Bin Guo

As societies digitize, aging populations face emerging forms of digital inequality, manifesting distinct spatial disparities in rapidly developing contexts

Background: Globally, nearly 15% of people suffer from various kinds of disabilities, and China has the largest disabled population in the world. The poor mental health status of people with disabilities has become an essential issue in most countries. The main aim of this study was to explore the potential impact of internet use on depression risk among middle-aged and older adults with different types of disabilities. Methods: The data used in this study were obtained from the 2018 China Health and Retirement Longitudinal Study (CHARLS) collected by Peking University. A binary logit model was used to analyze the impact of internet use on the depression risk among adults with disabilities, and the substitute variable method and the propensity score matching method were used to examine the robustness of the results. Results: (1) Internet use was negatively associated with depression risk among disabled people, and the higher the frequency of their internet use, the lower the probability of their depression risk. (2) Different social activities related to the internet had different impacts on the depression risk, and the decline in depression risk was mainly related to watching videos, watching news, and chatting via the internet. (3) Internet use reduced the depression risk of adults with physical disabilities, but had no impact on those with other types of disabilities. Conclusions: Our study suggests that internet use may have a positive spillover effect on decreasing the depression risk of disabled people, but the reduction effect is significantly affected by the social activities related to the internet and the types of disabilities.

Background: In an aging and digital society, Internet use is significantly associated with residents’ physical exercise. This study aimed to explore the association between Internet use and physical exercise among Chinese middle-aged and older adults in two respects: Internet use and the purpose of Internet use. Methods: The data used in this study were obtained from the 2018 China Health and Retirement Longitudinal Study (CHARLS) conducted by Peking University. The logit model and the ordered probit model were used to analyze the association between Internet use and physical exercise, and the substitution variable method was used to examine the robustness of the results. Results: (1) Internet use and the frequency of Internet use significantly increased the probability and frequency of middle-aged and older adults’ participation in physical exercise (p < 0.001). (2) “Watching news”, “chatting” and “watching videos” via the Internet were positively associated with physical exercise, while “playing games” had no impact. (3) Internet use had a greater impact on physical exercise participation among middle-aged adults and those living in urban areas than among older adults and those living in rural areas. Conclusions: This study suggests that Internet use among middle-aged and older adults is positively associated with their participation in physical exercise; the government should try to increase the popularity of Internet use to encourage their participation in physical exercise.

In the paper, the effect of Ge profiles on the performance of lateral SiGe heterojunction bipolar transistor (LHBT) on silicon-on-insulator (SOI) substrate with positive bias voltage has been studied. With the aid of substrate bias (V_S), the peak current gain (β) of LHBT with trapezoidal Ge profile is obviously enhanced, which is almost as same as LHBT with uniform Ge profile. At the same time, the β of LHBT with trapezoidal Ge profile is kept as temperature increases. However, the β of LHBT with uniform Ge profile is decreased as temperature increases. Furthermore, for LHBT with trapezoidal Ge profile, the peak junction temperature is lowered by 20.51K and the cut-off frequency (f_T) is also improved by 158.4 GHz when compared with that of the uniform one. The results show that LHBTs with trapezoidal Ge profile could achieve the superior electrical, thermal, and high frequency performance at the same time, which provides useful guidelines to design SiGe HBTs for microwave and digital or mixed-signal applications.

Ultra-wideband (UWB) Microwave imaging (MWI) is a promising breast cancer detection technology which exploits the significant contrast in dielectric properties between normal breast tissue and tumo...