Impact of COVID-19 on negative body image: Evidence based on social media data.

Body experiences and conditions bear close relations to social development and human well-being. However, no consensus has been reached regarding the impact of coronavirus disease 2019 on negative body image. Investigating a reliable relationship between COVID-19 and negative body image, we developed a dictionary of negative body image to obtain panel data on body image for 31 Chinese provinces/municipalities/autonomous regions. We compared negative body image before and after the pandemic and explored the impact of pandemic severity. The prevalence of negative body image decreased following the outbreak and remained at a relatively low level for two years. After controlling regional and temporal effects, we verified epidemic severity as an important predictor of the decline in negative body image. The findings suggest that the public is likely to accept their physical appearances during lockdown due to changes in lifestyle and the fear of mortality. This research has important implications for gaining insights into the dynamic transformation of public negative body image under the influence of catastrophic public health events.

Dynamic Electronic Doping for Correlated Oxides by a Triboelectric Nanogenerator.

The metal-insulator transition of vanadium dioxide (VO2 ) is exceptionally sensitive to charge density and electron orbital occupancy. Thus three-terminal field-effect transistors with VO2 channels are widely adopted to control the phase transition by external gating voltage. However, current leakage, electrical breakdown, or interfacial electrochemical reactions may be inevitable if conventional solid dielectrics or ionic-liquid layers are used, which possibly induce Joule heating or doping in the VO2 layer and make the voltage-controlled phase transition more complex. Here, a triboelectric nanogenerator (TENG) and a VO2 film are combined for a novel TENG-VO2 device, which can overcome the abovementioned challenges and achieve electron-doping-induced phase modulation. By taking advantage of the TENG structure, electrons can be induced in the VO2 channel and thus adjust the electronic states of the VO2 , simultaneously. The modulation degree of the VO2 resistance depends on the temperature, and the major variation occurs when the temperature is in the phase-transition region. The accumulation of electrons in the VO2 channel also is simulated by finite element analysis, and the electron doping mechanism is verified by theoretical calculations. The results provide a promising approach to develop a novel type of tribotronic transistor and new electronic doping technology.