Students' academic achievement relies on a variety of pedagogical, affective, and individual factors. The investigation of academic emotions and epistemic cognition has been a focal point in existing research. Previous studies have predominantly delved into the essence of students' epistemic cognition and academic emotions. Nonetheless, the correlation between the epistemic cognition, academic emotions, and academic success of Chinese undergraduate students remains inadequately explored. This research delves into the interconnectedness of these variables and examines which facets of epistemic cognition and academic emotions can forecast students' academic performance. A total of three hundred and eighty (380) Chinese undergraduate students were chosen via random sampling for this study. Their self-reported academic achievements were taken into account. Additionally, they completed questionnaires tailored to evaluate their epistemic cognition and academic emotions. The participants' scores underwent Pearson correlation and multiple regression analyses. The findings indicate that positive emotions correlate positively, while negative emotions correlate negatively with students' academic success. Furthermore, positive emotions and three categories of epistemic cognition were found to be predictors of students' academic accomplishments. In conclusion, it is deduced that both epistemic cognition and positive emotions play a role in enhancing students' academic success. The implications of these findings extend to educational psychologists, educators, and students, both theoretically and practically.

Core–shell composites with strong weather resistance, mechanical strength and creep resistance can be prepared using co-extrusion technology. Considering the weak bonding strength between core–shell interfaces, this study started from the concept of a mortise and tenon combination; three types of conical, rectangular and trapezoidal mortise and tenon joints were prepared, and their bending properties, long-term creep properties, interfacial bonding properties, and dimensional stability properties were tested. Results showed that the mortise and tenon structure could form a mechanical interlock between the outer-shell-layer polyvinyl chloride (PVC) wood–plastic composite (WPVC) and the inner-core-layer laminated veneer lumber (LVL), which could effectively improve the interface bonding property between the two layers. Among them, the trapezoidal mortise and tenon structure had the largest interface bonding force compared with the tapered and rectangular mortise and tenon structure, where the interface bonding strength reached 1.01 MPa. Excellent interface bonding can effectively transfer and disperse stress, so the trapezoidal mortise and tenon structure had the best bending properties and creep resistance, with a bending strength of 59.54 MPa and a bending modulus of 5.56 GPa. In the long-term creep test, the deformation was also the smallest at about 0.2%, and its bending properties, creep resistance and interface bonding performance were also the best. The bending strength was 59.54 MPa and the bending modulus was 5.56 GPa; in the long-term creep test, the strain curve was the lowest, about 0.2%. In addition, the mortise and tenon structure could disperse the stress of the inner shell LVL after water absorption and expansion, thus significantly improving the dimensional stability of the co-extruded composite after water absorption.