National Science Review最新文献

Direct recycling has emerged as a promising alternative to existing recycling methods due to its simplicity and cost-effectiveness. However, its scalable application remains a subject of debate, primarily due to the complexity of mixed degraded cathode materials in practice. The reason is that degraded materials with different compositions are extremely difficult to be repaired to produce cathode materials with uniform composition and performance. Herein, we have successfully realized direct regeneration of mixed heterogeneous degraded LiNi_0.5Co_0.2Mn_0.3O₂ from different sources on an industrial scale. First, uniform contact lithiation is achieved through the van der Waals force between Li-1-methyl-2-pyrrolidinone and LiNi_0.5Co_0.2Mn_0.3O₂ molecules, leaving them in a uniform lithium-rich state. A self-saturating synthetic lithiation process occurs during subsequent heating, ensuring that each particle from various sources is repaired as needed. This method has been demonstrated to treat 50 kg of cathode materials per batch, and the regenerated products show uniform and excellent performance, achieving a retention rate of 90.7% after 1500 cycles in Ah-level pouch cells. This performance is the best result reported to date and sets a new benchmark for regenerated LiNi_xCo_yMn_1-x-yO₂ cathode materials, which have reached the standard for direct commercial use.

Metal nanoparticles include molecular nanoclusters and metallic nanocrystals. Investigating the critical transition sizes from nanoclusters to nanocrystals is appealing. However, achieving precise size control near the critical size region remains challenging, especially for not-so-noble metal nanoparticles (Ag, Cu etc.). Herein, we introduced an active metal anti-galvanic doping strategy to resolve both stability and multi-dispersity issues and demonstrated the gram-scale synthesis (2.40 g of crystals, more than 200 times the existing crystal output record for over 100-metal-atom nanoparticles) of a 1796-atom Ag-Zn nanoparticle. Furthermore, we successfully de-alloyed the Ag-Zn nanoparticles with the remaining structure essentially unchanged via a ligand-exchange method, obtaining 1.03 g of mono-Ag nanoparticle crystals in a one-pot reaction. Such a surgery-like de-alloying was not previously reported. Both of the as-obtained nanoparticles exhibit penta-twinned face-centered cubic (fcc) structures with well-defined shape-number arrangements and display plasmon-like absorptions yet exist in molecular states, as evidenced by ultrafast dynamics measurements. Furthermore, crystallization-induced photothermal enhancement and size-dependent absorbance were observed.

Jacques Laskar (1955-) is a preeminent French astronomer and celestial mechanician whose work has fundamentally reshaped our understanding of the Solar System's long-term dynamics and Earth's climate history. As a Research Director at the CNRS (French National Centre for Scientific Research) and at the Paris Observatory, he is widely known for his 1989 numerical demonstration that the Solar System's long-term evolution is chaotic and therefore cannot be precisely predicted. He is also renowned for developing numerical astronomical solutions that underpin astronomically calibrated timescales. For these transformative contributions, he has received prestigious accolades, and an asteroid has been named after him. In recent years, he has focused on the AstroGeo project, which aims to invert geological records to infer past orbital parameters and reconstruct the precise planetary motions across large spans of geological time. In December 2025, NSR spoke with Prof. Laskar in Beijing. During the conversation, he shared insights on the Solar System's past, present and future, discussed his current research and reflected on his unusual career path, from a high-school teacher to a leading scientist.

Over the past decade, China has achieved remarkable progress in mitigating aerosol pollution. However, ozone (O₃) pollution still shows a worsening trend, implying that China's control measures may have been less effective in tackling O₃ pollution. Herein, we conduct synchronized observations of O₃ and its precursors across 37 cities in the heavily polluted North China Plain (NCP) during the summer of 2021 and apply a unified observation-based model to diagnose O₃ formation mechanisms. Our results reveal a significant transition in the urban O₃ formation regime, shifting from being primarily volatile organic compound (VOC) limited to VOC-nitrogen oxides (NO_x) co-limited across the NCP between the 2010s and the 2020s. Notably, the primary VOC species, their respective sources, and the optimal VOCs/NO_x reduction ratios exhibit remarkable regional consistency. Modeling analyses further indicate that a long-term national 'carbon neutrality' strategy could effectively alleviate O₃ pollution, with targeted VOC emission reductions from major anthropogenic sources offering the greatest mitigation potential. These findings underscore the efficacy of China's endeavors in mitigating O₃ pollution, although the effects are not immediately evident from ambient O₃ concentrations. O₃ pollution control in Chinese cities has reached a critical inflection point, offering considerable flexibility and feasibility in formulating future control policies.

The integration of high-temperature superconductors into electric propulsion systems, particularly applied-field magnetoplasmadynamic thrusters (AF-MPDTs), has recently garnered significant attention. However, research on low-power, high-temperature-superconducting (HTS)-based MPDTs, which are crucial for small satellites and CubeSats, remains limited. The increasing demand for compact, high-efficiency propulsion in low Earth orbit underscores the need for scalable HTS-AF-MPDT systems operating below 15 kW. Despite this, challenges such as the lack of detailed theoretical models, limited plasma diagnostics and excessive Joule heating in conventional copper magnets persist. In this work, using a downscaled version of a 25 kW HTS-based AF-MPDT, we address these limitations by developing and experimentally validating a theoretical MHD-based plasma-acceleration model for an AF-MPDT equipped with a conduction-cooled HTS magnet. The system achieves a specific impulse of 3265 s at an input power of 12 kW, more than eight times higher than traditional chemical propulsion, alongside a thrust of 320 mN and an efficiency of 25% at sub-12 kW. The HTS magnet reduces magnetic power consumption from 285 kW to under 1 kW and lowers magnet mass from 220 to 60 kg, enabling substantial improvements in system miniaturization and efficiency. These results represent the first reported demonstration of a 12 kW HTS AF-MPDT, bridging theoretical predictions with experimental outcomes and laying the groundwork for in-orbit demonstration of high-performance propulsion for small satellites.

Photocatalytic coupling of monofunctional molecules offers an atom-efficient route for the synthesis of value-added bifunctional organic compounds, yet its efficiency is significantly limited by the reverse reaction of radicals. Our density functional theory (DFT) calculations have indicated that a unique structure of partially exposed Pt encapsulated by a titanium oxide (TiO₂) overlayer could intrinsically facilitate the desorption and suppress re-adsorption of reactive radicals, hence impeding the reverse reaction in the photocatalytic acetonitrile coupling reaction. A TiO_2-x/Pt inverse heterostructure has then been developed via strong metal-support interaction (SMSI) with tunable TiO_2-x coverage. Among the catalysts, an optimal partially encapsulated TiO_2-x/Pt catalyst achieves a marked formation rate of succinonitrile of 8.41 mmol·g_cat ^-1· h^-1 from acetonitrile, reaching a 67.3% radical-to-product efficiency and a 5.6% apparent quantum yield, representing 3-fold enhancements over a conventional Pt-supported TiO₂ catalyst, over 1.9-fold higher than bare Pt/TiO₂ or fully encapsulated counterparts, respectively. Kinetic investigations demonstrate that the suppression of radical-proton recombination plays a more dominant role in the overall coupling performance compared to the radical initiation. This work underscores the critical role of tailored catalysts by coating with oxide domains to mitigate reverse reactions and establishes an effective strategy for advancing the efficiency in photocatalytic coupling.