RESUMO
Despite many additives have been reported for aqueous zinc ion batteries, steric-hindrance effect of additives and its correlation with Zn2+ solvation structure have been rarely reported. Herein, large-sized sucrose biomolecule is selected as a paradigm additive, and steric-hindrance electrolytes (STEs) are developed to investigate the steric-hindrance effect for solvation structure regulation. Sucrose molecules do not participate in Zn2+ solvation shell, but significantly homogenize the distribution of solvated Zn2+ and enlarge Zn2+ solvation shell with weakened Zn2+-H2O interaction due to the steric-hindrance effect. More importantly, STEs afford the water-shielding electric double layer and in situ construct the organic and inorganic hybrid solid electrolyte interface, which effectively boost Zn anode reversibility. Remarkably, Zn//NVO battery presents high capacity of 3.9â mAh â cm-2 with long cycling stability for over 650â cycles at lean electrolyte of 4.5â µL â mg-1 and low N/P ratio of 1.5, and the stable operation at wide temperature (-20 °C~+40 °C).
RESUMO
Observationally, kilonovae are astrophysical transients powered by the radioactive decay of nuclei heavier than iron, thought to be synthesized in the merger of two compact objects1-4. Over the first few days, the kilonova evolution is dominated by a large number of radioactive isotopes contributing to the heating rate2,5. On timescales of weeks to months, its behaviour is predicted to differ depending on the ejecta composition and the merger remnant6-8. Previous work has shown that the kilonova associated with gamma-ray burst 230307A is similar to kilonova AT2017gfo (ref. 9), and mid-infrared spectra revealed an emission line at 2.15 micrometres that was attributed to tellurium. Here we report a multi-wavelength analysis, including publicly available James Webb Space Telescope data9 and our own Hubble Space Telescope data, for the same gamma-ray burst. We model its evolution up to two months after the burst and show that, at these late times, the recession of the photospheric radius and the rapidly decaying bolometric luminosity (Lbol â t-2.7±0.4, where t is time) support the recombination of lanthanide-rich ejecta as they cool.
RESUMO
Undercoordination chemistry is an effective strategy to modulate the geometry-governed electronic structure and thereby regulate the activity of sulfur electrocatalysts. Efficient sulfur electrocatalysis is requisite to overcome the sluggish kinetics in lithium-sulfur (Li-S) batteries aroused by multi-electron transfer and multi-phase conversions. Recent advances unveil the great promise of undercoordination chemistry in facilitating and stabilizing sulfur electrochemistry, yet a related review with systematicness and perspectives is still missing. Herein, it is carefully combed through the recent progress of undercoordination chemistry in sulfur electrocatalysis. The typical material structures and operational strategies are elaborated, while the underlying working mechanism is also detailly introduced and generalized into polysulfide adsorption behaviors, polysulfide conversion kinetics, electron/ion transport, and dynamic reconstruction. Moreover, perspectives on the future development of undercoordination chemistry are further proposed.
RESUMO
Purpose: To evaluate the diagnostic yield of ultrasonography (US)-guided core needle biopsy (CNB) in the diagnosis of soft tissue tumors (STTs) and to analyze the failure factors. Methods: 139 patients with STTs that underwent both US-guided CNB and surgical resection were collected retrospectively. Compared with the histopathological results of surgical resection, the biopsy failure was defined as the following conditions: indefinitive diagnosis, including insufficient samples and unknown subtypes with correct biological potential classification; wrong diagnosis, including wrong biological potential classification and wrong subtypes with correct biological potential classification. Univariate and multivariate analyses from the perspectives of histopathological, demographic and US features together with biopsy procedures were performed to determine risk factors for diagnostic failure. Results: The diagnostic yield of US-guided CNB for STTs in our study was 78.4%, but when only considering the correct biological potential classification of STTs, the diagnostic yield was 80.6%. The multivariate analysis showed that adipocytic tumors (odds ratio (OR) = 10.195, 95% confidence interval (CI): 1.062 - 97.861, p = 0.044), vascular tumors (OR = 41.710, 95% CI: 3.126 - 556.581, p = 0.005) and indeterminate US diagnosis (OR = 8.641, 95% CI: 1.852 - 40.303, p = 0.006) were correlated with the diagnostic failure. The grade III vascular density (OR = 0.019, 95% CI: 0.001 - 0.273, p = 0.007) enabled a higher diagnostic accuracy. Conclusion: US-guided CNB can be an effective modality for the diagnosis of STTs. The diagnostic yield can be increased when the tumor vascular density was grade III in Color Doppler US, but can be decreased in adipocytic tumors, vascular tumors and masses with indeterminate US diagnosis.