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• According to COMSOL calculations, the absorption film has four perfect absorption peaks in the terahertz narrowband and exhibits polarization incoherence, which means that the absorption film has good performance. • By changing the physical parameters, the active tunability of the film in a wide range is achieved. • The absorption film has high refractive index sensitivity, which means it has extremely high application prospects. • With simple structures and materials, the phenomenon of absorption bandwidth of the absorber also facilitates the study of conversion and regulation between narrowband and broadband. Here, a simple four-band terahertz tunable narrowband absorber is proposed, which can achieve multimodal perfect absorption within 1–9 THz. We analyzed the physical mechanisms behind local surface plasmon resonance and impedance matching based on theoretical principles. By controlling the structural parameters, we use the eigen-mode and external field excitation to obtain the absorption peak and electromagnetic field distribution of the narrowband sensor under different structural parameters. Additionally, we studied the effect of the angle of incidence electromagnetic waves on the function of the absorber, found that the absorber has excellent characteristics in both low and high frequency states. We carry out a substance detection on four perfect absorption modes. The ambient refractive index sensitivity is 881.35 GHz / RIU , 439.65 GHz / RIU , 2664.46 GHz / RIU , 4501.19 GHz / RIU. The four-peak narrowband high-performance absorber designed by us has a huge development prospect in most important areas such as resource detection and biomedical diagnosis. [Display omitted] [ABSTRACT FROM AUTHOR]

In recent decades, the world's environmental troubles have become increasingly serious. Seeking new and environmentally friendly energy sources to replace chemical fuels is the key to improving environmental problems. As a renewable energy source, solar energy is the most promising and viable alternative energy source. In this paper, we present a spectrally selective solar broadband absorber with a hollow cylindrical microstructure. The model uses Ti film-Al2O3 film-Cu film as the substrate and Ti–Al2O3–Ti–Al2O3 (in the order from top to bottom) materials stacked to form hollow cylinders as the microstructure. The model was simulated using the FDTD Solutions software from Lumerical Solutions. From the simulation results, it can be seen that the absorption rates of the model in the solar radiation band 280 nm–4000 nm are all above 90%, and the average absorption rate is 94.1%; under the light of AM 1.5, the weighted average absorption rate is 94.8%. In addition, the reflectivity of the model in the 6516 nm–20000 nm band is all higher than 80%, with an average reflectivity of 94.2%, and the average reflectivity in the non-solar radiation band of 4000 nm–20000 nm is 85.4%, which has good thermal infrared suppression ability. In addition, we discovered the physical mechanism of model broadband absorption by analyzing the electric field distribution maps at different wavelengths. At the same time, the model has polarization insensitivity and wide-angle absorption properties. The excellent spectral selectivity allows this solar broadband absorber to operate in high temperature environments, which is very meaningful for the research of both solar thermophotovoltaic technology and thermal insulation and cooling materials. In this paper, we present a spectrally selective solar broadband absorber with a hollow cylindrical microstructure. The model is substrate of Ti film-Al2O3 film-Cu film (top-down order), and hollow cylinders made of Ti–Al2O3–Ti–Al2O3 (top-down order) materials stacked as microstructures, with seven layers and total thickness of only 1 μ m. We use FDTD software to simulate the model. The results show that the model has an average absorption of 94.1% in the 280 nm–4000 nm band of solar radiation, an absorption bandwidth (absorption >90%) of 3720 nm, a weighted average absorption of 94.8% under AM 1.5 illumination. And the reflectivity of the model starts to increase continuously after the wavelength of 4800 nm. The reflectivity is greater than 80% in all wavelengths after 6516 nm, up to 96.5%. After numerical calculations, the average reflectivity of the model is 94.2% in the 6516 nm-20,000 nm band and 85.4% in the 4000 nm-20,000 nm band outside the solar radiation band. This shows that the model has good spectral selectivity and thermal infrared suppression. [Display omitted] • Ultra-wideband high-efficiency solar absorber based on hollow cylindrical microstructures-. • The solar broadband absorber achieves excellent spectral selectivity and thermal infrared suppression. • The absorber has excellent polarization insensitivity and wide angle absorption characteristics. [ABSTRACT FROM AUTHOR]

This paper presents a novel graphene-based proportional structure for a tunable wideband absorber in the terahertz (THz) frequency range. In order to achieve the ideal design structure, we make the distance between the top graphene structure and the periodic edge remains proportional, enabling excellent absorption with an absorption rate exceeding 90 % within the frequency range of 3.1–6.97 (3.87)THz. Notably, a perfect absorption is achieved at f = 6.5 THz. At f = 4.2 THz, the absorption rate is close to 97 %, and at f = 5.2 THz, the absorption rate is about 91 %. The average absorption rate is 94.6 % in the range of 3.1–6.97 THz. The absorber's impedance is calculated to demonstrate its favorable absorption band. Furthermore, an analysis of the electric field within the absorber reveals the coupling effect of strong electric fields between different regions, leading to the overlapping of absorption peaks and the formation of a wideband response. This allows us to choose regions to combine according to the needs of the application. By adjusting the parameters of the absorber, it exhibits coordinated performance and manufacturing tolerance. Additionally, the absorber shows a certain degree of tolerance to the incident angle of electromagnetic waves. These findings highlight the potential applications of this absorber in optoelectronic devices, THz detection, and stealth technology. [Display omitted] • Through CST calculation, this model can achieve bandwidth absorption in the terahertz frequency band. • Designed through a single layer of graphene with strong adjustability. • The electric field distribution and absorption principle were investigated by structure decomposition. • The model has a wide absorption rate and can achieve THz stealth. [ABSTRACT FROM AUTHOR]

In recent years, as an important plasmonic nanomaterial, graphene has become the focus of research. In our research, we design a tunable plasmonic absorber composed of periodic H-shaped graphene arrays in the far-infrared and terahertz (THz) bands. We numerically investigate the structure parameters and the chemical potential of graphene that influence the optical properties of the periodic H-shaped graphene arrays. Compared with periodic H-shaped graphene arrays, under the same TM polarization, the complementary structure has higher absorption. In addition, the polarization sensitivity of the H-shaped graphene arrays is also investigated. Our research not only investigates the plasmonic resonance absorption characteristics, but also implies important potential applications in integrated optical circuits such as optical storage, ultra-fast plasmonic switches, high performance filters and modulators. [ABSTRACT FROM AUTHOR]

The pyramidal silicon substrate is formed by wet etching, then ZnO nanorods are grown on the surface of the pyramidal microstructure by a hydrothermal method to form a moth-eye composite heterostructure. The composite heterostructure of this material determines its excellent anti-reflection properties and ability to absorb light from all angles. In addition, due to the effective heterojunction binding area, the composite micro/nano structure has excellent photoelectric conversion performance. Its surface structure and the large specific surface area gives the material super hydrophilicity, excellent gas sensing characteristic, and photocatalytic properties. Based on the above characteristics, the micro/nano heterostructure can be used in solar cells, sensors, light-emitting devices, and photocatalytic fields. [ABSTRACT FROM AUTHOR]

We show a designed FePt nanoparticles for embedding in a single crystal MgO matrix and demonstrate plasmon resonance absorption can appear in the ultraviolet region. The state of the FePt alloy is confirmed by X-ray photoelectron spectroscopy and selected area electron diffraction. By increasing the laser energy density from 4 to 6 J/cm 2 , the shape of the FePt nanoparticles is changed from quasi-spherical to quasi-elliptical. Compared with pure MgO, a single plasmon resonance peak at 234 nm was found in the ultraviolet region for the embedded FePt. Increasing the laser energy density induces peak splitting into two peaks, located at 225 and 262 nm, respectively. With a high laser energy density, a red-shift and a blue-shift are observed for the two peaks, respectively. These results are accordance with the theoretical calculations. The ultraviolet plasmon resonance absorption for FePt NPs can be tuned by changing the shape of the nanoparticles. [ABSTRACT FROM AUTHOR]

We report a simple magnetron sputtering method to fabricate large-scale vertically aligned ZnO@Ag nanorods (NRs) arrays using aligned ZnO-NRs arrays as a template. Via changing the thickness of Ag film, the density of Ag nanoparticles (NPs) on the surface of ZnO-NRs arrays can be readily tuned. Due to synergistic and charge transfer (CT) effect of the adjacent Ag NPs and ZnO-NRs, the optimized ZnO@Ag-NRs arrays employing Ag film with 15 nm thickness show the best surface-enhanced Raman scattering (SERS) for 4-aminothiophenol (4-ATP). The considerable SERS enhancement of the 4-ATP is ascribed to the CT between the 4-ATP and Ag NPs through the ZnO-NRs. With the help of the valence band of ZnO, the photo-induced electrons from the Ag NPs can be transferred to the lowest unfilled orbital (LUMO) of 4-ATP, forming the so-called “donor-bridge-acceptor” system. The present research is not only beneficial to the development of ZnO-NRs arrays as a nontoxic, biocompatible, highly SERS active substrate, but also helpful to study the CT behavior between Ag and ZnO for optoelectronic chemistry. [ABSTRACT FROM AUTHOR]

Graphite oxide of various degrees of dehydration or chemically reduced with different concentrations of sodium borohydride have been synthesised. Samples were characterised with X-ray diffractometry and infrared spectroscopy, then studied using Raman, X-ray photoelectron (XPS), nuclear magnetic resonance (NMR) and impedance spectroscopies. The trend in their concentrations of epoxy, hydroxyl group and sp 2 carbon, as calculated from XPS and NMR data, agreed with their vacancies concentrations as deduced from Raman spectra. Analysis of observed complex impedance peaks points to three different relaxation processes. One, obviously, is the rotation of intercalated water. The other two involve dipoles originating from polar hydroxyl groups. Loss peaks seen in less reduced graphite oxide have an activation energy of 0.16 eV, and are ascribed to the breaking of a hydrogen bond (–O–H···O<) between a hydroxyl attached to a carbon grid and an epoxy group on the adjacent carbon grid. The other, displayed in more reduced samples and of 0.08 eV in activation energy, derive from hydrogen bonds (–O–H…π) between hydroxyls and π electrons on adjacent carbon grids. [ABSTRACT FROM AUTHOR]

Using the discrete dipole approximation, we analyze surface plasmon resonance (SPR) in the core(Au)/interlayer/shell(Ag) nanoparticles. Here, the role of the Au core is typically central. We focus on the effect of the interlayer properties on SPR. If the interlayer is metallic, the contribution of the Au core to SPR is found to be suppressed, while the semiconductor interlayer can enhance this contribution. The porous Si interlayer exhibits the combined features inherent to a cavity and amorphous Si. These conclusions are illustrated by showing the distribution of electric field in and near nanoparticles. [ABSTRACT FROM AUTHOR]

We investigate the surface-enhanced Raman spectroscopy of Ag nanorings antenna in both experiment and simulation. Self-organized Ag nanorings antenna were formed on quartz glass wafers by a simple chemistry reaction without any template. The three-dimensional finite-difference time-domain simulation calculations indicate that the electric field enhancement of Ag nanoring antenna is strongly dependent on the gap distance. A very strong surface plasmon coupling in the gap region of Ag nanoring antenna is observed, whose field intensity is enhanced four times compared to that for Ag nanodomes antenna with the same gap distance. Surface-enhanced Raman scattering (SERS) measurements have shown that the SERS intensity acquired from the Ag nanoring antenna is about 16 times stronger than that obtained from Ag nanodomes antenna. These results pave the way to design plasmonic nanostructures for practical applications that require coupled metallic nanoparticles with enhanced electric fields. [ABSTRACT FROM AUTHOR]

Abstract: Graphite oxide (GO) has been prepared by the modified Hummers method and hydrated to different concentrations. Samples were then characterized by nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, X-ray diffraction analysis, and gas adsorption. The results confirmed the existence of water molecules at two types of sites, namely the two-dimensional space between GO layers as well as inter-grain voids. Detailed impedance spectroscopic measurements have been performed to study the rotation and reorientation dynamics of confined water. Two dielectric loss peaks were observed in hydrated GO and attributed to relaxational motions of water molecules. The peak at the higher temperature arises from the rotation of intercalated molecules along the axis of their hydrogen bonds to hydroxyl radicals on the graphite oxide layers. The peak at lower temperature corresponds to the relaxation of inter-grain species, a relaxation that seems to deviate from Arrhenius behavior at higher temperatures. [Copyright &y& Elsevier]

Abstract: Dendritic Ag–Pd bimetallic nanostructures have been synthesized on the surface of Cu foil via a multi-stage galvanic replacement reaction (MGRR) of Ag dendrites in a Na2PdCl4 solution. After five stages of replacement reaction, one obtained structures with protruding Ag–Pd flakes; these will mature into many porous structures with a few Ag atoms that are left over dendrites. The dendritic Ag–Pd bimetallic nanostructures were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), selected area electron diffraction (SAED) and X-ray photoelectron spectroscopy (XPS). The morphology of the products strongly depended on the stage of galvanic replacement reaction and reaction temperature. The morphology and composition-dependent surface-enhanced Raman scattering (SERS) of the as-synthesized Ag–Pd bimetallic nanostructures were investigated. The effectiveness of these dendritic Ag–Pd bimetallic nanostructures on the surface of Cu foil as substrates toward SERS detection was evaluated by using rhodamine 6G (R6G) as a probe molecule. The results indicate that as-synthesized dendritic Ag–Pd bimetallic nanostructures are good candidates for SERS spectroscopy. [Copyright &y& Elsevier]

Abstract: The fact that a magnetic hysteresis loop is observed only in polymerized C60 and is absent in both pristine and depolymerized C60 establishes a close link between the weak ferromagnetism and the underlying structure. Furthermore, the correlation between the weak ferromagnetism and hydrogen presence has been explored by 1HNMR and 1H–13C cross-polarization NMR, whereby strong bonding between the H adducts and C60 has been verified. The adducted hydrogens most likely form bonds with the carbon atoms of inter-C60 four-membered rings. This conclusion is further supported by the formation energy of adducted H and the exchange energy among adducted H obtained from first-principle calculations on Rh-C60. [Copyright &y& Elsevier]

The energy density of aqueous supercapacitors can be enhanced by large capacitance and high operating voltage, which is mainly limited by the narrow stability window of the water. Herein, carbonaceous materials with nitrogen-doping and hierarchical porosity are successfully designed and prepared via a facile sol−gel route accompanied by the cooperative self-assembly of triblock copolymer and melamine-resorcinol-formaldehyde polymer, followed by carbonization and CO 2 activation. Based on the as-prepared carbon material, symmetric supercapacitors achieve a high cell voltage of 1.8 V in 1 M Li 2 SO 4 , and exhibit a high energy density of 27.8 Wh kg−1 at power density of 0.23 kW kg−1. Taking advantage of the reversible redox reaction of Mn3+/Mn4+ accompanied with the insertion/extraction of Li+ of birnessite-type MnO 2 , the working potential of positive electrode is further expanded to 0–1.2 V (vs SCE). Then asymmetric supercapacitors with high cell voltage of 2.2 V have been successfully fabricated, exhibiting a higher energy density of 44.5 Wh kg−1 at power density of 0.27 kW kg−1 and an acceptable energy density of 21.8 Wh kg−1 even at a high power density of 5.6 kW kg−1. • Hierarchical porosity and nitrogen-doped carbon material is designed and prepared. • HNCXs/Mn 3 O 4 composites expanding the working potential to 0–1.2 V (vs SCE). • The 2.2 V aqueous supercapacitor exhibits significantly enhanced energy density. [ABSTRACT FROM AUTHOR]

BACKGROUND Traditional open surgery for displaced scapular body and neck fractures often results in significant trauma and complications. This study aimed to assess the efficacy of a combined medial and lateral minimally invasive approach compared with the traditional Judet approach. MATERIAL AND METHODS A retrospective analysis was conducted on 36 patients (22 men, 14 women; mean age 45.6 years) with displaced scapular body and neck fractures treated between May 2016 and May 2022. Nineteen patients underwent the minimally invasive approach, while 17 received the traditional Judet approach. Primary outcomes included surgical incision length, intraoperative blood loss, complication rate, time to postoperative pain relief (VAS score ≤3), and Constant-Murley shoulder score at 12 months. Statistical analysis was done using the t test and chi-square test. RESULTS The minimally invasive group had shorter incision lengths (mean difference: 10.0 cm; 95% CI: 8.1-11.9; P<0.001) and lower blood loss (mean difference: 129.4 mL; 95% CI: 119.0-139.8; P<0.001). They also experienced faster pain relief (mean difference: 3.0 days; 95% CI: 2.5-3.5; P<0.001) and higher Constant-Murley scores (mean difference: 7.4 points; 95% CI: 4.9-9.9; P<0.001). There were no significant differences in operative duration or fracture healing time. CONCLUSIONS The combined medial and lateral minimally invasive approach offers superior outcomes in reducing incision length, blood loss, complications, and pain, with enhanced shoulder function, making it a safe and effective alternative to the traditional Judet approach.

Migraine is a prevalent and disabling neurovascular disorder, with women being more susceptible, characterized by unilateral throbbing headache, often accompanied by nausea and vomiting, and often associated with various comorbidities such as brain and cardiovascular diseases, which can have a serious impact on quality of life. Although nonsteroidal anti-inflammatory drugs (NSAIDs) are the main first-line medications for the treatment of pain, long-term use often leads to side effects and drug addiction, which emphasizes the need to investigate alternative pain management strategies with fewer adverse effects. Complementary and alternative medicine is a viable pain intervention often used in conjunction with traditional medications, including acupuncture, herbs, moxibustion, transcutaneous electrical stimulation, bio-supplements, and acupressure, which offer non-pharmacological alternatives that are now viable pain management options. This review focuses on the mechanistic doctrine of migraine generation and the role and potential mechanisms of Complementary and Alternative Therapies (CAT) in the treatment of migraine, summarizes the research evidences for CAT as an adjunct or alternative to conventional therapies for migraine, and focuses on the potential of novel migraine therapies (calcitonin gene-related peptide (CGRP) antagonists and pituitary adenylyl cyclase-activating peptide (PACAP) antagonists) with the aim of evaluating CAT therapies as adjunctive or alternative therapies to conventional migraine treatment, thereby providing a broader perspective on migraine management and the design of treatment programs for more effective pain management., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Song, Zhu, Su, Shi, Chi, Yan, Luo, Xu, Liu, Liu and Yang.)

We study numerically the structural transitions of two-dimensional systems of classic particles with competing interactions under a triangular confinement with two different types of soft-wall potentials. We observe a variety of novel confinement-induced equilibrium configurations as a function of particle density and confinement steepness for each considered confinement potential. The specific role played by the confining potentials on the ordering of the particle clusters is revealed. These findings allow us to control the self-organization of modulated systems through using external confinements., (© 2022. The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature.)

Cu@Cu 2 O core-shell nanoparticles (NPs) not only possess a stabilized structure but also exhibit better photocatalytic performance as compared to pure Cu 2 O. Therefore, preparation of Cu@Cu 2 O core-shell NPs is key toward efficient photocatalysis applications. In this paper, the fabrication of Cu@Cu 2 O core-shell NPs on single-crystal MgO(100) substrates has been studied systematically by pulse laser deposition. Scanning electron microscopy (SEM) images show that the average diameter of NPs is enlarged from 89.9 to 150.3 nm with the increasing of oxygen pressure. Transmission electron microscopy (TEM) images indicate that the NPs have elongated hexagons and a core-shell structure with a shell thickness of about 10 nm. UV-vis absorption spectra show that the position of the localized surface plasmon resonance (LSPR) peaks shifts from 648 to 858 nm and the full width at half-maximum (fwhm) of the LSPR peaks broadens from 226.7 to 436.5 nm with increasing average diameter of NPs. According to the analysis, the red shift of the LSPR peaks is caused by enlargement of the core diameter; higher fwhm is a result of broadened particle size distribution and the elongated morphology of NPs. Therefore, the width and range of LSPR peaks of the absorption spectrum can be tuned using this method, which is beneficial for enhancing the light absorption and improving the photocatalytic efficiency of Cu@Cu 2 O core-shell NPs., Competing Interests: The authors declare no competing financial interest.