bluuebunny/crossref_metadata_2025 huggingface dataset:
Behavior of a stationary jet of concentrated polyacrylonitrile solution
Authors: Skvortsov I. Yu. , Kuzin M. S. , Gerasimenko P. S. , Patsaev T. D. , Subbotin A. V. , Kulichikhin V. G.
Published: August 2024

The fiber formation process via the uniaxial stretching jet of concentrated polyacrylonitrile solutions in dimethyl sulfoxide has been investigated. Data on viscoelastic properties obtained by oscillatory shear rheometry have been compared with the evolution of jet thinning during stretching. It was found that at a fixed temperature and moderate air humidity (20%), the jet thinning process involves an initial rapid viscous thinning followed by phase separation and the formation of solid fibers coated with solvent droplets. Changes in morphology as the solution transforms into solid fiber were analyzed using cryo-microscopy. It was demonstrated that at the final thinning stages there exists an increase in a solvent concentration in the near-surface layers of the jet/fiber. Finally, the role of air humidity was analyzed. Two possible scenarios of fiber formation were considered: predominantly due to uniaxial deformation or through coagulation of solution with moisture from the air humidity. Comparative morphological analysis of prepared fiber cross sections showed that monolithic fibers with homogeneous transverse morphology are obtained in the case of strain-induced formation. In contrast, fibers obtained due to phase separation induced by air humidity have gradient porosity. The mechanisms underlying the observed behavior are discussed.
Structural visualization of inhibitor binding in prolyl oligopeptidase
Authors: Walczewska-Szewc Katarzyna , Rydzewski Jakub
Published: August 2024

The association and dissociation of proteins and ligands are crucial in biophysics for potential drug development [Baron and McCammon, Annu. Rev. Phys. Chem. 64, 151–175 (2013)]. However, identifying and characterizing the reaction pathways for these rare events has been a long-standing challenge. Molecular dynamics (MD) simulations are limited in exploring biophysical processes on experimental timescales, so ligand transport processes through complex transient tunnels formed by proteins during dynamics are often simulated using enhanced sampling MD [Rydzewski and Nowak, Phys. Life Rev. 22–23, 58–74 (2017)]. Erroneously identified ligand binding pathways can affect thermodynamic and kinetic characteristics calculated from MD trajectories. A system that has the potential to be a therapeutic target for neurodegenerative diseases is prolyl oligopeptidase (PREP). This is due to its involvement in promoting protein aggregation and disrupting cellular function through affecting protein–protein interactions (PPI). The recent discovery of a new type of PREP inhibitor that targets PPI raises important questions about the diversity of ligand binding pathways in PREP and their impact on protein dynamics [Pätsi et al., J. Med. Chem. 67, 5421–5436 (2024); Kilpeläinen et al., J. Med. Chem. 66, 7475–7496 (2023); and Walczewska-Szewc et al., Phys. Chem. Chem. Phys. 24, 4366–4373 (2022)]. In this article, using results from enhanced sampling MD, we visually present how the binding process in PREP depends on subtle changes in inhibitors, which could be crucial in treating neurodegenerative disorders.
Dynamic driving eliminates volume fraction inhomogeneity and apparent yield stress in flowing dense non-Brownian suspensions
Authors: Ness Christopher , Moussa Amgad S.
Published: August 2024

Dense suspensions of non-Brownian hard spheres are often characterized as yield-stress fluids despite having no intrinsic time or force scales that could lead to such rheology. One mechanism for the apparent yield stress is particle migration, which produces (or is caused by) inhomogeneous flow conditions and leads to local regions where the solids' content approaches or exceeds the limit of flowability. In such a scenario, one does not induce flow by exceeding a yield stress, but instead by exploring the only remaining control parameter, namely the flow history. We demonstrate using particle-based simulation that this apparent local yield stress behavior does indeed emerge in a model dense suspension of non-Brownian hard spheres and that it can be eliminated by imposing a time-varying flow field.
Raman enhancement via double optical resonances in all-dielectric photonic crystal slabs
Authors: Xu Yuyang , Wu Shunben , Hong Shaoxin , Wang Xinhao , Liu Xiaohan , Wang Jiajun , Shi Lei
Published: August 2024

All-dielectric photonic structures are an important class of substrates in surface-enhanced Raman spectroscopy (SERS), utilizing optical resonant modes to significantly enhance the electromagnetic field and amplify the Raman signals. In this study, we demonstrate the double-resonance approach to realize significant Raman enhancement using all-dielectric photonic crystal (PhC) slab. The double-resonance condition is satisfied by designing optical resonant modes in photonic bands to match frequencies of both excitation laser and Raman signals. By the fabricated PhC slab, the significant enhancement for the Raman signal of silicon is demonstrated. The enhanced Raman signals exhibit a uniform distribution on the PhC slab. The method of Raman enhancement via double optical resonances can advance the field of all-dielectric SERS and holds potential for future SERS applications.
Tunable origami metastructure based on liquid crystal for curvature sensing in terahertz band
Authors: Liu Fa-Zhan , Huang Jing-Wei , Xing Zhen-Hao , Zhang Hai-Feng
Published: August 2024

This paper introduces an origami metastructure (OMST), which realizes the conversion of electromagnetically induced transparency (EIT) to electromagnetically induced absorption (EIA), and realizes the liquid crystal adjustable curvature sensing (CS) function using EIA. The OMST consists of an upper resonator (resonator 1) and a lower resonator (resonator 2). Resonator 1 achieves the EIT phenomenon when 0–2 THz is excited by an electromagnetic wave (EMW), and a transparent window appears at 0.883 THz. When resonator 2 is introduced, the phase of OMST is regulated and the EIT phenomenon changes to EIA. The absorption peak is 0.998 THz, and the peak value is 0.937. OMST uses the flexible material polyimide, and the liquid crystal injected between the resonators 1 and 2 layers is a nematic liquid crystal (HTW114200-100). The metastructure is used on cylindrical surfaces of CS to measure their curvature. In the initial liquid crystal state, when EMW incident, the OMST resonance frequency changes from 0.998 to 1.006 THz, and the corresponding absorptivity changes from 0.937 to 0.650 (from 0.924 to 0.613 in the bias liquid crystal state). Regarding CS, OMST can be used for curvature detection in the micrometer class, with a detection range of 0–0.02 μm. The maximum curvature measurement sensitivity is 32.230 (33.690), and the quality-factor is 41.859 (40.840). Traditional CS is usually made of optical fiber, but because of the fragility of optical fiber sensors, it is difficult to directly apply to the curvature measurement of various objects. However, OMST's design overcomes this shortcoming and is simple to manufacture. OMST has a high detection accuracy and can be used to detect the curvature of small objects, which has a potential application value in flatness detection and intelligent robots.
Enhanced dipole-interaction in Nd-Dy-Fe-Co-B/Fe composite thick stacked trilayer
Authors: Li C. H. , Zhao X. T. , Liu L. , Liu W. , Ye Z. X. , Wu J. X. , Ma J. , Zhang Z. D.
Published: August 2024

It is crucial to better understand the magnetization reversal process between soft and hard magnets and to achieve a high maximum energy product in thick composite multilayers. In this study, we find that the exchange interactions dominate in soft–hard-magnetic composite bilayers, while dipole interactions are predominant in soft–hard-magnetic composite trilayers. Based on the first-order reversal curve, magnetization reversal models are developed for both the thick composite bilayer and trilayer. Dipole interactions play an important role in the long range, resulting in higher coercivity and remanence in the thick trilayer. A multilayer in a stacked trilayer structure is achieved, which is composed of thick films with a perpendicular magnetic anisotropy at a thickness of up to 16 μm. The enhanced dipole interactions lead to a remanent polarization of 1 T and a maximum energy product of 22.5 MGOe. This work contributes to the preparation of thick films with a high maximum energy product for applications in magnetic microelectromechanical systems.
Bouncing dynamics and directional migration of two off-center droplets impacting on a homogeneous/heterogeneous wettability surface
Authors: Li Meixuan , Wu Jie , Zhang Tongwei
Published: August 2024

Horizontal transport of droplets is important for anti-icing, self-cleaning, and water collection technologies. In this paper, the bouncing dynamics of two off-center droplets impacting on a solid surface are explored via numerical simulations. Two kinds of surface wettability are considered. One is a superhydrophobic surface (homogeneous wettability), and the other is a superhydrophobic surface arranged with a hydrophilic strip (heterogeneous wettability). First, the effect of an eccentric angle on the horizontal transport of two droplets impacting on a homogeneous wettability surface is investigated. As the eccentric angle increases, the merged droplet after impact may experience horizontal transportation in either the positive or negative direction. When a heterogeneous wettability surface is adopted, the changes in the transport direction of the merged droplet are consistent with the location of the hydrophilic strip upon eccentric impact. By adjusting the position of the hydrophilic strip, the maximum horizontal transportation distance is 7.53 times the diameter of the initial droplet when the eccentric angle is 10°, while it is only 2.01 times the diameter of the initial droplet when the eccentric angle is 20° for a homogeneous wettability surface. It is indicated that the use of the heterogeneous wettability surface is significantly efficient for droplet control after impact. The obtained results contribute to the fundamental understanding of droplet directional migration and are valuable for related engineering applications.
Coordination of force-generating actin-based modules stabilizes and remodels membranes in vivo
Authors: Heydecker Marco , Shitara Akiko , Chen Desu , Tran Duy T. , Masedunskas Andrius , Tora Muhibullah S. , Ebrahim Seham , Appaduray Mark A. , Galeano Niño Jorge Luis , Bhardwaj Abhishek , Narayan Kedar , Hardeman Edna C. , Gunning Peter W. , Weigert Roberto
Published: August 2024

Membrane remodeling drives a broad spectrum of cellular functions, and it is regulated through mechanical forces exerted on the membrane by cytoplasmic complexes. Here, we investigate how actin filaments dynamically tune their structure to control the active transfer of membranes between cellular compartments with distinct compositions and biophysical properties. Using intravital subcellular microscopy in live rodents we show that a lattice composed of linear filaments stabilizes the granule membrane after fusion with the plasma membrane and a network of branched filaments linked to the membranes by Ezrin, a regulator of membrane tension, initiates and drives to completion the integration step. Our results highlight how the actin cytoskeleton tunes its structure to adapt to dynamic changes in the biophysical properties of membranes.
Transcriptional network dynamics in early T cell development
Authors: Shin Boyoung , Chang Samantha J. , MacNabb Brendan W. , Rothenberg Ellen V.
Published: August 2024

The rate at which cells enter the T cell pathway depends not only on the immigration of hematopoietic precursors into the strong Notch signaling environment of the thymus but also on the kinetics with which each individual precursor cell reaches T-lineage commitment once it arrives. Notch triggers a complex, multistep gene regulatory network in the cells in which the steps are stereotyped but the transition speeds between steps are variable. Progenitor-associated transcription factors delay T-lineage differentiation even while Notch-induced transcription factors within the same cells push differentiation forward. Progress depends on regulator cross-repression, on breaching chromatin barriers, and on shifting, competitive collaborations between stage-specific and stably expressed transcription factors, as reviewed here.
Rad protein: An essential player in L-type Ca2+ channel localization and modulation in cardiomyocytes
Authors: Kong Cherrie H.T. , Dries Eef
Published: August 2024

Rad is an emerging key Cav1.2 modulator. In the present issue of JGP, Elmore, Ahern et al. examine how the Rad C-terminus affects its subcellular distribution and Cav1.2 regulation.
Improved model of large-field inflation with primordial black hole production in Starobinsky-like supergravity
Authors: Ishikawa Ryotaro , Ketov Sergei V
Published: August 2024

A viable model of large-field (chaotic) inflation with efficient production of primordial black holes is proposed in Starobinsky-like (modified) supergravity leading to the ‘no-scale-type’ Kähler potential and the Wess-Zumino-type (‘renormalizable’) superpotential. The cosmological tilts are in good (within 1σ) agreement with Planck measurements of the cosmic microwave background radiation. In addition, the power spectrum of scalar perturbations has a large peak at smaller scales, which leads to a production of primordial black holes from gravitational collapse of large perturbations with the masses about 1017g. The masses are beyond the Hawking (black hole) evaporation limit of 1015g, so that those primordial black holes may be viewed as viable candidates for a significant part or the whole of the current dark matter. The parameters of the superpotential were fine-tuned for those purposes, while the cubic term in the superpotential is essential whereas the quadratic term should vanish. The vacuum after inflation (relevant to reheating) is Minkowskian. The energy density fraction of the gravitational waves induced by the production of primordial black holes and their frequency were also calculated in the second order with respect to perturbations.
Enhanced microscale hydrodynamic near-cloaking using electro-osmosis
Authors: Liu Hongyu , Miao Zhi-Qiang , Zheng Guang-Hui
Published: August 2024

In this paper, we develop a general mathematical framework for enhanced hydrodynamic near-cloaking of electro-osmotic flow for more complex shapes, which is obtained by simultaneously perturbing the inner and outer boundaries of the perfect cloaking structure. We first derive the asymptotic expansions of perturbed fields and obtain a first-order coupled system. We then establish the representation formula of the solution to the first-order coupled system using the layer potential techniques. Based on the asymptotic analysis, the enhanced hydrodynamic near-cloaking conditions are derived for the control region with general cross-sectional shape. The conditions reveal the inner relationship between the shapes of the object and the control region. Especially, for the shape of a deformed annulus or confocal ellipses cylinder, the relationship of shapes is quantified more accurately by recursive formulas. Our theoretical findings are validated and supplemented by a variety of numerical results. The results in this paper also provide a mathematical foundation for more complex hydrodynamic cloaking. Additionally, the concept of cloaking has efficient applications in the field of microfluidics, including drag reduction, microfluidic manipulation, and biological tissue coculture.
Absolute nuclear charge radius by Na-like spectral line separation in high-Z elements
Authors: Hosier A , Dipti  , Blundell S A , Silwal R , Lapierre A , Gillaspy J D , Gwinner G , Tan J N , Kwiatkowski A A , Wang Y , Staiger H , Villari A C C , Ralchenko Yu , Takacs E
Published: August 2024

We describe a novel technique to determine absolute nuclear radii of high-Z nuclides. Utilizing accurate theoretical atomic structure calculations together with precise measurements of extreme ultraviolet transitions in highly charged ions this method allows for precise determinations of absolute nuclear charge radii based upon the well-known nuclear radii of their neighboring elements. This method can work for elements without stable isotopes, and its accuracy may be competitive with current methods (electron scattering and muonic x-ray spectroscopy).
Entanglement of a three-level atom interacting with two-modes field in a cavity
Authors: del Rio-Lima A , Poveda-Cuevas F J , Castaños O
Published: August 2024

The dynamics of an atom of three levels in Λ configuration interacting with a quantized field of two modes in a cavity is studied within the rotating wave approximation by considering experimental values of accessible hyperfine levels of alkali atoms. The Hamiltonian model is constructed on the basis of the direct product of the atomic states with Fock states of light. This simplified basis allows us to generalize the state of light to any quantum field. The interaction term of the Hamiltonian restricts the system to a 3D Hilbert space. The system’s time evolution results show some similarities with the effective two-level system, such as the presence of collapses and revivals and the atom-field entanglement. By an analysis of the statistics of the photons, we show that when the three-level atom is interacting with a coherent field of two modes, it is possible to control experimentally the statistics of the field to be super-Poissonian or sub-Poissonian by the choice of the initial atomic state.
Electrically-driven IMT and volatile memristor behavior in NdNiO3 films
Authors: Schneble O D , Leahy I A , Zimmerman J D , Tellekamp M B
Published: August 2024

Transition metal oxides with insulator-metal transitions (IMTs) are uniquely suited for volatile memristor devices that mimic the spiking of biological neurons. Unlike most non-volatile memristors, which often operate via ion migration into filaments, volatile devices utilize a reversible phase change that returns to a ground state in the absence of applied stimulus. In these devices, Joule heating triggers the IMT and changes the bulk resistivity rather than influencing conduction through defects, as in previous studies. This volatile resistive switching behavior has previous been leveraged in niobium and vanadium oxides, but not in rare-earth nickelates, despite their tunable transition temperatures. This study demonstrates an electrically driven IMT in the prototypical rare-earth nickelate, NdNiO3, in large area devices. While previous work examining the electrically-driven IMT in NdNiO3 suggests defect-dominated conduction, this study shows clear s-type negative differential resistance (NDR) consistent with temperature-dependent resistivity measurements. The NDR peak-to-valley voltage scales linearly with temperature as expected for conductivity pathways dominated by bulk IMT behavior. Unlike other transition metal oxides, which are modeled using the insulator-metal phase fraction as the internal state variable, a thermoelectric model with temperature as the internal state variable is found to more accurately describe the current–voltage characteristic of NdNiO3 volatile memristors. Overall, we report the synthesis, fabrication, and characterization of NdNiO3 volatile memristors with resistivity dominated by bulk-like IMT behavior which is scalable and not dependent upon oxygen vacancy migration or defect mediated conduction pathways.
Insights into the magnetic signature in VS2 nanosheets for spintronics applications: an experimental and ab initio approach
Authors: Lahiri Saurav , Kumar Manish , Parashar Ujjal Bikash , Thangavel R
Published: August 2024

VS2 nanosheets were synthesized using a facile hydrothermal method with varying hydrothermal durations for detailed study of their magnetic properties for spintronics applications. The (001) peak near 15.45° in the x-ray diffraction pattern confirmed the formation of the hexagonal phase of VS2 consistent with the Raman spectrum and high-resolution transmission electron microscopy study. X-ray photoelectron spectroscopy confirmed the formation of VS2 with the +4 oxidation state of V. Morphology was determined by field emission scanning electron microscopy that showed the morphological transition from nanoflowers to nanosheets with increase in the hydrothermal duration from 16 h to 24 h. The VS2 nanosheets were subject to magnetic measurements using a superconducting quantum interference device. The isothermal magnetization versus magnetic field plot showed typical hysteresis behaviour at low fields with maximum saturation magnetization

(

M

saturation

)

of 3.25 memu g−1 at 50 K which gradually decreased with increase in temperature. The coercivity

(

H
C

)

, however, increased with increase in temperature, hinting at the possible short range of the existing ferromagnetic (FM) order. The field-cooled and zero-field-cooled curves showed a lack of FM clustering. Fitting of the magnetization versus temperature plot showed the formation of a mixed magnetic phase, that is both a paramagnetic (PM) phase (at high fields) and a FM phase (at low fields). The PM Curie temperature

(

θ
p

)
=
−
3.124
 
K

obtained from the fitting hinted at canted antiferromagnetic order. Magnetoresistance (MR) measurement in a current parallel to the field configuration revealed a negative MR of 10.4%. Further, density functional theory and Monte Carlo simulations based on the Metropolis algorithm were used to study the layer-dependent electronic band structure of VS2 as well as its Curie temperature for its applicability in spintronics devices.
τSPECT: a spin-flip loaded magnetic ultracold neutron trap for a determination of the neutron lifetime
Authors: Auler J , Engler M , Franz K , Kahlenberg J , Karch J , Pfeifer N , Roß K , Strid C-F , Yazdandoost N , Adamek E , Kaufmann S , Schmidt Ch , Blümler P , Fertl M , Heil W , Ries D
Published: August 2024

The confinement of ultracold neutrons (UCNs) in three-dimensional magnetic field gradient or magneto-gravitational traps allows for a measurement of the free neutron lifetime τ

n
with superior control over loss channels related to UCNs interacting with material surfaces. The most precise measurement τ

n
has been achieved using a magneto-gravitational trap, in which UCN are prevented from escaping at the top of their trap by gravity. More compact horizontal confinement geometries with variable energy acceptance ranges can be obtained by using steep magnetic field gradients in all spatial directions, generated by combinations of either permanent or (variable) superconducting magnets. In this paper, we present the first successful implementation of a pulsed spin-flip based loading scheme to fill a three-dimensional magnetic trap with externally produced UCN. The measurements with the τSPECT experiment were performed at the pulsed UCN source of the research reactor TRIGA Mainz. The extracted neutron storage time constant of τ = 859(16) s is compatible with the most precise determinations of τ

n
. We report on detailed, but statistically limited, investigations of major systematic effects influencing the neutron storage time. The statistical limitations are mitigated by the relocation of the experiment to a stronger UCN source.
Station-based SDB correction for GPS triple-frequency observations and its application on relative positioning
Authors: Zhang Qiankun , Chai Hongzhou , Wang Min , Sun Shuang , Liu Yang
Published: August 2024

Due to the chip shapes of Global Navigation Satellite System (GNSS) live signals differ from ideal conditions, GNSS satellite signals are distorted, which leads to different code biases, namely signal distortion biases (SDB). Existing SDB estimation methods are based on code observation combinations with large noise and face the problem of unreasonable classification, which would seriously affect the reliability of SDB estimation and correction. To solve this problem, a station-based SDB estimation method is proposed in this study. First, a full-rank linear system independent of the ionosphere is derived based on the classical Uofc model. Then, triple-frequency SDBs relative to the reference stations are estimated with three types of virtual observations. To assess and validate the performance of the proposed method, real data of 335 stations from multi-GNSS experiment (MGEX) network in January 2023 are chosen for GPS triple-frequency SDB estimation. The results show that the estimated SDBs of all stations equipped with the same receiver types keep good consistency. In addition, the estimated SDBs are shown to be related to receiver types and antenna types, and maintain high stability over the whole month. Furthermore, the code residuals of 4 zero-baselines from Curtin University CORS and the real-time kinematic (RTK) ambiguity fixing rates of 8 short baselines from the MGEX network are evaluated to validate the correction performance of the estimated SDBs. The results show that the code residuals of zero-baselines are close to zero with SDB correction, and the systematic deviations in the code residuals can be effectively decreased. For the RTK application, the ambiguity fixing rates of the selected short baselines can be increased by about 40.0% after SDB correction. In addition, the percentage of ratio values after ambiguities are fixed with SDB correction is always higher than that without SDB correction, which effectively improves the reliability of RTK ambiguity resolution.
Enhanced anti-tumor and anti-metastatic activity of quercetin using pH-sensitive Alginate@ZIF-8 nanocomposites: in vitro and in vivo study
Authors: Rostamkhani Neda , Salimi Maryam , Adibifar Arghavan , Karami Zahra , Agh-Atabay Abdol-Hakim , Rostamizadeh Kobra , Abdi Zahra
Published: August 2024

Quercetin (Qc) possesses anti-cancer properties, such as cell signaling, growth suppression, pro-apoptotic, anti-proliferative, and antioxidant effects. In this study, we developed an alginate-modified ZIF-8 (Alg@ZIF-8) to enhance the anti-tumor efficacy of Qc. The developed alginate-modified quercetin-loaded ZIF-8 (Alg@Qc@ZIF-8) was characterized using scanning electron microscope (SEM), dynamic light scattering (DLS), fourier transform infrared spectroscopy Thermogravimetric analysis, Brunauer–Emmett–Teller, and x-ray diffraction. The drug release pattern was evaluated at pH 5.4 and 7.4. The cytotoxicity of nanoparticles was assessed on the 4T1 cell line. Finally, the anti-tumor activity of Alg@Qc@ZIF-8 was evaluated in 4T1 tumor-bearing mice. SEM showed that the nanoparticles were spherical with a diameter of mainly below 50 nm. The DLS showed that the developed nanoparticles’ hydrodynamic diameter, zeta potential, and polydispersity index were 154.9 ± 7.25 nm, −23.8 ± 5.33 mV, and 0.381 ± 0.09, respectively. The drug loading capacity was 10.40 ± 0.02%. Alg@Qc@ZIF-8 exhibited pH sensitivity, releasing more Qc at pH 5.4 (about 3.62 times) than at pH 7.4 after 24 h. Furthermore, the IC50 value of Alg@Qc@ZIF-8 on the 4T1 cell line was 2.16 times lower than net Qc. Importantly, in tumor-bearing mice, Alg@Qc@ZIF-8 demonstrated enhanced inhibitory effects on tumor growth and lung metastasis compared to net Qc. Considering the in vitro and in vivo outcomes, Alg@Qc@ZIF-8 might hold great potential for effective breast cancer management.
Investigating the optical and electrical performance of rod coated silver nanowire-based transparent conducting films
Authors: Thomas Neethu , S Bharathkumar , Mathew Koshy Aarju , Basavaraj Madivala G , Swaminathan Parasuraman
Published: August 2024

Silver nanowires (Ag NWs) are highly promising building blocks for developing transparent conducting films (TCFs) due to their high electrical conductivity and good optical transparency. The large-scale production of Ag NW-based high-quality TCFs using low-cost processing methods can replace the traditional oxide based TCFs. Therefore, developing a reliable technique for large-scale fabrication of Ag NW-based TCFs is vital. This work involves the synthesis of Ag NWs, the fabrication of large-area Ag NW-based TCFs using a simple rod coating process, its optimization, and the performance analysis of the fabricated TCFs, including their demonstration as transparent heaters. The polyol synthesis method produces Ag NWs of lengths ranging from 25–110 µm and diameters from 80–180 nm. The effect of Ag NW length, the number of coating passes, and the volume of the NW dispersion used per coating pass on the electrical and optical properties of the TCFs are studied by quantifying sheet resistance

(

R

s

)

and transmittance (T) of the film. The performance of the fabricated film is evaluated by estimating the figure of merit (FoM) in both percolative and bulk regimes. The TCF made with NWs of length 25.7 µm and diameter 85.1 nm had the largest value of bulk FoM (101.3), percolative FoM (43.9), and, conductivity exponent (0.6). This elucidated the superior performance of the fabricated TCFs over those fabricated by other techniques. The critical thickness of the film (

t

min

), at the crossover between the percolation and bulk, scales with the shortest dimension of the NW, namely its diameter. The percolative FoM showed an increase, with a decrease in both sheet resistance and diameter of the NWs, with lower n. The fabricated TCF is tested as a transparent heater and the demonstration proves that rod coated Ag NW-based TCFs can be used for transparent electrode applications.
First principles theoretical of designing sandwich-like metallic BP4 monolayer as anode for alkali metal-ion batteries
Authors: Yang Zhifang , Li Wenliang , Zhang Jingping
Published: August 2024

Phosphorene has been widely used as anode material for batteries. However, the huge volume change during charging and discharging process, the semiconductor properties, and the high open circuit voltage limit its application. Based on this, by introducing the electron-deficient boron atoms into blue phosphorene, we proposed a P-rich sandwich-like BP4 monolayer by density functional theory calculation and particle swarm optimization. The BP4 monolayer shows good thermodynamic and dynamic stability, as well as chemical stability in O2 atmosphere, mainly due to the strengthened P–P bond of the outer layer by the middle boron atoms adopting sp3
hybridization. According to the band structure, the BP4 monolayer shows metallic property, which is beneficial to electron conductivity. Furthermore, compared with blue phosphorene and black phosphorene, the P-rich BP4 monolayer shows higher theoretical capacity for Li, Na, and K of 1193.90, 1119.28, and 397.97 mA h g−1, respectively. The lattice constant of BP4 monolayer increases only 3.73% (Li), 2.52% (Na) after Li/Na fully adsorbed on the anode. More importantly, the wettability of BP4 monolayer in the electrolyte is comparable to that of graphene. These findings show that the stable sandwich-like BP4 monolayer has potential as a lightweight anode material.
Keeping food cool to save the planet
Authors: Hughes Stephen
Published: August 2024

Thermal insulation is an important topic in physics directly relevant to everyday life. Thermal insulation is used in the building and food industries. Thermal insulation is an effective way to extend the time food is kept below a critical temperature (5 °C for chilled food and −18 °C for frozen foods). An experiment was performed to simulate a power cut in a cold storage unit. Two temperature loggers were placed in plastic containers each containing 250 g of ice. The two containers were placed in a freezer and then removed to simulate a power cut. One container was left out in the open and the other placed in a cylinder of reflective bubble wrap insulation (GIBS). The ice container inside the GIBS insulation stayed cold for several hours longer. This is an experiment that could easily be performed in a school or university setting.
Suppression of grain boundary weak link by Ca doping in YBa2Cu3O7 coated conductor
Authors: Yamamoto Kentaro , Yoshida Yutaka , Horide Tomoya
Published: August 2024

YBa2Cu3O7 coated conductors are a strategic material for superconducting applications such as high field magnets, fusion, and motors. Grain boundaries reduce the critical current density (J
c) even at a tilt angle as low as 5°, but the successful development of the highly oriented substrates seemed to overcome the weak link problem at grain boundaries. However, it reappears when we visit the homogeneity of the coated conductors. To suppress the weak link in the coated conductors, the Ca doping was investigated. The Ca-doped YBa2Cu3O7 films were fabricated on the moderately oriented substrates. While the grain boundaries in the moderately oriented substrates significantly degraded the J
c without Ca doping, the Ca doping improved the J
c especially at low temperature. This indicates that the tilt angle dependence of J
c was varied by the Ca doping. While the J
c for the moderately oriented substrate was 20 times smaller than that for the highly oriented substrate, the Ca doping restored 1/2 of the J
c for the highly oriented substrate at 40 K and 9 T. The vortex structure changed from Abrikosov Josephson vortices to the Abrikosov vortices with increasing the Ca content. The combination of Ca doping and moderate substrate texture is another design of coated conductors. The Ca doping can patch the local degradation of the substrate texture to mass produce the practical coated conductors with improved homogeneity.
Investigations of the behaviour of superconducting magnetic levitating set-ups including a large MgB2 disc and a smaller NdFeB magnet
Authors: Bernstein Pierre , Xing Yiteng , Noudem Jacques , Morandi Antonio , Ribani Pier Luigi , Russo Giacomo , Lemonnier Sebastien , Delorme Fabian
Published: August 2024

We report the levitation and guidance forces of two set-ups including a 120 mm diameter MgB2 disc cooled down to 20 K. The first one included the disc and a 30 mm thick and 100 mm diameter NdFeB magnet and is labelled as PM100 set-up. The second one called PM70 set-up included a 70 mm diameter and 35 mm thick magnet. All the measurements were carried out after cooling down the superconductor with a 30 mm separation between the magnet and the superconductor. Some remarkable results were obtained. It was reported by Xing et al (2024 Supercond. Sci. Technol.
37 02LT01) that the levitation force measured with the PM100 set-up has reached the strong value of 678 N at 5 mm separation between the magnet and the superconductor. In this new report, in addition to a comparison of the levitation forces measured on both set-ups, we report guidance force measurements. We show that this force decreases for the PM100 set-up as the magnet-superconductor distance decreases, while the guidance force of the PM70 set-up increases, as was reported for set-ups including Halbach guideways sections. Reproducing the measured levitation forces with analytical models, we show, on the one hand, that the large levitation forces measured with the PM100 set-up are due to the non-homogeneity of the magnetic field above the PM100 magnet. On the other hand, we explain the behaviour of the PM70 set-up guidance force by the low modulation of the magnetic moment of the superconductor resulting from the magnet motion.
Direct laser acceleration in varying plasma density profiles
Authors: Babjak R , Martinez B , Krus M , Vranic M
Published: August 2024

Direct laser acceleration has proven to be an efficient source of high-charge electron bunches and high brilliance x-rays. However, an analytical description of the acceleration in the interaction with varying plasma density targets is still missing. Here, we provide an analytical estimate of the maximum energies that electrons can achieve in such a case. We demonstrate that the maximum energy depends on the local electron properties at the moment when the electron fulfills the resonant condition at the beginning of the acceleration. This knowledge enables density shaping for various purposes. One application is to decrease the required acceleration distance needed to achieve the maximum electron energy. Another use for density tailoring is to achieve acceleration beyond the radiation reaction limit. We derive the energy scaling law that is valid for arbitrary density profile that varies slowly compared with the betatron period. Our results can be applied to electron heating in exponential preplasma of thin foils, ablating plasma plumes, or gas jets with long-scale ramp-up.
Electron energy relaxation mechanism in n-type InxGa1-xAs1-yBiy alloys under electric and magnetic fields
Authors: Aydin Mustafa , Yilmaz Selen Nur , Erol Ayse , Bork James , Zide Joshua , Donmez Omer
Published: August 2024

We investigate the power loss per electron mechanism of hot electrons generated under electric and magnetic fields in n-type InxGa1-xAs1-yBiy epitaxial layers. Acoustic phonons are generated under various electric fields to determine the hot-electron energy relaxation mechanisms at low temperatures. The hot electron temperatures are determined by theoretical calculation of the amplitude of the magnetoresistance oscillation. The power loss per degenerate electron is analytically modeled with possible scattering mechanisms. The modeling of the experimental results reveals that power dissipation occurs by employing deformation potential energy scattering for all the samples. The deformation potential energy increases by ∼ 2.14 eV/Bi% when Bi atoms are introduced into ternary InGaAs alloy and the increase in the deformation potential energy is found to be independent of the electron density, which indicates that power dissipation occurs in the equipartition regime.
A single-layer low-angle-pass filter based on metasurface
Authors: Yan Mengyao , Zhou Dongfang , Liu Qikun , Wang Ziyue , Bian Chenge , Wan Zheng , Yao Zhenning
Published: August 2024

This paper presents the design and analysis of a low-angle-pass filter based on a single-layer metasurface for TE polarization. The designed angle filter comprises a metal pattern and a dielectric substrate. By properly designing the structure and dimensions, bandpass and band-stop are produced at the same frequency under normal and oblique incidences, respectively, resulting in excellent angular selectivity. Both simulation and experimental measurements of the sample are conducted for verification. The results exhibit remarkable angular selectivity, showing high transmission under normal incidence and low transmission under oblique incidence. The −3 dB angular bandwidth is only 8° and the overall thickness is only 1/4 wavelength. The introduced single-layer angular filter is suitable for various applications, including reducing co-channel interference in 5 G communication and energy harvesting.
Numerically stable algorithm for scattering of spherical particles embedded in an absorbing medium
Authors: Zhang Jianing
Published: August 2024

This study aims to develop a numerically stable Mie algorithm for solving the scattering problem of spherical particles in absorbing media. First, a new stable recursive algorithm for computing Bessel functions is presented. Compared to other algorithms, this new method can automatically determine the correct recurrence steps and construct more robust error analyses. Furthermore, we propose a new numerically stable algorithm based on the Lorenz-Mie theory framework. This algorithm employs forward recurrence formulas for Riccati-Hankel functions and backward recurrence formulas for ratios of Bessel functions. Numerical experiments demonstrate that this algorithm effectively handles the scattering phenomena of spherical particles in absorbing media. It not only accounts for the influence of absorbing media but also accurately computes scattering characteristics, including scattering and absorption coefficients, and other important parameters. Additionally, we also introduce a rescaling method to eliminate the overflow problem of Bessel functions as z → ∞ . This rescaling method can significantly extend the computational limits of traditional methods.
Construction of CdS/SnSSe heterostructures for direct Z-scheme photocatalysis: a first-principles computational study
Authors: Wang Guangzhao , Xu Chunping , Tang Wenyi , Guo San-Dong , Duan Junping , Hu Die , Yu Chenjiang , Chen Ying , Wang Biao , Zhang Wanli , Yuan Hongkuan
Published: August 2024

The construction of van der Waals (vdW) heterojunctions (HJs) offers an important means to enhance the properties and expand the applications of two-dimensional (2D) materials. The CdS/SnSSe HJs, comprising CdS/SSnSe and CdS/SeSnS HJs, have been designed and investigated as potential water-splitting photocatalysts using hybrid density functional theory. The suitable interface formation energies and interlayer distances confirm that both CdS/SSnSe and CdS/SeSnS HJs are vdW HJs. The small bandgaps allow CdS/SSnSe and CdS/SeSnS HJs to absorb adequate solar light. Based on the analysis of work functions, charge transfer, and band edge positions, the direct Z-scheme photocatalytic mechanism for CdS/SSnSe and CdS/SeSnS HJs is validated. This mechanism is beneficial for achieving spatial separation of photoexcited carriers and maintaining sufficient redox reaction driving potentials. All these results demonstrate that both CdS/SSnSe and CdS/SeSnS HJs are promising candidates as water-splitting photocatalysts.
First-principles study of cathode material LiMnPO4F for lithium-ion batteries
Authors: Chen Rui , Luo Jiaolian , Yang Anqi , Xie Zhenyu
Published: August 2024

The article employed first-principles calculations to investigate the electronic structure, delithiation mechanism, and lithium ion diffusion barriers of LiMnPO4F and LiMn0.5M0.5PO4F (M = Ni, V, Cr). The formation energies of the systems were also calculated. The study found that LiMnPO4F is a promising positive electrode material for lithium-ion batteries. The doping of transition metals at the Mn site can effectively modulate the band structure of LiMnPO4F, improving the electrical conductivity and lithium ion diffusion capability of the material.
Understanding the stabilities and non-linear optical response of transition metal endo-doped B12N12 and B12P12 nanocages; a density functional theory investigation
Authors: Asif Misbah , Abdul Hamid Malai Haniti Sheikh , Bayach Imene , Sheikh Nadeem S , Ayub Khurshid
Published: August 2024

Electronic and nonlinear optical properties of endohedral 3d transition metals (TMs) doped on B12N12 and B12P12 nanocages (TM@X12Y12) are studied. The spin-polarized calculations are carried out considering the four lowest possible spins in all TM@X12Y12 complexes. For understanding the interaction between transition metals and nanocages, Zero-point energies (ZPE) and Gibbs free energies of adsorption are considered. The results of Zero-point energies and Gibbs free energies reveal that transition metals (TMs) are chemisorbed with exothermic interaction energies in B12P12 nanocage. Natural Bond orbital (NBO) analysis reveals that the TM@B12N12 are true metallides, especially for Ti, V, and Cr with the negative values of NBO charges on metals whereas TM@B12P12 possesses electride characters. Dipole moments analysis reveals that metals placed in the center do not cause significant changes in the dipole moment. Bond order analysis gives the higher bond order values for early transition metals in B12N12 and B12P12 complexes. However, bond order tends to decrease in late transition metals for both nanocages. Frontier molecular orbital (FMO) analysis is performed to understand the effect of TMs on the electronic properties of B12N12 and B12P12 nanocages. By applying a long-range separated method, polarizability and hyperpolarizability values are calculated. The enhanced non-linear optical (NLO) response is observed for early transition metals in B12N12 nanocage. Whereas late transition metals showed a higher response for B12P12 nanocages. The values obtained of α and β
o for TM@B12N12 are in the range of 166–218 and 42–2695 au. Whereas the values of α and β
o for TM@B12P12 are in the range of 408–457 and 1–5122 au. These results prove that these nanocages are potentially effective for high-performance non-linear optical devices.
Electrochemical detection of mercury ions using glassy carbon electrode modified with silver sulphide nanoparticles
Authors: Helen Rani R , Rahale C Sharmila , S Girija , J Wilson , M Prasanthrajan , D Jeyasundara Sharmila , Saranya N , Maragatham S
Published: August 2024

Mercury (Hg2+) is a toxic heavy metal that can harm the environment and human health. This study introduces an innovative electrochemical sensor for the selective detection of Hg2+ions using square wave voltammetry (SWV). This research aims to develop a highly selective electrochemical sensor for detecting mercury ions by modifying a glassy carbon electrode (GCE) with silver sulphide (Ag2S) nanoparticles. The work intends to enhance the Ag2S modified GCE’s electroactive surface area and improve electron transport, leading to a more pronounced electrochemical response. The Ag2S crystalline structure was characterized by x-ray diffraction (XRD), while Transmission electron microscopy (TEM) confirmed spherical-shaped particles. Electrochemical impedance spectroscopy and cyclic voltammetry were employed to examine the electrochemical profile of the Ag2S nanoparticles, revealing an electroactive surface area of 9.93 cm2 for the modified GCE. The SWV technique demonstrated effective detection of Hg2+ ions with a detection limit of 0.14 nM. The designed sensor was found to demonstrate the qualities of selectivity, repeatability, reproducibility and anti-interference ability. The Ag2S modified GCE exhibited excellent stability and selectivity towards Hg2+ ions in the presence of potential interferents such as Cu2+, Na+, Ca2+, and Zn2+. These results highlight the potential of the Ag2S nanoparticles modified GCE as a robust platform for environmental monitoring of mercury contamination.
Relation of V/III ratio of AlN interlayer with the polarity of nitride
Authors: Su 苏 Zhaole 兆乐 , Li 李 Yangfeng 阳锋 , Hu 胡 Xiaotao 小涛 , Song 宋 Yimeng 祎萌 , Deng 邓 Zhen 震 , Ma 马 Ziguang 紫光 , Du 杜 Chunhua 春花 , Wang 王 Wenxin 文新 , Jia 贾 Haiqiang 海强 , Jiang 江 Yang 洋 , Chen 陈 Hong 弘
Published: August 2024

N-polar GaN film was obtained by using a high-temperature AlN buffer layer. It was found that the polarity could be inverted by a thin low-temperature AlN interlayer with the same V/III ratio as that of the high-temperature AlN layer. Continuing to increase the V/III ratio of the low-temperature AlN interlayer, the Ga-polarity of GaN film was inverted to N-polarity again but the crystal quality and surface roughness of GaN film greatly deteriorated. Finally, we analyzed the chemical environment of the AlN layer by x-ray photoelectron spectroscopy (XPS), which provides a new direction for the control of GaN polarity.
Manganese dioxide as wide adaptive ultrafast photonic device for pulsed laser generation
Authors: Dou 窦 Xin-He 鑫河 , Chen 陈 Zhen 震 , Zhang 张 Chen-Yan 辰妍 , Li 李 Xiang 响 , Qiao 乔 Fei-Hong 飞鸿 , Song 宋 Bo-Le 博乐 , Wang 王 Shan 珊 , Teng 滕 Hao 浩 , Lv 吕 Zhi-Guo 志国
Published: August 2024

Research on novel ultrafast photonic devices with wide adaptability has become important scientific technical means to realize both scheme innovation and performance breakthrough in fiber laser generation. As types of transition metal oxide, manganese dioxide (MnO2) materials exhibit remarkable properties including high photothermal stability, strong oxidation resistance, and excellent optical properties, making them promising candidate for utilization as modulation devices in nonlinear optics and ultrafast optics fields. We investigate the impact of MnO2-based saturable absorber (SA) on the pulse characteristics. The experiment reveals that MnO2-based SA supports effectively pulsed laser generation in wide pump power range and large dispersion parameter space with signal-to-noise ratio more than 85 dB. As far as we know, the pump power response range is outstanding among the most of the reported pulsed lasers, which is attributed to the large modulation depth of MnO2 SA. We also investigate the impact of dispersion on the characteristics of laser output, which is not involved in other similar works. This research indicates that MnO2 as a photonic device has vast potential in advanced ultrafast optics.