Search

Numerical simulation technology to assist the teaching of university physics is a higher education to continuously adapts to the social development of its own needs. This paper classifies the common forms of university physics courses involving numerical computation, explores the current computer simulation in physics teaching, and establishes the development process of the university physics computer numerical computation simulation program. Numerical simulation technology is applied to the design of university physics teaching, and two examples of numerical simulation technology assisting university physics teaching are designed from two cases of grating diffraction intensity distribution and gas diffusion based on Matlab. In Example N = 10, the light intensity distribution of diffraction grating with different slit numbers is analyzed by numerical simulation, and it is obtained that at 1, there are 9 minima between two adjacent main maxima, 8 sub-maxima, and the maximum value is 100, which verifies the theoretical results of the physical derivation of the grating diffraction intensity distribution. In the exposition, mathematical modeling is combined with examples to show that mathematical modeling can greatly exert the role of mathematical ideas in physics teaching, simplify physics teaching, and further cultivate students’ ability to solve practical problems.

Al content is of great importance for the evolution of the microstructure and compressive performance of the high‐Mn and high‐Al porous steels. Herein, Fe–Mn–Al porous steels with different Al contents are prepared via powder sintering at different temperatures. The results show that the main phases of the sintered samples at 640 °C are α‐Fe, α‐Mn, and Al, while a small amount of Fe2Al5 and Al8Mn5 exists in the samples with 15 and 20 wt% Al. At 1200 °C, the sintered sample with 5 wt% Al is composed of γ‐Fe, while those with 15 and 20 wt% Al are mainly α‐Fe. The length of Mn depletion region and porosity of the samples increase with the increase of Al content. The largest total and open porosity are observed in the 1200 °C‐sintered sample with 20 wt% Al, which are 63.1 and 60.7 vol%, respectively. The compressive strength decreases sharply from 770 MPa for the sample with 5 wt% Al to 7.5 MPa with 15 wt% Al, after sintering at 1200 °C. Ductile fracture occurs in the sample with 5 wt% Al, while brittle fracture is the main fracture mode in those with 15 and 20 wt% Al. [ABSTRACT FROM AUTHOR]

Abstract: A Fe-promoted Pt-Fe/Al2O3 catalyst was prepared by water/oil microemulsion. The physicochemical properties of the Pt/Al2O3 and Pt-Fe/Al2O3 catalyst were characterized by TEM, SAED, XRD, XPS, BET, ICP, and CO-chemisorption. The introduction of Fe could promote the formation of a catalytic active center Pt, enhance electron enrichment of Pt, and improve the degree of Pt dispersion. The effect of Fe on the catalytic performance of the Pt/Al2O3 catalyst was investigated by the liquid-phase hydrogenation of m-chloronitrobenzene to m-chloroaniline. The Fe-promoted Pt-Fe/Al2O3 catalyst was extremely active and more selective than the Pt/Al2O3 catalyst (conversion from 57.7 to 96.3%, selectivity from 98.5 to 99.2%). [ABSTRACT FROM AUTHOR]

A series of Cu/TiO2-SiO2 catalysts were prepared by a sol-gel hydrothermal method and characterized by BET, SEM, TEM, XRD, XPS, and H2-TPR. The catalysts were used for selective hydrogenation of furfural to furfuryl alcohol. Results show that based on the Cu/SiO2 catalyst, introducing a part of TiO2 into the carrier while keeping very large specific surface area would promote the reduction of CuO, inhibit the growth of Cu crystal particles, and improve the dispersity of Cu particles in the catalyst. The electronegativity of Cu is enhanced in the double-loaded Cu/TiO2-SiO2 catalyst, compared with single-loaded Cu/SiO2 or Cu/TiO2 catalysts. The Cu/TiO2-SiO2 catalyst containing 0.40 g/g (40 wt%) TiO2 in the carrier shows high furfural hydrogenation performance. [ABSTRACT FROM AUTHOR]