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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDendrimer and polystyrene surfactant structure at the air-water interfaceP. M. Saville, J. W. White, C. J. Hawker, K. L. Wooley, and J. M. J. FrechetCite this: J. Phys. Chem. 1993, 97, 2, 293–294Publication Date (Print):January 1, 1993Publication History Published online1 May 2002Published inissue 1 January 1993https://pubs.acs.org/doi/10.1021/j100104a006https://doi.org/10.1021/j100104a006research-articleACS PublicationsRequest reuse permissionsArticle Views337Altmetric-Citations69LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

Local chemical ordering (LCO) in the CrCoNi medium-entropy alloy was investigated by transmission electron microscopy (TEM) after different annealing treatments and their corresponding mechanical properties by bulk tensile tests and nanoindentation. A cold-rolled alloy was annealed at 1000°C for 0.5 h followed by ice water quenching and then aged at a number of different temperatures (600°C, 700°C, 800°C, 900°C, and 1000°C) under vacuum for 240 h to generate different degrees of chemical ordering. A splat-quenched sample rapidly cooled from the liquid phase was also examined. While bulk mechanical properties did not vary among samples with equivalent grain sizes, nanoindentation tests revealed notable differences. As indicated by the load at first pop-in using a Berkovich tip or the indentation yield strength via continuous stiffness measurements using a 10 μm spherical tip, the nanoindentation tests revealed that the stress for onset of plasticity during indentation varied with heat treatment and peaked in the 900°C aged sample. Energy-filtered TEM characterization indicated the presence of ordering in all specimens, with a higher degree of LCO in the aged samples relative to the splat-quenched and 1000°C-quenched samples. The evolution of LCO during aging was determined to occur on the time scale similar to those of bulk diffusion. The difference in nanoindentation strength was attributed to the difference in dislocation nucleation barriers imposed by different degrees of LCO.

We present far- and near-ultraviolet (UV) spectra of the Type II supernovae (SNe) SN~2023ixf from days 199 to 722 and SN~2024ggi at days 41 and 232. Both supernovae show broad, blueshifted, and asymmetric UV emission lines with an initial maximum velocity of $\sim9000\,km\,s^{-1}$ and narrow unresolved emission in CIV. We compare the optical and UV emission-line profiles, showing that they evolve from two distinct velocity profiles to a single profile tracing the UV emission. We interpret this as shock power from interaction with circumstellar material coming to dominate over the radioactive-decay power from the inner ejecta. Comparing our observations to radiative transfer models with injected shock power, we find SN~2024ggi is best matched by $P_{\mathrm{shock, abs}}=1\times10^{41}\,erg\,s^{-1}$ at day 40, SN~2023ixf at day 300 and SN~2024ggi at day 200 are best matched by $P_{\mathrm{shock,abs}}=1\times10^{40}\,erg\,s^{-1}$, and SN~2023ixf at day 600 is best matched by $P_{\mathrm{shock,abs}}=5\times10^{39}\,erg\,s^{-1}$. From these models, we find the mass-loss rate of both supernovae increased just before explosion. For SN~2023ixf our mass-loss rates go from $4\times10^{-5}\,M_{\odot}\,yr^{-1}$ at 600 yr before explosion to $2\times10^{-2}\,M_{\odot}\,yr^{-1}$ at 15 yr prior to explosion. For SN~2024ggi, we find a mass-loss rate of $9\times10^{-5}\,M_{\odot}\,yr^{-1}$ at 150 yr before explosion and $1\times10^{-3}\,M_{\odot}\,yr^{-1}$ at 30 yr before explosion.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.