Abstract In this study, ZnCo2O4/Ag3PO4 composite catalyst was prepared by the precipitation method, and their performance in the photocatalytic degradation of methyl orange (MO) was studied. The catalysts were characterized by scanning electron microscopy, high‐resolution transmission electron microscopy, X‐ray diffraction, energy‐dispersive X‐ray spectroscopy, selected area electron diffraction, X‐ray photoelectron spectroscopy, and UV‐Vis diffuse reflectance spectroscopy. The results indicate that the 0.1 ZnCo2O4/Ag3PO4 composite system has good photocatalytic activity in the degradation of methyl orange. Under simulated sunlight conditions, the degradation rate can reach 94% after 30 min. The maximum reaction rate constant of 0.1 ZnCo2O4/Ag3PO4 was 0.05301 min−1, which is 3 times and 52 times the rate constant of pure Ag3PO4 and pure ZnCo2O4, respectively. In catalyst recycling experiments, 0.1 ZnCo2O4/Ag3PO4 still degraded methyl orange at a rate of 84.4% after three cycles. Trapping experiments showed that holes and superoxide radicals mostly contributed to the photocatalytic degradation of methyl orange by the catalyst, while hydroxyl radicals played a partial role. The energy level structure of ZnCo2O4/Ag3PO4 is conducive to the effective separation of photogenerated electrons and holes, improving the lifespan of photogenerated charges. In the investigated catalyst series, 0.1 ZnCo2O4/Ag3PO4 demonstrated the best photocatalytic performance.

Abstract The paper proposes a single antenna that can generate dual‐mode plane spiral orbital angular momentum (PS‐OAM) beams. Six Vivaldi antennas placed in a tangential circular array make up the antenna, and the antenna is etched onto a substrate material and has a flat design, allowing for easy integration with other system components. The neighbouring ports of the antenna elements have phase differences, so phase‐shifting in the feeding network is unnecessary. When fed with the same phase and amplitude, the antenna can produce PS‐OAM beams with mode +1 at 7 GHz and mode +2 at 14 GHz, and the measured purity is 80.6% and 63%, respectively. The method may provide a new way to produce multi‐mode orbital angular momentum.

Abstract The tribological behaviors of nanoparticles (NPs) have attracted widespread attention in the fields of nano‐lubrication and ultra‐precision manufacturing. The frictional and dynamic behaviors of SiO 2 NPs acting with the single asperity were studied on silicon surface utilizing atomic force microscope. The friction forces of NPs, both static and kinetic, exhibit an initial decrease followed by an increase as the normal load increases (0–300 nN). The nonmonotonic load‐dependence of friction behavior corresponds to the dynamic transformation of “sliding‐rolling‐sliding” motion state of the manipulated NPs, which can be predicted by a Double‐Hertz model and further confirmed by nanoindentation‐marked NPs. This research has a significant implication for regulating dynamic behaviors of NPs in contemporary three‐body abrasive tribology.

Abstract Multi‐walled carbon nanotubes (MWCNTs) were successfully synthesized and functionalized by chemical vapour deposition and acid reflux methods, respectively. Chitosan (CTS) was prepared by a chemical extraction method from waste prawn shells. Various weight fractions of functionalized multi‐walled carbon nanotubes (f‐MWCNTs) have been used as reinforcing agent in CTS biopolymer matrix. Fourier transform infrared spectroscopy analysis was done, which confirms the presence of absorption bands of the various functional groups of chitin, CTS, and MWCNTs. Raman spectra revealed the quality of MWCNTs, the extent of their functionalization, and the quality of nanocomposites. The X‐ray diffraction analysis showed the distinctive peaks for f‐MWCNTs’ and also revealed the formation of CTS/f‐MWCNTs nanocomposites. Transmission Electron Microscopy (TEM) analysis also exhibited that the CTS/f‐MWCNTs nanoparticles have a well‐defined crystalline structure. The highest coercivity and magnetization (Ms) of the CTS/5%f‐MWCNTs nanocomposite are 602 Oe and 0.1202 emu/g, respectively that have been enhanced by 3.83 and 5.27 times compared to the pure CTS respectively. It showed that the conductivity is getting higher with the addition of f‐MWCNTs in the CTS matrix. CTS/5% f‐MWCNTs composites exhibit the highest conductivity than other composites and the conductivity of CTS/5% f‐MWCNTs composite is 4.0×10−4 S/m.

Abstract Micro‐electro‐mechanical system gyroscope detection output is susceptible to drift due to ambient temperature variations. Furthermore, the drive‐mode vibration amplitude is affected by the signal pickup circuit and structural parameters, which significantly influence the temperature drift of the bias and scale factor (SF). This study proposes a vibration amplitude control method based on harmonic amplitude sideband‐ratio (SBR), namely SBR‐AGC, which characterizes the vibration amplitude using the harmonic amplitude ratio of the vibrational electrical signal. The constancy of vibration amplitude is maintained via closed‐loop control to suppress bias and SF temperature drift. The experimental results on cobweb‐like disk resonator gyroscope reveal that the temperature coefficient of bias in the SBR‐AGC mode lies within −20 to 60°C and decreases by 36%, and the temperature coefficient of the SF lies within −10 to 50°C and decreases by 49.7%. Therefore, the environmental adaptability of the gyroscope is effectively improved.

Abstract In this investigation, a nanostructured Cu 2 O thin film absorber layer is electrodeposited, exploring the impact of varying negative applied voltages and deposition time. Notably, the Cu 2 O thin film demonstrated optimal absorbance at −0.95 V, contrasting sharply with a minimum at −0.97 V. The authors' findings underscore that the peak absorbance was achieved at −0.95 V, coinciding with the lowest transmittance observed after 80 min of deposition, aligning with a maximal absorption coefficient of 21 × 10 3 cm −1 . At a deposition time of 5 min, the Cu 2 O thin film exhibited a noteworthy maximum Urbach energy of 2.00 eV and a minimum steepness parameter of 0.013. In contrast, the lowest Urbach energy was recorded at 0.34 eV, with the highest steepness parameter occurring at an applied voltage of 0.93 V. Furthermore, this study revealed a gradual increase in the refractive index with higher applied voltages, reaching its pinnacle at −1.5 V. These results collectively emphasize the nuanced interplay between applied voltage, deposition time and the optical properties of the nanostructured Cu 2 O thin film. The observed trends hold significant implications for optimizing the performance of thin film absorber layers, particularly in the context of enhancing absorbance and tailoring optical characteristics for specific applications.

Abstract Here, the authors report a practical method for preparing nitrogen‐doped carbon materials using an orthogonal array design. The material with the highest specific capacitance value of 262 F·g−1 at a current density of 1 A·g−1 was obtained under the conditions (KOH as activation agent, activation temperature of 600°C, activation time of 3 h, respectively). Its high electrochemical properties are attributed to its high surface area and additional pseudo‐capacitance. After 5000 cycles, the specific capacitance remained 92.8%, with good cycle stability. Textural characterization of the carbon materials was performed using N2 adsorption/desorption and scanning electron microscopy.

Abstract The squeeze‐film damping (SQFD) is an important dissipation mechanism of Micro‐Electro‐Mechanical Systems resonators. The current SQFD models of perforated plates treat borders of plate and holes as the constant pressure boundary, without considering border effect. In this paper, the border effect on SQFD is studied by expanding simulation area. At the same time, based on the research of non‐perforated plate border effect, the calculation size of the perforated plate hole cell is modified, and the modified SQFD model of the perforated plate has been built. Compared with simulation results, it shows the border effect has a great influence on SQFD of perforated plate. The precision of the modified model is higher than that of recent models. For a rectangular plate, the maximum error of the modified model is 12%, while for the recent model it is 40%. For a circular plate, the modified model is 38%, while the recent model is 58%.

Abstract Silica‐aluminium composite powders are important precursors for the preparation of sealant coatings by supersonic flame spraying. Micron‐scale silica‐aluminium composite powders can be prepared using a planetary ball mill, but powder agglomeration often leads to composite failure. Using relevant modelling software to build the 3D modelling of the ball mill jar, which based on the discrete element method, using the Hertz–Mindlin contact model and after specifying the simulation boundary conditions, the ball mill process was simulated and analysed. Visualise the influence of important process parameters such as frequency, size and diameter of milling balls and ball‐to‐powder weight ratio, and systematically analyse the microscopic morphology and composite condition of the agglomerated and dispersed powders. The results show that the ball motion during the ball milling process is mainly divided into three representative types: ball–ball impact, ball crushing motion against the jar wall and ball–wall impact. The energy transfer efficiency of the milling balls to the powder system is highest when the ratio of the three types of motion is uniform. SEM images and EDS spectra showed that the aluminium powder was sufficiently crushed, with an average particle size below 1 μm. The aluminium powder was uniformly distributed on the surface of the silicon powder, and the particle size of the composite silicon aggregates was sufficiently reduced.