Browse Articles

Accessing Strain Engineered V‐Fe(O)OH from Prussian Blue Analogue Precatalyst for Efficient Anodic Oxidation Reactions

AbstractPrussian blue analogues (PBAs) are promising precatalysts to access active metal oxyhydroxide [M(O)OH] phases for anodic oxidation reactions (AORs). In this study, we have introduced a d‐d electron complementation strategy to fine‐tune the electronic features of a VOFe‐PBA precatalyst. Spectroscopic studies revealed the altered coordination and electronic features of the VOFe‐PBA precatalyst compared to the FeFe‐PBA counterpart. The electrochemical activation of the VOFe‐PBA precatalyst led to the formation of a strained V‐Fe(O)OH active catalyst. Notably, V‐Fe(O)OH demonstrated exceptional performance, requiring a potential of only 1.56 V versus RHE for oxygen evolution reaction (OER) and 1.42 V versus RHE for iodide oxidation reaction (IOR) at a current density of 100 mA cm−2, significantly outperforming the Fe(O)OH. When employed in IOR‐assisted water splitting, V‐Fe(O)OH achieved an energy efficiency of 60% compared to overall water splitting. In‐situ Raman studies reflected the potential dependent generation of active reaction intermediates, which participated in IOR to produce iodate. Mechanistic investigations suggested the involvement of a lattice oxygen mechanism (LOM) facilitated by a proton‐decoupled electron transfer (PDET) pathway.

Comparing neutralizing antibody activity over time between naïve and convalesced COVID-19 vaccinated individuals

A highly efficient photodetector for squeezed light measurement in the gigahertz range

Squeezed light plays a crucial role in state-of-the-art quantum metrology and quantum information experiments. There is significant interest in utilizing squeezed states at high MHz and GHz frequencies. However, past efforts to build suitable photodetectors at these frequencies have yet to yield the required high quantum efficiency. Here, we present the development of a high-frequency balanced photodetector with near-unity quantum efficiency, realized with off-the-shelf components. The detector operates in balanced mode up to approximately 500 MHz, above which the differential frequency response limits its performance. To obtain high sensitivity above 500 MHz, the detector can be efficiently used in an unbalanced homodyne detection scheme. We employ our detector in this unbalanced mode to measure a squeezing comb up to 6.4 GHz, achieving a squeezing level of up to 10.7 dB. By sharing our experience, specifically in identifying the unequal frequency response as a limiting factor, we aim to enable and advance further developments in the field.

Comparative efficacy of biologically and chemically synthesized nickel oxide nanoparticles for catalytic degradation of dyes and wastewater treatment

Piezoelectric tuning of the resonance frequency in the synthetic multiferroic structures α-Fe2O3/68%Pb(Mg1/3Nb2/3)O3-32%PbTiO3 in the sub-THz range

In this article, we present the results of studies carried out on the synthetic multiferroic structure α-Fe2O3/68%Pb(Mg1/3Nb2/3)O3-32%PbTiO3 (PMN-PT). The thicknesses of the α-Fe2O3 single crystal and PMN-PT piezoelectric substrate were 500 μm. Using Brillouin light scattering spectroscopy, we experimentally studied the excitation of quasi-ferro- and antiferromagnetic modes of α-Fe2O3, as well as the effect of induced deformations from the polarized piezoelectric layer on the frequencies of quasi-ferro- and antiferromagnetic modes. For the PMN-PT [001] and [011] cuts, we considered the dependencies of the frequency of the quasi-ferromagnetic mode on the in-plane rotation of the magnetic field at the applied electric field with a voltage of 0–1000 V and on the magnetic field at ϕH=0° and ϕH=45°. We built a model that describes the linear piezoelectric and the nonlinear electrostrictive contributions, which was applied to the “butterfly-shaped” strain–voltage characteristic of the PMN-PT and the following hysteresis shift of antiferromagnetic resonance frequency with an applied electric field of 0–1000 V. We proved that by applying voltage to the PMN-PT substrate, it was possible to achieve a significant tuning of the antiferromagnetic resonance mode frequency (up to 10%). Our results show that such a synthetic multiferroic structure is a suitable component for magnonic devices with frequency tuning in the GHz and sub-THz frequency ranges.

An integrated transcriptomic approach for identifying enhancers in limb motor pools

Enhancing the electrical performance and stability of Hf-doped InZnO thin film transistors using dual-target co-sputtering technique

In this study, hafnium (Hf) was doped into InZnO films and related thin-film transistors (TFTs) were fabricated using co-sputtering. The optimal concentration of Hf doping atoms was obtained by controlling the power of dual targets InZnO and HfO2 and comparing their performances with those of HfInZnO TFTs that were fabricated from a single target, thus achieving high-performance and highly stable HfInZnO TFTs. After optimization, high-performance HfInZnO (PIZO70W-PHfO250W) TFTs with μFE value of 26.1 cm2/V s, SS value of 0.251 V/dec., and Vth value of 0.7 V were obtained. The results of experimental characterization indicate that co-sputtering with Hf doping reduced the oxygen vacancies, surface defects, and other trap densities of the device. Moreover, the co-sputtering prepared HfInZnO TFT exhibited the highest stability for small Vth shifts of 0.8 (−0.9) and 1.2 (−1.6) V under the gate bias and light illumination stress tests. Furthermore, low-frequency noise measurements demonstrated that the optimal Hf doping concentration in the HfInZnO films was controlled by the dual-target co-sputtering method, resulting in a lower number of oxygen vacancies and a lower interface trap density of the devices, thus enhancing the stability of HfInZnO TFTs. Overall, HfInZnO TFTs prepared using dual-target co-sputtering are found to be useful for achieving high-performance oxide TFTs.

Multi‐Step Screening‐Guided Core‐Shell RuO₂@TaO_x Nanorods Electrocatalyst for Acidic Oxygen Evolution Reaction

AbstractIn the acidic oxygen evolution reaction (OER), the exploration of highly efficient and stable electrocatalysts is essential for the environmentally friendly production of hydrogen. Although RuO2 exhibits high catalytic activity, its solubility and corrosion in acidic environments are of concern. In this study, high‐melting‐point metal oxides were multi‐step rationally screened as protective layers for RuO2 to identify their roles in the acidic OER process. Among them, Ta‐related oxide was selected as the best candidate. To demonstrate the theoretical predictions, RuO2@TaOx with a core‐shell structure was deployed, which exhibited low overpotentials of 163 and 232 mV at 10  and 100 mA cm−2, respectively. In fact, the dense amorphous TaOx layer effectively prevented the dissolution of RuO2 and optimized the charge transfer through interfacial synergy, significantly improving both the activity and durability of OER. Meanwhile, the operando quick X‐ray absorption spectroscopy (Quick‐XAS) confirmed that Ru served as the active site during OER, while Ta inhibited the over‐oxidation of Ru, correlating with theoretical considerations. This study provides a new paradigm using targeted computational screening to guide the design of advanced catalysts, and serves as a proof‐of‐concept for the deployment of high‐melting‐point metal oxides as a protective layer for RuO2 in the acidic OER.

Comprehensive evaluation of medical quality and analysis of obstacle factors in specialized neurological hospitals based on a multi-dimensional evaluation model: a case study of China’s National Regional Medical Center for Neurological Diseases

Binder-free Co9S8/Ni7S6 heterostructure electrodes via one-step electrodeposition for high-performance coplanar micro-supercapacitors on paper

Coplanar micro-supercapacitors (CMSCs) are essential energy supply components for the development of wearable devices. However, inadequate energy density hinders their extensive utilization in flexible sensors and portable electronic gadgets. This study presents the design and preparation of a binder-free Co9S8/Ni7S6 electrode with a heterostructure, achieved by a one-step electrodeposition procedure to rectify existing deficiencies of CMSCs. Electrochemical evaluations are conducted to ascertain the appropriate amount of sulfur introduction, followed by the assembly of the optimized electrode and activated carbon into a hybrid supercapacitor. The resultant CMSC has an impressive energy density of 0.031 45 mW h cm−2 with 93.4% capacity retention after 8000 cycles. Notably, CMSC's capacity remains mostly unchanged even when folded, demonstrating its exceptional mechanical stability and usage. In addition, density functional theory simulations elucidate that the creation of heterostructures facilitates accelerated electron transportation in electrodes. This study provides a valuable viewpoint regarding fabrication techniques and electrode advancement of CMSCs.

Quest for Luminescent Low‐Spin Chromium(I) Complexes with Doublet Metal‐to‐Ligand Charge‐Transfer Excited States

AbstractTwo paramagnetic Cr(I) complexes with homoleptic fac‐bis(triarylisocyanide) ligands were prepared by chemical oxidation of the Cr(0) precursors and emission spectra with peak maximum at respective 568 and 525 nm have been recorded with THF solutions of these two low‐spin d5 metal complexes at 298 K. Structural, spectroscopic, and theoretical studies revealed that the emission of the Cr(I) complexes could be tentatively assigned to be spin‐allowed 2MLCT excited states. Femtosecond‐resolved transient absorption spectra confirmed that the lifetimes of the excited states were in the tens of picoseconds, which could be explained by the fast nonradiative decay of 2MLCT state through low‐lying quartet metal‐centered (4MC) states. The Cr(I) complexes with luminescent 2MLCT excited states were distinct from the previously reported d5 Fe(III) complexes with luminescent 2LMCT excited states, enriching the diversity of emissive excited states of earth‐abundant 3d transition metal complexes.

Modeling Moose–Wolf interactions in Isle Royale National Park using sparse identification of nonlinear dynamics

Superconducting spintronic device based on Fe3GaTe2/CsV3Sb5/Fe3GaTe2 van der Waals heterojunctions

van der Waals (vdW) heterojunctions have emerged as highly promising candidates for next-generation spintronic devices, owing to their exceptional interface quality, scalability, and tunable electronic properties. Here, we report a vdW superconducting heterojunction based on the Fe3GaTe2/CsV3Sb5/Fe3GaTe2, which combines the strong perpendicular magnetic anisotropy of Fe3GaTe2 with the superconductivity and charge density wave order of the Kagome metal CsV3Sb5. Notably, this superconducting heterojunction exhibits a magnetoresistance of 0.25% at 2 K, approximately two times higher than that observed at elevated temperatures. The magnetic proximity effect in CsV3Sb5 modulates superconductivity by suppressing spin-singlet Cooper pairing and enabling spin-triplet states. The interplay between magnetism and superconductivity not only elucidates the coexistence of competing electronic orders in CsV3Sb5 but also highlights the potential of such heterojunctions for energy-efficient, high-performance spintronic devices. Our work establishes Fe3GaTe2/CsV3Sb5/Fe3GaTe2 as a promising platform for engineering spin-polarized superconducting states and advancing quantum computing technologies.

Research on the open space ratios of residential plots in major Chinese cities meeting public centralized green space standards

Abstract The indicator of open space ratio has garnered significant international attention due to its ability to effectively balance equity and efficiency in urban development. In China, many studies have investigated the introduction of the open space ratio to address the disconnect between public benefit factors and development efficiency factors during the land development control process. However, these studies have not yet succeeded in linking the open space ratio with the core element of public interest—public centralized green spaces—resulting in an inability to further localize the open space ratio within the Chinese context. To address the gaps in existing research, our study focuses on residential plots in 15 major cities across different climate zones in China, exploring the open space ratios that meet the country’s standards for public centralized green spaces. We find that, after achieving standards, the open space ratios in residential plots across various cities have increased to varying degrees. The differences in open space ratios among specific cities are significantly influenced by factors such as geographical latitude, the intensity of per capita land use, regional economic development levels, and local construction practices. The application of the open space ratio with Chinese characteristics must be based on the premise of meeting the public interest baseline. It should be tailored to local conditions, stratified and classified, and scientifically determined, thereby promoting an effective balance between equity and efficiency in the urban land development process and advancing the sustainable development of the living environment.

Self-powered polycrystalline SrSnO3/NiO heterojunction for ultra-stable and high-responsivity ultraviolet photodetection

Strontium stannate (SrSnO3), an emerging wide-bandgap semiconductor, holds great promise for ultraviolet (UV) photodetectors in space and flame detection applications; yet, its development has been constrained by a reliance on single-crystal material quality. Herein, we overcome this critical limitation by constructing an all-oxide p–n heterojunction between polycrystalline La-doped SrSnO3 (n-type) and epitaxial NiO (p-type). The heterostructure achieves solar-blind UV detection at 254 nm with high performance. The optimized device delivers a responsivity of 31.83 mA W−1, a detectivity of 1.36 × 1012 Jones, an ultrafast response (rise/fall times = 18.0/27.9 ms), and an exceptional photocurrent-to-dark-current ratio (>1700). The device also shows excellent environmental stability, with a photocurrent loss of less than 1% after 100 on/off operating cycles and after one year of exposure to ambient atmosphere. This work establishes a general strategy for developing high-performance SrSnO3 photodetectors through heterojunction engineering, broadening the material design space beyond crystalline perfection.

Using a full thickness bioengineered human skin equivalent as a model for radiation biology research

Abstract Radiation exposure from radiological or nuclear events, medical treatments, or spaceflight poses significant health risks, yet human-specific models to investigate radiation effects on skin remain limited. This study establishes a novel in vitro platform using a full-thickness bioengineered human skin equivalent colonized with natural mixed human microbiota (coHSEs) to assess radiation-induced biological responses. We exposed coHSEs to acute doses of up to 4 Gy with x-rays and evaluated their viability, structural integrity, and molecular responses over 25 days. The coHSE model demonstrated sustained viability without dose-dependent opportunistic microbial overgrowth when procedural optimizations were applied. Radiation-induced epidermal remodeling did not compromise tissue architecture or swabbing-based sample collection. Cell proliferation analyses revealed dose- and time-dependent dynamics, with consistent dermal cell density maintained across radiation doses. Comparative multi-omic analyses, including untargeted metabolomics, targeted lipidomics, and 16 S metagenomics, revealed conserved metabolic and microbial responses to radiation in both coHSEs and skin from irradiated mice. Enriched pathways such as arachidonic acid and fatty acid metabolism, along with shifts in microbial taxa including Lachnospiraceae, support the translational relevance of the coHSE model. This system offers a scalable, ethical, and physiologically relevant platform for radiation biology, biodosimetry, and therapeutic development, advancing terrestrial health research with promising application for space research.

Arbitrary power splitting governed by quantum-like adiabatic transfer in acoustic multi-cavity coupled systems

In this work, a design approach for achieving arbitrary acoustic power splitting is proposed. Several space-varying air slits are adopted to connect multiple acoustic cavities, thus realizing quantum-like adiabatic transfer in acoustic systems. By altering the coupling actions between composing cavities, the splitting ratios can be customized on demand. The one to m-port power splitting is achieved in planar as well as spatial configurations, showing an excellent applicability to numerous different scenarios. Remarkably, the acoustic waves from adjacent output ports not only have desired splitting ratios, but also have opposite phases. Hence, a broadband and asymmetric acoustic metamaterial is further constructed, through which the beam splitting and asymmetric wave transmission behaviors can be realized simultaneously in a free space. The proposed acoustic power splitter design offers a simple configuration, broadband performance, and high flexibility, making it a promising candidate for applications in acoustic detection, sensing, and communication.

Determination of the bioavailability of barley grains for selected elements

Unconventional photon blockade in cavity optomechanical system

Traditionally, photon blockades (PB) are classified into two distinct categories—conventional and unconventional—based on their unique physical mechanisms. In relation to the cavity decay rate κ, conventional photon blockade occurs under conditions of strong nonlinearity (J>κ), while unconventional photon blockade is observed in situations of weak nonlinearity (J<κ). In this study, we examine a two-mode cavity optomechanical system (Jâ†â†b+Jââb̂†) and a two-photon parametric drive εp(â†â†+ââ). When the detunings significantly exceed the dissipation rates of the cavity (|Δa|,|Δb|≫κ), the optimal condition for PB becomes independent of the coupling strength. This implies that photon antibunching effects can occur in both strong and weak regimes (J>κ and J<κ), even when J∼κ, and we could achieve PB solely through the adjustment of detunings. Furthermore, we generalize the approach to the conversion between single photon and three photons (Jâ†3b+Jâ3b̂†) with a three-photon parametric drive εp(â†3+â3) and arrive at nearly identical conclusions. This work presents a method for implementing a single-photon source, which holds significant potential for practical engineering applications due to its independence from coupling strength.

Production, characterization, and genomic insights of a human lectin-binding exopolysaccharide from Haloarcula japonica strain SST1