As an efficient reinforcing material in resin matric composites, the application of basalt fibers (BFs) in composites is limited by the poor interfacial adhesion between BFs and the resin matrix. In this study, to obtain the basalt fibers/epoxy resin composites with enhanced mechanical properties, the modification solution containing different concentrations of Lanthanum ions (La³⁺) was synthesized to modify the BFs surfaces to enhance the poor interfacial adhesion between BFs and the matrix. The morphology, the chemical structure and the chemical composition of the modified BFs surface were observed and detected by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, respectively. The results show that, after BFs were soaked in the modification solution, the more active groups (C=O, –OH, C–O, etc.) were introduced to the BFs surfaces and effectively enhanced the bond strength between BFs and the resin matrix. The obtained mechanical performances of prepared basalt fibers/epoxy resin composites showed that the tensile strength, bending strength and interlaminar shear strength (ILSS) were improved with the modified BFs, and reached to 458.7, 556.7 and 16.77 Mpa with the 0.5 wt.% La. Finally, the enhancement mechanism of the modification solution containing La element is analyzed.

The electrospun PVDF fiber membranes with the characteristics of light weight, strong signal and measurability, have been widely applied in the fields of environment, energy sensors and biomedical treatment. Due to the weakness of the piezoelectric and service properties, the conventional PVDF fiber membranes cannot meet the operating requirements. Based on the obtained optimal technological parameter of electrospun pure PVDF fiber membranes (P-PVDF) in the previous experiment (unpublished), three inorganic reinforced substances (AgNO₃, FeCl₃·6H₂O, nanographene) were respectively used to dope and modify PVDF to prepare composite fiber membranes with the better piezoelectric performance. The morphology and crystal structure of the hybrid fiber membranes were observed and detected by scanning electron microscopy and X-ray diffraction, respectively. The results showed that the dopant could effectively promote the formation of β-phase, which can enhance the piezoelectric performance. The mechanical properties test and piezoelectric performance test exhibited that the static flexural strength, the elastic modulus, and the piezoelectric performance were improved with the addition of dopant. In addition, the influence on the addition of dopant and the doping modification mechanism were discussed. Finally, the conclusions showed that the minimum average diameter was obtained with the 0.3 wt% addition of AgNO₃; the piezoelectric performance reached the strongest with the 0.8 wt% addition of FeCl₃·6H₂O; the mechanical properties were best with the 1.0 wt% addition of nanographene.

Graphene’s Dirac point in the band structure and no current switching ratio make it hard to be used in sophisticated logic circuits. The graphene/MoS₂ heterojunction, which opens the Dirac point of graphene, can solve this problem. Based on the first-principles, the most stable monolayer graphene and MoS₂ were obtained through the convergence test. The accuracy of their models was verified. In addition, lattice matching mechanisms, stacking modes, electronic structures, and optical properties of the designed heterojunction structures were calculated. The graphene/MoS₂ heterojunction in a lattice matching way has the lowest relative energy. The band structures of nine heterojunctions were very similar. The maximum bandgap opening of heterojunctions was 14 meV. Compared with MoS₂, its absorption intensity in the visible range improved. The dielectric function of the heterojunction was not zero in the infrared range. It indicated that the absorption of infrared light by the heterojunction was stronger than that by the MoS₂.

The diversified microstructure and complex composition of cast iron affect its friction and wear properties. In this work, three kinds of cylinder liner cast iron with different graphite morphologies were selected to analyse the friction and wear properties. Microstructure effects on tribological properties during friction were investigated by finite element simulation and pin-on-disc dry friction test. Wear mechanisms were studied using scanning electron microscopy and X-ray photoelectron spectroscopy. The results show that graphite bears a considerable strain value during the friction process, which is prone to wear and fall off, and the fallen graphite can reduce the friction coefficient. Ferrite around graphite can buffer stress, but it also can reduce wear resistance. And the more significant the lamellar spacing of pearlite, the more abrasive and adhesive effect.