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A new precipitation strengthening NiCoCr-based superalloy with favorable mechanical performance and corrosion resistance was designed for ultra-supercritical power generation equipment. The degradation of mechanical properties and steam corrosion at high temperatures put forward higher requirements for alternative alloy materials; however, when the superalloy is processed to form complex shaped components through advanced additive manufacturing techniques such as laser metal deposition (LMD), hot cracks are prone to appear. This study proposed that microcracks in LMD alloys could be alleviated with powder decorated by Y2O3 nanoparticles. The results show that adding 0.5 wt.% Y2O3 can refine grains significantly. The increase in grain boundaries makes the residual thermal stress more uniform to reduces the risk of hot cracking. In addition, the addition of Y2O3 nanoparticles enhanced the ultimate tensile strength of the superalloy at room temperature by 18.3% compared to original superalloy. The corrosion resistance was also improved with 0.5 wt.% Y2O3, which was attributed to the reduction of defects and the addition of inert nanoparticles. [ABSTRACT FROM AUTHOR]

The stability of perovskite nanocrystals (NCs) is greatly limited due to highly dynamic binding of ligands, which hinders their applications in optoelectronic devices. In this paper, a new ligand strategy was employed to prepare CsPbBr3 NCs via a facile room temperature (RT) ligand-assisted reprecipitation (LARP) method, where N1.N2-didodecyl-N1.N1.N2.N2-tetramethylethane-1.2-diaminium bromide (DTDB) as the sole capping ligand and an additional Br resource was used. Compared to other ligands with one coordinating group, this class of bidentate ligand can be tightly anchored to the surface of NCs with double N+ sites. The as-synthesized DTDB-CsPbBr3 NCs exhibited a high photoluminescence quantum yield (PLQY) of 92.3% and also showed a superior colloidal stability even under intense purification for up to ten cycles. Compared to the dodecyltrimethyl ammonium bromide (DTAB) ligand capped-CsPbBr3 NCs, the DTDB-CsPbBr3 NCs display obviously enhanced stability to light, heat and water. X-ray photoelectron spectroscopy (XPS) results revealed that the DTDB-CsPbBr3 NCs have a Br− rich surface, which accounts for the high stability and PLQY. Hence, DTDB is a promising ligand to prepare perovskite NCs with higher optical performance. [ABSTRACT FROM AUTHOR]

As a kind of high linear energy transfer (LET) radiation, internal conversion electrons are emitted from some radionuclides, such as 125 I, triggering severe DNA damage to tumor cells when transported into the nucleus. Herein, we develop a curcumin-loaded nanomicelle composed of a photosensitizer chlorin e6 (Ce6) and amphiphilic poly(ethylene glycol) (poly(maleic anhydride- alt -1-octadecene)-poly(ethylene glycol) (C 18 -PMH-PEG)) to deliver 125 I into the nucleus under 660 nm laser irradiation, leading to the optimized imaging-guided internal conversion electron therapy of cancer. Ce6-containing nanomicelles (Ce6-C 18 -PEG) self-assemble with nucleus-targeted curcumin (Cur), obtaining Ce6-C 18 -PEG/Cur nanoparticles. After labeling Cur with 125 I, Ce6-C 18 -PEG/Cur enables single-photon emission computed tomography and fluorescence imaging of the tumor, serving as a guide for follow-up laser irradiation. Notably, the 660 nm laser-triggered photodynamic reaction of Ce6 optimizes the delivery of Ce6-C 18 -PEG/ 125 I-Cur at various stages, including tumor accumulation, cellular uptake, and lysosome escape, causing plenty of 125 I-Cur to enter the nucleus. By this strategy, Ce6-C 18 -PEG/ 125 I-Cur showed optimal antitumor efficacy and high biosafety in mice treated with local 660 nm laser irradiation using efficient energy deposition of internally converted electrons over short distances. Therefore, our work provides a novel strategy to optimize 125 I delivery for tumor treatment.