Abstract Healthy freshwater ecosystems are crucial for sustainable development, yet they face growing threats from unsustainable water use. However, current water scarcity metrics focus almost exclusively on human demand, overlooking whether sufficient water remains to sustain ecosystems. We address this gap by presenting the first evaluation of ecological water scarcity (EWS) across 1,182 river basins, introducing a novel indicator that recognizes ecosystems as legitimate water users to those of humans. Our findings reveal that in the 2000s, 412 basins (35% globally; 17% annual, 18% seasonal) experienced EWS, with affected areas expanding by 10 million km² since the 1950s. Human intervention intensified EWS in 13% of basins and caused 53% of seasonal and 60% of annual EWS cases. By the 2050s, affected basins range from 392 under RCP2.6–SSP1 to 416 under RCP8.5–SSP5, with persistent hotspots in regions of intensive water use. These findings show that climate mitigation can reduce future EWS risk, but environmental flow protection, water-use efficiency, water recycling, ecologically informed infrastructure operation and ecosystem restoration are also needed to safeguard freshwater ecosystems.
Abstract The insufficient lateral electric field gradient limits the programming/erasing speed of conventional semi-floating gate transistors, while charge leakage leads to poor data retention and compromised operating characteristics. Here we design a ferroelectric semi-gate (FSG) transistor featuring a triangular air gap adjacent to the drain region. The device exhibits an as-programmed on–off ratio exceeding 107, remaining above 105 after 11 weeks, and a memory window of approximately 6 V. The localized lateral electric field accelerates program and erase operations to 60 ns and 75 ns, respectively. The spontaneous polarization field of the ferroelectric HfZrO layer strengthens charge retention in the HfO2 charge-trapping layer, enabling robust nonvolatile memory performance with a retention time exceeding 106 s. This synergistic integration of air-gap engineering and ferroelectric polarization yields an optimal trade-off between speed, retention and multilevel operation. By exploiting its superior multilevel capability with 9-bit distinguishable current states, we realize Ising-model-based image denoising using a 32 × 32 transistor array. These FSG transistors show promising potential for high-speed, low-power random-access memory applications.
Abstract Liquid-phase separation underpins numerous sectors of modern chemical industry, yet achieving high selectivity for separation of mixtures of organic compounds remains a persistent challenge. Metal-organic frameworks (MOFs), showing exceptional tunability in composition, topology and pore environment, hold unique promise to address this challenge. This review surveys recent progress in studies of MOFs for the selective extraction and purification of organic substrates in liquid phase, with a focus on elucidating the mechanism of selectivity. Function-directed design principles, encompassing tailored bonding interactions, programmable supramolecular environments and pore-confinement effects, are discussed as enabling precise control over transport processes. These concepts are examined across key application domains, including removal of pollutants in water treatment, the separation of structurally similar hydrocarbons in petrochemical refinery and the selective discrimination of daily pharmaceuticals. Opportunities for the next generation of MOF-based sorbents are outlined, highlighting challenges associated with scalability and long-term operational stability, and the growing roles of artificial intelligence (AI)-guided discovery in developing sustainable separation technologies are further projected.
Abstract Over the past four decades, the National Natural Science Foundation of China (NSFC) has provided sustained and stable support for the development of surface chemistry in China, particularly in the field of scanning probe microscopy (SPM). Based on data from NSFC-funded SPM-related projects between 2000 and 2025, the funding landscape and its evolution in SPM research across different periods, as well as the shifting funding priorities among talent‑oriented, research‑oriented, and instrument development projects, are comprehensively analyzed. The major progress and innovative achievements in surface chemistry enabled by the advancement of SPM technologies under NSFC support are highlighted. The contribution of SPM to surface chemistry, the technical advancements of SPM, and the emerging new frontiers and challenges in surface chemistry are outlined. Finally, this review presents the key research directions and priority areas during the 15th Five-Year Plan period.
Abstract The fundamental elements that constitute amino acids (carbon, hydrogen, oxygen, and nitrogen) can all be obtained from the air. This raises a compelling question: ‘Could suitable catalytic pathways be developed to directly activate and couple these atmospheric elements into amino acids?’ However, due to the inherent inertness of air and the difficulty of coordinating multiple bond-cleavage and bond-formation steps, direct amino acid synthesis from air has not yet been achieved. In this work, we report an electrochemical-thermochemical-plasma cascade route for synthesizing glycine directly from air. This strategy relies on an electrolyzer with a solid-state electrolyte, a plasma device with a high working area, and a multifunctional SnO2 catalyst. In situ characterization and theoretical calculations demonstrate that the designed multifunctional SnO2 catalyst facilitated glycine synthesis by enriching key intermediates (*OCHO, *NH2OH, and *CHOCOOH), achieving 90.8% selectivity and a record production rate of 155 mmol g−1 h−1. This approach provides a practical strategy for synthesizing high-value compounds directly from atmospheric components.
