Calibration of a gated neutron time-of-flight spectrometer with low-afterglow.

Neutron Time-of-Flight (nTOF) detectors are key diagnostics to detect thermonuclear neutrons in laser-fusion experiments. This diagnostic, however, is often plagued by strong gamma-ray noise prior to neutron signals, especially in harsh fast-ignition (FI) environments. To address this issue, a combination of low-afterglow liquid scintillators with time-gated photomultiplier tubes as necessary nTOF components would be a natural solution.

High-Pressure Synthesis and Characterization of the Novel Potassium Superhydride KH.

Through high-pressure diamond anvil cell experiments, we report the synthesis of two novel potassium superhydrides (KH-I and KH-II) and investigate their structural and vibrational properties via synchrotron X-ray powder diffraction and Raman spectroscopy, complemented by density functional theory (DFT) calculations. Above 17 GPa at room temperature, KH-II and H react to form KH-I; this reaction can be accelerated with temperature. KH-I possesses a face-centered-cubic () potassium sublattice with a slight rhombohedral distortion (space group 3̅).

Elastocaloric evidence for a multicomponent superconductor stabilized within the nematic state in Ba(FeCo)As.

The iron-based high-[Formula: see text] superconductors (SCs) exhibit rich phase diagrams with intertwined phases, including magnetism, nematicity, and superconductivity. The superconducting [Formula: see text] in many of these materials is maximized in the regime of strong nematic fluctuations, making the role of nematicity in influencing the superconductivity a topic of intense research. Here, we use the AC elastocaloric effect (ECE) to map out the phase diagram of Ba(FeCo)As near optimal doping.

A geometric condition for robot-swarm cohesion and cluster-flock transition.

We present a geometric design rule for size-controlled clustering of self-propelled particles. We show that active particles that tend to rotate under an external force have an intrinsic, signed parameter with units of curvature which we call curvity, that can be derived from first principles. Experiments with robots and numerical simulations show that properties of individual robots (radius and curvity) control pair cohesion in a binary system, and the stability of flocking and self-limiting clustering in a swarm, with applications in metamaterials and in embodied decentralized control.

Self-Assembled Polypseudorotaxanes Crosslinked by Dynamic Disulfide Bonds as Modular Functionalization for Thiophilic Metal Nanoparticles.

As supramolecular assemblies, polypseudorotaxanes (PPR) exhibit inherent advantages in modular adaptability and structural programmability, with the potential to build tuneable platforms integrating various functionalities. Here we report the "one-pot" preparation of a self-assembled thiol-rich PPR (SPPR), where thiolated-α-cyclodextrins (SHαCD) spontaneously thread onto polymers, and are then crosslinked into a three-dimensional network by the thermally-triggered oxidation of thiols into disulfide bonds. The dynamic thiol groups along the SPPR provide remarkable modularity for the functionalization of thiophilic metal nanoparticles (NPs), exemplified by two application vectors.

In-Plane Ferroelectric p/n Superstructure Photoelectrode for Bias-Free Solar-Fuel Conversion.

Multijunction photoelectrodes, which generate active photocarriers with sufficient energy to drive unassisted solar-fuel conversion, represent a promising avenue for sustainable energy applications. However, achieving controllable p/n-type doping and high-quality growth remains a challenge for most emerging metal oxide semiconductors. In this study, we demonstrate the creation of in-plane ferroelectric p/n homojunction superstructures in BiFeO (BFO) films, enabling bias-free photoelectrochemical (PEC) reactions.

Impulsivity and neuroticism share distinct functional connectivity signatures with alcohol-use risk in youth.

Increases in impulsivity and negative affect (e.g., neuroticism) are common during adolescence and are both associated with risk for alcohol-use initiation and other risk behaviors.

Ultrafast all-optical switching in nonlinear 3R-MoS van der Waals metasurfaces.

Second-order nonlinear optical processes are fundamental to photonics, spectroscopy, and information technologies, with material platforms playing a pivotal role in advancing these applications. Here, we demonstrate the exceptional nonlinear optical properties of the van der Waals crystal 3R-MoS, a rhombohedral polymorph exhibiting high second-order optical susceptibility ( ) and remarkable second-harmonic generation (SHG) capabilities. By designing high quality factor resonances in 3R-MoS metasurfaces supporting quasi-bound states in the continuum (qBIC), we first demonstrate SHG efficiency enhancement exceeding 10.

Observation of the Charge Density Wave Excitonic Order Parameter in Topological Insulator Monolayer WTe.

Strong electron-hole interactions in a semimetal or narrow-gap semiconductor may drive a ground state of condensed excitons. Monolayer WTe has been proposed as a host material for such an exciton condensate, but the order parameter─the key signature of a macroscopic quantum-coherent condensate─has not been observed. Here, we use Fourier-transform scanning tunneling spectroscopy (FT-STS) to study quasiparticle interference (QPI) and periodic modulations of the local density of states (LDOS) in monolayer WTe.

Orthogonally polarized dual-wavelength Nd:LaMgAl11O19/Nd:SrAl12O19 laser at 1297 and 1306 nm with adjustable ratio of output powers.

Using tunable in-band laser diode (LD) pumping (791.1-798.2 nm), an orthogonally polarized dual-wavelength (OPDW) Nd:LaMgAl11O19/Nd:SrAl12O19 (Nd:LMA/Nd:SA) operation at 1297 nm and 1306 nm for the 4F3/2 → 4I13/2 transition is demonstrated for the first time.

Synthesis and Preclinical Evaluation of Novel Tc-Labeled Glucose Derivatives Containing Different Proline Analogs as Linker Moieties for Tumor Imaging.

2-[F]Fluoro-2-deoxy-d-glucose ([F]FDG) is the most extensively utilized tumor imaging agent in clinical positron emission tomography (PET) applications. Nevertheless, no radiolabeled glucose derivatives for single-photon emission computed tomography (SPECT) imaging have achieved clinical usage comparable to that of [F]FDG. Technetium-99m is a common single-photon-emitting radionuclide used in clinical practice and has potential for the development of novel radiopharmaceuticals.

Atomically dispersed Ru in ZIF-67 as a high-performance HER catalyst: structural evolution and deactivation mechanism elucidation.

Despite the prevalence of zeolitic imidazolate framework (ZIF-67)-derived catalysts for the hydrogen evolution reaction (HER), the catalytic potential of pristine ZIF-67 remains obscured by its inherent inertness. In this work, we address this gap by developing an annealing-free strategy to implant atomically dispersed noble metals (Ru, Rh, and Pd) into the intact ZIF-67 framework. Remarkably, Ru single-atom modification reduces the HER overpotential of ZIF-67/CC by 252 mV at 10 mA cm (from 331 mV to 79 mV) and slashes the Tafel slope by 70%, representing the most significant activation of pristine ZIF-67 reported for the HER.

Experimental signatures of interstitial electron density in transparent dense sodium.

The transparent 4 phase of dense sodium (Na), stable above 200 GPa, has been computed to be an electride in which valence electrons are localised on interstitial lattice sites within the structure. However, there is no experimental evidence for this interstitial electron localisation in Na, or indeed in other high-density electride phases. Using static compression and single-crystal X-ray diffraction techniques, we have grown and studied a single-crystal sample of Na in the 4 phase at 223 GPa.

Plasmodesmata Wall Biomechanics: Challenges and Opportunities.

Plant cell walls exist as a complex and varied blend of polysaccharides and proteins; the combination of which has evolved over millions of years. Research on how these components interact is key to understanding a plant's mechanical, structural, communicative, and biological traits. However, knowledge on cell wall components, its biophysical properties and cellular functions remains sparse.

Uncovering the impact of the cardiovascular system on cerebrovascular health using MRI.

Human cerebrovasculature is finely tuned to enable local changes in blood flow to meet the brain's demands, whilst protecting the brain from systemic changes in blood pressure, both acutely during a heartbeat and chronically over time. This review summarises cerebrovascular structure and function, their role in disease and neurodegeneration and the part MRI measurements can play in probing them. MRI methods to measure various aspects of cerebrovascular physiology are described and placed in context of applications studying cerebrovascular health.

Silicate precursor silane detected in cold low-metallicity brown dwarf.

Within 20 pc of the Sun, there are currently 29 known cold brown dwarfs-sources with measured distances and an estimated effective temperature between that of Jupiter (170 K) and approximately 500 K (ref. ). These sources are almost all isolated and are the closest laboratories we have for detailed atmospheric studies of giant planets formed outside the Solar System.

Hierarchical MoS/CuS photonic nanostructure accelerating photothermoelectric conversion of bacterial cellulose based phase change materials.

Phase change materials (PCMs)-integrated solar-thermal-electric generators (STEGs) have emerged as a promising platform for sustainable solar energy harvesting, yet faces critical challenges including liquid phase instability, insufficient photothermal efficiency, and limited thermoelectric output. Herein, we engineered hierarchical photonic confinement through the assembly of plasmonic CuS nanoparticles, broadband-absorbing MoS nanosheets, and porous bacterial cellulose (BC). In this tripartite architecture, BC matrix provides robust structural integrity and enhances heat transfer via its 3D interconnected nanoporous structure; MoS nanosheets enable extended photon harvesting across the ultraviolet to near-infrared spectrum; CuS nanoparticles amplify near-field optical effects through localized surface plasmon resonance.

Synthesis of flexible SERS sensing platform of graphene/Ag-popcorns/ PMMA for ultrasensitive detection.

Surface-enhanced Raman scattering (SERS) with ultrahigh sensitivity has garnered significant attention for quantitative analysis and chemically specific detection. However, conventional SERS platforms, typically structured by depositing plasmonic micro/nanoparticles onto rigid substrates, face limitations in further advancement and applications. In this study, we present a novel method to prepare a flexible SERS film substrate composed of graphene overlayer (G) atop a self-assembled array of silver micropopcorns (Ag MPs) and a polymethyl methacrylate (PMMA) membrane.

Detecting the Six Polytypes of Five-Layer Graphite.

Graphene layers can assemble in two shifted metastable positions per interface, leading to eight possible structural arrangements in five-layer graphene, six of which correspond to distinct periodic crystals. These polytypes exhibit diverse symmetries, interlayer electronic hybridization, van der Waals adhesion, and optical responses. Arrangements lacking inversion [I] and mirror [M] symmetries host intrinsic polarizations, while those with sufficiently flat electronic bands display orbital magnetization, unconventional superconductivity, and anomalous fractional quantum Hall states.

A mechanical route for cooperative transport in autonomous robotic swarms.

Cooperative transport is a striking phenomenon where multiple agents join forces to transit a payload too heavy for the individual. While social animals such as ants are routinely observed to coordinate transport at scale, reproducing the effect in artificial swarms remains challenging, as it requires synchronization in a noisy many-body system. Here we show that cooperative transport spontaneously emerges in swarms of stochastic self-propelled robots.

Suppression of Spin-Orbit Torque Switching by the Magnetic Proximity Effect.

Functional magnetic multilayers are particularly interesting for enabling many emerging spintronic physics, including spin-orbit torque (SOT), magnetic proximity effect (MPE), and perpendicular magnetic anisotropy (PMA), among many others. A comprehension of these spintronic phenomena is vital for the development of advanced spintronic materials and devices. Here, we investigate the interplay between the MPE and the current-induced SOT switching in the perpendicularly magnetized Pt/[Co/Pd] multilayers (with being the number of repetitions).

Molecular mobility of extraterrestrial ices: surface diffusion in astrochemistry and planetary science.

Molecules are ubiquitous in space. They are necessary components in the creation of habitable planetary systems and can provide the basic building blocks of life. Solid-state processes are pivotal in the formation of molecules in space and surface diffusion in particular is a key driver of chemistry in extraterrestrial environments, such as the massive clouds in which stars and planets are formed and the icy objects within our solar system.

High-Pressure MgCl Synthesized in a Diamond Anvil Cell as a Polar Metal with Second-Harmonic Generation.

Polar metals have attracted growing interest due to both their significance in fundamental science and their potential functionalities. Here, we report the discovery of a novel polar metal, magnesium chloride MgCl, in which the metallicity of the polar structure is uniquely driven by attractive halogen interactions. MgCl was synthesized in laser-heated diamond anvil cells and observed at pressures of 28(2)-93(3) GPa.

Sliding volume-based streak artifact reduction network (S-STAR Net) for ultra-sparse-view computed tomography.

Background: Cone-beam computed tomography (CBCT) is a widely used imaging technique. In practical applications, reducing projection views can decrease radiation exposure and accelerate scanning speed, with potential benefits for stationary CT systems. However, ultra-sparse-view acquisition (e.