WRF Numerical Simulation Analysis of Meteorological Elements in the Main Urban Area of Chongqing from 2013 to 2015

Using the WRF mesoscale numerical model,based on the FNL global reanalysis data of NCEP,numerical simulations with a resolution of 27,9 and 3 km were carried out on the meteorological elements in four national air quality control stations(Jinyun Mountain,Shapingba,Jiefangbei and Nanping)in the main urban area of Chongqing City in July from 2013 to 2015.The results show that at the concerned points,there was an obvious southeast dominant wind at 850 hPa.The meteorological conditions in July in the main urban area of Chongqing were favorable for the diffusion of pollutants.That is,the height of the mixed layer was higher,and the precipitation was higher;the temperature and wind speed at 850 hPa were higher.Compared with 2013 and 2014,the meteorological conditions in July 2015 were not more favorable for the diffusion of pollutants.

Numerical Simulation of Distribution of VOCs Concentration in the Main Urban Area of Chongqing Based on CALPUFF

The distribution of VOCs concentration in the main urban area of Chongqing was simulated based on the CALPUFF model.The results show that the long-term contribution of key industrial pollution sources of VOCs in the study area was not significant(0-0.13 mg/m^(3)),and the hourly average instantaneous contribution was significant(the maximum was up to 2.75 mg/m^(3));the hourly average concentration of VOCs in the area where the sensitive points were located rose abruptly at different times(with a maximum of 1.35 mg/m^(3)).The distribution of VOCs concentration in this area was influenced by the dominant wind,and the area where the sensitive points were located was not the area covered by the maximum landing concentration of pollutants.As the dominant wind changed,the pollution situation of the sensitive points may be worsen.

Effect of rolling deformation on microstructure and texture of spray-deposited magnesium alloy containing Mg-Nd-Zn typed LPSO

Billets of Mg-9Al-3Zn-1Mn-6Ca-2Nd alloy were produced by spray-deposition（the Osprey process）.Effect of rolling deformation（T = 350？C, ε = 5%, 10%, and 15%, respectively） on microstructure and texture evolution of the Mg-9Al-3Zn-1Mn-6Ca-2Nd alloy was investigated by scanning electron microscopy（SEM）, transmission electron microscopy（TEM） and X-ray diffraction（XRD）. Results show that at pass reduction of ε = 5%, 10% and 15% at 350？C respectively, Mg-Nd-Zn typed 24R-LPSO structure was formed in（Ca, Nd）Al2phase（C15 Laves phase）. With the increase in pass reduction（i.e. 5%, 10% and 15%）, the texture pole density level of basal texture（0002） changed little and pyramidal texture（10 1ˉ3） were increased.In contrast, those of prismatic texture {101ˉ0} 〈11 2ˉ0〉 were increased initially and followed by a reduction, indicating texture randomization in the grain-refined Mg alloy. The combined contribution of LPSO phase and C15 phase was key to randomize the texture of the grain-refined Mg alloy. It was noted that the microcosmic plastic deformation of LPSO phase and nanometer-sized dispersed C15 phase impeded dislocation movement, led to dislocation tangles, and facilitated recrystallization.

Impacts of reducing air pollutants and CO_(2) emissions in urban road transport through 2035 in Chongqing, China

The road transport sector in megacities is confronted with pressing local air pollution and carbon dioxide(CO_(2))control issues.To determine effective policy instruments for saving energy and the co-control of air pollutants and CO_(2),several mainstream measures were examined and compared in Chongqing's road transport sector from 2017 to 2035.An integration assessment framework was developed by combining the Long-range Energy Alternatives Planning(LEAP)system and a set of quantitative methods for evaluating the co-benefits of emission reductions(including the air pollutant equivalent(APeq),cocontrol coordinate system,and pollutant reduction cross-elasticity(Elsa/b)).Results showed that the shifting transportation modes scenario presented the most significant potential for energy-saving and emission reductions,reducing energy use by 30.9%and air pollutants and CO_(2) emissions by approximately 27e32%compared with the business as usual(BAU)scenario in 2035.The improving energy efficiency scenario also provided significant co-benefits for reducing air pollutants and CO_(2) emissions.Nevertheless,the promoting alternative fuel scenario may increase fine particulate matter(PM2.5)emissions by 2.2%compared to BAU in 2035 under the cleanness of regional electricity in 2017.Our findings suggest that the shifting transportation modes were effective measures to reduce air pollutants and CO_(2) in the short term synergistically,and highlighted the importance of cleaner electricity generation to develop electric vehicles in the medium and long term.