Thee persistent haze weather, around the introduction of a number of measures to improve air quality, such as vehicles, the elimination of old vehicles, replacing oil by gas and so on.
针对持续的雾霾天气，各地出台不少措施来改善空气质量，如限制车辆出行，淘汰老旧车辆，以气代油等等。
2
The equations are solved numerically using the method of Gauss elimination and under-relaxation iteration by computor, thus the air flows in every branch are determined.
采用高斯消去法和欠松弛迭代法并应用计算机对这些方程进行数值求解，从而计算出各支路的流量。
3
The determination of calcium by atomic absorption method in an air-acetylene flame is studied with emphasis on experimental conditions, its interfering factors and elimination of the latter.