Transport and public health in China: the road to a healthy future.

Transportation-related risk factors are a major source of morbidity and mortality in China, where the expansion of road networks and surges in personal vehicle ownership are having profound effects on public health. Road traffic injuries and fatalities have increased alongside increased use of motorised transport in China, and accident injury risk is aggravated by inadequate emergency response systems and trauma care. National air quality standards and emission control technologies are having a positive effect on air quality, but persistent air pollution is increasingly attributable to a growing and outdated vehicle fleet and to famously congested roads. Urban design favours motorised transport, and physical activity and its associated health benefits are hindered by poor urban infrastructure. Transport emissions of greenhouse gases contribute substantially to regional and global climate change, which compound public health risks from multiple factors. Despite these complex challenges, technological advances and innovations in planning and policy stand to make China a leader in sustainable, healthy transportation

Transport and public health in China: the road to a healthy future.

Transportation-related risk factors are a major source of morbidity and mortality in China, where the expansion of road networks and surges in personal vehicle ownership are having profound effects on public health. Road traffic injuries and fatalities have increased alongside increased use of motorised transport in China, and accident injury risk is aggravated by inadequate emergency response systems and trauma care. National air quality standards and emission control technologies are having a positive effect on air quality, but persistent air pollution is increasingly attributable to a growing and outdated vehicle fleet and to famously congested roads. Urban design favours motorised transport, and physical activity and its associated health benefits are hindered by poor urban infrastructure. Transport emissions of greenhouse gases contribute substantially to regional and global climate change, which compound public health risks from multiple factors. Despite these complex challenges, technological advances and innovations in planning and policy stand to make China a leader in sustainable, healthy transportation

Synthetic Lateral Metal-Semiconductor Heterostructures of Transition Metal Disulfides

Lateral heterostructures with planar integrity form the basis of two-dimensional (2D) electronics and optoelectronics. Here we report that, through a two-step chemical vapor deposition (CVD) process, high-quality lateral heterostructures can be constructed between metallic and semiconducting transition metal disulfide (TMD) layers. Instead of edge epitaxy, polycrystalline monolayer MoS₂ in such junctions was revealed to nucleate from the vertices of multilayered VS₂ crystals, creating one-dimensional junctions with ultralow contact resistance (0.5 kΩ·μm). This lateral contact contributes to 6-fold improved field-effect mobility for monolayer MoS₂, compared to the conventional on-top nickel contacts. The all-CVD strategy presented here hence opens up a new avenue for all-2D-based synthetic electronics.Air Force Office of Scientific Research (Grant FA9550-15-1-0514)National Science Foundation (U.S.) (Grant EFRI-1542815)National Science Foundation (U.S.) (Grant DMR-1507806)National Science Foundation (U.S.) (Grant DMR/ECCS-1509197)National Science Foundation (U.S.) (Award 0939514)United States. Department of Energy (Grant DE-SC0010538

Engineering single-atom dynamics with electron irradiation

Atomic engineering is envisioned to involve selectively inducing the desired dynamics of single atoms and combining these steps for larger-scale assemblies. Here, we focus on the first part by surveying the single-step dynamics of graphene dopants, primarily phosphorus, caused by electron irradiation both in experiment and simulation, and develop a theory for describing the probabilities of competing configurational outcomes depending on the postcollision momentum vector of the primary knock-on atom. The predicted branching ratio of configurational transformations agrees well with our atomically resolved experiments. This suggests a way for biasing the dynamics toward desired outcomes, paving the road for designing and further upscaling atomic engineering using electron irradiation.National Science Foundation (U.S.) (Grant ECCS-1610806)United States. Department of Energy (Grant DE-NE0008827)United States. Army Research Office (Grant W911NF-18-1-0431)National Science Foundation (U.S.) (Grant DMR/ECCS-1509197