[Pollution Characteristics of Cooking Fumes, Particulates, and Non-methane Hydrocarbons in the Exhaust of Typical Beijing Restaurants].

To understand the atmospheric pollution emission concentration and overall emission level of the Beijing catering industry, and thus provide a basis for the targeted formulation of pollution control measures for the catering industry, this study selected typical catering enterprises in Beijing to research. Combined with the use of stoves during the on-site measurement and testing period, the emission concentrations of cooking fumes, particulates, and non-methane hydrocarbons (NMHC), and the relationship between them in different types of catering enterprises, were analyzed, and the emission of atmospheric pollutants in the Beijing catering industry was estimated. The results showed that the average concentrations of cooking fumes, particulates, and NMHC of typical catering enterprises were (2.

[Emission Characteristics of the Catering Industry in Beijing].

The emissions of the catering industry are important sources of air pollution in megacities in China. A total of 41 restaurants in Beijing were selected as the sampling sites to evaluate the contribution of the catering industry to megacity air pollution. The original emissions load of cooking fume, particulate matter, and non-methane hydrocarbon (NMHC) were studied via field tests for different types of restaurants.

[Emission Characteristics of Wind Erosion Dust from Topsoil of Urban Roadside-Tree Pool].

This study characterized the wind erosion dust emissions from topsoil of urban roadside-tree pool. The study area is the Xicheng District of Beijing and uses GIS to obtain the spatial distribution of various road mileages. A full bore investigation method was carried out to survey tree pool in the Zhanlanlu Subdistrict to obtain the activity level of tree pool in the Xicheng district.

[Atmospheric Pollutant Emission Characteristics from the Cooking Process of Traditional Beijing Roast Duck].

As one of the characteristics of traditional food in Beijing, there is a significant difference between roast duck and other foods in the cooking process, in that fruit trees are used as fuel in the former. However, system research about the emission characteristics of this food source has not been done domestically. In order to grasp such food source emission characteristics and provide technical basis for pollution control, we selected the representative roast duck restaurant in Beijing and studied the emission characteristics of atmospheric pollutants in the cooking process of roast duck.

[Pollution Characteristics of NH,NO,SO in PMand Their Precursor Gases During 2015 in an Urban Area of Beijing].

Simultaneous measurements of precursor gases NH,NO,NO,SO and the main water-soluble ions in PM such as sulphate (SO),nitrate (NO) and ammonium (NH) (collectively called SNA)were carried out in the urban area of Beijing during 2015-01 to 2015-12,which obtained 325 groups of samples. PTFE membrane filters were used to collect particulate NH, NO and SO, followed by the online instruments to collect precursor gases. The pollution characteristics of the precursor gases and SNA were analyzed and their correlation was studied.

[Concentration Characteristics of PM in Beijing During Two Red Alert Periods].

Variations of PM concentrations and effects of pollution control measures during two red alert periods in 2015 in Beijing were analyzed based on atmospheric pollutant monitoring data. The results showed that during the first red alert, the highest hourly-averaged PM concentration occurred at 19:00 on 9th December with a value of 282 μg·m and the highest hourly PM concentration appeared at Yongledian station which is near the southeast border of Beijing, with the peak concentration of 496 μg·m. During the second red alert, the highest hourly-averaged concentration of PM occurred at 20:00 on 22th with a value of 421 μg·m.

Metal artifact reduction using virtual monochromatic images for patients with pedicle screws implants on CT.

Purpose: To evaluate the effect of spectral CT for metal artifact reduction in patients with pedicle screw.

Methods: 45 patients with 119 pairs of pedicle screws underwent spectral CT examination. One set of conventional (140 kVp) polychromatic image and nine sets of virtual monochromatic images (60-140 keV) were obtained.