study demonstrates the dynamic evolution of the Na3VP structure, paving the way for an in‐depth understanding of electrode materials for energy‐storage applications. [ABSTRACT FROM AUTHOR]

While the reduction in anthropogenic emissions due to Coronavirus disease 2019 (COVID‐19) lockdown in China and its impact on air quality have been reported extensively, its impact on ambient carbon dioxide (CO2) concentrations is still yet to be assessed. In this study, the impact of emission reductions on spatiotemporal changes of CO2 concentrations during the COVID‐19 pandemic was quantified in the Yangtze River Delta region (YRD), using high‐resolution dynamic emission inventory and the Weather Research and Forecasting model coupled with the Vegetation Photosynthesis and Respiration Model (WRF‐VPRM). The simulated CO2 concentrations from dynamic emission inventory shows a better agreement with surface observations compared with the Open‐source Data Inventory for Anthropogenic CO2 and Emission Database for Global Atmospheric Research emission, providing confidence in the quantification of CO2 concentrations variations. Our results show that emission reductions during the COVID‐19 pandemic lead to a CO2 decrease by 4.6 ppmv (−1.1%) in Shanghai and 3.1 ppmv (−0.7%) in YRD region. For the column‐averaged CO2 concentrations (denoted as XCO2), it also decreases by 0.20 ppmv (−0.05%) in Shanghai and 0.15 ppmv (−0.04%) in YRD region. Furthermore, emission reductions from transportation and industry are major contributors to the decline in CO2 concentrations at the near surface, accounting for 45.8% (41.1%) and 34.9% (41.0%) in Shanghai (YRD). Our study deepens the understanding of the response of CO2 concentrations to different sectors, which is helpful for emission management and climate adaption policies. Plain Language Summary: Carbon dioxide (CO2) is the most important greenhouse gas in the atmosphere and has a profound impact on global climate change. It kept increasing over the last decades. Although previous studies have investigated the sources and sinks of air pollutants, the variations of CO2 concentrations at regional to national scales remains poorly understood owing to a lack of long‐term observations and limited modeling studies. High‐resolution CO2 emission inventory is in high demand in accurate CO2 simulations. This work integrates a high‐resolution dynamic emission inventory with WRF‐VPRM model to quantify the influence of reduced emissions from different sectors on the spatiotemporal changes of CO2 concentrations during the COVID‐19 pandemic. This modeling system can help to understand the response of CO2 concentrations to emissions and serves as a basis for atmospheric inversion of CO2 emissions. Key Points: High‐resolution CO2 dynamic emission inventory greatly improves CO2 simulations compared with Open‐source Data Inventory for Anthropogenic CO2 and Emission Database for Global Atmospheric ResearchAnthropogenic emission reductions cause CO2 concentrations decrease by 4.6 (3.1) ppmv in Shanghai (Yangtze River Delta) during the COVID‐19 pandemicIndustrial and transportation emissions mainly dominate the reduction in CO2 concentrations at the near surface and vertical altitude [ABSTRACT FROM AUTHOR]

Plasmasphere plays an important role in the magnetospheric physics, defining many important inputs to the ionosphere from the middle to the auroral latitudes. Among them are electron thermal heat fluxes resulting from the Coulomb interaction of superthermal electrons (SE) and cold plasmaspheric electrons. These fluxes define the electron temperature at the upper ionospheric altitudes and are the input to the global ionospheric modeling networks. As was previously found from the calculation of lower energy SE and thermal heat fluxes, the knowledge of field‐aligned cold plasma distribution in the plasmasphere is a very sensitive parameter that introduces the most uncertainties in the calculation of these values. To verify the previously used SuperThermal Electron Transport code assumptions regarding plasmaspheric field‐aligned density structure ∼[B(s)/Bo]a, we used the latest version of 3D plasmaspheric model developed by Pierrard, Botek, and Darrouzet (2021, https://doi.org/10.3389/fspas.2021.681401). Such an assumption is found to be very reasonable in the calculations of electron thermal heat fluxes entering upper ionospheric altitudes and the associated electron temperature formation for the two selected dayside and nightside electron precipitation events driven by whistler‐mode wave activity. Key Points: The role of plasmaspheric field‐aligned density structure in the formation of electron thermal heat fluxesSuperThermal Electron Transport (STET) simulations of thermal heat fluxes using physics‐based 3D dynamic Belgian SWIFF Plasmasphere Model (BSPM)The BSPM simulation confirms the plasmaspheric field‐aligned density structure used in STET code and supports the heat flux calculations [ABSTRACT FROM AUTHOR]

Whistler‐mode chorus waves play an essential role in the acceleration and loss of energetic electrons in the Earth's inner magnetosphere, with the more intense waves producing the most dramatic effects. However, it is challenging to predict the amplitude of strong chorus waves due to the imbalanced nature of the data set, that is, there are many more non‐chorus data points than strong chorus waves. Thus, traditional models usually underestimate chorus wave amplitudes significantly during active times. Using an imbalanced regressive (IR) method, we develop a neural network model of lower‐band (LB) chorus waves using 7‐year observations from the EMFISIS instrument onboard Van Allen Probes. The feature selection process suggests that the auroral electrojet index alone captures most of the variations of chorus waves. The large amplitude of strong chorus waves can be predicted for the first time. Furthermore, our model shows that the equatorial LB chorus's spatiotemporal evolution is similar to the drift path of substorm‐injected electrons. We also show that the chorus waves have a peak amplitude at the equator in the source MLT near midnight, but toward noon, there is a local minimum in amplitude at the equator with two off‐equator amplitude peaks in both hemispheres, likely caused by the bifurcated drift paths of substorm injections on the dayside. The IR‐based chorus model will improve radiation belt prediction by providing chorus wave distributions, especially storm‐time strong chorus. Since data imbalance is ubiquitous and inherent in space physics and other physical systems, imbalanced regressive methods deserve more attention in space physics. Plain Language Summary: Whistler‐mode chorus waves are essential in accelerating radiation belt electrons. However, predicting the amplitude of strong chorus waves is difficult because of their imbalanced nature. In other words, there are many more observations of no‐chorus waves than strong chorus waves. A consequence is that these no‐chorus wave data dominate traditional models, so these models usually predict values that are too small for strong waves. Using an imbalanced regressive method, we developed a machine learning (ML) model of lower‐band chorus wave amplitude. For the first time, the ML‐chorus model can predict the amplitude of strong chorus waves. The ML‐chorus model shows the evolution of the chorus wave at the equator, similar to the drift path of injected electrons, which brings electron anisotropy that generates chorus waves. The ML‐chorus model shows that the chorus waves are stronger at the equator near midnight, the source region of plasma injection. Away from midnight, the chorus waves have an equatorial minimum instead. Our chorus model will improve the forecast of the radiation belt environment by providing chorus wave distributions, especially large‐amplitude strong chorus during geomagnetic storms. Because data imbalance is commonly seen in space physics and other physical systems, imbalanced regressive methods require more attention. Key Points: A neural network model of lower‐band chorus wave amplitude is developed using imbalanced regressionFor the first time, a chorus model can predict the large amplitude of strong chorus wavesChorus' evolution is consistent with electron injection drift paths, peak equatorial amplitude near midnight, and off‐equator peaks at noon [ABSTRACT FROM AUTHOR]

Decades lasting research on the pulsating aurora suggested that this phenomenon forms as result of interactions between the magnetospheric keVs electrons and whistler‐mode chorus waves. Arase satellite observation reported the direct evidence for this process confirming in situ measurement of highly correlated precipitated electrons and chorus wave activity. This paper presents the theoretical analysis of this observational event based on the SuperThermal Electron Transport (STET) code that simulates the highly dynamic environment of measured waves and particle data. Specifically, the STET code simulated results confirms the delicate loss‐cone observation results of this mission and further reveals the broader energy range of precipitated electron fluxes that was not measurable by Arase satellite. Key Points: Applying Arase satellite observations for the kinetic simulation of pulsating auroraSuperThermal Electron Transport (STET) code simulated precipitated electron fluxes driven by whistler‐mode chorus wavesRevealing hidden pulsating aurora dynamics in Arase observation using STET code [ABSTRACT FROM AUTHOR]

The cold ions, which are generally "invisible" to most instruments, have strong impacts on plasma wave and magnetic reconnection. Under particular situations, these cold ions could be accelerated and thus become detectable. In this study, we statistically investigated the properties of background cold ions based on Van Allen Probe observations. The cold ions could often be detected near the dusk sector, and a clear dawn‐dusk asymmetry is observed for all ion species with higher density at the dusk side, showing plasmaspheric plume‐like structures. Similar to the cold electrons, cold proton ions show a clear boundary of plasmapause with its location moving toward the Earth as geomagnetic activity increases. Furthermore, the percentage of oxygen increases, and the percentage of protons decreases as geomagnetic activity increases whereas the helium composition is generally small. Our results provide important information on ion compositions for the understanding of cold‐plasma dynamics in the inner magnetosphere. Plain Language Summary: The cold ions play an important role in magnetospheric dynamics since they are the source of thermal plasma and they could affect the magnetic reconnection and wave generation. However, the main population of cold ions is difficult to measure due to their low energy and spacecraft charging. Magnetospheric convection and/or induced electric field could increase the energy of cold ions sufficiently above the spacecraft potential so that these ions can be detected by particle instrument. In this study, we investigate the properties of background cold ions when the total ion density is comparable to the background electron density. We found the cold ion could often be measured near the dusk sector and a clear dawn‐dusk asymmetry is observed for all ion species. Similar to the cold electrons, cold protons also show a clear boundary of plasmapause with its location moving toward the Earth as geomagnetic activity increases. Furthermore, the percentage of oxygen ions increases, and the percentage of protons decreases as geomagnetic activity increases whereas the percentage of helium ions is generally small. Our results provide important information on cold ion density for the study of wave‐particle interactions and magnetic reconnection in the Earth's magnetosphere. Key Points: We statistically analyzed the cold ion densities and compositions based on Van Allen Probe observationsThe density above L = 3 decreases as geomagnetic activity increases for all three ion species, suggesting the shrinking of plasmasphereThe percentage of cold oxygen ions increases as geomagnetic activity increases [ABSTRACT FROM AUTHOR]

A new approach to the fast optimization of crystal electric field (CEF) parameters to fit experimental data is presented. This approach is implemented in a lightweight Python‐based program, CrysFieldExplorer. The main novelty of the method is the development of a unique loss function, referred to as the spectrum characteristic loss (LSpectrum), which is based on the characteristic polynomial of the Hamiltonian matrix. Particle swarm optimization and a covariance matrix adaptation evolution strategy are used to find the minimum of the total loss function. It is demonstrated that CrysFieldExplorer can perform direct fitting of CEF parameters to any experimental data such as a neutron spectrum, susceptibility or magnetization measurements etc. CrysFieldExplorer can handle a large number of non‐zero CEF parameters and reveal multiple local and global minimum solutions. Crystal field theory, the loss function, and the implementation and limitations of the program are discussed within the context of two examples. [ABSTRACT FROM AUTHOR]

Background: The economic burden of respiratory syncytial virus (RSV) infection and its impact on health‐related quality of life (HRQoL) are not well‐understood in China. This study assessed total cost and HRQoL for children hospitalized with RSV in Central China. Methods: Based on a prospective case series study in Henan Province in 2020–2021, inpatients aged 0–59 months with RSV‐related acute respiratory infections (ARIs) were included into analysis. Total cost included direct medical cost (sum of medical cost before and during hospitalization), direct non‐medical cost, and indirect cost. Direct medical cost during hospitalization data were extracted from the hospital information system. Other costs and HRQoL status were obtained from a telephone survey conducted in the caregivers of the enrolled patients. Results: Among 261 RSV‐infected inpatients, caregivers of 170 non‐severe cases (65.1%, 170/261) were successfully interviewed. Direct medical cost per episode was 1055.3 US dollars (US$) (95% CI: 998.2–1112.5 US$). Direct non‐medical cost and indirect cost per episode were 83.6 US$ (95% CI: 77.5–89.7 US$) and 162.4 US$ (95% CI: 127.9–197.0 US$), respectively. Quality adjusted life years (QALY) loss for non‐severe RSV hospitalization was 8.9 × 10−3 (95% CI: 7.9 × 10−3–9.9 × 10−3). The majority of inpatients were <1 year of age comprising significantly higher cost and more QALY loss than older children. Conclusions: RSV‐associated hospitalization poses high economic and health burden in Central China particularly for children <1 year old. Our findings are crucial for determining the priority of interventions and allocation of health resources. [ABSTRACT FROM AUTHOR]

Introduction: Myocardial hypoxia is an important factor causing myocardial infarction (MI). Interestingly, many unknown factors in the molecular mechanism of MI remain unclear. Our study explored the role of lncRNA growth arrest‐specific 5 (GAS5) in cell injury under hypoxia. Methods: AS5 expression was assessed in MI and human cardiomyocytes under hypoxia through RT‐qPCR assay. Methyl thiazolyl tetrazolium assay, flow cytometry assay, and transwell assay was carried out for cell viability, cell apoptosis, cell migration, and invasion, respectively. The regulatory target of GAS5 was explored through a dual‐luciferase reporter assay. Results: Our findings indicated that the upregulation of GAS5 was related to hypoxia. Downregulation of GAS5 expression could decrease hypoxia‐induced cell apoptosis and increase cell migration and invasion. Moreover, GAS 5 targeted miR‐21, which regulated the phosphatase and tension homology deleted on chromosome ten gene (PTEN) expression. Furthermore, the knockdown of miR‐21 eliminated the effect of GAS5 silencing on cell injury. Conclusion: These results indicated that lncRNA GAS5 silencing decreased cardiomyocyte injury by hypoxia‐induced through regulating miR‐21/PTEN. [ABSTRACT FROM AUTHOR]

Electromagnetic ion cyclotron (EMIC) waves play an important role in relativistic electron dynamics. In this study, we find a large‐amplitude EMIC wave event induced by the prompt enhancement of solar wind dynamic pressure on 6 November 2015. These large‐amplitude EMIC waves are simultaneously observed by multiple satellites over 13 hr in magnetic local time (MLT) with a peak amplitude of ∼4 nT. Satellites at different locations observed different bands of EMIC waves, implying the importance of background plasma density in EMIC wave generation. Electron pitch angle distributions show obvious responses to EMIC wave activities. During EMIC wave appearance, the fluxes of relativistic electrons with pitch angles around 90° increase, while the fluxes of field‐aligned relativistic electrons decrease, showing distinct "bite‐out" signatures, indicating pitch angle scattering by EMIC waves, and the scattering efficiency depends on the amplitude and polarization of EMIC waves. Combined with phase space density profiles of electrons that are nearly constant at energies below the minimum resonant energy of electrons (Emin) but show dropout at energies above the Emin after EMIC wave activities, we conclude that large‐amplitude EMIC waves can cause rapid electron loss down to several hundred keV. In addition, simultaneous observations of hundreds of keV electron precipitation and tens of keV proton precipitation by Polar Operational Environmental Satellites near the region where EMIC waves are observed, provide direct evidence of relativistic electron precipitation caused by the large‐amplitude EMIC waves, ultimately driven by solar wind structures. Plain Language Summary: Solar wind dynamic pressure enhancement leads to the compression of the magnetopause, which could induce various plasma waves. Our study shows the prompt appearance of large‐amplitude EMIC waves after the impact of solar wind dynamic pressure enhancement. The excited EMIC waves are observed simultaneously by multiple satellites over 13 hr in magnetic local time. Different bands of EMIC waves are observed by satellites at different locations, which may be related to the background plasma density. During EMIC wave appearance, the fluxes of relativistic electrons with pitch angles around 90° increase, while the fluxes of field‐aligned relativistic electrons decrease, showing distinct "bite‐out" signatures, and the scattering efficiency depends on the amplitude and polarization of EMIC waves. Besides, phase space density profiles of electrons show that PSDs are nearly constant at energies below the Emin but show evident dropout at energies above the Emin, demonstrating that large‐amplitude EMIC waves can cause a rapid loss of electrons down to several hundred keV. In addition, solid evidence of strong relativistic electron precipitation driven by EMIC waves is provided by the low‐altitude Polar Operational Environmental Satellites near the region where EMIC waves are observed, which shows the simultaneous observations of hundreds of keV electron precipitation and tens of keV proton precipitation. Key Points: Multi‐point spacecraft observations indicate a close correlation between solar wind dynamic pressure enhancement and Electromagnetic ion cyclotron (EMIC) wave appearanceEMIC waves have a broad magnetic local time (MLT) coverage (∼13 hr) and are associated with anisotropic electron fluxesCompression‐induced EMIC waves cause phase space density dropout of sub‐MeV to MeV electrons and subsequent precipitation to the atmosphere [ABSTRACT FROM AUTHOR]

Benefitting from the maximum atom utilization efficiency, special size quantum effects and tailored active sites, single‐atom catalysts (SACs) have been promising candidates for bifunctional catalysts toward water splitting. Besides, due to the unique structure and properties, some amorphous materials have been found to possess better performance than their crystalline counterparts in electrocatalytic water splitting. Herein, by combining the advantages of ruthenium (Ru) single atoms and amorphous substrates, amorphous molybdenum‐based oxide stabilized single‐atomic‐site Ru (Ru SAs‐MoO3−x/NF) catalysts are conceived as a self‐supported electrode. By virtue of the large surface area, enhanced intrinsic activity and fast reaction kinetics, the as‐prepared Ru SAs‐MoO3−x/NF electrode effectively drives both oxygen evolution reaction (209 mV @ 10 mA cm−2) and hydrogen evolution reaction (36 mV @ 10 mA cm−2) in alkaline media. Impressively, the assembled electrolyzer merely requires an ultralow cell voltage of 1.487 V to deliver the current density of 10 mA cm−2. Furthermore, such an electrode also exhibits a great application potential in alkaline seawater electrolysis, achieving a current density of 100 mA cm−2 at a low cell voltage of 1.759 V. In addition, Ru SAs‐MoO3−x/NF only has very small current density decay in the long‐term constant current water splitting test. [ABSTRACT FROM AUTHOR]

Hypoxia challenges aerobic organisms in numerous environments, and hypoxic conditions may become more severe under future climate‐change scenarios. The impact of hypoxia on the development of terrestrial insect embryos is not well understood. Here, to address this gap, embryonic life‐history traits of migratory locust Locusta migratoria from low‐altitude and high‐altitude regions were compared under 2 oxygen levels: normoxia (i.e., 21 kPa oxygen partial pressure and mild hypoxia (i.e., 10 kPa oxygen partial pressure). Our results demonstrated that, whether reared under normoxia or mild hypoxia, L. migratoria from high‐altitude populations had longer developmental times, reduced weight, and lower mean relative growth rate as compared with those from low‐altitude populations. When transferred from normoxia to mild hypoxia, nearly all the tested life‐history traits presented significant negative changes in the low‐altitude populations, but not in the high‐altitude populations. The factor 'strain' alone explained 18.26%–54.59% of the total variation for traits, suggesting that the phenotypic differences between L. migratoria populations from the 2 altitudes could be driven by genetic variation. Significant genetic correlations were found between life‐history traits, and most of these showed differentiation between the 2 altitudinal gradients. G‐matrix comparisons showed significant structural differences between L. migratoria from the 2 regions, as well as several negative covariances (i.e., trade‐offs) between traits in the low‐altitude populations. Overall, our study provides clear evidence that evolutionary divergence of embryonic traits between L. migratoria populations from different altitudes has occurred. [ABSTRACT FROM AUTHOR]

"Dao Ban Xiang" is a famous traditional Chinese dry‐cured meat product. This study aimed to comparatively analyze the difference in the volatile flavor information of "Dao Ban Xiang" produced in winter and summer. In this study, we determine the physical and chemical properties, free amino acids (FAAs), free fatty acids (FFAs), and volatile compounds in the four processing stages of samples in winter and summer. The content of FAAs decreased significantly during the curing period in winter while increasing steadily in summer. The content of total FFAs increased in both winter and summer, and polyunsaturated fatty acids (PUFAs) decreased significantly in summer. The characteristic compound in winter samples is hexanal, nonanal, and (E)‐2‐octenal, which may mainly come from the degradation of FAAs, while the characteristic compound in winter samples is hexanal, nonanal, and (E)‐2‐nonenal, which may mainly be derived from the oxidation of FFAs. This study extends our knowledge on flavor from traditional cured meat products at different processing stages in different seasons and could be useful for the standardization of the traditional and regional meat products. [ABSTRACT FROM AUTHOR]

Silica glass is a superior functional material due to its excellent thermophysical properties. With the increasing demand for large‐size and high‐purity silica glass, a novel chemical vapor deposition (CVD) furnace characterized by a crucible has been proposed, which requires a deep understanding of heat and mass transport characteristics inside for better control. Aimed at this, a comprehensive simulation model is developed in the paper. The model is well verified with the experimentally measured temperature and is then used to examine distributions of temperature and critical components in the furnace. Effects of the injection conditions are further investigated, among which the H2–O2 equivalence ratio and flow rate have a great influence on the temperature and components distributions, whereas the SiCl4 flow rate mainly affects the SiO2 distribution. An improved injection condition is put forward finally, which is much better than the reference case; the average for the temperature and SiO2 concentration on the deposition surface is increased, respectively, by 23 K and 0.018 mol/m3, and sufficient homogeneity is maintained. [ABSTRACT FROM AUTHOR]

Precipitation into the Earth's atmosphere due to pitch angle scattering by plasma waves has been recognized as one of the major loss mechanisms for energetic electrons. In this study, we quantitatively evaluate their roles in precipitating electrons during a conjunction event with modulated electron precipitation observed at low altitudes by Electron Loss and Fields INvestigation and three types of whistler mode waves (hiss, plume hiss, and chorus) measured near the equator by Time History of Events and Macroscale Interactions during Substorms. Electron precipitation was observed from ∼50 keV to <1 MeV with a spatial modulation, suggested by a good correlation between L shell‐sorted precipitation fluxes and wave intensities. A quasi‐linear analysis supports the observed energy range of precipitation and the ratio of precipitating‐to‐trapped flux. Our findings reveal that the modulated energetic electron precipitation is driven by hiss, plume hiss, and chorus waves. Plain Language Summary: Energetic electrons precipitated from the inner magnetosphere into the upper atmosphere can form diffuse and discrete aurora and modulate the ionospheric conductance. One of the major drivers of electron precipitation is wave‐particle interaction with whistler mode waves. In this study, we use the Electron Loss and Fields INvestigation CubeSats to measure electron precipitation at low altitudes and the Time History of Events and Macroscale Interactions during Substorms to provide wave and plasma measurements near the magnetic equator in the conjugate locations. We find that the electron precipitation rate is highly correlated to the whistler mode wave intensity near the equator. Through a quasi‐linear analysis, we demonstrate that the modulation of electron precipitation is driven by whistler mode hiss, plume hiss, and chorus waves that occur in an extensive region of the Earth's magnetosphere. Key Points: Modulated electron precipitation from tens to hundreds of keV over L shells of 4–9 is observed by Electron Loss and Fields INvestigation at low altitudesA good correlation is observed between the spatial variations of electron precipitation and wave intensities of hiss, plume hiss, and chorusQuasi‐linear modeling based on the observed wave and plasma parameters reproduced the observed electron precipitation [ABSTRACT FROM AUTHOR]

Resonant interactions with whistler‐mode waves are one of the most important drivers for rapid energetic electron precipitation. In this letter, we study a conjunction event, where bursts of energetic electron precipitation (50–800 keV) with timescales of several seconds are observed by the twin ELFIN Cubesats at low Earth orbit, while very‐oblique intense whistler‐mode waves are observed by the Time History of Events and Macroscale Interactions during Substorms E satellite at the conjugate magnetic equator. Our observation‐constrained test‐particle simulations reveal that the electron precipitation, particularly above 100 keV, results from high‐order resonant scattering by the very‐oblique whistler‐mode waves. Our study provides the first direct evidence for high‐order resonance driven precipitation, explaining a bursty precipitation event. The results demonstrate that high‐order resonant scattering could be important, not only in long‐term diffusion models, but also in models of short timescale events. Plain Language Summary: Resonant interactions between energetic electrons and whistler‐mode waves can efficiently scatter electrons from the Earth's magnetosphere into the atmosphere, which is recorded by spacecraft at low altitude as electron precipitation events. Resonant interactions are described by an integer harmonic number, representing the number of wave periods that fit within an electron cyclotron period. Harmonic numbers larger than 1 denote high‐order resonances. In previous studies, mostly low harmonic numbers have been associated with rapid electron precipitation. The contribution of harmonic numbers >1 to such resonant scattering and precipitation was discussed only rarely. In this letter, we study a fortuitous event of fast electron precipitation observed at ionospheric altitude, in conjunction with intense whistler‐mode waves, propagating at a large angle from the geomagnetic field, observed at the conjugate equator. Our data‐informed test particle simulations of this event show that the electron precipitation at 50–800 keV is mostly due to high‐order resonant diffusion by these waves. Comparisons between numerical models and observation of the precipitation by the new ELFIN Cubesats provide direct evidence that fast electron precipitation may be driven by diffusive scattering at high‐order resonances due to these very oblique whistler‐mode waves. Key Points: We report bursts of electron precipitation in conjunction with very oblique whistler‐mode wavesHigh‐order resonant scattering contributes to electron precipitation for energies at several hundred keVDiffusive‐like scattering by high‐order resonances may provide efficient filling of loss‐cone [ABSTRACT FROM AUTHOR]

Temporomandibular joint (TMJ) growth requires orchestrated interactions between various cell types. Recent studies revealed that fibrocartilage stem cells (FCSCs) in the TMJ cartilage play critical roles as cell resources for joint development and repair. However, the detailed molecular network that influences FCSC fate during TMJ cartilage development remains to be elucidated. Here, we investigate the functional role of Igf1 in FCSCs for TMJ cartilage growth and homeostasis by lineage tracing using Gli1‐CreER+; Tmflfl mice and conditional Igf1 deletion using Gli1‐/Col2‐CreER+; Igf1fl/fl mice. In Gli1‐CreER+; Tmflfl mice, red fluorescence+ (RFP+) FCSCs show a favorable proliferative capacity. Igf1 deletion in Gli1+/Col2+ cell lineages leads to distinct pathological changes in TMJ cartilage. More serious cartilage thickness and cell density reductions are found in the superficial layers in Gli1‐CreER+; Igf1fl/fl mice. After long‐term Igf1 deletion, a severe disordered cell arrangement is found in both groups. When Igf1 is conditionally deleted in vivo, the red fluorescent protein‐labeled Gli1+ FCSC shows a significant disruption of chondrogenic differentiation, cell proliferation, and apoptosis leading to TMJ cartilage disarrangement and subchondral bone loss. Immunostaining shows that pAkt signaling is blocked in all cartilage layers after the Gli1+‐specific deletion of Igf1. In vitro, Igf1 deletion disrupts FCSC capacities, including proliferation and chondrogenesis. Moreover, the deletion of Igf1 in FCSCs significantly aggravates the joint osteoarthritis phenotype in the unilateral anterior crossbite mouse model, characterized by decreased cartilage thickness and cell numbers as well as a loss of extracellular matrix secretions. These findings uncover Igf1 as a regulator of TMJ cartilage growth and repair. The deletion of Igf1 disrupts the progenitor capacity of FCSCs, leading to a disordered cell distribution and exaggerating TMJ cartilage dysfunction. © 2023 American Society for Bone and Mineral Research (ASBMR). [ABSTRACT FROM AUTHOR]