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Recent Advances in Cholesteric Liquid Crystal Elastomers: Fabrication, Functionalization, and Applications
ABSTRACT Cholesteric liquid crystal elastomers (CLCEs) are a vibrant subset of photonic materials exhibiting extraordinarily mechanochromic properties that make them an ideal platform for the development of displays, sensing, anti‐counterfeiting, and camouflage technologies. In recent years, researchers have increasingly extended the structure and morphology of CLCEs to uncover their fascinating functionalities and promising applications. In this review, the historical development of CLCEs is retrospect, recent advances in the preparation methods are highlighted, and the well‐ordered CLCEs with extended functionality are introduced. Within this scope, we highlight the unique advantages of CLCEs and present recent progress in expanding their structural, morphological, and functional versatility. We conclude with an outlook on current challenges and near‐term application opportunities.
Quantitatively separating superexchange and direct exchange interactions in 2D ferromagnetic materials
Two-dimensional (2D) ferromagnetic (FM) materials are promising candidates for emerging energy-efficient electronic devices. Various modulation strategies have been proposed to increase their rather low Curie temperatures, including ligand substitution, strain, and voltage control. Fundamentally, the improvement of the Curie temperature can be attributed to strengthened FM superexchange interactions, weakened direct exchange interactions, or both. With only a qualitative understanding, the effects of the modulation strategies on the entangled superexchange and direct exchange interactions, and hence on the Curie temperatures, often cannot be unambiguously determined. Therefore, we propose a descriptor-based computational approach to quantitatively separate the contributions of the superexchange and direct exchange interactions to each magnetic exchange parameter. The approach combines density-functional calculations with the exchange mechanisms, and we apply it to the archetypal 2D magnetic monolayers CrSX (X= Cl, Br, or I). This work provides a basis for rationally designing and modulating 2D FM materials to achieve high Curie temperatures.
Electrothermal Oxidation of Ethylene Glycol Over Co <sub>3</sub> O <sub>4</sub>
ABSTRACT Purely electrocatalytic routes for the selective oxidation of alcohols are often limited by overpotential, mass transport, and kinetics due to multiple proton‐coupled electron‐transfer steps. We report the electrothermal oxidation of ethylene glycol (EG) over cobalt oxide (Co 3 O 4 ) spinel acting simultaneously as an electrocatalyst and a solid thermocatalyst by integrating enhanced temperature and 15 bar O 2 pressure in alkaline electrolyte at controlled current density. Enhanced EG oxidation was observed with increasing temperature from 30°C to 90°C. Glycolate and formate were the main products, while oxalate was only detected in long‐term experiments at lower current densities. Selectivity shifted from formate at low temperature, caused by electrochemical C–C cleavage, to rapid glycolate desorption at increased thermal conditions. The virtual Faradaic efficiencies (vFEs), which are the sum of all charge stored in the reaction products, reached 180% at 90°C, confirming that thermal oxidation by O 2 at high pressure contributes to an additional oxidative electron transfer at the solid‐electrolyte interface beyond the applied electrochemical potential. These findings demonstrate that superimposing thermal and electrochemical driving forces boosts performance and enables control over reaction pathways. The approach establishes a conceptual and practical framework toward synergy between electro‐ and thermocatalytic heterogeneous alcohol oxidation toward sustainable chemical transformations.
Geometric and size effects on the thermal conductivity of fishbone-like nickel nanowires
Thermal conductivity at the nanoscale often deviates significantly from that of bulk materials due to the mean free path of heat carriers becoming comparable to the system's dimensions, which challenges traditional heat transfer models. While magnetic nanowires are widely employed in various applications, their thermal properties remain poorly understood. This study investigates the thermal conductivity of nickel nanowires with a fishbone-like structure, focusing on the influence of flank angles (45°, 90°, and 135°) and characteristic sizes. Our results show that thermal conductivity decreases with decreasing flank angle relative to the heat flow direction, with this effect becoming negligible as the wire width approaches the microscale. Additionally, the thermal conductivity demonstrates a stronger size dependence in nanowires with acute flank angles (45°) compared to those with obtuse angles (135°). These results experimentally demonstrate a coupled effect of flank angle and characteristic width on the thermal conductivity of fishbone-like nickel nanowires, providing new insights into geometry-dependent thermal transport and offering guidance for the structural design of efficient thermal management systems.
A metal-free phosphorus–oxygen/nitrogen–carbon configuration as an effective metal–nitrogen–carbon analog for accelerated lithium-sulfur redox kinetics
The practical deployment of lithium-sulfur batteries is limited by the polysulfide shuttle effect arising from sluggish sulfur redox kinetics. While metal–nitrogen–carbon (M–N–C) catalysts are effective in promoting sulfur conversion, their synthesis suffers from metal aggregation and the mass penalty of transition metals reduces the practical energy density. Here, we design a metal-free phosphorus–oxygen/nitrogen–carbon (P–O/N–C) electrocatalyst that functionally mimics M–N–C configurations, offering simplified synthesis without metal-related issues. Spectroscopic analysis confirms the formation of P–O/N–C coordination sites. Electrochemical evaluation reveals that PONCNT exhibits superior catalytic activity in accelerating polysulfide conversion, particularly for the rate-limiting Li2S nucleation process, with a low Tafel slope and high Li2S deposition capacity. Crucially, this catalytic behavior faithfully reproduces the hallmark of M–N–C catalysts: moderate polysulfide adsorption but dramatically accelerated conversion kinetics, demonstrating that enhanced kinetics, not strong trapping, is the primary origin of its performance. This work establishes a metal-free strategy for constructing M–N–C analogs, opening a pathway toward lightweight, low-cost electrocatalysts for high-energy lithium-sulfur batteries.
Diastereoselective Synthesis of Axially Chiral Skipped Ene–Allenes Containing a Quaternary Stereocenter by Cyclopropene–Allene Metathesis
ABSTRACT Functionalized skipped ene–allenes (1,4‐enallenes) bearing an all‑carbon quaternary stereocenter were prepared by a diastereoselective ring‐opening metathesis of mesomeric cyclopropene and allene for the first time. A strategic pairing of a broad range of allenes with cyclopropenes revealed a new way to access high reactivity and chemoselectivity, and delivered products with excellent diastereoselectivity at low Ru catalyst loading. Mechanistic studies delineate the reactivity order of the metathesis partners, identify the key diastereoselectivity‐determining step, and clarify the main factors governing the cross‐/homo‐metathesis ratio and diastereoselectivity. The presence of allenyl–Bpin, –silyl, and –germanyl groups allows highly chemoselective functionalization at the allene over the terminal alkene, demonstrating the synthetic utility of the products as versatile intermediates in organic synthesis
Uniaxial strain-induced spin textures transition in the kagome magnet Fe3Sn2
The mechanical control of magnetism represents a promising frontier in spintronics. However, its experimental application is mostly confined to the elastic strain regime, which limits the exploration of magnetic responses under larger strain. Here, by applying uniaxial compressive strain to induce plastic deformation in an Fe3Sn2 lamella, we directly observed the room-temperature transformation of stripes into an intermediate state comprising vortices, stripes, and antivortex chains. This intermediate state was accessed by cycling either the magnetic field under fixed strain or the strain under a fixed magnetic field. The mixed state is metastable and evolves into vortices under the applied magnetic field. Micromagnetic simulations indicate that large strain induces a transition from out-of-plane easy axis to easy-plane anisotropy in Fe3Sn2, thereby facilitating the stripe-to-vortex transformation. By unraveling the strain-mediated interactions between magnetic anisotropy and domain structures, we provide crucial insights for the development of strain-controlled spintronic devices.
Interface charge inhomogeneity at Al2O3/OH-diamond (111) characterized by time-resolved scanning nonlinear dielectric microscopy
Inversion-channel diamond metal-oxide-semiconductor field-effect transistors (MOSFETs) suffer from channel mobility far below the bulk value, yet the microscopic origin of this limitation has not been fully elucidated. Because carriers in the inversion layer are confined close to the MOS interface, spatial inhomogeneity of interface charges is expected to play an important role through Coulomb scattering. However, such effects cannot be fully assessed by conventional macroscopic capacitance–voltage (CV) profiling. Here, we investigated local charge states at the Al2O3/OH-diamond (111) interface used in inversion-channel diamond MOSFETs by local CV profiling based on time-resolved scanning nonlinear dielectric microscopy. The measured local CV profiles exhibit substantial spatial fluctuations with clustered non-uniformity. The corresponding interface charge fluctuation, estimated from the local CV profiles, was smaller than that previously obtained for an as-oxidized SiO2/SiC interface but larger than that for a nitrided SiO2/SiC interface. Numerical device simulations incorporating the experimental data indicate that these spatially fluctuating interface charges can induce Coulomb scattering more strongly than expected from the macroscopic interface characterization. This leads to a significant reduction in the peak field-effect mobility.
Bio-based self-powered triboelectric sensor for intelligent early-warning monitoring in rhythmic gymnastics
Rhythmic gymnastics is characterized by high flexibility, explosive power, and multi-joint coordination; during vertical jumps (VG), kick leg (KL), split leap (SL), and landing, the lower limbs are readily exposed to complex mechanical loads and injury. To address the limitations of current motion-capture systems, force platforms, and inertial sensing technologies in portability, continuous monitoring, and power supply, this study develops a bio-based fiber/graphene-enhanced triboelectric nanogenerator (BG-TENG). The graphene conductive network, in concert with a Kapton elastic layer, Cu electrode, and PTFE negative tribolayer, forms a flexible contact-separation sensor. The device achieves optimal output at 3 wt. % graphene loading and exhibits stable voltage responses and favorable cycling performance under varied velocities, loads, and bending angles. When deployed on the plantar region, ankle joint, and knee joint and validated in conjunction with an IMU, the BG-TENG effectively characterizes ankle acceleration, knee flexion-extension angle, and plantar deformation. Using multichannel signals, a recognition model was established for correct and injury-state movements involving VG, KL, and SL, enabling accurate classification of six action categories and real-time visualized early warning through an upper computer system. This system offers a green, flexible, and wearable intelligent-monitoring strategy for early warning of sports injuries, movement-quality assessment, and personalized training feedback.
DRP1-mediated mitochondrial fragmentation is a druggable vulnerability in multiple myeloma
Mitochondrial dynamics is a key regulator of cellular homeostasis, orchestrating metabolic reprogramming that fuels tumor progression and treatment resistance. In multiple myeloma (MM), however, the functional relevance of mitochondrial remodeling has not been fully defined. Using ultrastructural analyses, we reveal that MM cells display a highly fragmented mitochondrial network, a phenotype further exacerbated in both cell lines and primary MM cells resistant to proteasome inhibitors. Transcriptomic profiling across multiple patient-derived datasets consistently demonstrated upregulation of DNM1L gene, which encodes the mitochondrial fission GTPase DRP1, particularly in relapsed and refractory MM, and revealed a significant association with inferior overall survival. Disrupting mitochondrial fission, either through genetic targeting of DNM1L or pharmacologic inhibition of DRP1 with the selective small molecule inhibitor Drpitor1a, resulted in pronounced mitochondrial dysfunction, impaired oxidative phosphorylation, and potent anti-myeloma activity in vitro, culminating in a hybrid cell death program with a predominant apoptotic component accompanied by ferroptotic features. These effects were recapitulated in vivo in a bortezomib-resistant xenograft model, where either DNM1L depletion or DRP1 inhibition produced similar outcomes. Mechanistically, the transcription factor c-MYC upregulated DNM1L expression, and DRP1-dependent mitochondrial fragmentation sustained MYC-driven oxidative metabolism and lipid synthesis. Altogether, these findings establish aberrant mitochondrial fission as a pathogenic hallmark of MM and highlight DRP1 inhibition as a promising therapeutic approach, especially for relapsed or refractory disease.
A LiNbO3 A1 Lamb-wave resonator with Archimedean spiral electrodes
Lithium niobate (LiNbO3) thin-film-based A1 Lamb-wave resonators hold significant promise for high-frequency broadband radio frequency acoustic devices because of their high phase velocity and large electromechanical coupling. Most reported devices employ straight-strip interdigital electrodes. Although this configuration is relatively mature for A1-mode excitation, there remains room for further exploration in structural topology and coordinated device-parameter design. Here, we experimentally demonstrate a suspended A1 Lamb-wave resonator based on Archimedean spiral electrodes. The proposed structure incorporates a central release window and can be extended to multiple electrode pairs and turns, thereby providing greater design flexibility. Experimental results show that a one-pair, two-turn spiral resonator based on a Z-cut LiNbO3 thin film realizes the target A1-mode resonance near 4 GHz. At a duty factor of 0.38, the device achieves an electromechanical coupling coefficient of 30.17%, a Bode-Q of 471, and a figure of merit (FoM) of 142, indicating good overall performance. In addition, extension to multi-pair, multi-turn spiral electrodes enables tunable static capacitance (C0), highlighting the potential of this configuration for the co-design of resonant unit parameters. These results indicate that the Archimedean spiral electrode provides a viable structural solution for high-frequency A1 resonators and offers new insights into the topology design and performance optimization of related devices such as filters, sensors, actuators, and antennas.
Brightening otherwise-weak molecular electroluminescence via intermolecular energy transfer
Manipulating the electroluminescence of organic molecules is important for the development of advanced organic light-emitting diodes (OLEDs). Here, we demonstrate a single-molecule sensitization strategy to brighten an otherwise-weak molecular emitter by using the scanning tunneling microscope induced luminescence (STML) technique. We show that while the free-base phthalocyanine (H2Pc) molecule is a bright emitter, the molecule upon double deprotonation ([Pc]2−) exhibits electroluminescence that is suppressed by three orders of magnitude. The extremely weak emission of [Pc]2− is traced to a misalignment of its frontier orbitals with the substrate, which fundamentally shifts the excitation from an efficient carrier-injection mechanism in H2Pc to an inefficient inelastic electron scattering process in [Pc]2−. However, by bringing a zinc-phthalocyanine (ZnPc) molecule close to it to form a donor–acceptor dimer (ZnPc–[Pc]2−), we introduce an intermolecular energy transfer pathway that enhances the luminescence of [Pc]2− by approximately 135-fold. Furthermore, combined with theoretical calculations, the dependence of STML spectra on the intermolecular distances (d) indicates that the energy-transfer mechanism is dominated by Förster resonance energy transfer. Our findings demonstrate a viable strategy for overcoming molecular-level charge-injection limitations and provide actionable guidelines for designing OLED architectures with enhanced luminescence efficiency.
CMOS programmable metachip for terahertz multifunctional sensing
A CMOS-based programmable terahertz (THz) metachip for multifunctional sensing is proposed and experimentally demonstrated in this work. Fabricated using a standard 55-nm CMOS process, the metachip is composed of periodically arranged meta-atoms with on-chip circuits, enabling multi-frequency amplitude modulation at 360, 413, and 493 GHz with a peak modulation index exceeding 20 dB. Proof-of-concept experiments are carried out for sensing object motion and fingerprint objects at distinct operational frequencies using the proposed metachip array. This work realizes multifunctional sensing, which will promote the development of multifunctional and highly integrated terahertz on-chip sensing systems.
Phosphine‐Catalyzed Unsymmetric [2 + 2] Annulation of Allenyl Phosphonates for Highly Substituted Cyclobutenes
ABSTRACT Allenes, as versatile intermediates with unique cumulative double bond systems, have been widely used in cycloaddition reactions for constructing various cyclic skeletons, yet the selective synthesis of cyclobutenes via double allenes [2 + 2] annulation still remains a long‐standing challenge. Herein, we report a phosphine‐catalyzed unsymmetric [2 + 2] annulation of allenyl phosphonates for the efficient construction of highly substituted cyclobutenes. The reaction exhibits broad substrate scope, delivering the target cyclobutenes in moderate to good yields with exceptional Z / E selectivities and diastereoselectivities. Mechanistic studies reveal that the reaction proceeds via phosphine‐induced zwitterion formation and deprotonation of allene. The Lewis acid enables precise control of diastereoselectivity, while silane effectively suppresses allene isomerization to conjugated dienes and prevents catalyst deactivation, thus ensuring reaction efficiency. Furthermore, the synthesized cyclobutene derivatives demonstrate good structural modifiability through diverse transformations. This work enriches the field of phosphine‐catalyzed allene chemistry, fills a gap in allene‐based [2 + 2] cyclization modes, expands the methodological toolbox for cyclobutene synthesis, and provides a versatile platform for accessing complex cyclobutene‐containing molecules.
Inhibition of graphitization on diamond surfaces via flash joule heating and construction of chemical bonds for tungsten metallization
Surface metallization is a critical process for diamonds in thermal management applications. However, bottlenecks such as graphitization, inhomogeneous interfacial phases, and high interfacial thermal resistance persist during metallization. This study presents a novel strategy for tungsten coating on diamond particle surfaces within an extremely short time using flash joule heating. In situ chemical bonding of a composite consisting of W, W2C, and WC was achieved on the diamond surface, yielding a uniform and conformal coating that suppressed diamond surface graphitization, retained 93.2% of the intrinsic thermal conductivity of diamond, and resulted in an equivalent thermal conductivity of 1864.69 W m−1 K−1. The chemically bonded metallization shell introduced an equivalent interfacial thermal resistance as low as 9.11 × 10−10 m2 K W−1. Photothermal conversion cycling tests demonstrated that the chemically bonded metallization on the diamond surface possesses excellent thermal fatigue resistance. Through photothermal conversion studies and the construction of a two-node thermal relaxation model, the analysis indicates that the W, W2C, and WC interfacial phases introduce a moderate interfacial thermal resistance, which effectively suppresses instantaneous and intense heat dissipation to the environment, thereby enabling controllable and stable heat release.
Asymmetric Deoxygenative Difunctionalization of 1,2‐Dicarbonyl Compounds Enabled by Phosphinite and Chiral Salen‐Molybdenum Catalyst Synergy
ABSTRACT The 2‐aryl benzofuran‐3‐ones serve as pivotal scaffolds in natural products and bioactive molecules, yet their synthesis and subsequent asymmetric functionalization are hindered by multi‐step protocols and the lability of their derivatives lacking electron‐rich substituents on the aromatic ring of benzofuran‐3‐one core. Herein, we report a phosphinite‐mediated, Mo‐catalyzed intermolecular asymmetric deoxygenative coupling reaction between 1,2‐dicarbonyl compounds and 3‐(methoxymethyl)indoles, thus providing a series of chiral 2‐aryl benzofuran‐3‐ones with a chiral quaternary carbon center with generally good yields and enantioselectivities. Mechanistic studies reveal that phosphinite and the Mo‐complex synergistically promote the in situ generation of key intermediates, while the formally tetravalent mononuclear Mo‐complex serves as the key species governing the enantioselectivity of the reaction. This work expands the application of chiral salen‐Mo catalysts in asymmetric catalysis, offering an efficient route to valuable chiral benzofuranone derivatives.
Broadband and high-efficiency polarization rotation using a single-layer transmissive metastructure
A single-layer, free-standing metamaterial polarization rotator has been proposed, which achieves broadband and high-efficiency linear polarization rotation in transmission mode. The structure comprises a metal slab perforated with an array of subwavelength holes, each containing an embedded twisted U-shaped meander wire. By using the coupling between the perforated slab and the four adjacent excited modes of the meander wires, the incident linearly polarized wave is efficiently captured by the receiving arms and reradiated from the reradiating arms with a controllable polarization rotation angle. The proposed design offers a simple, efficient, and flexible approach to polarization manipulation, demonstrating potential value for applications in microwave and communication systems.
Enhancing the efficiency of ZnSeTe-based quantum-dot light-emitting diodes by manipulating charge dynamics
In conventional Cd-based quantum-dot light-emitting diodes (QLEDs), a reduced hole-injection barrier at the hole transport layer (HTL)–quantum-dot (QD) interface generally leads to enhanced device efficiency. However, this principle does not extend to the emerging class of environmentally friendly ZnSeTe blue QLEDs. In this work, we systematically examine the charge dynamics in ZnSeTe-based blue QLEDs, with particular focus on trap states, energy level alignment, and charge transport properties. Our findings reveal significant carrier accumulation at the ZnSeTe/ZnO interface, where emission quenching by ZnO substantially degrades device performance. To mitigate this issue, we introduce Mg-doped ZnO combined with an HTL featuring a shallow highest occupied molecular orbital level, thereby optimizing charge distribution across the device. Simulations corroborate that electrons and holes predominantly accumulate at the QD/HTL interface under this design. As a result, the efficiency of the ZnSeTe blue QLED is markedly improved, increasing from 2.1% to 6.3%. This study elucidates the critical influence of hole dynamics in ZnSeTe blue QLEDs and underscores the essential role of tailored charge management for high-performance QLED operation.
Comparative analysis of voltage losses in perovskite and GaAs solar cells at low temperatures
This study presents a comparative analysis of the open circuit voltage behavior of perovskite vs gallium arsenide (GaAs) solar cells at low temperatures relevant to space applications. While GaAs solar cells demonstrate high power conversion efficiencies and superior environmental stability, their widespread adoption is limited by high manufacturing costs. In contrast, perovskite solar cells have emerged as a promising alternative due to their high efficiency, excellent optoelectronic properties, and low fabrication costs. To evaluate and compare their optoelectronic characteristics and voltage losses at low temperatures, we have characterized both devices using temperature-dependent current–voltage (J–V) and photoluminescence-based radiative efficiency measurements in the range of 300–160 K. GaAs devices exhibited a linear increase in open-circuit voltage (Voc) with decreasing temperature, consistent with theory. In contrast, perovskite devices showed suppressed Voc enhancements and an S-shaped J–V response below 240 K. Using temperature-dependent external radiative efficiency measurements, we show that temperature-dependent entropic losses related to nonradiative recombination are higher in perovskite devices compared to GaAs at high temperatures, but the gap between the two shrinks substantially at lower temperatures. These findings provide valuable insight into temperature-dependent Voc in perovskite solar cells, particularly relevant for space deployment applications.
Bragg-grating engineering enables deterministic resonance control in an on-chip THz filter
On-chip filters are important for integrated terahertz (THz) communication and sensing systems. Deterministic control of resonance multiplicity in compact devices enables flexible spectral filtering. Here, we experimentally demonstrate an on-chip silicon THz filter based on a Bragg-grating-assisted Fabry–Pérot cavity, in which the resonance multiplicity is governed by the relation between the Bragg stopband and the cavity free spectral range (FSR). By engineering this stopband–FSR relation, single-, double-, and triple-resonance states are achieved within the 360–390 GHz band, with a packaged insertion loss of approximately 6 dB. The single-resonance device exhibits a through-port transmission minimum approaching −40 dB and a loaded quality factor of QL = 809.5. This work provides a compact strategy for deterministic spectral-state engineering in integrated THz filters.