0000000000236830
AUTHOR
Qi Zhao
Global, regional, and national burden of mortality associated with non-optimal ambient temperatures from 2000 to 2019: a three-stage modelling study
Background: Exposure to cold or hot temperatures is associated with premature deaths. We aimed to evaluate the global, regional, and national mortality burden associated with non-optimal ambient temperatures. Methods: In this modelling study, we collected time-series data on mortality and ambient temperatures from 750 locations in 43 countries and five meta-predictors at a grid size of 0·5° × 0·5° across the globe. A three-stage analysis strategy was used. First, the temperature–mortality association was fitted for each location by use of a time-series regression. Second, a multivariate meta-regression model was built between location-specific estimates and meta-predictors. Finally, the gri…
Fe-doped Beta zeolite from organotemplate-free synthesis for NH3-SCR of NOx
Two types of Beta zeolites, one from organotemplate-free synthesis with a Si/Al ratio of 9 and the other from a commercial one with a Si/Al ratio of 19, were employed here to dope Fe for NH3-SCR of NOx. Fe-Beta (Si/Al = 9) exhibits much higher activity than Fe-Beta (Si/Al = 19), especially at low-temperature regions (<250 °C). In addition, it also exhibits better hydrothermal stability as compared with Fe-Beta (Si/Al = 19), which demonstrates that it is a promising SCR catalyst with good activity as well as hydrothermal stability. The correlation between the quantitative calculation of the content of isolated Fe3+ in Beta zeolites and the NO conversion rate at 150 °C shows a linear relation…
Improvement of catalytic activity over Cu--Fe modified Al-rich Beta catalyst for the selective catalytic reduction of NOx with NH3
Copper and iron bimetal modified Al-rich Beta zeolites from template-free synthesis were prepared for selective catalytic reduction (SCR) of NOx with NH3 in exhaust gas streams. Comparing to the Cu-based and Fe-based mono-component Beta catalysts, Cu(3.0)-Fe(1.3)-Beta bi-component catalyst shows better low-temperature activity and wider reaction-temperature window. Over 80% of NO conversion can be achieved at the temperature region of 125–500 °C. Due to the synergistic effect of copper and iron evidenced by XRD, UV–Vis–NIR, EPR and XPS measurements, the dispersion state of active components as well as the ratio of Cu2+/Cu+ and Fe3+/Fe2+ were improved over Cu(3.0)-Fe(1.3)-Beta. Isolated Cu2+…