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Realization and regulation of negative magnetoresistance behavior in Dy-doped SnS2 with high Curie temperature
The magnetic two-dimensional transition metal dichalcogenides with high Curie temperature play a pivotal role in spintronic devices and exhibit promising application potentials. In this paper, rare earth Dy-doped SnS2 wafers are synthesized through gas–liquid phase deposition and high-temperature, high-pressure processes. The material exhibits comprehensive properties such as ferromagnetism, high Curie temperature (628 K), and large negative magnetoresistance at low magnetic fields over a wide temperature range (55%–4%, 50–350 K). The results of first-principles calculations indicate that it exhibits the half-metallic behavior of electrons with a single spin direction passing through the Fermi level, with a large spin bandgap of 1.7 eV, and a flatband exists near the Fermi level. Therefore, the substitution of Sn with Dy induces a global structural reorganization and disrupts the system's symmetry, resulting in the formation of a flatband near the Fermi level through the occupation of 4f orbital electrons, providing a stable local magnetic moment. Through the orbital hybridization between Dy and S, the ferromagnetic exchange interaction is formed, achieving the ferromagnetism of DyxSn1−xS2. This laid the foundation for the application of magnetoresistive sensors, electromagnetic shielding, and spin field-effect transistors.
Accurate multiplexed detection with magnetic particle spectroscopy
Accurate multiplexed detection of magnetic nanoparticles (MNPs) is essential for bioassays that require simultaneous quantification of multiple biomolecules. This study proposes a dual-frequency magnetic particle spectroscopy (MPS) approach that improves multiplexed detection accuracy by combining MPS signals acquired at two excitation frequencies. The frequency-dependent MPS responses of MNPs dominated by either Brownian or Néel relaxation are investigated and analyzed, with the complex harmonic components serving as the basis for distinguishing different MNP types. In the experiments, commercial bionized nanoferrite and Synomag MNPs—dominated by Brownian and Néel relaxation, respectively—are mixed with different percentages. The accuracy of multiplexed detection is quantitatively assessed and compared between single-frequency and dual-frequency excitation schemes. Experimental results show that combining MPS signals at 0.5 and 32.6 kHz significantly improves the accuracy of multiplexed detection of MNPs. We anticipate that this dual-frequency strategy is of great importance for enabling highly precise multiplexed detection in bioassay applications.
Defect passivation by short-chain ligands in all-solution-processed inverted ZnSeTe green QLEDs
High-efficiency green emission is essential for next-generation quantum dot light-emitting diodes (QLEDs); however, fully solution-processed inverted green QLEDs, particularly cadmium-free devices, are limited by surface defects, non-radiative recombination, and inefficient charge transport. Herein, we report all-solution-processed inverted ZnSeTe green QLEDs enabled by the passivation of ZnSeTe quantum dots (QDs) with the short-chain ligand of NH4PF6. This treatment effectively suppresses surface traps, prolongs photoluminescence lifetimes, and enhances carrier transport, increasing QD film conductivity from 1.42 × 10−6 to 6.15 × 10−5 S m−1 and reducing device recombination resistance from 36.2 to 16.6 kΩ. As a result, the NH4PF6-passivated QLEDs achieve a maximum external quantum efficiency of 7.3%, a peak luminance of 6732.7 cd m−2, and an operational T50 lifetime of 115 h at 100 cd m−2, a 46-fold enhancement compared to devices based on untreated QDs. These findings reveal that NH4PF6 short-chain ligands simultaneously passivate surface defects and accelerate radiative recombination, offering a viable strategy for high-efficiency, environmentally friendly green-emitting inverted QLEDs.
Crystallographic Study of DNA T‐Junction via Crystal Engineering
Abstract Engineering DNA crystals is the primary motivation for structural DNA nanotechnology. Among many potential applications, such crystals promise as a platform to precisely (in terms of both location and orientation) organize biomolecules into 3D crystals for X‐ray crystallographic studies of the guest biomolecules. The crystal formation depends on rationally designed DNA frameworks instead of unpredictable interactions between the guest molecule themselves; thus, avoiding the crystallization problem of biomolecules. This approach was proposed 40 years ago, however, has not been realized so far. Herein, we report an effort along this direction to study DNA T‐junction, a common DNA structure used in DNA nanoconstruction. This study is an initial demonstration of the feasibility of the 40‐year‐old proposal. We expect that it would be quickly adapted to study many other molecules, particularly nucleic acids (e.g., aptamers, catalytic DNAs/RNAs, ribozymes, and ribonucleoproteins) that are, otherwise, difficult to be studied.
Covalent bond chemistry enabling M2CN2 MXenes as anode materials for halide-ion batteries
The development of halide-ion batteries is limited by the lack of efficient electrode materials. Two-dimensional M2CN2 MXenes are promising anode candidates due to their structural flexibility and low molar mass, yet their stability and storage mechanism remain unclear. Using first-principles calculations, we identify Ti2CN2, Nb2CN2, and Ta2CN2 as stable MXenes. Ti2CN2 exhibits excellent performance with low voltages (0.07 V for F−) and high specific capacities (394.8 mAh/g for F−). The storage mechanism involves covalent bonding between surface N and halide-ions, where adsorption strength is governed by the energy difference between occupied σ* and unoccupied π* orbitals and their electron overlap. Moreover, O or Zr doping significantly enhances halide-ion diffusion kinetics. This work elucidates the covalent bond-mediated storage in M2CN2 MXenes and guides the design of high-performance halide-ion battery electrodes.
Rapid heat-assisted polarization reversal in a ferroelectric thin film
We demonstrate that switching of ferroelectric thin films sandwiched between metallic electrodes can be controlled by laser-assisted heating, reminiscent of heat-assisted magnetic recording. We employ electrical switching cycles that quantify the electrically switchable remanent polarization Pr and show that 300 ns voltage pulses alone change the polarization by less than ΔP<Pr. Transient heating of the metallic top electrode by synchronized ns laser pulses induces a reversal ΔPL>Pr of the average polarization. The transient average temperature modeled by the heat equation can rationalize the polarization change observed for different relative timings Δt of the laser pulse if it arrives before the electrical pulse.
Achieving Charge‐Transfer from the Boron‐Vertices of <i>o</i> ‐Carborane: Dual‐Emission with a Shift of 505 nm (2.1 eV)
Abstract The boron‐vertices of o ‐carborane have long been considered to be inert in conjugation with π‐substituents. Herein, we demonstrate that the boron vertices of o ‐carborane can be engineered to participate in intense charge‐transfer (CT) transitions. Through strategic design—appending electron‐donating carbazoles at the boron vertices—we synthesized three 9,12‐substituted o ‐carboranes ( 1 , 2a , and 2b ). While 1 only shows LE emission, compounds 2a and 2b , which contain phenyl groups at the carbon vertices, show unprecedented dual emission with a colossal gap of up to 505 nm (2.1 eV) between bands. Photophysical and theoretical studies reveal that photoexcitation triggers a unidirectional conversion from a locally excited (LE) state to a CT state, yielding the first direct evidence of CT from a boron‐functionalized donor into the carborane cage. This CT emission is highly sensitive to environment, exhibiting aggregation‐induced emission enhancement with quantum yields reaching 80%. Our findings disrupt the longstanding carbon‐centric view of carborane‐based luminescence, unveiling a new strategy to activate boron‐vertex participation in electronic conjugation, opening a pathway for the development of high‐performance dual‐emissive materials based on o ‐carborane.
Avalanche durability of high-voltage GaN <i>p</i> – <i>n</i> diodes with tunnel junctions as anode contacts
Tunnel junctions were applied to anode contacts in high-voltage GaN p–n diodes with sloped mesa terminations. The devices were composed of bottom p–n junctions with low doping concentrations to ensure a high blocking voltage, along with top n++/p++ tunnel junctions with doping concentrations greater than 3 × 1020 cm−3. The formation of fine square-shaped grooves through the tunnel junctions enabled dehydrogenation from the buried p-type layers, resulting in a reduction of the series resistance in the forward current–voltage curves. Repeatable reverse bias sweeps up to avalanche voltages were demonstrated for devices with and without grooves. The differential resistance in the voltage range of avalanche multiplication was reduced by the formation of grooves and by the reduction of the gaps, which corresponded to an increase in acceptor concentrations in the buried p-type layers, as indicated by capacitance–voltage curves. Because holes generated by avalanche events pass through the neutral region in the buried p-type layer, the resistance of this layer needs to be reduced by sufficient dehydrogenation to minimize Joule heating. In addition, GaN p–n diodes with tunnel junction anode contacts having fine square grooves passed a 1 h hold test at a constant current of 1 mA at the avalanche voltage. When the high-voltage p–n junction was in reverse bias, the tunnel junction was in forward bias; holes, therefore, passed through the tunnel junction. The results suggest that tunnel junctions enable the removal of holes generated by avalanche in high-voltage GaN transistors.
Discontinuous transition to active nematic turbulence
Abstract Active fluids exhibit chaotic flows at low Reynolds number known as active turbulence. Whereas the statistical properties of the chaotic flows are increasingly well understood, the nature of the transition from laminar to turbulent flows as activity increases remains unclear. Here, through simulations of a minimal model of unbounded and defect-free active nematics, we find that the transition to active turbulence is discontinuous. We show that the transition features a jump in the mean-squared velocity, as well as bistability and hysteresis between laminar and chaotic flows. From distributions of finite-time Lyapunov exponents, we identify the transition at a value A * ≈ 4900 of the dimensionless activity number. Below the transition to chaos, we find subcritical bifurcations that feature bistability of different laminar patterns. These bifurcations give rise to oscillations and to chaotic transients, which become very long close to the transition to turbulence. Overall, our findings contrast with the continuous transition to turbulence in channel confinement, where turbulent puffs emerge within a laminar background. We propose that, without confinement, the long-range hydrodynamic interactions of Stokes flow suppress the spatial coexistence of different flow states, and thus render the transition discontinuous.
Highly sensitive flexible pressure sensor based on gradient microcolumn structure for ocean wave monitoring
Monitoring the dynamic fluctuations of ocean waves using highly sensitive flexible pressure sensors is a highly promising marine observation technology. In this study, we propose a flexible pressure sensor with a gradient microcolumn structure (GCS) fabricated via micro-lithography precision molding technology. The exceptional compressibility of the microcolumn structure significantly enhances the sensor's sensitivity. The GCS sequentially contacts the electrode layer from high to low, effectively modulating the contact area between the sensitive layer and the electrode layer under varying pressures. This design reduces sensitivity attenuation and broadens the detection range. The sensor achieves a wide detection range of 0–600 kPa and an ultrahigh sensitivity of 3848.57 kPa−1. It retains stable performance even after 30 days of underwater immersion and over 3500 cyclic tests. For waterproofing, we encapsulated the sensor with polydimethylsiloxane and attached it to the bottom and sides of a buoy to detect pressure variations induced by waves of different magnitudes in a water tank, enabling real-time wave monitoring. These results demonstrate its great potential for ocean wave monitoring applications.
Population-scale gene expression analysis reveals the contribution of expression diversity to the modern wheat improvement
Molecular Design and Redox Chemistries for Aqueous Organic Redox Flow Batteries (AORFBs)
Abstract Aqueous organic redox flow batteries (AORFBs), utilizing redox‐active organic materials as energy storage materials, represent a promising frontier for sustainable long‐duration energy storage. This review highlights recent advances in redox‐active molecule design, analyzing how molecular structures govern electrochemical behavior and degradation pathways critical to stability. We categorize systems by positive and negative electrolyte pairings, examining performance and lifetime challenges across configurations. We explore molecular engineering approaches and full‐cell assembly principles to extend battery lifetime. By introducing representative studies within each category of redox couples, we outline state‐of‐the‐art developments and establish rational design and pairing principles. This framework proposes guidelines for selecting compatible electrolyte pairs based on molecular properties of organic redox‐active species, which may contribute to advancing stable materials and higher‐performance AORFBs.
Experimental determination of equilibrium stress in stress-induced martensitic transformation at low temperatures in Ni-rich TiNi
The exceptional broadening of superelastic stress hysteresis at low temperatures in Ni-rich Ti–Ni shape-memory alloys impedes their cryogenic applications. This broadening arises from thermally activated habit plane glide. Traditionally, equilibrium stress has been assumed to lie at the midpoint between forward and reverse martensitic transformation (MT) stresses, assuming reciprocal kinetics. Here, we assess this assumption using strain-rate jump tests, a simple method that detects the magnitude of stress change in response to strain-rate variation. The observed stress change is consistently larger during the forward MT than the reverse MT, indicating an asymmetric thermal activation and a shift in equilibrium stress toward the reverse MT stress. This result deviates from the classical midpoint approximation in systems with significant hysteresis broadening. Strain-rate jump test is demonstrated to be a simple yet effective method for locating the equilibrium stress, even when it is bracketed deep within a broadened stress hysteresis.
scRepli-RamDA-seq: a multi-omics technology enabling the analysis of gene expression dynamics during S-phase
Abstract Single-cell sequencing has advanced our understanding of cell-type diversity and heterogeneity. However, existing single-cell multi-omics methods lack the ability to monitor gene expression dynamics during S-phase progression. Here, we introduce single-cell (sc)Repli-RamDA-seq (scRR-seq), a multi-omics method that enables high-resolution DNA replication profiling and full-length total RNA sequencing from the same single cell in a haplotype-specific manner. scRR-seq generates DNA replication and RNA sequencing data comparable to individually obtained scRepli-seq and scRamDA-seq data, respectively. Unlike other scDNA/RNA-seq methods, scRR-seq allows one to tell the S-phase stage of a given cell based on the percentage of the replicated genome derived from scRepli-seq data. This facilitates analysis of gene expression dynamics during S-phase progression, enabling the identification of S-phase progression markers. scRR-seq also detects copy-number variation in non-S-phase cells and outperforms other scDNA/RNA-seq methods in various measures. Taken together, scRR-seq is a robust single-cell multi-omics method with promising potential for comprehensive genome/transcriptome analysis.
Microemulsion Engineering Reconciles Propylene Carbonate Electrolytes and Graphite Anodes for All‐Climate Lithium‐Ion Batteries
Abstract Propylene carbonate (PC)‐based electrolytes are promising for all‐climate lithium‐ion batteries due to their wide liquid range. However, detrimental Li + ‐PC co‐intercalation causes severe graphite (Gr) anode exfoliation, remaining the biggest barrier for their practical application. Although the issue can be mitigated via solvation regulation, complex interfacial chemistry limits long‐term cycling ability. Herein, we designed a PC‐based microemulsion electrolyte to achieve PC/Gr compatibility through interfacial manipulation. Specifically, insoluble glyceryl monostearate (GMS) and amphiphilic tetrahydrofuran (THF) are introduced into the PC‐based electrolyte. GMS self‐assembles in THF to form core‐shell GMS@THF micelles dispersed in the continuous PC electrolyte medium. This microemulsion structure generates abundant liquid‐liquid interfacial tension at micelle/electrolyte interfaces, spontaneously directing micelles to the electrode interfaces during operation. At the Gr anode, adsorbed GMS@THF micelles leverage solvophobic effects to synergistically form PC‐poor Li + solvation sheaths and block free PC, effectively suppressing detrimental PC co‐intercalation. This design enables Li||Gr cells achieve a high initial Coulombic efficiency of 92.8% and supports 1 Ah Gr||LiFePO 4 pouch cells to operate over 4000 cycles. Remarkably, the pouch cells work well across extreme temperatures (−40∼100 °C cycling; −60∼100 °C operation), demonstrating exceptional all‐climate capability. This microemulsion engineering establishes a universal paradigm for optimizing electrolyte/electrode interphases in the PC/Gr system.
On the origin of carrier loss in Mg-doped N-polar GaN
The neutral (VN-3MgGa)0 complex was found to be the primary compensator in Mg-doped N-polar GaN. The experimental data showed a sharp drop in hole concentration once [Mg] exceeded ∼1019 cm−3. Temperature-dependent Hall measurements, in conjunction with a charge balance model, revealed that the carrier loss was due to a drastic reduction in acceptor concentration (NA), suggesting that a significant fraction of Mg atoms was incorporated in an electrically neutral configuration. A quantitative semi-empirical model based on the grand canonical formalism pointed to the formation of (VN-3MgGa)0 complexes as the primary cause for the observed carrier loss.
Author Correction: An orally available Mpro/TMPRSS2 bispecific inhibitor with potent anti-coronavirus efficacy in vivo
Asymmetric Carbenoid Allylic C─H Alkylation of α‐Olefins Using Tailored Chiral Indenyl‐Rhodium Catalysts
Abstract Alpha (α)‐olefins represent cornerstone feedstocks in the chemical industry, offering a versatile platform for enhancing molecular complexity from readily available precursors. While remarkable strides have been made in the asymmetric functionalization of olefinic double bonds, the selective activation of allylic C─H bonds remain a formidable challenge. Herein, we unveil a catalytic asymmetric allylic C─H activation of α‐olefins through carbene transfer, leveraging highly active and synthetically accessible indenyl–rhodium complexes. These complexes, featuring indenyl ligands prepared via a streamlined, one‐step Pd‐catalyzed atropisomeric Suzuki–Miyaura coupling, enable precise control over chemo‐, regio‐, and enantioselectivity. This method exhibits exceptional versatility, accommodating a diverse array of olefins, ranging from bulk industrial products to those adorned with various functional groups. A comprehensive series of experiments was conducted to illustrate the wide‐ranging applicability of the asymmetric C─H activation reaction. Mechanistic investigations elucidate critical factors governing rhodium carbenoid formation, branch selectivity, and enantioselectivity during the C─H activation process.
Engineering ferroelectric interfaces: Delta-doping and millisecond flash lamp annealing for enhancing polarization properties in TiN/Al:HfO2/TiN capacitors
We identify two key strategies for enhancing polarization properties: the engineering of delta-doped interfacial layers and the application of millisecond-scale flashlamp annealing (FLA), using TiN/Al:HfO2 (HAO)/TiN ferroelectric capacitors. The delta-doped Al2O3 layer remains stably localized at the interfaces even after high-temperature annealing at 1000 °C for 5 ms. This interfacial localization between the electrodes and HAO films significantly influences both the polarization behavior and the crystallization characteristics. Delta doping at the top electrode interface yields a remanent polarization (2Pr) value approximately 10% higher than that observed by doping at the bottom interface. This enhancement is attributed to the position-dependent formation of oxygen vacancies (Vo), which vary with the location of the delta-doped layer. Grazing incidence x-ray diffraction analysis reveals that delta doping at the top interface promotes the formation of ferroelectric orthorhombic phases more effectively than in undoped structures. Furthermore, a peak angle analysis of HAO films indicates that capacitors with top interface delta doping exhibit higher diffraction angles compared to those without doping, suggesting an increased tensile stress exists within the HAO layer. FLA treatment further amplifies this tensile stress relative to rapid thermal annealing, thereby contributing to improved ferroelectric properties. These findings underscore the importance of both interfacial delta doping and low-thermal-budget FLA treatment in achieving enhanced ferroelectric performance and highlight their potential for the fabrication of high-performance ferroelectric devices.