Design and realization of antireflection coatings for the visible and the infrared based on mesoporous SiO2 and SiO2-TiO2 hybrid materials.

Five-layer antireflective coating for the visible and the infrared has been successfully fabricated by a solgel route on quartz substrate. The quarter-half-quarter multilayer structure with two buffer layers is optimized by the optical admittance approach. Mesoporous SiO2 film templated by an ethylene oxide-propylene oxide-ethylene oxide triblock copolymer is used as the top layer, and SiO2-TiO2 hybrid films are employed as the other layers. The grazing incidence small-angle x-ray scattering results indicate the ordered mesopores in the low-index SiO2 film, as well as the homogeneity of the SiO2-TiO2 hybrid films. Transmittance spectra are fitted to obtain film thicknesses and refractive indices, providing the main technological parameters for theory designs. A short heat-treatment step followed by a shock cooling process is introduced to suppress crack formation in film stacks. The transmittance of the obtained five-layer antireflective coating exceeds 99% at 500-700 nm, and the maximum value in the infrared region is 97.84% at 1100 nm. This work is a beneficial attempt to fabricate antireflective coatings with multilayer structure through the soft solgel route.

Research on Learning Evaluation of College Students Based on AHP and Fuzzy Comprehensive Evaluation.

The aim of this paper is to propose a scientific and practical evaluation method for college students' learning evaluation. The students' learning experience and harvest are the ultimate embodiment of colleges teaching quality. Considering the multilevel and fuzzy characteristics of learning evaluation, a novel college evaluation method is put forward based on the analytic hierarchy process and fuzzy comprehensive evaluation. The flow chart and index system for college students' learning evaluation are designed. Meanwhile, the weight of the evaluation index and the calculation steps of fuzzy evaluation is demonstrated and applied actually. The results show that the method is practical which has advantages over the simple analytic hierarchy process.

The Effect of COVID-19 Perceived Risk on Internet Addiction among College Students in China: An Empirical Study Based on the Structural Equation Model.

This study focused on COVID-19 perceived risk and Internet addiction among Chinese college students during the lockdown. On the basis of the Social Cognitive Theory, this study proposed a mediating model to evaluate the mediating role of difficulties in regulating emotion between the COVID-19 perceived risk and Internet addiction. A questionnaire survey was conducted among 690 college students during the COVID-19 lockdown in China. The results showed that the COVID-19 perceived risk was significantly positively associated with Internet addiction (r = 0.236, p < 0.001) and difficulties in emotion regulation (r = 0.220, p < 0.001), difficulties in emotion regulation was significantly positively associated with Internet addiction (r = 0.368, p < 0.001). The COVID-19 perceived risk had a significant and positive predictive effect on Internet addiction (ß = 0.233, p < 0.001) among Chinese college students. The analysis of the mediation model showed that difficulties in emotion regulation partially mediated the relationship between COVID-19 perceived risk and Internet addiction (indirect effect value was 0.051 with 95% Confidence Interval ranging from 0.027 to 0.085). The findings not only enhanced our understanding of the internal influence mechanism of COVID-19 perceived risk on Internet addiction but also provided a practical basis for college education works. Finally, discussions and suggestions were provided on the basis of the results.

Simulation and evaluation on the eco-industrial system of Changchun economic and technological development zone, China.

Reasonable structure, adaptive patterns and effective regulation of society, economy and environment subsystems should be taken into account in order to obtain harmonious development of urban eco-industrial system. We simulated and evaluated a redesigned eco-industrial system in Changchun Economic and Technological Development Zone (CCETDZ) in the present work using system dynamics and grey cluster methods. Four typical development strategies were simulated during 2005-2020 via standard system dynamic models. Furthermore, analytic hierarchy process and grey cluster allowed for the eco-industrial system evaluation and scenarios optimizing. Our dynamic simulation and statistical analysis revealed that: (1) CCETDZ would have different development scenarios under different strategies. The total population in scenario 2 grew most rapidly and reached 3.28 x 10(5) in 2020, exceeding its long-term planning expected population. And the GDP differences among these four scenarios would amount to 6.41 x 10(10) RMB. On the other hand, environmental pollution would become serious along with economy increasing. As a restriction factor, positive or negative increment of water resource will occur according to the selected strategy. (2) The fourth strategy would have the best efficiency, which means that the most efficiently development of CCETDZ required to take science, technology, environment progress and economy increase into account at the same time. (3) Positive environment protection measures, such as cleaner production, green manufacture, production life cycle management and environment friendly industries, should be attached great importance the same as economy development during 2005-2020 in CCETDZ.