P'2-NaMnO (NMO) features an ultra-high specific capacity in sodium-ion batteries, which, however, suffers from a fast capacity decay. To improve the stability, a high-entropy doped P'2-NaMnTiCuNiCoFeOF (NMHEOF) is developed to lessen the Jahn-Teller distortion and address the multiple phase transition issue. Physicochemical characterizations reveal that the NMHEOF yields a lower anisotropy in the Mn─O bond than does the undoped NMO.
View Article and Find Full Text PDFNew energy technology is in urgent demand for waste heat harvesting and utilization for energy saving and renewable energy development. Herein, an aqueous organic redox flow battery (AORFB) with designed tripyridinium-triazine radicals ((TPyTz))/(TPyTz)) as the negative redox couple is constructed as a thermoelectricity utilization system. The electrochemical test indicates that the (TPyTz)/(TPyTz) couple shows an interesting potential change about 27 mV accompanied by system temperature varying from 298 K to 343 K.
View Article and Find Full Text PDFParathyroid ultrasound is widely used in clinical practice and plays a crucial role in the diagnosis and treatment of parathyroid diseases. Nevertheless, ultrasound physicians frequently encounter a number of challenges and doubts in their professional practice. For this reason, Superficial Organs and Peripheral Vessels Committee of Chinese Association of Ultrasound in Medicine and Engineering has formulated the expert consensus on certain common clinical problems of parathyroid ultrasound based on the current research progress and clinical experience, in order to guide the clinical practice.
View Article and Find Full Text PDFHeavy metals (HMs) exert a profound influence on soil carbon storage potential. The microbially-mediated association between HM content and carbon structure in riverine sediments remains unclear in lotic ecosystems. We investigated the spatiotemporal variations of HMs content, carbon content and microbial communities in riverine surface sediments, and further explored the chemical structure of sediment organic carbon (OC), the molecular composition of dissolved organic matter (DOM), and their interactions with microorganisms.
View Article and Find Full Text PDFIn karst landscapes, where sustainable water management is increasingly challenged by drought-induced water scarcity, the adoption of road-based rainwater harvesting (RBWH) systems has emerged as a promising solution for improving water accessibility. Despite the growing implementation of such systems, the effectiveness of many RBWH projects in karst terrains remains suboptimal due to an inadequate understanding of runoff generation mechanisms associated with hilly road networks. This study focuses on quantifying the contributions of intercepted surface runoff (SR) and soil-epikarst lateral flow (SEF) from a newly exposed road-cut slope in a dolomite hillslope, with data collected across 156 rainfall events from May 2019 to May 2022.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Organic molecule in solutions is the energy storage unit in the organic redox flow batteries (ORFBs), of which the aggregation is acknowledged pivotal but has been rarely investigated. By establishing a pyridinium library, the manipulation over the aggregation in solutions is investigated at the molecular level. Both theoretical calculations and physiochemical methods are used to characterize the aggregate's structure, and salient findings are as follows.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2024
A novel Ir-Mn dual-atom electrocatalyst is synthesized by a facile ion-exchange method by incorporating Ir in SrMnO, which yields an extremely high activity and stability for the oxygen evolution reaction (OER). The ion exchange process occurs in a self-limitation way, which favors the formation of Ir-Mn dual-atom in the IrMnO unit. The incorporation of Ir modulates the electronic structure of both Ir and Mn, thereby resulting in a shorter distance of the Ir-Mn dual-atom (2.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
April 2024
The southwestern region of China is the largest exposed karst area in the world and serves as an important ecological security barrier for the upstream of Yangtze River and Pearl River. Different from the critical zone of non-karst areas, the epikarst, formed by an interwoven network of denudation pores, is the core area of karst critical zone. Water is the most active component that participates in internal material cycle and energy flow within the critical zone.
View Article and Find Full Text PDFElectrocardiogram (ECG) abnormalities are the most common cardiac complications after acute ischemic stroke (AIS) and predict poor outcomes. The arterial baroreflex is an essential determinant of cardiovascular autonomic regulation, with receptors mainly residing in carotid sinuses and aortic arch. The atherosclerosis of these baroreceptor-resident arteries (BRA) is very common in AIS patients and might impair baroreflex function.
View Article and Find Full Text PDFUnderstanding the chemical composition, origin, and molecular structure of dissolved organic matter (DOM) in multi-interface runoff is essential for comprehending the fate of laterally transported DOM in complex soil-epikarst systems of karst hillslopes. Limited information, however, is available for the optical properties and molecular compositions of the transported OM in multiple runoff components on the karst hillslope in relation to land-uses and soil thicknesses. In this study, we conducted a study to observe the changes in the quantity and quality of DOM in multiple interface flow (surface, subsurface, and epikarst) during natural rainfall events in 2022 in karst hillslopes that are covered by different land uses (cropland and shrubland) and soil thicknesses (with mean depths of 66.
View Article and Find Full Text PDFThe adoption of computerized tomography (CT) technology has significantly elevated the role of pulmonary CT imaging in diagnosing and treating pulmonary diseases. However, challenges persist due to the complex relationship between lesions within pulmonary tissue and the surrounding blood vessels. These challenges involve achieving precise three-dimensional reconstruction while maintaining accurate relative positioning of these elements.
View Article and Find Full Text PDFThe determinants of blood pressure variability (BPV) are complex. We aimed to evaluate whether circulating high-sensitivity C-reactive protein (hsCRP) is associated with short-term BPV during the subacute stage of ischemic stroke. In this observational study, a consecutive series of acute ischemic stroke patients who underwent 24 h ambulator blood pressure monitoring (ABPM) during day 4 to 10 after onset were enrolled.
View Article and Find Full Text PDFTo promote further commercialization of proton exchange membrane (PEM) fuel cells, developing a novel preparation method for high-performance and durable membrane electrode assemblies (MEAs) is imperative. In this study, we adopt the reverse membrane deposition process and expanded polytetrafluoroethylene (ePTFE) reinforcing technology to optimize the interface combination and durability of MEAs simultaneously for the preparation of novel MEAs with double-layer ePTFE reinforcement skeletons (DR-MEA). With the wet-contact between the liquid ionomer solution and porous catalyst layers (CLs), a tight 3D PEM/CL interface is formed in the DR-MEA.
View Article and Find Full Text PDFMembrane electrode assemblies (MEAs) are critical components in influencing the electrochemical performance of high-temperature proton exchange membrane fuel cells (HT-PEMFCs). MEA manufacturing processes are mainly divided into the catalyst-coated membrane (CCM) and the catalyst-coated substrate (CCS) methods. For conventional HT-PEMFCs based on phosphoric acid-doped polybenzimidazole (PBI) membranes, the wetting surface and extreme swelling of the PA-doped PBI membranes make the CCM method difficult to apply to the fabrication of MEAs.
View Article and Find Full Text PDFTemperature is an important near-surface microclimate parameter that plays a key role in hydrological, ecological, and biogeochemical functions. However, the spatio-temporal distribution of temperature on the invisible and inaccessible soil-weathered bedrock continuum, wherein hydrothermal processes are most active, remains poorly understood. Temperature dynamics were monitored at 5 min intervals in the air-soil-epikarst (∼3 m) system at different topographical positions of the karst peak-cluster depression in southwest China.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
February 2023
We selected a typical dolomite slope and set up three micro-plots (projection length was 2 m, width was 1.2 m) on the upper, middle, and lower slopes to analyze the variations of soil losses and the key influencing factors during two hydrological years (2020-2021). The results showed that soil losses at different slope positions on dolomite slopes followed an order of semi-alfisol in lower slopes (386 g·m·a) > inceptisol in middle slopes (77 g·m·a) > entisol in upper slopes (48 g·m·a).
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2023
Molecule aggregation in solution is acknowledged to be universal and can regulate the molecule's physiochemical properties, which however has been rarely investigated in electrochemistry. Herein, an electrochemical method is developed to quantitatively study the aggregation behavior of the target molecule methyl viologen dichloride. It is found that the oxidation state dicationic ions stay discrete, while the singly-reduced state monoradicals yield a concentration-dependent aggregation behavior.
View Article and Find Full Text PDFThis work exhibits an effective approach to enhance the performance of membrane-electrode assembly (MEA) with KH(PO)-doped PBI membrane, by adding phosphoric acid (PA) in the catalyst layer (CL). The ohmic resistance and single-cell performance of the MEA, treated with PA, are reduced by ~80% and improved by ~800%, respectively, compared to that of untreated MEA. Based on the MEA pretreated with PA, the influence of humidity and temperature on the resistance and the single-cell performance are investigated.
View Article and Find Full Text PDFElectrochemical reduction of CO (CO RR) to value-added chemicals is an effective way to harvest renewable energy and utilize carbon dioxide. However, the electrocatalysts for CO RR suffer from insufficient activity and selectivity due to the limitation of CO activation. In this work, a Ni-doped Bi nanosheet (Ni@Bi-NS) electrocatalyst is synthesized for the electrochemical reduction of CO to HCOOH.
View Article and Find Full Text PDFBackground: To analyze blood flow volume alteration that involved both retrobulbar artery and internal carotid artery (ICA) in patients with non-arteritic anterior ischemic optic neuropathy (NAION) and to assess their relevance for the pathogenesis of NAION.
Methods: Forty two patients with NAION (unilateral affected) and 42 age-matched controls participated in this study. By head-and-neck computed tomographic angiography (CTA), the diameter of ICA and ophthalmic artery (OA) were measured.
Angew Chem Int Ed Engl
September 2021
A novel organic molecule, 2,4,6-tris[1-(trimethylamonium)propyl-4-pyridiniumyl]-1,3,5-triazine hexachloride, was developed as a reversible six-electron storage electrolyte for use in an aqueous redox flow battery (ARFB). Physicochemical characterization reveals that the molecule evolves from a radical to a biradical and finally to a quinoid structure upon accepting four electrons. Both the diffusion coefficient and the rate constant were sufficiently high to run a flow battery with low concentration and kinetics polarization losses.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
June 2021
Epikarst is the core area of karst critical zone, with important hydrologic regulation and storage function. However, the effects of karst development degree on hydrologic characteristics of epikasrt is still unclear. We used geophysical exploration and hydrogeological techniques, combined with the dynamic monitoring of moisture and water levels, to quantify the karst development degrees and their hydrologic characteristics on slope lands.
View Article and Find Full Text PDFAdv Mater
February 2021
A rotating phenyl ring is introduced between the two pyridinium rings, namely, 1,1'-bis[3-(trimethylamonium)propyl]-4,4'-(1,4-phenylene)bispyridinium tetrachloride ((APBPy)Cl ), to form a switchable conjugation. In this design, the conjugation is switched "off" in the oxidized state and the two pyridinium rings behave independently during the redox process, yielding a concomitant transfer of two electrons at the same potential and, thus, simplifying the battery management. The conjugation is switched "on" in the reduced state and the charge can be effectively delocalized, lowering the Lewis basicity and improving its chemical stability.
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