Magnetic cavities (sometimes referred to as magnetic holes) at electron kinetic scale are thought to be one of the extremely small intermittent structures formed in magnetized turbulent plasmas, ...where the turbulence energy cascaded down to electron scale may finally be dissipated and consequently energize the electrons. However, the geometry and formation of these structures remain not definitively resolved. Here we discuss an electron scale magnetic cavity embedded in a proton scale magnetic cavity observed by the MMS spacecraft in the magnetosheath. By applying an innovative particle sounding technique, we directly depict the boundary of the electron scale magnetic cavity and uncover the geometry. We find that this structure is nearly circular with a radius of 10.0 km and its formation is due to the diamagnetic current. Investigation of the electron scale structure is only recently made possible by the high spatial and temporal resolution provided by MMS observations.
The radial velocity (RV) is a basic physical quantity that can be determined through the Doppler shift of the spectrum of a star. The precision of the RV measurement depends on the resolution of the ...spectrum we used and the accuracy of wavelength calibration. In this work, radial velocities of the Large Sky Area Multi-Object Fibre Spectroscopic Telescope-II (LAMOST-II) medium-resolution (R ∼ 7500) spectra are measured for 1,594,956 spectra (each spectrum has two wavebands) through matching with templates. A set of RV standard stars are used to recalibrate the zero point of the measurement, and some reference sets with RVs derived from medium-/high-resolution observations are used to evaluate the accuracy of the measurement. By comparing with reference sets, the accuracy of our measurement can get 0.0277 km s−1 with respect to radial velocities of standard stars. The intrinsic precision is estimated with the multiple observations of single stars, which can be achieved to 1.36 km s−1, 1.08 km s−1, and 0.91 km s−1 for the spectra at signal-to-noise levels of 10, 20, and 50, respectively.
Routine electrolyte additives are not effective enough for uniform zinc (Zn) deposition, because they are hard to proactively guide atomic‐level Zn deposition. Here, based on underpotential ...deposition (UPD), we propose an “escort effect” of electrolyte additives for uniform Zn deposition at the atomic level. With nickel ion (Ni2+) additives, we found that metallic Ni deposits preferentially and triggers the UPD of Zn on Ni. This facilitates firm nucleation and uniform growth of Zn while suppressing side reactions. Besides, Ni dissolves back into the electrolyte after Zn stripping with no influence on interfacial charge transfer resistance. Consequently, the optimized cell operates for over 900 h at 1 mA cm−2 (more than 4 times longer than the blank one). Moreover, the universality of “escort effect” is identified by using Cr3+ and Co2+ additives. This work would inspire a wide range of atomic‐level principles by controlling interfacial electrochemistry for various metal batteries.
M is a metal with a higher reduction potential and work function than Zn. If Mn+ is used as an electrolyte additive, Mn+ will deposit preferentially and then render UPD of Zn uniformly on M. Moreover, the deposited M can dissolve back into the electrolyte after Zn stripping and thus does not increase the interfacial charge transfer resistance, enabling a highly reversible Zn anode. Ni2+, Cr2+, and Co2+ have been verified to function as Mn+.
Sodium super‐ionic conductor (NASICON)‐structured phosphates are emerging as rising stars as cathodes for sodium‐ion batteries. However, they usually suffer from a relatively low capacity due to the ...limited activated redox couples and low intrinsic electronic conductivity. Herein, a reduced graphene oxide supported NASICON Na3Cr0.5V1.5(PO4)3 cathode (VC/C‐G) is designed, which displays ultrafast (up to 50 C) and ultrastable (1 000 cycles at 20 C) Na+ storage properties. The VC/C‐G can reach a high energy density of ≈470 W h kg−1 at 0.2 C with a specific capacity of 176 mAh g−1 (equivalent to the theoretical value); this corresponds to a three‐electron transfer reaction based on fully activated V5+/V4+, V4+/V3+, V3+/V2+ couples. In situ X‐ray diffraction (XRD) results disclose a combination of solid‐solution reaction and biphasic reaction mechanisms upon cycling. Density functional theory calculations reveal a narrow forbidden‐band gap of 1.41 eV and a low Na+ diffusion energy barrier of 0.194 eV. Furthermore, VC/C‐G shows excellent fast‐charging performance by only taking ≈11 min to reach 80% state of charge. The work provides a widely applicable strategy for realizing multi‐electron cathode design for high‐performance SIBs.
Na super‐ionic conductor (NASICON)‐structured materials are promising cathode candidates for Na‐ion batteries. Nevertheless, multi‐electron reaction and fast‐charging performance are still difficult to achieve. Herein, the authors design a reduced graphene oxide supported Na3Cr0.5V1.5(PO4)3 with the fully activated redox reactions of V5+/V4+, V4+/V3+, and V3+/V2+. The as‐developed materials display high capacity, stability, and fast‐charging capability.
As a rare systemic autoinflammatory disease, adult-onset Still's disease (AOSD) has heterogeneous clinical manifestations, response to treatment and outcome. This study tried to assess the clinical ...characteristics, laboratory tests, and treatments of Chinese AOSD patients, and make a retrospective analysis.
We collected from 7 hospitals in China a total of 517 Chinese patients with AOSD who satisfied the Yamaguchi criteria. We retrospectively evaluated their clinical features, laboratory tests, treatments and compared them with published data from different studies. All the data in this study were from medical records and further statistic analyses.
We evaluated a total of 517 AOSD patients, 72% female, average age of onset was 37.7; spiking fever, rash and arthralgia occurred in 472 (91.3%), 413 (79.9%), 378 (73.1%) cases, respectively. There were 439/513 (85.6%) cases with leukocytosis and 456/476 (95.8%) cases with raised serum ferritin. The highest frequently used medications and regimens for remission were glucocorticoids (498/517, 96.3%), methotrexate (273/517, 52.8%) and hydroxychloroquine (174/517, 33.7%). 84.4%. 357/423 of AOSD cases were able to achieve initial remission with different regimens, mostly including glucocorticoids, methotrexate or hydroxychloroquine. 47.2% of them (244/517) received 30<D≤60 mg/d of prednisone to reach final clinical remission. Further analysis indicated that risk factors, such as skin rash, pericarditis, splenomegaly and delayed diagnosis, are highly related to the dosage of prednisone for remission.
Glucocorticoids are mostly selected to induce remission in China and half of them required ~0.5-1mg/kgbw prednisone. In patients with skin rash, pericarditis, splenomegaly or delayed diagnosis, a higher dosage of prednisone was needed to obtain remission.
Aqueous zinc‐ion batteries (AZIBs) have experienced a rapid surge in popularity, as evident from the extensive research with over 30 000 articles published in the past 5 years. Previous studies on ...AZIBs have showcased impressive long‐cycle stability at high current densities, achieving thousands or tens of thousands of cycles. However, the practical stability of AZIBs at low current densities (<1C) is restricted to merely 50–100 cycles due to intensified cathode dissolution. This genuine limitation poses a considerable challenge to their transition from the laboratory to the industry. In this study, leveraging density functional theory (DFT) calculations, an artificial interphase that achieves both hydrophobicity and restriction of the outward penetration of dissolved vanadium cations, thereby shifting the reaction equilibrium and suppressing the vanadium dissolution following Le Chatelier's principle, is described. The approach has resulted in one of the best cycling stabilities to date, with no noticeable capacity fading after more than 200 cycles (≈720 h) at 200 mA g−1 (0.47C). These findings represent a significant advance in the design of ultrastable cathodes for aqueous batteries and accelerate the industrialization of aqueous zinc‐ion batteries.
Cathode dissolution significantly limits the cycle life of aqueous zinc‐ion batteries, particularly at low currents. An artificial constructed on V6O13 cathodes (ZnOTf‐LDH) is revealed to repel water, impede vanadium shuttling, and facilitate zinc transport. This suppresses vanadium dissolution and enables stable cycling for over 200 cycles at 200 mA g−1. The method is applicable to different vanadium oxide cathodes.
North China is known for its large population densities and rapid development of industry and agriculture. Air quality around Beijing improved substantially during the 2008 Summer Olympics. We ...measured atmospheric concentrations of various Nr compounds at three urban sites and three rural sites in North China from 2010 to 2012 and estimated N dry and wet deposition by inferential models and the rain gauge method to determine current air conditions with respect to reactive nitrogen (Nr) compounds and nitrogen (N) deposition in Beijing and the surrounding area. NH3, NO2, and HNO3 and particulate NH4+ and NO3−, and NH4+–N and NO3−–N in precipitation averaged 8.2, 11.5, 1.6, 8.2 and 4.6 μg N m−3, and 2.9 and 1.9 mg N L−1, respectively, with large seasonal and spatial variability. Atmospheric Nr (especially oxidized N) concentrations were highest at urban sites. Dry deposition of Nr ranged from 35.2 to 60.0 kg N ha−1 yr−1, with wet deposition of Nr of 16.3 to 43.2 kg N ha−1 yr−1 and total deposition of 54.4–103.2 kg N ha−1 yr−1. The rates of Nr dry and wet deposition were 36.4 and 33.2% higher, respectively, at the urban sites than at the rural sites. These high levels reflect the occurrence of a wide range of Nr pollution in North China and suggest that further strict air pollution control measures are required.
•Atmospheric Nr concentration and deposition were reported at six sites in North China.•High Nr concentrations in the air were found in North China several years after the Beijing Olympics.•Annual N dry and total deposition was 35.2–60.0 and 54.4–102.3 kg N ha−1 in North China, respectively.•Concentration and deposition of Nr were much higher at urban than at rural sites in North China.
The family Melanommataceae is widespread in temperate and subtropical regions and species invariably occur on twigs or bark of various woody plants in terrestrial, marine or freshwater habitats. In ...this paper, the type species of 26 genera of the family are re-described and illustrated. A multi-gene phylogeny based on maximum likelihood and Bayesian analyses of LSU, SSU, RPB2 and EF-1α sequence data of species of Melanommataceae is provided. The new genera, Muriformistrickeria, Pseudostrickeria and Thysanolaenae are introduced. Anomalemma is synonymized under Exosporiella. Acrocordiopsis, Astrosphaeriella, Beverwykella, Caryosporella, Sporidesmiella and Pseudotrichia are excluded from Melanommataceae based on molecular phylogenetic analyses. Presently, 20 genera are accepted in Melanommataceae. Based on the phylogenetic data, five new species, Byssosphaeria siamensis, Herpotrichia vaginatispora, Pseudostrickeria muriformis, Pseudostrickeria ononidis and Muriformistrickeria rubi, are introduced.
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