Browse Articles

Transcription factor FOXD1 and miRNA-204-5p play a major role in B4GALNT2 downregulation in colon cancer

Lowering the skyrmion depinning current in synthetic antiferromagnetic systems

Magnetic skyrmions, as topological spin textures, offer great potential for next-generation spintronic applications. Skyrmions in artificially synthesized antiferromagnets (SAFs) are particularly promising due to their ability to suppress the skyrmion Hall effect and achieve faster dynamics, making them highly attractive for spintronic devices. However, the critical current density required to drive SAF skyrmions using spin-transfer torque is significantly higher than in conventional ferromagnetic systems. In this work, we analytically and numerically demonstrate that the critical current density for SAF skyrmions can be significantly reduced by applying distinct currents to different layers within the system. This approach can be applied to periodically pinned skyrmions in SAFs, offering the dual benefits of a suppressed Hall effect and a reduced critical current density. Our findings pave the way for more efficient manipulation of SAF skyrmions in spintronic device architectures.

Attenuation of progressive surface gravity waves by floating spheres

High-temperature performance of metal/n-Ga2O3/p-diamond heterojunction diode fabricated by ALD method

A metal/n-Ga2O3/p-diamond heterojunction diode with superior high-temperature performance was demonstrated in this work. The p-type diamond was lightly boron doped, and the Ga2O3 film was grown via atomic layer deposition without intentional doping. The forward current density increased with temperature, while the reverse current decreased at elevated temperatures. This behavior was attributed to the distinct carrier ionization dynamics across varying temperature ranges. Under high reverse voltage stress, the reverse current remained relatively stable, with no breakdown occurring up to 498 K. An avalanche breakdown voltage of 186 V at 498 K indicates the diode's robust high-voltage endurance capability. These findings underscore the potential of the metal/n-Ga2O3/p-diamond heterojunction diode for high-temperature and high-voltage applications.

The role of impulsivity and emotional dysregulation in smartphone overdependence explored through network analysis

Synergistic physical and chemical effects of MOF-derived porous Fe3C–NC to boost the performance of Li–S batteries

Lithium–sulfur (Li–S) batteries are one of the key objects of next-generation energy storage systems due to their high energy density and low-cost characteristics. However, the slow reaction kinetics and serious shuttle effect of lithium polysulfides (LiPSs) have hindered their practical application. In this work, metal-organic framework-derived Fe3C decorated nitrogen-doped carbon matrix (Fe3C–NC) composites were prepared to modify the separator to promote the reaction kinetics of Li–S batteries. The porous and conductive NC facilitates the trapping of LiPSs, rapid transfer of charge, and alleviated volume expansion, while the Fe3C–NC with optimum Fe3C content can significantly reduce the energy barrier of the electrochemical conversion reaction, accelerate the transport of lithium ions, and enhance the reaction kinetics of LiPSs, which are conducive to inhibit the shuttle effect through synergistic physical and chemical interactions. The Li–S battery with Fe3C–NC separator exhibits excellent cycle stability with an initial discharge specific capacity of 1099.19 mAh g−1 at 1 C and a low-capacity decay of 0.068% per cycle over 500 cycles. Even at a high S loading of 5.93 mg cm−2, it still delivers reliable cyclic stability with an initial discharge specific capacity of 903.65 mAh g−1 at 0.1 C. This work provides a convenient and effective method for the application of metallic materials combined with nitrogen-doped carbon matrix in high-performance Li–S batteries.

Green synthesized FeNPs ameliorate drought stress in Spinacia oleracea L. through improved photosynthetic capacity, redox balance, and antioxidant defense

Spin injection and detection using perpendicularly magnetized Mn/Co bilayers grown on GaAs via all electrical methods

The electrical spin injection and detection in perpendicularly magnetized Mn/Co/n-GaAs junction was investigated using a non-local method. Clear non-local spin-valve signals and Hanle effect signals were observed at 77 K, providing direct evidence of the injection and detection of perpendicularly polarized spins through all electrical methods. The magnitude of the spin-valve signal was one order of magnitude smaller than that observed in a reference sample with an in-plane magnetized CoFe due to the low spin polarization of the ultrathin Mn/Co electrodes. It was found that the spin polarization at the interface between Mn/Co electrode and n+-GaAs had a relatively weak bias-current dependence in contrast to that at CoFe/n+-GaAs interface. The estimated spin lifetime of perpendicular spins injected from the Mn/Co bilayer into n-GaAs was approximately 1.9 ns at 77 K. This value is similar to that of in-plane spins injected from CoFe, indicating that the spin lifetime was not strongly dependent on the spin orientation in the bulk GaAs channel.

Biocompatible autonomous self-healing PVA-CS/TA hydrogels based on hydrogen bonding and electrostatic interaction

First-principles study on electronic and optical properties of perovskite light-emitting diodes CsPb(Br1<b>−</b> <i>x</i>I<i>x</i>)3

CsPb(Br1−xIx)3, a mixed-halide all-inorganic perovskite, is a promising light-emitting diode (LED) material due to its impressive performance. It has been demonstrated that the mixing parameter x of halogen composition significantly influences the luminescence efficiency of CsPb(Br1−xIx)3. However, the underlying microscopic mechanisms remain unclear. Using first-principles calculations, we investigate the effects of anion mixing on the radiative and non-radiative recombination properties of perovskite materials. Simulations on the carrier mobility, exciton binding energy, affinity energy, and defect formation energy of the materials in the CsPb(Br1−xIx)3 system collaboratively revealed that a high ratio off Br is associated with enhanced luminescence efficiency. Specifically, CsPb(Br1−xIx)3 exhibits optimal luminescent performance with a 2:1 bromine-to-iodine ratio, while it shows the performance degradation with a 1:1 ratio. The results demonstrate that the ratio of halogen atoms (Br and I) has a significant influence on the LED properties of cesium-based all-inorganic perovskites CsPb(Br1−xIx)3, providing a valuable guide for the experimental preparation of cesium-based all-inorganic perovskites.

Mechanical response of elevated bridge piles to adjacent deep excavation

Enhanced tunnel magnetoresistance of Fe/MgGa2O4/Fe(001) magnetic tunnel junctions by interface-tuning with atomic-scale MgO insertion layers

We demonstrate a significant effect of atomic-scale MgO insertion layers on the tunnel magnetoresistance (TMR) in epitaxial magnetic tunnel junctions (MTJs) using a small bandgap oxide MgGa2O4. An enhanced TMR ratio of 151% at room temperature (resistance area product, RA: 23 kΩ ⋅ μm2) and 291% at 5 K (RA: 26 kΩ ⋅ μm2) were observed using 0.3 nm MgO insertion layers at the bottom and top barrier interfaces in Fe/MgGa2O4/Fe(001) MTJs with a total barrier thickness of 2.3 nm. The TMR showed a strong MgO thickness dependence. Microstructure analyses revealed that after MgO insertion, a homogeneous rock-salt structured Mg0.55Ga0.45O(001) barrier is formed, which differs from the nominal spinel crystal MgGa2O4. Elemental mapping of the MTJ showed that Ga diffusion into the adjacent Fe can be effectively suppressed while maintaining perfect lattice-matching at the Fe/barrier interfaces, thereby improving effective tunneling spin polarization through the barrier. The RA of the Mg0.55Ga0.45O (2.3 nm) MTJ is smaller than that of a comparable MgAl2O4 barrier (2.3 nm), thanks to the lower barrier height of the Mg0.55Ga0.45O as confirmed by the current–voltage characteristics.

Selective fluoride ion sensing using novel quinoline chemosensor insights into kinetics and molecular logic gate functions

Segregation-induced co-passivation effect of S and Cl on CdTe grain boundaries

The efficiency of polycrystalline CdTe solar cells can be significantly enhanced through CdCl2 treatment. However, while this treatment promotes the diffusion of sulfur (S) into CdTe, the improvement cannot be solely attributed to chlorine (Cl); S may also play a crucial role. In this study, using first-principles calculations, we investigated the effects of S and Cl co-doping on the electronic properties of CdTe Σ3 (112) Te-core GBs. The Σ3 (112) Te-core GBs present challenges due to deep gap states caused by Te-Te and Cd-Cd wrong bonds. Notably, the segregation behavior of S dopants within the GBs suggests their potential to significantly influence the electronic properties. When co-doped with Cl, it is evident that S is more likely to occupy interstitial sites rather than substituting for Te atoms under Te-rich conditions. The co-passivation of S and Cl at the GBs can eliminate all gap states, thereby enhancing electrical performance. These findings provide insights into the synergistic effects of dopants on GBs and propose a promising strategy to improve the performance of CdTe solar cells through doping.

Efficacy of melatonin treatment in a cystic fibrosis mouse model of airway infection

Strong out-of-plane piezoelectric properties in Janus PdXY (X, Y = O, S, Se, Te; X ≠ Y) monolayers: A first-principles study

The development of piezoelectric materials is limited by incomplete internal mechanisms and a lack of vertical piezoelectricity. This study introduces Janus PdXY (X, Y= O, S, Se, Te; X ≠ Y) monolayers as innovative candidates for superior piezoelectric performance, as predicted by density functional theory. Our study reveals that these materials possess exceptional in-plane and out-of-plane piezoelectric properties, with the out-of-plane coefficient d33 being up to two orders of magnitude greater than that of conventional Janus materials. This enhancement is attributed to the electron contributions and correlates with the Bader charge difference and electronegativity difference ratio, which conforms to the P-R mechanism. Additionally, the impact of layer thickness on piezoelectric coefficients is evaluated. These findings highlight the potential of Janus PdXY monolayers for advanced nanoscale flexible piezoelectric devices and offer valuable insights for the design of transition metal dichalcogenide-based Janus materials with robust out-of-plane piezoelectricity.

Experimental study on the influence of lapping plate materials on the quality of both sides cylindrical rollers machining

Direct laser writing of planar and stretchable supercapacitors based on a graphene oxide and manganese dioxide nanoparticle composite on a paper substrate

Paper-based supercapacitors (P-SCs) exhibit superior electrochemical performance owing to the flexibility and unique surface properties of paper substrates. Currently, most P-SCs adopt a sandwich structure that is limited by electrode fabrication methods. However, the development of planar paper-based devices is crucial to satisfy the tremendous demand for wearable electronics. Herein, based on the mechanism of interaction between the laser and material, we used direct laser writing (DLW) techniques to fabricate in-plane P-SCs based on graphene oxide (GO) and manganese dioxide (MnO2) composite-covered paper substrates. Owing to the in-plane device structure and pseudocapacitive MnO2, the acquired rGO-MnO2-based planar P-SCs possessed a much higher specific capacitance value (17.7 mF/cm2) than that based on sandwich-structured reduced GO (rGO) (1.71 mF/cm2). In addition, three in-series integrated devices can be easily achieved via the DLW fabrication method, which shows potential for practical applications such as powering a light emitting diode. In addition, by carefully designing the paper substrate structure, the paper-based device exhibited excellent stretching stability. A specific capacitance retention of 86.8% remained after 5000 stretch cycles. Therefore, this study provides valuable insights into the design and fabrication of wearable paper-based electronics.

Development of immune-derived molecular markers for preeclampsia based on multiple machine learning algorithms

Origin of oxygen partial pressure-dependent conductivity in SrTiO3

SrTiO3 (STO) displays a broad spectrum of physical properties, including superconductivity, ferroelectricity, and photoconductivity, making it a standout semiconductor material. Despite extensive research, the oxygen partial pressure-dependent conductivity in STO has remained elusive. This study leverages first-principles calculations and systematically investigates the intrinsic defect properties of STO. The results reveal that VO, VSr, and TiSr are the dominant intrinsic defects, influencing STO's conductivity under varying O chemical potentials (oxygen partial pressures). Under O-poor condition, VO is the predominant donor, while VSr is the main acceptor. As the oxygen pressure increases, TiSr emerges as a critical donor defect under O-rich conditions, significantly affecting the conductivity. Additionally, the study elucidates the abnormal phenomenon where VTi, typically an acceptor, exhibits donor-like behavior due to the formation of O-trimer. This work offers a comprehensive understanding of how intrinsic defects tune the Fermi level, thereby altering STO's conductivity from metallic to n-type and eventually to p-type across different O chemical potentials. These insights resolve the long-standing issue of oxygen partial pressure-dependent conductivity and explain the observed metallic conductivity in oxygen-deficient STO.