Volume Expansion Research Articles

[Analysis of the effect and safety of lumen reshaping after endovascular repair of Stanford B type aortic dissection at different intervention times].

Objective: To Compare the effects and safety of lumen reshaping after thoracic endovascular aortic repair (TEVAR) for Stanford B type aortic dissection (AD) at different intervention times. Methods: A retrospective analysis was conducted on the clinical data of 189 patients with Stanford type B aortic dissection treated with TEVAR at the Affiliated Hospital of Chengde Medical College from January 2016 to December 2020.Based on the time from onset to surgery, patients were divided into an early intervention group (≤14 days, n=127) and a delayed intervention group (>14 days, n=62).The diameters of the total aorta, true lumen and false lumen at different times and planes (S1 plane: at the bifurcation of the pulmonary artery; S2 plane: at the lower edge of the left atrium; S3 plane: at the upper edge of the celiac trunk) post-surgery were compared between the two groups, and the rate of change in diameters of true and false lumens across these planes was calculated. The patients were followed until December 1st, 2023, and the median follow-up time was 45(40, 49) months. The postoperative complications and survival of the two groups were compared. Results: The early intervention group comprised 86 men and 41 women, with an average age of (58.3±10.7) years. The delayed intervention group included 41 men and 21 women, with an average age of (58.5±9.2) years. Both groups had an operation success rate of 100%. Six months post-surgery, the early intervention group had an expansion rate of the true lumen diameter at planes S2 and S3 of 40.1%(25.5%, 56.1%) and 5.3%(-2.5%, 15.8%), respectively, which was superior to the delayed intervention group's 18.5%(10.6%, 39.8%) and 1.0%(-8.2%, 9.6%) (both P<0.05).The early intervention group had a reduction rate of the false lumen diameter at planes S1, S2, and S3 of -56.2%(-61.3%, -48.8%), -70.4%(-81.8%, -56.6%), and -5.4%(-17.4%, 0.1%), respectively, better than the delayed intervention group's -44.2%(-53.7%, -38.3%), -49.0%(-57.6%, -35.8%), and -3.1%(-6.7%, 1.8%) (all P<0.05).At plane S1, the true lumen diameter of patients in both groups showed an increasing trend over 36 months post-surgery, while the false lumen diameter showed a decreasing trend (both P<0.05).At plane S2, the true lumen diameter of patients in the early intervention group exhibited an increasing trend over 36 months post-surgery, and the false lumen diameter exhibited a decreasing trend (both P<0.05).At plane S3, the total aortic diameter of patients in the delayed intervention group showed a slight increasing trend over 36 months post-surgery (P<0.05).The overall survival time were 45.0 months (95%CI: 42.9-47.1) for patients in the early intervention group and 46.0 months (95%CI: 43.5-48.5) for those in the delayed intervention group, with no statistically significant difference observed (P>0.05).The incidence rates of complications such as aortic rupture, retrograde Type A dissection, new distal endograft dissection, endoleak, paraplegia, and others showed no statistically significant difference between the two groups (all P>0.05), with no cases of stent migration or deformation observed. Conclusion: Early intervention for Stanford type B aortic dissection provides a better aortic remodeling outcome than delayed intervention, with similar safety.

Advances of NOTCH2NLC Repeat Expansions and Associated Diseases: A Bibliometric and Meta-analysis.

The unclear pathogenic mechanisms of neurodegenerative disorders stemming from NOTCH2NLC GGC repeat expansions drive focused research. Thus, a bibliometric and meta-analysis was conducted to uncover research trends and positivity rates in NOTCH2NLC. We conducted systematic searches in the Web of Science, PubMed, Embase, and Scopus databases for studies related to NOTCH2NLC up until August 2, 2023. Information regarding countries, institutions, authors, journals, and keywords of studies included in the Web of Science was analyzed and visualized. The positivity rates of NOTCH2NLC GGC repeat expansions across all screened patients and patients' families were pooled under the random-effects model. Publication bias and its impact were examined using funnel plots, Egger's linear regression, and trim-and-fill method. The bibliometric analysis, revealing pronounced publication growth, comprised 119 studies, which came from China and Japan particularly. "Neuronal intranuclear inclusion disease" emerged as a frequently used keyword. The meta-analysis comprised 36 studies, indicating global positivity rates of 1.79% (95% CI, 0.75-3.17) for all patients and 2.00% (95% CI, 0.26-4.78) for patients' families. Subgroup analyses based on region and phenotype suggested the highest NOTCH2NLC positivity rates in Taiwan population (5.42%, 95% CI 0.08-16.89) and in leukoencephalopathy-dominant patients (8.25%, 95% CI, 3.01-15.60). Sensitivity analysis affirmed the robustness of results. In conclusion, NOTCH2NLC GGC repeat expansions exhibit rare globally, primarily in East Asia, and leukoencephalopathy-dominant patients, emphasizing regional and phenotypic distinctions. Emerging focal points in NOTCH2NLC researches underscore the need for collaborative exploration.

Gap expansion is the dominant driver of canopy openings in a temperate mountain forest landscape

Abstract Natural disturbances are important drivers of forest dynamics, and canopy gaps are their fingerprints in forest ecosystems. Gaps form and persist because of the interplay of tree mortality and regeneration. They can have long‐lasting impacts on ecosystems, yet the temporal dynamics of gap formation and closure remains poorly quantified. We analysed 11,331 canopy gaps and their changes through time across 3999 ha of unmanaged temperate mountain forests at Berchtesgaden National Park (Germany). We assessed gap formation and closure using three repeat lidar acquisitions between 2009 and 2021, analysing canopy height changes at 1 m horizontal resolution. Our objective was to determine the dominant mode of gap formation, distinguishing the creation of new gaps from the expansion of existing ones. Additionally, we studied the rate of gap closure, considering closure from tree regeneration and lateral crown expansion. Gap formation was primarily driven by gap expansion rather than the initiation of new gaps. Gap expansion accounted for 81.3% of gap formation, although new gaps were on average twice as large as gap expansions. Only 1.4% of gaps did not expand over the 12‐year study period, and Norway spruce forests had the highest rate of gap expansion. Overall, gap closure rate (0.74 ha 100 ha−1 year−1) was higher than gap formation (0.58 ha 100 ha−1 year−1) in our study system. Ingrowth of the regenerating tree cohort was the primary mode of gap closure, with lateral crown expansion accounting for 20% of all gap area closed. Mixed‐species stands had the highest rate of gap closure, and gaps &lt;0.1 ha closed faster than larger gaps. Synthesis. While canopy openings are generally small in the European Alps, we show that they keep growing over multiple years, underlining that gap expansion is an important driver of temperate forest dynamics. Canopy gaps closed faster than they were created, highlighting the resilience of European mountain forests to natural disturbances. However, as disturbances are projected to increase under climate change, this resilience might be challenged in the future, requiring a continuous monitoring of gap dynamics as an important early warning indicator of forest change.

Interlayer Structure Manipulation of FeOCl/MXene with Soft/Hard Interface Design for Safe Water Production Using Dechlorination Battery Deionization

Suffering from the susceptibility to decomposition, the potential electrochemical application of FeOCl has greatly been hindered. The rational design of the soft‐hard material interface can effectively address the challenge of stress concentration and thus decomposition that may occur in the electrodes during charging and discharging. Herein, interlayer structure manipulation of FeOCl/MXene using soft‐hard interface design method were conducted for electrochemical dechlorination. FeOCl was encapsulated in Ti3C2Tx MXene nanosheets by electrostatic self‐assembly layer by layer to form a soft‐hard mechanical hierarchical structure, in which Ti3C2Tx was used as flexible buffer layers to relieve the huge volume change of FeOCl during Cl‐ intercalation/deintercalation and constructed a conductive network for fast charge transfer. The CDI dechlorination system of FeOCl/Ti3C2Tx delivered outstanding Cl‐ adsorption capacity (158.47 ± 6.98 mg g‐1), rate (6.07 ± 0.35 mg g‐1 min‐1), and stability (over 94.49% in 30 cycles), and achieved considerable energy recovery (21.14 ± 0.25%). The superior dechlorination performance was proved to originate from the Fe2+/Fe3+ topochemical transformation and the deformation constraint effect of Ti3C2Tx on FeOCl. Our interfacial design strategy enables a hard‐to‐soft integration capacity, which can serve as a universal technology for solving the translational problem of electrode volume expansion.

Utilizing poly(4‐hydroxybutyrate) as a reinforcing additive to produce high‐performance and biodegradable PBAT blends tailored for foaming applications

AbstractPoly(butylene‐adipate‐co‐terephthalate) (PBAT) is recognized for its advantages as a biodegradable thermoplastic polyester. However, its application is often limited due to low strength and poor processability. In contrast, poly(4‐hydroxybutyrate) (P4HB) emerges as a fully biodegradable polyester characterized by high strength, excellent toughness, and facile processing. In this study, P4HB was employed to reinforce PBAT, and glycidyl methacrylate grafted onto poly(4‐hydroxybutyrate) (P4HB‐g‐GMA) was introduced as an effective compatibilizer to address their inherent incompatibility. The study explored the influence of P4HB‐g‐GMA content on the mechanical, thermal, morphological, and rheological properties of the blends. The findings revealed that P4HB‐g‐GMA significantly enhanced the compatibility, mechanical properties, and melt strength of PBAT/P4HB blends. Furthermore, various PBAT/P4HB foams were prepared through a batch foaming process, employing supercritical CO2 as a physical foaming agent. The volume expansion ratio and cell size of PBAT/P4HB foams increased with higher levels of the compatibilizer.

Interlayer Structure Manipulation of FeOCl/MXene with Soft/Hard Interface Design for Safe Water Production Using Dechlorination Battery Deionization.

Suffering from the susceptibility to decomposition, the potential electrochemical application of FeOCl has greatly been hindered. The rational design of the soft-hard material interface can effectively address the challenge of stress concentration and thus decomposition that may occur in the electrodes during charging and discharging. Herein, interlayer structure manipulation of FeOCl/MXene using soft-hard interface design method were conducted for electrochemical dechlorination. FeOCl was encapsulated in Ti3C2Tx MXene nanosheets by electrostatic self-assembly layer by layer to form a soft-hard mechanical hierarchical structure, in which Ti3C2Tx was used as flexible buffer layers to relieve the huge volume change of FeOCl during Cl- intercalation/deintercalation and constructed a conductive network for fast charge transfer. The CDI dechlorination system of FeOCl/Ti3C2Tx delivered outstanding Cl- adsorption capacity (158.47 ± 6.98 mg g-1), rate (6.07 ± 0.35 mg g-1 min-1), and stability (over 94.49% in 30 cycles), and achieved considerable energy recovery (21.14 ± 0.25%). The superior dechlorination performance was proved to originate from the Fe2+/Fe3+ topochemical transformation and the deformation constraint effect of Ti3C2Tx on FeOCl. Our interfacial design strategy enables a hard-to-soft integration capacity, which can serve as a universal technology for solving the translational problem of electrode volume expansion.

Effect of Temperatures on Flame Propagation of Diethyl Ether Spray Explosion

ABSTRACT The study aims to identify the flame propagation in the diethyl ether (DEE) spray explosion through mathematical analysis by processing the gray-level histogram of the flame images. Different ambient and material temperatures’ effect on flame propagation and structure was investigated using a high-speed camera in a 20-L explosion vessel. The results showed that the overall duration could be divided into combustion and deflagration processes. With the ambient temperature increased, the combustion duration showed a trend of first decreasing, then increasing, and then decreasing again. The combustion zone first increased and then decreased. The explosion duration showed an overall decreasing trend. The explosion duration was longer than the combustion duration, ranging from 152.75 to 307 ms. The overall combustion and explosion duration trend was consistent with the explosion duration. When the ambient temperature was 308.15 K, the combustion duration reached its minimum value of 13.25 ms, and the equivalent radius of the combustion zone reached its maximum value of 52.89 mm. With the increase in material temperature, both the combustion and explosion durations showed a trend of first decreasing and then increasing, with combustion durations ranging from 12.42 to 16.25 ms and explosion durations ranging from 106 to 117.5 ms, respectively. When the material temperature was 308.15 K, the combustion zone expansion rate reached its maximum value of 10.20 m/s, and the explosion zone expansion rate reached its maximum value of 13.36 m/s. The effect of ambient temperature on the development of combustion zone is greater than that of material temperature, which is mainly reflected in the obvious change of equivalent radius.

A Review of Fluid Bolus in Critically Ill Patients After Initial Volume Expansion: Bayesian Probability Analysis and Case Studies

A Review of Fluid Bolus in Critically Ill Patients After Initial Volume Expansion: Bayesian Probability Analysis and Case Studies

The spin, expansion, and contraction of open star clusters

Empirical constraints on the internal dynamics of open clusters are important for understanding their evolution and evaporation. High-precision astrometry from Gaia DR3 is thus useful to observe aspects of the cluster dynamics. This work aims to identify dynamically peculiar clusters such as spinning and expanding clusters. We also quantify the spin frequency and expansion rate and compare them with $N$-body models to identify the origins of the peculiarities. We used the latest Gaia DR3 and archival spectroscopic surveys to analyse the radial velocities and proper motions of the cluster members in 1379 open clusters. A systematic analysis of synthetic clusters was performed to demonstrate the observability of the cluster spin along with effects of observational uncertainties. $N$-body simulations were used to understand the evolution of cluster spin and expansion for initially non-rotating clusters. We identified spin signatures in ten clusters (and 16 candidates). Additionally, we detected expansion in 18 clusters and contraction in three clusters. The expansion rate is compatible with previous theoretical estimates based on the expulsion of residual gas. The orientation of the spin axis is independent of the orbital angular momentum. The spin frequencies are much larger than what was expected from simulated, initially non-rotating clusters. This indicates that $&gt;1$&lt;!PCT!&gt; of the clusters are born rotating and/or they have undergone strong interactions. Higher precision observations are required to increase the sample of such dynamically peculiar clusters and to characterise them.

Dry Electrode Processing for High‐Performance Molten Salt Batteries

AbstractMolten salt batteries (MSBs) are renowned for their rapid reaction kinetics, high safety, and cost‐effectiveness. However, their electrode design faces challenges due to polymer binder incompatibility in molten salt electrolytes (MSEs). To address this, an expanded graphite (EG) electrode is proposed through a dry electrode processing method for MSE‐based aluminum‐ion batteries. This method facilitates the fabrication of large‐area electrodes featuring high active material loadings of up to ≈60 mg cm−2. Notably, the EG electrode exhibits remarkable rate performance, achieving a specific capacity of 84.4 mAh g−1 in the AlCl3‐NaCl‐KCl MSE at 125 °C with a current density of 5 A g−1. This outstanding performance can be attributed to its rapid multi‐step intercalation reaction kinetics and well‐developed pore structure. Leveraging the chemical stability and fibrillization binding mechanism of the polytetrafluoroethylene binder, the electrode demonstrates longevity over 10,000 cycles, despite experiencing a three‐fold volume expansion. Additionally, a 100‐mAh‐scale Al‐EG full‐cell cycled 100 times with an energy efficiency of 78.7% at 500 mA underscores its potential for large‐scale applications. Considering the broad applicability of this approach, it can also provide crucial references and insights for electrode design across various MSB systems.

Sandwich-like high-performance Ti3C2Tx MXene/NiCo2O4 nanosphere composites for asymmetric supercapacitor application

NiCo2O4 is a promising electrode material for supercapacitors due to its low cost, high theoretical specific capacitance and good cycling stability. However, NiCo2O4 has the disadvantages of poor electronic and ionic conductivities and easy agglomeration. Moreover, the irreversible structural damage caused by the NiCo2O4 volume expansions during charging and discharging limits its use in supercapacitors. Herein, we fabricated sandwich Ti3C2Tx MXene/NiCo2O4 composites via an electrostatic self-assembly method. The problem of easy agglomeration of the NiCo2O4 nanospheres was solved by intercalating Ti3C2Tx MXene layers with the NiCo2O4 nanospheres. Furthermore, the Ti3C2Tx MXene layer was also utilized as a protective layer to limit serious volume expansion and protect the structure of NiCo2O4 nanospheres from destruction. The results showed that the prepared Ti3C2Tx MXene/NiCo2O4 composite exhibited a high specific capacitance of 1025 F g−1 at a current density of 1 A g−1 and had an initial capacity of 81 % when the current density was increased to 10 A g−1. The Ti3C2Tx MXene/NiCo2O4 composite cathode and activated carbon anode were assembled in an asymmetric supercapacitor, which showed an energy density of 36.67 Wh kg−1 at 800 W kg−1 and a capacity retention of 88.2 % after 5000 cycles.

Advanced Anode Materials for Aqueous Potassium‐Ion Batteries

AbstractAqueous electrolytes are praised for their inherent safety, cost‐effectiveness, and minimal environmental impact, making aqueous potassium‐ion batteries (APIBs) a viable alternative for sustainable and eco‐friendly energy solutions. Researchers have endeavored to anode materials that align with the unique requirements of aqueous electrolytes, and some proud achievements are made. The research about APIBs anode has focused on organic materials and polyanionic compounds, both exhibiting desirable hydrated potassium storage performance, and in recent years, on the development of metal compounds and alloy‐based materials with high theoretical capacities. However, the anode of APIBs faces a narrow electrochemical stability window (ESW) caused by aqueous electrolytes and volume expansion problems due to the large radius of potassium ions, which prevents them from exhibiting appreciable capacity with satisfactory cycling stability. This review meticulously delineates the latest advancements and representative materials for the anode of APIBs and introduces several common aqueous electrolytes and effective improvement strategies for them. The focus is on the advantages and bottlenecks faced by different types of anode materials, culminating in a proposed methodology to enhance APIBs anode efficacy. This review endeavors to furnish novel perspectives on the development and pragmatic deployment of APIBs anodes.

Nano-silicon embedded in mildly-exfoliated graphite for lithium-ion battery anode materials

Silicon-based materials have a high theoretical specific capacity and a low discharge potential, whereas the significant capacity fading owing to weak conductivity and volume exfoliation effect. The co-utilization of silicon and graphite has become a feasible method for realizing high-performance lithium-ion batteries (LIBs). Herein, the C@p-Si/ESG composite anode material with “sandwich” structure was obtained by electrostatic assembly of mildly-exfoliated graphite and electrostatic modified nano silicon, and subsequent coated with amorphous carbon on the surface of the material. The carbon coating and the mildly-exfoliated graphite form a buffer space, which alleviates the volume expansion effect of silicon in the process of lithium alloying. In addition, the SEI film is generated outside the carbon layer, reducing the consumption of the electrolyte and the occurrence of side reactions. C@p-Si/ESG exhibits a high charge–discharge rate and an excellent long-term cycle stability.

Distortions of the Hubble diagram: Line-of-sight signatures of local galaxy clusters

The Universe expansion rate is modulated around local inhomogeneities due to their gravitational potential. Velocity waves are then observed around galaxy clusters in the Hubble diagram. This paper studies them in a sim 738 Mpc-wide, 2048$^3$-particle cosmological simulation of our cosmic environment (a.k.a. CLONE: Constrained LOcal Nesting Environment Simulation). For the first time, the simulation shows that velocity waves that arise in the lines of sight of the most massive dark matter halos agree with those observed in local galaxy velocity catalogs in the lines of sight of Coma and several other local (Abell) clusters. For the best-constrained clusters such as Virgo and Centaurus -- that is, those closest to us -- secondary waves caused by galaxy groups, further into the non-linear regime, also stand out. This match was not utterly expected given that before being evolved into a fully non-linear z=0 state, assuming Lambda CDM, CLONE initial conditions are constrained solely with linear theory, the power spectrum, and highly uncertain and sparse local peculiar velocities. Additionally, Gaussian fits to velocity wave envelopes show that wave properties are tightly tangled with cluster masses. This link is complex, though, and involves the environment and formation history of the clusters. A proposed metric, measuring the distance between the observed and several re-centred simulated lines of sight, waves included, is shown to be capable of providing a tight mass range estimate for massive local clusters. Using machine learning techniques to grasp more thoroughly the complex wave-mass relation, velocity waves could in the near future be used to provide additional and independent mass estimates from galaxy dynamics within large cluster radii.

Latest Evolution of the X-Ray Remnant of SN 1987A: Beyond the Inner Ring

Based on our Chandra imaging-spectroscopic observations, we present the latest evolution of the X-ray remnant of SN 1987A. Recent changes in the electron temperatures and volume emission measures suggest that the blast wave in SN 1987A is moving out of the dense inner ring structure, also called the equatorial ring (ER). The 0.5–2.0 keV X-ray light curve shows a linearly declining trend (by ∼4.5% yr−1) between 2016 and 2020 as the blast wave heats the hitherto unknown circumstellar medium (CSM) outside the ER. While the peak X-ray emission in the latest 0.3–8.0 keV image is still within the ER, the radial expansion rate in the 3.0–8.0 keV images suggests an increasing contribution of the X-ray emission from less dense CSM since 2012, at least partly from beyond the ER. It is remarkable that, since 2020, the declining soft X-ray flux has stabilized around ∼7 × 10−12 erg s−1 cm−2, which may signal a contribution from the reverse-shocked outer layers of ejecta as predicted by the three-dimensional magnetohydrodynamic models. In the latest ACIS spectrum of supernova remnant 1987A in 2022 we report a significant detection of the Fe K line at ∼6.7 keV, which may be due to changing thermal conditions of the X-ray emitting CSM and/or the onset of reverse shock interactions with the Fe ejecta.

Co3O4/RGO Nanoparticles Fabricated by Facile Solvothermal Method as an Anode Material for High‐Performance Lithium‐Ion Batteries

AbstractA potential anode material for lithium‐ion batteries (LIBs), Co3O4 has been widely considered by many scholars because of its excellent properties in terms of electrochemical characteristics and theoretical specific capacity. However, according to the existing research results, we found that the improvement of the electrochemical performance of Co3O4 has encountered a bottleneck because its intrinsic conductivity is not high enough, and more importantly, the volume expansion is too significant during the charge and discharge process, which leads to the material structure breaking. Therefore, this paper proposes a simple and scalable solvothermal and subsequent calcination method to prepare Co3O4 and reduced graphene oxide (RGO) composite nanoparticles with superior microstructures, and their morphological and electrochemical properties were investigated at different calcination temperatures. As a high‐performance anode material for lithium‐ion batteries, the Co3O4/RGO nanoparticles obtained at 550 °C exhibited terrific initial discharge capacity of 1714.2 mAh g−1, the reversible specific capacity of 1191.9 mAh g−1 with quality coulombic efficiency 98.17 % at 0.5 A g−1 after 100 cycles and extraordinary rate performance (907.6 mAh g−1 with a coulombic efficiency of 99.2 % at 2 A g−1). The facile synthesis method and excellent findings have led to better application prospects for Co3O4/RGO nanoparticles.

A volume-conservation particle shifting scheme for moving particle method simulating free-surface flow

AbstractIn this study, a novel particle shifting scheme for the moving particle method simulating free surface flow is developed. The overall method is based on the framework of least square moving particle semi-implicit (LSMPS) method, enabling accurate and stable treatment of wall boundary without configuration of dummy or virtual wall particles. To avoid volume expansion, a volume-conservation particle shifting (VCPS) model is developed. An additional term considering the variation of particle numerical density is incorporated into the VCPS model to avoid volume expansion. Several numerical simulations are calculated to validate the effectiveness of the VCPS. It is demonstrated that LSMPS incorporating with VCPS shows satisfactory accuracy and superior capability to conserve volume.

Influence of Stacking Order on the Structural and Optical Properties of Cu2ZnSnS4 Absorber Layer Prepared from DC-Sputtered Oxygenated Precursors

Several studies have attempted to overcome the sudden volume expansion of the precursor during sulfurization by the use of oxygen-containing precursors when growing the CZTS absorber. This work demonstrates the influence of precursor stacking orders on the properties of the CZTS thin film absorber layer from DC-sputtered oxygenated precursors for solar cell applications. CZTS absorber layers were prepared from three types of DC-sputtered stacks, namely, Zn-O/Sn/Cu, Sn/Zn-O/Cu, and Sn/Cu/Zn-O. The precursors were sequentially deposited on a soda lime glass (SLG) using DC-magnetron sputtering and annealed in a sulfur and nitrogen ambient. X-ray diffractometry (XRD) and Raman spectroscopy analyses reveal the formation of crystalline kesterite CZTS structure regardless of the precursor stacking order. Atomic force microscope (AFM) analysis showed that CZTS thin films grown from precursor stacks SLG/Zn-O/Sn/Cu and SLG/Sn/Zn-O/Cu had improved morphological properties with densely packed large grains compared to that with stack SLG/Sn/Cu/Zn-O. SLG/Zn-O/Sn/Cu is the best stack among the studied stacking orders since it exhibits large grains in the absorber layer, which is preferential for high-efficiency thin film solar cells. The use of oxygenated precursor with order Sn/Zn-O/Cu promises improved CZTS absorber properties as it exhibits better morphological properties.

Atomic‐Scale Engineering for New Generation Air Electrode Materials of Solid Oxide Cells: Quintuple Perovskite Sm2Ba3Co2Fe3O15‐δ with Twinned Crystal Structure

AbstractThe catalytic activity and thermomechanical stability of electrode materials are crucial for the efficient operation of reversible solid oxide cell (rSOC). However, these two traits often impose limitations on one another. In this work, a unique quintuple perovskite Sm2Ba3Co2Fe3O15‐δ (SBCF‐5L), comprising of A‐site ordered double perovskite layers and disordered simple perovskite layers, is reported as a high‐performance air electrode material for rSOC. The designed SBCF‐5L material exhibits a highly symmetrical tetragonal structure (pseudo‐cubic) with an isotropic thermal expansion and a limited chemical expansion. The formation barriers for oxygen vacancies are comparable between A‐site ordered layers and disordered simple perovskite layers, resulting in a high concentration of oxygen vacancies and 3D‐like bulk mobility of oxygen ions. Perpendicularly twinned nanodomains are developed in the particles, providing more active sites for surface electrode reaction. When applied in electrolyte‐supported cells, the SBCF‐5L electrode exhibits excellent electrochemical performance with low polarization resistance of 0.017 Ω cm−2, high power density of 1.01 W cm−2 and high electrolysis current density of 1.08 A cm−2 at 1.3 V at 800 °C in fuel cell and electrolysis modes, respectively. This study introduces a new approach of atomic‐scale engineering to rationally design a new generation of air electrodes for rSOC.

A Survey of Coronal Mass Ejections Measured In Situ by Parker Solar Probe during 2018–2022

Abstract We present a statistical investigation of the radial evolution of 28 interplanetary coronal mass ejections (ICMEs), measured in situ by the Parker Solar Probe spacecraft from 2018 October to 2022 August. First, by analyzing the radial distribution of ICME classification based on magnetic hodograms, we find that coherent configurations are more likely to be observed close to the Sun. By contrast, more complex configurations are observed farther out. We also notice that the post-ICME magnetic field is more impacted following an ICME passage at larger heliocentric distances. Second, with a multilinear robust regression, we derive a slower magnetic ejecta (ME) expansion rate within 1 au compared to previous statistical estimates. Then, investigating the magnetic field fluctuations within ICME sheaths, we see that these fluctuations are strongly coupled to the relative magnetic field strength gradient from the upstream solar wind to the ME. Third, we identify ME expansion as an important factor in the formation of sheaths. Finally, we determine the distortion parameter (DiP), which is a measure of magnetic field asymmetry in an ME. We discover lower overall asymmetries within MEs. We reveal that even for expanding MEs, the time duration over which an ME is sampled does not correlate with DiP values, indicating that the aging effect is not the sole contributor to the observed ME asymmetries.