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1. Tension‐Induced Cavitation in Li‐Metal Stripping

   https://doi.org/10.1002/adma.202209091  

   Wang, Chunyang; Lin, Ruoqian; He, Yubin; Zou, Peichao; Kisslinger, Kim; He, Qi; Li, Ju; Xin, Huolin_L (December 2022, Advanced Materials)

   Abstract Designing stable Li metal and supporting solid structures (SSS) is of fundamental importance in rechargeable Li‐metal batteries. Yet, the stripping kinetics of Li metal and its mechanical effect on the supporting solids (including solid electrolyte interface) remain mysterious to date. Here, through nanoscale in situ observations of a solid‐state Li‐metal battery in an electron microscope, two distinct cavitation‐mediated Li stripping modes controlled by the ratio of the SSS thickness (t) to the Li deposit's radius (r) are discovered. A quantitative criterion is established to understand the damage tolerance of SSS on the Li‐metal stripping pathways. For mechanically unstable SSS (t/r < 0.21), the stripping proceeds via tension‐induced multisite cavitation accompanied by severe SSS buckling and necking, ultimately leading to Li “trapping” or “dead Li” formation; for mechanically stable SSS (t/r > 0.21), the Li metal undergoes nearly planar stripping from the root via single cavitation, showing negligible buckling. This work proves the existence of an electronically conductive precursor film coated on the interior of solid electrolytes that however can be mechanically damaged, and it is of potential importance to the design of delicate Li‐metal supporting structures to high‐performance solid‐state Li‐metal batteries. 

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2. The Extremely Metal-poor SN 2023ufx: A Local Analog to High-redshift Type II Supernovae

   https://doi.org/10.3847/1538-4357/ad8448  

   Tucker, Michael_A; Hinkle, Jason; Angus, Charlotte_R; Auchettl, Katie; Hoogendam, Willem_B; Shappee, Benjamin; Kochanek, Christopher_S; Ashall, Chris; de_Boer, Thomas; Chambers, Kenneth_C; et al (November 2024, The Astrophysical Journal)

   Abstract We present extensive observations of the Type II supernova (SN II) SN 2023ufx, which is likely the most metal-poor SN II observed to date. It exploded in the outskirts of a low-metallicity (Z_host∼ 0.1Z_⊙) dwarf (M_g= −13.39 ± 0.16 mag,r_proj∼ 1 kpc) galaxy. The explosion is luminous, peaking atM_g≈ −18.5 mag, and shows rapid evolution. Ther-band (pseudobolometric) light curve has a shock-cooling phase lasting 20 (17) days followed by a 19 (23) day plateau. The entire optically thick phase lasts only ≈55 days following explosion, indicating that the red supergiant progenitor had a thinned H envelope prior to explosion. The early spectra obtained during the shock-cooling phase show no evidence for narrow emission features and limit the preexplosion mass-loss rate to $\dot{M}\lesssim {10}^{-3}$M_⊙yr⁻¹. The photospheric-phase spectra are devoid of prominent metal absorption features, indicating a progenitor metallicity of ≲0.1Z_⊙. The seminebular (∼60–130 days) spectra reveal weak Feii, but other metal species typically observed at these phases (Tiii, Scii, and Baii) are conspicuously absent. The late-phase optical and near-infrared spectra also reveal broad (≈10⁴km s⁻¹) double-peaked Hα, Pβ, and Pγemission profiles suggestive of a fast outflow launched during the explosion. Outflows are typically attributed to rapidly rotating progenitors, which also prefer metal-poor environments. This is only the second SN II with ≲0.1Z_⊙and both exhibit peculiar evolution, suggesting a sizable fraction of metal-poor SNe II have distinct properties compared to nearby metal-enriched SNe II. These observations lay the groundwork for modeling the metal-poor SNe II expected in the early Universe. 

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3. Peculiarities of the chemical enrichment of metal-poor stars in the Milky Way Galaxy

   https://doi.org/10.1051/0004-6361/202449816  

   Mishenina, T; Pignatari, M; Usenko, I; Soubiran, C; Thielemann, F-K; Kniazev, A Yu; Korotin, S A; Gorbaneva, T (July 2024, Astronomy & Astrophysics)

   Context. The oldest stars in the Milky Way are metal-poor with [Fe/H] < −1.0, displaying peculiar elemental abundances compared to solar values. The relative variations in the chemical compositions among stars is also increasing with decreasing stellar metallicity, allowing for the pure signature of unique nucleosynthesis processes to be revealed. The study of ther-process is, for instance, one of the main goals of stellar archaeology and metal-poor stars exhibit an unexpected complexity in the stellar production of ther-process elements in the early Galaxy. Aims. In this work, we report the atmospheric parameters, main dynamic properties, and the abundances of four metal-poor stars: HE 1523-0901, HD 6268, HD 121135, and HD 195636 (−1.5 > [Fe/H] > −3.0). Methods. The abundances were derived from spectra obtained with the HRS echelle spectrograph at the Southern African Large Telescope, using both local and non-local thermodynamic equilibrium (LTE and NLTE) approaches, with the average error between 0.10 and 0.20 dex. Results. Based on their kinematical properties, we show that HE 1523-0901 and HD 195636 are halo stars with typical high velocities. In particular, HD 121135 displays a peculiar kinematical behaviour, making it unclear whether it is a halo or an accreted star. Furthermore, HD 6268 is possibly a rare prototype of very metal-poor thick disk stars. The abundances derived for our stars are compared with theoretical stellar models and with other stars with similar metallicity values from the literature. Conclusions. HD 121135 is Al-poor and Sc-poor, compared to stars observed in the same metallicity range (−1.62 > [Fe/H] > −1.12). The most metal-poor stars in our sample, HE 1523-0901, HD 6268, and HD 195636, exhibit anomalies that are better explained by supernova models from fast-rotating stellar progenitors for elements up to the Fe group. Compared to other stars in the same metal-licity range, their common biggest anomaly is represented by the low Sc abundances. If we consider the elements beyond Zn, HE 1523-0901 can be classified as an r-II star, HD 6268 as an r-I candidate, and HD 195636 and HD 121135 exhibiting a borderliner-process enrichment between limited-r and r-I star. Significant relative differences are observed between the r-process signatures in these stars. 

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4. Trace metal contents of autotrophic flagellates from contrasting open‐ocean ecosystems

   https://doi.org/10.1002/lol2.10258  

   Sofen, Laura E.; Antipova, Olga A.; Ellwood, Michael J.; Gilbert, Naomi E.; LeCleir, Gary R.; Lohan, Maeve C.; Mahaffey, Claire; Mann, Elizabeth L.; Ohnemus, Daniel C.; Wilhelm, Steven W.; et al (May 2022, Limnology and Oceanography Letters)

   Abstract Nano‐ and picophytoplankton are a major component of open‐ocean ecosystems and one of the main plankton functional types in biogeochemical models, yet little is known about their trace metal contents. In cultures of the picoeukaryoteOstreococcus lucimarinus, iron limitation reduced iron quotas by 68%, a fraction of the plasticity known in diatoms. In contrast, a commonly co‐occurring cyanobacterium,Prochlorococcus, showed variable iron contents with iron availability in culture. Synchrotron X‐ray fluorescence was used to measure single‐cell metal (Mn, Fe, Co, Ni, Zn) quotas of autotrophic flagellates (1.4–16.8‐μm diameter) collected from four ocean regions. Iron quotas were tightly constrained and showed little response to iron availability, similar to culturedOstreococcus. Zinc quotas also did not vary with zinc availability but appeared to vary with phosphorus availability. These results suggest that macronutrient and metal availability may be equally important for controlling metal contents of small eukaryotic open‐ocean phytoplankton. 

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5. Hanensula anomala isolated from the Berkeley Pit, Butte, MT, is a metal-specific extremophile

   https://doi.org/10.1128/spectrum.00444-24  

   Roessler, Kyle; Friedlander, Mariah C; VanSickle, Marthe Y; Rush, Christina L (October 2024, Microbiology Spectrum)

   Hom, Erik_F Y (Ed.)

   ABSTRACT A yeast-like extremophile organism,Hansenula anomala, has been isolated from the superfund site the Berkeley Pit Lake in Butte, Montana. Studies demonstrateH. anomalagrowth in some of the known Berkeley Pit Lake solutes. Microbial growth dynamics under controlled conditions were compared ofH. anomalafor multiple metal concentrations. Each solute/metal was tested separately at previously reported concentrations on the geochemistry of the Berkeley Pit lake in the first 0.2 m in spring (pH 2.5).H. anomalagrew well with sulfur (S), MgSO₄, CaSO₄, potassium chloride (KCl), and NaSO₄and was inhibited with FeSO₄, MnSO₄, CuSO₄, AlSO₄, or ZnSO₄. With the addition of elemental S, growth was observed for FeSO₄indicating minimal growth rescue. PCR amplification of genomic DNA from the organism using known ribosomal primers indicates the strain to be ATCC8168 (CBS 5759). From this data, it can be concluded thatH. anomalaATCC8168 from the Berkeley Pit is an extremophile that exhibits metal-specific growth.IMPORTANCELaboratory growth studies of a strain ofHansenula anomalafrom the Berkeley Pit have found the organism to be metal specific indicating some unique metabolism possibilities. These studies show that this strain is metal-dependent and provides information about the adaptable tolerance of organisms in superfund sites as well as giving a basis for future bioremediation development utilizingH. anomala. 

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