The chemical composition, structure, and physical properties of aluminum nitride (AlN) films obtained using pulsed DC reactive magnetron sputtering in asymmetric bipolar mode have been studied. X-ray diffraction and electron diffraction confirmed the composition of c–axis textured hexagonal AlN films required for piezoelectric applications. The surface of the films obtained is quite smooth; the arithmetic average roughness does not exceed 2 nm. Transmission electron microscopy has shown the presence of a transition layer at the film–substrate interface. Transmission electron microscopy and X-ray photoelectron spectroscopy depth profile analysis have shown that the films have an oxidized surface layer which has an influence on the optical model of the films derived from ellipsometric data. However, it does not significantly influence the films’ piezoresponse. Piezoelectric force microscopy indicated a piezoelectric effect in the films that is uniform over their surface.

In the present study, the ability for novel carbon microspheres (CMs) derived from date palm (Phoenix dactylifera) biomass using a hydrothermal carbonization (HTC) process and activated using phosphoric acid to remove methylene blue dye was investigated. Three types of palm-based wastes (seeds, leaflet, and inedible crystallized date palm molasses) were used and converted to CMs via the HTC process. The prepared samples were then activated using phosphoric acid via the incipient wetness impregnation method. The CMs samples before and after activation were analyzed using scanning electron microscopy (SEM), elemental analysis and scanning (CHNS), and the Fourier transform infrared (FTIR) and Brunauer–Emmet–Teller (BET) methods. The samples exhibited high BET surface areas after activation (1584 m2/g). The methylene blue adsorption results showed good fitting to the Langmuir, Fruendlich, and Temkin isotherm models for all activated samples. The maximum adsorption capacity achieved was 409.84 mg/g for activated CM obtained from the palm date molasses, indicating its high potential for application as a dye-based adsorption material.

Waste resource utilization can save energy, reduce costs, and is one of the important means to protect the environment. Flue-gas desulphurized (FGD) gypsum is a common industrial by-product. These by-products are not only difficult to use, but also have serious impacts on the ecological environment. The conventional process of the industrial utilization of the calcium sulfate whisker pretreatment process leads to a low utilization rate of FGD gypsum, further increasing the consumption of resources and leading to secondary pollution. This study presents a method of preparing composites by adding FGD gypsum directly into epoxy resin with polyethylene-grafted maleic (PGM) anhydride as a compatibilizer of FGD gypsum/epoxy resin composites. Results showed weak tensile properties and impact properties of the composites when only FGD gypsum was added. When the amount of PGM added was 6 wt%, the tensile properties and impact properties of FGD gypsum/epoxy resin composites improved by 75% and 63%, and compared with the neat epoxy resin, the tensile properties and impact properties of FGD gypsum/epoxy resin composites, respectively, improved by 30% and 57%. Additionally, laser particle size analysis, X-ray diffraction (XRD) analysis, Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), a thermogravimetric analyzer (TGA), and a Differential scanning calorimeter (DSC) were used to examine the effects of PGM on the mechanical properties of FGD gypsum/epoxy resin composites and its mechanism of action. The recycling of FGD gypsum in resin materials has been extended in this study.

Styrene-butadiene rubber (SBR) is commonly used as a modifier to enhance the low-temperature performance of asphalt. However, it is worth noting that while SBR modified asphalt exhibits good low-temperature performance, its high-temperature performance is comparatively inferior. This limitation significantly restricts the widespread use of SBR modified asphalt. As a new type of nanomaterial, graphene (GR) can change the microstructure of asphalt binder and provide asphalt with better mechanical, thermal, and adhesion properties. The main purpose of this study is to explore the influence of GR and SBR composite incorporation on the performance indexes of modified asphalt, and to study its compatibility and modification mechanism from the microscopic point of view of asphalt. The weight factor optimization system of modified asphalt was established by an analytic hierarchy process, and the optimum content of GR was determined to be 0.1% in a quantifiable way. The test results demonstrate that the inclusion of graphene substantially enhances the high-temperature rutting resistance of asphalt, reduces the temperature sensitivity of modified asphalt, and improves its storage stability. However, its effect on the low-temperature performance of asphalt is relatively minimal. Microscopic experimental results reveal the formation of a stable structure at the interface between GR and SBR in the composite modified asphalt. Furthermore, the dispersed phase exhibits improved uniformity, which positively impacts the stability of the asphalt binder.

Yellow lasers have attracted much attention due to their applications in biomedicine, astronomy and spectroscopy, and the resonant cavity is an important part of lasers. In this work, the resonant cavity film was studied and prepared using physical vapor deposition (PVD) technology to couple and match the optical properties of Dy,Tb:LuLiF4 crystal to generate yellow laser. In the process of film deposition, the substrate temperature has an important influence on the quality of the film. Therefore, we first investigated the effect of HfO2 film quality at different substrate temperatures. Furthermore, the multilayer film was designed to couple and match the optical properties of Dy,Tb:LuLiF4 crystal. According to the designed film system scheme, HfO2 and UV-SiO2 were used as high- and low-refractive index film materials for resonant cavity film preparation using the PVD technique, and the effect of process parameters on the film quality was investigated. A 450 nm pump laser was used to directly pump Dy3+ to excite and generate the yellow laser. In this process, the excited radiation jump occurs in the crystal, and the generated laser in the new band reaches a certain threshold after oscillation and gain in the resonant cavity, thus successfully outputting a 575 nm yellow laser.

Acceleration sensors are tools for detecting acceleration and serve purposes like fault monitoring and behavior recognition. It is extensively employed in a variety of industries, including aerospace, artificial intelligence, biology, and many more. Among these, one of the major research hotspots and challenges is the development of low-energy, self-powered, miniature, mass-produced sensors. Due to its capacity to perceive human behavior and identify errors, the flexible acceleration sensor offers a distinct advantage in the use of flexible and miniaturized sensing systems. This review analyzes the current state of piezoelectric flexible acceleration sensors’ applications in the areas of sensitive materials, processing technology, and device structure and briefly summarizes the fundamental properties of these sensors. Additionally, it ends with a prognosis for the future growth of flexible piezoelectric acceleration sensors.

When detecting surface defects in the industrial cutting environment, the defects are easily contaminated and covered by many interference factors (such as chips and coolant residue) that exist on the machined surface. These interfering factors hinder the sustainable detection of surface defects. Furthermore, addressing the challenge of detecting surface defects in the presence of interference factors has proven to be a difficult problem in the current detection field. To solve this problem, a sustainable detection method for surface defects is proposed. The method is divided into two steps: one is the identification and removal of interference factors; the other is the detection of surface defects. First, a new FPN-DepResUnet model is constructed by modifying the Unet model from three aspects. The FPN-DepResUnet model is used to identify the interference factors in the image. Compared to the Unet model, the MAP of the FPN-DepResUnet model is increased by 5.77%, reaching 94.82%. The interfering factors are then removed using the RFR-net model. The RFR-net model performs point-to-point repair of interference regions. The repair process is performed by finding high-quality pixels similar to the interference region from the rest of the image. The negative effects of the interfering factors are removed by combining the FPN-DepResUnet model with the RFR-net model. On this basis, the SAM-Mask RCNN model is proposed for efficient defect detection of clean surface images. Compared with the Mask RCNN model, the MAP of the proposed SAM-Mask RCNN model increased by 2.00%, reaching 94.62%. Further, the inspection results can be fed back with a variety of surface defect information including defect types, the number of pixels in the different defect regions, and the proportion of different defect regions in the entire image. This enables predictive maintenance and control of the machined surface quality during machining.

The works available in the literature presenting the influence of impurities on the properties (mainly fatigue strength) of material give an answer with a high degree of probability for hard steels and large precipitations (usually above 10 µm). The impact of non-metallic impurities on the durability of high-ductility steels causes much greater problems and is much more difficult to explain. The results of the existing studies rarely take into account the diameter of the impurities in relation to the distance between the impurities. This paper presents the results of tests carried out on a low-carbon steel heated in a 100-tonne oxygen converter and deoxidized under vacuum. The fatigue strength test was carried out on cylindrical samples using rotational bending for different tempering temperatures of the steel. The quotient of the average size of the inclusions and the average distance between the inclusions were analyzed. Based on the obtained results, it was found that steel annealed in the converter and vacuum degassed has a content of both phosphorus and sulfur below 0.02% and a total volume of impurities of 0.086%. The main fraction of impurities are oxide inclusions with a diameter below 2 µm. An increase in fatigue strength was found along with an increase in the number of impurities, mainly of small diameters.

This research manuscript investigates the structural and thermal stability of CrZrON coatings synthesized through reactive magnetron sputtering. The coatings were deposited at different temperatures with 120 °C and 400 °C, and with varying oxygen-to-reactive gas ratios in the range of 8.3% to 25.7%. The average chemical composition, crystallographic orientation, microstructure, lattice parameter, crystallite size, and hardness of the coatings were evaluated. The results revealed that the coatings deposited at a lower temperature of 120 °C exhibited a columnar structure, while those deposited at a higher temperature of 400 °C showed a transition towards a featureless or amorphous structure. The lattice parameter and crystallite size were influenced by the deposition temperature and oxygen ratio, indicating the incorporation of oxygen into the coatings. Hardness measurements demonstrated that the coatings’ hardness decreased from 33.7 GPa to 28.6 GPa for a process temperature of 120 °C and from 32.1 GPa to 25.7 GPa for 400 °C with an increase in the oxygen ratio, primarily due to the formation of oxygen-rich compounds or oxides. Additionally, annealing experiments indicated that the coatings with featureless or amorphous structures exhibited improved thermal stability, as they maintained their structural integrity without delamination even at high annealing temperatures.

The performance of poly(3-hexylthiophene) (P3HT): phenyl-C61-butyric acid methyl ester (PCBM) organic photovoltaic (OPV) devices was found to be strongly influenced by environmental during preparation, thermal annealing conditions, and the material blend composition. We optimized laboratory fabricated devices for these variables. Humidity during the fabrication process can cause electrode oxidation and photo-oxidation in the active layer of the OPV. Thermal annealing of the device structure modifies the morphology of the active layer, resulting in changes in material domain sizes and percolation pathways which can enhance the performance of devices. Thermal annealing of the blended organic materials in the active layer also leads to the growth of crystalline for P3HT domains due to a more arrangement packing of chains in the polymer. Poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) acts as a hole transport layer in these P3HT:PCBM devices. Two commercially materials of PEDOT:PSS were utilizing in the optimization of the OPV in this research; high conductivity PEDOT:PSS-PH1000 and PEDOT:PSS-Al4083, which is specifically designed for OPV interfaces. It was demonstrated that OPVs were prepared with PEDOT:PSS-PH1000 have a less than the average performance of PEDOT:PSS-Al4083. The power conversion efficiency (PCE) decreased clearly with a reducing in masking area devices from 5 mm2 to 3.8 mm2 for OPVs based on PH1000 almost absolutely due to the reduced short circuit current (Jsc). This work provides a roadmap to understanding P3HT:PCBM OPV performance and outlines the preparation issues which need to be resolved for efficient device fabrication

Fiber sensors possess characteristics such as compact structure, simplicity, electromagnetic interference resistance, and reusability, making them widely applicable in various practical engineering applications. Traditional fiber sensors based on different microstructures solely rely on the thermal expansion effect of silica material itself, limiting their usage primarily to temperature or pressure sensing. By employing thin film technology to form Fabry–Perot (FP) cavities on the end-face or inside the fiber, sensitivity to different physical quantities can be achieved using different materials, and this greatly expands the application range of fiber sensing. This paper provides a systematic introduction to the principle of FP cavity fiber optic sensors based on thin film technology and reviews the applications and development trends of this sensor in various measurement fields. Currently, there is a growing need for precise measurements in both scientific research and industrial production. This has led to an increase in the variety of structures and sensing materials used in fiber sensors. The thin film discussed in this paper, suitable for various types of sensing, not only applies to fiber optic FP cavity sensors but also contributes to the research and advancement of other types of fiber sensors.

In this study, we introduced the method for the growth of titanium molybdenum oxide (TMO) nanotubes directly from metallic precursor solid state solution and provided their structural and chemical characterization. Precursor films with content of molybdenum from 32 to 82 at% were prepared using co-deposition magnetron sputtering. The optimization of deposition parameters allowed for the growth of a continuous nanotube array with a length up to 700 nm ± 10% by anodic oxidation. Scanning electron microscopy (SEM) combined with energy-dispersive spectroscopy (EDS) revealed nanotube formation with Ti1−xMoxO2 composition, where x can reach the value of 0.5. Scanning transmission electron microscopy combined with EDS (STEM-EDS) confirmed the incorporation of Mo into the TiO2 lattice and uniform elemental distribution across the nanotube at the submicron level. The nanobeam electron diffraction (NBD) and X-ray diffraction analyses (XRD) did not show any notable crystal phase formation for the titanium molybdenum oxide phase.

The development of technology that combines supercapacitors and lithium-ion batteries by externally connecting them in parallel is ongoing. This study examines the correlation between the volume ratio and electrical characteristics of a cell made by internally connecting a battery capacitor with Li4Ti5O12 as the anode active material and a supercapacitor in parallel. It was found that increasing the volume occupied by the battery capacitor in the cell led to increased cell energy and resistance, resulting in decreased output characteristics. Conversely, increasing the volume occupied by the supercapacitor in the cell led to a decrease in the IR drop during discharge and the cell temperature when evaluating cycle characteristics with a current of 20C. This study also examined the behavior of the current distributed during the charging and discharging process based on the volume ratio of the supercapacitor and the battery capacitor. Analyzing the correlation between the volume ratio and electrical characteristics of supercapacitors and battery capacitors could potentially lead to the development of a new type of energy storage device.

The wear of artificial joints can lead to joint noise and tissue pathology within the human body, which is a primary factor affecting their service life. In response to the issue of wear in ceramic–titanium alloy artificial hip joints, this study employed hip joint wear simulations and experimental wear testing on hip joint specimens to investigate the impact of different contact surface parameters on the wear of ceramic–titanium alloy articulating surfaces. The objective was to provide guidance for joint surface treatment to minimize wear. The simulation results demonstrated that the contacting surfaces of the articulating components exhibited a crescent-shaped surface composition before and after wear. The initial variation in the surface friction coefficient had minimal influence on the wear rate after stabilization, whereas excessively high friction coefficients led to erratic changes in wear depth. Based on the simulation results, experimental research was conducted to compare the wear results of different surface roughness values ranging from 60 to 550 nm. The findings revealed that a surface roughness of 150 nm exhibited the least amount of wear and the best anti-wear performance. Furthermore, an exploration of the mechanism behind the influence of different surface friction coefficients on the wear of the articulating surfaces provided valuable insights for surface processing and wear analysis of artificial joints.

Porous cellulose aerogels with different compositions have been fabricated via three methods, including regular freezing, directional freezing, and hydrothermal treatment, using pure cellulose oxide and cellulose oxide/graphite oxide composites, respectively. The cellulose aerogels are highly elastic and light in weight. The carbon aerogels show an ordered structure through directional freezing with layered skeleton bones and some folds. Unlike low-temperature freezing, the structures can obtain elastic properties. When the deformation is 20%, carbon aerogels can rebound to 95% of their original volume. The cellulose oxide/graphite oxide composite aerogels are synthesized into carbon–aerogel composites, which also have stable and robust structures of bone skeletons due to nanosheets. The carbon–aerogel composites have more than 85% resilience under 40% deformations. Carbon aerogels prepared from nanocelluloses have a novel three-dimensional network structure and have the application of elasticity, which is expected to be applied to metallurgical technology and the aerospace field. Through directional freezing, the carbon aerogels have regular structures of layered skeleton bones with some folds. In contrast to low-temperature freezing, the structures possess excellent elastic properties.

Electrochemical impedance spectroscopy (EIS) is a widely used method for monitoring coatings because it can be done in situ and causes little damage to the coating. However, interpreting the impedance data from coatings in order to determine the state of the coating and its protective abilities is challenging. A modified version of the rapid electrochemical assessment of paint (REAP) equivalent circuit is developed here, along with a method to calculate the impedance of a circuit using matrix algebra. This new equivalent circuit and the calculation method are used to analyze EIS data obtained from a two-layer commercial organic coating system immersed in NaCl solutions with different concentrations and at different temperatures. The matrix calculation method is validated by comparing results obtained from commercial analysis software to this method for two different equivalent circuits, and the parameter values are nearly equal. Physics-based models of the equivalent circuit elements are derived and used to obtain both initial estimates for the regressions and physics-based constraints on the model parameters. These models are integrated into the regression procedure, and the corrected Akaike information criterion (AICc) is used to compare fits between the new circuit and classic equivalent circuits. The AICc values indicate the new circuit results in better fits than classic equivalent circuits used for coatings analysis.

The known ferrocenyl-containing silicone materials have redox activity and electrical conductivity at the level of antistatic materials, but they are incapable of self-healing due to their irreversible cross-linking, which significantly reduces their application area. The development of novel self-healing ferrocenyl-containing silicone rubbers (FSRs) is a promising area of research that extends the possibilities of their application as protective coatings. In this work, a new method was developed to synthesize FSRs with different ferrocenyl unit content (25 and 50 mol.%) by anionic copolymerization of cyclic octamethylcyclotetrasiloxane (D4), cyclic tetraferrocenyl-substituted 1,3,5,7-tetramethyltetrasiloxane (Fc4D4), and bicyclic cross-linking agent (bis-D4). The optimal concentrations of the cross-linking agent and ferrocenyl-substituted unit content for FSRs are 5 wt.% and 25 mol.%, respectively. The FSRs exhibit tensile strength and elongation at break up to 0.1 MPa and 215%. The FSRs possess both self-healing at room and/or elevated temperatures (100 °C) and redox activity (Fc/Fc+ transformations at E0 = 0.43 V) and conductivity at the antistatic level (ca. 10–10–10–11 S·cm–1). The thermal properties of the FSRs were studied. The proposed approach is relevant for the creation of new functional silicone materials as flexible, self-healing, and antistatic protective coatings.

Some unavoidable factors in the operating environment could damage single-crystal components of nickel-based single-crystal superalloys. This work prepared an epitaxial growth NiCoCrAlYTa repaired coating without the columnar-to-equiaxed transition (CET) phenomenon on a nickel-based single-crystal superalloy by electron beam cladding. The microstructure of two cross-sections and two surfaces at different depths were characterized. Moreover, the formation mechanism of coating dendrite was revealed by studying the relationship between coating dendrite size, growth direction, and solidification rate. The microstructure evolution and crystal growth orientation of the coating were investigated. The microstructural investigation of the sample revealed that the dendrites’ orientations on the coating’s horizontal section were different, and its characteristics were highly visible on the surface of the coating. The crystal growth orientations of the coating on the vertical cross-section parallel/perpendicular to the scanning direction of the electron beam were also different. Moreover, the average primary dendrite arm spacing (PDAS) of the columnar dendrite in the different areas of the coating was different and increased from 2 μm to 4 μm. The oxidation resistance of the coating at 1000 °C was about three times higher than that of the substrate.

We report on the photo-mobility properties of a free standing large area graphene oxide (GO) paper (GOP). The thickness of the film is ≈20 μm. GOP is made by drop casting an aqueous suspension of GO on a microscope glass slide placed on a hot plate kept at the temperature of 70 °C. The film is peeled-off from the glass substrate and irradiated under different coherent and incoherent light sources. The film bends up to ≈55° when the irradiation is made using a near infra-red (NIR) incoherent incandescent lamp and returns back to the initial position when the NIR lamp is switched-off. The bending mechanism is attributed to the asymmetry of the GOP film obtained during the film formation process. We characterize the film morphology and structure using a Scanning Electron Microscopy (SEM) imaging and X-ray Diffraction (XRD) measurements, respectively. Remarkable differences between the two surfaces of the GOP are evidenced, both on a macroscopic length scale (surface roughness) and on a microscopic one (GO interlayer distance). This asymmetry results in different (negative) thermal expansion coefficients for the two film surfaces and hence in the bending of the film when the film temperature is increased by light absorption.

Ni-Cr-Si-alloy-cladding layers with Si contents of 0 wt.%, 1 wt.%, 3 wt.% and 5 wt.% were prepared via a laser-cladding technique, and the effect of Si content on the high-temperature corrosion resistance of the Ni-20Cr-Si-alloy-cladding layers in NaCl-KCl-K2SO4-Na2SO4 mixed salt was systematically investigated. The results show that at 600 °C, the four cladding layers rely mainly on the generation of dense Cr2O3 on the surface to hinder the continuation of corrosion. The addition of Si helps to improve the stability of Cr2O3 in the mixed salt, and on the other hand Si is enriched in the corrosion layer, which can effectively hinder the penetration of the corrosive medium. The addition of Si can effectively improve the high-temperature corrosion resistance of the Ni-20Cr-cladding layer, whereas the corrosion product layer is prone to spalling when the Si content is ≥3 wt.%. The best corrosion resistance was demonstrated by Ni-20Cr-1Si in NaCl-KCl-K2SO4-Na2SO4 mixed salt.