Silicon最新文献

Recycling cathode ray tube (CRT) glass is essential for minimizing environmental impact and enhancing sustainability. The recycling of CRT glass addresses waste management issues and fosters a circular economy. This study distinguishes between two components of CRT glass samples: panel glass and neck glass, with the latter exhibiting a higher concentration of lead. Lead effectively absorbs and attenuates ionizing radiation, such as gamma and X-rays, rendering neck glass an effective radiation shield. Various measurements have been conducted to identify the structural characteristics of CRT glass samples, including XRD analysis, which confirmed the amorphous nature of each sample. Differential Scanning Calorimetry (DSC) measurements reveal that the glass transition temperature of the neck sample exceeds that of the panel sample by 55 °C. The neck glass exhibits a reduced energy gap value due to the high lead content, which may suggest the glass's structural resistance to radiation. The oxygen packing density and Urbach values decline for the neck sample, whereas the density increases from 2.6196 to 3.4044 g/cm³ for the panel and neck samples, respectively. Additionally, the highest values for effective atomic number (Z_eff), effective atomic cross-section (C_eff), and effective electron density (N_eff) were found in the neck glass sample when shielding parameters, such as the half value layer, tenth value layer, and mean free path, were calculated using the Phy-X/PSD program at various gamma-ray energy. Mass attenuation coefficient values were recorded as practical and theoretical. The findings indicated that the neck sample exhibited enhanced protective properties.

With the development of society and the progress of science and technology, all kinds of radiation are getting closer and closer to human life, such as nuclear reactors, medical diagnostic instruments, electronic communication equipment, ultraviolet radiation and so on. Montmorillonite, as a natural two-dimensional layered clay mineral, has abundant reserves, low cost, good environmental compatibility, great ultraviolet reflection/scattering ability, and can provide controllable nano-sized spaces. Meanwhile, it has a high capacity, large specific surface area, good mechanical properties and chemical stability. By acting as additives or carriers, they can meet the shielding requirements of gamma rays, ultraviolet radiation, and electromagnetic interference by modification or composite processes. Herein, the latest research progresses of montmorillonite in gamma ray shielding, ultraviolet radiation shielding, and electromagnetic interference shielding was discussed, and the shielding mechanism of montmorillonite is analyzed. It holds great potential in the development of lightweight, flexible and environmentally friendly shielding materials. Moreover, montmorillonite is usually used as a lightweight filler, dispersion carrier or modifier to enhance the density, dispersity, mechanical properties and thermal stability of shielding materials. However, many challenges and unsolved problems, including further mechanism research, full utilization of montmorillonite, and low-cost and large-scale development methods, deserve further attention and development by researchers. This review has guiding significance for the application of montmorillonite in radiation shielding.

Short-channel effects (SCEs) significantly impact the performance of MOSHEMTs by degrading their electrostatic control and increasing leakage currents. Physics-based and charge-based models are useful to comprehend the physical charge flow mechanism along the channel in AlGaN/GaN metal-oxide semiconductors (MOSHEMTs). An innovative double π-gate engineering technique is proposed for short channel devices to address surface potential ambiguities and peak electric field phenomenon in the channel. To suppress surface traps, deep-level traps, and hot electron trapping/de-trapping in the gate-drain access region, a double layer of high-k insulators of Al₂O₃/HfO₂ is implemented. The proposed structure reduces the negative hysteresis at high drain bias. The proposed structure also trades off the traps by peak electric field redistribution and reducing hot electrons. It also offers the cut-off frequency (f_T)/maximum operating frequency (f_max) of 363/461 GHz respectively.

In this study, polyester resin composites were reinforced with varying ratios of Aluminum Oxide (Al₂O₃) and Silicon Carbide (SiC) powders, and their mechanical properties were systematically investigated. The composite samples were subjected to compressive strength tests and Specific Energy Absorption (SEA) evaluations. The Response Surface Methodology (RSM) was employed to perform a statistical analysis of the experimental results, allowing for the determination of significant factors and their interactions. The compressive strength of the composites was found to be significantly influenced by the content of Al₂O₃ with the highest compressive strength observed at a composition of 95% resin, 1.66% SiC, and 3.33% Al₂O₃, yielding a maximum stress of 8895.48 MPa. Similarly, the SEA results demonstrated that the addition of 3.33% Al₂O₃ and 6.66% SiC led to a remarkable improvement in energy absorption capabilities, achieving an SEA value of 73.20 J/kg. The statistical analysis confirmed the significance of both the individual and interaction effects of the filler materials, with p-values indicating high significance (p < 0.05). The developed models exhibited high accuracy with R² values of 0.9245 for compressive strength and 0.9492 for SEA, suggesting the reliability of the experimental data. These findings underline the potential of using ceramic powders like Al₂O₃ and SiC in enhancing the mechanical performance of polyester resin composites, making them suitable for high-performance applications.

Graphical Abstract

Using high-frequency induction fusion and rapid solidification under atmospheric pressure, we synthesized an Al–11 wt.% Cu alloy at ~ 800 °C for 30 min. A bimodal microstructure of silicon carbide (SiC) and diamond particles was observed, despite the absence of silicon or carbon in the initial melt. We hypothesize that carbon originated from atmospheric CO₂ absorbed during melting, while silicon likely derived from aluminum via in-situ transformation. This CO₂-induced carbonization led to the formation of SiC within the aluminum matrix, significantly enhancing the alloy’s mechanical and wear-resistant properties. Unlike conventional methods that introduce diamond externally, our process enables in-situ diamond and SiC formation during melting, offering a novel, sustainable pathway for CO₂ utilization. This approach not only improves material performance but also contributes to carbon capture and conversion at ambient pressure.

Acute myocardial infarction (AMI) results from acute coronary artery occlusion, leading to myocardial ischemia and necrosis. Ciprofol, an intravenous anesthetic, has antioxidant, anti-lipid peroxidation, anti-calcium overload, and anti-inflammatory properties. Effective drug delivery systems are crucial for addressing myocardial ischemia–reperfusion injury (MIRI). In this study, we developed an efficient composite drug delivery system by combining the high surface area of metal–organic frameworks (MOFs) with the biocompatibility and fluorescence properties of silica-based materials. We modified (3-aminopropyl)trimethoxysilane (APTMS) with compound 1 to create the APTMS-1@CP1 composite, which effectively encapsulates and transports Ciprofol. The composite exhibited strong fluorescence with peaks at 326 nm and 450 nm, a BET surface area of 689.7 m²/g, and a pore size of 5.1 nm, confirming its suitability for drug delivery. The drug loading capacity and controlled release properties were excellent, and fluorescence cycling tests showed no significant intensity decrease after five cycles, ensuring stability. The nitrogen adsorption/desorption isotherms indicated mesoporous material behavior, facilitating efficient encapsulation. In a H9c2 cell model of MIRI, pretreatment with APTMS-1@CP1@Ciprofol significantly restored cell viability compared to the MIRI group. The composite also reduced malondialdehyde (MDA) levels and inflammatory markers (IL-6, TNF-α), demonstrating its potential in alleviating oxidative stress and inflammation. These findings underscore the composite’s potential for treating cardiovascular diseases, especially myocardial ischemia–reperfusion injury, due to its high drug loading, controlled release, and therapeutic efficacy.

In this study, nanostructured thin films based on cadmium oxide doped with Indium (CdO:In) were fabricated by sol–gel spin-coating technique on p-type monocrystalline silicon (c-Si) for the integration in n-p heterojunction photodiode applications. A comprehensive analysis of structural, morphological, compositional, optical and electrical properties of the surface of undoped CdO and CdO:In films on silicon substrates was conducted. The doping of CdO films with Indium by incorporating In³⁺ ions maintained a nanocrystalline network in a cubic structure with reduced average grain size and smooth heterointerface with the c-Si substrate. The anti-reflection role of undoped CdO and doped CdO:In was validated through lower optical reflectance compared to the bare Si substrate, especially in short wavelength range. The electrical current–voltage I-V characteristics, measured in the dark and under illumination, were used to determine the main diode parameters of different CdO (n)/ c-Si (p) heterojunction structures. Compared to undoped CdO thin films, In-doping of CdO lead to higher ideality factor and reverse saturation current, but lower potential barrier and series resistance. Higher photogenerated current at the Si region with more light sensitivity was obtained in the CdO:In/Si diode owing to better transparency and wider bandgap than the undoped CdO film.Whereas, lower conduction band offset at the CdO:In/Si heterojunction enabled an improvement in charge carrier transport in the CdO:In/Si diode compared to the CdO/Si diode. Our results demonstrate the effective integration of nanostructured In-doped CdO thin films in CdO/Si n-p heterojunction photodiode applications.

The choice of silica-based precursors has an important impact on silica (SiO₂) aerogel materials. The main objective of this study is to explore a new route for the preparation of SiO₂ aerogels using micro-silica. Firstly, the difference in silica extraction rate between micro-silica and quartz and analytically pure SiO₂ under different conditions, and analyzed the reasons for the difference from the aspect of raw materials. Secondly, the SiO₂ was extracted by a low-temperature alkaline melting method using micro-silica as the silicon source, avoiding the disadvantages of the fire method and the wet method, and the SiO₂ aerogel was synthesized by drying under atmospheric pressure. The result shows the extraction rate of micro-silica was up to 94.2% comparing with the quartz and analytically pure SiO₂. It found that a high extraction rate and modulus of silica resources could be obtained at a mass ratio of NaOH to micro-silica of 1.4, a calcination temperature of 450 °C, and a calcination time of 60 min. The prepared SiO₂ aerogel had a typical nanoporous structure, with a density of 0.1421 g/cm³, a specific surface area of 236 m²/g, a porosity of 93.54%, and a thermally stable temperature of 400 °C, under 800 °C, the aerogel skeleton structure remains unchanged. This study gives a new way for exploring the high-value utilization of industrial solid waste.

Semi-solid casting is an advanced technique for fabricating aluminum components with enhanced mechanical properties. In this study, basalt fibers at volume fractions of 0, 2, 4, and 6% were uniformly dispersed within semi-solid A356 aluminum alloy to produce metal matrix composites. The fabrication was performed using an improved thixomixing method, a novel semi-solid processing technique that effectively overcomes poor fiber-matrix adhesion without relying on conventional fiber coatings or in-situ chemical treatments. This method employs shear forces to achieve uniform dispersion of basalt fibers within the semi-solid aluminum, facilitating the formation of intermetallic compounds at the fiber/matrix interface and thereby enhancing interfacial bonding. Semi-solid temperatures of 575 and 585 °C were selected for comparative analysis. The resulting composites were evaluated through shear punch tests, hardness measurements, compression testing, and microstructural characterization. The composite containing 6 vol.% basalt fibers cast at 575 °C exhibited the highest performance, with shear strength, hardness, and compression strength reaching 132 MPa, 71.3 Hb, and 458 MPa, respectively. Microstructural investigations revealed that the formation of intermetallic phases on the basalt fiber surfaces, along with the development of globular α-Al and non-dendritic Si-Al phases within the matrix, played a pivotal role in improving mechanical properties. This semi-solid continuous casting approach presents a promising route to fabricate high-performance composites with superior strength-to-weight ratios, offering a viable alternative to conventional metal components.

Herein, amorphous silicon (a-Si) thin films are coated with Ag₂O films of thickness of 100 nm and 500 nm by the thermal evaporation technique for the purpose of enhancing their dielectric and optical conduction properties. The structural and morphological studies on the a-Si/Ag₂O films (a-SA-xx; xx is the thickness of Ag₂O layer) have shown the preferred growth of hexagonal Ag₂O onto a-Si with increased strained structure. The increased oxide layers thickness change the morphology from spherical grains to resembling interconnects as a wavy networks organized in a hexagonal or quasi regular patterns. Ag₂O coating remarkably induced the free carrier absorption in the infrared range of light, redshifted the energy band gap, increased the light absorption by 24 times, enhanced the dielectric constant by ~ 100% in a-SA-100 and 4000% in a-SA-500 films. The optical conductivity of a-Si is improved ~ 26 and 132 times in the IR range. In addition, treating a-SA-xx films as optical filters workable as terahertz band filters have shown their ability to perform as electro-optical systems exhibiting enhanced cutoff frequency, drift mobility and free carrier concentration values. The drift mobility and terahertz cutoff frequency of a-SA-500 films reached 29.89 cm²/Vs and 9.50 THz in the IR range of light. The features of Ag₂O coated amorphous Si films are promising for IR laser sensing and other electro-optical applications.