First-principles computational screening of Ngas adsorption by two-dimensional MN-MXene.

The capture and utilization of Nhas been limited by the development of high-performance Ncapture and storage materials, and exploring the adsorption mechanism of Nand searching for new and efficient Nadsorption materials are the key to solving this technological challenge. In this study, the adsorption properties ofandtwo-dimensional MN-MXene (M = Sc, Ti, V, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, and Cd) on Nmolecules were investigated based on first principles. The results of cohesion energy, energy band structure and partition density indicate that the 15 MNs have excellent stability and electrical properties.

Designing Ultra-Narrow-Band Red Phosphor via Oxygen Vacancy Engineering for Transparent Display Application.

Narrow-band red phosphors have been crucial in enabling energy-efficient and wide color gamut display technologies. Developing novel red phosphors with narrower FWHM and suitable positions is still an urgent demand. Herein, a nanorod-shaped NbO:Pr phosphor, featuring a single ultra-narrow-band red emission at 612 nm with FWHM of only 19 nm, is reported.

Thermal radiation analysis of a broadband solar energy-capturing absorber using Ti and GaAs.

This study employed a time-domain finite-difference (FDTD) approach to design an efficient solar energy-capturing absorber consisting of a high melting point metal (Ti) and a semiconductor (GaAs). The structure generated cavity resonance (CR) and surface plasmon resonance (SPR), leading to extremely high absorption across different wavelength bands. The structure exhibited >90% absorption over a wide wavelength range (280-3000 nm).

Prediction of two-dimensional narrow-gap Janus TiOXY (X, Y = Cl, Br, I; X ≠ Y) monolayers for electronic and optoelectronic applications.

Two-dimensional (2D) transition metal oxyhalides have garnered significant interest due to their unique physical properties and promising potential applications. By using density functional theory and the non-equilibrium Green's function method, the anisotropic mechanical, electronic, optical, and transport properties of the Janus TiOXY (X, Y = Cl, Br, I; X ≠ Y) monolayers are systematically investigated. The proposed Janus TiOClBr, TiOBrI, and TiOClI monolayers exhibit favorable thermodynamic, dynamic, and mechanical stabilities, respectively.

Enhanced Phonon-Phonon Interactions and Weakened Electron-Phonon Coupling in Charge Density Wave Topological Semimetal EuAl with a Possible Intermediate Electronic State.

The origin of the charge density wave (CDW) is a long-term open issue. Furthermore, the evolution of phonon-phonon interactions (PPIs) across CDW transitions has rarely been investigated. Whether electron-phonon coupling (EPC) would be weakened or enhanced after CDW transitions is still under debate.

Effect of CHNO Additive on Ib-Type Diamond from Ni-Based Alloy under HPHT Conditions.

Natural diamond inclusions comprise elements such as carbon (C), hydrogen (H), oxygen (O), and nitrogen (N), which can be assumed to exist in the natural diamond growth environment. Therefore, the artificial construction of the C-H-O-N system plays an important role in exploring the growth mechanism of natural diamonds. Herein, diamond crystals were successfully synthesized in the NiMnCo-C system by adding carbohydrazide (CHNO) as the organic additive at 1280 to 1320 °C and 5.

Bio-assisted synthesis of cobalt-based heterostructures in carbon nanobelts for enhanced oxygen catalysis in Zn-air battery.

The delicate design and fabrication of transition metal-based heterostructures with abundant active sites are a crucial issue for achieving superior electrocatalytic properties. In this work, we introduce a novel bio-assisted strategy for assembling cobalt-based heterostructures on nitrogen and phosphorus codoped carbon nanobelts, which serve as highly efficient bifunctional oxygen catalysts. The fungus of Rhizopus is utilized to encapsulate the Co-CoTe within the in-situ formed nitrogen and phosphorus codoped carbon nanotubes (NPCNT), resulting in hairy nanobelts with a porous structure and excellent flexibility.

Controllable Growth of Wafer-Scale TeSe Thin Films Based on Selenium Phase Change-Induced Strategy for Single-Pixel Imaging.

Recently, TeSe films have shown significant potential for infrared detection. However, the conventional deposition process of TeSe films typically requires a cooled substrate, which results in the formation of poorly crystallized materials. Achieving controlled synthesis of large-area TeSe films remains a major challenge.

In Situ Ring Opening Polymerization of High-Performance Full-Color CsPbX@PDMS (X = Cl, Br, I) Nanospheres Toward Wide-Color-Gamut Displays.

Optimizing the three-primary-color perovskite quantum dots (TPC PQDs) is crucial for achieving ultra-wide color gamut displays. Although encapsulation is an effective strategy to improve the stability and optical performance of the TPC PQDs, the chemicals or environment employed in the coating procedure may attack the CsPbX PQDs and generate defects, damage, and ligand loss. Herein, a mild, facile and universal hexamethylcyclotrisiloxane (D3) in situ ring opening polymerization strategy is successfully developed for efficiently synthesizing high-brightness and extremely stable TPC CsPbX@PDMS (X = Cl, Br, I) nanospheres, with particularly friendlyness for fragile red and blue.

Molecular dynamics study on the mitigation of radiation damage caused by electron pulses.

The reduction of radiation damage represents a long-term objective for electron microscopists, particularly those engaged in the study of biological and organic matter. Recently, electron pulses in ultrafast transmission electron microscopy have been demonstrated to serve as a damage mitigation technique for radiation-sensitive materials. Nevertheless, the underlying mechanism of the mitigation effects remains unclear.

Bifunctional NiCoP nanofiber arrayed on carbon cloth for fast polysulfide conversion and uniform lithium deposition in lithium sulfur batteries.

The severe polysulfides shuttling and irregular lithium dendrites impede the widespread adoption of lithium-sulfur (Li-S) batteries. Here, a sulfiphilic/lithiophilic NiCoP nanofiber arrayed on carbon cloth (NiCoP@CC) as the sulfur/lithium host is reported, providing a dual solution for both cathode and anode issues. Both theoretical calculations and experiments confirm that NiCoP@CC enhances the cycling stability of sulfur cathode and lithium anode by facilitating polysulfides conversion and homogenizing lithium deposition.

Smith-Purcell Radiation in Two Dimensions.

Smith-Purcell radiation (SPR) is an electromagnetic radiation generated by the motion of free electrons in close to a periodic structure. Over the past 70 years, there has been significant interest in the generation of light in three-dimensional (3D) free space through SPR. Here, by using the interaction between moving electrons and a designed metallic nanoaperture array, the observation of two-dimensional (2D) SPR, e.

Electrically Switchable Longitudinal Nonlinear Conductivity in Magnetic Semiconductors.

Writing data by electric field (as opposed to electric current) offers promises for energy efficient memory devices. While this data writing scheme is enabled by the magnetoelectric effect, the narrow spectrum of room-temperature magnetoelectrics hinders the design of practical magnetoelectric memories, and the exploration of other mechanisms toward low-power memories is greatly demanding. Here, we propose a mechanism that allows the electric-field writing of data beyond the framework of magnetoelectric effect.

Dynamics Study of the CaC (∑) + C(P) → Ca+C (∑) Reaction: Based on a Full-Dimensional Neural Network Potential Energy Surface of CaC.

The CaC molecule, as an interstellar species that has already been detected, has attracted significant attention. To date, studies on the potential energy surface (PES) and the reaction dynamics of CaC are largely lacking. In this work, energy values were obtained for 3877 configurations using the icMRCI+Q method, and these energies were subsequently fitted using a neural network approach.

Electrostatic Co-Assembly of Cyanine Pair for Augmented Photoacoustic Imaging and Photothermal Therapy.

Molecular phototheranostic dyes are of eminent interest for oncological diagnosis and imaging-guided phototherapy. However, it remains challenging to develop photosensitizers (PSs) that simultaneously integrate high-contrast photoacoustic imaging and efficient therapeutic capabilities. In this work, a supramolecular strategy is employed to construct a molecular pair phototheranostic agent via the direct self-assembly of two cyanines, C5TNa (anionic) and Cy-Et (cationic).

Origin and enhancement of magnetoresistance in antiferromagnetic tunnel junctions: spin channel selection rules.

Antiferromagnetic materials offer superior stability and ultra-fast spin reversal, making them ideal for next-generation magnetoresistive memory. However, magnetoresistance in antiferromagnetic tunnel junctions (AFMTJs) is small because the two spin channels are typically identical. Here, we demonstrate that non-zero or even huge tunneling magnetoresistance (TMR) can be achieved in AFMTJs through a spin-channel selection model, specifically by manipulating the interface tilt angle (ITA) to control the different tunneling distances of the two spin channels.

Flexible Alternating-Current Electroluminescent Devices for Reliable Identification of Fingerprints.

Flexible bioelectronic devices, which can directly detect various external stimuli or biosignals and communicate the information to the users, have been broadly investigated due to the increasing demand for wearable devices. Among them, alternating-current electroluminescence (ACEL) devices are proposed as sensitive sensing systems for various targets, such as fingerprints. Herein, we propose a method for preparing high-performance ACEL devices by using an Ag electrode, polyethylene terephthalate (PET) substrate, FKM/EMI ionogel, and ZnS:Cu/BaTiO/Ecoflex emissive layer.

COVID-19 recognition from chest X-ray images by combining deep learning with transfer learning.

Objective: Based on the current research status, this paper proposes a deep learning model named Covid-DenseNet for COVID-19 detection from CXR (computed tomography) images, aiming to build a model with smaller computational complexity, stronger generalization ability, and excellent performance on benchmark datasets and other datasets with different sample distribution features and sample sizes.

Methods: The proposed model first extracts and obtains features of multiple scales from the input image through transfer learning, followed by assigning internal weights to the extracted features through the attention mechanism to enhance important features and suppress irrelevant features; finally, the model fuses these features of different scales through the multi-scale fusion architecture we designed to obtain richer semantic information and improve modeling efficiency.

Results: We evaluated our model and compared it with advanced models on three publicly available chest radiology datasets of different types, one of which is the baseline dataset, on which we constructed the model Covid-DenseNet, and the recognition accuracy on this test set was 96.

Acoustic-feedback wavefront-adapted photoacoustic microscopy.

Optical microscopy is indispensable to biomedical research and clinical investigations. As all molecules absorb light, optical-resolution photoacoustic microscopy (PAM) is an important tool to image molecules at high resolution without labeling. However, due to tissue-induced optical aberration, the imaging quality degrades with increasing imaging depth.

Defect Control and Strain Regulation Enabled High Efficiency and Stability in Flexible Perovskite Solar Cells.

Flexible perovskite solar cells (f-PSCs) show unique charm in the electronics industry due to their mechanical flexibility, portability, and compatibility with curved surfaces. However, severe interfacial defects and residual tensile strain remain pivotal limitations to their performance and stability. Here, a novel strategy using 4-amino-2-(trifluoromethyl) benzonitrile (ATMB) with multiple functional groups (-NH, -CF, and -C≡N) is proposed to modify the interface of perovskite/Spiro-OMeTAD, realizing significant improvements in both the efficiency and stability of PSCs.

Synergistic Integration of Halide Perovskite and Rare-Earth Ions toward Photonics.

Halide perovskites (HPs), emerging as a noteworthy class of semiconductors, hold great promise for an array of optoelectronic applications, including anti-counterfeiting, light-emitting diodes (LEDs), solar cells (SCs), and photodetectors, primarily due to their large absorption cross section, high fluorescence efficiency, tunable emission spectrum within the visible region, and high tolerance for lattice defects, as well as their adaptability for solution-based fabrication processes. Unlike luminescent HPs with band-edge emission, trivalent rare-earth (RE) ions typically emit low-energy light through intra-4f optical transitions, characterized by narrow emission spectra and long emission lifetimes. When fused, the cooperative interactions between HPs and REs endow the resulting binary composites not only with optoelectronic properties inherited from their parent materials but also introduce new attributes unattainable by either component alone.

Deep-Blue and Narrowband-Emitting Carbon Dots from a Sustainable Precursor for Random Lasing.

Deep-blue (DB) emitters that feature high photoluminescence quantum yield (PLQY) and narrow spectral bandwidth are desired for a variety of optoelectronic applications, particularly for lighting, illumination, and lasing. Currently favored DB emitters constitute quantum dots comprising cadmium or lead and organic compounds derived from petroleum, but they suffer from toxicity and sustainability issues. Here, we report the solvothermal synthesis of DB-emitting carbon dots (s) using bioderivable phloroglucinol as the sole starting material, which exhibit a peak emission wavelength of 403 nm, narrow spectral full width at half-maximum of 35 nm, and high PLQY of 61% in ethanol.

Trigger-Free and Low-Cross-Sensitivity Displacement Sensing System Using a Wavelength-Swept Laser and a Cascaded Balloon-like Interferometer.

A wavelength-swept laser (WSL) demodulation system offers a unique time-domain analysis solution for high-sensitivity optical fiber sensors, providing a high-resolution and high-speed method compared to optical spectrum analysis. However, most traditional WSL-demodulated sensing systems require a synchronous trigger signal or an additional optical dispersion link for sensing analysis and typically use a fiber Bragg grating (FBG) as the sensing unit, which limits displacement sensitivity and increases fabrication costs. We present a novel displacement sensing system that combines a trigger-free WSL demodulation method with a cascaded balloon-like interferometer, featuring a simple structure, high sensitivity, and low temperature cross-sensitivity.