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Obtaining the position of underground trapped personnel quickly and precisely is a key issue for life information detection in the early stage of borehole rescue. In the process of vertical drilling and rescue, due to the collapse of the roadway in the detection area or the displacement of the final hole position, it is impossible to obtain the position of the trapped personnel quickly and accurately. It delays the golden time of rescue and affects the safety of personnel. Through conducting a UWB radar wave transmission attenuation study, a rescue plan can be quickly formulated for on-site rescue commanders. This paper analyzes the current situation and demand of UWB radar wave application in mine borehold rescue. Combined with the background of mine borehold rescue, it is pointed out the attenuation law of UWB radar wave transmission. The study analyzes the influence of the characteristic parameters of the medium on the attenuation of radar wave transmission from the perspective of anisotropy of the medium. The influence of dielectric parameters on radar wave transmission attenuation is analyzed from four aspects: dielectric constant, conductivity, magnetic permeability and spatiotemporal variation. The influence of radar characteristic parameters on radar wave transmission attenuation is analyzed from two aspects: radar frequency and polarization. Based on the above analysis, it is pointed out that there are few studies on the simultaneous penetration of UWB radar waves through anisotropic media such as coal and rock masses and the mechanism of media propagation and attenuation. There are few theories and experiments on UWB radar wave transmission attenuation in complex and changeable underground or simulating disaster environments. And there are few summaries of relevant laws. The mapping relationship database between key parameters and influencing factors of UWB radar waves is not yet complete. The key technologies to be studied in the future are given as follows. It is suggested to conduct research on anisotropic media such as coal and rock masses at both macro and micro levels. It is suggested to establish an experimental simulation system for radar wave transmission attenuation under catastrophic environmental conditions. It is suggested to add research on UWB radar signal propagation characteristics and channel modeling numerical simulation in unstructured environments after disasters.

Ta-doped lithium-lanthanum-zirconium-oxygen (Li6.5La3Zr1.5Ta0.5O12, LLZTO) solid electrolytes with a high ionic conductivity at room temperature were prepared by the solid-phase reaction method, and the effects of irradiated electron beams on their structure and properties were investigated in detail. The results showed that no other heterogeneous phases were produced after irradiation with different doses (250 kGy and 500 kGy) of electron beams, and the lattice spacing became larger with an increase in the dose, which is conducive to the reduction of the diffusion energy barrier of ions in the lattice. First-principles calculations revealed that the Li+ diffusion energy barrier of the low-dose electron-beam irradiated sample was reduced by 0.07 eV compared with that of the unirradiated sample, suggesting that the defects created by irradiation can promote Li+ diffusion. An AC impedance test of the electrolytes before and after irradiation further confirmed that low-dose electron beam irradiation is beneficial for enhancing their ionic conductivity. Exploring the effect of electron beam irradiation on the structure and conductivity of LLZTO oxide solid state electrolytes holds significance in the study of solid state electrolytes.

Investigations on the damage and degradation mechanisms of epoxy resin under a high-energy irradiation and improvement in its stability in irradiation environments are crucial to expand the application of epoxy resin in numerous fields including the aerospace and nuclear industries. In this study, graphene quantum dots (GQDs) were used as free radical scavengers to slow down the degradation of epoxy resin under a γ-irradiation environment, and the anti-irradiation mechanism of the GQDs on epoxy resin was investigated. The results demonstrated that following irradiation, the mechanical properties of epoxy resin exhibited a reduction of 49%, accompanied by a decrease in glass transition temperature by 4.4 ℃. Similarly, the mechanical properties of graphene quantum dots/epoxy resin (GQDs/EP) composites experienced a decline of 35%, along with a decrease in glass transition temperature by 2.2 ℃. Notably, upon the incorporation of GQDs, the generation of free radicals within irradiated GQDs/EP composites was significantly suppressed compared to pure resin. Furthermore, GQDs nanoparticles enhanced both the mechanical properties and thermal stability of epoxy resin prior to and after irradiation. Therefore, GQDs nanoparticles can be used as free radical scavenger to effectively improve the irradiation stability of epoxy resin. The scavenging mechanisms for free radicals mediated by GQDs is closely associated with sp2 carbon domains and surface functional groups. This study provides a novel concept and method to improve the stability of epoxy resin under γ-ray radiation.

Green synthesis of Ag nanoparticles (AgNPs) by using the plant extract is a very important strategy to gain efficient antimicrobial agents with strong antimicrobial activity and low toxicity. In this study, jujube seed extract (JSE) is utilized to green synthesis of AgNPs by both hydrothermal process and solution‐based approaches. UV–vis absorption spectroscopy and infrared spectroscopy (FTIR) spectra confirm that jujube seed extract functionalized Ag nanoparticles are formed by both approaches and jujube seed extract covered on the surface of Ag nanoparticles. Transmission electron microscopy (TEM) images indicate that the JSE‐AgNPs are spherical with the average diameter of 17.7 and 14.2 nm for the hydrothermal process and solution‐based approaches, respectively. X‐ray diffraction (XRD) results indicate that the JSE‐AgNPs prepared by both approaches have face‐centered cubic crystal structure. The antimicrobial activity test reveals that minimum inhibitory concentrations (MIC) of JSE‐AgNPs by the solution‐based method are 62.5, 125, and 62.5 µg mL−1 against Escherichia coli, Staphylococcus aureus, and Candida albicans, respectively. These results imply that the JSE‐AgNPs have potential to be developed as efficient antimicrobial agents. [ABSTRACT FROM AUTHOR]

Green extraction of the active lignans from Schisandra chinensis has received considerable attention due to their promising applications in the biomedical field. In this study, microwave‐assisted deep eutectic solvent method was used to simultaneously extract five lignans: Schizandrol A, Schizandrol B, Schisantherin A, Schisandrin A and Schizandrin B. The extraction parameters were optimized according to the calculated comprehensive score obtained from the analytic hierarchy process combined with the entropy weight method. The optimal extraction conditions were that the molar ratio of choline chloride and glycolic acid is 4:1, water content is 30% (V/V), solid–liquid ratio is 1:20 (Wg:VmL), extraction time is 20 min, and extraction temperature is 70°C, under which the extraction rate of the five lignans were 10.89, 8.616, 4.019, 4.893, and 5.318 mg/g. These results confirmed that our extraction method is efficient and feasible for green extraction of lignans from S. chinensis. [ABSTRACT FROM AUTHOR]

We successfully synthesized a series of O3‐type NaNi1/3Fe1/3Mn1/3−xZrxO2 (x = 0, 0.01, 0.02, 0.04) cathode materials by the solid‐state reaction method. Energy dispersion spectroscopy, X‐ray diffraction (XRD), and X‐ray photoelectron spectroscopy results confirmed the successful incorporation of Zr elements into the lattice to substitute Mn. Due to the introduction of Zr4+, the crystal structure modulation of O3‐NaNi1/3Fe1/3Mn1/3O2 has been realized. By increasing the Zr4+ content, the width of the sodium diffusion layer expands, thereby facilitating the diffusion of sodium ions. Consequently, the material exhibits a remarkable enhancement in high‐rate capability. At the same time, increasing the Zr4+ content results in a notable decrease in both the average bond length of TM−O and the thickness of the TMO6 octahedron in the transition metal layer, resulting in a significant improvement in the cycling performance and structural stability of the cathode material. Additionally, the in‐situ XRD results demonstrate that the optimized cathode composition of O3‐NaNi1/3Fe1/3Mn1/3–0.02Zr0.02O2 (NFMZ2) undergoes a reversible phase transition of O3 → O3 + P3 → P3 → O3 + P3 → O3 during the charge–discharge process. [ABSTRACT FROM AUTHOR]

Magnetic anisotropy is an important character for magnetic materials. In this work, magnetic anisotropy of (110)-oriented ferrimagnetic NiCo2O4 (NCO) thin films deposited epitaxially on MgAl2O4 substrates by pulsed laser deposition is studied and compared with (001)-oriented NCO films. While the (001)-oriented films show a perpendicular magnetic anisotropy with the out-of-plane [001] direction as the magnetic easy axis, a jump in magnetic hysteresis loop is observed for the (110)-oriented films with a field applied vertically along the out-of-plane [110] direction. This jump in hysteresis loop is associated with a spin reorientation transition, depending on the applied field and temperature. Magnetic force microscopy reveals that this spin reorientation develops as domains nucleate, grow, and coalesce. This spin reorientation transition is discussed in terms of the competition between different magnetic anisotropy in an external field. [ABSTRACT FROM AUTHOR]

Ramie composites have been widely used in automobiles, daily necessities, aerospace, ships, cruise lines, etc., but their flame retardant properties are relatively poor, which is difficult to meet the flame retardant performance requirements of composites for rail transit. In order to improve the properties of ramie reinforced composites, flame retardant treatment is necessary. In this paper, phosphorus flame retardant phytic acid (PA) was used to modify ramie fabric, and then the composites were prepared. The flame retardancy and mechanical properties of ramie reinforced composites were investigated. It was found that the flame retardancy of ramie composites was improved after flame retardant modification with phytic acid, but the mechanical properties were decreased. In order to improve the mechanical properties of PA ramie composites, two kinds of layered PA ramie/glass fiber hybrid composites were prepared by replacing part of ramie with glass fiber. The results show that the addition of glass fiber can improve the mechanical properties and flame retardancy of composites. [ABSTRACT FROM AUTHOR]

In this study, proanthocyanidins-functionalized Fe3O4 magnetic nanocomposites were synthesized by the hydrothermal method. The prepared Fe3O4 nanocomposites were characterized by Fourier transform infrared spectrometer (FTIR), X-ray powder diffractometer (XRD), physical property measurement system (PPMS), particle size analyzer, scanning electron microscope (SEM), and transmission electron microscope (TEM). FTIR results indicated that the obtained products were coated with proanthocyanidins. The SEM and TEM results, as well as particle size distribution analysis, revealed that the obtained products were spherical particles with average diameter of 3 2 8. 6 2 ± 2 6. 7 5 nm. XRD and PPMS characterization confirmed that the Fe3O4 nanoparticles have a cubic spinel structure with magnetic properties. The performance of the Fe3O4 nanocomposites for removing organic dyes in an aqueous solution was investigated. The synthesized products were found to be effective on removing various organic dyes, such as Methylene blue (MB), neutral red (NR) and Rhodamine B (RhB), indicating their considerable potential as efficient dyes adsorbents for wastewater treatment. Proanthocyanidins-functionalized Fe3O4 magnetic nanocomposites were synthesized by the hydrothermal method. The obtained Fe3O4 nanocomposites can efficiently remove the organic dyes in an aqueous solution. Proanthocyanidins-functionalized Fe3O4 magnetic nanocomposites had the potential to be developed as efficient dyes adsorbents for wastewater treatment. [ABSTRACT FROM AUTHOR]

This study aims to explore the role of graphene in enhancing the radiation resistance of epoxy resin (EP) composites. Through the resin transfer molding process, we prepared 0.3 wt% graphene oxide (GO) and Hummer's method reduced graphene oxide (Hh-RGO) reinforced EP composites, respectively. By comparing the microstructure, free radical content, thermal stability, and mechanical properties of EP, GO/EP, and Hh-RGO/EP composites before and after γ-ray irradiation, we found that GO and Hh-RGO can effectively reduce the generation of free radicals in EP during irradiation, thereby reducing chemical bond breakage and enhancing its radiation resistance. Particularly, GO demonstrated stronger radiation damage resistance. The results showed that after γ-ray irradiation, the glass transition temperature, nano-indentation depth, and hardness of GO/EP composites decreased by 20.32%, 416.3 nm, and 16.00%, respectively, whereas EP decreased by 30.34%, 502.1 nm, and 41.82% respectively. This is mainly attributed to the fact that the addition of graphene nanoparticles as a reinforcement reduces the free radical content in EP and reduces the damage of free radicals to the EP crosslinked network during irradiation, thereby improving the thermal stability and mechanical properties of the composites. In addition, the Π electrons formed by the hexagonal honeycomb structure of GO and the Π-Π stacking effect formed with free radicals can slow down the aging of epoxy resin in a high-energy radiation environment, thereby prolonging its service life. This study provides important references for further optimization and application of graphene-modified epoxy resin. [ABSTRACT FROM AUTHOR]

A composite material with improved characteristics can be produced by combining metal‐organic frameworks (MOFs) with polymer fibers. In contrast to commonly used powdered MOFs, polymer fibers can offer flexible support for MOFs, and some of the fibers can even work in concert with MOFs. The molecular transport channels are significantly enlarged when polymer fibers are employed as the base material for composites rather than conventional polymer films and mixed matrix films. This makes it simpler for the molecules to bind to the active site, speeding up the reaction. First, a brief analysis of the binding of MOFs to fibers is provided, followed by a systematic summary of the MOF forming process, including the synthesis and modification of MOFs, which lays the foundation for the subsequent summary of the synthesis methods of MOFs–fiber composites. In this article, three strategies are presented for attaching MOFs to polymer fibers: cospinning MOFs with fibers, depositing MOFs on fiber surfaces, and in situ growing MOFs on fiber surfaces. Different binding techniques make MOFs–fiber composites promising for many applications. Finally, the improvement of MOFs–fiber composites and their possible application scope are discussed. [ABSTRACT FROM AUTHOR]

A taste sensor with global selectivity can be used to discriminate taste of foods and provide evaluations. Interfaces that could interact with broad food ingredients are beneficial for data collection. Here, we prepared electrochemically reduced graphene oxide (ERGO)-modified interdigital electrodes. The interfaces of modified electrodes showed good sensitivity towards cooking condiments in mixed multi-ingredients solutions under electrochemical impedance spectroscopy (EIS). A database of EIS of cooking condiments was established. Based on the principal component analysis (PCA), subsets of three taste dimensions were classified, which could distinguish an unknown dish from a standard dish. Further, we demonstrated the effectiveness of the electrodes on a typical dish of scrambled eggs with tomato. Our kind of electronic tongue did not measure the quantitation of each ingredient, instead relying on the database and classification algorithm. This method is facile and offers a universal approach to simultaneously identifying multiple ingredients. [ABSTRACT FROM AUTHOR]

Background: Ossification of the posterior longitudinal ligaments (OPLL) is common disorder characterized by heterotopic ossification of the spinal ligaments. Mechanical stimulation (MS) plays an important role in OPLL. DLX5 is an essential transcription factor required for osteoblast differentiation. However, the role of DLX5 during in OPLL is unclear. This study aims to investigate whether DLX5 is associated with OPLL progression under MS. Methods: Stretch stimulation was applied to spinal ligaments cells derived from OPLL (OPLL cells) and non‐OPLL (non‐OPLL cells) patients. Expression of DLX5 and osteogenesis‐related genes were determined by quantitative real‐time polymerase chain reaction and Western blot. The osteogenic differentiation ability of the cells was measured using alkaline phosphatase (ALP) staining and alizarin red staining. The protein expression of DLX5 in the tissues and the nuclear translocation of NOTCH intracellular domain (NICD) was examined by immunofluorescence. Results: Compared with non‐OPLL cells, OPLL cells expressed higher levels of DLX5 in vitro and vivo (p < 0.01). Upregulated expression of DLX5 and osteogenesis‐related genes (OSX, RUNX2, and OCN) were observed in OPLL cells induced with stretch stimulation and osteogenic medium, whereas there was no change in the non‐OPLL cells (p < 0.01). Cytoplasmic NICD protein translocated from the cytoplasm to the nucleus inducing DLX5 under stretch stimulation, which was reduced by the NOTCH signaling inhibitors (DAPT) (p < 0.01). Conclusions: These data suggest that DLX5 play a critical role in MS‐induced progression of OPLL through NOTCH signaling, which provides a new insight into the pathogenesis of OPLL. [ABSTRACT FROM AUTHOR]

Proanthocyanidins-functionalized Fe3O4 @ Ag nanoparticles (Fe3O4 @ AgNPs) were synthesized by one-step hydrothermal method wherein silver nanocrystals were grown in situ on the surface of Fe3O4 nanoparticles with the assistance of proanthocyanidins. The morphology and structure of Fe3O4 @ AgNPs were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier-transform infrared spectrometer (FTIR), UV–Vis spectrophotometer (UV–Vis), X-ray powder diffractometer (XRD), and physical property measurement system (PPMS). The characterization results indicated that sliver nanocrystals were deposited on the surface of Fe3O4 nanoparticles to form spherical and uniformly dispersed Fe3O4 @ AgNPs. Moreover, the Fe3O4 @ AgNPs had a high magnetic response, which can be recovered from the environment. The antibacterial activity of the Fe3O4 @ AgNPs against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Candida albicans (C. albicans) was investigated. The results confirmed that the Fe3O4 @ AgNPs had broad-spectrum antibacterial activity. At the same time, the adsorption property of the nanoparticles for heavy metal ions Cu2+, Pb2+, and Cd2+ was also studied. The results showed that pH and incubation time played an essential role in the removal of heavy metal ions, and the nanoparticles had excellent removal efficiency. The multifunctional nanomaterial Fe3O4 @ AgNPs prepared by this study have the potential to apply in the biomedical and water disinfection fields. [ABSTRACT FROM AUTHOR]