The COVID-19 pandemic has created a fundamental shift in the Chinese education system, which has compelled teachers and students to accommodate the process of online learning in a short period of time. Accompanied by the advancement of information technology and the emergence of small private online courses (SPOCs), a variety of online programs containing a wealth of new materials and novel pedagogical approaches have emerged. However, there is a lack of awareness among researchers about the efficacy of utilizing shared SPOCs in teaching at conventional universities. Flipped classroom model (FCM) can make up for this defect. This study aims to investigate the effectiveness of flipped learning on the basis of SPOC and to suggest explicit criteria for its reuse in conventional college education. We carried out a quasi-experiment in a course on inorganic chemistry and examined findings with regard to the engagement and performance of the learners. We also conducted a post-task questionnaire and interviews to examine the experiences of the students so that those experiences could be incorporated into the design and study plan for flipped learning based on SPOCs. It was shown that the average performance of students in the flipped SPOC-based classroom was superior to that of students in the traditional classroom. Furthermore, the combination of quantitative and qualitative data showed that the majority of students experienced the flipped classroom favorably regarding student interaction, accessible learning resources, and proactive academic outcomes.

A series of Al-doped ZnO (AZO) structures, including disk-like, flake-like, flower-like and dumbbell-like morphologies, have been synthesized by a hydrothermal method without any catalyst or template. The morphologies of these AZO structures can be conveniently controlled, by selecting the additives and controlling the experimental conditions, and the result has excellent reproducibility. Gas sensors based on AZO were fabricated and the gas sensing properties were investigated. The sensors showed high response values and reproducible response–recovery for 5–500 ppm ethanol at 332 °C, compared with NH₃, CH₃OH, H₂, CO, HCHO, NO_x and a specific mechanism was proposed.

The escalating issue of phenol-containing wastewater necessitates the development of efficient and sustainable treatment methods. In this context, we present a novel composite photocatalyst comprising ZnFe₂O₄ (ZFO) nanoparticles supported on nanocellulose (NC), aimed at addressing this environmental challenge. The synthesis involved a facile hydrothermal method followed by the impregnation of ZFO nanoparticles onto the NC matrix. The morphology and structure of ZFO, NC, and ZFO/NC were investigated by TEM, SEM-EDX, UV–vis, FT-IR, XRD, and XPS analyses. ZFO, as a weakly magnetic semiconductor catalytic material, was utilized in photocatalytic experiments under magnetic field conditions. By controlling the electron spin states through the magnetic field, electron–hole recombination was suppressed, resulting in improved photocatalytic performance. The results demonstrated that 43% and 76% degradation was achieved after 120 min of irradiation due to ZFO and 0.5ZFO/NC treatment. Furthermore, the composite 0.5ZFO/NC demonstrated the highest photocatalytic efficiency, showing promising recyclability by maintaining its activity after three cycles of use. This study underscores the potential of the ZFO/NC composite for sustainable wastewater treatment, offering a promising avenue for environmental remediation.

A large amount of wastewater from various and discharged sources that are not treated in any way could affect properties of both land and water, causing severe problems for the environment. Advanced oxidation processes seem to be a feasible option to address effluent treatment with regard to salvation of the environment. In this work, a CdO/ZnO/Yb₂O₃ composite composed of trimetallic semiconductors was synthesized through a simple one-pot hydrophile approach at low temperatures and then was employed as a photocatalyst. The degradation of phenol, a common organic persistent pollutant in industrial wastewater, was efficiently catalyzed in the presence of simulated sunlight. It was demonstrated that the synthesized CdO/ZnO/Yb₂O₃ photocatalyst was significantly active after 15 min of reaction and facilitated the effective degradation of the phenol. The CdO/ZnO/Yb₂O₃ photocatalyst achieved 71.5% and 97.81% degradation of the phenol without and with the existence of H₂O₂, correspondingly. The results show that the synthesized composite possesses high oxygen reduction capability and is available for rapid and potent photodegradation of the organic persistent pollutants such as phenol, with minimal damage to the environment.

Achieving an optimal balance between cement weight, viscosity, strength, and fluid loss is a persistent challenge in well cementing, especially in oil and gas applications. This study investigates the potential of MgO-PAM (polyacrylamide) nanocomposite as an additive to enhance the performance of Class-G cement. This research introduces a novel application of MgO-PAM nanocomposite in cement modification, addressing critical challenges in durability, viscosity control, and permeability reduction for oil and gas well cementing under extreme conditions. The study represents a unique approach by optimizing the synergy between magnesia nanoparticles and polyacrylamide, achieving significant mechanical and structural improvements not previously demonstrated in this combination. In this study, a base cement was formulated with a 50% water-cement ratio (WCR) and 10% pozzolan, and its properties were compared with modified formulations incorporating either 1 wt% polymer (PC) or 1 wt% nanocomposite (NC). The addition of the polymer and nanocomposite improved the cement slurry’s viscosity by 12% and 14%, respectively, and reduced fluid loss from 122 to 45 mL and 32 mL. Furthermore, the thickening time (time before reaching the slurry viscosity to 100 cp) was extended from 9 h for the base cement to 13 h for the polymer and 14 h for the nanocomposite. Calorimetric results confirmed that the modified cements showed increased hydration energy in the second peak, indicating improved hydration. After curing, the compressive strength of the polymer-modified cement increased by 17% and 19% at 7 and 28 days, respectively, while the nanocomposite cement exhibited even more pronounced improvements of 32% and 35%. Permeability was significantly reduced, with values reaching 0.5 mD, 0.8 mD, and 0.1 mD for the base, polymer, and nanocomposite cement, respectively. Microscopic analysis (SEM) revealed that the nanocomposite-modified cement exhibited a more uniform microstructure with minimal porosity compared to the polymer-modified cement, which showed particle settling and voids. These findings demonstrate the superior performance of the MgO-PAM nanocomposite in improving cement’s mechanical properties, fluid loss control, and long-term durability, providing significant advantages for oil and gas well integrity.