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We experimentally measure the spectral phase of plasma-mirror second-harmonic emission, reconstruct its near–transform-limited temporal profile, and validate through PIC simulations, demonstrating plasma mirrors as promising coherent sources for bright multi-color ultrafast field synthesis. 

While peer-to-peer conversations can be beneficial for children’s linguistic and mathematical development, the specific conditions needed to support optimal conversations remain elusive. As part of a larger project to infuse peer-to-peer interactions into mathematics instruction for multilingual students, 8- to 11-year-old children in the U.S. were videotaped by their teachers interviewing one another about their solution strategies to equal sharing problems. Partner Interviews were analyzed to determine the quality of the interactions between pairs using Barwell’s (2023) definition of negotiating meaning. This study examines the relationships among the quality of student negotiations, accuracy of strategies, similarities between strategies, and grade levels. Findings indicate that the degree to which students negotiated each other’s ideas varied, and the accuracy of students’ solutions was related to the quality of their negotiations. We provide a framework for assessing the quality of the peer-to-peer negotiations as well as concrete examples of the structures and scaffolds used to elicit these conversations. 

We demonstrate through high-fidelity particle-in-cell (PIC) simulations a simple approach for efficiently generating $20+$ GeV electron beams with the necessary charge, energy spread, and emittance for use as an injector in a future linear collider or a next generation XFEL. A high quality injected bunch is generated by self-focusing an unmatched electron driver in a nonlinear plasma wakefield. Over pump depletion distances, the drive beam dynamics and self-loading effects lead to high energy, low-energy spread output beams. For plasma densities of ${10}^{18}\mathrm{c}{\mathrm{m}}^{-3}$ , PIC simulation results indicate that self-injected beams with $0.52\mathrm{n}\mathrm{C}$ charge can be accelerated to 20 GeV with projected core energy spreads of $\lesssim 1\%$ , normalized slice emittances of $110\mathrm{n}\mathrm{m}$ , peak normalized brightness of $\gtrsim {10}^{19}\mathrm{A}/{\mathrm{m}}^2/{\mathrm{rad}}^2$ , and transfer efficiencies of $\gtrsim 44\%$ . 

The award ID is 2307525 but only 2007157 is shown in the column "What award(s) are associated with this product?". Besides, the journal editor told me that it has no ISSN 

This report presents the X-ray fluorescence (XRF) data generated by scanning sediment cores from International Ocean Discovery Program (IODP) Expedition 401 Site U1611 in the Alborán Sea as part of the Investigating Miocene Mediterranean–Atlantic Gateway Exchange (IMMAGE) Land-2-Sea drilling project. The main goal of Expedition 401 was to investigate the paleoclimate and paleoceanographic impact of changes in the Mediterranean–Atlantic gateway during the Late Miocene. Site U1611 is located on the eastern side of the Gibraltar Strait, the present-day gateway. The recovered succession is a nearly continuous record of sediment before, during, and after the formation of a salt giant in the Mediterranean, the Messinian Salinity Crisis (MSC; 5.33–5.97 Ma). XRF scanning of these sediment cores at very high resolution (ranging 2 mm to 5 cm) produces semiquantitative elemental abundance data providing geochemical information about paleoceanographic changes through time. These data show moderate positive correlation between terrigenous elements (e.g., Al strongly positively correlated to Si and Ti) and weak negative correlations between terrigenous and biogenic elements. In contrast with the well-developed orbital cyclicity visible in many Late Miocene Mediterranean successions, the XRF data from these cores lack obvious cyclicity. This is likely due to the Alborán Basin's complicated depositional environment, which consists of a mixture of gravity flows and thinly laminated pelagic/hemipelagic sediments. These new data provide additional evidence that permits the reconstruction of Late Miocene paleoceanographic conditions in the Alborán Basin. 

International Ocean Discovery Program Expedition 401 recovered 983 m of sediment from Portugal’s southwest margin in the northeast Atlantic Ocean at Site U1609 (37°22.6259′ N, 9°35.9120′ W; 1659.5 m water depth). This site was designed to recover the distal contourites deposited by the Mediterranean Overflow Water contour current from the late Miocene to the Pleistocene. We report semiquantitative elemental results from X-ray fluorescence scanning of sediment cores from Site U1609 (Holes U1609A and U1609B) scanned at a 4–5 cm resolution from ~202 to 509 m core depth below seafloor, Method A, equivalent to ~4.52 to ~7.8 Ma. Raw element intensities (in counts per second) for Al, Si, Ca, Ti, Mn, Fe, Rb, Sr, Zr, and Ba are presented here and correlated with lithofacies variations. We also identify biogenic-terrestrial input proportions and illustrate downcore cyclicity and correlation patterns between terrigenous components (Al, Si, Ti, Mn, and Ba), as well as their anticorrelations with biogenic (Ca and Sr) inputs. The cyclical variations in elemental ratios may help stratigraphic correlation between Holes U1609A and U1609B, astronomical tuning of the spliced record, and sedimentary interpretations of changes to the Mediterranean–Atlantic gateway and the bottom current circulation along the Atlantic margin of Portugal before, during, and after the Messinian Salinity Crisis.