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A Zincophilic and Negatively‐Charged Self‐Reconstructed Stratified Interface for Regulating Zn <sup>2+</sup> Conduction and Nucleation Toward Conformal Dendrite‐Free Deposition
ABSTRACT The practical deployment of aqueous Zn‐ion batteries (ZIBs) is hindered by poor cycling stability, a consequence of dendrite growth and side reactions originating from irregular Zn nucleation and sluggish Zn 2+ migration. Here, we construct a composite‐phase NaMgF 3 /Na 3 InF 6 nanocube interphase (NMIF@Zn) that undergoes dynamic in situ reconstruction during plating into a stratified architecture. This transformation generates a zincophilic inner layer via preferential In 3+ reduction, while the outer fluoride nanocubes retain a strong negative surface charge. The synergy between these reconstituted components and the nanocube matrix topology significantly enhances the interfacial electric double layer and creates unimpeded ion channels rich in zincophilic sites, collectively lowering the ion migration barrier and nucleation overpotential to enable conformal dendrite‐free deposition. Consequently, the NMIF@Zn symmetric cell achieves superior cycling stability for 2000 h at 3 mA cm −2 /3 mAh cm −2 , along with stable operation at a high depth of discharge of 81.9%. When paired with a MnO 2 cathode, the interphase‐optimized anode demonstrates excellent energy storage under high cathode loadings in both coin‐type and pouch‐cell configurations. This work establishes in situ interfacial conversion engineering as a powerful strategy to coordinately regulate ion flux and nucleation behavior, paving the way for durable Zn anodes in next‐generation energy storage.
Nozzle geometry optimization for high-current aluminum ion beam acceleration via direct plasma injection scheme
We report the generation of a record aluminum ion beam current exceeding 58 mA at the Al11+ charge state, accelerated to an energy of 5.5 MeV using the direct plasma injection scheme, which integrates a laser ion source (LIS) with a radio frequency quadrupole (RFQ) accelerator. The effect of nozzle geometry on beam extraction was systematically investigated using 8 and 12 mm tapered designs and an 18 mm cylindrical configuration. The 18 mm nozzle achieved the highest Al11+ beam current, while the 12 mm aperture provided a favorable balance between beam intensity and current density. Beam extraction simulations confirmed effective RFQ matching across multiple charge states, and solenoidal field tuning further enhanced plasma collimation. This work not only establishes a new benchmark for high-current ion beam generation but also provides a fundamental understanding of plasma–beam interface dynamics crucial for the next generation of high-intensity particle accelerators, particularly those employing LIS-RFQ systems.
Photochemical Cyclization of Tertiary Buta‐2,3‐dienamides to β‐Lactams Upon Triplet Energy Transfer
ABSTRACT A series of N , N ‐disubstituted buta‐2,3‐dienamides was prepared from 3‐butynoic acid and probed as substrates in a light‐induced photocyclization. It was found that xanthen‐9‐one (10 mol%) promotes the desired reaction to 3‐vinyl‐substituted 2‐azetidinones (β‐lactams) when performed at λ = 350 nm in acetonitrile as the solvent. Evidence was collected by transient absorption spectroscopy that the catalyst promotes excitation of the allene amide to its triplet state by Dexter energy transfer. Upon intramolecular hydrogen atom transfer from one of the nitrogen substituents, the ensuing 1,4‐diradical undergoes C─C bond formation to the lactam product. If the substituent at the nitrogen atom is a primary benzyl group, the product displays a stereogenic center in 4‐position and is formed exclusively as the trans ‐product (eleven examples, 18%–73% yield). If the substituent is secondary, 4,4‐disubstituted products are formed. If the buta‐2,3‐dienamide is substituted at the terminal carbon atom, the substituent at C3 in the 2‐azetidinone is an ( E )‐configured alkenyl group. Two alternative reaction pathways were observed, i.e. an intramolecular para photocycloaddition for N ‐phenyl substituted substrates and an elimination from the 1,4‐diradical intermediate. The vinyl group at C3 can serve as useful handle for consecutive transformations.
Investigation of backward switching and write margin optimization of SOT-MTJ devices
Spin–orbit-torque magnetic random access memory (SOT-MRAM) offers superior advantages compared to conventional spin-transfer-torque MRAM. However, it suffers from backward switching, which severely constrains the write current window, presenting critical challenges for commercialization. Here, we investigate this phenomenon in full SOT-magnetic tunnel junction structures fabricated on 300 mm wafers. Experiments and numerical simulations demonstrate that Joule heating and field-like torque are the primary factors that dominate the backward switching phenomenon. Based on these insights, the write margin is enhanced by optimizing the SOT layer thickness, pulse width engineering, and stray field optimizations. Our findings establish thermal management as a primary design consideration for scalable SOT-MRAM arrays.
Chemical Fluctuations and In‐Situ Structural Order Unlock High‐Performance Mg <sub>3</sub> Bi <sub>1.4</sub> Sb <sub>0.6</sub> ‐Based Thermoelectrics
ABSTRACT Carrier mobility ( µ H ) regulation is established as a core strategy for developing high‐performance thermoelectric (TE) materials. However, a long‐standing challenge lies in enhancing the overall TE performance for Mg 3 Bi 2 ‐based alloys through µ H optimization while retaining the favorable effects of multi‐scale defects on phonon scattering and strength‐ductility. Herein, we achieve the dual enhancement of TE and mechanical performance of Mg 3.2‐ x Q x (Bi 0.7 Sb 0.3 ) 1.99 Te 0.01 (Q = Cu or Ag) through chemical fluctuations and structural order. Specifically, Cu/Ag doping shifts the Fermi level deeper into the conduction band and narrows the bandgap, boosting the electrical conductivity. In‐situ synchrotron X‐ray pair distribution function and atomic probe tomography characterizations demonstrate that interstitial Cu/Ag atoms induce chemical fluctuations and structural order, thus effectively improving µ H while preserving strong phonon scattering. Meanwhile, multi‐scale defects not only scatter multi‐frequency phonons but also trigger multiple strengthening mechanisms, which concurrently reduce lattice thermal conductivity and improve mechanical properties. Ultimately, Mg 3.17 Cu 0.03 (Bi 0.7 Sb 0.3 ) 1.99 Te 0.01 and Mg 3.17 Ag 0.03 (Bi 0.7 Sb 0.3 ) 1.99 Te 0.01 demonstrate remarkable average zT values of 1.11 and 1.06 between 323 and 573 K, respectively, along with excellent compressive strengths of 402.3 and 386.9 MPa. This work demonstrates that chemical fluctuations and structural order establish a novel paradigm for the simultaneous optimization of zT ave and mechanical reliability of TE materials.
Experimental verification of acoustic wave focusing of sonic black holes
Broadband acoustic wave-focusing sonic black holes (SBHs) has recently been demonstrated numerically via topology optimization. Here, we present the first experimental characterization of an SBH-based wave-focusing structure. We design and fabricate a custom rectangular impedance tube to measure the transmission coefficient and to characterize the internal acoustic pressure distribution inside SBHs using a laser scanning vibrometer. Additionally, we experimentally investigate the effect of geometric asymmetry on the wave-focusing performance of SBH devices. The results show good agreement with numerical predictions and confirm the intrinsic acoustic wave-focusing behavior of SBH waveguides. Although both symmetric and asymmetric designs exhibit broadband transmission, their internal pressure fields differ significantly, demonstrating that broadband transmission does not necessarily correspond to enhanced acoustic wave focusing. These findings highlight the potential advantages of SBH configurations for improved acoustic wave sensing and facilitate practical applications that require improved detection of weak signals.
Fast Ultra‐Selective <sup>1</sup> H‐ <sup>15</sup> N 1D NMR Spectroscopy Unlocks Atom‐Resolved Dynamics of Low‐Complexity Protein Regions
ABSTRACT Insight into the conformational dynamics of proteins is essential toward understanding their function at a molecular level. The motions experienced by individual atoms in the protein can be precisely quantified through NMR relaxation rates, but their measurement requires well‐resolved spectral responses. Two‐dimensional 1 H‐ 15 N correlation spectra are the standard approach to resolve amide signals in protein NMR, but come with an excessive cost in experimental time when spectra are heavily congested due to limited 15 N chemical shift dispersions. This limitation often thwarts the characterization of dynamics for intrinsically disordered proteins, especially when they feature low‐complexity or homopolymer regions, or short sample life‐times. Here, we introduce a fast, ultra‐selective 1 H‐ 15 N 1D NMR method that allows high‐quality measurement of individual 15 N spin‐relaxation constants, even when 15 N resonances are merely 6–8 Hz apart. We demonstrate the new experiment by characterizing, for the first time, pico‐ to nanosecond dynamics along a 16‐residue polyglutamine stretch within the protein huntingtin, the causal agent of Huntington's disease, as well as millisecond conformational exchange in the SH3GL3 protein. The new experiment will find wide application in the study of conformational dynamics of intrinsically disordered proteins or any other biomacromolecule that features highly dense 1 H‐ 15 N 2D spectra.
Transient extension process of the off-state depletion region in GaN HEMTs with SiO2 passivation
This Letter investigates the transient extension process of the off-state depletion region along the channel in SiO2-passivated GaN HEMTs based on a channel-probe branch structure. An SiO2 passivation layer was deposited to partially suppress the surface traps and decelerate the dynamic extension process of the depletion region, facilitating measurements of the extension time of the depletion region (τext) at various probe distances (Ldp) under identical off-state conditions. For Ldp &lt; 4 μm, the depletion region extended quickly, then it slowed down and extended with a saturated extension rate for Ldp &gt; 4 μm. Technology Computer Aided Design simulation was performed to help understand the transient extension process of the depletion region. An exponential dependence of τext on the drain–gate bias (VDG) was also observed, which is due to the Poole–Frenkel emission-dominated surface trapping process under off-state conditions. The steady-state potential profile along the channel is also discussed.
Strategic Integration Between Trigonal Architecture Construction and Molecular Polarization Enhancement for Record SHG Effect in Selenates
ABSTRACT Although possessing similar structural and electronic configurations with the tetrahedral nonlinear optical (NLO) active units, such as [SO 4 ], [PO 4 ] and so on, the development of selenates with [SeO 4 ] units have been long term hindered due to the lack of effective approaches to enhance polarizability and optical anisotropy. Here, a strategic integration between trigonal architecture construction and molecular polarization enhancement was proposed, which resulted in the discovery of an exceedingly performant selenate optical material, namely Hg 6 O 2 H(SeO 4 ) 3 I 3 ( HSOI ). This compound possess unique pseudo‐planar [Hg 3 OI 3 ] secondary building units (SBUs), which formed the cloverleaf‐shaped layer and further construct the sandwich structure with the polar [SeO 4 H] FBUs inserted between the layers. Notably, HSOI exhibits an exceptionally large second harmonic generation (SHG) response (14.6×KDP), achieving a new record that is 170% higher than the previous value of nonlinear metal selenates. Meanwhile, a record high birefringence of selenates (∼ 0.2) was also achieved in HSOI . Theoretical calculations were carried out to reveal its optical origins and provide new insights for further structure‐driven functional materials design.
Narrow-linewidth diode laser using a dual-VBG external cavity feedback structure with polarization beam-splitting technology
High-power, narrow-linewidth diode lasers with a high side-mode suppression ratio (SMSR) are critical for achieving enhanced pumping efficiency in advanced laser systems. However, conventional volume Bragg grating (VBG)-based external cavity structures are prone to spectral self-excitation, which degrades spectral purity, reduces pump efficiency, and compromises overall system performance. This study aims to improve spectral purity and an SMSR by developing an external cavity feedback structure that integrates dual VBGs with polarization beam-splitting technology. The approach combines beam shaping with external cavity feedback from two VBGs. Experimental implementation produced a narrow-linewidth diode laser with a central wavelength of 780.112 nm, a spectral linewidth of 0.0767 nm, an SMSR exceeding 35 dB, and an output power of 8.56 W, corresponding to an electro-optical conversion efficiency of 46.27%. Results confirm that the proposed dual-VBG external cavity feedback structure simultaneously narrows the linewidth, enhances spectral purity, and improves the SMSR in high-power diode lasers. These improvements make the structure highly suitable for efficient gain media pumping in applications such as disk lasers, high-energy gas lasers, and fiber laser systems.
Benefits of Categorizing Noncovalent Bonds Based on Hydrogen, Halogen, Chalcogen, and Pnictogen Bonds
ABSTRACT Recent IUPAC recommendations define the halogen bond, the chalcogen bond, and the pnictogen bond as the interactions between nucleophilic sites and electrophilic elements of groups 17, 16, and 15 of the periodic table. In a recent paper Robin Taylor states that, the use of these three terms should be “deprecated” and he raises concern about the proposal that we made in a scientific perspective on this journal to use these three terms, along with the hydrogen bond one, as the core of a taxonomy of chemical interactions, wherein names refer to the electrophile group/atom. Here, we show how Taylor's position conflicts not only with the authoritative position of IUPAC, but also with the common practices of the chemists’ community. Our proposed naming scheme which refers to the electrophile group/atom far from concealing key information, as assumed by Taylor, enables for a precise language whose terminological richness is instrumental in communication efficiency. Our naming scheme presents the advantage to be invariant with respect to the evolving understanding of the nature of chemical interactions and to be tailored to automated database mining, ontology construction, and AI‐driven structure–property prediction.
Beyond Hydrogen Bonding: π···π Stacking Directed Self‐Assembly of Carboxylic Acid Clusters in the Gas Phase
ABSTRACT Carboxylic acids critically influence atmospheric chemistry by modulating acidity, new particle formation, and aerosol growth. The hydrogen‐bonding capability of the −COOH group drives the assembly of structurally diverse gas‐phase clusters with atmospheric species. Despite their importance, experimental data on larger carboxylic acid clusters remain limited, and computational predictions of their global minimum structures lack consensus. Here, we employ high‐resolution microwave spectroscopy to determine the geometries of formic acid and propiolic acid clusters, identifying three trimers and two tetramers. A total of 34 isotopologues were analyzed to robustly confirm the cluster structures. Symmetry‐adapted perturbation theory and many‐body expansion analyses demonstrate a fundamental transition in stabilization mechanisms: trimers rely on conventional hydrogen bonds, whereas tetramers exhibit cooperative π–π stacking interactions that drive a structural transformation from single‐layer to double‐layer architectures. These findings resolve long‐standing ambiguities in cluster configurations and establish essential benchmarks for modeling carboxylic acid‐driven atmospheric nucleation processes.
Modular Access to Nitriles From Carbonyls via Deoxygenative Transformation With Polarity Inversion
ABSTRACT The C─O bond cleavage has always been a central challenge for deoxygenation due to high bond dissociation energies. Here, we develop a Lewis acid‐promoted polarity inversion strategy that enables a strong C─O bond cleavage and rapid access to nitriles from carbonyls. Its broad applicability, together with the nontoxic and mild conditions, underscores the highly modular nature of this method.
Supramolecular Assembly of a Heavy‐Atom‐Free Highly Efficient Self‐Deliverable Photosensitizer for Activable Photodynamic Therapy
ABSTRACT This article introduces a heavy‐atom‐free, acceptor‐donor‐acceptor conjugated organic photosensitizer (ADA‐S), exhibiting an exceptional singlet oxygen ( 1 O 2 ) quantum yield (Φ∆) ∼1. The ADA‐S structure integrates two thionated naphthalene‐monoamide acceptors with a central thiophene donor moiety. To elucidate the impact of the extended conjugation on the photosensitizing efficiency, control molecules such as a less conjugated analogue (AD‐S), an acceptor‐only unit (NMIS‐Br) or an un‐thionated derivative (ADA‐O) were studied. Through the 1,3‐diphenylisobenzofuran (DPBF) assay, it was evident that ADA‐S significantly outperforms all controls in the 1 O 2 generation upon photoirradiation. Transient absorption spectroscopy studies, ranging from femtosecond‐to‐microsecond timescales revealed that extended conjugation is crucial for enhancing the triplet state longevity, which directly correlates with the observed enhancement in the 1 O 2 production. In sharp contrast, similar ADA‐type conjugated chromophore (ADA‐O), lacking thionation of the carbonyl groups, failed to produce any detectable 1 O 2 , indicating a remarkable impact of the sulphur atoms on the enhanced spin–orbit coupling, facilitating much faster intersystem crossing. Time‐dependent density functional theory calculations further supported these experimental findings, establishing ADA‐S as an outstanding new organic photosensitizer. Furthermore, an amphiphilic derivative of ADA‐S was prepared, which showed spontaneous self‐assembly in water producing nanoparticles, in which the photosensitizer remained in the dormant state due to π‐stacking. Such organic nanoparticles showed excellent cellular uptake and intra‐cellular swelling/ disassembly probed by FRET, facilitating reactivation of the photosensitization ability of the ADA‐S chromophore. Consequently, highly efficient light‐triggered cell death was noticed by reactive oxygen species.
A Constraining and Redox‐Active Aluminum Species With Diverse Reactivity
ABSTRACT This work reports the synthesis, full characterization, and multifaceted reactivity of a highly reactive aluminum complex ( 2 ·Et 2 O) supported by a sterically hindered, redox‐active pincer ligand. Characterization by X‐ray crystallography and spectroscopic methods confirmed its molecular structure, while Gutmann–Beckett studies and calculated fluoride ion affinity quantified its significant Lewis acidity. The reactivity profile of 2 ·Et 2 O is remarkably diverse: it undergoes facile photoinduced species formation, activates the O─H bond via metal–ligand cooperative heterolytic cleavage, and engages in redox reactions with substrates such as Ph 3 CCl and PhSSPh. Most notably, 2 ·Et 2 O demonstrates distinct selectivity in activating the C─I bond of iodoalkanes. This process proceeds via a kinetically favored or cooperative pathway, leading to alkyl group transfer to the ligand, rather than the thermodynamically preferred σ‐bond oxidative addition at the aluminum center. This study highlights how the synergy between an Al(III) center and a non‐innocent pincer ligand can unlock unique reaction manifolds, expanding the potential of main‐group elements in stoichiometric bond activation.
Efficient Organic‐Inorganic Sn <sup>4+</sup> ‐Based Halide Phosphorescent Scintillators Enabled by Enhanced Triplet Exciton Utilization and Excited Energy Level Regulation
ABSTRACT Despite remarkable X‐ray scintillation performance of inorganic or organic crystal materials, their practical application is often hindered by poor processability, weak X‐ray absorption, and/or inefficient exciton utilization. Developing organic‐inorganic hybrid metal‐halide phosphorescent scintillators is thus of vital importance for X‐ray imaging applications, yet remains scarcely explored. Herein, we report a series of organic‐inorganic hybrid Sn 4+ ‐based metal halides, designated as 3PP( R )‐Sn‐Cl ( R = H, F1, F2, Cl, Br), which exhibit efficient fluorescence, thermally activated delayed fluorescence (TADF), and room‐temperature phosphorescence (RTP) tailored through the substituent “ R ”. Multiple weak intermolecular interactions and strategic variation of the “ R ” group effectively modulate molecular stacking and excited‐state dynamics, thereby boosting X‐ray absorption and triplet exciton utilization. As a result, 3PP()‐Sn‐Cl achieves a record RTP efficiency of 79.1% and a long lifetime of 164.4 ms, the highest values reported to date for undoped Sn 4+ ‐based halides. Furthermore, we demonstrate multilevel information encryption applications leveraging the highly sensitive thermochromism properties of 3PP( R )‐Sn‐Cl. More importantly, benefiting from strong heavy‐atom‐effect and efficient triplet exciton utilization, 3PP( Br )‐Sn‐Cl exhibits a high light yield of 31213.3 photons MeV −1 and a low detection limit of 328.2 nGy/s under X‐ray irradiation, enabling efficient radiography with a spatial resolution over 14.0 lp mm −1 . This work for the first time demonstrates Sn 4+ ‐based metal halides as high‐performance scintillators for next‐generation X‐ray imaging technologies.
Trinuclear Heptamethine Dyes for Shortwave Infrared In Vivo Imaging
ABSTRACT The term polymethine dye (PMD) has been intimately connected to the dinuclear scaffold–two heterocycles linked together by a polymethine chain of varying length. Dinuclear PMDs have been a successful scaffold for noninvasive in vivo imaging in the biologically advantageous near infrared (NIR) and shortwave infrared (SWIR) regions of the electromagnetic spectrum. Trinuclear PMDs, resulting from the addition of a third heterocycle into the polymethine chain, possess the same photophysical properties that make dinuclear dyes excellent fluorescent probes, but have yet to be investigated for in vivo imaging. Herein, we expand upon the dinuclear and trinuclear heptamethine dye scaffolds by taking advantage of the increased reactivity of a cyclopentenyl linker and synthesizing flavylium‐ and chromenylium‐based SWIR‐emitting fluorophores. The trinuclear scaffold instills the fluorophores with increased steric bulk, leading to beneficial photophysical properties in micelles and outperforming their classic dinuclear counterparts. In this work, we apply trinuclear PMDs for in vivo SWIR imaging in mice and find them to be particularly efficient at lymph node labeling upon intravenous administration.
Ultrastable Enantiomeric Tetrapod Cu <sub>30</sub> Clusters With Near‐Infrared Circularly Polarized TADF
ABSTRACT The development of stable Cu(I) clusters exhibiting near‐infrared circularly polarized luminescence (NIR CPL) presents a significant challenge. In addressing this challenge, we present the synthesis of ultrastable chiral R / S ‐Cu 30 clusters through a dual‐ligand strategy, which feature a tetrapod metal skeleton and represent the largest nuclearity Cu(I) cluster reported to exhibit NIR CPL. The R / S ‐Cu 30 structure is self‐assembled from five octahedral Cu 6 units. R / S ‐Cu 30 exhibits excellent NIR CPL with high quantum yields of 40% in solution, benefiting from the characteristic of stable structure and thermally activated delayed fluorescence (TADF), marking the first observation of NIR circularly polarized TADF within the Cu(I) cluster family. Due to the exceptional stability, solution processability and NIR CPL property of R / S ‐Cu 30 , the NIR‐CP light‐emitting diodes were fabricated and exhibited g EL of +1.8/−2.1 × 10 −3 and an EQE of 8% with an emission wavelength of 732 nm. This study not only presents an enantiomeric pair of tetrapod‐like Cu 30 (I) clusters but also successfully addresses the intertwined challenges of stability, efficient NIR emission, and chiral luminescence in the design of copper clusters.
Enhancing Performance of CsSnBr <sub>3</sub> Light‐Emitting Diodes via Synergistic Ion Doping and in Situ Interfacial Reaction
ABSTRACT Tin‐based perovskites are among the most promising lead‐free emitters for perovskite light‐emitting diodes (PeLEDs), but their performance is severely hindered by the uncontrolled rapid crystallization and facile oxidation. Here, we report a synergistic bulk–interface strategy for enhancing performance of CsSnBr 3 PeLEDs by combining Zn 2+ bulk doping with an in situ interfacial reaction. Incorporation of ZnBr 2 suppresses Sn vacancies and residual SnBr 2 while regulating crystallization to improve film morphology. Concurrently, sodium citrate‐modified PEDOT:PSS promotes deprotonation of 6‐phosphonylhexyl acid, forming robust coordination bonds that delay crystallization and passivate defects. Benefiting from these dual effects, the optimized devices achieve a record external quantum efficiency for CsSnBr 3 PeLEDs. This work highlights the effectiveness of synergistic bulk–interface regulation in tuning crystallization kinetics, providing constructive insights for the development of efficient lead‐free perovskite optoelectronics.
Fluorescence Amplification Tags for Single‐Molecule Imaging and Tracking of Proteins, RNA, and DNA in Live Cells
ABSTRACT Single‐molecule imaging and tracking of DNA, RNA, and proteins have revolutionized molecular and cellular biology by shifting the focus from population‐level analyses to the direct observation of individual molecular events. However, conventional fluorescent labeling strategies, which tag biomolecules with a single fluorophore, are often hindered by low brightness, suboptimal signal‐to‐noise ratio (SNR), and rapid photobleaching, limiting localization precision and tracking duration. To overcome these challenges in single‐molecule imaging, fluorescence amplification tags (FATs) have been developed to enable the multiplexed labeling of individual macromolecules with multiple fluorescent reporters, enhancing signal intensity and photostability. This review presents a comprehensive overview of FAT design principles, working mechanisms, and their applications in labeling DNA, RNA, and proteins. We highlight their impact on elucidating dynamic genetic processes, including chromatin remodeling, gene expression regulation, mRNA translation, and protein interactions. Finally, we discuss existing challenges and propose future directions to further optimize FATs for single‐molecule imaging and tracking.