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Abstract Vehicle emissions have become the major source of air pollution as well as heavy metals pollution accompanied with unprecedented economic development and urbanization in China. Yunnan province, the congruity area of undeveloped region with high vehicle population increasing, as well as special natural conditions, was taken as the study area. We estimated the vehicle emissions during 2003–2015 with COPERT IV model, including private cars (PC), buses (BUS), light duty vehicles (LDV) and heavy duty trucks (HDT), then analyzed the vehicle emission characteristics, involving CO, CO 2 , SO 2 , NO x , NO, NO 2 , N 2 O, NH 3 , Volatile organic compounds (VOC), Ambient Air Non-Methane Volatile Organic compound (NMVOC), CH 4 , PM 2.5 , PM 10 , PM (exhaust), Cadmium and Zinc. The results indicated that all pollutants as well as heavy metals were increased at different growth trends except SO 2 although more stringent emission standard implementation, the rising of vehicle population become the main contributor to the vehicle emission growth, and CO 2 emission was the major vehicle emissions accounted for one third of total CO 2 emissions in Yunnan. PC was the main contributor to the rising of CO, VOC, NMVOC, CH 4 , NH 3 , CO 2 , Cadmium and Zinc, which was also the major vehicle growth type; HDT and LDV brought to the emissions of N 2 O, NO x , NO, PM 10 , NO 2 , PM 2.5 , and PM (exhaust) respectively. At last, uncertainty of emission estimation was analyzed based on the Monte Carlo simulation. The vehicle emission become one critical field of emission reduction in Yunnan which should be given greater emphasis to environmental concerns. Highlights • The vehicle emission inventory in Yunnan province during 2003–2015 was estimated. • Around one third of total CO 2 emissions came from vehicle emissions in Yunnan (2015). • Only SO 2 shown continuous downward trend during after 2010. • PC total emissions were in the top including heavy metals for its population. [ABSTRACT FROM AUTHOR]

• SeO 2 based glasses of composition 39PbO-(60- x)B 2 O 3 - x SeO 2 :1.0 Er 2 O 3 were synthesized. • IR/Raman spectra suggested growth of [SeO 3 ]2−/[SeO 4 ]2− units' ratio with SeO 2 content. • Analysis of OA spectra indicated J-O parameters to follow the order: Ω 2 > Ω 6 > Ω 4. • Green and NIR PL emission bands exhibited significant growth with SeO 2 content. • PL spectra quantitatively analysed using kinetic rate equations. • Gain co-efficient G(λ) of 4I 13/2 →4I 15/2 transition indicated its lasing behaviour. In this work we have studied impact of SeO 2 concentration on luminescence properties of 39PbO-(60- x)B 2 O 3 - x SeO 2 :1.0 Er 2 O 3 (10 ≤ x ≤ 50) glass system. The structural analysis of the samples carried out by XRD, SEM indicated that the prepared samples are in amorphous phase. IR, Raman and XPS studies revealed increasing presence of isolated selenite [SeO 3 ]2−groups and decreasing concentration of [SeO 4 ]2−(selenate) groups with increasing content of SeO 2 in the glass network. Optical absorption (OA) spectra revealed absorption bands due to 4I 15/2 → 4F 7/2 , 9/2 , 2H 11/2 , 4S 3/2 , 4I 9/2 , 11/2 , 13/2 transitions of Er3+ ions. Using J-O theory, the spectra were characterized and the evaluated Ω λ parameters are found to be in the order: Ω 2 > Ω 4 > Ω 6. The PL spectra recorded at λ exc = 378 nm exhibited the emission bands due to 2H 11/2 →4I 15/2 (B), S 3/2 →4I 15/2 (G), 4F 9/2 →4I 15/2 (O) and 4I 13/2 →4I 15/2 (NIR) transitionsof Er3+ ions. With the gradual increase SeO 2 content, the PL emission bands (especially green and NIR bands) have exhibited significant growth. The spectra were quantitatively analysed using kinetic rate equations and the causes for enhancement of PL emission were recognised and discussed. From the gain co-efficient G(λ) of the 4I 13/2 →4I 15/2 transition, its lasing behaviour is detected for a population inversion of nearly 50%. [ABSTRACT FROM AUTHOR]