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In order to overcome the various defects caused by the limitations of solid metal as a shielding material, the development of electromagnetic shielding materials with flexibility and excellent mechanical properties is of great significance for the next generation of intelligent electronic devices. Here, the aramid nanofiber/Ti3C2Tx MXene (ANF/MXene) composite films with multilayer structure were successfully prepared through a simple alternate vacuum-assisted filtration (AVAF) process. With the intervention of the ANF layer, the multilayer-structure film exhibits excellent mechanical properties. The ANF2/MXene1 composite film exhibits a tensile strength of 177.7 MPa and a breaking strain of 12.6%. In addition, the ANF5/MXene4 composite film with a thickness of only 30 μm exhibits an electromagnetic interference (EMI) shielding efficiency of 37.5 dB and a high EMI-specific shielding effectiveness value accounting for thickness (SSE/t) of 4718 dB·cm2 g−1. Moreover, the composite film was excellent in heat-insulation performance and in avoiding light-to-heat conversion. No burning sensation was produced on the surface of the film with a thickness of only 100 μm at a high temperature of 130 °C. Furthermore, the surface of the film was only mild when touched under simulated sunlight. Therefore, our multilayer-structure film has potential significance in practical applications such as next-generation smart electronic equipment, communications, and military applications.

Master's thesis in Economics ; To comply with increasingly strict government environmental regulations, companies have to identify new and innovative solutions to make their products and processes greener, without compromising their financial objectives. This paper investigates the effect of green innovation on financial performance in the US and the European oil and gas industry using longitudinal data from 2010 to 2018. The analysis finds a diminishing positive effect on the financial performance for US companies, where the effect is positive at low levels of green innovation and turns negative at higher levels. For European companies, we find an increasing negative effect, where the effect is negative at low levels of green innovation and turns positive at higher levels. Moreover, we find that for European companies there is evidence that higher oil prices negatively moderate the relationship between disruptive green innovation and financial performance. This suggests that the opportunity cost of disruptive green innovation is high when the oil price is high and that companies are more willing to implement green innovation when the oil price is low. However, this moderating effect is not found for US companies. Based on these findings, as the effect of green innovation on the financial performance of European oil and gas companies depends on the level of companies innovation as well as oil prices, we suggest that in order to encourage oil and gas companies to invest more in green innovation, the public policy makers should have less strict environmental regulations and provide more policy support when the oil price is high. We also suggest that for the European oil and gas companies operating under very strict regulations, it is better to exert full effort in green innovation to gain financial profits. However, for the US companies operating under less strict environmental regulations, low to medium levels of green innovation practices would be more profitable.

Unintentional injury is the leading cause of childhood death and disability in many countries worldwide. This study aimed to quantify rates and risk factors for childhood unintentional injury in areas of rural China, where many children are left behind by migrant worker parents. We administered a questionnaire to children aged 9 to 15, in 56 schools in five counties in Zhejiang and Guizhou provinces. Of the 3791 respondents, 44% lived with both parents, 23% with one parent, and 33% with neither. Around half the children (47.9%) had suffered at least one unintentional injury in the past year, with burns (26%), animal bites (20%) and mechanical injury (18%) the most common. Left-behind children had no increased risk of unintentional injury, but children living in poorer Guizhou (p = 0.001), of divorced parents (p = 0.02), and less well-educated mothers (p = 0.02) were associated with higher risk. Virtual absence of personal level risk factors highlights the importance of addressing environmental risk to reduce childhood injury. The findings have informed a community-based intervention to reduce injury risk through raising awareness of environmental hazards, and through removal of specific hazards. Importantly, the Chinese government should ensure that known effective interventions are subject to legislation and enforcement.

AbstractUtilizing the longitudinal SOEP data representative of the German population, we find that mental health shocks significantly decrease the willingness to take risks. We also find that mental health improvements increase the willingness to take risks significantly. Our findings are relevant for better understanding the economic decision making of the large number of individuals with mental health issues.