Science Bulletin最新文献

New particle formation (NPF) substantially affects air pollution and climate change. However, as an NPF hotspot, the mechanisms and impacts of NPF across broad spatial and temporal scales over China remain poorly understood, largely owing to the lack of critical NPF processes in atmospheric models. This study developed a comprehensive model that integrates 12 NPF mechanisms, including recent insights on various iodine-oxoacid-driven pathways and cluster-dynamics-based rate calculations. The updated model reduces model-observation discrepancies from around or over an order of magnitude to within ±30% across different sites and seasons. Simulations revealed that NPF over mainland China is driven primarily by sulfuric acid (H₂SO₄), dimethylamine (DMA), and iodic acid (HIO₃). Importantly, H₂SO₄-DMA nucleation is not only the dominant mechanism in urban atmospheres, but also a major contributor in agricultural and forested regions. Differently, the HIO₃-(H₂SO₄)-DMA mechanism contributes substantially in southeastern coastal areas, while iodine-oxoacid-H₂SO₄ pathways dominate in marine regions. High H₂SO₄ levels are identified as the main driver of eastern China's NPF hotspots, with temperature governing seasonal variations. Correspondingly, NPF contributes 10%-35% of cloud condensation nuclei (at 0.5% supersaturation) in the lower troposphere. Our models and findings support comprehensive understanding of NPF over China, and are also highly valuable for studying NPF in other regions with diverse emission sources and land cover types, and thereby contributing to accurate assessment of the environmental and climatic effects of aerosols.

The disordered quantum systems host three classes of quantum states, the extended, localized, and critical, which bring up seven distinct fundamental phases in nature: three pure phases and four coexisting ones with mobility edges, yet a unified theory built on universal mechanism and full realization of all these phases has not been developed. Here we propose a unified framework based on a spinful quasiperiodic (QP) system which realizes all the fundamental localization phases, with the exact and universal results being obtained for their characterization. First, we show that the pure phases are obtained when the chiral(-like) symmetry preserves in the proposed spinful QP model, giving a criterion for emergence of the pure phases and otherwise the coexisting ones. Further, we uncover a novel mechanism for the critical states that their emergence is protected by the generalized incommensurate matrix element zeros in the spinful QP model, which considerably broadens rigorous realizations of the exotic critical states. We then show criteria of exact solvability for the present spinful QP system, with which we construct various exactly solvable models for all distinct localization phases. In particular, we propose two novel models, dubbed spin-selective QP lattice model and QP optical Raman lattice model, to achieve all basic types of mobility edges and all the seven fundamental phases of Anderson localization physics, respectively. The experimental scheme is proposed and studied in detail to realize these models with high feasibility. This study establishes a complete and profound theoretical framework which enables an in-depth exploration of the broad classes of all fundamental localization phenomena in QP systems, and offers key insights for constructing their exactly solvable models with experimental feasibility.

The rapid rise in chip heat generation places increasing demands on thermal interface materials (TIMs), requiring higher thermal conductivity and more efficient thermal conduction pathways. Here, we introduce a new design strategy for TIMs that directs heat transfer in three stages: horizontal distribution, vertical transfer, and horizontal dissipation. Using the direct ink writing three-dimensional printing technique, we fabricate polydimethylsiloxane (PDMS)-based TIMs with a colonnade-inspired architecture. The top and bottom "corridors" are formed from a boron nitride nanosheet (BNNS)/PDMS composite, where BNNS fillers are aligned in the in-plane direction to enhance lateral heat conduction. The central "pillar" layer is composed of a reduced graphene oxide (rGO)/PDMS composite, with rGO fillers aligned in the through-plane direction to promote vertical heat transfer. Compared with conventional PDMS-based TIMs containing randomly dispersed fillers or sandwich structures with only in-plane alignment, our prepared colonnade-structured PDMS-based TIMs demonstrate significantly improved thermal conductivity and reduced thermal resistance for interfaces.

The rational design of dual-atom catalysts is pivotal for overcoming the intrinsic limitations imposed by Sabatier scaling relations in conventional single-atom catalysts. Herein, we present a homo-binuclear macrocyclic complex-mediated strategy for constructing cobalt-based diatomic catalysts, in which dioxygen-bridged cobalt dual-atom sites (Co-O₂-Co) are uniformly embedded within hierarchically porous carbon nanospheres (denoted Co-O₂-Co/HPCN) to promote efficient oxygen reduction reaction (ORR) catalysis. Notably, the hierarchically porous architecture, derived via a sacrificial-template approach, provides abundant and interconnected micro/mesopores that effectively confine the cobalt binuclear complex precursor, ensuring the atomic dispersion and structural integrity of Co-O₂-Co sites. Importantly, the unique Co-O₂-Co coordination motif stabilizes the *OOH intermediate through side-on bridge adsorption, thereby facilitating O-O bond cleavage and breaking the conventional *OOH-*OH scaling relationship. Benefiting from this synergistic structural and electronic modulation, Co-O₂-Co/HPCN achieves an onset potential of 1.016 V and a half-wave potential of 0.916 V, surpassing commercial Pt/C catalysts. Moreover, Co-O₂-Co/HPCN exhibits high power density and outstanding durability in both aqueous and flexible quasi-solid-state zinc-air batteries, underscoring its promise for next-generation energy technologies. This work establishes a robust molecular-to-material design platform for developing high-performance dual-atom catalysts and delivers atomic-level insights into optimizing sustainable energy conversion.

The advent of privileged chiral ligands has marked a transformative milestone in the realm of asymmetric catalysis, underscoring the imperative for developing efficient synthetic methodologies to access these compounds. Such advancements are crucial for the rapid generation of diverse chemical libraries endowed with varied steric and electronic properties. In this study, we unveil a highly efficient and streamlined approach for the construction of a broad spectrum of planar chiral [2.2]paracyclophane biarylphosphine (PCP-BPhos) ligands. Our innovative strategy leverages P(III)-directed C-H activation, which entails the direct arylation of triarylphosphines with enantiomerically enriched PCP bromides. A cornerstone of this methodology is the intrinsic phosphine moiety within the substrates, which serves as a directing group, thereby facilitating the formation of a benzo-fused four-membered metallacycle during the catalytic cycle. These in situ modified chiral ligands have exhibited exceptional efficacy in Pd-catalyzed asymmetric allylic alkylation and Suzuki-Miyaura coupling, underscoring their potential for widespread applications in asymmetric catalysis. Our comprehensive experimental and computational studies provide detailed mechanistic insights into these transformations, further elucidating the underlying principles of these catalytic processes.

Carrying more than 80% of the international trade volume, international shipping has become a critical challenge for achieving climate goals, yet prognostic approaches investigating future international shipping emission pathways and geographical patterns remain limited. Here, by constructing the "SEIM-forecast" (Shipping Emission Inventory Model-forecast) framework, we explicitly linked future international shipping emissions to trade demand, fleet dynamics, and spatial patterns and realized a multidimensional projection of international shipping CO₂ emissions under 24 trade-energy-technology scenarios. Overall, future international maritime trade demand growth alone is projected to increase international shipping CO₂ emissions in 2050 by 81%-96.9% relative to 2021, with other conditions held constant. Based on the fleet dynamic simulation, aligning international shipping CO₂ emissions with the International Maritime Organization (IMO) 2023 Strategy under increasing trade demand pressure requires advancing the full adoption of zero-carbon fuels for newly built vessels and accelerating fleet renewal. With the current average vessel lifespan of 25 years, full adoption of zero-carbon fuels for newly built vessels should occur by 2035. Extending full adoption to 2040 would require shortening the assumed lifespan of existing vessels by about five years (e.g., from 25 to 20 years). Evolving trade structures introduce strong spatial heterogeneity in future international shipping CO₂ emission intensity, with increases in the Gulf of Thailand (49.3%, 2050 relative to 2021), Andaman Sea (37.7%), and Gulf of Aden (34.4%) driven by South-South trade, and decreases along traditional fossil-fuel transport corridors, including the western Europe-Middle East-East Asia and Gulf of Mexico routes.

High spatiotemporal resolution remote sensing products are essential for advancing Earth system science. These products, which include key atmospheric and surface radiation parameters, are crucial not only for studying cloud-radiation-climate interactions and global radiative energy balance, but also for understanding multi-sphere interactions within the Earth system. The Cloud Remote Sensing, Atmospheric Radiation and Renewable Energy Application (CARE) algorithm system and products provide a comprehensive suite of around 30 parameters, including cloud and aerosol properties, atmospheric water vapor, and surface radiation budget. CARE products are primarily generated using observations from new-generation geostationary satellites like FY-4 and Himawari-8, combined with data from polar-orbiting satellites including FY-3 and MODIS, enabling multi-scale data coverage across East Asia and the globe. A key advantage of CARE products is their high spatiotemporal resolution: global products achieve a 5 km and 30-min spatiotemporal resolution, enabling detailed characterization of diurnal variations in parameters such as cloud cover, cloud water content and surface radiation flux. Notably, parameters like downward shortwave radiation show higher accuracy compared to other existing datasets. The CARE system integrates a full-spectrum ice crystal scattering model, the high-performance CARE radiative transfer model (CARE-RTM), advanced remote sensing retrieval algorithms incorporating artificial intelligence (AI) technology, and a near-real-time monitoring platform to facilitate product development. This study summarizes the recent development of CARE models, algorithms, and products, highlighting the unique features of the full-spectrum ice crystal scattering model, the enhanced RTM, high-performance remote sensing retrieval algorithms with accuracy evaluation, and the broad use of CARE-derived datasets in atmospheric and climate research.