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[Display omitted] • Double-peak age strengthening phenomenon was first found in the Cu–Be–Ni–Co alloys. • The coherency strengthening of tiny nanoprecipitates contributes significantly to the appearance of first peak. • The light-mass Be atoms were directly made out by using the iDPC-STEM technology. Unconventional double-peak age strengthening phenomenon has occasionally been observed in some alloys, yet the underlying mechanism responsible for this phenomenon are still unclear. Here, we for the first time report the double-peak age strengthening phenomenon in the Cu–Be–Ni–Co alloys and try to unveil the underlying mechanism. Both the theoretical and experimental analyses demonstrate that the strong coherency strengthening effect of tiny nanoprecipitates (<1 nm) contributes significantly to the appearance of first peak, whereas the order-to-Orowan strengthening transformation accounts for the appearance of second peak. Moreover, the precipitate evolution processes of the alloys are identified as Guinier–Preston (GP) zones → γ′′→ γ′ and the light-mass Be atoms in the γ′ phase are directly made out by using integrated differential phase-contrast scanning transmission electron microscopy (iDPC-STEM) technology. Our work may provide new insights into the coherency strengthening effects and demonstrates a powerful strategy for designing high performance via double-peak behavior. [ABSTRACT FROM AUTHOR]

[Display omitted] • A new method was proposed for preparing modified clays to control harmful algae blooms: single source with series modifications. • Kaolin that was modified by the new method could remove over 85% of Prorocentrum donghaiense cells. • Calcination, acid–alkali treatment, and the supplementation of raw kaolin during aging were indispensable processing steps in the new method. • A schematic mechanism of kaolin modification by the new method to obtain modified clay with high algal cell removal efficiency was illustrated. Modified clay (MC) is an effective and eco-friendly material that is widely used for controlling harmful algae blooms (HABs). In this study, a new method—single source with series modifications (SSSM)—was optimized for preparing a high-quality MC, and aluminum-rich clay (kaolin) was activated with a multistep treatment that included calcination (Cal), acid etching with alkali neutralization (Al–An), and raw clay supplementation and aging (RSA). The results showed that the removal efficiency of Prorocentrum donghaiense by the SSSM–MC exceeded 85%; Cal, Al–An, and RSA were indispensable processing steps for preparing the best MC with the SSSM method. The changes occurring in the mineral structure and chemical composition of kaolin treated by the different steps were characterized by FT-IR, XRD, 27Al-NMR and Al-Ferron. Surface dehydroxylation and disruption of the kaolin lattice after calcination significantly changed the aluminum structure from AlVI to AlV and AlIV. The relatively reactive AlV was readily released from the kaolin lattice with acid etching, and it subsequently reacted with external OH– to generate different polyhydroxyaluminum species because alkali was added during the Al–An step. The acidity of the above complex was further decreased by RSA, greatly increasing the yield of SSSM–MC while assuring the quality. [ABSTRACT FROM AUTHOR]