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The effects of mixed culture fermentation with yeast, Lactobacillus bulgaricus and Streptococcus thermophilus on the quality of non-fried instant noodles were studied by rehydration test, texture analysis, electronic nose analysis and scanning electron microscopic (SEM) observation. The results showed that yeast largely affected the rehydration property and texture, while L. bulgaricus and S. thermophilus were mainly responsible for improving the flavor of non-fried instant noodles. The primary fermentation process was conducive to maintaining the cooking tolerance of non-fried instant noodles, while the secondary fermentation process was beneficial to improve the rehydration property and flavor, reducing the rehydration time to 4.0 min; the R(2) and R(7) responses of the rehydrated sample were 2.8 and 2.9, respectively. The SEM results showed that the samples had a uniform pore distribution after the secondary fermentation. Taken collectively, the optimal starter culture for the primary and secondary fermentation was 1.5% yeast + 0.075% L. bulgaricus + 0.075% S. thermophilus.

Abstract In power electronic systems, when a power device turns on by mistake, there would be at least two devices in the short‐circuit (SC) current loop, forming series short‐circuit (SSC) fault. In this paper, the dynamic characteristics of SiC MOSFETs, Si IGBTs in SSC are investigated based on the half‐bridge circuit. The effect laws of load current and junction temperature to voltage division in SSC are discussed. Taking a three‐level (3‐L) active neutral point clamped (ANPC) topology based on hybrid utilization of Si IGBT and SiC MOSFET as the research object, the SSC performance is investigated. The theoretical and experimental results show that, in the process of SSC, the voltage division features of SiC MOSFETs and Si IGBTs are different and highly sensitive to circuit parameters. When both SiC MOSFET and Si IGBT are in the SC current loop, the device with a lower saturation current level limits the short circuit current and bears most of the dc‐bus voltage. Moreover, in the Si/SiC hybrid 3‐L ANPC topology, if the saturation current of selected SiC MOSFETs is higher than that of Si IGBTs, the SC withstanding level of SiC MOSFETs could be improved, thereby reducing the SC protection circuit requirements.

Phase-structured light beams carrying orbital angular momentum (OAM) have a wide range of applications ranging from particle trapping to optical communication. Many techniques exist to generate and manipulate such beams but most suffer from bulky configurations. In contrast, silicon photonics enables the integration of various functional components on a monolithic platform, providing a way to miniaturize optical systems to chip level. Here, we propose a series of on-chip subwavelength holographic waveguide structures that can convert the in-plane guided modes into desired wavefronts and realize complex free-space functions, including the generation of complex phase-structured light beams, arbitrarily directed vortex beam emission and vortex beam focusing. We use a holographic approach to design subwavelength holographic surface gratings, and demonstrate broadband generation of Laguerre–Gaussian (LG) and linearly polarized (LP) modes. Moreover, by assigning appropriate geometric phase profiles to the spiral phase distribution, the off-chip vortex beam manipulation including arbitrarily directed emission and beam focusing scenarios can be realized. In the experiment, directed vortex beam emission is realized by using a fabricated tilt subwavelength holographic fork grating. The proposed waveguide structures enrich the functionalities of dielectric meta-waveguide structures, which can find potential applications in optical communication, optical trapping, nonlinear interaction and imaging.

Wireless power transfer （WPT） has become a hot issue in the electric vehicle industry. However， the misalignment between the primary and secondary coils of the WPT magnetic coupler may decrease its efficiency. Therefore， this paper presents a WPT magnetic coupler with a movable intermediate coil to improve the anti-misalignment capacity of the system. First， the effect of the relay coil compensation capacitor on the efficiency of the magnetic coupler is analyzed， and the relay coil compensation capacitance at the maximum efficiency is decided. Then， the efficiency of the magnetic coupler under various misalignments of the secondary coil and relay coil is simulated and analyzed to conclude the optimal compensation parameter and the most favorable location of the relay coil. Finally， the proposed magnetic coupler and relay coil position control strategy is experimentally verified through a 3-kW prototype. The results show that with the optimal relay coil position， the efficiency of the magnetic coupler decreases by 1.8% when the horizontal misalignment of the secondary coil reaches up to 43% of the coil’s outer diameter （300 mm）.

Accumulating evidence indicates that ER-phagy serves as a key adaptive regulatory mechanism in response to various stress conditions. However, the exact mechanisms underlying ER-phagy in the pathogenesis of intervertebral disc degeneration remain largely unclear. In the present study, we demonstrated that RETREG1-mediated ER-phagy is induced by glucose deprivation (GD) treatment, along with ER stress activation and cell function decline. Importantly, ER-phagy was shown to be crucial for cell survival under GD conditions. Furthermore, ER stress was suggested as an upstream event of ER-phagy upon GD treatment and upregulation of ER-phagy could counteract the ER stress response. Therefore, our findings indicate that RETREG1-mediated ER-phagy activation protects against GD treatment-induced cell injury via modulating ER stress in human nucleus pulposus cells.

Uranium plant wastewater was treated in laboratory scale experiments by employing zero valent iron powder. Batch experiments conducted by the response surface methodology (RSM) proved significant decrease in concentrations of uranium due to a decrease in an oxidation-reduction potential and an increase in pH relative to an application of zero valent iron powder. Results indicated that it is effective on the removal of uranium from uranium plant wastewater with the uranium concentration of 2772.23 μg/L due to the adding of zero valent iron powder. it was found that the scope of pH is widely from 3 to 5 from the experimental data obtained in this study. The predicted model obtained from response surface methodology is in accordance with experimental results.

Response surface methodology (RSM) and Box-Behnken design (BBD) were applied to experiment optimization of microwave drying zinc oxide leach residues (ZOLR). The effects of different factors involving temperature, drying time, material mass, material thickness and their interaction on moisture content and dehydration rate of ZOLR were investigated. Two second-order polynomial models for moisture content and dehydration rate of ZOLR were established by multivariate regression analysis. Analysis of variance shows that all independent variable and quadratic terms of the four factors have significant influence on moisture content and dehydration rate of ZOLR. The optimum drying conditions are as follows: temperature is 93.41°C, drying time is 15.9 min, sample mass is 77.91 g and material thickness is 17 mm. The predicted values of moisture content and dehydration rate were 10.98% and 1 g/min, which were close to experimental values 11±0.03% and 1±0.01 g/min under the optimal conditions. Infrared spectra analysis show that no chemical reactions took place in the process of microwave dying ZOLR and only a part of the absorbed water was removed in the sample.

An analytical approach is proposed to optimize the thickness of petroleum coke for achieving maximum microwave power absorption in microwave heating based on analysis of reflection loss (RL). The microwave RL of the petroleum coke layer was studied over the moisture content range of 1%–5% at 20 °C and the petroleum coke (10% moisture content) in the temperature range of 20 to 100 °C at 2.45 GHz. The results show that RL depends sensitively on the thickness of the petroleum coke and the absorption peak shifts towards a larger thickness as the moisture content of the petroleum coke increases. There exists a matching thickness corresponding to the maximum microwave absorption, the maximum absorbing peak decreases when the thickness of petroleum coke exceeds the matching thickness. We also show that the absorption peak is found to move towards a smaller thickness region with increasing petroleum coke temperature.

Abstract The Na0.5Bi0.5TiO3(NBT) thin films sandwiched between Au electrodes and fluorine-doped tin oxide (FTO) conducting glass were deposited using a sol–gel method. Based on electrochemical workstation measurements, reproducible resistance switching characteristics and negative differential resistances were obtained at room temperature. A local impedance spectroscopy measurement of Au/NBT was performed to reveal the interface-related electrical characteristics. The DC-bias-dependent impedance spectra suggested the occurrence of charge and mass transfer at the interface of the Au/NBT/FTO device. It was proposed that the first and the second ionization of oxygen vacancies are responsible for the conduction in the low- and high-resistance states, respectively. The experimental results showed high potential for nonvolatile memory applications in NBT thin films.