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Laser-shock compression experiment on magnesium hydride
摘要： A dynamic high-pressure experiment was performed on magnesium hydride to measure the Hugoniot equation-of-state point using laser-driven shock waves. By measuring the mean shock velocity of MgH2 and the time-resolved shock velocity of the quartz reference, the Hugoniot state of MgH2 at 150 GPa was determined. The reliability of the data is ensured by using another reference material, polystyrene, which is next to the sample and is compressed by the same. This work validates the experimental methodology to obtain further high-pressure data of MgH2 with high accuracy.
关键词： Velocity interferometer,Magnesium hydride,Shock compression,Laser-driven shock,Hugoniot measurement
更新于2025-09-12 10:27:22
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Degradation of Mg-doped zinc oxide buffer layers in thin film CdTe solar cells
摘要： Cadmium Sulphide is the conventional n-type bu?er layer used in thin ?lm Cadmium Telluride solar cells. It is well known that Cadmium Sulphide causes optical losses and sulphur di?uses into the absorber during high temperature activation. Sputter-deposited Mg-doped ZnO (MZO) has been shown to be an attractive bu?er layer for Cadmium Telluride solar cells due to its transparency and tuneable band gap. It is also stable to high temperature processing and avoids di?usion of elements into the cadmium telluride absorber during the cadmium chloride activation treatment. However, degradation is observed in solar cells incorporating MZO bu?er layers. Analysis of the MZO ?lm surface potential has revealed signi?cant ?uctuations in the thin ?lm work function once the layer is exposed to the atmosphere following deposition. These ?uctuations are attributed to the high reactivity to water vapour of the MgO contained in the MZO ?lms. This has been analysed using X-ray Photoelectron Spectroscopy to determine corresponding changes in the surface chemistry. The Zinc Oxide component is relatively stable, but the analysis shows that MgO forms a Mg(OH)2 layer on the MZO surface which forms a secondary barrier at the MZO/CdTe interface and/or at the interface between MZO and the Fluorine-doped SnO2. This a?ects the Fill Factor and as a consequence it degrades the conversion e?ciency.
关键词： Surface contamination,Degradation,Thin ?lm solar cells,Cadmium telluride,Magnesium-doped zinc oxide,Hydroxide,Bu?er
更新于2025-09-11 14:15:04
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<i>In situ</i> spectroelectrochemical ellipsometry using super continuum white laser: Study of the anodization of magnesium alloy
摘要： This work shows the interest to use a real time, white laser-based ellipsometer to characterize a complex electrolyte|electrode interface during an electrochemical process in an aqueous-based medium. This method is proposed to probe electrochemical interfaces that are usually not suitable to the full extent application of ellipsometry due to great disturbance of the re?ected light ?ux provoked by gas evolution or roughness. In situ spectroelectrochemical ellipsometry combining such a visible super continuum ?ber laser-band source was not previously reported to the best of the authors’ knowledge. The setup was employed to monitor an electrochemical process whose mechanism was previously incompletely described: the prespark anodization regime of the plasma electrolytic oxidation process of the Mg alloy AZ91D in the 3M KOH electrolyte. Above the anodization voltage of 4 V, the side water oxidation reaction induced light diffusion that reduces re?ected light beam intensity. The process is monitored in an extended voltage range from 4 to 40 V and in an extended spectral range (495–800 nm). In the presented case, the use of a visible super continuum ?ber laser-band source enhanced the signal-to-noise ratio giving access to a deeper picture of the triplex layer structure during surface repassivation by monitoring the evolution of the outer, inner, and interfacial layers.
关键词： AZ91D,anodization,super continuum white laser,spectroelectrochemical ellipsometry,magnesium alloy
更新于2025-09-11 14:15:04
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Efficient Interfacial Solar Steam Generator with Controlled Macromorphology Derived from Flour via “Dough Figurine” Technology
摘要： Poor corrosion and wear resistance of magnesium (Mg) alloys restrict their applications. Herein, corrosion and wear-resistant films are formed upon Mg alloy AZ31 through a micro-arc oxidation (MAO) process in silicate electrolyte in the presence of carbon spheres (CS). Surface morphology, chemical composition, corrosion resistance, hardness, and coefficient of friction (CoF) of the MAO coatings are investigated using field-emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectrometry (FTIR), X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), electrochemical and hydrogen evolution measurements, automatic micro-hardness testing, and reciprocating tribometer, respectively. Results demonstrate that the surface morphology and hardness of MAO coatings vary with the concentration of CS. The presence of CS results in an increased coating thickness from 8.0 (cid:1) 1.8 to 12.2 (cid:1) 1.8 μm, mean pore size from 0.7 (cid:1) 0.1 to 1.9 (cid:1) 0.1 μm, open porosity of MAO coating from 4.2 (cid:1) 0.4 to 5.6% (cid:1) 1.1%, and coating hardness from 347.0 (cid:1) 59.0 to 853.0 (cid:1) 67.3 Vickers-hardness (HV). Furthermore, CS-modified MAO coatings lead to improved corrosion resistance in comparison with that of the neat MAO counterparts. Moreover, the high hardness and formation of SiC of CS-modified coatings lead to a low and stabilized CoF, which implies an enhanced wear resistance.
关键词： micro-arc oxidation,coatings,corrosion resistance,carbon spheres,magnesium alloys
更新于2025-09-11 14:15:04
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Hydrogen bond enables highly efficient and stable two-dimensional perovskite solar cells based on 4-pyridine-ethylamine
摘要： Magnesium lithospermate B (MLB) shows multiple biological activities including anti-oxidation and anti-proliferation in various diseases. However, the function of MLB in pulmonary arterial hypertension (PAH) is still unknown. This study aims to investigate the effect of MLB on hypoxia-induced phenotypic transformation of pulmonary arterial smooth muscle cells (PASMCs) and the underlying mechanisms. SD rats (or PASMCs) were exposed to 10% O2 for 3 weeks ( or 3% O2 for 48h) along with MLB or NADPH oxidase （NOX） inhibitor intervention. The effects of MLB on hemodynamics, pulmonary vascular remodeling and phenotypic transformation of PASMCs were observed first. Then, its effects on the protein levels of NOX (NOX2 and NOX4), ERK and p-ERK were examined. The results showed that MLB prevented the elevation in right ventricular systolic pressure and the increase in ratio of wall thickness to vessel external diameter of pulmonary arteries in PAH rats, and attenuated phenotypic transformation of PASMCs (decrease in α-smooth muscle actin while increase in osteopontin), accompanied by downregulation of NOX (NOX2 and NOX4) protein levels, decrease of ROS and H2O2 production, and suppression of the phosphorylation of ERK. NOX inhibitor (VAS2870) achieved similar results to that of MLB did in the hypoxia-treated PASMCs. Based on the observations, we conclude that MLB is able to prevent phenotypic transformation of pulmonary arteries in hypoxic PAH rats through suppression of NOX/ROS/ERK pathway, and MLB might have the potentials in PAH therapy.
关键词： pulmonary vascular remodeling,NADPH oxidase,phenotypic transformation,Magnesium lithospermate B,pulmonary arterial hypertension
更新于2025-09-11 14:15:04
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Influence of laser surface melting on the properties of MB26 and AZ80 magnesium alloys
摘要： In the present investigation, laser surface melting (LSM) was performed on MB26 and AZ80 magnesium alloys and their surface properties were evaluated. The finite element method (FEM) was used to calculate the resulting temperature during the laser surface melting process. The melted layer average thickness values were about 296 and 190 μm for MB26 and AZ80 alloys, respectively and the variation in the thickness is mainly attributed to the absorption in laser energy. The average grain size of the LSMed MB26 alloy was decreased about 14.5 times and AZ80 had very finer grains than the MB26 along with the fine distribution of second phases. Further, the X-ray diffraction results revealed that the second phase intensities were decreased in both the alloys due to their dispersion. The laser absorption efficiency of MB26 was higher due to the higher plasma attachment during LSM process, thereby has higher melt layer thickness compared to AZ80. The refined microstructure of the melted layer resulted in an increase of micro-hardness up to 110 Hv. Potentiodynamic polarization test results revealed that the corrosion current density (icorr) values of the LSMed MB26 and AZ80 alloys were decreased about 1.8 and 2.5 times, respectively compared to the as-received alloys. A variation in solidification rates of the melt pool due to the alloying elements were attributed to an improvement in the surface and electrochemical properties.
关键词： Corrosion,Polarization,Laser surface melting,Hardness,Magnesium alloys
更新于2025-09-11 14:15:04
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Effect of annealing treatment on transparent and conductive hydrated magnesium-carbon films
摘要： Transparent electronic technology has many urgent optoelectronic device applications. A key component of plasmonic materials in conventional semiconductors is the wide band gap of oxide thin films. Although transparent electronic materials have been developed for visible and near-infrared wavelengths, systems incorporating mid-infrared and far-infrared spectra are difficult to achieve. In this study, hydrated magnesium-carbon films, a new type of non-oxide transparent conductive thin films with a magnesium hydroxide structure, were generated using the three-step method. After annealing treatment, larger crystals in the thin films typically exhibited superior film resistivity, with conductivity values of approximately 8.63 × 10?3 Ω m. Due to the free electron concentration was not more than 1020 cm?3, the films demonstrated excellent optical properties, with plasma wavelength values of approximately 8 mm for infrared transmittance above 70%. After annealing, due to the Moss-Burstein (M-B) effect, the visible light transmittance was greater than 85% and the optical bandgap shifted towards the blue region. In addition, the influences of the sputtering power of the carbon target on the properties of hydrated magnesium-carbon film were also discussed in this paper.
关键词： Transparent conductive films,Electrical properties,Magnetron sputtering,Hydrated magnesium-carbon films
更新于2025-09-10 09:29:36
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Novel luminescent PLA/MgAl2O4:Sm3+ composite filaments for 3D printing application
摘要： In this work, luminescent bioplastic composite ?laments for 3D printing were fabricated from polylactic acid (PLA) and samarium doped magnesium aluminate phosphor (MgAl2O4:Sm3+). The phosphor was prepared by a metal-complex decomposition method. The obtained powder was then modi?ed by 3-aminopropyl triethoxysilane to improve compatibility with PLA matrix. Untreated and treated phosphors exhibited characteristic photoluminescent (PL) peaks of Sm3+ ion. Composite ?laments of PLA with different amounts of phosphors (0, 1, 2, 3 and 4 phr) were produced by an extrusion process. Differential scanning calorimetry (DSC) scans have revealed that the phosphor ?llers lowered glass-transition (Tg), crystallization (Tc), and melting (Tm) temperatures of the PLA. PL measurements have shown luminescent properties of 3D printed samples resembling those of phosphor powders. Luminescent intensity was increased with the increasing ratio of phosphors. The phosphors not only developed luminescence but also strengthened mechanical properties of the composites. Furthermore, surface modi?cation was able to improve the mechanical properties of the composite ?laments as evident in a series of mechanical tests.
关键词： Polymer composite,3D printing,Samarium doped magnesium aluminate,Polylactic acid,Phosphor
更新于2025-09-10 09:29:36
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Plasmons of magnesium nanodisks and their interactions with a dipole-carrying molecule
摘要： Magnesium nanostructures have recently emerged as an outstanding material with new and intriguing plasmonic properties. Here we investigate the optical properties of pristine and pyridine adsorbed magnesium nanodisks having diameter spanning in the range of 0.50 nm to 2.0 nm. We base our calculations on computationally efficient time-dependent density-functional theory calculations. Our results demonstrate that pristine magnesium nanodisks possess localized surface plasmon resonances. The adsorption of a dipole-carrying molecule significantly alters their plasmonic response due to the strong plasmon splitting, leading to new features in their optical response. We believe that magnesium nanodisks provide a versatile platform for sensing and in the design of novel ultra-sensitive plasmonic devices.
关键词： Magnesium nanodisks,Time-dependent density-functional theory,Plasmonics,Optical properties,Pyridine adsorption
更新于2025-09-09 09:28:46
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Magnesium for Transient Photonics
摘要： Optical recon?gurability has enabled the realization of photonic devices that including modulators, sensors, and signal processors. Yet, most change in functionality, approaches to date require the application of power, which severely limits their usage in portable devices. We demonstrate the concept of transient photonics based on Mg, a burgeoning material for (nano)photonics. We realize dynamic Mg/MgO/Mg color pixels covering the entire sRGB gamut color spectrum, where all hues vanish completely in less than 10 min upon exposure to water at room temperature and neutral pH, ideal for encryption. This scalable thin-?lm architecture has a robust angular response, maintaining vivid colors up to 80 degrees of incidence. Our transient photonics approach using materials that are earth-abundant and CMOS-compatible opens the door for the implementation of recon?gurable devices with controlled responses in the UV?IR that can disappear without leaving any trace after stable operation, relevant for healthcare, defense, and energy applications.
关键词： color pixels,recon?gurability,earth-abundant materials for photonics,dynamic optical response,magnesium,transient photonics
更新于2025-09-09 09:28:46