This paper develops an instruction method for promoting design innovation capability through a design-based program with identification, modeling, simulation, and prototyping (IMSP). The computational thinking and conceptualization of sustainability were incorporated. The interaction between instruction treatment and participants' personality was investigated. Eighty-six engineering undergraduates participated in this experimental study for exploring the effectiveness of the IMSP program. The findings indicate that 1) the IMSP program promoted undergraduates' computational thinking, and further enhanced their design innovation ability; 2) the program that integrated the conceptualization of sustainability has better teaching effects than that without the conceptual integration; 3) the personal characters of innovation proaction and emotional intelligence acted as moderators in the ISMP program. This study presents a practical method for improving design innovation capability, and supports the feasibility and necessity of emphasizing computational thinking and sustainability in the innovation training program for engineering education.
A Monte Carlo (MC) and molecular dynamics (MD) coupling simulation scheme for sputtered particle transport was first proposed in this work. In this scheme, the MC method was utilized to model the free-flight process of sputtered atoms, while the MD model was adopted to simulate the collision between the sputtered atom and background gas atom so as to self-consistently calculate the post-collision velocity of the sputtered atom. The reliability of the MD collision model has been verified by comparing the computation results of the MD model and of an analytical model. This MC-MD coupling simulation scheme was used to investigate the influence of target-substrate distance on the transport characteristic parameters of sputtered Cu atoms during magnetron sputtering discharge. As the target-substrate distance increased from 30 to 150 mm, the peak energy of the incident energy distribution of deposited Cu atoms decreased from 2 to 1 eV due to the gradual thermalization of sputtered atoms. The distribution of differential deposition rate in unit solid angle firstly became more forward-peaked and then reversely approached the cosine distribution, which was agreed with the existing experimental observations. This work is expected to provide a more realistic simulation scheme for sputtered particle transport, which can be further combined with the MD simulation of sputtered film growth to explore the influence mechanism of process parameters on the properties of sputtered film.
This paper reports on spectroscopic properties and energy transfer of Tm3+/Ho3+-codoped ZnO-WO3-TeO2 glass upon excitation of 808nm diode laser. The J-O strength parameters, spontaneous emission probability and radiative lifetime of Ho3+ were calculated using Judd-Ofelt theory. The absorption cross-section and stimulated emission cross-section were also investigated. Our result indicates that the highest gain of 2.0 μm emission, which comes from 5I7 to 5I8 transition of Ho3+, might be achieved from the glass at the rare-earth ion concentration of 0.5 mol% of Tm2O3 and 0.15 mol% of Ho2O3. It is found that coefficients of the forward Tm3+→Ho3+ energy transfer is about 18 times that for the backward Tm3+←Ho3+ energy transfer. The calculated fluorescence lifetime of the 5I7 level of Ho3+ is 3.9 ms and the emission cross section of the 5I7→5I8 transition of Ho3+ exhibits a maximum of 9.15×10-21 cm2 at 2027 nm. We also found that Tm3+/Ho3+-codoped tellurite glass is a promising host material for potential 2.0 μm laser by comparing the quantum efficiencies, the values of σe×τm and gain coefficients of fluoride and heavy metal oxide glasses respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.