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A novel core–shell architecture is proposed and proved to be effective in achieving temperature-stable LiF-CaTiO3 microwave dielectric ceramics. Dense CaTiO3 ceramics are initially prepared using the solid-state reaction method and then inserted into the inner core of LiF green pellets. The assembled green pellets are pre-densified using a cold-sintering process (150 °C, 350 MPa, 60 min) and then post-annealed at 800 °C to obtain densified core–shell-structured LiF-xwt%CaTiO3 ceramics (x = 3, 5, 10, 15). The SEM images confirm the core-shelled microstructure, and the excellent chemical compatibility between LiF and CaTiO3 components is revealed from the XRD and EDS results. The large negative temperature coefficient of the resonant frequency of LiF ceramics (− 138 ppm/°C) can be effectively tuned to 2.89 ppm/°C at x = 3, together with a Qf value of 26,580 GHz and εr = 10.89. Therefore, cold sintering and post-annealing treatments open up new ways in designing and constructing novel microwave dielectric ceramics with high performance and should also be instructive in areas, such as ferroelectrics and energy storage ceramics. [ABSTRACT FROM AUTHOR]

Based on the high-resolution coal-fired power plant emission database, GEOS-Chem Adjoint, a global-regional nested atmospheric chemistry model and its adjoint were applied to analyze PM 2.5 -related premature deaths caused by the power sector in six grid regions of China due to air pollutant emissions and subsequent pollution. The results show that power sector-related PM 2.5 pollution caused 106000 (95% CI:68000-132000) premature deaths in 2010, accounting for 9.8% of China's anthropogenic PM 2.5 -related premature deaths. The health loss intensity (defined as number of premature deaths caused by a unit of power generation) of small and old units is significantly higher than that of large and new units:units with a capacity below 100 MW reach 62 people·(TW·h) -1 , 2.8 times that of units with a capacity above 600 MW. Similarly, the health loss intensity of units older than thirty years is 58 people·(TW·h) -1 , 2.1 times that of new units. From the perspective of regional grids, the health impact index of Central China is relatively large, reaching 77 people·(TW·h) -1 . Further analysis reveals that transregional power transmission led to a net increase of 680 premature deaths compared with the scenario without transmission in 2010. Our study implies that China should accelerate the pace of phasing out small and old units and optimize the power transmission distribution between grid regions to reduce the overall level of pollution and health losses.