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Metacognition is important in self-regulated learning and understanding its epistemic network can improve teaching and learning. We collected self-reported metacognition reflections on collaborative learning activities from 87 college students to analyze how students' metacognitive patterns differ by performance level and discipline type. We used an epistemic network analysis to identify these differences, and the results indicated that description of goals appeared most in self-reported reflections. There are variations in metacognitive patterns between different groups. High-score students had stronger connections around actions, while low-score students had stronger connections between metacognitive knowledge and context. The natural science students focused more on metacognitive knowledge and actions, while the humanities science students focused more on metacognitive experience and context. This implies that teachers should provide clear explanations about the collaborative learning goal, and a group strategy that takes both performance and discipline types into consideration could address the variation in metacognitive patterns. • Students' metacognitive patterns were investigated through self-report reflections. • Epistemic network analysis was used to compare the metacognition differences between different groups. • Students use most of their energy on thinking about learning goals in metacognitive process. • Different groups (performance, discipline) have different metacognitive patterns in collaborative learning. [ABSTRACT FROM AUTHOR]

To achieve high flow hydrogen production, a laminated self-thermal methanol reforming microreactor was designed. Through simulation and experiments, the hydrogen production performance of the microreactor and the compatibility between the methanol catalytic combustion module and the methanol steam reforming module were investigated. The results show that the microreactor exhibits impressive hydrogen production performance, with a methanol conversion rate of 95.27%. When the inlet flow rate of the mixture of methanol and deionized water was increased to a high flow rate, the microreactor exhibits significant cold spots over a wide range in the reaction chamber plates, which could be effectively solved by enhancing the methanol catalytic combustion intensity. The methanol catalytic combustion module inside the microreactor can meet the heat demand of the methanol reforming module. The microreactor operated for 20 h with a methanol-deionized water mixture inlet flow rate of 12 mL/min and a methanol inlet flow rate of 7.5 mL/min; the methanol conversion rate finally stabilized at 90.1%, which was decreased by about 2.2% compared with the initial methanol conversion rate. • Laminated self-thermal methanol steam reforming microreactor was designed with a maximum hydrogen flow rate of 10 L/min. • Thermal matching of methanol catalytic combustion reaction and methanol reforming reaction gained explored. • Methanol conversion rate was improved from 58.6% to 91.2% at the inlet flow rate of methanol of 7.5 mL/min. [ABSTRACT FROM AUTHOR]

A traveling-wave flow field is established and investigated for the performance improvement effect of proton exchange membrane fuel cell (PEMFC). This study analyzes the influence of multiple structural parameters of traveling-wave length, wave height, wave number, and wave spacing on the flow law, mass transfer characteristics, and output performance of PEMFC, and obtains the weight coefficient of each structural parameter through the Grey-relational theory. Simulation results show that the traveling-wave flow field has excellent oxygen transport and drainage functions, and its corresponding functional structures are wave crest and wave trough respectively. Compared with the conventional flow field (CFF), the effective mass transfer coefficient (EMTC) at the BPP/GDL interface can be increased about 35.89–118%, and the drainage at the BPP/GDL interface can be increased about 0.9–2.24%, and the net power density of the PEMFC can be increased about 4.45–11.17% of the PEMFC with traveling-wave flow field. In addition, the weighting relationship of the traveling-wave structural parameters on the mass transfer performance and net power density is wave height > wave number > wave length > wave spacing. • Flow field with a traveling-wave structure for PEMFC is designed. • Effects of traveling-wave structural parameters on the PEMFC performance are investigated. • Increasing the height of the traveling-wave has a significant impact on the PEMFC performance. • Mass transfer coefficient of a traveling-wave flow field can be increased about 35.89–118%. • Net power density of the PEMFC achieves an improvement between 4.45% and 11.17%. [ABSTRACT FROM AUTHOR]

To obtain the flexible microreactor for potential application in constrained space, a novel flexible tubular microreactor was designed by using a corrugated shell and a high porosity porous copper fiber rod (PCFR) as catalyst support. The effect of placement position, bending direction, and bending angle on reaction performance of flexible tubular microreactor was investigated. Then, the stability of flexible tubular microreactor was further evaluated. The experimental results showed that the placement position and bending direction had a significant influence on the reaction performance of flexible tubular microreactor. Methanol conversion of flexible tubular microreactor with the vertical placement was 6.67% higher than that with horizontal placement. Higher methanol conversion and H 2 flow rate were obtained when the microreactor bent along the vertical direction. The reaction performance of flexible tubular microreactor was found to decrease as the bending angle increased, and the methanol conversion decreased by around 14.07% with a bend of 90°. When the flexible tubular microreactor was horizontal placed with a bend of 60° in the vertical direction, the reaction performance of microreactor was not changed little after 20 cyclic bending. After continuous bending for 10 h, the methanol conversion and H 2 flow rate of flexible tubular microreactor were 70.58% and 0.88 mol/h, showing good reaction performance. • A novel flexible tubular microreactor was developed. • A high porosity porous copper fiber rod as catalyst support was designed. • Effect of factors on reaction performance of the microreactor was investigated. • Microreactor exhibited better hydrogen production performance under different bending conditions. [ABSTRACT FROM AUTHOR]

As one of the critical components of the proton exchange membrane fuel cell (PEMFC), the flow channel design in the bipolar plate is crucial to improve the mass transfer performance and stability. In this study, the effect of the structural characteristics and location arrangement of traveling wave flow channels, with a concave surface as the mass transfer surface, on the fuel cell performance is investigated, and the evaluation indexes, such as oxygen mass flux, net power density, synergistic coefficient, and unevenness coefficient, are established to evaluate the flow law of fluid, distribution law of pressure, synergistic mass transfer, and performance stability of the fuel cell. Results show that the synergistic mass transfer performance is better in the traveling wave channels with identical structural characteristics and uniform arrangement. Furthermore, a 21.20 % increase in the average fluid flow velocity can enhance oxygen and liquid water flux at the bipolar plate (BP)/gas diffusion layer (GDL) interfaces by about 198.48 % and 207.94 %, respectively, resulting in an 87.13 % increase in net power density and 70.95 % improvement in the performance stability of the fuel cell. • Multiple traveling wave flow channels with a concave surface are verified. • A Novel evaluation method for mass transfer and performance stability is established. • Traveling wave channel of Model 1 has the best synergistic mass transfer performance. • Efficiency of oxygen mass transfer improved by about 198.48 %. • Stability of output power increased by approximately 70.95 %. [ABSTRACT FROM AUTHOR]

Abstract An optimised 1,8-cineole-loaded self-microemulsifying drug delivery system (CIN-SMEDDS) with a mean droplet size, polydispersity index, mean zeta potential and encapsulation efficiency of 38.14 ± 1.47 nm, 0.208 ± 0.036, −9.312 ± 1.764 mV and 95.35% ± 1.13%, respectively, successfully ameliorated the lipopolysaccharide (LPS)-induced endothelial injury in mice. Acute toxicity assay in mice through the oral administration of CIN-SMEDDS showed that the median lethal dose of CIN-SMEDDS was 2998.9 mg/kg. The results of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay indicated that the cytotoxicity of CIN-SMEDDS to Caco-2 cells may be ascribed to the surfactant/co-surfactant mixture. In particular, CIN-SMEDDS remarkably inhibited inflammatory cytokines IL-1β, IL-6 and IL-8 with a simultaneous increase in IL-10 in LPS-treated mice. Haematoxylin-eosin staining results showed that CIN-SMEDDS attenuated LPS-induced vascular endothelial injury. Western blot results showed that the vascular protective effects of CIN-SMEDDS were associated with the NF-κB and peroxisome proliferator-activated receptor γ signalling pathways. These findings indicated that CIN-SMEDDS can attenuate LPS-induced endothelial injury and thus was proposed as a promising agent for the treatment of inflammatory cardiovascular disease. [ABSTRACT FROM AUTHOR]

While virtual reality (VR) provides a great potential for musical instrument learning, little attention has been paid to the instructional design in creating a VR musical instrument. Previous research has suggested that high embodied interaction or added visual cues (e.g., distinctive colors, flashing areas) on VR-based musical instrument may aid students' learning. In this study, we investigated the feasibility and efficacy of the embodied design (low and high level of embodiment; LoEmb and HiEmb) and visual cues (low and high level of visual cues; LoViz and HiViz) on students' musical instrument learning. Four corresponding virtual Chinese dulcimers (Yangqin) were thereby designed. A sample of 112 university students participated in our study, and they were randomly assigned into the four conditions (LoEmb & LoViz, LoEmb & HiViz, HiEmb & LoViz, and HiEmb & HiViz). Results showed that the LoEmb design benefited students' completion rate, the HiViz improved students' playing rhythmic accuracy. Both LoEmb and HiViz decreased students' playing errors and improved their overall performance. Moreover, we found that the HiViz and HiEmb designs had a combined effect on reducing students' cognitive load and improving the instructional efficiency of learning material. These findings collectively reveal that the design of VR learning materials should carefully consider the trade-off between the level of embodiment and visual cues. • The effect of embodiment and visual cues was investigated in musical instrument learning. • The LoEmb design benefited students' musical playing completion rate, and the HiViz facilitated students' playing rhythm. • Both LoEmb and HiViz decreased students' playing errors and improved their overall performance. • HiViz and HiEmb design can reduce students' cognitive load and improve the instructional efficiency of learning material. • Designing a VR learning material should carefully consider the trade-off between the level of embodiment and visual cues. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mechanism of performance uniformity of the PEMFC stack is explored. • Novel evaluation method for the performance uniformity is established. • Power density of the PEMFC achieves an improvement between 4.78% and 15.44%. • Performance uniformity can be increased about 29.95–66.94%. The performance uniformity of the proton-exchange membrane fuel cell (PEMFC) stack depends sensitively on the operating parameters. In this work, the dispersion of performance across the cells is explored through experiments and simulations, and the effects of operating conditions on the performance uniformity are evaluated using a novel criterion. According to the results, operating conditions such as stoichiometric ratio (SR), back pressure (P B), dew point temperature (T D), and heating temperature (T H) have a great influence on the performance uniformity and determine the content of liquid-saturated water and the uniformity of oxygen distribution at the catalytic layer (CL)/gas diffusion layer (GDL) interface of fuel cell. Further research shows that decreasing the content of liquid-saturated water and increasing the uniformity of oxygen distribution can improve the output performance stability, while increasing the oxygen content can improve the output performance of the PEMFC stack. What's more, when the stoichiometric ratio (SR), back pressure (P B), dew point temperature (T D), and heating temperature (T H) are 2.0, 3.0, 0.7 bar, 0.6 bar, 343 K, 333 K, and 348 K, respectively, the performance uniformity of the PEMFC stack achieves the best. [ABSTRACT FROM AUTHOR]